| Catret-Ruber P, Garcia-Rodriguez D, Iglesias Fuente DJ, López-Baeza E, Javier Samper-Zapater J and Martínez Durá JJ (2026), "An open, reproducible benchmark of daily CO2 forecasting models with applications to GHG monitoring", Environmental Modelling & Software., January, 2026. Vol. 196, pp. 106781. Elsevier BV. |
BibTeX:
@article{CatretRuber2026,
author = {Catret-Ruber, Pablo and Garcia-Rodriguez, David and Iglesias Fuente, Domingo J. and López-Baeza, Ernesto and Javier Samper-Zapater, J. and Martínez Durá, Juan José},
title = {An open, reproducible benchmark of daily CO2 forecasting models with applications to GHG monitoring},
journal = {Environmental Modelling & Software},
publisher = {Elsevier BV},
year = {2026},
volume = {196},
pages = {106781},
doi = {10.1016/j.envsoft.2025.106781}
}
|
| Fischer S, Queck R, Bernhofer C and Mauder M (2026), "Quantifying evaporation of intercepted rainfall: a hybrid correction approach for eddy-covariance measurements", Hydrology and Earth System Sciences., February, 2026. Vol. 30(4), pp. 965-984. Copernicus GmbH. |
BibTeX:
@article{Fischer2026,
author = {Fischer, Stefanie and Queck, Ronald and Bernhofer, Christian and Mauder, Matthias},
title = {Quantifying evaporation of intercepted rainfall: a hybrid correction approach for eddy-covariance measurements},
journal = {Hydrology and Earth System Sciences},
publisher = {Copernicus GmbH},
year = {2026},
volume = {30},
number = {4},
pages = {965--984},
doi = {10.5194/hess-30-965-2026}
}
|
| Nijp JJ, Huseby Karlsen R, Nilsson MB and Bishop K (2026), "Ecohydrological feedbacks increase water storage, streamflow and resilience of natural peatlands", Journal of Hydrology., January, 2026. Vol. 664, pp. 134282. Elsevier BV. |
BibTeX:
@article{Nijp2026,
author = {Nijp, Jelmer J. and Huseby Karlsen, Reinert and Nilsson, Mats B. and Bishop, Kevin},
title = {Ecohydrological feedbacks increase water storage, streamflow and resilience of natural peatlands},
journal = {Journal of Hydrology},
publisher = {Elsevier BV},
year = {2026},
volume = {664},
pages = {134282},
doi = {10.1016/j.jhydrol.2025.134282}
}
|
| Vasile M, Tîrlă M-L, Lemmetyinen J, Popescu R, Hoinic T and Șandric I (2026), "Detection of thermokarst landforms in the European Arctic region using Earth observation and Artificial Intelligence", Remote Sensing Applications: Society and Environment., January, 2026. Vol. 41, pp. 101832. Elsevier BV. |
BibTeX:
@article{Vasile2026,
author = {Vasile, Mirela and Tîrlă, Maria-Laura and Lemmetyinen, Juha and Popescu, Răzvan and Hoinic, Toma and Șandric, Ionuț},
title = {Detection of thermokarst landforms in the European Arctic region using Earth observation and Artificial Intelligence},
journal = {Remote Sensing Applications: Society and Environment},
publisher = {Elsevier BV},
year = {2026},
volume = {41},
pages = {101832},
doi = {10.1016/j.rsase.2025.101832}
}
|
| Aalto T, Tsuruta A, Mäkelä J, Müller J, Tenkanen M, Burke E, Chadburn S, Gao Y, Mannisenaho V, Kleinen T, Lee H, Leppänen A, Markkanen T, Materia S, Miller PA, Peano D, Peltola O, Poulter B, Raivonen M, Saunois M, Wårlind D and Zaehle S (2025), "Air temperature and precipitation constraining the modelled wetland methane emissions in a boreal region in northern Europe", Biogeosciences., January, 2025. Vol. 22(1), pp. 323-340. Copernicus GmbH. |
BibTeX:
@article{Aalto2025,
author = {Aalto, Tuula and Tsuruta, Aki and Mäkelä, Jarmo and Müller, Jurek and Tenkanen, Maria and Burke, Eleanor and Chadburn, Sarah and Gao, Yao and Mannisenaho, Vilma and Kleinen, Thomas and Lee, Hanna and Leppänen, Antti and Markkanen, Tiina and Materia, Stefano and Miller, Paul A. and Peano, Daniele and Peltola, Olli and Poulter, Benjamin and Raivonen, Maarit and Saunois, Marielle and Wårlind, David and Zaehle, Sönke},
title = {Air temperature and precipitation constraining the modelled wetland methane emissions in a boreal region in northern Europe},
journal = {Biogeosciences},
publisher = {Copernicus GmbH},
year = {2025},
volume = {22},
number = {1},
pages = {323--340},
doi = {10.5194/bg-22-323-2025}
}
|
| Åström O, Geldhauser C, Grillitsch M, Hall O and Sopasakis A (2025), "Enhancing carbon emission reduction strategies using OCO and ICOS data", Scientific Reports., October, 2025. Vol. 15(1) Springer Science and Business Media LLC. |
BibTeX:
@article{Aastroem2025,
author = {Åström, Oskar and Geldhauser, Carina and Grillitsch, Markus and Hall, Ola and Sopasakis, Alexandros},
title = {Enhancing carbon emission reduction strategies using OCO and ICOS data},
journal = {Scientific Reports},
publisher = {Springer Science and Business Media LLC},
year = {2025},
volume = {15},
number = {1},
doi = {10.1038/s41598-025-22022-1}
}
|
| Angove C, Wiesenberg GLB, Lehmann MM, Saurer M, Tang Y, Sahlstedt E, Speckert TC, Schiestl‐Aalto PP and Rinne‐Garmston KT (2025), "Time‐integrated δ2H in n‐alkanes and carbohydrates from boreal needles reveal intra‐annual physiological and environmental signals", New Phytologist., February, 2025. Vol. 246(2), pp. 498-514. Wiley. |
BibTeX:
@article{Angove2025,
author = {Angove, Charlotte and Wiesenberg, Guido L. B. and Lehmann, Marco M. and Saurer, Matthias and Tang, Yu and Sahlstedt, Elina and Speckert, Tatjana C. and Schiestl‐Aalto, Pauliina P. and Rinne‐Garmston, Katja T.},
title = {Time‐integrated δ2H in n‐alkanes and carbohydrates from boreal needles reveal intra‐annual physiological and environmental signals},
journal = {New Phytologist},
publisher = {Wiley},
year = {2025},
volume = {246},
number = {2},
pages = {498--514},
doi = {10.1111/nph.20448}
}
|
| Arriga N, Campioli M, Bernardi M, Cerasa A, Peñuelas J, Brunetti M, Cocozza C, Dell’Acqua A, Koffi EN, Goded I, Manca G, Matteucci M, Nocetti M, Scartazza A and Giovannelli A (2025), "Mediterranean pine forests: Comparison of fluxes and tree rings of Pinus pinaster Aiton and Pinus pinea L", Agricultural and Forest Meteorology., October, 2025. Vol. 373, pp. 110761. Elsevier BV. |
BibTeX:
@article{Arriga2025,
author = {Arriga, Nicola and Campioli, Matteo and Bernardi, Mara and Cerasa, Andrea and Peñuelas, Josep and Brunetti, Michele and Cocozza, Claudia and Dell’Acqua, Alessandro and Koffi, Ernest N. and Goded, Ignacio and Manca, Giovanni and Matteucci, Marco and Nocetti, Michela and Scartazza, Andrea and Giovannelli, Alessio},
title = {Mediterranean pine forests: Comparison of fluxes and tree rings of Pinus pinaster Aiton and Pinus pinea L},
journal = {Agricultural and Forest Meteorology},
publisher = {Elsevier BV},
year = {2025},
volume = {373},
pages = {110761},
doi = {10.1016/j.agrformet.2025.110761}
}
|
| Aslan T, Katul GG and Aurela M (2025), "The Turbulent Pressure Spectrum Within the Roughness Sublayer of a Subarctic Forest Canopy", Journal of Geophysical Research: Atmospheres., February, 2025. Vol. 130(4) American Geophysical Union (AGU). |
BibTeX:
@article{Aslan2025,
author = {Aslan, Toprak and Katul, Gabriel G. and Aurela, Mika},
title = {The Turbulent Pressure Spectrum Within the Roughness Sublayer of a Subarctic Forest Canopy},
journal = {Journal of Geophysical Research: Atmospheres},
publisher = {American Geophysical Union (AGU)},
year = {2025},
volume = {130},
number = {4},
doi = {10.1029/2024jd042206}
}
|
| Ayala-Ortiz C, Hough M, Eder EK, Hoyt DW, Chu RK, Toyoda J, Blazewicz SJ, Crill PM, Varner R, Saleska SR, Rich VI and Tfaily MM (2025), "Tracing priming effects in palsa peat carbon dynamics using a stable isotope-assisted metabolomics approach", Frontiers in Molecular Biosciences., August, 2025. Vol. 12 Frontiers Media SA. |
BibTeX:
@article{AyalaOrtiz2025,
author = {Ayala-Ortiz, Christian and Hough, Moira and Eder, Elizabeth K. and Hoyt, David W. and Chu, Rosalie K. and Toyoda, Jason and Blazewicz, Steven J. and Crill, Patrick M. and Varner, Ruth and Saleska, Scott R. and Rich, Virginia I. and Tfaily, Malak M.},
title = {Tracing priming effects in palsa peat carbon dynamics using a stable isotope-assisted metabolomics approach},
journal = {Frontiers in Molecular Biosciences},
publisher = {Frontiers Media SA},
year = {2025},
volume = {12},
doi = {10.3389/fmolb.2025.1621357}
}
|
| Baráth BÁ, Varga T, Major I, Haszpra L, Vargas D, Barcza Z and Molnár M (2025), "Investigating the impact of COVID-19 on the atmospheric 14C trend and fossil carbon load at urban and background sites in Hungary", Radiocarbon., January, 2025. , pp. 1-14. Cambridge University Press (CUP). |
BibTeX:
@article{Barath2025,
author = {Baráth, Balázs Áron and Varga, Tamás and Major, István and Haszpra, László and Vargas, Danny and Barcza, Zoltán and Molnár, Mihály},
title = {Investigating the impact of COVID-19 on the atmospheric 14C trend and fossil carbon load at urban and background sites in Hungary},
journal = {Radiocarbon},
publisher = {Cambridge University Press (CUP)},
year = {2025},
pages = {1--14},
doi = {10.1017/rdc.2024.133}
}
|
| Basso LS, Georgievski G, Brovkin V, Beer C, Rödenbeck C and Göckede M (2025), "A top-down evaluation of bottom-up estimates to reduce uncertainty in methane emissions from Arctic wetlands", September, 2025. Copernicus GmbH. |
BibTeX:
@article{Basso2025,
author = {Basso, Luana S. and Georgievski, Goran and Brovkin, Victor and Beer, Christian and Rödenbeck, Christian and Göckede, Mathias},
title = {A top-down evaluation of bottom-up estimates to reduce uncertainty in methane emissions from Arctic wetlands},
publisher = {Copernicus GmbH},
year = {2025},
doi = {10.5194/egusphere-2025-4467}
}
|
| Bechtold EK, Ellenbogen JB, Villa JA, de Melo Ferreira DK, Oliverio AM, Kostka JE, Rich VI, Varner RK, Bansal S, Ward EJ, Bohrer G, Borton MA, Wrighton KC and Wilkins MJ (2025), "Metabolic interactions underpinning high methane fluxes across terrestrial freshwater wetlands", Nature Communications., January, 2025. Vol. 16(1) Springer Science and Business Media LLC. |
BibTeX:
@article{Bechtold2025,
author = {Bechtold, Emily K. and Ellenbogen, Jared B. and Villa, Jorge A. and de Melo Ferreira, Djennyfer K. and Oliverio, Angela M. and Kostka, Joel E. and Rich, Virginia I. and Varner, Ruth K. and Bansal, Sheel and Ward, Eric J. and Bohrer, Gil and Borton, Mikayla A. and Wrighton, Kelly C. and Wilkins, Michael J.},
title = {Metabolic interactions underpinning high methane fluxes across terrestrial freshwater wetlands},
journal = {Nature Communications},
publisher = {Springer Science and Business Media LLC},
year = {2025},
volume = {16},
number = {1},
doi = {10.1038/s41467-025-56133-0}
}
|
| Benson V, Bastos A, Reimers C, Winkler AJ, Yang F and Reichstein M (2025), "Atmospheric Transport Modeling of CO2 With Neural Networks", Journal of Advances in Modeling Earth Systems., February, 2025. Vol. 17(2) American Geophysical Union (AGU). |
BibTeX:
@article{Benson2025,
author = {Benson, Vitus and Bastos, Ana and Reimers, Christian and Winkler, Alexander J. and Yang, Fanny and Reichstein, Markus},
title = {Atmospheric Transport Modeling of CO2 With Neural Networks},
journal = {Journal of Advances in Modeling Earth Systems},
publisher = {American Geophysical Union (AGU)},
year = {2025},
volume = {17},
number = {2},
doi = {10.1029/2024ms004655}
}
|
| Biegel S, Schindler K and Stocker BD (2025), "Unrecognised water limitation is a main source of uncertainty for models of terrestrial photosynthesis", April, 2025. Copernicus GmbH. |
BibTeX:
@article{Biegel2025,
author = {Biegel, Samantha and Schindler, Konrad and Stocker, Benjamin D.},
title = {Unrecognised water limitation is a main source of uncertainty for models of terrestrial photosynthesis},
publisher = {Copernicus GmbH},
year = {2025},
doi = {10.5194/egusphere-2025-1617}
}
|
| Biegel S, Schindler K and Stocker BD (2025), "Unrecognised water limitation is a main source of uncertainty for models of terrestrial photosynthesis", Biogeosciences., December, 2025. Vol. 22(23), pp. 7455-7481. Copernicus GmbH. |
BibTeX:
@article{Biegel2025a,
author = {Biegel, Samantha and Schindler, Konrad and Stocker, Benjamin D.},
title = {Unrecognised water limitation is a main source of uncertainty for models of terrestrial photosynthesis},
journal = {Biogeosciences},
publisher = {Copernicus GmbH},
year = {2025},
volume = {22},
number = {23},
pages = {7455--7481},
doi = {10.5194/bg-22-7455-2025}
}
|
| Bloom CK, Koch TL, Meusburger K, Zweifel R, Walthert L, Etzold S, Scherrer D, Wilhelm M, Kahmen A and Baltensweiler A (2025), "Towards near real-time drought stress assessment in Europe’s temperate forests – comparing remote sensing time series with continuous in-situ tree-level measurements", Ecological Indicators., August, 2025. Vol. 177, pp. 113757. Elsevier BV. |
BibTeX:
@article{Bloom2025,
author = {Bloom, Colin K. and Koch, Tiziana L. and Meusburger, Katrin and Zweifel, Roman and Walthert, Lorenz and Etzold, Sophia and Scherrer, Daniel and Wilhelm, Micah and Kahmen, Ansgar and Baltensweiler, Andri},
title = {Towards near real-time drought stress assessment in Europe’s temperate forests – comparing remote sensing time series with continuous in-situ tree-level measurements},
journal = {Ecological Indicators},
publisher = {Elsevier BV},
year = {2025},
volume = {177},
pages = {113757},
doi = {10.1016/j.ecolind.2025.113757}
}
|
| de Bonfioli Cavalcabo’ G, Stagakis S, Feigenwinter C, Kalberer M, Damm A, Buchmann N and Brunner D (2025), "Modelling Urban Radiation Exchange Using a High-Resolution 3D Approach", In Geographic Approaches to Climate Change and Mitigation: Urban and Rural Perspectives (Volume 1). , pp. 237-244. Springer Nature Switzerland. |
BibTeX:
@inbook{BonfioliCavalcabo’2025,
author = {de Bonfioli Cavalcabo’, Guido and Stagakis, Stavros and Feigenwinter, Christian and Kalberer, Markus and Damm, Alexander and Buchmann, Nina and Brunner, Dominik},
title = {Modelling Urban Radiation Exchange Using a High-Resolution 3D Approach},
booktitle = {Geographic Approaches to Climate Change and Mitigation: Urban and Rural Perspectives (Volume 1)},
publisher = {Springer Nature Switzerland},
year = {2025},
pages = {237--244},
doi = {10.1007/978-3-031-92119-3_21}
}
|
| Bose AK, Etzold S, Meusburger K, Gessler A, Baltensweiler A, Braun S, Buchmann N, Camarero JJ, Haeni M, Kahmen A, Peters RL, Sterck FJ, Tresch S, Walthert L and Zweifel R (2025), "Decreasing Stem Growth in Common European Tree Species Despite Earlier Growth Onset", Global Change Biology., July, 2025. Vol. 31(7) Wiley. |
BibTeX:
@article{Bose2025,
author = {Bose, Arun K. and Etzold, Sophia and Meusburger, Katrin and Gessler, Arthur and Baltensweiler, Andri and Braun, Sabine and Buchmann, Nina and Camarero, J. Julio and Haeni, Matthias and Kahmen, Ansgar and Peters, Richard L. and Sterck, Frank J. and Tresch, Simon and Walthert, Lorenz and Zweifel, Roman},
title = {Decreasing Stem Growth in Common European Tree Species Despite Earlier Growth Onset},
journal = {Global Change Biology},
publisher = {Wiley},
year = {2025},
volume = {31},
number = {7},
doi = {10.1111/gcb.70318}
}
|
| Bouranis JA, McGivern BB, Makke G, Jurgensen SK, Bosman SH, Stemple B, Chanton JP, Wrighton KC and Tfaily MM (2025), "Metabolic Redox Coupling Controls Methane Production in Permafrost‐Affected Peatlands Through Organic Matter Quality‐Dependent Energy Allocation", Global Change Biology., August, 2025. Vol. 31(8) Wiley. |
BibTeX:
@article{Bouranis2025,
author = {Bouranis, John A. and McGivern, Bridget B. and Makke, Ghiwa and Jurgensen, Sophie K. and Bosman, Samantha H. and Stemple, Brooke and Chanton, Jeffrey P. and Wrighton, Kelly C. and Tfaily, Malak M.},
title = {Metabolic Redox Coupling Controls Methane Production in Permafrost‐Affected Peatlands Through Organic Matter Quality‐Dependent Energy Allocation},
journal = {Global Change Biology},
publisher = {Wiley},
year = {2025},
volume = {31},
number = {8},
doi = {10.1111/gcb.70390}
}
|
| Brogi C, Jakobi J, Huisman J, Schmidt M, Montzka C, Bates J, Akter S and Bogena H (2025), "Cosmic-ray neutron sensors provide scale-appropriate soil water content and vegetation observations for eddy covariance stations in agricultural ecosystems", Agricultural and Forest Meteorology., October, 2025. Vol. 373, pp. 110731. Elsevier BV. |
BibTeX:
@article{Brogi2025,
author = {Brogi, C. and Jakobi, J. and Huisman, J.A. and Schmidt, M. and Montzka, C. and Bates, J.S. and Akter, S. and Bogena, H.R.},
title = {Cosmic-ray neutron sensors provide scale-appropriate soil water content and vegetation observations for eddy covariance stations in agricultural ecosystems},
journal = {Agricultural and Forest Meteorology},
publisher = {Elsevier BV},
year = {2025},
volume = {373},
pages = {110731},
doi = {10.1016/j.agrformet.2025.110731}
}
|
| Brown LA, Fernandes R, Verrelst J, Morris H, Djamai N, Reyes-Muñoz P, D.Kovács D and Meier C (2025), "GROUNDED EO: Data-driven Sentinel-2 LAI and FAPAR retrieval using Gaussian processes trained with extensive fiducial reference measurements", Remote Sensing of Environment., August, 2025. Vol. 326, pp. 114797. Elsevier BV. |
BibTeX:
@article{Brown2025,
author = {Brown, Luke A. and Fernandes, Richard and Verrelst, Jochem and Morris, Harry and Djamai, Najib and Reyes-Muñoz, Pablo and D.Kovács, Dávid and Meier, Courtney},
title = {GROUNDED EO: Data-driven Sentinel-2 LAI and FAPAR retrieval using Gaussian processes trained with extensive fiducial reference measurements},
journal = {Remote Sensing of Environment},
publisher = {Elsevier BV},
year = {2025},
volume = {326},
pages = {114797},
doi = {10.1016/j.rse.2025.114797}
}
|
| Bruch V, Rösch T, Jiménez de la Cuesta Otero D, Ellerhoff B, Mamtimin B, Becker N, Blechschmidt A-M, Förstner J and Kaiser-Weiss AK (2025), "German methane fluxes in 2021 estimated with an ensemble-enhanced scaling inversion based on the ICON–ART model", May, 2025. Copernicus GmbH. |
BibTeX:
@article{Bruch2025,
author = {Bruch, Valentin and Rösch, Thomas and Jiménez de la Cuesta Otero, Diego and Ellerhoff, Beatrice and Mamtimin, Buhalqem and Becker, Niklas and Blechschmidt, Anne-Marlene and Förstner, Jochen and Kaiser-Weiss, Andrea K.},
title = {German methane fluxes in 2021 estimated with an ensemble-enhanced scaling inversion based on the ICON–ART model},
publisher = {Copernicus GmbH},
year = {2025},
doi = {10.5194/egusphere-2025-1464}
}
|
| Bruch V, Rösch T, Jiménez de la Cuesta Otero D, Ellerhoff B, Mamtimin B, Becker N, Blechschmidt A-M, Förstner J and Kaiser-Weiss AK (2025), "German methane fluxes estimated top-down using ICON–ART – Part 1: Ensemble-enhanced scaling inversion", Atmospheric Chemistry and Physics., December, 2025. Vol. 25(23), pp. 17159-17185. Copernicus GmbH. |
BibTeX:
@article{Bruch2025a,
author = {Bruch, Valentin and Rösch, Thomas and Jiménez de la Cuesta Otero, Diego and Ellerhoff, Beatrice and Mamtimin, Buhalqem and Becker, Niklas and Blechschmidt, Anne-Marlene and Förstner, Jochen and Kaiser-Weiss, Andrea K.},
title = {German methane fluxes estimated top-down using ICON–ART – Part 1: Ensemble-enhanced scaling inversion},
journal = {Atmospheric Chemistry and Physics},
publisher = {Copernicus GmbH},
year = {2025},
volume = {25},
number = {23},
pages = {17159--17185},
doi = {10.5194/acp-25-17159-2025}
}
|
| Brugnara Y, Steinbacher M, Baffelli S and Emmenegger L (2025), "Technical note: An interactive dashboard to facilitate quality control of in-situ atmospheric composition measurements", Atmospheric Chemistry and Physics., October, 2025. Vol. 25(21), pp. 14221-14236. Copernicus GmbH. |
BibTeX:
@article{Brugnara2025,
author = {Brugnara, Yuri and Steinbacher, Martin and Baffelli, Simone and Emmenegger, Lukas},
title = {Technical note: An interactive dashboard to facilitate quality control of in-situ atmospheric composition measurements},
journal = {Atmospheric Chemistry and Physics},
publisher = {Copernicus GmbH},
year = {2025},
volume = {25},
number = {21},
pages = {14221--14236},
doi = {10.5194/acp-25-14221-2025}
}
|
| Bussmann I, Brix H, Flöser G, Fischer PF, Jayachandran S, Achterberg EP, Carstens K, Kirstein IV, Sanders T, Raupers B, Voynova Y and Kamjunke N (2025), "Winter flood significantly changes salinity and nutrient export from land to sea", Frontiers in Marine Science., July, 2025. Vol. 12 Frontiers Media SA. |
BibTeX:
@article{Bussmann2025,
author = {Bussmann, Ingeborg and Brix, Holger and Flöser, Götz and Fischer, Philipp F. and Jayachandran, Saranya and Achterberg, Eric P. and Carstens, Kristine and Kirstein, Inga V. and Sanders, Tina and Raupers, Björn and Voynova, Yoana and Kamjunke, Norbert},
title = {Winter flood significantly changes salinity and nutrient export from land to sea},
journal = {Frontiers in Marine Science},
publisher = {Frontiers Media SA},
year = {2025},
volume = {12},
doi = {10.3389/fmars.2025.1599007}
}
|
| Callejas-Rodelas JÁ, Knohl A, Mammarella I, Vesala T, Peltola O and Markwitz C (2025), "Does increased spatial replication above heterogeneous agroforestry improve the representativeness of eddy covariance measurements?", Biogeosciences., September, 2025. Vol. 22(17), pp. 4507-4529. Copernicus GmbH. |
BibTeX:
@article{CallejasRodelas2025,
author = {Callejas-Rodelas, José Ángel and Knohl, Alexander and Mammarella, Ivan and Vesala, Timo and Peltola, Olli and Markwitz, Christian},
title = {Does increased spatial replication above heterogeneous agroforestry improve the representativeness of eddy covariance measurements?},
journal = {Biogeosciences},
publisher = {Copernicus GmbH},
year = {2025},
volume = {22},
number = {17},
pages = {4507--4529},
doi = {10.5194/bg-22-4507-2025}
}
|
| Chi J, Klosterhalfen A, Nilsson MB, Laudon H, Wallerman J, Larson J, Lindroth A, Kljun N, Fransson JE, Lundmark T and Peichl M (2025), "A managed boreal forest landscape in northern Sweden is a persistent net carbon sink despite large inter-annual weather anomalies", Agricultural and Forest Meteorology., October, 2025. Vol. 373, pp. 110758. Elsevier BV. |
BibTeX:
@article{Chi2025,
author = {Chi, Jinshu and Klosterhalfen, Anne and Nilsson, Mats B. and Laudon, Hjalmar and Wallerman, Jörgen and Larson, Johannes and Lindroth, Anders and Kljun, Natascha and Fransson, Johan E.S. and Lundmark, Tomas and Peichl, Matthias},
title = {A managed boreal forest landscape in northern Sweden is a persistent net carbon sink despite large inter-annual weather anomalies},
journal = {Agricultural and Forest Meteorology},
publisher = {Elsevier BV},
year = {2025},
volume = {373},
pages = {110758},
doi = {10.1016/j.agrformet.2025.110758}
}
|
| Coimbra PHH, Loubet B, Laurent O, Mauder M, Heinesch B, Bitton J, Delpierre N, Berveiller D, Depuydt J and Buysse P (2025), "Evaluation of a novel approach to partitioning respiration and photosynthesis using eddy covariance, wavelets and conditional sampling", Agricultural and Forest Meteorology., September, 2025. Vol. 372, pp. 110684. Elsevier BV. |
BibTeX:
@article{Coimbra2025,
author = {Coimbra, Pedro Henrique H. and Loubet, Benjamin and Laurent, Olivier and Mauder, Matthias and Heinesch, Bernard and Bitton, Jonathan and Delpierre, Nicolas and Berveiller, Daniel and Depuydt, Jérémie and Buysse, Pauline},
title = {Evaluation of a novel approach to partitioning respiration and photosynthesis using eddy covariance, wavelets and conditional sampling},
journal = {Agricultural and Forest Meteorology},
publisher = {Elsevier BV},
year = {2025},
volume = {372},
pages = {110684},
doi = {10.1016/j.agrformet.2025.110684}
}
|
| Cory AB, Wilson RM, Holmes ME, Riley WJ, Li Y-F, Tfaily MM, Bagby SC, Hough M, Dominguez S, Irwin-Raab N, Trubl G, Jones RM, Anderson D, Zayed A, Ferriere R, Ibba M, Varner RK, Hodgkins SB, Fahnestock MF, Sullivan MB, Rich VI, Crill PM, Ernakovich JG, Rich VI and Chanton JP (2025), "A climatically significant abiotic mechanism driving carbon loss and nitrogen limitation in peat bogs", Scientific Reports., January, 2025. Vol. 15(1) Springer Science and Business Media LLC. |
BibTeX:
@article{Cory2025,
author = {Cory, Alexandra B. and Wilson, Rachel M. and Holmes, M. Elizabeth and Riley, William J. and Li, Yueh-Fen and Tfaily, Malak M. and Bagby, Sarah C. and Hough, Moira and Dominguez, Sky and Irwin-Raab, Nicole and Trubl, Gareth and Jones, Robert M. and Anderson, Darya and Zayed, Ahmed and Ferriere, Regis and Ibba, Michael and Varner, Ruth K. and Hodgkins, Suzanne B. and Fahnestock, Maria F. and Sullivan, Matthew B. and Rich, Virginia I. and Crill, Patrick M. and Ernakovich, Jessica G. and Rich, Virginia I. and Chanton, Jeffrey P.},
title = {A climatically significant abiotic mechanism driving carbon loss and nitrogen limitation in peat bogs},
journal = {Scientific Reports},
publisher = {Springer Science and Business Media LLC},
year = {2025},
volume = {15},
number = {1},
doi = {10.1038/s41598-025-85928-w}
}
|
| Cory AB, Wilson RM, Ogles OC, Crill PM, Li Z, Chang K, Bosman SH, Rich VI, Chanton JP, Hough M, Dominguez S, Irwin‐Raab N, Trubl G, Jones RM and Anderson D (2025), "On the Relationship Between Methane Production in Anaerobic Incubations of Peat Material and In Situ Methane Emissions", Journal of Geophysical Research: Biogeosciences., March, 2025. Vol. 130(4) American Geophysical Union (AGU). |
BibTeX:
@article{Cory2025a,
author = {Cory, Alexandra B. and Wilson, Rachel M. and Ogles, Olivia C. and Crill, Patrick M. and Li, Zhen and Chang, Kuang‐Yu and Bosman, Samantha H. and Rich, Virginia I. and Chanton, Jeffrey P. and Hough, Moira and Dominguez, Sky and Irwin‐Raab, Nicole and Trubl, Gareth and Jones, Robert M. and Anderson, Darya},
title = {On the Relationship Between Methane Production in Anaerobic Incubations of Peat Material and In Situ Methane Emissions},
journal = {Journal of Geophysical Research: Biogeosciences},
publisher = {American Geophysical Union (AGU)},
year = {2025},
volume = {130},
number = {4},
doi = {10.1029/2024jg008371}
}
|
| Davidson SJ, Malhotra A, Jassey VEJ, Strack M, Aitova E, Anderson R, Atkinson LJ, Barel JM, Bird M, Brehier C, Donaldson-Selby G, Duley E, Eklof J, de Eyto E, Granath G, Grant A, Hartmann A, Holland A, Huth V, Jones CP, Lee S-C, Lopatin J, Milner AM, Peacock M, Peichl M, Perez-Quezada JF, Perryman CR, Pickard A, Rautakoski H, Silvester E, Virkkala A-M and Wegener E (2025), "The PeatPic project: predicting plot-scale green leaf phenology across peatlands", Environmental Research Letters., October, 2025. Vol. 20(11), pp. 114002. IOP Publishing. |
BibTeX:
@article{Davidson2025,
author = {Davidson, Scott J and Malhotra, Avni and Jassey, Vincent E J and Strack, Maria and Aitova, Elena and Anderson, Russell and Atkinson, Lindsey J and Barel, Janna M and Bird, Melanie and Brehier, Clarisse and Donaldson-Selby, Gillian and Duley, Emma and Eklof, Joel and de Eyto, Elvira and Granath, Gustaf and Grant, Alanna and Hartmann, Antonia and Holland, Aleicia and Huth, Vytas and Jones, Cheristy P and Lee, Sung-Ching and Lopatin, Javier and Milner, Alice M and Peacock, Mike and Peichl, Matthias and Perez-Quezada, Jorge F and Perryman, Clarice R and Pickard, Amy and Rautakoski, Helena and Silvester, Ewen and Virkkala, Anna-Maria and Wegener, Emma},
title = {The PeatPic project: predicting plot-scale green leaf phenology across peatlands},
journal = {Environmental Research Letters},
publisher = {IOP Publishing},
year = {2025},
volume = {20},
number = {11},
pages = {114002},
doi = {10.1088/1748-9326/ae0658}
}
|
| De R, Bao S, Koirala S, Brenning A, Reichstein M, Tagesson T, Liddell M, Ibrom A, Wolf S, Šigut L, Hörtnagl L, Woodgate W, Korkiakoski M, Merbold L, Black TA, Roland M, Klosterhalfen A, Blanken PD, Knox S, Sabbatini S, Gielen B, Montagnani L, Fensholt R, Wohlfahrt G, Desai AR, Paul‐Limoges E, Galvagno M, Hammerle A, Jocher G, Reverter BR, Holl D, Chen J, Vitale L, Arain MA and Carvalhais N (2025), "Addressing Challenges in Simulating Inter–Annual Variability of Gross Primary Production", Journal of Advances in Modeling Earth Systems., April, 2025. Vol. 17(5) American Geophysical Union (AGU). |
BibTeX:
@article{De2025,
author = {De, Ranit and Bao, Shanning and Koirala, Sujan and Brenning, Alexander and Reichstein, Markus and Tagesson, Torbern and Liddell, Michael and Ibrom, Andreas and Wolf, Sebastian and Šigut, Ladislav and Hörtnagl, Lukas and Woodgate, William and Korkiakoski, Mika and Merbold, Lutz and Black, T. Andrew and Roland, Marilyn and Klosterhalfen, Anne and Blanken, Peter D. and Knox, Sara and Sabbatini, Simone and Gielen, Bert and Montagnani, Leonardo and Fensholt, Rasmus and Wohlfahrt, Georg and Desai, Ankur R. and Paul‐Limoges, Eugénie and Galvagno, Marta and Hammerle, Albin and Jocher, Georg and Reverter, Borja Ruiz and Holl, David and Chen, Jiquan and Vitale, Luca and Arain, M. Altaf and Carvalhais, Nuno},
title = {Addressing Challenges in Simulating Inter–Annual Variability of Gross Primary Production},
journal = {Journal of Advances in Modeling Earth Systems},
publisher = {American Geophysical Union (AGU)},
year = {2025},
volume = {17},
number = {5},
doi = {10.1029/2024ms004697}
}
|
| Demina T, Marttila H, Pessi IS, Männistö MK, Dutilh BE, Roux S and Hultman J (2025), "Tunturi virus isolates and metagenome-assembled viral genomes provide insights into the virome of Acidobacteriota in Arctic tundra soils", Microbiome., March, 2025. Vol. 13(1) Springer Science and Business Media LLC. |
BibTeX:
@article{Demina2025,
author = {Demina, Tatiana and Marttila, Heli and Pessi, Igor S. and Männistö, Minna K. and Dutilh, Bas E. and Roux, Simon and Hultman, Jenni},
title = {Tunturi virus isolates and metagenome-assembled viral genomes provide insights into the virome of Acidobacteriota in Arctic tundra soils},
journal = {Microbiome},
publisher = {Springer Science and Business Media LLC},
year = {2025},
volume = {13},
number = {1},
doi = {10.1186/s40168-025-02053-6}
}
|
| DiMaria CA, Jones DBA, Ferracci V, Bloom AA, Worden HM, Seco R, Vettikkat L, Yáñez‐Serrano AM, Guenther AB, Araujo A, Goldstein AH, Langford B, Cash J, Harris NRP, Brown L, Rinnan R, Schobesberger S, Holst T and Mak JE (2025), "Optimizing the Temperature Sensitivity of the Isoprene Emission Model MEGAN in Different Ecosystems Using a Metropolis‐Hastings Markov Chain Monte Carlo Method", Journal of Geophysical Research: Biogeosciences., May, 2025. Vol. 130(5) American Geophysical Union (AGU). |
BibTeX:
@article{DiMaria2025,
author = {DiMaria, C. A. and Jones, D. B. A. and Ferracci, V. and Bloom, A. A. and Worden, H. M. and Seco, R. and Vettikkat, L. and Yáñez‐Serrano, A. M. and Guenther, A. B. and Araujo, A. and Goldstein, A. H. and Langford, B. and Cash, J. and Harris, N. R. P. and Brown, L. and Rinnan, R. and Schobesberger, S. and Holst, T. and Mak, J. E.},
title = {Optimizing the Temperature Sensitivity of the Isoprene Emission Model MEGAN in Different Ecosystems Using a Metropolis‐Hastings Markov Chain Monte Carlo Method},
journal = {Journal of Geophysical Research: Biogeosciences},
publisher = {American Geophysical Union (AGU)},
year = {2025},
volume = {130},
number = {5},
doi = {10.1029/2025jg008806}
}
|
| Duan W, Wu M, Peichl M, He H, Roulet N, Noumonvi KD, Ratcliffe JL, Nilsson MB and Jansson P (2025), "Seasonal and Diurnal Patterns of Methane Emissions From a Northern Pristine Peatland in the Last Decade", Global Biogeochemical Cycles., August, 2025. Vol. 39(8) American Geophysical Union (AGU). |
BibTeX:
@article{Duan2025,
author = {Duan, Wenzhuo and Wu, Mousong and Peichl, Matthias and He, Hongxing and Roulet, Nigel and Noumonvi, Koffi Dodji and Ratcliffe, Joshua L. and Nilsson, Mats B. and Jansson, Per‐Erik},
title = {Seasonal and Diurnal Patterns of Methane Emissions From a Northern Pristine Peatland in the Last Decade},
journal = {Global Biogeochemical Cycles},
publisher = {American Geophysical Union (AGU)},
year = {2025},
volume = {39},
number = {8},
doi = {10.1029/2025gb008518}
}
|
| Dubois K, Nilsson E and Rutgersson A (2025), "Assessing future changes in Baltic sea extreme wave heights using a machine learning approach", Theoretical and Applied Climatology., September, 2025. Vol. 156(10) Springer Science and Business Media LLC. |
BibTeX:
@article{Dubois2025,
author = {Dubois, Kévin and Nilsson, Erik and Rutgersson, Anna},
title = {Assessing future changes in Baltic sea extreme wave heights using a machine learning approach},
journal = {Theoretical and Applied Climatology},
publisher = {Springer Science and Business Media LLC},
year = {2025},
volume = {156},
number = {10},
doi = {10.1007/s00704-025-05758-8}
}
|
| du Bois d’Aische E, Jonard F, Hirst C, Villani M, Thomas M, Giesler R, Mörth C, Lundin E, Van Oost K, Vanacker V, Lambot S and Opfergelt S (2025), "Permafrost Thaw Drives Iron and Organic Carbon Release Into Soil Pore Water During Palsa to Degraded Palsa Transition", Permafrost and Periglacial Processes., November, 2025. Vol. 37(1), pp. 107-123. Wiley. |
BibTeX:
@article{du Bois d’Aische2025,
author = {du Bois d’Aische, Eléonore and Jonard, François and Hirst, Catherine and Villani, Maëlle and Thomas, Maxime and Giesler, Reiner and Mörth, Carl‐Magnus and Lundin, Erik and Van Oost, Kristof and Vanacker, Veerle and Lambot, Sébastien and Opfergelt, Sophie},
title = {Permafrost Thaw Drives Iron and Organic Carbon Release Into Soil Pore Water During Palsa to Degraded Palsa Transition},
journal = {Permafrost and Periglacial Processes},
publisher = {Wiley},
year = {2025},
volume = {37},
number = {1},
pages = {107--123},
doi = {10.1002/ppp.70018}
}
|
| Dutch VR, Bakker DCE, Roobaert A, Landschützer P, Roden NP, Hoppema M and Kaiser J (2025), "The Arctic Ocean CO2 Sink: Trends, Uncertainties, and the Impact of Sea Ice", Global Biogeochemical Cycles., August, 2025. Vol. 39(8) American Geophysical Union (AGU). |
BibTeX:
@article{Dutch2025,
author = {Dutch, Victoria R. and Bakker, Dorothee C. E. and Roobaert, Alizée and Landschützer, Peter and Roden, Nicholas P. and Hoppema, Mario and Kaiser, Jan},
title = {The Arctic Ocean CO2 Sink: Trends, Uncertainties, and the Impact of Sea Ice},
journal = {Global Biogeochemical Cycles},
publisher = {American Geophysical Union (AGU)},
year = {2025},
volume = {39},
number = {8},
doi = {10.1029/2025gb008576}
}
|
| Emmerichs T, Al Mamun A, Emberson L, Mao H, Zhang L, Ran L, Betancourt C, Wong A, Koren G, Gerosa G, Huang M and Guaita P (2025), "Can atmospheric chemistry deposition schemes reliably simulate stomatal ozone flux across global land covers and climates?", Biogeosciences., September, 2025. Vol. 22(18), pp. 4823-4849. Copernicus GmbH. |
BibTeX:
@article{Emmerichs2025,
author = {Emmerichs, Tamara and Al Mamun, Abdulla and Emberson, Lisa and Mao, Huiting and Zhang, Leiming and Ran, Limei and Betancourt, Clara and Wong, Anthony and Koren, Gerbrand and Gerosa, Giacomo and Huang, Min and Guaita, Pierluigi},
title = {Can atmospheric chemistry deposition schemes reliably simulate stomatal ozone flux across global land covers and climates?},
journal = {Biogeosciences},
publisher = {Copernicus GmbH},
year = {2025},
volume = {22},
number = {18},
pages = {4823--4849},
doi = {10.5194/bg-22-4823-2025}
}
|
| Eriksson Stenström K and Mattsson S (2025), "Current trends in radiocarbon in Skagerrak and Kattegat assessed by brown algae from Swedish coastal waters", Radiation Protection Dosimetry., August, 2025. Vol. 201(13–14), pp. 1006-1016. Oxford University Press (OUP). |
BibTeX:
@article{ErikssonStenstroem2025,
author = {Eriksson Stenström, K and Mattsson, S},
title = {Current trends in radiocarbon in Skagerrak and Kattegat assessed by brown algae from Swedish coastal waters},
journal = {Radiation Protection Dosimetry},
publisher = {Oxford University Press (OUP)},
year = {2025},
volume = {201},
number = {13–14},
pages = {1006--1016},
doi = {10.1093/rpd/ncaf032}
}
|
| Escobar D, Manzoni S, Tapasco J, Vestin P and Belyazid S (2025), "Evaluation of long-term carbon dynamics in a drained forested peatland using the ForSAFE-Peat model", Biogeosciences., April, 2025. Vol. 22(8), pp. 2023-2047. Copernicus GmbH. |
BibTeX:
@article{Escobar2025,
author = {Escobar, Daniel and Manzoni, Stefano and Tapasco, Jeimar and Vestin, Patrik and Belyazid, Salim},
title = {Evaluation of long-term carbon dynamics in a drained forested peatland using the ForSAFE-Peat model},
journal = {Biogeosciences},
publisher = {Copernicus GmbH},
year = {2025},
volume = {22},
number = {8},
pages = {2023--2047},
doi = {10.5194/bg-22-2023-2025}
}
|
| Ezhova E, Laanti T, Lintunen A, Kolari P, Nieminen T, Mammarella I, Heljanko K and Kulmala M (2025), "Explainable machine learning for modeling of net ecosystem exchange in boreal forests", Biogeosciences., January, 2025. Vol. 22(1), pp. 257-288. Copernicus GmbH. |
BibTeX:
@article{Ezhova2025,
author = {Ezhova, Ekaterina and Laanti, Topi and Lintunen, Anna and Kolari, Pasi and Nieminen, Tuomo and Mammarella, Ivan and Heljanko, Keijo and Kulmala, Markku},
title = {Explainable machine learning for modeling of net ecosystem exchange in boreal forests},
journal = {Biogeosciences},
publisher = {Copernicus GmbH},
year = {2025},
volume = {22},
number = {1},
pages = {257--288},
doi = {10.5194/bg-22-257-2025}
}
|
| Falvo G, Schuur EAG, Euskirchen ES, Natali SM, Sonnentag O, Alcock H, Arndt K, Edgar C, Hould-Gosselin G, Hung J and Ledman J (2025), "Record 2024 winter carbon emissions coincide with record warmth across boreal forest, tundra, and wetland ecosystems", Environmental Research Letters., October, 2025. Vol. 20(11), pp. 114032. IOP Publishing. |
BibTeX:
@article{Falvo2025,
author = {Falvo, Grant and Schuur, Edward A G and Euskirchen, Eugénie S and Natali, Susan M and Sonnentag, Oliver and Alcock, Haley and Arndt, Kyle and Edgar, Colin and Hould-Gosselin, Gabriel and Hung, Jacqueline and Ledman, Justin},
title = {Record 2024 winter carbon emissions coincide with record warmth across boreal forest, tundra, and wetland ecosystems},
journal = {Environmental Research Letters},
publisher = {IOP Publishing},
year = {2025},
volume = {20},
number = {11},
pages = {114032},
doi = {10.1088/1748-9326/ae09bb}
}
|
| Feng L, Palmer PI, Smallman L, Xiao J, Cristofanelli P, Hermansen O, Lee J, Labuschagne C, Montaguti S, Noe SM, Platt SM, Ren X, Steinbacher M and Xueref-Remy I (2025), "The role of the tropical carbon balance in determining the large atmospheric CO 2 growth rate in 2023", Atmospheric Chemistry and Physics., October, 2025. Vol. 25(20), pp. 13053-13076. Copernicus GmbH. |
BibTeX:
@article{Feng2025,
author = {Feng, Liang and Palmer, Paul I. and Smallman, Luke and Xiao, Jingfeng and Cristofanelli, Paolo and Hermansen, Ove and Lee, John and Labuschagne, Casper and Montaguti, Simonetta and Noe, Steffen M. and Platt, Stephen M. and Ren, Xinrong and Steinbacher, Martin and Xueref-Remy, Irène},
title = {The role of the tropical carbon balance in determining the large atmospheric CO 2 growth rate in 2023},
journal = {Atmospheric Chemistry and Physics},
publisher = {Copernicus GmbH},
year = {2025},
volume = {25},
number = {20},
pages = {13053--13076},
doi = {10.5194/acp-25-13053-2025}
}
|
| Fiedler B, Monteiro I, Almeida C, Zenk C, Silva P, Karstensen J, Rodrigues E, Vieira N, Pinto-Almeida A, Lima E, Hahn T, Koné D, Rodrigues Y and Körtzinger A (2025), "20 Years of Partnership in Marine Sciences Between Cabo Verde and Germany: From Ideas, Opportunities, and Observations to Long-Term and Sustained Capacity Sharing", Oceanography. Vol. 38(1) The Oceanography Society. |
BibTeX:
@article{Fiedler2025,
author = {Fiedler, Björn and Monteiro, Ivanice and Almeida, Corrine and Zenk, Cordula and Silva, Pericles and Karstensen, Johannes and Rodrigues, Elizandro and Vieira, Nuno and Pinto-Almeida, Antonio and Lima, Estanislau and Hahn, Tobias and Koné, Daouda and Rodrigues, Yara and Körtzinger, Arne},
title = {20 Years of Partnership in Marine Sciences Between Cabo Verde and Germany: From Ideas, Opportunities, and Observations to Long-Term and Sustained Capacity Sharing},
journal = {Oceanography},
publisher = {The Oceanography Society},
year = {2025},
volume = {38},
number = {1},
doi = {10.5670/oceanog.2025.127}
}
|
| Fransson P, Lim H, Zhao P, Tor-ngern P, Peichl M, Laudon H, Henriksson N, Näsholm T and Franklin O (2025), "An eco-physiological model of forest photosynthesis and transpiration under combined nitrogen and water limitation", Tree Physiology., January, 2025. Vol. 45(2) Oxford University Press (OUP). |
BibTeX:
@article{Fransson2025,
author = {Fransson, Peter and Lim, Hyungwoo and Zhao, Peng and Tor-ngern, Pantana and Peichl, Matthias and Laudon, Hjalmar and Henriksson, Nils and Näsholm, Torgny and Franklin, Oskar},
editor = {Holtta, Teemu},
title = {An eco-physiological model of forest photosynthesis and transpiration under combined nitrogen and water limitation},
journal = {Tree Physiology},
publisher = {Oxford University Press (OUP)},
year = {2025},
volume = {45},
number = {2},
doi = {10.1093/treephys/tpae168}
}
|
| Friedlingstein P, O’Sullivan M, Jones MW, Andrew RM, Bakker DCE, Hauck J, Landschützer P, Le Quéré C, Li H, Luijkx IT, Peters GP, Peters W, Pongratz J, Schwingshackl C, Sitch S, Canadell JG, Ciais P, Aas K, Alin SR, Anthoni P, Barbero L, Bates NR, Bellouin N, Benoit-Cattin A, Berghoff CF, Bernardello R, Bopp L, Brasika IBM, Chamberlain MA, Chandra N, Chevallier F, Chini LP, Collier NO, Colligan TH, Cronin M, Djeutchouang L, Dou X, Enright MP, Enyo K, Erb M, Evans W, Feely RA, Feng L, Ford DJ, Foster A, Fransner F, Gasser T, Gehlen M, Gkritzalis T, Goncalves De Souza J, Grassi G, Gregor L, Gruber N, Guenet B, Gürses Ö, Harrington K, Harris I, Heinke J, Hurtt GC, Iida Y, Ilyina T, Ito A, Jacobson AR, Jain AK, Jarníková T, Jersild A, Jiang F, Jones SD, Kato E, Keeling RF, Klein Goldewijk K, Knauer J, Kong Y, Korsbakken JI, Koven C, Kunimitsu T, Lan X, Liu J, Liu Z, Liu Z, Lo Monaco C, Ma L, Marland G, McGuire PC, McKinley GA, Melton J, Monacci N, Monier E, Morgan EJ, Munro DR, Müller JD, Nakaoka S-I, Nayagam LR, Niwa Y, Nutzel T, Olsen A, Omar AM, Pan N, Pandey S, Pierrot D, Qin Z, Regnier PAG, Rehder G, Resplandy L, Roobaert A, Rosan TM, Rödenbeck C, Schwinger J, Skjelvan I, Smallman TL, Spada V, Sreeush MG, Sun Q, Sutton AJ, Sweeney C, Swingedouw D, Séférian R, Takao S, Tatebe H, Tian H, Tian X, Tilbrook B, Tsujino H, Tubiello F, van Ooijen E, van der Werf G, van de Velde SJ, Walker A, Wanninkhof R, Yang X, Yuan W, Yue X and Zeng J (2025), "Global Carbon Budget 2025", November, 2025. Copernicus GmbH. |
BibTeX:
@article{Friedlingstein2025,
author = {Friedlingstein, Pierre and O’Sullivan, Michael and Jones, Matthew W. and Andrew, Robbie M. and Bakker, Dorothee C. E. and Hauck, Judith and Landschützer, Peter and Le Quéré, Corinne and Li, Hongmei and Luijkx, Ingrid T. and Peters, Glen P. and Peters, Wouter and Pongratz, Julia and Schwingshackl, Clemens and Sitch, Stephen and Canadell, Josep G. and Ciais, Philippe and Aas, Kjetil and Alin, Simone R. and Anthoni, Peter and Barbero, Leticia and Bates, Nicholas R. and Bellouin, Nicolas and Benoit-Cattin, Alice and Berghoff, Carla F. and Bernardello, Raffaele and Bopp, Laurent and Brasika, Ida B. M. and Chamberlain, Matthew A. and Chandra, Naveen and Chevallier, Frédéric and Chini, Louise P. and Collier, Nathan O. and Colligan, Thomas H. and Cronin, Margot and Djeutchouang, Laique and Dou, Xinyu and Enright, Matt P. and Enyo, Kazutaka and Erb, Michael and Evans, Wiley and Feely, Richard A. and Feng, Liang and Ford, Daniel J. and Foster, Adrianna and Fransner, Filippa and Gasser, Thomas and Gehlen, Marion and Gkritzalis, Thanos and Goncalves De Souza, Jefferson and Grassi, Giacomo and Gregor, Luke and Gruber, Nicolas and Guenet, Bertrand and Gürses, Özgür and Harrington, Kirsty and Harris, Ian and Heinke, Jens and Hurtt, George C. and Iida, Yosuke and Ilyina, Tatiana and Ito, Akihiko and Jacobson, Andrew R. and Jain, Atul K. and Jarníková, Tereza and Jersild, Annika and Jiang, Fei and Jones, Steve D. and Kato, Etsushi and Keeling, Ralph F. and Klein Goldewijk, Kees and Knauer, Jürgen and Kong, Yawen and Korsbakken, Jan Ivar and Koven, Charles and Kunimitsu, Taro and Lan, Xin and Liu, Junjie and Liu, Zhiqiang and Liu, Zhu and Lo Monaco, Claire and Ma, Lei and Marland, Gregg and McGuire, Patrick C. and McKinley, Galen A. and Melton, Joe and Monacci, Natalie and Monier, Erwan and Morgan, Eric J. and Munro, David R. and Müller, Jens D. and Nakaoka, Shin-Ichiro and Nayagam, Lorna R. and Niwa, Yosuke and Nutzel, Tobias and Olsen, Are and Omar, Abdirahman M. and Pan, Naiqing and Pandey, Sudhanshu and Pierrot, Denis and Qin, Zhangcai and Regnier, Pierre A. G. and Rehder, Gregor and Resplandy, Laure and Roobaert, Alizée and Rosan, Thais M. and Rödenbeck, Christian and Schwinger, Jörg and Skjelvan, Ingunn and Smallman, T. Luke and Spada, Victoria and Sreeush, Mohanan G. and Sun, Qing and Sutton, Adrienne J. and Sweeney, Colm and Swingedouw, Didier and Séférian, Roland and Takao, Shintaro and Tatebe, Hiroaki and Tian, Hanqin and Tian, Xiangjun and Tilbrook, Bronte and Tsujino, Hiroyuki and Tubiello, Francesco and van Ooijen, Erik and van der Werf, Guido and van de Velde, Sebastiaan J. and Walker, Anthony and Wanninkhof, Rik and Yang, Xiaojuan and Yuan, Wenping and Yue, Xu and Zeng, Jiye},
title = {Global Carbon Budget 2025},
publisher = {Copernicus GmbH},
year = {2025},
doi = {10.5194/essd-2025-659}
}
|
| Fu S, Qing X, Zang K, Lin Y, Liu S, Chen Y, Chen B, Gao W, Steinbacher M and Fang S (2025), "Observational Insights into Atmospheric CO 2 and CO at the Urban Canopy Layer Top in Metropolitan Shanghai, China", December, 2025. Copernicus GmbH. |
BibTeX:
@article{Fu2025,
author = {Fu, Shuang and Qing, Xuemei and Zang, Kunpeng and Lin, Yi and Liu, Shuo and Chen, Yuanyuan and Chen, Bingjiang and Gao, Wei and Steinbacher, Martin and Fang, Shuangxi},
title = {Observational Insights into Atmospheric CO 2 and CO at the Urban Canopy Layer Top in Metropolitan Shanghai, China},
publisher = {Copernicus GmbH},
year = {2025},
doi = {10.5194/egusphere-2025-5982}
}
|
| Gachkivskyi M, Karstens U, Fischer B, Kubistin D, Müller-Williams J, Lindauer M and Levin I (2025), "Radon-222 monitoring at German ICOS atmosphere stations", Earth System Science Data., November, 2025. Vol. 17(11), pp. 6173-6197. Copernicus GmbH. |
BibTeX:
@article{Gachkivskyi2025,
author = {Gachkivskyi, Maksym and Karstens, Ute and Fischer, Bernd and Kubistin, Dagmar and Müller-Williams, Jennifer and Lindauer, Matthias and Levin, Ingeborg},
title = {Radon-222 monitoring at German ICOS atmosphere stations},
journal = {Earth System Science Data},
publisher = {Copernicus GmbH},
year = {2025},
volume = {17},
number = {11},
pages = {6173--6197},
doi = {10.5194/essd-17-6173-2025}
}
|
| Gao Y, Burke EJ, Chadburn SE, Raivonen M, Markkanen T, Aurela M, Flanagan LB, Fortuniak K, Humphreys E, Lohila A, Li T, Mammarella I, Nevalainen O, Nilsson MB, Pawlak W, Tsuruta A, Yang H and Aalto T (2025), "Assessing modelled methane emissions over northern wetlands by the JULES-HIMMELI model", Science of The Total Environment., June, 2025. Vol. 980, pp. 179526. Elsevier BV. |
BibTeX:
@article{Gao2025,
author = {Gao, Yao and Burke, Eleanor J. and Chadburn, Sarah E. and Raivonen, Maarit and Markkanen, Tiina and Aurela, Mika and Flanagan, Lawrence B. and Fortuniak, Krzysztof and Humphreys, Elyn and Lohila, Annalea and Li, Tingting and Mammarella, Ivan and Nevalainen, Olli and Nilsson, Mats B. and Pawlak, Włodzimierz and Tsuruta, Aki and Yang, Huiyi and Aalto, Tuula},
title = {Assessing modelled methane emissions over northern wetlands by the JULES-HIMMELI model},
journal = {Science of The Total Environment},
publisher = {Elsevier BV},
year = {2025},
volume = {980},
pages = {179526},
doi = {10.1016/j.scitotenv.2025.179526}
}
|
| Geilfus N-X, Delille B, Villnäs A and Norkko A (2025), "Spatial heterogeneity of GHG dynamics across an estuarine ecosystem", October, 2025. Copernicus GmbH. |
BibTeX:
@article{Geilfus2025,
author = {Geilfus, Nicolas-Xavier and Delille, Bruno and Villnäs, Anna and Norkko, Alf},
title = {Spatial heterogeneity of GHG dynamics across an estuarine ecosystem},
publisher = {Copernicus GmbH},
year = {2025},
doi = {10.5194/egusphere-2025-5068}
}
|
| Gharun M, Shekhar A, Hörtnagl L, Krebs L, Arriga N, Migliavacca M, Roland M, Gielen B, Montagnani L, Tomelleri E, Šigut L, Peichl M, Zhao P, Schmidt M, Grünwald T, Korkiakoski M, Lohila A and Buchmann N (2025), "Impact of winter warming on CO 2 fluxes in evergreen needleleaf forests", Biogeosciences., March, 2025. Vol. 22(5), pp. 1393-1411. Copernicus GmbH. |
BibTeX:
@article{Gharun2025,
author = {Gharun, Mana and Shekhar, Ankit and Hörtnagl, Lukas and Krebs, Luana and Arriga, Nicola and Migliavacca, Mirco and Roland, Marilyn and Gielen, Bert and Montagnani, Leonardo and Tomelleri, Enrico and Šigut, Ladislav and Peichl, Matthias and Zhao, Peng and Schmidt, Marius and Grünwald, Thomas and Korkiakoski, Mika and Lohila, Annalea and Buchmann, Nina},
title = {Impact of winter warming on CO 2 fluxes in evergreen needleleaf forests},
journal = {Biogeosciences},
publisher = {Copernicus GmbH},
year = {2025},
volume = {22},
number = {5},
pages = {1393--1411},
doi = {10.5194/bg-22-1393-2025}
}
|
| Ghisi T, Fischer M, Bohuslav J, Orság M, Nieto H, Pozníková G, Žalud Z and Trnka M (2025), "Evaluating the ability of satellite remote sensing to detect changes in actual evapotranspiration under contrasting field management practices in the Czech Republic", Agricultural Water Management., December, 2025. Vol. 321, pp. 109940. Elsevier BV. |
BibTeX:
@article{Ghisi2025,
author = {Ghisi, T. and Fischer, M. and Bohuslav, J. and Orság, M. and Nieto, H. and Pozníková, G. and Žalud, Z. and Trnka, M.},
title = {Evaluating the ability of satellite remote sensing to detect changes in actual evapotranspiration under contrasting field management practices in the Czech Republic},
journal = {Agricultural Water Management},
publisher = {Elsevier BV},
year = {2025},
volume = {321},
pages = {109940},
doi = {10.1016/j.agwat.2025.109940}
}
|
| Gómez-Ortiz C, Monteil G, Karstens U and Scholze M (2025), "Modeling support for an extensive Δ 14 CO 2 flask sample monitoring campaign over Europe to constrain fossil CO 2 emissions", Atmospheric Chemistry and Physics., September, 2025. Vol. 25(18), pp. 10747-10771. Copernicus GmbH. |
BibTeX:
@article{GomezOrtiz2025,
author = {Gómez-Ortiz, Carlos and Monteil, Guillaume and Karstens, Ute and Scholze, Marko},
title = {Modeling support for an extensive Δ 14 CO 2 flask sample monitoring campaign over Europe to constrain fossil CO 2 emissions},
journal = {Atmospheric Chemistry and Physics},
publisher = {Copernicus GmbH},
year = {2025},
volume = {25},
number = {18},
pages = {10747--10771},
doi = {10.5194/acp-25-10747-2025}
}
|
| Gómez-Ortiz C, Monteil G, Basu S and Scholze M (2025), "A CO 2 –Δ 14 CO 2 inversion setup for estimating European fossil CO 2 emissions", Atmospheric Chemistry and Physics., January, 2025. Vol. 25(1), pp. 397-424. Copernicus GmbH. |
BibTeX:
@article{GomezOrtiz2025a,
author = {Gómez-Ortiz, Carlos and Monteil, Guillaume and Basu, Sourish and Scholze, Marko},
title = {A CO 2 –Δ 14 CO 2 inversion setup for estimating European fossil CO 2 emissions},
journal = {Atmospheric Chemistry and Physics},
publisher = {Copernicus GmbH},
year = {2025},
volume = {25},
number = {1},
pages = {397--424},
doi = {10.5194/acp-25-397-2025}
}
|
| Grange SK, Rubli P, Fischer A, Brunner D, Hueglin C and Emmenegger L (2025), "The ZiCOS-M CO 2 sensor network: measurement performance and CO 2 variability across Zurich", Atmospheric Chemistry and Physics., March, 2025. Vol. 25(5), pp. 2781-2806. Copernicus GmbH. |
BibTeX:
@article{Grange2025,
author = {Grange, Stuart K. and Rubli, Pascal and Fischer, Andrea and Brunner, Dominik and Hueglin, Christoph and Emmenegger, Lukas},
title = {The ZiCOS-M CO 2 sensor network: measurement performance and CO 2 variability across Zurich},
journal = {Atmospheric Chemistry and Physics},
publisher = {Copernicus GmbH},
year = {2025},
volume = {25},
number = {5},
pages = {2781--2806},
doi = {10.5194/acp-25-2781-2025}
}
|
| Grünwald T, Wanner L, Eichelmann U, Hehn M, Moderow U, Prasse H, Queck R, Bernhofer C and Mauder M (2025), "Carbon fluxes controlled by land management and disturbances at a cluster of long-term ecosystem monitoring sites in Central Europe", Agricultural and Forest Meteorology., June, 2025. Vol. 369, pp. 110533. Elsevier BV. |
BibTeX:
@article{Gruenwald2025,
author = {Grünwald, Thomas and Wanner, Luise and Eichelmann, Uwe and Hehn, Markus and Moderow, Uta and Prasse, Heiko and Queck, Ronald and Bernhofer, Christian and Mauder, Matthias},
title = {Carbon fluxes controlled by land management and disturbances at a cluster of long-term ecosystem monitoring sites in Central Europe},
journal = {Agricultural and Forest Meteorology},
publisher = {Elsevier BV},
year = {2025},
volume = {369},
pages = {110533},
doi = {10.1016/j.agrformet.2025.110533}
}
|
| Guidolotti G, Zenone T, Endreny T, Pace R, Ciolfi M, Mattioni M, Pallozzi E, Rezaie N, Bertolini T, Corradi C and Calfapietra C (2025), "Impact of drought on cooling capacity and carbon sequestration in urban green area", Urban Climate., February, 2025. Vol. 59, pp. 102244. Elsevier BV. |
BibTeX:
@article{Guidolotti2025,
author = {Guidolotti, Gabriele and Zenone, Terenzio and Endreny, Theodore and Pace, Rocco and Ciolfi, Marco and Mattioni, Michele and Pallozzi, Emanuele and Rezaie, Negar and Bertolini, Teresa and Corradi, Chiara and Calfapietra, Carlo},
title = {Impact of drought on cooling capacity and carbon sequestration in urban green area},
journal = {Urban Climate},
publisher = {Elsevier BV},
year = {2025},
volume = {59},
pages = {102244},
doi = {10.1016/j.uclim.2024.102244}
}
|
| Guo Z, Zhang H, Martínez-García E, Lv X, Laudon H, Nilsson MB and Peichl M (2025), "Spatio-temporal dynamics and controls of forest-floor evapotranspiration across a managed boreal forest landscape", Agricultural and Forest Meteorology., February, 2025. Vol. 361, pp. 110316. Elsevier BV. |
BibTeX:
@article{Guo2025,
author = {Guo, Zifan and Zhang, Hengshuo and Martínez-García, Eduardo and Lv, Xizhi and Laudon, Hjalmar and Nilsson, Mats B. and Peichl, Matthias},
title = {Spatio-temporal dynamics and controls of forest-floor evapotranspiration across a managed boreal forest landscape},
journal = {Agricultural and Forest Meteorology},
publisher = {Elsevier BV},
year = {2025},
volume = {361},
pages = {110316},
doi = {10.1016/j.agrformet.2024.110316}
}
|
| Guo X, Bayat B, Bates JS, Herbst M, Schmidt M, Vereecken H and Montzka C (2025), "Enhancing carbon flux estimation in a crop growth model by integrating UAS-derived leaf area index", Agricultural and Forest Meteorology., November, 2025. Vol. 374, pp. 110776. Elsevier BV. |
BibTeX:
@article{Guo2025a,
author = {Guo, Xuerui and Bayat, Bagher and Bates, Jordan Steven and Herbst, Michael and Schmidt, Marius and Vereecken, Harry and Montzka, Carsten},
title = {Enhancing carbon flux estimation in a crop growth model by integrating UAS-derived leaf area index},
journal = {Agricultural and Forest Meteorology},
publisher = {Elsevier BV},
year = {2025},
volume = {374},
pages = {110776},
doi = {10.1016/j.agrformet.2025.110776}
}
|
| Guzinski R, Nieto H, Barrios JM, Ghariani W, Gellens-Meulenberghs F, De Pue J and Lacaze R (2025), "Towards a global actual evapotranspiration product for the Copernicus Land Monitoring Service", September, 2025. Copernicus GmbH. |
BibTeX:
@article{Guzinski2025,
author = {Guzinski, Radoslaw and Nieto, Héctor and Barrios, José Miguel and Ghariani, Walid and Gellens-Meulenberghs, Francoise and De Pue, Jan and Lacaze, Roselyne},
title = {Towards a global actual evapotranspiration product for the Copernicus Land Monitoring Service},
publisher = {Copernicus GmbH},
year = {2025},
doi = {10.5194/egusphere-2025-4342}
}
|
| Haberstroh S, Scarpa F, Seeger S, Christen A and Werner C (2025), "Continuous Stem Water Potential Measurements of a Diffuse‐Porous Tree Species Offer New Insights Into Tree Water Relations", Ecohydrology., January, 2025. Vol. 18(1) Wiley. |
BibTeX:
@article{Haberstroh2025,
author = {Haberstroh, Simon and Scarpa, Fabio and Seeger, Stefan and Christen, Andreas and Werner, Christiane},
title = {Continuous Stem Water Potential Measurements of a Diffuse‐Porous Tree Species Offer New Insights Into Tree Water Relations},
journal = {Ecohydrology},
publisher = {Wiley},
year = {2025},
volume = {18},
number = {1},
doi = {10.1002/eco.2761}
}
|
| Haberstroh S, Christen A, Sulzer M, Scarpa F and Werner C (2025), "Recurrent hot droughts cause persistent legacy effects in a temperate Scots Pine forest", Plant Biology., June, 2025. Wiley. |
BibTeX:
@article{Haberstroh2025a,
author = {Haberstroh, S. and Christen, A. and Sulzer, M. and Scarpa, F. and Werner, C.},
title = {Recurrent hot droughts cause persistent legacy effects in a temperate Scots Pine forest},
journal = {Plant Biology},
publisher = {Wiley},
year = {2025},
doi = {10.1111/plb.70066}
}
|
| Haberstroh S, Sulzer M, Scarpa F, Plapp T, Christen A and Werner C (2025), "Persistent drought legacy effects in a Scots Pine forest after years of concurrent drought and heat", March, 2025. Copernicus GmbH. |
BibTeX:
@article{Haberstroh2025b,
author = {Haberstroh, Simon and Sulzer, Markus and Scarpa, Fabio and Plapp, Thomas and Christen, Andreas and Werner, Christiane},
title = {Persistent drought legacy effects in a Scots Pine forest after years of concurrent drought and heat},
publisher = {Copernicus GmbH},
year = {2025},
doi = {10.5194/egusphere-egu25-16453}
}
|
| Hamard S, Planchenault S, Walcker R, Sytiuk A, Le Geay M, Küttim M, Dorrepaal E, Lamentowicz M, Petchey OL, Robroek BJM, Tuittila E-S, Barret M, Céréghino R, Delarue F, Ferriol J, Lafont Rapnouil T, Leflaive J, Le Roux G and Jassey VEJ (2025), "Microbial photosynthesis mitigates carbon loss from northern peatlands under warming", Nature Climate Change., March, 2025. Vol. 15(4), pp. 436-443. Springer Science and Business Media LLC. |
BibTeX:
@article{Hamard2025,
author = {Hamard, Samuel and Planchenault, Sophie and Walcker, Romain and Sytiuk, Anna and Le Geay, Marie and Küttim, Martin and Dorrepaal, Ellen and Lamentowicz, Mariusz and Petchey, Owen L. and Robroek, Bjorn J. M. and Tuittila, Eeva-Stiina and Barret, Maialen and Céréghino, Régis and Delarue, Frédéric and Ferriol, Jessica and Lafont Rapnouil, Tristan and Leflaive, Joséphine and Le Roux, Gaël and Jassey, Vincent E. J.},
title = {Microbial photosynthesis mitigates carbon loss from northern peatlands under warming},
journal = {Nature Climate Change},
publisher = {Springer Science and Business Media LLC},
year = {2025},
volume = {15},
number = {4},
pages = {436--443},
doi = {10.1038/s41558-025-02271-8}
}
|
| Harris SJ, Schwietzke S, France JL, Velandia Salinas N, Meixus Fernandez T, Randles C, Guanter L, Irakulis-Loitxate I, Calcan A, Aben I, Abrahamsson K, Balcombe P, Berchet A, Biddle LC, Bittig HC, Böttcher C, Bouvard T, Broström G, Bruch V, Cassiani M, Chipperfield MP, Ciais P, Damm E, Dammers E, Denier van der Gon H, Dogniaux M, Dowd E, Dupouy F, Eckhardt S, Evangeliou N, Feng W, Jia M, Jiang F, Kaiser-Weiss AK, Kamoun I, Kerridge BJ, Lampert A, Lana J, Li F, Maasakkers JD, Maclean J-PW, Mamtimin B, Marshall J, Mauger G, Mekkas A, Mielke C, Mohrmann M, Moore DP, Nanni R, Pätzold F, Pison I, Pisso I, Platt SM, Préa R, Queste BY, Ramonet M, Rehder G, Remedios JJ, Reum F, Roiger A, Schmidbauer N, Siddans R, Sunkisala A, Thompson RL, Varon DJ, Ventress LJ, Wilson C and Zhang Y (2025), "Methane emissions from the Nord Stream subsea pipeline leaks", Nature., January, 2025. Vol. 637(8048), pp. 1124-1130. Springer Science and Business Media LLC. |
BibTeX:
@article{Harris2025,
author = {Harris, Stephen J. and Schwietzke, Stefan and France, James L. and Velandia Salinas, Nataly and Meixus Fernandez, Tania and Randles, Cynthia and Guanter, Luis and Irakulis-Loitxate, Itziar and Calcan, Andreea and Aben, Ilse and Abrahamsson, Katarina and Balcombe, Paul and Berchet, Antoine and Biddle, Louise C. and Bittig, Henry C. and Böttcher, Christian and Bouvard, Timo and Broström, Göran and Bruch, Valentin and Cassiani, Massimo and Chipperfield, Martyn P. and Ciais, Philippe and Damm, Ellen and Dammers, Enrico and Denier van der Gon, Hugo and Dogniaux, Matthieu and Dowd, Emily and Dupouy, François and Eckhardt, Sabine and Evangeliou, Nikolaos and Feng, Wuhu and Jia, Mengwei and Jiang, Fei and Kaiser-Weiss, Andrea K. and Kamoun, Ines and Kerridge, Brian J. and Lampert, Astrid and Lana, José and Li, Fei and Maasakkers, Joannes D. and Maclean, Jean-Philippe W. and Mamtimin, Buhalqem and Marshall, Julia and Mauger, Gédéon and Mekkas, Anouar and Mielke, Christian and Mohrmann, Martin and Moore, David P. and Nanni, Riccardo and Pätzold, Falk and Pison, Isabelle and Pisso, Ignacio and Platt, Stephen M. and Préa, Raphaël and Queste, Bastien Y. and Ramonet, Michel and Rehder, Gregor and Remedios, John J. and Reum, Friedemann and Roiger, Anke and Schmidbauer, Norbert and Siddans, Richard and Sunkisala, Anusha and Thompson, Rona L. and Varon, Daniel J. and Ventress, Lucy J. and Wilson, Chris and Zhang, Yuzhong},
title = {Methane emissions from the Nord Stream subsea pipeline leaks},
journal = {Nature},
publisher = {Springer Science and Business Media LLC},
year = {2025},
volume = {637},
number = {8048},
pages = {1124--1130},
doi = {10.1038/s41586-024-08396-8}
}
|
| Hilland R, Hashemi J, Stagakis S, Brunner D, Constantin L, Kljun N, Kunz A-K, Molinier B, Hammer S, Emmenegger L and Christen A (2025), "Sectoral attribution of greenhouse gas and pollutant emissions using multi-species eddy covariance on a tall tower in Zurich, Switzerland", Atmospheric Chemistry and Physics., October, 2025. Vol. 25(21), pp. 14279-14299. Copernicus GmbH. |
BibTeX:
@article{Hilland2025,
author = {Hilland, Rainer and Hashemi, Josh and Stagakis, Stavros and Brunner, Dominik and Constantin, Lionel and Kljun, Natascha and Kunz, Ann-Kristin and Molinier, Betty and Hammer, Samuel and Emmenegger, Lukas and Christen, Andreas},
title = {Sectoral attribution of greenhouse gas and pollutant emissions using multi-species eddy covariance on a tall tower in Zurich, Switzerland},
journal = {Atmospheric Chemistry and Physics},
publisher = {Copernicus GmbH},
year = {2025},
volume = {25},
number = {21},
pages = {14279--14299},
doi = {10.5194/acp-25-14279-2025}
}
|
| Jääskeläinen E, Luoto M, Putkiranta P, Aurela M and Virtanen T (2025), "High-resolution soil moisture mapping in northern boreal forests using SMAP data and downscaling techniques", Hydrology and Earth System Sciences., November, 2025. Vol. 29(21), pp. 6237-6256. Copernicus GmbH. |
BibTeX:
@article{Jaeaeskelaeinen2025,
author = {Jääskeläinen, Emmihenna and Luoto, Miska and Putkiranta, Pauli and Aurela, Mika and Virtanen, Tarmo},
title = {High-resolution soil moisture mapping in northern boreal forests using SMAP data and downscaling techniques},
journal = {Hydrology and Earth System Sciences},
publisher = {Copernicus GmbH},
year = {2025},
volume = {29},
number = {21},
pages = {6237--6256},
doi = {10.5194/hess-29-6237-2025}
}
|
| James RV, Shatadru RN, Smith GJ, McGivern BB, Ellenbogen JB, Jurgensen SK, Fofana A, Tfaily MM, Wrighton KC and Sullivan MB (2025), "Viruses help rewire carbon metabolism in a methane-suppressed peat microcosm", December, 2025. openRxiv. |
BibTeX:
@article{James2025,
author = {James, Riddell V and Shatadru, Rokaiya Nurani and Smith, Garrett J and McGivern, Bridget B and Ellenbogen, Jared B and Jurgensen, Sophie K and Fofana, Ami and Tfaily, Malak M and Wrighton, Kelly C and Sullivan, Matthew B},
title = {Viruses help rewire carbon metabolism in a methane-suppressed peat microcosm},
publisher = {openRxiv},
year = {2025},
doi = {10.64898/2025.12.19.695563}
}
|
| Janecka K, Treydte K, Piccinelli S, Francon L, Argelich Ninot M, Edvardsson J, Corona C, Lehsten V and Stoffel M (2025), "Peatland trees record strong and temporally stable hydroclimate information in tree-ring δ 13 C and δ 18 O", Climate of the Past., October, 2025. Vol. 21(10), pp. 1679-1697. Copernicus GmbH. |
BibTeX:
@article{Janecka2025,
author = {Janecka, Karolina and Treydte, Kerstin and Piccinelli, Silvia and Francon, Loïc and Argelich Ninot, Marçal and Edvardsson, Johannes and Corona, Christophe and Lehsten, Veiko and Stoffel, Markus},
title = {Peatland trees record strong and temporally stable hydroclimate information in tree-ring δ 13 C and δ 18 O},
journal = {Climate of the Past},
publisher = {Copernicus GmbH},
year = {2025},
volume = {21},
number = {10},
pages = {1679--1697},
doi = {10.5194/cp-21-1679-2025}
}
|
| Jentzsch K, Männistö E, Marushchak ME, Rettelbach T, Golde L, Korrensalo A, Hashemi J, van Delden L, Tuittila E, Knoblauch C and Treat CC (2025), "Seasonality in Diffusive Methane Emissions Differs Between Bog Microforms", Global Change Biology., July, 2025. Vol. 31(7) Wiley. |
BibTeX:
@article{Jentzsch2025,
author = {Jentzsch, Katharina and Männistö, Elisa and Marushchak, Maija E. and Rettelbach, Tabea and Golde, Lion and Korrensalo, Aino and Hashemi, Joshua and van Delden, Lona and Tuittila, Eeva‐Stiina and Knoblauch, Christian and Treat, Claire C.},
title = {Seasonality in Diffusive Methane Emissions Differs Between Bog Microforms},
journal = {Global Change Biology},
publisher = {Wiley},
year = {2025},
volume = {31},
number = {7},
doi = {10.1111/gcb.70372}
}
|
| Juráň S, Karl T, Ofori-Amanfo KK, Šigut L, Zavadilová I, Grace J and Urban O (2025), "Drought shifts ozone deposition pathways in spruce forest from stomatal to non-stomatal flux", Environmental Pollution., May, 2025. Vol. 372, pp. 126081. Elsevier BV. |
BibTeX:
@article{Juran2025,
author = {Juráň, Stanislav and Karl, Thomas and Ofori-Amanfo, Kojo Kwakye and Šigut, Ladislav and Zavadilová, Ina and Grace, John and Urban, Otmar},
title = {Drought shifts ozone deposition pathways in spruce forest from stomatal to non-stomatal flux},
journal = {Environmental Pollution},
publisher = {Elsevier BV},
year = {2025},
volume = {372},
pages = {126081},
doi = {10.1016/j.envpol.2025.126081}
}
|
| Juselius-Rajamäki T, Piilo S, Salminen-Paatero S, Tuomaala E, Virtanen T, Korhola A, Autio A, Marttila H, Ala-Aho P, Lohila A and Väliranta M (2025), "External and internal drivers behind the formation, vegetation succession, and carbon balance of a subarctic fen margin", Biogeosciences., July, 2025. Vol. 22(12), pp. 3047-3071. Copernicus GmbH. |
BibTeX:
@article{JuseliusRajamaeki2025,
author = {Juselius-Rajamäki, Teemu and Piilo, Sanna and Salminen-Paatero, Susanna and Tuomaala, Emilia and Virtanen, Tarmo and Korhola, Atte and Autio, Anna and Marttila, Hannu and Ala-Aho, Pertti and Lohila, Annalea and Väliranta, Minna},
title = {External and internal drivers behind the formation, vegetation succession, and carbon balance of a subarctic fen margin},
journal = {Biogeosciences},
publisher = {Copernicus GmbH},
year = {2025},
volume = {22},
number = {12},
pages = {3047--3071},
doi = {10.5194/bg-22-3047-2025}
}
|
| Kallingal JT, Scholze M, Miller PA, Lindström J, Rinne J, Aurela M, Vestin P and Weslien P (2025), "Assimilating multi-site eddy-covariance data to calibrate the wetland CH 4 emission module in a terrestrial ecosystem model", Biogeosciences., August, 2025. Vol. 22(16), pp. 4061-4086. Copernicus GmbH. |
BibTeX:
@article{Kallingal2025,
author = {Kallingal, Jalisha Theanutti and Scholze, Marko and Miller, Paul Anthony and Lindström, Johan and Rinne, Janne and Aurela, Mika and Vestin, Patrik and Weslien, Per},
title = {Assimilating multi-site eddy-covariance data to calibrate the wetland CH 4 emission module in a terrestrial ecosystem model},
journal = {Biogeosciences},
publisher = {Copernicus GmbH},
year = {2025},
volume = {22},
number = {16},
pages = {4061--4086},
doi = {10.5194/bg-22-4061-2025}
}
|
| Karimi S, Mosquera V, Maher Hasselquist E, Järveoja J and Laudon H (2025), "Does peatland rewetting mitigate flooding from extreme rainfall events?", Hydrology and Earth System Sciences., June, 2025. Vol. 29(12), pp. 2599-2614. Copernicus GmbH. |
BibTeX:
@article{Karimi2025,
author = {Karimi, Shirin and Mosquera, Virginia and Maher Hasselquist, Eliza and Järveoja, Järvi and Laudon, Hjalmar},
title = {Does peatland rewetting mitigate flooding from extreme rainfall events?},
journal = {Hydrology and Earth System Sciences},
publisher = {Copernicus GmbH},
year = {2025},
volume = {29},
number = {12},
pages = {2599--2614},
doi = {10.5194/hess-29-2599-2025}
}
|
| Katul GG, Aslan T and Aurela M (2025), "Scaling Exponents of Turbulent Static Pressure Structure Function in the Inertial Subrange", Geophysical Research Letters., June, 2025. Vol. 52(11) American Geophysical Union (AGU). |
BibTeX:
@article{Katul2025,
author = {Katul, Gabriel G. and Aslan, Toprak and Aurela, Mika},
title = {Scaling Exponents of Turbulent Static Pressure Structure Function in the Inertial Subrange},
journal = {Geophysical Research Letters},
publisher = {American Geophysical Union (AGU)},
year = {2025},
volume = {52},
number = {11},
doi = {10.1029/2025gl116176}
}
|
| Ke P, Lintunen A, Kolari P, Lohila A, Tuovinen S, Lampilahti J, Thakur R, Peltola M, Peräkylä O, Nieminen T, Ezhova E, Pihlatie M, Laasonen A, Koskinen M, Rautakoski H, Heimsch L, Kokkonen T, Vähä A, Mammarella I, Noe S, Bäck J, Kerminen V-M and Kulmala M (2025), "Potential of carbon uptake and local aerosol production in boreal and hemi-boreal ecosystems across Finland and in Estonia", Biogeosciences., July, 2025. Vol. 22(13), pp. 3235-3251. Copernicus GmbH. |
BibTeX:
@article{Ke2025,
author = {Ke, Piaopiao and Lintunen, Anna and Kolari, Pasi and Lohila, Annalea and Tuovinen, Santeri and Lampilahti, Janne and Thakur, Roseline and Peltola, Maija and Peräkylä, Otso and Nieminen, Tuomo and Ezhova, Ekaterina and Pihlatie, Mari and Laasonen, Asta and Koskinen, Markku and Rautakoski, Helena and Heimsch, Laura and Kokkonen, Tom and Vähä, Aki and Mammarella, Ivan and Noe, Steffen and Bäck, Jaana and Kerminen, Veli-Matti and Kulmala, Markku},
title = {Potential of carbon uptake and local aerosol production in boreal and hemi-boreal ecosystems across Finland and in Estonia},
journal = {Biogeosciences},
publisher = {Copernicus GmbH},
year = {2025},
volume = {22},
number = {13},
pages = {3235--3251},
doi = {10.5194/bg-22-3235-2025}
}
|
| Korrensalo A, Kettunen J, Mehtätalo L, Vanhatalo J and Tuittila E (2025), "Detecting Subtle Change in Species and Trait Composition and Quantifying Its Uncertainty in a Boreal Peatland", Journal of Vegetation Science., March, 2025. Vol. 36(2) Wiley. |
BibTeX:
@article{Korrensalo2025,
author = {Korrensalo, Aino and Kettunen, Juho and Mehtätalo, Lauri and Vanhatalo, Jarno and Tuittila, Eeva‐Stiina},
title = {Detecting Subtle Change in Species and Trait Composition and Quantifying Its Uncertainty in a Boreal Peatland},
journal = {Journal of Vegetation Science},
publisher = {Wiley},
year = {2025},
volume = {36},
number = {2},
doi = {10.1111/jvs.70025}
}
|
| Kraft B, Nelson JA, Walther S, Gans F, Weber U, Duveiller G, Reichstein M, Zhang W, Rußwurm M, Tuia D, Körner M, Hamdi Z and Jung M (2025), "On the added value of sequential deep learning for the upscaling of evapotranspiration", Biogeosciences., August, 2025. Vol. 22(15), pp. 3965-3987. Copernicus GmbH. |
BibTeX:
@article{Kraft2025,
author = {Kraft, Basil and Nelson, Jacob A. and Walther, Sophia and Gans, Fabian and Weber, Ulrich and Duveiller, Gregory and Reichstein, Markus and Zhang, Weijie and Rußwurm, Marc and Tuia, Devis and Körner, Marco and Hamdi, Zayd and Jung, Martin},
title = {On the added value of sequential deep learning for the upscaling of evapotranspiration},
journal = {Biogeosciences},
publisher = {Copernicus GmbH},
year = {2025},
volume = {22},
number = {15},
pages = {3965--3987},
doi = {10.5194/bg-22-3965-2025}
}
|
| Kranz J, Bauer K, Pampanoni V, Zhao L, Marrs C, Mauder M, Poděbradská M, van der Maaten-Theunissen M, Yebra M and Forkel M (2025), "Assessing predictors for fuel moisture content in Central European forests", Agricultural and Forest Meteorology., August, 2025. Vol. 371, pp. 110590. Elsevier BV. |
BibTeX:
@article{Kranz2025,
author = {Kranz, Johanna and Bauer, Konrad and Pampanoni, Valerio and Zhao, Li and Marrs, Christopher and Mauder, Matthias and Poděbradská, Markéta and van der Maaten-Theunissen, Marieke and Yebra, Marta and Forkel, Matthias},
title = {Assessing predictors for fuel moisture content in Central European forests},
journal = {Agricultural and Forest Meteorology},
publisher = {Elsevier BV},
year = {2025},
volume = {371},
pages = {110590},
doi = {10.1016/j.agrformet.2025.110590}
}
|
| Krebs L, Hörtnagl L, Scapucci L, Gharun M, Feigenwinter I and Buchmann N (2025), "Net Ecosystem CO2 Exchange of a Subalpine Spruce Forest in Switzerland Over 26 Years: Effects of Phenology and Contributions of Abiotic Drivers at Daily Time Scales", Global Change Biology., July, 2025. Vol. 31(7) Wiley. |
BibTeX:
@article{Krebs2025,
author = {Krebs, Luana and Hörtnagl, Lukas and Scapucci, Liliana and Gharun, Mana and Feigenwinter, Iris and Buchmann, Nina},
title = {Net Ecosystem CO2 Exchange of a Subalpine Spruce Forest in Switzerland Over 26 Years: Effects of Phenology and Contributions of Abiotic Drivers at Daily Time Scales},
journal = {Global Change Biology},
publisher = {Wiley},
year = {2025},
volume = {31},
number = {7},
doi = {10.1111/gcb.70371}
}
|
| Kunz A-K, Borchardt L, Christen A, Della Coletta J, Eritt M, Gutiérrez X, Hashemi J, Hilland R, Jordan A, Kneißl R, Legendre V, Levin I, Preunkert S, Rubli P, Stagakis S and Hammer S (2025), "A relaxed eddy accumulation flask sampling system for 14 C-based partitioning of fossil and non-fossil CO 2 fluxes", Atmospheric Measurement Techniques., October, 2025. Vol. 18(20), pp. 5349-5373. Copernicus GmbH. |
BibTeX:
@article{Kunz2025,
author = {Kunz, Ann-Kristin and Borchardt, Lars and Christen, Andreas and Della Coletta, Julian and Eritt, Markus and Gutiérrez, Xochilt and Hashemi, Josh and Hilland, Rainer and Jordan, Armin and Kneißl, Richard and Legendre, Virgile and Levin, Ingeborg and Preunkert, Susanne and Rubli, Pascal and Stagakis, Stavros and Hammer, Samuel},
title = {A relaxed eddy accumulation flask sampling system for 14 C-based partitioning of fossil and non-fossil CO 2 fluxes},
journal = {Atmospheric Measurement Techniques},
publisher = {Copernicus GmbH},
year = {2025},
volume = {18},
number = {20},
pages = {5349--5373},
doi = {10.5194/amt-18-5349-2025}
}
|
| Laasonen A, Buzacott A, Kohonen K-M, Lundin E, Meire A, Pihlatie M and Mammarella I (2025), "Radiation and surface wetness drive carbon monoxide fluxes from an Arctic peatland", May, 2025. Copernicus GmbH. |
BibTeX:
@article{Laasonen2025,
author = {Laasonen, Asta and Buzacott, Alexander and Kohonen, Kukka-Maaria and Lundin, Erik and Meire, Alexander and Pihlatie, Mari and Mammarella, Ivan},
title = {Radiation and surface wetness drive carbon monoxide fluxes from an Arctic peatland},
publisher = {Copernicus GmbH},
year = {2025},
doi = {10.5194/egusphere-2025-2094}
}
|
| Laasonen A, Buzacott A, Kohonen K-M, Lundin E, Meire A, Pihlatie M and Mammarella I (2025), "Radiation and surface wetness drive carbon monoxide fluxes from an Arctic peatland", Biogeosciences., December, 2025. Vol. 22(23), pp. 7505-7518. Copernicus GmbH. |
BibTeX:
@article{Laasonen2025a,
author = {Laasonen, Asta and Buzacott, Alexander and Kohonen, Kukka-Maaria and Lundin, Erik and Meire, Alexander and Pihlatie, Mari and Mammarella, Ivan},
title = {Radiation and surface wetness drive carbon monoxide fluxes from an Arctic peatland},
journal = {Biogeosciences},
publisher = {Copernicus GmbH},
year = {2025},
volume = {22},
number = {23},
pages = {7505--7518},
doi = {10.5194/bg-22-7505-2025}
}
|
| Laitinen A, Aaltonen H, Zellweger C, Tsuruta A, Aalto T and Hatakka J (2025), "Long-term observations of atmospheric CO 2 and CH 4 trends and comparison of two measurement systems at Pallas-Sammaltunturi station in Northern Finland", Atmospheric Measurement Techniques., July, 2025. Vol. 18(13), pp. 3109-3133. Copernicus GmbH. |
BibTeX:
@article{Laitinen2025,
author = {Laitinen, Antti and Aaltonen, Hermanni and Zellweger, Christoph and Tsuruta, Aki and Aalto, Tuula and Hatakka, Juha},
title = {Long-term observations of atmospheric CO 2 and CH 4 trends and comparison of two measurement systems at Pallas-Sammaltunturi station in Northern Finland},
journal = {Atmospheric Measurement Techniques},
publisher = {Copernicus GmbH},
year = {2025},
volume = {18},
number = {13},
pages = {3109--3133},
doi = {10.5194/amt-18-3109-2025}
}
|
| Lan C, Holst CC, Grünwald T and Mauder M (2025), "Linkage Between Vertical Coupling and Storage Flux: Insights from Urban Tall-Tower Eddy Covariance Measurement", Boundary-Layer Meteorology., January, 2025. Vol. 191(1) Springer Science and Business Media LLC. |
BibTeX:
@article{Lan2025,
author = {Lan, Changxing and Holst, Christopher Claus and Grünwald, Thomas and Mauder, Matthias},
title = {Linkage Between Vertical Coupling and Storage Flux: Insights from Urban Tall-Tower Eddy Covariance Measurement},
journal = {Boundary-Layer Meteorology},
publisher = {Springer Science and Business Media LLC},
year = {2025},
volume = {191},
number = {1},
doi = {10.1007/s10546-024-00894-6}
}
|
| Lapenna E, Buono A, Mauceri A, Zaccardo I, Cardellicchio F, D’Amico F, Laurita T, Amodio D, Colangelo C, Di Fiore G, Gorga A, Ripepi E, De Benedictis F, Pirelli S, Capozzo L, Lapenna V, Pappalardo G, Trippetta S and Mona L (2025), "ICOS Potenza (Italy) Atmospheric Station: A New Spot for the Observation of Greenhouse Gases in the Mediterranean Basin", Atmosphere., January, 2025. Vol. 16(1), pp. 57. MDPI AG. |
BibTeX:
@article{Lapenna2025,
author = {Lapenna, Emilio and Buono, Antonella and Mauceri, Alessandro and Zaccardo, Isabella and Cardellicchio, Francesco and D’Amico, Francesco and Laurita, Teresa and Amodio, Davide and Colangelo, Canio and Di Fiore, Gianluca and Gorga, Antonella and Ripepi, Ermann and De Benedictis, Francesco and Pirelli, Silvana and Capozzo, Liborio and Lapenna, Vincenzo and Pappalardo, Gelsomina and Trippetta, Serena and Mona, Lucia},
title = {ICOS Potenza (Italy) Atmospheric Station: A New Spot for the Observation of Greenhouse Gases in the Mediterranean Basin},
journal = {Atmosphere},
publisher = {MDPI AG},
year = {2025},
volume = {16},
number = {1},
pages = {57},
doi = {10.3390/atmos16010057}
}
|
| Lappalainen HK, Baklanov A, Bäck J, Arvanitidis C, Basart S, Bernier N, Berod D, Bornman T, Buttigieg PL, Carmichael G, Dañobeitia J, De Roeck Y-H, Dey S, Gerasopoulos E, Feig G, Gani S, Glaves H, Häme S, Juurola E, Klausen J, Laj P, Lefer B, Loescher HW, Mirtl M, Morris B, Muraoka H, Noda HM, Paton-Walsh C, Pade N, Petzold A, Salmon E, Schaap D, Scory S, Achuta Rao K, Rathore J, Steinbacher M, Teutsch G, Vermeulen A, Yu X, Zacharias S, Zhang L, Petäjä T, Luterbacher J, Hannigan JW and Kulmala M (2025), "Towards a Global Ground-Based Earth Observatory (GGBEO): Leveraging existing systems and networks", Big Earth Data., October, 2025. Vol. 9(4), pp. 615-650. Informa UK Limited. |
BibTeX:
@article{Lappalainen2025,
author = {Lappalainen, Hanna K. and Baklanov, Alexander and Bäck, Jaana and Arvanitidis, Christos and Basart, Sara and Bernier, Natacha and Berod, Dominique and Bornman, Thomas and Buttigieg, Pier Luigi and Carmichael, Gregory and Dañobeitia, Juanjo and De Roeck, Yann-Hervé and Dey, Sagnik and Gerasopoulos, Evangelos and Feig, Gregor and Gani, Shahzad and Glaves, Helen and Häme, Silja and Juurola, Eija and Klausen, Jörg and Laj, Paolo and Lefer, Barry and Loescher, Henry W. and Mirtl, Michael and Morris, Beryl and Muraoka, Hiroyuki and Noda, Hibiki M. and Paton-Walsh, Clare and Pade, Nicolas and Petzold, Andreas and Salmon, Emmanuel and Schaap, Dick and Scory, Serge and Achuta Rao, Krishna and Rathore, Jaswant and Steinbacher, Martin and Teutsch, Georg and Vermeulen, Alex and Yu, Xiubo and Zacharias, Steffen and Zhang, Leiming and Petäjä, Tuukka and Luterbacher, Jürg and Hannigan, James W. and Kulmala, Markku},
title = {Towards a Global Ground-Based Earth Observatory (GGBEO): Leveraging existing systems and networks},
journal = {Big Earth Data},
publisher = {Informa UK Limited},
year = {2025},
volume = {9},
number = {4},
pages = {615--650},
doi = {10.1080/20964471.2025.2574174}
}
|
| Lehtonen A, Heikkinen J, Boroski CA, Tikkasalo O-P, Rinne-Garmston KT, Sahlstedt E, Korkiakoski M, Kärkönen A, Lintunen A, Mäkinen H, Peltoniemi M, de Quesada G, Salmon Y, Young G, Mäkipää R and Oren R (2025), "Carbon allocation to roots of suppressed Norway spruce increases immediately after selection harvest", Forest Ecology and Management., June, 2025. Vol. 585, pp. 122645. Elsevier BV. |
BibTeX:
@article{Lehtonen2025,
author = {Lehtonen, Aleksi and Heikkinen, Juha and Boroski, Chainey A. and Tikkasalo, Olli-Pekka and Rinne-Garmston, Katja T. and Sahlstedt, Elina and Korkiakoski, Mika and Kärkönen, Anna and Lintunen, Anna and Mäkinen, Harri and Peltoniemi, Mikko and de Quesada, Gonzalo and Salmon, Yann and Young, Giles and Mäkipää, Raisa and Oren, Ram},
title = {Carbon allocation to roots of suppressed Norway spruce increases immediately after selection harvest},
journal = {Forest Ecology and Management},
publisher = {Elsevier BV},
year = {2025},
volume = {585},
pages = {122645},
doi = {10.1016/j.foreco.2025.122645}
}
|
| Leolini L, Costafreda-Aumedes S, Brilli L, Galvagno M, Bindi M, Argenti G, Cammarano D, Bellini E, Dibari C, Wohlfahrt G, Feigenwinter I, Dal Prà A, Dalmonech D, Collalti A, Cremonese E, Filippa G, Staglianò N and Moriondo M (2025), "Modeling carbon and water fluxes in agro-pastoral systems under contrasting climates and different management practices", Agricultural and Forest Meteorology., May, 2025. Vol. 367, pp. 110486. Elsevier BV. |
BibTeX:
@article{Leolini2025,
author = {Leolini, L. and Costafreda-Aumedes, S. and Brilli, L. and Galvagno, M. and Bindi, M. and Argenti, G. and Cammarano, D. and Bellini, E. and Dibari, C. and Wohlfahrt, G. and Feigenwinter, I. and Dal Prà, A. and Dalmonech, D. and Collalti, A. and Cremonese, E. and Filippa, G. and Staglianò, N. and Moriondo, M.},
title = {Modeling carbon and water fluxes in agro-pastoral systems under contrasting climates and different management practices},
journal = {Agricultural and Forest Meteorology},
publisher = {Elsevier BV},
year = {2025},
volume = {367},
pages = {110486},
doi = {10.1016/j.agrformet.2025.110486}
}
|
| Li X, Rinne J, Tuittila E and Vesala T (2025), "Year‐Round δ 13 C‐CH 4 Reveals Seasonal Transition in Methane‐Related Processes in a Boreal Mire", Journal of Geophysical Research: Biogeosciences., September, 2025. Vol. 130(9) American Geophysical Union (AGU). |
BibTeX:
@article{Li2025,
author = {Li, Xuefei and Rinne, Janne and Tuittila, Eeva‐Stiina and Vesala, Timo},
title = {Year‐Round δ 13 C‐CH 4 Reveals Seasonal Transition in Methane‐Related Processes in a Boreal Mire},
journal = {Journal of Geophysical Research: Biogeosciences},
publisher = {American Geophysical Union (AGU)},
year = {2025},
volume = {130},
number = {9},
doi = {10.1029/2025jg008922}
}
|
| Liu Q, Zhang P, Wang Y, Hu J and Li R (2025), "Global Evapotranspiration Retrieval Using Fengyun‐3D Passive Microwave Measurements With Genetic Algorithm Optimization", Journal of Geophysical Research: Atmospheres., August, 2025. Vol. 130(16) American Geophysical Union (AGU). |
BibTeX:
@article{Liu2025,
author = {Liu, Qingyang and Zhang, Peng and Wang, Yipu and Hu, Jiheng and Li, Rui},
title = {Global Evapotranspiration Retrieval Using Fengyun‐3D Passive Microwave Measurements With Genetic Algorithm Optimization},
journal = {Journal of Geophysical Research: Atmospheres},
publisher = {American Geophysical Union (AGU)},
year = {2025},
volume = {130},
number = {16},
doi = {10.1029/2025jd043823}
}
|
| Liu L, Qiu C, Xi Y, Salmon E, Kalhori A, Artz RRE, Guimbaud C, Peichl M, Ratcliffe JL, Noumonvi KD, López‐Blanco E, Dušek J, Markkanen T, Sachs T, Aurela M, Nguyen T, Lohila A, Mammarella I and Ciais P (2025), "Assessing CO2 Fluxes for European Peatlands in ORCHIDEE‐PEAT With Multiple Plant Functional Types", Journal of Advances in Modeling Earth Systems., June, 2025. Vol. 17(6) American Geophysical Union (AGU). |
BibTeX:
@article{Liu2025a,
author = {Liu, Liyang and Qiu, Chunjing and Xi, Yi and Salmon, Elodie and Kalhori, Aram and Artz, Rebekka R. E. and Guimbaud, Christophe and Peichl, Matthias and Ratcliffe, Joshua L. and Noumonvi, Koffi Dodji and López‐Blanco, Efrén and Dušek, Jiří and Markkanen, Tiina and Sachs, Torsten and Aurela, Mika and Nguyen, Thu‐Hang and Lohila, Annalea and Mammarella, Ivan and Ciais, Philippe},
title = {Assessing CO2 Fluxes for European Peatlands in ORCHIDEE‐PEAT With Multiple Plant Functional Types},
journal = {Journal of Advances in Modeling Earth Systems},
publisher = {American Geophysical Union (AGU)},
year = {2025},
volume = {17},
number = {6},
doi = {10.1029/2025ms004940}
}
|
| Lucarini A, Lo Cascio M, Marras S, Spano D and Sirca C (2025), "Eddy Covariance and Artificial Intelligence: a review", January, 2025. Copernicus GmbH. |
BibTeX:
@article{Lucarini2025,
author = {Lucarini, Arianna and Lo Cascio, Mauro and Marras, Serena and Spano, Donatella and Sirca, Costantino},
title = {Eddy Covariance and Artificial Intelligence: a review},
publisher = {Copernicus GmbH},
year = {2025},
doi = {10.5194/egusphere-egu24-12579}
}
|
| Macovei VA, Lefèvre N, Diverrès D, Kinski N, Listing O and Voynova YG (2025), "At‐sea intercomparison of a membrane‐based pCO2 sensor and a traditional showerhead equilibrator system on a Ship‐of‐Opportunity", Limnology and Oceanography: Methods., August, 2025. Vol. 23(10), pp. 729-741. Wiley. |
BibTeX:
@article{Macovei2025,
author = {Macovei, Vlad A. and Lefèvre, Nathalie and Diverrès, Denis and Kinski, Nadja and Listing, Oliver and Voynova, Yoana G.},
title = {At‐sea intercomparison of a membrane‐based pCO2 sensor and a traditional showerhead equilibrator system on a Ship‐of‐Opportunity},
journal = {Limnology and Oceanography: Methods},
publisher = {Wiley},
year = {2025},
volume = {23},
number = {10},
pages = {729--741},
doi = {10.1002/lom3.10719}
}
|
| Macovei VA, Rewrie LCV, Röttgers R and Voynova YG (2025), "Spring–neap tidal cycles modulate the strength of the carbon source at the estuary–coast interface", Biogeosciences., July, 2025. Vol. 22(13), pp. 3375-3396. Copernicus GmbH. |
BibTeX:
@article{Macovei2025a,
author = {Macovei, Vlad A. and Rewrie, Louise C. V. and Röttgers, Rüdiger and Voynova, Yoana G.},
title = {Spring–neap tidal cycles modulate the strength of the carbon source at the estuary–coast interface},
journal = {Biogeosciences},
publisher = {Copernicus GmbH},
year = {2025},
volume = {22},
number = {13},
pages = {3375--3396},
doi = {10.5194/bg-22-3375-2025}
}
|
| Magh R-K, Paligi SS, Papastefanou P, Klosterhalfen A, Rohde C, Dubbert M, Beyer M, Haberstroh S, Werner C, Pohl F and Hildebrandt A (2025), " Continuous Observations Highlight Depth-Dependent Soil Matric Potential as Drivers of Stem Water Potential in Temperate Forests under non-drought conditions", March, 2025. Copernicus GmbH. |
BibTeX:
@article{Magh2025,
author = {Magh, Ruth-Kristina and Paligi, Sharath Shyamappa and Papastefanou, Phillip and Klosterhalfen, Anne and Rohde, Clara and Dubbert, Maren and Beyer, Matthias and Haberstroh, Simon and Werner, Christiane and Pohl, Felix and Hildebrandt, Anke},
title = { Continuous Observations Highlight Depth-Dependent Soil Matric Potential as Drivers of Stem Water Potential in Temperate Forests under non-drought conditions},
publisher = {Copernicus GmbH},
year = {2025},
doi = {10.5194/egusphere-egu25-8878}
}
|
| Malacaria L, Sinopoli S, Lo Feudo T, De Benedetto G, D’Amico F, Ammoscato I, Cristofanelli P, De Pino M, Gullì D and Calidonna CR (2025), "Methodology for selecting near-surface CH4, CO, and CO2 observations reflecting atmospheric background conditions at the WMO/GAW station in Lamezia Terme, Italy", Atmospheric Pollution Research., July, 2025. Vol. 16(7), pp. 102515. Elsevier BV. |
BibTeX:
@article{Malacaria2025,
author = {Malacaria, Luana and Sinopoli, Salvatore and Lo Feudo, Teresa and De Benedetto, Giorgia and D’Amico, Francesco and Ammoscato, Ivano and Cristofanelli, Paolo and De Pino, Mariafrancesca and Gullì, Daniel and Calidonna, Claudia Roberta},
title = {Methodology for selecting near-surface CH4, CO, and CO2 observations reflecting atmospheric background conditions at the WMO/GAW station in Lamezia Terme, Italy},
journal = {Atmospheric Pollution Research},
publisher = {Elsevier BV},
year = {2025},
volume = {16},
number = {7},
pages = {102515},
doi = {10.1016/j.apr.2025.102515}
}
|
| Marsh H, Jin H, Duan Z, Holst J, Eklundh L and Zhang W (2025), "Plant Phenology Index leveraging over conventional vegetation indices to establish a new remote sensing benchmark of GPP for northern ecosystems", International Journal of Applied Earth Observation and Geoinformation., February, 2025. Vol. 136, pp. 104289. Elsevier BV. |
BibTeX:
@article{Marsh2025,
author = {Marsh, Hanna and Jin, Hongxiao and Duan, Zheng and Holst, Jutta and Eklundh, Lars and Zhang, Wenxin},
title = {Plant Phenology Index leveraging over conventional vegetation indices to establish a new remote sensing benchmark of GPP for northern ecosystems},
journal = {International Journal of Applied Earth Observation and Geoinformation},
publisher = {Elsevier BV},
year = {2025},
volume = {136},
pages = {104289},
doi = {10.1016/j.jag.2024.104289}
}
|
| Martellucci R, Dentico C, Coppola L, Skjelvan I, Giani M, Pensieri S, Cantoni C, Cardin V, Fourrier M, Bozzano R, Paulsen M and Mauri E (2025), "Air-sea CO2 exchange in the Eastern Atlantic and the Mediterranean Sea based on autonomous surface measurements", Frontiers in Marine Science., November, 2025. Vol. 12 Frontiers Media SA. |
BibTeX:
@article{Martellucci2025,
author = {Martellucci, Riccardo and Dentico, Carlotta and Coppola, Laurent and Skjelvan, Ingunn and Giani, Michele and Pensieri, Sara and Cantoni, Carolina and Cardin, Vanessa and Fourrier, Marine and Bozzano, Roberto and Paulsen, Melf and Mauri, Elena},
title = {Air-sea CO2 exchange in the Eastern Atlantic and the Mediterranean Sea based on autonomous surface measurements},
journal = {Frontiers in Marine Science},
publisher = {Frontiers Media SA},
year = {2025},
volume = {12},
doi = {10.3389/fmars.2025.1633617}
}
|
| Martellucci R, Paladini de Mendoza F, Menna M, Pirro A, Reale M, Gačić M, Poulain PM, Riminucci F, Le Meur J, Giordano P, Langone L, Cardin V, Cantoni C, Bergami C, Grilli F, Marini M, Gallo A, Notarstefano G, Toller S, Bastianini M, Kralj M, Diociaiuti T, Pacciaroni M, Bussani A, Miserocchi S and Mauri E (2025), "A Multiobservation Analysis of the 2017 Dense Water Formation Events: Climate Change, Bottom Density Currents, and Adriatic‐Ionian Sea Circulation (Mediterranean Sea)", Journal of Geophysical Research: Oceans., November, 2025. Vol. 130(11) American Geophysical Union (AGU). |
BibTeX:
@article{Martellucci2025a,
author = {Martellucci, R. and Paladini de Mendoza, F. and Menna, M. and Pirro, A. and Reale, M. and Gačić, M. and Poulain, P. M. and Riminucci, F. and Le Meur, J. and Giordano, P. and Langone, L. and Cardin, V. and Cantoni, C. and Bergami, C. and Grilli, F. and Marini, M. and Gallo, A. and Notarstefano, G. and Toller, S. and Bastianini, M. and Kralj, M. and Diociaiuti, T. and Pacciaroni, M. and Bussani, A. and Miserocchi, S. and Mauri, E.},
title = {A Multiobservation Analysis of the 2017 Dense Water Formation Events: Climate Change, Bottom Density Currents, and Adriatic‐Ionian Sea Circulation (Mediterranean Sea)},
journal = {Journal of Geophysical Research: Oceans},
publisher = {American Geophysical Union (AGU)},
year = {2025},
volume = {130},
number = {11},
doi = {10.1029/2024jc022306}
}
|
| McGivern BB, Ellenbogen JB, Hoyt DW, Bouranis JA, Stemple BP, Daly RA, Bosman SH, Sullivan MB, Hagerman AE, Chanton JP, Tfaily MM and Wrighton KC (2025), "Polyphenol rewiring of the microbiome reduces methane emissions", The ISME Journal., January, 2025. Vol. 19(1) Oxford University Press (OUP). |
BibTeX:
@article{McGivern2025,
author = {McGivern, Bridget B and Ellenbogen, Jared B and Hoyt, David W and Bouranis, John A and Stemple, Brooke P and Daly, Rebecca A and Bosman, Samantha H and Sullivan, Matthew B and Hagerman, Ann E and Chanton, Jeffrey P and Tfaily, Malak M and Wrighton, Kelly C},
title = {Polyphenol rewiring of the microbiome reduces methane emissions},
journal = {The ISME Journal},
publisher = {Oxford University Press (OUP)},
year = {2025},
volume = {19},
number = {1},
doi = {10.1093/ismejo/wraf108}
}
|
| Meixner K, Wagenhäuser T, Schuck TJ, Alber S, Manning AJ, Redington AL, Stanley KM, O’Doherty S, Young D, Pitt J, Wenger A, Frumau A, Stavert AR, Rennick C, Vollmer MK, Maione M, Arduini J, Lunder CR, Couret C, Jordan A, Gutiérrez XG, Kubistin D, Müller-Williams J, Lindauer M, Vojta M, Stohl A and Engel A (2025), "Characterization of German SF 6 Emissions", ACS ES&T Air., November, 2025. Vol. 2(12), pp. 2889-2899. American Chemical Society (ACS). |
BibTeX:
@article{Meixner2025,
author = {Meixner, Katharina and Wagenhäuser, Thomas and Schuck, Tanja J. and Alber, Sascha and Manning, Alistair J. and Redington, Alison L. and Stanley, Kieran M. and O’Doherty, Simon and Young, Dickon and Pitt, Joseph and Wenger, Angelina and Frumau, Arnoud and Stavert, Ann R. and Rennick, Christopher and Vollmer, Martin K. and Maione, Michela and Arduini, Jgor and Lunder, Chris R. and Couret, Cedric and Jordan, Armin and Gutiérrez, Xochilt Gutiérrez and Kubistin, Dagmar and Müller-Williams, Jennifer and Lindauer, Matthias and Vojta, Martin and Stohl, Andreas and Engel, Andreas},
title = {Characterization of German SF 6 Emissions},
journal = {ACS ES&T Air},
publisher = {American Chemical Society (ACS)},
year = {2025},
volume = {2},
number = {12},
pages = {2889--2899},
doi = {10.1021/acsestair.5c00234}
}
|
| Miinalainen T, Ojasalo A, Croft H, Aurela M, Peltoniemi M, Caldararu S, Zaehle S and Thum T (2025), "Evaluating the carbon and nitrogen cycles of the QUINCY terrestrial biosphere model using space-born optical remotely-sensed data", Biogeosciences., November, 2025. Vol. 22(22), pp. 6937-6962. Copernicus GmbH. |
BibTeX:
@article{Miinalainen2025,
author = {Miinalainen, Tuuli and Ojasalo, Amanda and Croft, Holly and Aurela, Mika and Peltoniemi, Mikko and Caldararu, Silvia and Zaehle, Sönke and Thum, Tea},
title = {Evaluating the carbon and nitrogen cycles of the QUINCY terrestrial biosphere model using space-born optical remotely-sensed data},
journal = {Biogeosciences},
publisher = {Copernicus GmbH},
year = {2025},
volume = {22},
number = {22},
pages = {6937--6962},
doi = {10.5194/bg-22-6937-2025}
}
|
| Mikola J, Juutinen S, Räsänen A, Virtanen T, Penttilä T, Hyvönen H, Heiskanen L and Aurela M (2025), "Relative importance of soil fertility and microtopography as CO2 and CH4 exchange drivers in a northern boreal fen ecosystem", Scientific Reports., March, 2025. Vol. 15(1) Springer Science and Business Media LLC. |
BibTeX:
@article{Mikola2025,
author = {Mikola, Juha and Juutinen, Sari and Räsänen, Aleksi and Virtanen, Tarmo and Penttilä, Timo and Hyvönen, Hanna and Heiskanen, Lauri and Aurela, Mika},
title = {Relative importance of soil fertility and microtopography as CO2 and CH4 exchange drivers in a northern boreal fen ecosystem},
journal = {Scientific Reports},
publisher = {Springer Science and Business Media LLC},
year = {2025},
volume = {15},
number = {1},
doi = {10.1038/s41598-025-90845-z}
}
|
| Minderytė A, Pauraite J, Ahlberg E, Kristensson A, Byčenkienė S and Eriksson AC (2025), "Long-range transport influence on wintertime submicron aerosol chemical composition from simultaneous measurements in Lithuania and Southern Sweden", Atmospheric Environment., June, 2025. Vol. 350, pp. 121162. Elsevier BV. |
BibTeX:
@article{Minderyte2025,
author = {Minderytė, Agnė and Pauraite, Julija and Ahlberg, Erik and Kristensson, Adam and Byčenkienė, Steigvilė and Eriksson, Axel C.},
title = {Long-range transport influence on wintertime submicron aerosol chemical composition from simultaneous measurements in Lithuania and Southern Sweden},
journal = {Atmospheric Environment},
publisher = {Elsevier BV},
year = {2025},
volume = {350},
pages = {121162},
doi = {10.1016/j.atmosenv.2025.121162}
}
|
| Mohrmann M, C. Biddle L, Rehder G, Bittig HC and Queste BY (2025), "Nord Stream methane leaks spread across 14% of Baltic waters", Nature Communications., January, 2025. Vol. 16(1) Springer Science and Business Media LLC. |
BibTeX:
@article{Mohrmann2025,
author = {Mohrmann, Martin and C. Biddle, Louise and Rehder, Gregor and Bittig, Henry C. and Queste, Bastien Y.},
title = {Nord Stream methane leaks spread across 14% of Baltic waters},
journal = {Nature Communications},
publisher = {Springer Science and Business Media LLC},
year = {2025},
volume = {16},
number = {1},
doi = {10.1038/s41467-024-53779-0}
}
|
| Mole R, von Appen WJ, Becker H, Haumann FA, Kanzow T, Piñango A, Stimpfle J, Trimborn S and Young EF (2025), "Wind‐Driven Iron Supply by Ekman Buoyancy Flux Enhances Phytoplankton Bloom in the Antarctic Circumpolar Current", Journal of Geophysical Research: Oceans., August, 2025. Vol. 130(8) American Geophysical Union (AGU). |
BibTeX:
@article{Mole2025,
author = {Mole, R. and von Appen, W. J. and Becker, H. and Haumann, F. A. and Kanzow, T. and Piñango, A. and Stimpfle, J. and Trimborn, S. and Young, E. F.},
title = {Wind‐Driven Iron Supply by Ekman Buoyancy Flux Enhances Phytoplankton Bloom in the Antarctic Circumpolar Current},
journal = {Journal of Geophysical Research: Oceans},
publisher = {American Geophysical Union (AGU)},
year = {2025},
volume = {130},
number = {8},
doi = {10.1029/2025jc022530}
}
|
| Monteil G, Theanutti Kallingal J and Scholze M (2025), "CH 4 emissions from Northern Europe wetlands: compared data assimilation approaches", Atmospheric Chemistry and Physics., October, 2025. Vol. 25(21), pp. 14251-14277. Copernicus GmbH. |
BibTeX:
@article{Monteil2025,
author = {Monteil, Guillaume and Theanutti Kallingal, Jalisha and Scholze, Marko},
title = {CH 4 emissions from Northern Europe wetlands: compared data assimilation approaches},
journal = {Atmospheric Chemistry and Physics},
publisher = {Copernicus GmbH},
year = {2025},
volume = {25},
number = {21},
pages = {14251--14277},
doi = {10.5194/acp-25-14251-2025}
}
|
| Mortarini L, Katul G, Mauricio Cely‐Toro I, Quaresma Dias‐Júnior C and Mammarella I (2025), "The role of thermal stratification on the co‐spectral properties of momentum transport above an Amazonian forest", Quarterly Journal of the Royal Meteorological Society., June, 2025. Vol. 151(772) Wiley. |
BibTeX:
@article{Mortarini2025,
author = {Mortarini, Luca and Katul, Gabriel and Mauricio Cely‐Toro, Ivan and Quaresma Dias‐Júnior, Cléo and Mammarella, Ivan},
title = {The role of thermal stratification on the co‐spectral properties of momentum transport above an Amazonian forest},
journal = {Quarterly Journal of the Royal Meteorological Society},
publisher = {Wiley},
year = {2025},
volume = {151},
number = {772},
doi = {10.1002/qj.5024}
}
|
| Munassar S, Rödenbeck C, Gałkowski M, Koch F-T, Totsche KU, Botía S and Gerbig C (2025), "To what extent does the CO 2 diurnal cycle impact flux estimates derived from global and regional inversions?", Atmospheric Chemistry and Physics., January, 2025. Vol. 25(1), pp. 639-656. Copernicus GmbH. |
BibTeX:
@article{Munassar2025,
author = {Munassar, Saqr and Rödenbeck, Christian and Gałkowski, Michał and Koch, Frank-Thomas and Totsche, Kai U. and Botía, Santiago and Gerbig, Christoph},
title = {To what extent does the CO 2 diurnal cycle impact flux estimates derived from global and regional inversions?},
journal = {Atmospheric Chemistry and Physics},
publisher = {Copernicus GmbH},
year = {2025},
volume = {25},
number = {1},
pages = {639--656},
doi = {10.5194/acp-25-639-2025}
}
|
| Mužić I, Hodnebrog Ø, Yilmaz YA, Berntsen TK, Sillmann J, Lawrence DM and Dirmeyer PA (2025), "Soil moisture–temperature coupling during extreme warm conditions in 2018 in Sweden: a case study with WRF-CTSM", Advances in Statistical Climatology, Meteorology and Oceanography., December, 2025. Vol. 11(2), pp. 273-292. Copernicus GmbH. |
BibTeX:
@article{Muzic2025,
author = {Mužić, Iris and Hodnebrog, Øivind and Yilmaz, Yeliz A. and Berntsen, Terje K. and Sillmann, Jana and Lawrence, David M. and Dirmeyer, Paul A.},
title = {Soil moisture–temperature coupling during extreme warm conditions in 2018 in Sweden: a case study with WRF-CTSM},
journal = {Advances in Statistical Climatology, Meteorology and Oceanography},
publisher = {Copernicus GmbH},
year = {2025},
volume = {11},
number = {2},
pages = {273--292},
doi = {10.5194/ascmo-11-273-2025}
}
|
| Nadolski L, El-Madany TS, Nelson J, Carrara A, Moreno G, Nair R, Luo Y, Hildebrandt A, Rolo V, Reichstein M and Lee S-C (2025), "Altered seasonal sensitivity of net ecosystem exchange to controls driven by nutrient balances in a semi-arid savanna", Biogeosciences., June, 2025. Vol. 22(12), pp. 2935-2958. Copernicus GmbH. |
BibTeX:
@article{Nadolski2025,
author = {Nadolski, Laura and El-Madany, Tarek S. and Nelson, Jacob and Carrara, Arnaud and Moreno, Gerardo and Nair, Richard and Luo, Yunpeng and Hildebrandt, Anke and Rolo, Victor and Reichstein, Markus and Lee, Sung-Ching},
title = {Altered seasonal sensitivity of net ecosystem exchange to controls driven by nutrient balances in a semi-arid savanna},
journal = {Biogeosciences},
publisher = {Copernicus GmbH},
year = {2025},
volume = {22},
number = {12},
pages = {2935--2958},
doi = {10.5194/bg-22-2935-2025}
}
|
| Niwa Y, Tohjima Y, Terao Y, Saeki T, Ito A, Umezawa T, Yamada K, Sasakawa M, Machida T, Nakaoka S-I, Nara H, Tanimoto H, Mukai H, Yoshida Y, Morimoto S, Takatsuji S, Tsuboi K, Sawa Y, Matsueda H, Ishijima K, Fujita R, Goto D, Lan X, Schuldt K, Heliasz M, Biermann T, Chmura L, Necki J, Xueref-Remy I and Sferlazzo D (2025), "Multi-observational estimation of regional and sectoral emission contributions to the persistent high growth rate of atmospheric CH 4 for 2020–2022", Atmospheric Chemistry and Physics., July, 2025. Vol. 25(13), pp. 6757-6785. Copernicus GmbH. |
BibTeX:
@article{Niwa2025,
author = {Niwa, Yosuke and Tohjima, Yasunori and Terao, Yukio and Saeki, Tazu and Ito, Akihiko and Umezawa, Taku and Yamada, Kyohei and Sasakawa, Motoki and Machida, Toshinobu and Nakaoka, Shin-Ichiro and Nara, Hideki and Tanimoto, Hiroshi and Mukai, Hitoshi and Yoshida, Yukio and Morimoto, Shinji and Takatsuji, Shinya and Tsuboi, Kazuhiro and Sawa, Yousuke and Matsueda, Hidekazu and Ishijima, Kentaro and Fujita, Ryo and Goto, Daisuke and Lan, Xin and Schuldt, Kenneth and Heliasz, Michal and Biermann, Tobias and Chmura, Lukasz and Necki, Jarsolaw and Xueref-Remy, Irène and Sferlazzo, Damiano},
title = {Multi-observational estimation of regional and sectoral emission contributions to the persistent high growth rate of atmospheric CH 4 for 2020–2022},
journal = {Atmospheric Chemistry and Physics},
publisher = {Copernicus GmbH},
year = {2025},
volume = {25},
number = {13},
pages = {6757--6785},
doi = {10.5194/acp-25-6757-2025}
}
|
| Noumonvi KD, Nilsson MB, Ratcliffe JL, Öquist MG, Kljun N, Fransson JES, Järveoja J, Lindroth A, Simpson G, Smeds J and Peichl M (2025), "Variations in Ecosystem‐Scale Methane Fluxes Across a Boreal Mire Complex Assessed by a Network of Flux Towers", Global Change Biology., May, 2025. Vol. 31(5) Wiley. |
BibTeX:
@article{Noumonvi2025,
author = {Noumonvi, Koffi Dodji and Nilsson, Mats B. and Ratcliffe, Joshua L. and Öquist, Mats G. and Kljun, Natascha and Fransson, Johan E. S. and Järveoja, Järvi and Lindroth, Anders and Simpson, Gillian and Smeds, Jacob and Peichl, Matthias},
title = {Variations in Ecosystem‐Scale Methane Fluxes Across a Boreal Mire Complex Assessed by a Network of Flux Towers},
journal = {Global Change Biology},
publisher = {Wiley},
year = {2025},
volume = {31},
number = {5},
doi = {10.1111/gcb.70223}
}
|
| Noumonvi KD, Havertz NH, Bohlin J, van der Linden S, Nilsson MB and Peichl M (2025), "HuHoLa: A novel Hummock-Hollow-Lawn mire microtopography modelling approach", Ecological Modelling., September, 2025. Vol. 508, pp. 111212. Elsevier BV. |
BibTeX:
@article{Noumonvi2025a,
author = {Noumonvi, Koffi Dodji and Havertz, Nils Helge and Bohlin, Jonas and van der Linden, Sebastian and Nilsson, Mats B. and Peichl, Matthias},
title = {HuHoLa: A novel Hummock-Hollow-Lawn mire microtopography modelling approach},
journal = {Ecological Modelling},
publisher = {Elsevier BV},
year = {2025},
volume = {508},
pages = {111212},
doi = {10.1016/j.ecolmodel.2025.111212}
}
|
| Organelli E, Bastianini M, Belgacem M, Bellacicco M, Bergami C, Berta M, Busatto J, Camatti E, Cantoni C, Canuti E, COLELLA S, Dall'Olmo G, Denni s, Di Russo E, D'Onofrio R, Fanelli C, Farace I, Felsani M, GALLO A, Gibertini A, Giuliano G, Kokoszka F, LA FORGIA G, Lastella A, Li M, Manfredonia F, Milena M, Francesco PdM, Pitarch Portero JS, Scaccia R, Schroeder A, Toller S, Vellucci V, Volpe G, Barbieri L, Borghini M, Bozzano R, Caccavale M, Capotondi L, Chiappini C, Cozzi S, De Martino R, Dionisi D, Ferrara N, Focaccia P, Graziani A, Kokkini Z, Langone L, Magaldi MG, Paulsen M, Riccobene G, Schroeder K, Sciascia R, Splisa C, Sprovieri M, Steinhoff T, Talone M and Santoleri R (2025), "ITINERIS' EYES - INTEGRATING, INNOVATING, EVOLVING RESEARCH INFRASTRUCTURES FOR HEALTHY AND PREDICTED MARINE ECOSYSTEMS". |
BibTeX:
@misc{Organelli2025,
author = {Organelli, Emanuele and Bastianini, Mauro and Belgacem, Malek and Bellacicco, Marco and Bergami, Caterina and Berta, Maristella and Busatto, Jacopo and Camatti, Elisa and Cantoni, Carolina and Canuti, Elisabetta and COLELLA, SIMONE and Dall'Olmo, Giorgio and Denni, simona and Di Russo, Edoardo and D'Onofrio, Roberta and Fanelli, Claudia and Farace, Ivan and Felsani, Marcello and GALLO, ANTONELLA and Gibertini, Alessandro and Giuliano, Giovanni and Kokoszka, Florian and LA FORGIA, GIOVANNI and Lastella, Alessandro and Li, Mengyu and Manfredonia, Filippo and Milena, Menna and Francesco, Paladini de Mendoza and Pitarch Portero, Jaime Silvino and Scaccia, Roberto and Schroeder, Anna and Toller, Simone and Vellucci, Vincenzo and Volpe, Gianluca and Barbieri, Laura and Borghini, Mireno and Bozzano, Roberto and Caccavale, Mauro and Capotondi, Lucilla and Chiappini, Catia and Cozzi, Stefano and De Martino, Rosaria and Dionisi, Davide and Ferrara, Nicola and Focaccia, Paola and Graziani, Americo and Kokkini, Zoi and Langone, Leonardo and Magaldi, Marcello Gatimu and Paulsen, Melf and Riccobene, Giorgio and Schroeder, Katrin and Sciascia, Roberta and Splisa, Carsten and Sprovieri, Mario and Steinhoff, Tobias and Talone, Marco and Santoleri, Rosalia},
title = {ITINERIS' EYES - INTEGRATING, INNOVATING, EVOLVING RESEARCH INFRASTRUCTURES FOR HEALTHY AND PREDICTED MARINE ECOSYSTEMS},
publisher = {Istituto di Scienze Marine del Consiglio Nazionale delle Ricerche},
year = {2025},
doi = {10.82175/IT-IOOS/VQ4G-0T11}
}
|
| Palosuo T, Heikkinen J, Hilasvuori E, Kulmala L, Launiainen S, Lehtilä A, Leinonen I, Liimatainen M, Salminen M, Shurpali N, Silfver T, Soinne H, Vira J and Liski J (2025), "Demands and possibilities for field-scale estimation of agricultural greenhouse gas balances", CATENA., February, 2025. Vol. 249, pp. 108649. Elsevier BV. |
BibTeX:
@article{Palosuo2025,
author = {Palosuo, Taru and Heikkinen, Jaakko and Hilasvuori, Emmi and Kulmala, Liisa and Launiainen, Samuli and Lehtilä, Anniina and Leinonen, Ilkka and Liimatainen, Maarit and Salminen, Miia and Shurpali, Narasinha and Silfver, Tarja and Soinne, Helena and Vira, Julius and Liski, Jari},
title = {Demands and possibilities for field-scale estimation of agricultural greenhouse gas balances},
journal = {CATENA},
publisher = {Elsevier BV},
year = {2025},
volume = {249},
pages = {108649},
doi = {10.1016/j.catena.2024.108649}
}
|
| Paulus SJ, Migliavacca M, Reichstein M, Orth R, Lee S, Carrara A, Hildebrandt A and Nelson JA (2025), "Insights Into Water Vapor Uptake by Dry Soils Using a Global Eddy Covariance Observation Network", Global Change Biology., October, 2025. Vol. 31(10) Wiley. |
BibTeX:
@article{Paulus2025,
author = {Paulus, Sinikka J. and Migliavacca, Mirco and Reichstein, Markus and Orth, Rene and Lee, Sung‐Ching and Carrara, Arnaud and Hildebrandt, Anke and Nelson, Jacob A.},
title = {Insights Into Water Vapor Uptake by Dry Soils Using a Global Eddy Covariance Observation Network},
journal = {Global Change Biology},
publisher = {Wiley},
year = {2025},
volume = {31},
number = {10},
doi = {10.1111/gcb.70547}
}
|
| Peltola O, Aslan T, Aurela M, Lohila A, Mammarella I, Papale D, Thomas CK, Vesala T and Laurila T (2025), "Towards an enhanced metric for detecting vertical flow decoupling in eddy covariance flux observations", Agricultural and Forest Meteorology., March, 2025. Vol. 362, pp. 110326. Elsevier BV. |
BibTeX:
@article{Peltola2025,
author = {Peltola, Olli and Aslan, Toprak and Aurela, Mika and Lohila, Annalea and Mammarella, Ivan and Papale, Dario and Thomas, Christoph K. and Vesala, Timo and Laurila, Tuomas},
title = {Towards an enhanced metric for detecting vertical flow decoupling in eddy covariance flux observations},
journal = {Agricultural and Forest Meteorology},
publisher = {Elsevier BV},
year = {2025},
volume = {362},
pages = {110326},
doi = {10.1016/j.agrformet.2024.110326}
}
|
| Petersen RC, Holst T, Wu C, Krejci R, Chan JK, Mohr C and Rinne J (2025), "BVOC and speciated monoterpene concentrations and fluxes at a Scandinavian boreal forest", Atmospheric Chemistry and Physics., December, 2025. Vol. 25(23), pp. 17205-17236. Copernicus GmbH. |
BibTeX:
@article{Petersen2025,
author = {Petersen, Ross C. and Holst, Thomas and Wu, Cheng and Krejci, Radovan and Chan, Jeremy K. and Mohr, Claudia and Rinne, Janne},
title = {BVOC and speciated monoterpene concentrations and fluxes at a Scandinavian boreal forest},
journal = {Atmospheric Chemistry and Physics},
publisher = {Copernicus GmbH},
year = {2025},
volume = {25},
number = {23},
pages = {17205--17236},
doi = {10.5194/acp-25-17205-2025}
}
|
| Piccinelli S, Edvardsson J, Lehsten V, Slamova L, Gouma L, Francon L, Janecka K, Corona C and Stoffel M (2025), "Disentangling intra-annual Pinus sylvestris growth responses to hydro-climatic conditions: Insights from quantitative wood anatomy in peatlands", Science of The Total Environment., October, 2025. Vol. 998, pp. 180280. Elsevier BV. |
BibTeX:
@article{Piccinelli2025,
author = {Piccinelli, Silvia and Edvardsson, Johannes and Lehsten, Veiko and Slamova, Lenka and Gouma, Lianne and Francon, Loïc and Janecka, Karolina and Corona, Christophe and Stoffel, Markus},
title = {Disentangling intra-annual Pinus sylvestris growth responses to hydro-climatic conditions: Insights from quantitative wood anatomy in peatlands},
journal = {Science of The Total Environment},
publisher = {Elsevier BV},
year = {2025},
volume = {998},
pages = {180280},
doi = {10.1016/j.scitotenv.2025.180280}
}
|
| Plapp T, Larsen A, Schindler D and Christen A (2025), "Leaf Area Index (LAI) at the Hartheim Forest Research Site (DE-Har) 2021-2025" University of Freiburg. |
BibTeX:
@article{Plapp2025,
author = {Plapp, Thomas and Larsen, Autumn and Schindler, Dirk and Christen, Andreas},
title = {Leaf Area Index (LAI) at the Hartheim Forest Research Site (DE-Har) 2021-2025},
publisher = {University of Freiburg},
year = {2025},
doi = {10.5281/ZENODO.16046572}
}
|
| Pohl F, Schrön M, Rebmann C and Hildebrandt A (2025), "Long-term soil moisture measurements and upscaled plot-level averages from a temperate deciduous forest in Germany (Hohes Holz, DE-HoH, 2014–2024)". |
BibTeX:
@misc{Pohl2025,
author = {Pohl, Felix and Schrön, Martin and Rebmann, Corinna and Hildebrandt, Anke},
title = {Long-term soil moisture measurements and upscaled plot-level averages from a temperate deciduous forest in Germany (Hohes Holz, DE-HoH, 2014–2024)},
publisher = {Zenodo},
year = {2025},
doi = {10.5281/ZENODO.17121123}
}
|
| Rahmsdorf E, Doktor D, Feilhauer H, Brede B, Dienstbach L, Eisenhauer N, Hildebrandt A, Rüger N and Lange M (2025), "Drivers of remotely sensed tree height heterogeneity across spatial scales: Tree species diversity effects depend on local conditions and forest type", Ecological Indicators., October, 2025. Vol. 179, pp. 114245. Elsevier BV. |
BibTeX:
@article{Rahmsdorf2025,
author = {Rahmsdorf, Elisabeth and Doktor, Daniel and Feilhauer, Hannes and Brede, Benjamin and Dienstbach, Laura and Eisenhauer, Nico and Hildebrandt, Anke and Rüger, Nadja and Lange, Maximilian},
title = {Drivers of remotely sensed tree height heterogeneity across spatial scales: Tree species diversity effects depend on local conditions and forest type},
journal = {Ecological Indicators},
publisher = {Elsevier BV},
year = {2025},
volume = {179},
pages = {114245},
doi = {10.1016/j.ecolind.2025.114245}
}
|
| Reum F, Marshall J, Bittig HC, Bretschneider L, Broström G, Dissanayake AL, Glauch T, Gottschaldt K-D, Gros J, Huntrieser H, Lampert A, Lichtenstern M, Miller SM, Mohrmann M, Pätzold F, Pühl M, Rehder G and Roiger A (2025), "Airborne observations reveal the fate of the methane from the Nord Stream pipelines", Nature Communications., January, 2025. Vol. 16(1) Springer Science and Business Media LLC. |
BibTeX:
@article{Reum2025,
author = {Reum, Friedemann and Marshall, Julia and Bittig, Henry C. and Bretschneider, Lutz and Broström, Göran and Dissanayake, Anusha L. and Glauch, Theo and Gottschaldt, Klaus-Dirk and Gros, Jonas and Huntrieser, Heidi and Lampert, Astrid and Lichtenstern, Michael and Miller, Scot M. and Mohrmann, Martin and Pätzold, Falk and Pühl, Magdalena and Rehder, Gregor and Roiger, Anke},
title = {Airborne observations reveal the fate of the methane from the Nord Stream pipelines},
journal = {Nature Communications},
publisher = {Springer Science and Business Media LLC},
year = {2025},
volume = {16},
number = {1},
doi = {10.1038/s41467-024-53780-7}
}
|
| Rewrie LCV, Baschek B, van Beusekom JEE, Körtzinger A, Petersen W, Röttgers R and Voynova YG (2025), "Impact of primary production and net ecosystem metabolism on carbon and nutrient cycling at the land-sea interface", Frontiers in Marine Science., April, 2025. Vol. 12 Frontiers Media SA. |
BibTeX:
@article{Rewrie2025,
author = {Rewrie, Louise C. V. and Baschek, Burkard and van Beusekom, Justus E. E. and Körtzinger, Arne and Petersen, Wilhelm and Röttgers, Rüdiger and Voynova, Yoana G.},
title = {Impact of primary production and net ecosystem metabolism on carbon and nutrient cycling at the land-sea interface},
journal = {Frontiers in Marine Science},
publisher = {Frontiers Media SA},
year = {2025},
volume = {12},
doi = {10.3389/fmars.2025.1548463}
}
|
| Reyes-Muñoz P, D.Kovács D and Verrelst J (2025), "Tower-to-global upscaling of terrestrial carbon fluxes driven by MODIS-LAI, Sentinel-3-LAI and ERA5-Land data", Ecological Indicators., August, 2025. Vol. 177, pp. 113597. Elsevier BV. |
BibTeX:
@article{ReyesMunoz2025,
author = {Reyes-Muñoz, Pablo and D.Kovács, Dávid and Verrelst, Jochem},
title = {Tower-to-global upscaling of terrestrial carbon fluxes driven by MODIS-LAI, Sentinel-3-LAI and ERA5-Land data},
journal = {Ecological Indicators},
publisher = {Elsevier BV},
year = {2025},
volume = {177},
pages = {113597},
doi = {10.1016/j.ecolind.2025.113597}
}
|
| Rinne J, Tuovinen J-P and Lohila A (2025), "A practical metric for estimating the current climate forcing of natural mires", Environmental Research Letters., May, 2025. Vol. 20(6), pp. 064033. IOP Publishing. |
BibTeX:
@article{Rinne2025,
author = {Rinne, Janne and Tuovinen, Juha-Pekka and Lohila, Annalea},
title = {A practical metric for estimating the current climate forcing of natural mires},
journal = {Environmental Research Letters},
publisher = {IOP Publishing},
year = {2025},
volume = {20},
number = {6},
pages = {064033},
doi = {10.1088/1748-9326/add607}
}
|
| Rinne E, Tuovinen J-P, Lohila A and Aurela M (2025), "Surface energy balance and surface temperature sensitivity in northern boreal ecosystems", Agricultural and Forest Meteorology., December, 2025. Vol. 375, pp. 110837. Elsevier BV. |
BibTeX:
@article{Rinne2025a,
author = {Rinne, Erkka and Tuovinen, Juha-Pekka and Lohila, Annalea and Aurela, Mika},
title = {Surface energy balance and surface temperature sensitivity in northern boreal ecosystems},
journal = {Agricultural and Forest Meteorology},
publisher = {Elsevier BV},
year = {2025},
volume = {375},
pages = {110837},
doi = {10.1016/j.agrformet.2025.110837}
}
|
| Schoderer M, Bittig H, Klein B, Hägele R, Steinhoff T, Castro‐Morales K, Cotrim da Cunha L, Hornidge A and Körtzinger A (2025), "From Individual Observations to Global Assessments: Tracing the Marine Carbon Knowledge Value Chain", Ocean and Society., January, 2025. Vol. 2 Cogitatio. |
BibTeX:
@article{Schoderer2025,
author = {Schoderer, Mirja and Bittig, Henry and Klein, Birgit and Hägele, Ramona and Steinhoff, Tobias and Castro‐Morales, Karel and Cotrim da Cunha, Leticia and Hornidge, Anna‐Katharina and Körtzinger, Arne},
title = {From Individual Observations to Global Assessments: Tracing the Marine Carbon Knowledge Value Chain},
journal = {Ocean and Society},
publisher = {Cogitatio},
year = {2025},
volume = {2},
doi = {10.17645/oas.8891}
}
|
| Schulz R, Sugand M and Hördt A (2025), "Induction effect removal for high frequency induced polarization data", Geophysical Journal International., October, 2025. Vol. 243(3) Oxford University Press (OUP). |
BibTeX:
@article{Schulz2025,
author = {Schulz, Raphael and Sugand, Madhuri and Hördt, Andreas},
title = {Induction effect removal for high frequency induced polarization data},
journal = {Geophysical Journal International},
publisher = {Oxford University Press (OUP)},
year = {2025},
volume = {243},
number = {3},
doi = {10.1093/gji/ggaf403}
}
|
| Shatadru RN, Solonenko NE, Sun CL and Sullivan MB (2025), "Benchmarking with synthetic communities provides a baseline for virus-host inferences from Hi-C proximity linking", PLOS Biology., November, 2025. Vol. 23(11), pp. e3003510. Public Library of Science (PLoS). |
BibTeX:
@article{Shatadru2025,
author = {Shatadru, Rokaiya Nurani and Solonenko, Natalie E. and Sun, Christine L. and Sullivan, Matthew B.},
editor = {Barr, Jeremy J.},
title = {Benchmarking with synthetic communities provides a baseline for virus-host inferences from Hi-C proximity linking},
journal = {PLOS Biology},
publisher = {Public Library of Science (PLoS)},
year = {2025},
volume = {23},
number = {11},
pages = {e3003510},
doi = {10.1371/journal.pbio.3003510}
}
|
| Shurpali N, Peltola O, Li Y, Manninen P, Semberg S, Launiainen S, Louhisuo A, Rinne J, Järvinen M, Virkajärvi P and Martikainen PJ (2025), "GHG balance, its seasonality and response to soil type and management of northern agricultural grasslands: Eddy-covariance flux measurements from three adjacent fields in Finland", Agriculture, Ecosystems & Environment., November, 2025. Vol. 393, pp. 109841. Elsevier BV. |
BibTeX:
@article{Shurpali2025,
author = {Shurpali, Narasinha and Peltola, Olli and Li, Yuan and Manninen, Petra and Semberg, Sanni and Launiainen, Samuli and Louhisuo, Arja and Rinne, Janne and Järvinen, Mikko and Virkajärvi, Perttu and Martikainen, Pertti J.},
title = {GHG balance, its seasonality and response to soil type and management of northern agricultural grasslands: Eddy-covariance flux measurements from three adjacent fields in Finland},
journal = {Agriculture, Ecosystems & Environment},
publisher = {Elsevier BV},
year = {2025},
volume = {393},
pages = {109841},
doi = {10.1016/j.agee.2025.109841}
}
|
| Skalák P, Meitner J, Fischer M, Orság M, Graf A, Hlavsová M and Trnka M (2025), "The Projected Changes in the Surface Energy Budget of the CMIP5 and EURO-CORDEX Models: Are We Heading toward Wetter Growing Seasons in Central Europe?", Journal of Hydrometeorology., April, 2025. Vol. 26(4), pp. 481-499. American Meteorological Society. |
BibTeX:
@article{Skalak2025,
author = {Skalák, Petr and Meitner, Jan and Fischer, Milan and Orság, Matěj and Graf, Alexander and Hlavsová, Monika and Trnka, Miroslav},
title = {The Projected Changes in the Surface Energy Budget of the CMIP5 and EURO-CORDEX Models: Are We Heading toward Wetter Growing Seasons in Central Europe?},
journal = {Journal of Hydrometeorology},
publisher = {American Meteorological Society},
year = {2025},
volume = {26},
number = {4},
pages = {481--499},
doi = {10.1175/jhm-d-24-0017.1}
}
|
| Smidt J, Wanner L, Ibrom A, Schmid H and Mauder M (2025), "High-frequency attenuation in eddy covariance measurements from the LI-7200 IRGA with various heating and filter configurations – a spectral correction approach", Agricultural and Forest Meteorology., February, 2025. Vol. 361, pp. 110312. Elsevier BV. |
BibTeX:
@article{Smidt2025,
author = {Smidt, Jamie and Wanner, Luise and Ibrom, Andreas and Schmid, HaPe and Mauder, Matthias},
title = {High-frequency attenuation in eddy covariance measurements from the LI-7200 IRGA with various heating and filter configurations – a spectral correction approach},
journal = {Agricultural and Forest Meteorology},
publisher = {Elsevier BV},
year = {2025},
volume = {361},
pages = {110312},
doi = {10.1016/j.agrformet.2024.110312}
}
|
| Soininen J, Kohonen K-M, Rantala P, Kulmala L, Aaltonen H and Järvi L (2025), "Carbon uptake of an urban green space inferred from carbonyl sulfide fluxes", npj Climate and Atmospheric Science., March, 2025. Vol. 8(1) Springer Science and Business Media LLC. |
BibTeX:
@article{Soininen2025,
author = {Soininen, Jesse and Kohonen, Kukka-Maaria and Rantala, Pekka and Kulmala, Liisa and Aaltonen, Hermanni and Järvi, Leena},
title = {Carbon uptake of an urban green space inferred from carbonyl sulfide fluxes},
journal = {npj Climate and Atmospheric Science},
publisher = {Springer Science and Business Media LLC},
year = {2025},
volume = {8},
number = {1},
doi = {10.1038/s41612-025-00958-5}
}
|
| Stagakis S, Brunner D, Li J, Backman L, Karvonen A, Constantin L, Järvi L, Havu M, Chen J, Emberger S and Kulmala L (2025), "Intercomparison of biogenic CO 2 flux models in four urban parks in the city of Zurich", Biogeosciences., May, 2025. Vol. 22(9), pp. 2133-2161. Copernicus GmbH. |
BibTeX:
@article{Stagakis2025,
author = {Stagakis, Stavros and Brunner, Dominik and Li, Junwei and Backman, Leif and Karvonen, Anni and Constantin, Lionel and Järvi, Leena and Havu, Minttu and Chen, Jia and Emberger, Sophie and Kulmala, Liisa},
title = {Intercomparison of biogenic CO 2 flux models in four urban parks in the city of Zurich},
journal = {Biogeosciences},
publisher = {Copernicus GmbH},
year = {2025},
volume = {22},
number = {9},
pages = {2133--2161},
doi = {10.5194/bg-22-2133-2025}
}
|
| Steinhoff T, Gkritzalis T, Jones S, Macovei VA, Neill C, Schuster U, Akl J, Arruda R, Atamanchuk D, Barry M, Beaumont L, Cantoni C, Dickson A, Fahning J, Fought J, Frangoulis C, Gutiérrez‐Loza L, Hagan C, Honkanen M, Kielosto S, Kinski N, Körtzinger A, Landschützer P, Lauvset SK, Lawrence‐Slavas N, Li Q, Luchetta A, Malarde D, Paulsen M, Ritschel M, Rutgersson A, Sanders R, Shitashima K, Spaulding R, Stamataki N, Stenbäck K, Sutton A, Tatkiewicz W, Telszewski M, Theetaert H, Tilbrook B and Wanninkhof R (2025), "The ICOS OTC p CO 2 instrument intercomparison", Limnology and Oceanography: Methods., August, 2025. Vol. 23(12), pp. 924-948. Wiley. |
BibTeX:
@article{Steinhoff2025,
author = {Steinhoff, Tobias and Gkritzalis, Thanos and Jones, Steve and Macovei, Vlad A. and Neill, Craig and Schuster, Ute and Akl, John and Arruda, Ricardo and Atamanchuk, Dariia and Barry, Mark and Beaumont, Laurence and Cantoni, Carolina and Dickson, Andrew and Fahning, Jana and Fought, Jac and Frangoulis, Constantin and Gutiérrez‐Loza, Lucía and Hagan, Clinton and Honkanen, Martti and Kielosto, Sami and Kinski, Nadja and Körtzinger, Arne and Landschützer, Peter and Lauvset, Siv K. and Lawrence‐Slavas, Noah and Li, Quanlong and Luchetta, Anna and Malarde, Damien and Paulsen, Melf and Ritschel, Markus and Rutgersson, Anna and Sanders, Richard and Shitashima, Kiminori and Spaulding, Reggie and Stamataki, Natalia and Stenbäck, Ken and Sutton, Adrienne and Tatkiewicz, Witold and Telszewski, Maciej and Theetaert, Hannelore and Tilbrook, Bronte and Wanninkhof, Rik},
title = {The ICOS OTC p CO 2 instrument intercomparison},
journal = {Limnology and Oceanography: Methods},
publisher = {Wiley},
year = {2025},
volume = {23},
number = {12},
pages = {924--948},
doi = {10.1002/lom3.10727}
}
|
| Sulzer M, Haberstroh S, Plapp T, Seifert T, Schindler D, Werner C and Christen A (2025), "Assessing carbon fluxes following non-invasive and clear-cut management responses to widespread drought mortality of a Scots Pine plantation", March, 2025. Copernicus GmbH. |
BibTeX:
@article{Sulzer2025,
author = {Sulzer, Markus and Haberstroh, Simon and Plapp, Thomas and Seifert, Thomas and Schindler, Dirk and Werner, Christiane and Christen, Andreas},
title = {Assessing carbon fluxes following non-invasive and clear-cut management responses to widespread drought mortality of a Scots Pine plantation},
publisher = {Copernicus GmbH},
year = {2025},
doi = {10.5194/egusphere-egu25-17497}
}
|
| Swindles GT, Mullan DJ, Brannigan NT, Fewster RE, Sim TG, Gallego-Sala A, Blaauw M, Lamentowicz M, Jassey VE, Marcisz K, Green SM, Roland TP, Loisel J, Amesbury MJ, Blundell A, Chambers FM, Charman DJ, Evans CR, Feurdean A, Galloway JM, Gałka M, Karofeld E, Keaveney EM, Korhola A, Lamentowicz Ł, Langdon P, Mauquoy D, McKeown MM, Mitchell EAD, Plunkett G, Roe HM, Turner TE, Sillasoo Ü, Väliranta M, van der Linden M and Warner B (2025), "Climate and water-table levels regulate peat accumulation rates across Europe", PLOS One., July, 2025. Vol. 20(7), pp. e0327422. Public Library of Science (PLoS). |
BibTeX:
@article{Swindles2025,
author = {Swindles, Graeme T. and Mullan, Donal J. and Brannigan, Neil T. and Fewster, Richard E. and Sim, Thomas G. and Gallego-Sala, Angela and Blaauw, Maarten and Lamentowicz, Mariusz and Jassey, Vincent E.J. and Marcisz, Katarzyna and Green, Sophie M. and Roland, Thomas P. and Loisel, Julie and Amesbury, Matthew J. and Blundell, Antony and Chambers, Frank M. and Charman, Dan J. and Evans, Callum R.C. and Feurdean, Angelica and Galloway, Jennifer M. and Gałka, Mariusz and Karofeld, Edgar and Keaveney, Evelyn M. and Korhola, Atte and Lamentowicz, Łukasz and Langdon, Peter and Mauquoy, Dmitri and McKeown, Michelle M. and Mitchell, Edward A. D. and Plunkett, Gill and Roe, Helen M. and Turner, T. Edward and Sillasoo, Ülle and Väliranta, Minna and van der Linden, Marjolein and Warner, Barry},
editor = {Van Stan II, John Toland},
title = {Climate and water-table levels regulate peat accumulation rates across Europe},
journal = {PLOS One},
publisher = {Public Library of Science (PLoS)},
year = {2025},
volume = {20},
number = {7},
pages = {e0327422},
doi = {10.1371/journal.pone.0327422}
}
|
| Tenkanen MK, Tsuruta A, Denier van der Gon H, Höglund-Isaksson L, Leppänen A, Markkanen T, Petrescu AMR, Raivonen M, Aaltonen H and Aalto T (2025), "Partitioning anthropogenic and natural methane emissions in Finland during 2000–2021 by combining bottom-up and top-down estimates", Atmospheric Chemistry and Physics., February, 2025. Vol. 25(4), pp. 2181-2206. Copernicus GmbH. |
BibTeX:
@article{Tenkanen2025,
author = {Tenkanen, Maria K. and Tsuruta, Aki and Denier van der Gon, Hugo and Höglund-Isaksson, Lena and Leppänen, Antti and Markkanen, Tiina and Petrescu, Ana Maria Roxana and Raivonen, Maarit and Aaltonen, Hermanni and Aalto, Tuula},
title = {Partitioning anthropogenic and natural methane emissions in Finland during 2000–2021 by combining bottom-up and top-down estimates},
journal = {Atmospheric Chemistry and Physics},
publisher = {Copernicus GmbH},
year = {2025},
volume = {25},
number = {4},
pages = {2181--2206},
doi = {10.5194/acp-25-2181-2025}
}
|
| Thanwerdas J, Berchet A, Constantin L, Tsuruta A, Steiner M, Reum F, Henne S and Brunner D (2025), "Improving the ensemble square root filter (EnSRF) in the Community Inversion Framework: a case study with ICON-ART 2024.01", Geoscientific Model Development., March, 2025. Vol. 18(5), pp. 1505-1544. Copernicus GmbH. |
BibTeX:
@article{Thanwerdas2025,
author = {Thanwerdas, Joël and Berchet, Antoine and Constantin, Lionel and Tsuruta, Aki and Steiner, Michael and Reum, Friedemann and Henne, Stephan and Brunner, Dominik},
title = {Improving the ensemble square root filter (EnSRF) in the Community Inversion Framework: a case study with ICON-ART 2024.01},
journal = {Geoscientific Model Development},
publisher = {Copernicus GmbH},
year = {2025},
volume = {18},
number = {5},
pages = {1505--1544},
doi = {10.5194/gmd-18-1505-2025}
}
|
| Thölix L, Backman L, Havu M, Karvinen E, Soininen J, Trémeau J, Nevalainen O, Ahongshangbam J, Järvi L and Kulmala L (2025), "Carbon sequestration in different urban vegetation types in Southern Finland", Biogeosciences., February, 2025. Vol. 22(3), pp. 725-749. Copernicus GmbH. |
BibTeX:
@article{Thoelix2025,
author = {Thölix, Laura and Backman, Leif and Havu, Minttu and Karvinen, Esko and Soininen, Jesse and Trémeau, Justine and Nevalainen, Olli and Ahongshangbam, Joyson and Järvi, Leena and Kulmala, Liisa},
title = {Carbon sequestration in different urban vegetation types in Southern Finland},
journal = {Biogeosciences},
publisher = {Copernicus GmbH},
year = {2025},
volume = {22},
number = {3},
pages = {725--749},
doi = {10.5194/bg-22-725-2025}
}
|
| Tikkasalo O-P, Peltola O, Alekseychik P, Heikkinen J, Launiainen S, Lehtonen A, Li Q, Martínez-García E, Peltoniemi M, Salovaara P, Tuominen V and Mäkipää R (2025), "Eddy-covariance fluxes of CO 2 , CH 4 and N 2 O in a drained peatland forest after clear-cutting", Biogeosciences., March, 2025. Vol. 22(5), pp. 1277-1300. Copernicus GmbH. |
BibTeX:
@article{Tikkasalo2025,
author = {Tikkasalo, Olli-Pekka and Peltola, Olli and Alekseychik, Pavel and Heikkinen, Juha and Launiainen, Samuli and Lehtonen, Aleksi and Li, Qian and Martínez-García, Eduardo and Peltoniemi, Mikko and Salovaara, Petri and Tuominen, Ville and Mäkipää, Raisa},
title = {Eddy-covariance fluxes of CO 2 , CH 4 and N 2 O in a drained peatland forest after clear-cutting},
journal = {Biogeosciences},
publisher = {Copernicus GmbH},
year = {2025},
volume = {22},
number = {5},
pages = {1277--1300},
doi = {10.5194/bg-22-1277-2025}
}
|
| Tong CHM, Peichl M, Noumonvi KD, Nilsson MB, Laudon H and Järveoja J (2025), "The Carbon Balance of a Rewetted Minerogenic Peatland Does Not Immediately Resemble That of Natural Mires in Boreal Sweden", Global Change Biology., April, 2025. Vol. 31(4) Wiley. |
BibTeX:
@article{Tong2025,
author = {Tong, Cheuk Hei Marcus and Peichl, Matthias and Noumonvi, Koffi Dodji and Nilsson, Mats B. and Laudon, Hjalmar and Järveoja, Järvi},
title = {The Carbon Balance of a Rewetted Minerogenic Peatland Does Not Immediately Resemble That of Natural Mires in Boreal Sweden},
journal = {Global Change Biology},
publisher = {Wiley},
year = {2025},
volume = {31},
number = {4},
doi = {10.1111/gcb.70169}
}
|
| Triches NY, Engel J, Bolek A, Vesala T, Marushchak ME, Virkkala A-M, Heimann M and Göckede M (2025), "Practical guidelines for reproducible N2O flux chamber measurements in nutrient-poor ecosystems", Atmospheric Measurement Techniques., July, 2025. Vol. 18(14), pp. 3407-3424. Copernicus GmbH. |
BibTeX:
@article{Triches2025,
author = {Triches, Nathalie Ylenia and Engel, Jan and Bolek, Abdullah and Vesala, Timo and Marushchak, Maija E. and Virkkala, Anna-Maria and Heimann, Martin and Göckede, Mathias},
title = {Practical guidelines for reproducible N2O flux chamber measurements in nutrient-poor ecosystems},
journal = {Atmospheric Measurement Techniques},
publisher = {Copernicus GmbH},
year = {2025},
volume = {18},
number = {14},
pages = {3407--3424},
doi = {10.5194/amt-18-3407-2025}
}
|
| Trubl G, Roux S, Borton MA, Varsani A, Li Y-F, Sun CL, Jang HB, Woodcroft BJ, Tyson GW, Wrighton KC, Saleska SR, Eloe-Fadrosh EA, Sullivan MB and Rich VI (2025), "Population ecology and biogeochemical implications of ssDNA and dsDNA viruses along a permafrost thaw gradient", Nature Communications., December, 2025. Vol. 17(1) Springer Science and Business Media LLC. |
BibTeX:
@article{Trubl2025,
author = {Trubl, Gareth and Roux, Simon and Borton, Mikayla A. and Varsani, Arvind and Li, Yueh-Fen and Sun, Christine L. and Jang, Ho Bin and Woodcroft, Ben J. and Tyson, Gene W. and Wrighton, Kelly C. and Saleska, Scott R. and Eloe-Fadrosh, Emiley A. and Sullivan, Matthew B. and Rich, Virginia I.},
title = {Population ecology and biogeochemical implications of ssDNA and dsDNA viruses along a permafrost thaw gradient},
journal = {Nature Communications},
publisher = {Springer Science and Business Media LLC},
year = {2025},
volume = {17},
number = {1},
doi = {10.1038/s41467-025-67057-0}
}
|
| Tsuruta A, Kuze A, Shiomi K, Kataoka F, Kikuchi N, Aalto T, Backman L, Kivimäki E, Tenkanen MK, McKain K, García OE, Hase F, Kivi R, Morino I, Ohyama H, Pollard DF, Sha MK, Strong K, Sussmann R, Te Y, Velazco VA, Vrekoussis M, Warneke T, Zhou M and Suto H (2025), "Global CH 4 fluxes derived from JAXA/GOSAT lower-tropospheric partial column data and the CarbonTracker Europe-CH 4 atmospheric inverse model", Atmospheric Chemistry and Physics., July, 2025. Vol. 25(14), pp. 7829-7862. Copernicus GmbH. |
BibTeX:
@article{Tsuruta2025,
author = {Tsuruta, Aki and Kuze, Akihiko and Shiomi, Kei and Kataoka, Fumie and Kikuchi, Nobuhiro and Aalto, Tuula and Backman, Leif and Kivimäki, Ella and Tenkanen, Maria K. and McKain, Kathryn and García, Omaira E. and Hase, Frank and Kivi, Rigel and Morino, Isamu and Ohyama, Hirofumi and Pollard, David F. and Sha, Mahesh K. and Strong, Kimberly and Sussmann, Ralf and Te, Yao and Velazco, Voltaire A. and Vrekoussis, Mihalis and Warneke, Thorsten and Zhou, Minqiang and Suto, Hiroshi},
title = {Global CH 4 fluxes derived from JAXA/GOSAT lower-tropospheric partial column data and the CarbonTracker Europe-CH 4 atmospheric inverse model},
journal = {Atmospheric Chemistry and Physics},
publisher = {Copernicus GmbH},
year = {2025},
volume = {25},
number = {14},
pages = {7829--7862},
doi = {10.5194/acp-25-7829-2025}
}
|
| Ullah A, Crétat J, Michel G, Mathieu O, Thevenot M, Dara A, Granat R, Wu Z, Bonnefoy-Claudet C, Capelle J, Cacot J and Kimball JS (2025), "Climate impact on mean annual cycle and interannual variability of CO 2 fluxes in European deciduous broadleaf and evergreen needleleaf forests: insights from observations and state-of-the-art data-driven and process-based models", Biogeosciences., August, 2025. Vol. 22(16), pp. 4135-4162. Copernicus GmbH. |
BibTeX:
@article{Ullah2025,
author = {Ullah, Asmat and Crétat, Julien and Michel, Gaïa and Mathieu, Olivier and Thevenot, Mathieu and Dara, Andrey and Granat, Robert and Wu, Zhendong and Bonnefoy-Claudet, Clément and Capelle, Julianne and Cacot, Jean and Kimball, John S.},
title = {Climate impact on mean annual cycle and interannual variability of CO 2 fluxes in European deciduous broadleaf and evergreen needleleaf forests: insights from observations and state-of-the-art data-driven and process-based models},
journal = {Biogeosciences},
publisher = {Copernicus GmbH},
year = {2025},
volume = {22},
number = {16},
pages = {4135--4162},
doi = {10.5194/bg-22-4135-2025}
}
|
| Unc A, Abou Najm MR, Aspholm PE, Bolisetti T, Charles C, Datta R, Eggen T, Flem B, Hailu G, Heimstad ES, Hurlbert M, Karlsson M, Korsnes M, Nash A, Parsons D, Sajeevan RS, Shurpali N, Valkenburg G, Wilde D, Wu B, Yanni SF and Misra D (2025), "Arctic food and energy security at the crossroads", Communications Earth & Environment., February, 2025. Vol. 6(1) Springer Science and Business Media LLC. |
BibTeX:
@article{Unc2025,
author = {Unc, Adrian and Abou Najm, Majdi R. and Aspholm, Paul Eric and Bolisetti, Tirupati and Charles, Colleen and Datta, Ranjan and Eggen, Trine and Flem, Belinda and Hailu, Getu and Heimstad, Eldbjørg Sofie and Hurlbert, Margot and Karlsson, Meriam and Korsnes, Marius and Nash, Arthur and Parsons, David and Sajeevan, Radha Sivarajan and Shurpali, Narasinha and Valkenburg, Govert and Wilde, Danielle and Wu, Bing and Yanni, Sandra F. and Misra, Debasmita},
title = {Arctic food and energy security at the crossroads},
journal = {Communications Earth & Environment},
publisher = {Springer Science and Business Media LLC},
year = {2025},
volume = {6},
number = {1},
doi = {10.1038/s43247-025-02122-6}
}
|
| Upton S, Reichstein M, Peters W, Botía S, Nelson JA, Walther S, Jung M, Gans F, Haszpra L and Bastos A (2025), "Constraining a data-driven CO 2 flux model by ecosystem and atmospheric observations using atmospheric transport", May, 2025. Copernicus GmbH. |
BibTeX:
@article{Upton2025,
author = {Upton, Samuel and Reichstein, Markus and Peters, Wouter and Botía, Santiago and Nelson, Jacob A. and Walther, Sophia and Jung, Martin and Gans, Fabian and Haszpra, László and Bastos, Ana},
title = {Constraining a data-driven CO 2 flux model by ecosystem and atmospheric observations using atmospheric transport},
publisher = {Copernicus GmbH},
year = {2025},
doi = {10.5194/egusphere-2025-2097}
}
|
| Vähä A, Vesala T, Guseva S, Lindroth A, Lorke A, MacIntyre S and Mammarella I (2025), "Temporal dynamics and environmental controls of carbon dioxide and methane fluxes measured by the eddy covariance method over a boreal river", Biogeosciences., March, 2025. Vol. 22(6), pp. 1651-1671. Copernicus GmbH. |
BibTeX:
@article{Vaehae2025,
author = {Vähä, Aki and Vesala, Timo and Guseva, Sofya and Lindroth, Anders and Lorke, Andreas and MacIntyre, Sally and Mammarella, Ivan},
title = {Temporal dynamics and environmental controls of carbon dioxide and methane fluxes measured by the eddy covariance method over a boreal river},
journal = {Biogeosciences},
publisher = {Copernicus GmbH},
year = {2025},
volume = {22},
number = {6},
pages = {1651--1671},
doi = {10.5194/bg-22-1651-2025}
}
|
| Varga T, Major I, Bán S, Baráth BÁ, Röckmann T, van Es J, van der Veen C and Molnár M (2025), "Methane and carbon dioxide observations at Debrecen, Hungary: mole fraction and isotope ratio measurements in three different seasons", January, 2025. Copernicus GmbH. |
BibTeX:
@article{Varga2025,
author = {Varga, Tamás and Major, István and Bán, Sándor and Baráth, Balázs Áron and Röckmann, Thomas and van Es, Jacoline and van der Veen, Carina and Molnár, Mihály},
title = {Methane and carbon dioxide observations at Debrecen, Hungary: mole fraction and isotope ratio measurements in three different seasons},
publisher = {Copernicus GmbH},
year = {2025},
doi = {10.5194/egusphere-egu24-7845}
}
|
| Varga T, Sajtos Z, Buró B, Lisztes-Szabó Z, Futó I and Molnár M (2025), "Tracing old carbon sources in Hungarian nectar samples using radiocarbon analysis", Scientific Reports., October, 2025. Vol. 15(1) Springer Science and Business Media LLC. |
BibTeX:
@article{Varga2025a,
author = {Varga, Tamás and Sajtos, Zsófi and Buró, Botond and Lisztes-Szabó, Zsuzsa and Futó, István and Molnár, Mihály},
title = {Tracing old carbon sources in Hungarian nectar samples using radiocarbon analysis},
journal = {Scientific Reports},
publisher = {Springer Science and Business Media LLC},
year = {2025},
volume = {15},
number = {1},
doi = {10.1038/s41598-025-20578-6}
}
|
| Vekuri H, Tuovinen J-P, Kulmala L, Aurela M, Thum T, Liski J and Lohila A (2025), "Improved uncertainty estimates for eddy covariance-based carbon dioxide balances using deep ensembles for gap-filling", Agricultural and Forest Meteorology., August, 2025. Vol. 371, pp. 110558. Elsevier BV. |
BibTeX:
@article{Vekuri2025,
author = {Vekuri, Henriikka and Tuovinen, Juha-Pekka and Kulmala, Liisa and Aurela, Mika and Thum, Tea and Liski, Jari and Lohila, Annalea},
title = {Improved uncertainty estimates for eddy covariance-based carbon dioxide balances using deep ensembles for gap-filling},
journal = {Agricultural and Forest Meteorology},
publisher = {Elsevier BV},
year = {2025},
volume = {371},
pages = {110558},
doi = {10.1016/j.agrformet.2025.110558}
}
|
| Vieira I, Meunier F, Duran Rojas MC, Sitch S, Brown F, Gerosa G, Fares S, Boeckx P, Bauters M and Verbeeck H (2025), "Modelling impacts of ozone on gross primary production across European forest ecosystems using JULES", Biogeosciences., October, 2025. Vol. 22(20), pp. 6205-6223. Copernicus GmbH. |
BibTeX:
@article{Vieira2025,
author = {Vieira, Inês and Meunier, Félicien and Duran Rojas, Maria Carolina and Sitch, Stephen and Brown, Flossie and Gerosa, Giacomo and Fares, Silvano and Boeckx, Pascal and Bauters, Marijn and Verbeeck, Hans},
title = {Modelling impacts of ozone on gross primary production across European forest ecosystems using JULES},
journal = {Biogeosciences},
publisher = {Copernicus GmbH},
year = {2025},
volume = {22},
number = {20},
pages = {6205--6223},
doi = {10.5194/bg-22-6205-2025}
}
|
| Villalobos Y, Gómez-Ortiz C, Scholze M, Monteil G, Karstens U, Fiore A, Brunner D, Thanwerdas J and Cristofanelli P (2025), "Towards improving top–down national CO2 estimation in Europe: potential from expanding the ICOS atmospheric network in Italy", Environmental Research Letters., April, 2025. Vol. 20(5), pp. 054002. IOP Publishing. |
BibTeX:
@article{Villalobos2025,
author = {Villalobos, Yohanna and Gómez-Ortiz, Carlos and Scholze, Marko and Monteil, Guillaume and Karstens, Ute and Fiore, Angela and Brunner, Dominik and Thanwerdas, Joël and Cristofanelli, Paolo},
title = {Towards improving top–down national CO2 estimation in Europe: potential from expanding the ICOS atmospheric network in Italy},
journal = {Environmental Research Letters},
publisher = {IOP Publishing},
year = {2025},
volume = {20},
number = {5},
pages = {054002},
doi = {10.1088/1748-9326/adc41e}
}
|
| Villani M, Hirst C, du Bois d’Aische E, Thomas M, Lundin E, Giesler R, Mörth C-M and Opfergelt S (2025), "Lengthening of biogeochemical processes during winter in degraded permafrost soils", Geochemical Perspectives Letters., April, 2025. Vol. 34, pp. 36-42. European Association of Geochemistry. |
BibTeX:
@article{Villani2025,
author = {Villani, M. and Hirst, C. and du Bois d’Aische, E. and Thomas, M. and Lundin, E. and Giesler, R. and Mörth, C.-M. and Opfergelt, S.},
title = {Lengthening of biogeochemical processes during winter in degraded permafrost soils},
journal = {Geochemical Perspectives Letters},
publisher = {European Association of Geochemistry},
year = {2025},
volume = {34},
pages = {36--42},
doi = {10.7185/geochemlet.2511}
}
|
| Virkkala A-M, Rogers BM, Watts JD, Arndt KA, Potter S, Wargowsky I, Schuur EAG, See CR, Mauritz M, Boike J, Bret-Harte MS, Burke EJ, Burrell A, Chae N, Chatterjee A, Chevallier F, Christensen TR, Commane R, Dolman H, Edgar CW, Elberling B, Emmerton CA, Euskirchen ES, Feng L, Göckede M, Grelle A, Helbig M, Holl D, Järveoja J, Karsanaev SV, Kobayashi H, Kutzbach L, Liu J, Luijkx IT, López-Blanco E, Lunneberg K, Mammarella I, Marushchak ME, Mastepanov M, Matsuura Y, Maximov TC, Merbold L, Meyer G, Nilsson MB, Niwa Y, Oechel W, Palmer PI, Park S-J, Parmentier F-JW, Peichl M, Peters W, Petrov R, Quinton W, Rödenbeck C, Sachs T, Schulze C, Sonnentag O, St. Louis VL, Tuittila E-S, Ueyama M, Varlagin A, Zona D and Natali SM (2025), "Wildfires offset the increasing but spatially heterogeneous Arctic–boreal CO2 uptake", Nature Climate Change., January, 2025. Vol. 15(2), pp. 188-195. Springer Science and Business Media LLC. |
BibTeX:
@article{Virkkala2025,
author = {Virkkala, Anna-Maria and Rogers, Brendan M. and Watts, Jennifer D. and Arndt, Kyle A. and Potter, Stefano and Wargowsky, Isabel and Schuur, Edward A. G. and See, Craig R. and Mauritz, Marguerite and Boike, Julia and Bret-Harte, M. Syndonia and Burke, Eleanor J. and Burrell, Arden and Chae, Namyi and Chatterjee, Abhishek and Chevallier, Frederic and Christensen, Torben R. and Commane, Roisin and Dolman, Han and Edgar, Colin W. and Elberling, Bo and Emmerton, Craig A. and Euskirchen, Eugenie S. and Feng, Liang and Göckede, Mathias and Grelle, Achim and Helbig, Manuel and Holl, David and Järveoja, Järvi and Karsanaev, Sergey V. and Kobayashi, Hideki and Kutzbach, Lars and Liu, Junjie and Luijkx, Ingrid T. and López-Blanco, Efrén and Lunneberg, Kyle and Mammarella, Ivan and Marushchak, Maija E. and Mastepanov, Mikhail and Matsuura, Yojiro and Maximov, Trofim C. and Merbold, Lutz and Meyer, Gesa and Nilsson, Mats B. and Niwa, Yosuke and Oechel, Walter and Palmer, Paul I. and Park, Sang-Jong and Parmentier, Frans-Jan W. and Peichl, Matthias and Peters, Wouter and Petrov, Roman and Quinton, William and Rödenbeck, Christian and Sachs, Torsten and Schulze, Christopher and Sonnentag, Oliver and St. Louis, Vincent L. and Tuittila, Eeva-Stiina and Ueyama, Masahito and Varlagin, Andrej and Zona, Donatella and Natali, Susan M.},
title = {Wildfires offset the increasing but spatially heterogeneous Arctic–boreal CO2 uptake},
journal = {Nature Climate Change},
publisher = {Springer Science and Business Media LLC},
year = {2025},
volume = {15},
number = {2},
pages = {188--195},
doi = {10.1038/s41558-024-02234-5}
}
|
| Virkkala A-M, Wargowsky I, Vogt J, Kuhn MA, Madaan S, O’Keefe R, Windholz T, Arndt KA, Rogers BM, Watts JD, Kent K, Göckede M, Olefeldt D, Rocher-Ros G, Schuur EAG, Bastviken D, Aalstad K, Aho K, Ala-Könni J, Alcock H, Althuizen I, Arp CD, Asanuma J, Attermeyer K, Aurela M, Balathandayuthabani S, Barr A, Barret M, Batkhishig O, Biasi C, Björkman MP, Black A, Blanc-Betes E, Bodmer P, Boike J, Bolek A, Bouchard F, Bussmann I, Cabrol L, Canfora E, Carey S, Castro-Morales K, Chae N, Christen A, Christensen TR, Christiansen CT, Chu H, Clark G, Clayer F, Crill P, Cunada C, Davidson SJ, Dean JF, Dengel S, Detto M, Dieleman C, Domine F, Dyukarev E, Edgar C, Elberling B, Emmerton CA, Euskirchen E, Falvo G, Friborg T, Garneau M, Giamberini M, Glagolev MV, Gonzalez-Meler MA, Granath G, Guðmundsson J, Happonen K, Harazono Y, Harris L, Hashemi J, Hasson N, Heerah J, Heffernan L, Helbig M, Helgason W, Heliasz M, Henry G, Hensgens G, Hiyama T, Hock M, Holl D, Holmes B, Holst J, Holst T, Hould-Gosselin G, Humphreys E, Hung J, Huotari J, Ikawa H, Ilyasov DV, Ishikawa M, Iwahana G, Iwata H, Jackowicz-Korczynski MA, Jansen J, Järveoja J, Jassey VEJ, Jensen R, Jentzsch K, Jespersen RG, Johannesson C-F, Jones CP, Jonsson A, Jung JY, Juutinen S, Kane E, Karlsson J, Karsanaev S, Kasak K, Kelly J, Kempton K, Klaus M, Kling GW, Kljun N, Knutson J, Kobayashi H, Kochendorfer J, Kohonen K-M, Kolari P, Korkiakoski M, Korrensalo A, Kortelainen P, Koster E, Koster K, Kotani A, Krishnan P, Kurbatova J, Kutzbach L, Kwon MJ, Kyzivat ED, Lagroix J, Langhorst T, Lapshina E, Larmola T, Larsen KS, Laurion I, Ledman J, Lee H, Leffler AJ, Lesack L, Lindroth A, Lipson D, Lohila A, López-Blanco E, St. Louis VL, Lundin E, Luoto M, Machimura T, Magnani M, Malhotra A, Maljanen M, Mammarella I, Männistö E, Marchesini LB, Marsh P, Martkainen PJ, Marushchak ME, Mastepanov M, Mavrovic A, Maximov T, Minions C, Montemayor M, Morishita T, Murphy P, Nadeau DF, Nicholls E, Nilsson MB, Niyazova A, Nordén J, Noumonvi KD, Nykanen H, Oechel W, Ojala A, Okadera T, Pal S, Panov AV, Papakyriakou T, Papale D, Park S-J, Parmentier F-JW, Pastorello G, Peacock M, Peichl M, Petrov R, St. Pierre K, Pirk N, Plein J, Preskienis V, Prokushkin A, Pumpanen J, Rains HA, Rakos N, Räsänen A, Rautakoski H, Rinnan R, Rinne J, Rocha A, Roulet N, Roy A, Rutgersson A, Sabrekov AF, Sachs T, Sahlée E, Salazar A, Sawakuchi HO, Schulze C, Seco R, Sepulveda-Jauregui A, Serikova S, Serrone A, Silvennoinen HM, Sjogersten S, Skeeter J, Snöälv J, Sobek S, Sonnentag O, Stanley EH, Strack M, Strom L, Sullivan P, Sullivan R, Sytiuk A, Tagesson T, Taillardat P, Talbot J, Tank SE, Tenuta M, Terenteva I, Thalasso F, Thiboult A, Thorgeirsson H, Garcia Tigreros F, Torn M, Townsend-Small A, Treat C, Tremblay A, Trotta C, Tuittila E-S, Turetsky M, Ueyama M, Umair M, Vähä A, van Delden L, van Hardenbroek M, Varlagin A, Varner RK, Veretennikova E, Vesala T, Virtanen T, Voigt C, Vonk JE, Wagner R, Walter Anthony K, Wang Q, Watanabe M, Webb H, Welker JM, Westergaard-Nielsen A, Westermann S, White JR, Wille C, Williamson SN, Zolkos S, Zona D and Natali SM (2025), "ABCFlux v2: Arctic–boreal CO 2 and CH 4 monthly flux observations and ancillary information across terrestrial and freshwater ecosystems", October, 2025. Copernicus GmbH. |
BibTeX:
@article{Virkkala2025a,
author = {Virkkala, Anna-Maria and Wargowsky, Isabel and Vogt, Judith and Kuhn, McKenzie A. and Madaan, Simran and O’Keefe, Richard and Windholz, Tiffany and Arndt, Kyle A. and Rogers, Brendan M. and Watts, Jennifer D. and Kent, Kelcy and Göckede, Mathias and Olefeldt, David and Rocher-Ros, Gerard and Schuur, Edward A. G. and Bastviken, David and Aalstad, Kristoffer and Aho, Kelly and Ala-Könni, Joonatan and Alcock, Haley and Althuizen, Inge and Arp, Christopher D. and Asanuma, Jun and Attermeyer, Katrin and Aurela, Mika and Balathandayuthabani, Sivakiruthika and Barr, Alan and Barret, Maialen and Batkhishig, Ochirbat and Biasi, Christina and Björkman, Mats P. and Black, Andrew and Blanc-Betes, Elena and Bodmer, Pascal and Boike, Julia and Bolek, Abdullah and Bouchard, Frédéric and Bussmann, Ingeborg and Cabrol, Lea and Canfora, Eleonora and Carey, Sean and Castro-Morales, Karel and Chae, Namyi and Christen, Andres and Christensen, Torben R. and Christiansen, Casper T. and Chu, Housen and Clark, Graham and Clayer, Francois and Crill, Patrick and Cunada, Christopher and Davidson, Scott J. and Dean, Joshua F. and Dengel, Sigrid and Detto, Matteo and Dieleman, Catherine and Domine, Florent and Dyukarev, Egor and Edgar, Colin and Elberling, Bo and Emmerton, Craig A. and Euskirchen, Eugenie and Falvo, Grant and Friborg, Thomas and Garneau, Michelle and Giamberini, Mariasilvia and Glagolev, Mikhail V. and Gonzalez-Meler, Miquel A. and Granath, Gustaf and Guðmundsson, Jón and Happonen, Konsta and Harazono, Yoshinobu and Harris, Lorna and Hashemi, Josh and Hasson, Nicholas and Heerah, Janna and Heffernan, Liam and Helbig, Manuel and Helgason, Warren and Heliasz, Michal and Henry, Greg and Hensgens, Geert and Hiyama, Tetsuya and Hock, Macall and Holl, David and Holmes, Beth and Holst, Jutta and Holst, Thomas and Hould-Gosselin, Gabriel and Humphreys, Elyn and Hung, Jacqueline and Huotari, Jussi and Ikawa, Hiroki and Ilyasov, Danil V. and Ishikawa, Mamoru and Iwahana, Go and Iwata, Hiroki and Jackowicz-Korczynski, Marcin Antoni and Jansen, Joachim and Järveoja, Järvi and Jassey, Vincent E. J. and Jensen, Rasmus and Jentzsch, Katharina and Jespersen, Robert G. and Johannesson, Carl-Fredrik and Jones, Chersity P. and Jonsson, Anders and Jung, Ji Young and Juutinen, Sari and Kane, Evan and Karlsson, Jan and Karsanaev, Sergey and Kasak, Kuno and Kelly, Julia and Kempton, Kasha and Klaus, Marcus and Kling, George W. and Kljun, Natacha and Knutson, Jacqueline and Kobayashi, Hideki and Kochendorfer, John and Kohonen, Kukka-Maaria and Kolari, Pasi and Korkiakoski, Mika and Korrensalo, Aino and Kortelainen, Pirkko and Koster, Egle and Koster, Kajar and Kotani, Ayumi and Krishnan, Praveena and Kurbatova, Juliya and Kutzbach, Lars and Kwon, Min Jung and Kyzivat, Ethan D. and Lagroix, Jessica and Langhorst, Theodore and Lapshina, Elena and Larmola, Tuula and Larsen, Klaus S. and Laurion, Isabelle and Ledman, Justin and Lee, Hanna and Leffler, A. Joshua and Lesack, Lance and Lindroth, Anders and Lipson, David and Lohila, Annalea and López-Blanco, Efrén and St. Louis, Vincent L. and Lundin, Erik and Luoto, Misha and Machimura, Takashi and Magnani, Marta and Malhotra, Avni and Maljanen, Marja and Mammarella, Ivan and Männistö, Elisa and Marchesini, Luca Belelli and Marsh, Phil and Martkainen, Pertti J. and Marushchak, Maija E. and Mastepanov, Mikhail and Mavrovic, Alex and Maximov, Trofim and Minions, Christina and Montemayor, Marco and Morishita, Tomoaki and Murphy, Patrick and Nadeau, Daniel F. and Nicholls, Erin and Nilsson, Mats B. and Niyazova, Anastasia and Nordén, Jenni and Noumonvi, Koffi Dodji and Nykanen, Hannu and Oechel, Walter and Ojala, Anne and Okadera, Tomohiro and Pal, Sujan and Panov, Alexey V. and Papakyriakou, Tim and Papale, Dario and Park, Sang-Jong and Parmentier, Frans-Jan W. and Pastorello, Gilberto and Peacock, Mike and Peichl, Matthias and Petrov, Roman and St. Pierre, Kyra and Pirk, Norbert and Plein, Jessica and Preskienis, Vilmantas and Prokushkin, Anatoly and Pumpanen, Jukka and Rains, Hilary A. and Rakos, Niklas and Räsänen, Aleski and Rautakoski, Helena and Rinnan, Riika and Rinne, Janne and Rocha, Adrian and Roulet, Nigel and Roy, Alexandre and Rutgersson, Anna and Sabrekov, Aleksandr F. and Sachs, Torsten and Sahlée, Erik and Salazar, Alejandro and Sawakuchi, Henrique Oliveira and Schulze, Christopher and Seco, Roger and Sepulveda-Jauregui, Armando and Serikova, Svetlana and Serrone, Abbey and Silvennoinen, Hanna M. and Sjogersten, Sofie and Skeeter, June and Snöälv, Jo and Sobek, Sebastian and Sonnentag, Oliver and Stanley, Emily H. and Strack, Maria and Strom, Lena and Sullivan, Patrick and Sullivan, Ryan and Sytiuk, Anna and Tagesson, Torbern and Taillardat, Pierre and Talbot, Julie and Tank, Suzanne E. and Tenuta, Mario and Terenteva, Irina and Thalasso, Frederic and Thiboult, Antoine and Thorgeirsson, Halldor and Garcia Tigreros, Fenix and Torn, Margaret and Townsend-Small, Amy and Treat, Claire and Tremblay, Alain and Trotta, Carlo and Tuittila, Eeva-Stiina and Turetsky, Merritt and Ueyama, Masahito and Umair, Muhammad and Vähä, Aki and van Delden, Lona and van Hardenbroek, Maarten and Varlagin, Andrej and Varner, Ruth K. and Veretennikova, Elena and Vesala, Timo and Virtanen, Tarmo and Voigt, Carolina and Vonk, Jorien E. and Wagner, Robert and Walter Anthony, Katey and Wang, Qinxue and Watanabe, Masataka and Webb, Hailey and Welker, Jeffrey M. and Westergaard-Nielsen, Andreas and Westermann, Sebastian and White, Jeffrey R. and Wille, Christian and Williamson, Scott N. and Zolkos, Scott and Zona, Donatella and Natali, Susan M.},
title = {ABCFlux v2: Arctic–boreal CO 2 and CH 4 monthly flux observations and ancillary information across terrestrial and freshwater ecosystems},
publisher = {Copernicus GmbH},
year = {2025},
doi = {10.5194/essd-2025-585}
}
|
| Voggenreiter E, ThomasArrigo L, Bottaro M, Kilian J, Straub D, Ring‐Hrubesh F, Bryce C, Stahl M, Kappler A and Joshi P (2025), "Suppression of Methanogenesis by Microbial Reduction of Iron‐Organic Carbon Associations in Fully Thawed Permafrost Soil", Journal of Geophysical Research: Biogeosciences., March, 2025. Vol. 130(3) American Geophysical Union (AGU). |
BibTeX:
@article{Voggenreiter2025,
author = {Voggenreiter, E. and ThomasArrigo, L. and Bottaro, M. and Kilian, J. and Straub, D. and Ring‐Hrubesh, F. and Bryce, C. and Stahl, M. and Kappler, A. and Joshi, P.},
title = {Suppression of Methanogenesis by Microbial Reduction of Iron‐Organic Carbon Associations in Fully Thawed Permafrost Soil},
journal = {Journal of Geophysical Research: Biogeosciences},
publisher = {American Geophysical Union (AGU)},
year = {2025},
volume = {130},
number = {3},
doi = {10.1029/2024jg008650}
}
|
| Voggenreiter E, ThomasArrigo L, Kilian J, Straub D, Friedel M, Stahl M, Kappler A and Joshi P (2025), "Reduction of iron-organic carbon associations shifts net greenhouse gas release after initial permafrost thaw", Soil Biology and Biochemistry., April, 2025. Vol. 203, pp. 109735. Elsevier BV. |
BibTeX:
@article{Voggenreiter2025a,
author = {Voggenreiter, Eva and ThomasArrigo, Laurel and Kilian, Joachim and Straub, Daniel and Friedel, Maike and Stahl, Mark and Kappler, Andreas and Joshi, Prachi},
title = {Reduction of iron-organic carbon associations shifts net greenhouse gas release after initial permafrost thaw},
journal = {Soil Biology and Biochemistry},
publisher = {Elsevier BV},
year = {2025},
volume = {203},
pages = {109735},
doi = {10.1016/j.soilbio.2025.109735}
}
|
| Voshtani S, Jones DBA, Wunch D, Pendergrass DC, Wennberg PO, Pollard DF, Morino I, Ohyama H, Deutscher NM, Hase F, Sussmann R, Weidmann D, Kivi R, García O, Té Y, Chen J, Anderson K, Stevens R, Kondragunta S, Zhu A, Worthy D, Racki S, McKain K, Makarova MV, Jones N, Mahieu E, Cadena-Caicedo A, Cristofanelli P, Labuschagne C, Kozlova E, Seitz T, Steinbacher M, Mahdi R and Murata I (2025), "Quantifying CO emissions from boreal wildfires by assimilating TROPOMI and TCCON observations", Atmospheric Chemistry and Physics., November, 2025. Vol. 25(21), pp. 15527-15565. Copernicus GmbH. |
BibTeX:
@article{Voshtani2025,
author = {Voshtani, Sina and Jones, Dylan B. A. and Wunch, Debra and Pendergrass, Drew C. and Wennberg, Paul O. and Pollard, David F. and Morino, Isamu and Ohyama, Hirofumi and Deutscher, Nicholas M. and Hase, Frank and Sussmann, Ralf and Weidmann, Damien and Kivi, Rigel and García, Omaira and Té, Yao and Chen, Jack and Anderson, Kerry and Stevens, Robin and Kondragunta, Shobha and Zhu, Aihua and Worthy, Douglas and Racki, Senen and McKain, Kathryn and Makarova, Maria V. and Jones, Nicholas and Mahieu, Emmanuel and Cadena-Caicedo, Andrea and Cristofanelli, Paolo and Labuschagne, Casper and Kozlova, Elena and Seitz, Thomas and Steinbacher, Martin and Mahdi, Reza and Murata, Isao},
title = {Quantifying CO emissions from boreal wildfires by assimilating TROPOMI and TCCON observations},
journal = {Atmospheric Chemistry and Physics},
publisher = {Copernicus GmbH},
year = {2025},
volume = {25},
number = {21},
pages = {15527--15565},
doi = {10.5194/acp-25-15527-2025}
}
|
| de Vries A, Wohlfahrt G, Kohonen K, Abadie C, Remaud M, Kesselmeier J, Laasonen A, Whelan M, Mammarella I and Vesala T (2025), "The Contribution of Boreal Wetlands to the Northern Hemisphere Carbonyl Sulfide Sink", Geophysical Research Letters., June, 2025. Vol. 52(12) American Geophysical Union (AGU). |
BibTeX:
@article{Vries2025,
author = {de Vries, Anna and Wohlfahrt, Georg and Kohonen, Kukka‐Maaria and Abadie, Camille and Remaud, Marine and Kesselmeier, Jürgen and Laasonen, Asta and Whelan, Mary and Mammarella, Ivan and Vesala, Timo},
title = {The Contribution of Boreal Wetlands to the Northern Hemisphere Carbonyl Sulfide Sink},
journal = {Geophysical Research Letters},
publisher = {American Geophysical Union (AGU)},
year = {2025},
volume = {52},
number = {12},
doi = {10.1029/2024gl112858}
}
|
| Williams TKE, Moreno Martínez Á, Martinuzzi F, Mahecha MD and Camps-Valls G (2025), "Sub-seasonal forest carbon dynamics lose persistence under extremes", Environmental Research Letters., July, 2025. Vol. 20(8), pp. 084052. IOP Publishing. |
BibTeX:
@article{Williams2025,
author = {Williams, Tristan K E and Moreno Martínez, Álvaro and Martinuzzi, Francesco and Mahecha, Miguel D and Camps-Valls, Gustau},
title = {Sub-seasonal forest carbon dynamics lose persistence under extremes},
journal = {Environmental Research Letters},
publisher = {IOP Publishing},
year = {2025},
volume = {20},
number = {8},
pages = {084052},
doi = {10.1088/1748-9326/ade8ff}
}
|
| Yang S, Tang J, Li Z, Yuan K, Wu Q, Chang K-Y, Hodgkins SB, Wilson RM, Zhu Q, Grant RF, Riley WJ, Saleska SR, Rich VI and Varner RK (2025), "Unraveling the depth-dependent causal dynamics of methanogenesis and methanotrophy in a high-latitude fen peatland", Environmental Research Letters., February, 2025. Vol. 20(3), pp. 034005. IOP Publishing. |
BibTeX:
@article{Yang2025,
author = {Yang, Shuai and Tang, Jinyun and Li, Zhen and Yuan, Kunxiaojia and Wu, Qiong and Chang, Kuang-Yu and Hodgkins, Suzanne B and Wilson, Rachel M and Zhu, Qing and Grant, Robert F and Riley, William J and Saleska, Scott R and Rich, Virginia I and Varner, Ruth K},
title = {Unraveling the depth-dependent causal dynamics of methanogenesis and methanotrophy in a high-latitude fen peatland},
journal = {Environmental Research Letters},
publisher = {IOP Publishing},
year = {2025},
volume = {20},
number = {3},
pages = {034005},
doi = {10.1088/1748-9326/adaf44}
}
|
| Yazbeck T, Schlutow M, Bolek A, Triches NY, Wahl E, Heimann M and Göckede M (2025), "Quantifying landcover-specific fluxes over a heterogeneous landscape through coupling UAV-measured mixing ratios with a large-eddy simulation model and Eddy-covariance measurements", August, 2025. Copernicus GmbH. |
BibTeX:
@article{Yazbeck2025,
author = {Yazbeck, Theresia and Schlutow, Mark and Bolek, Abdullah and Triches, Nathalie Ylenia and Wahl, Elias and Heimann, Martin and Göckede, Mathias},
title = {Quantifying landcover-specific fluxes over a heterogeneous landscape through coupling UAV-measured mixing ratios with a large-eddy simulation model and Eddy-covariance measurements},
publisher = {Copernicus GmbH},
year = {2025},
doi = {10.5194/egusphere-2025-3791}
}
|
| Yazbeck T, Schlutow M, Bolek A, Triches NY, Wahl E, Heimann M and Göckede M (2025), "Quantifying landcover-specific fluxes over a heterogeneous landscape through coupling UAV-measured mixing ratios with a large-eddy simulation model and Eddy-covariance measurements", Atmospheric Measurement Techniques., November, 2025. Vol. 18(22), pp. 6917-6932. Copernicus GmbH. |
BibTeX:
@article{Yazbeck2025a,
author = {Yazbeck, Theresia and Schlutow, Mark and Bolek, Abdullah and Triches, Nathalie Ylenia and Wahl, Elias and Heimann, Martin and Göckede, Mathias},
title = {Quantifying landcover-specific fluxes over a heterogeneous landscape through coupling UAV-measured mixing ratios with a large-eddy simulation model and Eddy-covariance measurements},
journal = {Atmospheric Measurement Techniques},
publisher = {Copernicus GmbH},
year = {2025},
volume = {18},
number = {22},
pages = {6917--6932},
doi = {10.5194/amt-18-6917-2025}
}
|
| Ying Q, Poulter B, Watts JD, Arndt KA, Virkkala A-M, Bruhwiler L, Oh Y, Rogers BM, Natali SM, Sullivan H, Armstrong A, Ward EJ, Schiferl LD, Elder CD, Peltola O, Bartsch A, Desai AR, Euskirchen E, Göckede M, Lehner B, Nilsson MB, Peichl M, Sonnentag O, Tuittila E-S, Sachs T, Kalhori A, Ueyama M and Zhang Z (2025), "WetCH 4 : a machine-learning-based upscaling of methane fluxes of northern wetlands during 2016–2022", Earth System Science Data., June, 2025. Vol. 17(6), pp. 2507-2534. Copernicus GmbH. |
BibTeX:
@article{Ying2025,
author = {Ying, Qing and Poulter, Benjamin and Watts, Jennifer D. and Arndt, Kyle A. and Virkkala, Anna-Maria and Bruhwiler, Lori and Oh, Youmi and Rogers, Brendan M. and Natali, Susan M. and Sullivan, Hilary and Armstrong, Amanda and Ward, Eric J. and Schiferl, Luke D. and Elder, Clayton D. and Peltola, Olli and Bartsch, Annett and Desai, Ankur R. and Euskirchen, Eugénie and Göckede, Mathias and Lehner, Bernhard and Nilsson, Mats B. and Peichl, Matthias and Sonnentag, Oliver and Tuittila, Eeva-Stiina and Sachs, Torsten and Kalhori, Aram and Ueyama, Masahito and Zhang, Zhen},
title = {WetCH 4 : a machine-learning-based upscaling of methane fluxes of northern wetlands during 2016–2022},
journal = {Earth System Science Data},
publisher = {Copernicus GmbH},
year = {2025},
volume = {17},
number = {6},
pages = {2507--2534},
doi = {10.5194/essd-17-2507-2025}
}
|
| Zhang Z, Poulter B, Melton JR, Riley WJ, Allen GH, Beerling DJ, Bousquet P, Canadell JG, Fluet-Chouinard E, Ciais P, Gedney N, Hopcroft PO, Ito A, Jackson RB, Jain AK, Jensen K, Joos F, Kleinen T, Knox SH, Li T, Li X, Liu X, McDonald K, McNicol G, Miller PA, Müller J, Patra PK, Peng C, Peng S, Qin Z, Riggs RM, Saunois M, Sun Q, Tian H, Xu X, Yao Y, Xi Y, Zhang W, Zhu Q, Zhu Q and Zhuang Q (2025), "Ensemble estimates of global wetland methane emissions over 2000–2020", Biogeosciences., January, 2025. Vol. 22(1), pp. 305-321. Copernicus GmbH. |
BibTeX:
@article{Zhang2025,
author = {Zhang, Zhen and Poulter, Benjamin and Melton, Joe R. and Riley, William J. and Allen, George H. and Beerling, David J. and Bousquet, Philippe and Canadell, Josep G. and Fluet-Chouinard, Etienne and Ciais, Philippe and Gedney, Nicola and Hopcroft, Peter O. and Ito, Akihiko and Jackson, Robert B. and Jain, Atul K. and Jensen, Katherine and Joos, Fortunat and Kleinen, Thomas and Knox, Sara H. and Li, Tingting and Li, Xin and Liu, Xiangyu and McDonald, Kyle and McNicol, Gavin and Miller, Paul A. and Müller, Jurek and Patra, Prabir K. and Peng, Changhui and Peng, Shushi and Qin, Zhangcai and Riggs, Ryan M. and Saunois, Marielle and Sun, Qing and Tian, Hanqin and Xu, Xiaoming and Yao, Yuanzhi and Xi, Yi and Zhang, Wenxin and Zhu, Qing and Zhu, Qiuan and Zhuang, Qianlai},
title = {Ensemble estimates of global wetland methane emissions over 2000–2020},
journal = {Biogeosciences},
publisher = {Copernicus GmbH},
year = {2025},
volume = {22},
number = {1},
pages = {305--321},
doi = {10.5194/bg-22-305-2025}
}
|
| Zhang X, Peng H, Osterwalder S, Bishop K, Nilsson MB, Peichl M, Björn E and Zhu W (2025), "Limited response of boreal forest litterfall mercury deposition to declines in atmospheric mercury concentrations (1987–2000)", Environmental Pollution., October, 2025. Vol. 383, pp. 126901. Elsevier BV. |
BibTeX:
@article{Zhang2025a,
author = {Zhang, Xiangwen and Peng, Haijun and Osterwalder, Stefan and Bishop, Kevin and Nilsson, Mats B. and Peichl, Matthias and Björn, Erik and Zhu, Wei},
title = {Limited response of boreal forest litterfall mercury deposition to declines in atmospheric mercury concentrations (1987–2000)},
journal = {Environmental Pollution},
publisher = {Elsevier BV},
year = {2025},
volume = {383},
pages = {126901},
doi = {10.1016/j.envpol.2025.126901}
}
|
| Zignol F, Lidberg W, Greiser C, Larson J, Hoffrén R and Ågren AM (2025), "Controls on spatial and temporal variability of soil moisture across a heterogeneous boreal forest landscape", Hydrology and Earth System Sciences., October, 2025. Vol. 29(20), pp. 5493-5513. Copernicus GmbH. |
BibTeX:
@article{Zignol2025,
author = {Zignol, Francesco and Lidberg, William and Greiser, Caroline and Larson, Johannes and Hoffrén, Raúl and Ågren, Anneli M.},
title = {Controls on spatial and temporal variability of soil moisture across a heterogeneous boreal forest landscape},
journal = {Hydrology and Earth System Sciences},
publisher = {Copernicus GmbH},
year = {2025},
volume = {29},
number = {20},
pages = {5493--5513},
doi = {10.5194/hess-29-5493-2025}
}
|
| Zou J, Zhang Y, Tobin B, Saunders M, Cacciotti E, Benanti G and Osborne B (2025), "Contrasting effects of water deficits and rewetting on greenhouse gas emissions in two grassland and forest ecosystems", Agricultural and Forest Meteorology., March, 2025. Vol. 362, pp. 110396. Elsevier BV. |
BibTeX:
@article{Zou2025,
author = {Zou, Junliang and Zhang, Yun and Tobin, Brian and Saunders, Matthew and Cacciotti, Erica and Benanti, Giuseppi and Osborne, Bruce},
title = {Contrasting effects of water deficits and rewetting on greenhouse gas emissions in two grassland and forest ecosystems},
journal = {Agricultural and Forest Meteorology},
publisher = {Elsevier BV},
year = {2025},
volume = {362},
pages = {110396},
doi = {10.1016/j.agrformet.2025.110396}
}
|
| Adam B, Western LM, Mühle J, Choi H, Krummel PB, O’Doherty S, Young D, Stanley KM, Fraser PJ, Harth CM, Salameh PK, Weiss RF, Prinn RG, Kim J, Park H, Park S and Rigby M (2024), "Emissions of HFC-23 do not reflect commitments made under the Kigali Amendment", Communications Earth & Environment., December, 2024. Vol. 5(1) Springer Science and Business Media LLC. |
BibTeX:
@article{Adam2024,
author = {Adam, Ben and Western, Luke M. and Mühle, Jens and Choi, Haklim and Krummel, Paul B. and O’Doherty, Simon and Young, Dickon and Stanley, Kieran M. and Fraser, Paul J. and Harth, Christina M. and Salameh, Peter K. and Weiss, Ray F. and Prinn, Ronald G. and Kim, Jooil and Park, Hyeri and Park, Sunyoung and Rigby, Matt},
title = {Emissions of HFC-23 do not reflect commitments made under the Kigali Amendment},
journal = {Communications Earth & Environment},
publisher = {Springer Science and Business Media LLC},
year = {2024},
volume = {5},
number = {1},
doi = {10.1038/s43247-024-01946-y}
}
|
| Adame J, Padilla R, Gutierrez-Alvarez I, Bogeat J, Lopez A and Yela M (2024), "Greenhouse gases in the tall tower of El Arenosillo station in Southwestern Europe: First-year of measurements", Atmospheric Research., April, 2024. Vol. 299, pp. 107221. Elsevier BV. |
BibTeX:
@article{Adame2024,
author = {Adame, J.A. and Padilla, R. and Gutierrez-Alvarez, I. and Bogeat, J.A. and Lopez, A. and Yela, M.},
title = {Greenhouse gases in the tall tower of El Arenosillo station in Southwestern Europe: First-year of measurements},
journal = {Atmospheric Research},
publisher = {Elsevier BV},
year = {2024},
volume = {299},
pages = {107221},
doi = {10.1016/j.atmosres.2024.107221}
}
|
| Akter S, Huisman JA and Bogena HR (2024), "Estimating soil moisture from environmental gamma radiation monitoring data", Vadose Zone Journal., October, 2024. Vol. 23(6) Wiley. |
BibTeX:
@article{Akter2024,
author = {Akter, Sonia and Huisman, Johan Alexander and Bogena, Heye Reemt},
title = {Estimating soil moisture from environmental gamma radiation monitoring data},
journal = {Vadose Zone Journal},
publisher = {Wiley},
year = {2024},
volume = {23},
number = {6},
doi = {10.1002/vzj2.20384}
}
|
| Anav A, Sorrentino B, Collalti A, Paoletti E, Sicard P, Coulibaly F, Manzini J, Hoshika Y and De Marco A (2024), "Meteorological, chemical and biological evaluation of the coupled chemistry-climate WRF-Chem model from regional to urban scale. An impact-oriented application for human health", Environmental Research., September, 2024. Vol. 257, pp. 119401. Elsevier BV. |
BibTeX:
@article{Anav2024,
author = {Anav, Alessandro and Sorrentino, Beatrice and Collalti, Alessio and Paoletti, Elena and Sicard, Pierre and Coulibaly, Fatimatou and Manzini, Jacopo and Hoshika, Yasutomo and De Marco, Alessandra},
title = {Meteorological, chemical and biological evaluation of the coupled chemistry-climate WRF-Chem model from regional to urban scale. An impact-oriented application for human health},
journal = {Environmental Research},
publisher = {Elsevier BV},
year = {2024},
volume = {257},
pages = {119401},
doi = {10.1016/j.envres.2024.119401}
}
|
| Bange HW, Mongwe P, Shutler JD, Arévalo-Martínez DL, Bianchi D, Lauvset SK, Liu C, Löscher CR, Martins H, Rosentreter JA, Schmale O, Steinhoff T, Upstill-Goddard RC, Wanninkhof R, Wilson ST and Xie H (2024), "Advances in understanding of air–sea exchange and cycling of greenhouse gases in the upper ocean", Elem Sci Anth. Vol. 12(1) University of California Press. |
BibTeX:
@article{Bange2024,
author = {Bange, Hermann W. and Mongwe, Precious and Shutler, Jamie D. and Arévalo-Martínez, Damian L. and Bianchi, Daniele and Lauvset, Siv K. and Liu, Chunying and Löscher, Carolin R. and Martins, Helena and Rosentreter, Judith A. and Schmale, Oliver and Steinhoff, Tobias and Upstill-Goddard, Robert C. and Wanninkhof, Rik and Wilson, Samuel T. and Xie, Huixiang},
title = {Advances in understanding of air–sea exchange and cycling of greenhouse gases in the upper ocean},
journal = {Elem Sci Anth},
publisher = {University of California Press},
year = {2024},
volume = {12},
number = {1},
doi = {10.1525/elementa.2023.00044}
}
|
| Barczok M, Smith C, Kinsman-Costello L, Patzner M, Bryce C, Kappler A, Singer D and Herndon E (2024), "Iron transformation mediates phosphate retention across a permafrost thaw gradient", Communications Earth & Environment., October, 2024. Vol. 5(1) Springer Science and Business Media LLC. |
BibTeX:
@article{Barczok2024,
author = {Barczok, Maximilian and Smith, Chelsea and Kinsman-Costello, Lauren and Patzner, Monique and Bryce, Casey and Kappler, Andreas and Singer, David and Herndon, Elizabeth},
title = {Iron transformation mediates phosphate retention across a permafrost thaw gradient},
journal = {Communications Earth & Environment},
publisher = {Springer Science and Business Media LLC},
year = {2024},
volume = {5},
number = {1},
doi = {10.1038/s43247-024-01810-z}
}
|
| Barrios JM, Arboleda A, Dutra E, Trigo I and Gellens‐Meulenberghs F (2024), "Evapotranspiration and surface energy fluxes across Europe, Africa and Eastern South America throughout the operational life of the Meteosat second generation satellite", Geoscience Data Journal., January, 2024. Wiley. |
BibTeX:
@article{Barrios2024,
author = {Barrios, J. M. and Arboleda, A. and Dutra, E. and Trigo, I. and Gellens‐Meulenberghs, F.},
title = {Evapotranspiration and surface energy fluxes across Europe, Africa and Eastern South America throughout the operational life of the Meteosat second generation satellite},
journal = {Geoscience Data Journal},
publisher = {Wiley},
year = {2024},
doi = {10.1002/gdj3.235}
}
|
| Bayat B, Raj R, Graf A, Vereecken H and Montzka C (2024), "Comprehensive accuracy assessment of long-term geostationary SEVIRI-MSG evapotranspiration estimates across Europe", Remote Sensing of Environment., feb, 2024. Vol. 301, pp. 113875. Elsevier BV. |
BibTeX:
@article{Bayat2024,
author = {Bayat, Bagher and Raj, Rahul and Graf, Alexander and Vereecken, Harry and Montzka, Carsten},
title = {Comprehensive accuracy assessment of long-term geostationary SEVIRI-MSG evapotranspiration estimates across Europe},
journal = {Remote Sensing of Environment},
publisher = {Elsevier BV},
year = {2024},
volume = {301},
pages = {113875},
url = {http://dx.doi.org/10.1016/j.rse.2023.113875},
doi = {10.1016/j.rse.2023.113875}
}
|
| Baysinger M, Jentzsch K, Liebner S, Strauss J, Yang S and Treat CC (2024), "Anaerobic respiration in a boreal wetland and surrounding habitats, across a hydrological transect". |
BibTeX:
@misc{Baysinger2024,
author = {Baysinger, Mackenzie and Jentzsch, Katharina and Liebner, Susanne and Strauss, Jens and Yang, Sizhong and Treat, Claire C},
title = {Anaerobic respiration in a boreal wetland and surrounding habitats, across a hydrological transect},
publisher = {PANGAEA},
year = {2024},
doi = {10.1594/PANGAEA.964303}
}
|
| Baysinger MR, Liebner S, Strauss J, Yang S, Jentzsch K, Bartholomäus A and Treat CC (2024), "Anaerobic respiration and temperature response along a boreal hydrological transect on a slope from upland forest to peatland", March, 2024. Authorea, Inc.. |
BibTeX:
@article{Baysinger2024a,
author = {Baysinger, Mackenzie Rae and Liebner, Susanne and Strauss, Jens and Yang, Sizhong and Jentzsch, Katharina and Bartholomäus, Alexander and Treat, Claire Clark},
title = {Anaerobic respiration and temperature response along a boreal hydrological transect on a slope from upland forest to peatland},
publisher = {Authorea, Inc.},
year = {2024},
doi = {10.22541/essoar.170957468.81072167/v1}
}
|
| Bazzi H, Ciais P, Abbessi E, Makowski D, Santaren D, Ceschia E, Brut A, Tallec T, Buchmann N, Maier R, Acosta M, Loubet B, Buysse P, Léonard J, Bornet F, Fayad I, Lian J, Baghdadi N, Segura Barrero R, Brümmer C, Schmidt M, Heinesch B, Mauder M and Gruenwald T (2024), "Assimilating Sentinel-2 data in a modified vegetation photosynthesis and respiration model (VPRM) to improve the simulation of croplands CO2 fluxes in Europe", International Journal of Applied Earth Observation and Geoinformation., March, 2024. Vol. 127, pp. 103666. Elsevier BV. |
BibTeX:
@article{Bazzi2024,
author = {Bazzi, Hassan and Ciais, Philippe and Abbessi, Ezzeddine and Makowski, David and Santaren, Diego and Ceschia, Eric and Brut, Aurore and Tallec, Tiphaine and Buchmann, Nina and Maier, Regine and Acosta, Manuel and Loubet, Benjamin and Buysse, Pauline and Léonard, Joël and Bornet, Frédéric and Fayad, Ibrahim and Lian, Jinghui and Baghdadi, Nicolas and Segura Barrero, Ricard and Brümmer, Christian and Schmidt, Marius and Heinesch, Bernard and Mauder, Matthias and Gruenwald, Thomas},
title = {Assimilating Sentinel-2 data in a modified vegetation photosynthesis and respiration model (VPRM) to improve the simulation of croplands CO2 fluxes in Europe},
journal = {International Journal of Applied Earth Observation and Geoinformation},
publisher = {Elsevier BV},
year = {2024},
volume = {127},
pages = {103666},
doi = {10.1016/j.jag.2024.103666}
}
|
| Beauclaire Q, De Cannière S, Jonard F, Pezzetti N, Delhez L and Longdoz B (2024), "Modeling gross primary production and transpiration from sun-induced chlorophyll fluorescence using a mechanistic light-response approach", Remote Sensing of Environment., June, 2024. Vol. 307, pp. 114150. Elsevier BV. |
BibTeX:
@article{Beauclaire2024,
author = {Beauclaire, Quentin and De Cannière, Simon and Jonard, François and Pezzetti, Natacha and Delhez, Laura and Longdoz, Bernard},
title = {Modeling gross primary production and transpiration from sun-induced chlorophyll fluorescence using a mechanistic light-response approach},
journal = {Remote Sensing of Environment},
publisher = {Elsevier BV},
year = {2024},
volume = {307},
pages = {114150},
doi = {10.1016/j.rse.2024.114150}
}
|
| Behncke J, Landschützer P and Tanhua T (2024), "A detectable change in the air-sea CO2 flux estimate from sailboat measurements", Scientific Reports., February, 2024. Vol. 14(1) Springer Science and Business Media LLC. |
BibTeX:
@article{Behncke2024,
author = {Behncke, Jacqueline and Landschützer, Peter and Tanhua, Toste},
title = {A detectable change in the air-sea CO2 flux estimate from sailboat measurements},
journal = {Scientific Reports},
publisher = {Springer Science and Business Media LLC},
year = {2024},
volume = {14},
number = {1},
doi = {10.1038/s41598-024-53159-0}
}
|
| Bittig HC, Jacobs E, Neumann T and Rehder G (2024), "A regional pCO2 climatology of the Baltic Sea from in situ pCO2 observations and a model-based extrapolation approach", Earth System Science Data., February, 2024. Vol. 16(2), pp. 753-773. Copernicus GmbH. |
BibTeX:
@article{Bittig2024,
author = {Bittig, Henry C. and Jacobs, Erik and Neumann, Thomas and Rehder, Gregor},
title = {A regional pCO2 climatology of the Baltic Sea from in situ pCO2 observations and a model-based extrapolation approach},
journal = {Earth System Science Data},
publisher = {Copernicus GmbH},
year = {2024},
volume = {16},
number = {2},
pages = {753--773},
doi = {10.5194/essd-16-753-2024}
}
|
| Bolek A, Heimann M and Göckede M (2024), "UAV-based in situ measurements of CO2 and CH4 fluxes over complex natural ecosystems", Atmospheric Measurement Techniques., September, 2024. Vol. 17(18), pp. 5619-5636. Copernicus GmbH. |
BibTeX:
@article{Bolek2024,
author = {Bolek, Abdullah and Heimann, Martin and Göckede, Mathias},
title = {UAV-based in situ measurements of CO2 and CH4 fluxes over complex natural ecosystems},
journal = {Atmospheric Measurement Techniques},
publisher = {Copernicus GmbH},
year = {2024},
volume = {17},
number = {18},
pages = {5619--5636},
doi = {10.5194/amt-17-5619-2024}
}
|
| Bowling DR, Schädel C, Smith KR, Richardson AD, Bahn M, Arain MA, Varlagin A, Ouimette AP, Frank JM, Barr AG, Mammarella I, Šigut L, Foord V, Burns SP, Montagnani L, Litvak ME, Munger JW, Ikawa H, Hollinger DY, Blanken PD, Ueyama M, Matteucci G, Bernhofer C, Bohrer G, Iwata H, Ibrom A, Pilegaard K, Spittlehouse DL, Kobayashi H, Desai AR, Staebler RM and Black TA (2024), "Phenology of Photosynthesis in Winter‐Dormant Temperate and Boreal Forests: Long‐Term Observations From Flux Towers and Quantitative Evaluation of Phenology Models", Journal of Geophysical Research: Biogeosciences., April, 2024. Vol. 129(5) American Geophysical Union (AGU). |
BibTeX:
@article{Bowling2024,
author = {Bowling, David R. and Schädel, Christina and Smith, Kenneth R. and Richardson, Andrew D. and Bahn, Michael and Arain, M. Altaf and Varlagin, Andrej and Ouimette, Andrew P. and Frank, John M. and Barr, Alan G. and Mammarella, Ivan and Šigut, Ladislav and Foord, Vanessa and Burns, Sean P. and Montagnani, Leonardo and Litvak, Marcy E. and Munger, J. William and Ikawa, Hiroki and Hollinger, David Y. and Blanken, Peter D. and Ueyama, Masahito and Matteucci, Giorgio and Bernhofer, Christian and Bohrer, Gil and Iwata, Hiroki and Ibrom, Andreas and Pilegaard, Kim and Spittlehouse, David L. and Kobayashi, Hideki and Desai, Ankur R. and Staebler, Ralf M. and Black, T. Andrew},
title = {Phenology of Photosynthesis in Winter‐Dormant Temperate and Boreal Forests: Long‐Term Observations From Flux Towers and Quantitative Evaluation of Phenology Models},
journal = {Journal of Geophysical Research: Biogeosciences},
publisher = {American Geophysical Union (AGU)},
year = {2024},
volume = {129},
number = {5},
doi = {10.1029/2023jg007839}
}
|
| Brown F, Folberth G, Sitch S, Artaxo P, Bauters M, Boeckx P, Cheesman AW, Detto M, Komala N, Rizzo L, Rojas N, dos Santos Vieira I, Turnock S, Verbeeck H and Zambrano A (2024), "Performance evaluation of UKESM1 for surface ozone across the pan-tropics", Atmospheric Chemistry and Physics., November, 2024. Vol. 24(21), pp. 12537-12555. Copernicus GmbH. |
BibTeX:
@article{Brown2024,
author = {Brown, Flossie and Folberth, Gerd and Sitch, Stephen and Artaxo, Paulo and Bauters, Marijn and Boeckx, Pascal and Cheesman, Alexander W. and Detto, Matteo and Komala, Ninong and Rizzo, Luciana and Rojas, Nestor and dos Santos Vieira, Ines and Turnock, Steven and Verbeeck, Hans and Zambrano, Alfonso},
title = {Performance evaluation of UKESM1 for surface ozone across the pan-tropics},
journal = {Atmospheric Chemistry and Physics},
publisher = {Copernicus GmbH},
year = {2024},
volume = {24},
number = {21},
pages = {12537--12555},
doi = {10.5194/acp-24-12537-2024}
}
|
| Callejas-Rodelas JÁ, Knohl A, van Ramshorst J, Mammarella I and Markwitz C (2024), "Comparison between lower-cost and conventional eddy covariance setups for CO2 and evapotranspiration measurements above monocropping and agroforestry systems", Agricultural and Forest Meteorology., July, 2024. Vol. 354, pp. 110086. Elsevier BV. |
BibTeX:
@article{CallejasRodelas2024,
author = {Callejas-Rodelas, José Ángel and Knohl, Alexander and van Ramshorst, Justus and Mammarella, Ivan and Markwitz, Christian},
title = {Comparison between lower-cost and conventional eddy covariance setups for CO2 and evapotranspiration measurements above monocropping and agroforestry systems},
journal = {Agricultural and Forest Meteorology},
publisher = {Elsevier BV},
year = {2024},
volume = {354},
pages = {110086},
doi = {10.1016/j.agrformet.2024.110086}
}
|
| Cantoni C, De Vittor C, Faganeli J, Giani M, Kovač N, Malej A, Ogrinc N, Tamše S and Turk V (2024), "Carbonate system and acidification of the Adriatic Sea", Marine Chemistry., November, 2024. Vol. 267, pp. 104462. Elsevier BV. |
BibTeX:
@article{Cantoni2024,
author = {Cantoni, Carolina and De Vittor, Cinzia and Faganeli, Jadran and Giani, Michele and Kovač, Nives and Malej, Alenka and Ogrinc, Nives and Tamše, Samo and Turk, Valentina},
title = {Carbonate system and acidification of the Adriatic Sea},
journal = {Marine Chemistry},
publisher = {Elsevier BV},
year = {2024},
volume = {267},
pages = {104462},
doi = {10.1016/j.marchem.2024.104462}
}
|
| Carrasco-Molina T, Marzuoli R, Calatayud V, Simpson D, Gerosa G, Carrara A, Rábago I, Alonso R and González-Fernández I (2024), "Validation and parametrization of the soil moisture index for stomatal conductance modelling and flux-based ozone risk assessment of Mediterranean plant species", Agricultural and Forest Meteorology., July, 2024. Vol. 354, pp. 110080. Elsevier BV. |
BibTeX:
@article{CarrascoMolina2024,
author = {Carrasco-Molina, Tania and Marzuoli, Riccardo and Calatayud, Vicent and Simpson, David and Gerosa, Giacomo and Carrara, Arnaud and Rábago, Isaura and Alonso, Rocío and González-Fernández, Ignacio},
title = {Validation and parametrization of the soil moisture index for stomatal conductance modelling and flux-based ozone risk assessment of Mediterranean plant species},
journal = {Agricultural and Forest Meteorology},
publisher = {Elsevier BV},
year = {2024},
volume = {354},
pages = {110080},
doi = {10.1016/j.agrformet.2024.110080}
}
|
| Chauhan A, Patzner MS, Bhattacharyya A, Borch T, Fischer S, Obst M, ThomasArrigo LK, Kretzschmar R, Mansor M, Bryce C, Kappler A and Joshi P (2024), "Interactions between iron and carbon in permafrost thaw ponds", Science of The Total Environment., October, 2024. Vol. 946, pp. 174321. Elsevier BV. |
BibTeX:
@article{Chauhan2024,
author = {Chauhan, Ankita and Patzner, Monique S. and Bhattacharyya, Amrita and Borch, Thomas and Fischer, Stefan and Obst, Martin and ThomasArrigo, Laurel K. and Kretzschmar, Ruben and Mansor, Muammar and Bryce, Casey and Kappler, Andreas and Joshi, Prachi},
title = {Interactions between iron and carbon in permafrost thaw ponds},
journal = {Science of The Total Environment},
publisher = {Elsevier BV},
year = {2024},
volume = {946},
pages = {174321},
doi = {10.1016/j.scitotenv.2024.174321}
}
|
| Chen S, Liu L, Ma Y, Zhuang Q and Shurpali NJ (2024), "Quantifying Global Wetland Methane Emissions With In Situ Methane Flux Data and Machine Learning Approaches", Earth’s Future., October, 2024. Vol. 12(11) American Geophysical Union (AGU). |
BibTeX:
@article{Chen2024,
author = {Chen, Shuo and Liu, Licheng and Ma, Yuchi and Zhuang, Qianlai and Shurpali, Narasinha J.},
title = {Quantifying Global Wetland Methane Emissions With In Situ Methane Flux Data and Machine Learning Approaches},
journal = {Earth’s Future},
publisher = {American Geophysical Union (AGU)},
year = {2024},
volume = {12},
number = {11},
doi = {10.1029/2023ef004330}
}
|
| Cooper DLM, Lewis SL, Sullivan MJP, Prado PI, ter Steege H, Barbier N, Slik F, Sonké B, Ewango CEN, Adu-Bredu S, Affum-Baffoe K, de Aguiar DPP, Ahuite Reategui MA, Aiba S-I, Albuquerque BW, de Almeida Matos FD, Alonso A, Amani CA, do Amaral DD, do Amaral IL, Andrade A, de Andrade Miranda IP, Angoboy IB, Araujo-Murakami A, Arboleda NC, Arroyo L, Ashton P, Aymard C GA, Baider C, Baker TR, Balinga MPB, Balslev H, Banin LF, Bánki OS, Baraloto C, Barbosa EM, Barbosa FR, Barlow J, Bastin J-F, Beeckman H, Begne S, Bengone NN, Berenguer E, Berry N, Bitariho R, Boeckx P, Bogaert J, Bonyoma B, Boundja P, Bourland N, Boyemba Bosela F, Brambach F, Brienen R, Burslem DFRP, Camargo JL, Campelo W, Cano A, Cárdenas S, Cárdenas López D, de Sá Carpanedo R, Carrero Márquez YA, Carvalho FA, Casas LF, Castellanos H, Castilho CV, Cerón C, Chapman CA, Chave J, Chhang P, Chutipong W, Chuyong GB, Cintra BBL, Clark CJ, Coelho de Souza F, Comiskey JA, Coomes DA, Cornejo Valverde F, Correa DF, Costa FRC, Costa JBP, Couteron P, Culmsee H, Cuni-Sanchez A, Dallmeier F, Damasco G, Dauby G, Dávila N, Dávila Doza HP, De Alban JDT, de Assis RL, De Canniere C, De Haulleville T, de Jesus Veiga Carim M, Demarchi LO, Dexter KG, Di Fiore A, Din HHM, Disney MI, Djiofack BY, Djuikouo M-NK, Do TV, Doucet J-L, Draper FC, Droissart V, Duivenvoorden JF, Engel J, Estienne V, Farfan-Rios W, Fauset S, Feeley KJ, Feitosa YO, Feldpausch TR, Ferreira C, Ferreira J, Ferreira LV, Fletcher CD, Flores BM, Fofanah A, Foli EG, Fonty É, Fredriksson GM, Fuentes A, Galbraith D, Gallardo Gonzales GP, Garcia-Cabrera K, García-Villacorta R, Gomes VHF, Gómez RZ, Gonzales T, Gribel R, Guedes MC, Guevara JE, Hakeem KR, Hall JS, Hamer KC, Hamilton AC, Harris DJ, Harrison RD, Hart TB, Hector A, Henkel TW, Herbohn J, Hockemba MBN, Hoffman B, Holmgren M, Honorio Coronado EN, Huamantupa-Chuquimaco I, Hubau W, Imai N, Irume MV, Jansen PA, Jeffery KJ, Jimenez EM, Jucker T, Junqueira AB, Kalamandeen M, Kamdem NG, Kartawinata K, Kasongo Yakusu E, Katembo JM, Kearsley E, Kenfack D, Kessler M, Khaing TT, Killeen TJ, Kitayama K, Klitgaard B, Labrière N, Laumonier Y, Laurance SGW, Laurance WF, Laurent F, Le TC, Le TT, Leal ME, Leão de Moraes Novo EM, Levesley A, Libalah MB, Licona JC, Lima Filho DdA, Lindsell JA, Lopes A, Lopes MA, Lovett JC, Lowe R, Lozada JR, Lu X, Luambua NK, Luize BG, Maas P, Magalhães JLL, Magnusson WE, Mahayani NPD, Makana J-R, Malhi Y, Maniguaje Rincón L, Mansor A, Manzatto AG, Marimon BS, Marimon-Junior BH, Marshall AR, Martins MP, Mbayu FM, de Medeiros MB, Mesones I, Metali F, Mihindou V, Millet J, Milliken W, Mogollón HF, Molino J-F, Mohd. Said MN, Monteagudo Mendoza A, Montero JC, Moore S, Mostacedo B, Mozombite Pinto LF, Mukul SA, Munishi PKT, Nagamasu H, Nascimento HEM, Nascimento MT, Neill D, Nilus R, Noronha JC, Nsenga L, Núñez Vargas P, Ojo L, Oliveira AA, de Oliveira EA, Ondo FE, Palacios Cuenca W, Pansini S, Pansonato MP, Paredes MR, Paudel E, Pauletto D, Pearson RG, Pena JLM, Pennington RT, Peres CA, Permana A, Petronelli P, Peñuela Mora MC, Phillips JF, Phillips OL, Pickavance G, Piedade MTF, Pitman NCA, Ploton P, Popelier A, Poulsen JR, Prieto A, Primack RB, Priyadi H, Qie L, Quaresma AC, de Queiroz HL, Ramirez-Angulo H, Ramos JF, Reis NFC, Reitsma J, Revilla JDC, Riutta T, Rivas-Torres G, Robiansyah I, Rocha M, Rodrigues DdJ, Rodriguez-Ronderos ME, Rovero F, Rozak AH, Rudas A, Rutishauser E, Sabatier D, Sagang LB, Sampaio AF, Samsoedin I, Satdichanh M, Schietti J, Schöngart J, Scudeller VV, Seuaturien N, Sheil D, Sierra R, Silman MR, Silva TSF, da Silva Guimarães JR, Simo-Droissart M, Simon MF, Sist P, Sousa TR, de Sousa Farias E, de Souza Coelho L, Spracklen DV, Stas SM, Steinmetz R, Stevenson PR, Stropp J, Sukri RS, Sunderland TCH, Suzuki E, Swaine MD, Tang J, Taplin J, Taylor DM, Tello JS, Terborgh J, Texier N, Theilade I, Thomas DW, Thomas R, Thomas SC, Tirado M, Toirambe B, de Toledo JJ, Tomlinson KW, Torres-Lezama A, Tran HD, Tshibamba Mukendi J, Tumaneng RD, Umaña MN, Umunay PM, Urrego Giraldo LE, Valderrama Sandoval EH, Valenzuela Gamarra L, Van Andel TR, van de Bult M, van de Pol J, van der Heijden G, Vasquez R, Vela CIA, Venticinque EM, Verbeeck H, Veridiano RKA, Vicentini A, Vieira ICG, Vilanova Torre E, Villarroel D, Villa Zegarra BE, Vleminckx J, von Hildebrand P, Vos VA, Vriesendorp C, Webb EL, White LJT, Wich S, Wittmann F, Zagt R, Zang R, Zartman CE, Zemagho L, Zent EL and Zent S (2024), "Consistent patterns of common species across tropical tree communities", Nature., January, 2024. Vol. 625(7996), pp. 728-734. Springer Science and Business Media LLC. |
BibTeX:
@article{Cooper2024,
author = {Cooper, Declan L. M. and Lewis, Simon L. and Sullivan, Martin J. P. and Prado, Paulo I. and ter Steege, Hans and Barbier, Nicolas and Slik, Ferry and Sonké, Bonaventure and Ewango, Corneille E. N. and Adu-Bredu, Stephen and Affum-Baffoe, Kofi and de Aguiar, Daniel P. P. and Ahuite Reategui, Manuel Augusto and Aiba, Shin-Ichiro and Albuquerque, Bianca Weiss and de Almeida Matos, Francisca Dionízia and Alonso, Alfonso and Amani, Christian A. and do Amaral, Dário Dantas and do Amaral, Iêda Leão and Andrade, Ana and de Andrade Miranda, Ires Paula and Angoboy, Ilondea B. and Araujo-Murakami, Alejandro and Arboleda, Nicolás Castaño and Arroyo, Luzmila and Ashton, Peter and Aymard C, Gerardo A. and Baider, Cláudia and Baker, Timothy R. and Balinga, Michael Philippe Bessike and Balslev, Henrik and Banin, Lindsay F. and Bánki, Olaf S. and Baraloto, Chris and Barbosa, Edelcilio Marques and Barbosa, Flávia Rodrigues and Barlow, Jos and Bastin, Jean-Francois and Beeckman, Hans and Begne, Serge and Bengone, Natacha Nssi and Berenguer, Erika and Berry, Nicholas and Bitariho, Robert and Boeckx, Pascal and Bogaert, Jan and Bonyoma, Bernard and Boundja, Patrick and Bourland, Nils and Boyemba Bosela, Faustin and Brambach, Fabian and Brienen, Roel and Burslem, David F. R. P. and Camargo, José Luís and Campelo, Wegliane and Cano, Angela and Cárdenas, Sasha and Cárdenas López, Dairon and de Sá Carpanedo, Rainiellen and Carrero Márquez, Yrma Andreina and Carvalho, Fernanda Antunes and Casas, Luisa Fernanda and Castellanos, Hernán and Castilho, Carolina V. and Cerón, Carlos and Chapman, Colin A. and Chave, Jerome and Chhang, Phourin and Chutipong, Wanlop and Chuyong, George B. and Cintra, Bruno Barçante Ladvocat and Clark, Connie J. and Coelho de Souza, Fernanda and Comiskey, James A. and Coomes, David A. and Cornejo Valverde, Fernando and Correa, Diego F. and Costa, Flávia R. C. and Costa, Janaina Barbosa Pedrosa and Couteron, Pierre and Culmsee, Heike and Cuni-Sanchez, Aida and Dallmeier, Francisco and Damasco, Gabriel and Dauby, Gilles and Dávila, Nállarett and Dávila Doza, Hilda Paulette and De Alban, Jose Don T. and de Assis, Rafael L. and De Canniere, Charles and De Haulleville, Thales and de Jesus Veiga Carim, Marcelo and Demarchi, Layon O. and Dexter, Kyle G. and Di Fiore, Anthony and Din, Hazimah Haji Mohammad and Disney, Mathias I. and Djiofack, Brice Yannick and Djuikouo, Marie-Noël K. and Do, Tran Van and Doucet, Jean-Louis and Draper, Freddie C. and Droissart, Vincent and Duivenvoorden, Joost F. and Engel, Julien and Estienne, Vittoria and Farfan-Rios, William and Fauset, Sophie and Feeley, Kenneth J. and Feitosa, Yuri Oliveira and Feldpausch, Ted R. and Ferreira, Cid and Ferreira, Joice and Ferreira, Leandro Valle and Fletcher, Christine D. and Flores, Bernardo Monteiro and Fofanah, Alusine and Foli, Ernest G. and Fonty, Émile and Fredriksson, Gabriella M. and Fuentes, Alfredo and Galbraith, David and Gallardo Gonzales, George Pepe and Garcia-Cabrera, Karina and García-Villacorta, Roosevelt and Gomes, Vitor H. F. and Gómez, Ricardo Zárate and Gonzales, Therany and Gribel, Rogerio and Guedes, Marcelino Carneiro and Guevara, Juan Ernesto and Hakeem, Khalid Rehman and Hall, Jefferson S. and Hamer, Keith C. and Hamilton, Alan C. and Harris, David J. and Harrison, Rhett D. and Hart, Terese B. and Hector, Andy and Henkel, Terry W. and Herbohn, John and Hockemba, Mireille B. N. and Hoffman, Bruce and Holmgren, Milena and Honorio Coronado, Euridice N. and Huamantupa-Chuquimaco, Isau and Hubau, Wannes and Imai, Nobuo and Irume, Mariana Victória and Jansen, Patrick A. and Jeffery, Kathryn J. and Jimenez, Eliana M. and Jucker, Tommaso and Junqueira, André Braga and Kalamandeen, Michelle and Kamdem, Narcisse G. and Kartawinata, Kuswata and Kasongo Yakusu, Emmanuel and Katembo, John M. and Kearsley, Elizabeth and Kenfack, David and Kessler, Michael and Khaing, Thiri Toe and Killeen, Timothy J. and Kitayama, Kanehiro and Klitgaard, Bente and Labrière, Nicolas and Laumonier, Yves and Laurance, Susan G. W. and Laurance, William F. and Laurent, Félix and Le, Tinh Cong and Le, Trai Trong and Leal, Miguel E. and Leão de Moraes Novo, Evlyn Márcia and Levesley, Aurora and Libalah, Moses B. and Licona, Juan Carlos and Lima Filho, Diógenes de Andrade and Lindsell, Jeremy A. and Lopes, Aline and Lopes, Maria Aparecida and Lovett, Jon C. and Lowe, Richard and Lozada, José Rafael and Lu, Xinghui and Luambua, Nestor K. and Luize, Bruno Garcia and Maas, Paul and Magalhães, José Leonardo Lima and Magnusson, William E. and Mahayani, Ni Putu Diana and Makana, Jean-Remy and Malhi, Yadvinder and Maniguaje Rincón, Lorena and Mansor, Asyraf and Manzatto, Angelo Gilberto and Marimon, Beatriz S. and Marimon-Junior, Ben Hur and Marshall, Andrew R and Martins, Maria Pires and Mbayu, Faustin M. and de Medeiros, Marcelo Brilhante and Mesones, Italo and Metali, Faizah and Mihindou, Vianet and Millet, Jerome and Milliken, William and Mogollón, Hugo F. and Molino, Jean-François and Mohd. Said, Mohd. Nizam and Monteagudo Mendoza, Abel and Montero, Juan Carlos and Moore, Sam and Mostacedo, Bonifacio and Mozombite Pinto, Linder Felipe and Mukul, Sharif Ahmed and Munishi, Pantaleo K. T. and Nagamasu, Hidetoshi and Nascimento, Henrique Eduardo Mendonça and Nascimento, Marcelo Trindade and Neill, David and Nilus, Reuben and Noronha, Janaína Costa and Nsenga, Laurent and Núñez Vargas, Percy and Ojo, Lucas and Oliveira, Alexandre A. and de Oliveira, Edmar Almeida and Ondo, Fidèle Evouna and Palacios Cuenca, Walter and Pansini, Susamar and Pansonato, Marcelo Petratti and Paredes, Marcos Ríos and Paudel, Ekananda and Pauletto, Daniela and Pearson, Richard G. and Pena, José Luis Marcelo and Pennington, R. Toby and Peres, Carlos A. and Permana, Andrea and Petronelli, Pascal and Peñuela Mora, Maria Cristina and Phillips, Juan Fernando and Phillips, Oliver L. and Pickavance, Georgia and Piedade, Maria Teresa Fernandez and Pitman, Nigel C. A. and Ploton, Pierre and Popelier, Andreas and Poulsen, John R. and Prieto, Adriana and Primack, Richard B. and Priyadi, Hari and Qie, Lan and Quaresma, Adriano Costa and de Queiroz, Helder Lima and Ramirez-Angulo, Hirma and Ramos, José Ferreira and Reis, Neidiane Farias Costa and Reitsma, Jan and Revilla, Juan David Cardenas and Riutta, Terhi and Rivas-Torres, Gonzalo and Robiansyah, Iyan and Rocha, Maira and Rodrigues, Domingos de Jesus and Rodriguez-Ronderos, M. Elizabeth and Rovero, Francesco and Rozak, Andes H. and Rudas, Agustín and Rutishauser, Ervan and Sabatier, Daniel and Sagang, Le Bienfaiteur and Sampaio, Adeilza Felipe and Samsoedin, Ismayadi and Satdichanh, Manichanh and Schietti, Juliana and Schöngart, Jochen and Scudeller, Veridiana Vizoni and Seuaturien, Naret and Sheil, Douglas and Sierra, Rodrigo and Silman, Miles R. and Silva, Thiago Sanna Freire and da Silva Guimarães, José Renan and Simo-Droissart, Murielle and Simon, Marcelo Fragomeni and Sist, Plinio and Sousa, Thaiane R. and de Sousa Farias, Emanuelle and de Souza Coelho, Luiz and Spracklen, Dominick V. and Stas, Suzanne M. and Steinmetz, Robert and Stevenson, Pablo R. and Stropp, Juliana and Sukri, Rahayu S. and Sunderland, Terry C. H. and Suzuki, Eizi and Swaine, Michael D. and Tang, Jianwei and Taplin, James and Taylor, David M. and Tello, J. Sebastián and Terborgh, John and Texier, Nicolas and Theilade, Ida and Thomas, Duncan W. and Thomas, Raquel and Thomas, Sean C. and Tirado, Milton and Toirambe, Benjamin and de Toledo, José Julio and Tomlinson, Kyle W. and Torres-Lezama, Armando and Tran, Hieu Dang and Tshibamba Mukendi, John and Tumaneng, Roven D. and Umaña, Maria Natalia and Umunay, Peter M. and Urrego Giraldo, Ligia Estela and Valderrama Sandoval, Elvis H. and Valenzuela Gamarra, Luis and Van Andel, Tinde R. and van de Bult, Martin and van de Pol, Jaqueline and van der Heijden, Geertje and Vasquez, Rodolfo and Vela, César I. A. and Venticinque, Eduardo Martins and Verbeeck, Hans and Veridiano, Rizza Karen A. and Vicentini, Alberto and Vieira, Ima Célia Guimarães and Vilanova Torre, Emilio and Villarroel, Daniel and Villa Zegarra, Boris Eduardo and Vleminckx, Jason and von Hildebrand, Patricio and Vos, Vincent Antoine and Vriesendorp, Corine and Webb, Edward L. and White, Lee J. T. and Wich, Serge and Wittmann, Florian and Zagt, Roderick and Zang, Runguo and Zartman, Charles Eugene and Zemagho, Lise and Zent, Egleé L. and Zent, Stanford},
title = {Consistent patterns of common species across tropical tree communities},
journal = {Nature},
publisher = {Springer Science and Business Media LLC},
year = {2024},
volume = {625},
number = {7996},
pages = {728--734},
doi = {10.1038/s41586-023-06820-z}
}
|
| Cristofanelli P, Trisolino P, Calzolari F, Busetto M, Calidonna CR, Amendola S, Arduini J, Fratticioli C, Hundal RA, Maione M, Marcucci F, Marinoni A, Montaguti S, Renzi L, Roccato F, Bonasoni P and Putero D (2024), "Influence of wildfire emissions to carbon dioxide (CO2) observed at the Mt. Cimone station (Italy, 2165 m asl): A multi-year investigation", Atmospheric Environment., August, 2024. Vol. 330, pp. 120577. Elsevier BV. |
BibTeX:
@article{Cristofanelli2024,
author = {Cristofanelli, Paolo and Trisolino, Pamela and Calzolari, Francescopiero and Busetto, Maurizio and Calidonna, Claudia Roberta and Amendola, Stefano and Arduini, Jgor and Fratticioli, Cosimo and Hundal, Rabia Ali and Maione, Michela and Marcucci, Francesca and Marinoni, Angela and Montaguti, Simonetta and Renzi, Laura and Roccato, Fabrizio and Bonasoni, Paolo and Putero, Davide},
title = {Influence of wildfire emissions to carbon dioxide (CO2) observed at the Mt. Cimone station (Italy, 2165 m asl): A multi-year investigation},
journal = {Atmospheric Environment},
publisher = {Elsevier BV},
year = {2024},
volume = {330},
pages = {120577},
doi = {10.1016/j.atmosenv.2024.120577}
}
|
| Daelman R, Bauters M, Barthel M, Bulonza E, Lefevre L, Mbifo J, Six J, Butterbach-Bahl K, Wolf B, Kiese R and Boeckx P (2024), "Spatiotemporal variability of CO2, N2O and CH4 fluxes from a semi-deciduous tropical forest soil in the Congo basin", August, 2024. Copernicus GmbH. |
BibTeX:
@article{Daelman2024,
author = {Daelman, Roxanne and Bauters, Marijn and Barthel, Matti and Bulonza, Emmanuel and Lefevre, Lodewijk and Mbifo, José and Six, Johan and Butterbach-Bahl, Klaus and Wolf, Benjamin and Kiese, Ralf and Boeckx, Pascal},
title = {Spatiotemporal variability of CO2, N2O and CH4 fluxes from a semi-deciduous tropical forest soil in the Congo basin},
publisher = {Copernicus GmbH},
year = {2024},
doi = {10.5194/egusphere-2024-2346}
}
|
| Delpierre N, Garnier S, Treuil‐Dussouet H, Hufkens K, Lin J, Beier C, Bell M, Berveiller D, Cuntz M, Curioni G, Dahlin K, Denham SO, Desai AR, Domec J, Hart KM, Ibrom A, Joetzjer E, King J, Klosterhalfen A, Koebsch F, McHale P, Morfin A, Munger JW, Noormets A, Pilegaard K, Pohl F, Rebmann C, Richardson AD, Rothstein D, Schwartz MD, Wilkinson M and Soudani K (2024), "Phenology Across Scales: An Intercontinental Analysis of Leaf‐Out Dates in Temperate Deciduous Tree Communities", Global Ecology and Biogeography., October, 2024. Vol. 33(12) Wiley. |
BibTeX:
@article{Delpierre2024,
author = {Delpierre, Nicolas and Garnier, Suzon and Treuil‐Dussouet, Hugo and Hufkens, Koen and Lin, Jianhong and Beier, Colin and Bell, Michael and Berveiller, Daniel and Cuntz, Matthias and Curioni, Giulio and Dahlin, Kyla and Denham, Sander O. and Desai, Ankur R. and Domec, Jean‐Christophe and Hart, Kris M. and Ibrom, Andreas and Joetzjer, Emilie and King, John and Klosterhalfen, Anne and Koebsch, Franziska and McHale, Patrick and Morfin, Alexandre and Munger, J. William and Noormets, Asko and Pilegaard, Kim and Pohl, Felix and Rebmann, Corinna and Richardson, Andrew D. and Rothstein, David and Schwartz, Mark D. and Wilkinson, Matthew and Soudani, Kamel},
title = {Phenology Across Scales: An Intercontinental Analysis of Leaf‐Out Dates in Temperate Deciduous Tree Communities},
journal = {Global Ecology and Biogeography},
publisher = {Wiley},
year = {2024},
volume = {33},
number = {12},
doi = {10.1111/geb.13910}
}
|
| De Luca G, Papp M, Fóti S, Posta K, Mészáros Á, Pintér K, Nagy Z, Péli ER, Fekete S and Balogh J (2024), "Mycorrhizal fungi respiration dynamics in relation to gross primary production in a Hungarian dry grassland", Plant and Soil., February, 2024. Springer Science and Business Media LLC. |
BibTeX:
@article{DeLuca2024,
author = {De Luca, Giulia and Papp, Marianna and Fóti, Szilvia and Posta, Katalin and Mészáros, Ádám and Pintér, Krisztina and Nagy, Zoltán and Péli, Evelin Ramóna and Fekete, Sándor and Balogh, János},
title = {Mycorrhizal fungi respiration dynamics in relation to gross primary production in a Hungarian dry grassland},
journal = {Plant and Soil},
publisher = {Springer Science and Business Media LLC},
year = {2024},
doi = {10.1007/s11104-024-06557-2}
}
|
| Derwent RG, Parrish DD, Manning AJ, Spain TG, Simmonds PG and O’Doherty S (2024), "Ozone at Mace Head, Ireland from 1987 to 2021: Declining baselines, phase-out of European regional pollution, COVID-19 impacts", Atmospheric Environment., March, 2024. Vol. 320, pp. 120322. Elsevier BV. |
BibTeX:
@article{Derwent2024,
author = {Derwent, Richard G. and Parrish, David D. and Manning, Alistair J. and Spain, T. Gerard and Simmonds, Peter G. and O’Doherty, Simon},
title = {Ozone at Mace Head, Ireland from 1987 to 2021: Declining baselines, phase-out of European regional pollution, COVID-19 impacts},
journal = {Atmospheric Environment},
publisher = {Elsevier BV},
year = {2024},
volume = {320},
pages = {120322},
doi = {10.1016/j.atmosenv.2023.120322}
}
|
| Dowd E, Manning AJ, Orth-Lashley B, Girard M, France J, Fisher RE, Lowry D, Lanoisellé M, Pitt JR, Stanley KM, O’Doherty S, Young D, Thistlethwaite G, Chipperfield MP, Gloor E and Wilson C (2024), "First validation of high-resolution satellite-derived methane emissions from an active gas leak in the UK", Atmospheric Measurement Techniques., March, 2024. Vol. 17(5), pp. 1599-1615. Copernicus GmbH. |
BibTeX:
@article{Dowd2024,
author = {Dowd, Emily and Manning, Alistair J. and Orth-Lashley, Bryn and Girard, Marianne and France, James and Fisher, Rebecca E. and Lowry, Dave and Lanoisellé, Mathias and Pitt, Joseph R. and Stanley, Kieran M. and O’Doherty, Simon and Young, Dickon and Thistlethwaite, Glen and Chipperfield, Martyn P. and Gloor, Emanuel and Wilson, Chris},
title = {First validation of high-resolution satellite-derived methane emissions from an active gas leak in the UK},
journal = {Atmospheric Measurement Techniques},
publisher = {Copernicus GmbH},
year = {2024},
volume = {17},
number = {5},
pages = {1599--1615},
doi = {10.5194/amt-17-1599-2024}
}
|
| Dukat P, Hölttä T, Oren R, Salmon Y, Urbaniak M, Vesala T, Aalto J and Lintunen A (2024), "Partitioning seasonal stem carbon dioxide efflux into stem respiration, bark photosynthesis, and transport-related flux in Scots pine", Journal of Experimental Botany., May, 2024. Vol. 75(16), pp. 4944-4959. Oxford University Press (OUP). |
BibTeX:
@article{Dukat2024,
author = {Dukat, Paulina and Hölttä, Teemu and Oren, Ram and Salmon, Yann and Urbaniak, Marek and Vesala, Timo and Aalto, Juho and Lintunen, Anna},
editor = {Rogers, Alistair},
title = {Partitioning seasonal stem carbon dioxide efflux into stem respiration, bark photosynthesis, and transport-related flux in Scots pine},
journal = {Journal of Experimental Botany},
publisher = {Oxford University Press (OUP)},
year = {2024},
volume = {75},
number = {16},
pages = {4944--4959},
doi = {10.1093/jxb/erae242}
}
|
| Faassen KAP, Vilà-Guerau de Arellano J, González-Armas R, Heusinkveld BG, Mammarella I, Peters W and Luijkx IT (2024), "Separating above-canopy CO2 and O2 measurements into their atmospheric and biospheric signatures", Biogeosciences., June, 2024. Vol. 21(12), pp. 3015-3039. Copernicus GmbH. |
BibTeX:
@article{Faassen2024,
author = {Faassen, Kim A. P. and Vilà-Guerau de Arellano, Jordi and González-Armas, Raquel and Heusinkveld, Bert G. and Mammarella, Ivan and Peters, Wouter and Luijkx, Ingrid T.},
title = {Separating above-canopy CO2 and O2 measurements into their atmospheric and biospheric signatures},
journal = {Biogeosciences},
publisher = {Copernicus GmbH},
year = {2024},
volume = {21},
number = {12},
pages = {3015--3039},
doi = {10.5194/bg-21-3015-2024}
}
|
| Feig G, Brümmer C, Maluleke A and Midgley G (2024), "Research Infrastructures as Anchor Points for Long-Term Environmental Observation", In Sustainability of Southern African Ecosystems under Global Change. , pp. 881-902. Springer International Publishing. |
BibTeX:
@inbook{Feig2024,
author = {Feig, Gregor and Brümmer, Christian and Maluleke, Amukelani and Midgley, Guy F.},
title = {Research Infrastructures as Anchor Points for Long-Term Environmental Observation},
booktitle = {Sustainability of Southern African Ecosystems under Global Change},
publisher = {Springer International Publishing},
year = {2024},
pages = {881--902},
doi = {10.1007/978-3-031-10948-5_30}
}
|
| Fenner D, Christen A, Grimmond S, Meier F, Morrison W, Zeeman M, Barlow J, Birkmann J, Blunn L, Chrysoulakis N, Clements M, Glazer R, Hertwig D, Kotthaus S, König K, Looschelders D, Mitraka Z, Poursanidis D, Tsirantonakis D, Bechtel B, Benjamin K, Beyrich F, Briegel F, Feigel G, Gertsen C, Iqbal N, Kittner J, Lean H, Liu Y, Luo Z, McGrory M, Metzger S, Paskin M, Ravan M, Ruhtz T, Saunders B, Scherer D, Smith ST, Stretton M, Trachte K and Van Hove M (2024), "urbisphere-Berlin Campaign: Investigating Multiscale Urban Impacts on the Atmospheric Boundary Layer", Bulletin of the American Meteorological Society., October, 2024. Vol. 105(10), pp. E1929-E1961. American Meteorological Society. |
BibTeX:
@article{Fenner2024,
author = {Fenner, Daniel and Christen, Andreas and Grimmond, Sue and Meier, Fred and Morrison, William and Zeeman, Matthias and Barlow, Janet and Birkmann, Jörn and Blunn, Lewis and Chrysoulakis, Nektarios and Clements, Matthew and Glazer, Russell and Hertwig, Denise and Kotthaus, Simone and König, Kai and Looschelders, Dana and Mitraka, Zina and Poursanidis, Dimitris and Tsirantonakis, Dimitris and Bechtel, Benjamin and Benjamin, Kit and Beyrich, Frank and Briegel, Ferdinand and Feigel, Gregor and Gertsen, Carlotta and Iqbal, Nimra and Kittner, Jonas and Lean, Humphrey and Liu, Yiqing and Luo, Zhiwen and McGrory, Megan and Metzger, Swen and Paskin, Matthew and Ravan, Marvin and Ruhtz, Thomas and Saunders, Bethany and Scherer, Dieter and Smith, Stefan Thor and Stretton, Megan and Trachte, Katja and Van Hove, Melania},
title = {urbisphere-Berlin Campaign: Investigating Multiscale Urban Impacts on the Atmospheric Boundary Layer},
journal = {Bulletin of the American Meteorological Society},
publisher = {American Meteorological Society},
year = {2024},
volume = {105},
number = {10},
pages = {E1929--E1961},
doi = {10.1175/bams-d-23-0030.1}
}
|
| Forsmark B, Bizjak T, Nordin A, Rosenstock NP, Wallander H and Gundale MJ (2024), "Shifts in microbial community composition and metabolism correspond with rapid soil carbon accumulation in response to 20 years of simulated nitrogen deposition", Science of The Total Environment., March, 2024. Vol. 918, pp. 170741. Elsevier BV. |
BibTeX:
@article{Forsmark2024,
author = {Forsmark, Benjamin and Bizjak, Tinkara and Nordin, Annika and Rosenstock, Nicholas P. and Wallander, Håkan and Gundale, Michael J.},
title = {Shifts in microbial community composition and metabolism correspond with rapid soil carbon accumulation in response to 20 years of simulated nitrogen deposition},
journal = {Science of The Total Environment},
publisher = {Elsevier BV},
year = {2024},
volume = {918},
pages = {170741},
doi = {10.1016/j.scitotenv.2024.170741}
}
|
| Freire-Zapata V, Holland-Moritz H, Cronin DR, Aroney S, Smith DA, Wilson RM, Ernakovich JG, Woodcroft BJ, Bagby SC, Hodgkins SB, Mondav R, E. Cross J, Fahnestock MF, Ferriere R, Ibba M, Saleska SR, Varner RK, Zayed AA, Rich VI, Sullivan MB, Stegen JC and Tfaily MM (2024), "Microbiome–metabolite linkages drive greenhouse gas dynamics over a permafrost thaw gradient", Nature Microbiology., October, 2024. Vol. 9(11), pp. 2892-2908. Springer Science and Business Media LLC. |
BibTeX:
@article{FreireZapata2024,
author = {Freire-Zapata, Viviana and Holland-Moritz, Hannah and Cronin, Dylan R. and Aroney, Sam and Smith, Derek A. and Wilson, Rachel M. and Ernakovich, Jessica G. and Woodcroft, Ben J. and Bagby, Sarah C. and Hodgkins, Suzanne B. and Mondav, Rhiannon and E. Cross, Jennifer and Fahnestock, Maria Florencia and Ferriere, Regis and Ibba, Michael and Saleska, Scott R. and Varner, Ruth K. and Zayed, Ahmed A. and Rich, Virginia I. and Sullivan, Matthew B. and Stegen, James C. and Tfaily, Malak M.},
title = {Microbiome–metabolite linkages drive greenhouse gas dynamics over a permafrost thaw gradient},
journal = {Nature Microbiology},
publisher = {Springer Science and Business Media LLC},
year = {2024},
volume = {9},
number = {11},
pages = {2892--2908},
doi = {10.1038/s41564-024-01800-z}
}
|
| Friedlingstein P, O’Sullivan M, Jones MW, Andrew RM, Hauck J, Landschützer P, Le Quéré C, Li H, Luijkx IT, Olsen A, Peters GP, Peters W, Pongratz J, Schwingshackl C, Sitch S, Canadell JG, Ciais P, Jackson RB, Alin SR, Arneth A, Arora V, Bates NR, Becker M, Bellouin N, Berghoff CF, Bittig HC, Bopp L, Cadule P, Campbell K, Chamberlain MA, Chandra N, Chevallier F, Chini LP, Colligan T, Decayeux J, Djeutchouang L, Dou X, Duran Rojas C, Enyo K, Evans W, Fay A, Feely RA, Ford DJ, Foster A, Gasser T, Gehlen M, Gkritzalis T, Grassi G, Gregor L, Gruber N, Gürses Ö, Harris I, Hefner M, Heinke J, Hurtt GC, Iida Y, Ilyina T, Jacobson AR, Jain A, Jarníková T, Jersild A, Jiang F, Jin Z, Kato E, Keeling RF, Klein Goldewijk K, Knauer J, Korsbakken JI, Lauvset SK, Lefèvre N, Liu Z, Liu J, Ma L, Maksyutov S, Marland G, Mayot N, McGuire P, Metzl N, Monacci NM, Morgan EJ, Nakaoka S-I, Neill C, Niwa Y, Nützel T, Olivier L, Ono T, Palmer PI, Pierrot D, Qin Z, Resplandy L, Roobaert A, Rosan TM, Rödenbeck C, Schwinger J, Smallman TL, Smith S, Sospedra-Alfonso R, Steinhoff T, Sun Q, Sutton AJ, Séférian R, Takao S, Tatebe H, Tian H, Tilbrook B, Torres O, Tourigny E, Tsujino H, Tubiello F, van der Werf G, Wanninkhof R, Wang X, Yang D, Yang X, Yu Z, Yuan W, Yue X, Zaehle S, Zeng N and Zeng J (2024), "Global Carbon Budget 2024", Earth System Science Data., November, 2024. Copernicus GmbH. |
BibTeX:
@article{Friedlingstein2024,
author = {Friedlingstein, Pierre and O’Sullivan, Michael and Jones, Matthew W. and Andrew, Robbie M. and Hauck, Judith and Landschützer, Peter and Le Quéré, Corinne and Li, Hongmei and Luijkx, Ingrid T. and Olsen, Are and Peters, Glen P. and Peters, Wouter and Pongratz, Julia and Schwingshackl, Clemens and Sitch, Stephen and Canadell, Josep G. and Ciais, Philippe and Jackson, Robert B. and Alin, Simone R. and Arneth, Almut and Arora, Vivek and Bates, Nicholas R. and Becker, Meike and Bellouin, Nicolas and Berghoff, Carla F. and Bittig, Henry C. and Bopp, Laurent and Cadule, Patricia and Campbell, Katie and Chamberlain, Matthew A. and Chandra, Naveen and Chevallier, Frédéric and Chini, Louise P. and Colligan, Thomas and Decayeux, Jeanne and Djeutchouang, Laique and Dou, Xinyu and Duran Rojas, Carolina and Enyo, Kazutaka and Evans, Wiley and Fay, Amanda and Feely, Richard A. and Ford, Daniel J. and Foster, Adrianna and Gasser, Thomas and Gehlen, Marion and Gkritzalis, Thanos and Grassi, Giacomo and Gregor, Luke and Gruber, Nicolas and Gürses, Özgür and Harris, Ian and Hefner, Matthew and Heinke, Jens and Hurtt, George C. and Iida, Yosuke and Ilyina, Tatiana and Jacobson, Andrew R. and Jain, Atul and Jarníková, Tereza and Jersild, Annika and Jiang, Fei and Jin, Zhe and Kato, Etsushi and Keeling, Ralph F. and Klein Goldewijk, Kees and Knauer, Jürgen and Korsbakken, Jan Ivar and Lauvset, Siv K. and Lefèvre, Nathalie and Liu, Zhu and Liu, Junjie and Ma, Lei and Maksyutov, Shamil and Marland, Gregg and Mayot, Nicolas and McGuire, Patrick and Metzl, Nicolas and Monacci, Natalie M. and Morgan, Eric J. and Nakaoka, Shin-Ichiro and Neill, Craig and Niwa, Yosuke and Nützel, Tobias and Olivier, Lea and Ono, Tsuneo and Palmer, Paul I. and Pierrot, Denis and Qin, Zhangcai and Resplandy, Laure and Roobaert, Alizée and Rosan, Thais M. and Rödenbeck, Christian and Schwinger, Jörg and Smallman, T. Luke and Smith, Stephen and Sospedra-Alfonso, Reinel and Steinhoff, Tobias and Sun, Qing and Sutton, Adrienne J. and Séférian, Roland and Takao, Shintaro and Tatebe, Hiroaki and Tian, Hanqin and Tilbrook, Bronte and Torres, Olivier and Tourigny, Etienne and Tsujino, Hiroyuki and Tubiello, Francesco and van der Werf, Guido and Wanninkhof, Rik and Wang, Xuhui and Yang, Dongxu and Yang, Xiaojuan and Yu, Zhen and Yuan, Wenping and Yue, Xu and Zaehle, Sönke and Zeng, Ning and Zeng, Jiye},
title = {Global Carbon Budget 2024},
journal = {Earth System Science Data},
publisher = {Copernicus GmbH},
year = {2024},
doi = {10.5194/essd-2024-519}
}
|
| Gao Y, Burke EJ, Chadburn SE, Raivonen M, Markkanen T, Aurela M, Flanagan L, Fortuniak K, Humphreys E, Lohila A, Li T, Mammarella I, Nevalainen O, Nilsson MB, Pawlak W, Tsuruta A, Yang H and Aalto T (2024), "Assessing Modelled Methane Emissions Over Northern Wetlands by the Jules Land Surface Model Coupled with the Himmeli Peatland Methane Emission Model" Elsevier BV. |
BibTeX:
@article{Gao2024,
author = {Gao, Yao and Burke, Eleanor J. and Chadburn, Sarah E. and Raivonen, Maarit and Markkanen, Tiina and Aurela, Mika and Flanagan, Lawrence and Fortuniak, Krzysztof and Humphreys, Elyn and Lohila, Annalea and Li, Tingting and Mammarella, Ivan and Nevalainen, Olli and Nilsson, Mats B. and Pawlak, Włodzimierz and Tsuruta, Aki and Yang, Huiyi and Aalto, Tuula},
title = {Assessing Modelled Methane Emissions Over Northern Wetlands by the Jules Land Surface Model Coupled with the Himmeli Peatland Methane Emission Model},
publisher = {Elsevier BV},
year = {2024},
doi = {10.2139/ssrn.4957878}
}
|
| Ge M, Korrensalo A, Laiho R, Kohl L, Lohila A, Pihlatie M, Li X, Laine AM, Anttila J, Putkinen A, Wang W and Koskinen M (2024), "Plant-mediated CH4 exchange in wetlands: A review of mechanisms and measurement methods with implications for modelling", Science of The Total Environment., March, 2024. Vol. 914, pp. 169662. Elsevier BV. |
BibTeX:
@article{Ge2024,
author = {Ge, Mengyu and Korrensalo, Aino and Laiho, Raija and Kohl, Lukas and Lohila, Annalea and Pihlatie, Mari and Li, Xuefei and Laine, Anna M. and Anttila, Jani and Putkinen, Anuliina and Wang, Weifeng and Koskinen, Markku},
title = {Plant-mediated CH4 exchange in wetlands: A review of mechanisms and measurement methods with implications for modelling},
journal = {Science of The Total Environment},
publisher = {Elsevier BV},
year = {2024},
volume = {914},
pages = {169662},
doi = {10.1016/j.scitotenv.2023.169662}
}
|
| Gharun M, Shekhar A, Hörtnagl L, Krebs L, Arriga N, Migliavacca M, Roland M, Gielen B, Montagnani L, Tomelleri E, Šigut L, Peichl M, Zhao P, Schmidt M, Grünwald T, Korkiakoski M, Lohila A and Buchmann N (2024), "Divergent responses of evergreen needle-leaf forests in Europe to the 2020 warm winter", January, 2024. Copernicus GmbH. |
BibTeX:
@article{Gharun2024,
author = {Gharun, Mana and Shekhar, Ankit and Hörtnagl, Lukas and Krebs, Luana and Arriga, Nicola and Migliavacca, Mirco and Roland, Marilyn and Gielen, Bert and Montagnani, Leonardo and Tomelleri, Enrico and Šigut, Ladislav and Peichl, Matthias and Zhao, Peng and Schmidt, Marius and Grünwald, Thomas and Korkiakoski, Mika and Lohila, Annalea and Buchmann, Nina},
title = {Divergent responses of evergreen needle-leaf forests in Europe to the 2020 warm winter},
publisher = {Copernicus GmbH},
year = {2024},
doi = {10.5194/egusphere-2023-2964}
}
|
| Gillespie LM, Kolari P, Kulmala L, Leitner SM, Pihlatie M, Zechmeister-Boltenstern S and Díaz-Pinés E (2024), "Drought effects on soil greenhouse gas fluxes in a boreal and a temperate forest", Biogeochemistry., March, 2024. Vol. 167(2), pp. 155-175. Springer Science and Business Media LLC. |
BibTeX:
@article{Gillespie2024,
author = {Gillespie, L. M. and Kolari, P. and Kulmala, L. and Leitner, S. M. and Pihlatie, M. and Zechmeister-Boltenstern, S. and Díaz-Pinés, E.},
title = {Drought effects on soil greenhouse gas fluxes in a boreal and a temperate forest},
journal = {Biogeochemistry},
publisher = {Springer Science and Business Media LLC},
year = {2024},
volume = {167},
number = {2},
pages = {155--175},
doi = {10.1007/s10533-024-01126-2}
}
|
| González AG, Aldrich-Rodríguez A, González-Santana D, González-Dávila M and Santana-Casiano JM (2024), "Seasonal variability of coastal pH and CO2 using an oceanographic buoy in the Canary Islands", Frontiers in Marine Science., April, 2024. Vol. 11 Frontiers Media SA. |
BibTeX:
@article{Gonzalez2024,
author = {González, Aridane G. and Aldrich-Rodríguez, Ariadna and González-Santana, David and González-Dávila, Melchor and Santana-Casiano, J. Magdalena},
title = {Seasonal variability of coastal pH and CO2 using an oceanographic buoy in the Canary Islands},
journal = {Frontiers in Marine Science},
publisher = {Frontiers Media SA},
year = {2024},
volume = {11},
doi = {10.3389/fmars.2024.1337929}
}
|
| Guimarães LM, Montes MJF and Lefèvre N (2024), "Regional differences in the air–sea CO2 flux between 3 and 14°S in the south-western tropical Atlantic", Marine and Freshwater Research., May, 2024. Vol. 75(7) CSIRO Publishing. |
BibTeX:
@article{Guimaraes2024,
author = {Guimarães, Lucas Medeiros and Montes, Manuel J. Flores and Lefèvre, Nathalie},
editor = {Zhang, Yunlin},
title = {Regional differences in the air–sea CO2 flux between 3 and 14°S in the south-western tropical Atlantic},
journal = {Marine and Freshwater Research},
publisher = {CSIRO Publishing},
year = {2024},
volume = {75},
number = {7},
doi = {10.1071/mf22276}
}
|
| Guo Z, Martínez-García E, Chi J, Nilsson M, Jia X and Peichl M (2024), "Divergent apparent temperature sensitivity of forest-floor respiration across a managed boreal forest landscape", Science of The Total Environment., December, 2024. Vol. 955, pp. 176950. Elsevier BV. |
BibTeX:
@article{Guo2024,
author = {Guo, Zifan and Martínez-García, Eduardo and Chi, Jinshu and Nilsson, Mats.B. and Jia, Xin and Peichl, Matthias},
title = {Divergent apparent temperature sensitivity of forest-floor respiration across a managed boreal forest landscape},
journal = {Science of The Total Environment},
publisher = {Elsevier BV},
year = {2024},
volume = {955},
pages = {176950},
doi = {10.1016/j.scitotenv.2024.176950}
}
|
| Gustin MS, Dunham-Cheatham SM, Osterwalder S, Magand O and Dommergue A (2024), "What is the utility of measuring gaseous HgII dry deposition using Aerohead samplers?: A review", Science of The Total Environment., jan, 2024. Vol. 907, pp. 167895. Elsevier BV. |
BibTeX:
@article{Gustin2024,
author = {Gustin, Mae Sexauer and Dunham-Cheatham, Sarrah M and Osterwalder, Stefan and Magand, Olivier and Dommergue, Aurélien},
title = {What is the utility of measuring gaseous HgII dry deposition using Aerohead samplers?: A review},
journal = {Science of The Total Environment},
publisher = {Elsevier BV},
year = {2024},
volume = {907},
pages = {167895},
url = {http://dx.doi.org/10.1016/j.scitotenv.2023.167895},
doi = {10.1016/j.scitotenv.2023.167895}
}
|
| Haszpra L (2024), "Magyarország részvétele a pán-európai üvegházgáz mérőhálózatban", Légkör. Vol. 69(3), pp. 180-185. Orszagos Meteorologiai Szolgalat. |
BibTeX:
@article{Haszpra2024,
author = {Haszpra, László},
title = {Magyarország részvétele a pán-európai üvegházgáz mérőhálózatban},
journal = {Légkör},
publisher = {Orszagos Meteorologiai Szolgalat},
year = {2024},
volume = {69},
number = {3},
pages = {180--185},
doi = {10.56474/legkor.2024.3.4}
}
|
| Havu M, Kulmala L, Lee HS, Saranko O, Soininen J, Ahongshangbam J and Järvi L (2024), "CO2 uptake of urban vegetation in a warming Nordic city", Urban Forestry & Urban Greening., April, 2024. Vol. 94, pp. 128261. Elsevier BV. |
BibTeX:
@article{Havu2024,
author = {Havu, Minttu and Kulmala, Liisa and Lee, Hei Shing and Saranko, Olli and Soininen, Jesse and Ahongshangbam, Joyson and Järvi, Leena},
title = {CO2 uptake of urban vegetation in a warming Nordic city},
journal = {Urban Forestry & Urban Greening},
publisher = {Elsevier BV},
year = {2024},
volume = {94},
pages = {128261},
doi = {10.1016/j.ufug.2024.128261}
}
|
| Heikkilä M, Luoma K, Mäkelä T and Grönholm T (2024), "The local ship speed reduction effect on black carbon emissions measured at a remote marine station", Atmospheric Chemistry and Physics., August, 2024. Vol. 24(15), pp. 8927-8941. Copernicus GmbH. |
BibTeX:
@article{Heikkilae2024,
author = {Heikkilä, Mikko and Luoma, Krista and Mäkelä, Timo and Grönholm, Tiia},
title = {The local ship speed reduction effect on black carbon emissions measured at a remote marine station},
journal = {Atmospheric Chemistry and Physics},
publisher = {Copernicus GmbH},
year = {2024},
volume = {24},
number = {15},
pages = {8927--8941},
doi = {10.5194/acp-24-8927-2024}
}
|
| Högberg P, Klatt C, Franklin O, Henriksson N, Lim H, Inselsbacher E, Hurry V, Näsholm T and Högberg MN (2024), "Improved methodology for tracing a pulse of 13C-labelled tree photosynthate carbon to ectomycorrhizal roots, other soil biota and soil processes in the field", Tree Physiology., December, 2024. Vol. 45(1) Oxford University Press (OUP). |
BibTeX:
@article{Hoegberg2024,
author = {Högberg, Peter and Klatt, Christian and Franklin, Oskar and Henriksson, Nils and Lim, Hyungwoo and Inselsbacher, Erich and Hurry, Vaughan and Näsholm, Torgny and Högberg, Mona N},
editor = {Epron, Daniel},
title = {Improved methodology for tracing a pulse of 13C-labelled tree photosynthate carbon to ectomycorrhizal roots, other soil biota and soil processes in the field},
journal = {Tree Physiology},
publisher = {Oxford University Press (OUP)},
year = {2024},
volume = {45},
number = {1},
doi = {10.1093/treephys/tpae169}
}
|
| Holmgaard SB and Burlingame K (2024), "Monitoring materialities: Anthropocene landscapes of environing technologies in the High North", Landscape Research., November, 2024. , pp. 1-17. Informa UK Limited. |
BibTeX:
@article{Holmgaard2024,
author = {Holmgaard, Sanne Bech and Burlingame, Katherine},
title = {Monitoring materialities: Anthropocene landscapes of environing technologies in the High North},
journal = {Landscape Research},
publisher = {Informa UK Limited},
year = {2024},
pages = {1--17},
doi = {10.1080/01426397.2024.2416409}
}
|
| Honkanen M, Aurela M, Hatakka J, Haraguchi L, Kielosto S, Mäkelä T, Seppälä J, Siiriä S-M, Stenbäck K, Tuovinen J-P, Ylöstalo P and Laakso L (2024), "Interannual and seasonal variability of the air–sea CO2 exchange at Utö in the coastal region of the Baltic Sea", Biogeosciences., October, 2024. Vol. 21(19), pp. 4341-4359. Copernicus GmbH. |
BibTeX:
@article{Honkanen2024,
author = {Honkanen, Martti and Aurela, Mika and Hatakka, Juha and Haraguchi, Lumi and Kielosto, Sami and Mäkelä, Timo and Seppälä, Jukka and Siiriä, Simo-Matti and Stenbäck, Ken and Tuovinen, Juha-Pekka and Ylöstalo, Pasi and Laakso, Lauri},
title = {Interannual and seasonal variability of the air–sea CO2 exchange at Utö in the coastal region of the Baltic Sea},
journal = {Biogeosciences},
publisher = {Copernicus GmbH},
year = {2024},
volume = {21},
number = {19},
pages = {4341--4359},
doi = {10.5194/bg-21-4341-2024}
}
|
| Hordijk I, Bialic‐Murphy L, Lauber T, Routh D, Poorter L, Rivers MC, ter Steege H, Liang J, Reich PB, de‐Miguel S, Nabuurs G, Gamarra JGP, Chen HYH, Zhou M, Wiser SK, Pretzsch H, Paquette A, Picard N, Hérault B, Bastin J, Alberti G, Abegg M, Adou Yao YC, Almeyda Zambrano AM, Alvarado BV, Alvarez‐Davila E, Alvarez‐Loayza P, Alves LF, Ammer C, Antón‐Fernández C, Araujo‐Murakami A, Arroyo L, Avitabile V, Aymard Corredor GA, Baker T, Banki O, Barroso J, Bastian ML, Birigazzi L, Birnbaum P, Bitariho R, Boeckx P, Bongers F, Bouriaud O, Brancalion PHS, Brandl S, Brienen R, Broadbent EN, Bruelheide H, Bussotti F, Gatti RC, Cesar RG, Cesljar G, Chazdon R, Chisholm C, Cienciala E, Clark CJ, Clar DB, Colletta G, Coomes D, Valverde FC, Corral‐Rivas JJ, Crim P, Cumming J, Dayanandan S, de Gasper AL, Decuyper M, Derroire G, DeVries B, Djordjevic I, Iêda A, Dourdain A, Dolezal J, Obiang NLE, Enquist B, Eyre T, Fandohan AB, Fayle TM, Ferreira LV, Feldpausch TR, Finér L, Fischer M, Fletcher C, Frizzera L, Gianelle D, Glick HB, Harris D, Hector A, Hemp A, Hengeveld G, Herbohn J, Hillers A, Honorio Coronado EN, Hui C, Cho H, Ibanez T, Jung I, Imai N, Jagodzinski AM, Jaroszewicz B, Johannsen V, Joly CA, Jucker T, Karminov V, Kartawinata K, Kearsley E, Kenfack D, Kennard D, Kepfer‐Rojas S, Keppel G, Khan ML, Killeen T, Kim HS, Kitayama K, Köhl M, Korjus H, Kraxner F, Laarmann D, Lang M, Lewis S, Lu H, Lukina N, Maitner B, Malhi Y, Marcon E, Marimon BS, Marimon‐Junior BH, Marshall AR, Martin E, Martynenko O, Meave JA, Melo‐Cruz O, Mendoza C, Merow C, Miscicki S, Mendoza AM, Moreno V, Mukul SA, Mundhenk P, Nava‐Miranda MG, Neill D, Neldner V, Nevenic R, Ngugi M, Niklaus PA, Oleksyn J, Ontikov P, Ortiz‐Malavasi E, Pan Y, Parada‐Gutierrez A, Parfenova E, Park M, Parren M, Parthasarathy N, Peri PL, Pfautsch S, Phillips OL, Piedade MT, Piotto D, Pitman NCA, Polo I, Poulsen AD, Poulsen JR, Arevalo FR, Restrepo‐Correa Z, Rodeghiero M, Rolim S, Roopsind A, Rovero F, Rutishauser E, Saikia P, Salas‐Eljatib C, Schall P, Schepaschenko D, Scherer‐Lorenzen M, Schmid B, Schöngart J, Searle EB, Seben V, Serra‐Diaz JM, Sheil D, Shvidenko A, Silva‐Espejo J, Silveira M, Singh J, Sist P, Slik F, Sonké B, Souza AF, Stereńczak K, Svenning J, Svoboda M, Swanepoel B, Targhetta N, Tchebakova N, Thomas R, Tikhonova E, Umunay P, Usoltsev V, Valencia R, Valladares F, van der Plas F, Van Do T, Van Nuland ME, Martinez RV, Verbeeck H, Viana H, Vibrans AC, Vieira S, von Gadow K, Wang H, Watson J, Werner GDA, Wittmann F, Wortel V, Zagt R, Zawila‐Niedzwiecki T, Zhang C, Zhao X, Zhu Z, Zo‐Bi IC, Maynard DS and Crowther TW (2024), "Dominance and rarity in tree communities across the globe: Patterns, predictors and threats", Global Ecology and Biogeography., July, 2024. Vol. 33(10) Wiley. |
BibTeX:
@article{Hordijk2024,
author = {Hordijk, Iris and Bialic‐Murphy, Lalasia and Lauber, Thomas and Routh, Devin and Poorter, Lourens and Rivers, Malin C. and ter Steege, Hans and Liang, Jingjing and Reich, Peter B. and de‐Miguel, Sergio and Nabuurs, Gert‐Jan and Gamarra, Javier G. P. and Chen, Han Y. H. and Zhou, Mo and Wiser, Susan K. and Pretzsch, Hans and Paquette, Alain and Picard, Nicolas and Hérault, Bruno and Bastin, Jean‐Francois and Alberti, Giorgio and Abegg, Meinrad and Adou Yao, Yves C. and Almeyda Zambrano, Angelica M. and Alvarado, Braulio V. and Alvarez‐Davila, Esteban and Alvarez‐Loayza, Patricia and Alves, Luciana F. and Ammer, Christian and Antón‐Fernández, Clara and Araujo‐Murakami, Alejandro and Arroyo, Luzmila and Avitabile, Valerio and Aymard Corredor, Gerardo A. and Baker, Timothy and Banki, Olaf and Barroso, Jorcely and Bastian, Meredith L. and Birigazzi, Luca and Birnbaum, Philippe and Bitariho, Robert and Boeckx, Pascal and Bongers, Frans and Bouriaud, Olivier and Brancalion, Pedro H. S. and Brandl, Susanne and Brienen, Roel and Broadbent, Eben N. and Bruelheide, Helge and Bussotti, Filippo and Gatti, Roberto Cazzolla and Cesar, Ricardo G. and Cesljar, Goran and Chazdon, Robin and Chisholm, Chelsea and Cienciala, Emil and Clark, Connie J. and Clar, David B. and Colletta, Gabriel and Coomes, David and Valverde, Fernando Cornejo and Corral‐Rivas, Jose J. and Crim, Philip and Cumming, Jonathan and Dayanandan, Selvadurai and de Gasper, André L. and Decuyper, Mathieu and Derroire, Géraldine and DeVries, Ben and Djordjevic, Ilija and Iêda, Amaral and Dourdain, Aurélie and Dolezal, Jiri and Obiang, Nestor Laurier Engone and Enquist, Brian and Eyre, Teresa and Fandohan, Adandé Belarmain and Fayle, Tom M. and Ferreira, Leandro V. and Feldpausch, Ted R. and Finér, Leena and Fischer, Markus and Fletcher, Christine and Frizzera, Lorenzo and Gianelle, Damiano and Glick, Henry B. and Harris, David and Hector, Andrew and Hemp, Andreas and Hengeveld, Geerten and Herbohn, John and Hillers, Annika and Honorio Coronado, Eurídice N. and Hui, Cang and Cho, Hyunkook and Ibanez, Thomas and Jung, Ilbin and Imai, Nobuo and Jagodzinski, Andrzej M. and Jaroszewicz, Bogdan and Johannsen, Vivian and Joly, Carlos A. and Jucker, Tommaso and Karminov, Viktor and Kartawinata, Kuswata and Kearsley, Elizabeth and Kenfack, David and Kennard, Deborah and Kepfer‐Rojas, Sebastian and Keppel, Gunnar and Khan, Mohammed Latif and Killeen, Timothy and Kim, Hyun Seok and Kitayama, Kanehiro and Köhl, Michael and Korjus, Henn and Kraxner, Florian and Laarmann, Diana and Lang, Mait and Lewis, Simon and Lu, Huicui and Lukina, Natalia and Maitner, Brian and Malhi, Yadvinder and Marcon, Eric and Marimon, Beatriz Schwantes and Marimon‐Junior, Ben Hur and Marshall, Andrew Robert and Martin, Emanuel and Martynenko, Olga and Meave, Jorge A. and Melo‐Cruz, Omar and Mendoza, Casimiro and Merow, Cory and Miscicki, Stanislaw and Mendoza, Abel Monteagudo and Moreno, Vanessa and Mukul, Sharif A. and Mundhenk, Philip and Nava‐Miranda, Maria G. and Neill, David and Neldner, Victor and Nevenic, Radovan and Ngugi, Michael and Niklaus, Pascal A. and Oleksyn, Jacek and Ontikov, Petr and Ortiz‐Malavasi, Edgar and Pan, Yude and Parada‐Gutierrez, Alexander and Parfenova, Elena and Park, Minjee and Parren, Marc and Parthasarathy, Narayanaswamy and Peri, Pablo L. and Pfautsch, Sebastian and Phillips, Oliver L. and Piedade, Maria Teresa and Piotto, Daniel and Pitman, Nigel C. A. and Polo, Irina and Poulsen, Axel Dalberg and Poulsen, John R. and Arevalo, Freddy Ramirez and Restrepo‐Correa, Zorayda and Rodeghiero, Mirco and Rolim, Samir and Roopsind, Anand and Rovero, Francesco and Rutishauser, Ervan and Saikia, Purabi and Salas‐Eljatib, Christian and Schall, Peter and Schepaschenko, Dmitry and Scherer‐Lorenzen, Michael and Schmid, Bernhard and Schöngart, Jochen and Searle, Eric B. and Seben, Vladimír and Serra‐Diaz, Josep M. and Sheil, Douglas and Shvidenko, Anatoly and Silva‐Espejo, Javier and Silveira, Marcos and Singh, James and Sist, Plinio and Slik, Ferry and Sonké, Bonaventure and Souza, Alexandre F. and Stereńczak, Krzysztof and Svenning, Jens‐Christian and Svoboda, Miroslav and Swanepoel, Ben and Targhetta, Natalia and Tchebakova, Nadja and Thomas, Raquel and Tikhonova, Elena and Umunay, Peter and Usoltsev, Vladimir and Valencia, Renato and Valladares, Fernando and van der Plas, Fons and Van Do, Tran and Van Nuland, Michael E. and Martinez, Rodolfo Vasquez and Verbeeck, Hans and Viana, Helder and Vibrans, Alexander C. and Vieira, Simone and von Gadow, Klaus and Wang, Hua‐Feng and Watson, James and Werner, Gijsbert D. A. and Wittmann, Florian and Wortel, Verginia and Zagt, Roderick and Zawila‐Niedzwiecki, Tomasz and Zhang, Chunyu and Zhao, Xiuhai and Zhu, Zhi‐Xin and Zo‐Bi, Irie Casimir and Maynard, Daniel S. and Crowther, Thomas W.},
title = {Dominance and rarity in tree communities across the globe: Patterns, predictors and threats},
journal = {Global Ecology and Biogeography},
publisher = {Wiley},
year = {2024},
volume = {33},
number = {10},
doi = {10.1111/geb.13889}
}
|
| Hu T, Malone SL, Rumpel C and Chabbi A (2024), "Maximizing soil organic carbon stocks through optimal ploughing and renewal strategies in (Ley) grassland", Communications Earth & Environment., jan, 2024. Vol. 5(1) Springer Science and Business Media LLC. |
BibTeX:
@article{Hu2024,
author = {Hu, Teng and Malone, Sparkle L and Rumpel, Cornelia and Chabbi, Abad},
title = {Maximizing soil organic carbon stocks through optimal ploughing and renewal strategies in (Ley) grassland},
journal = {Communications Earth & Environment},
publisher = {Springer Science and Business Media LLC},
year = {2024},
volume = {5},
number = {1},
url = {http://dx.doi.org/10.1038/s43247-024-01202-3},
doi = {10.1038/s43247-024-01202-3}
}
|
| Huang W, Junninen H, Garmash O, Lehtipalo K, Stolzenburg D, Lampilahti JLP, Ezhova E, Schallhart S, Rantala P, Aliaga D, Ahonen L, Sulo J, Quéléver LLJ, Cai R, Alekseychik P, Mazon SB, Yao L, Blichner SM, Zha Q, Mammarella I, Kirkby J, Kerminen V-M, Worsnop DR, Kulmala M and Bianchi F (2024), "Potential pre-industrial–like new particle formation induced by pure biogenic organic vapors in Finnish peatland", Science Advances., April, 2024. Vol. 10(14) American Association for the Advancement of Science (AAAS). |
BibTeX:
@article{Huang2024,
author = {Huang, Wei and Junninen, Heikki and Garmash, Olga and Lehtipalo, Katrianne and Stolzenburg, Dominik and Lampilahti, Janne L. P. and Ezhova, Ekaterina and Schallhart, Simon and Rantala, Pekka and Aliaga, Diego and Ahonen, Lauri and Sulo, Juha and Quéléver, Lauriane L. J. and Cai, Runlong and Alekseychik, Pavel and Mazon, Stephany B. and Yao, Lei and Blichner, Sara M. and Zha, Qiaozhi and Mammarella, Ivan and Kirkby, Jasper and Kerminen, Veli-Matti and Worsnop, Douglas R. and Kulmala, Markku and Bianchi, Federico},
title = {Potential pre-industrial–like new particle formation induced by pure biogenic organic vapors in Finnish peatland},
journal = {Science Advances},
publisher = {American Association for the Advancement of Science (AAAS)},
year = {2024},
volume = {10},
number = {14},
doi = {10.1126/sciadv.adm9191}
}
|
| Islam MR, Jönsson AM, Bergkvist J, Lagergren F, Lindeskog M, Mölder M, Scholze M and Kljun N (2024), "Projected effects of climate change and forest management on carbon fluxes and biomass of a boreal forest", Agricultural and Forest Meteorology., April, 2024. Vol. 349, pp. 109959. Elsevier BV. |
BibTeX:
@article{Islam2024,
author = {Islam, Md. Rafikul and Jönsson, Anna Maria and Bergkvist, John and Lagergren, Fredrik and Lindeskog, Mats and Mölder, Meelis and Scholze, Marko and Kljun, Natascha},
title = {Projected effects of climate change and forest management on carbon fluxes and biomass of a boreal forest},
journal = {Agricultural and Forest Meteorology},
publisher = {Elsevier BV},
year = {2024},
volume = {349},
pages = {109959},
doi = {10.1016/j.agrformet.2024.109959}
}
|
| Jentzsch K, van Delden L, Fuchs M and Treat CC (2024), "An expert survey on chamber measurement techniques for methane fluxes", December, 2024. Copernicus GmbH. |
BibTeX:
@article{Jentzsch2024,
author = {Jentzsch, Katharina and van Delden, Lona and Fuchs, Matthias and Treat, Claire C.},
title = {An expert survey on chamber measurement techniques for methane fluxes},
publisher = {Copernicus GmbH},
year = {2024},
doi = {10.5194/essd-2024-381}
}
|
| Jentzsch K, Männistö E, Marushchak ME, Korrensalo A, van Delden L, Tuittila E-S, Knoblauch C and Treat CC (2024), "Shoulder season controls on methane emissions from a boreal peatland", Biogeosciences., August, 2024. Vol. 21(16), pp. 3761-3788. Copernicus GmbH. |
BibTeX:
@article{Jentzsch2024a,
author = {Jentzsch, Katharina and Männistö, Elisa and Marushchak, Maija E. and Korrensalo, Aino and van Delden, Lona and Tuittila, Eeva-Stiina and Knoblauch, Christian and Treat, Claire C.},
title = {Shoulder season controls on methane emissions from a boreal peatland},
journal = {Biogeosciences},
publisher = {Copernicus GmbH},
year = {2024},
volume = {21},
number = {16},
pages = {3761--3788},
doi = {10.5194/bg-21-3761-2024}
}
|
| Jersild A and Landschützer P (2024), "A Spatially Explicit Uncertainty Analysis of the Air‐Sea CO2 Flux From Observations", Geophysical Research Letters., February, 2024. Vol. 51(4) American Geophysical Union (AGU). |
BibTeX:
@article{Jersild2024,
author = {Jersild, Annika and Landschützer, Peter},
title = {A Spatially Explicit Uncertainty Analysis of the Air‐Sea CO2 Flux From Observations},
journal = {Geophysical Research Letters},
publisher = {American Geophysical Union (AGU)},
year = {2024},
volume = {51},
number = {4},
doi = {10.1029/2023gl106636}
}
|
| Jongen HJ, Vulova S, Meier F, Steeneveld GJ, Jansen FA, Tetzlaff D, Kleinschmit B, Haacke N and Teuling AJ (2024), "Attributing Urban Evapotranspiration From Eddy‐Covariance to Surface Cover: Bottom‐Up Versus Top‐Down", Water Resources Research., September, 2024. Vol. 60(9) American Geophysical Union (AGU). |
BibTeX:
@article{Jongen2024,
author = {Jongen, H. J. and Vulova, S. and Meier, F. and Steeneveld, G. J. and Jansen, F. A. and Tetzlaff, D. and Kleinschmit, B. and Haacke, N. and Teuling, A. J.},
title = {Attributing Urban Evapotranspiration From Eddy‐Covariance to Surface Cover: Bottom‐Up Versus Top‐Down},
journal = {Water Resources Research},
publisher = {American Geophysical Union (AGU)},
year = {2024},
volume = {60},
number = {9},
doi = {10.1029/2024wr037508}
}
|
| Kallingal JT, Scholze M, Miller PA, Lindström J, Rinne J, Aurela M, Vestin P and Weslien P (2024), "Assimilating Multi-site Eddy-Covariance Data to Calibrate the CH4 Wetland Emission Module in a Terrestrial Ecosystem Model", EGUsphere., February, 2024. Copernicus GmbH. |
BibTeX:
@article{Kallingal2024,
author = {Kallingal, Jalisha Theanutti and Scholze, Marko and Miller, Paul Anthony and Lindström, Johan and Rinne, Janne and Aurela, Mika and Vestin, Patrik and Weslien, Per},
title = {Assimilating Multi-site Eddy-Covariance Data to Calibrate the CH4 Wetland Emission Module in a Terrestrial Ecosystem Model},
journal = {EGUsphere},
publisher = {Copernicus GmbH},
year = {2024},
doi = {10.5194/egusphere-2024-373}
}
|
| Kallingal JT, Lindström J, Miller PA, Rinne J, Raivonen M and Scholze M (2024), "Optimising CH4 simulations from the LPJ-GUESS model v4.1 using an adaptive Markov chain Monte Carlo algorithm", Geoscientific Model Development., March, 2024. Vol. 17(6), pp. 2299-2324. Copernicus GmbH. |
BibTeX:
@article{Kallingal2024a,
author = {Kallingal, Jalisha T. and Lindström, Johan and Miller, Paul A. and Rinne, Janne and Raivonen, Maarit and Scholze, Marko},
title = {Optimising CH4 simulations from the LPJ-GUESS model v4.1 using an adaptive Markov chain Monte Carlo algorithm},
journal = {Geoscientific Model Development},
publisher = {Copernicus GmbH},
year = {2024},
volume = {17},
number = {6},
pages = {2299--2324},
doi = {10.5194/gmd-17-2299-2024}
}
|
| Karimi S, Maher Hasselquist E, Salimi S, Järveoja J and Laudon H (2024), "Rewetting impact on the hydrological function of a drained peatland in the boreal landscape", Journal of Hydrology., September, 2024. Vol. 641, pp. 131729. Elsevier BV. |
BibTeX:
@article{Karimi2024,
author = {Karimi, Shirin and Maher Hasselquist, Eliza and Salimi, Shokoufeh and Järveoja, Järvi and Laudon, Hjalmar},
title = {Rewetting impact on the hydrological function of a drained peatland in the boreal landscape},
journal = {Journal of Hydrology},
publisher = {Elsevier BV},
year = {2024},
volume = {641},
pages = {131729},
doi = {10.1016/j.jhydrol.2024.131729}
}
|
| Karvinen E, Backman L, Järvi L and Kulmala L (2024), "Soil respiration across a variety of tree-covered urban green spaces in Helsinki, Finland", SOIL., June, 2024. Vol. 10(1), pp. 381-406. Copernicus GmbH. |
BibTeX:
@article{Karvinen2024,
author = {Karvinen, Esko and Backman, Leif and Järvi, Leena and Kulmala, Liisa},
title = {Soil respiration across a variety of tree-covered urban green spaces in Helsinki, Finland},
journal = {SOIL},
publisher = {Copernicus GmbH},
year = {2024},
volume = {10},
number = {1},
pages = {381--406},
doi = {10.5194/soil-10-381-2024}
}
|
| Katul G, Bragg A, Mammarella I, Liu H, Li Q and Bou‐Zeid E (2024), "Gas Transfer Across Air‐Water Interfaces in Inland Waters: From Micro‐Eddies to Super‐Statistics", Water Resources Research., October, 2024. Vol. 60(11) American Geophysical Union (AGU). |
BibTeX:
@article{Katul2024,
author = {Katul, Gabriel and Bragg, Andrew and Mammarella, Ivan and Liu, Heping and Li, Qi and Bou‐Zeid, Elie},
title = {Gas Transfer Across Air‐Water Interfaces in Inland Waters: From Micro‐Eddies to Super‐Statistics},
journal = {Water Resources Research},
publisher = {American Geophysical Union (AGU)},
year = {2024},
volume = {60},
number = {11},
doi = {10.1029/2023wr036615}
}
|
| Kearsley E, Verbeeck H, Stoffelen P, Janssens SB, Yakusu EK, Kosmala M, De Mil T, Bauters M, Kitima ER, Ndiapo JM, Chuda AL, Richardson AD, Wingate L, Ilondea BA, Beeckman H, van den Bulcke J, Boeckx P and Hufkens K (2024), "Historical tree phenology data reveal the seasonal rhythms of the Congo Basin rainforest", Plant-Environment Interactions., March, 2024. Vol. 5(2) Wiley. |
BibTeX:
@article{Kearsley2024,
author = {Kearsley, Elizabeth and Verbeeck, Hans and Stoffelen, Piet and Janssens, Steven B. and Yakusu, Emmanuel Kasongo and Kosmala, Margaret and De Mil, Tom and Bauters, Marijn and Kitima, Elasi Ramanzani and Ndiapo, José Mbifo and Chuda, Adelard Lonema and Richardson, Andrew D. and Wingate, Lisa and Ilondea, Bhély Angoboy and Beeckman, Hans and van den Bulcke, Jan and Boeckx, Pascal and Hufkens, Koen},
title = {Historical tree phenology data reveal the seasonal rhythms of the Congo Basin rainforest},
journal = {Plant-Environment Interactions},
publisher = {Wiley},
year = {2024},
volume = {5},
number = {2},
doi = {10.1002/pei3.10136}
}
|
| Kloos S, Klosterhalfen A, Knohl A and Menzel A (2024), "Decoding autumn phenology: Unraveling the link between observation methods and detected environmental cues", Global Change Biology., March, 2024. Vol. 30(3) Wiley. |
BibTeX:
@article{Kloos2024,
author = {Kloos, Simon and Klosterhalfen, Anne and Knohl, Alexander and Menzel, Annette},
title = {Decoding autumn phenology: Unraveling the link between observation methods and detected environmental cues},
journal = {Global Change Biology},
publisher = {Wiley},
year = {2024},
volume = {30},
number = {3},
doi = {10.1111/gcb.17231}
}
|
| Kouznetsov R, Hänninen R, Uppstu A, Kadantsev E, Fatahi Y, Prank M, Kouznetsov D, Noe SM, Junninen H and Sofiev M (2024), "A bottom-up emission estimate for the 2022 Nord Stream gas leak: derivation, simulations, and evaluation", Atmospheric Chemistry and Physics., April, 2024. Vol. 24(8), pp. 4675-4691. Copernicus GmbH. |
BibTeX:
@article{Kouznetsov2024,
author = {Kouznetsov, Rostislav and Hänninen, Risto and Uppstu, Andreas and Kadantsev, Evgeny and Fatahi, Yalda and Prank, Marje and Kouznetsov, Dmitrii and Noe, Steffen Manfred and Junninen, Heikki and Sofiev, Mikhail},
title = {A bottom-up emission estimate for the 2022 Nord Stream gas leak: derivation, simulations, and evaluation},
journal = {Atmospheric Chemistry and Physics},
publisher = {Copernicus GmbH},
year = {2024},
volume = {24},
number = {8},
pages = {4675--4691},
doi = {10.5194/acp-24-4675-2024}
}
|
| Krebs L, Burri S, Feigenwinter I, Gharun M, Meier P and Buchmann N (2024), "Forest-floor respiration, N2O fluxes, and CH4 fluxes in a subalpine spruce forest: drivers and annual budgets", Biogeosciences., April, 2024. Vol. 21(8), pp. 2005-2028. Copernicus GmbH. |
BibTeX:
@article{Krebs2024,
author = {Krebs, Luana and Burri, Susanne and Feigenwinter, Iris and Gharun, Mana and Meier, Philip and Buchmann, Nina},
title = {Forest-floor respiration, N2O fluxes, and CH4 fluxes in a subalpine spruce forest: drivers and annual budgets},
journal = {Biogeosciences},
publisher = {Copernicus GmbH},
year = {2024},
volume = {21},
number = {8},
pages = {2005--2028},
doi = {10.5194/bg-21-2005-2024}
}
|
| Kuhn MA, Varner RK, McCalley CK, Perryman CR, Aurela M, Burke SA, Chanton JP, Crill PM, DelGreco J, Deng J, Heffernan L, Herrick C, Hodgkins SB, Jones CP, Juutinen S, Kane ES, Lamit LJ, Larmola T, Lilleskov E, Olefeldt D, Palace MW, Rich VI, Schulze C, Shorter JH, Sullivan FB, Sonnentag O, Turetsky MR and Waldrop MP (2024), "Controls on Stable Methane Isotope Values in Northern Peatlands and Potential Shifts in Values Under Permafrost Thaw Scenarios", Journal of Geophysical Research: Biogeosciences., July, 2024. Vol. 129(7) American Geophysical Union (AGU). |
BibTeX:
@article{Kuhn2024,
author = {Kuhn, McKenzie A. and Varner, Ruth K. and McCalley, Carmody K. and Perryman, Clarice R. and Aurela, Mika and Burke, Sophia A. and Chanton, Jeffrey P. and Crill, Patrick M. and DelGreco, Jessica and Deng, Jia and Heffernan, Liam and Herrick, Christina and Hodgkins, Suzanne B. and Jones, Cheristy P. and Juutinen, Sari and Kane, Evan S. and Lamit, Louis J. and Larmola, Tuula and Lilleskov, Erik and Olefeldt, David and Palace, Michael W. and Rich, Virginia I. and Schulze, Christopher and Shorter, Joanne H. and Sullivan, Franklin B. and Sonnentag, Oliver and Turetsky, Merritt R. and Waldrop, Mark P.},
title = {Controls on Stable Methane Isotope Values in Northern Peatlands and Potential Shifts in Values Under Permafrost Thaw Scenarios},
journal = {Journal of Geophysical Research: Biogeosciences},
publisher = {American Geophysical Union (AGU)},
year = {2024},
volume = {129},
number = {7},
doi = {10.1029/2023jg007837}
}
|
| Lakshmiprasad RB, Peth S, Woche SK and Graf T (2024), "New Method for Hydraulic Characterization of Variably Saturated Zone in Peatland-Dominated Permafrost Mires", Land., November, 2024. Vol. 13(12), pp. 1990. MDPI AG. |
BibTeX:
@article{Lakshmiprasad2024,
author = {Lakshmiprasad, Radhakrishna Bangalore and Peth, Stephan and Woche, Susanne K. and Graf, Thomas},
title = {New Method for Hydraulic Characterization of Variably Saturated Zone in Peatland-Dominated Permafrost Mires},
journal = {Land},
publisher = {MDPI AG},
year = {2024},
volume = {13},
number = {12},
pages = {1990},
doi = {10.3390/land13121990}
}
|
| Lane DJ, Sippula O, Jokiniemi J, Heimonen M, Kinnunen NM, Virkajärvi P and Shurpali N (2024), "Fates of nutrient elements and heavy metals during thermal conversion of cattle slurry-derived anaerobic digestates", Bioresources and Bioprocessing., December, 2024. Vol. 11(1) Springer Science and Business Media LLC. |
BibTeX:
@article{Lane2024,
author = {Lane, Daniel J. and Sippula, Olli and Jokiniemi, Jorma and Heimonen, Mikko and Kinnunen, Niko M. and Virkajärvi, Perttu and Shurpali, Narasinha},
title = {Fates of nutrient elements and heavy metals during thermal conversion of cattle slurry-derived anaerobic digestates},
journal = {Bioresources and Bioprocessing},
publisher = {Springer Science and Business Media LLC},
year = {2024},
volume = {11},
number = {1},
doi = {10.1186/s40643-024-00828-7}
}
|
| Lange N, Fiedler B, Álvarez M, Benoit-Cattin A, Benway H, Buttigieg PL, Coppola L, Currie K, Flecha S, Gerlach DS, Honda M, Huertas IE, Lauvset SK, Muller-Karger F, Körtzinger A, O’Brien KM, Ólafsdóttir SR, Pacheco FC, Rueda-Roa D, Skjelvan I, Wakita M, White A and Tanhua T (2024), "Synthesis Product for Ocean Time Series (SPOTS) – a ship-based biogeochemical pilot", Earth System Science Data., April, 2024. Vol. 16(4), pp. 1901-1931. Copernicus GmbH. |
BibTeX:
@article{Lange2024,
author = {Lange, Nico and Fiedler, Björn and Álvarez, Marta and Benoit-Cattin, Alice and Benway, Heather and Buttigieg, Pier Luigi and Coppola, Laurent and Currie, Kim and Flecha, Susana and Gerlach, Dana S. and Honda, Makio and Huertas, I. Emma and Lauvset, Siv K. and Muller-Karger, Frank and Körtzinger, Arne and O’Brien, Kevin M. and Ólafsdóttir, Sólveig R. and Pacheco, Fernando C. and Rueda-Roa, Digna and Skjelvan, Ingunn and Wakita, Masahide and White, Angelicque and Tanhua, Toste},
title = {Synthesis Product for Ocean Time Series (SPOTS) – a ship-based biogeochemical pilot},
journal = {Earth System Science Data},
publisher = {Copernicus GmbH},
year = {2024},
volume = {16},
number = {4},
pages = {1901--1931},
doi = {10.5194/essd-16-1901-2024}
}
|
| Leppänen P-K, Kinnunen A, Hautamäki R, Järvi L, Havu M, Junnila S and Tahvonen O (2024), "Impact of changing urban typologies on residential vegetation and its climate-effects – A case study from Helsinki, Finland", Urban Forestry & Urban Greening., June, 2024. Vol. 96, pp. 128343. Elsevier BV. |
BibTeX:
@article{Leppaenen2024,
author = {Leppänen, Paula-Kaisa and Kinnunen, Antti and Hautamäki, Ranja and Järvi, Leena and Havu, Minttu and Junnila, Seppo and Tahvonen, Outi},
title = {Impact of changing urban typologies on residential vegetation and its climate-effects – A case study from Helsinki, Finland},
journal = {Urban Forestry & Urban Greening},
publisher = {Elsevier BV},
year = {2024},
volume = {96},
pages = {128343},
doi = {10.1016/j.ufug.2024.128343}
}
|
| Li Z, Grant RF, Chang K-Y, Hodgkins SB, Tang J, Cory A, Mekonnen ZA, Saleska SR, Brodie EL, Varner RK, Rich VI, Wilson RM, Chanton JP, Crill P and Riley WJ (2024), "Soil incubation methods lead to large differences in inferred methane production temperature sensitivity", Environmental Research Letters., April, 2024. Vol. 19(4), pp. 044069. IOP Publishing. |
BibTeX:
@article{Li2024,
author = {Li, Zhen and Grant, Robert F and Chang, Kuang-Yu and Hodgkins, Suzanne B and Tang, Jinyun and Cory, Alexandra and Mekonnen, Zelalem A and Saleska, Scott R and Brodie, Eoin L and Varner, Ruth K and Rich, Virginia I and Wilson, Rachel M and Chanton, Jeff P and Crill, Patrick and Riley, William J},
title = {Soil incubation methods lead to large differences in inferred methane production temperature sensitivity},
journal = {Environmental Research Letters},
publisher = {IOP Publishing},
year = {2024},
volume = {19},
number = {4},
pages = {044069},
doi = {10.1088/1748-9326/ad3565}
}
|
| Li X, Markkanen T, Korkiakoski M, Lohila A, Leppänen A, Aalto T, Peltoniemi M, Mäkipää R, Kleinen T and Raivonen M (2024), "Modelling alternative harvest effects on soil CO2 and CH4 fluxes from peatland forests", Science of The Total Environment., November, 2024. Vol. 951, pp. 175257. Elsevier BV. |
BibTeX:
@article{Li2024a,
author = {Li, Xuefei and Markkanen, Tiina and Korkiakoski, Mika and Lohila, Annalea and Leppänen, Antti and Aalto, Tuula and Peltoniemi, Mikko and Mäkipää, Raisa and Kleinen, Thomas and Raivonen, Maarit},
title = {Modelling alternative harvest effects on soil CO2 and CH4 fluxes from peatland forests},
journal = {Science of The Total Environment},
publisher = {Elsevier BV},
year = {2024},
volume = {951},
pages = {175257},
doi = {10.1016/j.scitotenv.2024.175257}
}
|
| Lu X, Groh J, Graf A, Pütz T, Schneider K, Si B, Vereecken H and Franssen H-JH (2024), "Analysis of scale-dependent spatial correlations of actual evapotranspiration measured by lysimeters", Agricultural and Forest Meteorology., December, 2024. Vol. 359, pp. 110288. Elsevier BV. |
BibTeX:
@article{Lu2024,
author = {Lu, Xiao and Groh, Jannis and Graf, Alexander and Pütz, Thomas and Schneider, Katrin and Si, Bingcheng and Vereecken, Harry and Franssen, Harrie-Jan Hendricks},
title = {Analysis of scale-dependent spatial correlations of actual evapotranspiration measured by lysimeters},
journal = {Agricultural and Forest Meteorology},
publisher = {Elsevier BV},
year = {2024},
volume = {359},
pages = {110288},
doi = {10.1016/j.agrformet.2024.110288}
}
|
| Lucarini A, Cascio ML, Marras S, Sirca C and Spano D (2024), "Artificial intelligence and Eddy covariance: A review", Science of The Total Environment., November, 2024. Vol. 950, pp. 175406. Elsevier BV. |
BibTeX:
@article{Lucarini2024,
author = {Lucarini, Arianna and Cascio, Mauro Lo and Marras, Serena and Sirca, Costantino and Spano, Donatella},
title = {Artificial intelligence and Eddy covariance: A review},
journal = {Science of The Total Environment},
publisher = {Elsevier BV},
year = {2024},
volume = {950},
pages = {175406},
doi = {10.1016/j.scitotenv.2024.175406}
}
|
| Ma Lu S, Yang D, Anderson MC, Zainali S, Stridh B, Avelin A and Campana PE (2024), "Photosynthetically active radiation separation model for high-latitude regions in agrivoltaic systems modeling", Journal of Renewable and Sustainable Energy., January, 2024. Vol. 16(1) AIP Publishing. |
BibTeX:
@article{MaLu2024,
author = {Ma Lu, S. and Yang, D. and Anderson, M. C. and Zainali, S. and Stridh, B. and Avelin, A. and Campana, P. E.},
title = {Photosynthetically active radiation separation model for high-latitude regions in agrivoltaic systems modeling},
journal = {Journal of Renewable and Sustainable Energy},
publisher = {AIP Publishing},
year = {2024},
volume = {16},
number = {1},
doi = {10.1063/5.0181311}
}
|
| Martellucci R, Giani M, Mauri E, Coppola L, Paulsen M, Fourrier M, Pensieri S, Cardin V, Dentico C, Bozzano R, Cantoni C, Lucchetta A, Izquierdo A, Bruno M and Skjelvan I (2024), "CO2 and hydrography acquired by autonomous surface vehicles from the Atlantic Ocean to the Mediterranean Sea: data correction and validation", Earth System Science Data., November, 2024. Vol. 16(11), pp. 5333-5356. Copernicus GmbH. |
BibTeX:
@article{Martellucci2024,
author = {Martellucci, Riccardo and Giani, Michele and Mauri, Elena and Coppola, Laurent and Paulsen, Melf and Fourrier, Marine and Pensieri, Sara and Cardin, Vanessa and Dentico, Carlotta and Bozzano, Roberto and Cantoni, Carolina and Lucchetta, Anna and Izquierdo, Alfredo and Bruno, Miguel and Skjelvan, Ingunn},
title = {CO2 and hydrography acquired by autonomous surface vehicles from the Atlantic Ocean to the Mediterranean Sea: data correction and validation},
journal = {Earth System Science Data},
publisher = {Copernicus GmbH},
year = {2024},
volume = {16},
number = {11},
pages = {5333--5356},
doi = {10.5194/essd-16-5333-2024}
}
|
| Martínez-García E, Nilsson MB, Laudon H, Lundmark T, Fransson JES, Wallerman J and Peichl M (2024), "Drought response of the boreal forest carbon sink is driven by understorey–tree composition", Nature Geoscience. Vol. 17(3), pp. 197-204. |
| Abstract: The boreal forest is an important global carbon sink, but its response to drought remains uncertain. Here, we compiled biometric- and chamber-based flux data from 50 boreal forest stands to assess the impact of the 2018 European summer drought on net ecosystem production (NEP) across a 68 km2 managed landscape in northern Sweden. Our results reveal a non-uniform reduction in NEP (on average by 80 ± 16 g C m−2 yr−1 or 57 ± 13%) across the landscape, which was greatest in young stands of 20–50 years (95 ± 39 g C m−2 yr−1), but gradually decreased towards older stands (54 ± 57 g C m−2 yr−1). This pattern was attributed to the higher sensitivity of forest-floor understorey to drought and its decreasing contribution to production relative to trees during stand development. This suggests that an age-dependent shift in understorey–tree composition with increasing stand age drives the drought response of the boreal forest NEP. Thus, our study advocates the need for partitioning ecosystem responses to improve empirical and modelling assessments of carbon cycle–climate feedbacks in boreal forests. It further implies that the forest age structure may strongly determine the carbon sink response to the projected increase in drought events across the managed boreal landscape. |
BibTeX:
@article{MartinezGarcia2024,
author = {Martínez-García, Eduardo and Nilsson, Mats B and Laudon, Hjalmar and Lundmark, Tomas and Fransson, Johan E S and Wallerman, Jörgen and Peichl, Matthias},
title = {Drought response of the boreal forest carbon sink is driven by understorey–tree composition},
journal = {Nature Geoscience},
year = {2024},
volume = {17},
number = {3},
pages = {197--204},
url = {https://doi.org/10.1038/s41561-024-01374-9},
doi = {10.1038/s41561-024-01374-9}
}
|
| Mauder M, Jung M, Stoy P, Nelson J and Wanner L (2024), "Energy balance closure at FLUXNET sites revisited", Agricultural and Forest Meteorology., November, 2024. Vol. 358, pp. 110235. Elsevier BV. |
BibTeX:
@article{Mauder2024,
author = {Mauder, Matthias and Jung, Martin and Stoy, Paul and Nelson, Jacob and Wanner, Luise},
title = {Energy balance closure at FLUXNET sites revisited},
journal = {Agricultural and Forest Meteorology},
publisher = {Elsevier BV},
year = {2024},
volume = {358},
pages = {110235},
doi = {10.1016/j.agrformet.2024.110235}
}
|
| Mayer L, Degrendele C, Šenk P, Kohoutek J, Přibylová P, Kukučka P, Melymuk L, Durand A, Ravier S, Alastuey A, Baker AR, Baltensperger U, Baumann-Stanzer K, Biermann T, Bohlin-Nizzetto P, Ceburnis D, Conil S, Couret C, Degórska A, Diapouli E, Eckhardt S, Eleftheriadis K, Forster GL, Freier K, Gheusi F, Gini MI, Hellén H, Henne S, Herrmann H, Holubová Šmejkalová A, Hõrrak U, Hüglin C, Junninen H, Kristensson A, Langrene L, Levula J, Lothon M, Ludewig E, Makkonen U, Matejovičová J, Mihalopoulos N, Mináriková V, Moche W, Noe SM, Pérez N, Petäjä T, Pont V, Poulain L, Quivet E, Ratz G, Rehm T, Reimann S, Simmons I, Sonke JE, Sorribas M, Spoor R, Swart DPJ, Vasilatou V, Wortham H, Yela M, Zarmpas P, Zellweger Fäsi C, Tørseth K, Laj P, Klánová J and Lammel G (2024), "Widespread Pesticide Distribution in the European Atmosphere Questions their Degradability in Air", Environmental Science & Technology., February, 2024. American Chemical Society (ACS). |
BibTeX:
@article{Mayer2024,
author = {Mayer, Ludovic and Degrendele, Céline and Šenk, Petr and Kohoutek, Jiři and Přibylová, Petra and Kukučka, Petr and Melymuk, Lisa and Durand, Amandine and Ravier, Sylvain and Alastuey, Andres and Baker, Alex R. and Baltensperger, Urs and Baumann-Stanzer, Kathrin and Biermann, Tobias and Bohlin-Nizzetto, Pernilla and Ceburnis, Darius and Conil, Sébastien and Couret, Cédric and Degórska, Anna and Diapouli, Evangelia and Eckhardt, Sabine and Eleftheriadis, Konstantinos and Forster, Grant L. and Freier, Korbinian and Gheusi, François and Gini, Maria I. and Hellén, Heidi and Henne, Stephan and Herrmann, Hartmut and Holubová Šmejkalová, Adéla and Hõrrak, Urmas and Hüglin, Christoph and Junninen, Heikki and Kristensson, Adam and Langrene, Laurent and Levula, Janne and Lothon, Marie and Ludewig, Elke and Makkonen, Ulla and Matejovičová, Jana and Mihalopoulos, Nikolaos and Mináriková, Veronika and Moche, Wolfgang and Noe, Steffen M. and Pérez, Noemí and Petäjä, Tuukka and Pont, Véronique and Poulain, Laurent and Quivet, Etienne and Ratz, Gabriela and Rehm, Till and Reimann, Stefan and Simmons, Ivan and Sonke, Jeroen E. and Sorribas, Mar and Spoor, Ronald and Swart, Daan P. J. and Vasilatou, Vasiliki and Wortham, Henri and Yela, Margarita and Zarmpas, Pavlos and Zellweger Fäsi, Claudia and Tørseth, Kjetil and Laj, Paolo and Klánová, Jana and Lammel, Gerhard},
title = {Widespread Pesticide Distribution in the European Atmosphere Questions their Degradability in Air},
journal = {Environmental Science & Technology},
publisher = {American Chemical Society (ACS)},
year = {2024},
doi = {10.1021/acs.est.3c08488}
}
|
| McDonald MD, Owusu-Ansah C, Ellenbogen JB, Malone ZD, Ricketts MP, Frolking SE, Ernakovich JG, Ibba M, Bagby SC and Weissman J (2024), "What is microbial dormancy?", Trends in Microbiology., February, 2024. Vol. 32(2), pp. 142-150. Elsevier BV. |
BibTeX:
@article{McDonald2024,
author = {McDonald, Mark D. and Owusu-Ansah, Carlos and Ellenbogen, Jared B. and Malone, Zachary D. and Ricketts, Michael P. and Frolking, Steve E. and Ernakovich, Jessica Gilman and Ibba, Michael and Bagby, Sarah C. and Weissman, J.L.},
title = {What is microbial dormancy?},
journal = {Trends in Microbiology},
publisher = {Elsevier BV},
year = {2024},
volume = {32},
number = {2},
pages = {142--150},
doi = {10.1016/j.tim.2023.08.006}
}
|
| McGivern BB, Cronin DR, Ellenbogen JB, Borton MA, Knutson EL, Freire-Zapata V, Bouranis JA, Bernhardt L, Hernandez AI, Flynn RM, Woyda R, Cory AB, Wilson RM, Chanton JP, Woodcroft BJ, Ernakovich JG, Tfaily MM, Sullivan MB, Tyson GW, Rich VI, Hagerman AE and Wrighton KC (2024), "Microbial polyphenol metabolism is part of the thawing permafrost carbon cycle", Nature Microbiology., May, 2024. Vol. 9(6), pp. 1454-1466. Springer Science and Business Media LLC. |
BibTeX:
@article{McGivern2024,
author = {McGivern, Bridget B. and Cronin, Dylan R. and Ellenbogen, Jared B. and Borton, Mikayla A. and Knutson, Eleanor L. and Freire-Zapata, Viviana and Bouranis, John A. and Bernhardt, Lukas and Hernandez, Alma I. and Flynn, Rory M. and Woyda, Reed and Cory, Alexandra B. and Wilson, Rachel M. and Chanton, Jeffrey P. and Woodcroft, Ben J. and Ernakovich, Jessica G. and Tfaily, Malak M. and Sullivan, Matthew B. and Tyson, Gene W. and Rich, Virginia I. and Hagerman, Ann E. and Wrighton, Kelly C.},
title = {Microbial polyphenol metabolism is part of the thawing permafrost carbon cycle},
journal = {Nature Microbiology},
publisher = {Springer Science and Business Media LLC},
year = {2024},
volume = {9},
number = {6},
pages = {1454--1466},
doi = {10.1038/s41564-024-01691-0}
}
|
| Mironov VL and Linkevich EV (2024), "Effects of the lunar cycle on ecosystem and heterotrophic respiration in a boreal Sphagnum -dominated peatland", Chronobiology International., June, 2024. Vol. 41(7), pp. 929-940. Informa UK Limited. |
BibTeX:
@article{Mironov2024,
author = {Mironov, Victor L. and Linkevich, Elizaveta V.},
title = {Effects of the lunar cycle on ecosystem and heterotrophic respiration in a boreal Sphagnum -dominated peatland},
journal = {Chronobiology International},
publisher = {Informa UK Limited},
year = {2024},
volume = {41},
number = {7},
pages = {929--940},
doi = {10.1080/07420528.2024.2365825}
}
|
| Monteil G, Theanutti Kallingal J and Scholze M (2024), "CH4 emissions from Northern Europe wetlands: compared data assimilation approaches", EGUsphere., December, 2024. Copernicus GmbH. |
BibTeX:
@article{Monteil2024,
author = {Monteil, Guillaume and Theanutti Kallingal, Jalisha and Scholze, Marko},
title = {CH4 emissions from Northern Europe wetlands: compared data assimilation approaches},
journal = {EGUsphere},
publisher = {Copernicus GmbH},
year = {2024},
doi = {10.5194/egusphere-2024-3122}
}
|
| Monteith A, Ulander L, Steele-Dunne S, Bennet P, Westin J, Persson H, Leistner T, Laudon H and Fransson JE (2024), "A Tower-Based Radar Experiment for Studying the Effects of Boreal Forest Tree-Water Relations" Elsevier BV. |
BibTeX:
@article{Monteith2024,
author = {Monteith, Albert and Ulander, Lars and Steele-Dunne, Susan and Bennet, Patrik and Westin, Johan and Persson, Henrik and Leistner, Theresa and Laudon, Hjalmar and Fransson, Johan E.S.},
title = {A Tower-Based Radar Experiment for Studying the Effects of Boreal Forest Tree-Water Relations},
publisher = {Elsevier BV},
year = {2024},
doi = {10.2139/ssrn.4991471}
}
|
| Morichetti M, Vangi E and Collalti A (2024), "Predicted Future Changes in the Mean Seasonal Carbon Cycle Due to Climate Change", Forests., June, 2024. Vol. 15(7), pp. 1124. MDPI AG. |
BibTeX:
@article{Morichetti2024,
author = {Morichetti, Mauro and Vangi, Elia and Collalti, Alessio},
title = {Predicted Future Changes in the Mean Seasonal Carbon Cycle Due to Climate Change},
journal = {Forests},
publisher = {MDPI AG},
year = {2024},
volume = {15},
number = {7},
pages = {1124},
doi = {10.3390/f15071124}
}
|
| Mosquera V, Laudon H, Karimi S, Sponseller R and Hasselquist EM (2024), "Cumulative and Discrete Effects of Forest Harvest and Drainage on the Hydrological Regime and Nutrient Dynamics in Boreal Catchments", Forest Ecology and Management. Elsevier BV. |
BibTeX:
@article{Mosquera2024,
author = {Mosquera, Virginia and Laudon, Hjalmar and Karimi, Shirin and Sponseller, Ryan and Hasselquist, Eliza Maher},
title = {Cumulative and Discrete Effects of Forest Harvest and Drainage on the Hydrological Regime and Nutrient Dynamics in Boreal Catchments},
journal = {Forest Ecology and Management},
publisher = {Elsevier BV},
year = {2024},
doi = {10.2139/ssrn.4948880}
}
|
| Müller M, Olsson P-O, Eklundh L, Jamali S and Ardö J (2024), "Response and resilience to drought in northern forests revealed by Sentinel-2", International Journal of Remote Sensing., July, 2024. Vol. 45(15), pp. 5130-5157. Informa UK Limited. |
BibTeX:
@article{Mueller2024,
author = {Müller, M. and Olsson, P.-O. and Eklundh, L. and Jamali, S. and Ardö, J.},
title = {Response and resilience to drought in northern forests revealed by Sentinel-2},
journal = {International Journal of Remote Sensing},
publisher = {Informa UK Limited},
year = {2024},
volume = {45},
number = {15},
pages = {5130--5157},
doi = {10.1080/01431161.2024.2372076}
}
|
| Nagy Z, Balogh J, Petrás D, Fóti S, MacArthur A and Pintér K (2024), "Detecting drought stress occurrence using synergies between Sun induced fluorescence and vegetation surface temperature spatial records", Science of The Total Environment., jan, 2024. Vol. 907, pp. 168053. Elsevier BV. |
BibTeX:
@article{Nagy2024,
author = {Nagy, Zoltán and Balogh, János and Petrás, Dóra and Fóti, Szilvia and MacArthur, Alasdair and Pintér, Krisztina},
title = {Detecting drought stress occurrence using synergies between Sun induced fluorescence and vegetation surface temperature spatial records},
journal = {Science of The Total Environment},
publisher = {Elsevier BV},
year = {2024},
volume = {907},
pages = {168053},
url = {http://dx.doi.org/10.1016/J.SCITOTENV.2023.168053},
doi = {10.1016/j.scitotenv.2023.168053}
}
|
| Nelson JA, Walther S, Gans F, Kraft B, Weber U, Novick K, Buchmann N, Migliavacca M, Wohlfahrt G, Šigut L, Ibrom A, Papale D, Göckede M, Duveiller G, Knohl A, Hörtnagl L, Scott RL, Dušek J, Zhang W, Hamdi ZM, Reichstein M, Aranda-Barranco S, Ardö J, Op de Beeck M, Billesbach D, Bowling D, Bracho R, Brümmer C, Camps-Valls G, Chen S, Cleverly JR, Desai A, Dong G, El-Madany TS, Euskirchen ES, Feigenwinter I, Galvagno M, Gerosa GA, Gielen B, Goded I, Goslee S, Gough CM, Heinesch B, Ichii K, Jackowicz-Korczynski MA, Klosterhalfen A, Knox S, Kobayashi H, Kohonen K-M, Korkiakoski M, Mammarella I, Gharun M, Marzuoli R, Matamala R, Metzger S, Montagnani L, Nicolini G, O’Halloran T, Ourcival J-M, Peichl M, Pendall E, Ruiz Reverter B, Roland M, Sabbatini S, Sachs T, Schmidt M, Schwalm CR, Shekhar A, Silberstein R, Silveira ML, Spano D, Tagesson T, Tramontana G, Trotta C, Turco F, Vesala T, Vincke C, Vitale D, Vivoni ER, Wang Y, Woodgate W, Yepez EA, Zhang J, Zona D and Jung M (2024), "X-BASE: the first terrestrial carbon and water flux products from an extended data-driven scaling framework, FLUXCOM-X", Biogeosciences., November, 2024. Vol. 21(22), pp. 5079-5115. Copernicus GmbH. |
BibTeX:
@article{Nelson2024,
author = {Nelson, Jacob A. and Walther, Sophia and Gans, Fabian and Kraft, Basil and Weber, Ulrich and Novick, Kimberly and Buchmann, Nina and Migliavacca, Mirco and Wohlfahrt, Georg and Šigut, Ladislav and Ibrom, Andreas and Papale, Dario and Göckede, Mathias and Duveiller, Gregory and Knohl, Alexander and Hörtnagl, Lukas and Scott, Russell L. and Dušek, Jiří and Zhang, Weijie and Hamdi, Zayd Mahmoud and Reichstein, Markus and Aranda-Barranco, Sergio and Ardö, Jonas and Op de Beeck, Maarten and Billesbach, Dave and Bowling, David and Bracho, Rosvel and Brümmer, Christian and Camps-Valls, Gustau and Chen, Shiping and Cleverly, Jamie Rose and Desai, Ankur and Dong, Gang and El-Madany, Tarek S. and Euskirchen, Eugenie Susanne and Feigenwinter, Iris and Galvagno, Marta and Gerosa, Giacomo A. and Gielen, Bert and Goded, Ignacio and Goslee, Sarah and Gough, Christopher Michael and Heinesch, Bernard and Ichii, Kazuhito and Jackowicz-Korczynski, Marcin Antoni and Klosterhalfen, Anne and Knox, Sara and Kobayashi, Hideki and Kohonen, Kukka-Maaria and Korkiakoski, Mika and Mammarella, Ivan and Gharun, Mana and Marzuoli, Riccardo and Matamala, Roser and Metzger, Stefan and Montagnani, Leonardo and Nicolini, Giacomo and O’Halloran, Thomas and Ourcival, Jean-Marc and Peichl, Matthias and Pendall, Elise and Ruiz Reverter, Borja and Roland, Marilyn and Sabbatini, Simone and Sachs, Torsten and Schmidt, Marius and Schwalm, Christopher R. and Shekhar, Ankit and Silberstein, Richard and Silveira, Maria Lucia and Spano, Donatella and Tagesson, Torbern and Tramontana, Gianluca and Trotta, Carlo and Turco, Fabio and Vesala, Timo and Vincke, Caroline and Vitale, Domenico and Vivoni, Enrique R. and Wang, Yi and Woodgate, William and Yepez, Enrico A. and Zhang, Junhui and Zona, Donatella and Jung, Martin},
title = {X-BASE: the first terrestrial carbon and water flux products from an extended data-driven scaling framework, FLUXCOM-X},
journal = {Biogeosciences},
publisher = {Copernicus GmbH},
year = {2024},
volume = {21},
number = {22},
pages = {5079--5115},
doi = {10.5194/bg-21-5079-2024}
}
|
| Nelson JA, Walther S, Gans F, Kraft B, Weber U, Novick K, Buchmann N, Migliavacca M, Wohlfahrt G, Šigut L, Ibrom A, Papale D, Göckede M, Duveiller G, Knohl A, Hörtnagl L, Scott RL, Zhang W, Hamdi ZM, Reichstein M, Aranda-Barranco S, Ardö J, Op de Beeck M, Billdesbach D, Bowling D, Bracho R, Brümmer C, Camps-Valls G, Chen S, Cleverly JR, Desai A, Dong G, El-Madany TS, Euskirchen ES, Feigenwinter I, Galvagno M, Gerosa G, Gielen B, Goded I, Goslee S, Gough CM, Heinesch B, Ichii K, Jackowicz-Korczynski MA, Klosterhalfen A, Knox S, Kobayashi H, Kohonen K-M, Korkiakoski M, Mammarella I, Mana G, Marzuoli R, Matamala R, Metzger S, Montagnani L, Nicolini G, O’Halloran T, Ourcival J-M, Peichl M, Pendall E, Ruiz Reverter B, Roland M, Sabbatini S, Sachs T, Schmidt M, Schwalm CR, Shekhar A, Silberstein R, Silveira ML, Spano D, Tagesson T, Tramontana G, Trotta C, Turco F, Vesala T, Vincke C, Vitale D, Vivoni ER, Wang Y, Woodgate W, Yepez EA, Zhang J, Zona D and Jung M (2024), "X-BASE: the first terrestrial carbon and water flux products from an extended data-driven scaling framework, FLUXCOM-X", February, 2024. Copernicus GmbH. |
BibTeX:
@article{Nelson2024a,
author = {Nelson, Jacob A. and Walther, Sophia and Gans, Fabian and Kraft, Basil and Weber, Ulrich and Novick, Kimberly and Buchmann, Nina and Migliavacca, Mirco and Wohlfahrt, Georg and Šigut, Ladislav and Ibrom, Andreas and Papale, Dario and Göckede, Mathias and Duveiller, Gregory and Knohl, Alexander and Hörtnagl, Lukas and Scott, Russell L. and Zhang, Weijie and Hamdi, Zayd Mahmoud and Reichstein, Markus and Aranda-Barranco, Sergio and Ardö, Jonas and Op de Beeck, Maarten and Billdesbach, Dave and Bowling, David and Bracho, Rosvel and Brümmer, Christian and Camps-Valls, Gustau and Chen, Shiping and Cleverly, Jamie Rose and Desai, Ankur and Dong, Gang and El-Madany, Tarek S. and Euskirchen, Eugenie Susanne and Feigenwinter, Iris and Galvagno, Marta and Gerosa, Giacomo and Gielen, Bert and Goded, Ignacio and Goslee, Sarah and Gough, Christopher Michael and Heinesch, Bernard and Ichii, Kazuhito and Jackowicz-Korczynski, Marcin Antoni and Klosterhalfen, Anne and Knox, Sara and Kobayashi, Hideki and Kohonen, Kukka-Maaria and Korkiakoski, Mika and Mammarella, Ivan and Mana, Gharun and Marzuoli, Riccardo and Matamala, Roser and Metzger, Stefan and Montagnani, Leonardo and Nicolini, Giacomo and O’Halloran, Thomas and Ourcival, Jean-Marc and Peichl, Matthias and Pendall, Elise and Ruiz Reverter, Borja and Roland, Marilyn and Sabbatini, Simone and Sachs, Torsten and Schmidt, Marius and Schwalm, Christopher R. and Shekhar, Ankit and Silberstein, Richard and Silveira, Maria Lucia and Spano, Donatella and Tagesson, Torbern and Tramontana, Gianluca and Trotta, Carlo and Turco, Fabio and Vesala, Timo and Vincke, Caroline and Vitale, Domenico and Vivoni, Enrique R. and Wang, Yi and Woodgate, William and Yepez, Enrico A. and Zhang, Junhui and Zona, Donatella and Jung, Martin},
title = {X-BASE: the first terrestrial carbon and water flux products from an extended data-driven scaling framework, FLUXCOM-X},
publisher = {Copernicus GmbH},
year = {2024},
doi = {10.5194/egusphere-2024-165}
}
|
| Nousu J-P, Leppä K, Marttila H, Ala-aho P, Mazzotti G, Manninen T, Korkiakoski M, Aurela M, Lohila A and Launiainen S (2024), "Multi-scale soil moisture data and process-based modeling reveal the importance of lateral groundwater flow in a subarctic catchment", Hydrology and Earth System Sciences., October, 2024. Vol. 28(20), pp. 4643-4666. Copernicus GmbH. |
BibTeX:
@article{Nousu2024,
author = {Nousu, Jari-Pekka and Leppä, Kersti and Marttila, Hannu and Ala-aho, Pertti and Mazzotti, Giulia and Manninen, Terhikki and Korkiakoski, Mika and Aurela, Mika and Lohila, Annalea and Launiainen, Samuli},
title = {Multi-scale soil moisture data and process-based modeling reveal the importance of lateral groundwater flow in a subarctic catchment},
journal = {Hydrology and Earth System Sciences},
publisher = {Copernicus GmbH},
year = {2024},
volume = {28},
number = {20},
pages = {4643--4666},
doi = {10.5194/hess-28-4643-2024}
}
|
| Nousu J-P, Lafaysse M, Mazzotti G, Ala-aho P, Marttila H, Cluzet B, Aurela M, Lohila A, Kolari P, Boone A, Fructus M and Launiainen S (2024), "Modeling snowpack dynamics and surface energy budget in boreal and subarctic peatlands and forests", The Cryosphere., January, 2024. Vol. 18(1), pp. 231-263. Copernicus GmbH. |
BibTeX:
@article{Nousu2024a,
author = {Nousu, Jari-Pekka and Lafaysse, Matthieu and Mazzotti, Giulia and Ala-aho, Pertti and Marttila, Hannu and Cluzet, Bertrand and Aurela, Mika and Lohila, Annalea and Kolari, Pasi and Boone, Aaron and Fructus, Mathieu and Launiainen, Samuli},
title = {Modeling snowpack dynamics and surface energy budget in boreal and subarctic peatlands and forests},
journal = {The Cryosphere},
publisher = {Copernicus GmbH},
year = {2024},
volume = {18},
number = {1},
pages = {231--263},
doi = {10.5194/tc-18-231-2024}
}
|
| Padilla R, Adame J, Hidalgo P, Bolivar J and Yela M (2024), "Short-term trend and temporal variations in atmospheric methane at an Atlantic coastal site in Southwestern Europe", Atmospheric Environment., September, 2024. Vol. 333, pp. 120665. Elsevier BV. |
BibTeX:
@article{Padilla2024,
author = {Padilla, R. and Adame, J.A. and Hidalgo, P.J. and Bolivar, J.P. and Yela, M.},
title = {Short-term trend and temporal variations in atmospheric methane at an Atlantic coastal site in Southwestern Europe},
journal = {Atmospheric Environment},
publisher = {Elsevier BV},
year = {2024},
volume = {333},
pages = {120665},
doi = {10.1016/j.atmosenv.2024.120665}
}
|
| Paulus SJ, Orth R, Lee S-C, Hildebrandt A, Jung M, Nelson JA, El-Madany TS, Carrara A, Moreno G, Mauder M, Groh J, Graf A, Reichstein M and Migliavacca M (2024), "Interpretability of negative latent heat fluxes from eddy covariance measurements in dry conditions", Biogeosciences., April, 2024. Vol. 21(8), pp. 2051-2085. Copernicus GmbH. |
BibTeX:
@article{Paulus2024,
author = {Paulus, Sinikka J. and Orth, Rene and Lee, Sung-Ching and Hildebrandt, Anke and Jung, Martin and Nelson, Jacob A. and El-Madany, Tarek Sebastian and Carrara, Arnaud and Moreno, Gerardo and Mauder, Matthias and Groh, Jannis and Graf, Alexander and Reichstein, Markus and Migliavacca, Mirco},
title = {Interpretability of negative latent heat fluxes from eddy covariance measurements in dry conditions},
journal = {Biogeosciences},
publisher = {Copernicus GmbH},
year = {2024},
volume = {21},
number = {8},
pages = {2051--2085},
doi = {10.5194/bg-21-2051-2024}
}
|
| Peng H, Nijp JJ, Ratcliffe JL, Li C, Hong B, Lidberg W, Zeng M, Mauquoy D, Bishop K and Nilsson MB (2024), "Climatic controls on the dynamic lateral expansion of northern peatlands and its potential implication for the ‘anomalous’ atmospheric CH4 rise since the mid-Holocene", Science of The Total Environment., January, 2024. Vol. 908, pp. 168450. Elsevier BV. |
BibTeX:
@article{Peng2024,
author = {Peng, Haijun and Nijp, Jelmer J. and Ratcliffe, Joshua L. and Li, Chuxian and Hong, Bing and Lidberg, William and Zeng, Mengxiu and Mauquoy, Dmitri and Bishop, Kevin and Nilsson, Mats B.},
title = {Climatic controls on the dynamic lateral expansion of northern peatlands and its potential implication for the ‘anomalous’ atmospheric CH4 rise since the mid-Holocene},
journal = {Science of The Total Environment},
publisher = {Elsevier BV},
year = {2024},
volume = {908},
pages = {168450},
doi = {10.1016/j.scitotenv.2023.168450}
}
|
| Peräkylä O, Rinne E, Ezhova E, Lintunen A, Lohila A, Aalto J, Aurela M, Kolari P and Kulmala M (2024), "Comparison of shortwave radiation dynamics between boreal forest and open peatland pairs in southern and northern Finland", March, 2024. Copernicus GmbH. |
BibTeX:
@article{Peraekylae2024,
author = {Peräkylä, Otso and Rinne, Erkka and Ezhova, Ekaterina and Lintunen, Anna and Lohila, Annalea and Aalto, Juho and Aurela, Mika and Kolari, Pasi and Kulmala, Markku},
title = {Comparison of shortwave radiation dynamics between boreal forest and open peatland pairs in southern and northern Finland},
publisher = {Copernicus GmbH},
year = {2024},
doi = {10.5194/egusphere-2024-712}
}
|
| Petersen RC, Holst T, Wu C, Krejci R, Chan J, Mohr C and Rinne J (2024), "BVOC and speciated monoterpene concentrations and fluxes at a Scandinavian boreal forest", EGUsphere., December, 2024. Copernicus GmbH. |
BibTeX:
@article{Petersen2024,
author = {Petersen, Ross Charles and Holst, Thomas and Wu, Cheng and Krejci, Radovan and Chan, Jeremy and Mohr, Claudia and Rinne, Janne},
title = {BVOC and speciated monoterpene concentrations and fluxes at a Scandinavian boreal forest},
journal = {EGUsphere},
publisher = {Copernicus GmbH},
year = {2024},
doi = {10.5194/egusphere-2024-3410}
}
|
| Poursanidis K, Sharanik J and Hadjistassou C (2024), "World’s largest natural gas leak from nord stream pipeline estimated at 478,000 tonnes", iScience., January, 2024. Vol. 27(1), pp. 108772. Elsevier BV. |
BibTeX:
@article{Poursanidis2024,
author = {Poursanidis, Kostas and Sharanik, Jumana and Hadjistassou, Constantinos},
title = {World’s largest natural gas leak from nord stream pipeline estimated at 478,000 tonnes},
journal = {iScience},
publisher = {Elsevier BV},
year = {2024},
volume = {27},
number = {1},
pages = {108772},
doi = {10.1016/j.isci.2023.108772}
}
|
| Pulliainen J, Aurela M, Aalto T, Böttcher K, Cohen J, Derksen C, Heimann M, Helbig M, Kolari P, Kontu A, Krasnova A, Launiainen S, Lemmetyinen J, Lindqvist H, Lindroth A, Lohila A, Luojus K, Mammarella I, Markkanen T, Nevala E, Noe S, Peichl M, Pumpanen J, Rautiainen K, Salminen M, Sonnentag O, Takala M, Thum T, Vesala T and Vestin P (2024), "Increase in gross primary production of boreal forests balanced out by increase in ecosystem respiration", Remote Sensing of Environment., November, 2024. Vol. 313, pp. 114376. Elsevier BV. |
BibTeX:
@article{Pulliainen2024,
author = {Pulliainen, Jouni and Aurela, Mika and Aalto, Tuula and Böttcher, Kristin and Cohen, Juval and Derksen, Chris and Heimann, Martin and Helbig, Manuel and Kolari, Pasi and Kontu, Anna and Krasnova, Alisa and Launiainen, Samuli and Lemmetyinen, Juha and Lindqvist, Hannakaisa and Lindroth, Anders and Lohila, Annalea and Luojus, Kari and Mammarella, Ivan and Markkanen, Tiina and Nevala, Elma and Noe, Steffen and Peichl, Matthias and Pumpanen, Jukka and Rautiainen, Kimmo and Salminen, Miia and Sonnentag, Oliver and Takala, Matias and Thum, Tea and Vesala, Timo and Vestin, Patrik},
title = {Increase in gross primary production of boreal forests balanced out by increase in ecosystem respiration},
journal = {Remote Sensing of Environment},
publisher = {Elsevier BV},
year = {2024},
volume = {313},
pages = {114376},
doi = {10.1016/j.rse.2024.114376}
}
|
| Rautakoski H, Korkiakoski M, Mäkelä J, Koskinen M, Minkkinen K, Aurela M, Ojanen P and Lohila A (2024), "Exploring temporal and spatial variation of nitrous oxide flux using several years of peatland forest automatic chamber data", Biogeosciences., April, 2024. Vol. 21(7), pp. 1867-1886. Copernicus GmbH. |
BibTeX:
@article{Rautakoski2024,
author = {Rautakoski, Helena and Korkiakoski, Mika and Mäkelä, Jarmo and Koskinen, Markku and Minkkinen, Kari and Aurela, Mika and Ojanen, Paavo and Lohila, Annalea},
title = {Exploring temporal and spatial variation of nitrous oxide flux using several years of peatland forest automatic chamber data},
journal = {Biogeosciences},
publisher = {Copernicus GmbH},
year = {2024},
volume = {21},
number = {7},
pages = {1867--1886},
doi = {10.5194/bg-21-1867-2024}
}
|
| Resplandy L, Hogikyan A, Müller JD, Najjar RG, Bange HW, Bianchi D, Weber T, Cai W, Doney SC, Fennel K, Gehlen M, Hauck J, Lacroix F, Landschützer P, Le Quéré C, Roobaert A, Schwinger J, Berthet S, Bopp L, Chau TTT, Dai M, Gruber N, Ilyina T, Kock A, Manizza M, Lachkar Z, Laruelle GG, Liao E, Lima ID, Nissen C, Rödenbeck C, Séférian R, Toyama K, Tsujino H and Regnier P (2024), "A Synthesis of Global Coastal Ocean Greenhouse Gas Fluxes", Global Biogeochemical Cycles., January, 2024. Vol. 38(1) American Geophysical Union (AGU). |
BibTeX:
@article{Resplandy2024,
author = {Resplandy, L. and Hogikyan, A. and Müller, J. D. and Najjar, R. G. and Bange, H. W. and Bianchi, D. and Weber, T. and Cai, W.‐J. and Doney, S. C. and Fennel, K. and Gehlen, M. and Hauck, J. and Lacroix, F. and Landschützer, P. and Le Quéré, C. and Roobaert, A. and Schwinger, J. and Berthet, S. and Bopp, L. and Chau, T. T. T. and Dai, M. and Gruber, N. and Ilyina, T. and Kock, A. and Manizza, M. and Lachkar, Z. and Laruelle, G. G. and Liao, E. and Lima, I. D. and Nissen, C. and Rödenbeck, C. and Séférian, R. and Toyama, K. and Tsujino, H. and Regnier, P.},
title = {A Synthesis of Global Coastal Ocean Greenhouse Gas Fluxes},
journal = {Global Biogeochemical Cycles},
publisher = {American Geophysical Union (AGU)},
year = {2024},
volume = {38},
number = {1},
doi = {10.1029/2023gb007803}
}
|
| Rinnan R (2024), "Volatile Organic Compound Emissions in the Changing Arctic", Annual Review of Ecology, Evolution, and Systematics., November, 2024. Vol. 55(1), pp. 227-249. Annual Reviews. |
BibTeX:
@article{Rinnan2024,
author = {Rinnan, Riikka},
title = {Volatile Organic Compound Emissions in the Changing Arctic},
journal = {Annual Review of Ecology, Evolution, and Systematics},
publisher = {Annual Reviews},
year = {2024},
volume = {55},
number = {1},
pages = {227--249},
doi = {10.1146/annurev-ecolsys-102722-125156}
}
|
| Rocha AD, Vulova S, Förster M, Gioli B, Matthews B, Helfter C, Meier F, Steeneveld G-J, Barlow JF, Järvi L, Chrysoulakis N, Nicolini G and Kleinschmit B (2024), "Unprivileged groups are less served by green cooling services in major European urban areas", Nature Cities., May, 2024. Vol. 1(6), pp. 424-435. Springer Science and Business Media LLC. |
BibTeX:
@article{Rocha2024,
author = {Rocha, Alby Duarte and Vulova, Stenka and Förster, Michael and Gioli, Beniamino and Matthews, Bradley and Helfter, Carole and Meier, Fred and Steeneveld, Gert-Jan and Barlow, Janet F. and Järvi, Leena and Chrysoulakis, Nektarios and Nicolini, Giacomo and Kleinschmit, Birgit},
title = {Unprivileged groups are less served by green cooling services in major European urban areas},
journal = {Nature Cities},
publisher = {Springer Science and Business Media LLC},
year = {2024},
volume = {1},
number = {6},
pages = {424--435},
doi = {10.1038/s44284-024-00077-x}
}
|
| Saboya E, Manning AJ, Levy P, Stanley KM, Pitt J, Young D, Say D, Grant A, Arnold T, Rennick C, Tomlinson SJ, Carnell EJ, Artioli Y, Stavart A, Spain TG, O’Doherty S, Rigby M and Ganesan AL (2024), "Combining Top‐Down and Bottom‐Up Approaches to Evaluate Recent Trends and Seasonal Patterns in UK N2O Emissions", Journal of Geophysical Research: Atmospheres., July, 2024. Vol. 129(14) American Geophysical Union (AGU). |
BibTeX:
@article{Saboya2024,
author = {Saboya, Eric and Manning, Alistair J. and Levy, Peter and Stanley, Kieran M. and Pitt, Joseph and Young, Dickon and Say, Daniel and Grant, Aoife and Arnold, Tim and Rennick, Chris and Tomlinson, Samuel J. and Carnell, Edward J. and Artioli, Yuri and Stavart, Ann and Spain, T. Gerard and O’Doherty, Simon and Rigby, Matthew and Ganesan, Anita L.},
title = {Combining Top‐Down and Bottom‐Up Approaches to Evaluate Recent Trends and Seasonal Patterns in UK N2O Emissions},
journal = {Journal of Geophysical Research: Atmospheres},
publisher = {American Geophysical Union (AGU)},
year = {2024},
volume = {129},
number = {14},
doi = {10.1029/2024jd040785}
}
|
| Sang J, Zhao Y, Shen Y, Shurpali NJ and Li Y (2024), "Optimizing irrigation and nitrogen addition to balance grassland biomass production with greenhouse gas emissions: A mesocosm study", Environmental Research., May, 2024. Vol. 249, pp. 118387. Elsevier BV. |
BibTeX:
@article{Sang2024,
author = {Sang, Jianhui and Zhao, Yixuan and Shen, Yuying and Shurpali, Narasinha J. and Li, Yuan},
title = {Optimizing irrigation and nitrogen addition to balance grassland biomass production with greenhouse gas emissions: A mesocosm study},
journal = {Environmental Research},
publisher = {Elsevier BV},
year = {2024},
volume = {249},
pages = {118387},
doi = {10.1016/j.envres.2024.118387}
}
|
| Santoro M, Cartus O, Quegan S, Kay H, Lucas RM, Araza A, Herold M, Labrière N, Chave J, Rosenqvist Å, Tadono T, Kobayashi K, Kellndorfer J, Avitabile V, Brown H, Carreiras J, Campbell MJ, Cavlovic J, Bispo PdC, Gilani H, Khan ML, Kumar A, Lewis SL, Liang J, Mitchard ET, Pacheco-Pascagaza AM, Phillips OL, Ryan CM, Saikia P, Schepaschenko D, Sukhdeo H, Verbeeck H, Vieilledent G, Wijaya A, Willcock S and Seifert FM (2024), "Design and performance of the Climate Change Initiative Biomass global retrieval algorithm", Science of Remote Sensing., December, 2024. Vol. 10, pp. 100169. Elsevier BV. |
BibTeX:
@article{Santoro2024,
author = {Santoro, Maurizio and Cartus, Oliver and Quegan, Shaun and Kay, Heather and Lucas, Richard M. and Araza, Arnan and Herold, Martin and Labrière, Nicolas and Chave, Jérôme and Rosenqvist, Åke and Tadono, Takeo and Kobayashi, Kazufumi and Kellndorfer, Josef and Avitabile, Valerio and Brown, Hugh and Carreiras, João and Campbell, Michael J. and Cavlovic, Jura and Bispo, Polyanna da Conceição and Gilani, Hammad and Khan, Mohammed Latif and Kumar, Amit and Lewis, Simon L. and Liang, Jingjing and Mitchard, Edward T.A. and Pacheco-Pascagaza, Ana María and Phillips, Oliver L. and Ryan, Casey M. and Saikia, Purabi and Schepaschenko, Dmitry and Sukhdeo, Hansrajie and Verbeeck, Hans and Vieilledent, Ghislain and Wijaya, Arief and Willcock, Simon and Seifert, Frank Martin},
title = {Design and performance of the Climate Change Initiative Biomass global retrieval algorithm},
journal = {Science of Remote Sensing},
publisher = {Elsevier BV},
year = {2024},
volume = {10},
pages = {100169},
doi = {10.1016/j.srs.2024.100169}
}
|
| Sarneel JM, Hefting MM, Sandén T, van den Hoogen J, Routh D, Adhikari BS, Alatalo JM, Aleksanyan A, Althuizen IHJ, Alsafran MHSA, Atkins JW, Augusto L, Aurela M, Azarov AV, Barrio IC, Beier C, Bejarano MD, Benham SE, Berg B, Bezler NV, Björnsdóttir K, Bolinder MA, Carbognani M, Cazzolla Gatti R, Chelli S, Chistotin MV, Christiansen CT, Courtois P, Crowther TW, Dechoum MS, Djukic I, Duddigan S, Egerton‐Warburton LM, Fanin N, Fantappiè M, Fares S, Fernandes GW, Filippova NV, Fliessbach A, Fuentes D, Godoy R, Grünwald T, Guzmán G, Hawes JE, He Y, Hero J, Hess LL, Hogendoorn K, Høye TT, Jans WWP, Jónsdóttir IS, Keller S, Kepfer‐Rojas S, Kuz’menko NN, Larsen KS, Laudon H, Lembrechts JJ, Li J, Limousin J, Lukin SM, Marques R, Marín C, McDaniel MD, Meek Q, Merzlaya GE, Michelsen A, Montagnani L, Mueller P, Murugan R, Myers‐Smith IH, Nolte S, Ochoa‐Hueso R, Okafor BN, Okorkov VV, Onipchenko VG, Orozco MC, Parkhurst T, Peres CA, Petit Bon M, Petraglia A, Pingel M, Rebmann C, Scheffers BR, Schmidt I, Scholes MC, Sheffer E, Shevtsova LK, Smith SW, Sofo A, Stevenson PR, Strouhalová B, Sundsdal A, Sühs RB, Tamene G, Thomas HJD, Tolunay D, Tomaselli M, Tresch S, Tucker DL, Ulyshen MD, Valdecantos A, Vandvik V, Vanguelova EI, Verheyen K, Wang X, Yahdjian L, Yumashev XS and Keuskamp JA (2024), "Reading tea leaves worldwide: Decoupled drivers of initial litter decomposition mass‐loss rate and stabilization", Ecology Letters., May, 2024. Vol. 27(5) Wiley. |
BibTeX:
@article{Sarneel2024,
author = {Sarneel, Judith M. and Hefting, Mariet M. and Sandén, Taru and van den Hoogen, Johan and Routh, Devin and Adhikari, Bhupendra S. and Alatalo, Juha M. and Aleksanyan, Alla and Althuizen, Inge H. J. and Alsafran, Mohammed H. S. A. and Atkins, Jeff W. and Augusto, Laurent and Aurela, Mika and Azarov, Aleksej V. and Barrio, Isabel C. and Beier, Claus and Bejarano, María D. and Benham, Sue E. and Berg, Björn and Bezler, Nadezhda V. and Björnsdóttir, Katrín and Bolinder, Martin A. and Carbognani, Michele and Cazzolla Gatti, Roberto and Chelli, Stefano and Chistotin, Maxim V. and Christiansen, Casper T. and Courtois, Pascal and Crowther, Thomas W. and Dechoum, Michele S. and Djukic, Ika and Duddigan, Sarah and Egerton‐Warburton, Louise M. and Fanin, Nicolas and Fantappiè, Maria and Fares, Silvano and Fernandes, Geraldo W. and Filippova, Nina V. and Fliessbach, Andreas and Fuentes, David and Godoy, Roberto and Grünwald, Thomas and Guzmán, Gema and Hawes, Joseph E. and He, Yue and Hero, Jean‐Marc and Hess, Laura L. and Hogendoorn, Katja and Høye, Toke T. and Jans, Wilma W. P. and Jónsdóttir, Ingibjörg S. and Keller, Sabina and Kepfer‐Rojas, Sebastian and Kuz’menko, Natalya N. and Larsen, Klaus S. and Laudon, Hjalmar and Lembrechts, Jonas J. and Li, Junhui and Limousin, Jean‐Marc and Lukin, Sergey M. and Marques, Renato and Marín, César and McDaniel, Marshall D. and Meek, Qi and Merzlaya, Genrietta E. and Michelsen, Anders and Montagnani, Leonardo and Mueller, Peter and Murugan, Rajasekaran and Myers‐Smith, Isla H. and Nolte, Stefanie and Ochoa‐Hueso, Raúl and Okafor, Bernard N. and Okorkov, Vladimir V. and Onipchenko, Vladimir G. and Orozco, María C. and Parkhurst, Tina and Peres, Carlos A. and Petit Bon, Matteo and Petraglia, Alessandro and Pingel, Martin and Rebmann, Corinna and Scheffers, Brett R. and Schmidt, Inger and Scholes, Mary C. and Sheffer, Efrat and Shevtsova, Lyudmila K. and Smith, Stuart W. and Sofo, Adriano and Stevenson, Pablo R. and Strouhalová, Barbora and Sundsdal, Anders and Sühs, Rafael B. and Tamene, Gebretsadik and Thomas, Haydn J. D. and Tolunay, Duygu and Tomaselli, Marcello and Tresch, Simon and Tucker, Dominique L. and Ulyshen, Michael D. and Valdecantos, Alejandro and Vandvik, Vigdis and Vanguelova, Elena I. and Verheyen, Kris and Wang, Xuhui and Yahdjian, Laura and Yumashev, Xaris S. and Keuskamp, Joost A.},
title = {Reading tea leaves worldwide: Decoupled drivers of initial litter decomposition mass‐loss rate and stabilization},
journal = {Ecology Letters},
publisher = {Wiley},
year = {2024},
volume = {27},
number = {5},
doi = {10.1111/ele.14415}
}
|
| Saunois M, Martinez A, Poulter B, Zhang Z, Raymond P, Regnier P, Canadell JG, Jackson RB, Patra PK, Bousquet P, Ciais P, Dlugokencky EJ, Lan X, Allen GH, Bastviken D, Beerling DJ, Belikov DA, Blake DR, Castaldi S, Crippa M, Deemer BR, Dennison F, Etiope G, Gedney N, Höglund-Isaksson L, Holgerson MA, Hopcroft PO, Hugelius G, Ito A, Jain AK, Janardanan R, Johnson MS, Kleinen T, Krummel P, Lauerwald R, Li T, Liu X, McDonald KC, Melton JR, Mühle J, Müller J, Murguia-Flores F, Niwa Y, Noce S, Pan S, Parker RJ, Peng C, Ramonet M, Riley WJ, Rocher-Ros G, Rosentreter JA, Sasakawa M, Segers A, Smith SJ, Stanley EH, Thanwerdas J, Tian H, Tsuruta A, Tubiello FN, Weber TS, van der Werf G, Worthy DE, Xi Y, Yoshida Y, Zhang W, Zheng B, Zhu Q, Zhu Q and Zhuang Q (2024), "Global Methane Budget 2000–2020", Earth System Science Data., June, 2024. Copernicus GmbH. |
BibTeX:
@article{Saunois2024,
author = {Saunois, Marielle and Martinez, Adrien and Poulter, Benjamin and Zhang, Zhen and Raymond, Peter and Regnier, Pierre and Canadell, Joseph G. and Jackson, Robert B. and Patra, Prabir K. and Bousquet, Philippe and Ciais, Philippe and Dlugokencky, Edward J. and Lan, Xin and Allen, George H. and Bastviken, David and Beerling, David J. and Belikov, Dmitry A. and Blake, Donald R. and Castaldi, Simona and Crippa, Monica and Deemer, Bridget R. and Dennison, Fraser and Etiope, Giuseppe and Gedney, Nicola and Höglund-Isaksson, Lena and Holgerson, Meredith A. and Hopcroft, Peter O. and Hugelius, Gustaf and Ito, Akihito and Jain, Atul K. and Janardanan, Rajesh and Johnson, Matthew S. and Kleinen, Thomas and Krummel, Paul and Lauerwald, Ronny and Li, Tingting and Liu, Xiangyu and McDonald, Kyle C. and Melton, Joe R. and Mühle, Jens and Müller, Jurek and Murguia-Flores, Fabiola and Niwa, Yosuke and Noce, Sergio and Pan, Shufen and Parker, Robert J. and Peng, Changhui and Ramonet, Michel and Riley, William J. and Rocher-Ros, Gerard and Rosentreter, Judith A. and Sasakawa, Motoki and Segers, Arjo and Smith, Steven J. and Stanley, Emily H. and Thanwerdas, Joel and Tian, Hanquin and Tsuruta, Aki and Tubiello, Francesco N. and Weber, Thomas S. and van der Werf, Guido and Worthy, Doug E. and Xi, Yi and Yoshida, Yukio and Zhang, Wenxin and Zheng, Bo and Zhu, Qing and Zhu, Qiuan and Zhuang, Qianlai},
title = {Global Methane Budget 2000–2020},
journal = {Earth System Science Data},
publisher = {Copernicus GmbH},
year = {2024},
doi = {10.5194/essd-2024-115}
}
|
| Scapucci L, Shekhar A, Aranda-Barranco S, Bolshakova A, Hörtnagl L, Gharun M and Buchmann N (2024), "Compound soil and atmospheric drought (CSAD) events and CO2 fluxes of a mixed deciduous forest: the occurrence, impact, and temporal contribution of main drivers", Biogeosciences., August, 2024. Vol. 21(15), pp. 3571-3592. Copernicus GmbH. |
BibTeX:
@article{Scapucci2024,
author = {Scapucci, Liliana and Shekhar, Ankit and Aranda-Barranco, Sergio and Bolshakova, Anastasiia and Hörtnagl, Lukas and Gharun, Mana and Buchmann, Nina},
title = {Compound soil and atmospheric drought (CSAD) events and CO2 fluxes of a mixed deciduous forest: the occurrence, impact, and temporal contribution of main drivers},
journal = {Biogeosciences},
publisher = {Copernicus GmbH},
year = {2024},
volume = {21},
number = {15},
pages = {3571--3592},
doi = {10.5194/bg-21-3571-2024}
}
|
| Schneider E, Rüger CP, Chacón-Patiño ML, Somero M, Ruppel MM, Ihalainen M, Köster K, Sippula O, Czech H and Zimmermann R (2024), "The complex composition of organic aerosols emitted during burning varies between Arctic and boreal peat", Communications Earth & Environment., March, 2024. Vol. 5(1) Springer Science and Business Media LLC. |
BibTeX:
@article{Schneider2024,
author = {Schneider, Eric and Rüger, Christopher P. and Chacón-Patiño, Martha L. and Somero, Markus and Ruppel, Meri M. and Ihalainen, Mika and Köster, Kajar and Sippula, Olli and Czech, Hendryk and Zimmermann, Ralf},
title = {The complex composition of organic aerosols emitted during burning varies between Arctic and boreal peat},
journal = {Communications Earth & Environment},
publisher = {Springer Science and Business Media LLC},
year = {2024},
volume = {5},
number = {1},
doi = {10.1038/s43247-024-01304-y}
}
|
| Schneider E, Neumann A, Chacón-Patiño ML, Somero M, Ruppel MM, Ihalainen M, Köster K, Sippula O, Czech H, Rüger CP and Zimmermann R (2024), "Accessing the Low-Polar Molecular Composition of Boreal and Arctic Peat-Burning Organic Aerosol via Thermal Analysis and Ultrahigh-Resolution Mass Spectrometry: Structural Motifs and Their Formation", Journal of the American Society for Mass Spectrometry., July, 2024. Vol. 35(8), pp. 1713-1725. American Chemical Society (ACS). |
BibTeX:
@article{Schneider2024a,
author = {Schneider, Eric and Neumann, Anika and Chacón-Patiño, Martha L. and Somero, Markus and Ruppel, Meri M. and Ihalainen, Mika and Köster, Kajar and Sippula, Olli and Czech, Hendryk and Rüger, Christopher P. and Zimmermann, Ralf},
title = {Accessing the Low-Polar Molecular Composition of Boreal and Arctic Peat-Burning Organic Aerosol via Thermal Analysis and Ultrahigh-Resolution Mass Spectrometry: Structural Motifs and Their Formation},
journal = {Journal of the American Society for Mass Spectrometry},
publisher = {American Chemical Society (ACS)},
year = {2024},
volume = {35},
number = {8},
pages = {1713--1725},
doi = {10.1021/jasms.4c00120}
}
|
| See CR, Virkkala A-M, Natali SM, Rogers BM, Mauritz M, Biasi C, Bokhorst S, Boike J, Bret-Harte MS, Celis G, Chae N, Christensen TR, Murner SJ, Dengel S, Dolman H, Edgar CW, Elberling B, Emmerton CA, Euskirchen ES, Göckede M, Grelle A, Heffernan L, Helbig M, Holl D, Humphreys E, Iwata H, Järveoja J, Kobayashi H, Kochendorfer J, Kolari P, Kotani A, Kutzbach L, Kwon MJ, Lathrop ER, López-Blanco E, Mammarella I, Marushchak ME, Mastepanov M, Matsuura Y, Merbold L, Meyer G, Minions C, Nilsson MB, Nojeim J, Oberbauer SF, Olefeldt D, Park S-J, Parmentier F-JW, Peichl M, Peter D, Petrov R, Poyatos R, Prokushkin AS, Quinton W, Rodenhizer H, Sachs T, Savage K, Schulze C, Sjögersten S, Sonnentag O, St. Louis VL, Torn MS, Tuittila E-S, Ueyama M, Varlagin A, Voigt C, Watts JD, Zona D, Zyryanov VI and Schuur EAG (2024), "Decadal increases in carbon uptake offset by respiratory losses across northern permafrost ecosystems", Nature Climate Change., July, 2024. Vol. 14(8), pp. 853-862. Springer Science and Business Media LLC. |
BibTeX:
@article{See2024,
author = {See, Craig R. and Virkkala, Anna-Maria and Natali, Susan M. and Rogers, Brendan M. and Mauritz, Marguerite and Biasi, Christina and Bokhorst, Stef and Boike, Julia and Bret-Harte, M. Syndonia and Celis, Gerardo and Chae, Namyi and Christensen, Torben R. and Murner, Sara June and Dengel, Sigrid and Dolman, Han and Edgar, Colin W. and Elberling, Bo and Emmerton, Craig A. and Euskirchen, Eugénie S. and Göckede, Mathias and Grelle, Achim and Heffernan, Liam and Helbig, Manuel and Holl, David and Humphreys, Elyn and Iwata, Hiroki and Järveoja, Järvi and Kobayashi, Hideki and Kochendorfer, John and Kolari, Pasi and Kotani, Ayumi and Kutzbach, Lars and Kwon, Min Jung and Lathrop, Emma R. and López-Blanco, Efrén and Mammarella, Ivan and Marushchak, Maija E. and Mastepanov, Mikhail and Matsuura, Yojiro and Merbold, Lutz and Meyer, Gesa and Minions, Christina and Nilsson, Mats B. and Nojeim, Julia and Oberbauer, Steven F. and Olefeldt, David and Park, Sang-Jong and Parmentier, Frans-Jan W. and Peichl, Matthias and Peter, Darcy and Petrov, Roman and Poyatos, Rafael and Prokushkin, Anatoly S. and Quinton, William and Rodenhizer, Heidi and Sachs, Torsten and Savage, Kathleen and Schulze, Christopher and Sjögersten, Sofie and Sonnentag, Oliver and St. Louis, Vincent L. and Torn, Margaret S. and Tuittila, Eeva-Stiina and Ueyama, Masahito and Varlagin, Andrej and Voigt, Carolina and Watts, Jennifer D. and Zona, Donatella and Zyryanov, Viacheslav I. and Schuur, Edward A. G.},
title = {Decadal increases in carbon uptake offset by respiratory losses across northern permafrost ecosystems},
journal = {Nature Climate Change},
publisher = {Springer Science and Business Media LLC},
year = {2024},
volume = {14},
number = {8},
pages = {853--862},
doi = {10.1038/s41558-024-02057-4}
}
|
| Shekhar A, Hörtnagl L, Paul-Limoges E, Etzold S, Zweifel R, Buchmann N and Gharun M (2024), "Contrasting impact of extreme soil and atmospheric dryness on the functioning of trees and forests", Science of The Total Environment., mar, 2024. Vol. 916, pp. 169931. Elsevier BV. |
BibTeX:
@article{Shekhar2024,
author = {Shekhar, Ankit and Hörtnagl, Lukas and Paul-Limoges, Eugénie and Etzold, Sophia and Zweifel, Roman and Buchmann, Nina and Gharun, Mana},
title = {Contrasting impact of extreme soil and atmospheric dryness on the functioning of trees and forests},
journal = {Science of The Total Environment},
publisher = {Elsevier BV},
year = {2024},
volume = {916},
pages = {169931},
url = {http://dx.doi.org/10.1016/j.scitotenv.2024.169931},
doi = {10.1016/j.scitotenv.2024.169931}
}
|
| Sparrow KJ, Chanton JP, Hanke UM, Kurz MD and McNichol AP (2024), "Peatland organic matter quality varies with latitude as suggested by combination of FTIR and Ramped Pyrolysis Oxidation", PLOS ONE., November, 2024. Vol. 19(11), pp. e0309654. Public Library of Science (PLoS). |
BibTeX:
@article{Sparrow2024,
author = {Sparrow, Katy J. and Chanton, Jeffrey P. and Hanke, Ulrich M. and Kurz, Mark D. and McNichol, Ann P.},
editor = {Zhang, Mingming},
title = {Peatland organic matter quality varies with latitude as suggested by combination of FTIR and Ramped Pyrolysis Oxidation},
journal = {PLOS ONE},
publisher = {Public Library of Science (PLoS)},
year = {2024},
volume = {19},
number = {11},
pages = {e0309654},
doi = {10.1371/journal.pone.0309654}
}
|
| Speranskaya L, Campbell DI, Lafleur PM and Humphreys ER (2024), "Peatland evaporation across hemispheres: contrasting controls and sensitivity to climate warming driven by plant functional types", Biogeosciences., March, 2024. Vol. 21(5), pp. 1173-1190. Copernicus GmbH. |
BibTeX:
@article{Speranskaya2024,
author = {Speranskaya, Leeza and Campbell, David I. and Lafleur, Peter M. and Humphreys, Elyn R.},
title = {Peatland evaporation across hemispheres: contrasting controls and sensitivity to climate warming driven by plant functional types},
journal = {Biogeosciences},
publisher = {Copernicus GmbH},
year = {2024},
volume = {21},
number = {5},
pages = {1173--1190},
doi = {10.5194/bg-21-1173-2024}
}
|
| Stagakis S, Brunner D, Li J, Backman L, Karvonen A, Constantin L, Järvi L, Havu M, Chen J, Emberger S and Kulmala L (2024), "Intercomparison of biogenic CO2 flux models in four urban parks in the city of Zurich", September, 2024. Copernicus GmbH. |
BibTeX:
@article{Stagakis2024,
author = {Stagakis, Stavros and Brunner, Dominik and Li, Junwei and Backman, Leif and Karvonen, Anni and Constantin, Lionel and Järvi, Leena and Havu, Minttu and Chen, Jia and Emberger, Sophie and Kulmala, Liisa},
title = {Intercomparison of biogenic CO2 flux models in four urban parks in the city of Zurich},
publisher = {Copernicus GmbH},
year = {2024},
doi = {10.5194/egusphere-2024-2475}
}
|
| Steiner M, Peters W, Luijkx I, Henne S, Chen H, Hammer S and Brunner D (2024), "European CH4 inversions with ICON-ART coupled to the CarbonTracker Data Assimilation Shell", Atmospheric Chemistry and Physics., March, 2024. Vol. 24(4), pp. 2759-2782. Copernicus GmbH. |
BibTeX:
@article{Steiner2024,
author = {Steiner, Michael and Peters, Wouter and Luijkx, Ingrid and Henne, Stephan and Chen, Huilin and Hammer, Samuel and Brunner, Dominik},
title = {European CH4 inversions with ICON-ART coupled to the CarbonTracker Data Assimilation Shell},
journal = {Atmospheric Chemistry and Physics},
publisher = {Copernicus GmbH},
year = {2024},
volume = {24},
number = {4},
pages = {2759--2782},
doi = {10.5194/acp-24-2759-2024}
}
|
| Sun CL, Pratama AA, Gazitúa MC, Cronin D, McGivern BB, Wainaina JM, Vik DR, Zayed AA, Bolduc B, Wrighton KC, Rich VI and Sullivan MB (2024), "Virus ecology and 7‐year temporal dynamics across a permafrost thaw gradient", Environmental Microbiology., July, 2024. Vol. 26(8) Wiley. |
BibTeX:
@article{Sun2024,
author = {Sun, Christine L. and Pratama, Akbar Adjie and Gazitúa, Maria Consuelo and Cronin, Dylan and McGivern, Bridget B. and Wainaina, James M. and Vik, Dean R. and Zayed, Ahmed A. and Bolduc, Benjamin and Wrighton, Kelly C. and Rich, Virginia I. and Sullivan, Matthew B.},
title = {Virus ecology and 7‐year temporal dynamics across a permafrost thaw gradient},
journal = {Environmental Microbiology},
publisher = {Wiley},
year = {2024},
volume = {26},
number = {8},
doi = {10.1111/1462-2920.16665}
}
|
| Taghavi-Bayat A, Ullmann T, Riedel B and Gerke M (2024), "Detecting soil freeze-thaw dynamics with C-band SAR over permafrost in Northern Sweden and seasonally frozen grounds in the Tibetan Plateau, China", International Journal of Remote Sensing., July, 2024. Vol. 45(16), pp. 5317-5358. Informa UK Limited. |
BibTeX:
@article{TaghaviBayat2024,
author = {Taghavi-Bayat, Aida and Ullmann, Tobias and Riedel, Björn and Gerke, Markus},
title = {Detecting soil freeze-thaw dynamics with C-band SAR over permafrost in Northern Sweden and seasonally frozen grounds in the Tibetan Plateau, China},
journal = {International Journal of Remote Sensing},
publisher = {Informa UK Limited},
year = {2024},
volume = {45},
number = {16},
pages = {5317--5358},
doi = {10.1080/01431161.2024.2372079}
}
|
| Tan Z, Yao H, Melack J, Grossart H, Jansen J, Balathandayuthabani S, Sargsyan K and Leung LR (2024), "A Lake Biogeochemistry Model for Global Methane Emissions: Model Development, Site‐Level Validation, and Global Applicability", Journal of Advances in Modeling Earth Systems., October, 2024. Vol. 16(10) American Geophysical Union (AGU). |
BibTeX:
@article{Tan2024,
author = {Tan, Zeli and Yao, Huaxia and Melack, John and Grossart, Hans‐Peter and Jansen, Joachim and Balathandayuthabani, Sivakiruthika and Sargsyan, Khachik and Leung, L. Ruby},
title = {A Lake Biogeochemistry Model for Global Methane Emissions: Model Development, Site‐Level Validation, and Global Applicability},
journal = {Journal of Advances in Modeling Earth Systems},
publisher = {American Geophysical Union (AGU)},
year = {2024},
volume = {16},
number = {10},
doi = {10.1029/2024ms004275}
}
|
| Tangarife‐Escobar A, Guggenberger G, Feng X, Muñoz E, Chanca I, Peichl M, Smith P and Sierra CA (2024), "Radiocarbon Isotopic Disequilibrium Shows Little Incorporation of New Carbon in Mineral Soils of a Boreal Forest Ecosystem", Journal of Geophysical Research: Biogeosciences., August, 2024. Vol. 129(9) American Geophysical Union (AGU). |
BibTeX:
@article{Tangarife‐Escobar2024,
author = {Tangarife‐Escobar, Andrés and Guggenberger, Georg and Feng, Xiaojuan and Muñoz, Estefanía and Chanca, Ingrid and Peichl, Matthias and Smith, Paul and Sierra, Carlos A.},
title = {Radiocarbon Isotopic Disequilibrium Shows Little Incorporation of New Carbon in Mineral Soils of a Boreal Forest Ecosystem},
journal = {Journal of Geophysical Research: Biogeosciences},
publisher = {American Geophysical Union (AGU)},
year = {2024},
volume = {129},
number = {9},
doi = {10.1029/2024jg008191}
}
|
| Terryn L, Calders K, Meunier F, Bauters M, Boeckx P, Brede B, Burt A, Chave J, da Costa ACL, D’hont B, Disney M, Jucker T, Lau A, Laurance SGW, Maeda EE, Meir P, Krishna Moorthy SM, Nunes MH, Shenkin A, Sibret T, Verhelst TE, Wilkes P and Verbeeck H (2024), "New tree height allometries derived from terrestrial laser scanning reveal substantial discrepancies with forest inventory methods in tropical rainforests", Global Change Biology., August, 2024. Vol. 30(8) Wiley. |
BibTeX:
@article{Terryn2024,
author = {Terryn, Louise and Calders, Kim and Meunier, Félicien and Bauters, Marijn and Boeckx, Pascal and Brede, Benjamin and Burt, Andrew and Chave, Jerome and da Costa, Antonio Carlos Lola and D’hont, Barbara and Disney, Mathias and Jucker, Tommaso and Lau, Alvaro and Laurance, Susan G. W. and Maeda, Eduardo Eiji and Meir, Patrick and Krishna Moorthy, Sruthi M. and Nunes, Matheus Henrique and Shenkin, Alexander and Sibret, Thomas and Verhelst, Tom E. and Wilkes, Phil and Verbeeck, Hans},
title = {New tree height allometries derived from terrestrial laser scanning reveal substantial discrepancies with forest inventory methods in tropical rainforests},
journal = {Global Change Biology},
publisher = {Wiley},
year = {2024},
volume = {30},
number = {8},
doi = {10.1111/gcb.17473}
}
|
| Thompson RL, Montzka SA, Vollmer MK, Arduini J, Crotwell M, Krummel PB, Lunder C, Mühle J, O’Doherty S, Prinn RG, Reimann S, Vimont I, Wang H, Weiss RF and Young D (2024), "Estimation of the atmospheric hydroxyl radical oxidative capacity using multiple hydrofluorocarbons (HFCs)", Atmospheric Chemistry and Physics., January, 2024. Vol. 24(2), pp. 1415-1427. Copernicus GmbH. |
BibTeX:
@article{Thompson2024,
author = {Thompson, Rona L. and Montzka, Stephen A. and Vollmer, Martin K. and Arduini, Jgor and Crotwell, Molly and Krummel, Paul B. and Lunder, Chris and Mühle, Jens and O’Doherty, Simon and Prinn, Ronald G. and Reimann, Stefan and Vimont, Isaac and Wang, Hsiang and Weiss, Ray F. and Young, Dickon},
title = {Estimation of the atmospheric hydroxyl radical oxidative capacity using multiple hydrofluorocarbons (HFCs)},
journal = {Atmospheric Chemistry and Physics},
publisher = {Copernicus GmbH},
year = {2024},
volume = {24},
number = {2},
pages = {1415--1427},
doi = {10.5194/acp-24-1415-2024}
}
|
| Tian H, Pan N, Thompson RL, Canadell JG, Suntharalingam P, Regnier P, Davidson EA, Prather M, Ciais P, Muntean M, Pan S, Winiwarter W, Zaehle S, Zhou F, Jackson RB, Bange HW, Berthet S, Bian Z, Bianchi D, Bouwman AF, Buitenhuis ET, Dutton G, Hu M, Ito A, Jain AK, Jeltsch-Thömmes A, Joos F, Kou-Giesbrecht S, Krummel PB, Lan X, Landolfi A, Lauerwald R, Li Y, Lu C, Maavara T, Manizza M, Millet DB, Mühle J, Patra PK, Peters GP, Qin X, Raymond P, Resplandy L, Rosentreter JA, Shi H, Sun Q, Tonina D, Tubiello FN, van der Werf GR, Vuichard N, Wang J, Wells KC, Western LM, Wilson C, Yang J, Yao Y, You Y and Zhu Q (2024), "Global nitrous oxide budget (1980–2020)", Earth System Science Data., June, 2024. Vol. 16(6), pp. 2543-2604. Copernicus GmbH. |
BibTeX:
@article{Tian2024,
author = {Tian, Hanqin and Pan, Naiqing and Thompson, Rona L. and Canadell, Josep G. and Suntharalingam, Parvadha and Regnier, Pierre and Davidson, Eric A. and Prather, Michael and Ciais, Philippe and Muntean, Marilena and Pan, Shufen and Winiwarter, Wilfried and Zaehle, Sönke and Zhou, Feng and Jackson, Robert B. and Bange, Hermann W. and Berthet, Sarah and Bian, Zihao and Bianchi, Daniele and Bouwman, Alexander F. and Buitenhuis, Erik T. and Dutton, Geoffrey and Hu, Minpeng and Ito, Akihiko and Jain, Atul K. and Jeltsch-Thömmes, Aurich and Joos, Fortunat and Kou-Giesbrecht, Sian and Krummel, Paul B. and Lan, Xin and Landolfi, Angela and Lauerwald, Ronny and Li, Ya and Lu, Chaoqun and Maavara, Taylor and Manizza, Manfredi and Millet, Dylan B. and Mühle, Jens and Patra, Prabir K. and Peters, Glen P. and Qin, Xiaoyu and Raymond, Peter and Resplandy, Laure and Rosentreter, Judith A. and Shi, Hao and Sun, Qing and Tonina, Daniele and Tubiello, Francesco N. and van der Werf, Guido R. and Vuichard, Nicolas and Wang, Junjie and Wells, Kelley C. and Western, Luke M. and Wilson, Chris and Yang, Jia and Yao, Yuanzhi and You, Yongfa and Zhu, Qing},
title = {Global nitrous oxide budget (1980–2020)},
journal = {Earth System Science Data},
publisher = {Copernicus GmbH},
year = {2024},
volume = {16},
number = {6},
pages = {2543--2604},
doi = {10.5194/essd-16-2543-2024}
}
|
| Tikkasalo O-P, Peltola O, Alekseychik P, Heikkinen J, Launiainen S, Lehtonen A, Li Q, Martinez-García E, Peltoniemi M, Salovaara P, Tuominen V and Mäkipää R (2024), "Eddy covariance fluxes of CO2, CH4 and N2O on a drained peatland forest after clearcutting", Biogeosciences., August, 2024. Copernicus GmbH. |
BibTeX:
@article{Tikkasalo2024,
author = {Tikkasalo, Olli-Pekka and Peltola, Olli and Alekseychik, Pavel and Heikkinen, Juha and Launiainen, Samuli and Lehtonen, Aleksi and Li, Qian and Martinez-García, Eduardo and Peltoniemi, Mikko and Salovaara, Petri and Tuominen, Ville and Mäkipää, Raisa},
title = {Eddy covariance fluxes of CO2, CH4 and N2O on a drained peatland forest after clearcutting},
journal = {Biogeosciences},
publisher = {Copernicus GmbH},
year = {2024},
doi = {10.5194/egusphere-2024-1994}
}
|
| Tomelleri E, Scholz K, Pighini S, Carotenuto F, Gioli B, Miglietta F, Sommaruga R, Tonon G, Zaldei A and Wohlfahrt G (2024), "A Novel Method for Characterizing the Inter‐ and Intra‐Lake Variability of CH4 Emissions: Validation and Application Across a Latitudinal Transect in the Alpine Region", Journal of Geophysical Research: Biogeosciences., April, 2024. Vol. 129(5) American Geophysical Union (AGU). |
BibTeX:
@article{Tomelleri2024,
author = {Tomelleri, Enrico and Scholz, Katharina and Pighini, Sylvie and Carotenuto, Federico and Gioli, Beniamino and Miglietta, Franco and Sommaruga, Ruben and Tonon, Giustino and Zaldei, Alessandro and Wohlfahrt, Georg},
title = {A Novel Method for Characterizing the Inter‐ and Intra‐Lake Variability of CH4 Emissions: Validation and Application Across a Latitudinal Transect in the Alpine Region},
journal = {Journal of Geophysical Research: Biogeosciences},
publisher = {American Geophysical Union (AGU)},
year = {2024},
volume = {129},
number = {5},
doi = {10.1029/2023jg007392}
}
|
| Tong CHM, Noumonvi KD, Ratcliffe J, Laudon H, Järveoja J, Drott A, Nilsson MB and Peichl M (2024), "A drained nutrient‐poor peatland forest in boreal Sweden constitutes a net carbon sink after integrating terrestrial and aquatic fluxes", Global Change Biology., March, 2024. Vol. 30(3) Wiley. |
BibTeX:
@article{Tong2024,
author = {Tong, Cheuk Hei Marcus and Noumonvi, Koffi Dodji and Ratcliffe, Joshua and Laudon, Hjalmar and Järveoja, Järvi and Drott, Andreas and Nilsson, Mats B. and Peichl, Matthias},
title = {A drained nutrient‐poor peatland forest in boreal Sweden constitutes a net carbon sink after integrating terrestrial and aquatic fluxes},
journal = {Global Change Biology},
publisher = {Wiley},
year = {2024},
volume = {30},
number = {3},
doi = {10.1111/gcb.17246}
}
|
| Trisolino P, Putero D, Arduini J, Amendola S, Calzolari F and Cristofanelli P (2024), "Influence of deep stratosphere-to-troposphere transport on atmospheric carbon dioxide and methane at the Mt. Cimone WMO/GAW global station (2165 m a.s.l., Italy): A multi-year (2015–2022) investigation", Atmospheric Research., November, 2024. Vol. 310, pp. 107627. Elsevier BV. |
BibTeX:
@article{Trisolino2024,
author = {Trisolino, Pamela and Putero, Davide and Arduini, Jgor and Amendola, Stefano and Calzolari, Francescopiero and Cristofanelli, Paolo},
title = {Influence of deep stratosphere-to-troposphere transport on atmospheric carbon dioxide and methane at the Mt. Cimone WMO/GAW global station (2165 m a.s.l., Italy): A multi-year (2015–2022) investigation},
journal = {Atmospheric Research},
publisher = {Elsevier BV},
year = {2024},
volume = {310},
pages = {107627},
doi = {10.1016/j.atmosres.2024.107627}
}
|
| Tyystjärvi V, Niittynen P, Kemppinen J, Luoto M, Rissanen T and Aalto J (2024), "Variability and drivers of winter near-surface temperatures over boreal and tundra landscapes", The Cryosphere., January, 2024. Vol. 18(1), pp. 403-423. Copernicus GmbH. |
BibTeX:
@article{Tyystjaervi2024,
author = {Tyystjärvi, Vilna and Niittynen, Pekka and Kemppinen, Julia and Luoto, Miska and Rissanen, Tuuli and Aalto, Juha},
title = {Variability and drivers of winter near-surface temperatures over boreal and tundra landscapes},
journal = {The Cryosphere},
publisher = {Copernicus GmbH},
year = {2024},
volume = {18},
number = {1},
pages = {403--423},
doi = {10.5194/tc-18-403-2024}
}
|
| Ulander LMH, Monteith AR, Persson HJ and Fransson JES (2024), "Borealscat-2: Backscatter Measurements of Forest Water Dynamics", In IGARSS 2024 - 2024 IEEE International Geoscience and Remote Sensing Symposium., July, 2024. , pp. 2332-2335. IEEE. |
BibTeX:
@inproceedings{Ulander2024,
author = {Ulander, Lars M. H. and Monteith, Albert R. and Persson, Henrik J. and Fransson, Johan E. S.},
title = {Borealscat-2: Backscatter Measurements of Forest Water Dynamics},
booktitle = {IGARSS 2024 - 2024 IEEE International Geoscience and Remote Sensing Symposium},
publisher = {IEEE},
year = {2024},
pages = {2332--2335},
doi = {10.1109/igarss53475.2024.10642923}
}
|
| Varga T, Nagy D, Molnár M, Jull AT, Futó I and Lisztes-Szabó Z (2024), "Spring buds of European woody plants have old 14C age", Heliyon., June, 2024. Vol. 10(12), pp. e32777. Elsevier BV. |
BibTeX:
@article{Varga2024,
author = {Varga, Tamás and Nagy, Dominik and Molnár, Mihály and Jull, A.J. Timothy and Futó, István and Lisztes-Szabó, Zsuzsa},
title = {Spring buds of European woody plants have old 14C age},
journal = {Heliyon},
publisher = {Elsevier BV},
year = {2024},
volume = {10},
number = {12},
pages = {e32777},
doi = {10.1016/j.heliyon.2024.e32777}
}
|
| Vernay A, Hasselquist N, Leppä K, Klosterhalfen A, Gutierrez Lopez J, Stangl ZR, Chi J, Kozii N and Marshall JD (2024), "Partitioning gross primary production of a boreal forest among species and strata: A multi-method approach", Agricultural and Forest Meteorology., February, 2024. Vol. 345, pp. 109857. Elsevier BV. |
BibTeX:
@article{Vernay2024,
author = {Vernay, Antoine and Hasselquist, Niles and Leppä, Kersti and Klosterhalfen, Anne and Gutierrez Lopez, Jose and Stangl, Zsofia R and Chi, Jinshu and Kozii, Nathaliia and Marshall, John D},
title = {Partitioning gross primary production of a boreal forest among species and strata: A multi-method approach},
journal = {Agricultural and Forest Meteorology},
publisher = {Elsevier BV},
year = {2024},
volume = {345},
pages = {109857},
doi = {10.1016/j.agrformet.2023.109857}
}
|
| Vitale D, Fratini G, Helfter C, Hortnagl L, Kohonen K-M, Mammarella I, Nemitz E, Nicolini G, Rebmann C, Sabbatini S and Papale D (2024), "A pre-whitening with block-bootstrap cross-correlation procedure for temporal alignment of data sampled by eddy covariance systems", Environmental and Ecological Statistics., April, 2024. Vol. 31(2), pp. 219-244. Springer Science and Business Media LLC. |
BibTeX:
@article{Vitale2024,
author = {Vitale, Domenico and Fratini, Gerardo and Helfter, Carole and Hortnagl, Lukas and Kohonen, Kukka-Maaria and Mammarella, Ivan and Nemitz, Eiko and Nicolini, Giacomo and Rebmann, Corinna and Sabbatini, Simone and Papale, Dario},
title = {A pre-whitening with block-bootstrap cross-correlation procedure for temporal alignment of data sampled by eddy covariance systems},
journal = {Environmental and Ecological Statistics},
publisher = {Springer Science and Business Media LLC},
year = {2024},
volume = {31},
number = {2},
pages = {219--244},
doi = {10.1007/s10651-024-00615-9}
}
|
| Vitali B, Bettineschi M, Cholakian A, Zardi D, Bianchi F, Sinclair VA, Mikkola J, Cristofanelli P, Marinoni A, Mazzini M, Heikkinen L, Aurela M, Paglione M, Bessagnet B, Tuccella P and Ciarelli G (2024), "Analysis of chemical and transport processes of biogenic aerosols over the northern Apennines: insights from the WRF-CHIMERE model", Environmental Science: Atmospheres. Vol. 4(9), pp. 967-987. Royal Society of Chemistry (RSC). |
BibTeX:
@article{Vitali2024,
author = {Vitali, Bruno and Bettineschi, Manuel and Cholakian, Arineh and Zardi, Dino and Bianchi, Federico and Sinclair, Victoria A. and Mikkola, Johannes and Cristofanelli, Paolo and Marinoni, Angela and Mazzini, Martina and Heikkinen, Liine and Aurela, Minna and Paglione, Marco and Bessagnet, Bertrand and Tuccella, Paolo and Ciarelli, Giancarlo},
title = {Analysis of chemical and transport processes of biogenic aerosols over the northern Apennines: insights from the WRF-CHIMERE model},
journal = {Environmental Science: Atmospheres},
publisher = {Royal Society of Chemistry (RSC)},
year = {2024},
volume = {4},
number = {9},
pages = {967--987},
doi = {10.1039/d4ea00040d}
}
|
| Voggenreiter E, Schmitt-Kopplin P, ThomasArrigo L, Bryce C, Kappler A and Joshi P (2024), "Emerging investigator series: preferential adsorption and coprecipitation of permafrost organic matter with poorly crystalline iron minerals", Environmental Science: Processes & Impacts. Vol. 26(8), pp. 1322-1335. Royal Society of Chemistry (RSC). |
BibTeX:
@article{Voggenreiter2024,
author = {Voggenreiter, Eva and Schmitt-Kopplin, Philippe and ThomasArrigo, Laurel and Bryce, Casey and Kappler, Andreas and Joshi, Prachi},
title = {Emerging investigator series: preferential adsorption and coprecipitation of permafrost organic matter with poorly crystalline iron minerals},
journal = {Environmental Science: Processes & Impacts},
publisher = {Royal Society of Chemistry (RSC)},
year = {2024},
volume = {26},
number = {8},
pages = {1322--1335},
doi = {10.1039/d4em00241e}
}
|
| Vries Ad, Wohlfahrt G, Kohonen K-M, Abadie C, Remaud M, Kesselmeier J, Laasonen AT, Whelan M, Mammarella I and Vesala T (2024), "The contribution of boreal wetlands to the Northern hemisphere carbonyl sulfide sink", October, 2024. Authorea, Inc.. |
BibTeX:
@article{Vries2024,
author = {Vries, Anna de and Wohlfahrt, Georg and Kohonen, Kukka-Maaria and Abadie, Camille and Remaud, Marine and Kesselmeier, Jürgen and Laasonen, Asta Tuulia and Whelan, Mary and Mammarella, Ivan and Vesala, Timo},
title = {The contribution of boreal wetlands to the Northern hemisphere carbonyl sulfide sink},
publisher = {Authorea, Inc.},
year = {2024},
doi = {10.22541/essoar.172838630.01134399/v1}
}
|
| Wang H, Welch AM, Nagalingam S, Leong C, Czimczik CI, Tang J, Seco R, Rinnan R, Vettikkat L, Schobesberger S, Holst T, Brijesh S, Sheesley RJ, Barsanti KC and Guenther AB (2024), "High temperature sensitivity of Arctic isoprene emissions explained by sedges", Nature Communications., July, 2024. Vol. 15(1) Springer Science and Business Media LLC. |
BibTeX:
@article{Wang2024,
author = {Wang, Hui and Welch, Allison M. and Nagalingam, Sanjeevi and Leong, Christopher and Czimczik, Claudia I. and Tang, Jing and Seco, Roger and Rinnan, Riikka and Vettikkat, Lejish and Schobesberger, Siegfried and Holst, Thomas and Brijesh, Shobhit and Sheesley, Rebecca J. and Barsanti, Kelley C. and Guenther, Alex B.},
title = {High temperature sensitivity of Arctic isoprene emissions explained by sedges},
journal = {Nature Communications},
publisher = {Springer Science and Business Media LLC},
year = {2024},
volume = {15},
number = {1},
doi = {10.1038/s41467-024-49960-0}
}
|
| Wei J, von Arx G, Fan Z, Ibrom A, Mund M, Knohl A, Peters RL and Babst F (2024), "Drought alters aboveground biomass production efficiency: Insights from two European beech forests", Science of The Total Environment., April, 2024. Vol. 919, pp. 170726. Elsevier BV. |
BibTeX:
@article{Wei2024,
author = {Wei, Jingshu and von Arx, Georg and Fan, Zexin and Ibrom, Andreas and Mund, Martina and Knohl, Alexander and Peters, Richard L. and Babst, Flurin},
title = {Drought alters aboveground biomass production efficiency: Insights from two European beech forests},
journal = {Science of The Total Environment},
publisher = {Elsevier BV},
year = {2024},
volume = {919},
pages = {170726},
doi = {10.1016/j.scitotenv.2024.170726}
}
|
| Western LM, Daniel JS, Vollmer MK, Clingan S, Crotwell M, Fraser PJ, Ganesan AL, Hall B, Harth CM, Krummel PB, Mühle J, O’Doherty S, Salameh PK, Stanley KM, Reimann S, Vimont I, Young D, Rigby M, Weiss RF, Prinn RG and Montzka SA (2024), "A decrease in radiative forcing and equivalent effective chlorine from hydrochlorofluorocarbons", Nature Climate Change., June, 2024. Vol. 14(8), pp. 805-807. Springer Science and Business Media LLC. |
BibTeX:
@article{Western2024,
author = {Western, Luke M. and Daniel, John S. and Vollmer, Martin K. and Clingan, Scott and Crotwell, Molly and Fraser, Paul J. and Ganesan, Anita L. and Hall, Brad and Harth, Christina M. and Krummel, Paul B. and Mühle, Jens and O’Doherty, Simon and Salameh, Peter K. and Stanley, Kieran M. and Reimann, Stefan and Vimont, Isaac and Young, Dickon and Rigby, Matt and Weiss, Ray F. and Prinn, Ronald G. and Montzka, Stephen A.},
title = {A decrease in radiative forcing and equivalent effective chlorine from hydrochlorofluorocarbons},
journal = {Nature Climate Change},
publisher = {Springer Science and Business Media LLC},
year = {2024},
volume = {14},
number = {8},
pages = {805--807},
doi = {10.1038/s41558-024-02038-7}
}
|
| Wilson C, Kerridge BJ, Siddans R, Moore DP, Ventress LJ, Dowd E, Feng W, Chipperfield MP and Remedios JJ (2024), "Quantifying large methane emissions from the Nord Stream pipeline gas leak of September 2022 using IASI satellite observations and inverse modelling", Atmospheric Chemistry and Physics., September, 2024. Vol. 24(18), pp. 10639-10653. Copernicus GmbH. |
BibTeX:
@article{Wilson2024,
author = {Wilson, Chris and Kerridge, Brian J. and Siddans, Richard and Moore, David P. and Ventress, Lucy J. and Dowd, Emily and Feng, Wuhu and Chipperfield, Martyn P. and Remedios, John J.},
title = {Quantifying large methane emissions from the Nord Stream pipeline gas leak of September 2022 using IASI satellite observations and inverse modelling},
journal = {Atmospheric Chemistry and Physics},
publisher = {Copernicus GmbH},
year = {2024},
volume = {24},
number = {18},
pages = {10639--10653},
doi = {10.5194/acp-24-10639-2024}
}
|
| Wimart-Rousseau C, Steinhoff T, Klein B, Bittig H and Körtzinger A (2024), "Technical note: Assessment of float pH data quality control methods – a case study in the subpolar northwest Atlantic Ocean", Biogeosciences., March, 2024. Vol. 21(5), pp. 1191-1211. Copernicus GmbH. |
BibTeX:
@article{WimartRousseau2024,
author = {Wimart-Rousseau, Cathy and Steinhoff, Tobias and Klein, Birgit and Bittig, Henry and Körtzinger, Arne},
title = {Technical note: Assessment of float pH data quality control methods – a case study in the subpolar northwest Atlantic Ocean},
journal = {Biogeosciences},
publisher = {Copernicus GmbH},
year = {2024},
volume = {21},
number = {5},
pages = {1191--1211},
doi = {10.5194/bg-21-1191-2024}
}
|
| Wu Z, Vermeulen A, Sawa Y, Karstens U, Peters W, de Kok R, Lan X, Nagai Y, Ogi A and Tarasova O (2024), "Investigating the differences in calculating global mean surface CO 2 abundance: the impact of analysis methodologies and site selection", Atmospheric Chemistry and Physics., 1, 2024. Vol. 24, pp. 1249-1264. |
| Abstract: Abstract. The World Meteorological Organization (WMO) Global Atmosphere Watch (GAW) coordinates high-quality atmospheric greenhouse gas observations globally and provides these observations through the WMO World Data Centre for Greenhouse Gases (WDCGG) supported by Japan Meteorological Agency. The WDCGG and the National Oceanic and Atmospheric Administration (NOAA) analyse these measurements using different methodologies and site selection to calculate global annual mean surface CO2 and its growth rate as a headline climate indicator. This study introduces a third hybrid method named GFIT, which serves as an independent validation and open-source alternative to the methods described by NOAA and WDCGG. We apply GFIT to incorporate observations from most WMO GAW stations and 3D modelled CO2 fields from CarbonTracker Europe (CTE). We find that different observational networks (i.e. NOAA, GAW, and CTE networks) and analysis methods result in differences in the calculated global surface CO2 mole fractions equivalent to the current atmospheric growth rate over a 3-month period. However, the CO2 growth rate derived from these networks and the CTE model output shows good agreement. Over the long-term period (40 years), both networks with and without continental sites exhibit the same trend in the growth rate (0.030 ± 0.002 ppm yr−1 each year). However, a clear difference emerges in the short-term (1-month) change in the growth rate. The network that includes continental sites improves the early detection of changes in biogenic emissions. |
BibTeX:
@article{Wu2024,
author = {Zhendong Wu and Alex Vermeulen and Yousuke Sawa and Ute Karstens and Wouter Peters and Remco de Kok and Xin Lan and Yasuyuki Nagai and Akinori Ogi and Oksana Tarasova},
title = {Investigating the differences in calculating global mean surface CO 2 abundance: the impact of analysis methodologies and site selection},
journal = {Atmospheric Chemistry and Physics},
year = {2024},
volume = {24},
pages = {1249-1264},
doi = {10.5194/acp-24-1249-2024}
}
|
| Xiao H, Song C, Li S, Lu X, Liang M, Xia X and Yuan W (2024), "Global Wetland Methane Emissions From 2001 to 2020: Magnitude, Dynamics and Controls", Earth’s Future., September, 2024. Vol. 12(9) American Geophysical Union (AGU). |
BibTeX:
@article{Xiao2024,
author = {Xiao, Han and Song, Chaoqing and Li, Shihua and Lu, Xiao and Liang, Minqi and Xia, Xiaosheng and Yuan, Wenping},
title = {Global Wetland Methane Emissions From 2001 to 2020: Magnitude, Dynamics and Controls},
journal = {Earth’s Future},
publisher = {American Geophysical Union (AGU)},
year = {2024},
volume = {12},
number = {9},
doi = {10.1029/2024ef004794}
}
|
| Xu L, Liu H, Mammarella I, Vähä A, Ala-Könni J, Li X, Du Q, Liu Y and Vesala T (2024), "Characteristics of Energy Fluxes and Cold Frontal Effects on Energy Exchange over a Boreal Lake", Advances in Atmospheric Sciences., December, 2024. Vol. 42(2), pp. 357-372. Springer Science and Business Media LLC. |
BibTeX:
@article{Xu2024,
author = {Xu, Lujun and Liu, Huizhi and Mammarella, Ivan and Vähä, Aki and Ala-Könni, Joonatan and Li, Xuefei and Du, Qun and Liu, Yang and Vesala, Timo},
title = {Characteristics of Energy Fluxes and Cold Frontal Effects on Energy Exchange over a Boreal Lake},
journal = {Advances in Atmospheric Sciences},
publisher = {Springer Science and Business Media LLC},
year = {2024},
volume = {42},
number = {2},
pages = {357--372},
doi = {10.1007/s00376-024-3214-y}
}
|
| Yu K, Su Y, Ciais P, Lauerwald R, Ceschia E, Makowski D, Xu Y, Abbessi E, Bazzi H, Tallec T, Brut A, Heinesch B, Brümmer C, Schmidt M, Acosta M, Buysse P, Gruenwald T and Goll DS (2024), "Quantifying albedo impact and radiative forcing of management practices in European wheat cropping systems", Environmental Research Letters., June, 2024. Vol. 19(7), pp. 074042. IOP Publishing. |
BibTeX:
@article{Yu2024,
author = {Yu, Ke and Su, Yang and Ciais, Philippe and Lauerwald, Ronny and Ceschia, Eric and Makowski, David and Xu, Yidi and Abbessi, Ezzeddine and Bazzi, Hassan and Tallec, Tiphaine and Brut, Aurore and Heinesch, Bernard and Brümmer, Christian and Schmidt, Marius and Acosta, Manuel and Buysse, Pauline and Gruenwald, Thomas and Goll, Daniel S},
title = {Quantifying albedo impact and radiative forcing of management practices in European wheat cropping systems},
journal = {Environmental Research Letters},
publisher = {IOP Publishing},
year = {2024},
volume = {19},
number = {7},
pages = {074042},
doi = {10.1088/1748-9326/ad5859}
}
|
| Zacharias S, Loescher HW, Bogena H, Kiese R, Schrön M, Attinger S, Blume T, Borchardt D, Borg E, Bumberger J, Chwala C, Dietrich P, Fersch B, Frenzel M, Gaillardet J, Groh J, Hajnsek I, Itzerott S, Kunkel R, Kunstmann H, Kunz M, Liebner S, Mirtl M, Montzka C, Musolff A, Pütz T, Rebmann C, Rinke K, Rode M, Sachs T, Samaniego L, Schmid HP, Vogel H, Weber U, Wollschläger U and Vereecken H (2024), "Fifteen Years of Integrated Terrestrial Environmental Observatories (TERENO) in Germany: Functions, Services, and Lessons Learned", Earth’s Future., June, 2024. Vol. 12(6) American Geophysical Union (AGU). |
BibTeX:
@article{Zacharias2024,
author = {Zacharias, Steffen and Loescher, Henry W. and Bogena, Heye and Kiese, Ralf and Schrön, Martin and Attinger, Sabine and Blume, Theresa and Borchardt, Dietrich and Borg, Erik and Bumberger, Jan and Chwala, Christian and Dietrich, Peter and Fersch, Benjamin and Frenzel, Mark and Gaillardet, Jérôme and Groh, Jannis and Hajnsek, Irena and Itzerott, Sibylle and Kunkel, Ralf and Kunstmann, Harald and Kunz, Matthias and Liebner, Susanne and Mirtl, Michael and Montzka, Carsten and Musolff, Andreas and Pütz, Thomas and Rebmann, Corinna and Rinke, Karsten and Rode, Michael and Sachs, Torsten and Samaniego, Luis and Schmid, Hans Peter and Vogel, Hans‐Jörg and Weber, Ute and Wollschläger, Ute and Vereecken, Harry},
title = {Fifteen Years of Integrated Terrestrial Environmental Observatories (TERENO) in Germany: Functions, Services, and Lessons Learned},
journal = {Earth’s Future},
publisher = {American Geophysical Union (AGU)},
year = {2024},
volume = {12},
number = {6},
doi = {10.1029/2024ef004510}
}
|
| Zhang W, Luo G, Hamdi R, Ma X, Termonia P and De Maeyer P (2024), "Drought changes the dominant water stress on the grassland and forest production in the northern hemisphere", Agricultural and Forest Meteorology., February, 2024. Vol. 345, pp. 109831. Elsevier BV. |
BibTeX:
@article{Zhang2024,
author = {Zhang, Wenqiang and Luo, Geping and Hamdi, Rafiq and Ma, Xiumei and Termonia, Piet and De Maeyer, Philippe},
title = {Drought changes the dominant water stress on the grassland and forest production in the northern hemisphere},
journal = {Agricultural and Forest Meteorology},
publisher = {Elsevier BV},
year = {2024},
volume = {345},
pages = {109831},
doi = {10.1016/j.agrformet.2023.109831}
}
|
| Zhang W, Nelson JA, Miralles DG, Mauder M, Migliavacca M, Poyatos R, Reichstein M and Jung M (2024), "A New Post‐Hoc Method to Reduce the Energy Imbalance in Eddy Covariance Measurements", Geophysical Research Letters., January, 2024. Vol. 51(2) American Geophysical Union (AGU). |
BibTeX:
@article{Zhang2024a,
author = {Zhang, Weijie and Nelson, Jacob A. and Miralles, Diego G. and Mauder, Matthias and Migliavacca, Mirco and Poyatos, Rafael and Reichstein, Markus and Jung, Martin},
title = {A New Post‐Hoc Method to Reduce the Energy Imbalance in Eddy Covariance Measurements},
journal = {Geophysical Research Letters},
publisher = {American Geophysical Union (AGU)},
year = {2024},
volume = {51},
number = {2},
doi = {10.1029/2023gl107084}
}
|
| Zhu Q, Yuan K, Li F, Riley WJ, Hoyt A, Jackson R, McNicol G, Chen M, Knox SH, Briner O, Beerling D, Gedney N, Hopcroft PO, Ito A, Jain AK, Jensen K, Kleinen T, Li T, Liu X, McDonald KC, Melton JR, Miller PA, Müller J, Peng C, Poulter B, Qin Z, Peng S, Tian H, Xu X, Yao Y, Xi Y, Zhang Z, Zhang W, Zhu Q and Zhuang Q (2024), "Critical needs to close monitoring gaps in pan-tropical wetland CH4 emissions", Environmental Research Letters., October, 2024. Vol. 19(11), pp. 114046. IOP Publishing. |
BibTeX:
@article{Zhu2024,
author = {Zhu, Qing and Yuan, Kunxiaojia and Li, Fa and Riley, William J and Hoyt, Alison and Jackson, Robert and McNicol, Gavin and Chen, Min and Knox, Sara H and Briner, Otto and Beerling, David and Gedney, Nicola and Hopcroft, Peter O and Ito, Akihito and Jain, Atul K and Jensen, Katherine and Kleinen, Thomas and Li, Tingting and Liu, Xiangyu and McDonald, Kyle C and Melton, Joe R and Miller, Paul A and Müller, Jurek and Peng, Changhui and Poulter, Benjamin and Qin, Zhangcai and Peng, Shushi and Tian, Hanqin and Xu, Xiaoming and Yao, Yuanzhi and Xi, Yi and Zhang, Zhen and Zhang, Wenxin and Zhu, Qiuan and Zhuang, Qianlai},
title = {Critical needs to close monitoring gaps in pan-tropical wetland CH4 emissions},
journal = {Environmental Research Letters},
publisher = {IOP Publishing},
year = {2024},
volume = {19},
number = {11},
pages = {114046},
doi = {10.1088/1748-9326/ad8019}
}
|
| Zinke J, Nilsson ED, Markuszewski P, Zieger P, Mårtensson EM, Rutgersson A, Nilsson E and Salter ME (2024), "Sea spray emissions from the Baltic Sea: comparison of aerosol eddy covariance fluxes and chamber-simulated sea spray emissions", Atmospheric Chemistry and Physics., February, 2024. Vol. 24(3), pp. 1895-1918. Copernicus GmbH. |
BibTeX:
@article{Zinke2024,
author = {Zinke, Julika and Nilsson, Ernst Douglas and Markuszewski, Piotr and Zieger, Paul and Mårtensson, Eva Monica and Rutgersson, Anna and Nilsson, Erik and Salter, Matthew Edward},
title = {Sea spray emissions from the Baltic Sea: comparison of aerosol eddy covariance fluxes and chamber-simulated sea spray emissions},
journal = {Atmospheric Chemistry and Physics},
publisher = {Copernicus GmbH},
year = {2024},
volume = {24},
number = {3},
pages = {1895--1918},
doi = {10.5194/acp-24-1895-2024}
}
|
| (2023), "ICOS-Spain. Activity Report 2021-2022" Agencia Estatal de Meteorología. |
BibTeX:
@book{2023,,
title = {ICOS-Spain. Activity Report 2021-2022},
publisher = {Agencia Estatal de Meteorología},
year = {2023},
url = {http://dx.doi.org/10.31978/666-23-010-3},
doi = {10.31978/666-23-010-3}
}
|
| Abdalla M, Feigenwinter I, Richards M, Vetter SH, Wohlfahrt G, Skiba U, Pintér K, Nagy Z, Hejduk S, Buchmann N, Newell-Price P and Smith P (2023), "Evaluation of the ECOSSE Model for Estimating Soil Respiration from Eight European Permanent Grassland Sites", Agronomy., jun, 2023. Vol. 13(7), pp. 1734. MDPI AG. |
BibTeX:
@article{Abdalla2023,
author = {Abdalla, Mohamed and Feigenwinter, Iris and Richards, Mark and Vetter, Sylvia Helga and Wohlfahrt, Georg and Skiba, Ute and Pintér, Krisztina and Nagy, Zoltán and Hejduk, Stanislav and Buchmann, Nina and Newell-Price, Paul and Smith, Pete},
title = {Evaluation of the ECOSSE Model for Estimating Soil Respiration from Eight European Permanent Grassland Sites},
journal = {Agronomy},
publisher = {MDPI AG},
year = {2023},
volume = {13},
number = {7},
pages = {1734},
url = {http://dx.doi.org/10.3390/agronomy13071734},
doi = {10.3390/agronomy13071734}
}
|
| Adcock KE, Pickers PA, Manning AC, Forster GL, Fleming LS, Barningham T, Wilson PA, Kozlova EA, Hewitt M, Etchells AJ and Macdonald AJ (2023), "12 years of continuous atmospheric O2, CO2 and APO data from Weybourne Atmospheric Observatory in the United Kingdom", Earth System Science Data., nov, 2023. Vol. 15(11), pp. 5183-5206. Copernicus GmbH. |
BibTeX:
@article{Adcock2023,
author = {Adcock, Karina E and Pickers, Penelope A and Manning, Andrew C and Forster, Grant L and Fleming, Leigh S and Barningham, Thomas and Wilson, Philip A and Kozlova, Elena A and Hewitt, Marica and Etchells, Alex J and Macdonald, Andy J},
title = {12 years of continuous atmospheric O2, CO2 and APO data from Weybourne Atmospheric Observatory in the United Kingdom},
journal = {Earth System Science Data},
publisher = {Copernicus GmbH},
year = {2023},
volume = {15},
number = {11},
pages = {5183--5206},
url = {http://dx.doi.org/10.5194/essd-15-5183-2023},
doi = {10.5194/essd-15-5183-2023}
}
|
| Ahlberg E, Ausmeel S, Nilsson L, Spanne M, Pauraite J, Klenø Nøjgaard J, Bertò M, Skov H, Roldin P, Kristensson A, Swietlicki E and Eriksson A (2023), "Measurement report: Black carbon properties and concentrations in southern Sweden urban and rural air – the importance of long-range transport", Atmospheric Chemistry and Physics., mar, 2023. Vol. 23(5), pp. 3051-3064. Copernicus GmbH. |
BibTeX:
@article{Ahlberg2023,
author = {Ahlberg, Erik and Ausmeel, Stina and Nilsson, Lovisa and Spanne, Mårten and Pauraite, Julija and Klenø Nøjgaard, Jacob and Bertò, Michele and Skov, Henrik and Roldin, Pontus and Kristensson, Adam and Swietlicki, Erik and Eriksson, Axel},
title = {Measurement report: Black carbon properties and concentrations in southern Sweden urban and rural air – the importance of long-range transport},
journal = {Atmospheric Chemistry and Physics},
publisher = {Copernicus GmbH},
year = {2023},
volume = {23},
number = {5},
pages = {3051--3064},
url = {http://dx.doi.org/10.5194/acp-23-3051-2023},
doi = {10.5194/acp-23-3051-2023}
}
|
| Ahongshangbam J, Kulmala L, Soininen J, Frühauf Y, Karvinen E, Salmon Y, Lintunen A, Karvonen A and Järvi L (2023), "Sap flow and leaf gas exchange response to a drought and heatwave in urban green spaces in a Nordic city", Biogeosciences., nov, 2023. Vol. 20(21), pp. 4455-4475. Copernicus GmbH. |
BibTeX:
@article{Ahongshangbam2023,
author = {Ahongshangbam, Joyson and Kulmala, Liisa and Soininen, Jesse and Frühauf, Yasmin and Karvinen, Esko and Salmon, Yann and Lintunen, Anna and Karvonen, Anni and Järvi, Leena},
title = {Sap flow and leaf gas exchange response to a drought and heatwave in urban green spaces in a Nordic city},
journal = {Biogeosciences},
publisher = {Copernicus GmbH},
year = {2023},
volume = {20},
number = {21},
pages = {4455--4475},
url = {http://dx.doi.org/10.5194/bg-20-4455-2023},
doi = {10.5194/bg-20-4455-2023}
}
|
| Autio A, Ala-Aho P, Rossi PM, Ronkanen A-K, Aurela M, Lohila A, Korpelainen P, Kumpula T, Klöve B and Marttila H (2023), "Groundwater exfiltration pattern determination in the sub-arctic catchment using thermal imaging, stable water isotopes and fully-integrated groundwater-surface water modelling", Journal of Hydrology., nov, 2023. Vol. 626, pp. 130342. Elsevier BV. |
BibTeX:
@article{Autio2023,
author = {Autio, Anna and Ala-Aho, Pertti and Rossi, Pekka M and Ronkanen, Anna-Kaisa and Aurela, Mika and Lohila, Annalea and Korpelainen, Pasi and Kumpula, Timo and Klöve, Björn and Marttila, Hannu},
title = {Groundwater exfiltration pattern determination in the sub-arctic catchment using thermal imaging, stable water isotopes and fully-integrated groundwater-surface water modelling},
journal = {Journal of Hydrology},
publisher = {Elsevier BV},
year = {2023},
volume = {626},
pages = {130342},
url = {http://dx.doi.org/10.1016/j.jhydrol.2023.130342},
doi = {10.1016/j.jhydrol.2023.130342}
}
|
| Balathandayuthabani S, Wallin MB, Klemedtsson L, Crill P and Bastviken D (2023), "Aquatic carbon fluxes in a hemiboreal catchment are predictable from landscape morphology, temperature, and runoff", Limnology and Oceanography Letters., feb, 2023. Vol. 8(2), pp. 313-322. Wiley. |
BibTeX:
@article{Balathandayuthabani2023,
author = {Balathandayuthabani, Sivakiruthika and Wallin, Marcus B and Klemedtsson, Leif and Crill, Patrick and Bastviken, David},
title = {Aquatic carbon fluxes in a hemiboreal catchment are predictable from landscape morphology, temperature, and runoff},
journal = {Limnology and Oceanography Letters},
publisher = {Wiley},
year = {2023},
volume = {8},
number = {2},
pages = {313--322},
url = {http://dx.doi.org/10.1002/lol2.10312},
doi = {10.1002/lol2.10312}
}
|
| Balde H, Hmimina G, Goulas Y, Latouche G and Soudani K (2023), "Synergy between TROPOMI sun-induced chlorophyll fluorescence and MODIS spectral reflectance for understanding the dynamics of gross primary productivity at Integrated Carbon Observatory System (ICOS) ecosystem flux sites", Biogeosciences., apr, 2023. Vol. 20(7), pp. 1473-1490. Copernicus GmbH. |
BibTeX:
@article{Balde2023,
author = {Balde, Hamadou and Hmimina, Gabriel and Goulas, Yves and Latouche, Gwendal and Soudani, Kamel},
title = {Synergy between TROPOMI sun-induced chlorophyll fluorescence and MODIS spectral reflectance for understanding the dynamics of gross primary productivity at Integrated Carbon Observatory System (ICOS) ecosystem flux sites},
journal = {Biogeosciences},
publisher = {Copernicus GmbH},
year = {2023},
volume = {20},
number = {7},
pages = {1473--1490},
url = {http://dx.doi.org/10.5194/bg-20-1473-2023},
doi = {10.5194/bg-20-1473-2023}
}
|
| Beauclaire Q, Heinesch B and Longdoz B (2023), "Non-stomatal processes are responsible for the decrease in gross primary production of a potato crop during edaphic drought", Agricultural and Forest Meteorology., dec, 2023. Vol. 343, pp. 109782. Elsevier BV. |
BibTeX:
@article{Beauclaire2023,
author = {Beauclaire, Quentin and Heinesch, Bernard and Longdoz, Bernard},
title = {Non-stomatal processes are responsible for the decrease in gross primary production of a potato crop during edaphic drought},
journal = {Agricultural and Forest Meteorology},
publisher = {Elsevier BV},
year = {2023},
volume = {343},
pages = {109782},
url = {http://dx.doi.org/10.1016/j.agrformet.2023.109782},
doi = {10.1016/j.agrformet.2023.109782}
}
|
| Bennett AC, de Sousa T, Monteagudo-Mendoza A, Esquivel-Muelbert A, Morandi PS, de Souza F, Castro W, Duque LF, Flores Llampazo G, dos Santos R, Ramos E, Vilanova Torre E, Alvarez-Davila E, Baker TR, Costa FRC, Lewis SL, Marimon BS, Schietti J, Burban B, Berenguer E, Araujo-Murakami A, Restrepo Correa Z, Lopez W, Delgado Santana F, Viscarra LJ, Elias F, Vasquez Martinez R, Marimon-Junior BH, Galbraith D, Sullivan MJP, Emilio T, Prestes NCCS, Barlow J, Alencar Fagundes NC, de Oliveira E, Alvarez Loayza P, Alves LF, Aparecida Vieira S, Andrade Maia V, Aragão LEOC, Arets EJMM, Arroyo L, Bánki O, Baraloto C, Barbosa Camargo P, Barroso J, da Silva W, Bonal D, Borges Miranda Santos A, Brienen RJW, Brown F, Castilho CV, Cerruto Ribeiro S, Chama Moscoso V, Chavez E, Comiskey JA, Cornejo Valverde F, Dávila Cardozo N, de Aguiar-Campos N, de Oliveira Melo L, del Aguila Pasquel J, Derroire G, Disney M, do Socorro M, Dourdain A, Feldpausch TR, Ferreira J, Forni Martins V, Gardner T, Gloor E, Gutierrez Sibauty G, Guillen R, Hase E, Hérault B, Honorio Coronado EN, Huaraca Huasco W, Janovec JP, Jimenez-Rojas E, Joly C, Kalamandeen M, Killeen TJ, Lais Farrapo C, Levesley A, Lizon Romano L, Lopez Gonzalez G, dos Santos FA, Magnusson WE, Malhi Y, de Almeida Reis S, Melgaço K, Melo Cruz OA, Mendoza Polo I, Montañez T, Morel JD, Núñez Vargas MP, de Araújo R, Pallqui Camacho NC, Parada Gutierrez A, Pennington T, Pickavance GC, Pipoly J, Pitman NCA, Quesada C, Ramirez Arevalo F, Ramírez‐Angulo H, Flora Ramos R, Richardson JE, de Souza C, Roopsind A, Schwartz G, Silva RC, Silva Espejo J, Silveira M, Singh J, Soto Shareva Y, Steininger M, Stropp J, Talbot J, ter Steege H, Terborgh J, Thomas R, Valenzuela Gamarra L, van der Heijden G, van der Hout P, Zagt R and Phillips OL (2023), "Sensitivity of South American tropical forests to an extreme climate anomaly", Nature Climate Change., sep, 2023. Vol. 13(9), pp. 967-974. Springer Science and Business Media LLC. |
BibTeX:
@article{Bennett2023,
author = {Bennett, Amy C and de Sousa, Thaiane and Monteagudo-Mendoza, Abel and Esquivel-Muelbert, Adriane and Morandi, Paulo S and de Souza, Fernanda and Castro, Wendeson and Duque, Luisa Fernanda and Flores Llampazo, Gerardo and dos Santos, Rubens and Ramos, Eliana and Vilanova Torre, Emilio and Alvarez-Davila, Esteban and Baker, Timothy R and Costa, Flávia R C and Lewis, Simon L and Marimon, Beatriz S and Schietti, Juliana and Burban, Benoît and Berenguer, Erika and Araujo-Murakami, Alejandro and Restrepo Correa, Zorayda and Lopez, Wilmar and Delgado Santana, Flávia and Viscarra, Laura Jessica and Elias, Fernando and Vasquez Martinez, Rodolfo and Marimon-Junior, Ben Hur and Galbraith, David and Sullivan, Martin J P and Emilio, Thaise and Prestes, Nayane C C S and Barlow, Jos and Alencar Fagundes, Nathalle Cristine and de Oliveira, Edmar and Alvarez Loayza, Patricia and Alves, Luciana F and Aparecida Vieira, Simone and Andrade Maia, Vinícius and Aragão, Luiz E O C and Arets, Eric J M M and Arroyo, Luzmila and Bánki, Olaf and Baraloto, Christopher and Barbosa Camargo, Plínio and Barroso, Jorcely and da Silva, Wilder and Bonal, Damien and Borges Miranda Santos, Alisson and Brienen, Roel J W and Brown, Foster and Castilho, Carolina V and Cerruto Ribeiro, Sabina and Chama Moscoso, Victor and Chavez, Ezequiel and Comiskey, James A and Cornejo Valverde, Fernando and Dávila Cardozo, Nállarett and de Aguiar-Campos, Natália and de Oliveira Melo, Lia and del Aguila Pasquel, Jhon and Derroire, Géraldine and Disney, Mathias and do Socorro, Maria and Dourdain, Aurélie and Feldpausch, Ted R and Ferreira, Joice and Forni Martins, Valeria and Gardner, Toby and Gloor, Emanuel and Gutierrez Sibauty, Gloria and Guillen, René and Hase, Eduardo and Hérault, Bruno and Honorio Coronado, Eurídice N and Huaraca Huasco, Walter and Janovec, John P and Jimenez-Rojas, Eliana and Joly, Carlos and Kalamandeen, Michelle and Killeen, Timothy J and Lais Farrapo, Camila and Levesley, Aurora and Lizon Romano, Leon and Lopez Gonzalez, Gabriela and dos Santos, Flavio Antonio and Magnusson, William E and Malhi, Yadvinder and de Almeida Reis, Simone and Melgaço, Karina and Melo Cruz, Omar A and Mendoza Polo, Irina and Montañez, Tatiana and Morel, Jean Daniel and Núñez Vargas, M Percy and de Araújo, Raimunda and Pallqui Camacho, Nadir C and Parada Gutierrez, Alexander and Pennington, Toby and Pickavance, Georgia C and Pipoly, John and Pitman, Nigel C A and Quesada, Carlos and Ramirez Arevalo, Freddy and Ramírez‐Angulo, Hirma and Flora Ramos, Rafael and Richardson, James E and de Souza, Cléber and Roopsind, Anand and Schwartz, Gustavo and Silva, Richarlly C and Silva Espejo, Javier and Silveira, Marcos and Singh, James and Soto Shareva, Yhan and Steininger, Marc and Stropp, Juliana and Talbot, Joey and ter Steege, Hans and Terborgh, John and Thomas, Raquel and Valenzuela Gamarra, Luis and van der Heijden, Geertje and van der Hout, Peter and Zagt, Roderick and Phillips, Oliver L},
title = {Sensitivity of South American tropical forests to an extreme climate anomaly},
journal = {Nature Climate Change},
publisher = {Springer Science and Business Media LLC},
year = {2023},
volume = {13},
number = {9},
pages = {967--974},
url = {http://dx.doi.org/10.1038/s41558-023-01776-4},
doi = {10.1038/s41558-023-01776-4}
}
|
| Bergkvist J, Lagergren F, Linderson M-LF, Miller P, Lindeskog M and Jönsson AM (2023), "Modelling managed forest ecosystems in Sweden: An evaluation from the stand to the regional scale", Ecological Modelling., mar, 2023. Vol. 477, pp. 110253. Elsevier BV. |
BibTeX:
@article{Bergkvist2023,
author = {Bergkvist, John and Lagergren, Fredrik and Linderson, Maj-Lena Finnander and Miller, Paul and Lindeskog, Mats and Jönsson, Anna Maria},
title = {Modelling managed forest ecosystems in Sweden: An evaluation from the stand to the regional scale},
journal = {Ecological Modelling},
publisher = {Elsevier BV},
year = {2023},
volume = {477},
pages = {110253},
url = {http://dx.doi.org/10.1016/j.ecolmodel.2022.110253},
doi = {10.1016/j.ecolmodel.2022.110253}
}
|
| Bittig HC, Jacobs E, Neumann T and Rehder G (2023), "A regional pCO2 climatology of the Baltic Sea from in situ pCO2 observations and a model-based extrapolation approach", jul, 2023. Copernicus GmbH. |
BibTeX:
@article{Bittig2023,
author = {Bittig, Henry C and Jacobs, Erik and Neumann, Thomas and Rehder, Gregor},
title = {A regional pCO2 climatology of the Baltic Sea from in situ pCO2 observations and a model-based extrapolation approach},
publisher = {Copernicus GmbH},
year = {2023},
url = {http://dx.doi.org/10.5194/essd-2023-264},
doi = {10.5194/essd-2023-264}
}
|
| Bloomfield KJ, van Hoolst R, Balzarolo M, Janssens IA, Vicca S, Ghent D and Prentice IC (2023), "Towards a General Monitoring System for Terrestrial Primary Production: A Test Spanning the European Drought of 2018", Remote Sensing., mar, 2023. Vol. 15(6), pp. 1693. MDPI AG. |
BibTeX:
@article{Bloomfield2023,
author = {Bloomfield, Keith J and van Hoolst, Roel and Balzarolo, Manuela and Janssens, Ivan A and Vicca, Sara and Ghent, Darren and Prentice, I Colin},
title = {Towards a General Monitoring System for Terrestrial Primary Production: A Test Spanning the European Drought of 2018},
journal = {Remote Sensing},
publisher = {MDPI AG},
year = {2023},
volume = {15},
number = {6},
pages = {1693},
url = {http://dx.doi.org/10.3390/rs15061693},
doi = {10.3390/rs15061693}
}
|
| Brown LA, Morris H, Meier C, Knohl A, Lanconelli C, Gobron N, Dash J and Danson FM (2023), "Stage 1 Validation of Plant Area Index From the Global Ecosystem Dynamics Investigation", IEEE Geoscience and Remote Sensing Letters. Vol. 20, pp. 1-5. Institute of Electrical and Electronics Engineers (IEEE). |
BibTeX:
@article{Brown2023,
author = {Brown, Luke A and Morris, Harry and Meier, Courtney and Knohl, Alexander and Lanconelli, Christian and Gobron, Nadine and Dash, Jadunandan and Danson, F Mark},
title = {Stage 1 Validation of Plant Area Index From the Global Ecosystem Dynamics Investigation},
journal = {IEEE Geoscience and Remote Sensing Letters},
publisher = {Institute of Electrical and Electronics Engineers (IEEE)},
year = {2023},
volume = {20},
pages = {1--5},
url = {http://dx.doi.org/10.1109/LGRS.2023.3319528},
doi = {10.1109/lgrs.2023.3319528}
}
|
| Burdun I, Bechtold M, Aurela M, De Lannoy G, Desai AR, Humphreys E, Kareksela S, Komisarenko V, Liimatainen M, Marttila H, Minkkinen K, Nilsson MB, Ojanen P, Salko S-S, Tuittila E-S, Uuemaa E and Rautiainen M (2023), "Hidden becomes clear: Optical remote sensing of vegetation reveals water table dynamics in northern peatlands", Remote Sensing of Environment., oct, 2023. Vol. 296, pp. 113736. Elsevier BV. |
BibTeX:
@article{Burdun2023,
author = {Burdun, Iuliia and Bechtold, Michel and Aurela, Mika and De Lannoy, Gabrielle and Desai, Ankur R and Humphreys, Elyn and Kareksela, Santtu and Komisarenko, Viacheslav and Liimatainen, Maarit and Marttila, Hannu and Minkkinen, Kari and Nilsson, Mats B and Ojanen, Paavo and Salko, Sini-Selina and Tuittila, Eeva-Stiina and Uuemaa, Evelyn and Rautiainen, Miina},
title = {Hidden becomes clear: Optical remote sensing of vegetation reveals water table dynamics in northern peatlands},
journal = {Remote Sensing of Environment},
publisher = {Elsevier BV},
year = {2023},
volume = {296},
pages = {113736},
url = {http://dx.doi.org/10.1016/j.rse.2023.113736},
doi = {10.1016/j.rse.2023.113736}
}
|
| Charoenpornpukdee K, Stanley K, Pitt J, Wenger A, Manning A, Young D, Say D and O’Doherty S (2023), "Recreational drug-use as an urban source of nitrous oxide", Environmental Science: Atmospheres. Vol. 3(6), pp. 962-969. Royal Society of Chemistry (RSC). |
BibTeX:
@article{Charoenpornpukdee2023,
author = {Charoenpornpukdee, Kanokrat and Stanley, Kieran and Pitt, Joe and Wenger, Angelina and Manning, Alistair and Young, Dickon and Say, Daniel and O’Doherty, Simon},
title = {Recreational drug-use as an urban source of nitrous oxide},
journal = {Environmental Science: Atmospheres},
publisher = {Royal Society of Chemistry (RSC)},
year = {2023},
volume = {3},
number = {6},
pages = {962--969},
doi = {10.1039/d3ea00025g}
}
|
| Charoenpornpukdee K, O’Doherty S, Webber EM, Hill-Pearce R, Hillier A, Worton DR, Arnold T, Rennick C, Safi E and Brewer P (2023), "Step Change in Improving the Accuracy of Nitrous Oxide Reference Materials for Underpinning Atmospheric Composition Measurements", Analytical Chemistry., August, 2023. Vol. 95(34), pp. 12867-12874. American Chemical Society (ACS). |
BibTeX:
@article{Charoenpornpukdee2023a,
author = {Charoenpornpukdee, Kanokrat and O’Doherty, Simon and Webber, Eric Mussell and Hill-Pearce, Ruth and Hillier, Aimee and Worton, David R. and Arnold, Tim and Rennick, Chris and Safi, Emmal and Brewer, Paul},
title = {Step Change in Improving the Accuracy of Nitrous Oxide Reference Materials for Underpinning Atmospheric Composition Measurements},
journal = {Analytical Chemistry},
publisher = {American Chemical Society (ACS)},
year = {2023},
volume = {95},
number = {34},
pages = {12867--12874},
doi = {10.1021/acs.analchem.3c02160}
}
|
| Chrysoulakis N, Ludlow D, Mitraka Z, Somarakis G, Khan Z, Lauwaet D, Hooyberghs H, Feliu E, Navarro D, Feigenwinter C, Holsten A, Soukup T, Dohr M, Marconcini M and Holt Andersen B (2023), "Copernicus for Urban Resilience in Europe: Final results from the CURE project", may, 2023. Copernicus GmbH. |
BibTeX:
@article{Chrysoulakis2023,
author = {Chrysoulakis, Nektarios and Ludlow, David and Mitraka, Zina and Somarakis, Giorgos and Khan, Zaheer and Lauwaet, Dirk and Hooyberghs, Hans and Feliu, Efrén and Navarro, Daniel and Feigenwinter, Christian and Holsten, Anne and Soukup, Tomas and Dohr, Mario and Marconcini, Mattia and Holt Andersen, Birgitte},
title = {Copernicus for Urban Resilience in Europe: Final results from the CURE project},
publisher = {Copernicus GmbH},
year = {2023},
url = {http://dx.doi.org/10.5194/egusphere-egu23-1976},
doi = {10.5194/egusphere-egu23-1976}
}
|
| Cintolesi C, Barbano F, Trudu PL, Finco A, Gerosa G and Di Sabatino S (2023), "Characterisation of flow dynamics within and around an isolated forest, through measurements and numerical simulations", Agricultural and Forest Meteorology., aug, 2023. Vol. 339, pp. 109557. Elsevier BV. |
BibTeX:
@article{Cintolesi2023,
author = {Cintolesi, Carlo and Barbano, Francesco and Trudu, Pier Luigi and Finco, Angelo and Gerosa, Giacomo and Di Sabatino, Silvana},
title = {Characterisation of flow dynamics within and around an isolated forest, through measurements and numerical simulations},
journal = {Agricultural and Forest Meteorology},
publisher = {Elsevier BV},
year = {2023},
volume = {339},
pages = {109557},
url = {http://dx.doi.org/10.1016/j.agrformet.2023.109557},
doi = {10.1016/j.agrformet.2023.109557}
}
|
| Clifton OE, Schwede D, Hogrefe C, Bash JO, Bland S, Cheung P, Coyle M, Emberson L, Flemming J, Fredj E, Galmarini S, Ganzeveld L, Gazetas O, Goded I, Holmes CD, Horváth L, Huijnen V, Li Q, Makar PA, Mammarella I, Manca G, Munger JW, Pérez-Camanyo JL, Pleim J, Ran L, San Jose R, Silva SJ, Staebler R, Sun S, Tai APK, Tas E, Vesala T, Weidinger T, Wu Z and Zhang L (2023), "A single-point modeling approach for the intercomparison and evaluation of ozone dry deposition across chemical transport models (Activity 2 of AQMEII4)", Atmospheric Chemistry and Physics., sep, 2023. Vol. 23(17), pp. 9911-9961. Copernicus GmbH. |
BibTeX:
@article{Clifton2023,
author = {Clifton, Olivia E and Schwede, Donna and Hogrefe, Christian and Bash, Jesse O and Bland, Sam and Cheung, Philip and Coyle, Mhairi and Emberson, Lisa and Flemming, Johannes and Fredj, Erick and Galmarini, Stefano and Ganzeveld, Laurens and Gazetas, Orestis and Goded, Ignacio and Holmes, Christopher D and Horváth, László and Huijnen, Vincent and Li, Qian and Makar, Paul A and Mammarella, Ivan and Manca, Giovanni and Munger, J William and Pérez-Camanyo, Juan L and Pleim, Jonathan and Ran, Limei and San Jose, Roberto and Silva, Sam J and Staebler, Ralf and Sun, Shihan and Tai, Amos P K and Tas, Eran and Vesala, Timo and Weidinger, Tamás and Wu, Zhiyong and Zhang, Leiming},
title = {A single-point modeling approach for the intercomparison and evaluation of ozone dry deposition across chemical transport models (Activity 2 of AQMEII4)},
journal = {Atmospheric Chemistry and Physics},
publisher = {Copernicus GmbH},
year = {2023},
volume = {23},
number = {17},
pages = {9911--9961},
url = {http://dx.doi.org/10.5194/acp-23-9911-2023},
doi = {10.5194/acp-23-9911-2023}
}
|
| Cristofanelli P, Fratticioli C, Hazan L, Chariot M, Couret C, Gazetas O, Kubistin D, Laitinen A, Leskinen A, Laurila T, Lindauer M, Manca G, Ramonet M, Trisolino P and Steinbacher M (2023), "Identification of spikes in continuous ground-based in situ time series of CO2, CH4 and CO: an extended experiment within the European ICOS Atmosphere network", Atmospheric Measurement Techniques., dec, 2023. Vol. 16(24), pp. 5977-5994. Copernicus GmbH. |
BibTeX:
@article{Cristofanelli2023,
author = {Cristofanelli, Paolo and Fratticioli, Cosimo and Hazan, Lynn and Chariot, Mali and Couret, Cedric and Gazetas, Orestis and Kubistin, Dagmar and Laitinen, Antti and Leskinen, Ari and Laurila, Tuomas and Lindauer, Matthias and Manca, Giovanni and Ramonet, Michel and Trisolino, Pamela and Steinbacher, Martin},
title = {Identification of spikes in continuous ground-based in situ time series of CO2, CH4 and CO: an extended experiment within the European ICOS Atmosphere network},
journal = {Atmospheric Measurement Techniques},
publisher = {Copernicus GmbH},
year = {2023},
volume = {16},
number = {24},
pages = {5977--5994},
url = {http://dx.doi.org/10.5194/amt-16-5977-2023},
doi = {10.5194/amt-16-5977-2023}
}
|
| Delandmeter M, Léonard J, Ferchaud F, Heinesch B, Manise T, Faurès A, Bindelle J and Dumont B (2023), "A comprehensive analysis of CO2 exchanges in agro-ecosystems based on a generic soil-crop model-derived methodology", Agricultural and Forest Meteorology., sep, 2023. Vol. 340, pp. 109621. Elsevier BV. |
BibTeX:
@article{Delandmeter2023,
author = {Delandmeter, Mathieu and Léonard, Joël and Ferchaud, Fabien and Heinesch, Bernard and Manise, Tanguy and Faurès, Ariane and Bindelle, Jérôme and Dumont, Benjamin},
title = {A comprehensive analysis of CO2 exchanges in agro-ecosystems based on a generic soil-crop model-derived methodology},
journal = {Agricultural and Forest Meteorology},
publisher = {Elsevier BV},
year = {2023},
volume = {340},
pages = {109621},
url = {http://dx.doi.org/10.1016/j.agrformet.2023.109621},
doi = {10.1016/j.agrformet.2023.109621}
}
|
| De Pue J, Wieneke S, Bastos A, Barrios JM, Liu L, Ciais P, Arboleda A, Hamdi R, Maleki M, Maignan F, Gellens-Meulenberghs F, Janssens I and Balzarolo M (2023), "Temporal variability of observed and simulated gross primary productivity, modulated by vegetation state and hydrometeorological drivers", Biogeosciences., dec, 2023. Vol. 20(23), pp. 4795-4818. Copernicus GmbH. |
BibTeX:
@article{DePue2023,
author = {De Pue, Jan and Wieneke, Sebastian and Bastos, Ana and Barrios, José Miguel and Liu, Liyang and Ciais, Philippe and Arboleda, Alirio and Hamdi, Rafiq and Maleki, Maral and Maignan, Fabienne and Gellens-Meulenberghs, Françoise and Janssens, Ivan and Balzarolo, Manuela},
title = {Temporal variability of observed and simulated gross primary productivity, modulated by vegetation state and hydrometeorological drivers},
journal = {Biogeosciences},
publisher = {Copernicus GmbH},
year = {2023},
volume = {20},
number = {23},
pages = {4795--4818},
url = {http://dx.doi.org/10.5194/bg-20-4795-2023},
doi = {10.5194/bg-20-4795-2023}
}
|
| Derrien D, Barré P, Basile-Doelsch I, Cécillon L, Chabbi A, Crème A, Fontaine S, Henneron L, Janot N, Lashermes G, Quénéa K, Rees F and Dignac M-F (2023), "Current controversies on mechanisms controlling soil carbon storage: implications for interactions with practitioners and policy-makers. A review", Agronomy for Sustainable Development., feb, 2023. Vol. 43(1) Springer Science and Business Media LLC. |
BibTeX:
@article{Derrien2023,
author = {Derrien, Delphine and Barré, Pierre and Basile-Doelsch, Isabelle and Cécillon, Lauric and Chabbi, Abad and Crème, Alexandra and Fontaine, Sébastien and Henneron, Ludovic and Janot, Noémie and Lashermes, Gwenaëlle and Quénéa, Katell and Rees, Frédéric and Dignac, Marie-France},
title = {Current controversies on mechanisms controlling soil carbon storage: implications for interactions with practitioners and policy-makers. A review},
journal = {Agronomy for Sustainable Development},
publisher = {Springer Science and Business Media LLC},
year = {2023},
volume = {43},
number = {1},
url = {http://dx.doi.org/10.1007/s13593-023-00876-x},
doi = {10.1007/s13593-023-00876-x}
}
|
| Derwent RG, Simmonds PG, O’Doherty S, Manning AJ and Spain TG (2023), "High-frequency, continuous hydrogen observations at Mace Head, Ireland from 1994 to 2022: Baselines, pollution events and ‘missing’ sources", Atmospheric Environment., November, 2023. Vol. 312, pp. 120029. Elsevier BV. |
BibTeX:
@article{Derwent2023,
author = {Derwent, Richard G. and Simmonds, Peter G. and O’Doherty, Simon and Manning, Alistair J. and Spain, T. Gerard},
title = {High-frequency, continuous hydrogen observations at Mace Head, Ireland from 1994 to 2022: Baselines, pollution events and ‘missing’ sources},
journal = {Atmospheric Environment},
publisher = {Elsevier BV},
year = {2023},
volume = {312},
pages = {120029},
doi = {10.1016/j.atmosenv.2023.120029}
}
|
| Diao H, Wang A, Gharun M, Saurer M, Yuan F, Guan D, Dai G and Wu J (2023), "Tree-ring δ13C of Pinus koraiensis is a better tracer of gross primary productivity than tree-ring width index in an old-growth temperate forest", Ecological Indicators., sep, 2023. Vol. 153, pp. 110418. Elsevier BV. |
BibTeX:
@article{Diao2023,
author = {Diao, Haoyu and Wang, Anzhi and Gharun, Mana and Saurer, Matthias and Yuan, Fenghui and Guan, Dexin and Dai, Guanhua and Wu, Jiabing},
title = {Tree-ring δ13C of Pinus koraiensis is a better tracer of gross primary productivity than tree-ring width index in an old-growth temperate forest},
journal = {Ecological Indicators},
publisher = {Elsevier BV},
year = {2023},
volume = {153},
pages = {110418},
url = {http://dx.doi.org/10.1016/j.ecolind.2023.110418},
doi = {10.1016/j.ecolind.2023.110418}
}
|
| DiMaria CA, Jones DBA, Worden H, Bloom AA, Bowman K, Stavrakou T, Miyazaki K, Worden J, Guenther A, Sarkar C, Seco R, Park J, Tota J, Alves EG and Ferracci V (2023), "Optimizing the Isoprene Emission Model MEGAN With Satellite and Ground‐Based Observational Constraints", Journal of Geophysical Research: Atmospheres., February, 2023. Vol. 128(4) American Geophysical Union (AGU). |
BibTeX:
@article{DiMaria2023,
author = {DiMaria, Christian A. and Jones, Dylan B. A. and Worden, Helen and Bloom, A. Anthony and Bowman, Kevin and Stavrakou, Trissevgeni and Miyazaki, Kazuyuki and Worden, John and Guenther, Alex and Sarkar, Chinmoy and Seco, Roger and Park, Jeong‐Hoo and Tota, Julio and Alves, Eliane Gomes and Ferracci, Valerio},
title = {Optimizing the Isoprene Emission Model MEGAN With Satellite and Ground‐Based Observational Constraints},
journal = {Journal of Geophysical Research: Atmospheres},
publisher = {American Geophysical Union (AGU)},
year = {2023},
volume = {128},
number = {4},
doi = {10.1029/2022jd037822}
}
|
| Dissanayake AL, Gros J, Drews HJ, Nielsen JW and Drews A (2023), "Fate of Methane from the Nord Stream Pipeline Leaks", Environmental Science & Technology Letters., sep, 2023. Vol. 10(10), pp. 903-908. American Chemical Society (ACS). |
BibTeX:
@article{Dissanayake2023,
author = {Dissanayake, Anusha L and Gros, Jonas and Drews, Henning Johannes and Nielsen, Jacob Woge and Drews, Annika},
title = {Fate of Methane from the Nord Stream Pipeline Leaks},
journal = {Environmental Science & Technology Letters},
publisher = {American Chemical Society (ACS)},
year = {2023},
volume = {10},
number = {10},
pages = {903--908},
url = {http://dx.doi.org/10.1021/acs.estlett.3c00493},
doi = {10.1021/acs.estlett.3c00493}
}
|
| Erdbrügger J, van Meerveld I, Seibert J and Bishop K (2023), "Shallow-groundwater-level time series and a groundwater chemistry survey from a boreal headwater catchment, Krycklan, Sweden", Earth System Science Data., apr, 2023. Vol. 15(4), pp. 1779-1800. Copernicus GmbH. |
BibTeX:
@article{Erdbruegger2023,
author = {Erdbrügger, Jana and van Meerveld, Ilja and Seibert, Jan and Bishop, Kevin},
title = {Shallow-groundwater-level time series and a groundwater chemistry survey from a boreal headwater catchment, Krycklan, Sweden},
journal = {Earth System Science Data},
publisher = {Copernicus GmbH},
year = {2023},
volume = {15},
number = {4},
pages = {1779--1800},
url = {http://dx.doi.org/10.5194/essd-15-1779-2023},
doi = {10.5194/essd-15-1779-2023}
}
|
| Ericson Y, Fransson A, Chierici M, Jones EM, Skjelvan I, Omar A, Olsen A and Becker M (2023), "Rapid fCO2 rise in the northern Barents Sea and Nansen Basin", Progress in Oceanography., sep, 2023. Vol. 217, pp. 103079. Elsevier BV. |
BibTeX:
@article{Ericson2023,
author = {Ericson, Ylva and Fransson, Agneta and Chierici, Melissa and Jones, Elizabeth M and Skjelvan, Ingunn and Omar, Abdirahman and Olsen, Are and Becker, Meike},
title = {Rapid fCO2 rise in the northern Barents Sea and Nansen Basin},
journal = {Progress in Oceanography},
publisher = {Elsevier BV},
year = {2023},
volume = {217},
pages = {103079},
url = {http://dx.doi.org/10.1016/j.pocean.2023.103079},
doi = {10.1016/j.pocean.2023.103079}
}
|
| Faassen KAP, Nguyen LNT, Broekema ER, Kers BAM, Mammarella I, Vesala T, Pickers PA, Manning AC, de Arellano J, Meijer HAJ, Peters W and Luijkx IT (2023), "Diurnal variability of atmospheric O2, CO2, and their exchange ratio above a boreal forest in southern Finland", Atmospheric Chemistry and Physics., jan, 2023. Vol. 23(2), pp. 851-876. Copernicus GmbH. |
BibTeX:
@article{Faassen2023,
author = {Faassen, Kim A P and Nguyen, Linh N T and Broekema, Eadin R and Kers, Bert A M and Mammarella, Ivan and Vesala, Timo and Pickers, Penelope A and Manning, Andrew C and de Arellano, Jordi and Meijer, Harro A J and Peters, Wouter and Luijkx, Ingrid T},
title = {Diurnal variability of atmospheric O2, CO2, and their exchange ratio above a boreal forest in southern Finland},
journal = {Atmospheric Chemistry and Physics},
publisher = {Copernicus GmbH},
year = {2023},
volume = {23},
number = {2},
pages = {851--876},
url = {http://dx.doi.org/10.5194/acp-23-851-2023},
doi = {10.5194/acp-23-851-2023}
}
|
| Fatima E, Kumar R, Attinger S, Kaluza M, Rakovec O, Rebmann C, Rosolem R, Oswald S, Samaniego L, Zacharias S and Schrön M (2023), "Improved representation of soil moisture simulations through incorporation of cosmic-ray neutron count measurements in a large-scale hydrologic model", July, 2023. Copernicus GmbH. |
BibTeX:
@article{Fatima2023,
author = {Fatima, Eshrat and Kumar, Rohini and Attinger, Sabine and Kaluza, Maren and Rakovec, Oldrich and Rebmann, Corinna and Rosolem, Rafael and Oswald, Sascha and Samaniego, Luis and Zacharias, Steffen and Schrön, Martin},
title = {Improved representation of soil moisture simulations through incorporation of cosmic-ray neutron count measurements in a large-scale hydrologic model},
publisher = {Copernicus GmbH},
year = {2023},
doi = {10.5194/egusphere-2023-1548}
}
|
| Feng L, Palmer PI, Parker RJ, Lunt MF and Bösch H (2023), "Methane emissions are predominantly responsible for record-breaking atmospheric methane growth rates in 2020 and 2021", Atmospheric Chemistry and Physics., apr, 2023. Vol. 23(8), pp. 4863-4880. Copernicus GmbH. |
BibTeX:
@article{Feng2023,
author = {Feng, Liang and Palmer, Paul I and Parker, Robert J and Lunt, Mark F and Bösch, Hartmut},
title = {Methane emissions are predominantly responsible for record-breaking atmospheric methane growth rates in 2020 and 2021},
journal = {Atmospheric Chemistry and Physics},
publisher = {Copernicus GmbH},
year = {2023},
volume = {23},
number = {8},
pages = {4863--4880},
url = {http://dx.doi.org/10.5194/acp-23-4863-2023},
doi = {10.5194/acp-23-4863-2023}
}
|
| Fillola E, Santos-Rodriguez R, Manning A, O’Doherty S and Rigby M (2023), "A machine learning emulator for Lagrangian particle dispersion model footprints: a case study using NAME", Geoscientific Model Development., April, 2023. Vol. 16(7), pp. 1997-2009. Copernicus GmbH. |
BibTeX:
@article{Fillola2023,
author = {Fillola, Elena and Santos-Rodriguez, Raul and Manning, Alistair and O’Doherty, Simon and Rigby, Matt},
title = {A machine learning emulator for Lagrangian particle dispersion model footprints: a case study using NAME},
journal = {Geoscientific Model Development},
publisher = {Copernicus GmbH},
year = {2023},
volume = {16},
number = {7},
pages = {1997--2009},
doi = {10.5194/gmd-16-1997-2023}
}
|
| Fischer M, Katul G, Noormets A, Pozníková G, Domec J-C, Orság M, Žalud Z, Trnka M and King JS (2023), "Merging flux-variance with surface renewal methods in the roughness sublayer and the atmospheric surface layer", Agricultural and Forest Meteorology., nov, 2023. Vol. 342, pp. 109692. Elsevier BV. |
BibTeX:
@article{Fischer2023,
author = {Fischer, Milan and Katul, Gabriel and Noormets, Asko and Pozníková, Gabriela and Domec, Jean-Christophe and Orság, Matěj and Žalud, Zdeněk and Trnka, Miroslav and King, John S},
title = {Merging flux-variance with surface renewal methods in the roughness sublayer and the atmospheric surface layer},
journal = {Agricultural and Forest Meteorology},
publisher = {Elsevier BV},
year = {2023},
volume = {342},
pages = {109692},
url = {http://dx.doi.org/10.1016/j.agrformet.2023.109692},
doi = {10.1016/j.agrformet.2023.109692}
}
|
| Fleming LS, Manning AC, Pickers PA, Forster GL and Etchells AJ (2023), "Evaluating the performance of a Picarro G2207-i analyser for high-precision atmospheric O2 measurements", Atmospheric Measurement Techniques., jan, 2023. Vol. 16(2), pp. 387-401. Copernicus GmbH. |
BibTeX:
@article{Fleming2023,
author = {Fleming, Leigh S and Manning, Andrew C and Pickers, Penelope A and Forster, Grant L and Etchells, Alex J},
title = {Evaluating the performance of a Picarro G2207-i analyser for high-precision atmospheric O2 measurements},
journal = {Atmospheric Measurement Techniques},
publisher = {Copernicus GmbH},
year = {2023},
volume = {16},
number = {2},
pages = {387--401},
url = {http://dx.doi.org/10.5194/amt-16-387-2023},
doi = {10.5194/amt-16-387-2023}
}
|
| Fóti S, Bartha S, Balogh J, Pintér K, Koncz P, Biró M, Süle G, Petrás D, De Luca G, Mészáros Á, Zimmermann Z, Szabó G, Csathó AI, Ladányi M, Péli ER and Nagy Z (2023), "Fluctuations and trends in spatio‐temporal patterns of plant species and diversity in a sandy pasture", Journal of Vegetation Science., may, 2023. Vol. 34(3) Wiley. |
BibTeX:
@article{Foti2023,
author = {Fóti, Szilvia and Bartha, Sándor and Balogh, János and Pintér, Krisztina and Koncz, Péter and Biró, Marianna and Süle, Gabriella and Petrás, Dóra and De Luca, Giulia and Mészáros, Ádám and Zimmermann, Zita and Szabó, Gábor and Csathó, András István and Ladányi, Márta and Péli, Evelin Ramóna and Nagy, Zoltán},
title = {Fluctuations and trends in spatio‐temporal patterns of plant species and diversity in a sandy pasture},
journal = {Journal of Vegetation Science},
publisher = {Wiley},
year = {2023},
volume = {34},
number = {3},
url = {http://dx.doi.org/10.1111/jvs.13190},
doi = {10.1111/jvs.13190}
}
|
| Fratticioli C, Trisolino P, Maione M, Calzolari F, Calidonna C, Biron D, Amendola S, Steinbacher M and Cristofanelli P (2023), "Continuous atmospheric in-situ measurements of the CH4/CO ratio at the Mt. Cimone station (Italy, 2165 m a.s.l.) and their possible use for estimating regional CH4 emissions", Environmental Research., sep, 2023. Vol. 232, pp. 116343. Elsevier BV. |
BibTeX:
@article{Fratticioli2023,
author = {Fratticioli, C and Trisolino, P and Maione, M and Calzolari, F and Calidonna, C and Biron, D and Amendola, S and Steinbacher, M and Cristofanelli, P},
title = {Continuous atmospheric in-situ measurements of the CH4/CO ratio at the Mt. Cimone station (Italy, 2165 m a.s.l.) and their possible use for estimating regional CH4 emissions},
journal = {Environmental Research},
publisher = {Elsevier BV},
year = {2023},
volume = {232},
pages = {116343},
url = {http://dx.doi.org/10.1016/j.envres.2023.116343},
doi = {10.1016/j.envres.2023.116343}
}
|
| Friedlingstein P, O'Sullivan M, Jones MW, Andrew RM, Bakker DCE, Hauck J, Landschützer P, Le Quéré C, Luijkx IT, Peters GP, Peters W, Pongratz J, Schwingshackl C, Sitch S, Canadell JG, Ciais P, Jackson RB, Alin SR, Anthoni P, Barbero L, Bates NR, Becker M, Bellouin N, Decharme B, Bopp L, Brasika IBM, Cadule P, Chamberlain MA, Chandra N, Chau T-T-T, Chevallier F, Chini LP, Cronin M, Dou X, Enyo K, Evans W, Falk S, Feely RA, Feng L, Ford DJ, Gasser T, Ghattas J, Gkritzalis T, Grassi G, Gregor L, Gruber N, Gürses Ö, Harris I, Hefner M, Heinke J, Houghton RA, Hurtt GC, Iida Y, Ilyina T, Jacobson AR, Jain A, Jarníková T, Jersild A, Jiang F, Jin Z, Joos F, Kato E, Keeling RF, Kennedy D, Klein Goldewijk K, Knauer J, Korsbakken JI, Körtzinger A, Lan X, Lefèvre N, Li H, Liu J, Liu Z, Ma L, Marland G, Mayot N, McGuire PC, McKinley GA, Meyer G, Morgan EJ, Munro DR, Nakaoka S-I, Niwa Y, O'Brien KM, Olsen A, Omar AM, Ono T, Paulsen M, Pierrot D, Pocock K, Poulter B, Powis CM, Rehder G, Resplandy L, Robertson E, Rödenbeck C, Rosan TM, Schwinger J, Séférian R, Smallman TL, Smith SM, Sospedra-Alfonso R, Sun Q, Sutton AJ, Sweeney C, Takao S, Tans PP, Tian H, Tilbrook B, Tsujino H, Tubiello F, van der Werf GR, van Ooijen E, Wanninkhof R, Watanabe M, Wimart-Rousseau C, Yang D, Yang X, Yuan W, Yue X, Zaehle S, Zeng J and Zheng B (2023), "Global Carbon Budget 2023", Earth System Science Data., dec, 2023. Vol. 15(12), pp. 5301-5369. Copernicus GmbH. |
BibTeX:
@article{Friedlingstein2023,
author = {Friedlingstein, Pierre and O'Sullivan, Michael and Jones, Matthew W and Andrew, Robbie M and Bakker, Dorothee C E and Hauck, Judith and Landschützer, Peter and Le Quéré, Corinne and Luijkx, Ingrid T and Peters, Glen P and Peters, Wouter and Pongratz, Julia and Schwingshackl, Clemens and Sitch, Stephen and Canadell, Josep G and Ciais, Philippe and Jackson, Robert B and Alin, Simone R and Anthoni, Peter and Barbero, Leticia and Bates, Nicholas R and Becker, Meike and Bellouin, Nicolas and Decharme, Bertrand and Bopp, Laurent and Brasika, Ida Bagus Mandhara and Cadule, Patricia and Chamberlain, Matthew A and Chandra, Naveen and Chau, Thi-Tuyet-Trang and Chevallier, Frédéric and Chini, Louise P and Cronin, Margot and Dou, Xinyu and Enyo, Kazutaka and Evans, Wiley and Falk, Stefanie and Feely, Richard A and Feng, Liang and Ford, Daniel J and Gasser, Thomas and Ghattas, Josefine and Gkritzalis, Thanos and Grassi, Giacomo and Gregor, Luke and Gruber, Nicolas and Gürses, Özgür and Harris, Ian and Hefner, Matthew and Heinke, Jens and Houghton, Richard A and Hurtt, George C and Iida, Yosuke and Ilyina, Tatiana and Jacobson, Andrew R and Jain, Atul and Jarníková, Tereza and Jersild, Annika and Jiang, Fei and Jin, Zhe and Joos, Fortunat and Kato, Etsushi and Keeling, Ralph F and Kennedy, Daniel and Klein Goldewijk, Kees and Knauer, Jürgen and Korsbakken, Jan Ivar and Körtzinger, Arne and Lan, Xin and Lefèvre, Nathalie and Li, Hongmei and Liu, Junjie and Liu, Zhiqiang and Ma, Lei and Marland, Greg and Mayot, Nicolas and McGuire, Patrick C and McKinley, Galen A and Meyer, Gesa and Morgan, Eric J and Munro, David R and Nakaoka, Shin-Ichiro and Niwa, Yosuke and O'Brien, Kevin M and Olsen, Are and Omar, Abdirahman M and Ono, Tsuneo and Paulsen, Melf and Pierrot, Denis and Pocock, Katie and Poulter, Benjamin and Powis, Carter M and Rehder, Gregor and Resplandy, Laure and Robertson, Eddy and Rödenbeck, Christian and Rosan, Thais M and Schwinger, Jörg and Séférian, Roland and Smallman, T Luke and Smith, Stephen M and Sospedra-Alfonso, Reinel and Sun, Qing and Sutton, Adrienne J and Sweeney, Colm and Takao, Shintaro and Tans, Pieter P and Tian, Hanqin and Tilbrook, Bronte and Tsujino, Hiroyuki and Tubiello, Francesco and van der Werf, Guido R and van Ooijen, Erik and Wanninkhof, Rik and Watanabe, Michio and Wimart-Rousseau, Cathy and Yang, Dongxu and Yang, Xiaojuan and Yuan, Wenping and Yue, Xu and Zaehle, Sönke and Zeng, Jiye and Zheng, Bo},
title = {Global Carbon Budget 2023},
journal = {Earth System Science Data},
publisher = {Copernicus GmbH},
year = {2023},
volume = {15},
number = {12},
pages = {5301--5369},
url = {http://dx.doi.org/10.5194/essd-15-5301-2023},
doi = {10.5194/essd-15-5301-2023}
}
|
| Fung PL, Rannik Ü, Mammarella I and Vesala T (2023), "Ozone Fluxes Over a Boreal Lake Exhibit Enhanced Deposition at Nights", Geophysical Research Letters., dec, 2023. Vol. 50(23) American Geophysical Union (AGU). |
BibTeX:
@article{Fung2023,
author = {Fung, P L and Rannik, Ü and Mammarella, I and Vesala, T},
title = {Ozone Fluxes Over a Boreal Lake Exhibit Enhanced Deposition at Nights},
journal = {Geophysical Research Letters},
publisher = {American Geophysical Union (AGU)},
year = {2023},
volume = {50},
number = {23},
url = {http://dx.doi.org/10.1029/2023GL104354},
doi = {10.1029/2023gl104354}
}
|
| Futter MN, Dirnböck T, Forsius M, Bäck JK, Cools N, Diaz-Pines E, Dick J, Gaube V, Gillespie LM, Högbom L, Laudon H, Mirtl M, Nikolaidis N, Poppe Terán C, Skiba U, Vereecken H, Villwock H, Weldon J, Wohner C and Alam SA (2023), "Leveraging research infrastructure co-location to evaluate constraints on terrestrial carbon cycling in northern European forests", Ambio., sep, 2023. Vol. 52(11), pp. 1819-1831. Springer Science and Business Media LLC. |
BibTeX:
@article{Futter2023,
author = {Futter, Martyn N and Dirnböck, Thomas and Forsius, Martin and Bäck, Jaana K and Cools, Nathalie and Diaz-Pines, Eugenio and Dick, Jan and Gaube, Veronika and Gillespie, Lauren M and Högbom, Lars and Laudon, Hjalmar and Mirtl, Michael and Nikolaidis, Nikolaos and Poppe Terán, Christian and Skiba, Ute and Vereecken, Harry and Villwock, Holger and Weldon, James and Wohner, Christoph and Alam, Syed Ashraful},
title = {Leveraging research infrastructure co-location to evaluate constraints on terrestrial carbon cycling in northern European forests},
journal = {Ambio},
publisher = {Springer Science and Business Media LLC},
year = {2023},
volume = {52},
number = {11},
pages = {1819--1831},
url = {http://dx.doi.org/10.1007/s13280-023-01930-4},
doi = {10.1007/s13280-023-01930-4}
}
|
| Ganeva D, Tallec T, Brut A, Prikaziuk E, Tomelleri E, Koren G, Verrelst J, Berger K, Graf LV, Belda S, Cai Z and Silva CF (2023), "In-situ start and end of growing season dates of major European crop types from France and Bulgaria at a field level", Data in Brief., dec, 2023. Vol. 51, pp. 109623. Elsevier BV. |
BibTeX:
@article{Ganeva2023,
author = {Ganeva, Dessislava and Tallec, Tiphaine and Brut, Aurore and Prikaziuk, Egor and Tomelleri, Enrico and Koren, Gerbrand and Verrelst, Jochem and Berger, Katja and Graf, Lukas Valentin and Belda, Santiago and Cai, Zhanzhang and Silva, Cláudio F},
title = {In-situ start and end of growing season dates of major European crop types from France and Bulgaria at a field level},
journal = {Data in Brief},
publisher = {Elsevier BV},
year = {2023},
volume = {51},
pages = {109623},
url = {http://dx.doi.org/10.1016/j.dib.2023.109623},
doi = {10.1016/j.dib.2023.109623}
}
|
| García-García A, Cuesta-Valero FJ, Miralles DG, Mahecha MD, Quaas J, Reichstein M, Zscheischler J and Peng J (2023), "Soil heat extremes can outpace air temperature extremes", Nature Climate Change., sep, 2023. Vol. 13(11), pp. 1237-1241. Springer Science and Business Media LLC. |
BibTeX:
@article{GarciaGarcia2023,
author = {García-García, Almudena and Cuesta-Valero, Francisco José and Miralles, Diego G and Mahecha, Miguel D and Quaas, Johannes and Reichstein, Markus and Zscheischler, Jakob and Peng, Jian},
title = {Soil heat extremes can outpace air temperature extremes},
journal = {Nature Climate Change},
publisher = {Springer Science and Business Media LLC},
year = {2023},
volume = {13},
number = {11},
pages = {1237--1241},
url = {http://dx.doi.org/10.1038/s41558-023-01812-3},
doi = {10.1038/s41558-023-01812-3}
}
|
| Gialesakis N, Kalivitis N, Kouvarakis G, Ramonet M, Lopez M, Kwok CY, Narbaud C, Daskalakis N, Mermigkas M, Mihalopoulos N and Kanakidou M (2023), "A twenty year record of greenhouse gases in the Eastern Mediterranean atmosphere", Science of The Total Environment., mar, 2023. Vol. 864, pp. 161003. Elsevier BV. |
BibTeX:
@article{Gialesakis2023,
author = {Gialesakis, Nikos and Kalivitis, Nikos and Kouvarakis, Giorgos and Ramonet, Michel and Lopez, Morgan and Kwok, Camille Yver and Narbaud, Clement and Daskalakis, Nikos and Mermigkas, Marios and Mihalopoulos, Nikolaos and Kanakidou, Maria},
title = {A twenty year record of greenhouse gases in the Eastern Mediterranean atmosphere},
journal = {Science of The Total Environment},
publisher = {Elsevier BV},
year = {2023},
volume = {864},
pages = {161003},
url = {http://dx.doi.org/10.1016/j.scitotenv.2022.161003},
doi = {10.1016/j.scitotenv.2022.161003}
}
|
| Gilmullina A, Rumpel C, Blagodatskaya E, Klumpp K, Bertrand I, Dippold MA and Chabbi A (2023), "Is plant biomass input driving soil organic matter formation processes in grassland soil under contrasting management?", Science of The Total Environment., oct, 2023. Vol. 893, pp. 164550. Elsevier BV. |
BibTeX:
@article{Gilmullina2023,
author = {Gilmullina, Aliia and Rumpel, Cornelia and Blagodatskaya, Evgenia and Klumpp, Katja and Bertrand, Isabelle and Dippold, Michaela A and Chabbi, Abad},
title = {Is plant biomass input driving soil organic matter formation processes in grassland soil under contrasting management?},
journal = {Science of The Total Environment},
publisher = {Elsevier BV},
year = {2023},
volume = {893},
pages = {164550},
url = {http://dx.doi.org/10.1016/j.scitotenv.2023.164550},
doi = {10.1016/j.scitotenv.2023.164550}
}
|
| Gomarasca U, Migliavacca M, Kattge J, Nelson JA, Niinemets Ü, Wirth C, Cescatti A, Bahn M, Nair R, Acosta ATR, Arain MA, Beloiu M, Black TA, Bruun HH, Bucher SF, Buchmann N, Byun C, Carrara A, Conte A, da Silva AC, Duveiller G, Fares S, Ibrom A, Knohl A, Komac B, Limousin J-M, Lusk CH, Mahecha MD, Martini D, Minden V, Montagnani L, Mori AS, Onoda Y, Peñuelas J, Perez-Priego O, Poschlod P, Powell TL, Reich PB, Šigut L, van Bodegom PM, Walther S, Wohlfahrt G, Wright IJ and Reichstein M (2023), "Leaf-level coordination principles propagate to the ecosystem scale", Nature Communications., jul, 2023. Vol. 14(1) Springer Science and Business Media LLC. |
BibTeX:
@article{Gomarasca2023,
author = {Gomarasca, Ulisse and Migliavacca, Mirco and Kattge, Jens and Nelson, Jacob A and Niinemets, Ülo and Wirth, Christian and Cescatti, Alessandro and Bahn, Michael and Nair, Richard and Acosta, Alicia T R and Arain, M Altaf and Beloiu, Mirela and Black, T Andrew and Bruun, Hans Henrik and Bucher, Solveig Franziska and Buchmann, Nina and Byun, Chaeho and Carrara, Arnaud and Conte, Adriano and da Silva, Ana C and Duveiller, Gregory and Fares, Silvano and Ibrom, Andreas and Knohl, Alexander and Komac, Benjamin and Limousin, Jean-Marc and Lusk, Christopher H and Mahecha, Miguel D and Martini, David and Minden, Vanessa and Montagnani, Leonardo and Mori, Akira S and Onoda, Yusuke and Peñuelas, Josep and Perez-Priego, Oscar and Poschlod, Peter and Powell, Thomas L and Reich, Peter B and Šigut, Ladislav and van Bodegom, Peter M and Walther, Sophia and Wohlfahrt, Georg and Wright, Ian J and Reichstein, Markus},
title = {Leaf-level coordination principles propagate to the ecosystem scale},
journal = {Nature Communications},
publisher = {Springer Science and Business Media LLC},
year = {2023},
volume = {14},
number = {1},
url = {http://dx.doi.org/10.1038/s41467-023-39572-5},
doi = {10.1038/s41467-023-39572-5}
}
|
| Graf A, Wohlfahrt G, Aranda-Barranco S, Arriga N, Brümmer C, Ceschia E, Ciais P, Desai AR, Di Lonardo S, Gharun M, Grünwald T, Hörtnagl L, Kasak K, Klosterhalfen A, Knohl A, Kowalska N, Leuchner M, Lindroth A, Mauder M, Migliavacca M, Morel AC, Pfennig A, Poorter H, Terán CP, Reitz O, Rebmann C, Sanchez-Azofeifa A, Schmidt M, Šigut L, Tomelleri E, Yu K, Varlagin A and Vereecken H (2023), "Joint optimization of land carbon uptake and albedo can help achieve moderate instantaneous and long-term cooling effects", Communications Earth & Environment., aug, 2023. Vol. 4(1) Springer Science and Business Media LLC. |
BibTeX:
@article{Graf2023,
author = {Graf, Alexander and Wohlfahrt, Georg and Aranda-Barranco, Sergio and Arriga, Nicola and Brümmer, Christian and Ceschia, Eric and Ciais, Philippe and Desai, Ankur R and Di Lonardo, Sara and Gharun, Mana and Grünwald, Thomas and Hörtnagl, Lukas and Kasak, Kuno and Klosterhalfen, Anne and Knohl, Alexander and Kowalska, Natalia and Leuchner, Michael and Lindroth, Anders and Mauder, Matthias and Migliavacca, Mirco and Morel, Alexandra C and Pfennig, Andreas and Poorter, Hendrik and Terán, Christian Poppe and Reitz, Oliver and Rebmann, Corinna and Sanchez-Azofeifa, Arturo and Schmidt, Marius and Šigut, Ladislav and Tomelleri, Enrico and Yu, Ke and Varlagin, Andrej and Vereecken, Harry},
title = {Joint optimization of land carbon uptake and albedo can help achieve moderate instantaneous and long-term cooling effects},
journal = {Communications Earth & Environment},
publisher = {Springer Science and Business Media LLC},
year = {2023},
volume = {4},
number = {1},
url = {http://dx.doi.org/10.1038/s43247-023-00958-4},
doi = {10.1038/s43247-023-00958-4}
}
|
| Guseva S, Armani F, Desai AR, Dias NL, Friborg T, Iwata H, Jansen J, Lükő G, Mammarella I, Repina I, Rutgersson A, Sachs T, Scholz K, Spank U, Stepanenko V, Torma P, Vesala T and Lorke A (2023), "Bulk Transfer Coefficients Estimated From Eddy‐Covariance Measurements Over Lakes and Reservoirs", Journal of Geophysical Research: Atmospheres., jan, 2023. Vol. 128(2) American Geophysical Union (AGU). |
BibTeX:
@article{Guseva2023,
author = {Guseva, S and Armani, F and Desai, A R and Dias, N L and Friborg, T and Iwata, H and Jansen, J and Lükő, G and Mammarella, I and Repina, I and Rutgersson, A and Sachs, T and Scholz, K and Spank, U and Stepanenko, V and Torma, P and Vesala, T and Lorke, A},
title = {Bulk Transfer Coefficients Estimated From Eddy‐Covariance Measurements Over Lakes and Reservoirs},
journal = {Journal of Geophysical Research: Atmospheres},
publisher = {American Geophysical Union (AGU)},
year = {2023},
volume = {128},
number = {2},
url = {http://dx.doi.org/10.1029/2022JD037219},
doi = {10.1029/2022jd037219}
}
|
| Gustafsson E, Carstensen J, Fleming V, Gustafsson BG, Hoikkala L and Rehder G (2023), "Causes and consequences of acidification in the Baltic Sea: implications for monitoring and management", Scientific Reports., sep, 2023. Vol. 13(1) Springer Science and Business Media LLC. |
BibTeX:
@article{Gustafsson2023,
author = {Gustafsson, Erik and Carstensen, Jacob and Fleming, Vivi and Gustafsson, Bo G and Hoikkala, Laura and Rehder, Gregor},
title = {Causes and consequences of acidification in the Baltic Sea: implications for monitoring and management},
journal = {Scientific Reports},
publisher = {Springer Science and Business Media LLC},
year = {2023},
volume = {13},
number = {1},
url = {http://dx.doi.org/10.1038/s41598-023-43596-8},
doi = {10.1038/s41598-023-43596-8}
}
|
| Haesen S, Lembrechts JJ, De Frenne P, Lenoir J, Aalto J, Ashcroft MB, Kopecký M, Luoto M, Maclean I, Nijs I, Niittynen P, van den Hoogen J, Arriga N, Brůna J, Buchmann N, Čiliak M, Collalti A, De Lombaerde E, Descombes P, Gharun M, Goded I, Govaert S, Greiser C, Grelle A, Gruening C, Hederová L, Hylander K, Kreyling J, Kruijt B, Macek M, Máliš F, Man M, Manca G, Matula R, Meeussen C, Merinero S, Minerbi S, Montagnani L, Muffler L, Ogaya R, Penuelas J, Plichta R, Portillo‐Estrada M, Schmeddes J, Shekhar A, Spicher F, Ujházyová M, Vangansbeke P, Weigel R, Wild J, Zellweger F and Van Meerbeek K (2023), " |
BibTeX:
@article{Haesen2023,
author = {Haesen, Stef and Lembrechts, Jonas J and De Frenne, Pieter and Lenoir, Jonathan and Aalto, Juha and Ashcroft, Michael B and Kopecký, Martin and Luoto, Miska and Maclean, Ilya and Nijs, Ivan and Niittynen, Pekka and van den Hoogen, Johan and Arriga, Nicola and Brůna, Josef and Buchmann, Nina and Čiliak, Marek and Collalti, Alessio and De Lombaerde, Emiel and Descombes, Patrice and Gharun, Mana and Goded, Ignacio and Govaert, Sanne and Greiser, Caroline and Grelle, Achim and Gruening, Carsten and Hederová, Lucia and Hylander, Kristoffer and Kreyling, Jürgen and Kruijt, Bart and Macek, Martin and Máliš, František and Man, Matěj and Manca, Giovanni and Matula, Radim and Meeussen, Camille and Merinero, Sonia and Minerbi, Stefano and Montagnani, Leonardo and Muffler, Lena and Ogaya, Romà and Penuelas, Josep and Plichta, Roman and Portillo‐Estrada, Miguel and Schmeddes, Jonas and Shekhar, Ankit and Spicher, Fabien and Ujházyová, Mariana and Vangansbeke, Pieter and Weigel, Robert and Wild, Jan and Zellweger, Florian and Van Meerbeek, Koenraad},
title = { |
| Hallgren C, Körnich H, Ivanell S, Vakkari V and Sahlée E (2023), "The winds are twisting: analysis of strong directional shear across the rotor plane using coastal lidar measurements and ERA5", oct, 2023. Copernicus GmbH. |
BibTeX:
@article{Hallgren2023,
author = {Hallgren, Christoffer and Körnich, Heiner and Ivanell, Stefan and Vakkari, Ville and Sahlée, Erik},
title = {The winds are twisting: analysis of strong directional shear across the rotor plane using coastal lidar measurements and ERA5},
publisher = {Copernicus GmbH},
year = {2023},
url = {http://dx.doi.org/10.5194/wes-2023-129},
doi = {10.5194/wes-2023-129}
}
|
| Hartman SE, Gates AR, Lopez-Garcia P, Bozzano R, Delory E, Favali P, Lefevre D, Chirurgien L, Pensieri S, Petihakis G, Nair R, Neves S, Dañobeitia JJ, Salvetat F, Le Menn M, Seppälä J, Schroeder K and Piera J (2023), "Proposed synergies between oceanography and metrology", Frontiers in Marine Science., oct, 2023. Vol. 10 Frontiers Media SA. |
BibTeX:
@article{Hartman2023,
author = {Hartman, Susan E and Gates, Andrew R and Lopez-Garcia, Patricia and Bozzano, Roberto and Delory, Eric and Favali, Paolo and Lefevre, Dominique and Chirurgien, Laure and Pensieri, Sara and Petihakis, George and Nair, Rajesh and Neves, Silvana and Dañobeitia, Juan José and Salvetat, Florence and Le Menn, Marc and Seppälä, Jukka and Schroeder, Katrin and Piera, Jaume},
title = {Proposed synergies between oceanography and metrology},
journal = {Frontiers in Marine Science},
publisher = {Frontiers Media SA},
year = {2023},
volume = {10},
url = {http://dx.doi.org/10.3389/fmars.2023.1192030},
doi = {10.3389/fmars.2023.1192030}
}
|
| Heiskanen L, Tuovinen J-P, Vekuri H, Räsänen A, Virtanen T, Juutinen S, Lohila A, Mikola J and Aurela M (2023), "Meteorological responses of carbon dioxide and methane fluxes in the terrestrial and aquatic ecosystems of a subarctic landscape", Biogeosciences., feb, 2023. Vol. 20(3), pp. 545-572. Copernicus GmbH. |
BibTeX:
@article{Heiskanen2023,
author = {Heiskanen, Lauri and Tuovinen, Juha-Pekka and Vekuri, Henriikka and Räsänen, Aleksi and Virtanen, Tarmo and Juutinen, Sari and Lohila, Annalea and Mikola, Juha and Aurela, Mika},
title = {Meteorological responses of carbon dioxide and methane fluxes in the terrestrial and aquatic ecosystems of a subarctic landscape},
journal = {Biogeosciences},
publisher = {Copernicus GmbH},
year = {2023},
volume = {20},
number = {3},
pages = {545--572},
url = {http://dx.doi.org/10.5194/bg-20-545-2023},
doi = {10.5194/bg-20-545-2023}
}
|
| Hörtnagl, Lukas, Buchmann, Nina, Meier, Philip, Gharun, Mana, Baur, Thomas, Eugster, Werner and Feigenwinter, Iris (2023), "CH-DAV FP2022.5 (1997-2022): Ecosystem fluxes and meteorological data from Davos, Switzerland". |
BibTeX:
@misc{Hoertnagl2023,
author = {Hörtnagl, Lukas and Buchmann, Nina and Meier, Philip and Gharun, Mana and Baur, Thomas and Eugster, Werner and Feigenwinter, Iris},
title = {CH-DAV FP2022.5 (1997-2022): Ecosystem fluxes and meteorological data from Davos, Switzerland},
publisher = {ETH Zurich},
year = {2023},
url = {http://hdl.handle.net/20.500.11850/597213},
doi = {10.3929/ETHZ-B-000597213}
}
|
| Hu T, Mallick K, Hitzelberger P, Didry Y, Boulet G, Szantoi Z, Koetz B, Alonso I, Pascolini‐Campbell M, Halverson G, Cawse‐Nicholson K, Hulley GC, Hook S, Bhattarai N, Olioso A, Roujean J, Gamet P and Su B (2023), "Evaluating European ECOSTRESS Hub Evapotranspiration Products Across a Range of Soil‐Atmospheric Aridity and Biomes Over Europe", Water Resources Research., aug, 2023. Vol. 59(8) American Geophysical Union (AGU). |
BibTeX:
@article{Hu2023,
author = {Hu, Tian and Mallick, Kaniska and Hitzelberger, Patrik and Didry, Yoanne and Boulet, Gilles and Szantoi, Zoltan and Koetz, Benjamin and Alonso, Itziar and Pascolini‐Campbell, Madeleine and Halverson, Gregory and Cawse‐Nicholson, Kerry and Hulley, Glynn C and Hook, Simon and Bhattarai, Nishan and Olioso, Albert and Roujean, Jean‐Louis and Gamet, Philippe and Su, Bob},
title = {Evaluating European ECOSTRESS Hub Evapotranspiration Products Across a Range of Soil‐Atmospheric Aridity and Biomes Over Europe},
journal = {Water Resources Research},
publisher = {American Geophysical Union (AGU)},
year = {2023},
volume = {59},
number = {8},
url = {http://dx.doi.org/10.1029/2022wr034132},
doi = {10.1029/2022wr034132}
}
|
| Hu T, Roujean J-L, Cao B, Mallick K, Boulet G, Li H, Xu Z, Du Y and Liu Q (2023), "Correction for LST directionality impact on the estimation of surface upwelling longwave radiation over vegetated surfaces at the satellite scale", Remote Sensing of Environment., sep, 2023. Vol. 295, pp. 113649. Elsevier BV. |
BibTeX:
@article{Hu2023a,
author = {Hu, Tian and Roujean, Jean-Louis and Cao, Biao and Mallick, Kaniska and Boulet, Gilles and Li, Hua and Xu, Zhihong and Du, Yongming and Liu, Qinhuo},
title = {Correction for LST directionality impact on the estimation of surface upwelling longwave radiation over vegetated surfaces at the satellite scale},
journal = {Remote Sensing of Environment},
publisher = {Elsevier BV},
year = {2023},
volume = {295},
pages = {113649},
url = {http://dx.doi.org/10.1016/j.rse.2023.113649},
doi = {10.1016/j.rse.2023.113649}
}
|
| Jaakkola E, Gärtner A, Jönsson AM, Ljung K, Olsson P-O and Holst T (2023), "Spruce bark beetles (Ips typographus) cause up to 700 times higher bark BVOC emission rates compared to healthy Norway spruce (Picea abies)", Biogeosciences., feb, 2023. Vol. 20(4), pp. 803-826. Copernicus GmbH. |
BibTeX:
@article{Jaakkola2023,
author = {Jaakkola, Erica and Gärtner, Antje and Jönsson, Anna Maria and Ljung, Karl and Olsson, Per-Ola and Holst, Thomas},
title = {Spruce bark beetles (Ips typographus) cause up to 700 times higher bark BVOC emission rates compared to healthy Norway spruce (Picea abies)},
journal = {Biogeosciences},
publisher = {Copernicus GmbH},
year = {2023},
volume = {20},
number = {4},
pages = {803--826},
url = {http://dx.doi.org/10.5194/bg-20-803-2023},
doi = {10.5194/bg-20-803-2023}
}
|
| Jacobson AR, Schuldt KN, Tans P, Arlyn Andrews, Miller JB, Oda T, Mund J, Weir B, Ott L, Aalto T, Abshire JB, Aikin K, Aoki S, Apadula F, Arnold S, Baier B, Bartyzel J, Beyersdorf A, Biermann T, Biraud SC, Boenisch H, Brailsford G, Brand WA, Chen G, Huilin Chen, Lukasz Chmura, Clark S, Colomb A, Commane R, Conil S, Couret C, Cox A, Cristofanelli P, Cuevas E, Curcoll R, Daube B, Davis KJ, De Wekker S, Coletta JD, Delmotte M, DiGangi E, DiGangi JP, Di Sarra AG, Dlugokencky E, Elkins JW, Emmenegger L, Shuangxi Fang, Fischer ML, Forster G, Frumau A, Galkowski M, Gatti LV, Gehrlein T, Gerbig C, Francois Gheusi, Gloor E, Gomez-Trueba V, Goto D, Griffis T, Hammer S, Hanson C, Haszpra L, Hatakka J, Heimann M, Heliasz M, Hensen A, Hermansen O, Hintsa E, Holst J, Ivakhov V, Jaffe DA, Jordan A, Joubert W, Karion A, Kawa SR, Kazan V, Keeling RF, Keronen P, Kneuer T, Kolari P, Kateřina Komínková, Kort E, Kozlova E, Krummel P, Kubistin D, Labuschagne C, Lam DHY, Lan X, Langenfelds RL, Laurent O, Laurila T, Lauvaux T, Lavric J, Law BE, Lee J, Lee OSM, Lehner I, Lehtinen K, Leppert R, Leskinen A, Leuenberger M, Levin I, Levula J, Lin J, Lindauer M, Loh Z, Lopez M, Luijkx IT, Lunder CR, Machida T, Mammarella I, Manca G, Manning A, Manning A, Marek MV, Martin MY, Matsueda H, McKain K, Meijer H, Meinhardt F, Merchant L, N. Mihalopoulos, Miles NL, Miller CE, Mitchell L, Mölder M, Montzka S, Moore F, Moossen H, Morgan E, Josep-Anton Morgui, Morimoto S, Müller-Williams J, J. William Munger, Munro D, Myhre CL, Shin-Ichiro Nakaoka, Jaroslaw Necki, Newman S, Nichol S, Niwa Y, Obersteiner F, O'Doherty S, Paplawsky B, Peischl J, Peltola O, Piacentino S, Jean-Marc Pichon, Pickers P, Piper S, Pitt J, Plass-Dülmer C, Platt SM, Prinzivalli S, Ramonet M, Ramos R, Reyes-Sanchez E, Richardson SJ, Riris H, Rivas PP, Ryerson T, Saito K, Sargent M, Sasakawa M, Scheeren B, Schuck T, Schumacher M, Seifert T, Sha MK, Shepson P, Shook M, Sloop CD, Smith P, Stanley K, Steinbacher M, Stephens B, Sweeney C, Thoning K, Timas H, Torn M, Tørseth K, Trisolino P, Turnbull J, Van Den Bulk P, Van Dinther D, Vermeulen A, Viner B, Vitkova G, Walker S, Watson A, Wofsy SC, Worsey J, Worthy D, Dickon Young, Zaehle S, Zahn A and Miroslaw Zimnoch (2023), "CarbonTracker CT2022". |
BibTeX:
@misc{Jacobson2023,
author = {Jacobson, Andrew R and Schuldt, Kenneth N and Tans, Pieter and Arlyn Andrews and Miller, John B and Oda, Tomohiro and Mund, John and Weir, Brad and Ott, Lesley and Aalto, Tuula and Abshire, James Brice and Aikin, Ken and Aoki, Shuji and Apadula, Francesco and Arnold, Sabrina and Baier, Bianca and Bartyzel, Jakub and Beyersdorf, Andreas and Biermann, Tobias and Biraud, Sebastien C and Boenisch, Harald and Brailsford, Gordon and Brand, Willi A and Chen, Gao and Huilin Chen and Lukasz Chmura and Clark, Shane and Colomb, Aurelie and Commane, Roisin and Conil, Sébastien and Couret, Cédric and Cox, Adam and Cristofanelli, Paolo and Cuevas, Emilio and Curcoll, Roger and Daube, Bruce and Davis, Kenneth J and De Wekker, Stephan and Coletta, Julian Della and Delmotte, Marc and DiGangi, Elizabeth and DiGangi, Joshua P and Di Sarra, Alcide Giorgio and Dlugokencky, Ed and Elkins, James W and Emmenegger, Lukas and Shuangxi Fang and Fischer, Marc L and Forster, Grant and Frumau, Arnoud and Galkowski, Michal and Gatti, Luciana V and Gehrlein, Torsten and Gerbig, Christoph and Francois Gheusi and Gloor, Emanuel and Gomez-Trueba, Vanessa and Goto, Daisuke and Griffis, Tim and Hammer, Samuel and Hanson, Chad and Haszpra, László and Hatakka, Juha and Heimann, Martin and Heliasz, Michal and Hensen, Arjan and Hermansen, Ove and Hintsa, Eric and Holst, Jutta and Ivakhov, Viktor and Jaffe, Daniel A and Jordan, Armin and Joubert, Warren and Karion, Anna and Kawa, Stephan Randolph and Kazan, Victor and Keeling, Ralph F and Keronen, Petri and Kneuer, Tobias and Kolari, Pasi and Kateřina Komínková and Kort, Eric and Kozlova, Elena and Krummel, Paul and Kubistin, Dagmar and Labuschagne, Casper and Lam, David H Y and Lan, Xin and Langenfelds, Ray L and Laurent, Olivier and Laurila, Tuomas and Lauvaux, Thomas and Lavric, Jost and Law, Beverly E and Lee, John and Lee, Olivia S M and Lehner, Irene and Lehtinen, Kari and Leppert, Reimo and Leskinen, Ari and Leuenberger, Markus and Levin, Ingeborg and Levula, Janne and Lin, John and Lindauer, Matthias and Loh, Zoe and Lopez, Morgan and Luijkx, Ingrid T and Lunder, Chris René and Machida, Toshinobu and Mammarella, Ivan and Manca, Giovanni and Manning, Alistair and Manning, Andrew and Marek, Michal V and Martin, Melissa Yang and Matsueda, Hidekazu and McKain, Kathryn and Meijer, Harro and Meinhardt, Frank and Merchant, Lynne and N. Mihalopoulos and Miles, Natasha L and Miller, Charles E and Mitchell, Logan and Mölder, Meelis and Montzka, Stephen and Moore, Fred and Moossen, Heiko and Morgan, Eric and Josep-Anton Morgui and Morimoto, Shinji and Müller-Williams, Jennifer and J. William Munger and Munro, David and Myhre, Cathrine Lund and Shin-Ichiro Nakaoka and Jaroslaw Necki and Newman, Sally and Nichol, Sylvia and Niwa, Yosuke and Obersteiner, Florian and O'Doherty, Simon and Paplawsky, Bill and Peischl, Jeff and Peltola, Olli and Piacentino, Salvatore and Jean-Marc Pichon and Pickers, Penelope and Piper, Steve and Pitt, Joseph and Plass-Dülmer, Christian and Platt, Stephen Matthew and Prinzivalli, Steve and Ramonet, Michel and Ramos, Ramon and Reyes-Sanchez, Enrique and Richardson, Scott J and Riris, Haris and Rivas, Pedro P and Ryerson, Thomas and Saito, Kazuyuki and Sargent, Maryann and Sasakawa, Motoki and Scheeren, Bert and Schuck, Tanja and Schumacher, Marcus and Seifert, Thomas and Sha, Mahesh Kumar and Shepson, Paul and Shook, Michael and Sloop, Christopher D and Smith, Paul and Stanley, Kieran and Steinbacher, Martin and Stephens, Britton and Sweeney, Colm and Thoning, Kirk and Timas, Helder and Torn, Margaret and Tørseth, Kjetil and Trisolino, Pamela and Turnbull, Jocelyn and Van Den Bulk, Pim and Van Dinther, Danielle and Vermeulen, Alex and Viner, Brian and Vitkova, Gabriela and Walker, Stephen and Watson, Andrew and Wofsy, Steven C and Worsey, Justin and Worthy, Doug and Dickon Young and Zaehle, Sönke and Zahn, Andreas and Miroslaw Zimnoch},
title = {CarbonTracker CT2022},
publisher = {NOAA Global Monitoring Laboratory},
year = {2023},
url = {https://gml.noaa.gov/ccgg/carbontracker/CT2022},
doi = {10.25925/Z1GJ-3254}
}
|
| Jansen FA, Jongen HJ, Jacobs CMJ, Bosveld FC, Buzacott AJV, Heusinkveld BG, Kruijt B, van der Molen M, Moors E, Steeneveld G, van der Tol C, van der Velde Y, Voortman B, Uijlenhoet R and Teuling AJ (2023), "Land Cover Control on the Drivers of Evaporation and Sensible Heat Fluxes: An Observation‐Based Synthesis for the Netherlands", Water Resources Research., nov, 2023. Vol. 59(11) American Geophysical Union (AGU). |
BibTeX:
@article{Jansen2023,
author = {Jansen, Femke A and Jongen, Harro J and Jacobs, Cor M J and Bosveld, Fred C and Buzacott, Alexander J V and Heusinkveld, Bert G and Kruijt, Bart and van der Molen, Michiel and Moors, Eddy and Steeneveld, Gert‐Jan and van der Tol, Christiaan and van der Velde, Ype and Voortman, Bernard and Uijlenhoet, Remko and Teuling, Adriaan J},
title = {Land Cover Control on the Drivers of Evaporation and Sensible Heat Fluxes: An Observation‐Based Synthesis for the Netherlands},
journal = {Water Resources Research},
publisher = {American Geophysical Union (AGU)},
year = {2023},
volume = {59},
number = {11},
url = {http://dx.doi.org/10.1029/2022WR034361},
doi = {10.1029/2022wr034361}
}
|
| Jiang L, Dunne J, Carter BR, Tjiputra JF, Terhaar J, Sharp JD, Olsen A, Alin S, Bakker DCE, Feely RA, Gattuso J, Hogan P, Ilyina T, Lange N, Lauvset SK, Lewis ER, Lovato T, Palmieri J, Santana‐Falcón Y, Schwinger J, Séférian R, Strand G, Swart N, Tanhua T, Tsujino H, Wanninkhof R, Watanabe M, Yamamoto A and Ziehn T (2023), "Global Surface Ocean Acidification Indicators From 1750 to 2100", Journal of Advances in Modeling Earth Systems., mar, 2023. Vol. 15(3) American Geophysical Union (AGU). |
BibTeX:
@article{Jiang2023,
author = {Jiang, Li‐Qing and Dunne, John and Carter, Brendan R and Tjiputra, Jerry F and Terhaar, Jens and Sharp, Jonathan D and Olsen, Are and Alin, Simone and Bakker, Dorothee C E and Feely, Richard A and Gattuso, Jean‐Pierre and Hogan, Patrick and Ilyina, Tatiana and Lange, Nico and Lauvset, Siv K and Lewis, Ernie R and Lovato, Tomas and Palmieri, Julien and Santana‐Falcón, Yeray and Schwinger, Jörg and Séférian, Roland and Strand, Gary and Swart, Neil and Tanhua, Toste and Tsujino, Hiroyuki and Wanninkhof, Rik and Watanabe, Michio and Yamamoto, Akitomo and Ziehn, Tilo},
title = {Global Surface Ocean Acidification Indicators From 1750 to 2100},
journal = {Journal of Advances in Modeling Earth Systems},
publisher = {American Geophysical Union (AGU)},
year = {2023},
volume = {15},
number = {3},
url = {http://dx.doi.org/10.1029/2022MS003563},
doi = {10.1029/2022ms003563}
}
|
| Junttila S, Ardö J, Cai Z, Jin H, Kljun N, Klemedtsson L, Krasnova A, Lange H, Lindroth A, Mölder M, Noe SM, Tagesson T, Vestin P, Weslien P and Eklundh L (2023), "Estimating local-scale forest GPP in Northern Europe using Sentinel-2: Model comparisons with LUE, APAR, the plant phenology index, and a light response function", Science of Remote Sensing., jun, 2023. Vol. 7, pp. 100075. Elsevier BV. |
BibTeX:
@article{Junttila2023,
author = {Junttila, Sofia and Ardö, Jonas and Cai, Zhanzhang and Jin, Hongxiao and Kljun, Natascha and Klemedtsson, Leif and Krasnova, Alisa and Lange, Holger and Lindroth, Anders and Mölder, Meelis and Noe, Steffen M and Tagesson, Torbern and Vestin, Patrik and Weslien, Per and Eklundh, Lars},
title = {Estimating local-scale forest GPP in Northern Europe using Sentinel-2: Model comparisons with LUE, APAR, the plant phenology index, and a light response function},
journal = {Science of Remote Sensing},
publisher = {Elsevier BV},
year = {2023},
volume = {7},
pages = {100075},
url = {http://dx.doi.org/10.1016/j.srs.2022.100075},
doi = {10.1016/j.srs.2022.100075}
}
|
| Kämäräinen M, Tuovinen J-P, Kulmala M, Mammarella I, Aalto J, Vekuri H, Lohila A and Lintunen A (2023), "Spatiotemporal lagging of predictors improves machine learning estimates of atmosphere–forest CO2 exchange", Biogeosciences., mar, 2023. Vol. 20(4), pp. 897-909. Copernicus GmbH. |
BibTeX:
@article{Kaemaeraeinen2023,
author = {Kämäräinen, Matti and Tuovinen, Juha-Pekka and Kulmala, Markku and Mammarella, Ivan and Aalto, Juha and Vekuri, Henriikka and Lohila, Annalea and Lintunen, Anna},
title = {Spatiotemporal lagging of predictors improves machine learning estimates of atmosphere–forest CO2 exchange},
journal = {Biogeosciences},
publisher = {Copernicus GmbH},
year = {2023},
volume = {20},
number = {4},
pages = {897--909},
url = {http://dx.doi.org/10.5194/bg-20-897-2023},
doi = {10.5194/bg-20-897-2023}
}
|
| Kaiser D, Voynova YG and Brix H (2023), "Effects of the 2018 European heatwave and drought on coastal biogeochemistry in the German Bight", Science of The Total Environment., sep, 2023. Vol. 892, pp. 164316. Elsevier BV. |
BibTeX:
@article{Kaiser2023,
author = {Kaiser, David and Voynova, Yoana G and Brix, Holger},
title = {Effects of the 2018 European heatwave and drought on coastal biogeochemistry in the German Bight},
journal = {Science of The Total Environment},
publisher = {Elsevier BV},
year = {2023},
volume = {892},
pages = {164316},
url = {http://dx.doi.org/10.1016/j.scitotenv.2023.164316},
doi = {10.1016/j.scitotenv.2023.164316}
}
|
| Kammer J, Simon L, Ciuraru R, Petit J-E, Lafouge F, Buysse P, Bsaibes S, Henderson B, Cristescu SM, Durand B, Fanucci O, Truong F, Gros V and Loubet B (2023), "New particle formation at a peri-urban agricultural site", Science of The Total Environment., jan, 2023. Vol. 857, pp. 159370. Elsevier BV. |
BibTeX:
@article{Kammer2023,
author = {Kammer, Julien and Simon, Leila and Ciuraru, Raluca and Petit, Jean-Eudes and Lafouge, Florence and Buysse, Pauline and Bsaibes, Sandy and Henderson, Ben and Cristescu, Simona M and Durand, Brigitte and Fanucci, Oliver and Truong, Francois and Gros, Valerie and Loubet, Benjamin},
title = {New particle formation at a peri-urban agricultural site},
journal = {Science of The Total Environment},
publisher = {Elsevier BV},
year = {2023},
volume = {857},
pages = {159370},
url = {http://dx.doi.org/10.1016/j.scitotenv.2022.159370},
doi = {10.1016/j.scitotenv.2022.159370}
}
|
| Karlsson PE, Pleijel H, Fowler P, Farahat EA, Linderholm HW, Engardt M and Andersson C (2023), "Stem growth of Norway spruce in south Sweden in relation to soil moisture, nitrogen deposition, ozone exposure and meteorological variables", Forest Ecology and Management., dec, 2023. Vol. 549, pp. 121455. Elsevier BV. |
BibTeX:
@article{Karlsson2023,
author = {Karlsson, Per Erik and Pleijel, Håkan and Fowler, Philip and Farahat, Emad A and Linderholm, Hans W and Engardt, Magnuz and Andersson, Camilla},
title = {Stem growth of Norway spruce in south Sweden in relation to soil moisture, nitrogen deposition, ozone exposure and meteorological variables},
journal = {Forest Ecology and Management},
publisher = {Elsevier BV},
year = {2023},
volume = {549},
pages = {121455},
url = {http://dx.doi.org/10.1016/j.foreco.2023.121455},
doi = {10.1016/j.foreco.2023.121455}
}
|
| Kasongo Yakusu E, Van Acker J, de Vyver H, Bourland N, Mbifo Ndiapo J, Besango Likwela T, Lokonda Wa Kipifo M, Mbuya Kankolongo A, den Bulcke J, Beeckman H, Bauters M, Boeckx P, Verbeeck H, Jacobsen K, Demarée G, Gellens-Meulenberghs F and Hubau W (2023), "Ground-based climate data show evidence of warming and intensification of the seasonal rainfall cycle during the 1960–2020 period in Yangambi, central Congo Basin", Climatic Change., oct, 2023. Vol. 176(10) Springer Science and Business Media LLC. |
BibTeX:
@article{KasongoYakusu2023,
author = {Kasongo Yakusu, Emmanuel and Van Acker, Joris and de Vyver, Hans and Bourland, Nils and Mbifo Ndiapo, José and Besango Likwela, Théophile and Lokonda Wa Kipifo, Michel and Mbuya Kankolongo, Amand and den Bulcke, Jan and Beeckman, Hans and Bauters, Marijn and Boeckx, Pascal and Verbeeck, Hans and Jacobsen, Kim and Demarée, Gaston and Gellens-Meulenberghs, Françoise and Hubau, Wannes},
title = {Ground-based climate data show evidence of warming and intensification of the seasonal rainfall cycle during the 1960–2020 period in Yangambi, central Congo Basin},
journal = {Climatic Change},
publisher = {Springer Science and Business Media LLC},
year = {2023},
volume = {176},
number = {10},
doi = {10.1007/s10584-023-03606-0}
}
|
| Kettunen J, Mehtätalo L, Tuittila E, Korrensalo A and Vanhatalo J (2023), "Joint species distribution modeling with competition for space", Environmetrics., oct, 2023. Wiley. |
BibTeX:
@article{Kettunen2023,
author = {Kettunen, Juho and Mehtätalo, Lauri and Tuittila, Eeva‐Stiina and Korrensalo, Aino and Vanhatalo, Jarno},
title = {Joint species distribution modeling with competition for space},
journal = {Environmetrics},
publisher = {Wiley},
year = {2023},
url = {http://dx.doi.org/10.1002/env.2830},
doi = {10.1002/env.2830}
}
|
| Khan MZ, Chabbi A, Hicks Pries CE, Torn MS and Rumpel C (2023), "Management impacts on whole soil warming responses of CO2 production and efflux in temperate climate", Geoderma., dec, 2023. Vol. 440, pp. 116725. Elsevier BV. |
BibTeX:
@article{Khan2023,
author = {Khan, Md. Zulfikar and Chabbi, Abad and Hicks Pries, Caitlin E and Torn, Margaret S and Rumpel, Cornelia},
title = {Management impacts on whole soil warming responses of CO2 production and efflux in temperate climate},
journal = {Geoderma},
publisher = {Elsevier BV},
year = {2023},
volume = {440},
pages = {116725},
url = {http://dx.doi.org/10.1016/j.geoderma.2023.116725},
doi = {10.1016/j.geoderma.2023.116725}
}
|
| Klosterhalfen A, Chi J, Kljun N, Lindroth A, Laudon H, Nilsson MB and Peichl M (2023), "Two-level eddy covariance measurements reduce bias in land-atmosphere exchange estimates over a heterogeneous boreal forest landscape", Agricultural and Forest Meteorology., aug, 2023. Vol. 339, pp. 109523. Elsevier BV. |
BibTeX:
@article{Klosterhalfen2023,
author = {Klosterhalfen, Anne and Chi, Jinshu and Kljun, Natascha and Lindroth, Anders and Laudon, Hjalmar and Nilsson, Mats B and Peichl, Matthias},
title = {Two-level eddy covariance measurements reduce bias in land-atmosphere exchange estimates over a heterogeneous boreal forest landscape},
journal = {Agricultural and Forest Meteorology},
publisher = {Elsevier BV},
year = {2023},
volume = {339},
pages = {109523},
url = {http://dx.doi.org/10.1016/j.agrformet.2023.109523},
doi = {10.1016/j.agrformet.2023.109523}
}
|
| Kohl L, Tenhovirta SAM, Koskinen M, Putkinen A, Haikarainen I, Polvinen T, Galeotti L, Mammarella I, Siljanen HMP, Robson TM, Adamczyk B and Pihlatie M (2023), "Radiation and temperature drive diurnal variation of aerobic methane emissions from Scots pine canopy", Proceedings of the National Academy of Sciences., dec, 2023. Vol. 120(52) Proceedings of the National Academy of Sciences. |
BibTeX:
@article{Kohl2023,
author = {Kohl, Lukas and Tenhovirta, Salla A M and Koskinen, Markku and Putkinen, Anuliina and Haikarainen, Iikka and Polvinen, Tatu and Galeotti, Luca and Mammarella, Ivan and Siljanen, Henri M P and Robson, Thomas Matthew and Adamczyk, Bartosz and Pihlatie, Mari},
title = {Radiation and temperature drive diurnal variation of aerobic methane emissions from Scots pine canopy},
journal = {Proceedings of the National Academy of Sciences},
publisher = {Proceedings of the National Academy of Sciences},
year = {2023},
volume = {120},
number = {52},
url = {http://dx.doi.org/10.1073/pnas.2308516120},
doi = {10.1073/pnas.2308516120}
}
|
| Korkiakoski M, Ojanen P, Tuovinen J-P, Minkkinen K, Nevalainen O, Penttilä T, Aurela M, Laurila T and Lohila A (2023), "Partial cutting of a boreal nutrient-rich peatland forest causes radically less short-term on-site CO2 emissions than clear-cutting", Agricultural and Forest Meteorology., apr, 2023. Vol. 332, pp. 109361. Elsevier BV. |
BibTeX:
@article{Korkiakoski2023,
author = {Korkiakoski, Mika and Ojanen, Paavo and Tuovinen, Juha-Pekka and Minkkinen, Kari and Nevalainen, Olli and Penttilä, Timo and Aurela, Mika and Laurila, Tuomas and Lohila, Annalea},
title = {Partial cutting of a boreal nutrient-rich peatland forest causes radically less short-term on-site CO2 emissions than clear-cutting},
journal = {Agricultural and Forest Meteorology},
publisher = {Elsevier BV},
year = {2023},
volume = {332},
pages = {109361},
url = {http://dx.doi.org/10.1016/j.agrformet.2023.109361},
doi = {10.1016/j.agrformet.2023.109361}
}
|
| Kulmala M, Kokkonen T, Ezhova E, Baklanov A, Mahura A, Mammarella I, Bäck J, Lappalainen HK, Tyuryakov S, Kerminen V-M, Zilitinkevich S and Petäjä T (2023), "Aerosols, Clusters, Greenhouse Gases, Trace Gases and Boundary-Layer Dynamics: on Feedbacks and Interactions", Boundary-Layer Meteorology., jan, 2023. Vol. 186(3), pp. 475-503. Springer Science and Business Media LLC. |
BibTeX:
@article{Kulmala2023,
author = {Kulmala, Markku and Kokkonen, Tom and Ezhova, Ekaterina and Baklanov, Alexander and Mahura, Alexander and Mammarella, Ivan and Bäck, Jaana and Lappalainen, Hanna K and Tyuryakov, Svyatoslav and Kerminen, Veli-Matti and Zilitinkevich, Sergej and Petäjä, Tuukka},
title = {Aerosols, Clusters, Greenhouse Gases, Trace Gases and Boundary-Layer Dynamics: on Feedbacks and Interactions},
journal = {Boundary-Layer Meteorology},
publisher = {Springer Science and Business Media LLC},
year = {2023},
volume = {186},
number = {3},
pages = {475--503},
url = {http://dx.doi.org/10.1007/s10546-022-00769-8},
doi = {10.1007/s10546-022-00769-8}
}
|
| Lange N, Fiedler B, Álvarez M, Benoit-Cattin A, Benway H, Buttigieg PL, Coppola L, Currie K, Flecha S, Honda M, Huertas IE, Lauvset SK, Muller-Karger F, Körtzinger A, O'Brien KM, Ólafsdóttir SR, Pacheco FC, Rueda-Roa D, Skjelvan I, Wakita M, White A and Tanhua T (2023), "Synthesis Product for Ocean Time-Series (SPOTS) – A ship-based biogeochemical pilot", jul, 2023. Copernicus GmbH. |
BibTeX:
@article{Lange2023,
author = {Lange, Nico and Fiedler, Björn and Álvarez, Marta and Benoit-Cattin, Alice and Benway, Heather and Buttigieg, Pier L and Coppola, Laurent and Currie, Kim and Flecha, Susana and Honda, Makio and Huertas, I Emma and Lauvset, Siv K and Muller-Karger, Frank and Körtzinger, Arne and O'Brien, Kevin M and Ólafsdóttir, Sólveig R and Pacheco, Fernando C and Rueda-Roa, Digna and Skjelvan, Ingunn and Wakita, Masahide and White, Angelicque and Tanhua, Toste},
title = {Synthesis Product for Ocean Time-Series (SPOTS) – A ship-based biogeochemical pilot},
publisher = {Copernicus GmbH},
year = {2023},
url = {http://dx.doi.org/10.5194/essd-2023-238},
doi = {10.5194/essd-2023-238}
}
|
| Lange N, Tanhua T, Pfeil B, Bange HW, Lauvset SK, Grégoire M, Bakker DCE, Jones SD, Fiedler B, O'Brien KM and Körtzinger A (2023), "A status assessment of selected data synthesis products for ocean biogeochemistry", Frontiers in Marine Science., apr, 2023. Vol. 10 Frontiers Media SA. |
BibTeX:
@article{Lange2023a,
author = {Lange, Nico and Tanhua, Toste and Pfeil, Benjamin and Bange, Hermann W and Lauvset, Siv K and Grégoire, Marilaure and Bakker, Dorothee C E and Jones, Steve D and Fiedler, Björn and O'Brien, Kevin M and Körtzinger, Arne},
title = {A status assessment of selected data synthesis products for ocean biogeochemistry},
journal = {Frontiers in Marine Science},
publisher = {Frontiers Media SA},
year = {2023},
volume = {10},
url = {http://dx.doi.org/10.3389/fmars.2023.1078908},
doi = {10.3389/fmars.2023.1078908}
}
|
| Larson J, Wallerman J, Peichl M and Laudon H (2023), "Soil moisture controls the partitioning of carbon stocks across a managed boreal forest landscape", Scientific Reports., sep, 2023. Vol. 13(1) Springer Science and Business Media LLC. |
BibTeX:
@article{Larson2023,
author = {Larson, Johannes and Wallerman, Jörgen and Peichl, Matthias and Laudon, Hjalmar},
title = {Soil moisture controls the partitioning of carbon stocks across a managed boreal forest landscape},
journal = {Scientific Reports},
publisher = {Springer Science and Business Media LLC},
year = {2023},
volume = {13},
number = {1},
url = {http://dx.doi.org/10.1038/s41598-023-42091-4},
doi = {10.1038/s41598-023-42091-4}
}
|
| Laudon H, Mosquera V, Eklöf K, Järveoja J, Karimi S, Krasnova A, Peichl M, Pinkwart A, Tong CHM, Wallin MB, Zannella A and Hasselquist EM (2023), "Consequences of rewetting and ditch cleaning on hydrology, water quality and greenhouse gas balance in a drained northern landscape", Scientific Reports., nov, 2023. Vol. 13(1) Springer Science and Business Media LLC. |
BibTeX:
@article{Laudon2023,
author = {Laudon, Hjalmar and Mosquera, Virginia and Eklöf, Karin and Järveoja, Järvi and Karimi, Shirin and Krasnova, Alisa and Peichl, Matthias and Pinkwart, Alexander and Tong, Cheuk Hei Marcus and Wallin, Marcus B and Zannella, Alberto and Hasselquist, Eliza Maher},
title = {Consequences of rewetting and ditch cleaning on hydrology, water quality and greenhouse gas balance in a drained northern landscape},
journal = {Scientific Reports},
publisher = {Springer Science and Business Media LLC},
year = {2023},
volume = {13},
number = {1},
url = {http://dx.doi.org/10.1038/s41598-023-47528-4},
doi = {10.1038/s41598-023-47528-4}
}
|
| Lefèvre N, Veleda D and Hartman SE (2023), "Outgassing of CO2 dominates in the coastal upwelling off the northwest African coast", Deep Sea Research Part I: Oceanographic Research Papers., oct, 2023. Vol. 200, pp. 104130. Elsevier BV. |
BibTeX:
@article{Lefevre2023,
author = {Lefèvre, Nathalie and Veleda, Doris and Hartman, Susan E},
title = {Outgassing of CO2 dominates in the coastal upwelling off the northwest African coast},
journal = {Deep Sea Research Part I: Oceanographic Research Papers},
publisher = {Elsevier BV},
year = {2023},
volume = {200},
pages = {104130},
url = {http://dx.doi.org/10.1016/j.dsr.2023.104130},
doi = {10.1016/j.dsr.2023.104130}
}
|
| Lehtonen A, Leppä K, Rinne-Garmston KT, Sahlstedt E, Schiestl-Aalto P, Heikkinen J, Young GHF, Korkiakoski M, Peltoniemi M, Sarkkola S, Lohila A and Mäkipää R (2023), "Fast recovery of suppressed Norway spruce trees after selection harvesting on a drained peatland forest site", Forest Ecology and Management., feb, 2023. Vol. 530, pp. 120759. Elsevier BV. |
BibTeX:
@article{Lehtonen2023,
author = {Lehtonen, Aleksi and Leppä, Kersti and Rinne-Garmston, Katja T and Sahlstedt, Elina and Schiestl-Aalto, Pauliina and Heikkinen, Juha and Young, Giles H F and Korkiakoski, Mika and Peltoniemi, Mikko and Sarkkola, Sakari and Lohila, Annalea and Mäkipää, Raisa},
title = {Fast recovery of suppressed Norway spruce trees after selection harvesting on a drained peatland forest site},
journal = {Forest Ecology and Management},
publisher = {Elsevier BV},
year = {2023},
volume = {530},
pages = {120759},
url = {http://dx.doi.org/10.1016/j.foreco.2022.120759},
doi = {10.1016/j.foreco.2022.120759}
}
|
| Li C, Jiskra M, Nilsson MB, Osterwalder S, Zhu W, Mauquoy D, Skyllberg U, Enrico M, Peng H, Song Y, Björn E and Bishop K (2023), "Mercury deposition and redox transformation processes in peatland constrained by mercury stable isotopes", Nature Communications., nov, 2023. Vol. 14(1) Springer Science and Business Media LLC. |
BibTeX:
@article{Li2023,
author = {Li, Chuxian and Jiskra, Martin and Nilsson, Mats B and Osterwalder, Stefan and Zhu, Wei and Mauquoy, Dmitri and Skyllberg, Ulf and Enrico, Maxime and Peng, Haijun and Song, Yu and Björn, Erik and Bishop, Kevin},
title = {Mercury deposition and redox transformation processes in peatland constrained by mercury stable isotopes},
journal = {Nature Communications},
publisher = {Springer Science and Business Media LLC},
year = {2023},
volume = {14},
number = {1},
url = {http://dx.doi.org/10.1038/s41467-023-43164-8},
doi = {10.1038/s41467-023-43164-8}
}
|
| Li X, Zhang W, Vermeulen A, Dong J and Duan Z (2023), "Triple collocation-based merging of multi-source gridded evapotranspiration data in the Nordic Region", Agricultural and Forest Meteorology., may, 2023. Vol. 335, pp. 109451. Elsevier BV. |
BibTeX:
@article{Li2023a,
author = {Li, Xueying and Zhang, Wenxin and Vermeulen, Alex and Dong, Jianzhi and Duan, Zheng},
title = {Triple collocation-based merging of multi-source gridded evapotranspiration data in the Nordic Region},
journal = {Agricultural and Forest Meteorology},
publisher = {Elsevier BV},
year = {2023},
volume = {335},
pages = {109451},
url = {http://dx.doi.org/10.1016/j.agrformet.2023.109451},
doi = {10.1016/j.agrformet.2023.109451}
}
|
| Lindroth A (2023), "Spatial Variability of Albedo and Net Radiation at Local Scale Using UAV Equipped with Radiation Sensors", Drones., apr, 2023. Vol. 7(4), pp. 276. MDPI AG. |
BibTeX:
@article{Lindroth2023,
author = {Lindroth, Anders},
title = {Spatial Variability of Albedo and Net Radiation at Local Scale Using UAV Equipped with Radiation Sensors},
journal = {Drones},
publisher = {MDPI AG},
year = {2023},
volume = {7},
number = {4},
pages = {276},
url = {http://dx.doi.org/10.3390/drones7040276},
doi = {10.3390/drones7040276}
}
|
| Liu H, Liu J, Yin Y, Walther S, Ma X, Zhang Z and Chen Y (2023), "Improved Vegetation Photosynthetic Phenology Monitoring in the Northern Ecosystems Using Total Canopy Solar‐Induced Chlorophyll Fluorescence Derived From TROPOMI", Journal of Geophysical Research: Biogeosciences., jun, 2023. Vol. 128(6) American Geophysical Union (AGU). |
BibTeX:
@article{Liu2023,
author = {Liu, Haoran and Liu, Junzhi and Yin, Yueqiang and Walther, Sophia and Ma, Xuanlong and Zhang, Zhaoying and Chen, Yuhan},
title = {Improved Vegetation Photosynthetic Phenology Monitoring in the Northern Ecosystems Using Total Canopy Solar‐Induced Chlorophyll Fluorescence Derived From TROPOMI},
journal = {Journal of Geophysical Research: Biogeosciences},
publisher = {American Geophysical Union (AGU)},
year = {2023},
volume = {128},
number = {6},
url = {http://dx.doi.org/10.1029/2022JG007369},
doi = {10.1029/2022jg007369}
}
|
| Männistö E, Ylänne H, Losoi M, Keinänen M, Yli-Pirilä P, Korrensalo A, Bäck J, Hellén H, Virtanen A and Tuittila E-S (2023), "Emissions of biogenic volatile organic compounds from adjacent boreal fen and bog as impacted by vegetation composition", Science of The Total Environment., feb, 2023. Vol. 858, pp. 159809. Elsevier BV. |
BibTeX:
@article{Maennistoe2023,
author = {Männistö, Elisa and Ylänne, Henni and Losoi, Mari and Keinänen, Markku and Yli-Pirilä, Pasi and Korrensalo, Aino and Bäck, Jaana and Hellén, Heidi and Virtanen, Annele and Tuittila, Eeva-Stiina},
title = {Emissions of biogenic volatile organic compounds from adjacent boreal fen and bog as impacted by vegetation composition},
journal = {Science of The Total Environment},
publisher = {Elsevier BV},
year = {2023},
volume = {858},
pages = {159809},
url = {http://dx.doi.org/10.1016/j.scitotenv.2022.159809},
doi = {10.1016/j.scitotenv.2022.159809}
}
|
| Mannisenaho V, Tsuruta A, Backman L, Houweling S, Segers A, Krol M, Saunois M, Poulter B, Zhang Z, Lan X, Dlugokencky EJ, Michel S, White JWC and Aalto T (2023), "Global Atmospheric δ13CH4 and CH4 Trends for 2000–2020 from the Atmospheric Transport Model TM5 Using CH4 from Carbon Tracker Europe–CH4 Inversions", Atmosphere., jul, 2023. Vol. 14(7), pp. 1121. MDPI AG. |
BibTeX:
@article{Mannisenaho2023,
author = {Mannisenaho, Vilma and Tsuruta, Aki and Backman, Leif and Houweling, Sander and Segers, Arjo and Krol, Maarten and Saunois, Marielle and Poulter, Benjamin and Zhang, Zhen and Lan, Xin and Dlugokencky, Edward J and Michel, Sylvia and White, James W C and Aalto, Tuula},
title = {Global Atmospheric δ13CH4 and CH4 Trends for 2000–2020 from the Atmospheric Transport Model TM5 Using CH4 from Carbon Tracker Europe–CH4 Inversions},
journal = {Atmosphere},
publisher = {MDPI AG},
year = {2023},
volume = {14},
number = {7},
pages = {1121},
url = {http://dx.doi.org/10.3390/atmos14071121},
doi = {10.3390/atmos14071121}
}
|
| Martellucci R, Giani M, Mauri E, Coppola L, Poulsen M, Fourrier M, Pensieri S, Cardin V, Dentico C, Bozzano R, Cantoni C, Lucchetta A and Skjelvan I (2023), "CO2 and hydrography acquired by Autonomous Surface Vehicles from the Atlantic Ocean to the Mediterranean Sea: data correction and validation", dec, 2023. Copernicus GmbH. |
BibTeX:
@article{Martellucci2023,
author = {Martellucci, Riccardo and Giani, Michele and Mauri, Elena and Coppola, Laurent and Poulsen, Melf and Fourrier, Marine and Pensieri, Sara and Cardin, Vanessa and Dentico, Carlotta and Bozzano, Roberto and Cantoni, Carolina and Lucchetta, Anna and Skjelvan, Ingunn},
title = {CO2 and hydrography acquired by Autonomous Surface Vehicles from the Atlantic Ocean to the Mediterranean Sea: data correction and validation},
publisher = {Copernicus GmbH},
year = {2023},
url = {http://dx.doi.org/10.5194/essd-2023-457},
doi = {10.5194/essd-2023-457}
}
|
| McGillen MR, Fried ZTP, Khan MAH, Kuwata KT, Martin CM, O’Doherty S, Pecere F, Shallcross DE, Stanley KM and Zhang K (2023), "Ozonolysis can produce long-lived greenhouse gases from commercial refrigerants", Proceedings of the National Academy of Sciences., December, 2023. Vol. 120(51) Proceedings of the National Academy of Sciences. |
BibTeX:
@article{McGillen2023,
author = {McGillen, Max R. and Fried, Zachary T. P. and Khan, M. Anwar H. and Kuwata, Keith T. and Martin, Connor M. and O’Doherty, Simon and Pecere, Francesco and Shallcross, Dudley E. and Stanley, Kieran M. and Zhang, Kexin},
title = {Ozonolysis can produce long-lived greenhouse gases from commercial refrigerants},
journal = {Proceedings of the National Academy of Sciences},
publisher = {Proceedings of the National Academy of Sciences},
year = {2023},
volume = {120},
number = {51},
doi = {10.1073/pnas.2312714120}
}
|
| McNicol G, Fluet‐Chouinard E, Ouyang Z, Knox S, Zhang Z, Aalto T, Bansal S, Chang K, Chen M, Delwiche K, Feron S, Goeckede M, Liu J, Malhotra A, Melton JR, Riley W, Vargas R, Yuan K, Ying Q, Zhu Q, Alekseychik P, Aurela M, Billesbach DP, Campbell DI, Chen J, Chu H, Desai AR, Euskirchen E, Goodrich J, Griffis T, Helbig M, Hirano T, Iwata H, Jurasinski G, King J, Koebsch F, Kolka R, Krauss K, Lohila A, Mammarella I, Nilson M, Noormets A, Oechel W, Peichl M, Sachs T, Sakabe A, Schulze C, Sonnentag O, Sullivan RC, Tuittila E, Ueyama M, Vesala T, Ward E, Wille C, Wong GX, Zona D, Windham‐Myers L, Poulter B and Jackson RB (2023), "Upscaling Wetland Methane Emissions From the FLUXNET‐CH4 Eddy Covariance Network (UpCH4 v1.0): Model Development, Network Assessment, and Budget Comparison", AGU Advances., sep, 2023. Vol. 4(5) American Geophysical Union (AGU). |
BibTeX:
@article{McNicol2023,
author = {McNicol, Gavin and Fluet‐Chouinard, Etienne and Ouyang, Zutao and Knox, Sara and Zhang, Zhen and Aalto, Tuula and Bansal, Sheel and Chang, Kuang‐Yu and Chen, Min and Delwiche, Kyle and Feron, Sarah and Goeckede, Mathias and Liu, Jinxun and Malhotra, Avni and Melton, Joe R and Riley, William and Vargas, Rodrigo and Yuan, Kunxiaojia and Ying, Qing and Zhu, Qing and Alekseychik, Pavel and Aurela, Mika and Billesbach, David P and Campbell, David I and Chen, Jiquan and Chu, Housen and Desai, Ankur R and Euskirchen, Eugenie and Goodrich, Jordan and Griffis, Timothy and Helbig, Manuel and Hirano, Takashi and Iwata, Hiroki and Jurasinski, Gerald and King, John and Koebsch, Franziska and Kolka, Randall and Krauss, Ken and Lohila, Annalea and Mammarella, Ivan and Nilson, Mats and Noormets, Asko and Oechel, Walter and Peichl, Matthias and Sachs, Torsten and Sakabe, Ayaka and Schulze, Christopher and Sonnentag, Oliver and Sullivan, Ryan C and Tuittila, Eeva‐Stiina and Ueyama, Masahito and Vesala, Timo and Ward, Eric and Wille, Christian and Wong, Guan Xhuan and Zona, Donatella and Windham‐Myers, Lisamarie and Poulter, Benjamin and Jackson, Robert B},
title = {Upscaling Wetland Methane Emissions From the FLUXNET‐CH4 Eddy Covariance Network (UpCH4 v1.0): Model Development, Network Assessment, and Budget Comparison},
journal = {AGU Advances},
publisher = {American Geophysical Union (AGU)},
year = {2023},
volume = {4},
number = {5},
url = {http://dx.doi.org/10.1029/2023AV000956},
doi = {10.1029/2023av000956}
}
|
| Müller JD, Gruber N, Carter B, Feely R, Ishii M, Lange N, Lauvset SK, Murata A, Olsen A, Pérez FF, Sabine C, Tanhua T, Wanninkhof R and Zhu D (2023), "Decadal Trends in the Oceanic Storage of Anthropogenic Carbon From 1994 to 2014", AGU Advances., aug, 2023. Vol. 4(4) American Geophysical Union (AGU). |
BibTeX:
@article{Mueller2023,
author = {Müller, Jens Daniel and Gruber, N and Carter, B and Feely, R and Ishii, M and Lange, N and Lauvset, S K and Murata, A and Olsen, A and Pérez, F F and Sabine, C and Tanhua, T and Wanninkhof, R and Zhu, D},
title = {Decadal Trends in the Oceanic Storage of Anthropogenic Carbon From 1994 to 2014},
journal = {AGU Advances},
publisher = {American Geophysical Union (AGU)},
year = {2023},
volume = {4},
number = {4},
url = {http://dx.doi.org/10.1029/2023AV000875},
doi = {10.1029/2023av000875}
}
|
| Müller M, Weigl S, Müller-Williams J, Lindauer M, Rück T, Jobst S, Bierl R and Matysik F-M (2023), "Comparison of photoacoustic spectroscopy and cavity ring-down spectroscopy for ambient methane monitoring at Hohenpeißenberg", Atmospheric Measurement Techniques., sep, 2023. Vol. 16(18), pp. 4263-4270. Copernicus GmbH. |
BibTeX:
@article{Mueller2023a,
author = {Müller, Max and Weigl, Stefan and Müller-Williams, Jennifer and Lindauer, Matthias and Rück, Thomas and Jobst, Simon and Bierl, Rudolf and Matysik, Frank-Michael},
title = {Comparison of photoacoustic spectroscopy and cavity ring-down spectroscopy for ambient methane monitoring at Hohenpeißenberg},
journal = {Atmospheric Measurement Techniques},
publisher = {Copernicus GmbH},
year = {2023},
volume = {16},
number = {18},
pages = {4263--4270},
url = {http://dx.doi.org/10.5194/amt-16-4263-2023},
doi = {10.5194/amt-16-4263-2023}
}
|
| Munassar S, Monteil G, Scholze M, Karstens U, Rödenbeck C, Koch F-T, Totsche KU and Gerbig C (2023), "Why do inverse models disagree? A case study with two European CO2 inversions", Atmospheric Chemistry and Physics., mar, 2023. Vol. 23(4), pp. 2813-2828. Copernicus GmbH. |
BibTeX:
@article{Munassar2023,
author = {Munassar, Saqr and Monteil, Guillaume and Scholze, Marko and Karstens, Ute and Rödenbeck, Christian and Koch, Frank-Thomas and Totsche, Kai U and Gerbig, Christoph},
title = {Why do inverse models disagree? A case study with two European CO2 inversions},
journal = {Atmospheric Chemistry and Physics},
publisher = {Copernicus GmbH},
year = {2023},
volume = {23},
number = {4},
pages = {2813--2828},
url = {http://dx.doi.org/10.5194/acp-23-2813-2023},
doi = {10.5194/acp-23-2813-2023}
}
|
| Muñoz E and Sierra CA (2023), "Deterministic and stochastic components of atmospheric CO |
BibTeX:
@article{Munoz2023,
author = {Muñoz, Estefanía and Sierra, Carlos A},
title = {Deterministic and stochastic components of atmospheric CO |
| Nayagam L, Maksyutov S, Oda T, Janardanan R, Trisolino P, Zeng J, Kaiser JW and Matsunaga T (2023), "A top-down estimation of subnational CO2 budget using a global high-resolution inverse model with data from regional surface networks", Environmental Research Letters., dec, 2023. Vol. 19(1), pp. 14031. IOP Publishing. |
BibTeX:
@article{Nayagam2023,
author = {Nayagam, Lorna and Maksyutov, Shamil and Oda, Tomohiro and Janardanan, Rajesh and Trisolino, Pamela and Zeng, Jiye and Kaiser, Johannes W and Matsunaga, Tsuneo},
title = {A top-down estimation of subnational CO2 budget using a global high-resolution inverse model with data from regional surface networks},
journal = {Environmental Research Letters},
publisher = {IOP Publishing},
year = {2023},
volume = {19},
number = {1},
pages = {14031},
url = {http://dx.doi.org/10.1088/1748-9326/ad0f74},
doi = {10.1088/1748-9326/ad0f74}
}
|
| Noumonvi KD, Ågren AM, Ratcliffe JL, Öquist MG, Ericson L, Tong CHM, Järveoja J, Zhu W, Osterwalder S, Peng H, Erefur C, Bishop K, Laudon H, Nilsson MB and Peichl M (2023), "The Kulbäcksliden Research Infrastructure: a unique setting for northern peatland studies", Frontiers in Earth Science., may, 2023. Vol. 11 Frontiers Media SA. |
BibTeX:
@article{Noumonvi2023,
author = {Noumonvi, Koffi Dodji and Ågren, Anneli M and Ratcliffe, Joshua L and Öquist, Mats G and Ericson, Lars and Tong, Cheuk Hei Marcus and Järveoja, Järvi and Zhu, Wei and Osterwalder, Stefan and Peng, Haijun and Erefur, Charlotta and Bishop, Kevin and Laudon, Hjalmar and Nilsson, Mats B and Peichl, Matthias},
title = {The Kulbäcksliden Research Infrastructure: a unique setting for northern peatland studies},
journal = {Frontiers in Earth Science},
publisher = {Frontiers Media SA},
year = {2023},
volume = {11},
url = {http://dx.doi.org/10.3389/feart.2023.1194749},
doi = {10.3389/feart.2023.1194749}
}
|
| Oda T, Feng L, Palmer PI, Baker DF and Ott LE (2023), "Assumptions about prior fossil fuel inventories impact our ability to estimate posterior net CO2 fluxes that are needed for verifying national inventories", Environmental Research Letters., nov, 2023. Vol. 18(12), pp. 124030. IOP Publishing. |
BibTeX:
@article{Oda2023,
author = {Oda, Tomohiro and Feng, Liang and Palmer, Paul I and Baker, David F and Ott, Lesley E},
title = {Assumptions about prior fossil fuel inventories impact our ability to estimate posterior net CO2 fluxes that are needed for verifying national inventories},
journal = {Environmental Research Letters},
publisher = {IOP Publishing},
year = {2023},
volume = {18},
number = {12},
pages = {124030},
url = {http://dx.doi.org/10.1088/1748-9326/ad059b},
doi = {10.1088/1748-9326/ad059b}
}
|
| Offermanns L, Tiemeyer B, Dettmann U, Rüffer J, Düvel D, Vogel I and Brümmer C (2023), "High greenhouse gas emissions after grassland renewal on bog peat soil", Agricultural and Forest Meteorology., mar, 2023. Vol. 331, pp. 109309. Elsevier BV. |
BibTeX:
@article{Offermanns2023,
author = {Offermanns, Liv and Tiemeyer, Bärbel and Dettmann, Ullrich and Rüffer, Jeremy and Düvel, Dominik and Vogel, Isabelle and Brümmer, Christian},
title = {High greenhouse gas emissions after grassland renewal on bog peat soil},
journal = {Agricultural and Forest Meteorology},
publisher = {Elsevier BV},
year = {2023},
volume = {331},
pages = {109309},
url = {http://dx.doi.org/10.1016/j.agrformet.2023.109309},
doi = {10.1016/j.agrformet.2023.109309}
}
|
| Osterholt L, Maier M and Schindler D (2023), "Small lateral air pressure gradients generated by a large chamber system have a strong effect on |
BibTeX:
@article{Osterholt2023,
author = {Osterholt, Laurin and Maier, Martin and Schindler, Dirk},
title = {Small lateral air pressure gradients generated by a large chamber system have a strong effect on |
| Padilla R, Adame JA, Hidalgo PJ, Bolivar JP and Yela M (2023), "Ground-based and AIRS carbon monoxide behavior at El Arenosillo observatory (Southwestern Europe)", Atmospheric Environment., oct, 2023. Vol. 310, pp. 119962. Elsevier BV. |
BibTeX:
@article{Padilla2023,
author = {Padilla, R and Adame, J A and Hidalgo, P J and Bolivar, J P and Yela, M},
title = {Ground-based and AIRS carbon monoxide behavior at El Arenosillo observatory (Southwestern Europe)},
journal = {Atmospheric Environment},
publisher = {Elsevier BV},
year = {2023},
volume = {310},
pages = {119962},
url = {http://dx.doi.org/10.1016/j.atmosenv.2023.119962},
doi = {10.1016/j.atmosenv.2023.119962}
}
|
| Panagiotakis E, Kochilakis G, Tsirantonakis D, Poursanidis D, Politakos K and Chrysoulakis N (2023), "A web-based tool for supporting USM in Heraklion", In 2023 Joint Urban Remote Sensing Event (JURSE)., may, 2023. IEEE. |
BibTeX:
@inproceedings{Panagiotakis2023,
author = {Panagiotakis, Emmanouil and Kochilakis, Giorgos and Tsirantonakis, Dimitris and Poursanidis, Dimitris and Politakos, Konstantinos and Chrysoulakis, Nektarios},
title = {A web-based tool for supporting USM in Heraklion},
booktitle = {2023 Joint Urban Remote Sensing Event (JURSE)},
publisher = {IEEE},
year = {2023},
url = {http://dx.doi.org/10.1109/JURSE57346.2023.10144144},
doi = {10.1109/jurse57346.2023.10144144}
}
|
| Papale D, Heiskanen J, Brümmer C, Buchmann N, Calfapietra C, Carrara A, Chen H, Gielen B, Gkritzalis T, Hammer S, Hartman S, Herbst M, Janssens IA, Jordan A, Juurola E, Karstens U, Kasurinen V, Kruijt B, Lankreijer H, Levin I, Linderson M-L, Loustau D, Merbold L, Myhre CL, Pavelka M, Pilegaard K, Ramonet M, Rebmann C, Rinne J, Rivier L, Saltikoff E, Sanders R, Steinbacher M, Steinhoff T, Watson A, Vermeulen AT, Vesala T, Vítková G and Kutsch W (2023), "Standards and Open Access are the ICOS Pillars: Reply to “Comments on ‘The Integrated Carbon Observation System in Europe'”", Bulletin of the American Meteorological Society., dec, 2023. Vol. 104(12), pp. 953-955. American Meteorological Society. |
BibTeX:
@article{Papale2023,
author = {Papale, Dario and Heiskanen, Jouni and Brümmer, Christian and Buchmann, Nina and Calfapietra, Carlo and Carrara, Arnaud and Chen, Huilin and Gielen, Bert and Gkritzalis, Thanos and Hammer, Samuel and Hartman, Susan and Herbst, Mathias and Janssens, Ivan A and Jordan, Armin and Juurola, Eija and Karstens, Ute and Kasurinen, Ville and Kruijt, Bart and Lankreijer, Harry and Levin, Ingeborg and Linderson, Maj-Lena and Loustau, Denis and Merbold, Lutz and Myhre, Cathrine Lund and Pavelka, Marian and Pilegaard, Kim and Ramonet, Michel and Rebmann, Corinna and Rinne, Janne and Rivier, Léonard and Saltikoff, Elena and Sanders, Richard and Steinbacher, Martin and Steinhoff, Tobias and Watson, Andrew and Vermeulen, Alex T and Vesala, Timo and Vítková, Gabriela and Kutsch, Werner},
title = {Standards and Open Access are the ICOS Pillars: Reply to “Comments on ‘The Integrated Carbon Observation System in Europe'”},
journal = {Bulletin of the American Meteorological Society},
publisher = {American Meteorological Society},
year = {2023},
volume = {104},
number = {12},
pages = {953--955},
url = {http://dx.doi.org/10.1175/BAMS-D-23-0216.1},
doi = {10.1175/bams-d-23-0216.1}
}
|
| Peters RL, Steppe K, Pappas C, Zweifel R, Babst F, Dietrich L, von Arx G, Poyatos R, Fonti M, Fonti P, Grossiord C, Gharun M, Buchmann N, Steger DN and Kahmen A (2023), "Daytime stomatal regulation in mature temperate trees prioritizes stem rehydration at night", New Phytologist., may, 2023. Vol. 239(2), pp. 533-546. Wiley. |
BibTeX:
@article{Peters2023,
author = {Peters, Richard L and Steppe, Kathy and Pappas, Christoforos and Zweifel, Roman and Babst, Flurin and Dietrich, Lars and von Arx, Georg and Poyatos, Rafael and Fonti, Marina and Fonti, Patrick and Grossiord, Charlotte and Gharun, Mana and Buchmann, Nina and Steger, David N and Kahmen, Ansgar},
title = {Daytime stomatal regulation in mature temperate trees prioritizes stem rehydration at night},
journal = {New Phytologist},
publisher = {Wiley},
year = {2023},
volume = {239},
number = {2},
pages = {533--546},
url = {http://dx.doi.org/10.1111/nph.18964},
doi = {10.1111/nph.18964}
}
|
| Petersen R, Holst T, Mölder M, Kljun N and Rinne J (2023), "Vertical distribution of sources and sinks of volatile organic compounds within a boreal forest canopy", Atmospheric Chemistry and Physics., jul, 2023. Vol. 23(13), pp. 7839-7858. Copernicus GmbH. |
BibTeX:
@article{Petersen2023,
author = {Petersen, Ross and Holst, Thomas and Mölder, Meelis and Kljun, Natascha and Rinne, Janne},
title = {Vertical distribution of sources and sinks of volatile organic compounds within a boreal forest canopy},
journal = {Atmospheric Chemistry and Physics},
publisher = {Copernicus GmbH},
year = {2023},
volume = {23},
number = {13},
pages = {7839--7858},
url = {http://dx.doi.org/10.5194/acp-23-7839-2023},
doi = {10.5194/acp-23-7839-2023}
}
|
| Petersson Sjögren M, Alsved M, Šantl-Temkiv T, Bjerring Kristensen T and Löndahl J (2023), "Measurement report: Atmospheric fluorescent bioaerosol concentrations measured during 18 months in a coniferous forest in the south of Sweden", Atmospheric Chemistry and Physics., may, 2023. Vol. 23(9), pp. 4977-4992. Copernicus GmbH. |
BibTeX:
@article{PeterssonSjoegren2023,
author = {Petersson Sjögren, Madeleine and Alsved, Malin and Šantl-Temkiv, Tina and Bjerring Kristensen, Thomas and Löndahl, Jakob},
title = {Measurement report: Atmospheric fluorescent bioaerosol concentrations measured during 18 months in a coniferous forest in the south of Sweden},
journal = {Atmospheric Chemistry and Physics},
publisher = {Copernicus GmbH},
year = {2023},
volume = {23},
number = {9},
pages = {4977--4992},
url = {http://dx.doi.org/10.5194/acp-23-4977-2023},
doi = {10.5194/acp-23-4977-2023}
}
|
| Pimentel R, Arheimer B, Crochemore L, Andersson JCM, Pechlivanidis IG and Gustafsson D (2023), "Which Potential Evapotranspiration Formula to Use in Hydrological Modeling World‐Wide?", Water Resources Research., may, 2023. Vol. 59(5) American Geophysical Union (AGU). |
BibTeX:
@article{Pimentel2023,
author = {Pimentel, R and Arheimer, B and Crochemore, L and Andersson, J C M and Pechlivanidis, I G and Gustafsson, D},
title = {Which Potential Evapotranspiration Formula to Use in Hydrological Modeling World‐Wide?},
journal = {Water Resources Research},
publisher = {American Geophysical Union (AGU)},
year = {2023},
volume = {59},
number = {5},
url = {http://dx.doi.org/10.1029/2022wr033447},
doi = {10.1029/2022wr033447}
}
|
| Pluntke T, Bernhofer C, Grünwald T, Renner M and Prasse H (2023), "Long-term climatological and ecohydrological analysis of a paired catchment – flux tower observatory near Dresden (Germany). Is there evidence of climate change in local evapotranspiration?", Journal of Hydrology. Vol. 617, pp. 128873. |
| Abstract: Water budgets and climate are related in many ways and at all scales. Therefore, we expect climate change to trigger changes in all water budget components at any scale. For Central Europe observed and projected climate change indicates higher variability of precipitation, while evapotranspiration (ET) should increase due to higher temperatures, yielding lower and more variable infiltration and runoff. However, evidence in ET records is limited, as long-term measurements of ET are methodologically challenging and as factors other than climate are changing in parallel, like vegetation and land use. In this study, we take advantage of long-term hydro-meteorological data from the small research catchment Wernersbach (4.6 km2, dominated by Norway spruce) in operation since 1967 and from two eddy-covariance (EC) flux towers, all located in the Tharandt Forest, Germany. The tower DE-Tha is located a few kilometres east of the catchment, is spruce dominated and in operation since 1996. After a wind break of a spruce stand (situated inside the catchment) and planting of deciduous oaks, the tower DE-Hzd was set up in 2009. For the first time, we report systematically about observation, correction methods and metadata of the long data series of the observatory, represented by the Wernersbach catchment and the EC flux towers. Climate change signals in the region are mirrored in the Tharandt Forest records. They show rising air temperature with a breakpoint around 1988 and complex changes in solar radiation associated to a regional peak in air pollution around the same time. The catchment and both towers did not show any systematic differences in climate or meteorological data, allowing us to address observed changes in the water budget components as related to (i) climate change, (ii) change in vegetation, and (iii) different responses due to different soil and hydrogeological characteristics as well as methodological aspects. The catchment term ET plus storage, derived from precipitation minus runoff, showed the expected high variability with a significant increase over the more than 50 years of operation. The flux-tower DE-Tha showed much lower inter-annual variability in ET with an average annual total of 486 mm (1997 to 2019), but no significant trend. For the same period, average catchment ET was 734 mm/yr. The younger flux-tower DE-Hzd showed ET values in between, closer to catchment ET at the very dry end of the ten-year record (2010 to 2019). An analysis of decadal trends in a Budyko framework at catchment level revealed the dominating response of ET to land use or vegetation change until around 1990. The climate induced change of ET increased in the last decades, on the one hand directly due to an increased atmospheric demand. On the other hand, extreme weather events exerted harmful effects on vegetation, especially triggered by two dry years at the end of the record. Furthermore, we found that the mean annual tower ET was about 250 mm lower than catchment ET despite the careful correction for energy balance closure. We attribute this difference to soil and to a lesser extend to vegetation characteristics, but also to methodological uncertainties. There is evidence from interception and transpiration measurements at the flux tower as well as from water budget modelling that a major contribution of this difference is related to an insufficient EC closure correction during interception events. A careful consideration of rain events and evaporation from interception is recommended when addressing ET of similar evergreen forests in a humid climate, as EC records might be generally too low. This illustrates the necessity of redundant and complementary measurements when dealing with large system complexity. |
BibTeX:
@article{Pluntke2023,
author = {Pluntke, T and Bernhofer, C and Grünwald, T and Renner, M and Prasse, H},
title = {Long-term climatological and ecohydrological analysis of a paired catchment – flux tower observatory near Dresden (Germany). Is there evidence of climate change in local evapotranspiration?},
journal = {Journal of Hydrology},
year = {2023},
volume = {617},
pages = {128873},
url = {https://www.sciencedirect.com/science/article/pii/S0022169422014433},
doi = {10.1016/j.jhydrol.2022.128873}
}
|
| Pohl F, Werban U, Kumar R, Hildebrandt A and Rebmann C (2023), "Observational evidence of legacy effects of the 2018 drought on a mixed deciduous forest in Germany", Scientific Reports., jul, 2023. Vol. 13(1) Springer Science and Business Media LLC. |
BibTeX:
@article{Pohl2023,
author = {Pohl, Felix and Werban, Ulrike and Kumar, Rohini and Hildebrandt, Anke and Rebmann, Corinna},
title = {Observational evidence of legacy effects of the 2018 drought on a mixed deciduous forest in Germany},
journal = {Scientific Reports},
publisher = {Springer Science and Business Media LLC},
year = {2023},
volume = {13},
number = {1},
url = {http://dx.doi.org/10.1038/s41598-023-38087-9},
doi = {10.1038/s41598-023-38087-9}
}
|
| Politakos K, Stagakis S, Feigenwinter C, Roth M and Chrysoulakis N (2023), "Dynamic changes in urban form and function affect Carbon Dioxide Fluxes in a Mediterranean city" Unpublished. |
BibTeX:
@article{Politakos2023,
author = {Politakos, Konstantinos and Stagakis, Stavros and Feigenwinter, Christian and Roth, Matthias and Chrysoulakis, Nektarios},
title = {Dynamic changes in urban form and function affect Carbon Dioxide Fluxes in a Mediterranean city},
publisher = {Unpublished},
year = {2023},
url = {https://rgdoi.net/10.13140/RG.2.2.14114.20166},
doi = {10.13140/RG.2.2.14114.20166}
}
|
| Politakos K, Stagakis S, Feigenwinter C, Roth M and Chrysoulakis N (2023), "Comparison of urban eddy covariance CO2 and heat fluxes measured at two flux towers in a Mediterranean city" Unpublished. |
BibTeX:
@article{Politakos2023a,
author = {Politakos, Konstantinos and Stagakis, Stavros and Feigenwinter, Christian and Roth, Matthias and Chrysoulakis, Nektarios},
title = {Comparison of urban eddy covariance CO2 and heat fluxes measured at two flux towers in a Mediterranean city},
publisher = {Unpublished},
year = {2023},
url = {https://rgdoi.net/10.13140/RG.2.2.34950.96325},
doi = {10.13140/RG.2.2.34950.96325}
}
|
| Poppe Terán C, Naz BS, Graf A, Qu Y, Hendricks Franssen H-J, Baatz R, Ciais P and Vereecken H (2023), "Rising water-use efficiency in European grasslands is driven by increased primary production", Communications Earth & Environment., mar, 2023. Vol. 4(1) Springer Science and Business Media LLC. |
BibTeX:
@article{PoppeTeran2023,
author = {Poppe Terán, Christian and Naz, Bibi S and Graf, Alexander and Qu, Yuquan and Hendricks Franssen, Harrie-Jan and Baatz, Roland and Ciais, Phillipe and Vereecken, Harry},
title = {Rising water-use efficiency in European grasslands is driven by increased primary production},
journal = {Communications Earth & Environment},
publisher = {Springer Science and Business Media LLC},
year = {2023},
volume = {4},
number = {1},
url = {http://dx.doi.org/10.1038/s43247-023-00757-x},
doi = {10.1038/s43247-023-00757-x}
}
|
| Prikaziuk E, Migliavacca M, Su Z(B and van der Tol C (2023), "Simulation of ecosystem fluxes with the SCOPE model: Sensitivity to parametrization and evaluation with flux tower observations", Remote Sensing of Environment., jan, 2023. Vol. 284, pp. 113324. Elsevier BV. |
BibTeX:
@article{Prikaziuk2023,
author = {Prikaziuk, Egor and Migliavacca, Mirco and Su, Zhongbo (Bob) and van der Tol, Christiaan},
title = {Simulation of ecosystem fluxes with the SCOPE model: Sensitivity to parametrization and evaluation with flux tower observations},
journal = {Remote Sensing of Environment},
publisher = {Elsevier BV},
year = {2023},
volume = {284},
pages = {113324},
url = {http://dx.doi.org/10.1016/j.rse.2022.113324},
doi = {10.1016/j.rse.2022.113324}
}
|
| Puche NJB, Kirschbaum MUF, Viovy N and Chabbi A (2023), "Potential impacts of climate change on the productivity and soil carbon stocks of managed grasslands", PLOS ONE., apr, 2023. Vol. 18(4), pp. e0283370. Public Library of Science (PLoS). |
BibTeX:
@article{Puche2023,
author = {Puche, N J B and Kirschbaum, M U F and Viovy, N and Chabbi, Abad},
editor = {Liu, Jian},
title = {Potential impacts of climate change on the productivity and soil carbon stocks of managed grasslands},
journal = {PLOS ONE},
publisher = {Public Library of Science (PLoS)},
year = {2023},
volume = {18},
number = {4},
pages = {e0283370},
url = {http://dx.doi.org/10.1371/journal.pone.0283370},
doi = {10.1371/journal.pone.0283370}
}
|
| R. M. M, G. L, D. M and N. C (2023), "Carbon monoxide fluxes measured using the eddy covariance method from an intensively managed grassland in Ireland", Environmental Science: Atmospheres. Vol. 3(12), pp. 1834-1846. Royal Society of Chemistry (RSC). |
BibTeX:
@article{R.M.2023,
author = {R. M., Murphy and G., Lanigan and D., Martin and N., Cowan},
title = {Carbon monoxide fluxes measured using the eddy covariance method from an intensively managed grassland in Ireland},
journal = {Environmental Science: Atmospheres},
publisher = {Royal Society of Chemistry (RSC)},
year = {2023},
volume = {3},
number = {12},
pages = {1834--1846},
url = {http://dx.doi.org/10.1039/D3EA00112A},
doi = {10.1039/d3ea00112a}
}
|
| Rahmati M, Graf A, Poppe Terán C, Amelung W, Dorigo W, Franssen H-JH, Montzka C, Or D, Sprenger M, Vanderborght J, Verhoest NEC and Vereecken H (2023), "Continuous increase in evaporative demand shortened the growing season of European ecosystems in the last decade", Communications Earth & Environment., jul, 2023. Vol. 4(1) Springer Science and Business Media LLC. |
BibTeX:
@article{Rahmati2023,
author = {Rahmati, Mehdi and Graf, Alexander and Poppe Terán, Christian and Amelung, Wulf and Dorigo, Wouter and Franssen, Harrie-Jan Hendricks and Montzka, Carsten and Or, Dani and Sprenger, Matthias and Vanderborght, Jan and Verhoest, Niko E C and Vereecken, Harry},
title = {Continuous increase in evaporative demand shortened the growing season of European ecosystems in the last decade},
journal = {Communications Earth & Environment},
publisher = {Springer Science and Business Media LLC},
year = {2023},
volume = {4},
number = {1},
url = {http://dx.doi.org/10.1038/s43247-023-00890-7},
doi = {10.1038/s43247-023-00890-7}
}
|
| Ramage J, Kuhn M, Virkkala A-M, Bastos A, Canadell JG, Ciais P, Poulter B, Watts J, Voigt C, Marushchak ME, Biasi C, López-Blanco E, Natali SM, Olefeldt D, Potter S, Rogers BM, Schuur EAG, Treat C, Turetsky MR and Hugelius G (2023), "The net GHG balance and budget of the permafrost region (2000-2020) from ecosystem flux upscaling", sep, 2023. Authorea, Inc.. |
BibTeX:
@article{Ramage2023,
author = {Ramage, Justine and Kuhn, McKenzie and Virkkala, Anna-Maria and Bastos, Ana and Canadell, Josep G and Ciais, Philippe and Poulter, Benjamin and Watts, Jennifer and Voigt, Carolina and Marushchak, Maija E and Biasi, Christina and López-Blanco, Efrèn and Natali, Susan M and Olefeldt, David and Potter, Stefano and Rogers, Brendan M and Schuur, Edward A G and Treat, Claire and Turetsky, Merritt R and Hugelius, Gustaf},
title = {The net GHG balance and budget of the permafrost region (2000-2020) from ecosystem flux upscaling},
publisher = {Authorea, Inc.},
year = {2023},
url = {http://dx.doi.org/10.22541/essoar.169447408.86275712/v1},
doi = {10.22541/essoar.169447408.86275712/v1}
}
|
| Raymond CM, Lechner AM, Havu M, Jalkanen J, Lampinen J, Antúnez OG, Olafsson AS, Gulsrud N, Kinnunen A, Backman L, Kulmala L and Järvi L (2023), "Identifying where nature-based solutions can offer win-wins for carbon mitigation and biodiversity across knowledge systems", npj Urban Sustainability., apr, 2023. Vol. 3(1) Springer Science and Business Media LLC. |
BibTeX:
@article{Raymond2023,
author = {Raymond, Christopher M and Lechner, Alex M and Havu, Minttu and Jalkanen, Joel and Lampinen, Jussi and Antúnez, Oriol García and Olafsson, Anton Stahl and Gulsrud, Natalie and Kinnunen, Antti and Backman, Leif and Kulmala, Liisa and Järvi, Leena},
title = {Identifying where nature-based solutions can offer win-wins for carbon mitigation and biodiversity across knowledge systems},
journal = {npj Urban Sustainability},
publisher = {Springer Science and Business Media LLC},
year = {2023},
volume = {3},
number = {1},
url = {http://dx.doi.org/10.1038/s42949-023-00103-2},
doi = {10.1038/s42949-023-00103-2}
}
|
| Rebmann C and Pohl F (2023), "Carbon, water and energy fluxes at the TERENO/ICOS ecosystem station Hohes Holz in Central Germany since 2015". |
BibTeX:
@misc{Rebmann2023,
author = {Rebmann, Corinna and Pohl, Felix},
title = {Carbon, water and energy fluxes at the TERENO/ICOS ecosystem station Hohes Holz in Central Germany since 2015},
publisher = {PANGAEA},
year = {2023},
url = {https://doi.pangaea.de/10.1594/PANGAEA.940760},
doi = {10.1594/PANGAEA.940760}
}
|
| Redington AL, Manning AJ, Henne S, Graziosi F, Western LM, Arduini J, Ganesan AL, Harth CM, Maione M, Mühle J, O’Doherty S, Pitt J, Reimann S, Rigby M, Salameh PK, Simmonds PG, Spain TG, Stanley K, Vollmer MK, Weiss RF and Young D (2023), "Western European emission estimates of CFC-11, CFC-12 and CCl4 derived from atmospheric measurements from 2008 to 2021", Atmospheric Chemistry and Physics., July, 2023. Vol. 23(13), pp. 7383-7398. Copernicus GmbH. |
BibTeX:
@article{Redington2023,
author = {Redington, Alison L. and Manning, Alistair J. and Henne, Stephan and Graziosi, Francesco and Western, Luke M. and Arduini, Jgor and Ganesan, Anita L. and Harth, Christina M. and Maione, Michela and Mühle, Jens and O’Doherty, Simon and Pitt, Joseph and Reimann, Stefan and Rigby, Matthew and Salameh, Peter K. and Simmonds, Peter G. and Spain, T. Gerard and Stanley, Kieran and Vollmer, Martin K. and Weiss, Ray F. and Young, Dickon},
title = {Western European emission estimates of CFC-11, CFC-12 and CCl4 derived from atmospheric measurements from 2008 to 2021},
journal = {Atmospheric Chemistry and Physics},
publisher = {Copernicus GmbH},
year = {2023},
volume = {23},
number = {13},
pages = {7383--7398},
doi = {10.5194/acp-23-7383-2023}
}
|
| Reitz O, Bogena H, Neuwirth B, Sanchez‐Azofeifa A, Graf A, Bates J and Leuchner M (2023), "Environmental Drivers of Gross Primary Productivity and Light Use Efficiency of a Temperate Spruce Forest", Journal of Geophysical Research: Biogeosciences., feb, 2023. Vol. 128(2) American Geophysical Union (AGU). |
BibTeX:
@article{Reitz2023,
author = {Reitz, O and Bogena, H and Neuwirth, B and Sanchez‐Azofeifa, A and Graf, A and Bates, J and Leuchner, M},
title = {Environmental Drivers of Gross Primary Productivity and Light Use Efficiency of a Temperate Spruce Forest},
journal = {Journal of Geophysical Research: Biogeosciences},
publisher = {American Geophysical Union (AGU)},
year = {2023},
volume = {128},
number = {2},
url = {http://dx.doi.org/10.1029/2022JG007197},
doi = {10.1029/2022jg007197}
}
|
| Rewrie LCV, Baschek B, van Beusekom JEE, Körtzinger A, Ollesch G and Voynova YG (2023), "Recent inorganic carbon increase in a temperate estuary driven by water quality improvement and enhanced by droughts", Biogeosciences., dec, 2023. Vol. 20(24), pp. 4931-4947. Copernicus GmbH. |
BibTeX:
@article{Rewrie2023,
author = {Rewrie, Louise C V and Baschek, Burkard and van Beusekom, Justus E E and Körtzinger, Arne and Ollesch, Gregor and Voynova, Yoana G},
title = {Recent inorganic carbon increase in a temperate estuary driven by water quality improvement and enhanced by droughts},
journal = {Biogeosciences},
publisher = {Copernicus GmbH},
year = {2023},
volume = {20},
number = {24},
pages = {4931--4947},
url = {http://dx.doi.org/10.5194/bg-20-4931-2023},
doi = {10.5194/bg-20-4931-2023}
}
|
| Rewrie LCV, Voynova YG, van Beusekom JEE, Sanders T, Körtzinger A, Brix H, Ollesch G and Baschek B (2023), "Significant shifts in inorganic carbon and ecosystem state in a temperate estuary (1985–2018)", Limnology and Oceanography., jun, 2023. Vol. 68(8), pp. 1920-1935. Wiley. |
BibTeX:
@article{Rewrie2023a,
author = {Rewrie, Louise C V and Voynova, Yoana G and van Beusekom, Justus E E and Sanders, Tina and Körtzinger, Arne and Brix, Holger and Ollesch, Gregor and Baschek, Burkard},
title = {Significant shifts in inorganic carbon and ecosystem state in a temperate estuary (1985–2018)},
journal = {Limnology and Oceanography},
publisher = {Wiley},
year = {2023},
volume = {68},
number = {8},
pages = {1920--1935},
url = {http://dx.doi.org/10.1002/lno.12395},
doi = {10.1002/lno.12395}
}
|
| Richardson JL, Desai AR, Thom J, Lindgren K, Laudon H, Peichl M, Nilsson M, Campeau A, Järveoja J, Hawman P, Mishra DR, Smith D, D'Acunha B, Knox SH, Ng D, Johnson MS, Blackstock J, Malone SL, Oberbauer SF, Detto M, Wickland KP, Forbrich I, Weston N, Hung JKY, Edgar C, Euskirchen ES, Bret-Harte S, Dobkowski J, Kling G, Kane ES, Badiou P, Bogard M, Bohrer G, O'Halloran T, Ritson J, Arias-Ortiz A, Baldocchi D, Oikawa P, Shahan J and Matsumura M (2023), "On the Relationship Between Aquatic CO2 Concentration and Ecosystem Fluxes in Some of the World's Key Wetland Types", Wetlands., dec, 2023. Vol. 44(1) Springer Science and Business Media LLC. |
BibTeX:
@article{Richardson2023,
author = {Richardson, Jessica L and Desai, Ankur R and Thom, Jonathan and Lindgren, Kim and Laudon, Hjalmar and Peichl, Matthias and Nilsson, Mats and Campeau, Audrey and Järveoja, Järvi and Hawman, Peter and Mishra, Deepak R and Smith, Dontrece and D'Acunha, Brenda and Knox, Sara H and Ng, Darian and Johnson, Mark S and Blackstock, Joshua and Malone, Sparkle L and Oberbauer, Steve F and Detto, Matteo and Wickland, Kimberly P and Forbrich, Inke and Weston, Nathaniel and Hung, Jacqueline K Y and Edgar, Colin and Euskirchen, Eugenie S and Bret-Harte, Syndonia and Dobkowski, Jason and Kling, George and Kane, Evan S and Badiou, Pascal and Bogard, Matthew and Bohrer, Gil and O'Halloran, Thomas and Ritson, Jonny and Arias-Ortiz, Ariane and Baldocchi, Dennis and Oikawa, Patty and Shahan, Julie and Matsumura, Maiyah},
title = {On the Relationship Between Aquatic CO2 Concentration and Ecosystem Fluxes in Some of the World's Key Wetland Types},
journal = {Wetlands},
publisher = {Springer Science and Business Media LLC},
year = {2023},
volume = {44},
number = {1},
url = {http://dx.doi.org/10.1007/s13157-023-01751-x},
doi = {10.1007/s13157-023-01751-x}
}
|
| Rodgers KB, Schwinger J, Fassbender AJ, Landschützer P, Yamaguchi R, Frenzel H, Stein K, Müller JD, Goris N, Sharma S, Bushinsky S, Chau T, Gehlen M, Gallego MA, Gloege L, Gregor L, Gruber N, Hauck J, Iida Y, Ishii M, Keppler L, Kim J, Schlunegger S, Tjiputra J, Toyama K, Vaittinada Ayar P and Velo A (2023), "Seasonal Variability of the Surface Ocean Carbon Cycle: A Synthesis", Global Biogeochemical Cycles., September, 2023. Vol. 37(9) American Geophysical Union (AGU). |
BibTeX:
@article{Rodgers2023,
author = {Rodgers, Keith B. and Schwinger, Jörg and Fassbender, Andrea J. and Landschützer, Peter and Yamaguchi, Ryohei and Frenzel, Hartmut and Stein, Karl and Müller, Jens Daniel and Goris, Nadine and Sharma, Sahil and Bushinsky, Seth and Chau, Thi‐Tuyet‐Trang and Gehlen, Marion and Gallego, M. Angeles and Gloege, Lucas and Gregor, Luke and Gruber, Nicolas and Hauck, Judith and Iida, Yosuke and Ishii, Masao and Keppler, Lydia and Kim, Ji‐Eun and Schlunegger, Sarah and Tjiputra, Jerry and Toyama, Katsuya and Vaittinada Ayar, Pradeebane and Velo, Antón},
title = {Seasonal Variability of the Surface Ocean Carbon Cycle: A Synthesis},
journal = {Global Biogeochemical Cycles},
publisher = {American Geophysical Union (AGU)},
year = {2023},
volume = {37},
number = {9},
doi = {10.1029/2023gb007798}
}
|
| Rödenbeck C, Adcock KE, Eritt M, Gachkivskyi M, Gerbig C, Hammer S, Jordan A, Keeling RF, Levin I, Maier F, Manning AC, Moossen H, Munassar S, Pickers PA, Rothe M, Tohjima Y and Zaehle S (2023), "The suitability of atmospheric oxygen measurements to constrain western European fossil-fuel CO2 emissions and their trends", Atmospheric Chemistry and Physics., dec, 2023. Vol. 23(24), pp. 15767-15782. Copernicus GmbH. |
BibTeX:
@article{Roedenbeck2023,
author = {Rödenbeck, Christian and Adcock, Karina E and Eritt, Markus and Gachkivskyi, Maksym and Gerbig, Christoph and Hammer, Samuel and Jordan, Armin and Keeling, Ralph F and Levin, Ingeborg and Maier, Fabian and Manning, Andrew C and Moossen, Heiko and Munassar, Saqr and Pickers, Penelope A and Rothe, Michael and Tohjima, Yasunori and Zaehle, Sönke},
title = {The suitability of atmospheric oxygen measurements to constrain western European fossil-fuel CO2 emissions and their trends},
journal = {Atmospheric Chemistry and Physics},
publisher = {Copernicus GmbH},
year = {2023},
volume = {23},
number = {24},
pages = {15767--15782},
url = {http://dx.doi.org/10.5194/acp-23-15767-2023},
doi = {10.5194/acp-23-15767-2023}
}
|
| Rust D, Vollmer MK, Henne S, Bühlmann T, Frumau A, van den Bulk P, Emmenegger L, Zenobi R and Reimann S (2023), "First Atmospheric Measurements and Emission Estimates of HFO-1336mzz(Z)", Environmental Science & Technology., jul, 2023. Vol. 57(32), pp. 11903-11912. American Chemical Society (ACS). |
BibTeX:
@article{Rust2023,
author = {Rust, Dominique and Vollmer, Martin K and Henne, Stephan and Bühlmann, Tobias and Frumau, Arnoud and van den Bulk, Pim and Emmenegger, Lukas and Zenobi, Renato and Reimann, Stefan},
title = {First Atmospheric Measurements and Emission Estimates of HFO-1336mzz(Z)},
journal = {Environmental Science & Technology},
publisher = {American Chemical Society (ACS)},
year = {2023},
volume = {57},
number = {32},
pages = {11903--11912},
url = {http://dx.doi.org/10.1021/acs.est.3c01826},
doi = {10.1021/acs.est.3c01826}
}
|
| Sadiktsis I, de Oliveira Galvão MF, Mustafa M, Toublanc M, Ünlü Endirlik B, Silvergren S, Johansson C and Dreij K (2023), "A yearlong monitoring campaign of polycyclic aromatic compounds and other air pollutants at three sites in Sweden: Source identification, in vitro toxicity and human health risk assessment", Chemosphere., aug, 2023. Vol. 332, pp. 138862. Elsevier BV. |
BibTeX:
@article{Sadiktsis2023,
author = {Sadiktsis, Ioannis and de Oliveira Galvão, Marcos Felipe and Mustafa, Musatak and Toublanc, Michaël and Ünlü Endirlik, Burcu and Silvergren, Sanna and Johansson, Christer and Dreij, Kristian},
title = {A yearlong monitoring campaign of polycyclic aromatic compounds and other air pollutants at three sites in Sweden: Source identification, in vitro toxicity and human health risk assessment},
journal = {Chemosphere},
publisher = {Elsevier BV},
year = {2023},
volume = {332},
pages = {138862},
url = {http://dx.doi.org/10.1016/j.chemosphere.2023.138862},
doi = {10.1016/j.chemosphere.2023.138862}
}
|
| Sánchez-Zapero J, Camacho F, Martínez-Sánchez E, Gorroño J, León-Tavares J, Benhadj I, Toté C, Swinnen E and Muñoz-Sabater J (2023), "Global estimates of surface albedo from Sentinel-3 OLCI and SLSTR data for Copernicus Climate Change Service: Algorithm and preliminary validation", Remote Sensing of Environment., mar, 2023. Vol. 287, pp. 113460. Elsevier BV. |
BibTeX:
@article{SanchezZapero2023,
author = {Sánchez-Zapero, Jorge and Camacho, Fernando and Martínez-Sánchez, Enrique and Gorroño, Javier and León-Tavares, Jonathan and Benhadj, Iskander and Toté, Carolien and Swinnen, Else and Muñoz-Sabater, Joaquín},
title = {Global estimates of surface albedo from Sentinel-3 OLCI and SLSTR data for Copernicus Climate Change Service: Algorithm and preliminary validation},
journal = {Remote Sensing of Environment},
publisher = {Elsevier BV},
year = {2023},
volume = {287},
pages = {113460},
url = {http://dx.doi.org/10.1016/j.rse.2023.113460},
doi = {10.1016/j.rse.2023.113460}
}
|
| Sánchez-Zapero J, Martínez-Sánchez E, Camacho F, Wang Z, Carrer D, Schaaf C, García-Haro FJ, Nickeson J and Cosh M (2023), "Surface ALbedo VALidation (SALVAL) Platform: Towards CEOS LPV Validation Stage 4—Application to Three Global Albedo Climate Data Records", Remote Sensing., feb, 2023. Vol. 15(4), pp. 1081. MDPI AG. |
BibTeX:
@article{SanchezZapero2023a,
author = {Sánchez-Zapero, Jorge and Martínez-Sánchez, Enrique and Camacho, Fernando and Wang, Zhuosen and Carrer, Dominique and Schaaf, Crystal and García-Haro, Francisco Javier and Nickeson, Jaime and Cosh, Michael},
title = {Surface ALbedo VALidation (SALVAL) Platform: Towards CEOS LPV Validation Stage 4—Application to Three Global Albedo Climate Data Records},
journal = {Remote Sensing},
publisher = {MDPI AG},
year = {2023},
volume = {15},
number = {4},
pages = {1081},
url = {http://dx.doi.org/10.3390/rs15041081},
doi = {10.3390/rs15041081}
}
|
| Sándor R, Ehrhardt F, Grace P, Recous S, Smith P, Snow V, Soussana J-F, Basso B, Bhatia A, Brilli L, Doltra J, Dorich CD, Doro L, Fitton N, Grant B, Harrison MT, Skiba U, Kirschbaum MUF, Klumpp K, Laville P, Léonard J, Martin R, Massad RS, Moore AD, Myrgiotis V, Pattey E, Rolinski S, Sharp J, Smith W, Wu L, Zhang Q and Bellocchi G (2023), "Residual correlation and ensemble modelling to improve crop and grassland models", Environmental Modelling & Software., mar, 2023. Vol. 161, pp. 105625. Elsevier BV. |
BibTeX:
@article{Sandor2023,
author = {Sándor, Renáta and Ehrhardt, Fiona and Grace, Peter and Recous, Sylvie and Smith, Pete and Snow, Val and Soussana, Jean-François and Basso, Bruno and Bhatia, Arti and Brilli, Lorenzo and Doltra, Jordi and Dorich, Christopher D and Doro, Luca and Fitton, Nuala and Grant, Brian and Harrison, Matthew Tom and Skiba, Ute and Kirschbaum, Miko U F and Klumpp, Katja and Laville, Patricia and Léonard, Joel and Martin, Raphaël and Massad, Raia Silvia and Moore, Andrew D and Myrgiotis, Vasileios and Pattey, Elizabeth and Rolinski, Susanne and Sharp, Joanna and Smith, Ward and Wu, Lianhai and Zhang, Qing and Bellocchi, Gianni},
title = {Residual correlation and ensemble modelling to improve crop and grassland models},
journal = {Environmental Modelling & Software},
publisher = {Elsevier BV},
year = {2023},
volume = {161},
pages = {105625},
url = {http://dx.doi.org/10.1016/j.envsoft.2023.105625},
doi = {10.1016/j.envsoft.2023.105625}
}
|
| Schuldt KN, Aalto T, Arlyn Andrews, Arnold S, Baier B, Bergamaschi P, Biermann T, Biraud SC, Chen G, Huilin Chen, Colomb A, Commane R, Conil S, Couret C, Cristofanelli P, Daube B, Davis KJ, Delmotte M, DiGangi JP, Diskin G, Emmenegger L, Fischer ML, Forster G, Gehrlein T, Hatakka J, Heimann M, Heliasz M, Hermansen O, Hoheisel A, Holst J, Jaffe DA, Karion A, Kazan V, Keronen P, Kneuer T, Kominkova K, Kort E, Kozlova E, Krummel P, Kubistin D, Langenfelds RL, Laurent O, Laurila T, Lee J, Lehner I, Lehtinen K, Leppert R, Leskinen A, Leuenberger M, Lindauer M, Loh Z, Lopez M, Lunder CR, Mammarella I, Manca G, Marek MV, Martin MY, De Mazière M, McKain K, Meinhardt F, Miles NL, Miller CE, Miller JB, Mölder M, Müller-Williams J, Myhre CL, Obersteiner F, Petron G, Piacentino S, Pichon JM, Pickers P, Plass-Dülmer C, Platt SM, Ramonet M, Richardson SJ, Di Sarra AG, Scharfe D, Scheeren B, Schmidt M, Schumacher M, Seifert T, Sha MK, Shepson P, Sloop CD, Smith PD, Steinbacher M, Stephens B, Sweeney C, Timas H, Tørseth K, Trisolino P, Turnbull J, Viner B, Vitkova G, Watson A, Wofsy SC, Worsey J and Zahn A (2023), "Multi-laboratory compilation of atmospheric carbon monoxide data for the period 1989-2021; obspack_co_1_GLOBALVIEWplus_v3.0_2023-03-08". |
BibTeX:
@misc{Schuldt2023,
author = {Schuldt, Kenneth N and Aalto, Tuula and Arlyn Andrews and Arnold, Sabrina and Baier, Bianca and Bergamaschi, Peter and Biermann, Tobias and Biraud, Sebastien C and Chen, Gao and Huilin Chen and Colomb, Aurelie and Commane, Roisin and Conil, Sébastien and Couret, Cédric and Cristofanelli, Paolo and Daube, Bruce and Davis, Kenneth J and Delmotte, Marc and DiGangi, Joshua P and Diskin, Glenn and Emmenegger, Lukas and Fischer, Marc L and Forster, Grant and Gehrlein, Torsten and Hatakka, Juha and Heimann, Martin and Heliasz, Michal and Hermansen, Ove and Hoheisel, Antje and Holst, Jutta and Jaffe, Daniel A and Karion, Anna and Kazan, Victor and Keronen, Petri and Kneuer, Tobias and Kominkova, Katerina and Kort, Eric and Kozlova, Elena and Krummel, Paul and Kubistin, Dagmar and Langenfelds, Ray L and Laurent, Olivier and Laurila, Tuomas and Lee, John and Lehner, Irene and Lehtinen, Kari and Leppert, Reimo and Leskinen, Ari and Leuenberger, Markus and Lindauer, Matthias and Loh, Zoe and Lopez, Morgan and Lunder, Chris René and Mammarella, Ivan and Manca, Giovanni and Marek, Michal V and Martin, Melissa Yang and De Mazière, Martine and McKain, Kathryn and Meinhardt, Frank and Miles, Natasha L and Miller, Charles E and Miller, John B and Mölder, Meelis and Müller-Williams, Jennifer and Myhre, Cathrine Lund and Obersteiner, Florian and Petron, Gabrielle and Piacentino, Salvatore and Pichon, Jean Marc and Pickers, Penelope and Plass-Dülmer, Christian and Platt, Stephen Matthew and Ramonet, Michel and Richardson, Scott J and Di Sarra, Alcide Giorgio and Scharfe, Dieter and Scheeren, Bert and Schmidt, Martina and Schumacher, Marcus and Seifert, Thomas and Sha, Mahesh Kumar and Shepson, Paul and Sloop, Christopher D and Smith, Paul D and Steinbacher, Martin and Stephens, Britton and Sweeney, Colm and Timas, Helder and Tørseth, Kjetil and Trisolino, Pamela and Turnbull, Jocelyn and Viner, Brian and Vitkova, Gabriela and Watson, Andrew and Wofsy, Steven C and Worsey, Justin and Zahn, Andreas},
title = {Multi-laboratory compilation of atmospheric carbon monoxide data for the period 1989-2021; obspack_co_1_GLOBALVIEWplus_v3.0_2023-03-08},
publisher = {NOAA Global Monitoring Laboratory},
year = {2023},
url = {https://gml.noaa.gov/ccgg/obspack/data.php?id=obspack_co_1_GLOBALVIEWplus_v3.0_2022-03-08},
doi = {10.25925/20221201}
}
|
| Schuldt KN, Mund J, Aalto T, Abshire JB, Aikin K, Allen G, Arlyn Andrews, Apadula F, Arnold S, Baier B, Bakwin P, Bäni L, Bartyzel J, Bentz G, Bergamaschi P, Beyersdorf A, Biermann T, Biraud SC, Pierre-Eric Blanc, Boenisch H, Bowling D, Brailsford G, Brand WA, Brunner D, Bui TPV, Van Den Bulk P, Francescopiero Calzolari, Chang CS, Chen G, Huilin Chen, Lukasz Chmura, St. Clair JM, Clark S, Sites Climadat, Coletta JD, Colomb A, Commane R, Condori L, Conen F, Conil S, Couret C, Cristofanelli P, Cuevas E, Curcoll R, Daube B, Davis KJ, Dean-Day JM, Delmotte M, Dickerson R, DiGangi E, DiGangi JP, Van Dinther D, Elkins JW, Elsasser M, Emmenegger L, Shuangxi Fang, Fischer ML, Forster G, France J, Frumau A, Fuente-Lastra M, Galkowski M, Gatti LV, Gehrlein T, Gerbig C, Francois Gheusi, Gloor E, Goto D, Griffis T, Hammer S, Hanisco TF, Hanson C, Haszpra L, Hatakka J, Heimann M, Heliasz M, Heltai D, Henne S, Hensen A, Hermans C, Hermansen O, Hintsa E, Hoheisel A, Holst J, Di Iorio T, Iraci LT, Ivakhov V, Jaffe DA, Jordan A, Joubert W, Kang H-Y, Karion A, Kawa SR, Kazan V, Keeling RF, Keronen P, Jooil Kim, Klausen J, Kneuer T, Ko M-Y, Kolari P, Kominkova K, Kort E, Kozlova E, Krummel PB, Kubistin D, Kulawik SS, Kumps N, Labuschagne C, Lam DHY, Lan X, Langenfelds RL, Lanza A, Laurent O, Laurila T, Lauvaux T, Lavric J, Law BE, Choong-Hoon Lee, Haeyoung Lee, Lee J, Lehner I, Lehtinen K, Leppert R, Leskinen A, Leuenberger M, W.H. Leung, Levin I, Levula J, Lin J, Lindauer M, Lindroth A, Mikaell Ottosson Löfvenius, Loh ZM, Lopez M, Lunder CR, Machida T, Mammarella I, Manca G, Manning A, Manning A, Marek MV, Marklund P, Marrero JE, Martin D, Martin MY, Giordane A. Martins, Matsueda H, De Mazière M, McKain K, Meijer H, Meinhardt F, Merchant L, Jean-Marc Metzger, N. Mihalopoulos, Miles NL, Miller CE, Miller JB, Mitchell L, Mölder M, Monteiro V, Montzka S, Moore F, Moossen H, Morgan E, Josep-Anton Morgui, Morimoto S, Müller-Williams J, J. William Munger, Munro D, Mutuku M, Myhre CL, Shin-Ichiro Nakaoka, Jaroslaw Necki, Newman S, Nichol S, Nisbet E, Niwa Y, Njiru DM, Noe SM, Nojiri Y, O'Doherty S, Obersteiner F, Paplawsky B, Parworth CL, Peischl J, Peltola O, Peters W, Philippon C, Piacentino S, Pichon JM, Pickers P, Piper S, Pitt J, Plass-Dülmer C, Platt SM, Prinzivalli S, Ramonet M, Ramos R, Xinrong Ren, Reyes-Sanchez E, Richardson SJ, Louis-Jeremy Rigouleau, Riris H, Rivas PP, Rothe M, Yves-Alain Roulet, Ryerson T, Ju-Mee Ryoo, Sargent M, Di Sarra AG, Sasakawa M, Scheeren B, Schmidt M, Schuck T, Schumacher M, Seibel J, Seifert T, Sha MK, Shepson P, Shook M, Sloop CD, Smith PD, Sørensen LL, De Souza RAF, Spain G, Steger D, Steinbacher M, Stephens B, Sweeney C, Taipale R, Takatsuji S, Tans P, Thoning K, Timas H, Torn M, Trisolino P, Turnbull J, Vermeulen A, Viner B, Vitkova G, Walker S, Watson A, Weiss R, De Wekker S, Weyrauch D, Wofsy SC, Worsey J, Worthy D, Xueref-Remy I, Yates EL, Dickon Young, Yver-Kwok C, Zaehle S, Zahn A, Zellweger C and Miroslaw Zimnoch (2023), "Multi-laboratory compilation of atmospheric carbon dioxide data for the period 1957-2022; obspack_co2_1_GLOBALVIEWplus_v9.1_2023-12-08". |
BibTeX:
@misc{Schuldt2023a,
author = {Schuldt, Kenneth N and Mund, John and Aalto, Tuula and Abshire, James Brice and Aikin, Ken and Allen, Grant and Arlyn Andrews and Apadula, Francesco and Arnold, Sabrina and Baier, Bianca and Bakwin, Peter and Bäni, Lukas and Bartyzel, Jakub and Bentz, Gilles and Bergamaschi, Peter and Beyersdorf, Andreas and Biermann, Tobias and Biraud, Sebastien C and Pierre-Eric Blanc and Boenisch, Harald and Bowling, David and Brailsford, Gordon and Brand, Willi A and Brunner, Dominik and Bui, Thao Paul V and Van Den Bulk, Pim and Francescopiero Calzolari and Chang, Cecilia S and Chen, Gao and Huilin Chen and Lukasz Chmura and St. Clair, Jason M and Clark, Shane and Sites Climadat and Coletta, Julian Della and Colomb, Aurelie and Commane, Roisin and Condori, Lino and Conen, Franz and Conil, Sébastien and Couret, Cédric and Cristofanelli, Paolo and Cuevas, Emilio and Curcoll, Roger and Daube, Bruce and Davis, Kenneth J and Dean-Day, Jonathan M and Delmotte, Marc and Dickerson, Russell and DiGangi, Elizabeth and DiGangi, Joshua P and Van Dinther, Danielle and Elkins, James W and Elsasser, Michael and Emmenegger, Lukas and Shuangxi Fang and Fischer, Marc L and Forster, Grant and France, James and Frumau, Arnoud and Fuente-Lastra, Marta and Galkowski, Michal and Gatti, Luciana V and Gehrlein, Torsten and Gerbig, Christoph and Francois Gheusi and Gloor, Emanuel and Goto, Daisuke and Griffis, Tim and Hammer, Samuel and Hanisco, Thomas F and Hanson, Chad and Haszpra, László and Hatakka, Juha and Heimann, Martin and Heliasz, Michal and Heltai, Daniela and Henne, Stephan and Hensen, Arjan and Hermans, Christian and Hermansen, Ove and Hintsa, Eric and Hoheisel, Antje and Holst, Jutta and Di Iorio, Tatiana and Iraci, Laura T and Ivakhov, Viktor and Jaffe, Daniel A and Jordan, Armin and Joubert, Warren and Kang, Hui-Yun and Karion, Anna and Kawa, Stephan Randolph and Kazan, Victor and Keeling, Ralph F and Keronen, Petri and Jooil Kim and Klausen, Jörg and Kneuer, Tobias and Ko, Mi-Young and Kolari, Pasi and Kominkova, Katerina and Kort, Eric and Kozlova, Elena and Krummel, Paul B and Kubistin, Dagmar and Kulawik, Susan S and Kumps, Nicolas and Labuschagne, Casper and Lam, David H Y and Lan, Xin and Langenfelds, Ray L and Lanza, Andrea and Laurent, Olivier and Laurila, Tuomas and Lauvaux, Thomas and Lavric, Jost and Law, Beverly E and Choong-Hoon Lee and Haeyoung Lee and Lee, John and Lehner, Irene and Lehtinen, Kari and Leppert, Reimo and Leskinen, Ari and Leuenberger, Markus and W.H. Leung and Levin, Ingeborg and Levula, Janne and Lin, John and Lindauer, Matthias and Lindroth, Anders and Mikaell Ottosson Löfvenius and Loh, Zoe M and Lopez, Morgan and Lunder, Chris René and Machida, Toshinobu and Mammarella, Ivan and Manca, Giovanni and Manning, Alistair and Manning, Andrew and Marek, Michal V and Marklund, Per and Marrero, Josette E and Martin, Damien and Martin, Melissa Yang and Giordane A. Martins and Matsueda, Hidekazu and De Mazière, Martine and McKain, Kathryn and Meijer, Harro and Meinhardt, Frank and Merchant, Lynne and Jean-Marc Metzger and N. Mihalopoulos and Miles, Natasha L and Miller, Charles E and Miller, John B and Mitchell, Logan and Mölder, Meelis and Monteiro, Vanessa and Montzka, Stephen and Moore, Fred and Moossen, Heiko and Morgan, Eric and Josep-Anton Morgui and Morimoto, Shinji and Müller-Williams, Jennifer and J. William Munger and Munro, David and Mutuku, Mathew and Myhre, Cathrine Lund and Shin-Ichiro Nakaoka and Jaroslaw Necki and Newman, Sally and Nichol, Sylvia and Nisbet, Euan and Niwa, Yosuke and Njiru, David Murithi and Noe, Steffen Manfred and Nojiri, Yukihiro and O'Doherty, Simon and Obersteiner, Florian and Paplawsky, Bill and Parworth, Caroline L and Peischl, Jeff and Peltola, Olli and Peters, Wouter and Philippon, Carole and Piacentino, Salvatore and Pichon, Jean Marc and Pickers, Penelope and Piper, Steve and Pitt, Joseph and Plass-Dülmer, Christian and Platt, Stephen Matthew and Prinzivalli, Steve and Ramonet, Michel and Ramos, Ramon and Xinrong Ren and Reyes-Sanchez, Enrique and Richardson, Scott J and Louis-Jeremy Rigouleau and Riris, Haris and Rivas, Pedro P and Rothe, Michael and Yves-Alain Roulet and Ryerson, Thomas and Ju-Mee Ryoo and Sargent, Maryann and Di Sarra, Alcide Giorgio and Sasakawa, Motoki and Scheeren, Bert and Schmidt, Martina and Schuck, Tanja and Schumacher, Marcus and Seibel, Jennifer and Seifert, Thomas and Sha, Mahesh Kumar and Shepson, Paul and Shook, Michael and Sloop, Christopher D and Smith, Paul D and Sørensen, Lise Lotte and De Souza, Rodrigo A F and Spain, Gerard and Steger, David and Steinbacher, Martin and Stephens, Britton and Sweeney, Colm and Taipale, Risto and Takatsuji, Shinya and Tans, Pieter and Thoning, Kirk and Timas, Helder and Torn, Margaret and Trisolino, Pamela and Turnbull, Jocelyn and Vermeulen, Alex and Viner, Brian and Vitkova, Gabriela and Walker, Stephen and Watson, Andrew and Weiss, Ray and De Wekker, Stephan and Weyrauch, Dietmar and Wofsy, Steven C and Worsey, Justin and Worthy, Doug and Xueref-Remy, Irène and Yates, Emma L and Dickon Young and Yver-Kwok, Camille and Zaehle, Sönke and Zahn, Andreas and Zellweger, Christoph and Miroslaw Zimnoch},
title = {Multi-laboratory compilation of atmospheric carbon dioxide data for the period 1957-2022; obspack_co2_1_GLOBALVIEWplus_v9.1_2023-12-08},
publisher = {NOAA Global Monitoring Laboratory},
year = {2023},
url = {https://gml.noaa.gov/ccgg/obspack/data.php?id=obspack_co2_1_GLOBALVIEWplus_v9.1_2023-12-08},
doi = {10.25925/20231201}
}
|
| Schuldt KN, Mund J, Aalto T, Arlyn Andrews, Apadula F, Jgor Arduini, Arnold S, Baier B, Bäni L, Bartyzel J, Bergamaschi P, Biermann T, Biraud SC, Pierre-Eric Blanc, Boenisch H, Brailsford G, Brand WA, Brunner D, Bui TPV, Van Den Bulk P, Francescopiero Calzolari, Chang CS, Huilin Chen, Lukasz Chmura, St. Clair JM, Sites Climadat, Coletta JD, Colomb A, Condori L, Conen F, Conil S, Couret C, Cristofanelli P, Cuevas E, Curcoll R, Daube B, Davis KJ, Dean-Day JM, Delmotte M, Ankur Desai, DiGangi E, DiGangi JP, Van Dinther D, Elkins JW, Elsasser M, Emmenegger L, Fischer ML, Forster G, Frumau A, Fuente-Lastra M, Galkowski M, Gatti LV, Gehrlein T, Gerbig C, Francois Gheusi, Gloor E, Goto D, Hammer S, Hanisco TF, Haszpra L, Hatakka J, Heimann M, Heimann M, Heliasz M, Heltai D, Henne S, Hensen A, Hermans C, Hermansen O, Hintsa E, Hoheisel A, Holst J, Di Iorio T, Iraci LT, Ivakhov V, Jaffe DA, Jordan A, Joubert W, Kang H-Y, Karion A, Kazan V, Keeling RF, Keronen P, Kers B, Jooil Kim, Klausen J, Kneuer T, Ko M-Y, Kolari P, Kominkova K, Kort E, Kozlova E, Krummel PB, Kubistin D, Kulawik SS, Kumps N, Labuschagne C, Lan X, Langenfelds RL, Lanza A, Laurent O, Laurila T, Lauvaux T, Lavric J, Choong-Hoon Lee, Haeyoung Lee, Lee J, Lehner I, Lehtinen K, Leppert R, Leskinen A, Leuenberger M, Levin I, Levula J, Lindauer M, Lindroth A, Mikaell Ottosson Löfvenius, Loh ZM, Lopez M, Lowry D, Lunder CR, Machida T, Mammarella I, Manca G, Manning A, Marek MV, Marklund P, Marrero JE, Martin D, Martin MY, Giordane A. Martins, Matsueda H, De Mazière M, McKain K, Meinhardt F, Menoud M, Jean-Marc Metzger, Miles NL, Miller CE, Miller JB, Mölder M, Monteiro V, Montzka S, Moore F, Moossen H, Morgan E, Josep-Anton Morgui, Morimoto S, Müller-Williams J, Munro D, Mutuku M, Myhre CL, Jaroslaw Necki, Nichol S, Nisbet E, Niwa Y, Njiru DM, Noe SM, O'Doherty S, Obersteiner F, Parworth CL, Peltola O, Peters W, Philippon C, Piacentino S, Pichon JM, Pickers P, Pitt J, Pittman J, Plass-Dülmer C, Platt SM, Popa ME, Prinzivalli S, Ramonet M, Richardson SJ, Louis-Jeremy Rigouleau, Rivas PP, Röckmann T, Rothe M, Yves-Alain Roulet, Ju-Mee Ryoo, Santoni G, Di Sarra AG, Sasakawa M, Scheeren B, Schmidt M, Schuck T, Schumacher M, Seifert T, Sha MK, Shepson P, Sloop CD, Smith PD, Sørensen LL, De Souza RAF, Spain G, Steger D, Steinbacher M, Stephens B, Sweeney C, Taipale R, Takatsuji S, Thoning K, Timas H, Torn M, Trisolino P, Turnbull J, Van Der Veen C, Vermeulen A, Vimont I, Viner B, Vitkova G, De Vries M, Watson A, Weiss R, Weyrauch D, Wofsy SC, Worsey J, Worthy D, Xueref-Remy I, Yates EL, Dickon Young, Yver-Kwok C, Zaehle S, Zahn A, Zazzeri G, Zellweger C and Miroslaw Zimnoch (2023), "Multi-laboratory compilation of atmospheric carbon dioxide data for the period 1983-2022; obspack_ch4_1_GLOBALVIEWplus_v6.0_2023-12-01". |
BibTeX:
@misc{Schuldt2023b,
author = {Schuldt, Kenneth N and Mund, John and Aalto, Tuula and Arlyn Andrews and Apadula, Francesco and Jgor Arduini and Arnold, Sabrina and Baier, Bianca and Bäni, Lukas and Bartyzel, Jakub and Bergamaschi, Peter and Biermann, Tobias and Biraud, Sebastien C and Pierre-Eric Blanc and Boenisch, Harald and Brailsford, Gordon and Brand, Willi A and Brunner, Dominik and Bui, Thao Paul V and Van Den Bulk, Pim and Francescopiero Calzolari and Chang, Cecilia S and Huilin Chen and Lukasz Chmura and St. Clair, Jason M and Sites Climadat and Coletta, Julian Della and Colomb, Aurelie and Condori, Lino and Conen, Franz and Conil, Sébastien and Couret, Cédric and Cristofanelli, Paolo and Cuevas, Emilio and Curcoll, Roger and Daube, Bruce and Davis, Kenneth J and Dean-Day, Jonathan M and Delmotte, Marc and Ankur Desai and DiGangi, Elizabeth and DiGangi, Joshua P and Van Dinther, Danielle and Elkins, James W and Elsasser, Michael and Emmenegger, Lukas and Fischer, Marc L and Forster, Grant and Frumau, Arnoud and Fuente-Lastra, Marta and Galkowski, Michal and Gatti, Luciana V and Gehrlein, Torsten and Gerbig, Christoph and Francois Gheusi and Gloor, Emanuel and Goto, Daisuke and Hammer, Samuel and Hanisco, Thomas F and Haszpra, László and Hatakka, Juha and Heimann, Martin and Heimann, Martin and Heliasz, Michal and Heltai, Daniela and Henne, Stephan and Hensen, Arjan and Hermans, Christian and Hermansen, Ove and Hintsa, Eric and Hoheisel, Antje and Holst, Jutta and Di Iorio, Tatiana and Iraci, Laura T and Ivakhov, Viktor and Jaffe, Daniel A and Jordan, Armin and Joubert, Warren and Kang, Hui-Yun and Karion, Anna and Kazan, Victor and Keeling, Ralph F and Keronen, Petri and Kers, Bert and Jooil Kim and Klausen, Jörg and Kneuer, Tobias and Ko, Mi-Young and Kolari, Pasi and Kominkova, Katerina and Kort, Eric and Kozlova, Elena and Krummel, Paul B and Kubistin, Dagmar and Kulawik, Susan S and Kumps, Nicolas and Labuschagne, Casper and Lan, Xin and Langenfelds, Ray L and Lanza, Andrea and Laurent, Olivier and Laurila, Tuomas and Lauvaux, Thomas and Lavric, Jost and Choong-Hoon Lee and Haeyoung Lee and Lee, John and Lehner, Irene and Lehtinen, Kari and Leppert, Reimo and Leskinen, Ari and Leuenberger, Markus and Levin, Ingeborg and Levula, Janne and Lindauer, Matthias and Lindroth, Anders and Mikaell Ottosson Löfvenius and Loh, Zoe M and Lopez, Morgan and Lowry, David and Lunder, Chris René and Machida, Toshinobu and Mammarella, Ivan and Manca, Giovanni and Manning, Alistair and Marek, Michal V and Marklund, Per and Marrero, Josette E and Martin, Damien and Martin, Melissa Yang and Giordane A. Martins and Matsueda, Hidekazu and De Mazière, Martine and McKain, Kathryn and Meinhardt, Frank and Menoud, Malika and Jean-Marc Metzger and Miles, Natasha L and Miller, Charles E and Miller, John B and Mölder, Meelis and Monteiro, Vanessa and Montzka, Stephen and Moore, Fred and Moossen, Heiko and Morgan, Eric and Josep-Anton Morgui and Morimoto, Shinji and Müller-Williams, Jennifer and Munro, David and Mutuku, Mathew and Myhre, Cathrine Lund and Jaroslaw Necki and Nichol, Sylvia and Nisbet, Euan and Niwa, Yosuke and Njiru, David Murithi and Noe, Steffen Manfred and O'Doherty, Simon and Obersteiner, Florian and Parworth, Caroline L and Peltola, Olli and Peters, Wouter and Philippon, Carole and Piacentino, Salvatore and Pichon, Jean Marc and Pickers, Penelope and Pitt, Joseph and Pittman, Jasna and Plass-Dülmer, Christian and Platt, Stephen Matthew and Popa, Maria Elena and Prinzivalli, Steve and Ramonet, Michel and Richardson, Scott J and Louis-Jeremy Rigouleau and Rivas, Pedro P and Röckmann, Thomas and Rothe, Michael and Yves-Alain Roulet and Ju-Mee Ryoo and Santoni, Greg and Di Sarra, Alcide Giorgio and Sasakawa, Motoki and Scheeren, Bert and Schmidt, Martina and Schuck, Tanja and Schumacher, Marcus and Seifert, Thomas and Sha, Mahesh Kumar and Shepson, Paul and Sloop, Christopher D and Smith, Paul D and Sørensen, Lise Lotte and De Souza, Rodrigo A F and Spain, Gerard and Steger, David and Steinbacher, Martin and Stephens, Britton and Sweeney, Colm and Taipale, Risto and Takatsuji, Shinya and Thoning, Kirk and Timas, Helder and Torn, Margaret and Trisolino, Pamela and Turnbull, Jocelyn and Van Der Veen, Carina and Vermeulen, Alex and Vimont, Isaac and Viner, Brian and Vitkova, Gabriela and De Vries, Marcel and Watson, Andrew and Weiss, Ray and Weyrauch, Dietmar and Wofsy, Steven C and Worsey, Justin and Worthy, Doug and Xueref-Remy, Irène and Yates, Emma L and Dickon Young and Yver-Kwok, Camille and Zaehle, Sönke and Zahn, Andreas and Zazzeri, Giulia and Zellweger, Christoph and Miroslaw Zimnoch},
title = {Multi-laboratory compilation of atmospheric carbon dioxide data for the period 1983-2022; obspack_ch4_1_GLOBALVIEWplus_v6.0_2023-12-01},
publisher = {NOAA Global Monitoring Laboratory},
year = {2023},
url = {https://gml.noaa.gov/ccgg/obspack/data.php?id=obspack_ch4_1_GLOBALVIEWplus_v6.0_2023-12-01},
doi = {10.25925/20231001}
}
|
| Schulz G, Sanders T, Voynova YG, Bange HW and Dähnke K (2023), "Seasonal variability of nitrous oxide concentrations and emissions in a temperate estuary", Biogeosciences., aug, 2023. Vol. 20(15), pp. 3229-3247. Copernicus GmbH. |
BibTeX:
@article{Schulz2023,
author = {Schulz, Gesa and Sanders, Tina and Voynova, Yoana G and Bange, Hermann W and Dähnke, Kirstin},
title = {Seasonal variability of nitrous oxide concentrations and emissions in a temperate estuary},
journal = {Biogeosciences},
publisher = {Copernicus GmbH},
year = {2023},
volume = {20},
number = {15},
pages = {3229--3247},
url = {http://dx.doi.org/10.5194/bg-20-3229-2023},
doi = {10.5194/bg-20-3229-2023}
}
|
| Shekhar A, Hörtnagl L, Buchmann N and Gharun M (2023), "Long‐term changes in forest response to extreme atmospheric dryness", Global Change Biology., jun, 2023. Vol. 29(18), pp. 5379-5396. Wiley. |
BibTeX:
@article{Shekhar2023,
author = {Shekhar, Ankit and Hörtnagl, Lukas and Buchmann, Nina and Gharun, Mana},
title = {Long‐term changes in forest response to extreme atmospheric dryness},
journal = {Global Change Biology},
publisher = {Wiley},
year = {2023},
volume = {29},
number = {18},
pages = {5379--5396},
url = {http://dx.doi.org/10.1111/gcb.16846},
doi = {10.1111/gcb.16846}
}
|
| Sironić A, Hess E, Barešić J, Kanduč T, Borković D and Krajcar Bronić I (2023), "ATMOSPHERIC CO2 CARBON ISOTOPE COMPOSITION IN URBAN AND CLEAN AREAS OF THE NORTHERN ADRIATIC COAST OF CROATIA", Radiocarbon., sep, 2023. , pp. 1-17. Cambridge University Press (CUP). |
BibTeX:
@article{Sironic2023,
author = {Sironić, Andreja and Hess, Emma and Barešić, Jadranka and Kanduč, Tjaša and Borković, Damir and Krajcar Bronić, Ines},
title = {ATMOSPHERIC CO2 CARBON ISOTOPE COMPOSITION IN URBAN AND CLEAN AREAS OF THE NORTHERN ADRIATIC COAST OF CROATIA},
journal = {Radiocarbon},
publisher = {Cambridge University Press (CUP)},
year = {2023},
pages = {1--17},
url = {http://dx.doi.org/10.1017/RDC.2023.72},
doi = {10.1017/rdc.2023.72}
}
|
| Skeie RB, Hodnebrog Ø and Myhre G (2023), "Trends in atmospheric methane concentrations since 1990 were driven and modified by anthropogenic emissions", Communications Earth & Environment., sep, 2023. Vol. 4(1) Springer Science and Business Media LLC. |
BibTeX:
@article{Skeie2023,
author = {Skeie, Ragnhild Bieltvedt and Hodnebrog, Øivind and Myhre, Gunnar},
title = {Trends in atmospheric methane concentrations since 1990 were driven and modified by anthropogenic emissions},
journal = {Communications Earth & Environment},
publisher = {Springer Science and Business Media LLC},
year = {2023},
volume = {4},
number = {1},
url = {http://dx.doi.org/10.1038/s43247-023-00969-1},
doi = {10.1038/s43247-023-00969-1}
}
|
| Smith MM, Angot H, Chamberlain EJ, Droste ES, Karam S, Muilwijk M, Webb AL, Archer SD, Beck I, Blomquist BW, Bowman J, Boyer M, Bozzato D, Chierici M, Creamean J, D'Angelo A, Delille B, Fer I, Fong AA, Fransson A, Fuchs N, Gardner J, Granskog MA, Hoppe CJM, Hoppema M, Hoppmann M, Mock T, Muller S, Müller O, Nicolaus M, Nomura D, Petäjä T, Salganik E, Schmale J, Schmidt K, Schulz KM, Shupe MD, Stefels J, Thielke L, Tippenhauer S, Ulfsbo A, van Leeuwe M, Webster M, Yoshimura M and Zhan L (2023), "Thin and transient meltwater layers and false bottoms in the Arctic sea ice pack—Recent insights on these historically overlooked features", Elem Sci Anth. Vol. 11(1) University of California Press. |
BibTeX:
@article{Smith2023,
author = {Smith, Madison M and Angot, Hélène and Chamberlain, Emelia J and Droste, Elise S and Karam, Salar and Muilwijk, Morven and Webb, Alison L and Archer, Stephen D and Beck, Ivo and Blomquist, Byron W and Bowman, Jeff and Boyer, Matthew and Bozzato, Deborah and Chierici, Melissa and Creamean, Jessie and D'Angelo, Alessandra and Delille, Bruno and Fer, Ilker and Fong, Allison A and Fransson, Agneta and Fuchs, Niels and Gardner, Jessie and Granskog, Mats A and Hoppe, Clara J M and Hoppema, Mario and Hoppmann, Mario and Mock, Thomas and Muller, Sofia and Müller, Oliver and Nicolaus, Marcel and Nomura, Daiki and Petäjä, Tuukka and Salganik, Evgenii and Schmale, Julia and Schmidt, Katrin and Schulz, Kirstin M and Shupe, Matthew D and Stefels, Jacqueline and Thielke, Linda and Tippenhauer, Sandra and Ulfsbo, Adam and van Leeuwe, Maria and Webster, Melinda and Yoshimura, Masaki and Zhan, Liyang},
title = {Thin and transient meltwater layers and false bottoms in the Arctic sea ice pack—Recent insights on these historically overlooked features},
journal = {Elem Sci Anth},
publisher = {University of California Press},
year = {2023},
volume = {11},
number = {1},
url = {http://dx.doi.org/10.1525/elementa.2023.00025},
doi = {10.1525/elementa.2023.00025}
}
|
| Stagakis S, Feigenwinter C, Vogt R, Brunner D and Kalberer M (2023), "A high-resolution monitoring approach of urban CO2 fluxes. Part 2 – surface flux optimisation using eddy covariance observations", Science of The Total Environment., dec, 2023. Vol. 903, pp. 166035. Elsevier BV. |
BibTeX:
@article{Stagakis2023,
author = {Stagakis, Stavros and Feigenwinter, Christian and Vogt, Roland and Brunner, Dominik and Kalberer, Markus},
title = {A high-resolution monitoring approach of urban CO2 fluxes. Part 2 – surface flux optimisation using eddy covariance observations},
journal = {Science of The Total Environment},
publisher = {Elsevier BV},
year = {2023},
volume = {903},
pages = {166035},
url = {http://dx.doi.org/10.1016/j.scitotenv.2023.166035},
doi = {10.1016/j.scitotenv.2023.166035}
}
|
| Stagakis S, Feigenwinter C, Vogt R and Kalberer M (2023), "diFUME eddy covariance dataset". |
BibTeX:
@misc{Stagakis2023a,
author = {Stagakis, Stavros and Feigenwinter, Christian and Vogt, Roland and Kalberer, Markus},
title = {diFUME eddy covariance dataset},
publisher = {Zenodo},
year = {2023},
url = {https://zenodo.org/doi/10.5281/zenodo.7573528},
doi = {10.5281/ZENODO.7573528}
}
|
| Stagakis S, Feigenwinter C, Vogt R, Kalberer M and Brunner D (2023), "diFUME Modeled CO2 fluxes V03". |
BibTeX:
@misc{Stagakis2023b,
author = {Stagakis, Stavros and Feigenwinter, Christian and Vogt, Roland and Kalberer, Markus and Brunner, Dominik},
title = {diFUME Modeled CO2 fluxes V03},
publisher = {Zenodo},
year = {2023},
url = {https://zenodo.org/doi/10.5281/zenodo.7875386},
doi = {10.5281/ZENODO.7875386}
}
|
| Storm I, Karstens U, D'Onofrio C, Vermeulen A and Peters W (2023), "A view of the European carbon flux landscape through the lens of the ICOS atmospheric observation network", Atmospheric Chemistry and Physics., may, 2023. Vol. 23(9), pp. 4993-5008. Copernicus GmbH. |
BibTeX:
@article{Storm2023,
author = {Storm, Ida and Karstens, Ute and D'Onofrio, Claudio and Vermeulen, Alex and Peters, Wouter},
title = {A view of the European carbon flux landscape through the lens of the ICOS atmospheric observation network},
journal = {Atmospheric Chemistry and Physics},
publisher = {Copernicus GmbH},
year = {2023},
volume = {23},
number = {9},
pages = {4993--5008},
url = {http://dx.doi.org/10.5194/acp-23-4993-2023},
doi = {10.5194/acp-23-4993-2023}
}
|
| Svensson N, Lundberg J, Janhäll S, Kulovuori S and Gustafsson M (2023), "Effects of a porous asphalt pavement on dust suspension and PM10 concentration", Transportation Research Part D: Transport and Environment., oct, 2023. Vol. 123, pp. 103921. Elsevier BV. |
BibTeX:
@article{Svensson2023,
author = {Svensson, Nina and Lundberg, Joacim and Janhäll, Sara and Kulovuori, Sami and Gustafsson, Mats},
title = {Effects of a porous asphalt pavement on dust suspension and PM10 concentration},
journal = {Transportation Research Part D: Transport and Environment},
publisher = {Elsevier BV},
year = {2023},
volume = {123},
pages = {103921},
url = {http://dx.doi.org/10.1016/j.trd.2023.103921},
doi = {10.1016/j.trd.2023.103921}
}
|
| Tang ACI, Flechard CR, Arriga N, Papale D, Stoy PC, Buchmann N, Cuntz M, Douros J, Fares S, Knohl A, Šigut L, Simioni G, Timmermans R, Grünwald T, Ibrom A, Loubet B, Mammarella I, Belelli Marchesini L, Nilsson M, Peichl M, Rebmann C, Schmidt M, Bernhofer C, Berveiller D, Cremonese E, El-Madany TS, Gharun M, Gianelle D, Hörtnagl L, Roland M, Varlagin A, Fu Z, Heinesch B, Janssens I, Kowalska N, Dušek J, Gerosa G, Mölder M, Tuittila E-S and Loustau D (2023), "Detection and attribution of an anomaly in terrestrial photosynthesis in Europe during the COVID-19 lockdown", Science of The Total Environment., dec, 2023. Vol. 903, pp. 166149. Elsevier BV. |
BibTeX:
@article{Tang2023,
author = {Tang, Angela Che Ing and Flechard, Christophe R and Arriga, Nicola and Papale, Dario and Stoy, Paul C and Buchmann, Nina and Cuntz, Matthias and Douros, John and Fares, Silvano and Knohl, Alexander and Šigut, Ladislav and Simioni, Guillaume and Timmermans, Renske and Grünwald, Thomas and Ibrom, Andreas and Loubet, Benjamin and Mammarella, Ivan and Belelli Marchesini, Luca and Nilsson, Mats and Peichl, Matthias and Rebmann, Corinna and Schmidt, Marius and Bernhofer, Christian and Berveiller, Daniel and Cremonese, Edoardo and El-Madany, Tarek S and Gharun, Mana and Gianelle, Damiano and Hörtnagl, Lukas and Roland, Marilyn and Varlagin, Andrej and Fu, Zheng and Heinesch, Bernard and Janssens, Ivan and Kowalska, Natalia and Dušek, Jiří and Gerosa, Giacomo and Mölder, Meelis and Tuittila, Eeva-Stiina and Loustau, Denis},
title = {Detection and attribution of an anomaly in terrestrial photosynthesis in Europe during the COVID-19 lockdown},
journal = {Science of The Total Environment},
publisher = {Elsevier BV},
year = {2023},
volume = {903},
pages = {166149},
url = {http://dx.doi.org/10.1016/J.SCITOTENV.2023.166149},
doi = {10.1016/j.scitotenv.2023.166149}
}
|
| Tenkanen MK, Tsuruta A, Tyystjärvi V, Törmä M, Autio I, Haakana M, Tuomainen T, Leppänen A, Markkanen T, Raivonen M, Niinistö S, Arslan AN and Aalto T (2023), "Using Atmospheric Inverse Modelling of Methane Budgets with Copernicus Land Water and Wetness Data to Detect Land Use-Related Emissions", Remote Sensing., dec, 2023. Vol. 16(1), pp. 124. MDPI AG. |
BibTeX:
@article{Tenkanen2023,
author = {Tenkanen, Maria K and Tsuruta, Aki and Tyystjärvi, Vilna and Törmä, Markus and Autio, Iida and Haakana, Markus and Tuomainen, Tarja and Leppänen, Antti and Markkanen, Tiina and Raivonen, Maarit and Niinistö, Sini and Arslan, Ali Nadir and Aalto, Tuula},
title = {Using Atmospheric Inverse Modelling of Methane Budgets with Copernicus Land Water and Wetness Data to Detect Land Use-Related Emissions},
journal = {Remote Sensing},
publisher = {MDPI AG},
year = {2023},
volume = {16},
number = {1},
pages = {124},
url = {http://dx.doi.org/10.3390/rs16010124},
doi = {10.3390/rs16010124}
}
|
| Tikkasalo O-P, Leppä K, Launiainen S, Peltoniemi M, Mäkipää R, Rinne-Garmston KT, Sahlstedt E, Young GHF, Bokareva A, Lohila A, Korkiakoski M, Schiestl-Aalto P and Lehtonen A (2023), "Modeling the response of Norway spruce tree-ring carbon and oxygen isotopes to selection harvest on a drained peatland forest", Tree Physiology., sep, 2023. Vol. 44(1) Oxford University Press (OUP). |
BibTeX:
@article{Tikkasalo2023,
author = {Tikkasalo, Olli-Pekka and Leppä, Kersti and Launiainen, Samuli and Peltoniemi, Mikko and Mäkipää, Raisa and Rinne-Garmston, Katja T and Sahlstedt, Elina and Young, Giles H F and Bokareva, Aleksandra and Lohila, Annalea and Korkiakoski, Mika and Schiestl-Aalto, Pauliina and Lehtonen, Aleksi},
editor = {Cernusak, Lucas},
title = {Modeling the response of Norway spruce tree-ring carbon and oxygen isotopes to selection harvest on a drained peatland forest},
journal = {Tree Physiology},
publisher = {Oxford University Press (OUP)},
year = {2023},
volume = {44},
number = {1},
url = {http://dx.doi.org/10.1093/treephys/tpad119},
doi = {10.1093/treephys/tpad119}
}
|
| Toda M, Knohl A, Luyssaert S and Hara T (2023), "Simulated effects of canopy structural complexity on forest productivity", Forest Ecology and Management., jun, 2023. Vol. 538, pp. 120978. Elsevier BV. |
BibTeX:
@article{Toda2023,
author = {Toda, Motomu and Knohl, Alexander and Luyssaert, Sebastiaan and Hara, Toshihiko},
title = {Simulated effects of canopy structural complexity on forest productivity},
journal = {Forest Ecology and Management},
publisher = {Elsevier BV},
year = {2023},
volume = {538},
pages = {120978},
url = {http://dx.doi.org/10.1016/j.foreco.2023.120978},
doi = {10.1016/j.foreco.2023.120978}
}
|
| Tsuruta A, Kivimäki E, Lindqvist H, Karppinen T, Backman L, Hakkarainen J, Schneising O, Buchwitz M, Lan X, Kivi R, Chen H, Buschmann M, Herkommer B, Notholt J, Roehl C, Té Y, Wunch D, Tamminen J and Aalto T (2023), "CH4 Fluxes Derived from Assimilation of TROPOMI XCH4 in CarbonTracker Europe-CH4: Evaluation of Seasonality and Spatial Distribution in the Northern High Latitudes", Remote Sensing., mar, 2023. Vol. 15(6), pp. 1620. MDPI AG. |
BibTeX:
@article{Tsuruta2023,
author = {Tsuruta, Aki and Kivimäki, Ella and Lindqvist, Hannakaisa and Karppinen, Tomi and Backman, Leif and Hakkarainen, Janne and Schneising, Oliver and Buchwitz, Michael and Lan, Xin and Kivi, Rigel and Chen, Huilin and Buschmann, Matthias and Herkommer, Benedikt and Notholt, Justus and Roehl, Coleen and Té, Yao and Wunch, Debra and Tamminen, Johanna and Aalto, Tuula},
title = {CH4 Fluxes Derived from Assimilation of TROPOMI XCH4 in CarbonTracker Europe-CH4: Evaluation of Seasonality and Spatial Distribution in the Northern High Latitudes},
journal = {Remote Sensing},
publisher = {MDPI AG},
year = {2023},
volume = {15},
number = {6},
pages = {1620},
url = {http://dx.doi.org/10.3390/rs15061620},
doi = {10.3390/rs15061620}
}
|
| Ueyama M, Knox SH, Delwiche KB, Bansal S, Riley WJ, Baldocchi D, Hirano T, McNicol G, Schafer K, Windham‐Myers L, Poulter B, Jackson RB, Chang K, Chen J, Chu H, Desai AR, Gogo S, Iwata H, Kang M, Mammarella I, Peichl M, Sonnentag O, Tuittila E, Ryu Y, Euskirchen ES, Göckede M, Jacotot A, Nilsson MB and Sachs T (2023), "Modeled production, oxidation, and transport processes of wetland methane emissions in temperate, boreal, and Arctic regions", Global Change Biology., jan, 2023. Vol. 29(8), pp. 2313-2334. Wiley. |
BibTeX:
@article{Ueyama2023,
author = {Ueyama, Masahito and Knox, Sara H and Delwiche, Kyle B and Bansal, Sheel and Riley, William J and Baldocchi, Dennis and Hirano, Takashi and McNicol, Gavin and Schafer, Karina and Windham‐Myers, Lisamarie and Poulter, Benjamin and Jackson, Robert B and Chang, Kuang‐Yu and Chen, Jiquen and Chu, Housen and Desai, Ankur R and Gogo, Sébastien and Iwata, Hiroki and Kang, Minseok and Mammarella, Ivan and Peichl, Matthias and Sonnentag, Oliver and Tuittila, Eeva‐Stiina and Ryu, Youngryel and Euskirchen, Eugénie S and Göckede, Mathias and Jacotot, Adrien and Nilsson, Mats B and Sachs, Torsten},
title = {Modeled production, oxidation, and transport processes of wetland methane emissions in temperate, boreal, and Arctic regions},
journal = {Global Change Biology},
publisher = {Wiley},
year = {2023},
volume = {29},
number = {8},
pages = {2313--2334},
url = {http://dx.doi.org/10.1111/gcb.16594},
doi = {10.1111/gcb.16594}
}
|
| Vara-Vela AL, Karoff C, Rojas Benavente N and Nascimento JP (2023), "Implementation of a satellite-based tool for the quantification of CH4 emissions over Europe (AUMIA v1.0) – Part 1: forward modelling evaluation against near-surface and satellite data", Geoscientific Model Development., nov, 2023. Vol. 16(21), pp. 6413-6431. Copernicus GmbH. |
BibTeX:
@article{VaraVela2023,
author = {Vara-Vela, Angel Liduvino and Karoff, Christoffer and Rojas Benavente, Noelia and Nascimento, Janaina P},
title = {Implementation of a satellite-based tool for the quantification of CH4 emissions over Europe (AUMIA v1.0) – Part 1: forward modelling evaluation against near-surface and satellite data},
journal = {Geoscientific Model Development},
publisher = {Copernicus GmbH},
year = {2023},
volume = {16},
number = {21},
pages = {6413--6431},
url = {http://dx.doi.org/10.5194/gmd-16-6413-2023},
doi = {10.5194/gmd-16-6413-2023}
}
|
| Vekuri H, Tuovinen J-P, Kulmala L, Papale D, Kolari P, Aurela M, Laurila T, Liski J and Lohila A (2023), "A widely-used eddy covariance gap-filling method creates systematic bias in carbon balance estimates", Scientific Reports., jan, 2023. Vol. 13(1) Springer Science and Business Media LLC. |
BibTeX:
@article{Vekuri2023,
author = {Vekuri, Henriikka and Tuovinen, Juha-Pekka and Kulmala, Liisa and Papale, Dario and Kolari, Pasi and Aurela, Mika and Laurila, Tuomas and Liski, Jari and Lohila, Annalea},
title = {A widely-used eddy covariance gap-filling method creates systematic bias in carbon balance estimates},
journal = {Scientific Reports},
publisher = {Springer Science and Business Media LLC},
year = {2023},
volume = {13},
number = {1},
url = {http://dx.doi.org/10.1038/s41598-023-28827-2},
doi = {10.1038/s41598-023-28827-2}
}
|
| Vettikkat L, Miettinen P, Buchholz A, Rantala P, Yu H, Schallhart S, Petäjä T, Seco R, Männistö E, Kulmala M, Tuittila E-S, Guenther AB and Schobesberger S (2023), "High emission rates and strong temperature response make boreal wetlands a large source of isoprene and terpenes", Atmospheric Chemistry and Physics., feb, 2023. Vol. 23(4), pp. 2683-2698. Copernicus GmbH. |
BibTeX:
@article{Vettikkat2023,
author = {Vettikkat, Lejish and Miettinen, Pasi and Buchholz, Angela and Rantala, Pekka and Yu, Hao and Schallhart, Simon and Petäjä, Tuukka and Seco, Roger and Männistö, Elisa and Kulmala, Markku and Tuittila, Eeva-Stiina and Guenther, Alex B and Schobesberger, Siegfried},
title = {High emission rates and strong temperature response make boreal wetlands a large source of isoprene and terpenes},
journal = {Atmospheric Chemistry and Physics},
publisher = {Copernicus GmbH},
year = {2023},
volume = {23},
number = {4},
pages = {2683--2698},
url = {http://dx.doi.org/10.5194/acp-23-2683-2023},
doi = {10.5194/acp-23-2683-2023}
}
|
| Vieira I, Verbeeck H, Meunier F, Peaucelle M, Sibret T, Lefevre L, Cheesman AW, Brown F, Sitch S, Mbifo J, Boeckx P and Bauters M (2023), "Global reanalysis products cannot reproduce seasonal and diurnal cycles of tropospheric ozone in the Congo Basin", Atmospheric Environment., jul, 2023. Vol. 304, pp. 119773. Elsevier BV. |
BibTeX:
@article{Vieira2023,
author = {Vieira, Inês and Verbeeck, Hans and Meunier, Félicien and Peaucelle, Marc and Sibret, Thomas and Lefevre, Lodewijk and Cheesman, Alexander W and Brown, Flossie and Sitch, Stephen and Mbifo, José and Boeckx, Pascal and Bauters, Marijn},
title = {Global reanalysis products cannot reproduce seasonal and diurnal cycles of tropospheric ozone in the Congo Basin},
journal = {Atmospheric Environment},
publisher = {Elsevier BV},
year = {2023},
volume = {304},
pages = {119773},
url = {http://dx.doi.org/10.1016/j.atmosenv.2023.119773},
doi = {10.1016/j.atmosenv.2023.119773}
}
|
| Vulova S, Rocha AD, Meier F, Nouri H, Schulz C, Soulsby C, Tetzlaff D and Kleinschmit B (2023), "City-wide, high-resolution mapping of evapotranspiration to guide climate-resilient planning", Remote Sensing of Environment., mar, 2023. Vol. 287, pp. 113487. Elsevier BV. |
BibTeX:
@article{Vulova2023,
author = {Vulova, Stenka and Rocha, Alby Duarte and Meier, Fred and Nouri, Hamideh and Schulz, Christian and Soulsby, Chris and Tetzlaff, Doerthe and Kleinschmit, Birgit},
title = {City-wide, high-resolution mapping of evapotranspiration to guide climate-resilient planning},
journal = {Remote Sensing of Environment},
publisher = {Elsevier BV},
year = {2023},
volume = {287},
pages = {113487},
url = {http://dx.doi.org/10.1016/j.rse.2023.113487},
doi = {10.1016/j.rse.2023.113487}
}
|
| Vurdelja N (2023), "Performative Scores for More-Than-Human Swamp Becomings", Performance Research., November, 2023. Vol. 28(8), pp. 46-51. Informa UK Limited. |
BibTeX:
@article{Vurdelja2023,
author = {Vurdelja, Nina},
title = {Performative Scores for More-Than-Human Swamp Becomings},
journal = {Performance Research},
publisher = {Informa UK Limited},
year = {2023},
volume = {28},
number = {8},
pages = {46--51},
doi = {10.1080/13528165.2023.2389651}
}
|
| Wang Y, Liu J, Wennberg PO, He L, Bonal D, Köhler P, Frankenberg C, Sitch S and Friedlingstein P (2023), "Elucidating climatic drivers of photosynthesis by tropical forests", Global Change Biology., jul, 2023. Vol. 29(17), pp. 4811-4825. Wiley. |
BibTeX:
@article{Wang2023,
author = {Wang, Yuan and Liu, Junjie and Wennberg, Paul O and He, Liyin and Bonal, Damien and Köhler, Philipp and Frankenberg, Christian and Sitch, Stephen and Friedlingstein, Pierre},
title = {Elucidating climatic drivers of photosynthesis by tropical forests},
journal = {Global Change Biology},
publisher = {Wiley},
year = {2023},
volume = {29},
number = {17},
pages = {4811--4825},
url = {http://dx.doi.org/10.1111/gcb.16837},
doi = {10.1111/gcb.16837}
}
|
| Watts JD, Farina M, Kimball JS, Schiferl LD, Liu Z, Arndt KA, Zona D, Ballantyne A, Euskirchen ES, Parmentier FW, Helbig M, Sonnentag O, Tagesson T, Rinne J, Ikawa H, Ueyama M, Kobayashi H, Sachs T, Nadeau DF, Kochendorfer J, Jackowicz‐Korczynski M, Virkkala A, Aurela M, Commane R, Byrne B, Birch L, Johnson MS, Madani N, Rogers B, Du J, Endsley A, Savage K, Poulter B, Zhang Z, Bruhwiler LM, Miller CE, Goetz S and Oechel WC (2023), "Carbon uptake in Eurasian boreal forests dominates the high‐latitude net ecosystem carbon budget", Global Change Biology., jan, 2023. Vol. 29(7), pp. 1870-1889. Wiley. |
BibTeX:
@article{Watts2023,
author = {Watts, Jennifer D and Farina, Mary and Kimball, John S and Schiferl, Luke D and Liu, Zhihua and Arndt, Kyle A and Zona, Donatella and Ballantyne, Ashley and Euskirchen, Eugénie S and Parmentier, Frans‐Jan W and Helbig, Manuel and Sonnentag, Oliver and Tagesson, Torbern and Rinne, Janne and Ikawa, Hiroki and Ueyama, Masahito and Kobayashi, Hideki and Sachs, Torsten and Nadeau, Daniel F and Kochendorfer, John and Jackowicz‐Korczynski, Marcin and Virkkala, Anna and Aurela, Mika and Commane, Roisin and Byrne, Brendan and Birch, Leah and Johnson, Matthew S and Madani, Nima and Rogers, Brendan and Du, Jinyang and Endsley, Arthur and Savage, Kathleen and Poulter, Ben and Zhang, Zhen and Bruhwiler, Lori M and Miller, Charles E and Goetz, Scott and Oechel, Walter C},
title = {Carbon uptake in Eurasian boreal forests dominates the high‐latitude net ecosystem carbon budget},
journal = {Global Change Biology},
publisher = {Wiley},
year = {2023},
volume = {29},
number = {7},
pages = {1870--1889},
url = {http://dx.doi.org/10.1111/gcb.16553},
doi = {10.1111/gcb.16553}
}
|
| Wefers WM, Lehnert LW, Schmidt D, Reuter M, Buchwitz M, Kammann C, Velten K, Hase F, Notholt J, Kubistin D, Mueller-Williams J and Lindauer M (2023), "Approximation of multi-year time series of XCO2 concentrations using satellite observations and statistical interpolation methods", Atmospheric Research., oct, 2023. Vol. 294, pp. 106965. Elsevier BV. |
BibTeX:
@article{Wefers2023,
author = {Wefers, W M and Lehnert, L W and Schmidt, D and Reuter, M and Buchwitz, M and Kammann, C and Velten, K and Hase, F and Notholt, J and Kubistin, D and Mueller-Williams, J and Lindauer, M},
title = {Approximation of multi-year time series of XCO2 concentrations using satellite observations and statistical interpolation methods},
journal = {Atmospheric Research},
publisher = {Elsevier BV},
year = {2023},
volume = {294},
pages = {106965},
url = {http://dx.doi.org/10.1016/j.atmosres.2023.106965},
doi = {10.1016/j.atmosres.2023.106965}
}
|
| Westermann SA, Hildebrandt A, Bousetta S and Thober S (2023), "Does dynamically modelled leaf area improve predictions of land surface water and carbon fluxes? – Insights into dynamic vegetation modules", October, 2023. Copernicus GmbH. |
BibTeX:
@article{Westermann2023,
author = {Westermann, Sven Armin and Hildebrandt, Anke and Bousetta, Souhail and Thober, Stephan},
title = {Does dynamically modelled leaf area improve predictions of land surface water and carbon fluxes? – Insights into dynamic vegetation modules},
publisher = {Copernicus GmbH},
year = {2023},
doi = {10.5194/egusphere-2023-2101}
}
|
| Western LM, Vollmer MK, Krummel PB, Adcock KE, Crotwell M, Fraser PJ, Harth CM, Langenfelds RL, Montzka SA, Mühle J, O’Doherty S, Oram DE, Reimann S, Rigby M, Vimont I, Weiss RF, Young D and Laube JC (2023), "Global increase of ozone-depleting chlorofluorocarbons from 2010 to 2020", Nature Geoscience., April, 2023. Vol. 16(4), pp. 309-313. Springer Science and Business Media LLC. |
BibTeX:
@article{Western2023,
author = {Western, Luke M. and Vollmer, Martin K. and Krummel, Paul B. and Adcock, Karina E. and Crotwell, Molly and Fraser, Paul J. and Harth, Christina M. and Langenfelds, Ray L. and Montzka, Stephen A. and Mühle, Jens and O’Doherty, Simon and Oram, David E. and Reimann, Stefan and Rigby, Matt and Vimont, Isaac and Weiss, Ray F. and Young, Dickon and Laube, Johannes C.},
title = {Global increase of ozone-depleting chlorofluorocarbons from 2010 to 2020},
journal = {Nature Geoscience},
publisher = {Springer Science and Business Media LLC},
year = {2023},
volume = {16},
number = {4},
pages = {309--313},
doi = {10.1038/s41561-023-01147-w}
}
|
| White JD, Ahrén D, Ström L, Kelly J, Klemedtsson L, Keane B and Parmentier FJW (2023), "Methane Producing and Oxidizing Microorganisms Display a High Resilience to Drought in a Swedish Hemi‐Boreal Mire", Journal of Geophysical Research: Biogeosciences., sep, 2023. Vol. 128(9) American Geophysical Union (AGU). |
BibTeX:
@article{White2023,
author = {White, J D and Ahrén, D and Ström, L and Kelly, J and Klemedtsson, L and Keane, B and Parmentier, F J W},
title = {Methane Producing and Oxidizing Microorganisms Display a High Resilience to Drought in a Swedish Hemi‐Boreal Mire},
journal = {Journal of Geophysical Research: Biogeosciences},
publisher = {American Geophysical Union (AGU)},
year = {2023},
volume = {128},
number = {9},
url = {http://dx.doi.org/10.1029/2022JG007362},
doi = {10.1029/2022jg007362}
}
|
| Winck BR, Bloor JMG and Klumpp K (2023), "Eighteen years of upland grassland carbon flux data: reference datasets, processing, and gap-filling procedure", Scientific Data., may, 2023. Vol. 10(1) Springer Science and Business Media LLC. |
BibTeX:
@article{Winck2023,
author = {Winck, Bruna R and Bloor, Juliette M G and Klumpp, Katja},
title = {Eighteen years of upland grassland carbon flux data: reference datasets, processing, and gap-filling procedure},
journal = {Scientific Data},
publisher = {Springer Science and Business Media LLC},
year = {2023},
volume = {10},
number = {1},
url = {http://dx.doi.org/10.1038/s41597-023-02221-z},
doi = {10.1038/s41597-023-02221-z}
}
|
| van der Woude AM, de Kok R, Smith N, Luijkx IT, Botía S, Karstens U, Kooijmans LMJ, Koren G, Meijer HAJ, Steeneveld G-J, Storm I, Super I, Scheeren HA, Vermeulen A and Peters W (2023), "Near-real-time CO2 fluxes from CarbonTracker Europe for high-resolution atmospheric modeling", Earth System Science Data., feb, 2023. Vol. 15(2), pp. 579-605. Copernicus GmbH. |
BibTeX:
@article{Woude2023,
author = {van der Woude, Auke M and de Kok, Remco and Smith, Naomi and Luijkx, Ingrid T and Botía, Santiago and Karstens, Ute and Kooijmans, Linda M J and Koren, Gerbrand and Meijer, Harro A J and Steeneveld, Gert-Jan and Storm, Ida and Super, Ingrid and Scheeren, Hubertus A and Vermeulen, Alex and Peters, Wouter},
title = {Near-real-time CO2 fluxes from CarbonTracker Europe for high-resolution atmospheric modeling},
journal = {Earth System Science Data},
publisher = {Copernicus GmbH},
year = {2023},
volume = {15},
number = {2},
pages = {579--605},
url = {http://dx.doi.org/10.5194/essd-15-579-2023},
doi = {10.5194/essd-15-579-2023}
}
|
| van der Woude AM, Peters W, Joetzjer E, Lafont S, Koren G, Ciais P, Ramonet M, Xu Y, Bastos A, Botía S, Sitch S, de Kok R, Kneuer T, Kubistin D, Jacotot A, Loubet B, Herig-Coimbra P-H, Loustau D and Luijkx IT (2023), "Temperature extremes of 2022 reduced carbon uptake by forests in Europe", Nature Communications., oct, 2023. Vol. 14(1) Springer Science and Business Media LLC. |
BibTeX:
@article{Woude2023a,
author = {van der Woude, Auke M and Peters, Wouter and Joetzjer, Emilie and Lafont, Sébastien and Koren, Gerbrand and Ciais, Philippe and Ramonet, Michel and Xu, Yidi and Bastos, Ana and Botía, Santiago and Sitch, Stephen and de Kok, Remco and Kneuer, Tobias and Kubistin, Dagmar and Jacotot, Adrien and Loubet, Benjamin and Herig-Coimbra, Pedro-Henrique and Loustau, Denis and Luijkx, Ingrid T},
title = {Temperature extremes of 2022 reduced carbon uptake by forests in Europe},
journal = {Nature Communications},
publisher = {Springer Science and Business Media LLC},
year = {2023},
volume = {14},
number = {1},
url = {http://dx.doi.org/10.1038/s41467-023-41851-0},
doi = {10.1038/s41467-023-41851-0}
}
|
| Xie M, Ma X, Wang Y, Li C, Shi H, Yuan X, Hellwich O, Chen C, Zhang W, Zhang C, Ling Q, Gao R, Zhang Y, Ochege FU, Frankl A, De Maeyer P, Buchmann N, Feigenwinter I, Olesen JE, Juszczak R, Jacotot A, Korrensalo A, Pitacco A, Varlagin A, Shekhar A, Lohila A, Carrara A, Brut A, Kruijt B, Loubet B, Heinesch B, Chojnicki B, Helfter C, Vincke C, Shao C, Bernhofer C, Brümmer C, Wille C, Tuittila E-S, Nemitz E, Meggio F, Dong G, Lanigan G, Niedrist G, Wohlfahrt G, Zhou G, Goded I, Gruenwald T, Olejnik J, Jansen J, Neirynck J, Tuovinen J-P, Zhang J, Klumpp K, Pilegaard K, Šigut L, Klemedtsson L, Tezza L, Hörtnagl L, Urbaniak M, Roland M, Schmidt M, Sutton MA, Hehn M, Saunders M, Mauder M, Aurela M, Korkiakoski M, Du M, Vendrame N, Kowalska N, Leahy PG, Alekseychik P, Shi P, Weslien P, Chen S, Fares S, Friborg T, Tallec T, Kato T, Sachs T, Maximov T, di Cella UM, Moderow U, Li Y, He Y, Kosugi Y and Luo G (2023), "Monitoring of carbon-water fluxes at Eurasian meteorological stations using random forest and remote sensing", Scientific Data., sep, 2023. Vol. 10(1) Springer Science and Business Media LLC. |
BibTeX:
@article{Xie2023,
author = {Xie, Mingjuan and Ma, Xiaofei and Wang, Yuangang and Li, Chaofan and Shi, Haiyang and Yuan, Xiuliang and Hellwich, Olaf and Chen, Chunbo and Zhang, Wenqiang and Zhang, Chen and Ling, Qing and Gao, Ruixiang and Zhang, Yu and Ochege, Friday Uchenna and Frankl, Amaury and De Maeyer, Philippe and Buchmann, Nina and Feigenwinter, Iris and Olesen, Jørgen E and Juszczak, Radoslaw and Jacotot, Adrien and Korrensalo, Aino and Pitacco, Andrea and Varlagin, Andrej and Shekhar, Ankit and Lohila, Annalea and Carrara, Arnaud and Brut, Aurore and Kruijt, Bart and Loubet, Benjamin and Heinesch, Bernard and Chojnicki, Bogdan and Helfter, Carole and Vincke, Caroline and Shao, Changliang and Bernhofer, Christian and Brümmer, Christian and Wille, Christian and Tuittila, Eeva-Stiina and Nemitz, Eiko and Meggio, Franco and Dong, Gang and Lanigan, Gary and Niedrist, Georg and Wohlfahrt, Georg and Zhou, Guoyi and Goded, Ignacio and Gruenwald, Thomas and Olejnik, Janusz and Jansen, Joachim and Neirynck, Johan and Tuovinen, Juha-Pekka and Zhang, Junhui and Klumpp, Katja and Pilegaard, Kim and Šigut, Ladislav and Klemedtsson, Leif and Tezza, Luca and Hörtnagl, Lukas and Urbaniak, Marek and Roland, Marilyn and Schmidt, Marius and Sutton, Mark A and Hehn, Markus and Saunders, Matthew and Mauder, Matthias and Aurela, Mika and Korkiakoski, Mika and Du, Mingyuan and Vendrame, Nadia and Kowalska, Natalia and Leahy, Paul G and Alekseychik, Pavel and Shi, Peili and Weslien, Per and Chen, Shiping and Fares, Silvano and Friborg, Thomas and Tallec, Tiphaine and Kato, Tomomichi and Sachs, Torsten and Maximov, Trofim and di Cella, Umberto Morra and Moderow, Uta and Li, Yingnian and He, Yongtao and Kosugi, Yoshiko and Luo, Geping},
title = {Monitoring of carbon-water fluxes at Eurasian meteorological stations using random forest and remote sensing},
journal = {Scientific Data},
publisher = {Springer Science and Business Media LLC},
year = {2023},
volume = {10},
number = {1},
url = {http://dx.doi.org/10.1038/s41597-023-02473-9},
doi = {10.1038/s41597-023-02473-9}
}
|
| Xue K, Song L, Xu Y, Liu S, Zhao G, Tao S, Magliulo E, Manco A, Liddell M, Wohlfahrt G, Varlagin A, Montagnani L, Woodgate W, Loubet B and Zhao L (2023), "Estimating ecosystem evaporation and transpiration using a soil moisture coupled two-source energy balance model across FLUXNET sites", Agricultural and Forest Meteorology., jun, 2023. Vol. 337, pp. 109513. Elsevier BV. |
BibTeX:
@article{Xue2023,
author = {Xue, Kejia and Song, Lisheng and Xu, Yanhao and Liu, Shaomin and Zhao, Gengle and Tao, Sinuo and Magliulo, Enzo and Manco, Antonio and Liddell, Michael and Wohlfahrt, Georg and Varlagin, Andrej and Montagnani, Leonardo and Woodgate, William and Loubet, Benjamin and Zhao, Long},
title = {Estimating ecosystem evaporation and transpiration using a soil moisture coupled two-source energy balance model across FLUXNET sites},
journal = {Agricultural and Forest Meteorology},
publisher = {Elsevier BV},
year = {2023},
volume = {337},
pages = {109513},
url = {http://dx.doi.org/10.1016/j.agrformet.2023.109513},
doi = {10.1016/j.agrformet.2023.109513}
}
|
| Zainali S, Ma Lu S, Stridh B, Avelin A, Amaducci S, Colauzzi M and Campana PE (2023), "Direct and diffuse shading factors modelling for the most representative agrivoltaic system layouts", Applied Energy., jun, 2023. Vol. 339, pp. 120981. Elsevier BV. |
BibTeX:
@article{Zainali2023,
author = {Zainali, Sebastian and Ma Lu, Silvia and Stridh, Bengt and Avelin, Anders and Amaducci, Stefano and Colauzzi, Michele and Campana, Pietro Elia},
title = {Direct and diffuse shading factors modelling for the most representative agrivoltaic system layouts},
journal = {Applied Energy},
publisher = {Elsevier BV},
year = {2023},
volume = {339},
pages = {120981},
url = {http://dx.doi.org/10.1016/j.apenergy.2023.120981},
doi = {10.1016/j.apenergy.2023.120981}
}
|
| Zanchetta A, Kooijmans LMJ, van Heuven S, Scifo A, Scheeren HA, Mammarella I, Karstens U, Ma J, Krol M and Chen H (2023), "Sources and sinks of carbonyl sulfide inferred from tower and mobile atmospheric observations in the Netherlands", Biogeosciences., aug, 2023. Vol. 20(16), pp. 3539-3553. Copernicus GmbH. |
BibTeX:
@article{Zanchetta2023,
author = {Zanchetta, Alessandro and Kooijmans, Linda M J and van Heuven, Steven and Scifo, Andrea and Scheeren, Hubertus A and Mammarella, Ivan and Karstens, Ute and Ma, Jin and Krol, Maarten and Chen, Huilin},
title = {Sources and sinks of carbonyl sulfide inferred from tower and mobile atmospheric observations in the Netherlands},
journal = {Biogeosciences},
publisher = {Copernicus GmbH},
year = {2023},
volume = {20},
number = {16},
pages = {3539--3553},
url = {http://dx.doi.org/10.5194/bg-20-3539-2023},
doi = {10.5194/bg-20-3539-2023}
}
|
| Zawilski BM, Granouillac F, Claverie N, Lemaire B, Brut A and Tallec T (2023), "Calculation of soil water content using dielectric-permittivity-based sensors – benefits of soil-specific calibration", Geoscientific Instrumentation, Methods and Data Systems., jan, 2023. Vol. 12(1), pp. 45-56. Copernicus GmbH. |
BibTeX:
@article{Zawilski2023,
author = {Zawilski, Bartosz M and Granouillac, Franck and Claverie, Nicole and Lemaire, Baptiste and Brut, Aurore and Tallec, Tiphaine},
title = {Calculation of soil water content using dielectric-permittivity-based sensors – benefits of soil-specific calibration},
journal = {Geoscientific Instrumentation, Methods and Data Systems},
publisher = {Copernicus GmbH},
year = {2023},
volume = {12},
number = {1},
pages = {45--56},
url = {http://dx.doi.org/10.5194/gi-12-45-2023},
doi = {10.5194/gi-12-45-2023}
}
|
| Zhang W, Jung M, Migliavacca M, Poyatos R, Miralles DG, El-Madany TS, Galvagno M, Carrara A, Arriga N, Ibrom A, Mammarella I, Papale D, Cleverly JR, Liddell M, Wohlfahrt G, Markwitz C, Mauder M, Paul-Limoges E, Schmidt M, Wolf S, Brümmer C, Arain MA, Fares S, Kato T, Ardö J, Oechel W, Hanson C, Korkiakoski M, Biraud S, Steinbrecher R, Billesbach D, Montagnani L, Woodgate W, Shao C, Carvalhais N, Reichstein M and Nelson JA (2023), "The effect of relative humidity on eddy covariance latent heat flux measurements and its implication for partitioning into transpiration and evaporation", Agricultural and Forest Meteorology., mar, 2023. Vol. 330, pp. 109305. Elsevier BV. |
BibTeX:
@article{Zhang2023,
author = {Zhang, Weijie and Jung, Martin and Migliavacca, Mirco and Poyatos, Rafael and Miralles, Diego G and El-Madany, Tarek S and Galvagno, Marta and Carrara, Arnaud and Arriga, Nicola and Ibrom, Andreas and Mammarella, Ivan and Papale, Dario and Cleverly, Jamie R and Liddell, Michael and Wohlfahrt, Georg and Markwitz, Christian and Mauder, Matthias and Paul-Limoges, Eugenie and Schmidt, Marius and Wolf, Sebastian and Brümmer, Christian and Arain, M Altaf and Fares, Silvano and Kato, Tomomichi and Ardö, Jonas and Oechel, Walter and Hanson, Chad and Korkiakoski, Mika and Biraud, Sébastien and Steinbrecher, Rainer and Billesbach, Dave and Montagnani, Leonardo and Woodgate, William and Shao, Changliang and Carvalhais, Nuno and Reichstein, Markus and Nelson, Jacob A},
title = {The effect of relative humidity on eddy covariance latent heat flux measurements and its implication for partitioning into transpiration and evaporation},
journal = {Agricultural and Forest Meteorology},
publisher = {Elsevier BV},
year = {2023},
volume = {330},
pages = {109305},
url = {http://dx.doi.org/10.1016/J.AGRFORMET.2022.109305},
doi = {10.1016/j.agrformet.2022.109305}
}
|
| Zheng Y, Havu M, Liu H, Cheng X, Wen Y, Lee HS, Ahongshangbam J and Järvi L (2023), "Simulating heat and CO2 fluxes in Beijing using SUEWS V2020b: sensitivity to vegetation phenology and maximum conductance", Geoscientific Model Development., aug, 2023. Vol. 16(15), pp. 4551-4579. Copernicus GmbH. |
BibTeX:
@article{Zheng2023,
author = {Zheng, Yingqi and Havu, Minttu and Liu, Huizhi and Cheng, Xueling and Wen, Yifan and Lee, Hei Shing and Ahongshangbam, Joyson and Järvi, Leena},
title = {Simulating heat and CO2 fluxes in Beijing using SUEWS V2020b: sensitivity to vegetation phenology and maximum conductance},
journal = {Geoscientific Model Development},
publisher = {Copernicus GmbH},
year = {2023},
volume = {16},
number = {15},
pages = {4551--4579},
url = {http://dx.doi.org/10.5194/gmd-16-4551-2023},
doi = {10.5194/gmd-16-4551-2023}
}
|
| Zhou X, Xin Q, Zhang S, Delzon S and Dai Y (2023), "A prognostic vegetation phenology model to predict seasonal maximum and time series of global leaf area index using climate variables", Agricultural and Forest Meteorology., nov, 2023. Vol. 342, pp. 109739. Elsevier BV. |
BibTeX:
@article{Zhou2023,
author = {Zhou, Xuewen and Xin, Qinchuan and Zhang, Shulei and Delzon, Sylvain and Dai, Yongjiu},
title = {A prognostic vegetation phenology model to predict seasonal maximum and time series of global leaf area index using climate variables},
journal = {Agricultural and Forest Meteorology},
publisher = {Elsevier BV},
year = {2023},
volume = {342},
pages = {109739},
url = {http://dx.doi.org/10.1016/j.agrformet.2023.109739},
doi = {10.1016/j.agrformet.2023.109739}
}
|
| Zinke J, Nilsson ED, Markuszewski P, Zieger P, Mårtensson EM, Rutgersson A, Nilsson E and Salter ME (2023), "Sea spray emissions from the Baltic Sea: Comparison of aerosol eddy covariance fluxes and chamber-simulated sea spray emissions", jun, 2023. Copernicus GmbH. |
BibTeX:
@article{Zinke2023,
author = {Zinke, Julika and Nilsson, E Douglas and Markuszewski, Piotr and Zieger, Paul and Mårtensson, E Monica and Rutgersson, Anna and Nilsson, Erik and Salter, Matthew E},
title = {Sea spray emissions from the Baltic Sea: Comparison of aerosol eddy covariance fluxes and chamber-simulated sea spray emissions},
publisher = {Copernicus GmbH},
year = {2023},
url = {http://dx.doi.org/10.5194/egusphere-2023-966},
doi = {10.5194/egusphere-2023-966}
}
|
| Zuccarini P, Delpierre N, Mariën B, Peñuelas J, Heinecke T and Campioli M (2023), "Drivers and dynamics of foliar senescence in temperate deciduous forest trees at their southern limit of distribution in Europe", Agricultural and Forest Meteorology., nov, 2023. Vol. 342, pp. 109716. Elsevier BV. |
BibTeX:
@article{Zuccarini2023,
author = {Zuccarini, Paolo and Delpierre, Nicolas and Mariën, Bertold and Peñuelas, Josep and Heinecke, Thilo and Campioli, Matteo},
title = {Drivers and dynamics of foliar senescence in temperate deciduous forest trees at their southern limit of distribution in Europe},
journal = {Agricultural and Forest Meteorology},
publisher = {Elsevier BV},
year = {2023},
volume = {342},
pages = {109716},
url = {http://dx.doi.org/10.1016/j.agrformet.2023.109716},
doi = {10.1016/j.agrformet.2023.109716}
}
|
| Zweifel R, Pappas C, Peters RL, Babst F, Balanzategui D, Basler D, Bastos A, Beloiu M, Buchmann N, Bose AK, Braun S, Damm A, D'Odorico P, Eitel JUH, Etzold S, Fonti P, Rouholahnejad Freund E, Gessler A, Haeni M, Hoch G, Kahmen A, Körner C, Krejza J, Krumm F, Leuchner M, Leuschner C, Lukovic M, Martínez-Vilalta J, Matula R, Meesenburg H, Meir P, Plichta R, Poyatos R, Rohner B, Ruehr N, Salomón RL, Scharnweber T, Schaub M, Steger DN, Steppe K, Still C, Stojanović M, Trotsiuk V, Vitasse Y, von Arx G, Wilmking M, Zahnd C and Sterck F (2023), "Networking the forest infrastructure towards near real-time monitoring – A white paper", Science of The Total Environment., may, 2023. Vol. 872, pp. 162167. Elsevier BV. |
BibTeX:
@article{Zweifel2023,
author = {Zweifel, Roman and Pappas, Christoforos and Peters, Richard L and Babst, Flurin and Balanzategui, Daniel and Basler, David and Bastos, Ana and Beloiu, Mirela and Buchmann, Nina and Bose, Arun K and Braun, Sabine and Damm, Alexander and D'Odorico, Petra and Eitel, Jan U H and Etzold, Sophia and Fonti, Patrick and Rouholahnejad Freund, Elham and Gessler, Arthur and Haeni, Matthias and Hoch, Günter and Kahmen, Ansgar and Körner, Christian and Krejza, Jan and Krumm, Frank and Leuchner, Michael and Leuschner, Christoph and Lukovic, Mirko and Martínez-Vilalta, Jordi and Matula, Radim and Meesenburg, Henning and Meir, Patrick and Plichta, Roman and Poyatos, Rafael and Rohner, Brigitte and Ruehr, Nadine and Salomón, Roberto L and Scharnweber, Tobias and Schaub, Marcus and Steger, David N and Steppe, Kathy and Still, Christopher and Stojanović, Marko and Trotsiuk, Volodymyr and Vitasse, Yann and von Arx, Georg and Wilmking, Martin and Zahnd, Cedric and Sterck, Frank},
title = {Networking the forest infrastructure towards near real-time monitoring – A white paper},
journal = {Science of The Total Environment},
publisher = {Elsevier BV},
year = {2023},
volume = {872},
pages = {162167},
url = {http://dx.doi.org/10.1016/j.scitotenv.2023.162167},
doi = {10.1016/j.scitotenv.2023.162167}
}
|
| Agustí-Panareda A, McNorton J, Balsamo G, Baier BC, Bousserez N, Boussetta S, Brunner D, Chevallier F, Choulga M, Diamantakis M, Engelen R, Flemming J, Granier C, Guevara M, Denier van der Gon H, Elguindi N, Haussaire J-M, Jung M, Janssens-Maenhout G, Kivi R, Massart S, Papale D, Parrington M, Razinger M, Sweeney C, Vermeulen A and Walther S (2022), "Global nature run data with realistic high-resolution carbon weather for the year of the Paris Agreement", Scientific Data. Vol. 9(1), pp. 160. |
| Abstract: The CO2 Human Emissions project has generated realistic high-resolution 9 km global simulations for atmospheric carbon tracers referred to as nature runs to foster carbon-cycle research applications with current and planned satellite missions, as well as the surge of in situ observations. Realistic atmospheric CO2, CH4 and CO fields can provide a reference for assessing the impact of proposed designs of new satellites and in situ networks and to study atmospheric variability of the tracers modulated by the weather. The simulations spanning 2015 are based on the Copernicus Atmosphere Monitoring Service forecasts at the European Centre for Medium Range Weather Forecasts, with improvements in various model components and input data such as anthropogenic emissions, in preparation of a CO2 Monitoring and Verification Support system. The relative contribution of different emissions and natural fluxes towards observed atmospheric variability is diagnosed by additional tagged tracers in the simulations. The evaluation of such high-resolution model simulations can be used to identify model deficiencies and guide further model improvements. |
BibTeX:
@article{AgustiPanareda2022,
author = {Agustí-Panareda, Anna and McNorton, Joe and Balsamo, Gianpaolo and Baier, Bianca C and Bousserez, Nicolas and Boussetta, Souhail and Brunner, Dominik and Chevallier, Frédéric and Choulga, Margarita and Diamantakis, Michail and Engelen, Richard and Flemming, Johannes and Granier, Claire and Guevara, Marc and Denier van der Gon, Hugo and Elguindi, Nellie and Haussaire, Jean-Matthieu and Jung, Martin and Janssens-Maenhout, Greet and Kivi, Rigel and Massart, Sébastien and Papale, Dario and Parrington, Mark and Razinger, Miha and Sweeney, Colm and Vermeulen, Alex and Walther, Sophia},
title = {Global nature run data with realistic high-resolution carbon weather for the year of the Paris Agreement},
journal = {Scientific Data},
year = {2022},
volume = {9},
number = {1},
pages = {160},
url = {https://doi.org/10.1038/s41597-022-01228-2},
doi = {10.1038/s41597-022-01228-2}
}
|
| Ahlberg E, Ausmeel S, Nilsson L, Spanne M, Pauraite J, KlenøNøjgaard J, Bertò M, Skov H, Roldin P, Kristensson A, Swietlicki E and Eriksson A (2022), "Measurement Report: Small effect of regional sources on black carbon properties and concentrations in Southern Sweden background air", Atmospheric Chemistry and Physics Discussions. Vol. 2022, pp. 1-20. |
BibTeX:
@article{Ahlberg2022,
author = {Ahlberg, E and Ausmeel, S and Nilsson, L and Spanne, M and Pauraite, J and KlenøNøjgaard, J and Bertò, M and Skov, H and Roldin, P and Kristensson, A and Swietlicki, E and Eriksson, A},
title = {Measurement Report: Small effect of regional sources on black carbon properties and concentrations in Southern Sweden background air},
journal = {Atmospheric Chemistry and Physics Discussions},
year = {2022},
volume = {2022},
pages = {1--20},
url = {https://acp.copernicus.org/preprints/acp-2022-156/},
doi = {10.5194/acp-2022-156}
}
|
| Ala-Könni J, Kohonen K-M, Leppäranta M and Mammarella I (2022), "Validation of turbulent heat transfer models against eddy covariance flux measurements over a seasonally ice-covered lake", Geoscientific Model Development. Vol. 15(12), pp. 4739-4755. |
BibTeX:
@article{AlaKoenni2022,
author = {Ala-Könni, J and Kohonen, K.-M. and Leppäranta, M and Mammarella, I},
title = {Validation of turbulent heat transfer models against eddy covariance flux measurements over a seasonally ice-covered lake},
journal = {Geoscientific Model Development},
year = {2022},
volume = {15},
number = {12},
pages = {4739--4755},
url = {https://gmd.copernicus.org/articles/15/4739/2022/},
doi = {10.5194/gmd-15-4739-2022}
}
|
| Bao S, Wutzler T, Koirala S, Cuntz M, Ibrom A, Besnard S, Walther S, Šigut L, Moreno A, Weber U, Wohlfahrt G, Cleverly J, Migliavacca M, Woodgate W, Merbold L, Veenendaal E and Carvalhais N (2022), "Environment-sensitivity functions for gross primary productivity in light use efficiency models", Agricultural and Forest Meteorology. Vol. 312, pp. 108708. |
| Abstract: The sensitivity of photosynthesis to environmental changes is essential for understanding carbon cycle responses to global climate change and for the development of modeling approaches that explains its spatial and temporal variability. We collected a large variety of published sensitivity functions of gross primary productivity (GPP) to different forcing variables to assess the response of GPP to environmental factors. These include the responses of GPP to temperature; vapor pressure deficit, some of which include the response to atmospheric CO2 concentrations; soil water availability (W); light intensity; and cloudiness. These functions were combined in a full factorial light use efficiency (LUE) model structure, leading to a collection of 5600 distinct LUE models. Each model was optimized against daily GPP and evapotranspiration fluxes from 196 FLUXNET sites and ranked across sites based on a bootstrap approach. The GPP sensitivity to each environmental factor, including CO2 fertilization, was shown to be significant, and that none of the previously published model structures performed as well as the best model selected. From daily and weekly to monthly scales, the best model's median Nash-Sutcliffe model efficiency across sites was 0.73, 0.79 and 0.82, respectively, but poorer at annual scales (0.23), emphasizing the common limitation of current models in describing the interannual variability of GPP. Although the best global model did not match the local best model at each site, the selection was robust across ecosystem types. The contribution of light saturation and cloudiness to GPP was observed across all biomes (from 23% to 43%). Temperature and W dominates GPP and LUE but responses of GPP to temperature and W are lagged in cold and arid ecosystems, respectively. The findings of this study provide a foundation towards more robust LUE-based estimates of global GPP and may provide a benchmark for other empirical GPP products. |
BibTeX:
@article{Bao2022,
author = {Bao, Shanning and Wutzler, Thomas and Koirala, Sujan and Cuntz, Matthias and Ibrom, Andreas and Besnard, Simon and Walther, Sophia and Šigut, Ladislav and Moreno, Alvaro and Weber, Ulrich and Wohlfahrt, Georg and Cleverly, Jamie and Migliavacca, Mirco and Woodgate, William and Merbold, Lutz and Veenendaal, Elmar and Carvalhais, Nuno},
title = {Environment-sensitivity functions for gross primary productivity in light use efficiency models},
journal = {Agricultural and Forest Meteorology},
year = {2022},
volume = {312},
pages = {108708},
url = {https://www.sciencedirect.com/science/article/pii/S0168192321003944},
doi = {10.1016/j.agrformet.2021.108708}
}
|
| Belviso S, Abadie C, Montagne D, Hadjar D, Tropée D, Vialettes L, Kazan V, Delmotte M, Maignan F, Remaud M, Ramonet M, Lopez M, Yver-Kwok C and Ciais P (2022), "Carbonyl sulfide (COS) emissions in two agroecosystems in central France", PloS one. Vol. 17(12), pp. e0278584. |
| Abstract: Carbonyl sulfide (COS) fluxes simulated by vegetation and soil component models, both implemented in the ORCHIDEE land surface model, were evaluated against field observations at two agroecosystems in central France. The dynamics of a biogenic process not yet accounted for by this model, i.e., COS emissions from croplands, was examined in the context of three independent and complementary approaches. First, during the growing seasons of 2019 and 2020, monthly variations in the nighttime ratio of vertical mole fraction gradients of COS and carbon dioxide measured between 5 and 180 m height (GradCOS/GradCO2), a proxy of the ratio of their respective nocturnal net fluxes, were monitored at a rural tall tower site near Orléans (i.e., a "profile vs. model" approach). Second, field observations of COS nocturnal fluxes, obtained by the Radon Tracer Method (RTM) at a sub-urban site near Paris, were used for that same purpose (i.e., a "RTM vs. model" approach of unaccounted biogenic emissions). This site has observations going back to 2014. Third, during the growing seasons of 2019, 2020 and 2021, horizontal mole fraction gradients of COS were calculated from downwind-upwind surveys of wheat and rapeseed crops as a proxy of their respective exchange rates at the plot scale (i.e., a "crop based" comparative approach). The "profile vs. model" approach suggests that the nocturnal net COS uptake gradually weakens during the peak growing season and recovers from August on. The "RTM vs. model" approach suggests that there exists a biogenic source of COS, the intensity of which culminates in late June early July. Our "crop based" comparative approach demonstrates that rapeseed crops shift from COS uptake to emission in early summer during the late stages of growth (ripening and senescence) while wheat crops uptake capacities lower markedly. Hence, rapeseed appears to be a much larger source of COS than wheat at the plot scale. Nevertheless, compared to current estimates of the largest COS sources (i.e., marine and anthropogenic emissions), agricultural emissions during the late stages of growth are of secondary importance. |
BibTeX:
@article{Belviso2022,
author = {Belviso, Sauveur and Abadie, Camille and Montagne, David and Hadjar, Dalila and Tropée, Didier and Vialettes, Laurence and Kazan, Victor and Delmotte, Marc and Maignan, Fabienne and Remaud, Marine and Ramonet, Michel and Lopez, Morgan and Yver-Kwok, Camille and Ciais, Philippe},
title = {Carbonyl sulfide (COS) emissions in two agroecosystems in central France},
journal = {PloS one},
year = {2022},
volume = {17},
number = {12},
pages = {e0278584},
doi = {10.1371/journal.pone.0278584}
}
|
| Bergamaschi P, Segers A, Brunner D, Haussaire J-M, Henne S, Ramonet M, Arnold T, Biermann T, Chen H, Conil S, Delmotte M, Forster G, Frumau A, Kubistin D, Lan X, Leuenberger M, Lindauer M, Lopez M, Manca G, Müller-Williams J, O'Doherty S, Scheeren B, Steinbacher M, Trisolino P, V\itková G and Yver Kwok C (2022), "High-resolution inverse modelling of European CH_4 emissions using the novel FLEXPART-COSMO TM5 4DVAR inverse modelling system", Atmospheric Chemistry and Physics. Vol. 22(20), pp. 13243-13268. |
BibTeX:
@article{Bergamaschi2022,
author = {Bergamaschi, P and Segers, A and Brunner, D and Haussaire, J.-M. and Henne, S and Ramonet, M and Arnold, T and Biermann, T and Chen, H and Conil, S and Delmotte, M and Forster, G and Frumau, A and Kubistin, D and Lan, X and Leuenberger, M and Lindauer, M and Lopez, M and Manca, G and Müller-Williams, J and O'Doherty, S and Scheeren, B and Steinbacher, M and Trisolino, P and V\itková, G and Yver Kwok, C},
title = {High-resolution inverse modelling of European CH_4 emissions using the novel FLEXPART-COSMO TM5 4DVAR inverse modelling system},
journal = {Atmospheric Chemistry and Physics},
year = {2022},
volume = {22},
number = {20},
pages = {13243--13268},
url = {https://acp.copernicus.org/articles/22/13243/2022/},
doi = {10.5194/acp-22-13243-2022}
}
|
| Bhattacharjee S, Mortikov E, Debolskiy A, Kadantsev E, Pandit R, Vesala T and Sahoo G (2022), "Direct Numerical Simulation of a Turbulent Channel Flow with Forchheimer Drag", Boundary-Layer Meteorology. Vol. 185(2), pp. 259-276. |
| Abstract: We characterize the turbulent flow, using direct numerical simulations (DNS), within a closed channel between two parallel walls with a canopy of constant areal density profile on the lower wall. The canopy is modelled using different formulations of the Forchheimer drag, and the characteristic properties of the turbulent flows are compared. In particular, we examine the influence of the added drag on the mean profiles of the flow and the balance equations of the turbulent kinetic energy. We find that the different formulations of the drag strongly affect the mean and the turbulent profiles close to the canopy. We also observe the changes in the local anisotropy of the turbulent flow in the presence of the canopy. We find that there is an equal transfer of energy from the streamwise component to both the transverse components outside the canopy by the pressure and velocity-gradient correlation; inside the canopy, this correlation removes energy from both the streamwise and the wall-normal fluctuations and injects into the spanwise component. As a result, the energy content of the spanwise fluctuations is comparable to that of the streamwise components inside the canopy. Inside the canopy, we observe that the turbulent transport of Reynolds stresses acts as an important source of turbulent kinetic energy. The pressure-fluctuation transport plays a significant role inside the canopy close to the wall and is comparable to turbulent transport. |
BibTeX:
@article{Bhattacharjee2022,
author = {Bhattacharjee, Soumak and Mortikov, Evgeny and Debolskiy, Andrey and Kadantsev, Evgeny and Pandit, Rahul and Vesala, Timo and Sahoo, Ganapati},
title = {Direct Numerical Simulation of a Turbulent Channel Flow with Forchheimer Drag},
journal = {Boundary-Layer Meteorology},
year = {2022},
volume = {185},
number = {2},
pages = {259--276},
url = {https://doi.org/10.1007/s10546-022-00731-8},
doi = {10.1007/s10546-022-00731-8}
}
|
| Bignotti L, Finco A, Marzuoli R, Urgnani R, Riccio A, Chianese E, Muys B and Gerosa GA (2022), "Seasonal variation of size-resolved aerosol fluxes in a Peri-urban deciduous broadleaved forest", Agricultural and Forest Meteorology., dec, 2022. Vol. 327, pp. 109206. Elsevier BV. |
BibTeX:
@article{Bignotti2022,
author = {Bignotti, Laura and Finco, Angelo and Marzuoli, Riccardo and Urgnani, Rossella and Riccio, Angelo and Chianese, Elena and Muys, Bart and Gerosa, Giacomo Alessandro},
title = {Seasonal variation of size-resolved aerosol fluxes in a Peri-urban deciduous broadleaved forest},
journal = {Agricultural and Forest Meteorology},
publisher = {Elsevier BV},
year = {2022},
volume = {327},
pages = {109206},
url = {http://dx.doi.org/10.1016/j.agrformet.2022.109206},
doi = {10.1016/j.agrformet.2022.109206}
}
|
| Boeing F, Rakovec O, Kumar R, Samaniego L, Schrön M, Hildebrandt A, Rebmann C, Thober S, Müller S, Zacharias S, Bogena H, Schneider K, Kiese R, Attinger S and Marx A (2022), "High-resolution drought simulations and comparison to soil moisture observations in Germany", Hydrology and Earth System Sciences. Vol. 26(19), pp. 5137-5161. |
BibTeX:
@article{Boeing2022,
author = {Boeing, F and Rakovec, O and Kumar, R and Samaniego, L and Schrön, M and Hildebrandt, A and Rebmann, C and Thober, S and Müller, S and Zacharias, S and Bogena, H and Schneider, K and Kiese, R and Attinger, S and Marx, A},
title = {High-resolution drought simulations and comparison to soil moisture observations in Germany},
journal = {Hydrology and Earth System Sciences},
year = {2022},
volume = {26},
number = {19},
pages = {5137--5161},
url = {https://hess.copernicus.org/articles/26/5137/2022/},
doi = {10.5194/hess-26-5137-2022}
}
|
| Bogena HR, Schrön M, Jakobi J, Ney P, Zacharias S, Andreasen M, Baatz R, Boorman D, Duygu MB, Eguibar-Galán MA, Fersch B, Franke T, Geris J, González Sanchis M, Kerr Y, Korf T, Mengistu Z, Mialon A, Nasta P, Nitychoruk J, Pisinaras V, Rasche D, Rosolem R, Said H, Schattan P, Zreda M, Achleitner S, Albentosa-Hernández E, Akyürek Z, Blume T, del Campo A, Canone D, Dimitrova-Petrova K, Evans JG, Ferraris S, Frances F, Gisolo D, Güntner A, Herrmann F, Iwema J, Jensen KH, Kunstmann H, Lidón A, Looms MC, Oswald S, Panagopoulos A, Patil A, Power D, Rebmann C, Romano N, Scheiffele L, Seneviratne S, Weltin G and Vereecken H (2022), "COSMOS-Europe: a European network of cosmic-ray neutron soil moisture sensors", Earth System Science Data. Vol. 14(3), pp. 1125-1151. |
BibTeX:
@article{Bogena2022,
author = {Bogena, H R and Schrön, M and Jakobi, J and Ney, P and Zacharias, S and Andreasen, M and Baatz, R and Boorman, D and Duygu, M B and Eguibar-Galán, M A and Fersch, B and Franke, T and Geris, J and González Sanchis, M and Kerr, Y and Korf, T and Mengistu, Z and Mialon, A and Nasta, P and Nitychoruk, J and Pisinaras, V and Rasche, D and Rosolem, R and Said, H and Schattan, P and Zreda, M and Achleitner, S and Albentosa-Hernández, E and Akyürek, Z and Blume, T and del Campo, A and Canone, D and Dimitrova-Petrova, K and Evans, J G and Ferraris, S and Frances, F and Gisolo, D and Güntner, A and Herrmann, F and Iwema, J and Jensen, K H and Kunstmann, H and Lidón, A and Looms, M C and Oswald, S and Panagopoulos, A and Patil, A and Power, D and Rebmann, C and Romano, N and Scheiffele, L and Seneviratne, S and Weltin, G and Vereecken, H},
title = {COSMOS-Europe: a European network of cosmic-ray neutron soil moisture sensors},
journal = {Earth System Science Data},
year = {2022},
volume = {14},
number = {3},
pages = {1125--1151},
url = {https://essd.copernicus.org/articles/14/1125/2022/},
doi = {10.5194/essd-14-1125-2022}
}
|
| Brümmer C, Rüffer JJ, Delorme J-P, Wintjen P, Schrader F, Beudert B, Schaap M and Ammann C (2022), "Reactive nitrogen fluxes over peatland and forest ecosystems using micrometeorological measurement techniques", Earth System Science Data. Vol. 14(2), pp. 743-761. |
BibTeX:
@article{Bruemmer2022,
author = {Brümmer, C and Rüffer, J J and Delorme, J.-P. and Wintjen, P and Schrader, F and Beudert, B and Schaap, M and Ammann, C},
title = {Reactive nitrogen fluxes over peatland and forest ecosystems using micrometeorological measurement techniques},
journal = {Earth System Science Data},
year = {2022},
volume = {14},
number = {2},
pages = {743--761},
url = {https://essd.copernicus.org/articles/14/743/2022/},
doi = {10.5194/essd-14-743-2022}
}
|
| Brunner C, Brem BT, Collaud Coen M, Conen F, Steinbacher M, Gysel-Beer M and Kanji ZA (2022), "The diurnal and seasonal variability of ice-nucleating particles at the High Altitude Station Jungfraujoch (3580,m,a.s.l.), Switzerland", Atmospheric Chemistry and Physics. Vol. 22(11), pp. 7557-7573. |
BibTeX:
@article{Brunner2022,
author = {Brunner, C and Brem, B T and Collaud Coen, M and Conen, F and Steinbacher, M and Gysel-Beer, M and Kanji, Z A},
title = {The diurnal and seasonal variability of ice-nucleating particles at the High Altitude Station Jungfraujoch (3580,m,a.s.l.), Switzerland},
journal = {Atmospheric Chemistry and Physics},
year = {2022},
volume = {22},
number = {11},
pages = {7557--7573},
url = {https://acp.copernicus.org/articles/22/7557/2022/},
doi = {10.5194/acp-22-7557-2022}
}
|
| Conen F, Einbock A, Mignani C and Hüglin C (2022), "Measurement report: Ice-nucleating particles active ge -15,degreeC in free tropospheric air over western Europe", Atmospheric Chemistry and Physics. Vol. 22(5), pp. 3433-3444. |
BibTeX:
@article{Conen2022,
author = {Conen, F and Einbock, A and Mignani, C and Hüglin, C},
title = {Measurement report: Ice-nucleating particles active ge -15,degreeC in free tropospheric air over western Europe},
journal = {Atmospheric Chemistry and Physics},
year = {2022},
volume = {22},
number = {5},
pages = {3433--3444},
url = {https://acp.copernicus.org/articles/22/3433/2022/},
doi = {10.5194/acp-22-3433-2022}
}
|
| Crisp D, Dolman H, Tanhua T, McKinley GA, Hauck J, Bastos A, Sitch S, Eggleston S and Aich V (2022), "How Well Do We Understand the Land-Ocean-Atmosphere Carbon Cycle?", Reviews of Geophysics. Vol. 60(2), pp. e2021RG000736. |
| Abstract: Abstract Fossil fuel combustion, land use change and other human activities have increased the atmospheric carbon dioxide (CO2) abundance by about 50% since the beginning of the industrial age. The atmospheric CO2 growth rates would have been much larger if natural sinks in the land biosphere and ocean had not removed over half of this anthropogenic CO2. As these CO2 emissions grew, uptake by the ocean increased in response to increases in atmospheric CO2 partial pressure (pCO2). On land, gross primary production also increased, but the dynamics of other key aspects of the land carbon cycle varied regionally. Over the past three decades, CO2 uptake by intact tropical humid forests declined, but these changes are offset by increased uptake across mid- and high-latitudes. While there have been substantial improvements in our ability to study the carbon cycle, measurement and modeling gaps still limit our understanding of the processes driving its evolution. Continued ship-based observations combined with expanded deployments of autonomous platforms are needed to quantify ocean-atmosphere fluxes and interior ocean carbon storage on policy-relevant spatial and temporal scales. There is also an urgent need for more comprehensive measurements of stocks, fluxes and atmospheric CO2 in humid tropical forests and across the Arctic and boreal regions, which are experiencing rapid change. Here, we review our understanding of the atmosphere, ocean, and land carbon cycles and their interactions, identify emerging measurement and modeling capabilities and gaps and the need for a sustainable, operational framework to ensure a scientific basis for carbon management. |
BibTeX:
@article{Crisp2022,
author = {Crisp, David and Dolman, Han and Tanhua, Toste and McKinley, Galen A and Hauck, Judith and Bastos, Ana and Sitch, Stephen and Eggleston, Simon and Aich, Valentin},
title = {How Well Do We Understand the Land-Ocean-Atmosphere Carbon Cycle?},
journal = {Reviews of Geophysics},
year = {2022},
volume = {60},
number = {2},
pages = {e2021RG000736},
url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2021RG000736},
doi = {10.1029/2021RG000736}
}
|
| Cronin MF, Swart S, Marandino CA, Anderson C, Browne P, Chen S, Joubert WR, Schuster U, Venkatesan R, Addey CI, Alves O, Ardhuin F, Battle S, Bourassa MA, Chen Z, Chory M, Clayson C, de Souza RB, du Plessis M, Edmondson M, Edson JB, Gille ST, Hermes J, Hormann V, Josey SA, Kurz M, Lee T, Maicu F, Moustahfid EH, Nicholson S-A, Nyadjro ES, Palter J, Patterson RG, Penny SG, Pezzi LP, Pinardi N, Reeves Eyre JEJ, Rome N, Subramanian AC, Stienbarger C, Steinhoff T, Sutton AJ, Tomita H, Wills SM, Wilson C and Yu L (2022), "Developing an Observing Air–Sea Interactions Strategy (OASIS) for the global ocean", ICES Journal of Marine Science. |
| Abstract: The Observing Air–Sea Interactions Strategy (OASIS) is a new United Nations Decade of Ocean Science for Sustainable Development programme working to develop a practical, integrated approach for observing air–sea interactions globally for improved Earth system (including ecosystem) forecasts, CO2 uptake assessments called for by the Paris Agreement, and invaluable surface ocean information for decision makers. Our “Theory of Change” relies upon leveraged multi-disciplinary activities, partnerships, and capacity strengthening. Recommendations from \>40 OceanObs'19 community papers and a series of workshops have been consolidated into three interlinked Grand Ideas for creating #1: a globally distributed network of mobile air–sea observing platforms built around an expanded array of long-term time-series stations; #2: a satellite network, with high spatial and temporal resolution, optimized for measuring air–sea fluxes; and #3: improved representation of air–sea coupling in a hierarchy of Earth system models. OASIS activities are organized across five Theme Teams: (1) Observing Network Design & Model Improvement; (2) Partnership & Capacity Strengthening; (3) UN Decade OASIS Actions; (4) Best Practices & Interoperability Experiments; and (5) Findable–Accessible–Interoperable–Reusable (FAIR) models, data, and OASIS products. Stakeholders, including researchers, are actively recruited to participate in Theme Teams to help promote a predicted, safe, clean, healthy, resilient, and productive ocean. |
BibTeX:
@article{Cronin2022,
author = {Cronin, M F and Swart, S and Marandino, C A and Anderson, C and Browne, P and Chen, S and Joubert, W R and Schuster, U and Venkatesan, R and Addey, C I and Alves, O and Ardhuin, F and Battle, S and Bourassa, M A and Chen, Z and Chory, M and Clayson, C and de Souza, R B and du Plessis, M and Edmondson, M and Edson, J B and Gille, S T and Hermes, J and Hormann, V and Josey, S A and Kurz, M and Lee, T and Maicu, F and Moustahfid, E H and Nicholson, S-A and Nyadjro, E S and Palter, J and Patterson, R G and Penny, S G and Pezzi, L P and Pinardi, N and Reeves Eyre, J E J and Rome, N and Subramanian, A C and Stienbarger, C and Steinhoff, T and Sutton, A J and Tomita, H and Wills, S M and Wilson, C and Yu, L},
title = {Developing an Observing Air–Sea Interactions Strategy (OASIS) for the global ocean},
journal = {ICES Journal of Marine Science},
year = {2022},
url = {https://doi.org/10.1093/icesjms/fsac149},
doi = {10.1093/icesjms/fsac149}
}
|
| Cuevas E, García OE, Luis SFL, Dávila MG, Adame JA, Carrara A, Belchí PV, Delory E, Soriano PPR, Méndez GV, Barreto A, Curcoll R, Yela M and González AG (2022), "ICOS-Spain. Activity Report 2021-2022"
[BibTeX] |
BibTeX:
@article{Cuevas2022,
author = {Cuevas, E and García, O E and Luis, S F León and Dávila, M González and Adame, J A and Carrara, A and Belchí, P Vélez and Delory, E and Soriano, P P Rivas and Méndez, G Villalba and Barreto, A and Curcoll, R and Yela, M and González, A González},
title = {ICOS-Spain. Activity Report 2021-2022},
year = {2022}
}
|
| Daghino S, Martino E, Voyron S and Perotto S (2022), "Metabarcoding of fungal assemblages in Vaccinium myrtillus endosphere suggests colonization of above-ground organs by some ericoid mycorrhizal and DSE fungi", Scientific Reports. Vol. 12(1), pp. 11013. |
| Abstract: Plants harbor in their external surfaces and internal tissues a highly diverse and finely structured microbial assembly, the microbiota. Each plant compartment usually represents a unique ecological niche hosting a distinct microbial community and niche differentiation, which may mirror distinct functions of a specialized microbiota, has been mainly investigated for bacteria. Far less is known for the fungal components of the plant-associated microbiota. Here, we applied a metabarcoding approach to describe the fungal assemblages in different organs of Vaccinium myrtillus plants (Ericaceae) collected in a subalpine meadow in North-West Italy, and identified specific taxa enriched in internal tissues of roots, stems, leaves and flowers. We also traced the distribution of some important fungi commonly associated with plants of the family Ericaceae, namely the ericoid mycorrhizal (ErM) fungi and the dark septate endophytes (DSE), both playing important roles in plant growth and health. Operational taxonomic units attributed to established ErM fungal species in the genus Hyaloscypha and to DSE species in the Phialocephala-Acephala applanata complex (PAC) were found in all the plant organs. Mycorrhizal fungi are thought to be strictly associated with the plant roots, and this first observation of ErM fungi in the above-ground organs of the host plant may be explained by the evolutionary closeness of ErM fungi in the genus Hyaloscypha with non mycorrhizal fungal endophytes. This is also witnessed by the closer similarities of the ErM fungal genomes with the genomes of plant endophytes than with those of other mycorrhizal fungi, such as arbuscular or ectomycorrhizal fungi. |
BibTeX:
@article{Daghino2022,
author = {Daghino, Stefania and Martino, Elena and Voyron, Samuele and Perotto, Silvia},
title = {Metabarcoding of fungal assemblages in Vaccinium myrtillus endosphere suggests colonization of above-ground organs by some ericoid mycorrhizal and DSE fungi},
journal = {Scientific Reports},
year = {2022},
volume = {12},
number = {1},
pages = {11013},
url = {https://doi.org/10.1038/s41598-022-15154-1},
doi = {10.1038/s41598-022-15154-1}
}
|
| Davies P, Baatz R, Bogena HR, Quansah E and Amekudzi LK (2022), "Optimal Temporal Filtering of the Cosmic-Ray Neutron Signal to Reduce Soil Moisture Uncertainty", Sensors. Vol. 22(23) |
| Abstract: Cosmic ray neutron sensors (CRNS) are increasingly used to determine field-scale soil moisture (SM). Uncertainty of the CRNS-derived soil moisture strongly depends on the CRNS count rate subject to Poisson distribution. State-of-the-art CRNS signal processing averages neutron counts over many hours, thereby accounting for soil moisture temporal dynamics at the daily but not sub-daily time scale. This study demonstrates CRNS signal processing methods to improve the temporal accuracy of the signal in order to observe sub-daily changes in soil moisture and improve the signal-to-noise ratio overall. In particular, this study investigates the effectiveness of the Moving Average (MA), Median filter (MF), Savitzky–Golay (SG) filter, and Kalman filter (KF) to reduce neutron count error while ensuring that the temporal SM dynamics are as good as possible. The study uses synthetic data from four stations for measuring forest ecosystem–atmosphere relations in Africa (Gorigo) and Europe (SMEAR II (Station for Measuring Forest Ecosystem–Atmosphere Relations), Rollesbroich, and Conde) with different soil properties, land cover and climate. The results showed that smaller window sizes (12 h) for MA, MF and SG captured sharp changes closely. Longer window sizes were more beneficial in the case of moderate soil moisture variations during long time periods. For MA, MF and SG, optimal window sizes were identified and varied by count rate and climate, i.e., estimated temporal soil moisture dynamics by providing a compromise between monitoring sharp changes and reducing the effects of outliers. The optimal window for these filters and the Kalman filter always outperformed the standard procedure of simple 24-h averaging. The Kalman filter showed its highest robustness in uncertainty reduction at three different locations, and it maintained relevant sharp changes in the neutron counts without the need to identify the optimal window size. Importantly, standard corrections of CRNS before filtering improved soil moisture accuracy for all filters. We anticipate the improved signal-to-noise ratio to benefit CRNS applications such as detection of rain events at sub-daily resolution, provision of SM at the exact time of a satellite overpass, and irrigation applications. |
BibTeX:
@article{Davies2022,
author = {Davies, Patrick and Baatz, Roland and Bogena, Heye Reemt and Quansah, Emmanuel and Amekudzi, Leonard Kofitse},
title = {Optimal Temporal Filtering of the Cosmic-Ray Neutron Signal to Reduce Soil Moisture Uncertainty},
journal = {Sensors},
year = {2022},
volume = {22},
number = {23},
url = {https://www.mdpi.com/1424-8220/22/23/9143},
doi = {10.3390/s22239143}
}
|
| Davila X, Gebbie G, Brakstad A, Lauvset SK, McDonagh EL, Schwinger J and Olsen A (2022), "How Is the Ocean Anthropogenic Carbon Reservoir Filled?", Global Biogeochemical Cycles. Vol. 36(5), pp. e2021GB007055. |
| Abstract: Abstract About a quarter of the total anthropogenic CO2 emissions during the industrial era has been absorbed by the ocean. The rate limiting step for this uptake is the transport of the anthropogenic carbon (Cant) from the ocean mixed layer where it is absorbed to the interior ocean where it is stored. While it is generally known that deep water formation sites are important for vertical carbon transport, the exact magnitude of the fluxes across the base of the mixed layer in different regions is uncertain. Here, we determine where, when, and how much Cant has been injected across the mixed-layer base and into the interior ocean since the start of the industrialized era. We do this by combining a transport matrix derived from observations with a time-evolving boundary condition obtained from already published estimates of ocean Cant. Our results show that most of the Cant stored below the mixed layer are injected in the subtropics (40.1%) and the Southern Ocean (36.0%), while the Subpolar North Atlantic has the largest fluxes. The Subpolar North Atlantic is also the most important region for injecting Cant into the deep ocean with 81.6% of the Cant reaching depths greater than 1,000 m. The subtropics, on the other hand, have been the most efficient in transporting Cant across the mixed-layer base per volume of water ventilated. This study shows how the oceanic Cant uptake relies on vertical transports in a few oceanic regions and sheds light on the pathways that fill the ocean Cant reservoir. |
BibTeX:
@article{Davila2022,
author = {Davila, Xabier and Gebbie, Geoffrey and Brakstad, Ailin and Lauvset, Siv K and McDonagh, Elaine L and Schwinger, Jörg and Olsen, Are},
title = {How Is the Ocean Anthropogenic Carbon Reservoir Filled?},
journal = {Global Biogeochemical Cycles},
year = {2022},
volume = {36},
number = {5},
pages = {e2021GB007055},
url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2021GB007055},
doi = {10.1029/2021GB007055}
}
|
| De Cannière S, Vereecken H, Defourny P and Jonard F (2022), "Remote Sensing of Instantaneous Drought Stress at Canopy Level Using Sun-Induced Chlorophyll Fluorescence and Canopy Reflectance", Remote Sensing. Vol. 14(11) |
| Abstract: Climate change amplifies the intensity and occurrence of dry periods leading to drought stress in vegetation. For monitoring vegetation stresses, sun-induced chlorophyll fluorescence (SIF) observations are a potential game-changer, as the SIF emission is mechanistically coupled to photosynthetic activity. Yet, the benefit of SIF for drought stress monitoring is not yet understood. This paper analyses the impact of drought stress on canopy-scale SIF emission and surface reflectance over a lettuce and mustard stand with continuous field spectrometer measurements. Here, the SIF measurements are linked to the plant’s photosynthetic efficiency, whereas the surface reflectance can be used to monitor the canopy structure. The mustard canopy showed a reduction in the biochemical component of its SIF emission (the fluorescence emission efficiency at 760 nm—ϵ760) as a reaction to drought stress, whereas its structural component (the Fluorescence Correction Vegetation Index—FCVI) barely showed a reaction. The lettuce canopy showed both an increase in the variability of its surface reflectance at a sub-daily scale and a decrease in ϵ760 during a drought stress event. These reactions occurred simultaneously, suggesting that sun-induced chlorophyll fluorescence and reflectance-based indices sensitive to the canopy structure provide complementary information. The intensity of these reactions depend on both the soil water availability and the atmospheric water demand. This paper highlights the potential for SIF from the upcoming FLuorescence EXplorer (FLEX) satellite to provide a unique insight on the plant’s water status. At the same time, data on the canopy reflectance with a sub-daily temporal resolution are a promising additional stress indicator for certain species. |
BibTeX:
@article{DeCanniere2022,
author = {De Cannière, Simon and Vereecken, Harry and Defourny, Pierre and Jonard, François},
title = {Remote Sensing of Instantaneous Drought Stress at Canopy Level Using Sun-Induced Chlorophyll Fluorescence and Canopy Reflectance},
journal = {Remote Sensing},
year = {2022},
volume = {14},
number = {11},
url = {https://www.mdpi.com/2072-4292/14/11/2642},
doi = {10.3390/rs14112642}
}
|
| Demol M, Wilkes P, Raumonen P, Moorthy SM, Calders K, Gielen B and Verbeeck H (2022), "Volumetric overestimation of small branches in 3D reconstructions of Fraxinus excelsior", Silva Fennica. Vol. 56(1), pp. 1-26. |
| Abstract: Terrestrial laser scanning (TLS) has been applied to estimate forest wood volume based on detailed 3D tree reconstructions from point cloud data. However, sources of uncertainties in the point cloud data (alignment and scattering errors, occlusion, foliage…) and the reconstruction algorithm type and parameterisation are known to affect the reconstruction, especially around finer branches. To better understand the impacts of these uncertainties on the accuracy of TLS-derived woody volume, high-quality TLS scans were collected in leaf-off conditions prior to destructive harvesting of two forest-grown common ash trees (Fraxinus excelsior L.; diameter at breast height ∼28 cm, woody volume of 732 and 868 L). We manually measured branch diameters at 265 locations in these trees. Estimates of branch diameters and tree volume from Quantitative Structure Models (QSM) were compared with these manual measurements. The accuracy of QSM branch diameter estimates decreased with smaller branch diameters. Tree woody volume was overes-timated (+336 L and +392 L) in both trees. Branches measuring < 5 cm in diameter accounted for 80% and 83% of this overestimation respectively. Filtering for scattering errors or improved coregistration approximately halved the overestimation. Range filtering and modified scanning layouts had mixed effects. The small branch overestimations originated primarily in limitations in scanner characteristics and coregistration errors rather than suboptimal QSM parameterisation. For TLS-derived estimates of tree volume, a higher quality point cloud allows smaller branches to be accurately reconstructed. Additional experiments need to elucidate if these results can be generalised beyond the setup of this study. |
BibTeX:
@article{Demol2022,
author = {Demol, Miro and Wilkes, Phil and Raumonen, Pasi and Moorthy, Sruthi M.Krishna and Calders, Kim and Gielen, Bert and Verbeeck, Hans},
title = {Volumetric overestimation of small branches in 3D reconstructions of Fraxinus excelsior},
journal = {Silva Fennica},
year = {2022},
volume = {56},
number = {1},
pages = {1--26},
doi = {10.14214/sf.10550}
}
|
| Donmez C, Blanchy G, Svoboda N, D'Hose T, Hoffmann C, Hierold W and Klumpp K (2022), "Provision of metadata of European agricultural long-term experiments through BonaRes and EJP SOIL collaboration", Data in Brief., jun, 2022. Vol. 42, pp. 108226. Elsevier BV. |
BibTeX:
@article{Donmez2022,
author = {Donmez, Cenk and Blanchy, Guillaume and Svoboda, Nikolai and D'Hose, Tommy and Hoffmann, Carsten and Hierold, Wilfried and Klumpp, Katja},
title = {Provision of metadata of European agricultural long-term experiments through BonaRes and EJP SOIL collaboration},
journal = {Data in Brief},
publisher = {Elsevier BV},
year = {2022},
volume = {42},
pages = {108226},
url = {http://dx.doi.org/10.1016/j.dib.2022.108226},
doi = {10.1016/j.dib.2022.108226}
}
|
| Dorodnikov M, Knorr K-H, Fan L, Kuzyakov Y and Nilsson MB (2022), "A novel belowground in-situ gas labeling approach: CH4 oxidation in deep peat using passive diffusion chambers and 13C excess", Science of The Total Environment. Vol. 806, pp. 150457. |
| Abstract: In-vitro incubation of environmental samples is a common approach to estimate CH4 oxidation potential. Here we developed and verified an in-situ method utilizing passive diffusion chambers (PDC, silicone tubes) to deliver 13C-labeled CH4 into peat for the determination of the CH4 oxidation potential based on 13C excess of CO2. To target CH4 oxidation under semi-aerobic and anaerobic conditions, we installed 20 PDCs (30 ml volume) below the water table in profiles from 35-cm to 2-m depths of a peatland in north-eastern Sweden in July 2017 using a peat auger. 13C-labeled CH4 was injected into PDCs through tubing twice during 12 days (day 0 and 6) and samples were collected at days 1, 3, 6, 8 and 11. Background (non-labeled) δ13C of CO2 ranged from −7.3 (35 cm) to +5.7‰ (200 cm) with depth. These δ13C values rose to +110 and + 204‰ after the CH4 injection. The estimated CH4-derived C in CO2 was the lowest at the bottom of the profile (0.3 μmol L−1), whereas the maximum was at 100 cm (6.1 μmol L−1) at five days after the second labeling. This corresponded to 1.5–7.2% of the total CH4 pool to be oxidized, depending on depth. This novel approach with belowground in-situ 13C labeling of gases demonstrated the suitability of tracing the transformations of these gases in soil depth by PDCs and for the first time verified the in-situ occurrence of a deep-peat CH4 oxidation. |
BibTeX:
@article{Dorodnikov2022,
author = {Dorodnikov, Maxim and Knorr, Klaus-Holger and Fan, Lichao and Kuzyakov, Yakov and Nilsson, Mats B},
title = {A novel belowground in-situ gas labeling approach: CH4 oxidation in deep peat using passive diffusion chambers and 13C excess},
journal = {Science of The Total Environment},
year = {2022},
volume = {806},
pages = {150457},
url = {https://www.sciencedirect.com/science/article/pii/S0048969721055340},
doi = {10.1016/j.scitotenv.2021.150457}
}
|
| Erdbrügger J, van Meerveld I, Seibert J and Bishop K (2022), "Shallow groundwater level time series and a groundwater chemistry survey from a boreal headwater catchment", Earth System Science Data Discussions. Vol. 2022, pp. 1-40. |
BibTeX:
@article{Erdbruegger2022,
author = {Erdbrügger, J and van Meerveld, I and Seibert, J and Bishop, K},
title = {Shallow groundwater level time series and a groundwater chemistry survey from a boreal headwater catchment},
journal = {Earth System Science Data Discussions},
year = {2022},
volume = {2022},
pages = {1--40},
url = {https://essd.copernicus.org/preprints/essd-2022-114/},
doi = {10.5194/essd-2022-114}
}
|
| Eriksson Stenström K, Skog G, Bernhardsson C, Mattsson S, Nielsen AB, Rundgren M, Muscheler R, Linderson H, Pédehontaa-Hiaa G and Rääf C (2022), "Environmental Levels of Radiocarbon in Lund, Sweden, Prior To the Start of the European Spallation Source", Radiocarbon. Vol. 64(1), pp. 51-67. |
| Abstract: The European Spallation Source (ESS) is a neutron-based research facility under construction in Lund in southern Sweden. The spallation reactions will generate not only the desired neutrons, but also many radioactive by-products, including 14C. As part of the licensing process, and as recommended by the IAEA, various preoperational studies are being carried out, including mapping the “zero-point” radiation environment around the site. As the city of Lund hosts several facilities using 14C-labeled substances, and since temporary and local 14C contamination have been observed in the past, 14C mapping is an important part of these baseline assessments. We here present a summary of 14C levels in various terrestrial environmental samples in Lund and in southern Sweden during the years 2012 to 2020. These environmental F14C do not display significantly elevated levels compared to sites located remote from Lund. We also describe a local 14C contamination event that was detected at the Lund Radiocarbon Dating Laboratory in 2009. Horse-chestnut leaves collected close to the laboratory exhibited F14C values of up to ∼25% above the clean air background. Elevated values of F14C were also found in a short tree-ring series, especially in 2007. The source of this contamination was identified and successfully removed. |
BibTeX:
@article{ErikssonStenstroem2022,
author = {Eriksson Stenström, Kristina and Skog, Göran and Bernhardsson, Christian and Mattsson, Sören and Nielsen, Anne Birgitte and Rundgren, Mats and Muscheler, Raimund and Linderson, Hans and Pédehontaa-Hiaa, Guillaume and Rääf, Christopher},
title = {Environmental Levels of Radiocarbon in Lund, Sweden, Prior To the Start of the European Spallation Source},
journal = {Radiocarbon},
year = {2022},
volume = {64},
number = {1},
pages = {51--67},
doi = {10.1017/RDC.2022.2}
}
|
| Etzold S, Sterck F, Bose AK, Braun S, Buchmann N, Eugster W, Gessler A, Kahmen A, Peters RL, Vitasse Y, Walthert L, Ziemiʼnska K and Zweifel R (2022), "Number of growth days and not length of the growth period determines radial stem growth of temperate trees", Ecology Letters., feb, 2022. Vol. 25(2), pp. 427-439. John Wiley & Sons, Ltd. |
| Abstract: Abstract Radial stem growth dynamics at seasonal resolution are essential to understand how forests respond to climate change. We studied daily radial growth of 160 individuals of seven temperate tree species at 47 sites across Switzerland over 8 years. Growth of all species peaked in the early part of the growth season and commenced shortly before the summer solstice, but with species-specific seasonal patterns. Day length set a window of opportunity for radial growth. Within this window, the probability of daily growth was constrained particularly by air and soil moisture, resulting in intermittent growth to occur only on 29 to 77 days (30% to 80%) within the growth period. The number of days with growth largely determined annual growth, whereas the growth period length contributed less. We call for accounting for these non-linear intra-annual and species-specific growth dynamics in tree and forest models to reduce uncertainties in predictions under climate change. |
BibTeX:
@article{Etzold2022,
author = {Etzold, Sophia and Sterck, Frank and Bose, Arun K and Braun, Sabine and Buchmann, Nina and Eugster, Werner and Gessler, Arthur and Kahmen, Ansgar and Peters, Richard L and Vitasse, Yann and Walthert, Lorenz and Ziemiʼnska, Kasia and Zweifel, Roman},
title = {Number of growth days and not length of the growth period determines radial stem growth of temperate trees},
journal = {Ecology Letters},
publisher = {John Wiley & Sons, Ltd},
year = {2022},
volume = {25},
number = {2},
pages = {427--439},
url = {https://doi.org/10.1111/ele.13933},
doi = {10.1111/ele.13933}
}
|
| Findlay HS, Artioli Y, Birchenough SNR, Hartman SE, Leon P and Stiasny M (2022), "Ocean acidification around the UK and Ireland", MCCIP Rolling Evidence Updates. Marine Climate Change Impacts Partnership (MCCIP), Lowestoft, UK. |
BibTeX:
@article{Findlay2022,
author = {Findlay, H S and Artioli, Y and Birchenough, S N R and Hartman, S E and Leon, P and Stiasny, M},
title = {Ocean acidification around the UK and Ireland},
journal = {MCCIP Rolling Evidence Updates},
publisher = {Marine Climate Change Impacts Partnership (MCCIP), Lowestoft, UK},
year = {2022},
url = {https://www.mccip.org.uk/ocean-acidification},
doi = {10.14465/2022.REU03.OAC}
}
|
| Friedlingstein P, O'Sullivan M, Jones MW, Andrew RM, Gregor L, Hauck J, Le Quéré C, Luijkx IT, Olsen A, Peters GP, Peters W, Pongratz J, Schwingshackl C, Sitch S, Canadell JG, Ciais P, Jackson RB, Alin SR, Alkama R, Arneth A, Arora VK, Bates NR, Becker M, Bellouin N, Bittig HC, Bopp L, Chevallier F, Chini LP, Cronin M, Evans W, Falk S, Feely RA, Gasser T, Gehlen M, Gkritzalis T, Gloege L, Grassi G, Gruber N, Gürses Ö, Harris I, Hefner M, Houghton RA, Hurtt GC, Iida Y, Ilyina T, Jain AK, Jersild A, Kadono K, Kato E, Kennedy D, Klein Goldewijk K, Knauer J, Korsbakken JI, Landschützer P, Lefèvre N, Lindsay K, Liu J, Liu Z, Marland G, Mayot N, McGrath MJ, Metzl N, Monacci NM, Munro DR, Nakaoka S-I, Niwa Y, O'Brien K, Ono T, Palmer PI, Pan N, Pierrot D, Pocock K, Poulter B, Resplandy L, Robertson E, Rödenbeck C, Rodriguez C, Rosan TM, Schwinger J, Séférian R, Shutler JD, Skjelvan I, Steinhoff T, Sun Q, Sutton AJ, Sweeney C, Takao S, Tanhua T, Tans PP, Tian X, Tian H, Tilbrook B, Tsujino H, Tubiello F, van der Werf GR, Walker AP, Wanninkhof R, Whitehead C, Willstrand Wranne A, Wright R, Yuan W, Yue C, Yue X, Zaehle S, Zeng J and Zheng B (2022), "Global Carbon Budget 2022", Earth System Science Data. Vol. 14(11), pp. 4811-4900. |
BibTeX:
@article{Friedlingstein2022,
author = {Friedlingstein, P and O'Sullivan, M and Jones, M W and Andrew, R M and Gregor, L and Hauck, J and Le Quéré, C and Luijkx, I T and Olsen, A and Peters, G P and Peters, W and Pongratz, J and Schwingshackl, C and Sitch, S and Canadell, J G and Ciais, P and Jackson, R B and Alin, S R and Alkama, R and Arneth, A and Arora, V K and Bates, N R and Becker, M and Bellouin, N and Bittig, H C and Bopp, L and Chevallier, F and Chini, L P and Cronin, M and Evans, W and Falk, S and Feely, R A and Gasser, T and Gehlen, M and Gkritzalis, T and Gloege, L and Grassi, G and Gruber, N and Gürses, Ö and Harris, I and Hefner, M and Houghton, R A and Hurtt, G C and Iida, Y and Ilyina, T and Jain, A K and Jersild, A and Kadono, K and Kato, E and Kennedy, D and Klein Goldewijk, K and Knauer, J and Korsbakken, J I and Landschützer, P and Lefèvre, N and Lindsay, K and Liu, J and Liu, Z and Marland, G and Mayot, N and McGrath, M J and Metzl, N and Monacci, N M and Munro, D R and Nakaoka, S.-I. and Niwa, Y and O'Brien, K and Ono, T and Palmer, P I and Pan, N and Pierrot, D and Pocock, K and Poulter, B and Resplandy, L and Robertson, E and Rödenbeck, C and Rodriguez, C and Rosan, T M and Schwinger, J and Séférian, R and Shutler, J D and Skjelvan, I and Steinhoff, T and Sun, Q and Sutton, A J and Sweeney, C and Takao, S and Tanhua, T and Tans, P P and Tian, X and Tian, H and Tilbrook, B and Tsujino, H and Tubiello, F and van der Werf, G R and Walker, A P and Wanninkhof, R and Whitehead, C and Willstrand Wranne, A and Wright, R and Yuan, W and Yue, C and Yue, X and Zaehle, S and Zeng, J and Zheng, B},
title = {Global Carbon Budget 2022},
journal = {Earth System Science Data},
year = {2022},
volume = {14},
number = {11},
pages = {4811--4900},
url = {https://essd.copernicus.org/articles/14/4811/2022/},
doi = {10.5194/essd-14-4811-2022}
}
|
| Fu Z, Ciais P, Prentice IC, Gentine P, Makowski D, Bastos A, Luo X, Green JK, Stoy PC, Yang H and Hajima T (2022), "Atmospheric dryness reduces photosynthesis along a large range of soil water deficits", Nature Communications. Vol. 13(1), pp. 989. |
| Abstract: Both low soil water content (SWC) and high atmospheric dryness (vapor pressure deficit, VPD) can negatively affect terrestrial gross primary production (GPP). The sensitivity of GPP to soil versus atmospheric dryness is difficult to disentangle, however, because of their covariation. Using global eddy-covariance observations, here we show that a decrease in SWC is not universally associated with GPP reduction. GPP increases in response to decreasing SWC when SWC is high and decreases only when SWC is below a threshold. By contrast, the sensitivity of GPP to an increase of VPD is always negative across the full SWC range. We further find canopy conductance decreases with increasing VPD (irrespective of SWC), and with decreasing SWC on drier soils. Maximum photosynthetic assimilation rate has negative sensitivity to VPD, and a positive sensitivity to decreasing SWC when SWC is high. Earth System Models underestimate the negative effect of VPD and the positive effect of SWC on GPP such that they should underestimate the GPP reduction due to increasing VPD in future climates. |
BibTeX:
@article{Fu2022a,
author = {Fu, Zheng and Ciais, Philippe and Prentice, I Colin and Gentine, Pierre and Makowski, David and Bastos, Ana and Luo, Xiangzhong and Green, Julia K and Stoy, Paul C and Yang, Hui and Hajima, Tomohiro},
title = {Atmospheric dryness reduces photosynthesis along a large range of soil water deficits},
journal = {Nature Communications},
year = {2022},
volume = {13},
number = {1},
pages = {989},
url = {https://doi.org/10.1038/s41467-022-28652-7},
doi = {10.1038/s41467-022-28652-7}
}
|
| Ganeva D, Chanev M, Filchev L, Jelev G and Valcheva D (2022), "Evaluation of PhenoCam phenology of barley", In Remote Sensing for Agriculture, Ecosystems, and Hydrology XXIV. Vol. 12262, pp. 1226208. SPIE. |
BibTeX:
@inproceedings{Ganeva2022,
author = {Ganeva, Dessislava and Chanev, Milen and Filchev, Lachezar and Jelev, Georgi and Valcheva, Darina},
editor = {Neale, Christopher M U and Maltese, Antonino},
title = {Evaluation of PhenoCam phenology of barley},
booktitle = {Remote Sensing for Agriculture, Ecosystems, and Hydrology XXIV},
publisher = {SPIE},
year = {2022},
volume = {12262},
pages = {1226208},
url = {https://doi.org/10.1117/12.2636335},
doi = {10.1117/12.2636335}
}
|
| Gerosa GA, Bignotti L and Marzuoli R (2022), "Effect of corrections for water vapor sensitivity of coumarin targets and for density fluctuations (WPL) on O3 fluxes measured with the eddy covariance technique", Bulletin of Atmospheric Science and Technology., dec, 2022. Vol. 3(1–4) Springer Science and Business Media LLC. |
BibTeX:
@article{Gerosa2022,
author = {Gerosa, Giacomo A and Bignotti, Laura and Marzuoli, Riccardo},
title = {Effect of corrections for water vapor sensitivity of coumarin targets and for density fluctuations (WPL) on O3 fluxes measured with the eddy covariance technique},
journal = {Bulletin of Atmospheric Science and Technology},
publisher = {Springer Science and Business Media LLC},
year = {2022},
volume = {3},
number = {1–4},
url = {http://dx.doi.org/10.1007/s42865-022-00053-0},
doi = {10.1007/s42865-022-00053-0}
}
|
| Gerosa GA, Marzuoli R and Finco A (2022), "Interannual variability of ozone fluxes in a broadleaf deciduous forest in Italy", Elementa: Science of the Anthropocene. Vol. 10(1) University of California Press. |
BibTeX:
@article{Gerosa2022a,
author = {Gerosa, Giacomo A and Marzuoli, Riccardo and Finco, Angelo},
title = {Interannual variability of ozone fluxes in a broadleaf deciduous forest in Italy},
journal = {Elementa: Science of the Anthropocene},
publisher = {University of California Press},
year = {2022},
volume = {10},
number = {1},
url = {http://dx.doi.org/10.1525/elementa.2021.00105},
doi = {10.1525/elementa.2021.00105}
}
|
| Goll DS, Bauters M, Zhang H, Ciais P, Balkanski Y, Wang R and Verbeeck H (2022), "Atmospheric phosphorus deposition amplifies carbon sinks in simulations of a tropical forest in Central Africa", New Phytologist., nov, 2022. Vol. 237(6), pp. 2054-2068. Wiley. |
BibTeX:
@article{Goll2022,
author = {Goll, Daniel S and Bauters, Marijn and Zhang, Haicheng and Ciais, Philippe and Balkanski, Yves and Wang, Rong and Verbeeck, Hans},
title = {Atmospheric phosphorus deposition amplifies carbon sinks in simulations of a tropical forest in Central Africa},
journal = {New Phytologist},
publisher = {Wiley},
year = {2022},
volume = {237},
number = {6},
pages = {2054--2068},
url = {http://dx.doi.org/10.1111/NPH.18535},
doi = {10.1111/nph.18535}
}
|
| Gutiérrez-Loza L, Nilsson E, Wallin MB, Sahlée E and Rutgersson A (2022), "On physical mechanisms enhancing air--sea CO_2 exchange", Biogeosciences. Vol. 19(24), pp. 5645-5665. |
BibTeX:
@article{GutierrezLoza2022,
author = {Gutiérrez-Loza, L and Nilsson, E and Wallin, M B and Sahlée, E and Rutgersson, A},
title = {On physical mechanisms enhancing air--sea CO_2 exchange},
journal = {Biogeosciences},
year = {2022},
volume = {19},
number = {24},
pages = {5645--5665},
url = {https://bg.copernicus.org/articles/19/5645/2022/},
doi = {10.5194/bg-19-5645-2022}
}
|
| Haberstroh S, Werner C, Grün M, Kreuzwieser J, Seifert T, Schindler D and Christen A (2022), "Central European 2018 hot drought shifts scots pine forest to its tipping point", Plant Biology. Vol. 24(7), pp. 1186-1197. |
| Abstract: Abstract The occurrence of hot drought, i.e. low water availability and simultaneous high air temperature, represents a severe threat to ecosystems. Here, we investigated how the 2018 hot drought in Central Europe caused a tipping point in tree and ecosystem functioning in a Scots pine (Pinus sylvestris L.) forest in southwest Germany. Measurements of stress indicators, such as needle water potential, carbon assimilation and volatile organic compound (VOC) emissions, of dominant P. sylvestris trees were deployed to evaluate tree functioning during hot drought. Ecosystem impact and recovery were assessed as ecosystem carbon exchange, normalized difference vegetation index (NDVI) from satellite data and tree mortality data. During summer 2018, needle water potentials of trees dropped to minimum values of −7.5 ± 0.2 MPa, which implied severe hydraulic impairment of P. sylvestris. Likewise, carbon assimilation and VOC emissions strongly declined after mid-July. Decreasing NDVI values from August 2018 onwards were detected, along with severe defoliation in P. sylvestris, impairing ecosystem carbon flux recovery in 2019, shifting the forest into a year-round carbon source. A total of 47% of all monitored trees (n = 368) died by September 2020. NDVI recovered to pre-2018 levels in 2019, likely caused by emerging broadleaved understorey species. The 2018 hot drought had severe negative impacts on P. sylvestris. The co-occurrence of unfavourable site-specific conditions with recurrent severe droughts resulted in accelerated mortality. Thus, the 2018 hot drought pushed the P. sylvestris stand towards its tipping point, with a subsequent vegetation shift to a broadleaf-dominated forest. |
BibTeX:
@article{Haberstroh2022,
author = {Haberstroh, S and Werner, C and Grün, M and Kreuzwieser, J and Seifert, T and Schindler, D and Christen, A},
title = {Central European 2018 hot drought shifts scots pine forest to its tipping point},
journal = {Plant Biology},
year = {2022},
volume = {24},
number = {7},
pages = {1186--1197},
url = {https://onlinelibrary.wiley.com/doi/abs/10.1111/plb.13455},
doi = {10.1111/plb.13455}
}
|
| Hallgren C, Arnqvist J, Nilsson E, Ivanell S, Shapkalijevski M, Thomasson A, Pettersson H and Sahlée E (2022), "Classification and properties of non-idealized coastal wind profiles -- an observational study", Wind Energy Science. Vol. 7(3), pp. 1183-1207. |
BibTeX:
@article{Hallgren2022,
author = {Hallgren, C and Arnqvist, J and Nilsson, E and Ivanell, S and Shapkalijevski, M and Thomasson, A and Pettersson, H and Sahlée, E},
title = {Classification and properties of non-idealized coastal wind profiles -- an observational study},
journal = {Wind Energy Science},
year = {2022},
volume = {7},
number = {3},
pages = {1183--1207},
url = {https://wes.copernicus.org/articles/7/1183/2022/},
doi = {10.5194/wes-7-1183-2022}
}
|
| Harris E, Yu L, Wang Y-P, Mohn J, Henne S, Bai E, Barthel M, Bauters M, Boeckx P, Dorich C, Farrell M, Krummel PB, Loh ZM, Reichstein M, Six J, Steinbacher M, Wells NS, Bahn M and Rayner P (2022), "Warming and redistribution of nitrogen inputs drive an increase in terrestrial nitrous oxide emission factor", Nature Communications. Vol. 13(1), pp. 4310. |
| Abstract: Anthropogenic nitrogen inputs cause major negative environmental impacts, including emissions of the important greenhouse gas N2O. Despite their importance, shifts in terrestrial N loss pathways driven by global change are highly uncertain. Here we present a coupled soil-atmosphere isotope model (IsoTONE) to quantify terrestrial N losses and N2O emission factors from 1850-2020. We find that N inputs from atmospheric deposition caused 51% of anthropogenic N2O emissions from soils in 2020. The mean effective global emission factor for N2O was 4.3 ± 0.3% in 2020 (weighted by N inputs), much higher than the surface area-weighted mean (1.1 ± 0.1%). Climate change and spatial redistribution of fertilisation N inputs have driven an increase in global emission factor over the past century, which accounts for 18% of the anthropogenic soil flux in 2020. Predicted increases in fertilisation in emerging economies will accelerate N2O-driven climate warming in coming decades, unless targeted mitigation measures are introduced. |
BibTeX:
@article{Harris2022,
author = {Harris, E and Yu, L and Wang, Y-P. and Mohn, J and Henne, S and Bai, E and Barthel, M and Bauters, M and Boeckx, P and Dorich, C and Farrell, M and Krummel, P B and Loh, Z M and Reichstein, M and Six, J and Steinbacher, M and Wells, N S and Bahn, M and Rayner, P},
title = {Warming and redistribution of nitrogen inputs drive an increase in terrestrial nitrous oxide emission factor},
journal = {Nature Communications},
year = {2022},
volume = {13},
number = {1},
pages = {4310},
url = {https://doi.org/10.1038/s41467-022-32001-z},
doi = {10.1038/s41467-022-32001-z}
}
|
| Hase N, Doktor D, Rebmann C, Dechant B, Mollenhauer H and Cuntz M (2022), "Identifying the main drivers of the seasonal decline of near-infrared reflectance of a temperate deciduous forest", Agricultural and Forest Meteorology. Vol. 313, pp. 108746. |
| Abstract: The physical mechanisms behind correlations of earth observations and remote sensing products are of vital importance. The so-called 'near-infrared reflectance of vegetation' (NIRV) and gross primary production (GPP) show high correlations among different ecosystems and temporal scales but the underlying relationship is still poorly understood. NIRV is defined as the product of normalized difference vegetation index (NDVI) and near-infrared (NIR) canopy reflectance (RNIR). We examined this relationship in the case of a temperate deciduous forest in Germany. GPP, RNIR and NIRV all exhibited a strong rise during leaf development in spring and a continual decline after the maximum in early summer. The decline of NIRV in late summer was mainly driven by the decline of RNIR, since NDVI remained saturated. Here we tested the RNIR decline attributions to changes in leaf area index, leaf optical properties, canopy structure, sun-sensor geometry, or understory vegetation by measuring seasonal variations of those factors of the temperate deciduous forest. Leaf area was nearly constant between May and mid September, leaf albedo decreased slightly, leaf angles increased over time towards more vertical leaves, and understory reflectance decreased considerably. We simulated the seasonal RNIR decline of the forest using the radiative transfer model FRT and quantified the sensitivity of the decline to variations in the measured parameters. FRT captured well the observed seasonal RNIR decline by Sentinel 2 using the measured optical and structural properties. Decreasing understory reflectance alone explained 43% of the simulated RNIR decrease, while leaf angle variations explained 31%, the solar zenith angle (SZA) 21%, leaf albedo 7%, and LAI 0%. The effect size of the SZA depended on the viewing angle and would hence be different for different satellites and for local instruments. The results may help to better understand and help to track seasonal changes in forest structure and leaf optical properties using remote sensing techniques. They also suggest that the proposed link between the seasonal evolution of GPP and NIRV may be weaker than expected. |
BibTeX:
@article{Hase2022,
author = {Hase, Niklas and Doktor, Daniel and Rebmann, Corinna and Dechant, Benjamin and Mollenhauer, Hannes and Cuntz, Matthias},
title = {Identifying the main drivers of the seasonal decline of near-infrared reflectance of a temperate deciduous forest},
journal = {Agricultural and Forest Meteorology},
year = {2022},
volume = {313},
pages = {108746},
url = {https://www.sciencedirect.com/science/article/pii/S0168192321004329},
doi = {10.1016/j.agrformet.2021.108746}
}
|
| Havu M, Kulmala L, Kolari P, Vesala T, Riikonen A and Järvi L (2022), "Carbon sequestration potential of street tree plantings in Helsinki", Biogeosciences. Vol. 19(8), pp. 2121-2143. |
BibTeX:
@article{Havu2022,
author = {Havu, M and Kulmala, L and Kolari, P and Vesala, T and Riikonen, A and Järvi, L},
title = {Carbon sequestration potential of street tree plantings in Helsinki},
journal = {Biogeosciences},
year = {2022},
volume = {19},
number = {8},
pages = {2121--2143},
url = {https://bg.copernicus.org/articles/19/2121/2022/},
doi = {10.5194/bg-19-2121-2022}
}
|
| Heiskanen J, Brümmer C, Buchmann N, Calfapietra C, Chen H, Gielen B, Gkritzalis T, Hammer S, Hartman S, Herbst M, Janssens IA, Jordan A, Juurola E, Karstens U, Kasurinen V, Kruijt B, Lankreijer H, Levin I, Linderson M-L, Loustau D, Merbold L, Myhre CL, Papale D, Pavelka M, Pilegaard K, Ramonet M, Rebmann C, Rinne J, Rivier L, Saltikoff E, Sanders R, Steinbacher M, Steinhoff T, Watson A, Vermeulen AT, Vesala T, Vítková G and Kutsch W (2022), "The Integrated Carbon Observation System in Europe", Bulletin of the American Meteorological Society., mar, 2022. Vol. 103(3), pp. E855-E872. American Meteorological Society. |
BibTeX:
@article{Heiskanen2022,
author = {Heiskanen, Jouni and Brümmer, Christian and Buchmann, Nina and Calfapietra, Carlo and Chen, Huilin and Gielen, Bert and Gkritzalis, Thanos and Hammer, Samuel and Hartman, Susan and Herbst, Mathias and Janssens, Ivan A and Jordan, Armin and Juurola, Eija and Karstens, Ute and Kasurinen, Ville and Kruijt, Bart and Lankreijer, Harry and Levin, Ingeborg and Linderson, Maj-Lena and Loustau, Denis and Merbold, Lutz and Myhre, Cathrine Lund and Papale, Dario and Pavelka, Marian and Pilegaard, Kim and Ramonet, Michel and Rebmann, Corinna and Rinne, Janne and Rivier, Léonard and Saltikoff, Elena and Sanders, Richard and Steinbacher, Martin and Steinhoff, Tobias and Watson, Andrew and Vermeulen, Alex T and Vesala, Timo and Vítková, Gabriela and Kutsch, Werner},
title = {The Integrated Carbon Observation System in Europe},
journal = {Bulletin of the American Meteorological Society},
publisher = {American Meteorological Society},
year = {2022},
volume = {103},
number = {3},
pages = {E855--E872},
url = {http://dx.doi.org/10.1175/BAMS-D-19-0364.1},
doi = {10.1175/bams-d-19-0364.1}
}
|
| Heistermann M, Bogena H, Francke T, Güntner A, Jakobi J, Rasche D, Schrön M, Döpper V, Fersch B, Groh J, Patil A, Pütz T, Reich M, Zacharias S, Zengerle C and Oswald S (2022), "Soil moisture observation in a forested headwater catchment: combining a dense cosmic-ray neutron sensor network with roving and hydrogravimetry at the TERENO site Wüstebach", Earth System Science Data. Vol. 14(5), pp. 2501-2519. |
BibTeX:
@article{Heistermann2022,
author = {Heistermann, M and Bogena, H and Francke, T and Güntner, A and Jakobi, J and Rasche, D and Schrön, M and Döpper, V and Fersch, B and Groh, J and Patil, A and Pütz, T and Reich, M and Zacharias, S and Zengerle, C and Oswald, S},
title = {Soil moisture observation in a forested headwater catchment: combining a dense cosmic-ray neutron sensor network with roving and hydrogravimetry at the TERENO site Wüstebach},
journal = {Earth System Science Data},
year = {2022},
volume = {14},
number = {5},
pages = {2501--2519},
url = {https://essd.copernicus.org/articles/14/2501/2022/},
doi = {10.5194/essd-14-2501-2022}
}
|
| Helbig M, Živković T, Alekseychik P, Aurela M, El-Madany TS, Euskirchen ES, Flanagan LB, Griffis TJ, Hanson PJ, Hattakka J, Helfter C, Hirano T, Humphreys ER, Kiely G, Kolka RK, Laurila T, Leahy PG, Lohila A, Mammarella I, Nilsson MB, Panov A, Parmentier FJW, Peichl M, Rinne J, Roman DT, Sonnentag O, Tuittila E-S, Ueyama M, Vesala T, Vestin P, Weldon S, Weslien P and Zaehle S (2022), "Warming response of peatland CO2 sink is sensitive to seasonality in warming trends", Nature Climate Change. Vol. 12(8), pp. 743-749. |
| Abstract: Peatlands have acted as net CO2 sinks over millennia, exerting a global climate cooling effect. Rapid warming at northern latitudes, where peatlands are abundant, can disturb their CO2 sink function. Here we show that sensitivity of peatland net CO2 exchange to warming changes in sign and magnitude across seasons, resulting in complex net CO2 sink responses. We use multiannual net CO2 exchange observations from 20 northern peatlands to show that warmer early summers are linked to increased net CO2 uptake, while warmer late summers lead to decreased net CO2 uptake. Thus, net CO2 sinks of peatlands in regions experiencing early summer warming, such as central Siberia, are more likely to persist under warmer climate conditions than are those in other regions. Our results will be useful to improve the design of future warming experiments and to better interpret large-scale trends in peatland net CO2 uptake over the coming few decades. |
BibTeX:
@article{Helbig2022,
author = {Helbig, M and Živković, T and Alekseychik, P and Aurela, M and El-Madany, T S and Euskirchen, E S and Flanagan, L B and Griffis, T J and Hanson, P J and Hattakka, J and Helfter, C and Hirano, T and Humphreys, E R and Kiely, G and Kolka, R K and Laurila, T and Leahy, P G and Lohila, A and Mammarella, I and Nilsson, M B and Panov, A and Parmentier, F J W and Peichl, M and Rinne, J and Roman, D T and Sonnentag, O and Tuittila, E.-S and Ueyama, M and Vesala, T and Vestin, P and Weldon, S and Weslien, P and Zaehle, S},
title = {Warming response of peatland CO2 sink is sensitive to seasonality in warming trends},
journal = {Nature Climate Change},
year = {2022},
volume = {12},
number = {8},
pages = {743--749},
url = {https://doi.org/10.1038/s41558-022-01428-z},
doi = {10.1038/s41558-022-01428-z}
}
|
| Hollós R, Fodor N, Merganičová K, Hidy D, Árendás T, Grünwald T and Barcza Z (2022), "Conditional interval reduction method: A possible new direction for the optimization of process based models", Environmental Modelling & Software. Vol. 158, pp. 105556. |
| Abstract: Application of process-based models at different spatial scales requires their proper parameterization. This task is typically executed using trial-and-error parameter adjustment or a probabilistic method. Practical application of the probabilistic methods is hampered by methodological complexity and lack of interpretability. Here we present a novel approach for the parameterization of process-based models that we call as conditional interval refinement method (CIRM). The method can be best described as the combination of a probabilistic approach and the advantages of the expert-based parameter adjustment. CIRM was demonstrated by optimizing the Biome-BGCMuSo biogeochemical model using maize yield observations. The proposed approach uses the General Likelihood Uncertainty Estimation (GLUE) method with additional expert knowledge, supplemented by the construction and interpretation of decision trees. It was demonstrated that the iterative, fully automatic method successfully constrained the parameter intervals meanwhile our confidence on the parameters increased. The algorithm can easily be implemented with other process-based models. |
BibTeX:
@article{Hollos2022,
author = {Hollós, R and Fodor, N and Merganičová, K and Hidy, D and Árendás, T and Grünwald, T and Barcza, Z},
title = {Conditional interval reduction method: A possible new direction for the optimization of process based models},
journal = {Environmental Modelling & Software},
year = {2022},
volume = {158},
pages = {105556},
url = {https://www.sciencedirect.com/science/article/pii/S1364815222002560},
doi = {10.1016/j.envsoft.2022.105556}
}
|
| Hough M, McCabe S, Vining SR, Pickering Pedersen E, Wilson RM, Lawrence R, Chang K-Y, Bohrer G, Coordinators TI, Riley WJ, Crill PM, Varner RK, Blazewicz SJ, Dorrepaal E, Tfaily MM, Saleska SR and Rich VI (2022), "Coupling plant litter quantity to a novel metric for litter quality explains C storage changes in a thawing permafrost peatland", Global Change Biology., feb, 2022. Vol. 28(3), pp. 950-968. John Wiley & Sons, Ltd. |
| Abstract: Abstract Permafrost thaw is a major potential feedback source to climate change as it can drive the increased release of greenhouse gases carbon dioxide (CO2) and methane (CH4). This carbon release from the decomposition of thawing soil organic material can be mitigated by increased net primary productivity (NPP) caused by warming, increasing atmospheric CO2, and plant community transition. However, the net effect on C storage also depends on how these plant community changes alter plant litter quantity, quality, and decomposition rates. Predicting decomposition rates based on litter quality remains challenging, but a promising new way forward is to incorporate measures of the energetic favorability to soil microbes of plant biomass decomposition. We asked how the variation in one such measure, the nominal oxidation state of carbon (NOSC), interacts with changing quantities of plant material inputs to influence the net C balance of a thawing permafrost peatland. We found: (1) Plant productivity (NPP) increased post-thaw, but instead of contributing to increased standing biomass, it increased plant biomass turnover via increased litter inputs to soil; (2) Plant litter thermodynamic favorability (NOSC) and decomposition rate both increased post-thaw, despite limited changes in bulk C:N ratios; (3) these increases caused the higher NPP to cycle more rapidly through both plants and soil, contributing to higher CO2 and CH4 fluxes from decomposition. Thus, the increased C-storage expected from higher productivity was limited and the high global warming potential of CH4 contributed a net positive warming effect. Although post-thaw peatlands are currently C sinks due to high NPP offsetting high CO2 release, this status is very sensitive to the plant community's litter input rate and quality. Integration of novel bioavailability metrics based on litter chemistry, including NOSC, into studies of ecosystem dynamics, is needed to improve the understanding of controls on arctic C stocks under continued ecosystem transition. |
BibTeX:
@article{Hough2022,
author = {Hough, Moira and McCabe, Samantha and Vining, S Rose and Pickering Pedersen, Emily and Wilson, Rachel M and Lawrence, Ryan and Chang, Kuang-Yu and Bohrer, Gil and Coordinators, The IsoGenie and Riley, William J and Crill, Patrick M and Varner, Ruth K and Blazewicz, Steven J and Dorrepaal, Ellen and Tfaily, Malak M and Saleska, Scott R and Rich, Virginia I},
title = {Coupling plant litter quantity to a novel metric for litter quality explains C storage changes in a thawing permafrost peatland},
journal = {Global Change Biology},
publisher = {John Wiley & Sons, Ltd},
year = {2022},
volume = {28},
number = {3},
pages = {950--968},
url = {https://doi.org/10.1111/gcb.15970},
doi = {10.1111/gcb.15970}
}
|
| Hu Z, Piao S, Knapp AK, Wang X, Peng S, Yuan W, Running S, Mao J, Shi X, Ciais P, Huntzinger DN, Yang J and Yu G (2022), "Decoupling of greenness and gross primary productivity as aridity decreases", Remote Sensing of Environment. Vol. 279, pp. 113120. |
| Abstract: Ecosystem primary productivity is a key ecological process influencing many ecosystem services, including carbon storage. Thus, clarifying how primary productivity in terrestrial ecosystems responds to climatic variability can reveal key mechanisms that will drive future changes in the global carbon budget. Satellite products of canopy greenness are widely used as proxies for vegetation productivity to evaluate how ecosystems respond to climate variability. However, to what degree inter-annual variations in productivity are consistent with greenness and how this relationship varies spatially remains unclear. Here we investigated the strength of the coupling between inter-annual variations in leaf area index (LAI, a measure of greenness) and ecosystem gross primary productivity (GPP) derived from eddy covariance towers, i.e., the r2 of the LAI-GPP relationship. Overall, inter-annual GPP and LAI were highly coupled (i.e., high r2) in arid grasslands, but were fully decoupled in mesic evergreen broadleaf forests, indicating that this relationship varies strongly along aridity gradients. A possible mechanism of the spatial variation in the LAI-GPP relationship is that the tradeoff between ecosystem structure (LAI) and physiology (photosynthesis per unit leaf area) becomes stronger in more humid climates. Land models overestimated the r2 of LAI-GPP correlation for most ecosystem types and failed to capture the spatial pattern along aridity gradients. We conclude that relying on greenness products for evaluating inter-annual changes in vegetation productivity may bias assessments, especially in tropical rainforest ecosystems. Our findings may also reconcile observed disparities between responses in greenness and GPP during drought in Amazon forests. |
BibTeX:
@article{Hu2022,
author = {Hu, Zhongmin and Piao, Shilong and Knapp, Alan K and Wang, Xuhui and Peng, Shushi and Yuan, Wenping and Running, Steve and Mao, Jiafu and Shi, Xiaoying and Ciais, Philippe and Huntzinger, Deborah N and Yang, Jia and Yu, Guirui},
title = {Decoupling of greenness and gross primary productivity as aridity decreases},
journal = {Remote Sensing of Environment},
year = {2022},
volume = {279},
pages = {113120},
url = {https://www.sciencedirect.com/science/article/pii/S0034425722002346},
doi = {10.1016/j.rse.2022.113120}
}
|
| Huang Y, Wei J, Jin J, Zhou Z and Gu Q (2022), "CO Fluxes in Western Europe during 2017–2020 Winter Seasons Inverted by WRF-Chem/Data Assimilation Research Testbed with MOPITT Observations", Remote Sensing. Vol. 14(5) |
| Abstract: The study of anthropogenic carbon monoxide (CO) emissions is crucial to investigate anthropogenic activities. Assuming the anthropogenic CO emissions accounted for the super majority of the winter CO fluxes in western Europe, they could be roughly estimated by the inversion approach. The CO fluxes and concentrations of four consecutive winter seasons (i.e., December–February) in western Europe since 2017 were estimated by a regional CO flux inversion system based on the Weather Research and Forecasting model coupled with Chemistry (WRF-Chem) and the Data Assimilation Research Testbed (DART). The CO retrievals from the Measurements Of Pollution In The Troposphere instrument (MOPITT) version 8 level 2 multi-spectral Thermal InfraRed (TIR)/Near-InfraRed (NIR) CO retrieval data products were assimilated by the inversion system. The analyses of the MOPITT data used by the inversion system indicated that the mean averaging kernel row sums of the surface level was about 0.25, and the difference percentage of the surface-level retrievals relative to a priori CO-mixing ratios was 14.79%, which was similar to that of the other levels. These results suggested the MOPITT’s surface-level observations contained roughly the same amount of information as the other levels. The inverted CO fluxes of the four winter seasons were 6198.15 kilotons, 4939.72 kilotons, 4697.80 kilotons, and 5456.19 kilotons, respectively. Based on the assumption, the United Nations Framework Convention on Climate Change (UNFCCC) inventories were used to evaluate the accuracy of the inverted CO fluxes. The evaluation results indicated that the differences between the inverted CO fluxes and UNFCCC inventories of the three winter seasons of 2017–2019 were 13.36%, −4.59%, and −4.76%, respectively. Detailed surface-CO concentrations and XCO comparative analyses between the experimental results and the external Community Atmosphere Model with Chemistry (CAM-Chem) results and the MOPITT data were conducted. The comparative analysis results indicated that the experimental results of the winter season of 2017 were obviously affected by high boundary conditions. The CO concentrations results of the experiments were also evaluated by the CO observation data from Integrated Carbon Observation System (ICOS), the average Mean Bias Error (MBE), and the Root Mean Square Error (RMSE) between the CO concentrations results of the inversion system, and the ICOS observations were −22.43 ppb and 57.59 ppb, respectively. The MBE and RMSE of the inversion system were 17.53-ppb and 4.17-ppb better than those of the simulation-only parallel experiments, respectively. |
BibTeX:
@article{Huang2022,
author = {Huang, Yongjian and Wei, Jianming and Jin, Jiupin and Zhou, Zhiwei and Gu, Qianrong},
title = {CO Fluxes in Western Europe during 2017–2020 Winter Seasons Inverted by WRF-Chem/Data Assimilation Research Testbed with MOPITT Observations},
journal = {Remote Sensing},
year = {2022},
volume = {14},
number = {5},
url = {https://www.mdpi.com/2072-4292/14/5/1133},
doi = {10.3390/rs14051133}
}
|
| Jaakkola E, Gärtner A, Jönsson AM, Ljung K, Olsson P-O and Holst T (2022), "Spruce bark beetle (Ips typographus) infestation cause up to 700 times higher bark BVOC emission rates from Norway spruce (Picea abies)", Biogeosciences Discussions. Vol. 2022, pp. 1-32. |
BibTeX:
@article{Jaakkola2022,
author = {Jaakkola, E and Gärtner, A and Jönsson, A M and Ljung, K and Olsson, P.-O. and Holst, T},
title = {Spruce bark beetle (Ips typographus) infestation cause up to 700 times higher bark BVOC emission rates from Norway spruce (Picea abies)},
journal = {Biogeosciences Discussions},
year = {2022},
volume = {2022},
pages = {1--32},
url = {https://bg.copernicus.org/preprints/bg-2022-125/},
doi = {10.5194/bg-2022-125}
}
|
| Jakobi J, Huisman JA, Fuchs H, Vereecken H and Bogena HR (2022), "Potential of Thermal Neutrons to Correct Cosmic-Ray Neutron Soil Moisture Content Measurements for Dynamic Biomass Effects", Water Resources Research. Vol. 58(8), pp. e2022WR031972. |
| Abstract: Abstract Cosmic-ray neutron sensors (CRNS) enable noninvasive determination of field-scale soil moisture content by exploiting the dependence of the intensity of aboveground epithermal neutrons on the hydrogen contained in soil moisture. However, there are other hydrogen pools besides soil moisture (e.g., biomass). Therefore, these hydrogen pools should be considered for accurate soil moisture content measurements, especially when they are changing dynamically (e.g., arable crops, deforestation, and reforestation). In this study, we test four approaches for the correction of biomass effects on soil moisture content measurements with CRNS using experiments with three crops (sugar beet, winter wheat, and maize) based on high-quality reference soil moisture: (a) site-specific functions based on in-situ measured biomass, (b) a generic approach, (c) the thermal-to-epithermal neutron ratio (Nr), and (d) the thermal neutron intensity. Bare soil calibration of the CRNS resulted in high root mean square errors (RMSEs) of 0.097, 0.041, and 0.019 m³/m³ between estimated and reference soil moisture content for sugar beet, winter wheat, and maize, respectively. Considering in-situ measured biomass for correction reduced the RMSE to 0.015, 0.018, and 0.009 m³/m³. The consideration of thermal neutron intensity for correction was similarly accurate. We also explored the use of CRNS for biomass estimation and found that Nr only provided accurate biomass estimates for sugar beet. In contrast, we found significant site-specific relationships between biomass and thermal neutron intensity for all three crops, suggesting that thermal neutron intensity can be used both to improve CRNS-based soil moisture content measurements and to quantify crop biomass. |
BibTeX:
@article{Jakobi2022,
author = {Jakobi, J and Huisman, J A and Fuchs, H and Vereecken, H and Bogena, H R},
title = {Potential of Thermal Neutrons to Correct Cosmic-Ray Neutron Soil Moisture Content Measurements for Dynamic Biomass Effects},
journal = {Water Resources Research},
year = {2022},
volume = {58},
number = {8},
pages = {e2022WR031972},
url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2022WR031972},
doi = {10.1029/2022WR031972}
}
|
| Jakobsson JKF, Waman DB, Phillips VTJ and Bjerring Kristensen T (2022), "Time dependence of heterogeneous ice nucleation by ambient aerosols: laboratory observations and a formulation for models", Atmospheric Chemistry and Physics. Vol. 22(10), pp. 6717-6748. |
BibTeX:
@article{Jakobsson2022,
author = {Jakobsson, J K F and Waman, D B and Phillips, V T J and Bjerring Kristensen, T},
title = {Time dependence of heterogeneous ice nucleation by ambient aerosols: laboratory observations and a formulation for models},
journal = {Atmospheric Chemistry and Physics},
year = {2022},
volume = {22},
number = {10},
pages = {6717--6748},
url = {https://acp.copernicus.org/articles/22/6717/2022/},
doi = {10.5194/acp-22-6717-2022}
}
|
| Jia M, Li F, Zhang Y, Wu M, Li Y, Feng S, Wang H, Chen H, Ju W, Lin J, Cai J, Zhang Y and Jiang F (2022), "The Nord Stream pipeline gas leaks released approximately 220,000 tonnes of methane into the atmosphere", Environmental Science and Ecotechnology. Vol. 12, pp. 100210. |
| Abstract: Sudden mega natural gas leaks of two Nord Stream pipelines in the Baltic Sea (Denmark) occurred from late September to early October 2022, releasing large amounts of methane into the atmosphere. We inferred the methane emissions of this event based on surface in situ observations using two inversion methods and two meteorological reanalysis datasets, supplemented with satellite-based observations. We conclude that approximately 220 ± 30 Gg of methane was released from September 26 to October 1, 2022. |
BibTeX:
@article{Jia2022,
author = {Jia, Mengwei and Li, Fei and Zhang, Yuzhong and Wu, Mousong and Li, Yingsong and Feng, Shuzhuang and Wang, Hengmao and Chen, Huilin and Ju, Weimin and Lin, Jun and Cai, Jianwei and Zhang, Yongguang and Jiang, Fei},
title = {The Nord Stream pipeline gas leaks released approximately 220,000 tonnes of methane into the atmosphere},
journal = {Environmental Science and Ecotechnology},
year = {2022},
volume = {12},
pages = {100210},
url = {https://www.sciencedirect.com/science/article/pii/S2666498422000667},
doi = {10.1016/j.ese.2022.100210}
}
|
| Jiang N, Shen M, Ciais P, Campioli M, Peñuelas J, Körner C, Cao R, Piao S, Liu L, Wang S, Liang E, Delpierre N, Soudani K, Rao Y, Montagnani L, Hörtnagl L, Paul-Limoges E, Myneni R, Wohlfahrt G, Fu Y, Šigut L, Varlagin A, Chen J, Tang Y and Zhao W (2022), "Warming does not delay the start of autumnal leaf coloration but slows its progress rate", Global Ecology and Biogeography. Vol. 31(11), pp. 2297-2313. |
| Abstract: Abstract Aim Initiation of autumnal leaf senescence is crucial for plant overwintering and ecosystem dynamics. Previous studies have focused on the advanced stages of autumnal leaf senescence and reported that climatic warming delayed senescence, despite the fundamental differences among the stages of senescence. However, the timing of onset of leaf coloration (DLCO), the earliest visual sign of senescence, has rarely been studied. Here, we assessed the response of DLCO to temperature. Location 30–75° N in the Northern Hemisphere. Time period 2000–2018. Major taxa studied Deciduous vegetation. Methods We retrieved DLCO from high-temporal-resolution satellite data, which were then validated by PhenoCam observations. We investigated the temporal changes in DLCO and the relationship between DLCO and temperature by using satellite and ground observations. Results DLCO was not significantly (p > .05) delayed between 2000 and 2018 in 94% of the area. DLCO was positively (p < .05) correlated with pre-DLCO mean daily minimum temperature (Tmin) in only 9% of the area, whereas the end of leaf coloration (DLCE) was positively correlated with pre-DLCE mean Tmin over a larger area (34%). Further analyses showed that warming slowed the progress of leaf coloration. Interestingly, DLCO was less responsive to pre-DLCO mean Tmin in areas where daylength was longer across the Northern Hemisphere, particularly for woody vegetation. Main conclusions The rate of progress of coloration is more sensitive to temperature than its start date, resulting in an extension of the duration of leaf senescence under warming. The dependence of DLCO response to temperature on daylength indicates stronger photoperiodic control on initiation of leaf senescence in areas with longer daylength (i.e., shorter nights), possibly because plants respond to the length of uninterrupted darkness rather than daylength. This study indicates that the onset of leaf coloration was not responsive to climate warming and provides observational evidence of photoperiod control of autumnal leaf senescence at biome and continental scales. |
BibTeX:
@article{Jiang2022,
author = {Jiang, Nan and Shen, Miaogen and Ciais, Philippe and Campioli, Matteo and Peñuelas, Josep and Körner, Christian and Cao, Ruyin and Piao, Shilong and Liu, Licong and Wang, Shiping and Liang, Eryuan and Delpierre, Nicolas and Soudani, Kamel and Rao, Yuhan and Montagnani, Leonardo and Hörtnagl, Lukas and Paul-Limoges, Eugénie and Myneni, Ranga and Wohlfahrt, Georg and Fu, Yongshuo and Šigut, Ladislav and Varlagin, Andrej and Chen, Jin and Tang, Yanhong and Zhao, Wenwu},
title = {Warming does not delay the start of autumnal leaf coloration but slows its progress rate},
journal = {Global Ecology and Biogeography},
year = {2022},
volume = {31},
number = {11},
pages = {2297--2313},
url = {https://onlinelibrary.wiley.com/doi/abs/10.1111/geb.13581},
doi = {10.1111/geb.13581}
}
|
| Jongen HJ, Steeneveld GJ, Beringer J, Christen A, Chrysoulakis N, Fortuniak K, Hong J, Hong JW, Jacobs CMJ, Järvi L, Meier F, Pawlak W, Roth M, Theeuwes NE, Velasco E, Vogt R and Teuling AJ (2022), "Urban Water Storage Capacity Inferred From Observed Evapotranspiration Recession", Geophysical Research Letters. Vol. 49(3), pp. e2021GL096069. |
| Abstract: Abstract Water storage plays an important role in mitigating heat and flooding in urban areas. Assessment of the water storage capacity of cities remains challenging due to the inherent heterogeneity of the urban surface. Traditionally, effective storage has been estimated from runoff. Here, we present a novel approach to estimate effective water storage capacity from recession rates of observed evaporation during precipitation-free periods. We test this approach for cities at neighborhood scale with eddy-covariance based latent heat flux observations from 14 contrasting sites with different local climate zones, vegetation cover and characteristics, and climates. Based on analysis of 583 drydowns, we find storage capacities to vary between 1.3 and 28.4 mm, corresponding to e-folding timescales of 1.8–20.1 days. This makes the urban storage capacity at least five times smaller than all the observed values for natural ecosystems, reflecting an evaporation regime characterized by extreme water limitation. |
BibTeX:
@article{Jongen2022,
author = {Jongen, H J and Steeneveld, G J and Beringer, J and Christen, A and Chrysoulakis, N and Fortuniak, K and Hong, J and Hong, J W and Jacobs, C M J and Järvi, L and Meier, F and Pawlak, W and Roth, M and Theeuwes, N E and Velasco, E and Vogt, R and Teuling, A J},
title = {Urban Water Storage Capacity Inferred From Observed Evapotranspiration Recession},
journal = {Geophysical Research Letters},
year = {2022},
volume = {49},
number = {3},
pages = {e2021GL096069},
url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2021GL096069},
doi = {10.1029/2021GL096069}
}
|
| Jordan A, Schumacher M and ICOS CAL - FCL (2022), "ICOS CAL - Quality Control Report 2021" ICOS CAL - FCL. |
BibTeX:
@article{Jordan2022,
author = {Jordan, Armin and Schumacher, Marcus and ICOS CAL - FCL},
title = {ICOS CAL - Quality Control Report 2021},
publisher = {ICOS CAL - FCL},
year = {2022},
url = {https://meta.icos-cp.eu/objects/8_58EsZZCIwHto3WYAFtw4w-},
doi = {10.18160/RS2Q-RA1Q}
}
|
| Juutinen S, Aurela M, Tuovinen J-P, Ivakhov V, Linkosalmi M, Räsänen A, Virtanen T, Mikola J, Nyman J, Vähä E, Loskutova M, Makshtas A and Laurila T (2022), "Variation in CO_2 and CH_4 fluxes among land cover types in heterogeneous Arctic tundra in northeastern Siberia", Biogeosciences. Vol. 19(13), pp. 3151-3167. |
BibTeX:
@article{Juutinen2022,
author = {Juutinen, S and Aurela, M and Tuovinen, J.-P. and Ivakhov, V and Linkosalmi, M and Räsänen, A and Virtanen, T and Mikola, J and Nyman, J and Vähä, E and Loskutova, M and Makshtas, A and Laurila, T},
title = {Variation in CO_2 and CH_4 fluxes among land cover types in heterogeneous Arctic tundra in northeastern Siberia},
journal = {Biogeosciences},
year = {2022},
volume = {19},
number = {13},
pages = {3151--3167},
url = {https://bg.copernicus.org/articles/19/3151/2022/},
doi = {10.5194/bg-19-3151-2022}
}
|
| Kashi NN, Hobbie EA, Varner RK, Wymore AS, Ernakovich JG and Giesler R (2022), "Nutrients Alter Methane Production and Oxidation in a Thawing Permafrost Mire", Ecosystems., apr, 2022. Vol. 26(2), pp. 302-317. Springer Science and Business Media LLC. |
BibTeX:
@article{Kashi2022,
author = {Kashi, N Niloufar and Hobbie, Erik A and Varner, Ruth K and Wymore, Adam S and Ernakovich, Jessica G and Giesler, Reiner},
title = {Nutrients Alter Methane Production and Oxidation in a Thawing Permafrost Mire},
journal = {Ecosystems},
publisher = {Springer Science and Business Media LLC},
year = {2022},
volume = {26},
number = {2},
pages = {302--317},
url = {http://dx.doi.org/10.1007/s10021-022-00758-5},
doi = {10.1007/s10021-022-00758-5}
}
|
| Kohonen K-M, Dewar R, Tramontana G, Mauranen A, Kolari P, Kooijmans LMJ, Papale D, Vesala T and Mammarella I (2022), "Intercomparison of methods to estimate gross primary production based on CO_2 and COS flux measurements", Biogeosciences. Vol. 19(17), pp. 4067-4088. |
BibTeX:
@article{Kohonen2022,
author = {Kohonen, K.-M. and Dewar, R and Tramontana, G and Mauranen, A and Kolari, P and Kooijmans, L M J and Papale, D and Vesala, T and Mammarella, I},
title = {Intercomparison of methods to estimate gross primary production based on CO_2 and COS flux measurements},
journal = {Biogeosciences},
year = {2022},
volume = {19},
number = {17},
pages = {4067--4088},
url = {https://bg.copernicus.org/articles/19/4067/2022/},
doi = {10.5194/bg-19-4067-2022}
}
|
| Korkiakoski M, Määttä T, Peltoniemi K, Penttilä T and Lohila A (2022), "Excess soil moisture and fresh carbon input are prerequisites for methane production in podzolic soil", Biogeosciences. Vol. 19(7), pp. 2025-2041. |
BibTeX:
@article{Korkiakoski2022,
author = {Korkiakoski, M and Määttä, T and Peltoniemi, K and Penttilä, T and Lohila, A},
title = {Excess soil moisture and fresh carbon input are prerequisites for methane production in podzolic soil},
journal = {Biogeosciences},
year = {2022},
volume = {19},
number = {7},
pages = {2025--2041},
url = {https://bg.copernicus.org/articles/19/2025/2022/},
doi = {10.5194/bg-19-2025-2022}
}
|
| Korrensalo A, Mammarella I, Alekseychik P, Vesala T and Tuittila E-S (2022), "Plant mediated methane efflux from a boreal peatland complex", Plant and Soil. Vol. 471(1), pp. 375-392. |
| Abstract: Aerenchymous plants are an important control for methane efflux from peatlands to the atmosphere, providing a bypass from the anoxic peat and avoiding oxidation in the oxic peat. We aimed to quantify the drivers of aerenchymous peatland species methane transport and the importance of this process for ecosystem-scale methane efflux. |
BibTeX:
@article{Korrensalo2022,
author = {Korrensalo, A and Mammarella, I and Alekseychik, P and Vesala, T and Tuittila, E-S.},
title = {Plant mediated methane efflux from a boreal peatland complex},
journal = {Plant and Soil},
year = {2022},
volume = {471},
number = {1},
pages = {375--392},
url = {https://doi.org/10.1007/s11104-021-05180-9},
doi = {10.1007/s11104-021-05180-9}
}
|
| Kou D, Virtanen T, Treat CC, Tuovinen J-P, Räsänen A, Juutinen S, Mikola J, Aurela M, Heiskanen L, Heikkilä M, Weckström J, Juselius T, Piilo SR, Deng J, Zhang Y, Chaudhary N, Huang C, Väliranta M, Biasi C, Liu X, Guo M, Zhuang Q, Korhola A and Shurpali NJ (2022), "Peatland Heterogeneity Impacts on Regional Carbon Flux and Its Radiative Effect Within a Boreal Landscape", Journal of Geophysical Research: Biogeosciences. Vol. 127(9), pp. e2021JG006774. |
| Abstract: Abstract Peatlands, with high spatial variability in ecotypes and microforms, constitute a significant part of the boreal landscape and play an important role in the global carbon (C) cycle. However, the effects of this peatland heterogeneity within the boreal landscape are rarely quantified. Here, we use field-based measurements, high-resolution land cover classification, and biogeochemical and atmospheric models to estimate the atmosphere-ecosystem C fluxes and the corresponding radiative effect (RE) for a boreal landscape (Kaamanen) in northern Finland. Our result shows that the Kaamanen catchment currently functioned as a sink of carbon dioxide (CO2) and a source of methane (CH4). Peatlands (26% of the area) contributed 22% of the total CO2 uptake and 89% of CH4 emissions; forests (61%) accounted for 78% of CO2 uptake and offset 6% of CH4 emissions; water bodies (13%) offset 7% of CO2 uptake and contributed 11% of CH4 emissions. The heterogeneity of peatlands accounted for 11%, 88%, and 75% of the area-weighted variability (deviation from the area-weighted mean among different land cover types (LCTs) within the catchment) in CO2 flux, CH4 flux, and the combined RE of CO2 and CH4 exchanges over the 25-year time horizon, respectively. Aggregating peatland LCTs or misclassifying them as nonpeatland LCTs can significantly (p < 0.05) bias the regional CH4 exchange and RE estimates, while differentiating between drier noninundated and wetter inundated peatlands can effectively reduce the bias. Current land cover products lack such details in peatland heterogeneity, which would be needed to better constrain boreal C budgets and global C-climate feedbacks. |
BibTeX:
@article{Kou2022,
author = {Kou, Dan and Virtanen, Tarmo and Treat, Claire C and Tuovinen, Juha-Pekka and Räsänen, Aleksi and Juutinen, Sari and Mikola, Juha and Aurela, Mika and Heiskanen, Lauri and Heikkilä, Maija and Weckström, Jan and Juselius, Teemu and Piilo, Sanna R and Deng, Jia and Zhang, Yu and Chaudhary, Nitin and Huang, Conghong and Väliranta, Minna and Biasi, Christina and Liu, Xiangyu and Guo, Mingyang and Zhuang, Qianlai and Korhola, Atte and Shurpali, Narasinha J},
title = {Peatland Heterogeneity Impacts on Regional Carbon Flux and Its Radiative Effect Within a Boreal Landscape},
journal = {Journal of Geophysical Research: Biogeosciences},
year = {2022},
volume = {127},
number = {9},
pages = {e2021JG006774},
url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2021JG006774},
doi = {10.1029/2021JG006774}
}
|
| Kováč D, Ač A, Šigut L, Peñuelas J, Grace J and Urban O (2022), "Combining NDVI, PRI and the quantum yield of solar-induced fluorescence improves estimations of carbon fluxes in deciduous and evergreen forests", Science of The Total Environment. Vol. 829, pp. 154681. |
| Abstract: We used automated spectroradiometers to continuously monitor changes in the optical parameters of phenological and photosynthetic traits in beech and spruce forests. We examined seasonal variations in the normalized difference vegetation index (NDVI), photochemical reflectance index (PRI), and solar-induced fluorescence in the oxygen A band (SIFA) that was estimated using a 3-FLD discrimination method from radiance data. The optical parameters tracked the activation and cessation of photosynthesis in spring and autumn. Data at photon fluxes >1200 μmol m−2 s−1 during extended noon hours were used to link the seasonal PRI and SIFA variations to the dynamics of photosynthesis. Seasonal PRI was significantly correlated with photosynthetic light-use efficiency (LUE) with R2 values of 0.66 and 0.48 for the measurements in beech and spruce forests, respectively. SIFA emissions were significantly correlated with the gross primary production (GPP) of the evergreen spruce forest (R2 = 0.47), but R2 was only 0.13 when measured in the beech forest. The correlations between the optical parameters and GPP or LUE, however, tended to be lower when using a dataset with constant NDVI. Introducing an equation combining NDVI, PRI, and the quantum yield of SIFA emission increased R2 for LUE estimation to 0.77 in the spruce forest and 0.63 in the beech forest. GPP was estimated from the parametric equation with improved accuracy reaching R2 = 0.53 and RMSE = 5.95 μmol CO2 m−2 s−1 in spruce forest and R2 = 0.58 and RMSE = 5.23 μmol CO2 m−2 s−1 in beech forest. Parametric equations were more efficient in estimating photosynthesis in datasets that consisted of an entire season's data. By combining NDVI, PRI and the quantum yield of SIFA, we could thus substantially improve estimations of carbon fluxes in diverse deciduous and evergreen canopies. |
BibTeX:
@article{Kovac2022,
author = {Kováč, Daniel and Ač, Alexander and Šigut, Ladislav and Peñuelas, Josep and Grace, John and Urban, Otmar},
title = {Combining NDVI, PRI and the quantum yield of solar-induced fluorescence improves estimations of carbon fluxes in deciduous and evergreen forests},
journal = {Science of The Total Environment},
year = {2022},
volume = {829},
pages = {154681},
url = {https://www.sciencedirect.com/science/article/pii/S0048969722017740},
doi = {10.1016/j.scitotenv.2022.154681}
}
|
| Krasnova A, Mander Ü, Noe SM, Uri V, Krasnov D and Soosaar K (2022), "Hemiboreal forests' CO2 fluxes response to the European 2018 heatwave", Agricultural and Forest Meteorology. Vol. 323, pp. 109042. |
| Abstract: In summer 2018, Europe experienced a heatwave that impacted the forest carbon cycle. We assessed the influence of elevated temperatures on the carbon exchange of three forest stands of different types (coniferous, deciduous, and conifer-broadleaved) and a clear-cut area located in the geographical vicinity within a hemiboreal zone. The carbon fluxes were calculated using the eddy-covariance technique. Over the period of anomaly high temperatures, the NEE of a deciduous (alder) forest was similar to the previous year due to the reduction of both GPP and ER of the same magnitude. Warm days in spring and autumn allowed for the GPP offset, and the total NEE of vegetation season 2018 was more negative than of 2017. Coniferous (pine and spruce) forest carbon uptake decreased during the temperature anomaly as a result of GPP reduction being higher than the decrease in ER. Spring warming had almost no effect on the carbon exchange, while ER and GPP increased in autumn warm days. As a result, annual ER was higher in 2018 than in 2017, and the NEE was smaller. The coniferous forest was most resistant to the heatwave, most probably because of its adaption to low soil water content. Contrary to our expectations, a mixed conifer-broadleaved forest (pine, spruce, birch, clear-cuts) was more affected by the heatwave than a pine-dominated forest. It switched from net carbon sink during the vegetation season of 2017 to net carbon source in 2018. Almost three times higher amount of carbon was released in 2018 as a result of GPP reduction. The clear-cut area carbon exchange was the most vulnerable to the heatwave influence out of all study sites. A more prominent reduction of GPP resulted in smaller NEE. Warm days in spring and autumn did not offset the temperature anomaly impact, as was observed for the forested ecosystems. |
BibTeX:
@article{Krasnova2022,
author = {Krasnova, A and Mander, Ü and Noe, S M and Uri, V and Krasnov, D and Soosaar, K},
title = {Hemiboreal forests' CO2 fluxes response to the European 2018 heatwave},
journal = {Agricultural and Forest Meteorology},
year = {2022},
volume = {323},
pages = {109042},
url = {https://www.sciencedirect.com/science/article/pii/S0168192322002313},
doi = {10.1016/j.agrformet.2022.109042}
}
|
| Krejza J, Haeni M, Darenova E, Foltýnová L, Fajstavr M, Jan Světlík, Nezval O, Bednář P, Šigut L, Horáček P and Zweifel R (2022), "Disentangling carbon uptake and allocation in the stems of a spruce forest", Environmental and Experimental Botany. Vol. 196, pp. 104787. |
| Abstract: Although forests store significant amounts of carbon in tree stems, the extent to which stem growth depends on carbon assimilation and environmental factors is poorly understood. In this study, gross primary productivity (GPP) and net ecosystem productivity (NEP) are compared for the first time at daily resolution with stem carbon allocation (SCA) in a spruce forest. We found substantial differences in the seasonal patterns of all variables as a function of environmental conditions, leading to three important findings. First, carbon uptake was only marginally invested in wood growth during the first half of the growing season. This means that there were other priorities for carbon allocation than stem growth at this time of year. Second, our results show that SRI at the beginning of the stem growth period, which mainly involves cell division and expansion, is a process that requires less carbon than the process of xylem lignification and thickening that follows. And third, NEP was generally less sensitive to drought than SCA. This suggests that the carbon uptake balance is less sensitive to dry periods than growth, particularly because the carbon uptake period is much longer than the growth window. These results may change the way we perceive the effects of climate change on forests, as tree carbon dynamics are primarily explained by the seasonal timing of dry periods rather than the intensity of these events. |
BibTeX:
@article{Krejza2022,
author = {Krejza, Jan and Haeni, Matthias and Darenova, Eva and Foltýnová, Lenka and Fajstavr, Marek and Jan Světlík and Nezval, Ondřej and Bednář, Pavel and Šigut, Ladislav and Horáček, Petr and Zweifel, Roman},
title = {Disentangling carbon uptake and allocation in the stems of a spruce forest},
journal = {Environmental and Experimental Botany},
year = {2022},
volume = {196},
pages = {104787},
url = {https://www.sciencedirect.com/science/article/pii/S0098847222000090},
doi = {10.1016/j.envexpbot.2022.104787}
}
|
| Kuliʼnski K, Rehder G, Asmala E, Bartosova A, Carstensen J, Gustafsson B, Hall POJ, Humborg C, Jilbert T, Jürgens K, Meier HEM, Müller-Karulis B, Naumann M, Olesen JE, Savchuk O, Schramm A, Slomp CP, Sofiev M, Sobek A, Szymczycha B and Undeman E (2022), "Biogeochemical functioning of the Baltic Sea", Earth System Dynamics. Vol. 13(1), pp. 633-685. |
BibTeX:
@article{Kulinski2022,
author = {Kuliʼnski, K and Rehder, G and Asmala, E and Bartosova, A and Carstensen, J and Gustafsson, B and Hall, P O J and Humborg, C and Jilbert, T and Jürgens, K and Meier, H E M and Müller-Karulis, B and Naumann, M and Olesen, J E and Savchuk, O and Schramm, A and Slomp, C P and Sofiev, M and Sobek, A and Szymczycha, B and Undeman, E},
title = {Biogeochemical functioning of the Baltic Sea},
journal = {Earth System Dynamics},
year = {2022},
volume = {13},
number = {1},
pages = {633--685},
url = {https://esd.copernicus.org/articles/13/633/2022/},
doi = {10.5194/esd-13-633-2022}
}
|
| Launiainen S, Katul GG, Leppä K, Kolari P, Aslan T, Grönholm T, Korhonen L, Mammarella I and Vesala T (2022), "Does growing atmospheric CO2 explain increasing carbon sink in a boreal coniferous forest?", Global Change Biology., feb, 2022. Vol. n/a(n/a) John Wiley & Sons, Ltd. |
| Abstract: Abstract The terrestrial net ecosystem productivity (NEP) has increased during the past three decades, but the mechanisms responsible are still unclear. We analyzed 17 years (2001?2017) of eddy-covariance measurements of NEP, evapotranspiration (ET) and light and water use efficiency from a boreal coniferous forest in Southern Finland for trends and inter-annual variability (IAV). The forest was a mean annual carbon sink (252 [±42] gC m-2a-1), and NEP increased at rate +6.4?7.0 gC m-2a-1 (or ca. +2.5% a-1) during the period. This was attributed to the increasing gross-primary productivity GPP and occurred without detectable change in ET. The start of annual carbon uptake period was advanced by 0.7 d a-1, and increase in GPP and NEP outside the main growing season contributed ca. one-third and one-fourth of the annual trend, respectively. Meteorological factors were responsible for the IAV of fluxes but did not explain the long-term trends. The growing season GPP trend was strongest in ample light during the peak growing season. Using a multi-layer ecosystem model, we showed that direct CO2 fertilization effect diminishes when moving from leaf to ecosystem, and only 30?40% of the observed ecosystem GPP increase could be attributed to CO2. The increasing trend in leaf-area index (LAI), stimulated by forest thinning in 2002, was the main driver of the enhanced GPP and NEP of the mid-rotation managed forest. It also compensated for the decrease of mean leaf stomatal conductance with increasing CO2 and LAI, explaining the apparent proportionality between observed GPP and CO2 trends. The results emphasize that attributing trends to their physical and physiological drivers is challenged by strong IAV, and uncertainty of LAI and species composition changes due to the dynamic flux footprint. The results enlighten the underlying mechanisms responsible for the increasing terrestrial carbon uptake in the boreal zone. |
BibTeX:
@article{Launiainen2022,
author = {Launiainen, Samuli and Katul, Gabriel G and Leppä, Kersti and Kolari, Pasi and Aslan, Toprak and Grönholm, Tiia and Korhonen, Lauri and Mammarella, Ivan and Vesala, Timo},
title = {Does growing atmospheric CO2 explain increasing carbon sink in a boreal coniferous forest?},
journal = {Global Change Biology},
publisher = {John Wiley & Sons, Ltd},
year = {2022},
volume = {n/a},
number = {n/a},
url = {https://doi.org/10.1111/gcb.16117},
doi = {10.1111/gcb.16117}
}
|
| Lelandais L, Xueref-Remy I, Riandet A, Blanc PE, Armengaud A, Oppo S, Yohia C, Ramonet M and Delmotte M (2022), "Analysis of 5.5 years of atmospheric CO2, CH4, CO continuous observations (2014–2020) and their correlations, at the Observatoire de Haute Provence, a station of the ICOS-France national greenhouse gases observation network", Atmospheric Environment. Vol. 277, pp. 119020. |
| Abstract: Since 2014, a 100 m tall tower measures continuously greenhouse gases at the Observatoire de haute Provence (OHP) located in the southeast of France (43° 55′ 51″ N, 5° 42′ 48″ E) as a monitoring station of the French National Greenhouse Gases Observation network (ICOS-Fr). This rural station allows to study the short, mid, and long terms variability of atmospheric CO2, CH4 and CO concentrations at the continental, regional and local scales in a region characterized by a Mediterranean climate. Measurements are performed using cavity ring-down spectroscopy at three levels above ground level (AGL); 10 m, 50 m and 100 m. Using the ICOS European Infrastructure procedure to calibrate and ensure the data quality control, the precision of our datasets matches the international WMO/GAW recommendations. Time series from July 2014 to February 2020 were analysed. We inferred a mean annual growth rate at 100 m AGL of 2.7 ppm/year for CO2 (7.8 ppb/year for CH4) over the period of study, whereas no significant annual growth rate was found for CO. These growth rates are comparable to other remote ICOS and WMO/GAW sites. A seasonal amplitude of 13 ppm, 30 ppb, 45 ppb was found for atmospheric CO2, CH4 and CO, respectively. As expected, the amplitude of the diurnal cycle of these three species varies in function of the season, from 2.6 (1.6) ppm in winter and 10.7 (6.6) ppm in summer for CO2, 3.7 (5.1) and 7.7 (7.1) ppb for CH4, and contrary to CO2 and CH4 smaller amplitude in summer with 2.15 (2.5) ppb and 9.3 (8.9) ppb in winter for CO at 10 m (100 m) AGL. Significant correlations (R2 between 0.67 and 0.91) between the three species have been detected, especially in the winter season. Using thresholds on wind speed and on the standard variation of hourly concentrations, more than 16% of the data were identified to be enriched either: 1/by regional anthropogenic plumes; 2/during stable synoptic conditions inducing the accumulation of anthropogenic emissions in the atmospheric boundary layer (13%); and 3/by local's sources inducing short pollution events (3%). On average, ΔCO/Δ CO2 ratios of 3.72 ± 0.06 ppb/ppm and 0.8 ± 0.2 ppb/ppm for Δ CH4/ΔCO were inferred during local pollution events in winter and are typical of traffic and residential heating as given by the local bottom-up emissions inventory delivered by the regional air quality agency ATMOSUD. Adding specific tracers or isotopic measurements would be very interesting to distinguish anthropogenic sources and monitor the evolution of their characteristics as emission ratios at the OHP station. Filtering out these conditions, about 84% of the data are not undergoing the influence of local and regional anthropogenic plumes, and are thus representative of “background” CO2, CO and CH4 concentrations at the local to the regional scales. These background conditions are shown to be dependent on wind speed and direction. |
BibTeX:
@article{Lelandais2022,
author = {Lelandais, L and Xueref-Remy, I and Riandet, A and Blanc, P E and Armengaud, A and Oppo, S and Yohia, C and Ramonet, M and Delmotte, M},
title = {Analysis of 5.5 years of atmospheric CO2, CH4, CO continuous observations (2014–2020) and their correlations, at the Observatoire de Haute Provence, a station of the ICOS-France national greenhouse gases observation network},
journal = {Atmospheric Environment},
year = {2022},
volume = {277},
pages = {119020},
url = {https://www.sciencedirect.com/science/article/pii/S1352231022000851},
doi = {10.1016/j.atmosenv.2022.119020}
}
|
| Lento J, Culp JM, Levenstein B, Aroviita J, Baturina MA, Bogan D, Brittain JE, Chin K, Christoffersen KS, Docherty C, Friberg N, Ingimarsson F, Jacobsen D, Lau DCP, Loskutova OA, Milner A, Mykrä H, Novichkova AA, Ólafsson JS, Schartau AK, Shaftel R and Goedkoop W (2022), "Temperature and spatial connectivity drive patterns in freshwater macroinvertebrate diversity across the Arctic", Freshwater Biology., jan, 2022. Vol. 67(1), pp. 159-175. John Wiley & Sons, Ltd. |
| Abstract: Abstract Warming in the Arctic is predicted to change freshwater biodiversity through loss of unique taxa and northward range expansion of lower latitude taxa. Detecting such changes requires establishing circumpolar baselines for diversity, and understanding the primary drivers of diversity. We examined benthic macroinvertebrate diversity using a circumpolar dataset of >1,500 Arctic lake and river sites. Rarefied α diversity within catchments was assessed along latitude and temperature gradients. Community composition was assessed through region-scale analysis of ? diversity and its components (nestedness and turnover), and analysis of biotic?abiotic relationships. Rarefied α diversity of lakes and rivers declined with increasing latitude, although more strongly across mainland regions than islands. Diversity was strongly related to air temperature, with the lowest diversity in the coldest catchments. Regional dissimilarity was highest when mainland regions were compared with islands, suggesting that connectivity limitations led to the strongest dissimilarity. High contributions of nestedness indicated that island regions contained a subset of the taxa found in mainland regions. High Arctic rivers and lakes were predominately occupied by Chironomidae and Oligochaeta, whereas Ephemeroptera, Plecoptera, and Trichoptera taxa were more abundant at lower latitudes. Community composition was strongly associated with temperature, although geology and precipitation were also important correlates. The strong association with temperature supports the prediction that warming will increase Arctic macroinvertebrate diversity, although low diversity on islands suggests that this increase will be limited by biogeographical constraints. Long-term harmonised monitoring across the circumpolar region is necessary to detect such changes to diversity and inform science-based management. |
BibTeX:
@article{Lento2022,
author = {Lento, Jennifer and Culp, Joseph M and Levenstein, Brianna and Aroviita, Jukka and Baturina, Maria A and Bogan, Daniel and Brittain, John E and Chin, Krista and Christoffersen, Kirsten S and Docherty, Catherine and Friberg, Nikolai and Ingimarsson, Finnur and Jacobsen, Dean and Lau, Danny Chun Pong and Loskutova, Olga A and Milner, Alexander and Mykrä, Heikki and Novichkova, Anna A and Ólafsson, Jón S and Schartau, Ann Kristin and Shaftel, Rebecca and Goedkoop, Willem},
title = {Temperature and spatial connectivity drive patterns in freshwater macroinvertebrate diversity across the Arctic},
journal = {Freshwater Biology},
publisher = {John Wiley & Sons, Ltd},
year = {2022},
volume = {67},
number = {1},
pages = {159--175},
url = {https://doi.org/10.1111/fwb.13805},
doi = {10.1111/fwb.13805}
}
|
| Limousin J-M, Roussel A, Rodríguez-Calcerrada J, Torres-Ruiz JM, Moreno M, de Jalon L, Ourcival J-M, Simioni G, Cochard H and Martin-StPaul N (2022), "Drought acclimation of Quercus ilex leaves improves tolerance to moderate drought but not resistance to severe water stress", Plant, Cell & Environment. Vol. 45(7), pp. 1967-1984. |
| Abstract: Abstract Increasing temperature and drought can result in leaf dehydration and defoliation even in drought-adapted tree species such as the Mediterranean evergreen Quercus ilex L. The stomatal regulation of leaf water potential plays a central role in avoiding this phenomenon and is constrained by a suite of leaf traits including hydraulic conductance and vulnerability, hydraulic capacitance, minimum conductance to water vapour, osmotic potential and cell wall elasticity. We investigated whether the plasticity in these traits may improve leaf tolerance to drought in two long-term rainfall exclusion experiments in Mediterranean forests. Osmotic adjustment was observed to lower the water potential at turgor loss in the rainfall-exclusion treatments, thus suggesting a stomatal closure at more negative water potentials and a more anisohydric behaviour in drier conditions. Conversely, leaf hydraulic conductance and vulnerability did not exhibit any plasticity between treatments so the hydraulic safety margins were narrower in the rainfall-exclusion treatments. The sequence of leaf responses to seasonal drought and dehydration was conserved among treatments and sites but trees were more likely to suffer losses of turgor and hydraulic functioning in the rainfall-exclusion treatments. We conclude that leaf plasticity might help the trees to tolerate moderate drought but not to resist severe water stress. |
BibTeX:
@article{Limousin2022,
author = {Limousin, Jean-Marc and Roussel, Amélie and Rodríguez-Calcerrada, Jesús and Torres-Ruiz, José M and Moreno, Myriam and de Jalon, Laura and Ourcival, Jean-Marc and Simioni, Guillaume and Cochard, Hervé and Martin-StPaul, Nicolas},
title = {Drought acclimation of Quercus ilex leaves improves tolerance to moderate drought but not resistance to severe water stress},
journal = {Plant, Cell & Environment},
year = {2022},
volume = {45},
number = {7},
pages = {1967--1984},
url = {https://onlinelibrary.wiley.com/doi/abs/10.1111/pce.14326},
doi = {10.1111/pce.14326}
}
|
| Lindberg O, Lingfors D and Arnqvist J (2022), "Analyzing the mechanisms behind temporal correlation between power sources using frequency separated time scales: A Swedish case study on PV and wind", Energy. Vol. 259, pp. 124817. |
| Abstract: The temporal correlation between different power generation sources is important for quantifying the reduction in variability when constructing co-located hybrid power parks (HPPs) that combine multiple power sources. This study investigates the physical mechanisms behind correlation on time scales relevant for the power system using frequency separated time scales. The methodology is universally applicable to any data set consisting of at least two power sources and could be adjusted accordingly. The methodology is demonstrated and validated in a case study across Sweden for wind and PV power generation, using the meteorological reanalysis dataset CosmoREA-6. All studied time-scales (seasonal, mid-term, synoptic and diurnal) showed anti-correlated characteristics, although the magnitude of temporal correlation is highly dependent on the time-scale considered. The highest potential for useful anti-correlation is found on the seasonal cycle, followed by the diurnal cycle where existing wind turbine sites, on average, have stronger anti-correlation than the average site. The validation showed good correspondence with measurements for all time-scales. However, an underestimations of the results were found for the diurnal and seasonal cycle while this was shown to have a minor effect when analyzing the correlation on different time scales. The methodology of the case study should be generally valid for all similar climates. |
BibTeX:
@article{Lindberg2022,
author = {Lindberg, O and Lingfors, D and Arnqvist, J},
title = {Analyzing the mechanisms behind temporal correlation between power sources using frequency separated time scales: A Swedish case study on PV and wind},
journal = {Energy},
year = {2022},
volume = {259},
pages = {124817},
url = {https://www.sciencedirect.com/science/article/pii/S0360544222017200},
doi = {10.1016/j.energy.2022.124817}
}
|
| Linkosalmi M, Tuovinen J-P, Nevalainen O, Peltoniemi M, Taniş CM, Arslan AN, Rainne J, Lohila A, Laurila T and Aurela M (2022), "Tracking vegetation phenology of pristine northern boreal peatlands by combining digital photography with CO_2 flux and remote sensing data", Biogeosciences. Vol. 19(19), pp. 4747-4765. |
BibTeX:
@article{Linkosalmi2022,
author = {Linkosalmi, M and Tuovinen, J.-P. and Nevalainen, O and Peltoniemi, M and Tani, C M and Arslan, A N and Rainne, J and Lohila, A and Laurila, T and Aurela, M},
title = {Tracking vegetation phenology of pristine northern boreal peatlands by combining digital photography with CO_2 flux and remote sensing data},
journal = {Biogeosciences},
year = {2022},
volume = {19},
number = {19},
pages = {4747--4765},
url = {https://bg.copernicus.org/articles/19/4747/2022/},
doi = {10.5194/bg-19-4747-2022}
}
|
| Liu Y, Wu C, Tian F, Wang X, Gamon JA, Wong CYS, Zhang X, Gonsamo A and Jassal RS (2022), "Modeling plant phenology by MODIS derived photochemical reflectance index (PRI)", Agricultural and Forest Meteorology. Vol. 324, pp. 109095. |
| Abstract: Vegetation phenology is a sensitive indicator of ecosystem responses to climate change, and thus the accurate estimation of vegetation phenology is critical to evaluate the impact of climate change on terrestrial ecosystems. Common structural vegetation indices (VIs) such as the Normalized Difference Vegetation Index (NDVI), Enhanced Vegetation Index (EVI), Near-infrared Reflectance of Vegetation (NIRv) and Plant Phenology Index (PPI), are the most widely used indicators of phenology, but they have limited potential in tracking autumn phenology, especially for evergreen species with low seasonal variability of canopy greenness. Given the important role of carotenoid pigments in regulating photosynthetic activity and plant phenology, we hypothesize that satellite-based indicators of leaf pigments derived from MODIS ocean bands could be useful for phenology modeling. Using 624 site-years of flux data at 84 FLUXNET sites and 9979 ground observations at 138 PEP725 sites, we first explored the potential of different forms of scaled photochemical reflectance index (sPRIref) in monitoring photosynthetic activity, and found that band 10 and band 13 were more suitable for tracking gross primary productivity (GPP) than other reference bands. By comparing with canopy photosynthetic phenology, sPRI10 and sPRI13 showed improved representation of phenological transitions (the start and end of growing season, SOS and EOS, respectively) than structural VIs. In spring, all VIs exhibited comparable performances for estimating SOS at deciduous broadleaf forests (DBF) and grasslands (GRA) sites; however, sPRI10 and sPRI13 were better predictors of SOS than structural VIs at evergreen needleleaf forests (ENF) and mixed forests (MF) sites. In autumn, sPRI10 and sPRI13 showed improved predictive strength of EOS than structural VIs for ENF, MF and GRA sites. Further investigations using the ground observed phenological records also confirmed the improved performances of sPRI10 and sPRI13 for both SOS and EOS estimation. We also investigated the spatial patterns of sPRI10-derived SOS and EOS over the Northern Hemisphere with respect to different plant functional types. We showed that sPRI10 reliably tracked plant phenology with 83.0% and 78.8% success in detecting SOS and EOS, respectively. Spatial patterns of SOS exhibited obvious latitudinal gradients, while EOS showed a strong regional heterogeneity. In addition, sPRI10 predicted an overall earlier SOS (61.8%) and later EOS (51.2%) than the MODIS phenology product (VNP22Q2 v001) estimated from structural VI, suggesting the latter underestimated the greening potential of the Northern Hemisphere. Our results suggest that MODIS PRI could be useful to monitor vegetation phenology, and further reveal the importance of underappreciated carotenoid pigments in tracking plant seasonal changes, particularly in autumn months. |
BibTeX:
@article{Liu2022,
author = {Liu, Ying and Wu, Chaoyang and Tian, Feng and Wang, Xiaoyue and Gamon, John A and Wong, Christopher Y S and Zhang, Xiaoyang and Gonsamo, Alemu and Jassal, Rachhpal S},
title = {Modeling plant phenology by MODIS derived photochemical reflectance index (PRI)},
journal = {Agricultural and Forest Meteorology},
year = {2022},
volume = {324},
pages = {109095},
url = {https://www.sciencedirect.com/science/article/pii/S0168192322002830},
doi = {10.1016/j.agrformet.2022.109095}
}
|
| Lucas-Moffat AM, Schrader F, Herbst M and Brümmer C (2022), "Multiple gap-filling for eddy covariance datasets", Agricultural and Forest Meteorology. Vol. 325, pp. 109114. |
| Abstract: With novel developments in technology, eddy covariance flux measurements have become feasible for a variety of trace gases. While the statistical properties and gap-filling strategies have been well examined for carbon dioxide, these are much less understood for other gases. Here, we propose a universal methodology deploying multiple gap-filling techniques and artificial gap scenarios to evaluate the techniques' performances, infer the statistical flux properties, and fill the real gaps in eddy covariance datasets of any trace gas. The methodology was implemented in a gap-filling framework with techniques spanning from simple and diurnal interpolations, look-up tables, artificial neural networks, to an inferential model. For the new scheme of half-hourly and daily artificial gaps, each additional gap was superimposed one at a time (thus keeping the disturbance to a minimum) for the whole dataset and the scenarios were resampled by bootstrapping. The gap-filled sums were then estimated from the ensemble of well-performing gap-filling techniques. The gap-filling framework was applied to campaign data of three different trace gases (51 days of ammonia, 79 days of total reactive nitrogen, and 89 days of methane flux measurements). The aggregated fluxes are stated as ensemble ranges of multiple techniques plus the techniques' uncertainties. Additionally, the framework was used to gap-fill a full year of carbon dioxide flux measurements yielding similar performances as previously reported. Based on a review of gap-filling comparison studies and on our findings, we suggest reconsidering the standard procedure of using one gap-filling technique for multi-site studies. Deploying multiple gap-filling techniques and providing ensemble results of gap-filled sums will help to minimize the influence of a single technique and thus lead to a more robust flux aggregation. Furthermore, the estimated overall uncertainty will be more realistic by accounting for the ensemble range of multiple techniques. |
BibTeX:
@article{LucasMoffat2022,
author = {Lucas-Moffat, Antje M and Schrader, Frederik and Herbst, Mathias and Brümmer, Christian},
title = {Multiple gap-filling for eddy covariance datasets},
journal = {Agricultural and Forest Meteorology},
year = {2022},
volume = {325},
pages = {109114},
url = {https://www.sciencedirect.com/science/article/pii/S016819232200301X},
doi = {10.1016/j.agrformet.2022.109114}
}
|
| Mäki M, Ryhti K, Fer I, Ťupek B, Vestin P, Roland M, Lehner I, Köster E, Lehtonen A, Bäck J, Heinonsalo J, Pumpanen J and Kulmala L (2022), "Heterotrophic and rhizospheric respiration in coniferous forest soils along a latitudinal gradient", Agricultural and Forest Meteorology. Vol. 317, pp. 108876. |
| Abstract: Northern forest soils are a major carbon (C) reservoir of global importance. To estimate how the C balance in these soils will change, the roles of tree roots and soil microbes in C balance should first be decoupled. This study determined how the activity of heterotrophs and tree roots together with root-associated microbes in the rhizosphere varies in coniferous forest soils in boreal, hemiboreal, and temperate climates along a latitudinal gradient using a trenching approach. We created experimental plots without living tree roots, measured soil respiration (CO2 efflux) from these and from unmanipulated plots using the chamber technique, and partitioned the efflux into root-rhizosphere (RR) and heterotrophic (RH) respiration. The share of RR in ecosystem gross primary production (GPP) decreased from north to south in the Scots pine (Pinus sylvestris L.) and the Norway spruce (Picea abies (L.) Karst.) forests, with the exception of a mixed site, where the share of RR in GPP varied strongly between the years. RR per ground area and per root biomass were mainly independent of climate within the gradient. RH per ground area increased from north to south with temperature, while RH per soil C did not change with temperature. Soil moisture did not significantly affect the respiration components in the northernmost site, whereas soil moisture was positively connected with RH and negatively with RR in other Scots pine sites and positively connected with RR in pure Norway spruce stands. The dynamic ecosystem model LPJ-GUESS was able to capture the seasonal dynamics of RH and RR at the sites, but overall accuracy varied markedly between the sites, as the model underestimated RH in the southern site and RR elsewhere. Our study provides knowledge about the nature of soil respiration components. The valuable insights can be used in more accurate land-ecosystem modelling of forest ecosystems. |
BibTeX:
@article{Maeki2022,
author = {Mäki, Mari and Ryhti, Kira and Fer, Istem and Ťupek, Boris and Vestin, Patrik and Roland, Marilyn and Lehner, Irene and Köster, Egle and Lehtonen, Aleksi and Bäck, Jaana and Heinonsalo, Jussi and Pumpanen, Jukka and Kulmala, Liisa},
title = {Heterotrophic and rhizospheric respiration in coniferous forest soils along a latitudinal gradient},
journal = {Agricultural and Forest Meteorology},
year = {2022},
volume = {317},
pages = {108876},
url = {https://www.sciencedirect.com/science/article/pii/S0168192322000697},
doi = {10.1016/j.agrformet.2022.108876}
}
|
| Mahrt L, Nilsson E and Rutgersson A (2022), "The Sea Surface Heat Flux at a Coastal Site", Journal of Physical Oceanography. Boston MA, USA Vol. 52(12), pp. 3297-3307. American Meteorological Society. |
BibTeX:
@article{Mahrt2022,
author = {Mahrt, L and Nilsson, Erik and Rutgersson, Anna},
title = {The Sea Surface Heat Flux at a Coastal Site},
journal = {Journal of Physical Oceanography},
publisher = {American Meteorological Society},
year = {2022},
volume = {52},
number = {12},
pages = {3297--3307},
url = {https://journals.ametsoc.org/view/journals/phoc/52/12/JPO-D-22-0094.1.xml},
doi = {10.1175/JPO-D-22-0094.1}
}
|
| Maier F, Gerbig C, Levin I, Super I, Marshall J and Hammer S (2022), "Effects of point source emission heights in WRF--STILT: a step towards exploiting nocturnal observations in models", Geoscientific Model Development. Vol. 15(13), pp. 5391-5406. |
BibTeX:
@article{Maier2022,
author = {Maier, F and Gerbig, C and Levin, I and Super, I and Marshall, J and Hammer, S},
title = {Effects of point source emission heights in WRF--STILT: a step towards exploiting nocturnal observations in models},
journal = {Geoscientific Model Development},
year = {2022},
volume = {15},
number = {13},
pages = {5391--5406},
url = {https://gmd.copernicus.org/articles/15/5391/2022/},
doi = {10.5194/gmd-15-5391-2022}
}
|
| Maier R, Hörtnagl L and Buchmann N (2022), "Greenhouse gas fluxes (CO2, N2O and CH4) of pea and maize during two cropping seasons: Drivers, budgets, and emission factors for nitrous oxide", Science of The Total Environment. Vol. 849, pp. 157541. |
| Abstract: Agriculture contributes considerably to the increase of global greenhouse gas (GHG) emissions. Hence, magnitude and drivers of temporal variations in carbon dioxide (CO2), nitrous oxide (N2O) and methane (CH4) fluxes in croplands are urgently needed to develop sustainable, climate-smart agricultural practices. However, our knowledge of GHG fluxes from croplands is still very limited. The eddy covariance technique was used to quantify GHG budgets and N2O emission factors (EF) for pea and maize in Switzerland. The random forest technique was applied for gap-filling N2O and CH4 fluxes as well as to determine the relevance of environmental, vegetation vs. management drivers of the GHG fluxes during two cropping seasons. Environmental (i.e., net radiation, soil water content, soil temperature) and vegetation drivers (i.e., vegetation height) were more important drivers for GHG fluxes at field scale than time since management for the two crop species. Both crops acted as GHG sinks between sowing and harvest, clearly dominated by net CO2 fluxes, while CH4 emissions were negligible. However, considerable N2O emissions occurred in both crop fields early in the season when crops were still establishing. N2O fluxes in both crops were small later in the season when vegetation was tall, despite high soil water contents and temperatures. Results clearly show a strong and highly dynamic microbial-plant competition for N driving N2O fluxes at the field scale. The total loss was 1.4 kg N2O-N ha−1 over 55 days for pea and 4.8 kg N2O-N ha−1 over 127 days for maize. EFs of N2O were 1.5 % (pea) and 4.4 % (maize) during the cropping seasons, clearly exceeding the IPCC Tier 1 EF for N2O. Thus, sustainable, climate-smart agriculture needs to consider crop phenology and better adapt N supply to crop N demand for growth, particularly during the early cropping season when competition for N between establishing crops and soil microorganisms modulates N2O losses. |
BibTeX:
@article{Maier2022a,
author = {Maier, Regine and Hörtnagl, Lukas and Buchmann, Nina},
title = {Greenhouse gas fluxes (CO2, N2O and CH4) of pea and maize during two cropping seasons: Drivers, budgets, and emission factors for nitrous oxide},
journal = {Science of The Total Environment},
year = {2022},
volume = {849},
pages = {157541},
url = {https://www.sciencedirect.com/science/article/pii/S0048969722046393},
doi = {10.1016/j.scitotenv.2022.157541}
}
|
| Martínez-García E, Nilsson MB, Laudon H, Lundmark T, Fransson JES, Wallerman J and Peichl M (2022), "Overstory dynamics regulate the spatial variability in forest-floor CO2 fluxes across a managed boreal forest landscape", Agricultural and Forest Meteorology. Vol. 318, pp. 108916. |
| Abstract: The forest-floor represents an important interface for various carbon dioxide (CO2) fluxes, however, our knowledge of their variability and drivers across a managed boreal forest landscape is limited. Here, we used a three-year (2016−2018) data set of biometric- and chamber-based flux measurements to investigate the net forest-floor CO2 exchange (NEff) and its component fluxes across 50 forest stands spanning different soil types, tree species, and age classes within a 68 km2 boreal catchment in Sweden. We found that the forest-floor acted as a net CO2 source with the 10th–90th percentile (used hereafter for describing reported variations) ranging from 149 to 399 g C m−2 yr−1. Among the key landscape attributes, stand age strongly affected most NEff component fluxes, whereas tree species and soil type effects were weak and absent, respectively. Specifically, forest-floor net CO2 emissions increased with stand age due to declining understory gross and net primary production, ranging between 77–275 and 49–163 g C m−2 yr−1, respectively. Furthermore, we observed higher understory production rates in pine than in spruce stands. Across the 50 stands, the total forest-floor respiration ranged between 340 and 549 g C m−2 yr−1 and its spatial variation was primarily regulated by its autotrophic components, i.e., understory and tree root respiration, which displayed divergent increasing and decreasing age-related trends, respectively. Furthermore, heterotrophic soil respiration remained within a relatively narrow range (154–290 g C m−2 yr−1), possibly owing to compensating gradients in forest-floor properties. We further identified tree biomass as the major driver of the landscape-scale variations of CO2 fluxes, likely attributable to modulating effects on forest-floor resource availability and growing conditions. This implies that tree growth responses to forest management and global change will be particularly important for regulating magnitudes and spatial variations of forest-floor CO2 fluxes in boreal forests. |
BibTeX:
@article{MartinezGarcia2022,
author = {Martínez-García, Eduardo and Nilsson, Mats B and Laudon, Hjalmar and Lundmark, Tomas and Fransson, Johan E S and Wallerman, Jörgen and Peichl, Matthias},
title = {Overstory dynamics regulate the spatial variability in forest-floor CO2 fluxes across a managed boreal forest landscape},
journal = {Agricultural and Forest Meteorology},
year = {2022},
volume = {318},
pages = {108916},
url = {https://www.sciencedirect.com/science/article/pii/S0168192322001095},
doi = {10.1016/j.agrformet.2022.108916}
}
|
| Mathijssen PJH, Tuovinen J-P, Lohila A, Väliranta M and Tuittila E-S (2022), "Identifying main uncertainties in estimating past and present radiative forcing of peatlands", Global Change Biology. Vol. 28(13), pp. 4069-4084. |
| Abstract: Abstract Reconstructions of past climate impact, that is, radiative forcing (RF), of peatland carbon (C) dynamics show that immediately after peatland initiation the climate warming effect of CH4 emissions exceeds the cooling effect of CO2 uptake, but thereafter the net effect of most peatlands will move toward cooling, when RF switches from positive to negative. Reconstructing peatland C dynamics necessarily involves uncertainties related to basic assumptions on past CO2 flux, CH4 emission and peatland expansion. We investigated the effect of these uncertainties on the RF of three peatlands, using either apparent C accumulation rates, net C balance (NCB) or NCB plus C loss during fires as basis for CO2 uptake estimate; applying a plausible range for CH4 emission; and assuming linearly interpolated expansion between basal dates or comparatively early or late expansion. When we factored that some C would only be stored temporarily (NCB and NCB+fire), the estimated past cooling effect of CO2 uptake increased, but the present-day RF was affected little. Altering the assumptions behind the reconstructed CO2 flux or expansion patterns caused the RF to peak earlier and advanced the switch from positive to negative RF by several thousand years. Compared with NCB, including fires had only small additional effect on RF lasting less than 1000 year. The largest uncertainty in reconstructing peatland RF was associated with CH4 emissions. As shown by the consistently positive RF modelled for one site, and in some cases for the other two, peatlands with high CH4 emissions and low C accumulation rates may have remained climate warming agents since their initiation. Although uncertainties in present-day RF were mainly due to the assumed CH4 emission rates, the uncertainty in lateral expansion still had a significant effect on the present-day RF, highlighting the importance to consider uncertainties in the past peatland C balance in RF reconstructions. |
BibTeX:
@article{Mathijssen2022,
author = {Mathijssen, Paul J H and Tuovinen, Juha-Pekka and Lohila, Annalea and Väliranta, Minna and Tuittila, Eeva-Stiina},
title = {Identifying main uncertainties in estimating past and present radiative forcing of peatlands},
journal = {Global Change Biology},
year = {2022},
volume = {28},
number = {13},
pages = {4069--4084},
url = {https://onlinelibrary.wiley.com/doi/abs/10.1111/gcb.16189},
doi = {10.1111/gcb.16189}
}
|
| Meusburger K, Trotsiuk V, Schmidt-Walter P, Baltensweiler A, Brun P, Bernhard F, Gharun M, Habel R, Hagedorn F, Köchli R, Psomas A, Puhlmann H, Thimonier A, Waldner P, Zimmermann S and Walthert L (2022), "Soil–plant interactions modulated water availability of Swiss forests during the 2015 and 2018 droughts", Global Change Biology. Vol. 28(20), pp. 5928-5944. |
| Abstract: Abstract Central Europe has been experiencing unprecedented droughts during the last decades, stressing the decrease in tree water availability. However, the assessment of physiological drought stress is challenging, and feedback between soil and vegetation is often omitted because of scarce belowground data. Here we aimed to model Swiss forests' water availability during the 2015 and 2018 droughts by implementing the mechanistic soil-vegetation-atmosphere-transport (SVAT) model LWF-Brook90 taking advantage of regionalized depth-resolved soil information. We calibrated the model against soil matric potential data measured from 2014 to 2018 at 44 sites along a Swiss climatic and edaphic drought gradient. Swiss forest soils' storage capacity of plant-available water ranged from 53 mm to 341 mm, with a median of 137 ± 42 mm down to the mean potential rooting depth of 1.2 m. Topsoil was the primary water source. However, trees switched to deeper soil water sources during drought. This effect was less pronounced for coniferous trees with a shallower rooting system than for deciduous trees, which resulted in a higher reduction of actual transpiration (transpiration deficit) in coniferous trees. Across Switzerland, forest trees reduced the transpiration by 23% (compared to potential transpiration) in 2015 and 2018, maintaining annual actual transpiration comparable to other years. Together with lower evaporative fluxes, the Swiss forests did not amplify the blue water deficit. The 2018 drought, characterized by a higher and more persistent transpiration deficit than in 2015, triggered widespread early wilting across Swiss forests that was better predicted by the SVAT-derived mean soil matric potential in the rooting zone than by climatic predictors. Such feedback-driven quantification of ecosystem water fluxes in the soil–plant-atmosphere continuum will be crucial to predicting physiological drought stress under future climate extremes. |
BibTeX:
@article{Meusburger2022,
author = {Meusburger, Katrin and Trotsiuk, Volodymyr and Schmidt-Walter, Paul and Baltensweiler, Andri and Brun, Philipp and Bernhard, Fabian and Gharun, Mana and Habel, Raphael and Hagedorn, Frank and Köchli, Roger and Psomas, Achilleas and Puhlmann, Heike and Thimonier, Anne and Waldner, Peter and Zimmermann, Stephan and Walthert, Lorenz},
title = {Soil–plant interactions modulated water availability of Swiss forests during the 2015 and 2018 droughts},
journal = {Global Change Biology},
year = {2022},
volume = {28},
number = {20},
pages = {5928--5944},
url = {https://onlinelibrary.wiley.com/doi/abs/10.1111/gcb.16332},
doi = {10.1111/gcb.16332}
}
|
| Mühle J, Kuijpers LJM, Stanley KM, Rigby M, Western LM, Kim J, Park S, Harth CM, Krummel PB, Fraser PJ, O’Doherty S, Salameh PK, Schmidt R, Young D, Prinn RG, Wang RHJ and Weiss RF (2022), "Global emissions of perfluorocyclobutane (PFC-318, c-C4F8) resulting from the use of hydrochlorofluorocarbon-22 (HCFC-22) feedstock to produce polytetrafluoroethylene (PTFE) and related fluorochemicals", Atmospheric Chemistry and Physics., March, 2022. Vol. 22(5), pp. 3371-3378. Copernicus GmbH. |
BibTeX:
@article{Muehle2022,
author = {Mühle, Jens and Kuijpers, Lambert J. M. and Stanley, Kieran M. and Rigby, Matthew and Western, Luke M. and Kim, Jooil and Park, Sunyoung and Harth, Christina M. and Krummel, Paul B. and Fraser, Paul J. and O’Doherty, Simon and Salameh, Peter K. and Schmidt, Roland and Young, Dickon and Prinn, Ronald G. and Wang, Ray H. J. and Weiss, Ray F.},
title = {Global emissions of perfluorocyclobutane (PFC-318, c-C4F8) resulting from the use of hydrochlorofluorocarbon-22 (HCFC-22) feedstock to produce polytetrafluoroethylene (PTFE) and related fluorochemicals},
journal = {Atmospheric Chemistry and Physics},
publisher = {Copernicus GmbH},
year = {2022},
volume = {22},
number = {5},
pages = {3371--3378},
doi = {10.5194/acp-22-3371-2022}
}
|
| Munassar S, Monteil G, Scholze M, Karstens U, Rödenbeck C, Koch F-T, Totsche KU and Gerbig C (2022), "Impact of atmospheric transport on CO_2 flux estimates derived from the atmospheric tracer inversions", Atmospheric Chemistry and Physics Discussions. Vol. 2022, pp. 1-26. |
BibTeX:
@article{Munassar2022,
author = {Munassar, S and Monteil, G and Scholze, M and Karstens, U and Rödenbeck, C and Koch, F.-T. and Totsche, K U and Gerbig, C},
title = {Impact of atmospheric transport on CO_2 flux estimates derived from the atmospheric tracer inversions},
journal = {Atmospheric Chemistry and Physics Discussions},
year = {2022},
volume = {2022},
pages = {1--26},
url = {https://acp.copernicus.org/preprints/acp-2022-510/},
doi = {10.5194/acp-2022-510}
}
|
| Munassar S, Rödenbeck C, Koch F-T, Totsche KU, Gałkowski M, Walther S and Gerbig C (2022), "Net ecosystem exchange (NEE) estimates 2006--2019 over Europe from a pre-operational ensemble-inversion system", Atmospheric Chemistry and Physics. Vol. 22(12), pp. 7875-7892. |
BibTeX:
@article{Munassar2022a,
author = {Munassar, S and Rödenbeck, C and Koch, F.-T. and Totsche, K U and Gałkowski, M and Walther, S and Gerbig, C},
title = {Net ecosystem exchange (NEE) estimates 2006--2019 over Europe from a pre-operational ensemble-inversion system},
journal = {Atmospheric Chemistry and Physics},
year = {2022},
volume = {22},
number = {12},
pages = {7875--7892},
url = {https://acp.copernicus.org/articles/22/7875/2022/},
doi = {10.5194/acp-22-7875-2022}
}
|
| Nicolini G, Antoniella G, Carotenuto F, Christen A, Ciais P, Feigenwinter C, Gioli B, Stagakis S, Velasco E, Vogt R, Ward HC, Barlow J, Chrysoulakis N, Duce P, Graus M, Helfter C, Heusinkveld B, Järvi L, Karl T, Marras S, Masson V, Matthews B, Meier F, Nemitz E, Sabbatini S, Scherer D, Schume H, Sirca C, Steeneveld G-J, Vagnoli C, Wang Y, Zaldei A, Zheng B and Papale D (2022), "Direct observations of CO2 emission reductions due to COVID-19 lockdown across European urban districts", Science of The Total Environment. Vol. 830, pp. 154662. |
| Abstract: The measures taken to contain the spread of COVID-19 in 2020 included restrictions of people's mobility and reductions in economic activities. These drastic changes in daily life, enforced through national lockdowns, led to abrupt reductions of anthropogenic CO2 emissions in urbanized areas all over the world. To examine the effect of social restrictions on local emissions of CO2, we analysed district level CO2 fluxes measured by the eddy-covariance technique from 13 stations in 11 European cities. The data span several years before the pandemic until October 2020 (six months after the pandemic began in Europe). All sites showed a reduction in CO2 emissions during the national lockdowns. The magnitude of these reductions varies in time and space, from city to city as well as between different areas of the same city. We found that, during the first lockdowns, urban CO2 emissions were cut with respect to the same period in previous years by 5% to 87% across the analysed districts, mainly as a result of limitations on mobility. However, as the restrictions were lifted in the following months, emissions quickly rebounded to their pre-COVID levels in the majority of sites. |
BibTeX:
@article{Nicolini2022,
author = {Nicolini, Giacomo and Antoniella, Gabriele and Carotenuto, Federico and Christen, Andreas and Ciais, Philippe and Feigenwinter, Christian and Gioli, Beniamino and Stagakis, Stavros and Velasco, Erik and Vogt, Roland and Ward, Helen C and Barlow, Janet and Chrysoulakis, Nektarios and Duce, Pierpaolo and Graus, Martin and Helfter, Carole and Heusinkveld, Bert and Järvi, Leena and Karl, Thomas and Marras, Serena and Masson, Valéry and Matthews, Bradley and Meier, Fred and Nemitz, Eiko and Sabbatini, Simone and Scherer, Dieter and Schume, Helmut and Sirca, Costantino and Steeneveld, Gert-Jan and Vagnoli, Carolina and Wang, Yilong and Zaldei, Alessandro and Zheng, Bo and Papale, Dario},
title = {Direct observations of CO2 emission reductions due to COVID-19 lockdown across European urban districts},
journal = {Science of The Total Environment},
year = {2022},
volume = {830},
pages = {154662},
url = {https://www.sciencedirect.com/science/article/pii/S0048969722017557},
doi = {10.1016/j.scitotenv.2022.154662}
}
|
| Oehri J, Schaepman-Strub G, Kim JS, Grysko R, Kropp H, Grünberg I, Zemlianskii V, Sonnentag O, Euskirchen ES, Reji Chacko M, Muscari G, Blanken PD, Dean JF, di Sarra A, Harding RJ, Sobota I, Kutzbach L, Plekhanova E, Riihelä A, Boike J, Miller NB, Beringer J, López-Blanco E, Stoy PC, Sullivan RC, Kejna M, Parmentier FJW, Gamon JA, Mastepanov M, Wille C, Jackowicz-Korczynski M, Karger DN, Quinton WL, Putkonen J, van As D, Christensen TR, Hakuba MZ, Stone RS, Metzger S, Vandecrux B, Frost GV, Wild M, Hansen B, Meloni D, Domine F, te Beest M, Sachs T, Kalhori A, Rocha AV, Williamson SN, Morris S, Atchley AL, Essery R, Runkle BR, Holl D, Riihimaki LD, Iwata H, Schuur EA, Cox CJ, Grachev AA, McFadden JP, Fausto RS, Göckede M, Ueyama M, Pirk N, de Boer G, Bret-Harte MS, Leppäranta M, Steffen K, Friborg T, Ohmura A, Edgar CW, Olofsson J and Chambers SD (2022), "Vegetation type is an important predictor of the arctic summer land surface energy budget", Nature Communications. Vol. 13(1), pp. 21-27. |
| Abstract: Despite the importance of high-latitude surface energy budgets (SEBs) for land-climate interactions in the rapidly changing Arctic, uncertainties in their prediction persist. Here, we harmonize SEB observations across a network of vegetated and glaciated sites at circumpolar scale (1994–2021). Our variance-partitioning analysis identifies vegetation type as an important predictor for SEB-components during Arctic summer (June-August), compared to other SEB-drivers including climate, latitude and permafrost characteristics. Differences among vegetation types can be of similar magnitude as between vegetation and glacier surfaces and are especially high for summer sensible and latent heat fluxes. The timing of SEB-flux summer-regimes (when daily mean values exceed 0 Wm−2) relative to snow-free and -onset dates varies substantially depending on vegetation type, implying vegetation controls on snow-cover and SEB-flux seasonality. Our results indicate complex shifts in surface energy fluxes with land-cover transitions and a lengthening summer season, and highlight the potential for improving future Earth system models via a refined representation of Arctic vegetation types. |
BibTeX:
@article{Oehri2022,
author = {Oehri, Jacqueline and Schaepman-Strub, Gabriela and Kim, Jin Soo and Grysko, Raleigh and Kropp, Heather and Grünberg, Inge and Zemlianskii, Vitalii and Sonnentag, Oliver and Euskirchen, Eugénie S. and Reji Chacko, Merin and Muscari, Giovanni and Blanken, Peter D. and Dean, Joshua F. and di Sarra, Alcide and Harding, Richard J. and Sobota, Ireneusz and Kutzbach, Lars and Plekhanova, Elena and Riihelä, Aku and Boike, Julia and Miller, Nathaniel B. and Beringer, Jason and López-Blanco, Efrén and Stoy, Paul C. and Sullivan, Ryan C. and Kejna, Marek and Parmentier, Frans Jan W. and Gamon, John A. and Mastepanov, Mikhail and Wille, Christian and Jackowicz-Korczynski, Marcin and Karger, Dirk N. and Quinton, William L. and Putkonen, Jaakko and van As, Dirk and Christensen, Torben R. and Hakuba, Maria Z. and Stone, Robert S. and Metzger, Stefan and Vandecrux, Baptiste and Frost, Gerald V. and Wild, Martin and Hansen, Birger and Meloni, Daniela and Domine, Florent and te Beest, Mariska and Sachs, Torsten and Kalhori, Aram and Rocha, Adrian V. and Williamson, Scott N. and Morris, Sara and Atchley, Adam L. and Essery, Richard and Runkle, Benjamin R.K. and Holl, David and Riihimaki, Laura D. and Iwata, Hiroki and Schuur, Edward A.G. and Cox, Christopher J. and Grachev, Andrey A. and McFadden, Joseph P. and Fausto, Robert S. and Göckede, Mathias and Ueyama, Masahito and Pirk, Norbert and de Boer, Gijs and Bret-Harte, M. Syndonia and Leppäranta, Matti and Steffen, Konrad and Friborg, Thomas and Ohmura, Atsumu and Edgar, Colin W. and Olofsson, Johan and Chambers, Scott D.},
title = {Vegetation type is an important predictor of the arctic summer land surface energy budget},
journal = {Nature Communications},
year = {2022},
volume = {13},
number = {1},
pages = {21--27},
doi = {10.1038/s41467-022-34049-3}
}
|
| Olin M, Okuljar M, Rissanen MP, Kalliokoski J, Shen J, Dada L, Lampimäki M, Wu Y, Lohila A, Duplissy J, Sipilä M, Petäjä T, Kulmala M and Dal Maso M (2022), "Measurement report: Atmospheric new particle formation in a coastal agricultural site explained with binPMF analysis of nitrate CI-APi-TOF spectra", Atmospheric Chemistry and Physics. Vol. 22(12), pp. 8097-8115. |
BibTeX:
@article{Olin2022,
author = {Olin, M and Okuljar, M and Rissanen, M P and Kalliokoski, J and Shen, J and Dada, L and Lampimäki, M and Wu, Y and Lohila, A and Duplissy, J and Sipilä, M and Petäjä, T and Kulmala, M and Dal Maso, M},
title = {Measurement report: Atmospheric new particle formation in a coastal agricultural site explained with binPMF analysis of nitrate CI-APi-TOF spectra},
journal = {Atmospheric Chemistry and Physics},
year = {2022},
volume = {22},
number = {12},
pages = {8097--8115},
url = {https://acp.copernicus.org/articles/22/8097/2022/},
doi = {10.5194/acp-22-8097-2022}
}
|
| Pang Y, Räsänen A, Lindholm V, Aurela M and Virtanen T (2022), "Detecting peatland vegetation patterns with multi-temporal field spectroscopy", GIScience & Remote Sensing. Vol. 59(1), pp. 2111-2126. Taylor & Francis. |
BibTeX:
@article{Pang2022,
author = {Pang, Yuwen and Räsänen, Aleksi and Lindholm, Viivi and Aurela, Mika and Virtanen, Tarmo},
title = {Detecting peatland vegetation patterns with multi-temporal field spectroscopy},
journal = {GIScience & Remote Sensing},
publisher = {Taylor & Francis},
year = {2022},
volume = {59},
number = {1},
pages = {2111--2126},
url = {https://doi.org/10.1080/15481603.2022.2152303},
doi = {10.1080/15481603.2022.2152303}
}
|
| PATRA PK, DLUGOKENCKY EJ, ELKINS JW, DUTTON GS, TOHJIMA Y, SASAKAWA M, ITO A, WEISS RF, MANIZZA M, KRUMMEL PB, PRINN RG, O’DOHERTY S, BIANCHI D, NEVISON C, SOLAZZO E, LEE H, JOO S, KORT EA, MAITY S and TAKIGAWA M (2022), "Forward and Inverse Modelling of Atmospheric Nitrous Oxide Using MIROC4-Atmospheric Chemistry-Transport Model", Journal of the Meteorological Society of Japan. Ser. II. Vol. 100(2), pp. 361-386. Meteorological Society of Japan. |
BibTeX:
@article{PATRA2022,
author = {PATRA, Prabir K. and DLUGOKENCKY, Edward J. and ELKINS, James W. and DUTTON, Geoff S. and TOHJIMA, Yasunori and SASAKAWA, Motoki and ITO, Akihiko and WEISS, Ray F. and MANIZZA, Manfredi and KRUMMEL, Paul B. and PRINN, Ronald G. and O’DOHERTY, Simon and BIANCHI, Daniele and NEVISON, Cynthia and SOLAZZO, Efisio and LEE, Haeyoung and JOO, Sangwon and KORT, Eric A. and MAITY, Suman and TAKIGAWA, Masayuki},
title = {Forward and Inverse Modelling of Atmospheric Nitrous Oxide Using MIROC4-Atmospheric Chemistry-Transport Model},
journal = {Journal of the Meteorological Society of Japan. Ser. II},
publisher = {Meteorological Society of Japan},
year = {2022},
volume = {100},
number = {2},
pages = {361--386},
doi = {10.2151/jmsj.2022-018}
}
|
| Patzner MS, Kainz N, Lundin E, Barczok M, Smith C, Herndon E, Kinsman-Costello L, Fischer S, Straub D, Kleindienst S, Kappler A and Bryce C (2022), "Seasonal Fluctuations in Iron Cycling in Thawing Permafrost Peatlands", Environmental Science & Technology., apr, 2022. Vol. 56(7), pp. 4620-4631. American Chemical Society. |
BibTeX:
@article{Patzner2022,
author = {Patzner, Monique S and Kainz, Nora and Lundin, Erik and Barczok, Maximilian and Smith, Chelsea and Herndon, Elizabeth and Kinsman-Costello, Lauren and Fischer, Stefan and Straub, Daniel and Kleindienst, Sara and Kappler, Andreas and Bryce, Casey},
title = {Seasonal Fluctuations in Iron Cycling in Thawing Permafrost Peatlands},
journal = {Environmental Science & Technology},
publisher = {American Chemical Society},
year = {2022},
volume = {56},
number = {7},
pages = {4620--4631},
url = {https://doi.org/10.1021/acs.est.1c06937},
doi = {10.1021/acs.est.1c06937}
}
|
| Peltola O, Aurela M, Launiainen S and Katul G (2022), "Probing eddy size and its effective mixing length in stably stratified roughness sublayer flows", Quarterly Journal of the Royal Meteorological Society. Vol. 148(749), pp. 3756-3773. |
| Abstract: Stably stratified roughness sublayer flows are ubiquitous yet remain difficult to represent in models and to interpret using field experiments. Here, continuous high-frequency potential temperature profiles from the forest floor up to 6.5 times the canopy height observed with distributed temperature sensing (DTS) are used to link eddy topology to roughness sublayer stability correction functions and coupling between air layers within and above the canopy. The experiments are conducted at two forest stands classified as hydrodynamically sparse and dense. Near-continuous profiles of eddy sizes (length scales) and effective mixing lengths for heat are derived from the observed profiles using a novel conditional sampling approach. The approach utilizes potential temperature isoline fluctuations from a statically stable background state. The transport of potential temperature by an observed eddy is assumed to be conserved (adiabatic movement) and we assume that irreversible heat exchange between the eddy and the surrounding background occurs along the (vertical) periphery of the eddy. This assumption is analogous to Prandtl's mixing-length concept, where momentum is transported rapidly vertically and then equilibrated with the local mean velocity gradient. A distinct dependence of the derived length scales on background stratification, height above ground, and canopy characteristics emerges from the observed profiles. Implications of these findings for (1) the failure of Monin–Obukhov similarity in the roughness sublayer and (2) above-canopy flow coupling to the forest floor are examined. The findings have practical applications in terms of analysing similar DTS data sets with the proposed approach, modelling roughness sublayer flows, and interpreting nocturnal eddy covariance measurements above tall forested canopies. |
BibTeX:
@article{Peltola2022,
author = {Peltola, Olli and Aurela, Mika and Launiainen, Samuli and Katul, Gabriel},
title = {Probing eddy size and its effective mixing length in stably stratified roughness sublayer flows},
journal = {Quarterly Journal of the Royal Meteorological Society},
year = {2022},
volume = {148},
number = {749},
pages = {3756--3773},
url = {https://rmets.onlinelibrary.wiley.com/doi/abs/10.1002/qj.4386},
doi = {10.1002/qj.4386}
}
|
| Peng S, Lin X, Thompson RL, Xi Y, Liu G, Hauglustaine D, Lan X, Poulter B, Ramonet M, Saunois M, Yin Y, Zhang Z, Zheng B and Ciais P (2022), "Wetland emission and atmospheric sink changes explain methane growth in 2020", Nature. Vol. 612(7940), pp. 477-482. |
| Abstract: Atmospheric methane growth reached an exceptionally high rate of 15.1 ± 0.4 parts per billion per year in 2020 despite a probable decrease in anthropogenic methane emissions during COVID-19 lockdowns1. Here we quantify changes in methane sources and in its atmospheric sink in 2020 compared with 2019. We find that, globally, total anthropogenic emissions decreased by 1.2 ± 0.1 teragrams of methane per year (Tg CH4 yr−1), fire emissions decreased by 6.5 ± 0.1 Tg CH4 yr−1 and wetland emissions increased by 6.0 ± 2.3 Tg CH4 yr−1. Tropospheric OH concentration decreased by 1.6 ± 0.2 per cent relative to 2019, mainly as a result of lower anthropogenic nitrogen oxide (NOx) emissions and associated lower free tropospheric ozone during pandemic lockdowns2. From atmospheric inversions, we also infer that global net emissions increased by 6.9 ± 2.1 Tg CH4 yr−1 in 2020 relative to 2019, and global methane removal from reaction with OH decreased by 7.5 ± 0.8 Tg CH4 yr−1. Therefore, we attribute the methane growth rate anomaly in 2020 relative to 2019 to lower OH sink (53 ± 10 per cent) and higher natural emissions (47 ± 16 per cent), mostly from wetlands. In line with previous findings3,4, our results imply that wetland methane emissions are sensitive to a warmer and wetter climate and could act as a positive feedback mechanism in the future. Our study also suggests that nitrogen oxide emission trends need to be taken into account when implementing the global anthropogenic methane emissions reduction pledge5. |
BibTeX:
@article{Peng2022,
author = {Peng, Shushi and Lin, Xin and Thompson, Rona L and Xi, Yi and Liu, Gang and Hauglustaine, Didier and Lan, Xin and Poulter, Benjamin and Ramonet, Michel and Saunois, Marielle and Yin, Yi and Zhang, Zhen and Zheng, Bo and Ciais, Philippe},
title = {Wetland emission and atmospheric sink changes explain methane growth in 2020},
journal = {Nature},
year = {2022},
volume = {612},
number = {7940},
pages = {477--482},
url = {https://doi.org/10.1038/s41586-022-05447-w},
doi = {10.1038/s41586-022-05447-w}
}
|
| Petäjä T, Tabakova K, Manninen A, Ezhova E, O'Connor E, Moisseev D, Sinclair VA, Backman J, Levula J, Luoma K, Virkkula A, Paramonov M, Räty M, Äijälä M, Heikkinen L, Ehn M, Sipilä M, Yli-Juuti T, Virtanen A, Ritsche M, Hickmon N, Pulik G, Rosenfeld D, Worsnop DR, Bäck J, Kulmala M and Kerminen V-M (2022), "Influence of biogenic emissions from boreal forests on aerosol–cloud interactions", Nature Geoscience. Vol. 15(1), pp. 42-47. |
| Abstract: Boreal forest acts as a carbon sink and contributes to the formation of secondary organic aerosols via emission of aerosol precursor compounds. However, these influences on the climate system are poorly quantified. Here we show direct observational evidence that aerosol emissions from the boreal forest biosphere influence warm cloud microphysics and cloud–aerosol interactions in a scale-dependent and highly dynamic manner. Analyses of in situ and ground-based remote-sensing observations from the SMEAR II station in Finland, conducted over eight months in 2014, reveal substantial increases in aerosol load over the forest one to three days after aerosol-poor marine air enters the forest environment. We find that these changes are consistent with secondary organic aerosol formation and, together with water-vapour emissions from evapotranspiration, are associated with changes in the radiative properties of warm, low-level clouds. The feedbacks between boreal forest emissions and aerosol–cloud interactions and the highly dynamic nature of these interactions in air transported over the forest over timescales of several days suggest boreal forests have the potential to mitigate climate change on a continental scale. Our findings suggest that even small changes in aerosol precursor emissions, whether due to changing climatic or anthropogenic factors, may substantially modify the radiative properties of clouds in moderately polluted environments. |
BibTeX:
@article{Petaejae2022,
author = {Petäjä, T and Tabakova, K and Manninen, A and Ezhova, E and O'Connor, E and Moisseev, D and Sinclair, V A and Backman, J and Levula, J and Luoma, K and Virkkula, A and Paramonov, M and Räty, M and Äijälä, M and Heikkinen, L and Ehn, M and Sipilä, M and Yli-Juuti, T and Virtanen, A and Ritsche, M and Hickmon, N and Pulik, G and Rosenfeld, D and Worsnop, D R and Bäck, J and Kulmala, M and Kerminen, V.-M.},
title = {Influence of biogenic emissions from boreal forests on aerosol–cloud interactions},
journal = {Nature Geoscience},
year = {2022},
volume = {15},
number = {1},
pages = {42--47},
url = {https://doi.org/10.1038/s41561-021-00876-0},
doi = {10.1038/s41561-021-00876-0}
}
|
| Petersen RC, Holst T, Mölder M, Kljun N and Rinne J (2022), "Vertical distribution of sources and sinks of VOCs within a boreal forest canopy", EGUsphere. Vol. 2022, pp. 1-30. |
BibTeX:
@article{Petersen2022,
author = {Petersen, R C and Holst, T and Mölder, M and Kljun, N and Rinne, J},
title = {Vertical distribution of sources and sinks of VOCs within a boreal forest canopy},
journal = {EGUsphere},
year = {2022},
volume = {2022},
pages = {1--30},
url = {https://egusphere.copernicus.org/preprints/egusphere-2022-952/},
doi = {10.5194/egusphere-2022-952}
}
|
| Petersson Sjögren M, Alsved M, Šantl-Temkiv T, Bjerring Kristensen T and Löndahl J (2022), "Measurement report: Atmospheric fluorescent bioaerosol concentrations measured during 18 months in a coniferous forest in the south of Sweden", Atmospheric Chemistry and Physics Discussions. Vol. 2022, pp. 1-26. |
BibTeX:
@article{PeterssonSjoegren2022,
author = {Petersson Sjögren, M and Alsved, M and Šantl-Temkiv, T and Bjerring Kristensen, T and Löndahl, J},
title = {Measurement report: Atmospheric fluorescent bioaerosol concentrations measured during 18 months in a coniferous forest in the south of Sweden},
journal = {Atmospheric Chemistry and Physics Discussions},
year = {2022},
volume = {2022},
pages = {1--26},
url = {https://acp.copernicus.org/preprints/acp-2022-560/},
doi = {10.5194/acp-2022-560}
}
|
| Pickers PA, Manning AC, Quéré CL, Forster GL, Luijkx IT, Gerbig C, Fleming LS and Sturges WT (2022), "Novel quantification of regional fossil fuel CO2 reductions during COVID-19 lockdowns using atmospheric oxygen measurements", Science Advances. Vol. 8(16), pp. eabl9250. |
| Abstract: It is not currently possible to quantify regional-scale fossil fuel carbon dioxide (ffCO2) emissions with high accuracy in near real time. Existing atmospheric methods for separating ffCO2 from large natural carbon dioxide variations are constrained by sampling limitations, so that estimates of regional changes in ffCO2 emissions, such as those occurring in response to coronavirus disease 2019 (COVID-19) lockdowns, rely on indirect activity data. We present a method for quantifying regional signals of ffCO2 based on continuous atmospheric measurements of oxygen and carbon dioxide combined into the tracer “atmospheric potential oxygen” (APO). We detect and quantify ffCO2 reductions during 2020–2021 caused by the two U.K. COVID-19 lockdowns individually using APO data from Weybourne Atmospheric Observatory in the United Kingdom and a machine learning algorithm. Our APO-based assessment has near–real-time potential and provides high-frequency information that is in good agreement with the spread of ffCO2 emissions reductions from three independent lower-frequency U.K. estimates. “Atmospheric potential oxygen” is used to quantify fossil fuel CO2 reductions from COVID-19 U.K. lockdowns in 2020–2021. |
BibTeX:
@article{Pickers2022,
author = {Pickers, Penelope A and Manning, Andrew C and Quéré, Corinne Le and Forster, Grant L and Luijkx, Ingrid T and Gerbig, Christoph and Fleming, Leigh S and Sturges, William T},
title = {Novel quantification of regional fossil fuel CO2 reductions during COVID-19 lockdowns using atmospheric oxygen measurements},
journal = {Science Advances},
year = {2022},
volume = {8},
number = {16},
pages = {eabl9250},
url = {https://www.science.org/doi/abs/10.1126/sciadv.abl9250},
doi = {10.1126/sciadv.abl9250}
}
|
| Pieber SM, Tuzson B, Henne S, Karstens U, Gerbig C, Koch F-T, Brunner D, Steinbacher M and Emmenegger L (2022), "Analysis of regional CO_2 contributions at the high Alpine observatory Jungfraujoch by means of atmospheric transport simulations and 13C", Atmospheric Chemistry and Physics. Vol. 22(16), pp. 10721-10749. |
BibTeX:
@article{Pieber2022,
author = {Pieber, S M and Tuzson, B and Henne, S and Karstens, U and Gerbig, C and Koch, F.-T. and Brunner, D and Steinbacher, M and Emmenegger, L},
title = {Analysis of regional CO_2 contributions at the high Alpine observatory Jungfraujoch by means of atmospheric transport simulations and 13C},
journal = {Atmospheric Chemistry and Physics},
year = {2022},
volume = {22},
number = {16},
pages = {10721--10749},
url = {https://acp.copernicus.org/articles/22/10721/2022/},
doi = {10.5194/acp-22-10721-2022}
}
|
| Pintér K and Nagy Z (2022), "Building a UAV Based System to Acquire High Spatial Resolution Thermal Imagery for Energy Balance Modelling", Sensors. Vol. 22(9) |
| Abstract: High spatial resolution and geolocation accuracy canopy evapotranspiration (ET) maps are well suited tools for evaluation of small plot field trials. While creating such a map by use of an energy balance model is routinely performed, the acquisition of the necessary imagery at a suitable quality is still challenging. An UAV based thermal/RGB integrated imaging system was built using the RaspberryPi (RPi) microcomputer as a central unit. The imagery served as input to the two-source energy balance model pyTSEB to derive the ET map. The setup’s flexibility and modularity are based on the multiple interfaces provided by the RPi and the software development kit (SDK) provided for the thermal camera. The SDK was installed on the RPi and used to trigger cameras, retrieve and store images and geolocation information from an onboard GNSS rover for PPK processing. The system allows acquisition of 8 cm spatial resolution thermal imagery from a 60 m height of flight and less than 7 cm geolocation accuracy of the mosaicked RGB imagery. Modelled latent heat flux data have been validated against latent heat fluxes measured by eddy covariance stations at two locations with RMSE of 75 W/m2 over a two-year study period. |
BibTeX:
@article{Pinter2022,
author = {Pintér, Krisztina and Nagy, Zoltán},
title = {Building a UAV Based System to Acquire High Spatial Resolution Thermal Imagery for Energy Balance Modelling},
journal = {Sensors},
year = {2022},
volume = {22},
number = {9},
url = {https://www.mdpi.com/1424-8220/22/9/3251},
doi = {10.3390/s22093251}
}
|
| Płaczkowska E, Mostowik K, Bogena HR and Leuchner M (2022), "The Impact of Partial Deforestation on Solute Fluxes and Stream Water Ionic Composition in a Headwater Catchment", Water., dec, 2022. Vol. 15(1), pp. 107. MDPI AG. |
BibTeX:
@article{Placzkowska2022,
author = {Płaczkowska, Eliza and Mostowik, Karolina and Bogena, Heye Reemt and Leuchner, Michael},
title = {The Impact of Partial Deforestation on Solute Fluxes and Stream Water Ionic Composition in a Headwater Catchment},
journal = {Water},
publisher = {MDPI AG},
year = {2022},
volume = {15},
number = {1},
pages = {107},
url = {http://dx.doi.org/10.3390/w15010107},
doi = {10.3390/w15010107}
}
|
| Platt SM, Hov Ø, Berg T, Breivik K, Eckhardt S, Eleftheriadis K, Evangeliou N, Fiebig M, Fisher R, Hansen G, Hansson H-C, Heintzenberg J, Hermansen O, Heslin-Rees D, Holmén K, Hudson S, Kallenborn R, Krejci R, Krognes T, Larssen S, Lowry D, Lund Myhre C, Lunder C, Nisbet E, Nizzetto PB, Park K-T, Pedersen CA, Aspmo Pfaffhuber K, Röckmann T, Schmidbauer N, Solberg S, Stohl A, Ström J, Svendby T, Tunved P, Tørnkvist K, van der Veen C, Vratolis S, Yoon YJ, Yttri KE, Zieger P, Aas W and Tørseth K (2022), "Atmospheric composition in the European Arctic and 30∼years of the Zeppelin Observatory, Ny-Ålesund", Atmospheric Chemistry and Physics. Vol. 22(5), pp. 3321-3369. |
BibTeX:
@article{Platt2022,
author = {Platt, S M and Hov, Ø and Berg, T and Breivik, K and Eckhardt, S and Eleftheriadis, K and Evangeliou, N and Fiebig, M and Fisher, R and Hansen, G and Hansson, H.-C. and Heintzenberg, J and Hermansen, O and Heslin-Rees, D and Holmén, K and Hudson, S and Kallenborn, R and Krejci, R and Krognes, T and Larssen, S and Lowry, D and Lund Myhre, C and Lunder, C and Nisbet, E and Nizzetto, P B and Park, K.-T. and Pedersen, C A and Aspmo Pfaffhuber, K and Röckmann, T and Schmidbauer, N and Solberg, S and Stohl, A and Ström, J and Svendby, T and Tunved, P and Tørnkvist, K and van der Veen, C and Vratolis, S and Yoon, Y J and Yttri, K E and Zieger, P and Aas, W and Tørseth, K},
title = {Atmospheric composition in the European Arctic and 30∼years of the Zeppelin Observatory, Ny-Ålesund},
journal = {Atmospheric Chemistry and Physics},
year = {2022},
volume = {22},
number = {5},
pages = {3321--3369},
url = {https://acp.copernicus.org/articles/22/3321/2022/},
doi = {10.5194/acp-22-3321-2022}
}
|
| Poorter H, Knopf O, Wright IJ, Temme AA, Hogewoning SW, Graf A, Cernusak LA and Pons TL (2022), "A meta-analysis of responses of C3 plants to atmospheric CO2: dose–response curves for 85 traits ranging from the molecular to the whole-plant level", New Phytologist., feb, 2022. Vol. 233(4), pp. 1560-1596. John Wiley & Sons, Ltd. |
| Abstract: Summary Generalised dose?response curves are essential to understand how plants acclimate to atmospheric CO2. We carried out a meta-analysis of 630 experiments in which C3 plants were experimentally grown at different [CO2] under relatively benign conditions, and derived dose?response curves for 85 phenotypic traits. These curves were characterised by form, plasticity, consistency and reliability. Considered over a range of 200?1200 µmol mol?1 CO2, some traits more than doubled (e.g. area-based photosynthesis; intrinsic water-use efficiency), whereas others more than halved (area-based transpiration). At current atmospheric [CO2], 64% of the total stimulation in biomass over the 200?1200 µmol mol?1 range has already been realised. We also mapped the trait responses of plants to [CO2] against those we have quantified before for light intensity. For most traits, CO2 and light responses were of similar direction. However, some traits (such as reproductive effort) only responded to light, others (such as plant height) only to [CO2], and some traits (such as area-based transpiration) responded in opposite directions. This synthesis provides a comprehensive picture of plant responses to [CO2] at different integration levels and offers the quantitative dose?response curves that can be used to improve global change simulation models. |
BibTeX:
@article{Poorter2022,
author = {Poorter, Hendrik and Knopf, Oliver and Wright, Ian J and Temme, Andries A and Hogewoning, Sander W and Graf, Alexander and Cernusak, Lucas A and Pons, Thijs L},
title = {A meta-analysis of responses of C3 plants to atmospheric CO2: dose–response curves for 85 traits ranging from the molecular to the whole-plant level},
journal = {New Phytologist},
publisher = {John Wiley & Sons, Ltd},
year = {2022},
volume = {233},
number = {4},
pages = {1560--1596},
url = {https://doi.org/10.1111/nph.17802},
doi = {10.1111/nph.17802}
}
|
| Ramsden AE, Ganesan AL, Western LM, Rigby M, Manning AJ, Foulds A, France JL, Barker P, Levy P, Say D, Wisher A, Arnold T, Rennick C, Stanley KM, Young D and O’Doherty S (2022), "Quantifying fossil fuel methane emissions using observations of atmospheric ethane and an uncertain emission ratio", Atmospheric Chemistry and Physics., March, 2022. Vol. 22(6), pp. 3911-3929. Copernicus GmbH. |
BibTeX:
@article{Ramsden2022,
author = {Ramsden, Alice E. and Ganesan, Anita L. and Western, Luke M. and Rigby, Matthew and Manning, Alistair J. and Foulds, Amy and France, James L. and Barker, Patrick and Levy, Peter and Say, Daniel and Wisher, Adam and Arnold, Tim and Rennick, Chris and Stanley, Kieran M. and Young, Dickon and O’Doherty, Simon},
title = {Quantifying fossil fuel methane emissions using observations of atmospheric ethane and an uncertain emission ratio},
journal = {Atmospheric Chemistry and Physics},
publisher = {Copernicus GmbH},
year = {2022},
volume = {22},
number = {6},
pages = {3911--3929},
doi = {10.5194/acp-22-3911-2022}
}
|
| Reitz O, Graf A, Schmidt M, Ketzler G and Leuchner M (2022), "Effects of Measurement Height and Low-Pass-Filtering Corrections on Eddy-Covariance Flux Measurements Over a Forest Clearing with Complex Vegetation", Boundary-Layer Meteorology. Vol. 184(2), pp. 277-299. |
| Abstract: Flux measurements over heterogeneous surfaces with growing vegetation and a limited fetch are a difficult task, as measurement heights that are too high or too low above the canopy adversely affect results. The aim of this study is to assess implications from measurement height in regard to low-pass filtering, footprint representativeness, and energy balance closure for a clear-cut site with regrowing vegetation of varying height. For this, measurements from two open-path eddy-covariance systems at different heights are compared over the course of one growing season. Particular attention is paid to low-pass-filtering corrections, for which five different methods are compared. Results indicate significant differences between fluxes from the upper and lower systems, which likely result from footprint differences and an insufficient spectral correction for the lower system. Different low-pass-filtering corrections add an uncertainty of 3.4% (7.0%) to CO2 fluxes and 1.4% (3.0%) to H2O fluxes for the upper (lower) system, also leading to considerable differences in cumulative fluxes. Despite limitations in the analysis, which include the difficulty of applying a footprint model at this study site and the likely influence of advection on the total exchange, the analysis confirms that information about the choice of spectral correction method and measurement-height changes are critical for interpreting data at complex sites. |
BibTeX:
@article{Reitz2022,
author = {Reitz, Oliver and Graf, Alexander and Schmidt, Marius and Ketzler, Gunnar and Leuchner, Michael},
title = {Effects of Measurement Height and Low-Pass-Filtering Corrections on Eddy-Covariance Flux Measurements Over a Forest Clearing with Complex Vegetation},
journal = {Boundary-Layer Meteorology},
year = {2022},
volume = {184},
number = {2},
pages = {277--299},
url = {https://doi.org/10.1007/s10546-022-00700-1},
doi = {10.1007/s10546-022-00700-1}
}
|
| Revenga JC, Trepekli K, Oehmcke S, Jensen R, Li L, Igel C, Gieseke FC and Friborg T (2022), "Above-Ground Biomass Prediction for Croplands at a Sub-Meter Resolution Using UAV–LiDAR and Machine Learning Methods", Remote Sensing. Vol. 14(16) |
| Abstract: Current endeavors to enhance the accuracy of in situ above-ground biomass (AGB) prediction for croplands rely on close-range monitoring surveys that use unstaffed aerial vehicles (UAVs) and mounted sensors. In precision agriculture, light detection and ranging (LiDAR) technologies are currently used to monitor crop growth, plant phenotyping, and biomass dynamics at the ecosystem scale. In this study, we utilized a UAV–LiDAR sensor to monitor two crop fields and a set of machine learning (ML) methods to predict real-time AGB over two consecutive years in the region of Mid-Jutland, Denmark. During each crop growing period, UAV surveys were conducted in parallel with AGB destructive sampling every 7–15 days, the AGB samples from which were used as the ground truth data. We evaluated the ability of the ML models to estimate the real-time values of AGB at a sub-meter resolution (0.17–0.52 m2). An extremely randomized trees (ERT) regressor was selected for the regression analysis, based on its predictive performance for the first year’s growing season. The model was retrained using previously identified hyperparameters to predict the AGB of the crops in the second year. The ERT performed AGB estimation using height and reflectance metrics from LiDAR-derived point cloud data and achieved a prediction performance of R2 = 0.48 at a spatial resolution of 0.35 m2. The prediction performance could be improved significantly by aggregating adjacent predictions (R2 = 0.71 and R2 = 0.93 at spatial resolutions of 1 m2 and 2 m2, respectively) as they ultimately converged to the reference biomass values because any individual errors averaged out. The AGB prediction results were examined as function of predictor type, training set size, sampling resolution, phenology, and canopy density. The results demonstrated that when combined with ML regression methods, the UAV–LiDAR method could be used to provide accurate real-time AGB prediction for crop fields at a high resolution, thereby providing a way to map their biochemical constituents. |
BibTeX:
@article{Revenga2022,
author = {Revenga, Jaime C and Trepekli, Katerina and Oehmcke, Stefan and Jensen, Rasmus and Li, Lei and Igel, Christian and Gieseke, Fabian Cristian and Friborg, Thomas},
title = {Above-Ground Biomass Prediction for Croplands at a Sub-Meter Resolution Using UAV–LiDAR and Machine Learning Methods},
journal = {Remote Sensing},
year = {2022},
volume = {14},
number = {16},
url = {https://www.mdpi.com/2072-4292/14/16/3912},
doi = {10.3390/rs14163912}
}
|
| Riddick SN, Cheptonui F, Yuan K, Mbua M, Day R, Vaughn TL, Duggan A, Bennett KE and Zimmerle DJ (2022), "Estimating Regional Methane Emission Factors from Energy and Agricultural Sector Sources Using a Portable Measurement System: Case Study of the Denver–Julesburg Basin", Sensors. Vol. 22(19) |
| Abstract: Methane (CH4), a powerful greenhouse gas (GHG), has been identified as a key target for emission reduction in the Paris agreement, but it is not currently clear where efforts should be focused to make the greatest impact. Currently, activity data and standard emission factors (EF) are used to generate GHG emission inventories. Many of the EFs are globally uniform and do not account for regional variability in industrial or agricultural practices and/or regulation. Regional EFs can be derived from top–down emissions measurements and used to make bespoke regional GHG emission inventories that account for geopolitical and social variability. However, most large-scale top–down approaches campaigns require significant investment. To address this, lower-cost driving surveys (DS) have been identified as a viable alternative to more established methods. DSs can take top–down measurements of many emission sources in a relatively short period of time, albeit with a higher uncertainty. To investigate the use of a portable measurement system, a 2260 km DS was conducted throughout the Denver–Julesburg Basin (DJB). The DJB covers an area of 8000 km2 north of Denver, CO and is densely populated with CH4 emission sources, including oil and gas (O and G) operations, agricultural operations (AGOs), lakes and reservoirs. During the DS, 157 individual CH4 emission sources were detected; 51%, 43% and 4% of sources were AGOs, O and G operations, and natural sources, respectively. Methane emissions from each source were quantified using downwind concentration and meteorological data and AGOs and O and G operations represented nearly all the CH4 emissions in the DJB, accounting for 54% and 37% of the total emission, respectively. Operations with similar emission sources were grouped together and average facility emission estimates were generated. For agricultural sources, emissions from feedlot cattle, dairy cows and sheep were estimated at 5, 31 and 1 g CH4 head−1 h−1, all of which agreed with published values taken from focused measurement campaigns. Similarly, for O and G average emissions for well pads, compressor stations and gas processing plants (0.5, 14 and 110 kg CH4 facility−1 h−1) were in reasonable agreement with emission estimates from intensive measurement campaigns. A comparison of our basin wide O and G emissions to measurements taken a decade ago show a decrease of a factor of three, which can feasibly be explained by changes to O and G regulation over the past 10 years, while emissions from AGOs have remained constant over the same time period. Our data suggest that DSs could be a low-cost alternative to traditional measurement campaigns and used to screen many emission sources within a region to derive representative regionally specific and time-sensitive EFs. The key benefit of the DS is that many regions can be screened and emission reduction targets identified where regional EFs are noticeably larger than the regional, national or global averages. |
BibTeX:
@article{Riddick2022,
author = {Riddick, Stuart N and Cheptonui, Fancy and Yuan, Kexin and Mbua, Mercy and Day, Rachel and Vaughn, Timothy L and Duggan, Aidan and Bennett, Kristine E and Zimmerle, Daniel J},
title = {Estimating Regional Methane Emission Factors from Energy and Agricultural Sector Sources Using a Portable Measurement System: Case Study of the Denver–Julesburg Basin},
journal = {Sensors},
year = {2022},
volume = {22},
number = {19},
url = {https://www.mdpi.com/1424-8220/22/19/7410},
doi = {10.3390/s22197410}
}
|
| Rocha AD, Vulova S, Meier F, Förster M and Kleinschmit B (2022), "Mapping evapotranspirative and radiative cooling services in an urban environment", Sustainable Cities and Society. Vol. 85, pp. 104051. |
| Abstract: As impervious surfaces have seized most areas in cities worldwide, urban heat island (UHI) has become a global concern. Urban green infrastructures (UGI) are crucial to providing microclimate regulation and thermal comfort through evapotranspiration (ET) and shading. High-spatiotemporal-resolution ET maps are required to plan and manage UGI to mitigate the UHI and droughts. We propose a method using open-access data, including hourly meteorological data and remote sensing vegetation parameters, to predict heat fluxes using a soil-vegetation-atmosphere model. The ET prediction accuracy was assessed using eddy covariance towers, showing an R2 of 0.84 for the residential-vegetated site and 0.57 for the built-up site during 2019. A greening cooling service index (GCoS), divided into evapotranspirative (ECoS) and radiative (RCoS) cooling effects were mapped for Berlin, Germany. Almost half of the population and 21% of the city area are located in low GCoS (<0.25). Based upon climate change scenarios, a rise in temperature increases the annual ET, while plant stress and droughts considerably decrease overall cooling services. Simulation of climatological scenarios and plant traits can help to define more suitable species adapted for urban environments. The presented method provides an effective decision-making tool for urban planning to reduce heat risk for urban residents. |
BibTeX:
@article{Rocha2022,
author = {Rocha, Alby Duarte and Vulova, Stenka and Meier, Fred and Förster, Michael and Kleinschmit, Birgit},
title = {Mapping evapotranspirative and radiative cooling services in an urban environment},
journal = {Sustainable Cities and Society},
year = {2022},
volume = {85},
pages = {104051},
url = {https://www.sciencedirect.com/science/article/pii/S2210670722003699},
doi = {10.1016/j.scs.2022.104051}
}
|
| Röttger S, Röttger A, Grossi C, Vargas A, Karstens U, Cinelli G, Chung E, Kikaj D, Rennick C, Mertes F and Radulescu I (2022), "Radon metrology for use in climate change observation and radiation protection at the environmental level", Advances in Geosciences. Vol. 57, pp. 37-47. |
BibTeX:
@article{Roettger2022,
author = {Röttger, S and Röttger, A and Grossi, C and Vargas, A and Karstens, U and Cinelli, G and Chung, E and Kikaj, D and Rennick, C and Mertes, F and Radulescu, I},
title = {Radon metrology for use in climate change observation and radiation protection at the environmental level},
journal = {Advances in Geosciences},
year = {2022},
volume = {57},
pages = {37--47},
url = {https://adgeo.copernicus.org/articles/57/37/2022/},
doi = {10.5194/adgeo-57-37-2022}
}
|
| Rust D, Katharopoulos I, Vollmer MK, Henne S, O'Doherty S, Say D, Emmenegger L, Zenobi R and Reimann S (2022), "Swiss halocarbon emissions for 2019 to 2020 assessed from regional atmospheric observations", Atmospheric Chemistry and Physics. Vol. 22(4), pp. 2447-2466. |
BibTeX:
@article{Rust2022,
author = {Rust, D and Katharopoulos, I and Vollmer, M K and Henne, S and O'Doherty, S and Say, D and Emmenegger, L and Zenobi, R and Reimann, S},
title = {Swiss halocarbon emissions for 2019 to 2020 assessed from regional atmospheric observations},
journal = {Atmospheric Chemistry and Physics},
year = {2022},
volume = {22},
number = {4},
pages = {2447--2466},
url = {https://acp.copernicus.org/articles/22/2447/2022/},
doi = {10.5194/acp-22-2447-2022}
}
|
| Salmon E, Jégou F, Guenet B, Jourdain L, Qiu C, Bastrikov V, Guimbaud C, Zhu D, Ciais P, Peylin P, Gogo S, Laggoun-Défarge F, Aurela M, Bret-Harte MS, Chen J, Chojnicki BH, Chu H, Edgar CW, Euskirchen ES, Flanagan LB, Fortuniak K, Holl D, Klatt J, Kolle O, Kowalska N, Kutzbach L, Lohila A, Merbold L, Pawlak W, Sachs T and Ziembliʼnska K (2022), "Assessing methane emissions for northern peatlands in ORCHIDEE-PEAT revision 7020", Geoscientific Model Development. Vol. 15(7), pp. 2813-2838. |
| Abstract: In the global methane budget, the largest natural source is attributed to wetlands, which encompass all ecosystems composed of waterlogged or inundated ground, capable of methane production. Among them, northern peatlands that store large amounts of soil organic carbon have been functioning, since the end of the last glaciation period, as long-term sources of methane (CH4) and are one of the most significant methane sources among wetlands. To reduce uncertainty of quantifying methane flux in the global methane budget, it is of significance to understand the underlying processes for methane production and fluxes in northern peatlands. A methane model that features methane production and transport by plants, ebullition process and diffusion in soil, oxidation to CO2, and CH4 fluxes to the atmosphere has been embedded in the ORCHIDEE-PEAT land surface model that includes an explicit representation of northern peatlands. ORCHIDEE-PCH4 was calibrated and evaluated on 14 peatland sites distributed on both the Eurasian and American continents in the northern boreal and temperate regions. Data assimilation approaches were employed to optimized parameters at each site and at all sites simultaneously. Results show that methanogenesis is sensitive to temperature and substrate availability over the top 75cm of soil depth. Methane emissions estimated using single site optimization (SSO) of model parameters are underestimated by 9gCH4m-2 yr-1 on average (i.e., 50% higher than the site average of yearly methane emissions). While using the multi-site optimization (MSO), methane emissions are overestimated by 5gCH4m-2 yr-1 on average across all investigated sites (i.e., 37% lower than the site average of yearly methane emissions). |
BibTeX:
@article{Salmon2022,
author = {Salmon, Elodie and Jégou, Fabrice and Guenet, Bertrand and Jourdain, Line and Qiu, Chunjing and Bastrikov, Vladislav and Guimbaud, Christophe and Zhu, Dan and Ciais, Philippe and Peylin, Philippe and Gogo, Sébastien and Laggoun-Défarge, Fatima and Aurela, Mika and Bret-Harte, M. Syndonia and Chen, Jiquan and Chojnicki, Bogdan H. and Chu, Housen and Edgar, Colin W. and Euskirchen, Eugenie S. and Flanagan, Lawrence B. and Fortuniak, Krzysztof and Holl, David and Klatt, Janina and Kolle, Olaf and Kowalska, Natalia and Kutzbach, Lars and Lohila, Annalea and Merbold, Lutz and Pawlak, Włodzimierz and Sachs, Torsten and Ziembliʼnska, Klaudia},
title = {Assessing methane emissions for northern peatlands in ORCHIDEE-PEAT revision 7020},
journal = {Geoscientific Model Development},
year = {2022},
volume = {15},
number = {7},
pages = {2813--2838},
doi = {10.5194/gmd-15-2813-2022}
}
|
| Salomón RL, Peters RL, Zweifel R, Sass-Klaassen UGW, Stegehuis AI, Smiljanic M, Poyatos R, Babst F, Cienciala E, Fonti P, Lerink BJW, Lindner M, Martinez-Vilalta J, Mencuccini M, Nabuurs G-J, van der Maaten E, von Arx G, Bär A, Akhmetzyanov L, Balanzategui D, Bellan M, Bendix J, Berveiller D, Blaženec M, Čada V, Carraro V, Cecchini S, Chan T, Conedera M, Delpierre N, Delzon S, Ditmarová Ľ, Dolezal J, Dufrêne E, Edvardsson J, Ehekircher S, Forner A, Frouz J, Ganthaler A, Gryc V, Güney A, Heinrich I, Hentschel R, Janda P, Ježík M, Kahle H-P, Knüsel S, Krejza J, Kuberski Ł, Kučera J, Lebourgeois F, Mikoláš M, Matula R, Mayr S, Oberhuber W, Obojes N, Osborne B, Paljakka T, Plichta R, Rabbel I, Rathgeber CBK, Salmon Y, Saunders M, Scharnweber T, Sitková Z, Stangler DF, Stereʼnczak K, Stojanović M, Střelcová K, Světlík J, Svoboda M, Tobin B, Trotsiuk V, Urban J, Valladares F, Vavrčík H, Vejpustková M, Walthert L, Wilmking M, Zin E, Zou J and Steppe K (2022), "The 2018 European heatwave led to stem dehydration but not to consistent growth reductions in forests", Nature Communications. Vol. 13(1), pp. 28. |
| Abstract: Heatwaves exert disproportionately strong and sometimes irreversible impacts on forest ecosystems. These impacts remain poorly understood at the tree and species level and across large spatial scales. Here, we investigate the effects of the record-breaking 2018 European heatwave on tree growth and tree water status using a collection of high-temporal resolution dendrometer data from 21 species across 53 sites. Relative to the two preceding years, annual stem growth was not consistently reduced by the 2018 heatwave but stems experienced twice the temporary shrinkage due to depletion of water reserves. Conifer species were less capable of rehydrating overnight than broadleaves across gradients of soil and atmospheric drought, suggesting less resilience toward transient stress. In particular, Norway spruce and Scots pine experienced extensive stem dehydration. Our high-resolution dendrometer network was suitable to disentangle the effects of a severe heatwave on tree growth and desiccation at large-spatial scales in situ, and provided insights on which species may be more vulnerable to climate extremes. |
BibTeX:
@article{Salomon2022,
author = {Salomón, Roberto L and Peters, Richard L and Zweifel, Roman and Sass-Klaassen, Ute G W and Stegehuis, Annemiek I and Smiljanic, Marko and Poyatos, Rafael and Babst, Flurin and Cienciala, Emil and Fonti, Patrick and Lerink, Bas J W and Lindner, Marcus and Martinez-Vilalta, Jordi and Mencuccini, Maurizio and Nabuurs, Gert-Jan and van der Maaten, Ernst and von Arx, Georg and Bär, Andreas and Akhmetzyanov, Linar and Balanzategui, Daniel and Bellan, Michal and Bendix, Jörg and Berveiller, Daniel and Blaženec, Miroslav and Čada, Vojtěch and Carraro, Vinicio and Cecchini, Sébastien and Chan, Tommy and Conedera, Marco and Delpierre, Nicolas and Delzon, Sylvain and Ditmarová, Ľubica and Dolezal, Jiri and Dufrêne, Eric and Edvardsson, Johannes and Ehekircher, Stefan and Forner, Alicia and Frouz, Jan and Ganthaler, Andrea and Gryc, Vladimír and Güney, Aylin and Heinrich, Ingo and Hentschel, Rainer and Janda, Pavel and Ježík, Marek and Kahle, Hans-Peter and Knüsel, Simon and Krejza, Jan and Kuberski, Łukasz and Kučera, Jiří and Lebourgeois, François and Mikoláš, Martin and Matula, Radim and Mayr, Stefan and Oberhuber, Walter and Obojes, Nikolaus and Osborne, Bruce and Paljakka, Teemu and Plichta, Roman and Rabbel, Inken and Rathgeber, Cyrille B K and Salmon, Yann and Saunders, Matthew and Scharnweber, Tobias and Sitková, Zuzana and Stangler, Dominik Florian and Stereʼnczak, Krzysztof and Stojanović, Marko and Střelcová, Katarína and Světlík, Jan and Svoboda, Miroslav and Tobin, Brian and Trotsiuk, Volodymyr and Urban, Josef and Valladares, Fernando and Vavrčík, Hanuš and Vejpustková, Monika and Walthert, Lorenz and Wilmking, Martin and Zin, Ewa and Zou, Junliang and Steppe, Kathy},
title = {The 2018 European heatwave led to stem dehydration but not to consistent growth reductions in forests},
journal = {Nature Communications},
year = {2022},
volume = {13},
number = {1},
pages = {28},
url = {https://doi.org/10.1038/s41467-021-27579-9},
doi = {10.1038/s41467-021-27579-9}
}
|
| Schneider M, Ertl B, Tu Q, Diekmann CJ, Khosrawi F, Röhling AN, Hase F, Dubravica D, Garc\ia OE, Sepúlveda E, Borsdorff T, Landgraf J, Lorente A, Butz A, Chen H, Kivi R, Laemmel T, Ramonet M, Crevoisier C, Pernin J, Steinbacher M, Meinhardt F, Strong K, Wunch D, Warneke T, Roehl C, Wennberg PO, Morino I, Iraci LT, Shiomi K, Deutscher NM, Griffith DWT, Velazco VA and Pollard DF (2022), "Synergetic use of IASI profile and TROPOMI total-column level 2 methane retrieval products", Atmospheric Measurement Techniques. Vol. 15(14), pp. 4339-4371. |
BibTeX:
@article{Schneider2022,
author = {Schneider, M and Ertl, B and Tu, Q and Diekmann, C J and Khosrawi, F and Röhling, A N and Hase, F and Dubravica, D and Garc\ia, O E and Sepúlveda, E and Borsdorff, T and Landgraf, J and Lorente, A and Butz, A and Chen, H and Kivi, R and Laemmel, T and Ramonet, M and Crevoisier, C and Pernin, J and Steinbacher, M and Meinhardt, F and Strong, K and Wunch, D and Warneke, T and Roehl, C and Wennberg, P O and Morino, I and Iraci, L T and Shiomi, K and Deutscher, N M and Griffith, D W T and Velazco, V A and Pollard, D F},
title = {Synergetic use of IASI profile and TROPOMI total-column level 2 methane retrieval products},
journal = {Atmospheric Measurement Techniques},
year = {2022},
volume = {15},
number = {14},
pages = {4339--4371},
url = {https://amt.copernicus.org/articles/15/4339/2022/},
doi = {10.5194/amt-15-4339-2022}
}
|
| Seiler C, Melton JR, Arora VK, Sitch S, Friedlingstein P, Anthoni P, Goll D, Jain AK, Joetzjer E, Lienert S, Lombardozzi D, Luyssaert S, Nabel JE, Tian H, Vuichard N, Walker AP, Yuan W and Zaehle S (2022), "Are Terrestrial Biosphere Models Fit for Simulating the Global Land Carbon Sink?", Journal of Advances in Modeling Earth Systems. Vol. 14(5) |
| Abstract: The Global Carbon Project estimates that the terrestrial biosphere has absorbed about one-third of anthropogenic CO2 emissions during the 1959–2019 period. This sink-estimate is produced by an ensemble of terrestrial biosphere models and is consistent with the land uptake inferred from the residual of emissions and ocean uptake. The purpose of our study is to understand how well terrestrial biosphere models reproduce the processes that drive the terrestrial carbon sink. One challenge is to decide what level of agreement between model output and observation-based reference data is adequate considering that reference data are prone to uncertainties. To define such a level of agreement, we compute benchmark scores that quantify the similarity between independently derived reference data sets using multiple statistical metrics. Models are considered to perform well if their model scores reach benchmark scores. Our results show that reference data can differ considerably, causing benchmark scores to be low. Model scores are often of similar magnitude as benchmark scores, implying that model performance is reasonable given how different reference data are. While model performance is encouraging, ample potential for improvements remains, including a reduction in a positive leaf area index bias, improved representations of processes that govern soil organic carbon in high latitudes, and an assessment of causes that drive the inter-model spread of gross primary productivity in boreal regions and humid tropics. The success of future model development will increasingly depend on our capacity to reduce and account for observational uncertainties. |
BibTeX:
@article{Seiler2022,
author = {Seiler, Christian and Melton, Joe R. and Arora, Vivek K. and Sitch, Stephen and Friedlingstein, Pierre and Anthoni, Peter and Goll, Daniel and Jain, Atul K. and Joetzjer, Emilie and Lienert, Sebastian and Lombardozzi, Danica and Luyssaert, Sebastiaan and Nabel, Julia E.M.S. and Tian, Hanqin and Vuichard, Nicolas and Walker, Anthony P. and Yuan, Wenping and Zaehle, Sönke},
title = {Are Terrestrial Biosphere Models Fit for Simulating the Global Land Carbon Sink?},
journal = {Journal of Advances in Modeling Earth Systems},
year = {2022},
volume = {14},
number = {5},
doi = {10.1029/2021MS002946}
}
|
| Serk H, Nilsson MB, Figueira J, Krüger JP, Leifeld J, Alewell C and Schleucher J (2022), "Organochemical Characterization of Peat Reveals Decomposition of Specific Hemicellulose Structures as the Main Cause of Organic Matter Loss in the Acrotelm", Environmental Science & Technology., dec, 2022. Vol. 56(23), pp. 17410-17419. American Chemical Society. |
BibTeX:
@article{Serk2022,
author = {Serk, Henrik and Nilsson, Mats B and Figueira, João and Krüger, Jan Paul and Leifeld, Jens and Alewell, Christine and Schleucher, Jürgen},
title = {Organochemical Characterization of Peat Reveals Decomposition of Specific Hemicellulose Structures as the Main Cause of Organic Matter Loss in the Acrotelm},
journal = {Environmental Science & Technology},
publisher = {American Chemical Society},
year = {2022},
volume = {56},
number = {23},
pages = {17410--17419},
url = {https://doi.org/10.1021/acs.est.2c03513},
doi = {10.1021/acs.est.2c03513}
}
|
| Shahbaz M, Bengtson P, Mertes JR, Kulessa B and Kljun N (2022), "Spatial heterogeneity of soil carbon exchanges and their drivers in a boreal forest", Science of The Total Environment. Vol. 831, pp. 154876. |
| Abstract: Boreal forests have a large impact on the global greenhouse gas balance and their soils constitute an important carbon (C) reservoir. Mature boreal forests are typically a net CO2 sink, but there are also examples of boreal forests that are persistent CO2 sources. The reasons remain often unknown, presumably due to a lack of understanding of how biotic and abiotic drivers interact to determine the microbial respiration of soil organic matter (SOM). This study aimed at identifying the main drivers of microbial SOM respiration and CO2 and CH4 soil chamber-fluxes within dry and wet sampling areas at the mature boreal forest of Norunda, Sweden, a persistent net CO2 source. The spatial heterogeneity of the drivers was assessed with a geostatistical approach combined with stepwise multiple regression. We found that heterotrophic soil respiration increased with SOM content and nitrogen (N) availability, while the SOM reactivity, i.e., SOM specific respiration, was determined by soil moisture and N availability. The latter suggests that microbial activity was N rather than C limited and that microbial N mining might be driving old-SOM decomposition, which was observed through a positive correlation between soil respiration and its δ13C values. SOM specific heterotrophic respiration was lower in wet than in dry areas, while no such dependencies were found for chamber-based soil CO2 fluxes, implying that oxygen depletion resulted in lower SOM reactivity. The chamber-based soil CH4 flux differed significantly between the wet and dry areas. In the wet area, we observed net CH4 emission that was positively related to soil moisture and NH4+-N content. Taken together, our findings suggest that N availability has a strong regulatory effect on soil CO2 and CH4 emissions at Norunda, and that microbial decomposition of old-SOM to release bioavailable N might be partly responsible for the net CO2 emission at the site. |
BibTeX:
@article{Shahbaz2022,
author = {Shahbaz, Muhammad and Bengtson, Per and Mertes, Jordan R and Kulessa, Bernd and Kljun, Natascha},
title = {Spatial heterogeneity of soil carbon exchanges and their drivers in a boreal forest},
journal = {Science of The Total Environment},
year = {2022},
volume = {831},
pages = {154876},
url = {https://www.sciencedirect.com/science/article/pii/S0048969722019696},
doi = {10.1016/j.scitotenv.2022.154876}
}
|
| Shekhar A, Buchmann N and Gharun M (2022), "How well do recently reconstructed solar-induced fluorescence datasets model gross primary productivity?", Remote Sensing of Environment. Vol. 283, pp. 113282. |
| Abstract: The collection of various long-term reconstructed solar-induced fluorescence (SIF) datasets derived at a range of spatio-temporal scales provides new opportunities for modelling vegetation dynamics, in particular, gross primary productivity (GPP). Information about the proximity of the reconstructed SIF (SIFr) datasets to GPP across land cover types and climatic conditions provides important support for a better application of these products for modelling applications. We conducted a multiscale analysis of four different long-term (12 years, 2007–2018) high-resolution global SIFr datasets (0.05° × 0.05°), namely – CSIF (Contiguous SIF), GOSIF (Global OCO-2 SIF), LUE-SIF (Light Use Efficiency SIF), and HSIF (Harmonized SIF) - at 4-day, 8-day, and monthly time scales and found that for the majority of sites, the SIFr is linearly related to ground-based GPP measurements with the eddy covariance method. While the relationship between SIFr and GPP (i.e., the slope - GPP/SIFr) varied significantly across the SIFr datasets, sites, and land cover types, all four SIFr datasets were unequivocally a better predictor of GPP compared to remotely sensed vegetation indices – NDVI (normalized difference vegetation index) and EVI (enhanced vegetation index), sensed by the MODIS satellite. Furthermore, we also analyzed SIF-GPP relationships during drought vs non-drought conditions and found that for about 30% of the sites, comprising mostly non-forests site, the SIF-GPP relationship became weaker (decreased R2) with a lower slope during drought conditions compared to non-drought conditions. Among the four different products, the CSIF (at 4-day timescale) and GOSIF (at 8-day timescale) predicted GPP better compared to LUE-SIF and HSIF across all land cover types. Owing to their long-term availability (since 2000 for CSIF and GOSIF), these SIFr datasets combined with proxies of ecosystem properties can be used to appropriately capture vegetation dynamics and the interannual variabilities across a wide range of climatic conditions. |
BibTeX:
@article{Shekhar2022,
author = {Shekhar, Ankit and Buchmann, Nina and Gharun, Mana},
title = {How well do recently reconstructed solar-induced fluorescence datasets model gross primary productivity?},
journal = {Remote Sensing of Environment},
year = {2022},
volume = {283},
pages = {113282},
url = {https://www.sciencedirect.com/science/article/pii/S0034425722003881},
doi = {10.1016/j.rse.2022.113282}
}
|
| Stell AC, Bertolacci M, Zammit-Mangion A, Rigby M, Fraser PJ, Harth CM, Krummel PB, Lan X, Manizza M, Mühle J, O’Doherty S, Prinn RG, Weiss RF, Young D and Ganesan AL (2022), "Modelling the growth of atmospheric nitrous oxide using a global hierarchical inversion", Atmospheric Chemistry and Physics., October, 2022. Vol. 22(19), pp. 12945-12960. Copernicus GmbH. |
BibTeX:
@article{Stell2022,
author = {Stell, Angharad C. and Bertolacci, Michael and Zammit-Mangion, Andrew and Rigby, Matthew and Fraser, Paul J. and Harth, Christina M. and Krummel, Paul B. and Lan, Xin and Manizza, Manfredi and Mühle, Jens and O’Doherty, Simon and Prinn, Ronald G. and Weiss, Ray F. and Young, Dickon and Ganesan, Anita L.},
title = {Modelling the growth of atmospheric nitrous oxide using a global hierarchical inversion},
journal = {Atmospheric Chemistry and Physics},
publisher = {Copernicus GmbH},
year = {2022},
volume = {22},
number = {19},
pages = {12945--12960},
doi = {10.5194/acp-22-12945-2022}
}
|
| Strebel L, Bogena HR, Vereecken H and Hendricks Franssen H-J (2022), "Coupling the Community Land Model version 5.0 to the parallel data assimilation framework PDAF: description and applications", Geoscientific Model Development. Vol. 15(2), pp. 395-411. |
BibTeX:
@article{Strebel2022,
author = {Strebel, L and Bogena, H R and Vereecken, H and Hendricks Franssen, H.-J.},
title = {Coupling the Community Land Model version 5.0 to the parallel data assimilation framework PDAF: description and applications},
journal = {Geoscientific Model Development},
year = {2022},
volume = {15},
number = {2},
pages = {395--411},
url = {https://gmd.copernicus.org/articles/15/395/2022/},
doi = {10.5194/gmd-15-395-2022}
}
|
| Sungmin O, Bastos A, Reichstein M, Li W, Denissen J, Graefen H and Orth R (2022), "The Role of Climate and Vegetation in Regulating Drought-Heat Extremes", Journal of Climate. Vol. 35(17), pp. 5677-5685. |
| Abstract: Droughts cause serious environmental and societal impacts, often aggravated by simultaneously occurring heat waves. Climate and vegetation play key roles in the evolution of drought-associated temperature anomalies, but their relative importance is largely unknown. Here, we present the hottest temperature anomalies during drought in subhumid and tree-dominated regions using observation-based, global data over 2001-15. These anomalies are mainly driven by a drought-related net radiation surplus and further amplified by forests' water-saving strategies that result in diminished evaporative cooling. By contrast, in semiarid and short-vegetation regions, drought-related temperature increases are smaller. The reduction of evaporative cooling is weak and net radiation increases only marginally due to high albedo over drought-stressed vegetation. Our findings highlight the importance of considering all interacting factors in understanding diverse mechanisms of concurrent drought-heat extremes across different climate regimes. |
BibTeX:
@article{Sungmin2022,
author = {Sungmin, O. and Bastos, Ana and Reichstein, Markus and Li, Wantong and Denissen, Jasper and Graefen, Hanna and Orth, Rene},
title = {The Role of Climate and Vegetation in Regulating Drought-Heat Extremes},
journal = {Journal of Climate},
year = {2022},
volume = {35},
number = {17},
pages = {5677--5685},
doi = {10.1175/JCLI-D-21-0675.1}
}
|
| Sytiuk A, Céréghino R, Hamard S, Delarue F, Guittet A, Barel JM, Dorrepaal E, Küttim M, Lamentowicz M, Pourrut B, Robroek BJM, Tuittila E-S and Jassey VEJ (2022), "Predicting the structure and functions of peatland microbial communities from Sphagnum phylogeny, anatomical and morphological traits and metabolites", Journal of Ecology., jan, 2022. Vol. 110(1), pp. 80-96. John Wiley & Sons, Ltd. |
| Abstract: Abstract Sphagnum mosses are keystone species in northern peatlands. Notably, they play an important role in peatland carbon (C) cycling by regulating the composition and activity of microbial communities. However, it remains unclear whether information on Sphagnum phylogeny and/or traits-based composition (i.e. anatomical and morphological traits and metabolites) can be used to predict the structure of microbial communities and their functioning. Here we evaluated whether Sphagnum phylogeny and traits predict additional variation in peatland microbial community composition and functioning beyond what would be predicted from environmental characteristics (i.e. climatic and edaphic conditions). We collected Sphagnum and microbial data from five European peatlands distributed along a latitudinal gradient from northern Sweden to southern France. These data allowed us to assess Sphagnum anatomical and morphological traits and metabolites at different sites along changing environmental conditions. Using structural equation modelling (SEM) and phylogenetic distance analyses, we investigated the role of Sphagnum traits in shaping microbial community composition and functioning along with environmental conditions. We show that microbial community composition and traits varied independently from both Sphagnum phylogeny and the latitudinal gradient. Specifically, the addition of Sphagnum traits to climatic and edaphic variables to the SEM allowed it to explain a larger proportion of the explained variance (R2). This observation was most apparent for the biomass of decomposers (+42%) and phototrophs (+19%), as well as for growth yield microbial traits (+10%). As such, that Sphagnum metabolites were important drivers for microbial community structure and traits, while Sphagnum anatomical and morphological traits were poor predictors. Synthesis. Our results highlight that Sphagnum metabolites are more likely to influence peatland microbial food web structure and functioning than Sphagnum anatomical and morphological traits. We provide further evidence that measurements of the plant metabolome, when combined with classical functional traits, improve our understanding of how the plants interact with their associated microbiomes. |
BibTeX:
@article{Sytiuk2022,
author = {Sytiuk, Anna and Céréghino, Régis and Hamard, Samuel and Delarue, Frédéric and Guittet, Amélie and Barel, Janna M and Dorrepaal, Ellen and Küttim, Martin and Lamentowicz, Mariusz and Pourrut, Bertrand and Robroek, Bjorn J M and Tuittila, Eeva-Stiina and Jassey, Vincent E J},
title = {Predicting the structure and functions of peatland microbial communities from Sphagnum phylogeny, anatomical and morphological traits and metabolites},
journal = {Journal of Ecology},
publisher = {John Wiley & Sons, Ltd},
year = {2022},
volume = {110},
number = {1},
pages = {80--96},
url = {https://doi.org/10.1111/1365-2745.13728},
doi = {10.1111/1365-2745.13728}
}
|
| Sytiuk A, Hamard S, Céréghino R, Dorrepaal E, Geissel H, Küttim M, Lamentowicz M, Tuittila ES and Jassey VEJ (2022), "Linkages between Sphagnum metabolites and peatland |
BibTeX:
@article{Sytiuk2022a,
author = {Sytiuk, Anna and Hamard, Samuel and Céréghino, Régis and Dorrepaal, Ellen and Geissel, Honorine and Küttim, Martin and Lamentowicz, Mariusz and Tuittila, Eeva Stiina and Jassey, Vincent E J},
title = {Linkages between Sphagnum metabolites and peatland |
| Szatniewska J, Zavadilova I, Nezval O, Krejza J, Petrik P, Čater M and Stojanović M (2022), "Species-specific growth and transpiration response to changing environmental conditions in floodplain forest", Forest Ecology and Management. Vol. 516, pp. 120248. |
| Abstract: Recent changes in the floodplain forests of Central Europe, caused mainly by changes in hydrological management and the increased frequency of droughts due to climate change, have led to severe degradation of floodplain ecosystems. Our main objective was to determine the sensitivity of trees to drought by observing the response of the tree phenology, stem radial growth, and physiology (sap flow) of three predominant tree species, namely English oak, narrow-leaved ash, and common hornbeam, to the environmental variables (climate). Stem radial growth began before bud break in ring-porous oak and ash, whereas in diffuse-porous hornbeam, growth onset occurred after leaf formation. The early onset with intense growth during favorable months (April–May) observed in ring-porous species was a major prerequisite for the successful growth of oak and ash at this site. Tree water deficit (TWD), an indicator of stem hydration, was triggered by decreasing soil moisture in all species, and was most prominent in ash, followed by oak. Intriguingly, sap flow was decoupled from TWD in all species and was driven primarily by evaporative demand from the atmosphere. Oak was the least conservative in regulating sap flow under atmospheric drought followed by hornbeam, whereas ash was most restricted and reduced its transpiration during dry periods. In contrast, ash was characterized by the highest radial growth and growth-based water-use efficiency. The lower water storage capacity of oak and ash is likely compensated by deep rooting and drought avoidance strategies, respectively. Tree species that tend to use surface soil water could be severely limited by more extractive species such as hornbeam. Despite the contrasting leaf and wood phenology, stomatal control, and rooting depth among the studied floodplain tree species, they exhibited analogous sap flow and water storage dynamics responses to drier conditions that enabled them to co-exist in the South Moravian Region. Nevertheless, our results suggest that the severe droughts and human-induced alterations in groundwater pose serious threats to floodplain forests in Central Europe, with certain tree species being unable to adapt to these altered conditions. |
BibTeX:
@article{Szatniewska2022,
author = {Szatniewska, Justyna and Zavadilova, Ina and Nezval, Ondřej and Krejza, Jan and Petrik, Peter and Čater, Matjaž and Stojanović, Marko},
title = {Species-specific growth and transpiration response to changing environmental conditions in floodplain forest},
journal = {Forest Ecology and Management},
year = {2022},
volume = {516},
pages = {120248},
url = {https://www.sciencedirect.com/science/article/pii/S0378112722002420},
doi = {10.1016/j.foreco.2022.120248}
}
|
| Thompson RL, Groot Zwaaftink CD, Brunner D, Tsuruta A, Aalto T, Raivonen M, Crippa M, Solazzo E, Guizzardi D, Regnier P and Maisonnier M (2022), "Effects of extreme meteorological conditions in 2018 on European methane emissions estimated using atmospheric inversions", Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences. Vol. 380(2215) |
| Abstract: The effect of the 2018 extreme meteorological conditions in Europe on methane (CH 4) emissions is examined using estimates from four atmospheric inversions calculated for the period 2005-2018. For most of Europe, we find no anomaly in 2018 compared to the 2005-2018 mean. However, we find a positive anomaly for the Netherlands in April, which coincided with positive temperature and soil moisture anomalies suggesting an increase in biogenic sources. We also find a negative anomaly for the Netherlands for September-October, which coincided with a negative anomaly in soil moisture, suggesting a decrease in soil sources. In addition, we find a positive anomaly for Serbia in spring, summer and autumn, which coincided with increases in temperature and soil moisture, again suggestive of changes in biogenic sources, and the annual emission for 2018 was 33 ± 38% higher than the 2005-2017 mean. These results indicate that CH 4 emissions from areas where the natural source is thought to be relatively small can still vary due to meteorological conditions. At the European scale though, the degree of variability over 2005-2018 was small, and there was negligible impact on the annual CH 4 emissions in 2018 despite the extreme meteorological conditions. This article is part of a discussion meeting issue 'Rising methane: is warming feeding warming? (part 2)'. |
BibTeX:
@article{Thompson2022,
author = {Thompson, R. L. and Groot Zwaaftink, C. D. and Brunner, D. and Tsuruta, A. and Aalto, T. and Raivonen, M. and Crippa, M. and Solazzo, E. and Guizzardi, D. and Regnier, P. and Maisonnier, M.},
title = {Effects of extreme meteorological conditions in 2018 on European methane emissions estimated using atmospheric inversions},
journal = {Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences},
year = {2022},
volume = {380},
number = {2215},
doi = {10.1098/rsta.2020.0443}
}
|
| Thompson R and Pisso I (2022), "A Flexible Algorithm for Network Design Based on Information Theory", EGUsphere. Vol. 2022, pp. 1-18. |
BibTeX:
@article{Thompson2022a,
author = {Thompson, R and Pisso, I},
title = {A Flexible Algorithm for Network Design Based on Information Theory},
journal = {EGUsphere},
year = {2022},
volume = {2022},
pages = {1--18},
url = {https://egusphere.copernicus.org/preprints/egusphere-2022-213/},
doi = {10.5194/egusphere-2022-213}
}
|
| Van Damme F, Mertens H, Heinecke T, Lefevre L, De Meulder T, Portillo-Estrada M, Roland M, Gielen B, Janssens IA, Verheyen K and Campioli M (2022), "The Impact of Thinning and Clear Cut on the Ecosystem Carbon Storage of Scots Pine Stands under Maritime Influence in Flanders, Belgium", Forests. Vol. 13(10) |
| Abstract: A shift in management to improve the ecological function of mature plantations of exotic species can have important effects on the ecosystem climate mitigation potential. This study investigated the effect of two common forest management strategies for Scots pine (Pinus sylvestris L.) stands on the C storage after 15 years of management. Two pairs of forest stands on poor sandy soil and under the maritime influence in Brasschaat, Belgium, were observed as case studies. The observed forest management strategies were (i) thinning and group planting of oak saplings (Quercus robur L.) and (ii) clear cut, followed by replanting of young oak. For each stand, all forest C pools (aboveground biomass, belowground biomass, litter, and mineral soil) were determined. Results showed, surprisingly, no significant difference in the whole ecosystem C stock for both forest management strategies after 15 years of management. However, after the clear cut and the new plantation, the C in the top 30 cm layer of the mineral soil increased, while it decreased on the forest floor. For thinning with group planting, the C stocks reduced within the 10–30 cm soil layer without impact on the total soil C. Therefore, the shift in management did result in a different allocation of the belowground C, particularly after a clear cut. The results are not only relevant for the study region but also for managed Scots pine forests in neighboring regions of the Atlantic zone of Western Europe. |
BibTeX:
@article{VanDamme2022,
author = {Van Damme, Freke and Mertens, Hana and Heinecke, Thilo and Lefevre, Lodewijk and De Meulder, Tim and Portillo-Estrada, Miguel and Roland, Marilyn and Gielen, Bert and Janssens, Ivan A and Verheyen, Kris and Campioli, Matteo},
title = {The Impact of Thinning and Clear Cut on the Ecosystem Carbon Storage of Scots Pine Stands under Maritime Influence in Flanders, Belgium},
journal = {Forests},
year = {2022},
volume = {13},
number = {10},
url = {https://www.mdpi.com/1999-4907/13/10/1679},
doi = {10.3390/f13101679}
}
|
| Varner RK, Crill PM, Frolking S, McCalley CK, Burke SA, Chanton JP, Holmes ME, null Null, Saleska S and Palace MW (2022), "Permafrost thaw driven changes in hydrology and vegetation cover increase trace gas emissions and climate forcing in Stordalen Mire from 1970 to 2014", Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences., jan, 2022. Vol. 380(2215), pp. 20210022. Royal Society. |
BibTeX:
@article{Varner2022,
author = {Varner, Ruth K and Crill, Patrick M and Frolking, Steve and McCalley, Carmody K and Burke, Sophia A and Chanton, Jeffrey P and Holmes, M Elizabeth and null Null and Saleska, Scott and Palace, Michael W},
title = {Permafrost thaw driven changes in hydrology and vegetation cover increase trace gas emissions and climate forcing in Stordalen Mire from 1970 to 2014},
journal = {Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences},
publisher = {Royal Society},
year = {2022},
volume = {380},
number = {2215},
pages = {20210022},
url = {https://doi.org/10.1098/rsta.2021.0022},
doi = {10.1098/rsta.2021.0022}
}
|
| Velders GJM, Daniel JS, Montzka SA, Vimont I, Rigby M, Krummel PB, Muhle J, O’Doherty S, Prinn RG, Weiss RF and Young D (2022), "Projections of hydrofluorocarbon (HFC) emissions and the resulting global warming based on recent trends in observed abundances and current policies", Atmospheric Chemistry and Physics., May, 2022. Vol. 22(9), pp. 6087-6101. Copernicus GmbH. |
BibTeX:
@article{Velders2022,
author = {Velders, Guus J. M. and Daniel, John S. and Montzka, Stephen A. and Vimont, Isaac and Rigby, Matthew and Krummel, Paul B. and Muhle, Jens and O’Doherty, Simon and Prinn, Ronald G. and Weiss, Ray F. and Young, Dickon},
title = {Projections of hydrofluorocarbon (HFC) emissions and the resulting global warming based on recent trends in observed abundances and current policies},
journal = {Atmospheric Chemistry and Physics},
publisher = {Copernicus GmbH},
year = {2022},
volume = {22},
number = {9},
pages = {6087--6101},
doi = {10.5194/acp-22-6087-2022}
}
|
| Vesala T, Kohonen K-M, Kooijmans LMJ, Praplan AP, Foltýnová L, Kolari P, Kulmala M, Bäck J, Nelson D, Yakir D, Zahniser M and Mammarella I (2022), "Long-term fluxes of carbonyl sulfide and their seasonality and interannual variability in a boreal forest", Atmospheric Chemistry and Physics. Vol. 22(4), pp. 2569-2584. |
BibTeX:
@article{Vesala2022,
author = {Vesala, T and Kohonen, K.-M. and Kooijmans, L M J and Praplan, A P and Foltýnová, L and Kolari, P and Kulmala, M and Bäck, J and Nelson, D and Yakir, D and Zahniser, M and Mammarella, I},
title = {Long-term fluxes of carbonyl sulfide and their seasonality and interannual variability in a boreal forest},
journal = {Atmospheric Chemistry and Physics},
year = {2022},
volume = {22},
number = {4},
pages = {2569--2584},
url = {https://acp.copernicus.org/articles/22/2569/2022/},
doi = {10.5194/acp-22-2569-2022}
}
|
| Vestin P, Molder M, Kljun N, Cai Z, Hasan A, Holst J, Klemedtsson L and Lindroth A (2022), "Impacts of stump harvesting on carbon dioxide, methane and nitrous oxide fluxes", iForest - Biogeosciences and Forestry. (3), pp. 148-162. |
| Abstract: During 2010-2013, we investigated the effects of stump harvesting on greenhouse gas (GHG) fluxes of carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O) with the flux-gradient technique at four experimental plots in a hemiboreal forest in Sweden. All plots were clear-cut and soil scarified and two of the plots were additionally stump harvested. The two clear-cut plots served as control plots. Due to differences in topography, we had one wetter and one drier plot of each treatment. All plots exhibited substantial emissions of GHGs and we noted significant effects of wetness on CO2, CH4 and N2O fluxes within treatments and significant effects of stump harvesting on CO2 and N2O fluxes at the dry plots. The CO2 emissions were lower at the dry stump harvested plot than at the dry control, but when estimated emissions from the removed stumps were added, total CO2 emissions were higher at the stump harvested plot, indicating a small enhancement of soil respiration. In addition, we noted significant emissions of N2O at this plot. At the wet plots, CO2 emissions were higher at the stump harvested plot, also suggesting a treatment effect but differences in wetness and vegetation cover at these plots make this effect more uncertain. At the wet plots, we noted sustained periods (weeks to months) of net N2O uptake. During the year with simultaneous measurements of the abovementioned GHGs, GHG budgets were 1.224�103 and 1.442�103 gm-2 of CO2-equivalents at the wet and dry stump harvested plots, respectively, and 1.070�103 and 1.696�103 gm-2 of CO2-equivalents at the wet and dry control plots, respectively. CO2 fluxes dominated GHG budgets at all plots but N2O contributed with 17% at the dry stump harvested plot. For the full period 2010-2013, total carbon (CO2+CH4) budgets were 4.301�103 and 4.114�103 g m-2 of CO2-eqvivalents at the wet and dry stump harvest plots, respectively and 4.107�103 and 5.274�103 gm-2 of CO2-equivalents at the wet and dry control plots, respectively. Our results support recent studies suggesting that stump harvesting does not result in substantial increase in CO2 emissions but uncertainties regarding GHG fluxes (especially N2O) remain and more long-term measurements are needed before robust conclusions can be drawn. |
BibTeX:
@article{Vestin2022,
author = {Vestin, P and Molder, M and Kljun, N and Cai, Z and Hasan, A and Holst, J and Klemedtsson, L and Lindroth, A},
title = {Impacts of stump harvesting on carbon dioxide, methane and nitrous oxide fluxes},
journal = {iForest - Biogeosciences and Forestry},
year = {2022},
number = {3},
pages = {148--162},
url = {https://iforest.sisef.org/contents/?id=ifor4086-015},
doi = {10.3832/ifor4086-015}
}
|
| Virkkala A-M, Natali SM, Rogers BM, Watts JD, Savage K, Connon SJ, Mauritz M, Schuur EAG, Peter D, Minions C, Nojeim J, Commane R, Emmerton CA, Goeckede M, Helbig M, Holl D, Iwata H, Kobayashi H, Kolari P, López-Blanco E, Marushchak ME, Mastepanov M, Merbold L, Parmentier F-JW, Peichl M, Sachs T, Sonnentag O, Ueyama M, Voigt C, Aurela M, Boike J, Celis G, Chae N, Christensen TR, Bret-Harte MS, Dengel S, Dolman H, Edgar CW, Elberling B, Euskirchen E, Grelle A, Hatakka J, Humphreys E, Järveoja J, Kotani A, Kutzbach L, Laurila T, Lohila A, Mammarella I, Matsuura Y, Meyer G, Nilsson MB, Oberbauer SF, Park S-J, Petrov R, Prokushkin AS, Schulze C, St. Louis VL, Tuittila E-S, Tuovinen J-P, Quinton W, Varlagin A, Zona D and Zyryanov VI (2022), "The ABCflux database: Arctic--boreal CO_2 flux observations and ancillary information aggregated to monthly time steps across terrestrial ecosystems", Earth System Science Data. Vol. 14(1), pp. 179-208. |
BibTeX:
@article{Virkkala2022,
author = {Virkkala, A.-M. and Natali, S M and Rogers, B M and Watts, J D and Savage, K and Connon, S J and Mauritz, M and Schuur, E A G and Peter, D and Minions, C and Nojeim, J and Commane, R and Emmerton, C A and Goeckede, M and Helbig, M and Holl, D and Iwata, H and Kobayashi, H and Kolari, P and López-Blanco, E and Marushchak, M E and Mastepanov, M and Merbold, L and Parmentier, F.-J. W and Peichl, M and Sachs, T and Sonnentag, O and Ueyama, M and Voigt, C and Aurela, M and Boike, J and Celis, G and Chae, N and Christensen, T R and Bret-Harte, M S and Dengel, S and Dolman, H and Edgar, C W and Elberling, B and Euskirchen, E and Grelle, A and Hatakka, J and Humphreys, E and Järveoja, J and Kotani, A and Kutzbach, L and Laurila, T and Lohila, A and Mammarella, I and Matsuura, Y and Meyer, G and Nilsson, M B and Oberbauer, S F and Park, S.-J. and Petrov, R and Prokushkin, A S and Schulze, C and St. Louis, V L and Tuittila, E.-S. and Tuovinen, J.-P. and Quinton, W and Varlagin, A and Zona, D and Zyryanov, V I},
title = {The ABCflux database: Arctic--boreal CO_2 flux observations and ancillary information aggregated to monthly time steps across terrestrial ecosystems},
journal = {Earth System Science Data},
year = {2022},
volume = {14},
number = {1},
pages = {179--208},
url = {https://essd.copernicus.org/articles/14/179/2022/},
doi = {10.5194/essd-14-179-2022}
}
|
| Walther S, Besnard S, Nelson JA, El-Madany TS, Migliavacca M, Weber U, Carvalhais N, Ermida SL, Brümmer C, Schrader F, Prokushkin AS, Panov AV and Jung M (2022), "Technical note: A view from space on global flux towers by MODIS and Landsat: the FluxnetEO data set", Biogeosciences. Vol. 19(11), pp. 2805-2840. |
BibTeX:
@article{Walther2022,
author = {Walther, S and Besnard, S and Nelson, J A and El-Madany, T S and Migliavacca, M and Weber, U and Carvalhais, N and Ermida, S L and Brümmer, C and Schrader, F and Prokushkin, A S and Panov, A V and Jung, M},
title = {Technical note: A view from space on global flux towers by MODIS and Landsat: the FluxnetEO data set},
journal = {Biogeosciences},
year = {2022},
volume = {19},
number = {11},
pages = {2805--2840},
url = {https://bg.copernicus.org/articles/19/2805/2022/},
doi = {10.5194/bg-19-2805-2022}
}
|
| Wang Q, Qu Y, Robinson K-L, Bogena H, Graf A, Vereecken H, Tietema A and Bol R (2022), "Deforestation alters dissolved organic carbon and sulfate dynamics in a mountainous headwater catchment—A wavelet analysis", Frontiers in Forests and Global Change. Vol. 5(November), pp. 1-14. |
| Abstract: Deforestation has a wide range of effects on hydrological and geochemical processes. Dissolved organic carbon (DOC) dynamics, a sensitive environmental change indicator, is expected to be affected by deforestation, with changes in atmospheric sulfur (S) deposition compounding this. However, how precisely anthropogenic disturbance (deforestation) under a declining atmospheric S input scenario affects the underlying spatiotemporal dynamics and relationships of river DOC and sulfate with hydro-climatological variables e.g., stream water temperature, runoff, pH, total dissolved iron (Fe tot ), and calcium (Ca 2+ ) remains unclear. We, therefore, examined this issue within the TERENO Wüstebach catchment (Eifel, Germany), where partial deforestation had taken place in 2013. Wavelet transform coherence (WTC) analysis was applied based on a 10-year time series (2010–2020) from three sampling stations, whose (sub) catchment areas have different proportions of deforested area (W10: 31%, W14: 25%, W17: 3%). We found that water temperature and DOC, sulfate, and Fe tot concentrations showed distinct seasonal patterns, with DOC averaging concentrations ranging from 2.23 (W17) to 4.56 (W10) mg L –1 and sulfate concentration ranging from 8.04 (W10) to 10.58 (W17) mg L –1 . After clear-cut, DOC significantly increased by 59, 58% in the mainstream (W10, W14), but only 26% in the reference stream. WTC results indicated that DOC was negatively correlated with runoff and sulfate, but positively correlated with temperature, Ca 2+ , and Fe tot . The negative correlation between DOC with runoff and sulfate was apparent over the whole examined 10-year period in W17 but did end in W10 and W14 after the deforestation. Sulfate (SO 4 ) was highly correlated with stream water temperature, runoff, and Fe tot in W10 and W14 and with a longer lag time than W17. Additionally, pH was stronger correlated (higher R 2 ) with sulfate and DOC in W17 than in W10 and W14. In conclusion, WTC analysis indicates that within this low mountainous forest catchment deforestation levels over 25% (W10 and W14) affected the coupling of S and C cycling substantially more strongly than “natural” environmental changes as observed in W17. |
BibTeX:
@article{Wang2022,
author = {Wang, Qiqi and Qu, Yuquan and Robinson, Kerri-Leigh and Bogena, Heye and Graf, Alexander and Vereecken, Harry and Tietema, Albert and Bol, Roland},
title = {Deforestation alters dissolved organic carbon and sulfate dynamics in a mountainous headwater catchment—A wavelet analysis},
journal = {Frontiers in Forests and Global Change},
year = {2022},
volume = {5},
number = {November},
pages = {1--14},
doi = {10.3389/ffgc.2022.1044447}
}
|
| Wang Y-R, Buchmann N, Hessen DO, Stordal F, Erisman JW, Vollsnes AV, Andersen T and Dolman H (2022), "Disentangling effects of natural and anthropogenic drivers on forest net ecosystem production", Science of The Total Environment. Vol. 839, pp. 156326. |
| Abstract: Net Ecosystem Production (NEP) of forests is the net carbon dioxide (CO2) fluxes between land and the atmosphere due to forests' biogeochemical processes. NEP varies with natural drivers such as precipitation, air temperature, solar radiation, plant functional type (PFT), and soil texture, which affect the gross primary production and ecosystem respiration, and thus the net C sequestration. It is also known that deposition of sulphur and nitrogen influences NEP in forest ecosystems. These drivers' respective, unique effects on NEP, however, are often difficult to be individually identified by conventional bivariate analysis. Here we show that by analyzing 22 forest sites with 231 site-year data acquired from FLUXNET database across Europe for the years 2000–2014, the individual, unique effects of these drivers on annual forest CO2 fluxes can be disentangled using Generalized Additive Models (GAM) for nonlinear regression analysis. We show that S and N deposition have substantial impacts on NEP, where S deposition above 5 kg S ha−1 yr−1 can significantly reduce NEP, and N deposition around 22 kg N ha−1 yr−1 has the highest positive effect on NEP. Our results suggest that air quality management of S and N is crucial for maintaining healthy biogeochemical functions of forests to mitigate climate change. Furthermore, the empirical models we developed for estimating NEP of forests can serve as a forest management tool in the context of climate change mitigation. Potential applications include the assessment of forest carbon fluxes in the REDD+ framework of the UNFCCC. |
BibTeX:
@article{Wang2022a,
author = {Wang, You-Ren and Buchmann, Nina and Hessen, Dag O and Stordal, Frode and Erisman, Jan Willem and Vollsnes, Ane Victoria and Andersen, Tom and Dolman, Han},
title = {Disentangling effects of natural and anthropogenic drivers on forest net ecosystem production},
journal = {Science of The Total Environment},
year = {2022},
volume = {839},
pages = {156326},
url = {https://www.sciencedirect.com/science/article/pii/S0048969722034234},
doi = {10.1016/j.scitotenv.2022.156326}
}
|
| Western LM, Redington AL, Manning AJ, Trudinger CM, Hu L, Henne S, Fang X, Kuijpers LJM, Theodoridi C, Godwin DS, Arduini J, Dunse B, Engel A, Fraser PJ, Harth CM, Krummel PB, Maione M, Mühle J, O’Doherty S, Park H, Park S, Reimann S, Salameh PK, Say D, Schmidt R, Schuck T, Siso C, Stanley KM, Vimont I, Vollmer MK, Young D, Prinn RG, Weiss RF, Montzka SA and Rigby M (2022), "A renewed rise in global HCFC-141b emissions between 2017–2021", Atmospheric Chemistry and Physics., July, 2022. Vol. 22(14), pp. 9601-9616. Copernicus GmbH. |
BibTeX:
@article{Western2022,
author = {Western, Luke M. and Redington, Alison L. and Manning, Alistair J. and Trudinger, Cathy M. and Hu, Lei and Henne, Stephan and Fang, Xuekun and Kuijpers, Lambert J. M. and Theodoridi, Christina and Godwin, David S. and Arduini, Jgor and Dunse, Bronwyn and Engel, Andreas and Fraser, Paul J. and Harth, Christina M. and Krummel, Paul B. and Maione, Michela and Mühle, Jens and O’Doherty, Simon and Park, Hyeri and Park, Sunyoung and Reimann, Stefan and Salameh, Peter K. and Say, Daniel and Schmidt, Roland and Schuck, Tanja and Siso, Carolina and Stanley, Kieran M. and Vimont, Isaac and Vollmer, Martin K. and Young, Dickon and Prinn, Ronald G. and Weiss, Ray F. and Montzka, Stephen A. and Rigby, Matthew},
title = {A renewed rise in global HCFC-141b emissions between 2017–2021},
journal = {Atmospheric Chemistry and Physics},
publisher = {Copernicus GmbH},
year = {2022},
volume = {22},
number = {14},
pages = {9601--9616},
doi = {10.5194/acp-22-9601-2022}
}
|
| Wintjen P, Schrader F, Schaap M, Beudert B, Kranenburg R and Brümmer C (2022), "Forest--atmosphere exchange of reactive nitrogen in a remote region -- Part II: Modeling annual budgets", Biogeosciences. Vol. 19(22), pp. 5287-5311. |
BibTeX:
@article{Wintjen2022,
author = {Wintjen, P and Schrader, F and Schaap, M and Beudert, B and Kranenburg, R and Brümmer, C},
title = {Forest--atmosphere exchange of reactive nitrogen in a remote region -- Part II: Modeling annual budgets},
journal = {Biogeosciences},
year = {2022},
volume = {19},
number = {22},
pages = {5287--5311},
url = {https://bg.copernicus.org/articles/19/5287/2022/},
doi = {10.5194/bg-19-5287-2022}
}
|
| van der Woude AM, de Kok R, Smith N, Luijkx IT, Botia S, Karstens U, Kooijmans LMJ, Koren G, Meijer H, Steeneveld G-J, Storm I, Super I, Scheeren BA, Vermeulen A and Peters W (2022), "Near real-time CO_2 fluxes from CarbonTracker Europe for high resolution atmospheric modeling", Earth System Science Data Discussions. Vol. 2022, pp. 1-38. |
BibTeX:
@article{Woude2022,
author = {van der Woude, A M and de Kok, R and Smith, N and Luijkx, I T and Botia, S and Karstens, U and Kooijmans, L M J and Koren, G and Meijer, H and Steeneveld, G.-J. and Storm, I and Super, I and Scheeren, B A and Vermeulen, A and Peters, W},
title = {Near real-time CO_2 fluxes from CarbonTracker Europe for high resolution atmospheric modeling},
journal = {Earth System Science Data Discussions},
year = {2022},
volume = {2022},
pages = {1--38},
url = {https://essd.copernicus.org/preprints/essd-2022-175/},
doi = {10.5194/essd-2022-175}
}
|
| Yu X, Orth R, Reichstein M, Bahn M, Klosterhalfen A, Knohl A, Koebsch F, Migliavacca M, Mund M, Nelson JA, Stocker BD, Walther S and Bastos A (2022), "Contrasting drought legacy effects on gross primary productivity in a mixed versus pure beech forest", Biogeosciences. Vol. 19(17), pp. 4315-4329. |
BibTeX:
@article{Yu2022,
author = {Yu, X and Orth, R and Reichstein, M and Bahn, M and Klosterhalfen, A and Knohl, A and Koebsch, F and Migliavacca, M and Mund, M and Nelson, J A and Stocker, B D and Walther, S and Bastos, A},
title = {Contrasting drought legacy effects on gross primary productivity in a mixed versus pure beech forest},
journal = {Biogeosciences},
year = {2022},
volume = {19},
number = {17},
pages = {4315--4329},
url = {https://bg.copernicus.org/articles/19/4315/2022/},
doi = {10.5194/bg-19-4315-2022}
}
|
| Yuan K, Zhu Q, Li F, Riley WJ, Torn M, Chu H, McNicol G, Chen M, Knox S, Delwiche K, Wu H, Baldocchi D, Ma H, Desai AR, Chen J, Sachs T, Ueyama M, Sonnentag O, Helbig M, Tuittila E-S, Jurasinski G, Koebsch F, Campbell D, Schmid HP, Lohila A, Goeckede M, Nilsson MB, Friborg T, Jansen J, Zona D, Euskirchen E, Ward EJ, Bohrer G, Jin Z, Liu L, Iwata H, Goodrich J and Jackson R (2022), "Causality guided machine learning model on wetland CH4 emissions across global wetlands", Agricultural and Forest Meteorology. Vol. 324, pp. 109115. |
| Abstract: Wetland CH4 emissions are among the most uncertain components of the global CH4 budget. The complex nature of wetland CH4 processes makes it challenging to identify causal relationships for improving our understanding and predictability of CH4 emissions. In this study, we used the flux measurements of CH4 from eddy covariance towers (30 sites from 4 wetlands types: bog, fen, marsh, and wet tundra) to construct a causality-constrained machine learning (ML) framework to explain the regulative factors and to capture CH4 emissions at sub-seasonal scale. We found that soil temperature is the dominant factor for CH4 emissions in all studied wetland types. Ecosystem respiration (CO2) and gross primary productivity exert controls at bog, fen, and marsh sites with lagged responses of days to weeks. Integrating these asynchronous environmental and biological causal relationships in predictive models significantly improved model performance. More importantly, modeled CH4 emissions differed by up to a factor of 4 under a +1°C warming scenario when causality constraints were considered. These results highlight the significant role of causality in modeling wetland CH4 emissions especially under future warming conditions, while traditional data-driven ML models may reproduce observations for the wrong reasons. Our proposed causality-guided model could benefit predictive modeling, large-scale upscaling, data gap-filling, and surrogate modeling of wetland CH4 emissions within earth system land models. |
BibTeX:
@article{Yuan2022,
author = {Yuan, Kunxiaojia and Zhu, Qing and Li, Fa and Riley, William J and Torn, Margaret and Chu, Housen and McNicol, Gavin and Chen, Min and Knox, Sara and Delwiche, Kyle and Wu, Huayi and Baldocchi, Dennis and Ma, Hongxu and Desai, Ankur R and Chen, Jiquan and Sachs, Torsten and Ueyama, Masahito and Sonnentag, Oliver and Helbig, Manuel and Tuittila, Eeva-Stiina and Jurasinski, Gerald and Koebsch, Franziska and Campbell, David and Schmid, Hans Peter and Lohila, Annalea and Goeckede, Mathias and Nilsson, Mats B and Friborg, Thomas and Jansen, Joachim and Zona, Donatella and Euskirchen, Eugenie and Ward, Eric J and Bohrer, Gil and Jin, Zhenong and Liu, Licheng and Iwata, Hiroki and Goodrich, Jordan and Jackson, Robert},
title = {Causality guided machine learning model on wetland CH4 emissions across global wetlands},
journal = {Agricultural and Forest Meteorology},
year = {2022},
volume = {324},
pages = {109115},
url = {https://www.sciencedirect.com/science/article/pii/S0168192322003021},
doi = {10.1016/j.agrformet.2022.109115}
}
|
| Zawilski BM (2022), "The soil heat flux sensor functioning checks, imbalances' origins, and forgotten energies", Geoscientific Instrumentation, Methods and Data Systems. Vol. 11(2), pp. 223-234. |
BibTeX:
@article{Zawilski2022,
author = {Zawilski, B M},
title = {The soil heat flux sensor functioning checks, imbalances' origins, and forgotten energies},
journal = {Geoscientific Instrumentation, Methods and Data Systems},
year = {2022},
volume = {11},
number = {2},
pages = {223--234},
url = {https://gi.copernicus.org/articles/11/223/2022/},
doi = {10.5194/gi-11-223-2022}
}
|
| Zawilski BM (2022), "Wind speed influences corrected Autocalibrated Soil Evapo-respiration Chamber (ASERC) evaporation measures", Geoscientific Instrumentation, Methods and Data Systems. Vol. 11(1), pp. 163-182. |
BibTeX:
@article{Zawilski2022a,
author = {Zawilski, B M},
title = {Wind speed influences corrected Autocalibrated Soil Evapo-respiration Chamber (ASERC) evaporation measures},
journal = {Geoscientific Instrumentation, Methods and Data Systems},
year = {2022},
volume = {11},
number = {1},
pages = {163--182},
url = {https://gi.copernicus.org/articles/11/163/2022/},
doi = {10.5194/gi-11-163-2022}
}
|
| Zenone T, Vitale L, Famulari D and Magliulo V (2022), "Application of machine learning techniques to simulate the evaporative fraction and its relationship with environmental variables in corn crops", Ecological Processes. Vol. 11(1), pp. 1-14. Springer Berlin Heidelberg. |
| Abstract: Background: The evaporative fraction (EF) represents an important biophysical parameter reflecting the distribution of surface available energy. In this study, we investigated the daily and seasonal patterns of EF in a multi-year corn cultivation located in southern Italy and evaluated the performance of five machine learning (ML) classes of algorithms: the linear regression (LR), regression tree (RT), support vector machine (SVM), ensembles of tree (ETs) and Gaussian process regression (GPR) to predict the EF at daily time step. The adopted methodology consisted of three main steps that include: (i) selection of the EF predictors; (ii) comparison of the different classes of ML; (iii) application, cross-validation of the selected ML algorithms and comparison with the observed data. Results: Our results indicate that SVM and GPR were the best classes of ML at predicting the EF, with a total of four different algorithms: cubic SVM, medium Gaussian SVM, the Matern 5/2 GPR, and the rational quadratic GPR. The comparison between observed and predicted EF in all four algorithms, during the training phase, were within the 95% confidence interval: the R2 value between observed and predicted EF was 0.76 (RMSE 0.05) for the medium Gaussian SVM, 0.99 (RMSE 0.01) for the rational quadratic GPR, 0.94 (RMSE 0.02) for the Matern 5/2 GPR, and 0.83 (RMSE 0.05) for the cubic SVM algorithms. Similar results were obtained during the testing phase. The results of the cross-validation analysis indicate that the R2 values obtained between all iterations for each of the four adopted ML algorithms were basically constant, confirming the ability of ML as a tool to predict EF. Conclusion: ML algorithms represent a valid alternative able to predict the EF especially when remote sensing data are not available, or the sky conditions are not suitable. The application to different geographical areas, or crops, requires further development of the model based on different data sources of soils, climate, and cropping systems. |
BibTeX:
@article{Zenone2022,
author = {Zenone, Terenzio and Vitale, Luca and Famulari, Daniela and Magliulo, Vincenzo},
title = {Application of machine learning techniques to simulate the evaporative fraction and its relationship with environmental variables in corn crops},
journal = {Ecological Processes},
publisher = {Springer Berlin Heidelberg},
year = {2022},
volume = {11},
number = {1},
pages = {1--14},
url = {https://doi.org/10.1186/s13717-022-00400-1},
doi = {10.1186/s13717-022-00400-1}
}
|
| Zhang W, Yu G, Chen Z, Zhu X, Han L, Liu Z, Lin Y, Han S, Sha L, Wang H, Wang Y, Yan J, Zhang Y and Gharun M (2022), "Photosynthetic capacity dominates the interannual variation of annual gross primary productivity in the Northern Hemisphere", Science of The Total Environment. Vol. 849, pp. 157856. |
| Abstract: Annual gross primary productivity (AGPP) of terrestrial ecosystems is the largest carbon flux component in ecosystems; however, it's unclear whether photosynthetic capacity or phenology dominates interannual variation of AGPP, and a better understanding of this could contribute to estimation of carbon sinks and their interactions with climate change. In this study, observed GPP data of 494 site-years from 39 eddy covariance sites in Northern Hemisphere were used to investigate mechanisms of interannual variation of AGPP. This study first decomposed AGPP into three seasonal dynamic attribute parameters (growing season length (CUP), maximum daily GPP (GPPmax), and the ratio of mean daily GPP to GPPmax (αGPP)), and then decomposed AGPP into mean leaf area index (LAIm) and annual photosynthetic capacity per leaf area (AGPPlm). Furthermore, GPPmax was decomposed into leaf area index of DOYmax (the day when GPPmax appeared) (LAImax) and photosynthesis per leaf area of DOYmax (GPPlmax). Relative contributions of parameters to AGPP and GPPmax were then calculated. Finally, environmental variables of DOYmax were extracted to analyze factors influencing interannual variation of GPPlmax. Trends of AGPP in 39 ecosystems varied from −65.23 to 53.05 g C m−2 yr−2, with the mean value of 6.32 g C m−2 yr−2. Photosynthetic capacity (GPPmax and AGPPlm), not CUP or LAI, was the main factor dominating interannual variation of AGPP. GPPlmax determined the interannual variation of GPPmax, and temperature, water, and radiation conditions of DOYmax affected the interannual variation of GPPlmax. This study used the cascade relationship of “environmental variables-GPPlmax-GPPmax-AGPP” to explain the mechanism of interannual variation of AGPP, which can provide new ideas for the AGPP estimation based on seasonal dynamic of GPP. |
BibTeX:
@article{Zhang2022,
author = {Zhang, Weikang and Yu, Guirui and Chen, Zhi and Zhu, Xianjin and Han, Lang and Liu, Zhaogang and Lin, Yong and Han, Shijie and Sha, Liqing and Wang, Huimin and Wang, Yanfen and Yan, Junhua and Zhang, Yiping and Gharun, Mana},
title = {Photosynthetic capacity dominates the interannual variation of annual gross primary productivity in the Northern Hemisphere},
journal = {Science of The Total Environment},
year = {2022},
volume = {849},
pages = {157856},
url = {https://www.sciencedirect.com/science/article/pii/S0048969722049555},
doi = {10.1016/j.scitotenv.2022.157856}
}
|
| Zhao J, Lange H and Meissner H (2022), "Estimating Carbon Sink Strength of Norway Spruce Forests Using Machine Learning", Forests. Vol. 13(10) |
| Abstract: Forests sequester atmospheric carbon dioxide (CO2) which is important for climate mitigation. Net ecosystem production (NEP) varies significantly across forests in different regions depending on the dominant tree species, stand age, and environmental factors. Therefore, it is important to evaluate forest NEP and its potential changes under climate change in different regions to inform forestry policy making. Norway spruce (Picea abies) is the most prevalent species in conifer forests throughout Europe. Here, we focused on Norway spruce forests and used eddy covariance-based observations of CO2 fluxes and other variables from eight sites to build a XGBoost machine learning model for NEP estimation. The NEP values from the study sites varied between −296 (source) and 1253 (sink) g C m−2 yr−1. Overall, among the tested variables, air temperature was the most important factor driving NEP variations, followed by global radiation and stand age, while precipitation had a very limited contribution to the model. The model was used to predict the NEP of mature Norway spruce forests in different regions within Europe. The NEP median value was 494 g C m−2 yr−1 across the study areas, with higher NEP values, up to >800 g C m−2 yr−1, in lower latitude regions. Under the “middle-of-the-road” SSP2-4.5 scenario, the NEP values tended to be greater in almost all the studied regions by 2060 with the estimated median of NEP changes in 2041–2060 to be +45 g C m−2 yr−1. Our results indicate that Norway spruce forests show high productivity in a wide area of Europe with potentially future NEP enhancement. However, due to the limitations of the data, the potential decrease in NEP induced by temperature increases beyond the photosynthesis optima and frequent ecosystem disturbances (e.g., drought, bark beetle infestation, etc.) still needs to be evaluated. |
BibTeX:
@article{Zhao2022,
author = {Zhao, Junbin and Lange, Holger and Meissner, Helge},
title = {Estimating Carbon Sink Strength of Norway Spruce Forests Using Machine Learning},
journal = {Forests},
year = {2022},
volume = {13},
number = {10},
url = {https://www.mdpi.com/1999-4907/13/10/1721},
doi = {10.3390/f13101721}
}
|
| Zhao P, Chi J, Nilsson MB, Löfvenius MO, Högberg P, Jocher G, Lim H, Mäkelä A, Marshall J, Ratcliffe J, Tian X, Näsholm T, Lundmark T, Linder S and Peichl M (2022), "Long-term nitrogen addition raises the annual carbon sink of a boreal forest to a new steady-state", Agricultural and Forest Meteorology. Vol. 324, pp. 109112. |
| Abstract: The boreal forest is an important global carbon (C) sink. Since low soil nitrogen (N) availability is commonly a key constraint on forest productivity, the prevalent view is that increased N input enhances its C sink-strength. This understanding however relies primarily on observations of increased aboveground tree biomass and soil C stock following N fertilization, whereas empirical data evaluating the effects on the whole ecosystem-scale C balance are lacking. Here we use a unique long-term experiment consisting of paired forest stands with eddy covariance measurements to explore the effect of ecosystem-scale N fertilization on the C balance of a managed boreal pine forest. We find that the annual C uptake (i.e. net ecosystem production, NEP) at the fertilized stand was 16 ± 2% greater relative to the control stand by the end of the first decade of N addition. Subsequently, the ratio of NEP between the fertilized and control stand remained at a stable level during the following five years with an average NEP to N response of 7 ± 1 g C per g N. Our study reveals that this non-linear response of NEP to long-term N fertilization was the result of a cross-seasonal feedback between the N-induced increases in both growing-season C uptake and subsequent winter C emission. We further find that one decade of N addition altered the sensitivity of ecosystem C fluxes to key environmental drivers resulting in divergent responses to weather patterns. Thus, our study highlights the need to account for ecosystem-scale responses to perturbations to improve our understanding of nitrogen-carbon-climate feedbacks in boreal forests. |
BibTeX:
@article{Zhao2022a,
author = {Zhao, Peng and Chi, Jinshu and Nilsson, Mats B and Löfvenius, Mikaell Ottosson and Högberg, Peter and Jocher, Georg and Lim, Hyungwoo and Mäkelä, Annikki and Marshall, John and Ratcliffe, Joshua and Tian, Xianglin and Näsholm, Torgny and Lundmark, Tomas and Linder, Sune and Peichl, Matthias},
title = {Long-term nitrogen addition raises the annual carbon sink of a boreal forest to a new steady-state},
journal = {Agricultural and Forest Meteorology},
year = {2022},
volume = {324},
pages = {109112},
url = {https://www.sciencedirect.com/science/article/pii/S0168192322002994},
doi = {10.1016/j.agrformet.2022.109112}
}
|
| Zhu X, Chen L, Pumpanen J, Ojala A, Zobitz J, Zhou X, Laudon H, Palviainen M, Neitola K and Berninger F (2022), "The role of terrestrial productivity and hydrology in regulating aquatic dissolved organic carbon concentrations in boreal catchments", Global Change Biology. Vol. 28(8), pp. 2764-2778. |
| Abstract: Abstract The past decades have witnessed an increase in dissolved organic carbon (DOC) concentrations in the catchments of the Northern Hemisphere. Increasing terrestrial productivity and changing hydrology may be reasons for the increases in DOC concentration. The aim of this study is to investigate the impacts of increased terrestrial productivity and changed hydrology following climate change on DOC concentrations. We tested and quantified the effects of gross primary production (GPP), ecosystem respiration (RE) and discharge on DOC concentrations in boreal catchments over 3 years. As catchment characteristics can regulate the extent of rising DOC concentrations caused by the regional or global environmental changes, we selected four catchments with different sizes (small, medium and large) and landscapes (forest, mire and forest-mire mixed). We applied multiple models: Wavelet coherence analysis detected the delay-effects of terrestrial productivity and discharge on aquatic DOC variations of boreal catchments; thereafter, the distributed-lag linear models quantified the contributions of each factor on DOC variations. Our results showed that the combined impacts of terrestrial productivity and discharge explained 62% of aquatic DOC variations on average across all sites, whereas discharge, gross primary production (GPP) and RE accounted for 26%, 22% and 3%, respectively. The impact of GPP and discharge on DOC changes was directly related to catchment size: GPP dominated DOC fluctuations in small catchments (<1 km2), whereas discharge controlled DOC variations in big catchments (>1 km2). The direction of the relation between GPP and discharge on DOC varied. Increasing RE always made a positive contribution to DOC concentration. This study reveals that climate change-induced terrestrial greening and shifting hydrology change the DOC export from terrestrial to aquatic ecosystems. The work improves our mechanistic understanding of surface water DOC regulation in boreal catchments and confirms the importance of DOC fluxes in regulating ecosystem C budgets. |
BibTeX:
@article{Zhu2022,
author = {Zhu, Xudan and Chen, Liang and Pumpanen, Jukka and Ojala, Anne and Zobitz, John and Zhou, Xuan and Laudon, Hjalmar and Palviainen, Marjo and Neitola, Kimmo and Berninger, Frank},
title = {The role of terrestrial productivity and hydrology in regulating aquatic dissolved organic carbon concentrations in boreal catchments},
journal = {Global Change Biology},
year = {2022},
volume = {28},
number = {8},
pages = {2764--2778},
url = {https://onlinelibrary.wiley.com/doi/abs/10.1111/gcb.16094},
doi = {10.1111/gcb.16094}
}
|
| Zou J, Wu J, Osborne B and Luo Y (2022), "The response of ecosystem carbon and nitrogen pools to experimental warming in grasslands: a meta-analysis", Journal of Plant Ecology., February, 2022. Vol. 15(4), pp. 733-742. Oxford University Press (OUP). |
BibTeX:
@article{Zou2022,
author = {Zou, Junliang and Wu, Juying and Osborne, Bruce and Luo, Yiqi},
editor = {Yang, Yuanhe},
title = {The response of ecosystem carbon and nitrogen pools to experimental warming in grasslands: a meta-analysis},
journal = {Journal of Plant Ecology},
publisher = {Oxford University Press (OUP)},
year = {2022},
volume = {15},
number = {4},
pages = {733--742},
doi = {10.1093/jpe/rtac020}
}
|
| Affolter S, Schibig M, Berhanu T, Bukowiecki N, Steinbacher M, Nyfeler P, Hervo M, Lauper J and Leuenberger M (2021), "Assessing local CO2 contamination revealed by two near-by high altitude records at Jungfraujoch, Switzerland", Environmental Research Letters. Vol. 16(4), pp. 44037. IOP Publishing. |
| Abstract: Remote research stations are guarantor of high-quality atmospheric measurements as they are essentially exposed to pristine air masses. However, in a context of increasing touristic pressure for certain sites, attention should be paid to the local anthropogenic emission related to the infrastructure itself. Among emissions, carbon dioxide (CO2) is the most important anthropogenic greenhouse gas and a major contributor to the current global warming. Here, we compared two years of CO2 dry air mole fraction records from Jungfraujoch (Swiss Alps) measured at the Sphinx Laboratory (3580 m a.s.l.; JFJ) and the East Ridge facility (3705 m a.s.l.; JER; horizontal distance of ∼1 km), respectively. Both stations show an overall increase of the annual mean CO2 mole fraction in line with current global trends. On a daily basis, values during the night (00h00–06h00) show robust coherence with variability ranging within the measurement uncertainties matching the WMO compatibility goal of 0.1 ppm, which we considered to be background air CO2 mole fraction for Central and Western Europe. However, JFJ record shows superimposed short-term variability with diurnal CO2 spikes centered around noon. Whereas the variability occurring during time intervals ranging from days to weeks seem to be driven by inputs of air masses from the planetary boundary layer, we suppose that the super-imposed diurnal CO2 spikes occurring essentially in summer are explained by local emission sources related to the infrastructure (visitors, tourism, etc). Nevertheless, we cannot point to a single triggering cause for those spikes as it probably results from a combination of factors. In order to minimize these local emissions, smooth collaboration between all the involved stakeholders is required. |
BibTeX:
@article{Affolter2021,
author = {Affolter, Stéphane and Schibig, Michael and Berhanu, Tesfaye and Bukowiecki, Nicolas and Steinbacher, Martin and Nyfeler, Peter and Hervo, Maxime and Lauper, Jürg and Leuenberger, Markus},
title = {Assessing local CO2 contamination revealed by two near-by high altitude records at Jungfraujoch, Switzerland},
journal = {Environmental Research Letters},
publisher = {IOP Publishing},
year = {2021},
volume = {16},
number = {4},
pages = {44037},
url = {http://dx.doi.org/10.1088/1748-9326/abe74a},
doi = {10.1088/1748-9326/abe74a}
}
|
| Alekseychik P, Korrensalo A, Mammarella I, Launiainen S, Tuittila E-S, Korpela I and Vesala T (2021), "Carbon balance of a Finnish bog: temporal variability and limiting factors based on 6 years of eddy-covariance data", Biogeosciences. Vol. 18(16), pp. 4681-4704. |
BibTeX:
@article{Alekseychik2021,
author = {Alekseychik, P and Korrensalo, A and Mammarella, I and Launiainen, S and Tuittila, E.-S. and Korpela, I and Vesala, T},
title = {Carbon balance of a Finnish bog: temporal variability and limiting factors based on 6 years of eddy-covariance data},
journal = {Biogeosciences},
year = {2021},
volume = {18},
number = {16},
pages = {4681--4704},
url = {https://bg.copernicus.org/articles/18/4681/2021/},
doi = {10.5194/bg-18-4681-2021}
}
|
| Aslan T, Peltola O, Ibrom A, Nemitz E, Rannik Ü and Mammarella I (2021), "The high-frequency response correction of eddy covariance fluxes -- Part 2: An experimental approach for analysing noisy measurements of small fluxes", Atmospheric Measurement Techniques. Vol. 14(7), pp. 5089-5106. |
BibTeX:
@article{Aslan2021,
author = {Aslan, T and Peltola, O and Ibrom, A and Nemitz, E and Rannik, Ü and Mammarella, I},
title = {The high-frequency response correction of eddy covariance fluxes -- Part 2: An experimental approach for analysing noisy measurements of small fluxes},
journal = {Atmospheric Measurement Techniques},
year = {2021},
volume = {14},
number = {7},
pages = {5089--5106},
url = {https://amt.copernicus.org/articles/14/5089/2021/},
doi = {10.5194/amt-14-5089-2021}
}
|
| Awada H, Di Prima S, Sirca C, Giadrossich F, Marras S, Spano D and Pirastru M (2021), "Daily Actual Evapotranspiration Estimation in a Mediterranean Ecosystem from Landsat Observations Using SEBAL Approach", Forests. Vol. 12(2) |
| Abstract: Quantifying actual evapotranspiration (ETa) over natural vegetation is crucial in evaluating the water status of ecosystems and the water-use patterns in local or regional hydrological basins. Remote sensing-based surface energy balance models have been used extensively for estimating ETa in agro-environments; however, the application of these models to natural ecosystems is still limited. The surface energy balance algorithm for land (SEBAL) physical-based surface energy balance model was applied to estimate the actual evapotranspiration over a heterogeneous coverage of Mediterranean maquis in a natural reserve in Sardinia, Italy. The model was applied on 19 Landsat 5 and 8 images from 2009 to 2014, and the results were compared to the data of a micrometeorological station with eddy covariance flux measurements. Comparing the SEBAL-based evaporative fraction (ΛS) to the corresponding tower-derived evaporative fractions (ΛT) showed good flux estimations in the Landsat overpass time (Coefficient of determination R2 = 0.77, root mean square error RMSE = 0.05 and mean absolute error MAE = 0.076). Three methods were evaluated for upscaling instantaneous latent heat flux (λE) to daily actual evapotranspiration (ETa,D). The upscaling methods use the evaporative fraction (Λ), the reference evapotranspiration fraction (EFr) and the ratio of daily to instantaneous incoming shortwave radiation (Rs24/Rsi) as upscaling factors under the hypothesis of diurnal self-preservation. A preliminary analysis performed using only in-situ measured data demonstrated that the three factors were relatively self-preserved during the daytime, and can yield good ETa,D estimations, particularly when obtained at near the Landsat scene acquisition time (≈10:00 UTC). The upscaling factors obtained from SEBAL retrieved instantaneous fluxes, and some ancillary measured meteorological data were used to upscale SEBAL-estimated instantaneous actual λ to daily ET. The Λ EFr and Rs24/Rsi methods on average overestimated the measured ETa,D by nearly 20, 61 and 18%, respectively. The performance of the Λ and Rs24/Rsi methods was considered satisfactory, bearing in mind the high variable ground cover and the inherent variability of the biome composition, which cannot be properly represented in the Landsat moderate spatial resolution. In this study, we tested the potential of the SEBAL model application in a complex natural ecosystem. This modeling approach will be used to represent the spatial dynamics of ET, which will be integrated into further environmental and hydrological applications. |
BibTeX:
@article{Awada2021,
author = {Awada, Hassan and Di Prima, Simone and Sirca, Costantino and Giadrossich, Filippo and Marras, Serena and Spano, Donatella and Pirastru, Mario},
title = {Daily Actual Evapotranspiration Estimation in a Mediterranean Ecosystem from Landsat Observations Using SEBAL Approach},
journal = {Forests},
year = {2021},
volume = {12},
number = {2},
url = {https://www.mdpi.com/1999-4907/12/2/189},
doi = {10.3390/f12020189}
}
|
| Badraghi A, Ventura M, Polo A, Borruso L, Giammarchi F and Montagnani L (2021), "Soil respiration variation along an altitudinal gradient in the Italian Alps: Disentangling forest structure and temperature effects", PLOS ONE., aug, 2021. Vol. 16(8), pp. e0247893. Public Library of Science. |
| Abstract: On the mountains, along an elevation gradient, we generally observe an ample variation in temperature, with the associated difference in vegetation structure and composition and soil properties. With the aim of quantifying the relative importance of temperature, vegetation and edaphic properties on soil respiration (SR), we investigated changes in SR along an elevation gradient (404 to 2101 m a.s.l) in the southern slopes of the Alps in Northern Italy. We also analysed soil physicochemical properties, including soil organic carbon (SOC) and nitrogen (N) stocks, fine root C and N, litter C and N, soil bulk densities and soil pH at five forest sites, and also stand structural properties, including vegetation height, age and basal area. Our results indicated that SR rates increased with temperature in all sites, and 55–76% of SR variability was explained by temperature. Annual cumulative SR, ranging between 0.65–1.40 kg C m-2 yr-1, decreased along the elevation gradient, while temperature sensitivity (Q10) of SR increased with elevation. However, a high SR rate (1.27 kg C m-2 yr-1) and low Q10 were recorded in the mature conifer forest stand at 1731 m a.s.l., characterized by an uneven-aged structure and high dominant tree height, resulting in a nonlinear relationship between elevation and temperature. Reference SR at 10°C (SRref) was unrelated to elevation, but was related to tree height. A significant negative linear relationship was found between bulk density and elevation. Conversely, SOC, root C and N stock, pH, and litter mass were best fitted by nonlinear relationships with elevation. However, these parameters were not significantly correlated with SR when the effect of temperature was removed (SRref). These results demonstrate that the main factor affecting SR in forest ecosystems along this Alpine elevation gradient is temperature, but its regulating role can be strongly influenced by site biological characteristics, particularly vegetation type and structure, affecting litter quality and microclimate. This study also confirms that high elevation sites are rich in SOC and more sensitive to climate change, being prone to high C losses as CO2. Furthermore, our data indicate a positive relationship between Q10 and dominant tree height, suggesting that mature forest ecosystems characterized by an uneven-age structure, high SRref and moderate Q10, may be more resilient. |
BibTeX:
@article{Badraghi2021,
author = {Badraghi, Aysan and Ventura, Maurizio and Polo, Andrea and Borruso, Luigimaria and Giammarchi, Francesco and Montagnani, Leonardo},
title = {Soil respiration variation along an altitudinal gradient in the Italian Alps: Disentangling forest structure and temperature effects},
journal = {PLOS ONE},
publisher = {Public Library of Science},
year = {2021},
volume = {16},
number = {8},
pages = {e0247893},
url = {https://doi.org/10.1371/journal.pone.0247893}
}
|
| Bai Y, Zhang S, Zhang J, Wang J, Yang S, Magliulo V, Vitale L and Zhao Y (2021), "Using remote sensing information to enhance the understanding of the coupling of terrestrial ecosystem evapotranspiration and photosynthesis on a global scale", International Journal of Applied Earth Observation and Geoinformation. Vol. 100, pp. 102329. |
| Abstract: Understanding the coupling of terrestrial ecosystem evapotranspiration (ET) and photosynthesis (gross primary productivity, GPP) is limited by inherent difficulties to provide accurate approximations of transpiration (T) and leaf-to-air vapor pressure difference (D) that is a key variable needed to define the stomata behaviors in generic methods. To address the issues and better characterize the ET-GPP relationship, we developed a novel remote sensing (RS)-driven approach (RCEEP) based on the underlying water use efficiency (uWUE) method (termed uWUE-Model). RCEEP partitions T from ET using the RS-derived fraction (rsFt) of T in ET and then links T and GPP via RS-derived canopy conductance (rsGc) instead of D. RCEEP, the original uWUE-Model, and two other uWUE-based versions (RT or RG) that only incorporate rsFt or rsGc were adjusted using the calibration data, and then inter-compared in terms of their performances (Nash-Sutcliffe efficiency, NSE) in estimating GPP from ET on a daily and monthly scale for both calibration and validation datasets — two subsets of data from 177 flux sites covering 11 biome types over the globe. Results revealed better performances of RT and RG as compared to uWUE-Model over most biomes, implying remarkable contributions of rsFt and rsGc to a more meaningful relationship between ET and GPP. RCEEP yielded the best performances over all biome types except for evergreen forest with reasonable mean NSE values of 0.67 – 0.68 (0.75) on a daily (monthly) scale. Further comparisons between RCEEP and two existing approaches concerning estimating GPP from ET revealed consistently better performances of RCEEP and thus, positive implications of introducing rsFt and rsGc in bridging ecosystem ET and GPP. Besides, rsFt should be used combined with rsGc to avoid degraded effectiveness for specific biome types (Savannah and Woody Savannah). These results are promising in view of improving or developing algorithms on coupled estimates of ecosystem ET and GPP and understanding the GPP dynamics concerning ET on a global scale. |
BibTeX:
@article{Bai2021,
author = {Bai, Yun and Zhang, Sha and Zhang, Jiahua and Wang, Jingwen and Yang, Shanshan and Magliulo, Vincenzo and Vitale, Luca and Zhao, Yanchuang},
title = {Using remote sensing information to enhance the understanding of the coupling of terrestrial ecosystem evapotranspiration and photosynthesis on a global scale},
journal = {International Journal of Applied Earth Observation and Geoinformation},
year = {2021},
volume = {100},
pages = {102329},
url = {https://www.sciencedirect.com/science/article/pii/S0303243421000362},
doi = {10.1016/j.jag.2021.102329}
}
|
| Bassiouni M and Vico G (2021), "Parsimony vs predictive and functional performance of three stomatal optimization principles in a big-leaf framework", New Phytologist., jul, 2021. Vol. 231(2), pp. 586-600. John Wiley & Sons, Ltd. |
| Abstract: Summary Stomatal optimization models can improve estimates of water and carbon fluxes with relatively low complexity, yet there is no consensus on which formulations are most appropriate for ecosystem-scale applications. We implemented three existing analytical equations for stomatal conductance, based on different water penalty functions, in a big-leaf comparison framework, and determined which optimization principles were most consistent with flux tower observations from different biomes. We used information theory to dissect controls of soil water supply and atmospheric demand on evapotranspiration in wet to dry conditions and to quantify missing or inadequate information in model variants. We ranked stomatal optimization principles based on parameter uncertainty, parsimony, predictive accuracy, and functional accuracy of the interactions between soil moisture, vapor pressure deficit, and evapotranspiration. Performance was high for all model variants. Water penalty functions with explicit representation of plant hydraulics did not substantially improve predictive or functional accuracy of ecosystem-scale evapotranspiration estimates, and parameterizations were more uncertain, despite having physiological underpinnings at the plant level. Stomatal optimization based on water use efficiency thus provided more information about ecosystem-scale evapotranspiration compared to those based on xylem vulnerability and proved more useful in improving ecosystem-scale models with less complexity. |
BibTeX:
@article{Bassiouni2021,
author = {Bassiouni, Maoya and Vico, Giulia},
title = {Parsimony vs predictive and functional performance of three stomatal optimization principles in a big-leaf framework},
journal = {New Phytologist},
publisher = {John Wiley & Sons, Ltd},
year = {2021},
volume = {231},
number = {2},
pages = {586--600},
url = {https://doi.org/10.1111/nph.17392},
doi = {10.1111/nph.17392}
}
|
| Bates JS, Montzka C, Schmidt M and Jonard F (2021), "Estimating Canopy Density Parameters Time-Series for Winter Wheat Using UAS Mounted LiDAR", Remote Sensing. Vol. 13(4) |
| Abstract: Monitoring of canopy density with related metrics such as leaf area index (LAI) makes a significant contribution to understanding and predicting processes in the soil–plant–atmosphere system and to indicating crop health and potential yield for farm management. Remote sensing methods using optical sensors that rely on spectral reflectance to calculate LAI have become more mainstream due to easy entry and availability. Methods with vegetation indices (VI) based on multispectral reflectance data essentially measure the green area index (GAI) or response to chlorophyll content of the canopy surface and not the entire aboveground biomass that may be present from non-green elements that are key to fully assessing the carbon budget. Methods with light detection and ranging (LiDAR) have started to emerge using gap fraction (GF) to estimate the plant area index (PAI) based on canopy density. These LiDAR methods have the main advantage of being sensitive to both green and non-green plant elements. They have primarily been applied to forest cover with manned airborne LiDAR systems (ALS) and have yet to be used extensively with crops such as winter wheat using LiDAR on unmanned aircraft systems (UAS). This study contributes to a better understanding of the potential of LiDAR as a tool to estimate canopy structure in precision farming. The LiDAR method proved to have a high to moderate correlation in spatial variation to the multispectral method. The LiDAR-derived PAI values closely resemble the SunScan Ceptometer GAI ground measurements taken early in the growing season before major stages of senescence. Later in the growing season, when the canopy density was at its highest, a possible overestimation may have occurred. This was most likely due to the chosen flight parameters not providing the best depictions of canopy density with consideration of the LiDAR's perspective, as the ground-based destructive measurements provided lower values of PAI. Additionally, a distinction between total LiDAR-derived PAI, multispectral-derived GAI, and brown area index (BAI) is made to show how the active and passive optical sensor methods used in this study can complement each other throughout the growing season. |
BibTeX:
@article{Bates2021,
author = {Bates, Jordan Steven and Montzka, Carsten and Schmidt, Marius and Jonard, François},
title = {Estimating Canopy Density Parameters Time-Series for Winter Wheat Using UAS Mounted LiDAR},
journal = {Remote Sensing},
year = {2021},
volume = {13},
number = {4},
url = {https://www.mdpi.com/2072-4292/13/4/710},
doi = {10.3390/rs13040710}
}
|
| Becker M, Olsen A and Reverdin G (2021), "In-air one-point calibration of oxygen optodes in underway systems", Limnology and Oceanography: Methods., may, 2021. Vol. 19(5), pp. 293-302. John Wiley & Sons, Ltd. |
| Abstract: Abstract Ships of opportunity are a frequently used platform in surface ocean carbon observations and estimating the annual ocean carbon sink. For understanding the drivers behind changes in the ocean carbon system, oxygen measurements alongside the carbon dioxide measurements can be a valuable tool. We developed an in-air calibration system for oxygen optodes in underway systems. The regular measurements of atmospheric oxygen enable us to correct for sensor drift and biofouling. This new system can help to obtain reliable oxygen data from underway applications, especially if the vessel is not easily accessible and a frequent recalibration of the optode is not feasible. |
BibTeX:
@article{Becker2021,
author = {Becker, Meike and Olsen, Are and Reverdin, Gilles},
title = {In-air one-point calibration of oxygen optodes in underway systems},
journal = {Limnology and Oceanography: Methods},
publisher = {John Wiley & Sons, Ltd},
year = {2021},
volume = {19},
number = {5},
pages = {293--302},
url = {https://doi.org/10.1002/lom3.10423},
doi = {10.1002/lom3.10423}
}
|
| Bengtsson F, Rydin H, Baltzer JL, Bragazza L, Bu Z-J, Caporn SJM, Dorrepaal E, Flatberg KI, Galanina O, Gałka M, Ganeva A, Goia I, Goncharova N, Hájek M, Haraguchi A, Harris LI, Humphreys E, Jiroušek M, Kajukało K, Karofeld E, Koronatova NG, Kosykh NP, Laine AM, Lamentowicz M, Lapshina E, Limpens J, Linkosalmi M, Ma J-Z, Mauritz M, Mitchell EAD, Munir TM, Natali SM, Natcheva R, Payne RJ, Philippov DA, Rice SK, Robinson S, Robroek BJM, Rochefort L, Singer D, Stenøien HK, Tuittila E-S, Vellak K, Waddington JM and Granath G (2021), "Environmental drivers of Sphagnum growth in peatlands across the Holarctic region", Journal of Ecology., jan, 2021. Vol. 109(1), pp. 417-431. John Wiley & Sons, Ltd. |
| Abstract: Abstract The relative importance of global versus local environmental factors for growth and thus carbon uptake of the bryophyte genus Sphagnum?the main peat-former and ecosystem engineer in northern peatlands?remains unclear. We measured length growth and net primary production (NPP) of two abundant Sphagnum species across 99 Holarctic peatlands. We tested the importance of previously proposed abiotic and biotic drivers for peatland carbon uptake (climate, N deposition, water table depth and vascular plant cover) on these two responses. Employing structural equation models (SEMs), we explored both indirect and direct effects of drivers on Sphagnum growth. Variation in growth was large, but similar within and between peatlands. Length growth showed a stronger response to predictors than NPP. Moreover, the smaller and denser Sphagnum fuscum growing on hummocks had weaker responses to climatic variation than the larger and looser Sphagnum magellanicum growing in the wetter conditions. Growth decreased with increasing vascular plant cover within a site. Between sites, precipitation and temperature increased growth for S. magellanicum. The SEMs indicate that indirect effects are important. For example, vascular plant cover increased with a deeper water table, increased nitrogen deposition, precipitation and temperature. These factors also influenced Sphagnum growth indirectly by affecting moss shoot density. Synthesis. Our results imply that in a warmer climate, S. magellanicum will increase length growth as long as precipitation is not reduced, while S. fuscum is more resistant to decreased precipitation, but also less able to take advantage of increased precipitation and temperature. Such species-specific sensitivity to climate may affect competitive outcomes in a changing environment, and potentially the future carbon sink function of peatlands. |
BibTeX:
@article{Bengtsson2021,
author = {Bengtsson, Fia and Rydin, Håkan and Baltzer, Jennifer L and Bragazza, Luca and Bu, Zhao-Jun and Caporn, Simon J M and Dorrepaal, Ellen and Flatberg, Kjell Ivar and Galanina, Olga and Gałka, Mariusz and Ganeva, Anna and Goia, Irina and Goncharova, Nadezhda and Hájek, Michal and Haraguchi, Akira and Harris, Lorna I and Humphreys, Elyn and Jiroušek, Martin and Kajukało, Katarzyna and Karofeld, Edgar and Koronatova, Natalia G and Kosykh, Natalia P and Laine, Anna M and Lamentowicz, Mariusz and Lapshina, Elena and Limpens, Juul and Linkosalmi, Maiju and Ma, Jin-Ze and Mauritz, Marguerite and Mitchell, Edward A D and Munir, Tariq M and Natali, Susan M and Natcheva, Rayna and Payne, Richard J and Philippov, Dmitriy A and Rice, Steven K and Robinson, Sean and Robroek, Bjorn J M and Rochefort, Line and Singer, David and Stenøien, Hans K and Tuittila, Eeva-Stiina and Vellak, Kai and Waddington, James Michael and Granath, Gustaf},
title = {Environmental drivers of Sphagnum growth in peatlands across the Holarctic region},
journal = {Journal of Ecology},
publisher = {John Wiley & Sons, Ltd},
year = {2021},
volume = {109},
number = {1},
pages = {417--431},
url = {https://doi.org/10.1111/1365-2745.13499},
doi = {10.1111/1365-2745.13499}
}
|
| Boas T, Bogena H, Grünwald T, Heinesch B, Ryu D, Schmidt M, Vereecken H, Western A and Franssen HJH (2021), "Improving the representation of cropland sites in the Community Land Model (CLM) version 5.0", Geoscientific Model Development. Vol. 14(1), pp. 573-601. |
| Abstract: The incorporation of a comprehensive crop module in land surface models offers the possibility to study the effect of agricultural land use and land management changes on the terrestrial water, energy, and biogeochemical cycles. It may help to improve the simulation of biogeophysical and biogeochemical processes on regional and global scales in the framework of climate and land use change. In this study, the performance of the crop module of the Community Land Model version 5 (CLM5) was evaluated at point scale with site-specific field data focusing on the simulation of seasonal and inter-annual variations in crop growth, planting and harvesting cycles, and crop yields, as well as water, energy, and carbon fluxes. In order to better represent agricultural sites, the model was modified by (1) implementing the winter wheat subroutines following Lu et al. (2017) in CLM5; (2) implementing plant-specific parameters for sugar beet, potatoes, and winter wheat, thereby adding the two crop functional types (CFTs) for sugar beet and potatoes to the list of actively managed crops in CLM5; and (3) introducing a cover-cropping subroutine that allows multiple crop types on the same column within 1 year. The latter modification allows the simulation of cropping during winter months before usual cash crop planting begins in spring, which is an agricultural management technique with a long history that is regaining popularity as it reduces erosion and improves soil health and carbon storage and is commonly used in the regions evaluated in this study. We compared simulation results with field data and found that both the new crop-specific parameterization and the winter wheat subroutines led to a significant simulation improvement in terms of energy fluxes (root-mean-square error, RMSE, reduction for latent and sensible heat by up to 57 % and 59 %, respectively), leaf area index (LAI), net ecosystem exchange, and crop yield (up to 87 % improvement in winter wheat yield prediction) compared with default model results. The cover-cropping subroutine yielded a substantial improvement in representation of field conditions after harvest of the main cash crop (winter season) in terms of LAI magnitudes, seasonal cycle of LAI, and latent heat flux (reduction of wintertime RMSE for latent heat flux by 42 %). Our modifications significantly improved model simulations and should therefore be applied in future studies with CLM5 to improve regional yield predictions and to better understand large-scale impacts of agricultural management on carbon, water, and energy fluxes. |
BibTeX:
@article{Boas2021,
author = {Boas, Theresa and Bogena, Heye and Grünwald, Thomas and Heinesch, Bernard and Ryu, Dongryeol and Schmidt, Marius and Vereecken, Harry and Western, Andrew and Franssen, Harrie Jan Hendricks},
title = {Improving the representation of cropland sites in the Community Land Model (CLM) version 5.0},
journal = {Geoscientific Model Development},
year = {2021},
volume = {14},
number = {1},
pages = {573--601},
doi = {10.5194/gmd-14-573-2021}
}
|
| Brovkina O, Hanuš J and Novotný J (2021), "Airborne remote sensing for forest inventory attributes assessment: experience of Flying Laboratory of Imaging Systems (FLIS) in the Czech Republic", IOP Conference Series: Earth and Environmental Science. Vol. 806(1), pp. 12005. IOP Publishing. |
| Abstract: The paper contributes to the recent studies for forest inventory attributes assessment from airborne data using experience of Flying Laboratory of Imaging Systems (FLIS).The advanced methods of airborne hyperspectral and laser scanning data processing are summarized to demonstrate the applicability of FLIS in assessment of forest inventory attributes for tree and plot levels in selected forest areas in the Czech Republic. Specifically, assessments of tree height, tree position, crown base, crown width, aboveground biomass, species composition, dead trees, and health status are presented. |
BibTeX:
@article{Brovkina2021,
author = {Brovkina, O and Hanuš, J and Novotný, J},
title = {Airborne remote sensing for forest inventory attributes assessment: experience of Flying Laboratory of Imaging Systems (FLIS) in the Czech Republic},
journal = {IOP Conference Series: Earth and Environmental Science},
publisher = {IOP Publishing},
year = {2021},
volume = {806},
number = {1},
pages = {12005},
url = {http://dx.doi.org/10.1088/1755-1315/806/1/012005},
doi = {10.1088/1755-1315/806/1/012005}
}
|
| Brunner C, Brem BT, Collaud Coen M, Conen F, Hervo M, Henne S, Steinbacher M, Gysel-Beer M and Kanji ZA (2021), "The contribution of Saharan dust to the ice-nucleating particle concentrations at the High Altitude Station Jungfraujoch (3580,m,a.s.l.), Switzerland", Atmospheric Chemistry and Physics. Vol. 21(23), pp. 18029-18053. |
BibTeX:
@article{Brunner2021,
author = {Brunner, C and Brem, B T and Collaud Coen, M and Conen, F and Hervo, M and Henne, S and Steinbacher, M and Gysel-Beer, M and Kanji, Z A},
title = {The contribution of Saharan dust to the ice-nucleating particle concentrations at the High Altitude Station Jungfraujoch (3580,m,a.s.l.), Switzerland},
journal = {Atmospheric Chemistry and Physics},
year = {2021},
volume = {21},
number = {23},
pages = {18029--18053},
url = {https://acp.copernicus.org/articles/21/18029/2021/},
doi = {10.5194/acp-21-18029-2021}
}
|
| Bukowiecki N, Brem BT, Wehrle G, Močnik G, Affolter S, Leuenberger M, Coen MC, Hervo M, Baltensperger U and Gysel-Beer M (2021), "Elucidating local pollution and site representativeness at the Jungfraujoch, Switzerland through parallel aerosol measurements at an adjacent mountain ridge", Environmental Research Communications. Vol. 3(2), pp. 21001. IOP Publishing. |
| Abstract: Many long-term air pollution and climate monitoring stations face the issue of increasing anthropogenic activities in their vicinity. Furthermore, the spatial representativeness of the sites is often not entirely understood especially in mountainous terrain with complex topographic features. This study presents a 5-year comparison of parallel aerosol measurements (total particle number concentration and equivalent black carbon mass concentration) at the Jungfraujoch in the Swiss Alps (JFJ, 3580 m a.s.l.), and an adjacent mountain ridge, the Jungfrau East Ridge (JER, 3705 m a.s.l.), in 1000 m air-line distance to the main site. The parallel aerosol measurements reveal characteristic differences in the diurnal variations between the two sites under certain specific meteorological conditions. Our analysis estimates that on 20%–40% of the days local activities at the Jungfraujoch have a clear influence on the measured time series of the total aerosol number concentration and the equivalent black carbon mass concentration. This influence is mainly seen in form of strong isolated spikes rather than by an increase in the on-site background concentration. They can thus be flagged during the data quality assurance process and filtered from those measurement parameters available at high time resolution. Removing the spikes from the original time series results in daily mean values for the total aerosol number concentration and equivalent black carbon mass concentration that are 5%–10% lower compared to the original signals. During nighttime with hardly any local pollution sources that cause spikes this percentage decreases towards 0%. The signal baselines at the Jungfraujoch and Jungfrau East Ridge correlate well during more than 50% of the days. |
BibTeX:
@article{Bukowiecki2021,
author = {Bukowiecki, Nicolas and Brem, Benjamin T and Wehrle, Günther and Močnik, Griša and Affolter, Stéphane and Leuenberger, Markus and Coen, Martine Collaud and Hervo, Maxime and Baltensperger, Urs and Gysel-Beer, Martin},
title = {Elucidating local pollution and site representativeness at the Jungfraujoch, Switzerland through parallel aerosol measurements at an adjacent mountain ridge},
journal = {Environmental Research Communications},
publisher = {IOP Publishing},
year = {2021},
volume = {3},
number = {2},
pages = {21001},
url = {http://dx.doi.org/10.1088/2515-7620/abe987},
doi = {10.1088/2515-7620/abe987}
}
|
| Cael BB, Bisson K, Conte M, Duret MT, Follett CL, Henson SA, Honda MC, Iversen MH, Karl DM, Lampitt RS, Mouw CB, Muller-Karger F, Pebody CA, Smith Jr. KL and Talmy D (2021), "Open Ocean Particle Flux Variability From Surface to Seafloor", Geophysical Research Letters., may, 2021. Vol. 48(9), pp. e2021GL092895. John Wiley & Sons, Ltd. |
| Abstract: Abstract The sinking of carbon fixed via net primary production (NPP) into the ocean interior is an important part of marine biogeochemical cycles. NPP measurements follow a log-normal probability distribution, meaning NPP variations can be simply described by two parameters despite NPP's complexity. By analyzing a global database of open ocean particle fluxes, we show that this log-normal probability distribution propagates into the variations of near-seafloor fluxes of particulate organic carbon (POC), calcium carbonate, and opal. Deep-sea particle fluxes at subtropical and temperate time-series sites follow the same log-normal probability distribution, strongly suggesting the log-normal description is robust and applies on multiple scales. This log-normality implies that 29% of the highest measurements are responsible for 71% of the total near-seafloor POC flux. We discuss possible causes for the dampening of variability from NPP to deep-sea POC flux, and present an updated relationship predicting POC flux from mineral flux and depth. |
BibTeX:
@article{Cael2021,
author = {Cael, B B and Bisson, Kelsey and Conte, Maureen and Duret, Manon T and Follett, Christopher L and Henson, Stephanie A and Honda, Makio C and Iversen, Morten H and Karl, David M and Lampitt, Richard S and Mouw, Colleen B and Muller-Karger, Frank and Pebody, Corinne A and Smith Jr., Kenneth L and Talmy, David},
title = {Open Ocean Particle Flux Variability From Surface to Seafloor},
journal = {Geophysical Research Letters},
publisher = {John Wiley & Sons, Ltd},
year = {2021},
volume = {48},
number = {9},
pages = {e2021GL092895},
url = {https://doi.org/10.1029/2021GL092895},
doi = {10.1029/2021GL092895}
}
|
| Cai Z, Junttila S, Holst J, Jin H, Ardö J, Ibrom A, Peichl M, Mölder M, Jönsson P, Rinne J, Karamihalaki M and Eklundh L (2021), "Modelling Daily Gross Primary Productivity with Sentinel-2 Data in the Nordic Region–Comparison with Data from MODIS", Remote Sensing., jan, 2021. Vol. 13(3), pp. 469. |
| Abstract: The high-resolution Sentinel-2 data potentially enable the estimation of gross primary productivity (GPP) at finer spatial resolution by better capturing the spatial variation in a heterogeneous landscapes. This study investigates the potential of 10 m resolution reflectance from the Sentinel-2 Multispectral Instrument to improve the accuracy of GPP estimation across Nordic vegetation types, compared with the 250 m and 500 m resolution reflectance from the Moderate Resolution Imaging Spectroradiometer (MODIS). We applied linear regression models with inputs of two-band enhanced vegetation index (EVI2) derived from Sentinel-2 and MODIS reflectance, respectively, together with various environmental drivers to estimate daily GPP at eight Nordic eddy covariance (EC) flux tower sites. Compared with the GPP from EC measurements, the accuracies of modelled GPP were generally high (R2 = 0.84 for Sentinel-2; R2 = 0.83 for MODIS), and the differences between Sentinel-2 and MODIS were minimal. This demonstrates the general consistency in GPP estimates based on the two satellite sensor systems at the Nordic regional scale. On the other hand, the model accuracy did not improve by using the higher spatial-resolution Sentinel-2 data. More analyses of different model formulations, more tests of remotely sensed indices and biophysical parameters, and analyses across a wider range of geographical locations and times will be required to achieve improved GPP estimations from Sentinel-2 satellite data. |
BibTeX:
@article{Cai2021,
author = {Cai, Zhanzhang and Junttila, Sofia and Holst, Jutta and Jin, Hongxiao and Ardö, Jonas and Ibrom, Andreas and Peichl, Matthias and Mölder, Meelis and Jönsson, Per and Rinne, Janne and Karamihalaki, Maria and Eklundh, Lars},
title = {Modelling Daily Gross Primary Productivity with Sentinel-2 Data in the Nordic Region–Comparison with Data from MODIS},
journal = {Remote Sensing},
year = {2021},
volume = {13},
number = {3},
pages = {469},
url = {https://www.mdpi.com/2072-4292/13/3/469},
doi = {10.3390/rs13030469}
}
|
| Campeau A, Vachon D, Bishop K, Nilsson MB and Wallin MB (2021), "Autumn destabilization of deep porewater CO2 store in a northern peatland driven by turbulent diffusion", Nature Communications. Vol. 12(1), pp. 6857. |
| Abstract: The deep porewater of northern peatlands stores large amounts of carbon dioxide (CO2). This store is viewed as a stable feature in the peatland CO2 cycle. Here, we report large and rapid fluctuations in deep porewater CO2 concentration recurring every autumn over four consecutive years in a boreal peatland. Estimates of the vertical diffusion of heat indicate that CO2 diffusion occurs at the turbulent rather than molecular rate. The weakening of porewater thermal stratification in autumn likely increases turbulent diffusion, thus fostering a rapid diffusion of deeper porewater CO2 towards the surface where net losses occur. This phenomenon periodically decreases the peat porewater CO2 store by between 29 and 90 g C m−2 throughout autumn, which is comparable to the peatland's annual C-sink. Our results establish the need to consider the role of turbulent diffusion in regularly destabilizing the CO2 store in peat porewater. |
BibTeX:
@article{Campeau2021,
author = {Campeau, A and Vachon, D and Bishop, K and Nilsson, M B and Wallin, M B},
title = {Autumn destabilization of deep porewater CO2 store in a northern peatland driven by turbulent diffusion},
journal = {Nature Communications},
year = {2021},
volume = {12},
number = {1},
pages = {6857},
url = {https://doi.org/10.1038/s41467-021-27059-0},
doi = {10.1038/s41467-021-27059-0}
}
|
| Chan SS, Seidenfaden IK, Jensen KH and Sonnenborg TO (2021), "Climate change impacts and uncertainty on spatiotemporal variations of drought indices for an irrigated catchment", Journal of Hydrology. Vol. 601, pp. 126814. |
| Abstract: Droughts are responsible for severe vegetation loss and declining agricultural yields. As future climate change projections imply an increased risk of extreme events, the occurrence of droughts is potentially accelerating in the future. The influence of climate change on drought events in a Danish agricultural catchment under the emission scenario RCP8.5 are evaluated by three different drought indices covering soil moisture, groundwater and streamflow deficits. The indices are based on results from a hydrological model forced by downscaled climate outputs from 16 Euro-CORDEX climate models (GCM-RCMs), while considering uncertainties among climate model projections. The hydrological model demonstrated a satisfactory ability in modelling historical drought characteristics. The results from the future projections showed that the intensity and frequency of droughts increased towards the end of the century. The spatial patterns of changes in drought were found to be highly dependent on the climate model results, index formulations and assumptions, as well as the hydrogeological properties of the catchment. Groundwater based irrigation in the agricultural areas effectively mitigates soil moisture drought, leading to lower future uncertainty of the ensemble mean (higher model agreement) for soil moisture droughts at irrigated locations. This is obtained at the cost of lower groundwater levels in both reference and future periods resulting in larger uncertainties on the simulated groundwater droughts, because of the addition of irrigation uncertainty. While the joint impact of greater groundwater abstraction and changing dynamics of precipitation and groundwater recharge also leads to larger streamflow variability between model combinations (standard deviation) under RCP8.5 for the downstream discharge station. |
BibTeX:
@article{Chan2021,
author = {Chan, San Shing and Seidenfaden, Ida Karlsson and Jensen, Karsten Høgh and Sonnenborg, Torben Obel},
title = {Climate change impacts and uncertainty on spatiotemporal variations of drought indices for an irrigated catchment},
journal = {Journal of Hydrology},
year = {2021},
volume = {601},
pages = {126814},
url = {https://www.sciencedirect.com/science/article/pii/S0022169421008647},
doi = {10.1016/j.jhydrol.2021.126814}
}
|
| Chang K-Y, Riley WJ, Knox SH, Jackson RB, McNicol G, Poulter B, Aurela M, Baldocchi D, Bansal S, Bohrer G, Campbell DI, Cescatti A, Chu H, Delwiche KB, Desai AR, Euskirchen E, Friborg T, Goeckede M, Helbig M, Hemes KS, Hirano T, Iwata H, Kang M, Keenan T, Krauss KW, Lohila A, Mammarella I, Mitra B, Miyata A, Nilsson MB, Noormets A, Oechel WC, Papale D, Peichl M, Reba ML, Rinne J, Runkle BRK, Ryu Y, Sachs T, Schäfer KVR, Schmid HP, Shurpali N, Sonnentag O, Tang ACI, Torn MS, Trotta C, Tuittila E-S, Ueyama M, Vargas R, Vesala T, Windham-Myers L, Zhang Z and Zona D (2021), "Substantial hysteresis in emergent temperature sensitivity of global wetland CH4 emissions", Nature Communications., dec, 2021. Vol. 12(1), pp. 2266. |
| Abstract: Wetland methane (CH 4 ) emissions ( F_CH_4 F C H 4 ) are important in global carbon budgets and climate change assessments. Currently, F_CH_4 F C H 4 projections rely on prescribed static temperature sensitivity that varies among biogeochemical models. Meta-analyses have proposed a consistent F_CH_4 F C H 4 temperature dependence across spatial scales for use in models; however, site-level studies demonstrate that F_CH_4 F C H 4 are often controlled by factors beyond temperature. Here, we evaluate the relationship between F_CH_4 F C H 4 and temperature using observations from the FLUXNET-CH 4 database. Measurements collected across the globe show substantial seasonal hysteresis between F_CH_4 F C H 4 and temperature, suggesting larger F_CH_4 F C H 4 sensitivity to temperature later in the frost-free season (about 77% of site-years). Results derived from a machine-learning model and several regression models highlight the importance of representing the large spatial and temporal variability within site-years and ecosystem types. Mechanistic advancements in biogeochemical model parameterization and detailed measurements in factors modulating CH 4 production are thus needed to improve global CH 4 budget assessments. |
BibTeX:
@article{Chang2021,
author = {Chang, Kuang-Yu and Riley, William J and Knox, Sara H and Jackson, Robert B and McNicol, Gavin and Poulter, Benjamin and Aurela, Mika and Baldocchi, Dennis and Bansal, Sheel and Bohrer, Gil and Campbell, David I and Cescatti, Alessandro and Chu, Housen and Delwiche, Kyle B and Desai, Ankur R and Euskirchen, Eugenie and Friborg, Thomas and Goeckede, Mathias and Helbig, Manuel and Hemes, Kyle S and Hirano, Takashi and Iwata, Hiroki and Kang, Minseok and Keenan, Trevor and Krauss, Ken W and Lohila, Annalea and Mammarella, Ivan and Mitra, Bhaskar and Miyata, Akira and Nilsson, Mats B and Noormets, Asko and Oechel, Walter C and Papale, Dario and Peichl, Matthias and Reba, Michele L and Rinne, Janne and Runkle, Benjamin R K and Ryu, Youngryel and Sachs, Torsten and Schäfer, Karina V R and Schmid, Hans Peter and Shurpali, Narasinha and Sonnentag, Oliver and Tang, Angela C I and Torn, Margaret S and Trotta, Carlo and Tuittila, Eeva-Stiina and Ueyama, Masahito and Vargas, Rodrigo and Vesala, Timo and Windham-Myers, Lisamarie and Zhang, Zhen and Zona, Donatella},
title = {Substantial hysteresis in emergent temperature sensitivity of global wetland CH4 emissions},
journal = {Nature Communications},
year = {2021},
volume = {12},
number = {1},
pages = {2266},
url = {http://www.nature.com/articles/s41467-021-22452-1},
doi = {10.1038/s41467-021-22452-1}
}
|
| Choler P, Bayle A, Carlson BZ, Randin C, Filippa G and Cremonese E (2021), "The tempo of greening in the European Alps: Spatial variations on a common theme", Global Change Biology., nov, 2021. Vol. 27(21), pp. 5614-5628. John Wiley & Sons, Ltd. |
| Abstract: Abstract The long-term increase in satellite-based proxies of vegetation cover is a well-documented response of seasonally snow-covered ecosystems to climate warming. However, observed greening trends are far from uniform, and substantial uncertainty remains concerning the underlying causes of this spatial variability. Here, we processed surface reflectance of the moderate resolution imaging spectroradiometer (MODIS) to investigate trends and drivers of changes in the annual peak values of the Normalized Difference Vegetation Index (NDVI). Our study focuses on above-treeline ecosystems in the European Alps. NDVI changes in these ecosystems are highly sensitive to land cover and biomass changes and are marginally affected by anthropogenic disturbances. We observed widespread greening for the 2000?2020 period, a pattern that is consistent with the overall increase in summer temperature. At the local scale, the spatial variability of greening was mainly due to the preferential response of north-facing slopes between 1900 and 2400 m. Using high-resolution imagery, we noticed that the presence of screes and outcrops locally magnified this response. At the regional scale, we identified hotspots of greening where vegetation cover is sparser than expected given the elevation and exposure. Most of these hotspots experienced delayed snow melt and green-up dates in recent years. We conclude that the ongoing greening in the Alps primarily reflects the high responsiveness of sparsely vegetated ecosystems that are able to benefit the most from temperature and water-related habitat amelioration above treeline. |
BibTeX:
@article{Choler2021,
author = {Choler, Philippe and Bayle, Arthur and Carlson, Bradley Z and Randin, Christophe and Filippa, Gianluca and Cremonese, Edoardo},
title = {The tempo of greening in the European Alps: Spatial variations on a common theme},
journal = {Global Change Biology},
publisher = {John Wiley & Sons, Ltd},
year = {2021},
volume = {27},
number = {21},
pages = {5614--5628},
url = {https://doi.org/10.1111/gcb.15820},
doi = {10.1111/gcb.15820}
}
|
| Christensen TR (2021), "Arctic Permafrost and Ecosystem Functioning". feb, 2021. |
| Abstract: Summary Permafrost underlies most of the Arctic land mass. The two main climatic parameters that determine the presence or absence of permafrost are air temperature and precipitation (especially in the form of snow). No species is dependent on permafrost, and on a circumarctic scale no ecosystems are restricted by the existence of permafrost because both tundra ecosystems and boreal forest scan occur in the presence or absence of permafrost. One catastrophic impact of changing vegetation on permafrost is likely to be an increased frequency of fires. Wildfire is a major disturbance in the Arctic tundra and boreal forests, which has a significant impact on soil hydrology, carbon cycling, and permafrost dynamics. Thawing permafrost is associated with gradual or episodic disturbance (slumping) of the land surface that can affect large areas. Periglacial processes change land surfaces, which can in turn affect ecosystem function. |
BibTeX:
@misc{Christensen2021,
author = {Christensen, Torben R},
title = {Arctic Permafrost and Ecosystem Functioning},
booktitle = {Arctic Ecology},
year = {2021},
pages = {81--101},
url = {https://doi.org/10.1002/9781118846582.ch4},
doi = {10.1002/9781118846582.ch4}
}
|
| Conte A, Otu-Larbi F, Alivernini A, Hoshika Y, Paoletti E, Ashworth K and Fares S (2021), "Exploring new strategies for ozone-risk assessment: A dynamic-threshold case study", Environmental Pollution. Vol. 287, pp. 117620. |
| Abstract: Tropospheric ozone is a dangerous atmospheric pollutant for forest ecosystems when it penetrates stomata. Thresholds for ozone-risk assessment are based on accumulated stomatal ozone fluxes such as the Phytotoxic Ozone Dose (POD). In order to identify the effect of ozone on a Holm oak forest in central Italy, four flux-based ozone impact response functions were implemented and tested in a multi-layer canopy model AIRTREE and evaluated against Gross Primary Productivity (GPP) obtained from observations of Eddy Covariance fluxes of CO2. To evaluate if a clear phytotoxic threshold exists and if it changes during the year, six different detoxifying thresholds ranging between 0 and 5 nmol O3 m−2 s−1 were tested. The use of species-specific rather than more general response functions based on plant functional types (PFT) increased model accuracy (RMSE reduced by up to 8.5%). In the case of linear response functions, a threshold of 1 nmol m−2 s−2 produced the best results for simulations of the whole year, although the tolerance to ozone changed seasonally, with higher tolerance (5 nmol m−2 s−1 or no ozone impact) for Winter and Spring and lower thresholds in Summer and Fall (0–1 nmol m−2 s−1). A “dynamic threshold” obtained by extracting the best daily threshold values from a range of different simulations helped reduce model overestimation of GPP by 213 g C m−2 y−1 and reduce RMSE up to 7.7%. Finally, a nonlinear ozone correction based on manipulative experiments produced the best results when no detoxifying threshold was applied (0 nmol O3 m−2 s−1), suggesting that nonlinear functions fully account for ozone detoxification. The evidence of seasonal changes in ozone tolerance points to the need for seasonal thresholds to predict ozone damage and highlights the importance of performing more species-specific manipulative experiments to derive response functions for a broad range of plant species. |
BibTeX:
@article{Conte2021,
author = {Conte, A and Otu-Larbi, F and Alivernini, A and Hoshika, Y and Paoletti, E and Ashworth, K and Fares, S},
title = {Exploring new strategies for ozone-risk assessment: A dynamic-threshold case study},
journal = {Environmental Pollution},
year = {2021},
volume = {287},
pages = {117620},
url = {https://www.sciencedirect.com/science/article/pii/S0269749121012021},
doi = {10.1016/j.envpol.2021.117620}
}
|
| Crill P, Wik M and Jansen J (2021), "Temperatures in subarctic lakes on the Stordalen Mire, Abisko, Northern Sweden". |
BibTeX:
@misc{Crill2021,
author = {Crill, Patrick and Wik, Martin and Jansen, Joachim},
title = {Temperatures in subarctic lakes on the Stordalen Mire, Abisko, Northern Sweden},
publisher = {Bolin Centre Database},
year = {2021},
url = {https://bolin.su.se/data/stordalen-lake-temperatures-4},
doi = {10.17043/STORDALEN-LAKE-TEMPERATURES-4}
}
|
| Cristofanelli P, Gutiérrez I, Adame JA, Bonasoni P, Busetto M, Calzolari F, Putero D and Roccato F (2021), "Interannual and seasonal variability of NOx observed at the Mt. Cimone GAW/WMO global station (2165 m a.s.l., Italy)", Atmospheric Environment. Vol. 249, pp. 118245. |
| Abstract: In this work, we present and analyze a dataset of near-surface NO and NO2 observations carried out at the Mt. Cimone WMO/GAW global station (CMN, Italy, 2165 m a.s.l.) from 2015 to 2019. The purpose of this work is to provide a first characterization of NO and NO2 variability over different time scales, as well as to obtain preliminary information about transport processes able to affect the observed variability. NO was characterized by a peak in February–March (mean value: 0.08 ppb), while in summer the typical levels were near or lower than the detection limit. NO2 values maximized in winter (0.32–0.37 ppb) and minimized in summer (0.21 ppb in June). The evident NO and NO2 diel cycles point towards a joint role of vertical transport of air masses from the regional planetary boundary layer (PBL) and photochemistry. We combined nighttime observations (less affected by direct transport from the regional PBL) and 3D back-trajectories, calculated by the FLEXTRA model (2015 -2018), to analyze how long-range atmospheric circulation could impact NO2 observations. Even if some caveats should be considered when commenting results from back-trajectory analysis (i.e. NOx removal by oxidation processes not represented, possible residual impact of regional PBL air masses, impact of adding/removing a single year from the analysis), some robust outcomes can be considered: the atmospheric transport from northern Africa and the Mediterranean basin was tagged to baseline NO2 values, while the highest values were related to atmospheric circulation overpassing central/western Europe (spring) and North Italy (spring and summer). Less robust relationship were found between high NO2 values and air masses passing over central/western Europe (winter) and eastern Europe (winter and summer). On the other side, mountain thermal wind regime represents an important process for the occurrence of high NO2 events by transporting polluted air masses from the regional PBL to CMN. Our analysis suggested that it is not possible to define a unique set of O3/NOx threshold values able to discriminate the photochemical ages of air masses as done in previous studies; these values must be tuned as a function of the season and, possibly, of the measurement site. Finally, we segregated CMN observations as a function of conditions representative for the presence of free tropospheric- or PBL-affected air masses: higher NOx were observed under conditions representative for the transport of air masses from the regional PBL; the differences between the two regimes are maximized in winter for NO and in summer-autumn for NO2. |
BibTeX:
@article{Cristofanelli2021,
author = {Cristofanelli, P and Gutiérrez, I and Adame, J A and Bonasoni, P and Busetto, M and Calzolari, F and Putero, D and Roccato, F},
title = {Interannual and seasonal variability of NOx observed at the Mt. Cimone GAW/WMO global station (2165 m a.s.l., Italy)},
journal = {Atmospheric Environment},
year = {2021},
volume = {249},
pages = {118245},
url = {https://www.sciencedirect.com/science/article/pii/S1352231021000637},
doi = {10.1016/j.atmosenv.2021.118245}
}
|
| Cristofanelli P, Arduni J, Serva F, Calzolari F, Bonasoni P, Busetto M, Maione M, Sprenger M, Trisolino P and Putero D (2021), "Negative ozone anomalies at a high mountain site in northern Italy during 2020: a possible role of COVID-19 lockdowns?", Environmental Research Letters. Vol. 16(7), pp. 74029. IOP Publishing. |
| Abstract: Several studies investigated the possible impacts of the restriction measures related to the containment of the spread of the COrona VIrus Disease (COVID-19) to atmospheric ozone (O3) at global, regional, and local scales during 2020. O3 is a secondary pollutant with adverse effects on population health and ecosystems and with negative impacts on climate, acting as greenhouse gas. Most of these studies focused on spring 2020 (i.e. March–May) and on observations in the planetary boundary layer (PBL), mostly in the vicinity of urban agglomerates. Here, we analyzed the variability of O3 above the PBL of northern Italy in 2020 by using continuous observations carried out at a high mountain WMO/GAW global station in Italy (Mt. Cimone–CMN; 44°12′ N, 10°42′ E, 2165 m a.s.l.). Low O3 monthly anomalies were observed during spring (MAM) and summer (JJA), when periods of low O3 intertwined with periods with higher O3, within climatological ranges. A similar variability was observed for O3 precursors like NO2 and 15 anthropogenic non-methane volatile organic carbons, but the systematic O3 anomalies were not reflected in these variables. The analysis of meteorological variables and diel O3 cycles did not suggest major changes in the vertical transport related to the thermal circulation system in the mountain area. The analysis of five days back-trajectories suggested that the observed O3 anomalies cannot be explained by differences in the synoptic-scale circulation with respect to the previous years alone. On the other hand, the characterization of two transport patterns (i.e. air masses from the regional PBL or from the free troposphere) and the analysis of back-trajectories suggested an important contribution of transport from the continental PBL during the periods with the lowest O3 at CMN. When proxies of air mass transport from the regional PBL are considered, a lower NO x content was pointed out with respect to the previous years, suggesting a lower O3 production in a NO x -limited atmosphere. Our study suggested for the first time that, during MAM and JJA 2020, the reduced anthropogenic emissions related to the COVID-19 restrictions lowered the amount of this short-lived climate forcer/pollutant at remote locations above the PBL over northern Italy. This work suggests the importance of limiting anthropogenic precursor emissions for decreasing the O3 amount at remote locations and in upper atmospheric layers. |
BibTeX:
@article{Cristofanelli2021a,
author = {Cristofanelli, Paolo and Arduni, Jgor and Serva, Federico and Calzolari, Francescopiero and Bonasoni, Paolo and Busetto, Maurizio and Maione, Michela and Sprenger, Michael and Trisolino, Pamela and Putero, Davide},
title = {Negative ozone anomalies at a high mountain site in northern Italy during 2020: a possible role of COVID-19 lockdowns?},
journal = {Environmental Research Letters},
publisher = {IOP Publishing},
year = {2021},
volume = {16},
number = {7},
pages = {74029},
url = {http://dx.doi.org/10.1088/1748-9326/ac0b6a},
doi = {10.1088/1748-9326/ac0b6a}
}
|
| Curbelo-Hernández D, González-Dávila M, González AG, González-Santana D and Santana-Casiano JM (2021), "CO2 fluxes in the Northeast Atlantic Ocean based on measurements from a surface ocean observation platform", Science of The Total Environment. Vol. 775, pp. 145804. |
| Abstract: The seasonal and spatial variability of the CO2 system parameters and CO2 air-sea exchange were studied in the Northeast Atlantic Ocean between the northwest African coastal upwelling and the oligotrophic open-ocean waters of the North Atlantic subtropical gyre. Data was collected aboard a volunteer observing ship from February 2019 to February 2020. The seasonal and spatial variability of CO2 fugacity in seawater (fCO2,sw) was strongly driven by the seasonal temperature variation, which increased with latitude and was lower throughout the year in coastal regions where the upwelling and offshore transport was more intense. The thermal to biological effect ratio (T/B) was approximately 2, with minimum values along the African coastline related to higher biological activity in the upwelled waters. The fCO2,sw increased from winter to summer by 11.84 ± 0.28 μatm°C−1 on the inter-island routes and by 11.71 ± 0.25 μatm°C−1 along the northwest African continental shelf. The seasonality of total inorganic carbon normalized to constant salinity of 36.7 (NCT) was studied throughout the region. The effect of biological processes and calcification/dissolution on NCT between February and October represented >90% of the reduction of inorganic carbon while air-sea exchange described <6%. The seasonality of air-sea CO2 exchange was controlled by temperature. The surface waters of the entire region acted as a CO2 sink during the cold months and as a CO2 source during the warm months. The Canary basin acted as a net sink of −0.26 ± 0.04 molC m−2 yr−1. The northwest African continental shelf behaved as a stronger sink at −0.48 ± 0.09 molC m−2 yr−1. The calculated average CO2 flux for the entire area was −2.65 ± 0.44 TgCO2 yr−1 (−0.72 ± 0.12 TgC yr−1). |
BibTeX:
@article{CurbeloHernandez2021,
author = {Curbelo-Hernández, D and González-Dávila, M and González, A G and González-Santana, D and Santana-Casiano, J M},
title = {CO2 fluxes in the Northeast Atlantic Ocean based on measurements from a surface ocean observation platform},
journal = {Science of The Total Environment},
year = {2021},
volume = {775},
pages = {145804},
url = {https://www.sciencedirect.com/science/article/pii/S0048969721008718},
doi = {10.1016/j.scitotenv.2021.145804}
}
|
| Curbelo-Hernández D, Santana-Casiano JM, González AG and González-Dávila M (2021), "Air-Sea CO2 Exchange in the Strait of Gibraltar", Frontiers in Marine Science. Vol. 8 |
| Abstract: The seasonal and spatial variability of the CO2 system and air-sea fluxes were studied in surface waters of the Strait of Gibraltar between February 2019 and March 2021. High-resolution data was collected by a surface ocean observation platform aboard a volunteer observing ship. The CO2 system was strongly influenced by temperature and salinity fluctuations forced by the seasonal and spatial variability in the depth of the Atlantic–Mediterranean Interface layer and by the tidal and wind-induced upwelling. The changes in seawater CO2 fugacity (fCO2,sw) and fluxes were mainly driven by temperature despite the significant influence of non-thermal processes in the southernmost part. The thermal to non-thermal effect ratio (T/B) reached maximum values in the northern section (>1.8) and minimum values in the southern section (<1.30). The fCO2,sw increased with temperature by 9.02 ± 1.99 μatm °C–1 (r2 = 0.86 and ρ = 0.93) and 4.51 ± 1.66 μatm °C–1 (r2 = 0.48 and ρ = 0.69) in the northern and southern sections, respectively. The annual cycle of total inorganic carbon normalized to a constant salinity of 36.7 (NCT) was assessed. Net community production processes described 93.5–95.6% of the total NCT change, while air-sea exchange and horizontal and vertical advection accounted for <4.6%. The fCO2,sw in the Strait of Gibraltar since 1999 has been fitted to an equation with an interannual trend of 2.35 ± 0.06 μatm year–1 and a standard error of estimate of ±12.8 μatm. The seasonality of the air-sea CO2 fluxes reported the behavior as a strong CO2 sink during the cold months and as a weak CO2 source during the warm months. Both the northern and the southern sections acted as a net CO2 sink of −0.82 and −1.01 mol C m–2 year–1, respectively. The calculated average CO2 flux for the entire area was −7.12 Gg CO2 year–1 (−1.94 Gg C year–1). |
BibTeX:
@article{CurbeloHernandez2021a,
author = {Curbelo-Hernández, David and Santana-Casiano, J Magdalena and González, Aridane González and González-Dávila, Melchor},
title = {Air-Sea CO2 Exchange in the Strait of Gibraltar},
journal = {Frontiers in Marine Science},
year = {2021},
volume = {8},
url = {https://www.frontiersin.org/article/10.3389/fmars.2021.745304},
doi = {10.3389/fmars.2021.745304}
}
|
| Dacre HF, Western LM, Say D, O’Doherty S, Arnold T, Rennick C and Hawkins E (2021), "Detectability of COVID-19 global emissions reductions in local CO2 concentration measurements", Environmental Research Letters., September, 2021. Vol. 16(9), pp. 094043. IOP Publishing. |
BibTeX:
@article{Dacre2021,
author = {Dacre, H F and Western, L M and Say, D and O’Doherty, S and Arnold, T and Rennick, C and Hawkins, E},
title = {Detectability of COVID-19 global emissions reductions in local CO2 concentration measurements},
journal = {Environmental Research Letters},
publisher = {IOP Publishing},
year = {2021},
volume = {16},
number = {9},
pages = {094043},
doi = {10.1088/1748-9326/ac1eda}
}
|
| Dare-Idowu O, Jarlan L, Le-Dantec V, Rivalland V, Ceschia E, Boone A and Brut A (2021), "Hydrological Functioning of Maize Crops in Southwest France Using Eddy Covariance Measurements and a Land Surface Model". |
| Abstract: The primary objective of this study is to evaluate the representation of the energy budget for irrigated maize crops in soil–vegetation–atmosphere transfer (SVAT) models. To this end, a comparison between the original version of the interactions between the soil–biosphere–atmosphere (ISBA) model based on a single-surface energy balance and the new ISBA-multi-energy balance (ISBA-MEB) option was carried out. The second objective is to analyze the intra- and inter-seasonal variability of the crop water budget by implementing ISBA and ISBA-MEB over six irrigated maize seasons between 2008 and 2019 in Lamasquère, southwest France. Seasonal dynamics of the convective fluxes were properly reproduced by both models with R2 ranging between 0.66 and 0.80 (RMSE less than 59 W m−2) for the sensible heat flux and between 0.77 and 0.88 (RMSE less than 59 W m−2) for the latent heat flux. Statistical metrics also showed that over the six crop seasons, for the turbulent fluxes, ISBA-MEB was consistently in better agreement with the in situ measurements with RMSE 8–30% lower than ISBA, particularly when the canopy was heterogeneous. The ability of both models to partition the evapotranspiration (ET) term between soil evaporation and plant transpiration was also acceptable as transpiration predictions compared very well with the available sap flow measurements during the summer of 2015; (ISBA-MEB had slightly better statistics than ISBA with R2 of 0.91 and a RMSE value of 0.07 mm h−1). Finally, the results from the analysis of the inter-annual variability of the crop water budget can be summarized as follows: (1) The partitioning of the ET revealed a strong year-to-year variability with transpiration ranging between 40% and 67% of total ET, while soil evaporation was dominant in 2008 and 2010 due to the late and poor canopy development; (2) drainage losses are close to null because of an impervious layer at 60 cm depth; and (3) this very specific condition limited the inter-annual variability of irrigation scheduling as crops can always extract water that is stored in the root zone. |
BibTeX:
@misc{DareIdowu2021,
author = {Dare-Idowu, Oluwakemi and Jarlan, Lionel and Le-Dantec, Valerie and Rivalland, Vincent and Ceschia, Eric and Boone, Aaron and Brut, Aurore},
title = {Hydrological Functioning of Maize Crops in Southwest France Using Eddy Covariance Measurements and a Land Surface Model},
booktitle = {Water},
year = {2021},
volume = {13},
number = {11},
doi = {10.3390/w13111481}
}
|
| Darenova E, Kadavý J, Knott R, Kokrda L and Novotný J (2021), "Effect of tree harvest, silvopastoral practices, and microclimate conditions on forest floor CO2 efflux in a sessile oak (Quercus petraea agg. [Matt.] Liebl.) forest", Annals of Forest Science. Vol. 78(3), pp. 80. |
| Abstract: Forest floor CO2efflux (Rf; consisted of soil and potential vegetation) increased after forest harvest, but this response was changed by actual weather (especially drought and rains). |
BibTeX:
@article{Darenova2021,
author = {Darenova, Eva and Kadavý, Jan and Knott, Robert and Kokrda, Lukáš and Novotný, Jan},
title = {Effect of tree harvest, silvopastoral practices, and microclimate conditions on forest floor CO2 efflux in a sessile oak (Quercus petraea agg. [Matt.] Liebl.) forest},
journal = {Annals of Forest Science},
year = {2021},
volume = {78},
number = {3},
pages = {80},
url = {https://doi.org/10.1007/s13595-021-01101-z},
doi = {10.1007/s13595-021-01101-z}
}
|
| Delwiche KB, Knox SH, Malhotra A, Fluet-Chouinard E, McNicol G, Feron S, Ouyang Z, Papale D, Trotta C, Canfora E, Cheah Y-W, Christianson D, Alberto MCR, Alekseychik P, Aurela M, Baldocchi D, Bansal S, Billesbach DP, Bohrer G, Bracho R, Buchmann N, Campbell DI, Celis G, Chen J, Chen W, Chu H, Dalmagro HJ, Dengel S, Desai AR, Detto M, Dolman H, Eichelmann E, Euskirchen E, Famulari D, Fuchs K, Goeckede M, Gogo S, Gondwe MJ, Goodrich JP, Gottschalk P, Graham SL, Heimann M, Helbig M, Helfter C, Hemes KS, Hirano T, Hollinger D, Hörtnagl L, Iwata H, Jacotot A, Jurasinski G, Kang M, Kasak K, King J, Klatt J, Koebsch F, Krauss KW, Lai DYF, Lohila A, Mammarella I, Belelli Marchesini L, Manca G, Matthes JH, Maximov T, Merbold L, Mitra B, Morin TH, Nemitz E, Nilsson MB, Niu S, Oechel WC, Oikawa PY, Ono K, Peichl M, Peltola O, Reba ML, Richardson AD, Riley W, Runkle BRK, Ryu Y, Sachs T, Sakabe A, Sanchez CR, Schuur EA, Schäfer KVR, Sonnentag O, Sparks JP, Stuart-Haëntjens E, Sturtevant C, Sullivan RC, Szutu DJ, Thom JE, Torn MS, Tuittila E-S, Turner J, Ueyama M, Valach AC, Vargas R, Varlagin A, Vazquez-Lule A, Verfaillie JG, Vesala T, Vourlitis GL, Ward EJ, Wille C, Wohlfahrt G, Wong GX, Zhang Z, Zona D, Windham-Myers L, Poulter B and Jackson RB (2021), "FLUXNET-CH_4: a global, multi-ecosystem dataset and analysis of methane seasonality from freshwater wetlands", Earth System Science Data. Vol. 13(7), pp. 3607-3689. |
BibTeX:
@article{Delwiche2021,
author = {Delwiche, K B and Knox, S H and Malhotra, A and Fluet-Chouinard, E and McNicol, G and Feron, S and Ouyang, Z and Papale, D and Trotta, C and Canfora, E and Cheah, Y.-W. and Christianson, D and Alberto, Ma. C R and Alekseychik, P and Aurela, M and Baldocchi, D and Bansal, S and Billesbach, D P and Bohrer, G and Bracho, R and Buchmann, N and Campbell, D I and Celis, G and Chen, J and Chen, W and Chu, H and Dalmagro, H J and Dengel, S and Desai, A R and Detto, M and Dolman, H and Eichelmann, E and Euskirchen, E and Famulari, D and Fuchs, K and Goeckede, M and Gogo, S and Gondwe, M J and Goodrich, J P and Gottschalk, P and Graham, S L and Heimann, M and Helbig, M and Helfter, C and Hemes, K S and Hirano, T and Hollinger, D and Hörtnagl, L and Iwata, H and Jacotot, A and Jurasinski, G and Kang, M and Kasak, K and King, J and Klatt, J and Koebsch, F and Krauss, K W and Lai, D Y F and Lohila, A and Mammarella, I and Belelli Marchesini, L and Manca, G and Matthes, J H and Maximov, T and Merbold, L and Mitra, B and Morin, T H and Nemitz, E and Nilsson, M B and Niu, S and Oechel, W C and Oikawa, P Y and Ono, K and Peichl, M and Peltola, O and Reba, M L and Richardson, A D and Riley, W and Runkle, B R K and Ryu, Y and Sachs, T and Sakabe, A and Sanchez, C R and Schuur, E A and Schäfer, K V R and Sonnentag, O and Sparks, J P and Stuart-Haëntjens, E and Sturtevant, C and Sullivan, R C and Szutu, D J and Thom, J E and Torn, M S and Tuittila, E.-S. and Turner, J and Ueyama, M and Valach, A C and Vargas, R and Varlagin, A and Vazquez-Lule, A and Verfaillie, J G and Vesala, T and Vourlitis, G L and Ward, E J and Wille, C and Wohlfahrt, G and Wong, G X and Zhang, Z and Zona, D and Windham-Myers, L and Poulter, B and Jackson, R B},
title = {FLUXNET-CH_4: a global, multi-ecosystem dataset and analysis of methane seasonality from freshwater wetlands},
journal = {Earth System Science Data},
year = {2021},
volume = {13},
number = {7},
pages = {3607--3689},
url = {https://essd.copernicus.org/articles/13/3607/2021/},
doi = {10.5194/essd-13-3607-2021}
}
|
| Demol M, Calders K, Krishna Moorthy SM, Van den Bulcke J, Verbeeck H and Gielen B (2021), "Consequences of vertical basic wood density variation on the estimation of aboveground biomass with terrestrial laser scanning", Trees. Vol. 35(2), pp. 671-684. |
| Abstract: Stump-to-tip trends in basic wood density complicate the conversion of tree volume into aboveground biomass. We use 3D tree models from terrestrial laser scanning to obtain tree-level volume-weighted wood density. |
BibTeX:
@article{Demol2021,
author = {Demol, Miro and Calders, Kim and Krishna Moorthy, Sruthi M and Van den Bulcke, Jan and Verbeeck, Hans and Gielen, Bert},
title = {Consequences of vertical basic wood density variation on the estimation of aboveground biomass with terrestrial laser scanning},
journal = {Trees},
year = {2021},
volume = {35},
number = {2},
pages = {671--684},
url = {https://doi.org/10.1007/s00468-020-02067-7},
doi = {10.1007/s00468-020-02067-7}
}
|
| Demol M, Calders K, Verbeeck H and Gielen B (2021), "Forest above-ground volume assessments with terrestrial laser scanning: a ground-truth validation experiment in temperate, managed forests", Annals of Botany., nov, 2021. Vol. 128(6), pp. 805-819. |
| Abstract: Quantifying the Earth's forest above-ground biomass (AGB) is indispensable for effective climate action and developing forest policy. Yet, current allometric scaling models (ASMs) to estimate AGB suffer several drawbacks related to model selection and uncertainties about calibration data traceability. Terrestrial laser scanning (TLS) offers a promising non-destructive alternative. Tree volume is reconstructed from TLS point clouds with quantitative structure models (QSMs) and converted to AGB with wood basic density. Earlier studies have found overall TLS-derived forest volume estimates to be accurate, but highlighted problems for reconstructing finer branches. Our objective was to evaluate TLS for estimating tree volumes by comparison with reference volumes and volumes from ASMs.We quantified the woody volume of 65 trees in Belgium (from 77 to 2800 L; Pinus sylvestris, Fagus sylvatica, Larix decidua, and Fraxinus excelsior) with QSMs and destructive reference measurements. We tested a volume expansion factor (VEF) approach by multiplying the solid and merchantable volume from QSMs by literature VEF values.Stem volume was reliably estimated with TLS. Total volume was overestimated by +21 % using original QSMs, by +9 % and –12 % using two sets of VEF-augmented QSMs, and by –7.3 % using best-available ASMs. The most accurate method differed per site, and the prediction errors for each method varied considerably between sites.VEF-augmented QSMs were only slightly better than original QSMs for estimating tree volume for common species in temperate forests. Despite satisfying estimates with ASMs, the model choice was a large source of uncertainty, and species-specific models did not always exist. Therefore, we advocate for further improving tree volume reconstructions with QSMs, especially for fine branches, instead of collecting more ground-truth data to calibrate VEF and allometric models. Promising developments such as improved co-registration and smarter filtering approaches are ongoing to further constrain volumetric errors in TLS-derived estimates. |
BibTeX:
@article{Demol2021a,
author = {Demol, Miro and Calders, Kim and Verbeeck, Hans and Gielen, Bert},
title = {Forest above-ground volume assessments with terrestrial laser scanning: a ground-truth validation experiment in temperate, managed forests},
journal = {Annals of Botany},
year = {2021},
volume = {128},
number = {6},
pages = {805--819},
url = {https://doi.org/10.1093/aob/mcab110},
doi = {10.1093/aob/mcab110}
}
|
| Derwent RG, Simmonds PG, O’Doherty SJ, Spain TG and Young D (2021), "Natural greenhouse gas and ozone-depleting substance sources and sinks from the peat bogs of Connemara, Ireland from 1994–2020", Environmental Science: Atmospheres. Vol. 1(6), pp. 406-415. Royal Society of Chemistry (RSC). |
BibTeX:
@article{Derwent2021,
author = {Derwent, Richard G. and Simmonds, Peter G. and O’Doherty, Simon J. and Spain, T. Gerard and Young, D.},
title = {Natural greenhouse gas and ozone-depleting substance sources and sinks from the peat bogs of Connemara, Ireland from 1994–2020},
journal = {Environmental Science: Atmospheres},
publisher = {Royal Society of Chemistry (RSC)},
year = {2021},
volume = {1},
number = {6},
pages = {406--415},
doi = {10.1039/d1ea00040c}
}
|
| Dimitriou K, Bougiatioti A, Ramonet M, Pierros F, Michalopoulos P, Liakakou E, Solomos S, Quehe P-Y, Delmotte M, Gerasopoulos E, Kanakidou M and Mihalopoulos N (2021), "Greenhouse gases (CO2 and CH4) at an urban background site in Athens, Greece: Levels, sources and impact of atmospheric circulation", Atmospheric Environment. Vol. 253, pp. 118372. |
| Abstract: Year-round carbon dioxide (CO2) and methane (CH4) concentration measurements, performed for the first time in the city of Athens, Greece from December 21, 2018 to December 31, 2019, are presented in this study and analyzed in relation to atmospheric circulation patterns at a local, regional and long-range transport scale. Clear diurnal and seasonal variations of both greenhouse gases were detected. The observed increased levels during night and early morning hours are attributed to traffic/heating emissions and leakages of residential natural gas for CO2 and CH4, respectively. Using CO2 and CH4 levels simultaneously measured at the regional background site at Finokalia (Greece), increments in their levels due to local and regional anthropogenic sources within the city were assessed. For CO2, maximum and minimum increments were clearly observed during winter and summer respectively, suggesting a greater impact of combustion of fossil fuel and especially of biomass on CO2 levels during winter. On the other hand, CH4 increments were similar in all seasons, suggesting that local sources of CH4 remain quite constant year-round. Through the implementation of the Conditional Probability Function (CPF), the emission sources of theses greenhouse gases have been localized to the northern and the eastern domains of the Athens basin. Stagnant atmospheric conditions were also associated with an increased likelihood of CO2 and CH4 episodes. Backward modeling simulations with FLEXPART and HYSPLIT models indicate an industrial zone and a petrochemical zone, situated to the north and to the west of Athens respectively, as possible CH4 regional sources as well as possible CO2 contributions from southern directions attributed to shipping emissions from the port of Piraeus. The present study provides knowledge needed for the determination of greenhouse gas emission mitigation strategies in Athens. |
BibTeX:
@article{Dimitriou2021,
author = {Dimitriou, K and Bougiatioti, A and Ramonet, M and Pierros, F and Michalopoulos, P and Liakakou, E and Solomos, S and Quehe, P.-Y. and Delmotte, M and Gerasopoulos, E and Kanakidou, M and Mihalopoulos, N},
title = {Greenhouse gases (CO2 and CH4) at an urban background site in Athens, Greece: Levels, sources and impact of atmospheric circulation},
journal = {Atmospheric Environment},
year = {2021},
volume = {253},
pages = {118372},
url = {https://www.sciencedirect.com/science/article/pii/S1352231021001916},
doi = {10.1016/j.atmosenv.2021.118372}
}
|
| Dogniaux M, Crevoisier C, Armante R, Capelle V, Delahaye T, Cassé V, De Mazière M, Deutscher NM, Feist DG, Garcia OE, Griffith DWT, Hase F, Iraci LT, Kivi R, Morino I, Notholt J, Pollard DF, Roehl CM, Shiomi K, Strong K, Té Y, Velazco VA and Warneke T (2021), "The Adaptable 4A Inversion (5AI): description and first X_CO_2 retrievals from Orbiting Carbon Observatory-2 (OCO-2) observations", Atmospheric Measurement Techniques. Vol. 14(6), pp. 4689-4706. |
BibTeX:
@article{Dogniaux2021,
author = {Dogniaux, M and Crevoisier, C and Armante, R and Capelle, V and Delahaye, T and Cassé, V and De Mazière, M and Deutscher, N M and Feist, D G and Garcia, O E and Griffith, D W T and Hase, F and Iraci, L T and Kivi, R and Morino, I and Notholt, J and Pollard, D F and Roehl, C M and Shiomi, K and Strong, K and Té, Y and Velazco, V A and Warneke, T},
title = {The Adaptable 4A Inversion (5AI): description and first X_CO_2 retrievals from Orbiting Carbon Observatory-2 (OCO-2) observations},
journal = {Atmospheric Measurement Techniques},
year = {2021},
volume = {14},
number = {6},
pages = {4689--4706},
url = {https://amt.copernicus.org/articles/14/4689/2021/},
doi = {10.5194/amt-14-4689-2021}
}
|
| Dombrowski O, Hendricks Franssen H-J, Brogi C and Bogena HR (2021), "Performance of the ATMOS41 All-in-One Weather Station for Weather Monitoring", Sensors. Vol. 21(3) |
| Abstract: Affordable and accurate weather monitoring systems are essential in low-income and developing countries and, more recently, are needed in small-scale research such as precision agriculture and urban climate studies. A variety of low-cost solutions are available on the market, but the use of non-standard technologies raises concerns for data quality. Research-grade all-in-one weather stations could present a reliable, cost effective solution while being robust and easy to use. This study evaluates the performance of the commercially available ATMOS41 all-in-one weather station. Three stations were deployed next to a high-performance reference station over a three-month period. The ATMOS41 stations showed good performance compared to the reference, and close agreement among the three stations for most standard weather variables. However, measured atmospheric pressure showed uncertainties >0.6 hPa and solar radiation was underestimated by 3%, which could be corrected with a locally obtained linear regression function. Furthermore, precipitation measurements showed considerable variability, with observed differences of ±7.5% compared to the reference gauge, which suggests relatively high susceptibility to wind-induced errors. Overall, the station is well suited for private user applications such as farming, while the use in research should consider the limitations of the station, especially regarding precise precipitation measurements. |
BibTeX:
@article{Dombrowski2021,
author = {Dombrowski, Olga and Hendricks Franssen, Harrie-Jan and Brogi, Cosimo and Bogena, Heye Reemt},
title = {Performance of the ATMOS41 All-in-One Weather Station for Weather Monitoring},
journal = {Sensors},
year = {2021},
volume = {21},
number = {3},
url = {https://www.mdpi.com/1424-8220/21/3/741},
doi = {10.3390/s21030741}
}
|
| Dorigo W, Himmelbauer I, Aberer D, Schremmer L, Petrakovic I, Zappa L, Preimesberger W, Xaver A, Annor F, Ardö J, Baldocchi D, Bitelli M, Blöschl G, Bogena H, Brocca L, Calvet J-C, Camarero JJ, Capello G, Choi M, Cosh MC, van de Giesen N, Hajdu I, Ikonen J, Jensen KH, Kanniah KD, de Kat I, Kirchengast G, Kumar Rai P, Kyrouac J, Larson K, Liu S, Loew A, Moghaddam M, Mart\inez Fernández J, Mattar Bader C, Morbidelli R, Musial JP, Osenga E, Palecki MA, Pellarin T, Petropoulos GP, Pfeil I, Powers J, Robock A, Rüdiger C, Rummel U, Strobel M, Su Z, Sullivan R, Tagesson T, Varlagin A, Vreugdenhil M, Walker J, Wen J, Wenger F, Wigneron JP, Woods M, Yang K, Zeng Y, Zhang X, Zreda M, Dietrich S, Gruber A, van Oevelen P, Wagner W, Scipal K, Drusch M and Sabia R (2021), "The International Soil Moisture Network: serving Earth system science for over a decade", Hydrology and Earth System Sciences. Vol. 25(11), pp. 5749-5804. |
BibTeX:
@article{Dorigo2021,
author = {Dorigo, W and Himmelbauer, I and Aberer, D and Schremmer, L and Petrakovic, I and Zappa, L and Preimesberger, W and Xaver, A and Annor, F and Ardö, J and Baldocchi, D and Bitelli, M and Blöschl, G and Bogena, H and Brocca, L and Calvet, J.-C. and Camarero, J J and Capello, G and Choi, M and Cosh, M C and van de Giesen, N and Hajdu, I and Ikonen, J and Jensen, K H and Kanniah, K D and de Kat, I and Kirchengast, G and Kumar Rai, P and Kyrouac, J and Larson, K and Liu, S and Loew, A and Moghaddam, M and Mart\inez Fernández, J and Mattar Bader, C and Morbidelli, R and Musial, J P and Osenga, E and Palecki, M A and Pellarin, T and Petropoulos, G P and Pfeil, I and Powers, J and Robock, A and Rüdiger, C and Rummel, U and Strobel, M and Su, Z and Sullivan, R and Tagesson, T and Varlagin, A and Vreugdenhil, M and Walker, J and Wen, J and Wenger, F and Wigneron, J P and Woods, M and Yang, K and Zeng, Y and Zhang, X and Zreda, M and Dietrich, S and Gruber, A and van Oevelen, P and Wagner, W and Scipal, K and Drusch, M and Sabia, R},
title = {The International Soil Moisture Network: serving Earth system science for over a decade},
journal = {Hydrology and Earth System Sciences},
year = {2021},
volume = {25},
number = {11},
pages = {5749--5804},
url = {https://hess.copernicus.org/articles/25/5749/2021/},
doi = {10.5194/hess-25-5749-2021}
}
|
| Doro L, Wang X, Ammann C, De Antoni Migliorati M, Grünwald T, Klumpp K, Loubet B, Pattey E, Wohlfahrt G, Williams JR and Norfleet ML (2021), "Improving the simulation of soil temperature within the EPIC model", Environmental Modelling & Software. Vol. 144, pp. 105140. |
| Abstract: Soil temperature is a key driver of several physical, chemical, and biological processes. The Environmental Policy Integrated Climate (EPIC) is a comprehensive ecosystem model that simulates soil temperature dynamics using a cosine function approach driven by daily air temperature and average annual soil temperature at damping depth, which may erroneously predict lower soil temperatures in winter. A new cosine model and a pseudo-heat-transfer model were therefore developed and implemented for simulating soil temperature. The two methods were evaluated by comparing simulated daily soil temperatures with observed data at 24 study sites. Results showed that the two new methods had similar performance and the better statistical results obtained with these new methods demonstrated the ability to better predict the soil temperature for a wide range of pedoclimatic conditions, land management, and land uses. The main reason for the improved performance was due to a better prediction of soil temperature during the winter period. |
BibTeX:
@article{Doro2021,
author = {Doro, Luca and Wang, Xiuying and Ammann, Christof and De Antoni Migliorati, Massimiliano and Grünwald, Thomas and Klumpp, Katja and Loubet, Benjamin and Pattey, Elizabeth and Wohlfahrt, Georg and Williams, Jimmy R and Norfleet, M Lee},
title = {Improving the simulation of soil temperature within the EPIC model},
journal = {Environmental Modelling & Software},
year = {2021},
volume = {144},
pages = {105140},
url = {https://www.sciencedirect.com/science/article/pii/S1364815221001833},
doi = {10.1016/j.envsoft.2021.105140}
}
|
| Dumortier P, Gourlez de la Motte L, Andriamandroso ALH, Aubinet M, Beckers Y, Bindelle J, De Cock N, Lebeau F and Heinesch B (2021), "Beef cattle methane emission estimation using the eddy covariance technique in combination with geolocation", Agricultural and Forest Meteorology. Vol. 297, pp. 108249. |
| Abstract: Methane emissions of a grazing herd of Belgian Blue cattle were estimated per individual on the field by combining eddy covariance measurements with geolocation of the cattle and a footprint model. This method allows the measurement of outdoor non-invasive methane emissions but is complex and subject to methodological issues. Estimated emissions were 220 ±35 g CH4 LU−1 day−1 (grams of methane per livestock unit per day), where the uncertainty corresponds to the random error and does not include any possible systematic error. Cattle behavior was also monitored and presented a clear daily pattern of activity with more intense grazing after sunrise and before sunset. However, no significant methane emission pattern could be associated with it, the diurnal emission variation being lower than the measurement precision. |
BibTeX:
@article{Dumortier2021,
author = {Dumortier, P and Gourlez de la Motte, L and Andriamandroso, A L H and Aubinet, M and Beckers, Y and Bindelle, J and De Cock, N and Lebeau, F and Heinesch, B},
title = {Beef cattle methane emission estimation using the eddy covariance technique in combination with geolocation},
journal = {Agricultural and Forest Meteorology},
year = {2021},
volume = {297},
pages = {108249},
url = {https://www.sciencedirect.com/science/article/pii/S0168192320303518},
doi = {10.1016/j.agrformet.2020.108249}
}
|
| Dušek J, Nguyen VX, Le TX and Pavelka M (2021), "Methane and carbon dioxide emissions from different ecosystems at the end of dry period in South Vietnam", Tropical Ecology. Vol. 62(1), pp. 1-16. Springer India. |
| Abstract: The carbon cycle includes important fluxes of methane (CH4) and carbon dioxide (CO2) between the ecosystem and the atmosphere. The fluxes may acquire either positive (release) or negative values (consumption). We calculated these fluxes based on short-campaign in situ chamber measurements from four ecosystems of South Vietnam: intact mountain rain forest, rice field, Melaleuca forest and mangroves (different sites with Avicennia or Rhizophora and a typhoon-disturbed gap). Soil measurements were supplemented by chamber measurements of gas fluxes from the tree stems. Measuring CH4 and CO2 together facilitates the assessment of the ratio between these two gases in connection with current conditions and specificity of individual ecosystems. The highest fluxes of CH4 were recorded in the Melaleuca forest, being within the range from 356.7 to 784.2 mg CH4–C m−2 day−1 accompanied by higher fluxes of CH4 release from Melaleuca tree stems (8.0–262.1 mg CH4–C m−2 day−1). Significant negative soil fluxes of CH4 were recorded in the mountain rain forest, within the range from − 0.3 to − 0.8 mg CH4–C m−2 day−1. Fluxes of CO2 indicate prevailing aerobic activity in the soils of the ecosystems investigated. Quite a large variability of CO2 fluxes was recorded in the soil of the Avicennia mangroves. The in situ measurements of different ecosystems are fundamental for follow-up measurements at different levels such as aerial and satellite gas fluxes observations. |
BibTeX:
@article{Dusek2021,
author = {Dušek, Jiří and Nguyen, Vinh Xuan and Le, Thuyen Xuan and Pavelka, Marian},
title = {Methane and carbon dioxide emissions from different ecosystems at the end of dry period in South Vietnam},
journal = {Tropical Ecology},
publisher = {Springer India},
year = {2021},
volume = {62},
number = {1},
pages = {1--16},
url = {https://doi.org/10.1007/s42965-020-00118-1},
doi = {10.1007/s42965-020-00118-1}
}
|
| Dyukarev E, Zarov E, Alekseychik P, Nijp J, Filippova N, Mammarella I, Filippov I, Bleuten W, Khoroshavin V, Ganasevich G, Meshcheryakova A, Vesala T and Lapshina E (2021), "The Multiscale Monitoring of Peatland Ecosystem Carbon Cycling in the Middle Taiga Zone of Western Siberia: The Mukhrino Bog Case Study", Land. Vol. 10(8) |
| Abstract: The peatlands of the West Siberian Lowlands, comprising the largest pristine peatland area of the world, have not previously been covered by continuous measurement and monitoring programs. The response of peatlands to climate change occurs over several decades. This paper summarizes the results of peatland carbon balance studies collected over ten years at the Mukhrino field station (Mukhrino FS, MFS) operating in the Middle Taiga Zone of Western Siberia. A multiscale approach was applied for the investigations of peatland carbon cycling. Carbon dioxide fluxes at the local scale studied using the chamber method showed net accumulation with rates from 110, to 57.8 gC m−2 at the Sphagnum hollow site. Net CO2 fluxes at the pine-dwarf shrubs-Sphagnum ridge varied from negative (−32.1 gC m−2 in 2019) to positive (13.4 gC m−2 in 2017). The cumulative May-August net ecosystem exchange (NEE) from eddy-covariance (EC) measurements at the ecosystem scale was −202 gC m−2 in 2015, due to the impact of photosynthesis of pine trees which was not registered by the chamber method. The net annual accumulation of carbon in the live part of mosses was estimated at 24–190 gC m−2 depending on the Sphagnum moss species. Long-term carbon accumulation rates obtained by radiocarbon analysis ranged from 28.5 to 57.2 gC m−2 yr−1, with local extremes of up to 176.2 gC m−2 yr−1. The obtained estimates of various carbon fluxes using EC and chamber methods, the accounting for Sphagnum growth and decomposition, and long-term peat accumulation provided information about the functioning of the peatland ecosystems at different spatial and temporal scales. Multiscale carbon flux monitoring reveals useful new information for forecasting the response of northern peatland carbon cycles to climatic changes. |
BibTeX:
@article{Dyukarev2021,
author = {Dyukarev, Egor and Zarov, Evgeny and Alekseychik, Pavel and Nijp, Jelmer and Filippova, Nina and Mammarella, Ivan and Filippov, Ilya and Bleuten, Wladimir and Khoroshavin, Vitaly and Ganasevich, Galina and Meshcheryakova, Anastasiya and Vesala, Timo and Lapshina, Elena},
title = {The Multiscale Monitoring of Peatland Ecosystem Carbon Cycling in the Middle Taiga Zone of Western Siberia: The Mukhrino Bog Case Study},
journal = {Land},
year = {2021},
volume = {10},
number = {8},
url = {https://www.mdpi.com/2073-445X/10/8/824},
doi = {10.3390/land10080824}
}
|
| Emerson JB, Varner RK, Wik M, Parks DH, Neumann RB, Johnson JE, Singleton CM, Woodcroft BJ, Tollerson R, Owusu-Dommey A, Binder M, Freitas NL, Crill PM, Saleska SR, Tyson GW and Rich VI (2021), "Diverse sediment microbiota shape methane emission temperature sensitivity in Arctic lakes", Nature Communications. Vol. 12(1), pp. 5815. |
| Abstract: Northern post-glacial lakes are significant, increasing sources of atmospheric carbon through ebullition (bubbling) of microbially-produced methane (CH4) from sediments. Ebullitive CH4 flux correlates strongly with temperature, reflecting that solar radiation drives emissions. However, here we show that the slope of the temperature-CH4 flux relationship differs spatially across two post-glacial lakes in Sweden. We compared these CH4 emission patterns with sediment microbial (metagenomic and amplicon), isotopic, and geochemical data. The temperature-associated increase in CH4 emissions was greater in lake middles—where methanogens were more abundant—than edges, and sediment communities were distinct between edges and middles. Microbial abundances, including those of CH4-cycling microorganisms and syntrophs, were predictive of porewater CH4 concentrations. Results suggest that deeper lake regions, which currently emit less CH4 than shallower edges, could add substantially to CH4 emissions in a warmer Arctic and that CH4 emission predictions may be improved by accounting for spatial variations in sediment microbiota. |
BibTeX:
@article{Emerson2021,
author = {Emerson, Joanne B and Varner, Ruth K and Wik, Martin and Parks, Donovan H and Neumann, Rebecca B and Johnson, Joel E and Singleton, Caitlin M and Woodcroft, Ben J and Tollerson, Rodney and Owusu-Dommey, Akosua and Binder, Morgan and Freitas, Nancy L and Crill, Patrick M and Saleska, Scott R and Tyson, Gene W and Rich, Virginia I},
title = {Diverse sediment microbiota shape methane emission temperature sensitivity in Arctic lakes},
journal = {Nature Communications},
year = {2021},
volume = {12},
number = {1},
pages = {5815},
url = {https://doi.org/10.1038/s41467-021-25983-9},
doi = {10.1038/s41467-021-25983-9}
}
|
| Emmerichs T, Kerkweg A, Ouwersloot H, Fares S, Mammarella I and Taraborrelli D (2021), "A revised dry deposition scheme for land--atmosphere exchange of trace gases in ECHAM/MESSy v2.54", Geoscientific Model Development. Vol. 14(1), pp. 495-519. |
BibTeX:
@article{Emmerichs2021,
author = {Emmerichs, T and Kerkweg, A and Ouwersloot, H and Fares, S and Mammarella, I and Taraborrelli, D},
title = {A revised dry deposition scheme for land--atmosphere exchange of trace gases in ECHAM/MESSy v2.54},
journal = {Geoscientific Model Development},
year = {2021},
volume = {14},
number = {1},
pages = {495--519},
url = {https://gmd.copernicus.org/articles/14/495/2021/},
doi = {10.5194/gmd-14-495-2021}
}
|
| Ferrara RM, Carozzi M, Decuq C, Loubet B, Finco A, Marzuoli R, Gerosa G, Di Tommasi P, Magliulo V and Rana G (2021), "Ammonia, nitrous oxide, carbon dioxide, and water vapor fluxes after green manuring of faba bean under Mediterranean climate", Agriculture, Ecosystems & Environment. Vol. 315, pp. 107439. |
| Abstract: Green manuring of legume crops has increased in interest in recent years because of environmental and economic costs of synthetic fertilizers and need of sustainable cropping systems. Climatic conditions can reduce the agronomic and environmental effectiveness of green manuring promoting reactive nitrogen losses, or fostering soil heterotrophic respiration. This study aims to quantify ammonia and nitrous oxide losses, as well as carbon dioxide exchanges following green manuring of faba bean (Vicia faba spp. minor L.) under semi-arid climate conditions, typical of the Mediterranean basin. Ammonia emissions were measured by means of an aerodynamic gradient approach equipped with a multi-channel wet-denuder system (ROSAA), alongside with a concentration-based inverse dispersion modelling assessment. Nitrous oxide losses were measured with an automated chamber system, whereas carbon dioxide and water vapor exchanges were monitored jointly by means of eddy covariance technique. Ammonia volatilization lasted for three weeks and was triggered by the increase of soil water content due to rainfall, occurring 5 days after green manuring. Total emissions were 0.31% of the nitrogen supplied by green manuring (230 kg N ha−1). Nitrous oxide emissions from soil were of low intensity during the measurement period and were directly corelated to the water filled pore space. The biogeochemical model CERES-EGC was validated with the measurements of nitrous oxide, then used to reproduce the dynamic until the sowing of the succeeding crop. Cumulated emissions of nitrous oxide were 1% of the total nitrogen supplied. Soil became a net source both of carbon dioxide and water vapor soon after green manuring, with an emission of 900 kg C-CO2 ha−1 by heterotrophic respiration (23% of added carbon). In terms of water balance, 19 mm of water evaporated from soil surface, originated from the addition of fresh biomass. Green manuring proved to be a significant agronomic strategy to improve soil fertility, limiting reactive nitrogen and carbon losses to the atmosphere. |
BibTeX:
@article{Ferrara2021,
author = {Ferrara, Rossana Monica and Carozzi, Marco and Decuq, Céline and Loubet, Benjamin and Finco, Angelo and Marzuoli, Riccardo and Gerosa, Giacomo and Di Tommasi, Paul and Magliulo, Vincenzo and Rana, Gianfranco},
title = {Ammonia, nitrous oxide, carbon dioxide, and water vapor fluxes after green manuring of faba bean under Mediterranean climate},
journal = {Agriculture, Ecosystems & Environment},
year = {2021},
volume = {315},
pages = {107439},
url = {https://www.sciencedirect.com/science/article/pii/S0167880921001432},
doi = {10.1016/j.agee.2021.107439}
}
|
| Fischer G, Romero OE, Karstensen J, Baumann K-H, Moradi N, Iversen M, Ruhland G, Klann M and Körtzinger A (2021), "Seasonal flux patterns and carbon transport from low-oxygen eddies at the Cape Verde Ocean Observatory: lessons learned from a time series sediment trap study (2009--2016)", Biogeosciences. Vol. 18(24), pp. 6479-6500. |
BibTeX:
@article{Fischer2021,
author = {Fischer, G and Romero, O E and Karstensen, J and Baumann, K.-H. and Moradi, N and Iversen, M and Ruhland, G and Klann, M and Körtzinger, A},
title = {Seasonal flux patterns and carbon transport from low-oxygen eddies at the Cape Verde Ocean Observatory: lessons learned from a time series sediment trap study (2009--2016)},
journal = {Biogeosciences},
year = {2021},
volume = {18},
number = {24},
pages = {6479--6500},
url = {https://bg.copernicus.org/articles/18/6479/2021/},
doi = {10.5194/bg-18-6479-2021}
}
|
| Fodor N, Pásztor L, Szabó B, Laborczi A, Pokovai K, Hidy D, Hollós R, Kristóf E, Kis A, Dobor L, Kern A, Grünwald T and Barcza Z (2021), "Input database related uncertainty of Biome-BGCMuSo agro-environmental model outputs", International Journal of Digital Earth., nov, 2021. Vol. 14(11), pp. 1582-1601. Taylor & Francis. |
BibTeX:
@article{Fodor2021,
author = {Fodor, Nándor and Pásztor, László and Szabó, Brigitta and Laborczi, Annamária and Pokovai, Klára and Hidy, Dóra and Hollós, Roland and Kristóf, Erzsébet and Kis, Anna and Dobor, Laura and Kern, Anikó and Grünwald, Thomas and Barcza, Zoltán},
title = {Input database related uncertainty of Biome-BGCMuSo agro-environmental model outputs},
journal = {International Journal of Digital Earth},
publisher = {Taylor & Francis},
year = {2021},
volume = {14},
number = {11},
pages = {1582--1601},
url = {https://doi.org/10.1080/17538947.2021.1953161},
doi = {10.1080/17538947.2021.1953161}
}
|
| Foken T, Babel W, Munger JW, Grönholm T, Vesala T and Knohl A (2021), "Selected breakpoints of net forest carbon uptake at four eddy-covariance sites", Tellus, Series B: Chemical and Physical Meteorology. Vol. 73(1), pp. 1-12. Taylor & Francis. |
| Abstract: Extensive studies are available that analyse time series of carbon dioxide and water flux measurements of FLUXNET sites over many years and link these results to climate change such as changes in atmospheric carbon dioxide concentration, air temperature and growing season length and other factors. Many of the sites show trends to a larger carbon uptake. Here we analyse time series of net ecosystem exchange, gross primary production, respiration, and evapotranspiration of four forest sites with particularly long measurement periods of about 20 years. The regular trends shown are interrupted by periods with higher or lower increases of carbon uptake. These breakpoints can be of very different origin and include forest decline, increased vegetation period, drought effects, heat waves, and changes in site heterogeneity. The influence of such breakpoints should be included in long-term studies of land-atmosphere exchange processes. |
BibTeX:
@article{Foken2021,
author = {Foken, Thomas and Babel, Wolfgang and Munger, J. William and Grönholm, Tiia and Vesala, Timo and Knohl, Alexander},
title = {Selected breakpoints of net forest carbon uptake at four eddy-covariance sites},
journal = {Tellus, Series B: Chemical and Physical Meteorology},
publisher = {Taylor & Francis},
year = {2021},
volume = {73},
number = {1},
pages = {1--12},
url = {https://doi.org/10.1080/16000889.2021.1915648},
doi = {10.1080/16000889.2021.1915648}
}
|
| Friedlingstein P, Jones MW, O'Sullivan M, Andrew RM, Bakker DCE, Hauck J, Le Quéré C, Peters GP, Peters W, Pongratz J, Sitch S, Canadell JG, Ciais P, Jackson RB, Alin SR, Anthoni P, Bates NR, Becker M, Bellouin N, Bopp L, Chau TTT, Chevallier F, Chini LP, Cronin M, Currie KI, Decharme B, Djeutchouang L, Dou X, Evans W, Feely RA, Feng L, Gasser T, Gilfillan D, Gkritzalis T, Grassi G, Gregor L, Gruber N, Gürses Ö, Harris I, Houghton RA, Hurtt GC, Iida Y, Ilyina T, Luijkx IT, Jain AK, Jones SD, Kato E, Kennedy D, Klein Goldewijk K, Knauer J, Korsbakken JI, Körtzinger A, Landschützer P, Lauvset SK, Lefèvre N, Lienert S, Liu J, Marland G, McGuire PC, Melton JR, Munro DR, Nabel JEMS, Nakaoka S-I, Niwa Y, Ono T, Pierrot D, Poulter B, Rehder G, Resplandy L, Robertson E, Rödenbeck C, Rosan TM, Schwinger J, Schwingshackl C, Séférian R, Sutton AJ, Sweeney C, Tanhua T, Tans PP, Tian H, Tilbrook B, Tubiello F, van der Werf G, Vuichard N, Wada C, Wanninkhof R, Watson A, Willis D, Wiltshire AJ, Yuan W, Yue C, Yue X, Zaehle S and Zeng J (2021), "Global Carbon Budget 2021", Earth System Science Data Discussions. Vol. 2021, pp. 1-191. |
BibTeX:
@article{Friedlingstein2021,
author = {Friedlingstein, P and Jones, M W and O'Sullivan, M and Andrew, R M and Bakker, D C E and Hauck, J and Le Quéré, C and Peters, G P and Peters, W and Pongratz, J and Sitch, S and Canadell, J G and Ciais, P and Jackson, R B and Alin, S R and Anthoni, P and Bates, N R and Becker, M and Bellouin, N and Bopp, L and Chau, T T T and Chevallier, F and Chini, L P and Cronin, M and Currie, K I and Decharme, B and Djeutchouang, L and Dou, X and Evans, W and Feely, R A and Feng, L and Gasser, T and Gilfillan, D and Gkritzalis, T and Grassi, G and Gregor, L and Gruber, N and Gürses, Ö and Harris, I and Houghton, R A and Hurtt, G C and Iida, Y and Ilyina, T and Luijkx, I T and Jain, A K and Jones, S D and Kato, E and Kennedy, D and Klein Goldewijk, K and Knauer, J and Korsbakken, J I and Körtzinger, A and Landschützer, P and Lauvset, S K and Lefèvre, N and Lienert, S and Liu, J and Marland, G and McGuire, P C and Melton, J R and Munro, D R and Nabel, J E M S and Nakaoka, S.-I. and Niwa, Y and Ono, T and Pierrot, D and Poulter, B and Rehder, G and Resplandy, L and Robertson, E and Rödenbeck, C and Rosan, T M and Schwinger, J and Schwingshackl, C and Séférian, R and Sutton, A J and Sweeney, C and Tanhua, T and Tans, P P and Tian, H and Tilbrook, B and Tubiello, F and van der Werf, G and Vuichard, N and Wada, C and Wanninkhof, R and Watson, A and Willis, D and Wiltshire, A J and Yuan, W and Yue, C and Yue, X and Zaehle, S and Zeng, J},
title = {Global Carbon Budget 2021},
journal = {Earth System Science Data Discussions},
year = {2021},
volume = {2021},
pages = {1--191},
url = {https://essd.copernicus.org/preprints/essd-2021-386/},
doi = {10.5194/essd-2021-386}
}
|
| Fu Z, Ciais P, Makowski D, Bastos A, Stoy PC, Ibrom A, Knohl A, Migliavacca M, Cuntz M, Šigut L, Peichl M, Loustau D, El‐Madany TS, Buchmann N, Gharun M, Janssens I, Markwitz C, Grünwald T, Rebmann C, Mölder M, Varlagin A, Mammarella I, Kolari P, Bernhofer C, Heliasz M, Vincke C, Pitacco A, Cremonese E, Foltýnová L and Wigneron J (2021), "Uncovering the critical soil moisture thresholds of plant water stress for European ecosystems", Global Change Biology., dec, 2021. Vol. 28(6), pp. 2111-2123. Wiley. |
BibTeX:
@article{Fu2021,
author = {Fu, Zheng and Ciais, Philippe and Makowski, David and Bastos, Ana and Stoy, Paul C and Ibrom, Andreas and Knohl, Alexander and Migliavacca, Mirco and Cuntz, Matthias and Šigut, Ladislav and Peichl, Matthias and Loustau, Denis and El‐Madany, Tarek S and Buchmann, Nina and Gharun, Mana and Janssens, Ivan and Markwitz, Christian and Grünwald, Thomas and Rebmann, Corinna and Mölder, Meelis and Varlagin, Andrej and Mammarella, Ivan and Kolari, Pasi and Bernhofer, Christian and Heliasz, Michal and Vincke, Caroline and Pitacco, Andrea and Cremonese, Edoardo and Foltýnová, Lenka and Wigneron, Jean‐Pierre},
title = {Uncovering the critical soil moisture thresholds of plant water stress for European ecosystems},
journal = {Global Change Biology},
publisher = {Wiley},
year = {2021},
volume = {28},
number = {6},
pages = {2111--2123},
url = {http://dx.doi.org/10.1111/gcb.16050},
doi = {10.1111/gcb.16050}
}
|
| Gałkowski M, Jordan A, Rothe M, Marshall J, Koch F-T, Chen J, Agusti-Panareda A, Fix A and Gerbig C (2021), "In situ observations of greenhouse gases over Europe during the CoMet 1.0 campaign aboard the HALO aircraft", Atmospheric Measurement Techniques. Vol. 14(2), pp. 1525-1544. |
BibTeX:
@article{Galkowski2021,
author = {Gałkowski, M and Jordan, A and Rothe, M and Marshall, J and Koch, F.-T. and Chen, J and Agusti-Panareda, A and Fix, A and Gerbig, C},
title = {In situ observations of greenhouse gases over Europe during the CoMet 1.0 campaign aboard the HALO aircraft},
journal = {Atmospheric Measurement Techniques},
year = {2021},
volume = {14},
number = {2},
pages = {1525--1544},
url = {https://amt.copernicus.org/articles/14/1525/2021/},
doi = {10.5194/amt-14-1525-2021}
}
|
| George J-P, Yang W, Kobayashi H, Biermann T, Carrara A, Cremonese E, Cuntz M, Fares S, Gerosa G, Grünwald T, Hase N, Heliasz M, Ibrom A, Knohl A, Kruijt B, Lange H, Limousin J-M, Loustau D, Lukeš P, Marzuoli R, Mölder M, Montagnani L, Neirynck J, Peichl M, Rebmann C, Schmidt M, Serrano FRL, Soudani K, Vincke C and Pisek J (2021), "Method comparison of indirect assessments of understory leaf area index (LAIu): A case study across the extended network of ICOS forest ecosystem sites in Europe", Ecological Indicators., sep, 2021. Vol. 128, pp. 107841. |
BibTeX:
@article{George2021,
author = {George, Jan-Peter and Yang, Wei and Kobayashi, Hideki and Biermann, Tobias and Carrara, Arnaud and Cremonese, Edoardo and Cuntz, Matthias and Fares, Silvano and Gerosa, Giacomo and Grünwald, Thomas and Hase, Niklas and Heliasz, Michael and Ibrom, Andreas and Knohl, Alexander and Kruijt, Bart and Lange, Holger and Limousin, Jean-Marc and Loustau, Denis and Lukeš, Petr and Marzuoli, Riccardo and Mölder, Meelis and Montagnani, Leonardo and Neirynck, Johan and Peichl, Matthias and Rebmann, Corinna and Schmidt, Marius and Serrano, Francisco Ramon Lopez and Soudani, Kamel and Vincke, Caroline and Pisek, Jan},
title = {Method comparison of indirect assessments of understory leaf area index (LAIu): A case study across the extended network of ICOS forest ecosystem sites in Europe},
journal = {Ecological Indicators},
year = {2021},
volume = {128},
pages = {107841},
url = {https://linkinghub.elsevier.com/retrieve/pii/S1470160X21005069},
doi = {10.1016/j.ecolind.2021.107841}
}
|
| Gharun M, Klesse S, Tomlinson G, Waldner P, Stocker B, Rihm B, Siegwolf R and Buchmann N (2021), "Effect of nitrogen deposition on centennial forest water-use efficiency", Environmental Research Letters. Vol. 16(11), pp. 114036. IOP Publishing. |
| Abstract: The uptake of carbon dioxide (CO2) from the atmosphere through photosynthesis is accompanied by an inevitable loss of water vapor through the stomata of leaves. The rate of leaf-level CO2 assimilation per unit stomatal conductance, i.e. intrinsic water-use efficiency (WUEi), is thus a key characteristic of terrestrial ecosystem functioning that is central to the global hydroclimate system. Empirical evidence and theory suggest a positive response of forest WUE to increased CO2 levels globally. Although evidence exists for a positive effect of ecosystem nitrogen (N) inputs on WUEi, it is not clear how trends in atmospheric N deposition have affected WUEi in the past. Here we combine twentieth-century climate and nitrogen deposition with stable isotope signature in tree rings and document a WUEi trend reversal at two sites in Switzerland, that matches the timing of a trend reversal in atmospheric N deposition. Using generalized additive models (GAMs), we fitted observed WUEi time series to multiple environmental covariates. This suggested N deposition to have a significant effect on long-term WUEi at the site that was exposed to higher N deposition levels. The ratio of the increase in WUEi in response to increase in CO2 (dWUEi/dCO2) declined by 96% after 1980 (from 0.53 to 0.02) in the beech forest and declined by 72% in the spruce forest (from 0.46 to 0.13) concurrent with a sharp decline in N deposition. Using the GAM model for two scenarios, we show that had N deposition levels not declined after 1980s, WUEi would have increased more strongly in response to increasing CO2. Although the increase in N deposition was limited to the 1950–1980 decades and the signals have declined with improvements in air quality across Europe, the role of atmospheric pollution must be reconsidered in interpretation of tree ring studies and for building environmental proxies that are pivotal to understanding future sink capacity of terrestrial ecosystems in response to climate change. |
BibTeX:
@article{Gharun2021,
author = {Gharun, Mana and Klesse, Stefan and Tomlinson, Gregory and Waldner, Peter and Stocker, Benjamin and Rihm, Beat and Siegwolf, Rolf and Buchmann, Nina},
title = {Effect of nitrogen deposition on centennial forest water-use efficiency},
journal = {Environmental Research Letters},
publisher = {IOP Publishing},
year = {2021},
volume = {16},
number = {11},
pages = {114036},
url = {http://dx.doi.org/10.1088/1748-9326/ac30f9},
doi = {10.1088/1748-9326/ac30f9}
}
|
| Gisat SRO and Republic C (2021), "Copernicus for Urban Resilience in Europe : First Results From the Cure Project" , pp. 1186-1189.
[BibTeX] |
BibTeX:
@article{Gisat2021,
author = {Gisat, S R O and Republic, Czech},
title = {Copernicus for Urban Resilience in Europe : First Results From the Cure Project},
year = {2021},
pages = {1186--1189}
}
|
| Gomez LG, Loubet B, Lafouge F, Ciuraru R, Bsaibes S, Kammer J, Buysse P, Durand B, Gueudet J-C, Fanucci O, Zurfluh O, Decuq C, Truong F, Gros V and Boissard C (2021), "Effect of senescence on biogenic volatile organic compound fluxes in wheat plants", Atmospheric Environment. Vol. 266, pp. 118665. |
| Abstract: Exchanges of biogenic volatile organic compounds (BVOC) between plants and the atmosphere are likely to vary, in amount and composition, between different plant species but also for a single plant during its development. However, the effect of plant development stages, including senescence, on BVOC exchanges remains poorly investigated, especially in the case of crop plants. We investigated the BVOC exchange patterns for wheat plants, the most grown crop species worldwide, during seed maturation, senescence and after harvest. Fluxes were measured online, in situ, at the plant scale by combining automated chambers and a Proton Transfer - Reaction - Quadrupole ion guide - Time of Flight - Mass Spectrometer (PTR-Qi-Tof-MS). The high resolution and sensitivity of this method enabled the measurement of a large mass spectrum of compounds emitted at very small amounts, allowing a precise characterization of BVOC exchanges. We found that the overall BVOC emissions increased twofold during the senescence stage compared to the maturation stage. Methanol was found to be the most emitted compound (49–60% of the overall flux on a molar basis) followed by acetone (7.5–8.2% of the overall flux on a molar basis) during each developmental stage investigated. Acetaldehyde was another major emitted compound contributing mainly during late senescence to the overall flux (9.7%). When normalized for temperature and light conditions, most BVOC emissions increased during senescence, showing a clear effect of senescence on BVOC exchanges. Chamber emissions were comparable to whole ecosystem fluxes measured at the same site by eddy covariance the previous year. The OH reactivity of the emitted compounds was evaluated based on known reaction rate constants and was the largest during the first senescence stage, peaking at 12 s−1 in the chambers. The results of this study show the need for considering plant phenology when computing BVOC emissions from crops. |
BibTeX:
@article{Gomez2021,
author = {Gomez, Lais Gonzaga and Loubet, Benjamin and Lafouge, Florence and Ciuraru, Raluca and Bsaibes, Sandy and Kammer, Julien and Buysse, Pauline and Durand, Brigitte and Gueudet, Jean-Christophe and Fanucci, Olivier and Zurfluh, Olivier and Decuq, Céline and Truong, François and Gros, Valérie and Boissard, Christophe},
title = {Effect of senescence on biogenic volatile organic compound fluxes in wheat plants},
journal = {Atmospheric Environment},
year = {2021},
volume = {266},
pages = {118665},
url = {https://www.sciencedirect.com/science/article/pii/S1352231021004878},
doi = {10.1016/j.atmosenv.2021.118665}
}
|
| Gressent A, Rigby M, Ganesan AL, Prinn RG, Manning AJ, Mühle J, Salameh PK, Krummel PB, Fraser PJ, Steele LP, Mitrevski B, Weiss RF, Harth CM, Wang RH, O’Doherty S, Young D, Park S, Li S, Yao B, Reimann S, Vollmer MK, Maione M, Arduini J and Lunder CR (2021), "Growing Atmospheric Emissions of Sulfuryl Fluoride", Journal of Geophysical Research: Atmospheres., May, 2021. Vol. 126(9) American Geophysical Union (AGU). |
BibTeX:
@article{Gressent2021,
author = {Gressent, A. and Rigby, M. and Ganesan, A. L. and Prinn, R. G. and Manning, A. J. and Mühle, J. and Salameh, P. K. and Krummel, P. B. and Fraser, P. J. and Steele, L. P. and Mitrevski, B. and Weiss, R. F. and Harth, C. M. and Wang, R. H. and O’Doherty, S. and Young, D. and Park, S. and Li, S. and Yao, B. and Reimann, S. and Vollmer, M. K. and Maione, M. and Arduini, J. and Lunder, C. R.},
title = {Growing Atmospheric Emissions of Sulfuryl Fluoride},
journal = {Journal of Geophysical Research: Atmospheres},
publisher = {American Geophysical Union (AGU)},
year = {2021},
volume = {126},
number = {9},
doi = {10.1029/2020jd034327}
}
|
| Grönholm T, Mäkelä T, Hatakka J, Jalkanen J-P, Kuula J, Laurila T, Laakso L and Kukkonen J (2021), "Evaluation of Methane Emissions Originating from LNG Ships Based on the Measurements at a Remote Marine Station", Environmental Science & Technology., oct, 2021. Vol. 55(20), pp. 13677-13686. American Chemical Society. |
BibTeX:
@article{Groenholm2021,
author = {Grönholm, Tiia and Mäkelä, Timo and Hatakka, Juha and Jalkanen, Jukka-Pekka and Kuula, Joel and Laurila, Tuomas and Laakso, Lauri and Kukkonen, Jaakko},
title = {Evaluation of Methane Emissions Originating from LNG Ships Based on the Measurements at a Remote Marine Station},
journal = {Environmental Science & Technology},
publisher = {American Chemical Society},
year = {2021},
volume = {55},
number = {20},
pages = {13677--13686},
url = {https://doi.org/10.1021/acs.est.1c03293},
doi = {10.1021/acs.est.1c03293}
}
|
| Groß-Schmölders M, Klein K, Birkholz A, Leifeld J and Alewell C (2021), "Rewetting and Drainage of Nutrient-Poor Peatlands Indicated by Specific Bacterial Membrane Fatty Acids and a Repeated Sampling of Stable Isotopes (δ15N, δ13C)", Frontiers in Environmental Science. Vol. 9 |
| Abstract: Peatland degradation impairs soil functions such as carbon storage and the existence of biodiversity hotspots. Therefore, and in view of the ongoing climate change, an efficient method of evaluating peatland hydrology and the success of restoration efforts is needed. To understand the role of microbial groups in biogeochemical cycling, gaseous loss and isotopic fractionation that lead to specific isotopic depth patterns (δ13C, δ15N), we integrated previously published stable isotope data with a membrane fatty acid (mFA) analysis related to various microbial groups that are known to be common in peatlands. We performed two sampling campaigns to verify the observed stable isotope depth trends in nutrient-poor peatlands in Northern Europe. Cores were taken from adjacent drained (or rewetted) and undrained sites. Fungal-derived mFA abundance was highest in the uppermost part of the drained layer. We found increasing bacterial-derived mFA concentrations with depth peaking in the middle of the drained layers, which correlates with a δ15N peak of bulk material. The results support our hypothesis that changing peatland hydrology induce a shift in microbial community and metabolism processes and is therefore also imprinted in stable isotope values. Under waterlogged conditions overall levels of microbial-derived mFAs were generally low. Drained layers showed simultaneous changes in microbial abundance and composition and depth trends in stable isotope bulk values. Bacteria, particularly acidobacteria, can be expected to dominate increased denitrification with low oxygen saturation accompanied by increased δ15N bulk values in the remaining substrate. Interestingly, cores from recent rewetted peatlands show no depth trend of δ15N in the layers grown under rewetting conditions; this is congruent with relatively low concentrations of microbial-derived mFAs. Hence, we conclude that stable isotopes, especially δ15N values, reflect changing microbial metabolic processes, which differ between drained and undrained - and especially also for recent rewetted–peatlands. As today stable isotope measurements are routine measurements, these findings enable us to get cost- and time efficient reliable information of drainage and restoration success. |
BibTeX:
@article{GrossSchmoelders2021,
author = {Groß-Schmölders, Miriam and Klein, Kristy and Birkholz, Axel and Leifeld, Jens and Alewell, Christine},
title = {Rewetting and Drainage of Nutrient-Poor Peatlands Indicated by Specific Bacterial Membrane Fatty Acids and a Repeated Sampling of Stable Isotopes (δ15N, δ13C)},
journal = {Frontiers in Environmental Science},
year = {2021},
volume = {9},
url = {https://www.frontiersin.org/article/10.3389/fenvs.2021.730106},
doi = {10.3389/fenvs.2021.730106}
}
|
| Gu C, Tang Q, Zhu G, Ma J, Gu C, Zhang K, Sun S, Yu Q and Niu S (2021), "Discrepant responses between evapotranspiration- and transpiration-based ecosystem water use efficiency to interannual precipitation fluctuations", Agricultural and Forest Meteorology. Vol. 303, pp. 108385. |
| Abstract: Climate change intensifies precipitation fluctuation and increases drought frequency around the globe. Water use efficiency (WUE) has proven to be a crucial metric to quantify the trade-off linking global carbon and water cycles in many aspects of terrestrial ecosystem function. Investigating the response of ecosystem WUE to multiannual precipitation fluctuations has major implications for our understanding of ecosystem carbon and water dynamics. However, the impacts of water availability variation on evapotranspiration- and transpiration-based ecosystem WUE and their mechanisms are poorly understood due to limited observations. We investigated ecosystem WUE in response to interannual precipitation fluctuations in order to reveal the regularity underlying WUE changes under different levels of water stress. We optimized the parameters of two remote sensing models (PT-JPL and PM) based on different biophysical processes using the differential-evolution Markov Chain (DE-MC) method. We investigated ecosystem WUEET (GPP/ET) and WUET (GPP/T) in response to interannual precipitation fluctuations at 73 sites. We found ecosystem WUET appears to decline during drought years and to increase in wet years contrasting with WUEET, which was mostly attributable to differing sensitivities of GPP, ET and T to multiannual precipitation fluctuations. The vegetation generally consumes more T to improve ecosystem GPP during dry years, meanwhile, no apparent change in WUEET during dry years because of the trade of between GPP/T and T/ET. The replenishment of soil moisture to ecosystem transpiration is higher than we thought during dry years. This was masked in analysis that considered the responses of GPP and T to annual precipitation changes separately, but was revealed by the changes in ecosystem WUET. This research advances our understanding of the consequences of water fluctuation on ecosystem carbon and water exchange. |
BibTeX:
@article{Gu2021,
author = {Gu, Chunjie and Tang, Qiuhong and Zhu, Gaofeng and Ma, Jinzhu and Gu, Chunli and Zhang, Kun and Sun, Shuang and Yu, Qiang and Niu, Shuli},
title = {Discrepant responses between evapotranspiration- and transpiration-based ecosystem water use efficiency to interannual precipitation fluctuations},
journal = {Agricultural and Forest Meteorology},
year = {2021},
volume = {303},
pages = {108385},
url = {https://www.sciencedirect.com/science/article/pii/S016819232100068X},
doi = {10.1016/j.agrformet.2021.108385}
}
|
| Guseva S, Aurela M, Cortés A, Kivi R, Lotsari E, MacIntyre S, Mammarella I, Ojala A, Stepanenko V, Uotila P, Vähä A, Vesala T, Wallin MB and Lorke A (2021), "Variable Physical Drivers of Near-Surface Turbulence in a Regulated River", Water Resources Research., nov, 2021. Vol. 57(11), pp. e2020WR027939. John Wiley & Sons, Ltd. |
| Abstract: Abstract Inland waters, such as lakes, reservoirs and rivers, are important sources of climate forcing trace gases. A key parameter that regulates the gas exchange between water and the atmosphere is the gas transfer velocity, which itself is controlled by near-surface turbulence in the water. While in lakes and reservoirs, near-surface turbulence is mainly driven by atmospheric forcing, in shallow rivers and streams it is generated by bottom friction of gravity-forced flow. Large rivers represent a transition between these two cases. Near-surface turbulence has rarely been measured in rivers and the drivers of turbulence have not been quantified. We analyzed continuous measurements of flow velocity and quantified turbulence as the rate of dissipation of turbulent kinetic energy over the ice-free season in a large regulated river in Northern Finland. Measured dissipation rates agreed with predictions from bulk parameters, including mean flow velocity, wind speed, surface heat flux, and with a one-dimensional numerical turbulence model. Values ranged from to . Atmospheric forcing or gravity was the dominant driver of near-surface turbulence for similar fraction of the time. Large variability in near-surface dissipation rate occurred at diel time scales, when the flow velocity was strongly affected by downstream dam operation. By combining scaling relations for boundary-layer turbulence at the river bed and at the air-water interface, we derived a simple model for estimating the relative contributions of wind speed and bottom friction of river flow as a function of depth. |
BibTeX:
@article{Guseva2021,
author = {Guseva, S and Aurela, M and Cortés, A and Kivi, R and Lotsari, E and MacIntyre, S and Mammarella, I and Ojala, A and Stepanenko, V and Uotila, P and Vähä, A and Vesala, T and Wallin, M B and Lorke, A},
title = {Variable Physical Drivers of Near-Surface Turbulence in a Regulated River},
journal = {Water Resources Research},
publisher = {John Wiley & Sons, Ltd},
year = {2021},
volume = {57},
number = {11},
pages = {e2020WR027939},
url = {https://doi.org/10.1029/2020WR027939},
doi = {10.1029/2020WR027939}
}
|
| Gutiérrez-Loza L, Wallin MB, Sahlée E, Holding T, Shutler JD, Rehder G and Rutgersson A (2021), "Air–sea CO2 exchange in the Baltic Sea—A sensitivity analysis of the gas transfer velocity", Journal of Marine Systems. Vol. 222, pp. 103603. |
| Abstract: Air–sea gas fluxes are commonly estimated using wind-based parametrizations of the gas transfer velocity. However, neglecting gas exchange forcing mechanisms – other than wind speed – may lead to large uncertainties in the flux estimates and the carbon budgets, in particular, in heterogeneous environments such as marginal seas and coastal areas. In this study we investigated the impact of including relevant processes to the air–sea CO2 flux parametrization for the Baltic Sea. We used six parametrizations of the gas transfer velocity to evaluate the effect of precipitation, water-side convection, and surfactants on the net CO2 flux at regional and sub-regional scale. The differences both in the mean CO2 fluxes and the integrated net fluxes were small between the different cases. However, the implications on the seasonal variability were shown to be significant. The inter-annual and spatial variability were also found to be associated with the forcing mechanisms evaluated in the study. In addition to wind, water-side convection was the most relevant parameter controlling the air–sea gas exchange at seasonal and inter-annual scales. The effect of precipitation and surfactants seemed negligible in terms of the inter-annual variability. The effect of water-side convection and surfactants resulted in a reduction of the downward fluxes, while precipitation was the only parameter that resulted in an enhancement of the net uptake in the Baltic Sea. |
BibTeX:
@article{GutierrezLoza2021,
author = {Gutiérrez-Loza, Lucía and Wallin, Marcus B and Sahlée, Erik and Holding, Thomas and Shutler, Jamie D and Rehder, Gregor and Rutgersson, Anna},
title = {Air–sea CO2 exchange in the Baltic Sea—A sensitivity analysis of the gas transfer velocity},
journal = {Journal of Marine Systems},
year = {2021},
volume = {222},
pages = {103603},
url = {https://www.sciencedirect.com/science/article/pii/S0924796321001007},
doi = {10.1016/j.jmarsys.2021.103603}
}
|
| Haesen S, Lembrechts JJ, De Frenne P, Lenoir J, Aalto J, Ashcroft MB, Kopecký M, Luoto M, Maclean I, Nijs I, Niittynen P, van den Hoogen J, Arriga N, Brůna J, Buchmann N, Čiliak M, Collalti A, De Lombaerde E, Descombes P, Gharun M, Goded I, Govaert S, Greiser C, Grelle A, Gruening C, Hederová L, Hylander K, Kreyling J, Kruijt B, Macek M, Máliš F, Man M, Manca G, Matula R, Meeussen C, Merinero S, Minerbi S, Montagnani L, Muffler L, Ogaya R, Penuelas J, Plichta R, Portillo-Estrada M, Schmeddes J, Shekhar A, Spicher F, Ujházyová M, Vangansbeke P, Weigel R, Wild J, Zellweger F and Van Meerbeek K (2021), "ForestTemp – Sub-canopy microclimate temperatures of European forests", Global Change Biology., dec, 2021. Vol. 27(23), pp. 6307-6319. John Wiley & Sons, Ltd. |
| Abstract: Abstract Ecological research heavily relies on coarse-gridded climate data based on standardized temperature measurements recorded at 2 m height in open landscapes. However, many organisms experience environmental conditions that differ substantially from those captured by these macroclimatic (i.e. free air) temperature grids. In forests, the tree canopy functions as a thermal insulator and buffers sub-canopy microclimatic conditions, thereby affecting biological and ecological processes. To improve the assessment of climatic conditions and climate-change-related impacts on forest-floor biodiversity and functioning, high-resolution temperature grids reflecting forest microclimates are thus urgently needed. Combining more than 1200 time series of in situ near-surface forest temperature with topographical, biological and macroclimatic variables in a machine learning model, we predicted the mean monthly offset between sub-canopy temperature at 15 cm above the surface and free-air temperature over the period 2000?2020 at a spatial resolution of 25 m across Europe. This offset was used to evaluate the difference between microclimate and macroclimate across space and seasons and finally enabled us to calculate mean annual and monthly temperatures for European forest understories. We found that sub-canopy air temperatures differ substantially from free-air temperatures, being on average 2.1°C (standard deviation ± 1.6°C) lower in summer and 2.0°C higher (±0.7°C) in winter across Europe. Additionally, our high-resolution maps expose considerable microclimatic variation within landscapes, not captured by the gridded macroclimatic products. The provided forest sub-canopy temperature maps will enable future research to model below-canopy biological processes and patterns, as well as species distributions more accurately. |
BibTeX:
@article{Haesen2021,
author = {Haesen, Stef and Lembrechts, Jonas J and De Frenne, Pieter and Lenoir, Jonathan and Aalto, Juha and Ashcroft, Michael B and Kopecký, Martin and Luoto, Miska and Maclean, Ilya and Nijs, Ivan and Niittynen, Pekka and van den Hoogen, Johan and Arriga, Nicola and Brůna, Josef and Buchmann, Nina and Čiliak, Marek and Collalti, Alessio and De Lombaerde, Emiel and Descombes, Patrice and Gharun, Mana and Goded, Ignacio and Govaert, Sanne and Greiser, Caroline and Grelle, Achim and Gruening, Carsten and Hederová, Lucia and Hylander, Kristoffer and Kreyling, Jürgen and Kruijt, Bart and Macek, Martin and Máliš, František and Man, Matěj and Manca, Giovanni and Matula, Radim and Meeussen, Camille and Merinero, Sonia and Minerbi, Stefano and Montagnani, Leonardo and Muffler, Lena and Ogaya, Romà and Penuelas, Josep and Plichta, Roman and Portillo-Estrada, Miguel and Schmeddes, Jonas and Shekhar, Ankit and Spicher, Fabien and Ujházyová, Mariana and Vangansbeke, Pieter and Weigel, Robert and Wild, Jan and Zellweger, Florian and Van Meerbeek, Koenraad},
title = {ForestTemp – Sub-canopy microclimate temperatures of European forests},
journal = {Global Change Biology},
publisher = {John Wiley & Sons, Ltd},
year = {2021},
volume = {27},
number = {23},
pages = {6307--6319},
url = {https://doi.org/10.1111/gcb.15892},
doi = {10.1111/gcb.15892}
}
|
| Hamard S, Céréghino R, Barret M, Sytiuk A, Lara E, Dorrepaal E, Kardol P, Küttim M, Lamentowicz M, Leflaive J, Le Roux G, Tuittila E-S and Jassey VEJ (2021), "Contribution of microbial photosynthesis to peatland carbon uptake along a latitudinal gradient", Journal of Ecology., sep, 2021. Vol. 109(9), pp. 3424-3441. John Wiley & Sons, Ltd. |
| Abstract: Abstract Phototrophic microbes, also known as micro-algae, display a high abundance in many terrestrial surface soils. They contribute to atmospheric carbon dioxide fluxes through their photosynthesis, and thus regulate climate similar to plants. However, microbial photosynthesis remains overlooked in most terrestrial ecosystems. Here, we hypothesise that phototrophic microbes significantly contribute to peatland C uptake, unless environmental conditions limit their development and their photosynthetic activity. To test our hypothesis, we studied phototrophic microbial communities in five peatlands distributed along a latitudinal gradient in Europe. By means of metabarcoding, microscopy and cytometry analyses, as well as measures of photosynthesis, we investigated the diversity, absolute abundance and photosynthetic rates of the phototrophic microbial communities. We identified 351 photosynthetic prokaryotic and eukaryotic operational taxonomic units (OTUs) across the five peatlands. We found that water availability and plant composition were important determinants of the composition and the structure of phototrophic microbial communities. Despite environmental shifts in community structure and composition, we showed that microbial C fixation rates remained similar along the latitudinal gradient. Our results further revealed that phototrophic microbes accounted for approximately 10% of peatland C uptake. Synthesis. Our findings show that phototrophic microbes are extremely diverse and abundant in peatlands. While species turnover with environmental conditions, microbial photosynthesis similarly contributed to peatland C uptake at all latitudes. We estimate that phototrophic microbes take up around 75 MT CO2 per year in northern peatlands. This amount roughly equals the magnitude of projected peatland C loss due to climate warming and highlights the importance of phototrophic microbes for the peatland C cycle. |
BibTeX:
@article{Hamard2021,
author = {Hamard, Samuel and Céréghino, Regis and Barret, Maialen and Sytiuk, Anna and Lara, Enrique and Dorrepaal, Ellen and Kardol, Paul and Küttim, Martin and Lamentowicz, Mariusz and Leflaive, Joséphine and Le Roux, Gaël and Tuittila, Eeva-Stiina and Jassey, Vincent E J},
title = {Contribution of microbial photosynthesis to peatland carbon uptake along a latitudinal gradient},
journal = {Journal of Ecology},
publisher = {John Wiley & Sons, Ltd},
year = {2021},
volume = {109},
number = {9},
pages = {3424--3441},
url = {https://doi.org/10.1111/1365-2745.13732},
doi = {10.1111/1365-2745.13732}
}
|
| Han Q, Wang T, Wang L, Smettem K, Mai M and Chen X (2021), "Comparison of Nighttime With Daytime Evapotranspiration Responses to Environmental Controls Across Temporal Scales Along a Climate Gradient", Water Resources Research., jul, 2021. Vol. 57(7), pp. e2021WR029638. John Wiley & Sons, Ltd. |
| Abstract: Abstract Understanding daytime (ETD) and nighttime (ETN) evapotranspiration is critical for accurately evaluating terrestrial water and carbon cycles. However, unlike ETD, the factors influencing ETN remain poorly understood. Here, long-term ETD and ETN data from five FLUXNET sites along a climate gradient in Northern Australia were analyzed to compare their responses to environmental drivers at different temporal scales. We found that (a) across the sites, mean annual ETN/ETD (/) ranged between 5.1% and 11.7%, which was mainly determined by variations. Particularly, vegetation and meteorological variables mostly controlled , while was largely related to air temperature and net radiation (Rn) due to lower nighttime atmospheric water demands; (b) At individual sites, ETD and ETN exhibited higher correlations with meteorological and vegetation variables at monthly timescales than at annual timescales. Monthly ETD and ETN were also strongly coupled, especially under drier climatic conditions. At daily timescales, leaf area index and soil water content (SWC) controlled ETD with SWC being more important at drier sites; whereas, SWC was the dominant factor controlling ETN. At half-hourly timescales, the boosted regression tree method quantitively showed that ETD and ETN were controlled by Rn and SWC, respectively. Overall, the results showed that ETN was less responsive to environmental variables, illustrating that ETD and ETN responded differently to diverse climate regimes and ecosystems at varying temporal scales. These findings provide a critical evaluation for contrasting ETD and ETN interactions in constantly changing environments, which has important implications for ecosystem water balance and land surface processes modeling. |
BibTeX:
@article{Han2021,
author = {Han, Qiong and Wang, Tiejun and Wang, Lichun and Smettem, Keith and Mai, Mai and Chen, Xi},
title = {Comparison of Nighttime With Daytime Evapotranspiration Responses to Environmental Controls Across Temporal Scales Along a Climate Gradient},
journal = {Water Resources Research},
publisher = {John Wiley & Sons, Ltd},
year = {2021},
volume = {57},
number = {7},
pages = {e2021WR029638},
url = {https://doi.org/10.1029/2021WR029638},
doi = {10.1029/2021WR029638}
}
|
| Harper AB, Williams KE, McGuire PC, Duran Rojas MC, Hemming D, Verhoef A, Huntingford C, Rowland L, Marthews T, Breder Eller C, Mathison C, Nobrega RLB, Gedney N, Vidale PL, Otu-Larbi F, Pandey D, Garrigues S, Wright A, Slevin D, De Kauwe MG, Blyth E, Ardö J, Black A, Bonal D, Buchmann N, Burban B, Fuchs K, de Grandcourt A, Mammarella I, Merbold L, Montagnani L, Nouvellon Y, Restrepo-Coupe N and Wohlfahrt G (2021), "Improvement of modeling plant responses to low soil moisture in JULESvn4.9 and evaluation against flux tower measurements", Geoscientific Model Development. Vol. 14(6), pp. 3269-3294. |
BibTeX:
@article{Harper2021,
author = {Harper, A B and Williams, K E and McGuire, P C and Duran Rojas, M C and Hemming, D and Verhoef, A and Huntingford, C and Rowland, L and Marthews, T and Breder Eller, C and Mathison, C and Nobrega, R L B and Gedney, N and Vidale, P L and Otu-Larbi, F and Pandey, D and Garrigues, S and Wright, A and Slevin, D and De Kauwe, M G and Blyth, E and Ardö, J and Black, A and Bonal, D and Buchmann, N and Burban, B and Fuchs, K and de Grandcourt, A and Mammarella, I and Merbold, L and Montagnani, L and Nouvellon, Y and Restrepo-Coupe, N and Wohlfahrt, G},
title = {Improvement of modeling plant responses to low soil moisture in JULESvn4.9 and evaluation against flux tower measurements},
journal = {Geoscientific Model Development},
year = {2021},
volume = {14},
number = {6},
pages = {3269--3294},
url = {https://gmd.copernicus.org/articles/14/3269/2021/},
doi = {10.5194/gmd-14-3269-2021}
}
|
| Hartman SE, Bett BJ, Durden JM, Henson SA, Iversen M, Jeffreys RM, Horton T, Lampitt R and Gates AR (2021), "Enduring science: Three decades of observing the Northeast Atlantic from the Porcupine Abyssal Plain Sustained Observatory (PAP-SO)", Progress in Oceanography. Vol. 191 Elsevier Ltd. |
| Abstract: Until the 1980s, the deep sea was generally considered to be a particularly stable environment, free from major temporal variations (Sanders, 1968). Studies in the abyssal northeast Atlantic by Billett et al. (1983), and subsequently Lampitt (1985) discovered seasonal pulses of surface primary production-derived particulate organic matter (phytodetritus), and hence carbon, at abyssal depths. These early observations were subsequently extended to the central oceanic region of the NE Atlantic (Pfannkuche, 1993; Thiel et al., 1989), and prompted the establishment of more concerted time series studies in the Porcupine Abyssal Plain area. Today, the Porcupine Abyssal Plain Sustained Observatory (PAP–SO) is a multidisciplinary open-ocean time series site in the NE Atlantic (48°50′N 16°30′W, 4850 m water depth; Fig. 1), focused on the study of connections between the surface and deep ocean. In situ measurements of climatically and environmentally relevant variables have been made for more than 30 years. This represents an exceptionally long time series - a recent compilation of biological time series data, across terrestrial, freshwater, and marine realms, indicates an average duration of only 13-years (Dornelas et al., 2018). Long-term time series in the deep sea are rare, particularly those collecting data from surface to seabed. The PAP-SO is one of two abyssal long-term time series sites globally (Smith et al. 2015), the other being a thirty-year time series at Station M in the northeastern Pacific Ocean (34°50′N, 123°00′W, ˜4000 m water depth), maintained by the Monterey Bay Aquarium Research Institute (Smith et al., 2020). This ‘sibling' abyssal time series site also aims to understand the connections between the surface ocean and the seabed, using many similar techniques (Smith et al., 2017), facilitating comparisons between the two sites (e.g. Durden et al., 2019; Durden et al., 2020a; Laguionie-Marchais et al., 2013; Smith et al., 2009). Another source of extended comparison is the 21 year time series Long-Term Ecological Research Observatory HAUSGARTEN, Frontiers in Arctic Marine Monitoring (FRAM) in the Fram Strait between the North Atlantic and the central Arctic Ocean (78.5°N–80°N, 05°W–11°E, 250–5500 m water depth), maintained by the Alfred Wegener Institute for Polar and Marine Research (Soltwedel et al., 2016; Soltwedel et al., 2005). Much of our understanding of temporal variation in the deep sea, and connections between the surface ocean and the seabed have been derived from research conducted at these observatories. |
BibTeX:
@article{Hartman2021,
author = {Hartman, Susan E and Bett, Brian J and Durden, Jennifer M and Henson, Stephanie A and Iversen, Morten and Jeffreys, Rachel M and Horton, Tammy and Lampitt, Richard and Gates, Andrew R},
title = {Enduring science: Three decades of observing the Northeast Atlantic from the Porcupine Abyssal Plain Sustained Observatory (PAP-SO)},
journal = {Progress in Oceanography},
publisher = {Elsevier Ltd},
year = {2021},
volume = {191},
doi = {10.1016/j.pocean.2020.102508}
}
|
| Haszpra L and Prácser E (2021), "Uncertainty of hourly-average concentration values derived from non-continuous measurements", Atmospheric Measurement Techniques. Vol. 14(5), pp. 3561-3571. |
BibTeX:
@article{Haszpra2021,
author = {Haszpra, L and Prácser, E},
title = {Uncertainty of hourly-average concentration values derived from non-continuous measurements},
journal = {Atmospheric Measurement Techniques},
year = {2021},
volume = {14},
number = {5},
pages = {3561--3571},
url = {https://amt.copernicus.org/articles/14/3561/2021/},
doi = {10.5194/amt-14-3561-2021}
}
|
| He Q, Ju W, Dai S, He W, Song L, Wang S, Li X and Mao G (2021), "Drought Risk of Global Terrestrial Gross Primary Productivity Over the Last 40 Years Detected by a Remote Sensing-Driven Process Model", Journal of Geophysical Research: Biogeosciences., jun, 2021. Vol. 126(6), pp. e2020JG005944. John Wiley & Sons, Ltd. |
| Abstract: Abstract Gross primary productivity (GPP) is the largest flux in the global terrestrial carbon cycle. Drought has significantly impacted global terrestrial GPP in recent decades, and has been projected to occur with increasing frequency and intensity. However, the drought risk of global terrestrial GPP has not been well investigated. In this study, global terrestrial GPP during 1981?2016 was simulated with the process-based Boreal Ecosystem Productivity Simulator model. Then, the drought risk of GPP was quantified as the product of drought probability and reduction of GPP caused by drought, which was determined using the standardized precipitation evapotranspiration index. During the study period, the drought risk of GPP was high in the southeastern United States, most of South America, southern Europe, central and eastern Africa, eastern and southeastern Asia, and eastern Australia. It was low at some high latitudes of the Northern Hemisphere and in part of tropical South America, where terrestrial GPP increased slightly in drought years. The drought risk of terrestrial GPP was greater during 2000?2016 than during 1981?1999 in 21 out of 24 climatic zones. The global mean drought risk of GPP increased from 13.6 g C m?2 yr?1 during 1981?1999 to 19.3 g C m?2 yr?1 during 2000?2016. The increase in drought risk of GPP was mainly caused by the increase in drought vulnerability. Simulation experiments indicated that the drought vulnerability of GPP was mainly induced by climatic variability. This study advances our understanding on the impact of drought on GPP over the globe. |
BibTeX:
@article{He2021,
author = {He, Qiaoning and Ju, Weimin and Dai, Shengpei and He, Wei and Song, Lian and Wang, Songhan and Li, Xinchuan and Mao, Guangxiong},
title = {Drought Risk of Global Terrestrial Gross Primary Productivity Over the Last 40 Years Detected by a Remote Sensing-Driven Process Model},
journal = {Journal of Geophysical Research: Biogeosciences},
publisher = {John Wiley & Sons, Ltd},
year = {2021},
volume = {126},
number = {6},
pages = {e2020JG005944},
url = {https://doi.org/10.1029/2020JG005944},
doi = {10.1029/2020JG005944}
}
|
| Heiskanen L, Tuovinen J-P, Räsänen A, Virtanen T, Juutinen S, Lohila A, Penttilä T, Linkosalmi M, Mikola J, Laurila T and Aurela M (2021), "Carbon dioxide and methane exchange of a patterned subarctic fen during two contrasting growing seasons", Biogeosciences. Vol. 18(3), pp. 873-896. |
BibTeX:
@article{Heiskanen2021a,
author = {Heiskanen, L and Tuovinen, J.-P. and Räsänen, A and Virtanen, T and Juutinen, S and Lohila, A and Penttilä, T and Linkosalmi, M and Mikola, J and Laurila, T and Aurela, M},
title = {Carbon dioxide and methane exchange of a patterned subarctic fen during two contrasting growing seasons},
journal = {Biogeosciences},
year = {2021},
volume = {18},
number = {3},
pages = {873--896},
url = {https://bg.copernicus.org/articles/18/873/2021/},
doi = {10.5194/bg-18-873-2021}
}
|
| Helbig M, Gerken T, Beamesderfer ER, Baldocchi DD, Banerjee T, Biraud SC, Brown WOJ, Brunsell NA, Burakowski EA, Burns SP, Butterworth BJ, Chan WS, Davis KJ, Desai AR, Fuentes JD, Hollinger DY, Kljun N, Mauder M, Novick KA, Perkins JM, Rahn DA, Rey-Sanchez C, Santanello JA, Scott RL, Seyednasrollah B, Stoy PC, Sullivan RC, de Arellano JV-G, Wharton S, Yi C and Richardson AD (2021), "Integrating continuous atmospheric boundary layer and tower-based flux measurements to advance understanding of land-atmosphere interactions", Agricultural and Forest Meteorology. Vol. 307, pp. 108509. |
| Abstract: The atmospheric boundary layer mediates the exchange of energy, matter, and momentum between the land surface and the free troposphere, integrating a range of physical, chemical, and biological processes and is defined as the lowest layer of the atmosphere (ranging from a few meters to 3 km). In this review, we investigate how continuous, automated observations of the atmospheric boundary layer can enhance the scientific value of co-located eddy covariance measurements of land-atmosphere fluxes of carbon, water, and energy, as are being made at FLUXNET sites worldwide. We highlight four key opportunities to integrate tower-based flux measurements with continuous, long-term atmospheric boundary layer measurements: (1) to interpret surface flux and atmospheric boundary layer exchange dynamics and feedbacks at flux tower sites, (2) to support flux footprint modelling, the interpretation of surface fluxes in heterogeneous and mountainous terrain, and quality control of eddy covariance flux measurements, (3) to support regional-scale modeling and upscaling of surface fluxes to continental scales, and (4) to quantify land-atmosphere coupling and validate its representation in Earth system models. Adding a suite of atmospheric boundary layer measurements to eddy covariance flux tower sites, and supporting the sharing of these data to tower networks, would allow the Earth science community to address new emerging research questions, better interpret ongoing flux tower measurements, and would present novel opportunities for collaborations between FLUXNET scientists and atmospheric and remote sensing scientists. |
BibTeX:
@article{Helbig2021,
author = {Helbig, Manuel and Gerken, Tobias and Beamesderfer, Eric R and Baldocchi, Dennis D and Banerjee, Tirtha and Biraud, Sébastien C and Brown, William O J and Brunsell, Nathaniel A and Burakowski, Elizabeth A and Burns, Sean P and Butterworth, Brian J and Chan, W Stephen and Davis, Kenneth J and Desai, Ankur R and Fuentes, Jose D and Hollinger, David Y and Kljun, Natascha and Mauder, Matthias and Novick, Kimberly A and Perkins, John M and Rahn, David A and Rey-Sanchez, Camilo and Santanello, Joseph A and Scott, Russell L and Seyednasrollah, Bijan and Stoy, Paul C and Sullivan, Ryan C and de Arellano, Jordi Vilà-Guerau and Wharton, Sonia and Yi, Chuixiang and Richardson, Andrew D},
title = {Integrating continuous atmospheric boundary layer and tower-based flux measurements to advance understanding of land-atmosphere interactions},
journal = {Agricultural and Forest Meteorology},
year = {2021},
volume = {307},
pages = {108509},
url = {https://www.sciencedirect.com/science/article/pii/S0168192321001933},
doi = {10.1016/j.agrformet.2021.108509}
}
|
| Hermanns F, Pohl F, Rebmann C, Schulz G, Werban U and Lausch A (2021), "Inferring Grassland Drought Stress with Unsupervised Learning from Airborne Hyperspectral VNIR Imagery". |
| Abstract: The 2018–2019 Central European drought had a grave impact on natural and managed ecosystems, affecting their health and productivity. We examined patterns in hyperspectral VNIR imagery using an unsupervised learning approach to improve ecosystem monitoring and the understanding of grassland drought responses. The main objectives of this study were (1) to evaluate the application of simplex volume maximisation (SiVM), an unsupervised learning method, for the detection of grassland drought stress in high-dimensional remote sensing data at the ecosystem scale and (2) to analyse the contributions of different spectral plant and soil traits to the computed stress signal. The drought status of the research site was assessed with a non-parametric standardised precipitation–evapotranspiration index (SPEI) and soil moisture measurements. We used airborne HySpex VNIR-1800 data from spring 2018 and 2019 to compare vegetation condition at the onset of the drought with the state after one year. SiVM, an interpretable matrix factorisation technique, was used to derive typical extreme spectra (archetypes) from the hyperspectral data. The classification of archetypes allowed for the inference of qualitative drought stress levels. The results were evaluated using a set of geophysical measurements and vegetation indices as proxy variables for drought-inhibited vegetation growth. The successful application of SiVM for grassland stress detection at the ecosystem canopy scale was verified in a correlation analysis. The predictor importance was assessed with boosted beta regression. In the resulting interannual stress model, carotenoid-related variables had among the highest coefficient values. The significance of the photochemical reflectance index that uses 512 nm as reference wavelength (PRI512) demonstrates the value of combining imaging spectrometry and unsupervised learning for the monitoring of vegetation stress. It also shows the potential of archetypical reflectance spectra to be used for the remote estimation of photosynthetic efficiency. More conclusive results could be achieved by using vegetation measurements instead of proxy variables for evaluation. It must also be investigated how the method can be generalised across ecosystems. |
BibTeX:
@misc{Hermanns2021,
author = {Hermanns, Floris and Pohl, Felix and Rebmann, Corinna and Schulz, Gundula and Werban, Ulrike and Lausch, Angela},
title = {Inferring Grassland Drought Stress with Unsupervised Learning from Airborne Hyperspectral VNIR Imagery},
booktitle = {Remote Sensing},
year = {2021},
volume = {13},
number = {10},
doi = {10.3390/rs13101885}
}
|
| Hill-Pearce RE, Hillier A, Mussell Webber E, Charoenpornpukdee K, O’Doherty S, Mohn J, Zellweger C, Worton DR and Brewer PJ (2021), "Characterisation of gas reference materials for underpinning atmospheric measurements of stable isotopes of nitrous oxide", Atmospheric Measurement Techniques., August, 2021. Vol. 14(8), pp. 5447-5458. Copernicus GmbH. |
BibTeX:
@article{HillPearce2021,
author = {Hill-Pearce, Ruth E. and Hillier, Aimee and Mussell Webber, Eric and Charoenpornpukdee, Kanokrat and O’Doherty, Simon and Mohn, Joachim and Zellweger, Christoph and Worton, David R. and Brewer, Paul J.},
title = {Characterisation of gas reference materials for underpinning atmospheric measurements of stable isotopes of nitrous oxide},
journal = {Atmospheric Measurement Techniques},
publisher = {Copernicus GmbH},
year = {2021},
volume = {14},
number = {8},
pages = {5447--5458},
doi = {10.5194/amt-14-5447-2021}
}
|
| Holik L, Vranova V, Foltynova L and Acosta M (2021), "Forest soil properties under elevated CO2: A five-year experiment", European Journal of Soil Biology. Vol. 106, pp. 103346. |
| Abstract: Whether rising carbon dioxide (CO2) is causing changes in soil properties remains unclear. Therefore, the objective of our study was to determine the effects of elevated CO2 concentration on a mountain forest soil with respect to soil organic matter content and its quality, cation exchange capacity, nutrient availability and quantity, and activity of soil microbes. In our study, a young mountain beech–spruce forest soil was exposed to ambient (385 ppm) and elevated CO2 (700 ppm) concentrations for a 5-year period. We found that exposure of beech–spruce forest soil to elevated. CO2 over a 5-year period had no effect on the quantity of soil organic carbon or nitrogen or on the availability of nutrients. The cation exchange capacity decreased under both conditions, ambient and elevated CO2 (over a 5-year period). Changes in soil organic matter content, nutrient availability, and soil enzyme activities showed positive trend. Nevertheless, our results overall showed no significant impact of elevated CO2 on mountain beech-spruce forest soil through 5 years of exposure. |
BibTeX:
@article{Holik2021,
author = {Holik, Ladislav and Vranova, Valerie and Foltynova, Lenka and Acosta, Manuel},
title = {Forest soil properties under elevated CO2: A five-year experiment},
journal = {European Journal of Soil Biology},
year = {2021},
volume = {106},
pages = {103346},
url = {https://www.sciencedirect.com/science/article/pii/S1164556321000820},
doi = {10.1016/j.ejsobi.2021.103346}
}
|
| Holtmann A, Huth A, Pohl F, Rebmann C and Fischer R (2021), "Carbon Sequestration in Mixed Deciduous Forests: The Influence of Tree Size and Species Composition Derived from Model Experiments". |
| Abstract: Forests play an important role in climate regulation due to carbon sequestration. However, a deeper understanding of forest carbon flux dynamics is often missing due to a lack of information about forest structure and species composition, especially for non-even-aged and species-mixed forests. In this study, we integrated field inventory data of a species-mixed deciduous forest in Germany into an individual-based forest model to investigate daily carbon fluxes and to examine the role of tree size and species composition for stand productivity. This approach enables to reproduce daily carbon fluxes derived from eddy covariance measurements (R2 of 0.82 for gross primary productivity and 0.77 for ecosystem respiration). While medium-sized trees (stem diameter 30–60 cm) account for the largest share (66%) of total productivity at the study site, small (0–30 cm) and large trees (>60 cm) contribute less with 8.3% and 25.5% respectively. Simulation experiments indicate that vertical stand structure and shading influence forest productivity more than species composition. Hence, it is important to incorporate small-scale information about forest stand structure into modelling studies to decrease uncertainties of carbon dynamic predictions. |
BibTeX:
@misc{Holtmann2021,
author = {Holtmann, Anne and Huth, Andreas and Pohl, Felix and Rebmann, Corinna and Fischer, Rico},
title = {Carbon Sequestration in Mixed Deciduous Forests: The Influence of Tree Size and Species Composition Derived from Model Experiments},
booktitle = {Forests},
year = {2021},
volume = {12},
number = {6},
doi = {10.3390/f12060726}
}
|
| Hrachowitz M, Stockinger M, Coenders-Gerrits M, van der Ent R, Bogena H, Lücke A and Stumpp C (2021), "Reduction of vegetation-accessible water storage capacity after deforestation affects catchment travel time distributions and increases young water fractions in a headwater catchment", Hydrology and Earth System Sciences. Vol. 25(9), pp. 4887-4915. |
BibTeX:
@article{Hrachowitz2021,
author = {Hrachowitz, M and Stockinger, M and Coenders-Gerrits, M and van der Ent, R and Bogena, H and Lücke, A and Stumpp, C},
title = {Reduction of vegetation-accessible water storage capacity after deforestation affects catchment travel time distributions and increases young water fractions in a headwater catchment},
journal = {Hydrology and Earth System Sciences},
year = {2021},
volume = {25},
number = {9},
pages = {4887--4915},
url = {https://hess.copernicus.org/articles/25/4887/2021/},
doi = {10.5194/hess-25-4887-2021}
}
|
| Huber R, D'Onofrio C, Devaraju A, Klump J, Loescher HW, Kindermann S, Guru S, Grant M, Morris B, Wyborn L, Evans B, Goldfarb D, Genazzio MA, Ren X, Magagna B, Thiemann H and Stocker M (2021), "Integrating data and analysis technologies within leading environmental research infrastructures: Challenges and approaches", Ecological Informatics., mar, 2021. Vol. 61, pp. 101245. |
BibTeX:
@article{Huber2021,
author = {Huber, Robert and D'Onofrio, Claudio and Devaraju, Anusuriya and Klump, Jens and Loescher, Henry W. and Kindermann, Stephan and Guru, Siddeswara and Grant, Mark and Morris, Beryl and Wyborn, Lesley and Evans, Ben and Goldfarb, Doron and Genazzio, Melissa A. and Ren, Xiaoli and Magagna, Barbara and Thiemann, Hannes and Stocker, Markus},
title = {Integrating data and analysis technologies within leading environmental research infrastructures: Challenges and approaches},
journal = {Ecological Informatics},
year = {2021},
volume = {61},
pages = {101245},
url = {https://linkinghub.elsevier.com/retrieve/pii/S1574954121000364},
doi = {10.1016/j.ecoinf.2021.101245}
}
|
| Irvin J, Zhou S, McNicol G, Lu F, Liu V, Fluet-Chouinard E, Ouyang Z, Knox SH, Lucas-Moffat A, Trotta C, Papale D, Vitale D, Mammarella I, Alekseychik P, Aurela M, Avati A, Baldocchi D, Bansal S, Bohrer G, Campbell DI, Chen J, Chu H, Dalmagro HJ, Delwiche KB, Desai AR, Euskirchen E, Feron S, Goeckede M, Heimann M, Helbig M, Helfter C, Hemes KS, Hirano T, Iwata H, Jurasinski G, Kalhori A, Kondrich A, Lai DYF, Lohila A, Malhotra A, Merbold L, Mitra B, Ng A, Nilsson MB, Noormets A, Peichl M, Rey-Sanchez AC, Richardson AD, Runkle BRK, Schäfer KVR, Sonnentag O, Stuart-Haëntjens E, Sturtevant C, Ueyama M, Valach AC, Vargas R, Vourlitis GL, Ward EJ, Wong GX, Zona D, Alberto MCR, Billesbach DP, Celis G, Dolman H, Friborg T, Fuchs K, Gogo S, Gondwe MJ, Goodrich JP, Gottschalk P, Hörtnagl L, Jacotot A, Koebsch F, Kasak K, Maier R, Morin TH, Nemitz E, Oechel WC, Oikawa PY, Ono K, Sachs T, Sakabe A, Schuur EA, Shortt R, Sullivan RC, Szutu DJ, Tuittila E-S, Varlagin A, Verfaillie JG, Wille C, Windham-Myers L, Poulter B and Jackson RB (2021), "Gap-filling eddy covariance methane fluxes: Comparison of machine learning model predictions and uncertainties at FLUXNET-CH4 wetlands", Agricultural and Forest Meteorology. Vol. 308-309, pp. 108528. |
| Abstract: Time series of wetland methane fluxes measured by eddy covariance require gap-filling to estimate daily, seasonal, and annual emissions. Gap-filling methane fluxes is challenging because of high variability and complex responses to multiple drivers. To date, there is no widely established gap-filling standard for wetland methane fluxes, with regards both to the best model algorithms and predictors. This study synthesizes results of different gap-filling methods systematically applied at 17 wetland sites spanning boreal to tropical regions and including all major wetland classes and two rice paddies. Procedures are proposed for: 1) creating realistic artificial gap scenarios, 2) training and evaluating gap-filling models without overstating performance, and 3) predicting half-hourly methane fluxes and annual emissions with realistic uncertainty estimates. Performance is compared between a conventional method (marginal distribution sampling) and four machine learning algorithms. The conventional method achieved similar median performance as the machine learning models but was worse than the best machine learning models and relatively insensitive to predictor choices. Of the machine learning models, decision tree algorithms performed the best in cross-validation experiments, even with a baseline predictor set, and artificial neural networks showed comparable performance when using all predictors. Soil temperature was frequently the most important predictor whilst water table depth was important at sites with substantial water table fluctuations, highlighting the value of data on wetland soil conditions. Raw gap-filling uncertainties from the machine learning models were underestimated and we propose a method to calibrate uncertainties to observations. The python code for model development, evaluation, and uncertainty estimation is publicly available. This study outlines a modular and robust machine learning workflow and makes recommendations for, and evaluates an improved baseline of, methane gap-filling models that can be implemented in multi-site syntheses or standardized products from regional and global flux networks (e.g., FLUXNET). |
BibTeX:
@article{Irvin2021,
author = {Irvin, Jeremy and Zhou, Sharon and McNicol, Gavin and Lu, Fred and Liu, Vincent and Fluet-Chouinard, Etienne and Ouyang, Zutao and Knox, Sara Helen and Lucas-Moffat, Antje and Trotta, Carlo and Papale, Dario and Vitale, Domenico and Mammarella, Ivan and Alekseychik, Pavel and Aurela, Mika and Avati, Anand and Baldocchi, Dennis and Bansal, Sheel and Bohrer, Gil and Campbell, David I and Chen, Jiquan and Chu, Housen and Dalmagro, Higo J and Delwiche, Kyle B and Desai, Ankur R and Euskirchen, Eugenie and Feron, Sarah and Goeckede, Mathias and Heimann, Martin and Helbig, Manuel and Helfter, Carole and Hemes, Kyle S and Hirano, Takashi and Iwata, Hiroki and Jurasinski, Gerald and Kalhori, Aram and Kondrich, Andrew and Lai, Derrick Y F and Lohila, Annalea and Malhotra, Avni and Merbold, Lutz and Mitra, Bhaskar and Ng, Andrew and Nilsson, Mats B and Noormets, Asko and Peichl, Matthias and Rey-Sanchez, A Camilo and Richardson, Andrew D and Runkle, Benjamin R K and Schäfer, Karina V R and Sonnentag, Oliver and Stuart-Haëntjens, Ellen and Sturtevant, Cove and Ueyama, Masahito and Valach, Alex C and Vargas, Rodrigo and Vourlitis, George L and Ward, Eric J and Wong, Guan Xhuan and Zona, Donatella and Alberto, Ma. Carmelita R and Billesbach, David P and Celis, Gerardo and Dolman, Han and Friborg, Thomas and Fuchs, Kathrin and Gogo, Sébastien and Gondwe, Mangaliso J and Goodrich, Jordan P and Gottschalk, Pia and Hörtnagl, Lukas and Jacotot, Adrien and Koebsch, Franziska and Kasak, Kuno and Maier, Regine and Morin, Timothy H and Nemitz, Eiko and Oechel, Walter C and Oikawa, Patricia Y and Ono, Keisuke and Sachs, Torsten and Sakabe, Ayaka and Schuur, Edward A and Shortt, Robert and Sullivan, Ryan C and Szutu, Daphne J and Tuittila, Eeva-Stiina and Varlagin, Andrej and Verfaillie, Joeseph G and Wille, Christian and Windham-Myers, Lisamarie and Poulter, Benjamin and Jackson, Robert B},
title = {Gap-filling eddy covariance methane fluxes: Comparison of machine learning model predictions and uncertainties at FLUXNET-CH4 wetlands},
journal = {Agricultural and Forest Meteorology},
year = {2021},
volume = {308-309},
pages = {108528},
url = {https://www.sciencedirect.com/science/article/pii/S0168192321002124},
doi = {10.1016/j.agrformet.2021.108528}
}
|
| Jackson TD, Sethi S, Dellwik E, Angelou N, Bunce A, van Emmerik T, Duperat M, Ruel J-C, Wellpott A, Van Bloem S, Achim A, Kane B, Ciruzzi DM, Loheide II SP, James K, Burcham D, Moore J, Schindler D, Kolbe S, Wiegmann K, Rudnicki M, Lieffers VJ, Selker J, Gougherty AV, Newson T, Koeser A, Miesbauer J, Samelson R, Wagner J, Ambrose AR, Detter A, Rust S, Coomes D and Gardiner B (2021), "The motion of trees in the wind: a data synthesis", Biogeosciences. Vol. 18(13), pp. 4059-4072. |
BibTeX:
@article{Jackson2021,
author = {Jackson, T D and Sethi, S and Dellwik, E and Angelou, N and Bunce, A and van Emmerik, T and Duperat, M and Ruel, J.-C. and Wellpott, A and Van Bloem, S and Achim, A and Kane, B and Ciruzzi, D M and Loheide II, S P and James, K and Burcham, D and Moore, J and Schindler, D and Kolbe, S and Wiegmann, K and Rudnicki, M and Lieffers, V J and Selker, J and Gougherty, A V and Newson, T and Koeser, A and Miesbauer, J and Samelson, R and Wagner, J and Ambrose, A R and Detter, A and Rust, S and Coomes, D and Gardiner, B},
title = {The motion of trees in the wind: a data synthesis},
journal = {Biogeosciences},
year = {2021},
volume = {18},
number = {13},
pages = {4059--4072},
url = {https://bg.copernicus.org/articles/18/4059/2021/},
doi = {10.5194/bg-18-4059-2021}
}
|
| Jacobs E, Bittig HC, Gräwe U, Graves CA, Glockzin M, Müller JD, Schneider B and Rehder G (2021), "Upwelling-induced trace gas dynamics in the Baltic Sea inferred from 8∼years of autonomous measurements on a ship of opportunity", Biogeosciences. Vol. 18(8), pp. 2679-2709. |
BibTeX:
@article{Jacobs2021,
author = {Jacobs, E and Bittig, H C and Gräwe, U and Graves, C A and Glockzin, M and Müller, J D and Schneider, B and Rehder, G},
title = {Upwelling-induced trace gas dynamics in the Baltic Sea inferred from 8∼years of autonomous measurements on a ship of opportunity},
journal = {Biogeosciences},
year = {2021},
volume = {18},
number = {8},
pages = {2679--2709},
url = {https://bg.copernicus.org/articles/18/2679/2021/},
doi = {10.5194/bg-18-2679-2021}
}
|
| Johnston ASA, Meade A, Ardö J, Arriga N, Black A, Blanken PD, Bonal D, Brümmer C, Cescatti A, Dušek J, Graf A, Gioli B, Goded I, Gough CM, Ikawa H, Jassal R, Kobayashi H, Magliulo V, Manca G, Montagnani L, Moyano FE, Olesen JE, Sachs T, Shao C, Tagesson T, Wohlfahrt G, Wolf S, Woodgate W, Varlagin A and Venditti C (2021), "Temperature thresholds of ecosystem respiration at a global scale", Nature Ecology & Evolution., apr, 2021. Vol. 5(4), pp. 487-494. |
BibTeX:
@article{Johnston2021,
author = {Johnston, Alice S A and Meade, Andrew and Ardö, Jonas and Arriga, Nicola and Black, Andy and Blanken, Peter D and Bonal, Damien and Brümmer, Christian and Cescatti, Alessandro and Dušek, Jiří and Graf, Alexander and Gioli, Beniamino and Goded, Ignacio and Gough, Christopher M and Ikawa, Hiroki and Jassal, Rachhpal and Kobayashi, Hideki and Magliulo, Vincenzo and Manca, Giovanni and Montagnani, Leonardo and Moyano, Fernando E and Olesen, Jørgen E and Sachs, Torsten and Shao, Changliang and Tagesson, Torbern and Wohlfahrt, Georg and Wolf, Sebastian and Woodgate, William and Varlagin, Andrej and Venditti, Chris},
title = {Temperature thresholds of ecosystem respiration at a global scale},
journal = {Nature Ecology & Evolution},
year = {2021},
volume = {5},
number = {4},
pages = {487--494},
url = {http://www.nature.com/articles/s41559-021-01398-z},
doi = {10.1038/s41559-021-01398-z}
}
|
| Junttila S, Kelly J, Kljun N, Aurela M, Klemedtsson L, Lohila A, Nilsson M, Rinne J, Tuittila E-S, Vestin P, Weslien P and Eklundh L (2021), "Upscaling Northern Peatland CO2 Fluxes Using Satellite Remote Sensing Data", Remote Sensing., feb, 2021. Vol. 13(4), pp. 818. |
| Abstract: Peatlands play an important role in the global carbon cycle as they contain a large soil carbon stock. However, current climate change could potentially shift peatlands from being carbon sinks to carbon sources. Remote sensing methods provide an opportunity to monitor carbon dioxide (CO2) exchange in peatland ecosystems at large scales under these changing conditions. In this study, we developed empirical models of the CO2 balance (net ecosystem exchange, NEE), gross primary production (GPP), and ecosystem respiration (ER) that could be used for upscaling CO2 fluxes with remotely sensed data. Two to three years of eddy covariance (EC) data from five peatlands in Sweden and Finland were compared to modelled NEE, GPP and ER based on vegetation indices from 10 m resolution Sentinel-2 MSI and land surface temperature from 1 km resolution MODIS data. To ensure a precise match between the EC data and the Sentinel-2 observations, a footprint model was applied to derive footprint-weighted daily means of the vegetation indices. Average model parameters for all sites were acquired with a leave-one-out-cross-validation procedure. Both the GPP and the ER models gave high agreement with the EC-derived fluxes (R2 = 0.70 and 0.56, NRMSE = 14% and 15%, respectively). The performance of the NEE model was weaker (average R2 = 0.36 and NRMSE = 13%). Our findings demonstrate that using optical and thermal satellite sensor data is a feasible method for upscaling the GPP and ER of northern boreal peatlands, although further studies are needed to investigate the sources of the unexplained spatial and temporal variation of the CO2 fluxes. |
BibTeX:
@article{Junttila2021,
author = {Junttila, Sofia and Kelly, Julia and Kljun, Natascha and Aurela, Mika and Klemedtsson, Leif and Lohila, Annalea and Nilsson, Mats and Rinne, Janne and Tuittila, Eeva-Stiina and Vestin, Patrik and Weslien, Per and Eklundh, Lars},
title = {Upscaling Northern Peatland CO2 Fluxes Using Satellite Remote Sensing Data},
journal = {Remote Sensing},
year = {2021},
volume = {13},
number = {4},
pages = {818},
url = {https://www.mdpi.com/2072-4292/13/4/818},
doi = {10.3390/rs13040818}
}
|
| Jurečka F, Fischer M, Hlavinka P, Balek J, Semerádová D, Bláhová M, Anderson MC, Hain C, Žalud Z and Trnka M (2021), "Potential of water balance and remote sensing-based evapotranspiration models to predict yields of spring barley and winter wheat in the Czech Republic", Agricultural Water Management. Vol. 256, pp. 107064. |
| Abstract: Indicators based on evapotranspiration (ET) provide useful information about surface water status, response of vegetation to drought stress, and potential growth limitations. The capability of ET-based indicators, including actual ET and the evaporative stress index (ESI), to predict crop yields of spring barley and winter wheat was analyzed for 33 districts of the Czech Republic. In this study, the ET-based indicators were computed using two different approaches: (i) a prognostic model, SoilClim, which computes the water balance based on ground weather observations and information about soil and land cover; (ii) the diagnostic Atmosphere–Land Exchange Inverse (ALEXI) model based primarily on remotely sensed land surface temperature data. The capability of both sets of indicators to predict yields of spring barley and winter wheat was tested using artificial neural networks (ANNs) applied to the adjusting number and timeframe of inputs during the growing season. Yield predictions based on ANNs were computed for both crops for all districts together, as well as for individual districts. The root mean square error (RMSE) and coefficient of determination (R2) between observed and predicted yields varied with date within the growing season and with the number of ANN inputs used for yield prediction. The period with the highest predictive capability started from early-June to mid-June. This optimal period for yield prediction was identifiable already at the lower number of ANN inputs, nevertheless, the accuracy of the prediction improved as more inputs were included within ANNs.The RMSE values for individual districts varied between 0.4 and 0.7 t ha–1 while R2 reached values of 0.5–0.8 during the optimal period. Results of the study demonstrated that ET-based indicators can be used for yield prediction in real time during the growing season and therefore have great potential for decision making at regional and district levels. |
BibTeX:
@article{Jurecka2021,
author = {Jurečka, František and Fischer, Milan and Hlavinka, Petr and Balek, Jan and Semerádová, Daniela and Bláhová, Monika and Anderson, Martha C and Hain, Christopher and Žalud, Zdeněk and Trnka, Miroslav},
title = {Potential of water balance and remote sensing-based evapotranspiration models to predict yields of spring barley and winter wheat in the Czech Republic},
journal = {Agricultural Water Management},
year = {2021},
volume = {256},
pages = {107064},
url = {https://www.sciencedirect.com/science/article/pii/S0378377421003292},
doi = {10.1016/j.agwat.2021.107064}
}
|
| Keane JB, Toet S, Ineson P, Weslien P, Stockdale JE and Klemedtsson L (2021), "Carbon Dioxide and Methane Flux Response and Recovery From Drought in a Hemiboreal Ombrotrophic Fen", Frontiers in Earth Science. Vol. 8 |
| Abstract: Globally peatlands store 500 Gt carbon (C), with northern blanket bogs accumulating 23 g C m−2 y−1 due to cool wet conditions. As a sink of carbon dioxide (CO2) peat bogs slow anthropogenic climate change, but warming climate increases the likelihood of drought which may reduce net ecosystem exchange (NEE) and increase soil respiration, tipping C sinks to sources. High water tables make bogs a globally important source of methane (CH4), another greenhouse gas (GHG) with a global warming potential (GWP) 34 times that of CO2. Warming may increase CH4 emissions, but drying may cause a reduction. Predicted species composition changes may also influence GHG balance, due to different traits such as erenchyma, e.g., Eriophorum vaginatum (eriophorum) and non-aerenchymatous species, e.g., Calluna vulgaris (heather). To understand how these ecosystems will respond to climate change, it is vital to measure GHG responses to drought at the species level. An automated chamber system, SkyLine2D, measured NEE and CH4 fluxes near-continuously from an ombrotrophic fen from August 2017 to September 2019. Four ecotypes were identified: sphagnum (Sphagnum spp), eriophorum, heather and water, hypothesizing that fluxes would significantly differ between ecotypes. The 2018 drought allowed comparison of fluxes between drought and non-drought years (May to September), and their recovery the following year. Methane emissions differed between ecotypes (p < 0.02), ordered high to low: eriophorum > sphagnum > water > heather, ranging from 23 to 8 mg CH4-C m−2 d−1. Daily NEE was similar between ecotypes (p > 0.7), but under 2018 drought conditions all ecotypes were greater sources of CO2 compared to 2019, losing 1.14 g and 0.24 g CO2-C m−2 d−1 respectively (p < 0.001). CH4 emissions were ca. 40% higher during 2018 than 2019, 17 mg compared to 12 mg CH4-C m−2 d−1 (p < 0.0001), and fluxes exhibited hysteresis with water table depth. A lag of 84–88 days was observed between rising water table and increased CH4 emissions. A significant interaction between ecotype and year showed fluxes from open water did not return to pre-drought levels. Our findings suggest that short-term drought may lead to a net increase in C emissions from northern wetlands. |
BibTeX:
@article{Keane2021,
author = {Keane, J B and Toet, S and Ineson, P and Weslien, P and Stockdale, J E and Klemedtsson, L},
title = {Carbon Dioxide and Methane Flux Response and Recovery From Drought in a Hemiboreal Ombrotrophic Fen},
journal = {Frontiers in Earth Science},
year = {2021},
volume = {8},
url = {https://www.frontiersin.org/article/10.3389/feart.2020.562401},
doi = {10.3389/feart.2020.562401}
}
|
| Kelly J, Kljun N, Eklundh L, Klemedtsson L, Liljebladh B, Olsson P-O, Weslien P and Xie X (2021), "Modelling and upscaling ecosystem respiration using thermal cameras and UAVs: Application to a peatland during and after a hot drought", Agricultural and Forest Meteorology., apr, 2021. Vol. 300, pp. 108330. |
BibTeX:
@article{Kelly2021,
author = {Kelly, Julia and Kljun, Natascha and Eklundh, Lars and Klemedtsson, Leif and Liljebladh, Bengt and Olsson, Per-Ola and Weslien, Per and Xie, Xianghua},
title = {Modelling and upscaling ecosystem respiration using thermal cameras and UAVs: Application to a peatland during and after a hot drought},
journal = {Agricultural and Forest Meteorology},
year = {2021},
volume = {300},
pages = {108330},
url = {https://linkinghub.elsevier.com/retrieve/pii/S0168192321000137},
doi = {10.1016/j.agrformet.2021.108330}
}
|
| Kim D, Baik J, Umair M and Choi M (2021), "Water use efficiency in terrestrial ecosystem over East Asia: Effects of climate regimes and land cover types", Science of The Total Environment. Vol. 773, pp. 145519. |
| Abstract: Water use efficiency (WUE) is an environmental factor to account for the metabolism of terrestrial ecosystems using various climate systems and vegetation types. It is estimated by the ratio of gross primary productivity (GPP) to evapotranspiration (ET), the largest carbon and water fluxes with respect to plant respiration. In this study, the WUE was calculated using GPP and ET from the community land model version 4.0 (CLM4.0), inclusive of the prognostic carbon-nitrogen model in the community earth system model (CESM). The estimated WUE in East Asia was analyzed for climate zones, land cover types, and water- and energy-limited zones, with aridity index (AI). Spatial variations from 2001 to 2015 in annual WUE gradually increased as latitude decreased, though small year-to-year differences appeared between monthly GPP and ET. Monthly WUE was lower in summer than fall because the water loss rate in summer was higher than the carbon assimilation increase. The WUE under arid conditions (AI<0.5) was lower than under humid conditions. The GPP, ET, and WUE were higher in the forest, savannas, cropland, and permanent wetland with dense vegetation or abundant water resources than in other land cover types. The WUE was lower in water-limited zones than in energy-limited zones due to the low amount of water to use for the physical processes of GPP and ET. Based on this study, we identified general spatial and temporal variations of carbon fluxes in East Asia with various climate zones and land cover types. |
BibTeX:
@article{Kim2021,
author = {Kim, Daeun and Baik, Jongjin and Umair, Muhammad and Choi, Minha},
title = {Water use efficiency in terrestrial ecosystem over East Asia: Effects of climate regimes and land cover types},
journal = {Science of The Total Environment},
year = {2021},
volume = {773},
pages = {145519},
url = {https://www.sciencedirect.com/science/article/pii/S0048969721005878},
doi = {10.1016/j.scitotenv.2021.145519}
}
|
| Kluge M, Wauthy M, Clemmensen KE, Wurzbacher C, Hawkes JA, Einarsdottir K, Rautio M, Stenlid J and Peura S (2021), "Declining fungal diversity in Arctic freshwaters along a permafrost thaw gradient", Global Change Biology., nov, 2021. Vol. 27(22), pp. 5889-5906. John Wiley & Sons, Ltd. |
| Abstract: Abstract Climate change?driven permafrost thaw has a strong influence on pan-Arctic regions, via, for example, the formation of thermokarst ponds. These ponds are hotspots of microbial carbon cycling and greenhouse gas production, and efforts have been put on disentangling the role of bacteria and archaea in recycling the increasing amounts of carbon arriving to the ponds from degrading watersheds. However, despite the well-established role of fungi in carbon cycling in the terrestrial environments, the interactions between permafrost thaw and fungal communities in Arctic freshwaters have remained unknown. We integrated data from 60 ponds in Arctic hydro-ecosystems, representing a gradient of permafrost integrity and spanning over five regions, namely Alaska, Greenland, Canada, Sweden, and Western Siberia. The results revealed that differences in pH and organic matter quality and availability were linked to distinct fungal community compositions and that a large fraction of the community represented unknown fungal phyla. Results display a 16%?19% decrease in fungal diversity, assessed by beta diversity, across ponds in landscapes with more degraded permafrost. At the same time, sites with similar carbon quality shared more species, aligning a shift in species composition with the quality and availability of terrestrial dissolved organic matter. We demonstrate that the degradation of permafrost has a strong negative impact on aquatic fungal diversity, likely via interactions with the carbon pool released from ancient deposits. This is expected to have implications for carbon cycling and climate feedback loops in the rapidly warming Arctic. |
BibTeX:
@article{Kluge2021,
author = {Kluge, Mariana and Wauthy, Maxime and Clemmensen, Karina Engelbrecht and Wurzbacher, Christian and Hawkes, Jeffrey A and Einarsdottir, Karolina and Rautio, Milla and Stenlid, Jan and Peura, Sari},
title = {Declining fungal diversity in Arctic freshwaters along a permafrost thaw gradient},
journal = {Global Change Biology},
publisher = {John Wiley & Sons, Ltd},
year = {2021},
volume = {27},
number = {22},
pages = {5889--5906},
url = {https://doi.org/10.1111/gcb.15852},
doi = {10.1111/gcb.15852}
}
|
| Kluge M, Wurzbacher C, Wauthy M, Clemmensen KE, Hawkes JA, Einarsdottir K, Stenlid J and Peura S (2021), "Community composition of aquatic fungi across the thawing Arctic", Scientific Data. Vol. 8(1), pp. 221. |
| Abstract: Thermokarst activity at permafrost sites releases considerable amounts of ancient carbon to the atmosphere. A large part of this carbon is released via thermokarst ponds, and fungi could be an important organismal group enabling its recycling. However, our knowledge about aquatic fungi in thermokarstic systems is extremely limited. In this study, we collected samples from five permafrost sites distributed across circumpolar Arctic and representing different stages of permafrost integrity. Surface water samples were taken from the ponds and, additionally, for most of the ponds also the detritus and sediment samples were taken. All the samples were extracted for total DNA, which was then amplified for the fungal ITS2 region of the ribosomal genes. These amplicons were sequenced using PacBio technology. Water samples were also collected to analyze the chemical conditions in the ponds, including nutrient status and the quality and quantity of dissolved organic carbon. This dataset gives a unique overview of the impact of the thawing permafrost on fungal communities and their potential role on carbon recycling. |
BibTeX:
@article{Kluge2021a,
author = {Kluge, Mariana and Wurzbacher, Christian and Wauthy, Maxime and Clemmensen, Karina Engelbrecht and Hawkes, Jeffrey Alistair and Einarsdottir, Karolina and Stenlid, Jan and Peura, Sari},
title = {Community composition of aquatic fungi across the thawing Arctic},
journal = {Scientific Data},
year = {2021},
volume = {8},
number = {1},
pages = {221},
url = {https://doi.org/10.1038/s41597-021-01005-7},
doi = {10.1038/s41597-021-01005-7}
}
|
| Knox SH, Bansal S, McNicol G, Schafer K, Sturtevant C, Ueyama M, Valach AC, Baldocchi D, Delwiche K, Desai AR, Euskirchen E, Liu J, Lohila A, Malhotra A, Melling L, Riley W, Runkle BRK, Turner J, Vargas R, Zhu Q, Alto T, Fluet-Chouinard E, Goeckede M, Melton JR, Sonnentag O, Vesala T, Ward E, Zhang Z, Feron S, Ouyang Z, Alekseychik P, Aurela M, Bohrer G, Campbell DI, Chen J, Chu H, Dalmagro HJ, Goodrich JP, Gottschalk P, Hirano T, Iwata H, Jurasinski G, Kang M, Koebsch F, Mammarella I, Nilsson MB, Ono K, Peichl M, Peltola O, Ryu Y, Sachs T, Sakabe A, Sparks JP, Tuittila E-S, Vourlitis GL, Wong GX, Windham-Myers L, Poulter B and Jackson RB (2021), "Identifying dominant environmental predictors of freshwater wetland methane fluxes across diurnal to seasonal time scales", Global Change Biology., aug, 2021. Vol. 27(15), pp. 3582-3604. John Wiley & Sons, Ltd. |
| Abstract: Abstract While wetlands are the largest natural source of methane (CH4) to the atmosphere, they represent a large source of uncertainty in the global CH4 budget due to the complex biogeochemical controls on CH4 dynamics. Here we present, to our knowledge, the first multi-site synthesis of how predictors of CH4 fluxes (FCH4) in freshwater wetlands vary across wetland types at diel, multiday (synoptic), and seasonal time scales. We used several statistical approaches (correlation analysis, generalized additive modeling, mutual information, and random forests) in a wavelet-based multi-resolution framework to assess the importance of environmental predictors, nonlinearities and lags on FCH4 across 23 eddy covariance sites. Seasonally, soil and air temperature were dominant predictors of FCH4 at sites with smaller seasonal variation in water table depth (WTD). In contrast, WTD was the dominant predictor for wetlands with smaller variations in temperature (e.g., seasonal tropical/subtropical wetlands). Changes in seasonal FCH4 lagged fluctuations in WTD by ∼17 ± 11 days, and lagged air and soil temperature by median values of 8 ± 16 and 5 ± 15 days, respectively. Temperature and WTD were also dominant predictors at the multiday scale. Atmospheric pressure (PA) was another important multiday scale predictor for peat-dominated sites, with drops in PA coinciding with synchronous releases of CH4. At the diel scale, synchronous relationships with latent heat flux and vapor pressure deficit suggest that physical processes controlling evaporation and boundary layer mixing exert similar controls on CH4 volatilization, and suggest the influence of pressurized ventilation in aerenchymatous vegetation. In addition, 1- to 4-h lagged relationships with ecosystem photosynthesis indicate recent carbon substrates, such as root exudates, may also control FCH4. By addressing issues of scale, asynchrony, and nonlinearity, this work improves understanding of the predictors and timing of wetland FCH4 that can inform future studies and models, and help constrain wetland CH4 emissions. |
BibTeX:
@article{Knox2021,
author = {Knox, Sara H and Bansal, Sheel and McNicol, Gavin and Schafer, Karina and Sturtevant, Cove and Ueyama, Masahito and Valach, Alex C and Baldocchi, Dennis and Delwiche, Kyle and Desai, Ankur R and Euskirchen, Eugenie and Liu, Jinxun and Lohila, Annalea and Malhotra, Avni and Melling, Lulie and Riley, William and Runkle, Benjamin R K and Turner, Jessica and Vargas, Rodrigo and Zhu, Qing and Alto, Tuula and Fluet-Chouinard, Etienne and Goeckede, Mathias and Melton, Joe R and Sonnentag, Oliver and Vesala, Timo and Ward, Eric and Zhang, Zhen and Feron, Sarah and Ouyang, Zutao and Alekseychik, Pavel and Aurela, Mika and Bohrer, Gil and Campbell, David I and Chen, Jiquan and Chu, Housen and Dalmagro, Higo J and Goodrich, Jordan P and Gottschalk, Pia and Hirano, Takashi and Iwata, Hiroki and Jurasinski, Gerald and Kang, Minseok and Koebsch, Franziska and Mammarella, Ivan and Nilsson, Mats B and Ono, Keisuke and Peichl, Matthias and Peltola, Olli and Ryu, Youngryel and Sachs, Torsten and Sakabe, Ayaka and Sparks, Jed P and Tuittila, Eeva-Stiina and Vourlitis, George L and Wong, Guan X and Windham-Myers, Lisamarie and Poulter, Benjamin and Jackson, Robert B},
title = {Identifying dominant environmental predictors of freshwater wetland methane fluxes across diurnal to seasonal time scales},
journal = {Global Change Biology},
publisher = {John Wiley & Sons, Ltd},
year = {2021},
volume = {27},
number = {15},
pages = {3582--3604},
url = {https://doi.org/10.1111/gcb.15661},
doi = {10.1111/gcb.15661}
}
|
| Kooijmans LMJ, Cho A, Ma J, Kaushik A, Haynes KD, Baker I, Luijkx IT, Groenink M, Peters W, Miller JB, Berry JA, Ogée J, Meredith LK, Sun W, Kohonen K-M, Vesala T, Mammarella I, Chen H, Spielmann FM, Wohlfahrt G, Berkelhammer M, Whelan ME, Maseyk K, Seibt U, Commane R, Wehr R and Krol M (2021), "Evaluation of carbonyl sulfide biosphere exchange in the Simple Biosphere Model (SiB4)", Biogeosciences. Vol. 18(24), pp. 6547-6565. |
BibTeX:
@article{Kooijmans2021,
author = {Kooijmans, L M J and Cho, A and Ma, J and Kaushik, A and Haynes, K D and Baker, I and Luijkx, I T and Groenink, M and Peters, W and Miller, J B and Berry, J A and Ogée, J and Meredith, L K and Sun, W and Kohonen, K.-M. and Vesala, T and Mammarella, I and Chen, H and Spielmann, F M and Wohlfahrt, G and Berkelhammer, M and Whelan, M E and Maseyk, K and Seibt, U and Commane, R and Wehr, R and Krol, M},
title = {Evaluation of carbonyl sulfide biosphere exchange in the Simple Biosphere Model (SiB4)},
journal = {Biogeosciences},
year = {2021},
volume = {18},
number = {24},
pages = {6547--6565},
url = {https://bg.copernicus.org/articles/18/6547/2021/},
doi = {10.5194/bg-18-6547-2021}
}
|
| Krich C, Migliavacca M, Miralles DG, Kraemer G, El-Madany TS, Reichstein M, Runge J and Mahecha MD (2021), "Functional convergence of biosphere--atmosphere interactions in response to meteorological conditions", Biogeosciences. Vol. 18(7), pp. 2379-2404. |
BibTeX:
@article{Krich2021,
author = {Krich, C and Migliavacca, M and Miralles, D G and Kraemer, G and El-Madany, T S and Reichstein, M and Runge, J and Mahecha, M D},
title = {Functional convergence of biosphere--atmosphere interactions in response to meteorological conditions},
journal = {Biogeosciences},
year = {2021},
volume = {18},
number = {7},
pages = {2379--2404},
url = {https://bg.copernicus.org/articles/18/2379/2021/},
doi = {10.5194/bg-18-2379-2021}
}
|
| Łakomiec P, Holst J, Friborg T, Crill P, Rakos N, Kljun N, Olsson P-O, Eklundh L, Persson A and Rinne J (2021), "Field-scale CH_4 emission at a subarctic mire with heterogeneous permafrost thaw status", Biogeosciences. Vol. 18(20), pp. 5811-5830. |
BibTeX:
@article{Lakomiec2021,
author = {Łakomiec, P and Holst, J and Friborg, T and Crill, P and Rakos, N and Kljun, N and Olsson, P.-O. and Eklundh, L and Persson, A and Rinne, J},
title = {Field-scale CH_4 emission at a subarctic mire with heterogeneous permafrost thaw status},
journal = {Biogeosciences},
year = {2021},
volume = {18},
number = {20},
pages = {5811--5830},
url = {https://bg.copernicus.org/articles/18/5811/2021/},
doi = {10.5194/bg-18-5811-2021}
}
|
| Lammirato C, Wallman M, Weslien P, Klemedtsson L and Rütting T (2021), "Measuring frequency and accuracy of annual nitrous oxide emission estimates", Agricultural and Forest Meteorology. Vol. 310, pp. 108624. |
| Abstract: Accurate estimates of cumulative N2O fluxes from agricultural soil are essential for quantifying global N2O emissions and for identifying effective mitigation strategies. This study focuses on the short term temporal variability of N2O fluxes, and on how the accuracy of annual cumulative estimates is affected by different (simulated) measuring frequencies of an automatic system based on the closed chamber method. Fluxes were measured with high temporal resolution (24 per day) for approximately one year on agricultural soil in the southwest of Sweden. The short-term temporal variability of N2O fluxes was considerable: the predictive power of measured fluxes decreased to negligible levels in a time frame of 4-5 h, and large intraday flux ranges were observed frequently, particularly in days with soil temperatures below 0∘C. A time of day well suited for consistently providing good estimates of the mean daily flux could not be identified. Consequently, the accuracy of annual emission estimates strongly depended on the measuring frequency. Multiple measurements per day were necessary for consistently quantifying annual emission estimates with accuracy. Accuracy improved with measuring frequency increasing up to four times per day, and higher frequencies generated negligible further improvements. Based on this study the following recommendations are made with regard to measuring frequency: i) measure four times per day for maximum accuracy and ii) measure twice per day for a good compromise between accuracy and the number of plots that can be monitored. |
BibTeX:
@article{Lammirato2021,
author = {Lammirato, C and Wallman, M and Weslien, P and Klemedtsson, L and Rütting, T},
title = {Measuring frequency and accuracy of annual nitrous oxide emission estimates},
journal = {Agricultural and Forest Meteorology},
year = {2021},
volume = {310},
pages = {108624},
url = {https://www.sciencedirect.com/science/article/pii/S0168192321003105},
doi = {10.1016/j.agrformet.2021.108624}
}
|
| Lau DCP, Jonsson A, Isles PDF, Creed IF and Bergström A (2021), "Lowered nutritional quality of plankton caused by global environmental changes", Global Change Biology., dec, 2021. Vol. 27(23), pp. 6294-6306. John Wiley & Sons, Ltd. |
| Abstract: Abstract Global environmental changes are causing widespread nutrient depletion, declines in the ratio of dissolved inorganic nitrogen (N) to total phosphorus (DIN:TP), and increases in both water temperature and terrestrial colored dissolved organic carbon (DOC) concentration (browning) in high-latitude northern lakes. Declining lake DIN:TP, warming, and browning alter the nutrient limitation regime and biomass of phytoplankton, but how these stressors together affect the nutritional quality in terms of polyunsaturated fatty acid (PUFA) contents of the pelagic food web components remains unknown. We assessed the fatty acid compositions of seston and zooplankton in 33 lakes across south-to-north and boreal-to-subarctic gradients in Sweden. Data showed higher lake DIN:TP in the south than in the north, and that boreal lakes were warmer and browner than subarctic lakes. Lake DIN:TP strongly affected the PUFA contents?especially eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA)?in seston, calanoids, and copepods (as a group), but not in cladocerans. The EPA+DHA contents increased by 123% in seston, 197% in calanoids, and 230% in copepods across a lake molar DIN:TP gradient from 0.17 to 14.53, indicating lower seston and copepod nutritional quality in the more N-limited lakes (those with lower DIN:TP). Water temperature affected EPA+DHA contents of zooplankton, especially cladocerans, but not seston. Cladoceran EPA+DHA contents were reduced by ca. 6% for every 1°C increase in surface water. Also, the EPA, DHA, or EPA+DHA contents of Bosmina, cyclopoids, and copepods increased in lakes with higher DOC concentrations or aromaticity. Our findings indicate that zooplankton food quality for higher consumers will decrease with warming alone (for cladocerans) or in combination with declining lake DIN:TP (for copepods), but impacts of these stressors are moderated by lake browning. Global environmental changes that drive northern lakes toward more N-limited, warmer, and browner conditions will reduce PUFA availability and nutritional quality of the pelagic food web components. |
BibTeX:
@article{Lau2021,
author = {Lau, Danny C P and Jonsson, Anders and Isles, Peter D F and Creed, Irena F and Bergström, Ann‑Kristin},
title = {Lowered nutritional quality of plankton caused by global environmental changes},
journal = {Global Change Biology},
publisher = {John Wiley & Sons, Ltd},
year = {2021},
volume = {27},
number = {23},
pages = {6294--6306},
url = {https://doi.org/10.1111/gcb.15887},
doi = {10.1111/gcb.15887}
}
|
| Laudon H, Hasselquist EM, Peichl M, Lindgren K, Sponseller R, Lidman F, Kuglerová L, Hasselquist NJ, Bishop K, Nilsson MB and Ågren AM (2021), "Northern landscapes in transition: Evidence, approach and ways forward using the Krycklan Catchment Study", Hydrological Processes., apr, 2021. Vol. 35(4), pp. e14170. John Wiley & Sons, Ltd. |
| Abstract: Abstract Improving our ability to detect changes in terrestrial and aquatic systems is a grand challenge in the environmental sciences. In a world experiencing increasingly rapid rates of climate change and ecosystem transformation, our ability to understand and predict how, when, where, and why changes occur is essential for adapting and mitigating human behaviours. In this context, long-term field research infrastructures have a fundamentally important role to play. For northern boreal landscapes, the Krycklan Catchment Study (KCS) has supported monitoring and research aimed at revealing these changes since it was initiated in 1980. Early studies focused on forest regeneration and microclimatic conditions, nutrient balances and forest hydrology, which included monitoring climate variables, water balance components, and stream water chemistry. The research infrastructure has expanded over the years to encompass a 6790?ha catchment, which currently includes 11 gauged streams, ca. 1000 soil lysimeters, 150 groundwater wells, >500 permanent forest inventory plots, and a 150 m tall tower (a combined ecosystem-atmosphere station of the ICOS, Integrated Carbon Observation System) for measurements of atmospheric gas concentrations and biosphere-atmosphere exchanges of carbon, water, and energy. In addition, the KCS has also been the focus of numerous high resolution multi-spectral LiDAR measurements and large scale experiments. This large collection of equipment and data generation supports a range of disciplinary studies, but more importantly fosters multi-, trans-, and interdisciplinary research opportunities. The KCS attracts a broad collection of scientists, including biogeochemists, ecologists, foresters, geologists, hydrologists, limnologists, soil scientists, and social scientists, all of whom bring their knowledge and experience to the site. The combination of long-term monitoring, shorter-term research projects, and large-scale experiments, including manipulations of climate and various forest management practices, has contributed much to our understanding of boreal landscape functioning, while also supporting the development of models and guidelines for research, policy, and management. |
BibTeX:
@article{Laudon2021,
author = {Laudon, Hjalmar and Hasselquist, Eliza Maher and Peichl, Matthias and Lindgren, Kim and Sponseller, Ryan and Lidman, Fredrik and Kuglerová, Lenka and Hasselquist, Niles J and Bishop, Kevin and Nilsson, Mats B and Ågren, Anneli M},
title = {Northern landscapes in transition: Evidence, approach and ways forward using the Krycklan Catchment Study},
journal = {Hydrological Processes},
publisher = {John Wiley & Sons, Ltd},
year = {2021},
volume = {35},
number = {4},
pages = {e14170},
url = {https://doi.org/10.1002/hyp.14170},
doi = {10.1002/hyp.14170}
}
|
| Lembrechts JJ, van den Hoogen J, Aalto J, Ashcroft MB, De Frenne P, Kemppinen J, Kopecký M, Luoto M, Maclean IMD, Crowther TW, Bailey JJ, Haesen S, Klinges DH, Niittynen P, Scheffers BR, Van Meerbeek K, Aartsma P, Abdalaze O, Abedi M, Aerts R, Ahmadian N, Ahrends A, Alatalo JM, Alexander JM, Allonsius CN, Altman J, Ammann C, Andres C, Andrews C, Ardö J, Arriga N, Arzac A, Aschero V, Assis RL, Assmann JJ, Bader MY, Bahalkeh K, Barančok P, Barrio IC, Barros A, Barthel M, Basham EW, Bauters M, Bazzichetto M, Marchesini LB, Bell MC, Benavides JC, Benito Alonso JL, Berauer BJ, Bjerke JW, Björk RG, Björkman MP, Björnsdóttir K, Blonder B, Boeckx P, Boike J, Bokhorst S, Brum BNS, Brůna J, Buchmann N, Buysse P, Camargo JL, Campoe OC, Candan O, Canessa R, Cannone N, Carbognani M, Carnicer J, Casanova-Katny A, Cesarz S, Chojnicki B, Choler P, Chown SL, Cifuentes EF, Čiliak M, Contador T, Convey P, Cooper EJ, Cremonese E, Curasi SR, Curtis R, Cutini M, Dahlberg CJ, Daskalova GN, de Pablo MA, Della Chiesa S, Dengler J, Deronde B, Descombes P, Di Cecco V, Di Musciano M, Dick J, Dimarco RD, Dolezal J, Dorrepaal E, Dušek J, Eisenhauer N, Eklundh L, Erickson TE, Erschbamer B, Eugster W, Ewers RM, Exton DA, Fanin N, Fazlioglu F, Feigenwinter I, Fenu G, Ferlian O, Fernández Calzado MR, Fernández-Pascual E, Finckh M, Higgens RF, Forte TGW, Freeman EC, Frei ER, Fuentes-Lillo E, García RA, García MB, Géron C, Gharun M, Ghosn D, Gigauri K, Gobin A, Goded I, Goeckede M, Gottschall F, Goulding K, Govaert S, Graae BJ, Greenwood S, Greiser C, Grelle A, Guénard B, Guglielmin M, Guillemot J, Haase P, Haider S, Halbritter AH, Hamid M, Hammerle A, Hampe A, Haugum SV, Hederová L, Heinesch B, Helfter C, Hepenstrick D, Herberich M, Herbst M, Hermanutz L, Hik DS, Hoffrén R, Homeier J, Hörtnagl L, Høye TT, Hrbacek F, Hylander K, Iwata H, Jackowicz-Korczynski MA, Jactel H, Järveoja J, Jastrzebowski S, Jentsch A, Jiménez JJ, Jónsdóttir IS, Jucker T, Jump AS, Juszczak R, Kanka R, Kašpar V, Kazakis G, Kelly J, Khuroo AA, Klemedtsson L, Klisz M, Kljun N, Knohl A, Kobler J, Kollár J, Kotowska MM, Kovács B, Kreyling J, Lamprecht A, Lang SI, Larson C, Larson K, Laska K, le Maire G, Leihy RI, Lens L, Liljebladh B, Lohila A, Lorite J, Loubet B, Lynn J, Macek M, Mackenzie R, Magliulo E, Maier R, Malfasi F, Máliš F, Man M, Manca G, Manco A, Manise T, Manolaki P, Marciniak F, Matula R, Mazzolari AC, Medinets S, Medinets V, Meeussen C, Merinero S, Mesquita RdCG, Meusburger K, Meysman FJR, Michaletz ST, Milbau A, Moiseev D, Moiseev P, Mondoni A, Monfries R, Montagnani L, Moriana-Armendariz M, Morra di Cella U, Mörsdorf M, Mosedale JR, Muffler L, Muñoz-Rojas M, Myers JA, Myers-Smith IH, Nagy L, Nardino M, Naujokaitis-Lewis I, Newling E, Nicklas L, Niedrist G, Niessner A, Nilsson MB, Normand S, Nosetto MD, Nouvellon Y, Nuñez MA, Ogaya R, Ogée J, Okello J, Olejnik J, Olesen JE, Opedal ØH, Orsenigo S, Palaj A, Pampuch T, Panov AV, Pärtel M, Pastor A, Pauchard A, Pauli H, Pavelka M, Pearse WD, Peichl M, Pellissier L, Penczykowski RM, Penuelas J, Petit Bon M, Petraglia A, Phartyal SS, Phoenix GK, Pio C, Pitacco A, Pitteloud C, Plichta R, Porro F, Portillo-Estrada M, Poulenard J, Poyatos R, Prokushkin AS, Puchalka R, Pușcaș M, Radujković D, Randall K, Ratier Backes A, Remmele S, Remmers W, Renault D, Risch AC, Rixen C, Robinson SA, Robroek BJM, Rocha AV, Rossi C, Rossi G, Roupsard O, Rubtsov AV, Saccone P, Sagot C, Sallo Bravo J, Santos CC, Sarneel JM, Scharnweber T, Schmeddes J, Schmidt M, Scholten T, Schuchardt M, Schwartz N, Scott T, Seeber J, Segalin de Andrade AC, Seipel T, Semenchuk P, Senior RA, Serra-Diaz JM, Sewerniak P, Shekhar A, Sidenko NV, Siebicke L, Siegwart Collier L, Simpson E, Siqueira DP, Sitková Z, Six J, Smiljanic M, Smith SW, Smith-Tripp S, Somers B, Sørensen MV, Souza JJLL, Souza BI, Souza Dias A, Spasojevic MJ, Speed JDM, Spicher F, Stanisci A, Steinbauer K, Steinbrecher R, Steinwandter M, Stemkovski M, Stephan JG, Stiegler C, Stoll S, Svátek M, Svoboda M, Tagesson T, Tanentzap AJ, Tanneberger F, Theurillat J-P, Thomas HJD, Thomas AD, Tielbörger K, Tomaselli M, Treier UA, Trouillier M, Turtureanu PD, Tutton R, Tyystjärvi VA, Ueyama M, Ujházy K, Ujházyová M, Uogintas D, Urban AV, Urban J, Urbaniak M, Ursu T-M, Vaccari FP, Van de Vondel S, van den Brink L, Van Geel M, Vandvik V, Vangansbeke P, Varlagin A, Veen GF, Veenendaal E, Venn SE, Verbeeck H, Verbrugggen E, Verheijen FGA, Villar L, Vitale L, Vittoz P, Vives-Ingla M, von Oppen J, Walz J, Wang R, Wang Y, Way RG, Wedegärtner REM, Weigel R, Wild J, Wilkinson M, Wilmking M, Wingate L, Winkler M, Wipf S, Wohlfahrt G, Xenakis G, Yang Y, Yu Z, Yu K, Zellweger F, Zhang J, Zhang Z, Zhao P, Ziembliʼnska K, Zimmermann R, Zong S, Zyryanov VI, Nijs I and Lenoir J (2021), "Global maps of soil temperature", Global Change Biology., dec, 2021. Vol. n/a(n/a) John Wiley & Sons, Ltd. |
| Abstract: Abstract Research in global change ecology relies heavily on global climatic grids derived from estimates of air temperature in open areas at around 2 m above the ground. These climatic grids do not reflect conditions below vegetation canopies and near the ground surface, where critical ecosystem functions occur and most terrestrial species reside. Here, we provide global maps of soil temperature and bioclimatic variables at a 1-km2 resolution for 0?5 and 5?15 cm soil depth. These maps were created by calculating the difference (i.e. offset) between in situ soil temperature measurements, based on time series from over 1200 1-km2 pixels (summarized from 8519 unique temperature sensors) across all the world's major terrestrial biomes, and coarse-grained air temperature estimates from ERA5-Land (an atmospheric reanalysis by the European Centre for Medium-Range Weather Forecasts). We show that mean annual soil temperature differs markedly from the corresponding gridded air temperature, by up to 10°C (mean = 3.0 ± 2.1°C), with substantial variation across biomes and seasons. Over the year, soils in cold and/or dry biomes are substantially warmer (+3.6 ± 2.3°C) than gridded air temperature, whereas soils in warm and humid environments are on average slightly cooler (?0.7 ± 2.3°C). The observed substantial and biome-specific offsets emphasize that the projected impacts of climate and climate change on near-surface biodiversity and ecosystem functioning are inaccurately assessed when air rather than soil temperature is used, especially in cold environments. The global soil-related bioclimatic variables provided here are an important step forward for any application in ecology and related disciplines. Nevertheless, we highlight the need to fill remaining geographic gaps by collecting more in situ measurements of microclimate conditions to further enhance the spatiotemporal resolution of global soil temperature products for ecological applications. |
BibTeX:
@article{Lembrechts2021,
author = {Lembrechts, Jonas J and van den Hoogen, Johan and Aalto, Juha and Ashcroft, Michael B and De Frenne, Pieter and Kemppinen, Julia and Kopecký, Martin and Luoto, Miska and Maclean, Ilya M D and Crowther, Thomas W and Bailey, Joseph J and Haesen, Stef and Klinges, David H and Niittynen, Pekka and Scheffers, Brett R and Van Meerbeek, Koenraad and Aartsma, Peter and Abdalaze, Otar and Abedi, Mehdi and Aerts, Rien and Ahmadian, Negar and Ahrends, Antje and Alatalo, Juha M and Alexander, Jake M and Allonsius, Camille Nina and Altman, Jan and Ammann, Christof and Andres, Christian and Andrews, Christopher and Ardö, Jonas and Arriga, Nicola and Arzac, Alberto and Aschero, Valeria and Assis, Rafael L and Assmann, Jakob Johann and Bader, Maaike Y and Bahalkeh, Khadijeh and Barančok, Peter and Barrio, Isabel C and Barros, Agustina and Barthel, Matti and Basham, Edmund W and Bauters, Marijn and Bazzichetto, Manuele and Marchesini, Luca Belelli and Bell, Michael C and Benavides, Juan C and Benito Alonso, José Luis and Berauer, Bernd J and Bjerke, Jarle W and Björk, Robert G and Björkman, Mats P and Björnsdóttir, Katrin and Blonder, Benjamin and Boeckx, Pascal and Boike, Julia and Bokhorst, Stef and Brum, Bárbara N S and Brůna, Josef and Buchmann, Nina and Buysse, Pauline and Camargo, José Luís and Campoe, Otávio C and Candan, Onur and Canessa, Rafaella and Cannone, Nicoletta and Carbognani, Michele and Carnicer, Jofre and Casanova-Katny, Angélica and Cesarz, Simone and Chojnicki, Bogdan and Choler, Philippe and Chown, Steven L and Cifuentes, Edgar F and Čiliak, Marek and Contador, Tamara and Convey, Peter and Cooper, Elisabeth J and Cremonese, Edoardo and Curasi, Salvatore R and Curtis, Robin and Cutini, Maurizio and Dahlberg, C Johan and Daskalova, Gergana N and de Pablo, Miguel Angel and Della Chiesa, Stefano and Dengler, Jürgen and Deronde, Bart and Descombes, Patrice and Di Cecco, Valter and Di Musciano, Michele and Dick, Jan and Dimarco, Romina D and Dolezal, Jiri and Dorrepaal, Ellen and Dušek, Jiří and Eisenhauer, Nico and Eklundh, Lars and Erickson, Todd E and Erschbamer, Brigitta and Eugster, Werner and Ewers, Robert M and Exton, Dan A and Fanin, Nicolas and Fazlioglu, Fatih and Feigenwinter, Iris and Fenu, Giuseppe and Ferlian, Olga and Fernández Calzado, M Rosa and Fernández-Pascual, Eduardo and Finckh, Manfred and Higgens, Rebecca Finger and Forte, T'ai G W and Freeman, Erika C and Frei, Esther R and Fuentes-Lillo, Eduardo and García, Rafael A and García, María B and Géron, Charly and Gharun, Mana and Ghosn, Dany and Gigauri, Khatuna and Gobin, Anne and Goded, Ignacio and Goeckede, Mathias and Gottschall, Felix and Goulding, Keith and Govaert, Sanne and Graae, Bente Jessen and Greenwood, Sarah and Greiser, Caroline and Grelle, Achim and Guénard, Benoit and Guglielmin, Mauro and Guillemot, Joannès and Haase, Peter and Haider, Sylvia and Halbritter, Aud H and Hamid, Maroof and Hammerle, Albin and Hampe, Arndt and Haugum, Siri V and Hederová, Lucia and Heinesch, Bernard and Helfter, Carole and Hepenstrick, Daniel and Herberich, Maximiliane and Herbst, Mathias and Hermanutz, Luise and Hik, David S and Hoffrén, Raúl and Homeier, Jürgen and Hörtnagl, Lukas and Høye, Toke T and Hrbacek, Filip and Hylander, Kristoffer and Iwata, Hiroki and Jackowicz-Korczynski, Marcin Antoni and Jactel, Hervé and Järveoja, Järvi and Jastrzebowski, Szymon and Jentsch, Anke and Jiménez, Juan J and Jónsdóttir, Ingibjörg S and Jucker, Tommaso and Jump, Alistair S and Juszczak, Radoslaw and Kanka, Róbert and Kašpar, Vít and Kazakis, George and Kelly, Julia and Khuroo, Anzar A and Klemedtsson, Leif and Klisz, Marcin and Kljun, Natascha and Knohl, Alexander and Kobler, Johannes and Kollár, Jozef and Kotowska, Martyna M and Kovács, Bence and Kreyling, Juergen and Lamprecht, Andrea and Lang, Simone I and Larson, Christian and Larson, Keith and Laska, Kamil and le Maire, Guerric and Leihy, Rachel I and Lens, Luc and Liljebladh, Bengt and Lohila, Annalea and Lorite, Juan and Loubet, Benjamin and Lynn, Joshua and Macek, Martin and Mackenzie, Roy and Magliulo, Enzo and Maier, Regine and Malfasi, Francesco and Máliš, František and Man, Matěj and Manca, Giovanni and Manco, Antonio and Manise, Tanguy and Manolaki, Paraskevi and Marciniak, Felipe and Matula, Radim and Mazzolari, Ana Clara and Medinets, Sergiy and Medinets, Volodymyr and Meeussen, Camille and Merinero, Sonia and Mesquita, Rita de Cássia Guimarães and Meusburger, Katrin and Meysman, Filip J R and Michaletz, Sean T and Milbau, Ann and Moiseev, Dmitry and Moiseev, Pavel and Mondoni, Andrea and Monfries, Ruth and Montagnani, Leonardo and Moriana-Armendariz, Mikel and Morra di Cella, Umberto and Mörsdorf, Martin and Mosedale, Jonathan R and Muffler, Lena and Muñoz-Rojas, Miriam and Myers, Jonathan A and Myers-Smith, Isla H and Nagy, Laszlo and Nardino, Marianna and Naujokaitis-Lewis, Ilona and Newling, Emily and Nicklas, Lena and Niedrist, Georg and Niessner, Armin and Nilsson, Mats B and Normand, Signe and Nosetto, Marcelo D and Nouvellon, Yann and Nuñez, Martin A and Ogaya, Romà and Ogée, Jérôme and Okello, Joseph and Olejnik, Janusz and Olesen, Jørgen Eivind and Opedal, Øystein H and Orsenigo, Simone and Palaj, Andrej and Pampuch, Timo and Panov, Alexey V and Pärtel, Meelis and Pastor, Ada and Pauchard, Aníbal and Pauli, Harald and Pavelka, Marian and Pearse, William D and Peichl, Matthias and Pellissier, Loïc and Penczykowski, Rachel M and Penuelas, Josep and Petit Bon, Matteo and Petraglia, Alessandro and Phartyal, Shyam S and Phoenix, Gareth K and Pio, Casimiro and Pitacco, Andrea and Pitteloud, Camille and Plichta, Roman and Porro, Francesco and Portillo-Estrada, Miguel and Poulenard, Jérôme and Poyatos, Rafael and Prokushkin, Anatoly S and Puchalka, Radoslaw and Pușcaș, Mihai and Radujković, Dajana and Randall, Krystal and Ratier Backes, Amanda and Remmele, Sabine and Remmers, Wolfram and Renault, David and Risch, Anita C and Rixen, Christian and Robinson, Sharon A and Robroek, Bjorn J M and Rocha, Adrian V and Rossi, Christian and Rossi, Graziano and Roupsard, Olivier and Rubtsov, Alexey V and Saccone, Patrick and Sagot, Clotilde and Sallo Bravo, Jhonatan and Santos, Cinthya C and Sarneel, Judith M and Scharnweber, Tobias and Schmeddes, Jonas and Schmidt, Marius and Scholten, Thomas and Schuchardt, Max and Schwartz, Naomi and Scott, Tony and Seeber, Julia and Segalin de Andrade, Ana Cristina and Seipel, Tim and Semenchuk, Philipp and Senior, Rebecca A and Serra-Diaz, Josep M and Sewerniak, Piotr and Shekhar, Ankit and Sidenko, Nikita V and Siebicke, Lukas and Siegwart Collier, Laura and Simpson, Elizabeth and Siqueira, David P and Sitková, Zuzana and Six, Johan and Smiljanic, Marko and Smith, Stuart W and Smith-Tripp, Sarah and Somers, Ben and Sørensen, Mia Vedel and Souza, José João L L and Souza, Bartolomeu Israel and Souza Dias, Arildo and Spasojevic, Marko J and Speed, James D M and Spicher, Fabien and Stanisci, Angela and Steinbauer, Klaus and Steinbrecher, Rainer and Steinwandter, Michael and Stemkovski, Michael and Stephan, Jörg G and Stiegler, Christian and Stoll, Stefan and Svátek, Martin and Svoboda, Miroslav and Tagesson, Torbern and Tanentzap, Andrew J and Tanneberger, Franziska and Theurillat, Jean-Paul and Thomas, Haydn J D and Thomas, Andrew D and Tielbörger, Katja and Tomaselli, Marcello and Treier, Urs Albert and Trouillier, Mario and Turtureanu, Pavel Dan and Tutton, Rosamond and Tyystjärvi, Vilna A and Ueyama, Masahito and Ujházy, Karol and Ujházyová, Mariana and Uogintas, Domas and Urban, Anastasiya V and Urban, Josef and Urbaniak, Marek and Ursu, Tudor-Mihai and Vaccari, Francesco Primo and Van de Vondel, Stijn and van den Brink, Liesbeth and Van Geel, Maarten and Vandvik, Vigdis and Vangansbeke, Pieter and Varlagin, Andrej and Veen, G F and Veenendaal, Elmar and Venn, Susanna E and Verbeeck, Hans and Verbrugggen, Erik and Verheijen, Frank G A and Villar, Luis and Vitale, Luca and Vittoz, Pascal and Vives-Ingla, Maria and von Oppen, Jonathan and Walz, Josefine and Wang, Runxi and Wang, Yifeng and Way, Robert G and Wedegärtner, Ronja E M and Weigel, Robert and Wild, Jan and Wilkinson, Matthew and Wilmking, Martin and Wingate, Lisa and Winkler, Manuela and Wipf, Sonja and Wohlfahrt, Georg and Xenakis, Georgios and Yang, Yan and Yu, Zicheng and Yu, Kailiang and Zellweger, Florian and Zhang, Jian and Zhang, Zhaochen and Zhao, Peng and Ziembliʼnska, Klaudia and Zimmermann, Reiner and Zong, Shengwei and Zyryanov, Viacheslav I and Nijs, Ivan and Lenoir, Jonathan},
title = {Global maps of soil temperature},
journal = {Global Change Biology},
publisher = {John Wiley & Sons, Ltd},
year = {2021},
volume = {n/a},
number = {n/a},
url = {https://doi.org/10.1111/gcb.16060},
doi = {10.1111/gcb.16060}
}
|
| Levin I, Hammer S, Kromer B, Preunkert S, Weller R and Worthy DE (2021), "RADIOCARBON IN GLOBAL TROPOSPHERIC CARBON DIOXIDE", Radiocarbon. , pp. 1-11. Cambridge University Press. |
| Abstract: Since the 1950s, observations of radiocarbon (14C) in tropospheric carbon dioxide (CO2) have been conducted in both hemispheres, documenting the so-called nuclear “bomb spike” and its transfer into the oceans and the terrestrial biosphere, the two compartments permanently exchanging carbon with the atmosphere. Results from the Heidelberg global network of Δ14C-CO2 observations are revisited here with respect to the insights and quantitative constraints they provided on these carbon exchange fluxes. The recent development of global and hemispheric trends of Δ14C-CO2 are further discussed in regard to their suitability to continue providing constraints for 14C-free fossil CO2 emission changes on the global and regional scale. |
BibTeX:
@article{Levin2021,
author = {Levin, Ingeborg and Hammer, Samuel and Kromer, Bernd and Preunkert, Susanne and Weller, Rolf and Worthy, Douglas E},
title = {RADIOCARBON IN GLOBAL TROPOSPHERIC CARBON DIOXIDE},
journal = {Radiocarbon},
publisher = {Cambridge University Press},
year = {2021},
pages = {1--11},
edition = {2021/12/23},
url = {https://www.cambridge.org/core/article/radiocarbon-in-global-tropospheric-carbon-dioxide/2FB547BD4488086C216BBD60A13740C3},
doi = {10.1017/RDC.2021.102}
}
|
| Levin I, Karstens U, Hammer S, DellaColetta J, Maier F and Gachkivskyi M (2021), "Limitations of the radon tracer method (RTM) to estimate regional greenhouse gas (GHG) emissions -- a case study for methane in Heidelberg", Atmospheric Chemistry and Physics. Vol. 21(23), pp. 17907-17926. |
BibTeX:
@article{Levin2021a,
author = {Levin, I and Karstens, U and Hammer, S and DellaColetta, J and Maier, F and Gachkivskyi, M},
title = {Limitations of the radon tracer method (RTM) to estimate regional greenhouse gas (GHG) emissions -- a case study for methane in Heidelberg},
journal = {Atmospheric Chemistry and Physics},
year = {2021},
volume = {21},
number = {23},
pages = {17907--17926},
url = {https://acp.copernicus.org/articles/21/17907/2021/},
doi = {10.5194/acp-21-17907-2021}
}
|
| Li H, Claremar B, Wu L, Hallgren C, Körnich H, Ivanell S and Sahlée E (2021), "A sensitivity study of the WRF model in offshore wind modeling over the Baltic Sea", Geoscience Frontiers. Vol. 12(6), pp. 101229. |
| Abstract: Accurate wind modeling is important for wind resources assessment and wind power forecasting. To improve the WRF model configuration for the offshore wind modeling over the Baltic Sea, this study performed a sensitivity study of the WRF model to multiple model configurations, including domain setup, grid resolution, sea surface temperature, land surface data, and atmosphere-wave coupling. The simulated offshore wind was evaluated against LiDAR observations under different wind directions, atmospheric stabilities, and sea status. Generally, the simulated wind profiles matched observations, despite systematic underestimations. Strengthening the forcing from the reanalysis data through reducing the number of nested domains played the largest role in improving wind modeling. Atmosphere-wave coupling further improved the simulated wind, especially under the growing and mature sea conditions. Increasing the vertical resolution, and updating the sea surface temperature and the land surface information only had a slight impact, mainly visible during very stable conditions. Increasing the horizontal resolution also only had a slight impact, most visible during unstable conditions. Our study can help to improve the wind resources assessment and wind power forecasting over the Baltic Sea. |
BibTeX:
@article{Li2021,
author = {Li, Huidong and Claremar, Björn and Wu, Lichuan and Hallgren, Christoffer and Körnich, Heiner and Ivanell, Stefan and Sahlée, Erik},
title = {A sensitivity study of the WRF model in offshore wind modeling over the Baltic Sea},
journal = {Geoscience Frontiers},
year = {2021},
volume = {12},
number = {6},
pages = {101229},
url = {https://www.sciencedirect.com/science/article/pii/S1674987121000931},
doi = {10.1016/j.gsf.2021.101229}
}
|
| Lian J, Bréon F-M, Broquet G, Lauvaux T, Zheng B, Ramonet M, Xueref-Remy I, Kotthaus S, Haeffelin M and Ciais P (2021), "Sensitivity to the sources of uncertainties in the modeling of atmospheric CO_2 concentration within and in the vicinity of Paris", Atmospheric Chemistry and Physics. Vol. 21(13), pp. 10707-10726. |
BibTeX:
@article{Lian2021,
author = {Lian, J and Bréon, F.-M. and Broquet, G and Lauvaux, T and Zheng, B and Ramonet, M and Xueref-Remy, I and Kotthaus, S and Haeffelin, M and Ciais, P},
title = {Sensitivity to the sources of uncertainties in the modeling of atmospheric CO_2 concentration within and in the vicinity of Paris},
journal = {Atmospheric Chemistry and Physics},
year = {2021},
volume = {21},
number = {13},
pages = {10707--10726},
url = {https://acp.copernicus.org/articles/21/10707/2021/},
doi = {10.5194/acp-21-10707-2021}
}
|
| Lickley M, Solomon S, Kinnison D, Krummel P, Mühle J, O’Doherty S, Prinn R, Rigby M, Stone KA, Wang P, Weiss R and Young D (2021), "Quantifying the Imprints of Stratospheric Contributions to Interhemispheric Differences in Tropospheric CFC‐11, CFC‐12, and N2O Abundances", Geophysical Research Letters., July, 2021. Vol. 48(15) American Geophysical Union (AGU). |
BibTeX:
@article{Lickley2021,
author = {Lickley, Megan and Solomon, Susan and Kinnison, Doug and Krummel, Paul and Mühle, Jens and O’Doherty, Simon and Prinn, Ronald and Rigby, Matthew and Stone, Kane A. and Wang, Peidong and Weiss, Ray and Young, Dickon},
title = {Quantifying the Imprints of Stratospheric Contributions to Interhemispheric Differences in Tropospheric CFC‐11, CFC‐12, and N2O Abundances},
journal = {Geophysical Research Letters},
publisher = {American Geophysical Union (AGU)},
year = {2021},
volume = {48},
number = {15},
doi = {10.1029/2021gl093700}
}
|
| Lin S, Li J, Liu Q, Gioli B, Paul-Limoges E, Buchmann N, Gharun M, Hörtnagl L, Foltýnová L, Dušek J, Li L and Yuan W (2021), "Improved global estimations of gross primary productivity of natural vegetation types by incorporating plant functional type", International Journal of Applied Earth Observation and Geoinformation. Vol. 100, pp. 102328. |
| Abstract: Satellite-based light use efficiency (LUE) models are important tools for estimating regional and global vegetation gross primary productivity (GPP). However, all LUE models assume a constant value of maximum LUE at canopy scale (LUEmaxcanopy) over a given vegetation type. This assumption is not supported by observed plant traits regulating LUEmaxcanopy, which varies greatly even within the same ecosystem type. In this study, we developed an improved satellite data driven GPP model by identifying the potential maximal GPP (GPPPOT) and their dominant climate control factor in various plant functional types (PFT), which takes into account both plant trait and climatic control inter-dependence. We selected 161 sites from the FLUXNET2015 dataset with eddy covariance CO2 flux data and continuous meteorology to derive GPPPOT and their dominant climate control factor of vegetation growth for 42 natural PFTs. Results showed that (1) under the same phenology and incident photosynthetic active radiation, the maximal variance of GPPPOT is found in different PFTs of forests (10.9 g C m−2 day−1) and in different climatic zones of grasslands (>10 g C m−2 day−1); (2) intra-annual change of GPP in tropical and arid climate zones is mostly driven by vapor pressure deficit (VPD) changes, while temperature is the dominant climate control factor in temperate, boreal and polar climate zones; even under the same climate condition, physiological stress in photosynthesis is different across PFTs; (3) the model that takes into account the plant trait difference across PFTs had a higher agreement with flux tower-based GPP data (GPPflux) than the GPP products that omit PFT differences. Such agreement was highest for natural vegetation cover sites (R2 = 0.77, RMSE = 1.79 g C m−2 day−1). These results suggest that global scale GPP models should incorporate both plant traits and their dominant climate control factor variance in various PFT to reduce the uncertainties in terrestrial carbon assessments. |
BibTeX:
@article{Lin2021,
author = {Lin, Shangrong and Li, Jing and Liu, Qinhuo and Gioli, Beniamino and Paul-Limoges, Eugenie and Buchmann, Nina and Gharun, Mana and Hörtnagl, Lukas and Foltýnová, Lenka and Dušek, Jiří and Li, Longhui and Yuan, Wenping},
title = {Improved global estimations of gross primary productivity of natural vegetation types by incorporating plant functional type},
journal = {International Journal of Applied Earth Observation and Geoinformation},
year = {2021},
volume = {100},
pages = {102328},
url = {https://www.sciencedirect.com/science/article/pii/S0303243421000350},
doi = {10.1016/j.jag.2021.102328}
}
|
| Lindroth A, Holst J, Linderson ML, Aurela M, Biermann T, Heliasz M, Chi J, Ibrom A, Kolari P, Klemedtsson L, Krasnova A, Laurila T, Lehner I, Lohila A, Mammarella I, Mölder M, Löfvenius MO, Peichl M, Pilegaard K, Soosaar K, Vesala T, Vestin P, Weslien P and Nilsson M (2021), "Erratum: Effects of drought and meteorological forcing on carbon and water fluxes in Nordic forests during the dry summer of 2018 (Philosophical Transactions of the Royal Society B: Biological Sciences (2020) 375 (20190516) DOI: 10.1098/rstb.2019.0516)", Philosophical Transactions of the Royal Society B: Biological Sciences. Vol. 376(1817) |
| Abstract: The originally published version of this paper incorrectly spelt the author Kaido Soosaar's name as Kaido Soosar. This has been corrected on the publisher's website. |
BibTeX:
@article{Lindroth2021,
author = {Lindroth, Anders and Holst, Jutta and Linderson, Maj Lena and Aurela, Mika and Biermann, Tobias and Heliasz, Michal and Chi, Jinshu and Ibrom, Andreas and Kolari, Pasi and Klemedtsson, Leif and Krasnova, Alisa and Laurila, Tuomas and Lehner, Irene and Lohila, Annalea and Mammarella, Ivan and Mölder, Meelis and Löfvenius, Mikaell Ottosson and Peichl, Matthias and Pilegaard, Kim and Soosaar, Kaido and Vesala, Timo and Vestin, Patrik and Weslien, Per and Nilsson, Mats},
title = {Erratum: Effects of drought and meteorological forcing on carbon and water fluxes in Nordic forests during the dry summer of 2018 (Philosophical Transactions of the Royal Society B: Biological Sciences (2020) 375 (20190516) DOI: 10.1098/rstb.2019.0516)},
journal = {Philosophical Transactions of the Royal Society B: Biological Sciences},
year = {2021},
volume = {376},
number = {1817},
doi = {10.1098/rstb.2020.0453}
}
|
| Liu Y, Wu C, Liu L, Gu C, Andrew Black T, Jassal RS, Hörtnagl L, Montagnani L, Moyano F, Varlagin A, Altaf Arain M and Govind A (2021), "Interannual and spatial variability of net ecosystem production in forests explained by an integrated physiological indicator in summer", Ecological Indicators. Vol. 129, pp. 107982. |
| Abstract: Understanding the feedback of ecosystem carbon uptake on climate change at temporal and spatial scales is crucial for developing ecosystem models. Previous studies have focused on the role of spring and autumn phenology in regulating carbon sequestration in forest stands, but few on the impact of physiological status in summer. However, plant accumulated the most carbon in summer compared with spring and autumn, therefore, it is of great significance to explore the role of summer phenological metrics on the variability of carbon sequestration. Using 514 site-years of flux data obtained at 40 FLUXNET sites including three forest ecosystems (i.e. evergreen needleleaf forest (ENF), deciduous broadleaf forest (DBF) and mixed forest (MF)) in Europe and North America, we compared the potential of physiological and phenological metrics of Gross Primary Production (GPP) and Ecosystem Respiration (RECO) in explaining the interannual and spatial variability (IAV and SV) of forest net ecosystem production (NEP). In view of the better performance of physiological metrics, we developed the maximum carbon uptake index (MCUI), which integrated the physiology metrics of photosynthesis and respiration in summer, and further explored its ability in explaining the IAV and SV of NEP. The results suggest that the MCUI had a better ability than respiration-growth length ratio (RGR) in predicting NEP for all three forest types. The interpretation of MCUI based on meteorological variables illustrated that the controlling meteorological factors of MCUI differed substantially among ecosystems. The summer shortwave radiation had the greatest influence on MCUI at DBF sites, while the soil water content played an important but opposite role at ENF and DBF sites, and no significant meteorological driver was found at MF sites. The higher potential of MCUI in explaining IAV and SV of NEP highlights the importance of summer physiology in controlling the forest carbon sequestration, and further confirms the significant role of peak plant growth in regulating carbon cycle of forest ecosystems. Understanding the drivers of peak plant growth is therefore of a great significance for further improving the precious of ecosystem model in the future. |
BibTeX:
@article{Liu2021,
author = {Liu, Ying and Wu, Chaoyang and Liu, Lin and Gu, Chengyan and Andrew Black, T and Jassal, Rachhpal S and Hörtnagl, Lukas and Montagnani, Leonardo and Moyano, Fernando and Varlagin, Andrej and Altaf Arain, M and Govind, Ajit},
title = {Interannual and spatial variability of net ecosystem production in forests explained by an integrated physiological indicator in summer},
journal = {Ecological Indicators},
year = {2021},
volume = {129},
pages = {107982},
url = {https://www.sciencedirect.com/science/article/pii/S1470160X21006476},
doi = {10.1016/j.ecolind.2021.107982}
}
|
| Lunt MF, Manning AJ, Allen G, Arnold T, Bauguitte SJ-B, Boesch H, Ganesan AL, Grant A, Helfter C, Nemitz E, O'Doherty SJ, Palmer PI, Pitt JR, Rennick C, Say D, Stanley KM, Stavert AR, Young D and Rigby M (2021), "Atmospheric observations consistent with reported decline in the UK's methane emissions (2013--2020)", Atmospheric Chemistry and Physics. Vol. 21(21), pp. 16257-16276. |
BibTeX:
@article{Lunt2021,
author = {Lunt, M F and Manning, A J and Allen, G and Arnold, T and Bauguitte, S J.-B. and Boesch, H and Ganesan, A L and Grant, A and Helfter, C and Nemitz, E and O'Doherty, S J and Palmer, P I and Pitt, J R and Rennick, C and Say, D and Stanley, K M and Stavert, A R and Young, D and Rigby, M},
title = {Atmospheric observations consistent with reported decline in the UK's methane emissions (2013--2020)},
journal = {Atmospheric Chemistry and Physics},
year = {2021},
volume = {21},
number = {21},
pages = {16257--16276},
url = {https://acp.copernicus.org/articles/21/16257/2021/},
doi = {10.5194/acp-21-16257-2021}
}
|
| Mahrt L, Nilsson E, Rutgersson A and Pettersson H (2021), "Vertical Divergence of the Atmospheric Momentum Flux near the Sea Surface at a Coastal Site", Journal of Physical Oceanography. Boston MA, USA Vol. 51(11), pp. 3529-3537. American Meteorological Society. |
BibTeX:
@article{Mahrt2021,
author = {Mahrt, L and Nilsson, Erik and Rutgersson, Anna and Pettersson, Heidi},
title = {Vertical Divergence of the Atmospheric Momentum Flux near the Sea Surface at a Coastal Site},
journal = {Journal of Physical Oceanography},
publisher = {American Meteorological Society},
year = {2021},
volume = {51},
number = {11},
pages = {3529--3537},
url = {https://journals.ametsoc.org/view/journals/phoc/51/11/JPO-D-21-0081.1.xml},
doi = {10.1175/JPO-D-21-0081.1}
}
|
| Maignan F, Abadie C, Remaud M, Kooijmans LMJ, Kohonen K-M, Commane R, Wehr R, Campbell JE, Belviso S, Montzka SA, Raoult N, Seibt U, Shiga YP, Vuichard N, Whelan ME and Peylin P (2021), "Carbonyl sulfide: comparing a mechanistic representation of the vegetation uptake in a land surface model and the leaf relative uptake approach", Biogeosciences. Vol. 18(9), pp. 2917-2955. |
BibTeX:
@article{Maignan2021,
author = {Maignan, F and Abadie, C and Remaud, M and Kooijmans, L M J and Kohonen, K.-M. and Commane, R and Wehr, R and Campbell, J E and Belviso, S and Montzka, S A and Raoult, N and Seibt, U and Shiga, Y P and Vuichard, N and Whelan, M E and Peylin, P},
title = {Carbonyl sulfide: comparing a mechanistic representation of the vegetation uptake in a land surface model and the leaf relative uptake approach},
journal = {Biogeosciences},
year = {2021},
volume = {18},
number = {9},
pages = {2917--2955},
url = {https://bg.copernicus.org/articles/18/2917/2021/},
doi = {10.5194/bg-18-2917-2021}
}
|
| Manco A, Brilli F, Famulari D, Gasbarra D, Gioli B, Vitale L, di Tommasi P, Loubet B, Arena C and Magliulo V (2021), "Cross-correlations of Biogenic Volatile Organic Compounds (BVOC) emissions typify different phenological stages and stressful events in a Mediterranean Sorghum plantation", Agricultural and Forest Meteorology. Vol. 303, pp. 108380. |
| Abstract: Climate change will affect the growing season and increase the occurrence of extreme stressful events, thus altering crop phenological phases and the associated emission of biogenic volatile organic compounds (BVOC). BVOC exchange has been poorly investigated in field crops, especially in the Mediterranean area. In this study we report continuous measurements of BVOC fluxes and CO2 net ecosystem exchange (NEE), together with environmental variables, green area index (GAI) and aboveground biomass (AGB) during a whole growing season in a grain sorghum (Sorghum bicolor x Sorghum sudangrass., cv. Nicol, Pioneer) plantation located in Southern Europe. Results of this intensive field campaign showed that, while the bare soil of our site was a sink of BVOC, the sorghum plantation became a source of oxygenated BVOC, mainly methanol and acetaldehyde, which were emitted over the season at an average rate of 0.137 ± 0.013 and 0.070 ± 0.004 nmol m−2 s−1, respectively. In addition, the application of the advanced data mining method of Self-Organizing Maps (SOM) revealed distinctive patterns of BVOC fluxes correlating with sorghum growth stages (GS): in the first stage (GS1), developing plantlets emitted a mixture of BVOC uniquely characterized by monoterpenes; in GS2, adult plants forming an homogeneous dense canopy emitted the most abundant fluxes of a mixture of oxygenated BVOC comprising methanol, acetaldehyde, formic acid, acetone, acetic acid and n-pentenol; once plants entered the flowering stage (in GS3), only a few BVOC continued to be emitted at the highest rates (i.e. formic acid, acetone, acetic acid, n-pentenol). Moreover, the application of SOM to a sub-set of BVOC fluxes highlighted the possibility to qualitatively differentiate stressful events of plant lodging and harvest cutting. In fact, enhanced emission of acetaldehyde distinguished the BVOC mixture emitted from lodged rather than from cut and harvested sorghum plants in the field. |
BibTeX:
@article{Manco2021,
author = {Manco, Antonio and Brilli, Federico and Famulari, Daniela and Gasbarra, Daniele and Gioli, Beniamino and Vitale, Luca and di Tommasi, Paul and Loubet, Benjamin and Arena, Carmen and Magliulo, Vincenzo},
title = {Cross-correlations of Biogenic Volatile Organic Compounds (BVOC) emissions typify different phenological stages and stressful events in a Mediterranean Sorghum plantation},
journal = {Agricultural and Forest Meteorology},
year = {2021},
volume = {303},
pages = {108380},
url = {https://www.sciencedirect.com/science/article/pii/S0168192321000630},
doi = {10.1016/j.agrformet.2021.108380}
}
|
| Manning AJ, Redington AL, Say D, O'Doherty S, Young D, Simmonds PG, Vollmer MK, Mühle J, Arduini J, Spain G, Wisher A, Maione M, Schuck TJ, Stanley K, Reimann S, Engel A, Krummel PB, Fraser PJ, Harth CM, Salameh PK, Weiss RF, Gluckman R, Brown PN, Watterson JD and Arnold T (2021), "Evidence of a recent decline in UK emissions of hydrofluorocarbons determined by the InTEM inverse model and atmospheric measurements", Atmospheric Chemistry and Physics. Vol. 21(16), pp. 12739-12755. |
BibTeX:
@article{Manning2021,
author = {Manning, A J and Redington, A L and Say, D and O'Doherty, S and Young, D and Simmonds, P G and Vollmer, M K and Mühle, J and Arduini, J and Spain, G and Wisher, A and Maione, M and Schuck, T J and Stanley, K and Reimann, S and Engel, A and Krummel, P B and Fraser, P J and Harth, C M and Salameh, P K and Weiss, R F and Gluckman, R and Brown, P N and Watterson, J D and Arnold, T},
title = {Evidence of a recent decline in UK emissions of hydrofluorocarbons determined by the InTEM inverse model and atmospheric measurements},
journal = {Atmospheric Chemistry and Physics},
year = {2021},
volume = {21},
number = {16},
pages = {12739--12755},
url = {https://acp.copernicus.org/articles/21/12739/2021/},
doi = {10.5194/acp-21-12739-2021}
}
|
| Marañón-Jiménez S, Radujković D, Verbruggen E, Grau O, Cuntz M, Peñuelas J, Richter A, Schrumpf M and Rebmann C (2021), "Shifts in the Abundances of Saprotrophic and Ectomycorrhizal Fungi With Altered Leaf Litter Inputs", Frontiers in Plant Science. Vol. 12 |
| Abstract: Ectomycorrhizal (EcM) and saprotrophic fungi interact in the breakdown of organic matter, but the mechanisms underlying the EcM role on organic matter decomposition are not totally clear. We hypothesized that the ecological relations between EcM and saprotroph fungi are modulated by resources availability and accessibility, determining decomposition rates. We manipulated the amount of leaf litter inputs (No-Litter, Control Litter, Doubled Litter) on Trenched (root exclusion) and Non-Trenched plots (with roots) in a temperate deciduous forest of EcM-associated trees. Resultant shifts in soil fungal communities were determined by phospholipid fatty acids and DNA sequencing after 3 years, and CO2 fluxes were measured throughout this period. Different levels of leaf litter inputs generated a gradient of organic substrate availability and accessibility, altering the composition and ecological relations between EcM and saprotroph fungal communities. EcM fungi dominated at low levels of fresh organic substrates and lower organic matter quality, where short-distances exploration types seem to be better competitors, whereas saprotrophs and longer exploration types of EcM fungi tended to dominate at high levels of leaf litter inputs, where labile organic substrates were easily accessible. We were, however, not able to detect unequivocal signs of competition between these fungal groups for common resources. These results point to the relevance of substrate quality and availability as key factors determining the role of EcM and saprotroph fungi on litter and soil organic matter decay and represent a path forward on the capacity of organic matter decomposition of different exploration types of EcM fungi. |
BibTeX:
@article{MaranonJimenez2021,
author = {Marañón-Jiménez, Sara and Radujković, Dajana and Verbruggen, Erik and Grau, Oriol and Cuntz, Matthias and Peñuelas, Josep and Richter, Andreas and Schrumpf, Marion and Rebmann, Corinna},
title = {Shifts in the Abundances of Saprotrophic and Ectomycorrhizal Fungi With Altered Leaf Litter Inputs},
journal = {Frontiers in Plant Science},
year = {2021},
volume = {12},
url = {https://www.frontiersin.org/article/10.3389/fpls.2021.682142},
doi = {10.3389/fpls.2021.682142}
}
|
| Marshall JD, Laudon H, Mäkelä A, Peichl M, Hasselquist N and Näsholm T (2021), "Isotopic Branchpoints: Linkages and Efficiencies in Carbon and Water Budgets", Journal of Geophysical Research: Biogeosciences., jan, 2021. Vol. 126(1), pp. e2020JG006043. John Wiley & Sons, Ltd. |
| Abstract: Abstract Forests pass water and carbon through while converting portions to streamflow, soil organic matter, wood production, and other ecosystem services. The efficiencies of these transfers are but poorly quantified. New theory and new instruments have made it possible to use stable isotope composition to provide this quantification of efficiencies wherever there is a measurable difference between the branches of a branchpoint. We present a linked conceptual model that relies on isotopes of hydrogen, carbon, and oxygen to describe these branchpoints along the pathway from precipitation to soil and biomass carbon sequestration and illustrate how it can be tested and generalized. |
BibTeX:
@article{Marshall2021,
author = {Marshall, John D and Laudon, Hjalmar and Mäkelä, Annikki and Peichl, Matthias and Hasselquist, Niles and Näsholm, Torgny},
title = {Isotopic Branchpoints: Linkages and Efficiencies in Carbon and Water Budgets},
journal = {Journal of Geophysical Research: Biogeosciences},
publisher = {John Wiley & Sons, Ltd},
year = {2021},
volume = {126},
number = {1},
pages = {e2020JG006043},
url = {https://doi.org/10.1029/2020JG006043},
doi = {10.1029/2020JG006043}
}
|
| Marttila H, Aurela M, Büngener L, Rossi PM, Lohila A, Postila H, Saari M, Penttilä T and Kløve B (2021), "Quantifying groundwater fluxes from an aapa mire to a riverside esker formation", Hydrology Research., mar, 2021. Vol. 52(2), pp. 585-596. |
| Abstract: Water flows in peatland margins is an under-researched topic. This study examines recharge from a peatland to an esker aquifer in an aapa mire complex of northern Finland. Our objective was to study how the aapa mire margin is hydrogeologically connected to the riverside aquifer and spatial and temporal variations in the recharge of peatland water to groundwater (GW). Following geophysical studies and monitoring of the saturated zone, a GW model (MODFLOW) was used in combination with stable isotopes to quantify GW flow volumes and directions. Peatland water recharge to the sandy aquifer indicated a strong connection at the peatland–aquifer boundary. Recharge volumes from peatland to esker were high and rather constant (873 m3 d−1) and dominated esker recharge at the study site. The peat water recharging the esker boundary was rich in dissolved organic carbon (DOC). Stable isotope studies on water (δ18O, δ2H, and d-excess) from GW wells verified the recharge of DOC-rich water from peatlands to mineral soil esker. Biogeochemical analysis revealed changes from DOC to dissolved inorganic carbon in the flow pathway from peatland margin to the river Kitinen. This study highlights the importance of careful investigation of aapa mire margin areas and their potential role in regional GW recharge patterns. |
BibTeX:
@article{Marttila2021,
author = {Marttila, H and Aurela, M and Büngener, L and Rossi, P M and Lohila, A and Postila, H and Saari, M and Penttilä, T and Kløve, B},
title = {Quantifying groundwater fluxes from an aapa mire to a riverside esker formation},
journal = {Hydrology Research},
year = {2021},
volume = {52},
number = {2},
pages = {585--596},
url = {https://doi.org/10.2166/nh.2021.064},
doi = {10.2166/nh.2021.064}
}
|
| Marttila H, Lohila A, Ala-Aho P, Noor K, Welker JM, Croghan D, Mustonen K, Meriö L-J, Autio A, Muhic F, Bailey H, Aurela M, Vuorenmaa J, Penttilä T, Hyöky V, Klein E, Kuzmin A, Korpelainen P, Kumpula T, Rauhala A and Kløve B (2021), "Subarctic catchment water storage and carbon cycling – Leading the way for future studies using integrated datasets at Pallas, Finland", Hydrological Processes., sep, 2021. Vol. 35(9), pp. e14350. John Wiley & Sons, Ltd. |
| Abstract: Abstract Subarctic ecohydrological processes are changing rapidly, but detailed and integrated ecohydrological investigations are not as widespread as necessary. We introduce an integrated research catchment site (Pallas) for atmosphere, ecosystems, and ecohydrology studies in subarctic conditions in Finland that can be used for a new set of comparative catchment investigations. The Pallas site provides unique observational data and high-intensity field measurement datasets over long periods. The infrastructure for atmosphere- to landscape-scale research in ecosystem processes in a subarctic landscape has recently been complemented with detailed ecohydrological measurements. We identify three dominant processes in subarctic ecohydrology: (a) strong seasonality drives ecohydrological regimes, (b) limited dynamic storage causes rapid stream response to water inputs (snowmelt and intensive storms), and (c) hydrological state of the system regulates catchment-scale dissolved carbon dynamics and greenhouse (GHG) fluxes. Surface water and groundwater interactions play an important role in regulating catchment-scale carbon balances and ecosystem respiration within subarctic peatlands, particularly their spatial variability in the landscape. Based on our observations from Pallas, we highlight key research gaps in subarctic ecohydrology and propose several ways forward. We also demonstrate that the Pallas catchment meets the need for sustaining and pushing the boundaries of critical long-term integrated ecohydrological research in high-latitude environments. |
BibTeX:
@article{Marttila2021a,
author = {Marttila, Hannu and Lohila, Annalea and Ala-Aho, Pertti and Noor, Kashif and Welker, Jeffrey M and Croghan, Danny and Mustonen, Kaisa and Meriö, Leo-Juhani and Autio, Anna and Muhic, Filip and Bailey, Hannah and Aurela, Mika and Vuorenmaa, Jussi and Penttilä, Timo and Hyöky, Valtteri and Klein, Eric and Kuzmin, Anton and Korpelainen, Pasi and Kumpula, Timo and Rauhala, Anssi and Kløve, Bjørn},
title = {Subarctic catchment water storage and carbon cycling – Leading the way for future studies using integrated datasets at Pallas, Finland},
journal = {Hydrological Processes},
publisher = {John Wiley & Sons, Ltd},
year = {2021},
volume = {35},
number = {9},
pages = {e14350},
url = {https://doi.org/10.1002/hyp.14350},
doi = {10.1002/hyp.14350}
}
|
| Matkala L, Kulmala L, Kolari P, Aurela M and Bäck J (2021), "Resilience of subarctic Scots pine and Norway spruce forests to extreme weather events", Agricultural and Forest Meteorology. Vol. 296, pp. 108239. |
| Abstract: We studied the occurrence of extreme weather events and their effects on the carbon dioxide and water exchange of two subarctic forest stands. One study site was a Scots pine site in eastern Finnish Lapland (Värriö), and the other was a Norway spruce site in western Finnish Lapland (Kenttärova). We compared short-term meteorological data with long-term data and found that the pine forest had experienced extremely warm, wet and dry years as well as cold spells during the growing season in the studied period of 2012–2018. The spruce forest was studied during the period 2003–2013, during which time it experienced extremely warm and wet summers, and dry periods, although the dry times were not statistically defined as such. The spruce forest was less resilient to warm and dry periods, as its total ecosystem respiration and respiration potential decreased during warm and dry summers, while the same effect was not seen in the pine forest. The decreased respiration values may have occurred due to slowed decomposition of organic matter. The pine forest experienced two cold spells during the studied period. One of these cold periods was more of a continuation of the previous cold spring and late start of the growing season in 2017, while the other one occurred after a warm period in 2014. The ecosystem respiration rates and gross primary production in 2017 remained low for the whole July–August time period likely due to cold-inhibited growth of ground vegetation, while in 2014 no such effect could be seen. We saw no effect of extreme weather events in the water exchange related measurements in either of the forests. Overall, both forests, especially the trees, were resilient to the weather extremes and experienced no long-term damage. |
BibTeX:
@article{Matkala2021,
author = {Matkala, L and Kulmala, L and Kolari, P and Aurela, M and Bäck, J},
title = {Resilience of subarctic Scots pine and Norway spruce forests to extreme weather events},
journal = {Agricultural and Forest Meteorology},
year = {2021},
volume = {296},
pages = {108239},
url = {https://www.sciencedirect.com/science/article/pii/S0168192320303415},
doi = {10.1016/j.agrformet.2020.108239}
}
|
| Mauder M, Ibrom A, Wanner L, De Roo F, Brugger P, Kiese R and Pilegaard K (2021), "Options to correct local turbulent flux measurements for large-scale fluxes using an approach based on large-eddy simulation", Atmospheric Measurement Techniques. Vol. 14(12), pp. 7835-7850. |
BibTeX:
@article{Mauder2021,
author = {Mauder, M and Ibrom, A and Wanner, L and De Roo, F and Brugger, P and Kiese, R and Pilegaard, K},
title = {Options to correct local turbulent flux measurements for large-scale fluxes using an approach based on large-eddy simulation},
journal = {Atmospheric Measurement Techniques},
year = {2021},
volume = {14},
number = {12},
pages = {7835--7850},
url = {https://amt.copernicus.org/articles/14/7835/2021/},
doi = {10.5194/amt-14-7835-2021}
}
|
| Mbengue S, Zikova N, Schwarz J, Vodička P, Šmejkalová AH and Holoubek I (2021), "Mass absorption cross-section and absorption enhancement from long term black and elemental carbon measurements: A rural background station in Central Europe", Science of The Total Environment. Vol. 794, pp. 148365. |
| Abstract: Black carbon (BC) is a dominant aerosol light absorber, and its brown carbon (BrC) coating can enhance absorption and lead to uncertainties concerning the radiative forcing estimation. This study investigates the mass absorption cross-section of equivalent BC (MACeBC) during a long-term field measurement (2013–2017) at a rural Central European site. The MAC enhancement factor (Eabs) and the contribution of BrC coatings to the absorption coefficient (Babs) were estimated by combining different approaches. The annual mean Babs and MACeBC values decreased slightly over the measurement period associated with change in the submicron aerosol size distribution. Regardless of the wavelength, Babs exhibited clear seasonal and diurnal variations, with higher values in winter when a higher absorption Ångström exponent (1.4) was observed due to the local biomass burning (BB). In contrast, MACeBC did not have a distinct temporal trend at 600 nm (7.84 ± 2.79 m2 g−1), while it showed a seasonal trend at 370 nm with higher values in winter (15.64 ± 4.77 m2 g−1). During this season, Eabs_660 was 1.18 ± 0.27 and did not exhibit any clear wavelength dependence, despite the influence of BB. During the study period, BrC-attributed absorption was observed in 31% of the samples, with a contribution of up to 40% of total Babs. In summer, the Eabs_660 increased to 1.59 ± 0.60, when a larger BC coating could be formed by secondary aerosol fractions. During this season, MACeBC_660 and Eabs_660 showed comparable source profiles that were mainly associated with aged air masses over central Europe, thereby supporting the fact that characteristics of coating materials formed during atmospheric aging are a major factor driving the MACeBC_660 measured at the regional background site. Further field investigations of the composition of BC coatings would help to better understand and estimate uncertainties related to the radiative effect of aerosols. |
BibTeX:
@article{Mbengue2021,
author = {Mbengue, Saliou and Zikova, Nadezda and Schwarz, Jaroslav and Vodička, Petr and Šmejkalová, Adéla Holubová and Holoubek, Ivan},
title = {Mass absorption cross-section and absorption enhancement from long term black and elemental carbon measurements: A rural background station in Central Europe},
journal = {Science of The Total Environment},
year = {2021},
volume = {794},
pages = {148365},
url = {https://www.sciencedirect.com/science/article/pii/S0048969721034367},
doi = {10.1016/j.scitotenv.2021.148365}
}
|
| Mejdová M, Dušek J, Foltýnová L, Macálková L and Čížková H (2021), "Photosynthetic parameters of a sedge-grass marsh as a big-leaf: effect of plant species composition", Scientific Reports. Vol. 11(1), pp. 3723. |
| Abstract: The study estimates the parameters of the photosynthesis–irradiance relationship (PN/I) of a sedge-grass marsh (Czech Republic, Europe), represented as an active “green” surface—a hypothetical “big-leaf”. Photosynthetic parameters of the “big-leaf” are based on in situ measurements of the leaf PN/I curves of the dominant plant species. The non-rectangular hyperbola was selected as the best model for fitting the PN/I relationships. The plant species had different parameters of this relationship. The highest light-saturated rate of photosynthesis (Asat) was recorded for Glyceria maxima and Acorus calamus followed by Carex acuta and Phalaris arundinacea. The lowest Asat was recorded for Calamagrostis canescens. The parameters of the PN/I relationship were calculated also for different growth periods. The highest Asat was calculated for the spring period followed by the summer and autumn periods. The effect of the species composition of the local plant community on the photosynthetic parameters of the “big-leaf” was addressed by introducing both real (recorded) and hypothetical species compositions corresponding to “wet” and “dry” hydrological conditions. We can conclude that the species composition (or diversity) is essential for reaching a high Asat of the “big-leaf ”representing the sedge-grass marsh in different growth periods. |
BibTeX:
@article{Mejdova2021,
author = {Mejdová, Markéta and Dušek, Jiří and Foltýnová, Lenka and Macálková, Lenka and Čížková, Hana},
title = {Photosynthetic parameters of a sedge-grass marsh as a big-leaf: effect of plant species composition},
journal = {Scientific Reports},
year = {2021},
volume = {11},
number = {1},
pages = {3723},
url = {https://doi.org/10.1038/s41598-021-82382-2},
doi = {10.1038/s41598-021-82382-2}
}
|
| Mengen D, Montzka C, Jagdhuber T, Fluhrer A, Brogi C, Baum S, Schüttemeyer D, Bayat B, Bogena H, Coccia A, Masalias G, Trinkel V, Jakobi J, Jonard F, Ma Y, Mattia F, Palmisano D, Rascher U, Satalino G, Schumacher M, Koyama C, Schmidt M and Vereecken H (2021), "The SARSense Campaign: Air- and Space-Borne C- and L-Band SAR for the Analysis of Soil and Plant Parameters in Agriculture", Remote Sensing. Vol. 13(4) |
| Abstract: With the upcoming L-band Synthetic Aperture Radar (SAR) satellite mission Radar Observing System for Europe L-band SAR (ROSE-L) and its integration into existing C-band satellite missions such as Sentinel-1, multi-frequency SAR observations with high temporal and spatial resolution will become available. The SARSense campaign was conducted between June and August 2019 to investigate the potential for estimating soil and plant parameters at the agricultural test site in Selhausen (Germany). It included C- and L-band air- and space-borne observations accompanied by extensive in situ soil and plant sampling as well as unmanned aerial system (UAS) based multispectral and thermal infrared measurements. In this regard, we introduce a new publicly available SAR data set and present the first analysis of C- and L-band co- and cross-polarized backscattering signals regarding their sensitivity to soil and plant parameters. Results indicate that a multi-frequency approach is relevant to disentangle soil and plant contributions to the SAR signal and to identify specific scattering mechanisms associated with the characteristics of different crop type, especially for root crops and cereals. |
BibTeX:
@article{Mengen2021,
author = {Mengen, David and Montzka, Carsten and Jagdhuber, Thomas and Fluhrer, Anke and Brogi, Cosimo and Baum, Stephani and Schüttemeyer, Dirk and Bayat, Bagher and Bogena, Heye and Coccia, Alex and Masalias, Gerard and Trinkel, Verena and Jakobi, Jannis and Jonard, François and Ma, Yueling and Mattia, Francesco and Palmisano, Davide and Rascher, Uwe and Satalino, Giuseppe and Schumacher, Maike and Koyama, Christian and Schmidt, Marius and Vereecken, Harry},
title = {The SARSense Campaign: Air- and Space-Borne C- and L-Band SAR for the Analysis of Soil and Plant Parameters in Agriculture},
journal = {Remote Sensing},
year = {2021},
volume = {13},
number = {4},
url = {https://www.mdpi.com/2072-4292/13/4/825},
doi = {10.3390/rs13040825}
}
|
| Mensah C, Šigut L, Fischer M, Foltýnová L, Jocher G, Acosta M, Kowalska N, Kokrda L, Pavelka M, Marshall JD, Nyantakyi EK and Marek MV (2021), "Assessing the Contrasting Effects of the Exceptional 2015 Drought on the Carbon Dynamics in Two Norway Spruce Forest Ecosystems", Atmosphere. Vol. 12(8) |
| Abstract: The occurrence of extreme drought poses a severe threat to forest ecosystems and reduces their capability to sequester carbon dioxide. This study analysed the impacts of a central European summer drought in 2015 on gross primary productivity (GPP) at two Norway spruce forest sites representing two contrasting climatic conditions—cold and humid climate at Bílý Kříž (CZ-BK1) vs. moderately warm and dry climate at Rájec (CZ-RAJ). The comparative analyses of GPP was based on a three-year eddy covariance dataset, where 2014 and 2016 represented years with normal conditions, while 2015 was characterized by dry conditions. A significant decline in the forest GPP was found during the dry year of 2015, reaching 14% and 6% at CZ-BK1 and CZ-RAJ, respectively. The reduction in GPP coincided with high ecosystem respiration (Reco) during the dry year period, especially during July and August, when several heat waves hit the region. Additional analyses of GPP decline during the dry year period suggested that a vapour pressure deficit played a more important role than the soil volumetric water content at both investigated sites, highlighting the often neglected importance of considering the species hydraulic strategy (isohydric vs. anisohydric) in drought impact assessments. The study indicates the high vulnerability of the Norway spruce forest to drought stress, especially at sites with precipitation equal or smaller than the atmospheric evaporative demand. Since central Europe is currently experiencing large-scale dieback of Norway spruce forests in lowlands and uplands (such as for CZ-RAJ conditions), the findings of this study may help to quantitatively assess the fate of these widespread cultures under future climate projections, and may help to delimitate the areas of their sustainable production. |
BibTeX:
@article{Mensah2021,
author = {Mensah, Caleb and Šigut, Ladislav and Fischer, Milan and Foltýnová, Lenka and Jocher, Georg and Acosta, Manuel and Kowalska, Natalia and Kokrda, Lukáš and Pavelka, Marian and Marshall, John David and Nyantakyi, Emmanuel K and Marek, Michal V},
title = {Assessing the Contrasting Effects of the Exceptional 2015 Drought on the Carbon Dynamics in Two Norway Spruce Forest Ecosystems},
journal = {Atmosphere},
year = {2021},
volume = {12},
number = {8},
url = {https://www.mdpi.com/2073-4433/12/8/988},
doi = {10.3390/atmos12080988}
}
|
| Mensah C, Šigut L, Fischer M, Foltýnová L, Jocher G, Urban O, Wemegah CS, Nyantakyi EK, Chawla S, Pavelka M and Marek MV (2021), "Environmental Effects on Normalized Gross Primary Productivity in Beech and Norway Spruce Forests", Atmosphere. Vol. 12(9) |
| Abstract: The strong effects of climate change are expected to negatively impact the long-term resilience and function of forest ecosystems, which could lead to changes in forest carbon balance and productivity. However, these forest responses may vary with local conditions and forest types. Accordingly, this study was carried out to determine gross primary productivity (GPP) sensitivity to changes in environmental parameters. Central European beech (at Štítná) and spruce species (at Bílý Kr̆íz̆ and Rájec), growing under contrasting climatic conditions, were studied. The comparative analyses of GPP were based on a five-year-long dataset of eddy covariance fluxes during the main growing season (2012–2016). Results of forest GPP responses with changes in environmental factors from a traditional Stepwise multiple linear regression model (SMLR) were used and compared with Random forest (RF) analyses. To demonstrate how actual GPP trends compare to potential GPP (GPPpot) courses expected under near-optimal environmental conditions, we computed normalized GPP (GPPnorm) with values between 0 and 1 as the ratio of the estimated daily sum of GPP to GPPpot. The study confirmed the well-known effect of total intensity of the photosynthetically active radiation and its diffuse fraction on GPPnorm across all the forest types. However, the study also showed the secondary effects of other environmental variables on forest productivity depending on the species and local climatic conditions. The reduction in forest productivity at the beech forest in Štítná was presumed to be mainly induced by edaphic drought (anisohydric behaviour). In contrast, reduced forest productivity at the spruce forest sites was presumably induced by both meteorological and hydrological drought events, especially at the moderately dry climate in Rájec. Overall, our analyses call for more studies on forest productivity across different forest types and contrasting climatic conditions, as this productivity is strongly dependent on species type and site-specific environmental conditions. |
BibTeX:
@article{Mensah2021a,
author = {Mensah, Caleb and Šigut, Ladislav and Fischer, Milan and Foltýnová, Lenka and Jocher, Georg and Urban, Otmar and Wemegah, Cosmos Senyo and Nyantakyi, Emmanuel K and Chawla, Shilpi and Pavelka, Marian and Marek, Michal V},
title = {Environmental Effects on Normalized Gross Primary Productivity in Beech and Norway Spruce Forests},
journal = {Atmosphere},
year = {2021},
volume = {12},
number = {9},
url = {https://www.mdpi.com/2073-4433/12/9/1128},
doi = {10.3390/atmos12091128}
}
|
| Merbold L, Scholes RJ, Acosta M, Beck J, Bombelli A, Fiedler B, Grieco E, Helmschrot J, Hugo W, Kasurinen V, Kim D-G, Körtzinger A, Leitner S, López-Ballesteros A, Ndisi M, Nickless A, Salmon E, Saunders M, Skjelvan I, Vermeulen AT and Kutsch WL (2021), "Opportunities for an African greenhouse gas observation system", Regional Environmental Change., dec, 2021. Vol. 21(4), pp. 104. |
| Abstract: Global population projections foresee the biggest increase to occur in Africa with most of the available uncultivated land to ensure food security remaining on the continent. Simultaneously, greenhouse gas emissions are expected to rise due to ongoing land use change, industrialisation, and transport amongst other reasons with Africa becoming a major emitter of greenhouse gases globally. However, distinct knowledge on greenhouse gas emissions sources and sinks as well as their variability remains largely unknown caused by its vast size and diversity and an according lack of observations across the continent. Thus, an environmental research infrastructure—as being setup in other regions—is more needed than ever. Here, we present the results of a design study that developed a blueprint for establishing such an environmental research infrastructure in Africa. The blueprint comprises an inventory of already existing observations, the spatial disaggregation of locations that will enable to reduce the uncertainty in climate forcing's in Africa and globally as well as an overall estimated cost for such an endeavour of about 550 M€ over the next 30 years. We further highlight the importance of the development of an e-infrastructure, the necessity for capacity development and the inclusion of all stakeholders to ensure African ownership. |
BibTeX:
@article{Merbold2021,
author = {Merbold, Lutz and Scholes, Robert J and Acosta, Manuel and Beck, Johannes and Bombelli, Antonio and Fiedler, Bjoern and Grieco, Elisa and Helmschrot, Joerg and Hugo, Wim and Kasurinen, Ville and Kim, Dong-Gill and Körtzinger, Arne and Leitner, Sonja and López-Ballesteros, Ana and Ndisi, Mylene and Nickless, Aecia and Salmon, Emmanuel and Saunders, Matthew and Skjelvan, Ingunn and Vermeulen, Alexander T and Kutsch, Werner L},
title = {Opportunities for an African greenhouse gas observation system},
journal = {Regional Environmental Change},
year = {2021},
volume = {21},
number = {4},
pages = {104},
url = {https://link.springer.com/10.1007/s10113-021-01823-w},
doi = {10.1007/s10113-021-01823-w}
}
|
| Migliavacca M, Musavi T, Mahecha MD, Nelson JA, Knauer J, Baldocchi DD, Perez-Priego O, Christiansen R, Peters J, Anderson K, Bahn M, Black TA, Blanken PD, Bonal D, Buchmann N, Caldararu S, Carrara A, Carvalhais N, Cescatti A, Chen J, Cleverly J, Cremonese E, Desai AR, El-Madany TS, Farella MM, Fernández-Martínez M, Filippa G, Forkel M, Galvagno M, Gomarasca U, Gough CM, Göckede M, Ibrom A, Ikawa H, Janssens IA, Jung M, Kattge J, Keenan TF, Knohl A, Kobayashi H, Kraemer G, Law BE, Liddell MJ, Ma X, Mammarella I, Martini D, Macfarlane C, Matteucci G, Montagnani L, Pabon-Moreno DE, Panigada C, Papale D, Pendall E, Penuelas J, Phillips RP, Reich PB, Rossini M, Rotenberg E, Scott RL, Stahl C, Weber U, Wohlfahrt G, Wolf S, Wright IJ, Yakir D, Zaehle S and Reichstein M (2021), "The three major axes of terrestrial ecosystem function", Nature. Vol. 598(7881), pp. 468-472. |
| Abstract: The leaf economics spectrum1,2 and the global spectrum of plant forms and functions3 revealed fundamental axes of variation in plant traits, which represent different ecological strategies that are shaped by the evolutionary development of plant species2. Ecosystem functions depend on environmental conditions and the traits of species that comprise the ecological communities4. However, the axes of variation of ecosystem functions are largely unknown, which limits our understanding of how ecosystems respond as a whole to anthropogenic drivers, climate and environmental variability4,5. Here we derive a set of ecosystem functions6 from a dataset of surface gas exchange measurements across major terrestrial biomes. We find that most of the variability within ecosystem functions (71.8%) is captured by three key axes. The first axis reflects maximum ecosystem productivity and is mostly explained by vegetation structure. The second axis reflects ecosystem water-use strategies and is jointly explained by variation in vegetation height and climate. The third axis, which represents ecosystem carbon-use efficiency, features a gradient related to aridity, and is explained primarily by variation in vegetation structure. We show that two state-of-the-art land surface models reproduce the first and most important axis of ecosystem functions. However, the models tend to simulate more strongly correlated functions than those observed, which limits their ability to accurately predict the full range of responses to environmental changes in carbon, water and energy cycling in terrestrial ecosystems7,8. |
BibTeX:
@article{Migliavacca2021,
author = {Migliavacca, Mirco and Musavi, Talie and Mahecha, Miguel D and Nelson, Jacob A and Knauer, Jürgen and Baldocchi, Dennis D and Perez-Priego, Oscar and Christiansen, Rune and Peters, Jonas and Anderson, Karen and Bahn, Michael and Black, T Andrew and Blanken, Peter D and Bonal, Damien and Buchmann, Nina and Caldararu, Silvia and Carrara, Arnaud and Carvalhais, Nuno and Cescatti, Alessandro and Chen, Jiquan and Cleverly, Jamie and Cremonese, Edoardo and Desai, Ankur R and El-Madany, Tarek S and Farella, Martha M and Fernández-Martínez, Marcos and Filippa, Gianluca and Forkel, Matthias and Galvagno, Marta and Gomarasca, Ulisse and Gough, Christopher M and Göckede, Mathias and Ibrom, Andreas and Ikawa, Hiroki and Janssens, Ivan A and Jung, Martin and Kattge, Jens and Keenan, Trevor F and Knohl, Alexander and Kobayashi, Hideki and Kraemer, Guido and Law, Beverly E and Liddell, Michael J and Ma, Xuanlong and Mammarella, Ivan and Martini, David and Macfarlane, Craig and Matteucci, Giorgio and Montagnani, Leonardo and Pabon-Moreno, Daniel E and Panigada, Cinzia and Papale, Dario and Pendall, Elise and Penuelas, Josep and Phillips, Richard P and Reich, Peter B and Rossini, Micol and Rotenberg, Eyal and Scott, Russell L and Stahl, Clement and Weber, Ulrich and Wohlfahrt, Georg and Wolf, Sebastian and Wright, Ian J and Yakir, Dan and Zaehle, Sönke and Reichstein, Markus},
title = {The three major axes of terrestrial ecosystem function},
journal = {Nature},
year = {2021},
volume = {598},
number = {7881},
pages = {468--472},
url = {https://doi.org/10.1038/s41586-021-03939-9},
doi = {10.1038/s41586-021-03939-9}
}
|
| Moderow U, Grünwald T, Queck R, Spank U and Bernhofer C (2021), "Energy balance closure and advective fluxes at ADVEX sites", Theoretical and Applied Climatology. Vol. 143(1), pp. 761-779. |
| Abstract: When measuring the energy balance at the earth's surface using the Eddy covariance technique, the obtained budgets seldom produce a closed energy balance. The measurements often miss some of the energy fluxes. A possible reason is the neglect of non-turbulent surface fluxes of latent heat and sensible heat, i.e. advective fluxes of these quantities. We present estimates of advective latent and sensible heat fluxes for three different sites across Europe based on the ADVEX dataset. The obtained horizontal and vertical advective fluxes were site-specific and characterized by large scatter. In relative terms, the data indicated that the sensible heat budget was less affected by advection than the latent heat budget during nighttime; this is because vertical turbulent latent heat fluxes were very small or close to zero during the night. The results further showed that the additional energy gain by sensible heat advection might have triggered enhanced evaporation for two sites during nighttime. Accounting for advective fluxes improved the energy balance closure for one of the three ADVEX sites. However, the energy balance closure of the other two sites did not improve overall. A comparison with energy balance residuals (energy missed by the measurements without accounting for advection) indicated a large influence of systematic errors. An inspection of the energy balance for the sloped site of the ADVEX dataset underlined the necessity of slope-parallel measurement of radiation. |
BibTeX:
@article{Moderow2021,
author = {Moderow, Uta and Grünwald, Thomas and Queck, Ronald and Spank, Uwe and Bernhofer, Christian},
title = {Energy balance closure and advective fluxes at ADVEX sites},
journal = {Theoretical and Applied Climatology},
year = {2021},
volume = {143},
number = {1},
pages = {761--779},
url = {https://doi.org/10.1007/s00704-020-03412-z},
doi = {10.1007/s00704-020-03412-z}
}
|
| Mohammad Harmay NS, Kim D and Choi M (2021), "Urban Heat Island associated with Land Use/Land Cover and climate variations in Melbourne, Australia", Sustainable Cities and Society. Vol. 69, pp. 102861. |
| Abstract: Urbanization is known as one of the most prominent global problems that alter the atmosphere and land surface properties. The intensity of Urban Heat Island (UHI) associated with surface temperature and component attributes were assessed using the Community Land Model (CLM). The variations of UHI with Land Use/Land Cover (LULC) and climate variations were also investigated to provide a link among urbanization, surface energy balance interactions, and extreme hydroclimatic events which are drought (‘big dry' and ‘angry summer') and heavy rainfall (‘big wet') in Melbourne, Australia. Generally, UHI demonstrated a uniform increasing trend with an ∼1.20 ± 0.20 °C increment, along with urbanization expansion of +14.93 % from 2001 to 2014. Furthermore, urban area showed positive contribution to UHI based on Land Contribution Index (LCI). High surface temperatures also resulted in higher sensible heat flux (Qh) and lower latent heat flux (Qle). During the multiple extreme climate events, the UHI biophysical drivers were majorly related to the convection reduction during ‘big dry' (2001−2009), surface evaporative cooling during ‘big wet' (2010−2011), and heat storage release during ‘angry summer' (2012–2013). Overall, this analysis demonstrated correlation of UHI intensity and its component attributes with urban expansion, which was associated with LULC and climate variations in Melbourne. |
BibTeX:
@article{MohammadHarmay2021,
author = {Mohammad Harmay, Nurul Syahira and Kim, Daeun and Choi, Minha},
title = {Urban Heat Island associated with Land Use/Land Cover and climate variations in Melbourne, Australia},
journal = {Sustainable Cities and Society},
year = {2021},
volume = {69},
pages = {102861},
url = {https://www.sciencedirect.com/science/article/pii/S2210670721001517},
doi = {10.1016/j.scs.2021.102861}
}
|
| Montzka C, Bogena HR, Herbst M, Cosh MH, Jagdhuber T and Vereecken H (2021), "Estimating the Number of Reference Sites Necessary for the Validation of Global Soil Moisture Products", IEEE Geoscience and Remote Sensing Letters. Vol. 18(9), pp. 1530-1534. |
BibTeX:
@article{Montzka2021,
author = {Montzka, Carsten and Bogena, Heye R and Herbst, Michael and Cosh, Michael H and Jagdhuber, Thomas and Vereecken, Harry},
title = {Estimating the Number of Reference Sites Necessary for the Validation of Global Soil Moisture Products},
journal = {IEEE Geoscience and Remote Sensing Letters},
year = {2021},
volume = {18},
number = {9},
pages = {1530--1534},
doi = {10.1109/LGRS.2020.3005730}
}
|
| Mowlem M, Beaton A, Pascal R, Schaap A, Loucaides S, Monk S, Morris A, Cardwell CL, Fowell SE, Patey MD and López-García P (2021), "Industry Partnership: Lab on Chip Chemical Sensor Technology for Ocean Observing", Frontiers in Marine Science. Vol. 8 |
| Abstract: We introduce for the first time a new product line able to make high accuracy measurements of a number of water chemistry parameters in situ: i.e., submerged in the environment including in the deep sea (to 6,000 m). This product is based on the developments of in situ lab on chip technology at the National Oceanography Centre (NOC), and the University of Southampton and is produced under license by Clearwater Sensors Ltd., a start-up and industrial partner in bringing this technology to global availability and further developing its potential. The technology has already been deployed by the NOC, and with their partners worldwide over 200 times including to depths of ∼4,800 m, in turbid estuaries and rivers, and for up to a year in seasonally ice-covered regions of the arctic. The technology is capable of making accurate determinations of chemical and biological parameters that require reagents and which produce an electrical, absorbance, fluorescence, or luminescence signal. As such it is suitable for a wide range of environmental measurements. Whilst further parameters are in development across this partnership, Nitrate, Nitrite, Phosphate, Silicate, Iron, and pH sensors are currently available commercially. Theses sensors use microfluidics and optics combined in an optofluidic chip with electromechanical valves and pumps mounted upon it to mix water samples with reagents and measure the optical response. An overview of the sensors and the underlying components and technologies is given together with examples of deployments and integrations with observing platforms such as gliders, autonomous underwater vehicles and moorings. |
BibTeX:
@article{Mowlem2021,
author = {Mowlem, Matt and Beaton, Alexander and Pascal, Robin and Schaap, Allison and Loucaides, Socratis and Monk, Sam and Morris, Andrew and Cardwell, Christopher L and Fowell, Sara E and Patey, Matthew D and López-García, Patricia},
title = {Industry Partnership: Lab on Chip Chemical Sensor Technology for Ocean Observing},
journal = {Frontiers in Marine Science},
year = {2021},
volume = {8},
url = {https://www.frontiersin.org/article/10.3389/fmars.2021.697611},
doi = {10.3389/fmars.2021.697611}
}
|
| Müller JD, Schneider B, Gräwe U, Fietzek P, Wallin MB, Rutgersson A, Wasmund N, Krüger S and Rehder G (2021), "Cyanobacteria net community production in the Baltic Sea as inferred from profiling pCO_2 measurements", Biogeosciences. Vol. 18(17), pp. 4889-4917. |
BibTeX:
@article{Mueller2021,
author = {Müller, J D and Schneider, B and Gräwe, U and Fietzek, P and Wallin, M B and Rutgersson, A and Wasmund, N and Krüger, S and Rehder, G},
title = {Cyanobacteria net community production in the Baltic Sea as inferred from profiling pCO_2 measurements},
journal = {Biogeosciences},
year = {2021},
volume = {18},
number = {17},
pages = {4889--4917},
url = {https://bg.copernicus.org/articles/18/4889/2021/},
doi = {10.5194/bg-18-4889-2021}
}
|
| Nadal-Sala D, Grote R, Birami B, Lintunen A, Mammarella I, Preisler Y, Rotenberg E, Salmon Y, Tatarinov F, Yakir D and Ruehr NK (2021), "Assessing model performance via the most limiting environmental driver in two differently stressed pine stands", Ecological Applications., jun, 2021. Vol. 31(4), pp. e02312. John Wiley & Sons, Ltd. |
| Abstract: Abstract Climate change will impact forest productivity worldwide. Forecasting the magnitude of such impact, with multiple environmental stressors changing simultaneously, is only possible with the help of process-based models. In order to assess their performance, such models require careful evaluation against measurements. However, direct comparison of model outputs against observational data is often not reliable, as models may provide the right answers due to the wrong reasons. This would severely hinder forecasting abilities under unprecedented climate conditions. Here, we present a methodology for model assessment, which supplements the traditional output-to-observation model validation. It evaluates model performance through its ability to reproduce observed seasonal changes of the most limiting environmental driver (MLED) for a given process, here daily gross primary productivity (GPP). We analyzed seasonal changes of the MLED for GPP in two contrasting pine forests, the Mediterranean Pinus halepensis Mill. Yatir (Israel) and the boreal Pinus sylvestris L. Hyytiälä (Finland) from three years of eddy-covariance flux data. Then, we simulated the same period with a state-of-the-art process-based simulation model (LandscapeDNDC). Finally, we assessed if the model was able to reproduce both GPP observations and MLED seasonality. We found that the model reproduced the seasonality of GPP in both stands, but it was slightly overestimated without site-specific fine-tuning. Interestingly, although LandscapeDNDC properly captured the main MLED in Hyytiälä (temperature) and in Yatir (soil water availability), it failed to reproduce high-temperature and high-vapor pressure limitations of GPP in Yatir during spring and summer. We deduced that the most likely reason for this divergence is an incomplete description of stomatal behavior. In summary, this study validates the MLED approach as a model evaluation tool, and opens up new possibilities for model improvement. |
BibTeX:
@article{NadalSala2021,
author = {Nadal-Sala, Daniel and Grote, Rüdiger and Birami, Benjamin and Lintunen, Anna and Mammarella, Ivan and Preisler, Yakir and Rotenberg, Eyal and Salmon, Yann and Tatarinov, Fedor and Yakir, Dan and Ruehr, Nadine K},
title = {Assessing model performance via the most limiting environmental driver in two differently stressed pine stands},
journal = {Ecological Applications},
publisher = {John Wiley & Sons, Ltd},
year = {2021},
volume = {31},
number = {4},
pages = {e02312},
url = {https://doi.org/10.1002/eap.2312},
doi = {10.1002/eap.2312}
}
|
| Nerobelov G, Timofeyev Y, Smyshlyaev S, Foka S, Mammarella I and Virolainen Y (2021), "Validation of WRF-Chem Model and CAMS Performance in Estimating Near-Surface Atmospheric CO2 Mixing Ratio in the Area of Saint Petersburg (Russia)", Atmosphere. Vol. 12(3) |
| Abstract: Nowadays, different approaches for CO2 anthropogenic emission estimation are applied to control agreements on greenhouse gas reduction. Some methods are based on the inverse modelling of emissions using various measurements and the results of numerical chemistry transport models (CTMs). Since the accuracy and precision of CTMs largely determine errors in the approaches for emission estimation, it is crucial to validate the performance of such models through observations. In the current study, the near-surface CO2 mixing ratio simulated by the CTM Weather Research and Forecasting—Chemistry (WRF-Chem) at a high spatial resolution (3 km) using three different sets of CO2 fluxes (anthropogenic + biogenic fluxes, time-varying and constant anthropogenic emissions) and from Copernicus Atmosphere Monitoring Service (CAMS) datasets have been validated using in situ observations near the Saint Petersburg megacity (Russia) in March and April 2019. It was found that CAMS reanalysis data with a low spatial resolution (1.9° × 3.8°) can match the observations better than CAMS analysis data with a high resolution (0.15° × 0.15°). The CAMS analysis significantly overestimates the observed near-surface CO2 mixing ratio in Peterhof in March and April 2019 (by more than 10 ppm). The best match for the CAMS reanalysis and observations was observed in March, when the wind was predominantly opposite to the Saint Petersburg urbanized area. In contrast, the CAMS analysis fits the observed trend of the mixing ratio variation in April better than the reanalysis with the wind directions from the Saint Petersburg urban zone. Generally, the WRF-Chem predicts the observed temporal variations in the near-surface CO2 reasonably well (mean bias ≈ (−0.3) − (−0.9) ppm, RMSD ≈ 8.7 ppm, correlation coefficient ≈ 0.61 ± 0.04). The WRF-Chem data where anthropogenic and biogenic fluxes were used match the observations a bit better than the WRF-Chem data without biogenic fluxes. The diurnal time variation in the anthropogenic emissions influenced the WRF-Chem data insignificantly. However, in general, the data of all three WRF-Chem model runs give almost the same CO2 temporal variation in Peterhof in March and April 2019. This could be related to the late start of the growing season, which influences biogenic CO2 fluxes, inaccuracies in the estimation of the biogenic fluxes, and the simplified time variation pattern of the CO2 anthropogenic emissions. |
BibTeX:
@article{Nerobelov2021,
author = {Nerobelov, Georgy and Timofeyev, Yuri and Smyshlyaev, Sergei and Foka, Stefani and Mammarella, Ivan and Virolainen, Yana},
title = {Validation of WRF-Chem Model and CAMS Performance in Estimating Near-Surface Atmospheric CO2 Mixing Ratio in the Area of Saint Petersburg (Russia)},
journal = {Atmosphere},
year = {2021},
volume = {12},
number = {3},
url = {https://www.mdpi.com/2073-4433/12/3/387},
doi = {10.3390/atmos12030387}
}
|
| Neuwirth B, Rabbel I, Bendix J, Bogena HR and Thies B (2021), "The European Heat Wave 2018: The Dendroecological Response of Oak and Spruce in Western Germany", Forests. Vol. 12(3) |
| Abstract: The European heat wave of 2018 was characterized by extraordinarily dry and hot spring and summer conditions in many central and northern European countries. The average temperatures from June to August 2018 were the second highest since 1881. Accordingly, many plants, especially trees, were pushed to their physiological limits. However, while the drought and heat response of field crops and younger trees have been well investigated in laboratory experiments, little is known regarding the drought and heat response of mature forest trees. In this study, we compared the response of a coniferous and a deciduous tree species, located in western and central–western Germany, to the extreme environmental conditions during the European heat wave of 2018. Combining classic dendroecological techniques (tree–ring analysis) with measurements of the intra–annual stem expansion (dendrometers) and tree water uptake (sap flow sensors), we found contrasting responses of spruce and oak trees. While spruce trees developed a narrow tree ring in 2018 combined with decreasing correlations of daily sap flow and dendrometer parameters to the climatic parameters, oak trees developed a ring with above–average tree–ring width combined with increasing correlations between the daily climatic parameters and the parameters derived from sap flow and the dendrometer sensors. In conclusion, spruce trees reacted to the 2018 heat wave with the early completion of their growth activities, whereas oaks appeared to intensify their activities based on the water content in their tree stems. |
BibTeX:
@article{Neuwirth2021,
author = {Neuwirth, Burkhard and Rabbel, Inken and Bendix, Jörg and Bogena, Heye R and Thies, Boris},
title = {The European Heat Wave 2018: The Dendroecological Response of Oak and Spruce in Western Germany},
journal = {Forests},
year = {2021},
volume = {12},
number = {3},
url = {https://www.mdpi.com/1999-4907/12/3/283},
doi = {10.3390/f12030283}
}
|
| Nilsson H, Pilesjö P, Hasan A and Persson A (2021), "Dynamic spatio-temporal flow modeling with raster DEMs", Transactions in GIS., nov, 2021. Vol. n/a(n/a) John Wiley & Sons, Ltd. |
| Abstract: Abstract A user-friendly high-resolution intermediate complexity dynamic and spatially distributed flow model is crucial in urban flood modeling. Planners and consultants need to improve the accuracy of floods and estimation of risks. A new flow model will serve as a rapid tool to improve identification of these. This article provides a detailed explanation of a model based on a multiple flow algorithm. Model testing was performed on selected urban and rural areas. Additionally, a sensitivity analysis is conducted to analyze functionality. The model includes basic hydrological processes and is therefore less complex than fully physical models. The data needed to set up and run the new model include spatially and temporally distributed basic geometric and hydrologic variables (i.e., digital elevation model, precipitation, infiltration, and surface roughness). The model is implemented using open-source coding and can easily be applied to any selected area. Outputs are water volumes, depths, and velocities at different modeling times. Using GIS, results can be visualized and utilized for further analyses. The test, applied in urban as well as rural areas, demonstrates its user-friendliness, and that the estimated distributed water depths and water velocity at any time step can be saved and visualized. |
BibTeX:
@article{Nilsson2021,
author = {Nilsson, Hampus and Pilesjö, Petter and Hasan, Abdulghani and Persson, Andreas},
title = {Dynamic spatio-temporal flow modeling with raster DEMs},
journal = {Transactions in GIS},
publisher = {John Wiley & Sons, Ltd},
year = {2021},
volume = {n/a},
number = {n/a},
url = {https://doi.org/10.1111/tgis.12870},
doi = {10.1111/tgis.12870}
}
|
| Niu B, Zhang X, Piao S, Janssens IA, Fu G, He Y, Zhang Y, Shi P, Dai E, Yu C, Zhang J, Yu G, Xu M, Wu J, Zhu L, Desai AR, Chen J, Bohrer G, Gough CM, Mammarella I, Varlagin A, Fares S, Zhao X, Li Y, Wang H and Ouyang Z (2021), "Warming homogenizes apparent temperature sensitivity of ecosystem respiration", Science Advances. Vol. 7(15) |
| Abstract: Warming-induced carbon loss through terrestrial ecosystem respiration (Re) is likely getting stronger in high latitudes and cold regions because of the more rapid warming and higher temperature sensitivity of Re (Q10). However, it is not known whether the spatial relationship between Q10 and temperature also holds temporally under a future warmer climate. Here, we analyzed apparent Q10 values derived from multiyear observations at 74 FLUXNET sites spanning diverse climates and biomes. We found warming-induced decline in Q10 is stronger at colder regions than other locations, which is consistent with a meta-analysis of 54 field warming experiments across the globe. We predict future warming will shrink the global variability of Q10 values to an average of 1.44 across the globe under a high emission trajectory (RCP 8.5) by the end of the century. Therefore, warming-induced carbon loss may be less than previously assumed because of Q10 homogenization in a warming world. |
BibTeX:
@article{Niu2021,
author = {Niu, Ben and Zhang, Xianzhou and Piao, Shilong and Janssens, Ivan A. and Fu, Gang and He, Yongtao and Zhang, Yangjian and Shi, Peili and Dai, Erfu and Yu, Chengqun and Zhang, Jing and Yu, Guirui and Xu, Ming and Wu, Jianshuang and Zhu, Liping and Desai, Ankur R. and Chen, Jiquan and Bohrer, Gil and Gough, Christopher M. and Mammarella, Ivan and Varlagin, Andrej and Fares, Silvano and Zhao, Xinquan and Li, Yingnian and Wang, Huiming and Ouyang, Zhu},
title = {Warming homogenizes apparent temperature sensitivity of ecosystem respiration},
journal = {Science Advances},
year = {2021},
volume = {7},
number = {15},
doi = {10.1126/SCIADV.ABC7358}
}
|
| Oddi L, Cremonese E, Ascari L, Filippa G, Galvagno M, Serafino D and di Cella UM (2021), "Using UAV Imagery to Detect and Map Woody Species Encroachment in a Subalpine Grassland: Advantages and Limits", Remote Sensing. Vol. 13(7) |
| Abstract: Woody species encroachment on grassland ecosystems is occurring worldwide with both negative and positive consequences for biodiversity conservation and ecosystem services. Remote sensing and image analysis represent useful tools for the monitoring of this process. In this paper, we aimed at evaluating quantitatively the potential of using high-resolution UAV imagery to monitor the encroachment process during its early development and at comparing the performance of manual and semi-automatic classification methods. The RGB images of an abandoned subalpine grassland on the Western Italian Alps were acquired by drone and then classified through manual photo-interpretation, with both pixel- and object-based semi-automatic models, using machine-learning algorithms. The classification techniques were applied at different resolution levels and tested for their accuracy against reference data including measurements of tree dimensions collected in the field. Results showed that the most accurate method was the photo-interpretation (≈99%), followed by the pixel-based approach (≈86%) that was faster than the manual technique and more accurate than the object-based one (≈78%). The dimensional threshold for juvenile tree detection was lower for the photo-interpretation but comparable to the pixel-based one. Therefore, for the encroachment mapping at its early stages, the pixel-based approach proved to be a promising and pragmatic choice. |
BibTeX:
@article{Oddi2021,
author = {Oddi, Ludovica and Cremonese, Edoardo and Ascari, Lorenzo and Filippa, Gianluca and Galvagno, Marta and Serafino, Davide and di Cella, Umberto Morra},
title = {Using UAV Imagery to Detect and Map Woody Species Encroachment in a Subalpine Grassland: Advantages and Limits},
journal = {Remote Sensing},
year = {2021},
volume = {13},
number = {7},
url = {https://www.mdpi.com/2072-4292/13/7/1239},
doi = {10.3390/rs13071239}
}
|
| Öhrn P, Berlin M, Elfstrand M, Krokene P and Jönsson AM (2021), "Seasonal variation in Norway spruce response to inoculation with bark beetle-associated bluestain fungi one year after a severe drought", Forest Ecology and Management. Vol. 496, pp. 119443. |
| Abstract: In 2018, up to 4 million m3 Norway spruce was killed by the spruce bark beetle Ips typographus in Sweden. The event was unique for Sweden, in terms of both affected volume and the fact that it was triggered by severe drought stress, not by ample availability of relatively defenseless storm-felled trees. The outbreak continued in 2019 and 2020, each year with twice as many trees killed as in 2018. The aim of this study was to quantify seasonal variation and potential lag-effects in tree defense capacity the year after a severe drought stress. Inoculation with a bark beetle-associated bluestain fungus, repeated four times with one-month-intervals between May and August 2019, were carried out at three field sites with spruce provenances of Swedish and East European origin representing early and late bud burst, respectively. All sites had experienced moderate to severe drought stress in 2018, and site-specific defense capacity correlated positively with the cumulative precipitation two months before inoculation. Sites with two-month precipitation levels <100 mm had larger necrotic lesions in the phloem following inoculation, an indication of lower tree defense capacity. Lesion size did not differ between provenances, and all trees were able to confine fungal infection successfully. There were some seasonal differences in necrotic lesion size, with the sites Skärsnäs and Norberg having significantly larger lesions in June than in May, and site Lugnet having large lesions also in May. Lesions were generally smaller in July and August than in June. The cross-sectional area and number of traumatic resin ducts was measured in sapwood samples from one site, Lugnet, to quantify an additional aspect of tree defenses. The area of resin ducts produced in May and June were larger than that in July and August. This is in line with a positive correlation between lesion area and resin duct area, indicating that a stronger fungal infection following inoculation in spring triggered a stronger induced defense response. The East European provenances had more resin ducts than Swedish provenances, but the area of resin ducts did not differ significantly between provenances. |
BibTeX:
@article{Oehrn2021,
author = {Öhrn, Petter and Berlin, Mats and Elfstrand, Malin and Krokene, Paal and Jönsson, Anna Maria},
title = {Seasonal variation in Norway spruce response to inoculation with bark beetle-associated bluestain fungi one year after a severe drought},
journal = {Forest Ecology and Management},
year = {2021},
volume = {496},
pages = {119443},
url = {https://www.sciencedirect.com/science/article/pii/S0378112721005326},
doi = {10.1016/j.foreco.2021.119443}
}
|
| Ogundare MO, Fransson A, Chierici M, Joubert WR and Roychoudhury AN (2021), "Variability of Sea-Air Carbon Dioxide Flux in Autumn Across the Weddell Gyre and Offshore Dronning Maud Land in the Southern Ocean", Frontiers in Marine Science. Vol. 7 |
| Abstract: Sea surface fugacity of carbon dioxide (fCO2ssw) was measured across the Weddell gyre and the eastern sector in the Atlantic Southern Ocean in autumn. During the occupation between February and April 2019, the region of the study transect was a potential ocean CO2 sink. A net CO2 flux (FCO2) of −6.2 (± 8; sink) mmol m–2 d–1 was estimated for the entire study region, with the largest average CO2 sink of −10.0 (± 8) mmol m–2 d–1 in the partly ice-covered Astrid Ridge (AR) region near the coast at 68°S and −6.1 (± 8) mmol m–2d–1 was observed in the Maud Rise (MR) region. A CO2 sink was also observed south of 66°S in the Weddell Sea (WS). To assess the main drivers describing the variability of fCO2ssw, a correlation model using fCO2 and oxygen saturation was considered. Spatial distributions of the fCO2 saturation/O2 saturation correlations, described relative to the surface water properties of the controlling variables (chlorophyll a, apparent oxygen utilization (AOU), sea surface temperature, and sea surface salinity) further constrained the interplay of the processes driving the fCO2ssw distributions. Photosynthetic CO2 drawdown significantly offsets the influence of the upwelling of CO2-rich waters in the central Weddell gyre and enhanced the CO2 sink in the region. FCO2 of −6.9 mmol m–2 d–1 estimated for the Weddell gyre in this study was different from FCO2 of −2.5 mmol m–2 d–1 in autumn estimated in a previous study. Due to low CO2 data coverage during autumn, limited sea-air CO2 flux estimates from direct sea-surface CO2 observations particularly for the Weddell gyre region are available with which to compare the values estimated in this study. This highlights the importance of increasing seasonal CO2 observations especially during autumn/winter to improving the seasonal coverage of flux estimates in the seasonal sea ice-covered regions of the Southern Ocean. |
BibTeX:
@article{Ogundare2021,
author = {Ogundare, Margaret Ojone and Fransson, Agneta and Chierici, Melissa and Joubert, Warren R and Roychoudhury, Alakendra N},
title = {Variability of Sea-Air Carbon Dioxide Flux in Autumn Across the Weddell Gyre and Offshore Dronning Maud Land in the Southern Ocean},
journal = {Frontiers in Marine Science},
year = {2021},
volume = {7},
url = {https://www.frontiersin.org/article/10.3389/fmars.2020.614263},
doi = {10.3389/fmars.2020.614263}
}
|
| Ollivier C, Olioso A, Carrière SD, Boulet G, Chalikakis K, Chanzy A, Charlier J-B, Combemale D, Davi H, Emblanch C, Marloie O, Martin-StPaul N, Mazzilli N, Simioni G and Weiss M (2021), "An evapotranspiration model driven by remote sensing data for assessing groundwater resource in karst watershed", Science of The Total Environment. Vol. 781, pp. 146706. |
| Abstract: Aquifer recharge may depend mainly on the difference between precipitation and evapotranspiration. Hydrological models used to estimate groundwater reserves use evapotranspiration models that are mainly determined by climate demand. In particular, mechanisms of plant transpiration are neglected, although transpiration constitutes 70% of evapotranspiration. This is problematic when considering karst watershed, which are poorly documented at the interface between soil and atmosphere where vegetation and soil properties control water flows. To fill this gap, we propose an evapotranspiration model that integrates the processes of plant transpiration and soil evaporation. The dynamics of vegetation is evaluated using the Enhanced Vegetation Indexes from the Terra and Aqua Moderate Resolution Imaging Spectroradiometers. The soil evaporation calculation account for the impact of coarse elements at soil surface. The “Simple Crop coefficient for Evapotranspiration” (SimpKcET) model is tested at flux tower sites over forest of Font-Blanche, Puechabon and the agricultural area of Avignon. The simulated daily evapotranspirations are very close to the observations (RMSE ∼0.5 mm.d-1), while the model is simple compared to other models proposed in the literature. The SimpKcET is implemented in a karst hydrological model to evaluate the impact of evapotranspiration estimation on the aquifer flow rate simulation. This approach is applied to the vast watershed of Fontaine de Vaucluse. In comparison to the water bucket model that is frequently used in karst models, SimpKcET provide ET simulations that are more in line with ET processes. A cross wavelet analysis highlighted the improvement of the simulated recharge and observed flow rate relationship brought by the consideration of evaporation and transpiration processes. The use of remote sensing data related to plant activity makes it possible to propose a parsimonious model that can be applied to all types of vegetation (agricultural, natural, mixed forest) and that can be transferred to other karst models. |
BibTeX:
@article{Ollivier2021,
author = {Ollivier, Chloé and Olioso, Albert and Carrière, Simon Damien and Boulet, Gilles and Chalikakis, Konstantinos and Chanzy, André and Charlier, Jean-Baptiste and Combemale, David and Davi, Hendrik and Emblanch, Christophe and Marloie, Olivier and Martin-StPaul, Nicolas and Mazzilli, Naomi and Simioni, Guillaume and Weiss, Marie},
title = {An evapotranspiration model driven by remote sensing data for assessing groundwater resource in karst watershed},
journal = {Science of The Total Environment},
year = {2021},
volume = {781},
pages = {146706},
url = {https://www.sciencedirect.com/science/article/pii/S0048969721017745},
doi = {10.1016/j.scitotenv.2021.146706}
}
|
| Osterwalder S, Nerentorp M, Zhu W, Jiskra M, Nilsson E, Nilsson MB, Rutgersson A, Soerensen AL, Sommar J, Wallin MB, Wängberg I and Bishop K (2021), "Critical Observations of Gaseous Elemental Mercury Air-Sea Exchange", Global Biogeochemical Cycles., aug, 2021. Vol. 35(8), pp. e2020GB006742. John Wiley & Sons, Ltd. |
| Abstract: Abstract Air-sea exchange of gaseous elemental mercury (Hg0) is not well constrained, even though it is a major component of the global Hg cycle. Lack of Hg0 flux measurements to validate parameterizations of the Hg0 transfer velocity contributes to this uncertainty. We measured the Hg0 flux on the Baltic Sea coast using micrometeorological methods (gradient-based and relaxed eddy accumulation [REA]) and also simulated the flux with a gas exchange model. The coastal waters were typically supersaturated with Hg0 (mean ± 1σ = 13.5 ± 3.5 ng m?3; ca. 10% of total Hg) compared to the atmosphere (1.3 ± 0.2 ng m?3). The Hg0 flux calculated using the gas exchange model ranged from 0.1?1.3 ng m?2 h?1 (10th and 90th percentile) over the course of the campaign (May 10?June 20, 2017) and showed a distinct diel fluctuation. The mean coastal Hg0 fluxes determined with the two gradient-based approaches and REA were 0.3, 0.5, and 0.6 ng m?2 h?1, respectively. In contrast, the mean open sea Hg0 flux measured with REA was larger (6.3 ng m?2 h?1). The open sea Hg0 flux indicated a stronger wind speed dependence for the Hg0 transfer velocity compared to commonly used parameterizations. Although based on a limited data set, we suggest that the wind speed dependence of the Hg0 transfer velocity is more consistent with gases that have less water solubility than CO2 (e.g., O2). These pioneering flux measurements using micrometeorological techniques show that more such measurements would improve our understanding of air-sea Hg exchange. |
BibTeX:
@article{Osterwalder2021,
author = {Osterwalder, S and Nerentorp, M and Zhu, W and Jiskra, M and Nilsson, E and Nilsson, M B and Rutgersson, A and Soerensen, A L and Sommar, J and Wallin, M B and Wängberg, I and Bishop, K},
title = {Critical Observations of Gaseous Elemental Mercury Air-Sea Exchange},
journal = {Global Biogeochemical Cycles},
publisher = {John Wiley & Sons, Ltd},
year = {2021},
volume = {35},
number = {8},
pages = {e2020GB006742},
url = {https://doi.org/10.1029/2020GB006742},
doi = {10.1029/2020GB006742}
}
|
| Otu-Larbi F, Conte A, Fares S, Wild O and Ashworth K (2021), "FORCAsT-gs: Importance of Stomatal Conductance Parameterization to Estimated Ozone Deposition Velocity", Journal of Advances in Modeling Earth Systems., sep, 2021. Vol. 13(9), pp. e2021MS002581. John Wiley & Sons, Ltd. |
| Abstract: Abstract The role of stomata in regulating photosynthesis and transpiration, and hence governing global biogeochemical cycles and climate, is well-known. Less well-understood, however, is the importance of stomatal control to the exchange of other trace gases between terrestrial vegetation and the atmosphere. Yet these gases determine atmospheric composition, and hence air quality and climate, on scales ranging from local to global, and seconds to decades. Vegetation is a major sink for ground-level ozone via the process of dry deposition and the primary source of many biogenic volatile organic compounds (BVOCs). The rate of dry deposition is largely controlled by the rate of diffusion of a gas through the stomata, and this also governs the emission rate of some key BVOCs. It is critical therefore that canopy-atmosphere exchange models capture the physiological processes controlling stomatal conductance and the transfer of trace gases other than carbon dioxide and water vapor. We incorporate three of the most widely used coupled stomatal conductance-photosynthesis models into the one-dimensional multi-layer FORest Canopy-Atmosphere Transfer (FORCAsT1.0) model to assess the importance of choice of parameterization on simulated ozone deposition rates. Modeled GPP and stomatal conductance across a broad range of ecosystems differ by up to a factor of two between the best and worst performing model configurations. This leads to divergences in seasonal and diel profiles of ozone deposition velocity of up to 30% and deposition rate of up to 13%, demonstrating that the choice of stomatal conductance parameterization is critical in accurate quantification of ozone deposition. |
BibTeX:
@article{OtuLarbi2021,
author = {Otu-Larbi, Frederick and Conte, Adriano and Fares, Silvano and Wild, Oliver and Ashworth, Kirsti},
title = {FORCAsT-gs: Importance of Stomatal Conductance Parameterization to Estimated Ozone Deposition Velocity},
journal = {Journal of Advances in Modeling Earth Systems},
publisher = {John Wiley & Sons, Ltd},
year = {2021},
volume = {13},
number = {9},
pages = {e2021MS002581},
url = {https://doi.org/10.1029/2021MS002581},
doi = {10.1029/2021MS002581}
}
|
| Oulehle F, Fischer M, Hruška J, Chuman T, Krám P, Navrátil T, Tesař M and Trnka M (2021), "The GEOMON network of Czech catchments provides long-term insights into altered forest biogeochemistry: From acid atmospheric deposition to climate change", Hydrological Processes., may, 2021. Vol. 35(5), pp. e14204. John Wiley & Sons, Ltd. |
| Abstract: Abstract In 1994, a network of small catchments (GEOMON) was established in the Czech Republic to determine input?output element fluxes in semi-natural forest ecosystems recovering from anthropogenic acidification. The network consists from 16 catchments and the primary observations of elements fluxes were complemented by monitoring of biomass stock, element pools in soil and vegetation, and the main water balance components. Over last three decades, reductions of SO2, NOx and NH3 emissions were followed by sulphur (S) and nitrogen (N) deposition reductions of 75% and 30%, respectively. Steeper declines of strong acid anion concentrations compared to cations (Ca, Mg, Na, K, NH4) in precipitation resulted in precipitation pH increase from 4.5 to 5.2 in bulk precipitation and from 4.0 to 5.1 in spruce throughfall. Stream chemistry responded to changes in deposition: S leaching declined. However at majority of catchments soils acted as a net source of S to runoff, delaying recovery. Stream pH increased at acidic streams (pH?6) and aluminium concentration decreased. Stream nitrate (NO3) concentration declined by 60%, considerably more than N deposition. Stream NO3 concentration was tightly positively related to stream total dissolved nitrogen to total phosphorus (P) ratio, suggesting the role of P availability on N retention. Trends in dissolved organic carbon fluxes responded to both acidification recovery and to runoff temporal variation. An exceptional drought occurred between 2014 and 2019. Over this recent period, streamflow decreased by ≈?40% on average compared to 1990s, due to the increases of soil evaporation and vegetation transpiration by ≈?30% and declines in precipitation by ≈?15% on average across the elevational gradient. Sharp decreases of stream runoff at catchments <650?m?a.s.l. corresponded to areas of recent forest decline caused by bark beetle infestation on drought stressed spruce forests. Understanding of the interactions among legacies of acidification and eutrophication, drought effects on the water cycle and forest disturbance dynamics is requisite for effective management of forested ecosystems under anthropogenic influence. |
BibTeX:
@article{Oulehle2021,
author = {Oulehle, Filip and Fischer, Milan and Hruška, Jakub and Chuman, Tomáš and Krám, Pavel and Navrátil, Tomáš and Tesař, Miroslav and Trnka, Miroslav},
title = {The GEOMON network of Czech catchments provides long-term insights into altered forest biogeochemistry: From acid atmospheric deposition to climate change},
journal = {Hydrological Processes},
publisher = {John Wiley & Sons, Ltd},
year = {2021},
volume = {35},
number = {5},
pages = {e14204},
url = {https://doi.org/10.1002/hyp.14204},
doi = {10.1002/hyp.14204}
}
|
| Pace R, Guidolotti G, Baldacchini C, Pallozzi E, Grote R, Nowak DJ and Calfapietra C (2021), "Comparing i-Tree Eco Estimates of Particulate Matter Deposition with Leaf and Canopy Measurements in an Urban Mediterranean Holm Oak Forest", Environmental Science & Technology., may, 2021. Vol. 55(10), pp. 6613-6622. American Chemical Society. |
BibTeX:
@article{Pace2021,
author = {Pace, Rocco and Guidolotti, Gabriele and Baldacchini, Chiara and Pallozzi, Emanuele and Grote, Rüdiger and Nowak, David J and Calfapietra, Carlo},
title = {Comparing i-Tree Eco Estimates of Particulate Matter Deposition with Leaf and Canopy Measurements in an Urban Mediterranean Holm Oak Forest},
journal = {Environmental Science & Technology},
publisher = {American Chemical Society},
year = {2021},
volume = {55},
number = {10},
pages = {6613--6622},
url = {https://doi.org/10.1021/acs.est.0c07679},
doi = {10.1021/acs.est.0c07679}
}
|
| Pallandt M, Kumar J, Mauritz M, Schuur E, Virkkala A-M, Celis G, Hoffman F and Göckede M (2021), "Representativeness assessment of the pan-Arctic eddy-covariance site network, and optimized future enhancements", Biogeosciences Discussions. , pp. 1-42. |
| Abstract: Large changes in the Arctic carbon balance are expected as warming linked to climate change threatens to 15 destabilize ancient permafrost carbon stocks. The eddy covariance (EC) method is an established technique to quantify net losses and gains of carbon between the biosphere and atmosphere at high spatio-temporal resolution. Over the past decades, a growing network of terrestrial EC tower sites has been established across the Arctic, but a comprehensive assessment of the network's representativeness within the heterogeneous Arctic region is still lacking. This creates additional uncertainties when integrating flux data across sites, for example when upscaling fluxes to constrain pan-Arctic carbon budgets, and 20 changes therein. This study provides an inventory of Arctic (here >= 60 O N) EC sites, which has also been made available online (https://cosima.nceas.ucsb.edu/carbon-flux-sites/). Our database currently comprises 120 EC sites, but only 83 are listed as active, and just 25 of these active sites remain operational throughout the winter. To map the representativeness of this EC network, based on 18 bioclimatic and edaphic variables, we evaluated the similarity between environmental conditions 25 observed at the tower locations and those within the larger Arctic study domain. With the majority of sites located in Fennoscandia and Alaska, these regions were assigned the highest level of network representativeness, while large parts of Siberia and patches of Canada were classified as under-represented. This division between regions is further emphasized for |
BibTeX:
@article{Pallandt2021,
author = {Pallandt, Martijn and Kumar, Jitendra and Mauritz, Marguerite and Schuur, Edward and Virkkala, Anna-Maria and Celis, Gerardo and Hoffman, Forrest and Göckede, Mathias},
title = {Representativeness assessment of the pan-Arctic eddy-covariance site network, and optimized future enhancements},
journal = {Biogeosciences Discussions},
year = {2021},
pages = {1--42},
doi = {10.5194/bg-2021-133}
}
|
| Park S-B, Knohl A, Migliavacca M, Thum T, Vesala T, Peltola O, Mammarella I, Prokushkin A, Kolle O, Lavrič J, Park SS and Heimann M (2021), "Temperature Control of Spring CO2 Fluxes at a Coniferous Forest and a Peat Bog in Central Siberia", Atmosphere. Vol. 12(8) |
| Abstract: Climate change impacts the characteristics of the vegetation carbon-uptake process in the northern Eurasian terrestrial ecosystem. However, the currently available direct CO2 flux measurement datasets, particularly for central Siberia, are insufficient for understanding the current condition in the northern Eurasian carbon cycle. Here, we report daily and seasonal interannual variations in CO2 fluxes and associated abiotic factors measured using eddy covariance in a coniferous forest and a bog near Zotino, Krasnoyarsk Krai, Russia, for April to early June, 2013–2017. Despite the snow not being completely melted, both ecosystems became weak net CO2 sinks if the air temperature was warm enough for photosynthesis. The forest became a net CO2 sink 7–16 days earlier than the bog. After the surface soil temperature exceeded ∼1 °C, the ecosystems became persistent net CO2 sinks. Net ecosystem productivity was highest in 2015 for both ecosystems because of the anomalously high air temperature in May compared with other years. Our findings demonstrate that long-term monitoring of flux measurements at the site level, particularly during winter and its transition to spring, is essential for understanding the responses of the northern Eurasian ecosystem to spring warming. |
BibTeX:
@article{Park2021,
author = {Park, Sung-Bin and Knohl, Alexander and Migliavacca, Mirco and Thum, Tea and Vesala, Timo and Peltola, Olli and Mammarella, Ivan and Prokushkin, Anatoly and Kolle, Olaf and Lavrič, Jošt and Park, Sang Seo and Heimann, Martin},
title = {Temperature Control of Spring CO2 Fluxes at a Coniferous Forest and a Peat Bog in Central Siberia},
journal = {Atmosphere},
year = {2021},
volume = {12},
number = {8},
url = {https://www.mdpi.com/2073-4433/12/8/984},
doi = {10.3390/atmos12080984}
}
|
| Pastorello G, Trotta C, Canfora E, Chu H, Christianson D, Cheah Y-W, Poindexter C, Chen J, Elbashandy A, Humphrey M, Isaac P, Polidori D, Reichstein M, Ribeca A, van Ingen C, Vuichard N, Zhang L, Amiro B, Ammann C, Arain MA, Ardö J, Arkebauer T, Arndt SK, Arriga N, Aubinet M, Aurela M, Baldocchi D, Barr A, Beamesderfer E, Marchesini LB, Bergeron O, Beringer J, Bernhofer C, Berveiller D, Billesbach D, Black TA, Blanken PD, Bohrer G, Boike J, Bolstad PV, Bonal D, Bonnefond J-M, Bowling DR, Bracho R, Brodeur J, Brümmer C, Buchmann N, Burban B, Burns SP, Buysse P, Cale P, Cavagna M, Cellier P, Chen S, Chini I, Christensen TR, Cleverly J, Collalti A, Consalvo C, Cook BD, Cook D, Coursolle C, Cremonese E, Curtis PS, D'Andrea E, da Rocha H, Dai X, Davis KJ, De Cinti B, de Grandcourt A, De Ligne A, De Oliveira RC, Delpierre N, Desai AR, Di Bella CM, di Tommasi P, Dolman H, Domingo F, Dong G, Dore S, Duce P, Dufrêne E, Dunn A, Dušek J, Eamus D, Eichelmann U, ElKhidir HAM, Eugster W, Ewenz CM, Ewers B, Famulari D, Fares S, Feigenwinter I, Feitz A, Fensholt R, Filippa G, Fischer M, Frank J, Galvagno M, Gharun M, Gianelle D, Gielen B, Gioli B, Gitelson A, Goded I, Goeckede M, Goldstein AH, Gough CM, Goulden ML, Graf A, Griebel A, Gruening C, Grünwald T, Hammerle A, Han S, Han X, Hansen BU, Hanson C, Hatakka J, He Y, Hehn M, Heinesch B, Hinko-Najera N, Hörtnagl L, Hutley L, Ibrom A, Ikawa H, Jackowicz-Korczynski M, Janouš D, Jans W, Jassal R, Jiang S, Kato T, Khomik M, Klatt J, Knohl A, Knox S, Kobayashi H, Koerber G, Kolle O, Kosugi Y, Kotani A, Kowalski A, Kruijt B, Kurbatova J, Kutsch WL, Kwon H, Launiainen S, Laurila T, Law B, Leuning R, Li Y, Liddell M, Limousin J-M, Lion M, Liska AJ, Lohila A, López-Ballesteros A, López-Blanco E, Loubet B, Loustau D, Lucas-Moffat A, Lüers J, Ma S, Macfarlane C, Magliulo V, Maier R, Mammarella I, Manca G, Marcolla B, Margolis HA, Marras S, Massman W, Mastepanov M, Matamala R, Matthes JH, Mazzenga F, McCaughey H, McHugh I, McMillan AMS, Merbold L, Meyer W, Meyers T, Miller SD, Minerbi S, Moderow U, Monson RK, Montagnani L, Moore CE, Moors E, Moreaux V, Moureaux C, Munger JW, Nakai T, Neirynck J, Nesic Z, Nicolini G, Noormets A, Northwood M, Nosetto M, Nouvellon Y, Novick K, Oechel W, Olesen JE, Ourcival J-M, Papuga SA, Parmentier F-J, Paul-Limoges E, Pavelka M, Peichl M, Pendall E, Phillips RP, Pilegaard K, Pirk N, Posse G, Powell T, Prasse H, Prober SM, Rambal S, Rannik Ü, Raz-Yaseef N, Rebmann C, Reed D, de Dios VR, Restrepo-Coupe N, Reverter BR, Roland M, Sabbatini S, Sachs T, Saleska SR, Sánchez-Cañete EP, Sanchez-Mejia ZM, Schmid HP, Schmidt M, Schneider K, Schrader F, Schroder I, Scott RL, Sedlák P, Serrano-Ortíz P, Shao C, Shi P, Shironya I, Siebicke L, Šigut L, Silberstein R, Sirca C, Spano D, Steinbrecher R, Stevens RM, Sturtevant C, Suyker A, Tagesson T, Takanashi S, Tang Y, Tapper N, Thom J, Tomassucci M, Tuovinen J-P, Urbanski S, Valentini R, van der Molen M, van Gorsel E, van Huissteden K, Varlagin A, Verfaillie J, Vesala T, Vincke C, Vitale D, Vygodskaya N, Walker JP, Walter-Shea E, Wang H, Weber R, Westermann S, Wille C, Wofsy S, Wohlfahrt G, Wolf S, Woodgate W, Li Y, Zampedri R, Zhang J, Zhou G, Zona D, Agarwal D, Biraud S, Torn M and Papale D (2021), "Author Correction: The FLUXNET2015 dataset and the ONEFlux processing pipeline for eddy covariance data", Scientific Data. Vol. 8(1), pp. 72. |
| Abstract: A Correction to this paper has been published: https://doi.org/10.1038/s41597-021-00851-9. |
BibTeX:
@article{Pastorello2021,
author = {Pastorello, Gilberto and Trotta, Carlo and Canfora, Eleonora and Chu, Housen and Christianson, Danielle and Cheah, You-Wei and Poindexter, Cristina and Chen, Jiquan and Elbashandy, Abdelrahman and Humphrey, Marty and Isaac, Peter and Polidori, Diego and Reichstein, Markus and Ribeca, Alessio and van Ingen, Catharine and Vuichard, Nicolas and Zhang, Leiming and Amiro, Brian and Ammann, Christof and Arain, M Altaf and Ardö, Jonas and Arkebauer, Timothy and Arndt, Stefan K and Arriga, Nicola and Aubinet, Marc and Aurela, Mika and Baldocchi, Dennis and Barr, Alan and Beamesderfer, Eric and Marchesini, Luca Belelli and Bergeron, Onil and Beringer, Jason and Bernhofer, Christian and Berveiller, Daniel and Billesbach, Dave and Black, Thomas Andrew and Blanken, Peter D and Bohrer, Gil and Boike, Julia and Bolstad, Paul V and Bonal, Damien and Bonnefond, Jean-Marc and Bowling, David R and Bracho, Rosvel and Brodeur, Jason and Brümmer, Christian and Buchmann, Nina and Burban, Benoit and Burns, Sean P and Buysse, Pauline and Cale, Peter and Cavagna, Mauro and Cellier, Pierre and Chen, Shiping and Chini, Isaac and Christensen, Torben R and Cleverly, James and Collalti, Alessio and Consalvo, Claudia and Cook, Bruce D and Cook, David and Coursolle, Carole and Cremonese, Edoardo and Curtis, Peter S and D'Andrea, Ettore and da Rocha, Humberto and Dai, Xiaoqin and Davis, Kenneth J and De Cinti, Bruno and de Grandcourt, Agnes and De Ligne, Anne and De Oliveira, Raimundo C and Delpierre, Nicolas and Desai, Ankur R and Di Bella, Carlos Marcelo and di Tommasi, Paul and Dolman, Han and Domingo, Francisco and Dong, Gang and Dore, Sabina and Duce, Pierpaolo and Dufrêne, Eric and Dunn, Allison and Dušek, Jiří and Eamus, Derek and Eichelmann, Uwe and ElKhidir, Hatim Abdalla M and Eugster, Werner and Ewenz, Cacilia M and Ewers, Brent and Famulari, Daniela and Fares, Silvano and Feigenwinter, Iris and Feitz, Andrew and Fensholt, Rasmus and Filippa, Gianluca and Fischer, Marc and Frank, John and Galvagno, Marta and Gharun, Mana and Gianelle, Damiano and Gielen, Bert and Gioli, Beniamino and Gitelson, Anatoly and Goded, Ignacio and Goeckede, Mathias and Goldstein, Allen H and Gough, Christopher M and Goulden, Michael L and Graf, Alexander and Griebel, Anne and Gruening, Carsten and Grünwald, Thomas and Hammerle, Albin and Han, Shijie and Han, Xingguo and Hansen, Birger Ulf and Hanson, Chad and Hatakka, Juha and He, Yongtao and Hehn, Markus and Heinesch, Bernard and Hinko-Najera, Nina and Hörtnagl, Lukas and Hutley, Lindsay and Ibrom, Andreas and Ikawa, Hiroki and Jackowicz-Korczynski, Marcin and Janouš, Dalibor and Jans, Wilma and Jassal, Rachhpal and Jiang, Shicheng and Kato, Tomomichi and Khomik, Myroslava and Klatt, Janina and Knohl, Alexander and Knox, Sara and Kobayashi, Hideki and Koerber, Georgia and Kolle, Olaf and Kosugi, Yoshiko and Kotani, Ayumi and Kowalski, Andrew and Kruijt, Bart and Kurbatova, Julia and Kutsch, Werner L and Kwon, Hyojung and Launiainen, Samuli and Laurila, Tuomas and Law, Bev and Leuning, Ray and Li, Yingnian and Liddell, Michael and Limousin, Jean-Marc and Lion, Marryanna and Liska, Adam J and Lohila, Annalea and López-Ballesteros, Ana and López-Blanco, Efrén and Loubet, Benjamin and Loustau, Denis and Lucas-Moffat, Antje and Lüers, Johannes and Ma, Siyan and Macfarlane, Craig and Magliulo, Vincenzo and Maier, Regine and Mammarella, Ivan and Manca, Giovanni and Marcolla, Barbara and Margolis, Hank A and Marras, Serena and Massman, William and Mastepanov, Mikhail and Matamala, Roser and Matthes, Jaclyn Hatala and Mazzenga, Francesco and McCaughey, Harry and McHugh, Ian and McMillan, Andrew M S and Merbold, Lutz and Meyer, Wayne and Meyers, Tilden and Miller, Scott D and Minerbi, Stefano and Moderow, Uta and Monson, Russell K and Montagnani, Leonardo and Moore, Caitlin E and Moors, Eddy and Moreaux, Virginie and Moureaux, Christine and Munger, J William and Nakai, Taro and Neirynck, Johan and Nesic, Zoran and Nicolini, Giacomo and Noormets, Asko and Northwood, Matthew and Nosetto, Marcelo and Nouvellon, Yann and Novick, Kimberly and Oechel, Walter and Olesen, Jørgen Eivind and Ourcival, Jean-Marc and Papuga, Shirley A and Parmentier, Frans-Jan and Paul-Limoges, Eugenie and Pavelka, Marian and Peichl, Matthias and Pendall, Elise and Phillips, Richard P and Pilegaard, Kim and Pirk, Norbert and Posse, Gabriela and Powell, Thomas and Prasse, Heiko and Prober, Suzanne M and Rambal, Serge and Rannik, Üllar and Raz-Yaseef, Naama and Rebmann, Corinna and Reed, David and de Dios, Victor Resco and Restrepo-Coupe, Natalia and Reverter, Borja R and Roland, Marilyn and Sabbatini, Simone and Sachs, Torsten and Saleska, Scott R and Sánchez-Cañete, Enrique P and Sanchez-Mejia, Zulia M and Schmid, Hans Peter and Schmidt, Marius and Schneider, Karl and Schrader, Frederik and Schroder, Ivan and Scott, Russell L and Sedlák, Pavel and Serrano-Ortíz, Penélope and Shao, Changliang and Shi, Peili and Shironya, Ivan and Siebicke, Lukas and Šigut, Ladislav and Silberstein, Richard and Sirca, Costantino and Spano, Donatella and Steinbrecher, Rainer and Stevens, Robert M and Sturtevant, Cove and Suyker, Andy and Tagesson, Torbern and Takanashi, Satoru and Tang, Yanhong and Tapper, Nigel and Thom, Jonathan and Tomassucci, Michele and Tuovinen, Juha-Pekka and Urbanski, Shawn and Valentini, Riccardo and van der Molen, Michiel and van Gorsel, Eva and van Huissteden, Ko and Varlagin, Andrej and Verfaillie, Joseph and Vesala, Timo and Vincke, Caroline and Vitale, Domenico and Vygodskaya, Natalia and Walker, Jeffrey P and Walter-Shea, Elizabeth and Wang, Huimin and Weber, Robin and Westermann, Sebastian and Wille, Christian and Wofsy, Steven and Wohlfahrt, Georg and Wolf, Sebastian and Woodgate, William and Li, Yuelin and Zampedri, Roberto and Zhang, Junhui and Zhou, Guoyi and Zona, Donatella and Agarwal, Deb and Biraud, Sebastien and Torn, Margaret and Papale, Dario},
title = {Author Correction: The FLUXNET2015 dataset and the ONEFlux processing pipeline for eddy covariance data},
journal = {Scientific Data},
year = {2021},
volume = {8},
number = {1},
pages = {72},
url = {https://doi.org/10.1038/s41597-021-00851-9},
doi = {10.1038/s41597-021-00851-9}
}
|
| Paz L, City I, Oducado RMF, Visayas AW, Paz L and City I (2021), "ot Pr ep rin pe er re vie we Pr ep rin t n ot pe er re vie we" Vol. 14(2), pp. 1170-1177.
[BibTeX] |
BibTeX:
@article{Paz2021,
author = {Paz, La and City, Iloilo and Oducado, Ryan Michael F and Visayas, Assistant West and Paz, La and City, Iloilo},
title = {ot Pr ep rin pe er re vie we Pr ep rin t n ot pe er re vie we},
year = {2021},
volume = {14},
number = {2},
pages = {1170--1177}
}
|
| Peltola O, Aslan T, Ibrom A, Nemitz E, Rannik Ü and Mammarella I (2021), "The high-frequency response correction of eddy covariance fluxes -- Part 1: An experimental approach and its interdependence with the time-lag estimation", Atmospheric Measurement Techniques. Vol. 14(7), pp. 5071-5088. |
BibTeX:
@article{Peltola2021,
author = {Peltola, O and Aslan, T and Ibrom, A and Nemitz, E and Rannik, Ü and Mammarella, I},
title = {The high-frequency response correction of eddy covariance fluxes -- Part 1: An experimental approach and its interdependence with the time-lag estimation},
journal = {Atmospheric Measurement Techniques},
year = {2021},
volume = {14},
number = {7},
pages = {5071--5088},
url = {https://amt.copernicus.org/articles/14/5071/2021/},
doi = {10.5194/amt-14-5071-2021}
}
|
| Petrescu AMR, Qiu C, Ciais P, Thompson RL, Peylin P, McGrath MJ, Solazzo E, Janssens-Maenhout G, Tubiello FN, Bergamaschi P, Brunner D, Peters GP, Höglund-Isaksson L, Regnier P, Lauerwald R, Bastviken D, Tsuruta A, Winiwarter W, Patra PK, Kuhnert M, Oreggioni GD, Crippa M, Saunois M, Perugini L, Markkanen T, Aalto T, Groot Zwaaftink CD, Tian H, Yao Y, Wilson C, Conchedda G, Günther D, Leip A, Smith P, Haussaire J-M, Leppänen A, Manning AJ, McNorton J, Brockmann P and Dolman AJ (2021), "The consolidated European synthesis of CH_{4} and N_{2}O emissions for the European Union and United Kingdom: 1990--2017", Earth System Science Data. Vol. 13(5), pp. 2307-2362. |
BibTeX:
@article{Petrescu2021,
author = {Petrescu, A M R and Qiu, C and Ciais, P and Thompson, R L and Peylin, P and McGrath, M J and Solazzo, E and Janssens-Maenhout, G and Tubiello, F N and Bergamaschi, P and Brunner, D and Peters, G P and Höglund-Isaksson, L and Regnier, P and Lauerwald, R and Bastviken, D and Tsuruta, A and Winiwarter, W and Patra, P K and Kuhnert, M and Oreggioni, G D and Crippa, M and Saunois, M and Perugini, L and Markkanen, T and Aalto, T and Groot Zwaaftink, C D and Tian, H and Yao, Y and Wilson, C and Conchedda, G and Günther, D and Leip, A and Smith, P and Haussaire, J.-M. and Leppänen, A and Manning, A J and McNorton, J and Brockmann, P and Dolman, A J},
title = {The consolidated European synthesis of CH_{4} and N_{2}O emissions for the European Union and United Kingdom: 1990--2017},
journal = {Earth System Science Data},
year = {2021},
volume = {13},
number = {5},
pages = {2307--2362},
url = {https://essd.copernicus.org/articles/13/2307/2021/},
doi = {10.5194/essd-13-2307-2021}
}
|
| Pisek J, Erb A, Korhonen L, Biermann T, Carrara A, Cremonese E, Cuntz M, Fares S, Gerosa G, Grünwald T, Hase N, Heliasz M, Ibrom A, Knohl A, Kobler J, Kruijt B, Lange H, Leppänen L, Limousin J-M, Serrano FRL, Loustau D, Lukeš P, Lundin L, Marzuoli R, Mölder M, Montagnani L, Neirynck J, Peichl M, Rebmann C, Rubio E, Santos-Reis M, Schaaf C, Schmidt M, Simioni G, Soudani K and Vincke C (2021), "Retrieval and validation of forest background reflectivity from daily Moderate Resolution Imaging Spectroradiometer (MODIS) bidirectional reflectance distribution function (BRDF) data across European forests", Biogeosciences., jan, 2021. Vol. 18(2), pp. 621-635. |
BibTeX:
@article{Pisek2021,
author = {Pisek, Jan and Erb, Angela and Korhonen, Lauri and Biermann, Tobias and Carrara, Arnaud and Cremonese, Edoardo and Cuntz, Matthias and Fares, Silvano and Gerosa, Giacomo and Grünwald, Thomas and Hase, Niklas and Heliasz, Michal and Ibrom, Andreas and Knohl, Alexander and Kobler, Johannes and Kruijt, Bart and Lange, Holger and Leppänen, Leena and Limousin, Jean-Marc and Serrano, Francisco Ramon Lopez and Loustau, Denis and Lukeš, Petr and Lundin, Lars and Marzuoli, Riccardo and Mölder, Meelis and Montagnani, Leonardo and Neirynck, Johan and Peichl, Matthias and Rebmann, Corinna and Rubio, Eva and Santos-Reis, Margarida and Schaaf, Crystal and Schmidt, Marius and Simioni, Guillaume and Soudani, Kamel and Vincke, Caroline},
title = {Retrieval and validation of forest background reflectivity from daily Moderate Resolution Imaging Spectroradiometer (MODIS) bidirectional reflectance distribution function (BRDF) data across European forests},
journal = {Biogeosciences},
year = {2021},
volume = {18},
number = {2},
pages = {621--635},
url = {https://bg.copernicus.org/articles/18/621/2021/},
doi = {10.5194/bg-18-621-2021}
}
|
| Platt SM, Hov Ø, Berg T, Breivik K, Eckhardt S, Eleftheriadis K, Evangeliou N, Fiebig M, Fisher R, Hansen G, Hansson H-C, Heintzenberg J, Hermansen O, Heslin-Rees D, Holmén K, Hudson S, Kallenborn R, Krejci R, Krognes T, Larssen S, Lowry D, Lund Myhre C, Lunder C, Nisbet E, Nizetto PB, Park K-T, Pedersen CA, Aspmo Pfaffhuber K, Röckmann T, Schmidbauer N, Solberg S, Stohl A, Ström J, Svendby T, Tunved P, Tørnkvist K, van der Veen C, Vratolis S, Yoon YJ, Yttri KE, Zieger P, Aas W and Tørseth K (2021), "Atmospheric composition in the European Arctic and 30 years of the Zeppelin Observatory, Ny-Ålesund", Atmospheric Chemistry and Physics Discussions. Vol. 2021, pp. 1-80. |
BibTeX:
@article{Platt2021,
author = {Platt, S M and Hov, Ø and Berg, T and Breivik, K and Eckhardt, S and Eleftheriadis, K and Evangeliou, N and Fiebig, M and Fisher, R and Hansen, G and Hansson, H.-C. and Heintzenberg, J and Hermansen, O and Heslin-Rees, D and Holmén, K and Hudson, S and Kallenborn, R and Krejci, R and Krognes, T and Larssen, S and Lowry, D and Lund Myhre, C and Lunder, C and Nisbet, E and Nizetto, P B and Park, K.-T. and Pedersen, C A and Aspmo Pfaffhuber, K and Röckmann, T and Schmidbauer, N and Solberg, S and Stohl, A and Ström, J and Svendby, T and Tunved, P and Tørnkvist, K and van der Veen, C and Vratolis, S and Yoon, Y J and Yttri, K E and Zieger, P and Aas, W and Tørseth, K},
title = {Atmospheric composition in the European Arctic and 30 years of the Zeppelin Observatory, Ny-Ålesund},
journal = {Atmospheric Chemistry and Physics Discussions},
year = {2021},
volume = {2021},
pages = {1--80},
url = {https://acp.copernicus.org/preprints/acp-2021-505/},
doi = {10.5194/acp-2021-505}
}
|
| Pold G, Baillargeon N, Lepe A, Rastetter EB and Sistla SA (2021), "Warming effects on arctic tundra biogeochemistry are limited but habitat-dependent: a meta-analysis", Ecosphere., oct, 2021. Vol. 12(10), pp. e03777. John Wiley & Sons, Ltd. |
| Abstract: Abstract Arctic tundra consists of diverse habitats that differ in dominant vegetation, soil moisture regimes, and relative importance of organic vs. inorganic nutrient cycling. The Arctic is also the most rapidly warming global area, with winter warming dominating. This warming is expected to have dramatic effects on tundra carbon and nutrient dynamics. We completed a meta-analysis of 166 experimental warming study papers to evaluate the hypotheses that warming changes tundra biogeochemical cycles in a habitat- and seasonally specific manner and that the carbon (C), nitrogen (N), and phosphorus (P) cycles will be differentially accelerated, leading to decoupling of elemental cycles. We found that nutrient availability and plant leaf stoichiometry responses to experimental warming were variable and overall weak, but that both gross primary productivity and the plant C pool tended to increase with growing season warming. The effects of winter warming on C fluxes did not extend into the growing season. Overall, although warming led to more consistent increases in C fluxes compared to N or P fluxes, evidence for decoupling of biogeochemical cycles is weak and any effect appears limited to heath habitats. However, data on many habitats are too sparse to be able to generalize how warming might decouple biogeochemical cycles, and too few year-round warming studies exist to ascertain whether the season under which warming occurs alters how ecosystems respond to warming. Coordinated field campaigns are necessary to more robustly document tundra habitat-specific responses to realistic climate warming scenarios in order to better understand the mechanisms driving this heterogeneity and identify the tundra habitats, communities, and soil pools most susceptible to warming. |
BibTeX:
@article{Pold2021,
author = {Pold, Grace and Baillargeon, Natalie and Lepe, Adan and Rastetter, Edward B and Sistla, Seeta A},
title = {Warming effects on arctic tundra biogeochemistry are limited but habitat-dependent: a meta-analysis},
journal = {Ecosphere},
publisher = {John Wiley & Sons, Ltd},
year = {2021},
volume = {12},
number = {10},
pages = {e03777},
url = {https://doi.org/10.1002/ecs2.3777},
doi = {10.1002/ecs2.3777}
}
|
| Poyatos R, Granda V, Flo V, Adams MA, Adorján B, Aguadé D, Aidar MPM, Allen S, Alvarado-Barrientos MS, Anderson-Teixeira KJ, Aparecido LM, Arain MA, Aranda I, Asbjornsen H, Baxter R, Beamesderfer E, Berry ZC, Berveiller D, Blakely B, Boggs J, Bohrer G, Bolstad PV, Bonal D, Bracho R, Brito P, Brodeur J, Casanoves F, Chave J, Chen H, Cisneros C, Clark K, Cremonese E, Dang H, David JS, David TS, Delpierre N, Desai AR, Do FC, Dohnal M, Domec J-C, Dzikiti S, Edgar C, Eichstaedt R, El-Madany TS, Elbers J, Eller CB, Euskirchen ES, Ewers B, Fonti P, Forner A, Forrester DI, Freitas HC, Galvagno M, Garcia-Tejera O, Ghimire CP, Gimeno TE, Grace J, Granier A, Griebel A, Guangyu Y, Gush MB, Hanson PJ, Hasselquist NJ, Heinrich I, Hernandez-Santana V, Herrmann V, Hölttä T, Holwerda F, Irvine J, Isarangkool Na Ayutthaya S, Jarvis PG, Jochheim H, Joly CA, Kaplick J, Kim HS, Klemedtsson L, Kropp H, Lagergren F, Lane P, Lang P, Lapenas A, Lechuga V, Lee M, Leuschner C, Limousin J-M, Linares JC, Linderson M-L, Lindroth A, Llorens P, López-Bernal Á, Loranty MM, Lüttschwager D, Macinnis-Ng C, Maréchaux I, Martin TA, Matheny A, McDowell N, McMahon S, Meir P, Mészáros I, Migliavacca M, Mitchell P, Mölder M, Montagnani L, Moore GW, Nakada R, Niu F, Nolan RH, Norby R, Novick K, Oberhuber W, Obojes N, Oishi AC, Oliveira RS, Oren R, Ourcival J-M, Paljakka T, Perez-Priego O, Peri PL, Peters RL, Pfautsch S, Pockman WT, Preisler Y, Rascher K, Robinson G, Rocha H, Rocheteau A, Röll A, Rosado BHP, Rowland L, Rubtsov AV, Sabaté S, Salmon Y, Salomón RL, Sánchez-Costa E, Schäfer KVR, Schuldt B, Shashkin A, Stahl C, Stojanović M, Suárez JC, Sun G, Szatniewska J, Tatarinov F, Tesař M, Thomas FM, Tor-ngern P, Urban J, Valladares F, van der Tol C, van Meerveld I, Varlagin A, Voigt H, Warren J, Werner C, Werner W, Wieser G, Wingate L, Wullschleger S, Yi K, Zweifel R, Steppe K, Mencuccini M and Martínez-Vilalta J (2021), "Global transpiration data from sap flow measurements: the SAPFLUXNET database", Earth System Science Data., jun, 2021. Vol. 13(6), pp. 2607-2649. |
BibTeX:
@article{Poyatos2021,
author = {Poyatos, Rafael and Granda, Víctor and Flo, Víctor and Adams, Mark A and Adorján, Balázs and Aguadé, David and Aidar, Marcos P M and Allen, Scott and Alvarado-Barrientos, M Susana and Anderson-Teixeira, Kristina J and Aparecido, Luiza Maria and Arain, M Altaf and Aranda, Ismael and Asbjornsen, Heidi and Baxter, Robert and Beamesderfer, Eric and Berry, Z Carter and Berveiller, Daniel and Blakely, Bethany and Boggs, Johnny and Bohrer, Gil and Bolstad, Paul V and Bonal, Damien and Bracho, Rosvel and Brito, Patricia and Brodeur, Jason and Casanoves, Fernando and Chave, Jérôme and Chen, Hui and Cisneros, Cesar and Clark, Kenneth and Cremonese, Edoardo and Dang, Hongzhong and David, Jorge S and David, Teresa S and Delpierre, Nicolas and Desai, Ankur R and Do, Frederic C and Dohnal, Michal and Domec, Jean-Christophe and Dzikiti, Sebinasi and Edgar, Colin and Eichstaedt, Rebekka and El-Madany, Tarek S and Elbers, Jan and Eller, Cleiton B and Euskirchen, Eugénie S and Ewers, Brent and Fonti, Patrick and Forner, Alicia and Forrester, David I and Freitas, Helber C and Galvagno, Marta and Garcia-Tejera, Omar and Ghimire, Chandra Prasad and Gimeno, Teresa E and Grace, John and Granier, André and Griebel, Anne and Guangyu, Yan and Gush, Mark B and Hanson, Paul J and Hasselquist, Niles J and Heinrich, Ingo and Hernandez-Santana, Virginia and Herrmann, Valentine and Hölttä, Teemu and Holwerda, Friso and Irvine, James and Isarangkool Na Ayutthaya, Supat and Jarvis, Paul G and Jochheim, Hubert and Joly, Carlos A and Kaplick, Julia and Kim, Hyun Seok and Klemedtsson, Leif and Kropp, Heather and Lagergren, Fredrik and Lane, Patrick and Lang, Petra and Lapenas, Andrei and Lechuga, Víctor and Lee, Minsu and Leuschner, Christoph and Limousin, Jean-Marc and Linares, Juan Carlos and Linderson, Maj-Lena and Lindroth, Anders and Llorens, Pilar and López-Bernal, Álvaro and Loranty, Michael M and Lüttschwager, Dietmar and Macinnis-Ng, Cate and Maréchaux, Isabelle and Martin, Timothy A and Matheny, Ashley and McDowell, Nate and McMahon, Sean and Meir, Patrick and Mészáros, Ilona and Migliavacca, Mirco and Mitchell, Patrick and Mölder, Meelis and Montagnani, Leonardo and Moore, Georgianne W and Nakada, Ryogo and Niu, Furong and Nolan, Rachael H and Norby, Richard and Novick, Kimberly and Oberhuber, Walter and Obojes, Nikolaus and Oishi, A Christopher and Oliveira, Rafael S and Oren, Ram and Ourcival, Jean-Marc and Paljakka, Teemu and Perez-Priego, Oscar and Peri, Pablo L and Peters, Richard L and Pfautsch, Sebastian and Pockman, William T and Preisler, Yakir and Rascher, Katherine and Robinson, George and Rocha, Humberto and Rocheteau, Alain and Röll, Alexander and Rosado, Bruno H P and Rowland, Lucy and Rubtsov, Alexey V and Sabaté, Santiago and Salmon, Yann and Salomón, Roberto L and Sánchez-Costa, Elisenda and Schäfer, Karina V R and Schuldt, Bernhard and Shashkin, Alexandr and Stahl, Clément and Stojanović, Marko and Suárez, Juan Carlos and Sun, Ge and Szatniewska, Justyna and Tatarinov, Fyodor and Tesař, Miroslav and Thomas, Frank M and Tor-ngern, Pantana and Urban, Josef and Valladares, Fernando and van der Tol, Christiaan and van Meerveld, Ilja and Varlagin, Andrej and Voigt, Holm and Warren, Jeffrey and Werner, Christiane and Werner, Willy and Wieser, Gerhard and Wingate, Lisa and Wullschleger, Stan and Yi, Koong and Zweifel, Roman and Steppe, Kathy and Mencuccini, Maurizio and Martínez-Vilalta, Jordi},
title = {Global transpiration data from sap flow measurements: the SAPFLUXNET database},
journal = {Earth System Science Data},
year = {2021},
volume = {13},
number = {6},
pages = {2607--2649},
url = {https://essd.copernicus.org/articles/13/2607/2021/},
doi = {10.5194/essd-13-2607-2021}
}
|
| Qiao W, Wu L, Song J, Li X, Qiao F and Rutgersson A (2021), "Momentum Flux Balance at the Air-Sea Interface", Journal of Geophysical Research: Oceans., feb, 2021. Vol. 126(2), pp. e2020JC016563. John Wiley & Sons, Ltd. |
| Abstract: Abstract Ocean waves can spatiotemporally redistribute the momentum flux at the air-sea interface, which varies with the sea state. Traditional atmosphere-ocean coupled systems assume the ocean-side stress (τoc) to be identical to the air-side stress (τa); consequently, the role of ocean waves is neglected. In this study, the wave impacts on the air-sea momentum flux are investigated based on 1-year high-resolution model simulations in the Baltic Sea using an atmosphere-wave coupled model (Uppsala University-Coupled Model, UU-CM). The simulation results show that τoc can differ significantly from τa in both direction and magnitude. The direction difference between τoc and τa (DD(τoc, τa)) and the normalized momentum flux () decrease with increasing inverse wave age. In general, and DD(τoc, τa) are pronounced under wind-following swell and wind-crossing swell conditions, respectively. The occurrence frequencies of large and DD(τoc, τa) are higher nearer the coast; statistically, both decrease significantly with increasing water depth because of the joint effect of dissipation processes. Based on four selected areas, we find that alongshore winds (winds blowing parallel to the coastline) are favorable for large angular differences between τoc and τa (DD(τoc, τa) > 5°). However, onshore winds predominate at . The τa in the wave model is generally less than that obtained from the atmospheric model under low-moderate wind conditions if the wave model feeds only the Charnock coefficient (roughness length) back to the atmospheric model in coupled systems. |
BibTeX:
@article{Qiao2021,
author = {Qiao, Wenli and Wu, Lichuan and Song, Jinbao and Li, Xue and Qiao, Fangli and Rutgersson, Anna},
title = {Momentum Flux Balance at the Air-Sea Interface},
journal = {Journal of Geophysical Research: Oceans},
publisher = {John Wiley & Sons, Ltd},
year = {2021},
volume = {126},
number = {2},
pages = {e2020JC016563},
url = {https://doi.org/10.1029/2020JC016563},
doi = {10.1029/2020JC016563}
}
|
| Qu Z-L, Santalahti M, Köster K, Berninger F, Pumpanen J, Heinonsalo J and Sun H (2021), "Soil Fungal Community Structure in Boreal Pine Forests: From Southern to Subarctic Areas of Finland", Frontiers in Microbiology. Vol. 12 |
| Abstract: The boreal forest environment plays an important role in the global C cycle due to its high carbon storage capacity. However, relatively little is known about the forest fungal community at a regional scale in boreal forests. In the present study, we have re-analyzed the data from our previous studies and highlighted the core fungal community composition and potential functional groups in three forests dominated by Scots pine (Pinus sylvestris L.) in Finland, and identified the fungal generalists that appear across geographic locations despite differences in local conditions. The three forests represent subarctic, northern and southern boreal forest, and are all in an un-managed state without human interference or management. The subarctic and northern areas are subject to reindeer grazing. The results showed that the three locations formed distinct fungal community structures (P < 0.05). Compared to the two northern locations, the southern boreal forest harbored a greater abundance of Zygomycota, Lactarius, Mortierella Umbelopsis, and Tylospora, in which aspect there were no differences between the two northern forests. Cortinarius, Piloderma, and Suillus were the core fungal genera in the boreal Scots pine forest. Functionally, the southern boreal forest harbored a greater abundance of saprotroph, endophytes and fungal parasite-lichen, whereas a greater abundance of ectomycorrhizal fungi was observed in the northern boreal forests. Moreover, the pathotroph and wood saprotrophs were commonly present in these three regions. The three locations formed two distinct fungal community functional structures, by which the southern forest was clearly separated from the two northern forests, suggesting a distance–decay relationship via geographic location. This study provides useful information for better understanding the common fungal communities and functions in boreal forests in different geographical locations. |
BibTeX:
@article{Qu2021,
author = {Qu, Zhao-Lei and Santalahti, Minna and Köster, Kajar and Berninger, Frank and Pumpanen, Jukka and Heinonsalo, Jussi and Sun, Hui},
title = {Soil Fungal Community Structure in Boreal Pine Forests: From Southern to Subarctic Areas of Finland},
journal = {Frontiers in Microbiology},
year = {2021},
volume = {12},
url = {https://www.frontiersin.org/article/10.3389/fmicb.2021.653896},
doi = {10.3389/fmicb.2021.653896}
}
|
| Raoult N, Ottlé C, Peylin P, Bastrikov V and Maugis P (2021), "Evaluating and Optimizing Surface Soil Moisture Drydowns in the ORCHIDEE Land Surface Model at In Situ Locations", Journal of Hydrometeorology. Boston MA, USA Vol. 22(4), pp. 1025-1043. American Meteorological Society. |
BibTeX:
@article{Raoult2021,
author = {Raoult, Nina and Ottlé, Catherine and Peylin, Philippe and Bastrikov, Vladislav and Maugis, Pascal},
title = {Evaluating and Optimizing Surface Soil Moisture Drydowns in the ORCHIDEE Land Surface Model at In Situ Locations},
journal = {Journal of Hydrometeorology},
publisher = {American Meteorological Society},
year = {2021},
volume = {22},
number = {4},
pages = {1025--1043},
url = {https://journals.ametsoc.org/view/journals/hydr/22/4/JHM-D-20-0115.1.xml},
doi = {10.1175/JHM-D-20-0115.1}
}
|
| Reitz O, Graf A, Schmidt M, Ketzler G and Leuchner M (2021), "Upscaling Net Ecosystem Exchange Over Heterogeneous Landscapes With Machine Learning", Journal of Geophysical Research: Biogeosciences. Vol. 126(2), pp. 1-16. |
| Abstract: This paper discusses different feature selection methods and CO2 flux datasets with a varying quality‐quantity balance for the application of a Random Forest model to predict daily CO2 fluxes at 250 m spatial resolution for the Rur catchment area in western Germany between 2010 and 2018. Measurements from eddy covariance stations of different ecosystem types, remotely sensed vegetation data from MODIS, and COSMO‐REA6 reanalysis data were used to train the model and predictions were validated by a spatial and temporal validation scheme. Results show the capabilities of a backwards feature elimination to remove irrelevant variables and an importance of high‐quality‐low‐quantity flux dataset to improve predictions. However, results also show that spatial prediction is more difficult than temporal prediction by reflecting the mean value accurately though underestimating the variance of CO2 fluxes. Vegetated parts of the catchment acted as a CO2 sink during the investigation period, net capturing about 237 g C m‐2y‐1. Croplands, coniferous forests, deciduous forests and grasslands were all sinks on average. The highest uptake was predicted to occur in late spring and early summer, while the catchment was a CO2 source in fall and winter. In conclusion, the Random Forest model predicted a narrower distribution of CO2 fluxes, though our methodological improvements look promising in order to achieve high resolution net ecosystem exchange datasets at the regional scale. |
BibTeX:
@article{Reitz2021,
author = {Reitz, O and Graf, A and Schmidt, M and Ketzler, G and Leuchner, M},
title = {Upscaling Net Ecosystem Exchange Over Heterogeneous Landscapes With Machine Learning},
journal = {Journal of Geophysical Research: Biogeosciences},
year = {2021},
volume = {126},
number = {2},
pages = {1--16},
doi = {10.1029/2020jg005814}
}
|
| Resovsky A, Ramonet M, Rivier L, Tarniewicz J, Ciais P, Steinbacher M, Mammarella I, Mölder M, Heliasz M, Kubistin D, Lindauer M, Müller-Williams J, Conil S and Engelen R (2021), "An algorithm to detect non-background signals in greenhouse gas time series from European tall tower and mountain stations", Atmospheric Measurement Techniques. Vol. 14(9), pp. 6119-6135. |
BibTeX:
@article{Resovsky2021,
author = {Resovsky, A and Ramonet, M and Rivier, L and Tarniewicz, J and Ciais, P and Steinbacher, M and Mammarella, I and Mölder, M and Heliasz, M and Kubistin, D and Lindauer, M and Müller-Williams, J and Conil, S and Engelen, R},
title = {An algorithm to detect non-background signals in greenhouse gas time series from European tall tower and mountain stations},
journal = {Atmospheric Measurement Techniques},
year = {2021},
volume = {14},
number = {9},
pages = {6119--6135},
url = {https://amt.copernicus.org/articles/14/6119/2021/},
doi = {10.5194/amt-14-6119-2021}
}
|
| Reuter M, Bovensmann H, Buchwitz M, Borchardt J, Krautwurst S, Gerilowski K, Lindauer M, Kubistin D and Burrows JP (2021), "Development of a small unmanned aircraft system to derive CO_2 emissions of anthropogenic point sources", Atmospheric Measurement Techniques. Vol. 14(1), pp. 153-172. |
BibTeX:
@article{Reuter2021,
author = {Reuter, M and Bovensmann, H and Buchwitz, M and Borchardt, J and Krautwurst, S and Gerilowski, K and Lindauer, M and Kubistin, D and Burrows, J P},
title = {Development of a small unmanned aircraft system to derive CO_2 emissions of anthropogenic point sources},
journal = {Atmospheric Measurement Techniques},
year = {2021},
volume = {14},
number = {1},
pages = {153--172},
url = {https://amt.copernicus.org/articles/14/153/2021/},
doi = {10.5194/amt-14-153-2021}
}
|
| Rivera Martinez R, Santaren D, Laurent O, Cropley F, Mallet C, Ramonet M, Caldow C, Rivier L, Broquet G, Bouchet C, Juery C and Ciais P (2021), "The Potential of Low-Cost Tin-Oxide Sensors Combined with Machine Learning for Estimating Atmospheric CH4 Variations around Background Concentration". |
| Abstract: Continued developments in instrumentation and modeling have driven progress in monitoring methane (CH4) emissions at a range of spatial scales. The sites that emit CH4 such as landfills, oil and gas extraction or storage infrastructure, intensive livestock farms account for a large share of global emissions, and need to be monitored on a continuous basis to verify the effectiveness of reductions policies. Low cost sensors are valuable to monitor methane (CH4) around such facilities because they can be deployed in a large number to sample atmospheric plumes and retrieve emission rates using dispersion models. Here we present two tests of three different versions of Figaro® TGS tin-oxide sensors for estimating CH4 concentrations variations, at levels similar to current atmospheric values, with a sought accuracy of 0.1 to 0.2 ppm. In the first test, we characterize the variation of the resistance of the tin-oxide semi-conducting sensors to controlled levels of CH4, H2O and CO in the laboratory, to analyze cross-sensitivities. In the second test, we reconstruct observed CH4 variations in a room, that ranged from 1.9 and 2.4 ppm during a three month experiment from observed time series of resistances and other variables. To do so, a machine learning model is trained against true CH4 recorded by a high precision instrument. The machine-learning model using 30% of the data for training reconstructs CH4 within the target accuracy of 0.1 ppm only if training variables are representative of conditions during the testing period. The model-derived sensitivities of the sensors resistance to H2O compared to CH4 are larger than those observed under controlled conditions, which deserves further characterization of all the factors influencing the resistance of the sensors. |
BibTeX:
@misc{RiveraMartinez2021,
author = {Rivera Martinez, Rodrigo and Santaren, Diego and Laurent, Olivier and Cropley, Ford and Mallet, Cécile and Ramonet, Michel and Caldow, Christopher and Rivier, Leonard and Broquet, Gregoire and Bouchet, Caroline and Juery, Catherine and Ciais, Philippe},
title = {The Potential of Low-Cost Tin-Oxide Sensors Combined with Machine Learning for Estimating Atmospheric CH4 Variations around Background Concentration},
booktitle = {Atmosphere},
year = {2021},
volume = {12},
number = {1},
doi = {10.3390/atmos12010107}
}
|
| Robroek BJM, Martí M, Svensson BH, Dumont MG, Veraart AJ and Jassey VEJ (2021), "Rewiring of peatland plant–microbe networks outpaces species turnover", Oikos., mar, 2021. Vol. 130(3), pp. 339-353. John Wiley & Sons, Ltd. |
| Abstract: Enviro?climatic changes are thought to be causing alterations in ecosystem processes through shifts in plant and microbial communities; however, how links between plant and microbial communities change with enviro?climatic change is likely to be less straightforward but may be fundamental for many ecological processes. To address this, we assessed the composition of the plant community and the prokaryotic community ? using amplicon-based sequencing ? of three European peatlands that were distinct in enviro?climatic conditions. Bipartite networks were used to construct site-specific plant?prokaryote co-occurrence networks. Our data show that between sites, plant and prokaryotic communities differ and that turnover in interactions between the communities was complex. Essentially, turnover in plant?microbial interactions is much faster than turnover in the respective communities. Our findings suggest that network rewiring does largely result from novel or different interactions between species common to all realised networks. Hence, turnover in network composition is largely driven by the establishment of new interactions between a core community of plants and microorganisms that are shared among all sites. Taken together our results indicate that plant?microbe associations are context dependent, and that changes in enviro?climatic conditions will likely lead to network rewiring. Integrating turnover in plant?microbe interactions into studies that assess the impact of enviro?climatic change on peatland ecosystems is essential to understand ecosystem dynamics and must be combined with studies on the impact of these changes on ecosystem processes. |
BibTeX:
@article{Robroek2021,
author = {Robroek, Bjorn J M and Martí, Magalí and Svensson, Bo H and Dumont, Marc G and Veraart, Annelies J and Jassey, Vincent E J},
title = {Rewiring of peatland plant–microbe networks outpaces species turnover},
journal = {Oikos},
publisher = {John Wiley & Sons, Ltd},
year = {2021},
volume = {130},
number = {3},
pages = {339--353},
url = {https://doi.org/10.1111/oik.07635},
doi = {10.1111/oik.07635}
}
|
| Rothfuss Y, Quade M, Brüggemann N, Graf A, Vereecken H and Dubbert M (2021), "Reviews and syntheses: Gaining insights into evapotranspiration partitioning with novel isotopic monitoring methods", Biogeosciences. Vol. 18(12), pp. 3701-3732. |
BibTeX:
@article{Rothfuss2021,
author = {Rothfuss, Y and Quade, M and Brüggemann, N and Graf, A and Vereecken, H and Dubbert, M},
title = {Reviews and syntheses: Gaining insights into evapotranspiration partitioning with novel isotopic monitoring methods},
journal = {Biogeosciences},
year = {2021},
volume = {18},
number = {12},
pages = {3701--3732},
url = {https://bg.copernicus.org/articles/18/3701/2021/},
doi = {10.5194/bg-18-3701-2021}
}
|
| Saiz E, Sgouridis F, Drijfhout FP, Peichl M, Nilsson MB and Ullah S (2021), "Chronic Atmospheric Reactive Nitrogen Deposition Suppresses Biological Nitrogen Fixation in Peatlands", Environmental Science & Technology., jan, 2021. Vol. 55(2), pp. 1310-1318. American Chemical Society. |
BibTeX:
@article{Saiz2021,
author = {Saiz, Ernesto and Sgouridis, Fotis and Drijfhout, Falko P and Peichl, Matthias and Nilsson, Mats B and Ullah, Sami},
title = {Chronic Atmospheric Reactive Nitrogen Deposition Suppresses Biological Nitrogen Fixation in Peatlands},
journal = {Environmental Science & Technology},
publisher = {American Chemical Society},
year = {2021},
volume = {55},
number = {2},
pages = {1310--1318},
url = {https://doi.org/10.1021/acs.est.0c04882},
doi = {10.1021/acs.est.0c04882}
}
|
| dos Santos T, Keppel-Aleks G, De Roo R and Steiner A (2021), "Can Land Surface Models Capture the Observed Soil Moisture Control of Water and Carbon Fluxes in Temperate To Boreal Forests?", Journal of Geophysical Research (Biogeosciences)., apr, 2021. Vol. 126(4), pp. e05999. |
BibTeX:
@article{Santos2021,
author = {dos Santos, T and Keppel-Aleks, G and De Roo, R and Steiner, A.∼L.},
title = {Can Land Surface Models Capture the Observed Soil Moisture Control of Water and Carbon Fluxes in Temperate To Boreal Forests?},
journal = {Journal of Geophysical Research (Biogeosciences)},
year = {2021},
volume = {126},
number = {4},
pages = {e05999},
doi = {10.1029/2020JG005999}
}
|
| Sathyanadh A, Monteil G, Scholze M, Klosterhalfen A, Laudon H, Wu Z, Gerbig C, Peters W, Bastrikov V, Nilsson MB and Peichl M (2021), "Reconciling the Carbon Balance of Northern Sweden Through Integration of Observations and Modelling", Journal of Geophysical Research: Atmospheres., dec, 2021. Vol. 126(23), pp. e2021JD035185. John Wiley & Sons, Ltd. |
| Abstract: Abstract The boreal biome plays an important role in the global carbon cycle. However, current estimates of its sink-source strength and responses to changes in climate are primarily derived from models and thus remain uncertain. A major challenge is the validation of these models at a regional scale since empirical flux estimates are typically confined to ecosystem or continental scales. The Integrated Carbon Observation System (ICOS)-Svartberget atmospheric station (SVB) provides observations including tall tower eddy covariance (EC) and atmospheric concentration measurements that can contribute to such validation in Northern Sweden. Thus, the overall aim of this study was to quantify the carbon balance in Northern Sweden region by integrating land-atmosphere fluxes and atmospheric carbon dioxide (CO2) concentrations. There were three specific objectives. First, to compare flux estimates from four models (VPRM, LPJ-GUESS, ORCHIDEE, and SiBCASA) to tall tower EC measurements at SVB during the years 2016?2018. Second to assess the fluxes' impact on atmospheric CO2 concentrations using a regional transport model. Third, to assess the impact of the drought in 2018. The comparison of estimated concentrations with ICOS observations helped the evaluation of the models' regional scale performance. Both the simulations and observations indicate there were similar reductions in the net CO2 uptake during drought. All the models (except for SiBCASA) and observations indicated the region was a net carbon sink during the 3-year study period. Our study highlights a need to improve vegetation models through comparisons with empirical data and demonstrate the ICOS network's potential utility for constraining CO2 fluxes in the region. |
BibTeX:
@article{Sathyanadh2021,
author = {Sathyanadh, Anusha and Monteil, Guillaume and Scholze, Marko and Klosterhalfen, Anne and Laudon, Hjalmar and Wu, Zhendong and Gerbig, Christoph and Peters, Wouter and Bastrikov, Vladislav and Nilsson, Mats B and Peichl, Matthias},
title = {Reconciling the Carbon Balance of Northern Sweden Through Integration of Observations and Modelling},
journal = {Journal of Geophysical Research: Atmospheres},
publisher = {John Wiley & Sons, Ltd},
year = {2021},
volume = {126},
number = {23},
pages = {e2021JD035185},
url = {https://doi.org/10.1029/2021JD035185},
doi = {10.1029/2021JD035185}
}
|
| Say D, Manning AJ, Western LM, Young D, Wisher A, Rigby M, Reimann S, Vollmer MK, Maione M, Arduini J, Krummel PB, Mühle J, Harth CM, Evans B, Weiss RF, Prinn RG and O'Doherty S (2021), "Global trends and European emissions of tetrafluoromethane (CF_4), hexafluoroethane (C_2F_6) and octafluoropropane (C_3F_8)", Atmospheric Chemistry and Physics. Vol. 21(3), pp. 2149-2164. |
BibTeX:
@article{Say2021,
author = {Say, D and Manning, A J and Western, L M and Young, D and Wisher, A and Rigby, M and Reimann, S and Vollmer, M K and Maione, M and Arduini, J and Krummel, P B and Mühle, J and Harth, C M and Evans, B and Weiss, R F and Prinn, R G and O'Doherty, S},
title = {Global trends and European emissions of tetrafluoromethane (CF_4), hexafluoroethane (C_2F_6) and octafluoropropane (C_3F_8)},
journal = {Atmospheric Chemistry and Physics},
year = {2021},
volume = {21},
number = {3},
pages = {2149--2164},
url = {https://acp.copernicus.org/articles/21/2149/2021/},
doi = {10.5194/acp-21-2149-2021}
}
|
| Scheller JH, Mastepanov M, Christiansen HH and Christensen TR (2021), "Methane in Zackenberg Valley, NE Greenland: multidecadal growing season fluxes of a high-Arctic tundra", Biogeosciences. Vol. 18(23), pp. 6093-6114. |
BibTeX:
@article{Scheller2021,
author = {Scheller, J H and Mastepanov, M and Christiansen, H H and Christensen, T R},
title = {Methane in Zackenberg Valley, NE Greenland: multidecadal growing season fluxes of a high-Arctic tundra},
journal = {Biogeosciences},
year = {2021},
volume = {18},
number = {23},
pages = {6093--6114},
url = {https://bg.copernicus.org/articles/18/6093/2021/},
doi = {10.5194/bg-18-6093-2021}
}
|
| Schiestl-Aalto P, Stangl ZR, Tarvainen L, Wallin G, Marshall J and Mäkelä A (2021), "Linking canopy-scale mesophyll conductance and phloem sugar δ13C using empirical and modelling approaches", New Phytologist., mar, 2021. Vol. 229(6), pp. 3141-3155. John Wiley & Sons, Ltd. |
| Abstract: Summary Interpreting phloem carbohydrate or xylem tissue carbon isotopic composition as measures of water-use efficiency or past tree productivity requires in-depth knowledge of the factors altering the isotopic composition within the pathway from ambient air to phloem contents and tree ring. One of least understood of these factors is mesophyll conductance (gm). We formulated a dynamic model describing the leaf photosynthetic pathway including seven alternative gm descriptions and a simple transport of sugars from foliage down the trunk. We parameterised the model for a boreal Scots pine stand and compared simulated gm responses with weather variations. We further compared the simulated δ13C of new photosynthates among the different gm descriptions and against measured phloem sugar δ13C. Simulated gm estimates of the seven descriptions varied according to weather conditions, resulting in varying estimates of phloem δ13C during cold/moist and warm/dry periods. The model succeeded in predicting a drought response and a postdrought release in phloem sugar δ13C indicating suitability of the model for inverse prediction of leaf processes from phloem isotopic composition. We suggest short-interval phloem sampling during and after extreme weather conditions to distinguish between mesophyll conductance drivers for future model development. |
BibTeX:
@article{SchiestlAalto2021,
author = {Schiestl-Aalto, Pauliina and Stangl, Zsofia R and Tarvainen, Lasse and Wallin, Göran and Marshall, John and Mäkelä, Annikki},
title = {Linking canopy-scale mesophyll conductance and phloem sugar δ13C using empirical and modelling approaches},
journal = {New Phytologist},
publisher = {John Wiley & Sons, Ltd},
year = {2021},
volume = {229},
number = {6},
pages = {3141--3155},
url = {https://doi.org/10.1111/nph.17094},
doi = {10.1111/nph.17094}
}
|
| Schneider J, Groh J, Pütz T, Helmig R, Rothfuss Y, Vereecken H and Vanderborght J (2021), "Prediction of soil evaporation measured with weighable lysimeters using the FAO Penman–Monteith method in combination with Richards' equation", Vadose Zone Journal. (April 2020), pp. 1-20. |
| Abstract: Multiannual data (2016–2018) from 12 weighed lysimeters (four soil types with textures ranging from sandy loam to silt loam, three replicates) of the TERENO SOILCan network were used to evaluate if evaporation (E) rates could be predicted from weather data using the FAO Penman–Monteith (PM) method combined with soil water flow simulations using the Richards equation. Soil hydraulic properties (SHPs) were estimated either from soil texture using the ROSETTA pedotransfer functions, from in situ measured water retention curves, or from soil surface water contents using inverse modeling. In all years, E was water limited and the measured evaporation rates (Em) surprisingly did not vary significantly among the four different soil types. When SHPs derived from pedotransfer functions were used, simulated evaporation rates of the finer textured soils overestimated the measured ones considerably. Better agreement was obtained when simulations were based on in situ measured or inversely estimated SHPs. The SHPs estimated from pedotransfer functions represented unrealistically large characteristic lengths of evaporation (Lc), and Lc was found to be a useful characteristic to constrain estimates of SHPs. Also, when soil evaporation was water limited and Em rates were below Epot (PM evaporation scaled by an empirical coefficient), the diurnal dynamics of Em followed those of Epot. The Richards equation that considers only isothermal liquid water flow did not reproduce these dynamics caused by temperature dependent vapor transport in the soil. |
BibTeX:
@article{Schneider2021,
author = {Schneider, Jana and Groh, Jannis and Pütz, Thomas and Helmig, Rainer and Rothfuss, Youri and Vereecken, Harry and Vanderborght, Jan},
title = {Prediction of soil evaporation measured with weighable lysimeters using the FAO Penman–Monteith method in combination with Richards' equation},
journal = {Vadose Zone Journal},
year = {2021},
number = {April 2020},
pages = {1--20},
doi = {10.1002/vzj2.20102}
}
|
| Schneider M, Ertl B, Diekmann CJ, Khosrawi F, Röhling AN, Hase F, Dubravica D, Garc\ia OE, Sepúlveda E, Borsdorff T, Landgraf J, Lorente A, Chen H, Kivi R, Laemmel T, Ramonet M, Crevoisier C, Pernin J, Steinbacher M, Meinhardt F, Deutscher NM, Griffith DWT, Velazco VA and Pollard DF (2021), "Synergetic use of IASI and TROPOMI space borne sensors for generating a tropospheric methane profile product", Atmospheric Measurement Techniques Discussions. Vol. 2021, pp. 1-37. |
BibTeX:
@article{Schneider2021a,
author = {Schneider, M and Ertl, B and Diekmann, C J and Khosrawi, F and Röhling, A N and Hase, F and Dubravica, D and Garc\ia, O E and Sepúlveda, E and Borsdorff, T and Landgraf, J and Lorente, A and Chen, H and Kivi, R and Laemmel, T and Ramonet, M and Crevoisier, C and Pernin, J and Steinbacher, M and Meinhardt, F and Deutscher, N M and Griffith, D W T and Velazco, V A and Pollard, D F},
title = {Synergetic use of IASI and TROPOMI space borne sensors for generating a tropospheric methane profile product},
journal = {Atmospheric Measurement Techniques Discussions},
year = {2021},
volume = {2021},
pages = {1--37},
url = {https://amt.copernicus.org/preprints/amt-2021-31/},
doi = {10.5194/amt-2021-31}
}
|
| Seiler C, Melton JR, Arora VK and Wang L (2021), "CLASSIC v1.0: the open-source community successor to the Canadian Land Surface Scheme (CLASS) and the Canadian Terrestrial Ecosystem Model (CTEM) -- Part 2: Global benchmarking", Geoscientific Model Development. Vol. 14(5), pp. 2371-2417. |
BibTeX:
@article{Seiler2021,
author = {Seiler, C and Melton, J R and Arora, V K and Wang, L},
title = {CLASSIC v1.0: the open-source community successor to the Canadian Land Surface Scheme (CLASS) and the Canadian Terrestrial Ecosystem Model (CTEM) -- Part 2: Global benchmarking},
journal = {Geoscientific Model Development},
year = {2021},
volume = {14},
number = {5},
pages = {2371--2417},
url = {https://gmd.copernicus.org/articles/14/2371/2021/},
doi = {10.5194/gmd-14-2371-2021}
}
|
| Serk H, Nilsson MB, Figueira J, Wieloch T and Schleucher J (2021), "CO2 fertilization of Sphagnum peat mosses is modulated by water table level and other environmental factors", Plant, Cell & Environment., jun, 2021. Vol. 44(6), pp. 1756-1768. John Wiley & Sons, Ltd. |
| Abstract: Abstract Sphagnum mosses account for most accumulated dead organic matter in peatlands. Therefore, understanding their responses to increasing atmospheric CO2 is needed for estimating peatland C balances under climate change. A key process is photorespiration: a major determinant of net photosynthetic C assimilation that depends on the CO2 to O2 ratio. We used climate chambers to investigate photorespiratory responses of Sphagnum fuscum hummocks to recent increases in atmospheric CO2 (from 280 to 400?ppm) under different water table, temperature, and light intensity levels. We tested the photorespiratory variability using a novel method based on deuterium isotopomers (D6S/D6R ratio) of photosynthetic glucose. The effect of elevated CO2 on photorespiration was highly dependent on water table. At low water table (?20?cm), elevated CO2 suppressed photorespiration relative to C assimilation, thus substantially increasing the net primary production potential. In contrast, a high water table (∼0 cm) favored photorespiration and abolished this CO2 effect. The response was further tested for Sphagnum majus lawns at typical water table levels (∼0 and ?7 cm), revealing no effect of CO2 under those conditions. Our results indicate that hummocks, which typically experience low water table levels, benefit from the 20th century's increase in atmospheric CO2. |
BibTeX:
@article{Serk2021,
author = {Serk, Henrik and Nilsson, Mats B and Figueira, João and Wieloch, Thomas and Schleucher, Jürgen},
title = {CO2 fertilization of Sphagnum peat mosses is modulated by water table level and other environmental factors},
journal = {Plant, Cell & Environment},
publisher = {John Wiley & Sons, Ltd},
year = {2021},
volume = {44},
number = {6},
pages = {1756--1768},
url = {https://doi.org/10.1111/pce.14043},
doi = {10.1111/pce.14043}
}
|
| Siewert MB and Olofsson J (2021), "UAV reveals substantial but heterogeneous effects of herbivores on Arctic vegetation", Scientific Reports. Vol. 11(1), pp. 19468. |
| Abstract: Understanding how herbivores shape plant biomass and distribution is a core challenge in ecology. Yet, the lack of suitable remote sensing technology limits our knowledge of temporal and spatial impacts of mammal herbivores in the Earth system. The regular interannual density fluctuations of voles and lemmings are exceptional with their large reduction of plant biomass in Arctic landscapes during peak years (12–24%) as previously shown at large spatial scales using satellites. This provides evidence that herbivores are important drivers of observed global changes in vegetation productivity. Here, we use a novel approach with repeated unmanned aerial vehicle (UAV) flights, to map vegetation impact by rodents, indicating that many important aspects of vegetation dynamics otherwise hidden by the coarse resolution of satellite images, including plant–herbivore interactions, can be revealed using UAVs. We quantify areas impacted by rodents at four complex Arctic landscapes with very high spatial resolution UAV imagery to get a new perspective on how herbivores shape Arctic ecosystems. The area impacted by voles and lemmings is indeed substantial, larger at higher altitude tundra environments, varies between habitats depending on local snow cover and plant community composition, and is heterogeneous even within habitats at submeter scales. Coupling this with spectral reflectance of vegetation (NDVI), we can show that the impact on central ecosystem properties like GPP and biomass is stronger than currently accounted for in Arctic ecosystems. As an emerging technology, UAVs will allow us to better disentangle important information on how herbivores maintain spatial heterogeneity, function and diversity in natural ecosystems. |
BibTeX:
@article{Siewert2021,
author = {Siewert, Matthias B and Olofsson, Johan},
title = {UAV reveals substantial but heterogeneous effects of herbivores on Arctic vegetation},
journal = {Scientific Reports},
year = {2021},
volume = {11},
number = {1},
pages = {19468},
url = {https://doi.org/10.1038/s41598-021-98497-5},
doi = {10.1038/s41598-021-98497-5}
}
|
| Sim TG, Swindles GT, Morris PJ, Baird AJ, Cooper CL, Gallego-Sala AV, Charman DJ, Roland TP, Borken W, Mullan DJ, Aquino-López MA and Gałka M (2021), "Divergent responses of permafrost peatlands to recent climate change", Environmental Research Letters., feb, 2021. Vol. 16(3), pp. 34001. IOP Publishing. |
| Abstract: Permafrost peatlands are found in high-latitude regions and store globally-important amounts of soil organic carbon. These regions are warming at over twice the global average rate, causing permafrost thaw, and exposing previously inert carbon to decomposition and emission to the atmosphere as greenhouse gases. However, it is unclear how peatland hydrological behaviour, vegetation structure and carbon balance, and the linkages between them, will respond to permafrost thaw in a warming climate. Here we show that permafrost peatlands follow divergent ecohydrological trajectories in response to recent climate change within the same rapidly warming region (northern Sweden). Whether a site becomes wetter or drier depends on local factors and the autogenic response of individual peatlands. We find that bryophyte-dominated vegetation demonstrates resistance, and in some cases resilience, to climatic and hydrological shifts. Drying at four sites is clearly associated with reduced carbon sequestration, while no clear relationship at wetting sites is observed. We highlight the complex dynamics of permafrost peatlands and warn against an overly-simple approach when considering their ecohydrological trajectories and role as C sinks under a warming climate. |
BibTeX:
@article{Sim2021,
author = {Sim, Thomas G and Swindles, Graeme T and Morris, Paul J and Baird, Andy J and Cooper, Claire L and Gallego-Sala, Angela V and Charman, Dan J and Roland, Thomas P and Borken, Werner and Mullan, Donal J and Aquino-López, Marco A and Gałka, Mariusz},
title = {Divergent responses of permafrost peatlands to recent climate change},
journal = {Environmental Research Letters},
publisher = {IOP Publishing},
year = {2021},
volume = {16},
number = {3},
pages = {34001},
url = {https://doi.org/10.1088/1748-9326/abe00b},
doi = {10.1088/1748-9326/abe00b}
}
|
| Simin T, Tang J, Holst T and Rinnan R (2021), "Volatile organic compound emission in tundra shrubs – Dependence on species characteristics and the near-surface environment", Environmental and Experimental Botany. Vol. 184, pp. 104387. |
| Abstract: Temperature is one of the key abiotic factors during the life of plants, especially in the Arctic region which is currently experiencing rapid climate change. We evaluated plant traits and environmental variables determining leaf temperature in tundra shrubs and volatile organic compound (VOC) emissions with field measurements on deciduous tundra shrubs, Salix myrsinites and Betula nana, and evergreen Cassiope tetragona and Rhododendron lapponicum. Higher leaf-to-air temperature difference was observed in evergreen, compared to deciduous shrubs. Evergreen shrubs also showed continuously increasing photosynthesis with increasing temperature, suggesting high thermal tolerance. For the deciduous species, the optimum temperature for net photosynthesis was between our measurement temperatures of 24 °C and 38 °C. Air temperature and vapor pressure deficit were the most important variables influencing leaf temperature and VOC emissions in all the studied plants, along with stomatal density and specific leaf area in the deciduous shrubs. Using climate data and emission factors from our measurements, we modelled total seasonal tundra shrub VOC emissions of 0.3–2.3 g m−2 over the main growing season. Our results showed higher-than-expected temperature optima for photosynthesis and VOC emission and demonstrated the relative importance of plant traits and local environments in determining leaf temperature and VOC emissions in a subarctic tundra. |
BibTeX:
@article{Simin2021,
author = {Simin, Tihomir and Tang, Jing and Holst, Thomas and Rinnan, Riikka},
title = {Volatile organic compound emission in tundra shrubs – Dependence on species characteristics and the near-surface environment},
journal = {Environmental and Experimental Botany},
year = {2021},
volume = {184},
pages = {104387},
url = {https://www.sciencedirect.com/science/article/pii/S0098847221000162},
doi = {10.1016/j.envexpbot.2021.104387}
}
|
| Simpson JE, Holman F, Nieto H, Voelksch I, Mauder M, Klatt J, Fiener P and Kaplan JO (2021), "High Spatial and Temporal Resolution Energy Flux Mapping of Different Land Covers Using an Off-the-Shelf Unmanned Aerial System". |
| Abstract: With the development of low-cost, lightweight, integrated thermal infrared-multispectral cameras, unmanned aerial systems (UAS) have recently become a flexible complement to eddy covariance (EC) station methods for mapping surface energy fluxes of vegetated areas. These sensors facilitate the measurement of several site characteristics in one flight (e.g., radiometric temperature, vegetation indices, vegetation structure), which can be used alongside in-situ meteorology data to provide spatially-distributed estimates of energy fluxes at very high resolution. Here we test one such system (MicaSense Altum) integrated into an off-the-shelf long-range vertical take-off and landing (VTOL) unmanned aerial vehicle, and apply and evaluate our method by comparing flux estimates with EC-derived data, with specific and novel focus on heterogeneous vegetation communities at three different sites in Germany. Firstly, we present an empirical method for calibrating airborne radiometric temperature in standard units (K) using the Altum multispectral and thermal infrared instrument. Then we provide detailed methods using the two-source energy balance model (TSEB) for mapping net radiation (Rn), sensible (H), latent (LE) and ground (G) heat fluxes at <0.82 m resolution, with root mean square errors (RMSE) less than 45, 37, 39, 52 W m−2 respectively. Converting to radiometric temperature using our empirical method resulted in a 19% reduction in RMSE across all fluxes compared to the standard conversion equation provided by the manufacturer. Our results show the potential of this UAS for mapping energy fluxes at high resolution over large areas in different conditions, but also highlight the need for further surveys of different vegetation types and land uses. |
BibTeX:
@misc{Simpson2021,
author = {Simpson, Jake E and Holman, Fenner and Nieto, Hector and Voelksch, Ingo and Mauder, Matthias and Klatt, Janina and Fiener, Peter and Kaplan, Jed O},
title = {High Spatial and Temporal Resolution Energy Flux Mapping of Different Land Covers Using an Off-the-Shelf Unmanned Aerial System},
booktitle = {Remote Sensing},
year = {2021},
volume = {13},
number = {7},
doi = {10.3390/rs13071286}
}
|
| Strand SM, Christiansen HH, Johansson M, Åkerman J and Humlum O (2021), "Active layer thickening and controls on interannual variability in the Nordic Arctic compared to the circum-Arctic", Permafrost and Periglacial Processes. Vol. 32(1), pp. 47-58. |
| Abstract: Active layer probing in northern Sweden, northeast Greenland, and central Svalbard indicates active layer thickening has occurred at Circumpolar Active Layer Monitoring (CALM) sites with long-term, continuous observations, since the sites were established at these locations in 1978, 1996, and 2000, respectively. The study areas exhibit a reverse latitudinal gradient in average active layer thickness (ALT), which is explained by site geomorphology and climate. Specifically, Svalbard has a more maritime climate and thus the thickest active layer of the study areas (average ALT = 99 cm, 2000–2018). The active layer is thinnest at the northern Sweden sites because it is primarily confined to superficial peat. Interannual variability in ALT is not synchronous across this Nordic Arctic region, but study sites in the same area respond similarly to local meteorology. ALT correlates positively with thawing degree days in Sweden and Greenland, as has been observed in other Arctic regions. However, ALT in Svalbard correlates with freezing degree days, where the maritime Arctic climate results in relatively high and variable winter air temperatures. The difference in annual ALT at adjacent sites is attributed to differences in snow cover and geomorphology. From 2000 to 2018, the average rate of active layer thickening at the Nordic Arctic CALM probing sites was 0.5 cm/yr. The average rate was 1 cm/yr for Nordic Arctic CALM database sites with significant trends, which includes a borehole in addition to probing sites. This range is in line with the circum-Arctic average of 0.8 cm/yr from 2000 to 2018. |
BibTeX:
@article{Strand2021,
author = {Strand, Sarah M and Christiansen, Hanne H and Johansson, Margareta and Åkerman, Jonas and Humlum, Ole},
title = {Active layer thickening and controls on interannual variability in the Nordic Arctic compared to the circum-Arctic},
journal = {Permafrost and Periglacial Processes},
year = {2021},
volume = {32},
number = {1},
pages = {47--58},
doi = {10.1002/ppp.2088}
}
|
| Sun J, Hermann M, Yuan Y, Birmili W, Collaud Coen M, Weinhold K, Madueño L, Poulain L, Tuch T, Ries L, Sohmer R, Couret C, Frank G, Brem BT, Gysel-Beer M, Ma N and Wiedensohler A (2021), "Long-term trends of black carbon and particle number concentration in the lower free troposphere in Central Europe", Environmental Sciences Europe. Vol. 33(1), pp. 47. |
| Abstract: The implementation of emission mitigation policies in Europe over the last two decades has generally improved the air quality, which resulted in lower aerosol particle mass, particle number, and black carbon mass concentration. However, little is known whether the decreasing particle concentrations at a lower-altitude level can be observed in the free troposphere (FT), an important layer of the atmosphere, where aerosol particles have a longer lifetime and may affect climate dynamics. In this study, we used data from two high-Alpine observatories, Zugspitze-Schneefernerhaus (ZSF) and Jungfraujoch (JFJ), to assess the long-term trends on size-resolved particle number concentrations (PNCs) and equivalent black carbon (eBC) mass concentration separated for undisturbed lower FT conditions and under the influence of air from the planetary boundary layer (PBL) from 2009 to 2018. |
BibTeX:
@article{Sun2021,
author = {Sun, Jia and Hermann, Markus and Yuan, Ye and Birmili, Wolfram and Collaud Coen, Martine and Weinhold, Kay and Madueño, Leizel and Poulain, Laurent and Tuch, Thomas and Ries, Ludwig and Sohmer, Ralf and Couret, Cedric and Frank, Gabriele and Brem, Benjamin Tobias and Gysel-Beer, Martin and Ma, Nan and Wiedensohler, Alfred},
title = {Long-term trends of black carbon and particle number concentration in the lower free troposphere in Central Europe},
journal = {Environmental Sciences Europe},
year = {2021},
volume = {33},
number = {1},
pages = {47},
url = {https://doi.org/10.1186/s12302-021-00488-w},
doi = {10.1186/s12302-021-00488-w}
}
|
| Tang Y, Xu X, Zhou Z, Qu Y and Sun Y (2021), "Estimating global maximum gross primary productivity of vegetation based on the combination of MODIS greenness and temperature data", Ecological Informatics. Vol. 63, pp. 101307. |
| Abstract: Accurate estimation of the spatial-temporal variation of the maximum gross primary productivity (GPPmax) of vegetation is of great significance for predicting carbon fluxes and vegetation-climate feedback. In this study, the GPPmax estimation models were constructed based on driving variables derived from the MODIS enhanced vegetation index (EVI) and land surface temperature (LST) time series data using a stepwise regression analysis. The models were calibrated and validated with the observed GPPmax from 145 FLUXNET sites with 734 site-year data from 2000 to 2014. The GPPmax estimates and the changes in their trends at the global scale were also compared with other GPPmax products from the vegetation photosynthesis model and the eddy covariance-light use efficiency model. The results showed that the GPPmax for both forest and non-forest vegetation types were estimated well, with R2 of 0.47–0.86 and 0.47–0.95 and relative root mean square error of 10.14–35.14% and 11.25–30.02% for calibration and validation data, respectively. Summer EVI and spring EVI and LST played important roles in explaining the variation in GPPmax. The GPPmax estimates from this study and the changes in their trends were highly correlated with GPPmax estimates from the vegetation photosynthesis model, with R2 > 0.70 for most vegetation types. The GPPmax significantly increased in western North America, northern Europe, and eastern China, but decreased in tropical regions. This study concluded that the variation in GPPmax for various vegetation types on a global scale can be accurately estimated based on MODIS EVI and LST time series data, which provides a simple but effective way for large-scale estimation of GPPmax. |
BibTeX:
@article{Tang2021,
author = {Tang, Yan and Xu, Xiaojun and Zhou, Zhongsheng and Qu, Yiling and Sun, Yue},
title = {Estimating global maximum gross primary productivity of vegetation based on the combination of MODIS greenness and temperature data},
journal = {Ecological Informatics},
year = {2021},
volume = {63},
pages = {101307},
url = {https://www.sciencedirect.com/science/article/pii/S1574954121000984},
doi = {10.1016/j.ecoinf.2021.101307}
}
|
| Tarvainen L, Wallin G, Linder S, Näsholm T, Oren R, Ottosson Löfvenius M, Räntfors M, Tor-Ngern P and Marshall JD (2021), "Limited vertical CO2 transport in stems of mature boreal Pinus sylvestris trees", Tree Physiology., jan, 2021. Vol. 41(1), pp. 63-75. |
| Abstract: Several studies have suggested that CO2 transport in the transpiration stream can considerably bias estimates of root and stem respiration in ring-porous and diffuse-porous tree species. Whether this also happens in species with tracheid xylem anatomy and lower sap flow rates, such as conifers, is currently unclear. We infused 13C-labelled solution into the xylem near the base of two 90-year-old Pinus sylvestris L. trees. A custom-built gas exchange system and an online isotopic analyser were used to sample the CO2 efflux and its isotopic composition continuously from four positions along the bole and one upper canopy shoot in each tree. Phloem and needle tissue 13C enrichment was also evaluated at these positions. Most of the 13C label was lost by diffusion within a few metres of the infusion point indicating rapid CO2 loss during vertical xylem transport. No 13C enrichment was detected in the upper bole needle tissues. Furthermore, mass balance calculations showed that c. 97% of the locally respired CO2 diffused radially to the atmosphere. Our results support the notion that xylem CO2 transport is of limited magnitude in conifers. This implies that the concerns that stem transport of CO2 derived from root respiration biases chamber-based estimates of forest carbon cycling may be unwarranted for mature conifer stands. |
BibTeX:
@article{Tarvainen2021,
author = {Tarvainen, Lasse and Wallin, Göran and Linder, Sune and Näsholm, Torgny and Oren, Ram and Ottosson Löfvenius, Mikaell and Räntfors, Mats and Tor-Ngern, Pantana and Marshall, John D},
editor = {Steppe, Kathy},
title = {Limited vertical CO2 transport in stems of mature boreal Pinus sylvestris trees},
journal = {Tree Physiology},
year = {2021},
volume = {41},
number = {1},
pages = {63--75},
url = {https://academic.oup.com/treephys/article/41/1/63/5898915},
doi = {10.1093/treephys/tpaa113}
}
|
| Tenkanen M, Tsuruta A, Rautiainen K, Kangasaho V, Ellul R and Aalto T (2021), "Utilizing Earth Observations of Soil Freeze/Thaw Data and Atmospheric Concentrations to Estimate Cold Season Methane Emissions in the Northern High Latitudes". |
| Abstract: The northern wetland methane emission estimates have large uncertainties. Inversion models are a qualified method to estimate the methane fluxes and emissions in northern latitudes but when atmospheric observations are sparse, the models are only as good as their a priori estimates. Thus, improving a priori estimates is a competent way to reduce uncertainties and enhance emission estimates in the sparsely sampled regions. Here, we use a novel way to integrate remote sensing soil freeze/thaw (F/T) status from SMOS satellite to better capture the seasonality of methane emissions in the northern high latitude. The SMOS F/T data provide daily information of soil freezing state in the northern latitudes, and in this study, the data is used to define the cold season in the high latitudes and, thus, improve our knowledge of the seasonal cycle of biospheric methane fluxes. The SMOS F/T data is implemented to LPX-Bern DYPTOP model estimates and the modified fluxes are used as a biospheric a priori in the inversion model CarbonTracker Europe-CH4. The implementation of the SMOS F/T soil state is shown to be beneficial in improving the inversion model’s cold season biospheric flux estimates. Our results show that cold season biospheric CH4 emissions in northern high latitudes are approximately 0.60 Tg lower than previously estimated, which corresponds to 17% reduction in the cold season biospheric emissions. This reduction is partly compensated by increased anthropogenic emissions in the same area (0.23 Tg), and the results also indicates that the anthropogenic emissions could have even larger contribution in cold season than estimated here. |
BibTeX:
@misc{Tenkanen2021,
author = {Tenkanen, Maria and Tsuruta, Aki and Rautiainen, Kimmo and Kangasaho, Vilma and Ellul, Raymond and Aalto, Tuula},
title = {Utilizing Earth Observations of Soil Freeze/Thaw Data and Atmospheric Concentrations to Estimate Cold Season Methane Emissions in the Northern High Latitudes},
booktitle = {Remote Sensing},
year = {2021},
volume = {13},
number = {24},
doi = {10.3390/rs13245059}
}
|
| Tian F, Cai Z, Jin H, Hufkens K, Scheifinger H, Tagesson T, Smets B, Van Hoolst R, Bonte K, Ivits E, Tong X, Ardö J and Eklundh L (2021), "Calibrating vegetation phenology from Sentinel-2 using eddy covariance, PhenoCam, and PEP725 networks across Europe", Remote Sensing of Environment., July, 2021. Vol. 260, pp. 112456. Elsevier BV. |
BibTeX:
@article{Tian2021,
author = {Tian, Feng and Cai, Zhanzhang and Jin, Hongxiao and Hufkens, Koen and Scheifinger, Helfried and Tagesson, Torbern and Smets, Bruno and Van Hoolst, Roel and Bonte, Kasper and Ivits, Eva and Tong, Xiaoye and Ardö, Jonas and Eklundh, Lars},
title = {Calibrating vegetation phenology from Sentinel-2 using eddy covariance, PhenoCam, and PEP725 networks across Europe},
journal = {Remote Sensing of Environment},
publisher = {Elsevier BV},
year = {2021},
volume = {260},
pages = {112456},
doi = {10.1016/j.rse.2021.112456}
}
|
| Trepekli K and Friborg T (2021), "Deriving Aerodynamic Roughness Length at Ultra-High Resolution in Agricultural Areas Using UAV-Borne LiDAR", Remote Sensing. Vol. 13(17) |
| Abstract: The aerodynamic roughness length (Z0) and surface geometry at ultra-high resolution in precision agriculture and agroforestry have substantial potential to improve aerodynamic process modeling for sustainable farming practices and recreational activities. We explored the potential of unmanned aerial vehicle (UAV)-borne LiDAR systems to provide Z0 maps with the level of spatiotemporal resolution demanded by precision agriculture by generating the 3D structure of vegetated surfaces and linking the derived geometry with morphometric roughness models. We evaluated the performance of three filtering algorithms to segment the LiDAR-derived point clouds into vegetation and ground points in order to obtain the vegetation height metrics and density at a 0.10 m resolution. The effectiveness of three morphometric models to determine the Z0 maps of Danish cropland and the surrounding evergreen trees was assessed by comparing the results with corresponding Z0 values from a nearby eddy covariance tower (Z0_EC). A morphological filter performed satisfactorily over a homogeneous surface, whereas the progressive triangulated irregular network densification algorithm produced fewer errors with a heterogeneous surface. Z0 from UAV-LiDAR-driven models converged with Z0_EC at the source area scale. The Raupach roughness model appropriately simulated temporal variations in Z0 conditioned by vertical and horizontal vegetation density. The Z0 calculated as a fraction of vegetation height or as a function of vegetation height variability resulted in greater differences with the Z0_EC. Deriving Z0 in this manner could be highly useful in the context of surface energy balance and wind profile estimations for micrometeorological, hydrologic, and ecologic applications in similar sites. |
BibTeX:
@article{Trepekli2021,
author = {Trepekli, Katerina and Friborg, Thomas},
title = {Deriving Aerodynamic Roughness Length at Ultra-High Resolution in Agricultural Areas Using UAV-Borne LiDAR},
journal = {Remote Sensing},
year = {2021},
volume = {13},
number = {17},
url = {https://www.mdpi.com/2072-4292/13/17/3538},
doi = {10.3390/rs13173538}
}
|
| Trewin B, Cazenave A, Howell S, Huss M, Isensee K, Palmer MD, Tarasova O and Vermeulen A (2021), "Headline Indicators for Global Climate Monitoring", Bulletin of the American Meteorological Society., 1, 2021. Vol. 102, pp. E20-E37. |
| Abstract: The World Meteorological Organization has developed a set of headline indicators for global climate monitoring. These seven indicators are a subset of the existing set of essential climate variables (ECVs) established by the Global Climate Observing System and are intended to provide the most essential parameters representing the state of the climate system. These indicators include global mean surface temperature, global ocean heat content, state of ocean acidification, glacier mass balance, Arctic and Antarctic sea ice extent, global CO 2 mole fraction, and global mean sea level. This paper describes how well each of these indicators are currently monitored, including the number and quality of the underlying datasets; the health of those datasets; observation systems used to estimate each indicator; the timeliness of information; and how well recent values can be linked to preindustrial conditions. These aspects vary widely between indicators. While global mean surface temperature is available in close to real time and changes from preindustrial levels can be determined with relatively low uncertainty, this is not the case for many other indicators. Some indicators (e.g., sea ice extent) are largely dependent on satellite data only available in the last 40 years, while some (e.g., ocean acidification) have limited underlying observational bases, and others (e.g., glacial mass balance) with data only available a year or more in arrears. |
BibTeX:
@article{Trewin2021,
author = {Blair Trewin and Anny Cazenave and Stephen Howell and Matthias Huss and Kirsten Isensee and Matthew D. Palmer and Oksana Tarasova and Alex Vermeulen},
title = {Headline Indicators for Global Climate Monitoring},
journal = {Bulletin of the American Meteorological Society},
year = {2021},
volume = {102},
pages = {E20-E37},
doi = {10.1175/BAMS-D-19-0196.1}
}
|
| Trisolino P, di Sarra A, Sferlazzo D, Piacentino S, Monteleone F, Di Iorio T, Apadula F, Heltai D, Lanza A, Vocino A, di Torchiarolo L, Bonasoni P, Calzolari F, Busetto M and Cristofanelli P (2021), "Application of a Common Methodology to Select in Situ CO2 Observations Representative of the Atmospheric Background to an Italian Collaborative Network", Atmosphere. Vol. 12(2) |
| Abstract: We describe and implement a data selection algorithm aimed at identifying background atmospheric CO2 observations from in situ continuous measurements. Several selection criteria for detecting the background data have been developed and are currently used: the main objective of this work was to define a common methodology to extract the atmospheric background signal minimizing heterogeneities due to the use of different selection algorithms. The algorithm used in this study, (BaDS, Background Data Selection) was tested and optimized using data (from 2014 to 2018) from four Italian stations characterized by markedly different environmental conditions (i.e., mountain, coastal and marine): Plateau Rosa (PRS), Mt. Cimone (CMN), Capo Granitola (CGR) and Lampedusa (LMP). Their locations extend from the Alps to the central Mediterranean. The adopted algorithm proved to be effective in separating the local/regional from the background signal in the CO2 time series. About 6% of the data at LMP, 11% at PRS, 20–38% at CMN and 65% at CGR were identified as non-background. LMP and PRS can be used as reference sites for the central Mediterranean, while CMN and CGR were more impacted by regional sources and sinks. Finally, we discuss a possible application of BaDS screened data. |
BibTeX:
@article{Trisolino2021,
author = {Trisolino, Pamela and di Sarra, Alcide and Sferlazzo, Damiano and Piacentino, Salvatore and Monteleone, Francesco and Di Iorio, Tatiana and Apadula, Francesco and Heltai, Daniela and Lanza, Andrea and Vocino, Antonio and di Torchiarolo, Luigi and Bonasoni, Paolo and Calzolari, Francescopiero and Busetto, Maurizio and Cristofanelli, Paolo},
title = {Application of a Common Methodology to Select in Situ CO2 Observations Representative of the Atmospheric Background to an Italian Collaborative Network},
journal = {Atmosphere},
year = {2021},
volume = {12},
number = {2},
url = {https://www.mdpi.com/2073-4433/12/2/246},
doi = {10.3390/atmos12020246}
}
|
| Vainio E, Peltola O, Kasurinen V, Kieloaho A-J, Tuittila E-S and Pihlatie M (2021), "Topography-based statistical modelling reveals high spatial variability and seasonal emission patches in forest floor methane flux", Biogeosciences. Vol. 18(6), pp. 2003-2025. |
BibTeX:
@article{Vainio2021,
author = {Vainio, E and Peltola, O and Kasurinen, V and Kieloaho, A.-J. and Tuittila, E.-S. and Pihlatie, M},
title = {Topography-based statistical modelling reveals high spatial variability and seasonal emission patches in forest floor methane flux},
journal = {Biogeosciences},
year = {2021},
volume = {18},
number = {6},
pages = {2003--2025},
url = {https://bg.copernicus.org/articles/18/2003/2021/},
doi = {10.5194/bg-18-2003-2021}
}
|
| Van Dam B, Polsenaere P, Barreras-Apodaca A, Lopes C, Sanchez-Mejia Z, Tokoro T, Kuwae T, Loza LG, Rutgersson A, Fourqurean J and Thomas H (2021), "Global Trends in Air-Water CO2 Exchange Over Seagrass Meadows Revealed by Atmospheric Eddy Covariance", Global Biogeochemical Cycles., apr, 2021. Vol. 35(4), pp. e2020GB006848. John Wiley & Sons, Ltd. |
| Abstract: Abstract Coastal vegetated habitats like seagrass meadows can mitigate anthropogenic carbon emissions by sequestering CO2 as ?blue carbon? (BC). Already, some coastal ecosystems are actively managed to enhance BC storage, with associated BC stocks included in national greenhouse gas inventories. However, the extent to which BC burial fluxes are enhanced or counteracted by other carbon fluxes, especially air-water CO2 flux (FCO2) remains poorly understood. In this study, we synthesized all available direct FCO2 measurements over seagrass meadows made using atmospheric Eddy Covariance, across a globally representative range of ecotypes. Of the four sites with seasonal data coverage, two were net CO2 sources, with average FCO2 equivalent to 44%?115% of the global average BC burial rate. At the remaining sites, net CO2 uptake was 101%?888% of average BC burial. A wavelet coherence analysis demonstrated that FCO2 was most strongly related to physical factors like temperature, wind, and tides. In particular, tidal forcing was a key driver of global-scale patterns in FCO2, likely due to a combination of lateral carbon exchange, bottom-driven turbulence, and pore-water pumping. Lastly, sea-surface drag coefficients were always greater than the prediction for the open ocean, supporting a universal enhancement of gas-transfer in shallow coastal waters. Our study points to the need for a more comprehensive approach to BC assessments, considering not only organic carbon storage, but also air-water CO2 exchange, and its complex biogeochemical and physical drivers. |
BibTeX:
@article{VanDam2021,
author = {Van Dam, Bryce and Polsenaere, Pierre and Barreras-Apodaca, Aylin and Lopes, Christian and Sanchez-Mejia, Zulia and Tokoro, Tatsuki and Kuwae, Tomohiro and Loza, Lucia Gutiérrez and Rutgersson, Anna and Fourqurean, James and Thomas, Helmuth},
title = {Global Trends in Air-Water CO2 Exchange Over Seagrass Meadows Revealed by Atmospheric Eddy Covariance},
journal = {Global Biogeochemical Cycles},
publisher = {John Wiley & Sons, Ltd},
year = {2021},
volume = {35},
number = {4},
pages = {e2020GB006848},
url = {https://doi.org/10.1029/2020GB006848},
doi = {10.1029/2020GB006848}
}
|
| Vanikiotis T, Stagakis S and Kyparissis A (2021), "MODIS PRI performance to track Light Use Efficiency of a Mediterranean coniferous forest: Determinants, restrictions and the role of LUE range", Agricultural and Forest Meteorology. Vol. 307, pp. 108518. |
| Abstract: The relationship between the Photochemical Reflectance Index (PRI) and Light Use Efficiency (LUE) is well established at leaf and small canopy scales, but upscaling to ecosystem level is still a challenge. Only few studies have applied satellite-derived PRI to estimate LUE, mostly using MODIS, and although the results are promising, many external factors have been identified affecting PRI performance. The present study investigates determinants and restrictions of MODIS-derived PRI potential to follow the LUE variability of a Mediterranean coniferous forest. Daily and half-hour LUE values were calculated from eddy covariance measurements, dividing GPP by either Photosynthetically Active Radiation (PAR) or the absorbed fraction of PAR (APAR). Also, various PRI datasets were created based on different sensor (Terra, Aqua, Both), reference band (1, 12, 13) and observation/illumination angles. Overall, PRI correlated better with LUE calculated using PAR instead of APAR and Aqua PRI yielded better results than Terra. Restricting acquisitions according to observation/illumination angles improves the PRI:LUE relationship (maximum R2 = 0.512), with backscatter observations yielding the best correlations. Our findings suggest that MODIS-derived PRI is more sensitive to relatively large seasonal LUE changes, but is unable to closely follow severe drought events. Among the tested reference bands, the best results were derived using band 12 (546 - 556 nm), although the optimum reference band seems to depend on viewing conditions. The PRI:LUE relationship was further improved when half-hour LUE of the satellite overpass was used instead of daily LUE. However, it was found that the PRI:LUE relationships for the different datasets were strongly affected by the range of LUE values corresponding to each PRI group, with lower LUE variability resulting to weaker PRI:LUE correlations. LUE range effect should be accounted for in future studies, when different PRI datasets are compared and might explain the contradicting findings in the existing literature. |
BibTeX:
@article{Vanikiotis2021,
author = {Vanikiotis, Theofilos and Stagakis, Stavros and Kyparissis, Aris},
title = {MODIS PRI performance to track Light Use Efficiency of a Mediterranean coniferous forest: Determinants, restrictions and the role of LUE range},
journal = {Agricultural and Forest Meteorology},
year = {2021},
volume = {307},
pages = {108518},
url = {https://www.sciencedirect.com/science/article/pii/S0168192321002021},
doi = {10.1016/j.agrformet.2021.108518}
}
|
| Virkkala A-M, Aalto J, Rogers BM, Tagesson T, Treat CC, Natali SM, Watts JD, Potter S, Lehtonen A, Mauritz M, Schuur EAG, Kochendorfer J, Zona D, Oechel W, Kobayashi H, Humphreys E, Goeckede M, Iwata H, Lafleur PM, Euskirchen ES, Bokhorst S, Marushchak M, Martikainen PJ, Elberling B, Voigt C, Biasi C, Sonnentag O, Parmentier F-JW, Ueyama M, Celis G, St.Louis VL, Emmerton CA, Peichl M, Chi J, Järveoja J, Nilsson MB, Oberbauer SF, Torn MS, Park S-J, Dolman H, Mammarella I, Chae N, Poyatos R, López-Blanco E, Christensen TR, Kwon MJ, Sachs T, Holl D and Luoto M (2021), "Statistical upscaling of ecosystem CO2 fluxes across the terrestrial tundra and boreal domain: Regional patterns and uncertainties", Global Change Biology., sep, 2021. Vol. 27(17), pp. 4040-4059. John Wiley & Sons, Ltd. |
| Abstract: Abstract The regional variability in tundra and boreal carbon dioxide (CO2) fluxes can be high, complicating efforts to quantify sink-source patterns across the entire region. Statistical models are increasingly used to predict (i.e., upscale) CO2 fluxes across large spatial domains, but the reliability of different modeling techniques, each with different specifications and assumptions, has not been assessed in detail. Here, we compile eddy covariance and chamber measurements of annual and growing season CO2 fluxes of gross primary productivity (GPP), ecosystem respiration (ER), and net ecosystem exchange (NEE) during 1990?2015 from 148 terrestrial high-latitude (i.e., tundra and boreal) sites to analyze the spatial patterns and drivers of CO2 fluxes and test the accuracy and uncertainty of different statistical models. CO2 fluxes were upscaled at relatively high spatial resolution (1 km2) across the high-latitude region using five commonly used statistical models and their ensemble, that is, the median of all five models, using climatic, vegetation, and soil predictors. We found the performance of machine learning and ensemble predictions to outperform traditional regression methods. We also found the predictive performance of NEE-focused models to be low, relative to models predicting GPP and ER. Our data compilation and ensemble predictions showed that CO2 sink strength was larger in the boreal biome (observed and predicted average annual NEE ?46 and ?29 g C m?2 yr?1, respectively) compared to tundra (average annual NEE +10 and ?2 g C m?2 yr?1). This pattern was associated with large spatial variability, reflecting local heterogeneity in soil organic carbon stocks, climate, and vegetation productivity. The terrestrial ecosystem CO2 budget, estimated using the annual NEE ensemble prediction, suggests the high-latitude region was on average an annual CO2 sink during 1990?2015, although uncertainty remains high. |
BibTeX:
@article{Virkkala2021,
author = {Virkkala, Anna-Maria and Aalto, Juha and Rogers, Brendan M and Tagesson, Torbern and Treat, Claire C and Natali, Susan M and Watts, Jennifer D and Potter, Stefano and Lehtonen, Aleksi and Mauritz, Marguerite and Schuur, Edward A G and Kochendorfer, John and Zona, Donatella and Oechel, Walter and Kobayashi, Hideki and Humphreys, Elyn and Goeckede, Mathias and Iwata, Hiroki and Lafleur, Peter M and Euskirchen, Eugenie S and Bokhorst, Stef and Marushchak, Maija and Martikainen, Pertti J and Elberling, Bo and Voigt, Carolina and Biasi, Christina and Sonnentag, Oliver and Parmentier, Frans-Jan W and Ueyama, Masahito and Celis, Gerardo and St.Louis, Vincent L and Emmerton, Craig A and Peichl, Matthias and Chi, Jinshu and Järveoja, Järvi and Nilsson, Mats B and Oberbauer, Steven F and Torn, Margaret S and Park, Sang-Jong and Dolman, Han and Mammarella, Ivan and Chae, Namyi and Poyatos, Rafael and López-Blanco, Efrén and Christensen, Torben Røjle and Kwon, Min Jung and Sachs, Torsten and Holl, David and Luoto, Miska},
title = {Statistical upscaling of ecosystem CO2 fluxes across the terrestrial tundra and boreal domain: Regional patterns and uncertainties},
journal = {Global Change Biology},
publisher = {John Wiley & Sons, Ltd},
year = {2021},
volume = {27},
number = {17},
pages = {4040--4059},
url = {https://doi.org/10.1111/gcb.15659},
doi = {10.1111/gcb.15659}
}
|
| Vollmer MK, Mühle J, Henne S, Young D, Rigby M, Mitrevski B, Park S, Lunder CR, Rhee TS, Harth CM, Hill M, Langenfelds RL, Guillevic M, Schlauri PM, Hermansen O, Arduini J, Wang RHJ, Salameh PK, Maione M, Krummel PB, Reimann S, O’Doherty S, Simmonds PG, Fraser PJ, Prinn RG, Weiss RF and Steele LP (2021), "Unexpected nascent atmospheric emissions of three ozone-depleting hydrochlorofluorocarbons", Proceedings of the National Academy of Sciences., January, 2021. Vol. 118(5) Proceedings of the National Academy of Sciences. |
BibTeX:
@article{Vollmer2021,
author = {Vollmer, Martin K. and Mühle, Jens and Henne, Stephan and Young, Dickon and Rigby, Matthew and Mitrevski, Blagoj and Park, Sunyoung and Lunder, Chris R. and Rhee, Tae Siek and Harth, Christina M. and Hill, Matthias and Langenfelds, Ray L. and Guillevic, Myriam and Schlauri, Paul M. and Hermansen, Ove and Arduini, Jgor and Wang, Ray H. J. and Salameh, Peter K. and Maione, Michela and Krummel, Paul B. and Reimann, Stefan and O’Doherty, Simon and Simmonds, Peter G. and Fraser, Paul J. and Prinn, Ronald G. and Weiss, Ray F. and Steele, L. Paul},
title = {Unexpected nascent atmospheric emissions of three ozone-depleting hydrochlorofluorocarbons},
journal = {Proceedings of the National Academy of Sciences},
publisher = {Proceedings of the National Academy of Sciences},
year = {2021},
volume = {118},
number = {5},
doi = {10.1073/pnas.2010914118}
}
|
| Wang F, Maksyutov S, Janardanan R, Tsuruta A, Ito A, Morino I, Yoshida Y, Tohjima Y, Kaiser JW, Janssens-Maenhout G, Lan X, Mammarella I, Lavric JV and Matsunaga T (2021), "Interannual variability on methane emissions in monsoon Asia derived from GOSAT and surface observations", Environmental Research Letters. Vol. 16(2), pp. 24040. IOP Publishing. |
| Abstract: In Asia, much effort is put into reducing methane (CH4) emissions due to the region's contribution to the recent rapid global atmospheric CH4 concentration growth. Accurate quantification of Asia's CH4 budgets is critical for conducting global stocktake and achieving the long-term temperature goal of the Paris Agreement. In this study, we present top-down estimates of CH4 emissions from 2009 to 2018 deduced from atmospheric observations from surface network and GOSAT satellite with the high-resolution global inverse model NIES-TM-FLEXPART-VAR. The optimized average CH4 budgets are 63.40 ± 10.52 Tg y−1 from East Asia (EA), 45.20 ± 6.22 Tg y−1 from Southeast Asia (SEA), and 64.35 ± 9.28 Tg y−1 from South Asia (SA) within the 10 years. We analyzed two 5 years CH4 emission budgets for three subregions and 13 top-emitting countries with an emission budget larger than 1 Tg y−1, and interannual variabilities for these subregions. Statistically significant increasing trends in emissions are found in EA with a lower emission growth rate during 2014–2018 compared to that during 2009–2013, while trends in SEA are not significant. In contrast to the prior emission, the posterior emission shows a significant decreasing trend in SA. The flux decrease is associated with the transition from strong La Ninña (2010–2011) to strong El Ninño (2015–2016) events, which modulate the surface air temperature and rainfall patterns. The interannual variability in CH4 flux anomalies was larger in SA compared to EA and SEA. The Southern Oscillation Index correlates strongly with interannual CH4 flux anomalies for SA. Our findings suggest that the interannual variability in the total CH4 flux is dominated by climate variability in SA. The contribution of climate variability driving interannual variability in natural and anthropogenic CH4 emissions should be further quantified, especially for tropical countries. Accounting for climate variability may be necessary to improve anthropogenic emission inventories. |
BibTeX:
@article{Wang2021,
author = {Wang, Fenjuan and Maksyutov, Shamil and Janardanan, Rajesh and Tsuruta, Aki and Ito, Akihiko and Morino, Isamu and Yoshida, Yukio and Tohjima, Yasunori and Kaiser, Johannes W and Janssens-Maenhout, Greet and Lan, Xin and Mammarella, Ivan and Lavric, Jost V and Matsunaga, Tsuneo},
title = {Interannual variability on methane emissions in monsoon Asia derived from GOSAT and surface observations},
journal = {Environmental Research Letters},
publisher = {IOP Publishing},
year = {2021},
volume = {16},
number = {2},
pages = {24040},
url = {http://dx.doi.org/10.1088/1748-9326/abd352},
doi = {10.1088/1748-9326/abd352}
}
|
| Wang J, Bogena H, Süß T, Graf A, Weuthen A and Brüggemann N (2021), "Investigating the controls on greenhouse gas emission in the riparian zone of a small headwater catchment using an automated monitoring system", Vadose Zone Journal., sep, 2021. Vol. 20(5), pp. e20149. John Wiley & Sons, Ltd. |
| Abstract: Abstract Riparian zones as the transition zone between terrestrial and aquatic ecosystems play an important role in C and N cycling and greenhouse gas (GHG) emissions. As such, they may help to mitigate climate change but could also accelerate it, depending on the particular processes affected by changes in the hydrologic regime. Hydrological observations indicated frequent shallow groundwater in the riparian zone, especially near the stream and during the wet winter and spring seasons with consequently frequent occurrence of soil water saturation. The redox potential was mainly governed by the soil water regime: under water saturation conditions, the redox potential of the soil decreased and returned to the oxic state after soil drainage. We found that soil temperature and soil water content were the main drivers of the variations in CO2 fluxes, with highest CO2 emission during summer and the lowest emissions in the winter period (162.2?5.4 mg CO2?C m?2 h?1). The annual average daily N2O emission rate was low (2.3 ?g N2O-N m?2 h?1), with the highest average daily N2O emission in March as a result of low temperature and partial soil saturation after heavy precipitation events (37.5 ?g N2O-N m?2 h?1). Our study showed that continuous measurement of redox potential, soil temperature, and soil water content can improve the understanding of GHG emissions in riparian zones. |
BibTeX:
@article{Wang2021a,
author = {Wang, Jihuan and Bogena, Heye and Süß, Thomas and Graf, Alexander and Weuthen, Ansgar and Brüggemann, Nicolas},
title = {Investigating the controls on greenhouse gas emission in the riparian zone of a small headwater catchment using an automated monitoring system},
journal = {Vadose Zone Journal},
publisher = {John Wiley & Sons, Ltd},
year = {2021},
volume = {20},
number = {5},
pages = {e20149},
url = {https://doi.org/10.1002/vzj2.20149},
doi = {10.1002/vzj2.20149}
}
|
| Wilson RM, Zayed AA, Crossen KB, Woodcroft B, Tfaily MM, Emerson J, Raab N, Hodgkins SB, Verbeke B, Tyson G, Crill P, Saleska S, Chanton JP, Rich VI, Coordinators IP and Team IPF (2021), "Functional capacities of microbial communities to carry out large scale geochemical processes are maintained during ex situ anaerobic incubation", PLOS ONE. Vol. 16(2), pp. 1-33. Public Library of Science. |
| Abstract: Mechanisms controlling CO2 and CH4 production in wetlands are central to understanding carbon cycling and greenhouse gas exchange. However, the volatility of these respiration products complicates quantifying their rates of production in the field. Attempts to circumvent the challenges through closed system incubations, from which gases cannot escape, have been used to investigate bulk in situ geochemistry. Efforts towards mapping mechanistic linkages between geochemistry and microbiology have raised concern regarding sampling and incubation-induced perturbations. Microorganisms are impacted by oxygen exposure, increased temperatures and accumulation of metabolic products during handling, storage, and incubation. We probed the extent of these perturbations, and their influence on incubation results, using high-resolution geochemical and microbial gene-based community profiling of anaerobically incubated material from three wetland habitats across a permafrost peatland. We compared the original field samples to the material anaerobically incubated over 50 days. Bulk geochemistry and phylum-level microbiota in incubations largely reflected field observations, but divergence between field and incubations occurred in both geochemistry and lineage-level microbial composition when examined at closer resolution. Despite the changes in representative lineages over time, inferred metabolic function with regards to carbon cycling largely reproduced field results suggesting functional consistency. Habitat differences among the source materials remained the largest driver of variation in geochemical and microbial differences among the samples in both incubations and field results. While incubations may have limited usefulness for identifying specific mechanisms, they remain a viable tool for probing bulk-scale questions related to anaerobic C cycling, including CO2 and CH4 dynamics. |
BibTeX:
@article{Wilson2021,
author = {Wilson, R M and Zayed, A A and Crossen, K B and Woodcroft, B and Tfaily, M M and Emerson, J and Raab, N and Hodgkins, S B and Verbeke, B and Tyson, G and Crill, P and Saleska, S and Chanton, J P and Rich, V I and Coordinators, IsoGenie Project and Team, IsoGenie Project Field},
title = {Functional capacities of microbial communities to carry out large scale geochemical processes are maintained during ex situ anaerobic incubation},
journal = {PLOS ONE},
publisher = {Public Library of Science},
year = {2021},
volume = {16},
number = {2},
pages = {1--33},
url = {https://doi.org/10.1371/journal.pone.0245857},
doi = {10.1371/journal.pone.0245857}
}
|
| Wu D, Liu S, Wu X, Yang X, Xu T, Xu Z and Shi H (2021), "Diagnosing the Temperature Sensitivity of Ecosystem Respiration in Northern High Latitude Regions", Journal of Geophysical Research (Biogeosciences). AA(State Key Laboratory of Earth Surface Processes and Resource Ecology, Faculty of Geographical Science, Beijing Normal University, Beijing, China), AB(State Key Laboratory of Earth Surface Processes and Resource Ecology, Faculty of Geographical Science, Beijing Normal University, Beijing, China), AC(State Key Laboratory of Earth Surface Processes and Resource Ecology, Faculty of Geographical Science, Beijing Normal University, Beijing, China), AD(State Key Laboratory of Earth Surface Processes and Resource Ecology, Faculty of Geographical Science, Beijing Normal University, Beijing, China), AE(State Key Laboratory of Earth Surface Processes and Resource Ecology, Faculty of Geographical Science, Beijing Normal University, Beijing, China), AF(State Key Laboratory of Earth Surface Processes and Resource Ecology, Faculty of Geographical Science, Beijing Normal University, Beijing, China), AG(State Key Laboratory of Remote Sensing Science, Faculty of Geographical Science, Beijing Normal University, Beijing, China), apr, 2021. Vol. 126, pp. e05998. |
| Abstract: The accurate estimation of the temperature sensitivity of ecosystem respiration (Q10) is important to understanding the terrestrial ecosystem carbon cycle, especially in northern high latitude regions (NHLs). Q10 estimated by the conventional approach at the annual scale is influenced by seasonal confounding effects. Based on singular spectrum analysis, scale dependent parameter estimation (SCAPE) is considered an effective approach to eliminate confounding effects. Nevertheless, the performance of the decomposition and reconstruction schemes in the SCAPE approach in Q10 estimation remains limited, which hampers its further application in larger scale systems. In this study, we utilized an improved scale dependent parameter estimation (iSCAPE) approach to analyze trends of the unconfounded Q10 and its environmental controls in NHLs. The results showed that in NHLs, the confounding effects in forest ecosystems were smaller than those in cropland and grassland ecosystems. The apparent Q10 estimated by the conventional approach varied among 32 sites with a mean value of 2.82 (95% confidence interval (CI): 2.72-2.91), while the mean intrinsic Q10 estimated by the iSCAPE approach across the 32 sites was 1.53 (95% CI: 1.48-1.57). The apparent Q10 increased with the annual mean temperature. The intrinsic Q10 decreased with the increasing of spatial temperature gradient. The current study indicates that ecosystem respiration in NHLs is less sensitive to climate warming than previously reported. The seasonality of ecosystem respiration should be eliminated when estimating Q10 to avoid overestimating climate carbon cycle feedback. |
BibTeX:
@article{Wu2021,
author = {Wu, Dongxing and Liu, Shaomin and Wu, Xiuchen and Yang, Xiaofan and Xu, Tongren and Xu, Ziwei and Shi, Hanyu},
title = {Diagnosing the Temperature Sensitivity of Ecosystem Respiration in Northern High Latitude Regions},
journal = {Journal of Geophysical Research (Biogeosciences)},
year = {2021},
volume = {126},
pages = {e05998},
url = {https://ui.adsabs.harvard.edu/abs/2021JGRG..12605998W},
doi = {10.1029/2020JG005998}
}
|
| Wu J, Peichl M, Luan J, Connolly J and Xu L (2021), "Editorial: Wetland Ecology and Biogeochemistry Under Natural and Human Disturbance", Frontiers in Earth Science. Vol. 9 |
BibTeX:
@article{Wu2021a,
author = {Wu, Jianghua and Peichl, Matthias and Luan, Junwei and Connolly, John and Xu, Ligang},
title = {Editorial: Wetland Ecology and Biogeochemistry Under Natural and Human Disturbance},
journal = {Frontiers in Earth Science},
year = {2021},
volume = {9},
url = {https://www.frontiersin.org/article/10.3389/feart.2021.752101},
doi = {10.3389/feart.2021.752101}
}
|
| Yazbeck T, Bohrer G, Gentine P, Ye L, Arriga N, Bernhofer C, Blanken PD, Desai AR, Durden D, Knohl A, Kowalska N, Metzger S, Mölder M, Noormets A, Novick K, Scott RL, Šigut L, Soudani K, Ueyama M and Varlagin A (2021), "Site Characteristics Mediate the Relationship Between Forest Productivity and Satellite Measured Solar Induced Fluorescence", Frontiers in Forests and Global Change. Vol. 4 |
| Abstract: Solar-Induced Chlorophyll Fluorescence (SIF) can provide key information about the state of photosynthesis and offers the prospect of defining remote sensing-based estimation of Gross Primary Production (GPP). There is strong theoretical support for the link between SIF and GPP and this relationship has been empirically demonstrated using ground-based, airborne, and satellite-based SIF observations, as well as modeling. However, most evaluations have been based on monthly and annual scales, yet the GPP:SIF relations can be strongly influenced by both vegetation structure and physiology. At the monthly timescales, the structural response often dominates but short-term physiological variations can strongly impact the GPP:SIF relations. Here, we test how well SIF can predict the inter-daily variation of GPP during the growing season and under stress conditions, while taking into account the local effect of sites and abiotic conditions. We compare the accuracy of GPP predictions from SIF at different timescales (half-hourly, daily, and weekly), while evaluating effect of adding environmental variables to the relationship. We utilize observations for years 2018–2019 at 31 mid-latitudes, forested, eddy covariance (EC) flux sites in North America and Europe and use TROPOMI satellite data for SIF. Our results show that SIF is a good predictor of GPP, when accounting for inter-site variation, probably due to differences in canopy structure. Seasonally averaged leaf area index, fraction of absorbed photosynthetically active radiation (fPAR) and canopy conductance provide a predictor to the site-level effect. We show that fPAR is the main factor driving errors in the linear model at high temporal resolution. Adding water stress indicators, namely canopy conductance, to a multi-linear SIF-based GPP model provides the best improvement in the model precision at the three considered timescales, showing the importance of accounting for water stress in GPP predictions, independent of the SIF signal. SIF is a promising predictor for GPP among other remote sensing variables, but more focus should be placed on including canopy structure, and water stress effects in the relationship, especially when considering intra-seasonal, and inter- and intra-daily resolutions. |
BibTeX:
@article{Yazbeck2021,
author = {Yazbeck, Theresia and Bohrer, Gil and Gentine, Pierre and Ye, Luping and Arriga, Nicola and Bernhofer, Christian and Blanken, Peter D and Desai, Ankur R and Durden, David and Knohl, Alexander and Kowalska, Natalia and Metzger, Stefan and Mölder, Meelis and Noormets, Asko and Novick, Kim and Scott, Russell L and Šigut, Ladislav and Soudani, Kamel and Ueyama, Masahito and Varlagin, Andrej},
title = {Site Characteristics Mediate the Relationship Between Forest Productivity and Satellite Measured Solar Induced Fluorescence},
journal = {Frontiers in Forests and Global Change},
year = {2021},
volume = {4},
url = {https://www.frontiersin.org/article/10.3389/ffgc.2021.695269},
doi = {10.3389/ffgc.2021.695269}
}
|
| Yin T, Papadimitriou S, Rérolle VMC, Arundell M, Cardwell CL, Walk J, Palmer MR, Fowell SE, Schaap A, Mowlem MC and Loucaides S (2021), "A Novel Lab-on-Chip Spectrophotometric pH Sensor for Autonomous In Situ Seawater Measurements to 6000 m Depth on Stationary and Moving Observing Platforms", Environmental Science & Technology., nov, 2021. Vol. 55(21), pp. 14968-14978. American Chemical Society. |
BibTeX:
@article{Yin2021,
author = {Yin, Tianya and Papadimitriou, Stathys and Rérolle, Victoire M C and Arundell, Martin and Cardwell, Christopher L and Walk, John and Palmer, Martin R and Fowell, Sara E and Schaap, Allison and Mowlem, Matthew C and Loucaides, Socratis},
title = {A Novel Lab-on-Chip Spectrophotometric pH Sensor for Autonomous In Situ Seawater Measurements to 6000 m Depth on Stationary and Moving Observing Platforms},
journal = {Environmental Science & Technology},
publisher = {American Chemical Society},
year = {2021},
volume = {55},
number = {21},
pages = {14968--14978},
url = {https://doi.org/10.1021/acs.est.1c03517},
doi = {10.1021/acs.est.1c03517}
}
|
| Yver-Kwok C, Philippon C, Bergamaschi P, Biermann T, Calzolari F, Chen H, Conil S, Cristofanelli P, Delmotte M, Hatakka J, Heliasz M, Hermansen O, Kominkova K, Kubistin D, Kumps N, Laurent O, Laurila T, Lehner I, Levula J, Lindauer M, Lopez M, Mammarella I, Manca G, Marklund P, Metzger JM, Mölder M, Platt SM, Ramonet M, Rivier L, Scheeren B, Kumar Sha M, Smith P, Steinbacher M, Vítková G and Wyss S (2021), "Evaluation and optimization of ICOS atmosphere station data as part of the labeling process", Atmospheric Measurement Techniques. Vol. 14(1), pp. 89-116. |
| Abstract: The Integrated Carbon Observation System (ICOS) is a pan-European research infrastructure which provides harmonized and high-precision scientific data on the carbon cycle and the greenhouse gas budget. All stations have to undergo a rigorous assessment before being labeled, i.e., receiving approval to join the network. In this paper, we present the labeling process for the ICOS atmosphere network through the 23 stations that were labeled between November 2017 and November 2019. We describe the labeling steps, as well as the quality controls, used to verify that the ICOS data (CO2, CH4, CO and meteorological measurements) attain the expected quality level defined within ICOS. To ensure the quality of the greenhouse gas data, three to four calibration gases and two target gases are measured: one target two to three times a day, the other gases twice a month. The data are verified on a weekly basis, and tests on the station sampling lines are performed twice a year. From these high-quality data, we conclude that regular calibrations of the CO2, CH4 and CO analyzers used here (twice a month) are important in particular for carbon monoxide (CO) due to the analyzer's variability and that reducing the number of calibration injections (from four to three) in a calibration sequence is possible, saving gas and extending the calibration gas lifespan. We also show that currently, the on-site water vapor correction test does not deliver quantitative results possibly due to environmental factors. Thus the use of a drying system is strongly recommended. Finally, the mandatory regular intake line tests are shown to be useful in detecting artifacts and leaks, as shown here via three different examples at the stations. . |
BibTeX:
@article{YverKwok2021,
author = {Yver-Kwok, Camille and Philippon, Carole and Bergamaschi, Peter and Biermann, Tobias and Calzolari, Francescopiero and Chen, Huilin and Conil, Sebastien and Cristofanelli, Paolo and Delmotte, Marc and Hatakka, Juha and Heliasz, Michal and Hermansen, Ove and Kominkova, Katerina and Kubistin, Dagmar and Kumps, Nicolas and Laurent, Olivier and Laurila, Tuomas and Lehner, Irene and Levula, Janne and Lindauer, Matthias and Lopez, Morgan and Mammarella, Ivan and Manca, Giovanni and Marklund, Per and Metzger, Jean Marc and Mölder, Meelis and Platt, Stephen M. and Ramonet, Michel and Rivier, Leonard and Scheeren, Bert and Kumar Sha, Mahesh and Smith, Paul and Steinbacher, Martin and Vítková, Gabriela and Wyss, Simon},
title = {Evaluation and optimization of ICOS atmosphere station data as part of the labeling process},
journal = {Atmospheric Measurement Techniques},
year = {2021},
volume = {14},
number = {1},
pages = {89--116},
doi = {10.5194/amt-14-89-2021}
}
|
| Zhang H, Tuittila E-S, Korrensalo A, Laine AM, Uljas S, Welti N, Kerttula J, Maljanen M, Elliott D, Vesala T and Lohila A (2021), "Methane production and oxidation potentials along a fen-bog gradient from southern boreal to subarctic peatlands in Finland", Global Change Biology., sep, 2021. Vol. 27(18), pp. 4449-4464. John Wiley & Sons, Ltd. |
| Abstract: Abstract Methane (CH4) emissions from northern peatlands are projected to increase due to climate change, primarily because of projected increases in soil temperature. Yet, the rates and temperature responses of the two CH4 emission-related microbial processes (CH4 production by methanogens and oxidation by methanotrophs) are poorly known. Further, peatland sites within a fen-bog gradient are known to differ in the variables that regulate these two mechanisms, yet the interaction between peatland type and temperature lacks quantitative understanding. Here, we investigated potential CH4 production and oxidation rates for 14 peatlands in Finland located between c. 60 and 70°N latitude, representing bogs, poor fens, and rich fens. Potentials were measured at three different temperatures (5, 17.5, and 30?) using the laboratory incubation method. We linked CH4 production and oxidation patterns to their methanogen and methanotroph abundance, peat properties, and plant functional types. We found that the rich fen-bog gradient-related nutrient availability and methanogen abundance increased the temperature response of CH4 production, with rich fens exhibiting the greatest production potentials. Oxidation potential showed a steeper temperature response than production, which was explained by aerenchymous plant cover, peat water holding capacity, peat nitrogen, and sulfate content. The steeper temperature response of oxidation suggests that, at higher temperatures, CH4 oxidation might balance increased CH4 production. Predicting net CH4 fluxes as an outcome of the two mechanisms is complicated due to their different controls and temperature responses. The lack of correlation between field CH4 fluxes and production/oxidation potentials, and the positive correlation with aerenchymous plants points toward the essential role of CH4 transport for emissions. The scenario of drying peatlands under climate change, which is likely to promote Sphagnum establishment over brown mosses in many places, will potentially reduce the predicted warming-related increase in CH4 emissions by shifting rich fens to Sphagnum-dominated systems. |
BibTeX:
@article{Zhang2021,
author = {Zhang, Hui and Tuittila, Eeva-Stiina and Korrensalo, Aino and Laine, Anna M and Uljas, Salli and Welti, Nina and Kerttula, Johanna and Maljanen, Marja and Elliott, David and Vesala, Timo and Lohila, Annalea},
title = {Methane production and oxidation potentials along a fen-bog gradient from southern boreal to subarctic peatlands in Finland},
journal = {Global Change Biology},
publisher = {John Wiley & Sons, Ltd},
year = {2021},
volume = {27},
number = {18},
pages = {4449--4464},
url = {https://doi.org/10.1111/gcb.15740},
doi = {10.1111/gcb.15740}
}
|
| Zhang Z, Zhang H, Cui Z, Tao F, Chen Z, Chang Y, Magliulo V, Wohlfahrt G and Zhao D (2021), "Global consistency in response of terrestrial ecosystem respiration to temperature", Agricultural and Forest Meteorology. Vol. 308-309, pp. 108576. |
| Abstract: Many studies have been carried out to quantify the trend of terrestrial ecosystem respiration (Re) in a warming world, but a conclusive answer has not yet been confirmed because the temperature sensitivity of Re was found inconsistent under different scales or regarding different types of respiratory flux. Aiming at reconciling the relationship between temperature and Re across different scales (i.e., short-term and site-to-site), we proposed a method to reduce noises of half-hourly Re measurements and applied nine empirical models to a 1387 site-year FLUXNET datasets. Regarding the temperature sensitivity of half-hourly Re records, we found a surprisingly consistent result that the sigmoid functions outcompeted other statistical models in 82% of site-year combinations, and on average, achieved a staggering R2 value of 0.92, indicating the positive correlation between Re and temperature on fine time scale (within one site-year dataset). Even though Re of all biomes followed sigmoid functions, the parameters of the S-curve varied strongly across sites or years. This explains why measured Q10 value (an index denote temperature sensitivity) largely depends on observation season and site. Furthermore, on the interannual variation of Re, we did not find any relationship between mean annual temperature (MAT) and mean annual Re within any site, which implies that the small year-to-year variation of the sigmoid pattern is large enough to counteract the warming effect on Re. This study brings up a conceptual framework to integrate the relationship between temperature and Re under short-term or site-to-site scales. It also provided evidence to support the argument that the relationship between MAT and mean annual Re by using data across multiple sites should not be used to interpret the response of respiration under global warming. |
BibTeX:
@article{Zhang2021a,
author = {Zhang, Zhiyuan and Zhang, Huanyuan and Cui, Zikun and Tao, Feng and Chen, Ziwei and Chang, Yaxuan and Magliulo, Vincenzo and Wohlfahrt, Georg and Zhao, Dongsheng},
title = {Global consistency in response of terrestrial ecosystem respiration to temperature},
journal = {Agricultural and Forest Meteorology},
year = {2021},
volume = {308-309},
pages = {108576},
url = {https://www.sciencedirect.com/science/article/pii/S0168192321002604},
doi = {10.1016/j.agrformet.2021.108576}
}
|
| Zhang S, Rutgersson A, Philipson P and Wallin MB (2021), "Remote Sensing Supported Sea Surface pCO2 Estimation and Variable Analysis in the Baltic Sea", Remote Sensing. Vol. 13(2) |
| Abstract: Marginal seas are a dynamic and still to large extent uncertain component of the global carbon cycle. The large temporal and spatial variations of sea-surface partial pressure of carbon dioxide (pCO2) in these areas are driven by multiple complex mechanisms. In this study, we analyzed the variable importance for the sea surface pCO2 estimation in the Baltic Sea and derived monthly pCO2 maps for the marginal sea during the period of July 2002–October 2011. We used variables obtained from remote sensing images and numerical models. The random forest algorithm was employed to construct regression models for pCO2 estimation and produce the importance of different input variables. The study found that photosynthetically available radiation (PAR) was the most important variable for the pCO2 estimation across the entire Baltic Sea, followed by sea surface temperature (SST), absorption of colored dissolved organic matter (aCDOM), and mixed layer depth (MLD). Interestingly, Chlorophyll-a concentration (Chl-a) and the diffuse attenuation coefficient for downwelling irradiance at 490 nm (Kd_490nm) showed relatively low importance for the pCO2 estimation. This was mainly attributed to the high correlation of Chl-a and Kd_490nm to other pCO2-relevant variables (e.g., aCDOM), particularly in the summer months. In addition, the variables’ importance for pCO2 estimation varied between seasons and sub-basins. For example, the importance of aCDOM were large in the Gulf of Finland but marginal in other sub-basins. The model for pCO2 estimate in the entire Baltic Sea explained 63% of the variation and had a root of mean squared error (RMSE) of 47.8 µatm. The pCO2 maps derived with this model displayed realistic seasonal variations and spatial features of sea surface pCO2 in the Baltic Sea. The spatially and seasonally varying variables’ importance for the pCO2 estimation shed light on the heterogeneities in the biogeochemical and physical processes driving the carbon cycling in the Baltic Sea and can serve as an important basis for future pCO2 estimation in marginal seas using remote sensing techniques. The pCO2 maps derived in this study provided a robust benchmark for understanding the spatiotemporal patterns of CO2 air-sea exchange in the Baltic Sea. |
BibTeX:
@article{Zhang2021b,
author = {Zhang, Shuping and Rutgersson, Anna and Philipson, Petra and Wallin, Marcus B},
title = {Remote Sensing Supported Sea Surface pCO2 Estimation and Variable Analysis in the Baltic Sea},
journal = {Remote Sensing},
year = {2021},
volume = {13},
number = {2},
url = {https://www.mdpi.com/2072-4292/13/2/259},
doi = {10.3390/rs13020259}
}
|
| Zhou H, Shao J, Liu H, Du Z, Zhou L, Liu R, Bernhofer C, Grünwald T, Dušek J, Montagnani L, Tagesson T, Black TA, Jassal R, Woodgate W, Biraud S, Varlagin A, Mammarella I, Gharun M, Shekhar A, Buchmann N, Manco A, Magliulo E, Billesbach D, Silberstein RP, Ohta T, Yu G, Chen Z, Zhang Y and Zhou X (2021), "Relative importance of climatic variables, soil properties and plant traits to spatial variability in net CO2 exchange across global forests and grasslands", Agricultural and Forest Meteorology. Vol. 307, pp. 108506. |
| Abstract: Compared to the well-known drivers of spatial variability in gross primary productivity (GPP), the relative importance of climatic variables, soil properties and plant traits to the spatial variability in net ecosystem exchange of CO2 between terrestrial ecosystem and atmosphere (NEE) is poorly understood. We used principal component regression to analyze data from 147 eddy flux sites to disentangle effects of climatic variables, soil properties and plant traits on the spatial variation in annual NEE and its components (GPP and ecosystem respiration (RE)) across global forests and grasslands. Our results showed that the largest unique contribution (proportion of variance only explained by one class of variables) to NEE variance came from climatic variables for forests (24%-30%) and soil properties for grasslands (41%-54%). Specifically, mean annual precipitation and potential evapotranspiration were the most important climatic variables driving forest NEE, whereas available soil water capacity, clay content and cation exchange capacity mainly influenced grassland NEE. Plant traits showed a small unique contribution to NEE in both forests and grasslands. However, leaf phosphorus content strongly interacted with soil total nitrogen density and clay content, and these combined factors represented a major contribution for grassland NEE. For GPP and RE, the majority of spatial variance was attributed to the common contribution of climate, soil and plant traits (50% - 62%, proportion of variance explained by more than one class of variables), rather than their unique contributions. Interestingly, those factors with only minor influences on GPP and RE variability (e.g., soil properties) have significant contributions to the spatial variability in NEE. Such emerging factors and the interactions between climatic variables, soil properties and plant traits are not well represented in current terrestrial biosphere models, which should be considered in future model improvement to accurately predict the spatial pattern of carbon cycling across forests and grasslands globally. |
BibTeX:
@article{Zhou2021,
author = {Zhou, Huimin and Shao, Junjiong and Liu, Huiying and Du, Zhenggang and Zhou, Lingyan and Liu, Ruiqiang and Bernhofer, Christian and Grünwald, Thomas and Dušek, Jiří and Montagnani, Leonardo and Tagesson, Torbern and Black, Thomas Andrew and Jassal, Rachhpal and Woodgate, William and Biraud, Sébastien and Varlagin, Andrej and Mammarella, Ivan and Gharun, Mana and Shekhar, Ankit and Buchmann, Nina and Manco, Antonio and Magliulo, Enzo and Billesbach, Dave and Silberstein, Richard P and Ohta, Takeshi and Yu, Guirui and Chen, Zhi and Zhang, Yiping and Zhou, Xuhui},
title = {Relative importance of climatic variables, soil properties and plant traits to spatial variability in net CO2 exchange across global forests and grasslands},
journal = {Agricultural and Forest Meteorology},
year = {2021},
volume = {307},
pages = {108506},
url = {https://www.sciencedirect.com/science/article/pii/S0168192321001908},
doi = {10.1016/j.agrformet.2021.108506}
}
|
| Zinke LA, Evans PN, Santos-Medellín C, Schroeder AL, Parks DH, Varner RK, Rich VI, Tyson GW and Emerson JB (2021), "Evidence for non-methanogenic metabolisms in globally distributed archaeal clades basal to the Methanomassiliicoccales.", Environmental microbiology., jan, 2021. Vol. 23(1), pp. 340-357. |
| Abstract: Recent discoveries of mcr and mcr-like genes in genomes from diverse archaeal lineages suggest that methane metabolism is an ancient pathway with a complicated evolutionary history. One conventional view is that methanogenesis is an ancestral metabolism of the class Thermoplasmata. Through comparative genomic analysis of 12 Thermoplasmata metagenome-assembled genomes (MAGs) basal to the Methanomassiliicoccales, we show that these microorganisms do not encode the genes required for methanogenesis. Further analysis of 770 Ca. Thermoplasmatota genomes/MAGs found no evidence of mcrA homologues outside of the Methanomassiliicoccales. Together, these results suggest that methanogenesis was laterally acquired by an ancestor of the Methanomassiliicoccales. The 12 analysed MAGs include representatives from four orders basal to the Methanomassiliicoccales, including a high-quality MAG that likely represents a new order, Ca. Lunaplasma lacustris ord. nov. sp. nov. These MAGs are predicted to use diverse energy conservation pathways, including heterotrophy, sulfur and hydrogen metabolism, denitrification, and fermentation. Two lineages are widespread among anoxic, sedimentary environments, whereas Ca. Lunaplasma lacustris has thus far only been detected in alpine caves and subarctic lake sediments. These findings advance our understanding of the metabolic potential, ecology, and global distribution of the Thermoplasmata and provide insight into the evolutionary history of methanogenesis within the Ca. Thermoplasmatota. |
BibTeX:
@article{Zinke2021,
author = {Zinke, Laura A and Evans, Paul N and Santos-Medellín, Christian and Schroeder, Alena L and Parks, Donovan H and Varner, Ruth K and Rich, Virginia I and Tyson, Gene W and Emerson, Joanne B},
title = {Evidence for non-methanogenic metabolisms in globally distributed archaeal clades basal to the Methanomassiliicoccales.},
journal = {Environmental microbiology},
year = {2021},
volume = {23},
number = {1},
pages = {340--357},
doi = {10.1111/1462-2920.15316}
}
|
| Zweifel R, Sterck F, Braun S, Buchmann N, Eugster W, Gessler A, Häni M, Peters RL, Walthert L, Wilhelm M, Ziemiʼnska K and Etzold S (2021), "Why trees grow at night", New Phytologist., sep, 2021. Vol. 231(6), pp. 2174-2185. John Wiley & Sons, Ltd. |
| Abstract: Summary The timing of diel stem growth of mature forest trees is still largely unknown, as empirical data with high temporal resolution have not been available so far. Consequently, the effects of day?night conditions on tree growth remained uncertain. Here we present the first comprehensive field study of hourly-resolved radial stem growth of seven temperate tree species, based on 57 million underlying data points over a period of up to 8?yr. We show that trees grow mainly at night, with a peak after midnight, when the vapour pressure deficit (VPD) is among the lowest. A high VPD strictly limits radial stem growth and allows little growth during daylight hours, except in the early morning. Surprisingly, trees also grow in moderately dry soil when the VPD is low. Species-specific differences in diel growth dynamics show that species able to grow earlier during the night are associated with the highest number of hours with growth per year and the largest annual growth increment. We conclude that species with the ability to overcome daily water deficits faster have greater growth potential. Furthermore, we conclude that growth is more sensitive than carbon uptake to dry air, as growth stops before stomata are known to close. |
BibTeX:
@article{Zweifel2021,
author = {Zweifel, Roman and Sterck, Frank and Braun, Sabine and Buchmann, Nina and Eugster, Werner and Gessler, Arthur and Häni, Matthias and Peters, Richard L and Walthert, Lorenz and Wilhelm, Micah and Ziemiʼnska, Kasia and Etzold, Sophia},
title = {Why trees grow at night},
journal = {New Phytologist},
publisher = {John Wiley & Sons, Ltd},
year = {2021},
volume = {231},
number = {6},
pages = {2174--2185},
url = {https://doi.org/10.1111/nph.17552},
doi = {10.1111/nph.17552}
}
|
| Zweifel R, Etzold S, Basler D, Bischoff R, Braun S, Buchmann N, Conedera M, Fonti P, Gessler A, Haeni M, Hoch G, Kahmen A, Köchli R, Maeder M, Nievergelt D, Peter M, Peters RL, Schaub M, Trotsiuk V, Walthert L, Wilhelm M and Eugster W (2021), "TreeNet–The Biological Drought and Growth Indicator Network", Frontiers in Forests and Global Change. Vol. 4 |
| Abstract: The TreeNet research and monitoring network has been continuously collecting data from point dendrometers and air and soil microclimate using an automated system since 2011. The goal of TreeNet is to generate high temporal resolution datasets of tree growth and tree water dynamics for research and to provide near real-time indicators of forest growth performance and drought stress to a wide audience. This paper explains the key working steps from the installation of sensors in the field to data acquisition, data transmission, data processing, and online visualization. Moreover, we discuss the underlying premises to convert dynamic stem size changes into relevant biological information. Every 10 min, the stem radii of about 420 trees from 13 species at 61 sites in Switzerland are measured electronically with micrometer precision, in parallel with the environmental conditions above and below ground. The data are automatically transmitted, processed and stored on a central server. Automated data processing (R-based functions) includes screening of outliers, interpolation of data gaps, and extraction of radial stem growth and water deficit for each tree. These long-term data are used for scientific investigations as well as to calculate and display daily indicators of growth trends and drought levels in Switzerland based on historical and current data. The current collection of over 100 million data points forms the basis for identifying dynamics of tree-, site- and species-specific processes along environmental gradients. TreeNet is one of the few forest networks capable of tracking the diurnal and seasonal cycles of tree physiology in near real-time, covering a wide range of temperate forest species and their respective environmental conditions. |
BibTeX:
@article{Zweifel2021a,
author = {Zweifel, Roman and Etzold, Sophia and Basler, David and Bischoff, Reinhard and Braun, Sabine and Buchmann, Nina and Conedera, Marco and Fonti, Patrick and Gessler, Arthur and Haeni, Matthias and Hoch, Günter and Kahmen, Ansgar and Köchli, Roger and Maeder, Marcus and Nievergelt, Daniel and Peter, Martina and Peters, Richard L and Schaub, Marcus and Trotsiuk, Volodymyr and Walthert, Lorenz and Wilhelm, Micah and Eugster, Werner},
title = {TreeNet–The Biological Drought and Growth Indicator Network},
journal = {Frontiers in Forests and Global Change},
year = {2021},
volume = {4},
url = {https://www.frontiersin.org/article/10.3389/ffgc.2021.776905},
doi = {10.3389/ffgc.2021.776905}
}
|
| Alton PB (2020), "Representativeness of global climate and vegetation by carbon-monitoring networks; implications for estimates of gross and net primary productivity at biome and global levels", Agricultural and Forest Meteorology., aug, 2020. Elsevier B.V.. |
| Abstract: One of the major uncertainties in estimating global Net Primary Productivity (NPP) and Gross Primary Productivity (GPP) is the ability of carbon-monitoring sites to represent the climate and canopy-density of global vegetation (“representativeness”). These sites are used for empirical upscaling and calibration of global land-surface models. The current study determines the representativeness of two important carbon-monitoring networks – FLUXNET2015 and the Ecosystem Model-Data Intercomparison (EMDI) – by calculating the euclidian distance in climate-canopy space between each global 0.5∘ cell and all carbon-monitoring sites of the same biome or Plant Functional Type (PFT). Reliance on the single (most similar) site has been adopted in the past. A straightforward weighted upscaling, using inverse euclidian distance, identifies which PFTs contribute most to global primary productivity in the context of how well they are represented in carbon-monitoring networks. Some vegetation types, which are numerically well-represented within the network, are sampled at the ‘wrong' latitude and in more temperate climes than their global distribution. This includes non-mediterranean needleleaf forest which is one of the main vegetation types contributing to global GPP and NPP. (Semi-)arid regions (mean annual precipitation textless 400 mm yr−1) are undersampled as well as the sparse vegetation that tends to characterise them. These regions include the tundra and the northern half of the boreal forest where growth is disproportionately affected by climate change. We find a large spread in NPP and GPP recorded at sites of the same PFT (standard deviation is 56% mean). Consequently, our bootstrap error analysis indicates that a minimum of 50 climate-representative sites per PFT is required to quantify adequately (2% precision) the primary productivity of each global vegetation type. Selecting unchartered climate-canopy space for new sites appears to be more important than a simple increase in site numbers. |
BibTeX:
@article{Alton2020,
author = {Alton, Paul B.},
title = {Representativeness of global climate and vegetation by carbon-monitoring networks; implications for estimates of gross and net primary productivity at biome and global levels},
journal = {Agricultural and Forest Meteorology},
publisher = {Elsevier B.V.},
year = {2020},
doi = {10.1016/j.agrformet.2020.108017}
}
|
| de Arellano J, Ney P, Hartogensis O, de Boer H, van Diepen K, Emin D, de Groot G, Klosterhalfen A, Langensiepen M, Matveeva M, Miranda-Garc$$'$$ia G, Moene AF, Rascher U, Röckmann T, Adnew G, Brüggemann N, Rothfuss Y and Graf A (2020), "CloudRoots: integration of advanced instrumental techniques and process modelling of sub-hourly and sub-kilometre land--atmosphere interactions", Biogeosciences. Vol. 17(17), pp. 4375-4404. |
BibTeX:
@article{Arellano2020,
author = {de Arellano, J and Ney, P and Hartogensis, O and de Boer, H and van Diepen, K and Emin, D and de Groot, G and Klosterhalfen, A and Langensiepen, M and Matveeva, M and Miranda-Garc$$'$$ia, G and Moene, A F and Rascher, U and Röckmann, T and Adnew, G and Brüggemann, N and Rothfuss, Y and Graf, A},
title = {CloudRoots: integration of advanced instrumental techniques and process modelling of sub-hourly and sub-kilometre land--atmosphere interactions},
journal = {Biogeosciences},
year = {2020},
volume = {17},
number = {17},
pages = {4375--4404},
url = {https://bg.copernicus.org/articles/17/4375/2020/},
doi = {10.5194/bg-17-4375-2020}
}
|
| Arruda R, Atamanchuk D, Cronin M, Steinhoff T and Wallace DWR (2020), "At‐sea intercomparison of three underway textlessitextgreaterptextless/itextgreater CO textlesssubtextgreater2textless/subtextgreater systems", Limnology and Oceanography: Methods., feb, 2020. Vol. 18(2), pp. 63-76. Wiley Blackwell. |
| Abstract: Ocean surface partial pressure of carbon dioxide (pCO2) is a key factor controlling air–sea CO2 fluxes. Most surface pCO2 data are collected with relatively large and complex air–water equilibrators coupled to stand-alone infrared analyzers installed on Ships of OPportunity (SOOP-CO2). This approach has proven itself through years of successful deployments, but expansion and sustainability of the future measurement network faces challenges in terms of certification, autonomy, and maintenance, which motivates development of new systems. Here, we compare performance of three underway pCO2 measurement systems (General Oceanics, SubCtech, and Pro-Oceanus), including a recently developed compact flow-through, sensor-based system. The systems were intercompared over a period of 34 days during two crossings of the subpolar North Atlantic Ocean. With a mean difference from the General Oceanics system of −5.7 ± 4.0 μatm (Pro-Oceanus) and −4.7 ± 2.9 μatm (SubCtech) during the 1st crossing, our results indicate potential for good agreement between the systems. The study highlighted the challenge of assuring accuracy over long periods of time, particularly seen in a worse agreement during the 2nd crossing, and revealed a number of sources of systematic errors. These can influence accuracy of the measurements, agreement between systems and include slow response of membrane-based systems to pCO2 changes, “within-ship” respiration due to biofouling, and bias in measurement of the temperature of equilibration. These error sources can be controlled or corrected for, however, if unidentified, their magnitude can be significant relative to accuracy criteria assigned to the highest-quality data in global databases. The advantages of the compact flow-through system are presented along with a discussion of future solutions for improving data quality. |
BibTeX:
@article{Arruda2020,
author = {Arruda, Ricardo and Atamanchuk, Dariia and Cronin, Margot and Steinhoff, Tobias and Wallace, Douglas W. R.},
title = {At‐sea intercomparison of three underway textlessitextgreaterptextless/itextgreater CO textlesssubtextgreater2textless/subtextgreater systems},
journal = {Limnology and Oceanography: Methods},
publisher = {Wiley Blackwell},
year = {2020},
volume = {18},
number = {2},
pages = {63--76},
url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/lom3.10346},
doi = {10.1002/lom3.10346}
}
|
| Bachy A, Aubinet M, Amelynck C, Schoon N, Bodson B, Delaplace P, De Ligne A, Digrado A, du Jardin P, Fauconnier ML, Mozaffar A, Müller JF and Heinesch B (2020), "Dynamics and mechanisms of volatile organic compound exchanges in a winter wheat field", Atmospheric Environment. Vol. 221(November 2019), pp. 117105. Elsevier Ltd. |
| Abstract: The understanding of biogenic volatile organic compound (BVOC) exchanges has become a key scientific issue because of their high reactivity and their impact in the atmosphere. However, so far, few studies have focused on BVOCs exchanged by agricultural species, and in particular by winter wheat, despite this species being the leading worldwide crop in terms of harvested area. This study for the first time investigated BVOC exchanges from winter wheat during most developmental stages of the plant. Fluxes were measured in Belgium at the ecosystem-scale using the disjunct eddy covariance by mass scanning technique, and a proton-transfer-reaction mass spectrometer for BVOC ambient mixing ratio measurements. As is usually observed for crops and grasses, the winter wheat field emitted mainly methanol, although bi-directional exchanges were observed. The second most exchanged compound was acetic acid which was captured during the entire growing season. Bi-directional exchanges of acetaldehyde and acetone were also reported. Terpene exchanges were 22 times smaller than oxygenated VOC (OVOC) exchanges. For all compounds, the exchanges were the most pronounced at the end of the growing season, i.e., under warm, dry and sunny conditions. Senescence-induced emissions were furthermore observed for methanol and acetaldehyde. For all investigated OVOCs, the exchanges very likely originated from both the soil and the plants. Despite their mixed origin, the MEGAN (Model of Emissions of Gases and Aerosols from Nature) v2.1 up-scaling model could adequately reproduce the methanol, acetaldehyde and acetone exchanges measured at this site during the mature and senescence phases of the plant, when the standard emission factor and the leaf age factor were adapted based on the measurements. In contrast, the model failed to reproduce the measured acetic acid exchanges. When the standard emission factor values currently assigned in MEGAN were applied, however, the exchanges were largely over-estimated for all compounds. |
BibTeX:
@article{Bachy2020,
author = {Bachy, A and Aubinet, M and Amelynck, C and Schoon, N and Bodson, B and Delaplace, P and De Ligne, A and Digrado, A and du Jardin, P and Fauconnier, M L and Mozaffar, A and Müller, J F and Heinesch, B},
title = {Dynamics and mechanisms of volatile organic compound exchanges in a winter wheat field},
journal = {Atmospheric Environment},
publisher = {Elsevier Ltd},
year = {2020},
volume = {221},
number = {November 2019},
pages = {117105},
url = {https://doi.org/10.1016/j.atmosenv.2019.117105},
doi = {10.1016/j.atmosenv.2019.117105}
}
|
| Bastos A, Ciais P, Friedlingstein P, Sitch S, Pongratz J, Fan L, Wigneron JP, Weber U, Reichstein M, Fu Z, Anthoni P, Arneth A, Haverd V, Jain AK, Joetzjer E, Knauer J, Lienert S, Loughran T, McGuire PC, Tian H, Viovy N and Zaehle S (2020), "Direct and seasonal legacy effects of the 2018 heat wave and drought on European ecosystem productivity", Science Advances., jun, 2020. Vol. 6(24), pp. eaba2724. |
| Abstract: In summer 2018, central and northern Europe were stricken by extreme drought and heat (DH2018). The DH2018 differed from previous events in being preceded by extreme spring warming and brightening, but moderate rainfall deficits, yet registering the fastest transition between wet winter conditions and extreme summer drought. Using 11 vegetation models, we show that spring conditions promoted increased vegetation growth, which, in turn, contributed to fast soil moisture depletion, amplifying the summer drought. We find regional asymmetries in summer ecosystem carbon fluxes: increased (reduced) sink in the northern (southern) areas affected by drought. These asymmetries can be explained by distinct legacy effects of spring growth and of water-use efficiency dynamics mediated by vegetation composition, rather than by distinct ecosystem responses to summer heat/drought. The asymmetries in carbon and water exchanges during spring and summer 2018 suggest that future land-management strategies could influence patterns of summer heat waves and droughts under long-term warming. |
BibTeX:
@article{Bastos2020,
author = {Bastos, A and Ciais, P and Friedlingstein, P and Sitch, S and Pongratz, J and Fan, L and Wigneron, J P and Weber, U and Reichstein, M and Fu, Z and Anthoni, P and Arneth, A and Haverd, V and Jain, A K and Joetzjer, E and Knauer, J and Lienert, S and Loughran, T and McGuire, P C and Tian, H and Viovy, N and Zaehle, S},
title = {Direct and seasonal legacy effects of the 2018 heat wave and drought on European ecosystem productivity},
journal = {Science Advances},
year = {2020},
volume = {6},
number = {24},
pages = {eaba2724},
url = {https://advances.sciencemag.org/lookup/doi/10.1126/sciadv.aba2724},
doi = {10.1126/sciadv.aba2724}
}
|
| Bastos A, Fu Z, Ciais P, Friedlingstein P, Sitch S, Pongratz J, Weber U, Reichstein M, Anthoni P, Arneth A, Haverd V, Jain A, Joetzjer E, Knauer J, Lienert S, Loughran T, McGuire PC, Obermeier W, Padrón RS, Shi H, Tian H, Viovy N and Zaehle S (2020), "Impacts of extreme summers on European ecosystems: a comparative analysis of 2003, 2010 and 2018", Philosophical Transactions of the Royal Society B: Biological Sciences., oct, 2020. Vol. 375(1810), pp. 20190507. |
| Abstract: In Europe, three widespread extreme summer drought and heat (DH) events have occurred in 2003, 2010 and 2018. These events were comparable in magnitude but varied in their geographical distribution and biomes affected. In this study, we perform a comparative analysis of the impact of the DH events on ecosystem CO 2 fluxes over Europe based on an ensemble of 11 dynamic global vegetation models (DGVMs), and the observation-based FLUXCOM product. We find that all DH events were associated with decreases in net ecosystem productivity (NEP), but the gross summer flux anomalies differ between DGVMs and FLUXCOM. At the annual scale, FLUXCOM and DGVMs indicate close to neutral or above-average land CO 2 uptake in DH2003 and DH2018, due to increased productivity in spring and reduced respiration in autumn and winter compensating for less photosynthetic uptake in summer. Most DGVMs estimate lower gross primary production (GPP) sensitivity to soil moisture during extreme summers than FLUXCOM. Finally, we show that the different impacts of the DH events at continental-scale GPP are in part related to differences in vegetation composition of the regions affected and to regional compensating or offsetting effects from climate anomalies beyond the DH centres. |
BibTeX:
@article{Bastos2020a,
author = {Bastos, A. and Fu, Z. and Ciais, P. and Friedlingstein, P. and Sitch, S. and Pongratz, J. and Weber, U. and Reichstein, M. and Anthoni, P. and Arneth, A. and Haverd, V. and Jain, A. and Joetzjer, E. and Knauer, J. and Lienert, S. and Loughran, T. and McGuire, P. C. and Obermeier, W. and Padrón, R. S. and Shi, H. and Tian, H. and Viovy, N. and Zaehle, S.},
title = {Impacts of extreme summers on European ecosystems: a comparative analysis of 2003, 2010 and 2018},
journal = {Philosophical Transactions of the Royal Society B: Biological Sciences},
year = {2020},
volume = {375},
number = {1810},
pages = {20190507},
url = {https://royalsocietypublishing.org/doi/10.1098/rstb.2019.0507},
doi = {10.1098/rstb.2019.0507}
}
|
| Becker M, Olsen A, Landschützer P, Omar A, Rehder G, Rödenbeck C and Skjelvan I (2020), "The northern European shelf as increasing net sink for CO2", Biogeosciences Discussions., jan, 2020. , pp. 1-28. Copernicus GmbH. |
BibTeX:
@article{Becker2020,
author = {Becker, Meike and Olsen, Are and Landschützer, Peter and Omar, Abdirhaman and Rehder, Gregor and Rödenbeck, Christian and Skjelvan, Ingunn},
title = {The northern European shelf as increasing net sink for CO2},
journal = {Biogeosciences Discussions},
publisher = {Copernicus GmbH},
year = {2020},
pages = {1--28},
doi = {10.5194/bg-2019-480}
}
|
| Beillouin D, Schauberger B, Bastos A, Ciais P and Makowski D (2020), "Impact of extreme weather conditions on European crop production in 2018", Philosophical Transactions of the Royal Society B: Biological Sciences., oct, 2020. Vol. 375(1810), pp. 20190510. |
| Abstract: Extreme weather increases the risk of large-scale crop failure. The mechanisms involved are complex and intertwined, hence undermining the identification of simple adaptation levers to help improve the resilience of agricultural production. Based on more than 82 000 yield data reported at the regional level in 17 European countries, we assess how climate affected the yields of nine crop species. Using machine learning models, we analyzed historical yield data since 1901 and then focus on 2018, which has experienced a multiplicity and a diversity of atypical extreme climatic conditions. Machine learning models explain up to 65% of historical yield anomalies. We find that both extremes in temperature and precipitation are associated with negative yield anomalies, but with varying impacts in different parts of Europe. In 2018, Northern and Eastern Europe experienced multiple and simultaneous crop failures—among the highest observed in recent decades. These yield losses were associated with extremely low rainfalls in combination with high temperatures between March and August 2018. However, the higher than usual yields recorded in Southern Europe—caused by favourable spring rainfall conditions—nearly offset the large decrease in Northern European crop production. Our results outline the importance of considering single and compound climate extremes to analyse the causes of yield losses in Europe. We found no clear upward or downward trend in the frequency of extreme yield losses for any of the considered crops between 1990 and 2018. |
BibTeX:
@article{Beillouin2020,
author = {Beillouin, Damien and Schauberger, Bernhard and Bastos, Ana and Ciais, Phillipe and Makowski, David},
title = {Impact of extreme weather conditions on European crop production in 2018},
journal = {Philosophical Transactions of the Royal Society B: Biological Sciences},
year = {2020},
volume = {375},
number = {1810},
pages = {20190510},
url = {https://royalsocietypublishing.org/doi/10.1098/rstb.2019.0510},
doi = {10.1098/rstb.2019.0510}
}
|
| Bergström AK, Jonsson A, Isles PDF, Creed IF and Lau DCP (2020), "Changes in nutritional quality and nutrient limitation regimes of phytoplankton in response to declining N deposition in mountain lakes", Aquatic Sciences. Vol. 82(2), pp. 1-16. Springer International Publishing. |
| Abstract: Phytoplankton play a key role in supporting aquatic food webs. However, the effects of ongoing large-scale changes in the concentrations and stoichiometry of important biological compounds [dissolved inorganic N (DIN), total phosphorus (TP), dissolved organic carbon (DOC) and DIN:TP] on the development and nutritional quality of phytoplankton for higher trophic levels are unclear. We conducted lake studies and in situ bioassay experiments in two Swedish mountain regions [Abisko (north) and Jämtland (south)] with different N deposition and where lakes in each region were distributed along a similar gradient in lake DOC (2–7 mg L−1) to assess whether differences in nutrients, DOC and DIN:TP induced differences in phytoplankton quantity [chlorophyll a (Chl-a) and seston carbon (C)] and quality [seston C:N:P stoichiometry and fatty acid (FA) composition]. Using long-term monitoring data from lakes in these two mountain regions, we found declining long-term trends in N deposition and lake DIN and total TP concentrations, but not in lake DIN:TP. Lakes in Abisko received lower N deposition and had lower DIN:TP than those in Jämtland. Phytoplankton was N- to NP-limited in Abisko lakes but NP dual-limited in Jämtland lakes. The N fertilization effects induced by higher DIN:TP were weak on phytoplankton quantity but strong on phytoplankton quality. The phytoplankton had lower eicosapentaenoic acid (EPA) content and higher P content (lower seston C:P) in Abisko compared to in Jämtland. In addition, the quality of the DOC (as indicated by its aromaticity and SUVA) influenced not only the light conditions and the seston C:P ratios, but also the FA composition. We found higher bacteria FA concentrations in seston in Abisko than in Jämtland, despite lower amounts of FA of terrestrial origin in Abisko. Our findings suggest that declining N deposition and enhanced colored terrestrial C loadings leads to lower nutritional quality of basal resources for higher consumers in mountain lakes. |
BibTeX:
@article{Bergstroem2020,
author = {Bergström, Ann Kristin and Jonsson, Anders and Isles, Peter D F and Creed, Irena F and Lau, Danny C P},
title = {Changes in nutritional quality and nutrient limitation regimes of phytoplankton in response to declining N deposition in mountain lakes},
journal = {Aquatic Sciences},
publisher = {Springer International Publishing},
year = {2020},
volume = {82},
number = {2},
pages = {1--16},
url = {https://doi.org/10.1007/s00027-020-0697-1},
doi = {10.1007/s00027-020-0697-1}
}
|
| Bolduc B, Hodgkins SB, Varner RK, Crill PM, McCalley CK, Chanton JP, Tyson GW, Riley WJ, Palace M, Duhaime MB, Hough MA, Saleska SR, Sullivan MB and Rich VI (2020), "The IsoGenie database: An interdisciplinary data management solution for ecosystems biology and environmental research", PeerJ. Vol. 8(ii), pp. 1-30. |
| Abstract: Modern microbial and ecosystem sciences require diverse interdisciplinary teams that are often challenged in “speaking” to one another due to different languages and data product types. Here we introduce the IsoGenie Database (IsoGenieDB; https://isogenie-db.asc.Ohio-state.edu/), a de novo developed data management and exploration platform, as a solution to this challenge of accurately representing and integrating heterogenous environmental and microbial data across ecosystem scales. The IsoGenieDB is a public and private data infrastructure designed to store and query data generated by the IsoGenie Project, a ˜10 year DOE-funded project focused on discovering ecosystem climate feedbacks in a thawing permafrost landscape. The IsoGenieDB provides (i) a platform for IsoGenie Project members to explore the project's interdisciplinary datasets across scales through the inherent relationships among data entities, (ii) a framework to consolidate and harmonize the datasets needed by the team's modelers, and (iii) a public venue that leverages the same spatially explicit, disciplinarily integrated data structure to share published datasets. The IsoGenieDB is also being expanded to cover the NASA-funded Archaea to Atmosphere (A2A) project, which scales the findings of IsoGenie to a broader suite of Arctic peatlands, via the umbrella A2A Database (A2A-DB). The IsoGenieDB's expandability and flexible architecture allow it to serve as an example ecosystems database. |
BibTeX:
@article{Bolduc2020,
author = {Bolduc, Benjamin and Hodgkins, Suzanne B and Varner, Ruth K and Crill, Patrick M and McCalley, Carmody K and Chanton, Jeffrey P and Tyson, Gene W and Riley, William J and Palace, Michael and Duhaime, Melissa B and Hough, Moira A and Saleska, Scott R and Sullivan, Matthew B and Rich, Virginia I},
title = {The IsoGenie database: An interdisciplinary data management solution for ecosystems biology and environmental research},
journal = {PeerJ},
year = {2020},
volume = {8},
number = {ii},
pages = {1--30},
doi = {10.7717/peerj.9467}
}
|
| Botter M, Zeeman M, Burlando P and Fatichi S (2020), "Impacts of fertilization on grassland productivity and water quality across the European Alps: insights from a mechanistic model", Biogeosciences Discussions. Vol. 2020, pp. 1-35. |
BibTeX:
@article{Botter2020,
author = {Botter, M and Zeeman, M and Burlando, P and Fatichi, S},
title = {Impacts of fertilization on grassland productivity and water quality across the European Alps: insights from a mechanistic model},
journal = {Biogeosciences Discussions},
year = {2020},
volume = {2020},
pages = {1--35},
url = {https://bg.copernicus.org/preprints/bg-2020-294/},
doi = {10.5194/bg-2020-294}
}
|
| Bowring SPK, Lauerwald R, Guenet B, Zhu D, Guimberteau M, Regnier P, Tootchi A, Ducharne A and Ciais P (2020), "ORCHIDEE MICT-LEAK (r5459), a global model for the production, transport, and transformation of dissolved organic carbon from Arctic permafrost regions - Part 2: Model evaluation over the Lena River basin", Geoscientific Model Development., feb, 2020. Vol. 13(2), pp. 507-520. Copernicus GmbH. |
| Abstract: In this second part of a two-part study, we performed a simulation of the carbon and water budget of the Lena catchment with the land surface model ORCHIDEE MICT-LEAK, enabled to simulate dissolved organic carbon (DOC) production in soils and its transport and fate in high-latitude inland waters. The model results are evaluated for their ability to reproduce the fluxes of DOC and carbon dioxide (CO2) along the soil-inland-water continuum and the exchange of CO2 with the atmosphere, including the evasion outgassing of CO2 from inland waters. We present simulation results over the years 1901-2007 and show that the model is able to broadly reproduce observed state variables and their emergent properties across a range of interacting physical and biogeochemical processes. These include (1) net primary production (NPP), respiration and riverine hydrologic amplitude, seasonality, and inter-annual variation; (2) DOC concentrations, bulk annual flow, and their volumetric attribution at the sub-catchment level; (3) high headwater versus downstream CO2 evasion, an emergent phenomenon consistent with observations over a spectrum of high-latitude observational studies. These quantities obey emergent relationships with environmental variables like air temperature and topographic slope that have been described in the literature. This gives us confidence in reporting the following additional findings: of the Ä'1/434TgCyr-1 left over as input to soil matter after NPP is diminished by heterotrophic respiration, 7TgCyr-1 is leached and transported into the aquatic system. Of this, over half (3.6TgCyr-1) is evaded from the inland water surface back into the atmosphere and the remainder (3.4TgCyr-1) flushed out into the Arctic Ocean, mirroring empirically derived studies. These riverine DOC exports represent Ä'1/41.5% of NPP. DOC exported from the floodplains is dominantly sourced from recent more "labile" terrestrial production in contrast to DOC leached from the rest of the watershed with runoff and drainage, which is mostly sourced from recalcitrant soil and litter. All else equal, both historical climate change (a spring-summer warming of 1.8Ä' C over the catchment) and rising atmospheric CO2 (+85.6ppm) are diagnosed from factorial simulations to contribute similar significant increases in DOC transport via primary production, although this similarity may not hold in the future. |
BibTeX:
@article{Bowring2020,
author = {Bowring, Simon P K and Lauerwald, Ronny and Guenet, Bertrand and Zhu, Dan and Guimberteau, Matthieu and Regnier, Pierre and Tootchi, Ardalan and Ducharne, Agnes and Ciais, Philippe},
title = {ORCHIDEE MICT-LEAK (r5459), a global model for the production, transport, and transformation of dissolved organic carbon from Arctic permafrost regions - Part 2: Model evaluation over the Lena River basin},
journal = {Geoscientific Model Development},
publisher = {Copernicus GmbH},
year = {2020},
volume = {13},
number = {2},
pages = {507--520},
doi = {10.5194/gmd-13-507-2020}
}
|
| Bridgman MJ, Lomax BH and Sjögersten S (2020), "Impacts of Elevated Atmospheric CO2 and Plant Species Composition on Methane Emissions from Subarctic Wetlands", Wetlands. Vol. 40(3), pp. 609-618. Wetlands. |
| Abstract: Elevated atmospheric CO2 may create greater methane (CH4) emissions from subarctic wetlands. To date such ecosystem feedbacks remain poorly understood, particularly in relation to how different wetland plant species will control such feedbacks. In this study we exposed plant-peat mesocosms planted with four Cyperaceae species to 400 and 800 ppm atmospheric CO2 concentrations and measured plant and peat properties as well as CH4 fluxes. Above ground biomass for plants grown at 800 ppm CO2 increased for E. angustifolium, Eriophorum vaginatum and Carex brunnescens, but the total biomass of C. acuta decreased relative to the ambient CO2 treatment. The plant species and elevated CO2 treatment affected both peat redox potential and pore water chemistry. There was no overall effect of the elevated CO2 on CH4 emissions, however, CH4 emissions were related to above ground biomass and redox potential, both of which were significantly altered by elevated CO2. Our study shows that species composition poses an important control on how wetland communities will respond to elevated CO2 and that plant mediated changes of peat biogeochemical processes, in response to elevated CO2 levels, may affect CH4 emissions from sub-arctic wetlands, but any such responses will differ among species. |
BibTeX:
@article{Bridgman2020,
author = {Bridgman, Matthew J and Lomax, Barry H and Sjögersten, Sofie},
title = {Impacts of Elevated Atmospheric CO2 and Plant Species Composition on Methane Emissions from Subarctic Wetlands},
journal = {Wetlands},
publisher = {Wetlands},
year = {2020},
volume = {40},
number = {3},
pages = {609--618},
doi = {10.1007/s13157-019-01203-5}
}
|
| Brogi C, Huisman JA, Herbst M, Weihermüller L, Klosterhalfen A, Montzka C, Reichenau TG and Vereecken H (2020), "Simulation of spatial variability in crop leaf area index and yield using agroecosystem modeling and geophysics-based quantitative soil information", Vadose Zone Journal. Vol. 19(1), pp. 1-24. |
| Abstract: Agroecosystem models that simulate crop growth as a function of weather conditions and soil characteristics are among the most promising tools for improving crop yield and achieving more sustainable agricultural production systems. This study aims at using spatially distributed crop growth simulations to investigate how field-scale patterns in soil properties obtained using geophysical mapping affect the spatial variability of soil water content dynamics and growth of crops at the square kilometer scale. For this, a geophysics-based soil map was intersected with land use information. Soil hydraulic parameters were calculated using pedotransfer functions. Simulations of soil water content dynamics performed with the agroecosystem model AgroC were compared with soil water content measured at two locations, resulting in RMSE of 0.032 and of 0.056 cm3 cm−3, respectively. The AgroC model was then used to simulate the growth of sugar beet (Beta vulgaris L.), silage maize (Zea mays L.), potato (Solanum tuberosum L.), winter wheat (Triticum aestivum L.), winter barley (Hordeum vulgare L.), and winter rapeseed (Brassica napus L.) in the 1- by 1-km study area. It was found that the simulated leaf area index (LAI) was affected by the magnitude of simulated water stress, which was a function of both the crop type and soil characteristics. Simulated LAI was generally consistent with the observed LAI calculated from normalized difference vegetation index (LAINDVI) obtained from RapidEye satellite data. Finally, maps of simulated agricultural yield were produced for four crops, and it was found that simulated yield matched well with actual harvest data and literature values. Therefore, it was concluded that the information obtained from geophysics-based soil mapping was valuable for practical agricultural applications. |
BibTeX:
@article{Brogi2020,
author = {Brogi, C and Huisman, J A and Herbst, M and Weihermüller, L and Klosterhalfen, A and Montzka, C and Reichenau, T G and Vereecken, H},
title = {Simulation of spatial variability in crop leaf area index and yield using agroecosystem modeling and geophysics-based quantitative soil information},
journal = {Vadose Zone Journal},
year = {2020},
volume = {19},
number = {1},
pages = {1--24},
doi = {10.1002/vzj2.20009}
}
|
| Broullón D, Pérez FF, Velo A, Hoppema M, Olsen A, Takahashi T, Key RM, Tanhua T, Santana-Casiano JM and Kozyr A (2020), "A global monthly climatology of oceanic total dissolved inorganic carbon: a neural network approach", Earth System Science Data., aug, 2020. Vol. 12(3), pp. 1725-1743. Copernicus GmbH. |
| Abstract: textlessptextgreatertextless![CDATA[Abstract. Anthropogenic emissions of CO2 to the atmosphere have modified the carbon cycle for more than 2 centuries. As the ocean stores most of the carbon on our planet, there is an important task in unraveling the natural and anthropogenic processes that drive the carbon cycle at different spatial and temporal scales. We contribute to this by designing a global monthly climatology of total dissolved inorganic carbon (TCO2), which offers a robust basis in carbon cycle modeling but also for other studies related to this cycle. A feedforward neural network (dubbed NNGv2LDEO) was configured to extract from the Global Ocean Data Analysis Project version 2.2019 (GLODAPv2.2019) and the Lamont–Doherty Earth Observatory (LDEO) datasets the relations between TCO2 and a set of variables related to the former's variability. The global root mean square error (RMSE) of mapping TCO2 is relatively low for the two datasets (GLODAPv2.2019: 7.2 µmol kg−1; LDEO: 11.4 µmol kg−1) and also for independent data, suggesting that the network does not overfit possible errors in data. The ability of NNGv2LDEO to capture the monthly variability of TCO2 was testified through the good reproduction of the seasonal cycle in 10 time series stations spread over different regions of the ocean (RMSE: 3.6 to 13.2 µmol kg−1). The climatology was obtained by passing through NNGv2LDEO the monthly climatological fields of temperature, salinity, and oxygen from the World Ocean Atlas 2013 and phosphate, nitrate, and silicate computed from a neural network fed with the previous fields. The resolution is 1∘×1∘ in the horizontal, 102 depth levels (0–5500 m), and monthly (0–1500 m) to annual (1550–5500 m) temporal resolution, and it is centered around the year 1995. The uncertainty of the climatology is low when compared with climatological values derived from measured TCO2 in the largest time series stations. Furthermore, a computed climatology of partial pressure of CO2 (pCO2) from a previous climatology of total alkalinity and the present one of TCO2 supports the robustness of this product through the good correlation with a widely used pCO2 climatology (Landschützer et al., 2017). Our TCO2 climatology is distributed through the data repository of the Spanish National Research Council (CSIC; https://doi.org/10.20350/digitalCSIC/10551, Broullón et al., 2020).]]textgreatertextless/ptextgreater |
BibTeX:
@article{Broullon2020,
author = {Broullón, Daniel and Pérez, Fiz F. and Velo, Antón and Hoppema, Mario and Olsen, Are and Takahashi, Taro and Key, Robert M. and Tanhua, Toste and Santana-Casiano, J. Magdalena and Kozyr, Alex},
title = {A global monthly climatology of oceanic total dissolved inorganic carbon: a neural network approach},
journal = {Earth System Science Data},
publisher = {Copernicus GmbH},
year = {2020},
volume = {12},
number = {3},
pages = {1725--1743},
url = {https://essd.copernicus.org/articles/12/1725/2020/},
doi = {10.5194/essd-12-1725-2020}
}
|
| Byrne B, Liu J, Lee M, Baker I, Bowman KW, Deutscher NM, Feist DG, Griffith DWT, Iraci LT, Kiel M, Kimball JS, Miller CE, Morino I, Parazoo NC, Petri C, Roehl CM, Sha MK, Strong K, Velazco VA, Wennberg PO and Wunch D (2020), " Improved Constraints on Northern Extratropical CO 2 Fluxes Obtained by Combining Surface‐Based and Space‐Based Atmospheric CO 2 Measurements ", Journal of Geophysical Research: Atmospheres., aug, 2020. Vol. 125(15) American Geophysical Union (AGU). |
BibTeX:
@article{Byrne2020,
author = {Byrne, B. and Liu, J. and Lee, M. and Baker, I. and Bowman, K. W. and Deutscher, N. M. and Feist, D. G. and Griffith, D. W. T. and Iraci, L. T. and Kiel, M. and Kimball, J. S. and Miller, C. E. and Morino, I. and Parazoo, N. C. and Petri, C. and Roehl, C. M. and Sha, M. K. and Strong, K. and Velazco, V. A. and Wennberg, P. O. and Wunch, D.},
title = { Improved Constraints on Northern Extratropical CO 2 Fluxes Obtained by Combining Surface‐Based and Space‐Based Atmospheric CO 2 Measurements },
journal = {Journal of Geophysical Research: Atmospheres},
publisher = {American Geophysical Union (AGU)},
year = {2020},
volume = {125},
number = {15},
doi = {10.1029/2019jd032029}
}
|
| Cai J, Xu K, Zhu Y, Hu F and Li L (2020), "Prediction and analysis of net ecosystem carbon exchange based on gradient boosting regression and random forest", Applied Energy., mar, 2020. Vol. 262 Elsevier Ltd. |
| Abstract: Carbon balance is essential to keep ecosystems sustainable and healthy. Net ecosystem carbon exchange (NEE), which is affected by a bunch of meteorological variables to different extent, helps to gauge the balance of the carbon cycle between biological organisms and atmosphere. In this study, the NEE data is collected from two flux measuring sites. Gradient boosting regression algorithm is employed to predict NEE based on the meteorology and flux data from site UK-Gri. During the training process, KFold cross-validation algorithm is implemented to avoid overfitting, and random forest algorithm is implemented to identify the important variables influencing NEE mostly. The four most important variables are found to be global radiation, photosynthetic active radiation, minimum soil temperature, and latent heat. The regression model was compared with three state-of-the-art prediction models: support vector machine, stochastic gradient descent, and bayesian ridge to verify its performance. The experimental results show that this regression model outperforms the other three models, and gives higher value of R-squared, lower values of mean absolute error and root mean squared error. To verify the regression model's generalization ability, the data from the second flux site, NL-Loo, was employed, and the hybrid data of the two sites was used. The results show that this model performs well on the hybrid data, too. In practical terms, the gradient boosting regression model provides many tunable hypterparameters and loss functions, which make it more flexible and accurate compared to the other three models. This study has conclusively demonstrated for the first time that the combination of gradient boosting regression and random forest models should be considered as valuable tools to make effective prediction for NEE and acquire reliable important variables influencing NEE mostly. The methodologies could be useful in the research fields of ecosystem stability evaluation, environmental restoration, trend analysis of climate change, and global warming monitoring. |
BibTeX:
@article{Cai2020,
author = {Cai, Jianchao and Xu, Kai and Zhu, Yanhui and Hu, Fang and Li, Liuhuan},
title = {Prediction and analysis of net ecosystem carbon exchange based on gradient boosting regression and random forest},
journal = {Applied Energy},
publisher = {Elsevier Ltd},
year = {2020},
volume = {262},
doi = {10.1016/j.apenergy.2020.114566}
}
|
| Calders K, Adams J, Armston J, Bartholomeus H, Bauwens S, Bentley LP, Chave J, Danson FM, Demol M, Disney M, Gaulton R, Krishna Moorthy SM, Levick SR, Saarinen N, Schaaf C, Stovall A, Terryn L, Wilkes P and Verbeeck H (2020), "Terrestrial laser scanning in forest ecology: Expanding the horizon", Remote Sensing of Environment., dec, 2020. Vol. 251, pp. 112102. |
BibTeX:
@article{Calders2020,
author = {Calders, Kim and Adams, Jennifer and Armston, John and Bartholomeus, Harm and Bauwens, Sebastien and Bentley, Lisa Patrick and Chave, Jerome and Danson, F. Mark and Demol, Miro and Disney, Mathias and Gaulton, Rachel and Krishna Moorthy, Sruthi M. and Levick, Shaun R. and Saarinen, Ninni and Schaaf, Crystal and Stovall, Atticus and Terryn, Louise and Wilkes, Phil and Verbeeck, Hans},
title = {Terrestrial laser scanning in forest ecology: Expanding the horizon},
journal = {Remote Sensing of Environment},
year = {2020},
volume = {251},
pages = {112102},
url = {https://linkinghub.elsevier.com/retrieve/pii/S0034425720304752},
doi = {10.1016/j.rse.2020.112102}
}
|
| Cao Z, Yang W, Zhao Y, Guo X, Yin Z, Du C, Zhao H and Dai M (2020), "Diagnosis of CO2 dynamics and fluxes in global coastal oceans", National Science Review., apr, 2020. Vol. 7(4), pp. 786-797. Oxford University Press (OUP). |
| Abstract: Global coastal oceans as a whole represent an important carbon sink but, due to high spatial–temporal variability, a mechanistic conceptualization of the coastal carbon cycle is still under development, hindering the modelling and inclusion of coastal carbon in Earth System Models. Although temperature is considered an important control of sea surface pCO2, we show that the latitudinal distribution of global coastal surface pCO2 does not match that of temperature, and its inter-seasonal changes are substantially regulated by non-thermal factors such as water mass mixing and net primary production. These processes operate in both ocean-dominated and river-dominated margins, with carbon and nutrients sourced from the open ocean and land, respectively. These can be conceptualized by a semi-analytical framework that assesses the consumption of dissolved inorganic carbon relative to nutrients, to determine how a coastal system is a CO2 source or sink. The framework also finds utility in accounting for additional nutrients in organic forms and testing hypotheses such as using Redfield stoichiometry, and is therefore an essential step toward comprehensively understanding and modelling the role of the coastal ocean in the global carbon cycle. |
BibTeX:
@article{Cao2020,
author = {Cao, Zhimian and Yang, Wei and Zhao, Yangyang and Guo, Xianghui and Yin, Zhiqiang and Du, Chuanjun and Zhao, Huade and Dai, Minhan},
title = {Diagnosis of CO2 dynamics and fluxes in global coastal oceans},
journal = {National Science Review},
publisher = {Oxford University Press (OUP)},
year = {2020},
volume = {7},
number = {4},
pages = {786--797},
url = {https://academic.oup.com/nsr/article/7/4/786/5542784},
doi = {10.1093/nsr/nwz105}
}
|
| Carrière SD, Martin-StPaul NK, Cakpo CB, Patris N, Gillon M, Chalikakis K, Doussan C, Olioso A, Babic M, Jouineau A, Simioni G and Davi H (2020), "The role of deep vadose zone water in tree transpiration during drought periods in karst settings – Insights from isotopic tracing and leaf water potential", Science of the Total Environment., jan, 2020. Vol. 699, pp. 134332. Elsevier BV. |
| Abstract: Karst environments are unusual because their dry, stony and shallow soils seem to be unfavorable to vegetation, and yet they are often covered with forests. How can trees survive in these environments? Where do they find the water that allows them to survive? This study uses midday and predawn water potentials and xylem water isotopes of branches to assess tree water status and the origin of transpired water. Monitoring was conducted during the summers of 2014 and 2015 in two dissimilar plots of Mediterranean forest located in karst environments. The results show that the three monitored tree species (Abies alba Mill, Fagus sylvatica L, and Quercus ilex L.) use deep water resources present in the karst vadose zone (unsaturated zone) more intensively during drier years. Quercus ilex, a species well- adapted to water stress, which grows at the drier site, uses the deep water resource very early in the summer season. Conversely, the two other species exploit the deep water resource only during severe drought. These results open up new perspectives to a better understanding of ecohydrological equilibrium and to improved water balance modeling in karst forest settings. |
BibTeX:
@article{Carriere2020,
author = {Carrière, Simon Damien and Martin-StPaul, Nicolas K and Cakpo, Coffi Belmys and Patris, Nicolas and Gillon, Marina and Chalikakis, Konstantinos and Doussan, Claude and Olioso, Albert and Babic, Milanka and Jouineau, Arnaud and Simioni, Guillaume and Davi, Hendrik},
title = {The role of deep vadose zone water in tree transpiration during drought periods in karst settings – Insights from isotopic tracing and leaf water potential},
journal = {Science of the Total Environment},
publisher = {Elsevier BV},
year = {2020},
volume = {699},
pages = {134332},
doi = {10.1016/j.scitotenv.2019.134332}
}
|
| Carrière SD, Ruffault J, Pimont F, Doussan C, Simioni G, Chalikakis K, Limousin JM, Scotti I, Courdier F, Cakpo CB, Davi H and Martin-StPaul NK (2020), "Impact of local soil and subsoil conditions on inter-individual variations in tree responses to drought: insights from Electrical Resistivity Tomography", Science of the Total Environment., jan, 2020. Vol. 698, pp. 134247. Elsevier BV. |
| Abstract: • Inter-individual variability of tree drought responses within a stand has received little attention. Here we explore whether the spatial variations in soil/subsoil properties assessed through Electrical Resistivity Tomography (ERT) could explain variations in drought response traits among trees. • We used ERT to compute the percent variation in resistivity (PVR) between dry and wet conditions as an indicator of spatial variability in total available water content. PVR was computed in two different depth ranges (0–2 and 2–5 m) for eleven Quercus ilex stools in a Mediterranean forest stand. PVR values were compared to biological traits, including tree water status (predawn water potential (Ψ)), leaf traits (δ13C, leaf mass area (LMA)), and canopy defoliation measured after intense drought. • We found significant correlations between PVR and biological variables. For Ψ, the nature and strength of the correlations vary according to the level of drought intensity. The correlation between Ψ and PVR was positive during well-watered conditions in the upper layer (0–2 m) and during water-limited conditions in the deeper layer (2–5 m). During most severe droughts, however, the Ψ was negatively correlated with PVR in the upper layer. Trees with lower PVR in the upper layer were also associated with water use efficiency (higher δ13C), higher LMA, and a lower level of defoliation after extreme drought. • Overall, our results indicate that local differences in soil/subsoil properties affect tree response to drought and suggest that less favorable soil/subsoil conditions (lower PVR) can lead to lower water stress during the driest period and to lower defoliation after extreme drought. Plausible explanations for this better acclimation include higher stomatal regulation and improved deep soil and subsoil water exploration by trees located in more adverse conditions. We encourage the development of ERT in ecological studies to further explore the interrelated relationships between soil/subsoil, climate, and tree functioning. |
BibTeX:
@article{Carriere2020a,
author = {Carrière, S D and Ruffault, J and Pimont, F and Doussan, C and Simioni, G and Chalikakis, K and Limousin, J M and Scotti, I and Courdier, F and Cakpo, C B and Davi, H and Martin-StPaul, N K},
title = {Impact of local soil and subsoil conditions on inter-individual variations in tree responses to drought: insights from Electrical Resistivity Tomography},
journal = {Science of the Total Environment},
publisher = {Elsevier BV},
year = {2020},
volume = {698},
pages = {134247},
doi = {10.1016/j.scitotenv.2019.134247}
}
|
| Carroll D, Menemenlis D, Adkins JF, Bowman KW, Brix H, Dutkiewicz S, Fenty I, Gierach MM, Hill C, Jahn O, Landschützer P, Lauderdale JM, Liu J, Manizza M, Naviaux JD, Rödenbeck C, Schimel DS, Van der Stocken T and Zhang H (2020), " The ECCO‐Darwin Data‐assimilative Global Ocean Biogeochemistry Model: Estimates of Seasonal to Multi‐decadal Surface Ocean pCO 2 and Air‐sea CO 2 Flux ", Journal of Advances in Modeling Earth Systems., jul, 2020. American Geophysical Union (AGU). |
BibTeX:
@article{Carroll2020,
author = {Carroll, D. and Menemenlis, D. and Adkins, J. F. and Bowman, K. W. and Brix, H. and Dutkiewicz, S. and Fenty, I. and Gierach, M. M. and Hill, C. and Jahn, O. and Landschützer, P. and Lauderdale, J. M. and Liu, J. and Manizza, M. and Naviaux, J. D. and Rödenbeck, C. and Schimel, D. S. and Van der Stocken, T. and Zhang, H.},
title = { The ECCO‐Darwin Data‐assimilative Global Ocean Biogeochemistry Model: Estimates of Seasonal to Multi‐decadal Surface Ocean pCO 2 and Air‐sea CO 2 Flux },
journal = {Journal of Advances in Modeling Earth Systems},
publisher = {American Geophysical Union (AGU)},
year = {2020},
url = {https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2019MS001888 https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2019MS001888 https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2019MS001888},
doi = {10.1029/2019ms001888}
}
|
| Chai F, Johnson KS, Claustre H, Xing X, Wang Y, Boss E, Riser S, Fennel K, Schofield O and Sutton A (2020), "Monitoring ocean biogeochemistry with autonomous platforms", Nature Reviews Earth & Environment., jun, 2020. Vol. 1(6), pp. 315-326. Springer Science and Business Media LLC. |
| Abstract: Human activities have altered the state of the ocean, leading to warming, acidification and deoxygenation. These changes impact ocean biogeochemistry and influence ecosystem functions and ocean health. The long-term global effects of these changes are difficult to predict using current satellite sensing and traditional in situ observation techniques. Autonomous platforms equipped with biogeochemical sensors allow for the observation of marine biogeochemical processes and ecosystem dynamics, covering a wide range of spatial and temporal scales. The international Biogeochemical-Argo (BGC-Argo) project is currently building a global, multidisciplinary ocean-observing network of autonomous Argo floats equipped with an extensive range of biogeochemical sensors. Other autonomous platforms, such as gliders and surface vehicles, have also incorporated such sensors, mainly operating on regional scales and near the ocean surface. Autonomous mobile assets, along with remotely sensed data, will provide the 4D information required to improve model simulations and forecasts of ocean conditions and ecosystem health. Traditional methods for ocean observation are often inadequate for detecting large-scale biogeochemical processes. This Perspective discusses the advantages of implementing autonomous observation platforms in complementing traditional observation methods and generating global biogeochemical data sets. |
BibTeX:
@article{Chai2020,
author = {Chai, Fei and Johnson, Kenneth S. and Claustre, Hervé and Xing, Xiaogang and Wang, Yuntao and Boss, Emmanuel and Riser, Stephen and Fennel, Katja and Schofield, Oscar and Sutton, Adrienne},
title = {Monitoring ocean biogeochemistry with autonomous platforms},
journal = {Nature Reviews Earth & Environment},
publisher = {Springer Science and Business Media LLC},
year = {2020},
volume = {1},
number = {6},
pages = {315--326},
url = {https://www.nature.com/articles/s43017-020-0053-y},
doi = {10.1038/s43017-020-0053-y}
}
|
| Chave J, Piponiot C, Maréchaux I, de Foresta H, Larpin D, Fischer FJ, Derroire G, Vincent G and Hérault B (2020), "Slow rate of secondary forest carbon accumulation in the Guianas compared with the rest of the Neotropics", Ecological Applications., oct, 2020. Vol. 30(1) Wiley. |
| Abstract: Secondary forests are a prominent component of tropical landscapes, and they constitute a major atmospheric carbon sink. Rates of carbon accumulation are usually inferred from chronosequence studies, but direct estimates of carbon accumulation based on long-term monitoring of stands are rarely reported. Recent compilations on secondary forest carbon accumulation in the Neotropics are heavily biased geographically as they do not include estimates from the Guiana Shield. We analysed the temporal trajectory of aboveground carbon accumulation and floristic composition at one 25-ha secondary forest site in French Guiana. The site was clear-cut in 1976, abandoned thereafter, and one large plot (6.25 ha) has been monitored continuously since. We used Bayesian modeling to assimilate inventory data and simulate the long-term carbon accumulation trajectory. Canopy change was monitored using two aerial lidar surveys conducted in 2009 and 2017. We compared the dynamics of this site with that of a surrounding old-growth forest. Finally, we compared our results with that from secondary forests in Costa Rica, which is one of the rare long-term monitoring programs reaching a duration comparable to our study. Twenty years after abandonment, aboveground carbon stock was 64.2 (95% credibility interval 46.4, 89.0) Mg C/ha, and this stock increased to 101.3 (78.7, 128.5) Mg C/ha 20 yr later. The time to accumulate one-half of the mean aboveground carbon stored in the nearby old-growth forest (185.6 [155.9, 200.2] Mg C/ha) was estimated at 35.0 [20.9, 55.9] yr. During the first 40 yr, the contribution of the long-lived pioneer species Xylopia nitida, Goupia glabra, and Laetia procera to the aboveground carbon stock increased continuously. Secondary forest mean-canopy height measured by lidar increased by 1.14 m in 8 yr, a canopy-height increase consistent with an aboveground carbon accumulation of 7.1 Mg C/ha (or 0.89 Mg Ctextperiodcenteredhaâˆ'1textperiodcenteredyrâˆ'1) during this period. Long-term AGC accumulation rate in Costa Rica was almost twice as fast as at our site in French Guiana. This may reflect higher fertility of Central American forest communities or a better adaptation of the forest tree community to intense and frequent disturbances. This finding may have important consequences for scaling-up carbon uptake estimates to continental scales. |
BibTeX:
@article{Chave2020,
author = {Chave, Jérôme and Piponiot, Camille and Maréchaux, Isabelle and de Foresta, Hubert and Larpin, Denis and Fischer, Fabian Jörg and Derroire, Géraldine and Vincent, Grégoire and Hérault, Bruno},
title = {Slow rate of secondary forest carbon accumulation in the Guianas compared with the rest of the Neotropics},
journal = {Ecological Applications},
publisher = {Wiley},
year = {2020},
volume = {30},
number = {1},
doi = {10.1002/eap.2004}
}
|
| Chen X, Maignan F, Viovy N, Bastos A, Goll D, Wu J, Liu L, Yue C, Peng S, Yuan W, da Conceição AC, O'Sullivan M and Ciais P (2020), "Novel Representation of Leaf Phenology Improves Simulation of Amazonian Evergreen Forest Photosynthesis in a Land Surface Model", Journal of Advances in Modeling Earth Systems., jan, 2020. Vol. 12(1) Blackwell Publishing Ltd. |
| Abstract: Leaf phenology in the humid tropics largely regulates the seasonality of forest carbon and water exchange. However, it is inadequately represented in most global land surface models due to limited understanding of its controls. Based on intensive field studies at four Amazonian evergreen forests, we propose a novel, quantitative representation of tropical forest leaf phenology, which links multiple environmental variables with the seasonality of new leaf production and old leaf litterfall. The new phenology simulates higher rates of leaf turnover (new leaves replacing old leaves) in dry seasons with more sunlight, which is then implemented in ORCHIDEE, together with recent findings of ontogeny-associated photosynthetic capacity, and is evaluated against ground-based measurements of leaf phenology (canopy leaf area index and litterfall), eddy covariance fluxes (photosynthesis and latent heat), and carbon allocations from field observations. Results show the periodical cycles of solar radiation and vapor pressure deficit are the two most important environmental variables that are empirically related to new leaf production and old leaf abscission in tropical evergreen forests. The model with new representation of leaf phenology captures the seasonality of canopy photosynthesis at three out of four sites, as well as the seasonality of litterfall, latent heat, and light use efficiency of photosynthesis at all tested sites, and improves the seasonality of carbon allocations to leaves, roots, and sapwoods. This study advances understanding of the environmental controls on tropical leaf phenology and offers an improved modeling tool for gridded simulations of interannual CO2 and water fluxes in the tropics. |
BibTeX:
@article{Chen2020,
author = {Chen, Xiuzhi and Maignan, Fabienne and Viovy, Nicolas and Bastos, Ana and Goll, Daniel and Wu, Jin and Liu, Liyang and Yue, Chao and Peng, Shushi and Yuan, Wenping and da Conceição, Adriana Castro and O'Sullivan, Michael and Ciais, Philippe},
title = {Novel Representation of Leaf Phenology Improves Simulation of Amazonian Evergreen Forest Photosynthesis in a Land Surface Model},
journal = {Journal of Advances in Modeling Earth Systems},
publisher = {Blackwell Publishing Ltd},
year = {2020},
volume = {12},
number = {1},
doi = {10.1029/2018MS001565}
}
|
| Ciais P, Wang Y, Andrew R, Bréon FM, Chevallier F, Broquet G, Nabuurs GJ, Peters G, McGrath M, Meng W, Zheng B and Tao S (2020), "Biofuel burning and human respiration bias on satellite estimates of fossil fuel CO 2 emissions", Environmental Research Letters., jul, 2020. Vol. 15(7), pp. 74036. |
BibTeX:
@article{Ciais2020,
author = {Ciais, P and Wang, Y and Andrew, R and Bréon, F M and Chevallier, F and Broquet, G and Nabuurs, G J and Peters, G and McGrath, M and Meng, W and Zheng, B and Tao, S},
title = {Biofuel burning and human respiration bias on satellite estimates of fossil fuel CO 2 emissions},
journal = {Environmental Research Letters},
year = {2020},
volume = {15},
number = {7},
pages = {74036},
url = {https://iopscience.iop.org/article/10.1088/1748-9326/ab7835},
doi = {10.1088/1748-9326/ab7835}
}
|
| Clifton OE, Fiore AM, Massman WJ, Baublitz CB, Coyle M, Emberson L, Fares S, Farmer DK, Gentine P, Gerosa G, Guenther AB, Helmig D, Lombardozzi DL, Munger JW, Patton EG, Pusede SE, Schwede DB, Silva SJ, Sörgel M, Steiner AL and Tai APK (2020), "Dry Deposition of Ozone Over Land: Processes, Measurement, and Modeling", Reviews of Geophysics., mar, 2020. Vol. 58(1) American Geophysical Union (AGU). |
BibTeX:
@article{Clifton2020,
author = {Clifton, Olivia E and Fiore, Arlene M and Massman, William J and Baublitz, Colleen B and Coyle, Mhairi and Emberson, Lisa and Fares, Silvano and Farmer, Delphine K and Gentine, Pierre and Gerosa, Giacomo and Guenther, Alex B and Helmig, Detlev and Lombardozzi, Danica L and Munger, J William and Patton, Edward G and Pusede, Sally E and Schwede, Donna B and Silva, Sam J and Sörgel, Matthias and Steiner, Allison L and Tai, Amos P K},
title = {Dry Deposition of Ozone Over Land: Processes, Measurement, and Modeling},
journal = {Reviews of Geophysics},
publisher = {American Geophysical Union (AGU)},
year = {2020},
volume = {58},
number = {1},
url = {http://dx.doi.org/10.1029/2019RG000670},
doi = {10.1029/2019rg000670}
}
|
| Collalti A, Ibrom A, Stockmarr A, Cescatti A, Alkama R, Fernández-Martínez M, Matteucci G, Sitch S, Friedlingstein P, Ciais P, Goll DS, Nabel JEMS, Pongratz J, Arneth A, Haverd V and Prentice IC (2020), "Forest production efficiency increases with growth temperature", Nature Communications. Vol. 11(1) Springer US. |
| Abstract: Forest production efficiency (FPE) metric describes how efficiently the assimilated carbon is partitioned into plants organs (biomass production, BP) or—more generally—for the production of organic matter (net primary production, NPP). We present a global analysis of the relationship of FPE to stand-age and climate, based on a large compilation of data on gross primary production and either BP or NPP. FPE is important for both forest production and atmospheric carbon dioxide uptake. We find that FPE increases with absolute latitude, precipitation and (all else equal) with temperature. Earlier findings—FPE declining with age—are also supported by this analysis. However, the temperature effect is opposite to what would be expected based on the short-term physiological response of respiration rates to temperature, implying a top-down regulation of carbon loss, perhaps reflecting the higher carbon costs of nutrient acquisition in colder climates. Current ecosystem models do not reproduce this phenomenon. They consistently predict lower FPE in warmer climates, and are therefore likely to overestimate carbon losses in a warming climate. |
BibTeX:
@article{Collalti2020,
author = {Collalti, A and Ibrom, A and Stockmarr, A and Cescatti, A and Alkama, R and Fernández-Martínez, M and Matteucci, G and Sitch, S and Friedlingstein, P and Ciais, P and Goll, D S and Nabel, J E M S and Pongratz, J and Arneth, A and Haverd, V and Prentice, I C},
title = {Forest production efficiency increases with growth temperature},
journal = {Nature Communications},
publisher = {Springer US},
year = {2020},
volume = {11},
number = {1},
url = {http://dx.doi.org/10.1038/s41467-020-19187-w},
doi = {10.1038/s41467-020-19187-w}
}
|
| Cristofanelli P, Arduini J, Calzolari F, Giostra U, Bonasoni P and Maione M (2020), "First Evidences of Methyl Chloride (CH3Cl) Transport from the Northern Italy Boundary Layer during Summer 2017", Atmosphere., feb, 2020. Vol. 11(3), pp. 238. |
| Abstract: Methyl Chloride (CH3Cl) is a chlorine-containing trace gas in the atmosphere contributing significantly to stratospheric ozone depletion. While the atmospheric CH3Cl emissions are predominantly caused by natural sources on the global budget, significant uncertainties still remain for the anthropogenic CH3Cl emission strengths. In summer 2007 an intensive field campaign within the ACTRIS-2 Project was hosted at the Mt. Cimone World Meteorological Organization/Global Atmosphere Watch global station (CMN, 44.17° N, 10.68° E, 2165 m a.s.l.). High-frequency and high precision in situ measurements of atmospheric CH3Cl revealed significant high-frequency variability superimposed on the seasonally varying regional background levels. The high-frequency CH3Cl variability was characterized by an evident cycle over 24 h with maxima during the afternoon which points towards a systematic role of thermal vertical transport of air-masses from the regional boundary layer. The temporal correlation analysis with specific tracers of anthropogenic activity (traffic, industry, petrochemical industry) together with bivariate analysis as a function of local wind regime suggested that, even if the role of natural marine emissions appears as predominant, the northern Italy boundary layer could potentially represent a non-negligible source of CH3Cl during summer. Since industrial production and use of CH3Cl have not been regulated under the Montreal Protocol (MP) or its successor amendments, continuous monitoring of CH3Cl outflow from the Po Basin is important to properly assess its anthropogenic emissions. |
BibTeX:
@article{Cristofanelli2020,
author = {Cristofanelli, Paolo and Arduini, Jgor and Calzolari, Francescopiero and Giostra, Umberto and Bonasoni, Paolo and Maione, Michela},
title = {First Evidences of Methyl Chloride (CH3Cl) Transport from the Northern Italy Boundary Layer during Summer 2017},
journal = {Atmosphere},
year = {2020},
volume = {11},
number = {3},
pages = {238},
url = {https://www.mdpi.com/2073-4433/11/3/238},
doi = {10.3390/atmos11030238}
}
|
| Dañobeitia JJ, Pouliquen S, Johannessen T, Basset A, Cannat M, Pfeil BG, Fredella MI, Materia P, Gourcuff C, Magnifico G, Delory E, del Rio Fernandez J, Rodero I, Beranzoli L, Nardello I, Iudicone D, Carval T, Gonzalez Aranda JM, Petihakis G, Blandin J, Kutsch WL, Rintala J-M, Gates AR and Favali P (2020), "Toward a Comprehensive and Integrated Strategy of the European Marine Research Infrastructures for Ocean Observations", Frontiers in Marine Science., mar, 2020. Vol. 7, pp. 180. Frontiers Media S.A.. |
| Abstract: Research Infrastructures (RIs) are large-scale facilities encompassing instruments, resources, data and services used by the scientific community to conduct high-level research in their respective fields. The development and integration of marine environmental RIs as European Research Vessel Operators [ERVO] (2020) is the response of the European Commission (EC) to global marine challenges through research, technological development and innovation. These infrastructures (EMSO ERIC, Euro-Argo ERIC, ICOS-ERIC Marine, LifeWatch ERIC, and EMBRC-ERIC) include specialized vessels, fixed-point monitoring systems, Lagrangian floats, test facilities, genomics observatories, bio-sensing, and Virtual Research Environments (VREs), among others. Marine ecosystems are vital for life on Earth. Global climate change is progressing rapidly, and geo-hazards, such as earthquakes, volcanic eruptions, and tsunamis, cause large losses of human life and have massive worldwide socio-economic impacts. Enhancing our marine environmental monitoring and prediction capabilities will increase our ability to respond adequately to major challenges and efficiently. Collaboration among European marine RIs aligns with and has contributed to the OceanObs'19 Conference statement and the objectives of the UN Decade of Ocean Science for Sustainable Development (2021–2030). This collaboration actively participates and supports concrete actions to increase the quality and quantity of more integrated and sustained observations in the ocean worldwide. From an innovation perspective, the next decade will increasingly count on marine RIs to support the development of new technologies and their validation in the field, increasing market uptake and produce a shift in observing capabilities and strategies. |
BibTeX:
@article{Danobeitia2020,
author = {Dañobeitia, Juan Jose and Pouliquen, Sylvie and Johannessen, Truls and Basset, Alberto and Cannat, Mathilde and Pfeil, Benjamin Gerrit and Fredella, Maria Incoronata and Materia, Paola and Gourcuff, Claire and Magnifico, Giuseppe and Delory, Eric and del Rio Fernandez, Joaquin and Rodero, Ivan and Beranzoli, Laura and Nardello, Ilaria and Iudicone, Daniele and Carval, Thierry and Gonzalez Aranda, Juan M. and Petihakis, George and Blandin, Jerome and Kutsch, Werner Leo and Rintala, Janne-Markus and Gates, Andrew R. and Favali, Paolo},
title = {Toward a Comprehensive and Integrated Strategy of the European Marine Research Infrastructures for Ocean Observations},
journal = {Frontiers in Marine Science},
publisher = {Frontiers Media S.A.},
year = {2020},
volume = {7},
pages = {180},
url = {https://www.frontiersin.org/article/10.3389/fmars.2020.00180/full},
doi = {10.3389/fmars.2020.00180}
}
|
| De Gruyter J, Weedon JT, Bazot S, Dauwe S, Fernandez-Garberí P-R, Geisen S, De La Motte LG, Heinesch B, Janssens IA, Leblans N, Manise T, Ogaya R, Löfvenius MO, Peñuelas J, Sigurdsson BD, Vincent G and Verbruggen E (2020), "Patterns of local, intercontinental and interseasonal variation of soil bacterial and eukaryotic microbial communities", FEMS Microbiology Ecology., mar, 2020. Vol. 96(3) |
| Abstract: Although ongoing research has revealed some of the main drivers behind global spatial patterns of microbial communities, spatio-temporal dynamics of these communities still remain largely unexplored. Here, we investigate spatio-temporal variability of both bacterial and eukaryotic soil microbial communities at local and intercontinental scales. We compare how temporal variation in community composition scales with spatial variation in community composition, and explore the extent to which bacteria, protists, fungi and metazoa have similar patterns of temporal community dynamics. All soil microbial groups displayed a strong correlation between spatial distance and community dissimilarity, which was related to the ratio of organism to sample size. Temporal changes were variable, ranging from equal to local between-sample variation, to as large as that between communities several thousand kilometers apart. Moreover, significant correlations were found between bacterial and protist communities, as well as between protist and fungal communities, indicating that these microbial groups change in tandem, potentially driven by interactions between them. We conclude that temporal variation can be considerable in soil microbial communities, and that future studies need to consider temporal variation in order to reliably capture all drivers of soil microbiome changes. |
BibTeX:
@article{DeGruyter2020,
author = {De Gruyter, Johan and Weedon, James T and Bazot, Stéphane and Dauwe, Steven and Fernandez-Garberí, Pere-Roc and Geisen, Stefan and De La Motte, Louis Gourlez and Heinesch, Bernard and Janssens, Ivan A and Leblans, Niki and Manise, Tanguy and Ogaya, Romà and Löfvenius, Mikaell Ottosson and Peñuelas, Josep and Sigurdsson, Bjarni D and Vincent, Gaëlle and Verbruggen, Erik},
title = {Patterns of local, intercontinental and interseasonal variation of soil bacterial and eukaryotic microbial communities},
journal = {FEMS Microbiology Ecology},
year = {2020},
volume = {96},
number = {3},
url = {https://academic.oup.com/femsec/article/doi/10.1093/femsec/fiaa018/5719567},
doi = {10.1093/femsec/fiaa018}
}
|
| Derwent R, Parrish D, Simmonds PG, O’Doherty SJ and Spain TG (2020), "Seasonal cycles in baseline mixing ratios of a large number of trace gases at the Mace Head, Ireland atmospheric research station", Atmospheric Environment., July, 2020. Vol. 233, pp. 117531. Elsevier BV. |
BibTeX:
@article{Derwent2020,
author = {Derwent, RichardG. and Parrish, DavidD. and Simmonds, Peter G. and O’Doherty, Simon J. and Spain, T. Gerard},
title = {Seasonal cycles in baseline mixing ratios of a large number of trace gases at the Mace Head, Ireland atmospheric research station},
journal = {Atmospheric Environment},
publisher = {Elsevier BV},
year = {2020},
volume = {233},
pages = {117531},
doi = {10.1016/j.atmosenv.2020.117531}
}
|
| Dobiʼnski W (2020), "Permafrost active layer", Earth-Science Reviews. Vol. 208(May) |
| Abstract: This article discusses the properties and occurrence of an active layer (AL) in the near-surface of the lithosphere in glacial and periglacial environments. This layer shows a seasonal variability in temperature, as a result of the climate. The AL, as classically understood, seasonally thaws and freezes, while in glacial environments it usually only reaches 0 °C. The definition of AL is currently not consistent with the definition of permafrost, even though both concepts usually appear linked. For these terms to be comparable, both should be defined based on temperature variability and not exclusively on phase change. Thus, the AL would be described not only as the upper section of perennially frozen ground presenting seasonal thaw-freeze cycles (# 1) but as a layer presenting a seasonal variation in temperature (# 2). Classical active layer can be thawed to a depth of approximately 2–8 cm, the thickest AL reaches over 20 m. In the particularly favorable conditions AL might be completely absent with the permafrost beginning at the ground surface. In glacial and sub-marine permafrost environments, the AL includes a layer of liquid water that seasonally accompanies the permafrost. Glaciers and ice sheets are usually devoid of the classical AL. In both cases, the AL is usually horizontal, but in specific terrains such as sea shore cliffs or karst environments, the AL may have a vertical course and may even be reversed. Both AL and permafrost are common in other frozen bodies in the solar system, differing mainly in their thermal character. |
BibTeX:
@article{Dobinski2020,
author = {Dobiʼnski, Wojciech},
title = {Permafrost active layer},
journal = {Earth-Science Reviews},
year = {2020},
volume = {208},
number = {May},
doi = {10.1016/j.earscirev.2020.103301}
}
|
| Doney SC, Busch DS, Cooley SR and Kroeker KJ (2020), "The Impacts of Ocean Acidification on Marine Ecosystems and Reliant Human Communities", Annual Review of Environment and Resources., oct, 2020. Vol. 45(1) Annual Reviews. |
| Abstract: Rising atmospheric carbon dioxide (CO 2 ) levels, from fossil fuel combustion and deforestation, along with agriculture and land-use practices are causing wholesale increases in seawater CO 2 and inorganic carbon levels; reductions in pH; and alterations in acid-base chemistry of estuarine, coastal, and surface open-ocean waters. On the basis of laboratory experiments and field studies of naturally elevated CO 2 marine environments, widespread biological impacts of human-driven ocean acidification have been posited, ranging from changes in organism physiology and population dynamics to altered communities and ecosystems. Acidification, in conjunction with other climate change–related environmental stresses, particularly under future climate change and further elevated atmospheric CO 2 levels, potentially puts at risk many of the valuable ecosystem services that the ocean provides to society, such as fisheries, aquaculture, and shoreline protection. This review emphasizes both current scientific understanding and knowledge gaps, highlighting directions for future research and recognizing the information needs of policymakers and stakeholders. Expected final online publication date for the Annual Review of Environment and Resources, Volume 45 is October 19, 2020. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates. |
BibTeX:
@article{Doney2020,
author = {Doney, Scott C. and Busch, D. Shallin and Cooley, Sarah R. and Kroeker, Kristy J.},
title = {The Impacts of Ocean Acidification on Marine Ecosystems and Reliant Human Communities},
journal = {Annual Review of Environment and Resources},
publisher = {Annual Reviews},
year = {2020},
volume = {45},
number = {1},
doi = {10.1146/annurev-environ-012320-083019}
}
|
| Eller CB, Rowland L, Mencuccini M, Rosas T, Williams K, Harper A, Medlyn BE, Wagner Y, Klein T, Teodoro GS, Oliveira RS, Matos IS, Rosado BH, Fuchs K, Wohlfahrt G, Montagnani L, Meir P, Sitch S and Cox PM (2020), "Stomatal optimization based on xylem hydraulics (SOX) improves land surface model simulation of vegetation responses to climate", New Phytologist., jun, 2020. Vol. 226(6), pp. 1622-1637. Blackwell Publishing Ltd. |
| Abstract: Land surface models (LSMs) typically use empirical functions to represent vegetation responses to soil drought. These functions largely neglect recent advances in plant ecophysiology that link xylem hydraulic functioning with stomatal responses to climate. We developed an analytical stomatal optimization model based on xylem hydraulics (SOX) to predict plant responses to drought. Coupling SOX to the Joint UK Land Environment Simulator (JULES) LSM, we conducted a global evaluation of SOX against leaf- and ecosystem-level observations. SOX simulates leaf stomatal conductance responses to climate for woody plants more accurately and parsimoniously than the existing JULES stomatal conductance model. An ecosystem-level evaluation at 70 eddy flux sites shows that SOX decreases the sensitivity of gross primary productivity (GPP) to soil moisture, which improves the model agreement with observations and increases the predicted annual GPP by 30% in relation to JULES. SOX decreases JULES root-mean-square error in GPP by up to 45% in evergreen tropical forests, and can simulate realistic patterns of canopy water potential and soil water dynamics at the studied sites. SOX provides a parsimonious way to incorporate recent advances in plant hydraulics and optimality theory into LSMs, and an alternative to empirical stress factors. |
BibTeX:
@article{Eller2020,
author = {Eller, Cleiton B. and Rowland, Lucy and Mencuccini, Maurizio and Rosas, Teresa and Williams, Karina and Harper, Anna and Medlyn, Belinda E. and Wagner, Yael and Klein, Tamir and Teodoro, Grazielle S. and Oliveira, Rafael S. and Matos, Ilaine S. and Rosado, Bruno H.P. and Fuchs, Kathrin and Wohlfahrt, Georg and Montagnani, Leonardo and Meir, Patrick and Sitch, Stephen and Cox, Peter M.},
title = {Stomatal optimization based on xylem hydraulics (SOX) improves land surface model simulation of vegetation responses to climate},
journal = {New Phytologist},
publisher = {Blackwell Publishing Ltd},
year = {2020},
volume = {226},
number = {6},
pages = {1622--1637},
doi = {10.1111/nph.16419}
}
|
| El-Madany TS, Carrara A, Martín MP, Moreno G, Kolle O, Pacheco-Labrador J, Weber U, Wutzler T, Reichstein M and Migliavacca M (2020), "Drought and heatwave impacts on semi-arid ecosystems' carbon fluxes along a precipitation gradient", Philosophical Transactions of the Royal Society B: Biological Sciences., oct, 2020. Vol. 375(1810), pp. 20190519. |
| Abstract: The inter-annual variability (IAV) of the terrestrial carbon cycle is tightly linked to the variability of semi-arid ecosystems. Thus, it is of utmost importance to understand what the main meteorological drivers for the IAV of such ecosystems are, and how they respond to extreme events such as droughts and heatwaves. To shed light onto these questions, we analyse the IAV of carbon fluxes, its relation with meteorological variables, and the impact of compound drought and heatwave on the carbon cycle of two similar ecosystems, along a precipitation gradient. A four-year long dataset from 2016 to 2019 was used for the FLUXNET sites ES-LMa and ES-Abr, located in central (39°56'25″ N 5°46'28″ W) and southeastern (38°42'6″ N 6°47'9″ W) Spain. We analyse the physiological impact of compound drought and heatwave on the dominant tree species, Quercus ilex. Our results show that the gross primary productivity of the wetter ecosystem was less sensitive to changes in soil water content, compared to the dryer site. Still, the wetter ecosystem was a source of CO 2 each year, owing to large ecosystem respiration during summer; while the dry site turned into a CO 2 sink during wet years. Overall, the impact of the summertime compound event on annual CO 2 fluxes was marginal at both sites, compared to drought events during spring or autumn. This highlights that drought timing is crucial to determine the annual carbon fluxes in these semi-arid ecosystems. |
BibTeX:
@article{ElMadany2020,
author = {El-Madany, Tarek S. and Carrara, Arnaud and Martín, M. Pilar and Moreno, Gerardo and Kolle, Olaf and Pacheco-Labrador, Javier and Weber, Ulrich and Wutzler, Thomas and Reichstein, Markus and Migliavacca, Mirco},
title = {Drought and heatwave impacts on semi-arid ecosystems' carbon fluxes along a precipitation gradient},
journal = {Philosophical Transactions of the Royal Society B: Biological Sciences},
year = {2020},
volume = {375},
number = {1810},
pages = {20190519},
url = {https://royalsocietypublishing.org/doi/10.1098/rstb.2019.0519},
doi = {10.1098/rstb.2019.0519}
}
|
| Fersch B, Senatore A, Adler B, Arnault J, Mauder M, Schneider K, Völksch I and Kunstmann H (2020), "High-resolution fully coupled atmospheric-hydrological modeling: A cross-compartment regional water and energy cycle evaluation", Hydrology and Earth System Sciences. Vol. 24(5), pp. 2457-2481. |
| Abstract: The land surface and the atmospheric boundary layer are closely intertwined with respect to the exchange of water, trace gases, and energy. Nonlinear feedback and scaledependent mechanisms are obvious by observations and theories. Modeling instead is often narrowed to single compartments of the terrestrial system or bound to traditional viewpoints of definite scientific disciplines. Coupled terrestrial hydrometeorological modeling systems attempt to overcome these limitations to achieve a better integration of the processes relevant for regional climate studies and local-area weather prediction. This study examines the ability of the hydrologically enhanced version of the Weather Research and Forecasting model (WRF-Hydro) to reproduce the regional water cycle by means of a two-way coupled approach and assesses the impact of hydrological coupling with respect to a traditional regional atmospheric model setting. It includes the observation-based calibration of the hydrological model component (offline WRF-Hydro) and a comparison of the classic WRF and the fully coupled WRFHydro models both with identically calibrated parameter settings for the land surface model (Noah-Multiparametrization; Noah-MP). The simulations are evaluated based on extensive observations at the Terrestrial Environmental Observatories (TERENO) Pre-Alpine Observatory for the Ammer (600 km2) and Rott (55 km2) river catchments in southern Germany, covering a 5-month period (June-October 2016). The sensitivity of seven land surface parameters is tested using the Latin-Hypercube-One-factor-At-a-Time (LH-OAT) method, and six sensitive parameters are subsequently optimized for six different subcatchments, using the modelindependent Parameter Estimation and Uncertainty Analysis software (PEST). The calibration of the offline WRF-Hydro gives Nash-Sutcliffe efficiencies between 0.56 and 0.64 and volumetric efficiencies between 0.46 and 0.81 for the six subcatchments. The comparison of the classic WRF and fully coupled WRF-Hydro models, both using the calibrated parameters from the offline model, shows only tiny alterations for radiation and precipitation but considerable changes for moisture and heat fluxes. By comparison with TERENO Pre- Alpine Observatory measurements, the fully coupled model slightly outperforms the classic WRF model with respect to evapotranspiration, sensible and ground heat flux, the nearsurface mixing ratio, temperature, and boundary layer profiles of air temperature. The subcatchment-based water budgets show uniformly directed variations for evapotranspiration, infiltration excess and percolation, whereas soil moisture and precipitation change randomly. |
BibTeX:
@article{Fersch2020,
author = {Fersch, Benjamin and Senatore, Alfonso and Adler, Bianca and Arnault, Joel and Mauder, Matthias and Schneider, Katrin and Völksch, Ingo and Kunstmann, Harald},
title = {High-resolution fully coupled atmospheric-hydrological modeling: A cross-compartment regional water and energy cycle evaluation},
journal = {Hydrology and Earth System Sciences},
year = {2020},
volume = {24},
number = {5},
pages = {2457--2481},
doi = {10.5194/hess-24-2457-2020}
}
|
| Fisher JB, Lee B, Purdy AJ, Halverson GH, Dohlen MB, Cawse-Nicholson K, Wang A, Anderson RG, Aragon B, Arain MA, Baldocchi DD, Baker JM, Barral H, Bernacchi CJ, Bernhofer C, Biraud SC, Bohrer G, Brunsell N, Cappelaere B, Castro-Contreras S, Chun J, Conrad BJ, Cremonese E, Demarty J, Desai AR, De Ligne A, Foltýnová L, Goulden ML, Griffis TJ, Grünwald T, Johnson MS, Kang M, Kelbe D, Kowalska N, Lim JH, Maïnassara I, McCabe MF, Missik JEC, Mohanty BP, Moore CE, Morillas L, Morrison R, Munger JW, Posse G, Richardson AD, Russell ES, Ryu Y, Sanchez-Azofeifa A, Schmidt M, Schwartz E, Sharp I, Šigut L, Tang Y, Hulley G, Anderson M, Hain C, French A, Wood E and Hook S (2020), "ECOSTRESS: NASA's Next Generation Mission to Measure Evapotranspiration From the International Space Station", Water Resources Research. Vol. 56(4), pp. 1-20. |
| Abstract: The ECOsystem Spaceborne Thermal Radiometer Experiment on Space Station (ECOSTRESS) was launched to the International Space Station on 29 June 2018 by the National Aeronautics and Space Administration (NASA). The primary science focus of ECOSTRESS is centered on evapotranspiration (ET), which is produced as Level-3 (L3) latent heat flux (LE) data products. These data are generated from the Level-2 land surface temperature and emissivity product (L2_LSTE), in conjunction with ancillary surface and atmospheric data. Here, we provide the first validation (Stage 1, preliminary) of the global ECOSTRESS clear-sky ET product (L3_ET_PT-JPL, Version 6.0) against LE measurements at 82 eddy covariance sites around the world. Overall, the ECOSTRESS ET product performs well against the site measurements (clear-sky instantaneous/time of overpass: r2 = 0.88; overall bias = 8%; normalized root-mean-square error, RMSE = 6%). ET uncertainty was generally consistent across climate zones, biome types, and times of day (ECOSTRESS samples the diurnal cycle), though temperate sites are overrepresented. The 70-m-high spatial resolution of ECOSTRESS improved correlations by 85%, and RMSE by 62%, relative to 1-km pixels. This paper serves as a reference for the ECOSTRESS L3 ET accuracy and Stage 1 validation status for subsequent science that follows using these data. |
BibTeX:
@article{Fisher2020,
author = {Fisher, Joshua B and Lee, Brian and Purdy, Adam J and Halverson, Gregory H and Dohlen, Matthew B and Cawse-Nicholson, Kerry and Wang, Audrey and Anderson, Ray G and Aragon, Bruno and Arain, M Altaf and Baldocchi, Dennis D and Baker, John M and Barral, Hélène and Bernacchi, Carl J and Bernhofer, Christian and Biraud, Sébastien C and Bohrer, Gil and Brunsell, Nathaniel and Cappelaere, Bernard and Castro-Contreras, Saulo and Chun, Junghwa and Conrad, Bryan J and Cremonese, Edoardo and Demarty, Jérôme and Desai, Ankur R and De Ligne, Anne and Foltýnová, Lenka and Goulden, Michael L and Griffis, Timothy J and Grünwald, Thomas and Johnson, Mark S and Kang, Minseok and Kelbe, Dave and Kowalska, Natalia and Lim, Jong Hwan and Maïnassara, Ibrahim and McCabe, Matthew F and Missik, Justine E C and Mohanty, Binayak P and Moore, Caitlin E and Morillas, Laura and Morrison, Ross and Munger, J William and Posse, Gabriela and Richardson, Andrew D and Russell, Eric S and Ryu, Youngryel and Sanchez-Azofeifa, Arturo and Schmidt, Marius and Schwartz, Efrat and Sharp, Iain and Šigut, Ladislav and Tang, Yao and Hulley, Glynn and Anderson, Martha and Hain, Christopher and French, Andrew and Wood, Eric and Hook, Simon},
title = {ECOSTRESS: NASA's Next Generation Mission to Measure Evapotranspiration From the International Space Station},
journal = {Water Resources Research},
year = {2020},
volume = {56},
number = {4},
pages = {1--20},
doi = {10.1029/2019WR026058}
}
|
| Flechard CR, van Oijen M, Cameron DR, de Vries W, Ibrom A, Buchmann N, Dise NB, Janssens IA, Neirynck J, Montagnani L, Varlagin A, Loustau D, Legout A, Ziembliʼnska K, Aubinet M, Aurela M, Chojnicki BH, Drewer J, Eugster W, Francez A-J, Juszczak R, Kitzler B, Kutsch WL, Lohila A, Longdoz B, Matteucci G, Moreaux V, Neftel A, Olejnik J, Sanz MJ, Siemens J, Vesala T, Vincke C, Nemitz E, Zechmeister-Boltenstern S, Butterbach-Bahl K, Skiba UM and Sutton MA (2020), "Carbon-nitrogen interactions in European forests and semi-natural vegetation; Part 2: Untangling climatic, edaphic, management and nitrogen deposition effects on carbon sequestration potentials", Biogeosciences., mar, 2020. Vol. 17(6), pp. 1621-1654. |
| Abstract: 2.5–3 g N mâˆ'2 yrâˆ'1) but accompanied by increasingly large ecosystem N losses by leaching and gaseous emissions. The reduced increase in productivity per unit N deposited at high Ndep levels implies that the forecast increased Nr emissions and increased Ndep levels in large areas of Asia may not positively impact the continent's forest CO2 sink. The large level of unexplained variability in observed carbon sequestration efficiency (CSE) across sites further adds to the uncertainty in the dC∕dN response.]] |
BibTeX:
@article{Flechard2020,
author = {Flechard, Chris R and van Oijen, Marcel and Cameron, David R and de Vries, Wim and Ibrom, Andreas and Buchmann, Nina and Dise, Nancy B and Janssens, Ivan A and Neirynck, Johan and Montagnani, Leonardo and Varlagin, Andrej and Loustau, Denis and Legout, Arnaud and Ziembliʼnska, Klaudia and Aubinet, Marc and Aurela, Mika and Chojnicki, Bogdan H and Drewer, Julia and Eugster, Werner and Francez, André-Jean and Juszczak, Radosław and Kitzler, Barbara and Kutsch, Werner L and Lohila, Annalea and Longdoz, Bernard and Matteucci, Giorgio and Moreaux, Virginie and Neftel, Albrecht and Olejnik, Janusz and Sanz, Maria J and Siemens, Jan and Vesala, Timo and Vincke, Caroline and Nemitz, Eiko and Zechmeister-Boltenstern, Sophie and Butterbach-Bahl, Klaus and Skiba, Ute M and Sutton, Mark A},
title = {Carbon-nitrogen interactions in European forests and semi-natural vegetation; Part 2: Untangling climatic, edaphic, management and nitrogen deposition effects on carbon sequestration potentials},
journal = {Biogeosciences},
year = {2020},
volume = {17},
number = {6},
pages = {1621--1654},
url = {https://www.biogeosciences.net/17/1621/2020/},
doi = {10.5194/bg-17-1621-2020}
}
|
| Flechard CR, Ibrom A, Skiba UM, de Vries W, van Oijen M, Cameron DR, Dise NB, Korhonen JFJ, Buchmann N, Legout A, Simpson D, Sanz MJ, Aubinet M, Loustau D, Montagnani L, Neirynck J, Janssens IA, Pihlatie M, Kiese R, Siemens J, Francez A-J, Augustin J, Varlagin A, Olejnik J, Juszczak R, Aurela M, Berveiller D, Chojnicki BH, Dämmgen U, Delpierre N, Djuricic V, Drewer J, Dufrêne E, Eugster W, Fauvel Y, Fowler D, Frumau A, Granier A, Gross P, Hamon Y, Helfter C, Hensen A, Horváth L, Kitzler B, Kruijt B, Kutsch WL, Lobo-do-Vale R, Lohila A, Longdoz B, Marek MV, Matteucci G, Mitosinkova M, Moreaux V, Neftel A, Ourcival J-M, Pilegaard K, Pita G, Sanz F, Schjoerring JK, Sebastià M-T, Tang YS, Uggerud H, Urbaniak M, van Dijk N, Vesala T, Vidic S, Vincke C, Weidinger T, Zechmeister-Boltenstern S, Butterbach-Bahl K, Nemitz E and Sutton MA (2020), "Carbon-nitrogen interactions in European forests and semi-natural vegetation; Part 1: Fluxes and budgets of carbon, nitrogen and greenhouse gases from ecosystem monitoring and modelling", Biogeosciences., mar, 2020. Vol. 17(6), pp. 1583-1620. |
| Abstract: 3 g N mâˆ'2 yrâˆ'1. Such large levels of Nr loss likely indicate that different stages of N saturation occurred at a number of sites. The joint analysis of the C and N budgets provided further hints that N saturation could be detected in altered patterns of forest growth. Net ecosystem productivity increased with Nr deposition up to 2–2.5 g N mâˆ'2 yrâˆ'1, with large scatter associated with a wide range in carbon sequestration efficiency (CSE, defined as the NEP ∕ GPP ratio). At elevated Ndep levels ( 2.5 g N mâˆ'2 yrâˆ'1), where inorganic Nr losses were also increasingly large, NEP levelled off and then decreased. The apparent increase in NEP at low to intermediate Ndep levels was partly the result of geographical cross-correlations between Ndep and climate, indicating that the actual mean dC∕dN response at individual sites was significantly lower than would be suggested by a simple, straightforward regression of NEP vs. Ndep.]] |
BibTeX:
@article{Flechard2020a,
author = {Flechard, Chris R and Ibrom, Andreas and Skiba, Ute M and de Vries, Wim and van Oijen, Marcel and Cameron, David R and Dise, Nancy B and Korhonen, Janne F J and Buchmann, Nina and Legout, Arnaud and Simpson, David and Sanz, Maria J and Aubinet, Marc and Loustau, Denis and Montagnani, Leonardo and Neirynck, Johan and Janssens, Ivan A and Pihlatie, Mari and Kiese, Ralf and Siemens, Jan and Francez, André-Jean and Augustin, Jürgen and Varlagin, Andrej and Olejnik, Janusz and Juszczak, Radosław and Aurela, Mika and Berveiller, Daniel and Chojnicki, Bogdan H and Dämmgen, Ulrich and Delpierre, Nicolas and Djuricic, Vesna and Drewer, Julia and Dufrêne, Eric and Eugster, Werner and Fauvel, Yannick and Fowler, David and Frumau, Arnoud and Granier, André and Gross, Patrick and Hamon, Yannick and Helfter, Carole and Hensen, Arjan and Horváth, László and Kitzler, Barbara and Kruijt, Bart and Kutsch, Werner L and Lobo-do-Vale, Raquel and Lohila, Annalea and Longdoz, Bernard and Marek, Michal V and Matteucci, Giorgio and Mitosinkova, Marta and Moreaux, Virginie and Neftel, Albrecht and Ourcival, Jean-Marc and Pilegaard, Kim and Pita, Gabriel and Sanz, Francisco and Schjoerring, Jan K and Sebastià, Maria-Teresa and Tang, Y Sim and Uggerud, Hilde and Urbaniak, Marek and van Dijk, Netty and Vesala, Timo and Vidic, Sonja and Vincke, Caroline and Weidinger, Tamás and Zechmeister-Boltenstern, Sophie and Butterbach-Bahl, Klaus and Nemitz, Eiko and Sutton, Mark A},
title = {Carbon-nitrogen interactions in European forests and semi-natural vegetation; Part 1: Fluxes and budgets of carbon, nitrogen and greenhouse gases from ecosystem monitoring and modelling},
journal = {Biogeosciences},
year = {2020},
volume = {17},
number = {6},
pages = {1583--1620},
url = {https://www.biogeosciences.net/17/1583/2020/},
doi = {10.5194/bg-17-1583-2020}
}
|
| Ford DA (2020), "Assessing the role and consistency of satellite observation products in global physical–biogeochemical ocean reanalysis", Ocean Science., jul, 2020. Vol. 16(4), pp. 875-893. Copernicus GmbH. |
| Abstract: textlessptextgreatertextless![CDATA[Abstract. As part of the European Space Agency's Climate Change Initiative, new sets of satellite observation products have been produced for essential climate variables including ocean colour, sea surface temperature, sea level, and sea ice. These new products have been assimilated into a global physical–biogeochemical ocean model to create a set of 13-year reanalyses at 1∘ resolution and 3-year reanalyses at 1∕4∘ resolution. In a series of experiments, the variables were assimilated individually and in combination in order to assess their consistency from a data assimilation perspective. The satellite products, and the reanalyses assimilating them, were found to be consistent in their representation of spatial features such as fronts, sea ice extent, and bloom activity. Assimilating multiple variables together often resulted in larger mean increments for a variable than assimilating it individually, providing information about model biases and compensating errors which could be addressed in the future development of the model and assimilation scheme. Sea surface fugacity of carbon dioxide had lower errors against independent observations in the higher-resolution simulations and was improved by assimilating ocean colour or sea ice concentration, but it was degraded by assimilating sea surface temperature or sea level anomaly. Phytoplankton biomass correlated more strongly with net air–sea heat fluxes in the reanalyses than chlorophyll concentration did, and the correlation was weakened by assimilating ocean colour data, suggesting that studies of phytoplankton bloom initiation based solely on chlorophyll data may not provide a full understanding of the underlying processes.]]textgreatertextless/ptextgreater |
BibTeX:
@article{Ford2020,
author = {Ford, David Andrew},
title = {Assessing the role and consistency of satellite observation products in global physical–biogeochemical ocean reanalysis},
journal = {Ocean Science},
publisher = {Copernicus GmbH},
year = {2020},
volume = {16},
number = {4},
pages = {875--893},
url = {https://os.copernicus.org/articles/16/875/2020/},
doi = {10.5194/os-16-875-2020}
}
|
| Fourrier M, Coppola L, Claustre H, D'Ortenzio F, Sauzède R and Gattuso J-P (2020), "A Regional Neural Network Approach to Estimate Water-Column Nutrient Concentrations and Carbonate System Variables in the Mediterranean Sea: CANYON-MED", Frontiers in Marine Science., aug, 2020. Vol. 7 |
| Abstract: A regional neural network-based method, “CANYON-MED” is developed to estimate nutrients and carbonate system variables specifically in the Mediterranean Sea over the water column from pressure, temperature, salinity, and oxygen together with geolocation and date of sampling. Six neural network ensembles were developed, one for each variable (i.e., three macronutrients: nitrates (NO 3 - ), phosphates (PO 4 3 - ) and silicates (SiOH 4 ), and three carbonate system variables: pH on the total scale (pH T ), total alkalinity ( A T ), and dissolved inorganic carbon or total carbon ( C T ), trained using a specific quality-controlled dataset of reference “bottle” data in the Mediterranean Sea. This dataset is representative of the peculiar conditions of this semi-enclosed sea, as opposed to the global ocean. For each variable, the neural networks were trained on 80% of the data chosen randomly and validated using the remaining 20%. CANYON-MED retrieved the variables with good accuracies (Root Mean Squared Error): 0.78 μmol.kg –1 for NO 3 - , 0.043 μmol.kg –1 for PO 4 3 - and 0.71 μmol.kg –1 for Si(OH) 4 , 0.014 units for pH T , 13 μmol.kg –1 for A T and 12 μmol.kg –1 for C T . A second validation on the ANTARES independent time series confirmed the method's applicability in the Mediterranean Sea. After comparison to other existing methods to estimate nutrients and carbonate system variables, CANYON-MED stood out as the most robust, using the aforementioned inputs. The application of CANYON-MED on the Mediterranean Sea data from autonomous observing systems (integrated network of Biogeochemical-Argo floats, Eulerian moorings and ocean gliders measuring hydrological properties together with oxygen concentration) could have a wide range of applications. These include data quality control or filling gaps in time series, as well as biogeochemical data assimilation and/or the initialization and validation of regional biogeochemical models still lacking crucial reference data. Matlab and R code are available at https:// github.com/MarineFou/CANYON-MED/ . |
BibTeX:
@article{Fourrier2020,
author = {Fourrier, Marine and Coppola, Laurent and Claustre, Hervé and D'Ortenzio, Fabrizio and Sauzède, Raphaëlle and Gattuso, Jean-Pierre},
title = {A Regional Neural Network Approach to Estimate Water-Column Nutrient Concentrations and Carbonate System Variables in the Mediterranean Sea: CANYON-MED},
journal = {Frontiers in Marine Science},
year = {2020},
volume = {7},
url = {https://www.frontiersin.org/articles/10.3389/fmars.2020.00620/full},
doi = {10.3389/fmars.2020.00620}
}
|
| Friedlingstein P, O’Sullivan M, Jones MW, Andrew RM, Hauck J, Olsen A, Peters GP, Peters W, Pongratz J, Sitch S, Le Quéré C, Canadell JG, Ciais P, Jackson RB, Alin S, Aragão LEOC, Arneth A, Arora V, Bates NR, Becker M, Benoit-Cattin A, Bittig HC, Bopp L, Bultan S, Chandra N, Chevallier F, Chini LP, Evans W, Florentie L, Forster PM, Gasser T, Gehlen M, Gilfillan D, Gkritzalis T, Gregor L, Gruber N, Harris I, Hartung K, Haverd V, Houghton RA, Ilyina T, Jain AK, Joetzjer E, Kadono K, Kato E, Kitidis V, Korsbakken JI, Landschützer P, Lefèvre N, Lenton A, Lienert S, Liu Z, Lombardozzi D, Marland G, Metzl N, Munro DR, Nabel JEMS, Nakaoka S-I, Niwa Y, O’Brien K, Ono T, Palmer PI, Pierrot D, Poulter B, Resplandy L, Robertson E, Rödenbeck C, Schwinger J, Séférian R, Skjelvan I, Smith AJP, Sutton AJ, Tanhua T, Tans PP, Tian H, Tilbrook B, van der Werf G, Vuichard N, Walker AP, Wanninkhof R, Watson AJ, Willis D, Wiltshire AJ, Yuan W, Yue X and Zaehle S (2020), "Global Carbon Budget 2020", Earth System Science Data., December, 2020. Vol. 12(4), pp. 3269-3340. Copernicus GmbH. |
BibTeX:
@article{Friedlingstein2020,
author = {Friedlingstein, Pierre and O’Sullivan, Michael and Jones, Matthew W. and Andrew, Robbie M. and Hauck, Judith and Olsen, Are and Peters, Glen P. and Peters, Wouter and Pongratz, Julia and Sitch, Stephen and Le Quéré, Corinne and Canadell, Josep G. and Ciais, Philippe and Jackson, Robert B. and Alin, Simone and Aragão, Luiz E. O. C. and Arneth, Almut and Arora, Vivek and Bates, Nicholas R. and Becker, Meike and Benoit-Cattin, Alice and Bittig, Henry C. and Bopp, Laurent and Bultan, Selma and Chandra, Naveen and Chevallier, Frédéric and Chini, Louise P. and Evans, Wiley and Florentie, Liesbeth and Forster, Piers M. and Gasser, Thomas and Gehlen, Marion and Gilfillan, Dennis and Gkritzalis, Thanos and Gregor, Luke and Gruber, Nicolas and Harris, Ian and Hartung, Kerstin and Haverd, Vanessa and Houghton, Richard A. and Ilyina, Tatiana and Jain, Atul K. and Joetzjer, Emilie and Kadono, Koji and Kato, Etsushi and Kitidis, Vassilis and Korsbakken, Jan Ivar and Landschützer, Peter and Lefèvre, Nathalie and Lenton, Andrew and Lienert, Sebastian and Liu, Zhu and Lombardozzi, Danica and Marland, Gregg and Metzl, Nicolas and Munro, David R. and Nabel, Julia E. M. S. and Nakaoka, Shin-Ichiro and Niwa, Yosuke and O’Brien, Kevin and Ono, Tsuneo and Palmer, Paul I. and Pierrot, Denis and Poulter, Benjamin and Resplandy, Laure and Robertson, Eddy and Rödenbeck, Christian and Schwinger, Jörg and Séférian, Roland and Skjelvan, Ingunn and Smith, Adam J. P. and Sutton, Adrienne J. and Tanhua, Toste and Tans, Pieter P. and Tian, Hanqin and Tilbrook, Bronte and van der Werf, Guido and Vuichard, Nicolas and Walker, Anthony P. and Wanninkhof, Rik and Watson, Andrew J. and Willis, David and Wiltshire, Andrew J. and Yuan, Wenping and Yue, Xu and Zaehle, Sönke},
title = {Global Carbon Budget 2020},
journal = {Earth System Science Data},
publisher = {Copernicus GmbH},
year = {2020},
volume = {12},
number = {4},
pages = {3269--3340},
doi = {10.5194/essd-12-3269-2020}
}
|
| Fu Z, Ciais P, Bastos A, Stoy PC, Yang H, Green JK, Wang B, Yu K, Huang Y, Knohl A, Šigut L, Gharun M, Cuntz M, Arriga N, Roland M, Peichl M, Migliavacca M, Cremonese E, Varlagin A, Brümmer C, Gourlez de la Motte L, Fares S, Buchmann N, El-Madany TS, Pitacco A, Vendrame N, Li Z, Vincke C, Magliulo E and Koebsch F (2020), "Sensitivity of gross primary productivity to climatic drivers during the summer drought of 2018 in Europe", Philosophical Transactions of the Royal Society B: Biological Sciences., oct, 2020. Vol. 375(1810), pp. 20190747. |
| Abstract: In summer 2018, Europe experienced a record drought, but it remains unknown how the drought affected ecosystem carbon dynamics. Using observations from 34 eddy covariance sites in different biomes across Europe, we studied the sensitivity of gross primary productivity (GPP) to environmental drivers during the summer drought of 2018 versus the reference summer of 2016. We found a greater drought-induced decline of summer GPP in grasslands (−38%) than in forests (−10%), which coincided with reduced evapotranspiration and soil water content (SWC). As compared to the ‘normal year' of 2016, GPP in different ecosystems exhibited more negative sensitivity to summer air temperature (Ta) but stronger positive sensitivity to SWC during summer drought in 2018, that is, a stronger reduction of GPP with soil moisture deficit. We found larger negative effects of Ta and vapour pressure deficit (VPD) but a lower positive effect of photosynthetic photon flux density on GPP in 2018 compared to 2016, which contributed to reduced summer GPP in 2018. Our results demonstrate that high temperature-induced increases in VPD and decreases in SWC aggravated drought impacts on GPP. |
BibTeX:
@article{Fu2020,
author = {Fu, Zheng and Ciais, Philippe and Bastos, Ana and Stoy, Paul C. and Yang, Hui and Green, Julia K. and Wang, Bingxue and Yu, Kailiang and Huang, Yuanyuan and Knohl, Alexander and Šigut, Ladislav and Gharun, Mana and Cuntz, Matthias and Arriga, Nicola and Roland, Marilyn and Peichl, Matthias and Migliavacca, Mirco and Cremonese, Edoardo and Varlagin, Andrej and Brümmer, Christian and Gourlez de la Motte, Louis and Fares, Silvano and Buchmann, Nina and El-Madany, Tarek S. and Pitacco, Andrea and Vendrame, Nadia and Li, Zhaolei and Vincke, Caroline and Magliulo, Enzo and Koebsch, Franziska},
title = {Sensitivity of gross primary productivity to climatic drivers during the summer drought of 2018 in Europe},
journal = {Philosophical Transactions of the Royal Society B: Biological Sciences},
year = {2020},
volume = {375},
number = {1810},
pages = {20190747},
url = {https://royalsocietypublishing.org/doi/10.1098/rstb.2019.0747},
doi = {10.1098/rstb.2019.0747}
}
|
| Gallego MA, Timmermann A, Friedrich T and Zeebe RE (2020), "Anthropogenic Intensification of Surface Ocean Interannual pCO textlesssubtextgreater2textless/subtextgreater Variability", Geophysical Research Letters., jul, 2020. Vol. 47(13) Blackwell Publishing Ltd. |
| Abstract: We use several global coupled atmosphere-ocean-biogeochemistry models from the Coupled Model Intercomparison Project (CMIP5) to show that the global interannual variability of the sea surface pCO2 (calculated as 1σ) will increase by ∼64 ± 20% by 2040–2090 relative to the beginning of the industrial revolution under the RCP8.5 scenario. All models agree that the increase in variability is a consequence of a larger background pCO2 and a lower buffering capacity that enhance the response of pCO2 to the fluctuations of surface temperature (T) and dissolved inorganic carbon (DIC). The most skillful group of models under present-day conditions shows a future global decrease in DIC fluctuations that will weaken the pCO2 interannual variability (IAV). The remaining uncertainties in the projected evolution of pCO2 variability regionally highlight the need for continuous carbon monitoring programs which will contribute to a better understanding of the oceanic carbon sink's response to increased green house emissions. |
BibTeX:
@article{Gallego2020,
author = {Gallego, M. Angeles and Timmermann, Axel and Friedrich, Tobias and Zeebe, Richard E.},
title = {Anthropogenic Intensification of Surface Ocean Interannual pCO textlesssubtextgreater2textless/subtextgreater Variability},
journal = {Geophysical Research Letters},
publisher = {Blackwell Publishing Ltd},
year = {2020},
volume = {47},
number = {13},
url = {https://onlinelibrary.wiley.com/doi/abs/10.1029/2020GL087104},
doi = {10.1029/2020GL087104}
}
|
| Gharun M, Hörtnagl L, Paul-Limoges E, Ghiasi S, Feigenwinter I, Burri S, Marquardt K, Etzold S, Zweifel R, Eugster W and Buchmann N (2020), "Physiological response of Swiss ecosystems to 2018 drought across plant types and elevation", Philosophical Transactions of the Royal Society B: Biological Sciences., oct, 2020. Vol. 375(1810), pp. 20190521. |
| Abstract: Using five eddy covariance flux sites (two forests and three grasslands), we investigated ecosystem physiological responses to the 2018 drought across elevational gradients in Switzerland. Flux measurements showed that at lower elevation sites (below 1000 m.a.s.l.; grassland and mixed forest) annual ecosystem productivity (GPP) declined by approximately 20% compared to the previous 2 years (2016 and 2017), which led to a reduced annual net ecosystem productivity (NEP). At the high elevation sites, however, GPP increased by approximately 14% and as a result NEP increased in the alpine and montane grasslands, but not in the subalpine coniferous forest. There, increased ecosystem respiration led to a reduced annual NEP, despite increased GPP and lengthening of the growing period. Among all ecosystems, the coniferous forest showed the most pronounced negative stomatal response to atmospheric dryness (i.e. vapour pressure deficit, VPD) that resulted in a decline in surface conductance and an increased water-use efficiency during drought. While increased temperature enhanced the water-use efficiency of both forests, de-coupling of GPP from evapotranspiration at the low-elevation grassland site negatively affected water-use efficiency due to non-stomatal reductions in photosynthesis. Our results show that hot droughts (such as in 2018) lead to different responses across plants types, and thus ecosystems. Particularly grasslands at lower elevations are the most vulnerable ecosystems to negative impacts of future drought in Switzerland. |
BibTeX:
@article{Gharun2020,
author = {Gharun, Mana and Hörtnagl, Lukas and Paul-Limoges, Eugénie and Ghiasi, Shiva and Feigenwinter, Iris and Burri, Susanne and Marquardt, Kristiina and Etzold, Sophia and Zweifel, Roman and Eugster, Werner and Buchmann, Nina},
title = {Physiological response of Swiss ecosystems to 2018 drought across plant types and elevation},
journal = {Philosophical Transactions of the Royal Society B: Biological Sciences},
year = {2020},
volume = {375},
number = {1810},
pages = {20190521},
url = {https://royalsocietypublishing.org/doi/10.1098/rstb.2019.0521},
doi = {10.1098/rstb.2019.0521}
}
|
| Ghirardo A, Lindstein F, Koch K, Buegger F, Schloter M, Albert A, Michelsen A, Winkler JB, Schnitzler JP and Rinnan R (2020), "Origin of volatile organic compound emissions from subarctic tundra under global warming", Global Change Biology. Vol. 26(3), pp. 1908-1925. |
| Abstract: Warming occurs in the Arctic twice as fast as the global average, which in turn leads to a large enhancement in terpenoid emissions from vegetation. Volatile terpenoids are the main class of biogenic volatile organic compounds (VOCs) that play crucial roles in atmospheric chemistry and climate. However, the biochemical mechanisms behind the temperature-dependent increase in VOC emissions from subarctic ecosystems are largely unexplored. Using 13CO2-labeling, we studied the origin of VOCs and the carbon (C) allocation under global warming in the soil–plant–atmosphere system of contrasting subarctic heath tundra vegetation communities characterized by dwarf shrubs of the genera Salix or Betula. The projected temperature rise of the subarctic summer by 5°C was realistically simulated in sophisticated climate chambers. VOC emissions strongly depended on the plant species composition of the heath tundra. Warming caused increased VOC emissions and significant changes in the pattern of volatiles toward more reactive hydrocarbons. The 13C was incorporated to varying degrees in different monoterpene and sesquiterpene isomers. We found that de novo monoterpene biosynthesis contributed to 40%–44% (Salix) and 60%–68% (Betula) of total monoterpene emissions under the current climate, and that warming increased the contribution to 50%–58% (Salix) and 87%–95% (Betula). Analyses of above- and belowground 12/13C showed shifts of C allocation in the plant–soil systems and negative effects of warming on C sequestration by lowering net ecosystem exchange of CO2 and increasing C loss as VOCs. This comprehensive analysis provides the scientific basis for mechanistically understanding the processes controlling terpenoid emissions, required for modeling VOC emissions from terrestrial ecosystems and predicting the future chemistry of the arctic atmosphere. By changing the chemical composition and loads of VOCs into the atmosphere, the current data indicate that global warming in the Arctic may have implications for regional and global climate and for the delicate tundra ecosystems. |
BibTeX:
@article{Ghirardo2020,
author = {Ghirardo, Andrea and Lindstein, Frida and Koch, Kerstin and Buegger, Franz and Schloter, Michael and Albert, Andreas and Michelsen, Anders and Winkler, J Barbro and Schnitzler, Jörg Peter and Rinnan, Riikka},
title = {Origin of volatile organic compound emissions from subarctic tundra under global warming},
journal = {Global Change Biology},
year = {2020},
volume = {26},
number = {3},
pages = {1908--1925},
doi = {10.1111/gcb.14935}
}
|
| Gourlez de la Motte L, Beauclaire Q, Heinesch B, Cuntz M, Foltýnová L, Šigut L, Kowalska N, Manca G, Ballarin IG, Vincke C, Roland M, Ibrom A, Lousteau D, Siebicke L, Neiryink J and Longdoz B (2020), "Non-stomatal processes reduce gross primary productivity in temperate forest ecosystems during severe edaphic drought", Philosophical Transactions of the Royal Society B: Biological Sciences., oct, 2020. Vol. 375(1810), pp. 20190527. |
| Abstract: Severe drought events are known to cause important reductions of gross primary productivity ( GPP ) in forest ecosystems. However, it is still unclear whether this reduction originates from stomatal closure (Stomatal Origin Limitation) and/or non-stomatal limitations (Non-SOL). In this study, we investigated the impact of edaphic drought in 2018 on GPP and its origin (SOL, NSOL) using a dataset of 10 European forest ecosystem flux towers. In all stations where GPP reductions were observed during the drought, these were largely explained by declines in the maximum apparent canopy scale carboxylation rate V CMAX,APP (NSOL) when the soil relative extractable water content dropped below around 0.4. Concurrently, we found that the stomatal slope parameter ( G 1 , related to SOL) of the Medlyn et al . unified optimization model linking vegetation conductance and GPP remained relatively constant. These results strengthen the increasing evidence that NSOL should be included in stomatal conductance/photosynthesis models to faithfully simulate both GPP and water fluxes in forest ecosystems during severe drought. |
BibTeX:
@article{GourlezdelaMotte2020,
author = {Gourlez de la Motte, Louis and Beauclaire, Quentin and Heinesch, Bernard and Cuntz, Mathias and Foltýnová, Lenka and Šigut, Ladislav and Kowalska, Natalia and Manca, Giovanni and Ballarin, Ignacio Goded and Vincke, Caroline and Roland, Marilyn and Ibrom, Andreas and Lousteau, Denis and Siebicke, Lukas and Neiryink, Johan and Longdoz, Bernard},
title = {Non-stomatal processes reduce gross primary productivity in temperate forest ecosystems during severe edaphic drought},
journal = {Philosophical Transactions of the Royal Society B: Biological Sciences},
year = {2020},
volume = {375},
number = {1810},
pages = {20190527},
url = {https://royalsocietypublishing.org/doi/10.1098/rstb.2019.0527},
doi = {10.1098/rstb.2019.0527}
}
|
| Graf A, Klosterhalfen A, Arriga N, Bernhofer C, Bogena H, Bornet F, Brüggemann N, Brümmer C, Buchmann N, Chi J, Chipeaux C, Cremonese E, Cuntz M, Dušek J, El-Madany TS, Fares S, Fischer M, Foltýnová L, Gharun M, Ghiasi S, Gielen B, Gottschalk P, Grünwald T, Heinemann G, Heinesch B, Heliasz M, Holst J, Hörtnagl L, Ibrom A, Ingwersen J, Jurasinski G, Klatt J, Knohl A, Koebsch F, Konopka J, Korkiakoski M, Kowalska N, Kremer P, Kruijt B, Lafont S, Léonard J, De Ligne A, Longdoz B, Loustau D, Magliulo V, Mammarella I, Manca G, Mauder M, Migliavacca M, Mölder M, Neirynck J, Ney P, Nilsson M, Paul-Limoges E, Peichl M, Pitacco A, Poyda A, Rebmann C, Roland M, Sachs T, Schmidt M, Schrader F, Siebicke L, Šigut L, Tuittila E-S, Varlagin A, Vendrame N, Vincke C, Völksch I, Weber S, Wille C, Wizemann H-D, Zeeman M and Vereecken H (2020), "Altered energy partitioning across terrestrial ecosystems in the European drought year 2018", Philosophical Transactions of the Royal Society B: Biological Sciences., oct, 2020. Vol. 375(1810), pp. 20190524. |
| Abstract: Drought and heat events, such as the 2018 European drought, interact with the exchange of energy between the land surface and the atmosphere, potentially affecting albedo, sensible and latent heat fluxes, as well as CO 2 exchange. Each of these quantities may aggravate or mitigate the drought, heat, their side effects on productivity, water scarcity and global warming. We used measurements of 56 eddy covariance sites across Europe to examine the response of fluxes to extreme drought prevailing most of the year 2018 and how the response differed across various ecosystem types (forests, grasslands, croplands and peatlands). Each component of the surface radiation and energy balance observed in 2018 was compared to available data per site during a reference period 2004–2017. Based on anomalies in precipitation and reference evapotranspiration, we classified 46 sites as drought affected. These received on average 9% more solar radiation and released 32% more sensible heat to the atmosphere compared to the mean of the reference period. In general, drought decreased net CO 2 uptake by 17.8%, but did not significantly change net evapotranspiration. The response of these fluxes differed characteristically between ecosystems; in particular, the general increase in the evaporative index was strongest in peatlands and weakest in croplands. |
BibTeX:
@article{Graf2020,
author = {Graf, Alexander and Klosterhalfen, Anne and Arriga, Nicola and Bernhofer, Christian and Bogena, Heye and Bornet, Frédéric and Brüggemann, Nicolas and Brümmer, Christian and Buchmann, Nina and Chi, Jinshu and Chipeaux, Christophe and Cremonese, Edoardo and Cuntz, Matthias and Dušek, Jiří and El-Madany, Tarek S. and Fares, Silvano and Fischer, Milan and Foltýnová, Lenka and Gharun, Mana and Ghiasi, Shiva and Gielen, Bert and Gottschalk, Pia and Grünwald, Thomas and Heinemann, Günther and Heinesch, Bernard and Heliasz, Michal and Holst, Jutta and Hörtnagl, Lukas and Ibrom, Andreas and Ingwersen, Joachim and Jurasinski, Gerald and Klatt, Janina and Knohl, Alexander and Koebsch, Franziska and Konopka, Jan and Korkiakoski, Mika and Kowalska, Natalia and Kremer, Pascal and Kruijt, Bart and Lafont, Sebastien and Léonard, Joël and De Ligne, Anne and Longdoz, Bernard and Loustau, Denis and Magliulo, Vincenzo and Mammarella, Ivan and Manca, Giovanni and Mauder, Matthias and Migliavacca, Mirco and Mölder, Meelis and Neirynck, Johan and Ney, Patrizia and Nilsson, Mats and Paul-Limoges, Eugénie and Peichl, Matthias and Pitacco, Andrea and Poyda, Arne and Rebmann, Corinna and Roland, Marilyn and Sachs, Torsten and Schmidt, Marius and Schrader, Frederik and Siebicke, Lukas and Šigut, Ladislav and Tuittila, Eeva-Stiina and Varlagin, Andrej and Vendrame, Nadia and Vincke, Caroline and Völksch, Ingo and Weber, Stephan and Wille, Christian and Wizemann, Hans-Dieter and Zeeman, Matthias and Vereecken, Harry},
title = {Altered energy partitioning across terrestrial ecosystems in the European drought year 2018},
journal = {Philosophical Transactions of the Royal Society B: Biological Sciences},
year = {2020},
volume = {375},
number = {1810},
pages = {20190524},
url = {https://royalsocietypublishing.org/doi/10.1098/rstb.2019.0524},
doi = {10.1098/rstb.2019.0524}
}
|
| Griebel A, Metzen D, Pendall E, Burba G and Metzger S (2020), "Generating Spatially Robust Carbon Budgets From Flux Tower Observations", Geophysical Research Letters., feb, 2020. Vol. 47(3) Blackwell Publishing Ltd. |
| Abstract: Estimating global terrestrial productivity is typically achieved by rescaling individual flux tower measurements, traditionally assumed to represent homogeneous areas, using gridded remote sensing and climate data. Using 154 locations from the FLUXNET2015 database, we demonstrate that variations in spatial homogeneity and nonuniform sampling patterns introduce variability in carbon budget estimates that propagate to the biome scale. We propose a practical solution to quantify the variability of vegetation characteristics and uniformity of sampling patterns and, moreover, account for contributions of sampling variations over heterogeneous surfaces to carbon budgets from flux towers. Our proposed space-time-equitable budgets reduce uncertainty related to heterogeneities, allow for more accurate attribution of physiological variations in productivity trends, and provide more representative grid cell averages for linking fluxes with gridded data products. |
BibTeX:
@article{Griebel2020,
author = {Griebel, Anne and Metzen, Daniel and Pendall, Elise and Burba, George and Metzger, Stefan},
title = {Generating Spatially Robust Carbon Budgets From Flux Tower Observations},
journal = {Geophysical Research Letters},
publisher = {Blackwell Publishing Ltd},
year = {2020},
volume = {47},
number = {3},
doi = {10.1029/2019GL085942}
}
|
| Grunicke S, Queck R and Bernhofer C (2020), "Long-term investigation of forest canopy rainfall interception for a spruce stand", Agricultural and Forest Meteorology. Vol. 292-293(February), pp. 108125. Elsevier. |
| Abstract: The factors influencing the interception process such as the vegetation structure and the meteorological conditions, especially rainfall characteristics, are diverse and highly variable. Therefore, derivation of canopy parameters for interception modelling requires data from field experiments over a long period. In this study, we analyse long-term changes in canopy parameters and rainfall interception for an old-growth spruce stand (composed mainly of Picea abies at a continuous flux site started within EUROFLUX in 1996) within the Tharandter Wald, Southwest of Dresden, Germany. The 10-minute data from the continuous measurements of gross precipitation (P) and throughfall (TF) from 1997 to 2018 were used as follows: Rainfall events were separated by a minimum time of three hours without rainfall and divided into rainfall classes according to their total amount and intensity. Due to vegetation changes in the measuring period caused by two thinning operations, the complete study period was divided into three periods. Canopy parameters S (storage capacity), p (free throughfall coefficient) and Ps (canopy saturation point) were then generated applying a regression-based method using the relationship between P and TF. We generated parameter sets for the complete period, for the three periods reflecting the vegetation changes and for single years. These parameter sets were further tested using a regression model. The statistical analysis of the long-term data set showed that stand parameters and interception are largely influenced by vegetation changes. S and Ps decreased with each thinning. Interestingly, interception and rainfall only changed after the first thinning (increase in p, decrease in interception), indicating counter-acting factors after the second thinning, such as changes in meteorological conditions, rainfall patterns or thinning induced changes in the microclimate of the canopy. Generally, the reliability of the derived canopy parameters depends on the length of the dataset used for the regression analysis. However, the parameter sets that considered three periods produced the best model fit compared to parameter sets for the complete period or for single years. This clearly shows that model performance of statistical interception models depend on a reliable parameterisation that can be improved when taking into account changes in stand characteristics. |
BibTeX:
@article{Grunicke2020,
author = {Grunicke, Sandra and Queck, Ronald and Bernhofer, Christian},
title = {Long-term investigation of forest canopy rainfall interception for a spruce stand},
journal = {Agricultural and Forest Meteorology},
publisher = {Elsevier},
year = {2020},
volume = {292-293},
number = {February},
pages = {108125},
url = {https://doi.org/10.1016/j.agrformet.2020.108125},
doi = {10.1016/j.agrformet.2020.108125}
}
|
| Hari V, Rakovec O, Markonis Y, Hanel M and Kumar R (2020), "Increased future occurrences of the exceptional 2018–2019 Central European drought under global warming", Scientific Reports., dec, 2020. Vol. 10(1), pp. 12207. |
BibTeX:
@article{Hari2020,
author = {Hari, Vittal and Rakovec, Oldrich and Markonis, Yannis and Hanel, Martin and Kumar, Rohini},
title = {Increased future occurrences of the exceptional 2018–2019 Central European drought under global warming},
journal = {Scientific Reports},
year = {2020},
volume = {10},
number = {1},
pages = {12207},
url = {http://www.nature.com/articles/s41598-020-68872-9},
doi = {10.1038/s41598-020-68872-9}
}
|
| Hartmann E, Schulz JP, Seibert R, Schmidt M, Zhang M, Luterbacher J and Tölle MH (2020), "Impact of environmental conditions on grass phenology in the regional climate model COSMO-CLM", Atmosphere. Vol. 11(12), pp. 1-19. |
| Abstract: Feedbacks of plant phenology to the regional climate system affect fluxes of energy, water, CO2, biogenic volatile organic compounds as well as canopy conductance, surface roughness length, and are influencing the seasonality of albedo. We performed simulations with the regional climate model COSMO-CLM (CCLM) at three locations in Germany covering the period 1999 to 2015 in order to study the sensitivity of grass phenology to different environmental conditions by implementing a new phenology module. We provide new evidence that the annually-recurring standard phenology of CCLM is improved by the new calculation of leaf area index (LAI) dependent upon surface temperature, day length, and water availability. Results with the new phenology implemented in the model show a significantly higher correlation with observations than simulations with the standard phenology. The interannual variability of LAI improves the representation of vegetation in years with extremely warm winter/spring (e.g., 2007) or extremely dry summer (e.g., 2003) and shows a more realistic growth period. The effect of the newly implemented phenology on atmospheric variables is small but tends to be positive. It should be used in future applications with an extension on more plant functional types. |
BibTeX:
@article{Hartmann2020,
author = {Hartmann, Eva and Schulz, Jan Peter and Seibert, Ruben and Schmidt, Marius and Zhang, Mingyue and Luterbacher, Jürg and Tölle, Merja H},
title = {Impact of environmental conditions on grass phenology in the regional climate model COSMO-CLM},
journal = {Atmosphere},
year = {2020},
volume = {11},
number = {12},
pages = {1--19},
doi = {10.3390/atmos11121364}
}
|
| Haverd V, Smith B, Canadell JG, Cuntz M, Mikaloffâ€Fletcher S, Farquhar G, Woodgate W, Briggs PR and Trudinger CM (2020), " Higher than expected CO 2 fertilization inferred from leaf to global observations ", Global Change Biology., feb, 2020. Vol. 26(4), pp. 2390-2402. Wiley. |
| Abstract: Several lines of evidence point to an increase in the activity of the terrestrial biosphere over recent decades, impacting the global net land carbon sink (NLS) and its control on the growth of atmospheric carbon dioxide (ca). Global terrestrial gross primary production (GPP)—the rate of carbon fixation by photosynthesis—is esti- mated to have risen by (31 ± 5)% since 1900, but the relative contributions of differ- ent putative drivers to this increase are not well known. Here we identify the rising atmospheric CO2 concentration as the dominant driver. We reconcile leaf-level and global atmospheric constraints on trends in modeled biospheric activity to reveal a global CO2 fertilization effect on photosynthesis of 30% since 1900, or 47% for a doubling of ca above the pre-industrial level. Our historic value is nearly twice as high as current estimates (17 ± 4)% that do not use the full range of available constraints. Consequently, under a future low-emission scenario, we project a land carbon sink (174 PgC, 2006–2099) that is 57 PgC larger than if a lower CO2 fertilization effect comparable with current estimates is assumed. These findings suggest a larger ben- eficial role of the land carbon sink in modulating future excess anthropogenic CO2 consistent with the target of the Paris Agreement to stay below 2°C warming, and underscore the importance of preserving terrestrial carbon sinks. |
BibTeX:
@article{Haverd2020,
author = {Haverd, Vanessa and Smith, Benjamin and Canadell, Josep G and Cuntz, Matthias and Mikaloffâ€Fletcher, Sara and Farquhar, Graham and Woodgate, William and Briggs, Peter R and Trudinger, Cathy M},
title = { Higher than expected CO 2 fertilization inferred from leaf to global observations },
journal = {Global Change Biology},
publisher = {Wiley},
year = {2020},
volume = {26},
number = {4},
pages = {2390--2402},
doi = {10.1111/gcb.14950}
}
|
| Helbig M, Waddington JM, Alekseychik P, Amiro BD, Aurela M, Barr AG, Black TA, Blanken PD, Carey SK, Chen J, Chi J, Desai AR, Dunn A, Euskirchen ES, Flanagan LB, Forbrich I, Friborg T, Grelle A, Harder S, Heliasz M, Humphreys ER, Ikawa H, Isabelle PE, Iwata H, Jassal R, Korkiakoski M, Kurbatova J, Kutzbach L, Lindroth A, Löfvenius MO, Lohila A, Mammarella I, Marsh P, Maximov T, Melton JR, Moore PA, Nadeau DF, Nicholls EM, Nilsson MB, Ohta T, Peichl M, Petrone RM, Petrov R, Prokushkin A, Quinton WL, Reed DE, Roulet NT, Runkle BR, Sonnentag O, Strachan IB, Taillardat P, Tuittila ES, Tuovinen JP, Turner J, Ueyama M, Varlagin A, Wilmking M, Wofsy SC and Zyrianov V (2020), "Increasing contribution of peatlands to boreal evapotranspiration in a warming climate", Nature Climate Change., jun, 2020. Vol. 10(6), pp. 555-560. Nature Research. |
| Abstract: The response of evapotranspiration (ET) to warming is of critical importance to the water and carbon cycle of the boreal biome, a mosaic of land cover types dominated by forests and peatlands. The effect of warming-induced vapour pressure deficit (VPD) increases on boreal ET remains poorly understood because peatlands are not specifically represented as plant functional types in Earth system models. Here we show that peatland ET increases more than forest ET with increasing VPD using observations from 95 eddy covariance tower sites. At high VPD of more than 2 kPa, peatland ET exceeds forest ET by up to 30%. Future (2091–2100) mid-growing season peatland ET is estimated to exceed forest ET by over 20% in about one-third of the boreal biome for RCP4.5 and about two-thirds for RCP8.5. Peatland-specific ET responses to VPD should therefore be included in Earth system models to avoid biases in water and carbon cycle projections. |
BibTeX:
@article{Helbig2020,
author = {Helbig, Manuel and Waddington, James Michael and Alekseychik, Pavel and Amiro, Brian D. and Aurela, Mika and Barr, Alan G. and Black, T. Andrew and Blanken, Peter D. and Carey, Sean K. and Chen, Jiquan and Chi, Jinshu and Desai, Ankur R. and Dunn, Allison and Euskirchen, Eugenie S. and Flanagan, Lawrence B. and Forbrich, Inke and Friborg, Thomas and Grelle, Achim and Harder, Silvie and Heliasz, Michal and Humphreys, Elyn R. and Ikawa, Hiroki and Isabelle, Pierre Erik and Iwata, Hiroki and Jassal, Rachhpal and Korkiakoski, Mika and Kurbatova, Juliya and Kutzbach, Lars and Lindroth, Anders and Löfvenius, Mikaell Ottosson and Lohila, Annalea and Mammarella, Ivan and Marsh, Philip and Maximov, Trofim and Melton, Joe R. and Moore, Paul A. and Nadeau, Daniel F. and Nicholls, Erin M. and Nilsson, Mats B. and Ohta, Takeshi and Peichl, Matthias and Petrone, Richard M. and Petrov, Roman and Prokushkin, Anatoly and Quinton, William L. and Reed, David E. and Roulet, Nigel T. and Runkle, Benjamin R.K. and Sonnentag, Oliver and Strachan, Ian B. and Taillardat, Pierre and Tuittila, Eeva Stiina and Tuovinen, Juha Pekka and Turner, Jessica and Ueyama, Masahito and Varlagin, Andrej and Wilmking, Martin and Wofsy, Steven C. and Zyrianov, Vyacheslav},
title = {Increasing contribution of peatlands to boreal evapotranspiration in a warming climate},
journal = {Nature Climate Change},
publisher = {Nature Research},
year = {2020},
volume = {10},
number = {6},
pages = {555--560},
doi = {10.1038/s41558-020-0763-7}
}
|
| Helbig M, Waddington JM, Alekseychik P, Amiro B, Aurela M, Barr AG, Black TA, Carey SK, Chen J, Chi J, Desai AR, Dunn A, Euskirchen ES, Flanagan LB, Friborg T, Garneau M, Grelle A, Harder S, Heliasz M, Humphreys ER, Ikawa H, Isabelle PE, Iwata H, Jassal R, Korkiakoski M, Kurbatova J, Kutzbach L, Lapshina E, Lindroth A, Löfvenius MO, Lohila A, Mammarella I, Marsh P, Moore PA, Maximov T, Nadeau DF, Nicholls EM, Nilsson MB, Ohta T, Peichl M, Petrone RM, Prokushkin A, Quinton WL, Roulet N, Runkle BRK, Sonnentag O, Strachan IB, Taillardat P, Tuittila ES, Tuovinen JP, Turner J, Ueyama M, Varlagin A, Vesala T, Wilmking M, Zyrianov V and Schulze C (2020), "The biophysical climate mitigation potential of boreal peatlands during the growing season", Environmental Research Letters. Vol. 15(10) |
| Abstract: Peatlands and forests cover large areas of the boreal biome and are critical for global climate regulation. They also regulate regional climate through heat and water vapour exchange with the atmosphere. Understanding how land-atmosphere interactions in peatlands differ from forests may therefore be crucial for modelling boreal climate system dynamics and for assessing climate benefits of peatland conservation and restoration. To assess the biophysical impacts of peatlands and forests on peak growing season air temperature and humidity, we analysed surface energy fluxes and albedo from 35 peatlands and 37 evergreen needleleaf forests - the dominant boreal forest type - and simulated air temperature and vapour pressure deficit (VPD) over hypothetical homogeneous peatland and forest landscapes. We ran an evapotranspiration model using land surface parameters derived from energy flux observations and coupled an analytical solution for the surface energy balance to an atmospheric boundary layer (ABL) model. We found that peatlands, compared to forests, are characterized by higher growing season albedo, lower aerodynamic conductance, and higher surface conductance for an equivalent VPD. This combination of peatland surface properties results in a ∼20% decrease in afternoon ABL height, a cooling (from 1.7 to 2.5 °C) in afternoon air temperatures, and a decrease in afternoon VPD (from 0.4 to 0.7 kPa) for peatland landscapes compared to forest landscapes. These biophysical climate impacts of peatlands are most pronounced at lower latitudes (∼45°N) and decrease toward the northern limit of the boreal biome (∼70°N). Thus, boreal peatlands have the potential to mitigate the effect of regional climate warming during the growing season. The biophysical climate mitigation potential of peatlands needs to be accounted for when projecting the future climate of the boreal biome, when assessing the climate benefits of conserving pristine boreal peatlands, and when restoring peatlands that have experienced peatland drainage and mining. |
BibTeX:
@article{Helbig2020a,
author = {Helbig, Manuel and Waddington, James M and Alekseychik, Pavel and Amiro, Brian and Aurela, Mika and Barr, Alan G and Black, T Andrew and Carey, Sean K and Chen, Jiquan and Chi, Jinshu and Desai, Ankur R and Dunn, Allison and Euskirchen, Eugenie S and Flanagan, Lawrence B and Friborg, Thomas and Garneau, Michelle and Grelle, Achim and Harder, Silvie and Heliasz, Michal and Humphreys, Elyn R and Ikawa, Hiroki and Isabelle, Pierre Erik and Iwata, Hiroki and Jassal, Rachhpal and Korkiakoski, Mika and Kurbatova, Juliya and Kutzbach, Lars and Lapshina, Elena and Lindroth, Anders and Löfvenius, Mikaell Ottosson and Lohila, Annalea and Mammarella, Ivan and Marsh, Philip and Moore, Paul A and Maximov, Trofim and Nadeau, Daniel F and Nicholls, Erin M and Nilsson, Mats B and Ohta, Takeshi and Peichl, Matthias and Petrone, Richard M and Prokushkin, Anatoly and Quinton, William L and Roulet, Nigel and Runkle, Benjamin R K and Sonnentag, Oliver and Strachan, Ian B and Taillardat, Pierre and Tuittila, Eeva Stiina and Tuovinen, Juha Pekka and Turner, Jessica and Ueyama, Masahito and Varlagin, Andrej and Vesala, Timo and Wilmking, Martin and Zyrianov, Vyacheslav and Schulze, Christopher},
title = {The biophysical climate mitigation potential of boreal peatlands during the growing season},
journal = {Environmental Research Letters},
year = {2020},
volume = {15},
number = {10},
doi = {10.1088/1748-9326/abab34}
}
|
| Henley SF, Cavan EL, Fawcett SE, Kerr R, Monteiro T, Sherrell RM, Bowie AR, Boyd PW, Barnes DKA, Schloss IR, Marshall T, Flynn R and Smith S (2020), "Changing Biogeochemistry of the Southern Ocean and Its Ecosystem Implications", Frontiers in Marine Science., jul, 2020. Vol. 7, pp. 581. Frontiers Media SA. |
| Abstract: The Southern Ocean plays a critical role in regulating global climate as a major sink for atmospheric carbon dioxide (CO2), and in global ocean biogeochemistry by supplying nutrients to the global thermocline, thereby influencing global primary production and carbon export. Biogeochemical processes within the Southern Ocean regulate regional primary production and biological carbon uptake, primarily through iron supply, and support ecosystem functioning over a range of spatial and temporal scales. Here we assimilate existing knowledge and present new data to examine the biogeochemical cycles of iron, carbon and major nutrients, their key drivers and their responses to, and roles in, contemporary climate and environmental change. Projected increases in iron supply, coupled with increases in light availability to phytoplankton through increased near-surface stratification and longer ice-free periods, are very likely to increase primary production and carbon export around Antarctica. Biological carbon uptake is likely to increase for the Southern Ocean as a whole, whilst there is greater uncertainty around projections of primary production in the Sub-Antarctic and basin-wide changes in phytoplankton species composition, as well as their biogeochemical consequences. Phytoplankton, zooplankton, higher trophic level organisms and microbial communities are strongly influenced by Southern Ocean biogeochemistry, in particular through nutrient supply and ocean acidification. In turn, these organisms exert important controls on biogeochemistry through carbon storage and export, nutrient recycling and redistribution, and benthic-pelagic coupling. The key processes described in this paper are summarised in the graphical abstract. Climate-mediated changes in Southern Ocean biogeochemistry over the coming decades are very likely to impact primary production, sea-air CO2 exchange and ecosystem functioning within and beyond this vast and critically important ocean region. |
BibTeX:
@article{Henley2020,
author = {Henley, Sian F. and Cavan, Emma L. and Fawcett, Sarah E. and Kerr, Rodrigo and Monteiro, Thiago and Sherrell, Robert M. and Bowie, Andrew R. and Boyd, Philip W. and Barnes, David K. A. and Schloss, Irene R. and Marshall, Tanya and Flynn, Raquel and Smith, Shantelle},
title = {Changing Biogeochemistry of the Southern Ocean and Its Ecosystem Implications},
journal = {Frontiers in Marine Science},
publisher = {Frontiers Media SA},
year = {2020},
volume = {7},
pages = {581},
url = {www.frontiersin.org},
doi = {10.3389/fmars.2020.00581}
}
|
| Hobeichi S, Abramowitz G and Evans J (2020), "Conserving Land–Atmosphere Synthesis Suite (CLASS)", Journal of Climate., mar, 2020. Vol. 33(5), pp. 1821-1844. |
| Abstract: Accurate estimates of terrestrial water and energy cycle components are needed to better understand climate processes and improve models' ability to simulate future change. Various observational estimates are available for the individual budget terms; however, these typically show inconsistencies when combined in a budget. In this work, a Conserving Land–Atmosphere Synthesis Suite (CLASS) of estimates of simultaneously balanced surface water and energy budget components is developed. Individual CLASS variable datasets, where possible, 1) combine a range of existing variable product estimates, and hence overcome the limitations of estimates from a single source; 2) are observationally constrained with in situ measurements; 3) have uncertainty estimates that are consistent with their agreement with in situ observations; and 4) are consistent with each other by being able to solve the water and energy budgets simultaneously. First, available datasets of a budget variable are merged by implementing a weighting method that accounts both for the ability of datasets to match in situ measurements and the error covariance between datasets. Then, the budget terms are adjusted by applying an objective variational data assimilation technique (DAT) that enforces the simultaneous closure of the surface water and energy budgets linked through the equivalence of evapotranspiration and latent heat. Comparing component estimates before and after applying the DAT against in situ measurements of energy fluxes and streamflow showed that modified estimates agree better with in situ observations across various metrics, but also revealed some inconsistencies between water budget terms in June over the higher latitudes. CLASS variable estimates are freely available via https://doi.org/10.25914/5c872258dc183. |
BibTeX:
@article{Hobeichi2020,
author = {Hobeichi, Sanaa and Abramowitz, Gab and Evans, Jason},
title = {Conserving Land–Atmosphere Synthesis Suite (CLASS)},
journal = {Journal of Climate},
year = {2020},
volume = {33},
number = {5},
pages = {1821--1844},
url = {https://journals.ametsoc.org/jcli/article/33/5/1821/347131/Conserving-LandAtmosphere-Synthesis-Suite-CLASS},
doi = {10.1175/JCLI-D-19-0036.1}
}
|
| Horemans JA, Janssens IA, Gielen B, Roland M, Deckmyn G, Verstraeten A, Neirynck J and Ceulemans R (2020), "Weather, pollution and biotic factors drive net forest - atmosphere exchange of CO2 at different temporal scales in a temperate-zone mixed forest", AGRICULTURAL AND FOREST METEOROLOGY., sep, 2020. Vol. 291 |
| Abstract: Understanding the drivers of net ecosystem exchange of carbon (NEE)
between forests and the atmosphere is crucial for the prediction of future global carbon dynamics. We therefore analyzed the long-term (1999-2014) ecosystem carbon fluxes of a mixed coniferous/deciduous forest (Brasschaat forest) in the Campine ecoregion of Belgium. The carbon uptake of this forest increased over the 16-year study period. By consecutively performing time series decomposition and the statistical technique of random forests, the correlative strength between multiple meteorological drivers, tropospheric pollutants and biotic indices with NEE was quantified at different time scales: i.e., long-term, seasonal and weekly, and separately for day- and nighttime NEE fluxes. The drivers that were most correlated with the trend in carbon sink capacity were the increasing atmospheric CO2 level and soil recovery from acidification. The radiation-saturated carbon uptake increased remarkably and explained much of the long-term variability of daytime NEE. When the long-term and seasonal variation were extracted the remaining weekly variation in daytime NEE was most strongly correlated with variation in the incoming radiation and cloudiness, and to a lesser extent by variation in vapor pressure deficit. In contrast to daytime NEE, nighttime NEE did not show a steady trend over time, but fluctuated, peaking in 1999 and in 2011. The long-term variability in nighttime NEE was most strongly correlated with the groundwater table depth. Air temperature was highly correlated to the seasonal as well as to the remaining weekly variation, i.e., after removal of the long-term and seasonal variability, in nighttime NEE. Biotic drivers (e.g., quantum yield and radiation saturated carbon uptake) explained less of the variation in NEE on a seasonal and short-term scale, but were more important at the long term. |
BibTeX:
@article{Horemans2020,
author = {Horemans, Joanna A and Janssens, Ivan A and Gielen, Bert and Roland, Marilyn and Deckmyn, Gaby and Verstraeten, Arne and Neirynck, Johan and Ceulemans, Reinhart},
title = {Weather, pollution and biotic factors drive net forest - atmosphere exchange of CO2 at different temporal scales in a temperate-zone mixed forest},
journal = {AGRICULTURAL AND FOREST METEOROLOGY},
year = {2020},
volume = {291},
doi = {10.1016/j.agrformet.2020.108059}
}
|
| Hough M, McClure A, Bolduc B, Dorrepaal E, Saleska S, Klepac-Ceraj V and Rich V (2020), "Biotic and Environmental Drivers of Plant Microbiomes Across a Permafrost Thaw Gradient", Frontiers in Microbiology. Vol. 11(May), pp. 1-18. |
| Abstract: Plant-associated microbiomes are structured by environmental conditions and plant associates, both of which are being altered by climate change. The future structure of plant microbiomes will depend on the, largely unknown, relative importance of each. This uncertainty is particularly relevant for arctic peatlands, which are undergoing large shifts in plant communities and soil microbiomes as permafrost thaws, and are potentially appreciable sources of climate change feedbacks due to their soil carbon (C) storage. We characterized phyllosphere and rhizosphere microbiomes of six plant species, and bulk peat, across a permafrost thaw progression (from intact permafrost, to partially- and fully-thawed stages) via 16S rRNA gene amplicon sequencing. We tested the hypothesis that the relative influence of biotic versus environmental filtering (the role of plant species versus thaw-defined habitat) in structuring microbial communities would differ among phyllosphere, rhizosphere, and bulk peat. Using both abundance- and phylogenetic-based approaches, we found that phyllosphere microbial composition was more strongly explained by plant associate, with little influence of habitat, whereas in the rhizosphere, plant and habitat had similar influence. Network-based community analyses showed that keystone taxa exhibited similar patterns with stronger responses to drivers. However, plant associates appeared to have a larger influence on organisms belonging to families associated with methane-cycling than the bulk community. Putative methanogens were more strongly influenced by plant than habitat in the rhizosphere, and in the phyllosphere putative methanotrophs were more strongly influenced by plant than was the community at large. We conclude that biotic effects can be stronger than environmental filtering, but their relative importance varies among microbial groups. For most microbes in this system, biotic filtering was stronger aboveground than belowground. However, for putative methane-cyclers, plant associations have a stronger influence on community composition than environment despite major hydrological changes with thaw. This suggests that plant successional dynamics may be as important as hydrological changes in determining microbial relevance to C-cycling climate feedbacks. By partitioning the degree that plant versus environmental filtering drives microbiome composition and function we can improve our ability to predict the consequences of warming for C-cycling in other arctic areas undergoing similar permafrost thaw transitions. |
BibTeX:
@article{Hough2020,
author = {Hough, Moira and McClure, Amelia and Bolduc, Benjamin and Dorrepaal, Ellen and Saleska, Scott and Klepac-Ceraj, Vanja and Rich, Virginia},
title = {Biotic and Environmental Drivers of Plant Microbiomes Across a Permafrost Thaw Gradient},
journal = {Frontiers in Microbiology},
year = {2020},
volume = {11},
number = {May},
pages = {1--18},
doi = {10.3389/fmicb.2020.00796}
}
|
| Hrachowitz M, Stockinger M, Coenders-Gerrits M, van der Ent R, Bogena H, Lücke A and Stumpp C (2020), "Deforestation reduces the vegetation-accessible water storage in the unsaturated soil and affects catchment travel time distributions and young water fractions", Hydrology and Earth System Sciences Discussions. Vol. 2020, pp. 1-43. |
BibTeX:
@article{Hrachowitz2020,
author = {Hrachowitz, M and Stockinger, M and Coenders-Gerrits, M and van der Ent, R and Bogena, H and Lücke, A and Stumpp, C},
title = {Deforestation reduces the vegetation-accessible water storage in the unsaturated soil and affects catchment travel time distributions and young water fractions},
journal = {Hydrology and Earth System Sciences Discussions},
year = {2020},
volume = {2020},
pages = {1--43},
url = {https://hess.copernicus.org/preprints/hess-2020-293/},
doi = {10.5194/hess-2020-293}
}
|
| Huang J, Desai AR, Zhu J, Hartemink AE, Stoy PC, Loheide SP, Bogena HR, Zhang Y, Zhang Z and Arriaga F (2020), "Retrieving Heterogeneous Surface Soil Moisture at 100 m Across the Globe via Fusion of Remote Sensing and Land Surface Parameters", Frontiers in Water. Vol. 2(October) |
BibTeX:
@article{Huang2020,
author = {Huang, Jingyi and Desai, Ankur R and Zhu, Jun and Hartemink, Alfred E and Stoy, Paul C and Loheide, Steven P and Bogena, Heye R and Zhang, Yakun and Zhang, Zhou and Arriaga, Francisco},
title = {Retrieving Heterogeneous Surface Soil Moisture at 100 m Across the Globe via Fusion of Remote Sensing and Land Surface Parameters},
journal = {Frontiers in Water},
year = {2020},
volume = {2},
number = {October},
doi = {10.3389/frwa.2020.578367}
}
|
| ERIC I (2020), "ICOS Handbook" Helsinki , pp. 1-150. ICOS ERIC. |
| Abstract: This book gives a comprehensive overview of ICOS research infrastructure, for example, of its data processing and data life cycle, organisational structure and technical details about station requirements. It also describes the National Networks and the process for a country to participate in this research infrastructure. Novel in this edition, we have added those prospective member countries, Spain and Poland, that have announced their intention to join ICOS ERIC in 2020. |
BibTeX:
@book{ICOS2020,
author = {ERIC, ICOS},
editor = {Ahlgren, Katri and Keski-Nisula, Mari},
title = {ICOS Handbook},
publisher = {ICOS ERIC},
year = {2020},
pages = {1--150},
edition = {2020-2},
url = {https://www.icos-cp.eu/sites/default/files/cmis/ICOS Handbook 2020.pdf}
}
|
| Järveoja J, Nilsson MB, Crill PM and Peichl M (2020), "Bimodal diel pattern in peatland ecosystem respiration rebuts uniform temperature response", Nature Communications., dec, 2020. Vol. 11(1), pp. 4255. |
BibTeX:
@article{Jaerveoja2020,
author = {Järveoja, Järvi and Nilsson, Mats B. and Crill, Patrick M. and Peichl, Matthias},
title = {Bimodal diel pattern in peatland ecosystem respiration rebuts uniform temperature response},
journal = {Nature Communications},
year = {2020},
volume = {11},
number = {1},
pages = {4255},
url = {http://www.nature.com/articles/s41467-020-18027-1},
doi = {10.1038/s41467-020-18027-1}
}
|
| Jakobi J, Huisman JA, Schrön M, Fiedler J, Brogi C, Vereecken H and Bogena HR (2020), "Error Estimation for Soil Moisture Measurements With Cosmic Ray Neutron Sensing and Implications for Rover Surveys", Frontiers in Water. Vol. 2(May), pp. 1-15. |
| Abstract: Cosmic ray neutron (CRN) sensing allows for non-invasive soil moisture measurements at the field scale and relies on the inverse correlation between aboveground measured epithermal neutron intensity (1 eV−100 keV) and environmental water content. The measurement uncertainty follows Poisson statistics and thus increases with decreasing neutron intensity, which corresponds to increasing soil moisture. In order to reduce measurement uncertainty, the neutron count rate is usually aggregated over 12 or 24 h time windows for stationary CRN probes. To obtain accurate soil moisture estimates with mobile CRN rover applications, the aggregation of neutron measurements is also necessary and should consider soil wetness and driving speed. To date, the optimization of spatial aggregation of mobile CRN observations in order to balance measurement accuracy and spatial resolution of soil moisture patterns has not been investigated in detail. In this work, we present and apply an easy-to-use method based on Gaussian error propagation theory for uncertainty quantification of soil moisture measurements obtained with CRN sensing. We used a 3 rd order Taylor expansion for estimating the soil moisture uncertainty from uncertainty in neutron counts and compared the results to a Monte Carlo approach with excellent agreement. Furthermore, we applied our method with selected aggregation times to investigate how CRN rover survey design affects soil moisture estimation uncertainty. We anticipate that the new approach can be used to improve the strategic planning and evaluation of CRN rover surveys based on uncertainty requirements. |
BibTeX:
@article{Jakobi2020,
author = {Jakobi, Jannis and Huisman, Johan A and Schrön, Martin and Fiedler, Justus and Brogi, Cosimo and Vereecken, Harry and Bogena, Heye R},
title = {Error Estimation for Soil Moisture Measurements With Cosmic Ray Neutron Sensing and Implications for Rover Surveys},
journal = {Frontiers in Water},
year = {2020},
volume = {2},
number = {May},
pages = {1--15},
doi = {10.3389/frwa.2020.00010}
}
|
| Janardanan R, Maksyutov S, Tsuruta A, Wang F, Tiwari YK, Valsala V, Ito A, Yoshida Y, Kaiser JW, Janssens-Maenhout G, Arshinov M, Sasakawa M, Tohjima Y, Worthy DEJ, Dlugokencky EJ, Ramonet M, Arduini J, Lavric JV, Piacentino S, Krummel PB, Langenfelds RL, Mammarella I and Matsunaga T (2020), "Country-Scale Analysis of Methane Emissions with a High-Resolution Inverse Model Using GOSAT and Surface Observations", Remote Sensing., jan, 2020. Vol. 12(3), pp. 375. MDPI AG. |
| Abstract: textlessptextgreaterWe employed a global high-resolution inverse model to optimize the CH4 emission using Greenhouse gas Observing Satellite (GOSAT) and surface observation data for a period from 2011–2017 for the two main source categories of anthropogenic and natural emissions. We used the Emission Database for Global Atmospheric Research (EDGAR v4.3.2) for anthropogenic methane emission and scaled them by country to match the national inventories reported to the United Nations Framework Convention on Climate Change (UNFCCC). Wetland and soil sink prior fluxes were simulated using the Vegetation Integrative Simulator of Trace gases (VISIT) model. Biomass burning prior fluxes were provided by the Global Fire Assimilation System (GFAS). We estimated a global total anthropogenic and natural methane emissions of 340.9 Tg CH4 yr−1 and 232.5 Tg CH4 yr−1, respectively. Country-scale analysis of the estimated anthropogenic emissions showed that all the top-emitting countries showed differences with their respective inventories to be within the uncertainty range of the inventories, confirming that the posterior anthropogenic emissions did not deviate from nationally reported values. Large countries, such as China, Russia, and the United States, had the mean estimated emission of 45.7 ± 8.6, 31.9 ± 7.8, and 29.8 ± 7.8 Tg CH4 yr−1, respectively. For natural wetland emissions, we estimated large emissions for Brazil (39.8 ± 12.4 Tg CH4 yr−1), the United States (25.9 ± 8.3 Tg CH4 yr−1), Russia (13.2 ± 9.3 Tg CH4 yr−1), India (12.3 ± 6.4 Tg CH4 yr−1), and Canada (12.2 ± 5.1 Tg CH4 yr−1). In both emission categories, the major emitting countries all had the model corrections to emissions within the uncertainty range of inventories. The advantages of the approach used in this study were: (1) use of high-resolution transport, useful for simulations near emission hotspots, (2) prior anthropogenic emissions adjusted to the UNFCCC reports, (3) combining surface and satellite observations, which improves the estimation of both natural and anthropogenic methane emissions over spatial scale of countries.textless/ptextgreater |
BibTeX:
@article{Janardanan2020,
author = {Janardanan, Rajesh and Maksyutov, Shamil and Tsuruta, Aki and Wang, Fenjuan and Tiwari, Yogesh K. and Valsala, Vinu and Ito, Akihiko and Yoshida, Yukio and Kaiser, Johannes W. and Janssens-Maenhout, Greet and Arshinov, Mikhail and Sasakawa, Motoki and Tohjima, Yasunori and Worthy, Douglas E. J. and Dlugokencky, Edward J. and Ramonet, Michel and Arduini, Jgor and Lavric, Jost V. and Piacentino, Salvatore and Krummel, Paul B. and Langenfelds, Ray L. and Mammarella, Ivan and Matsunaga, Tsuneo},
title = {Country-Scale Analysis of Methane Emissions with a High-Resolution Inverse Model Using GOSAT and Surface Observations},
journal = {Remote Sensing},
publisher = {MDPI AG},
year = {2020},
volume = {12},
number = {3},
pages = {375},
url = {https://www.mdpi.com/2072-4292/12/3/375},
doi = {10.3390/rs12030375}
}
|
| Jansen J, F. Thornton B, Cortés A, Snöälv J, Wik M, MacIntyre S and Crill PM (2020), "Drivers of diffusive CH4 emissions from shallow subarctic lakes on daily to multi-year timescales", Biogeosciences. Vol. 17(7), pp. 1911-1932. |
| Abstract: Lakes and reservoirs contribute to regional carbon budgets via significant emissions of climate forcing trace gases. Here, for improved modelling, we use 8 years of floating chamber measurements from three small, shallow subarctic lakes (2010-2017, n = 1306) to separate the contribution of physical and biogeochemical processes to the turbulence-driven, diffusion-limited flux of methane (CH4) on daily to multi-year timescales. Correlative data include surface water concentration measurements (2009-2017, n = 606), total water column storage (2010-2017, n = 237), and in situ meteorological observations. We used the last to compute near-surface turbulence based on similarity scaling and then applied the surface renewal model to compute gas transfer velocities. Chamber fluxes averaged 6.9±0.3 mg CH4 m-2 d-1 and gas transfer velocities (k600) averaged 4.0±0.1 cm h-1. Chamber-derived gas transfer velocities tracked the power-law wind speed relation of the model. Coefficients for the model and dissipation rates depended on shear production of turbulence, atmospheric stability, and exposure to wind. Fluxes increased with wind speed until daily average values exceeded 6.5 m s-1, at which point emissions were suppressed due to rapid water column degassing reducing the water-air concentration gradient. Arrhenius-type temperature functions of the CH4 flux (E′a = 0.90 ± 0.14eV) were robust (R2≥0.93, ptextless0.01) and also applied to the surface CH4 concentration ((E′a = 0.88 ± 0.09 eV). These results imply that emissions were strongly coupled to production and supply to the water column. Spectral analysis indicated that on timescales shorter than a month, emissions were driven by wind shear whereas on longer timescales variations in water temperature governed the flux. Long-term monitoring efforts are essential to identify distinct functional relations that govern flux variability on timescales of weather and climate change. |
BibTeX:
@article{Jansen2020,
author = {Jansen, Joachim and F. Thornton, Brett and Cortés, Alicia and Snöälv, Jo and Wik, Martin and MacIntyre, Sally and Crill, Patrick M},
title = {Drivers of diffusive CH4 emissions from shallow subarctic lakes on daily to multi-year timescales},
journal = {Biogeosciences},
year = {2020},
volume = {17},
number = {7},
pages = {1911--1932},
doi = {10.5194/bg-17-1911-2020}
}
|
| Jansen J, Thornton BF, Wik M, MacIntyre S and Crill PM (2020), "Temperature Proxies as a Solution to Biased Sampling of Lake Methane Emissions", Geophysical Research Letters. Vol. 47(14) |
| Abstract: Lake emissions of the climate forcing trace gas methane (CH4) are spatiotemporally variable, but biases in flux measurements arising from undersampling are poorly quantified. We use a multiyear data set (2009–2017) of ice-free CH4 emissions from three subarctic lakes obtained with bubble traps (n = 14,677), floating chambers (n = 1,306), and surface concentrations plus a gas transfer model (n = 535) to quantify these biases and evaluate corrections. Sampling primarily in warmer summer months, as is common, overestimates the ice-free season flux by a factor 1.4–1.8. Temperature proxies based on Arrhenius functions that closely fit measured fluxes (R2 ≥ 0.93) enable gap filling the colder months of the ice-free season and reduce sampling bias. Ebullition (activation energy 1.36 eV) expressed greater temperature sensitivity than diffusion (1.00 eV). Resolving seasonal and interannual variability in fluxes with proxies requires ∼135 sampling days for ebullition, and 22 and 14 days for diffusion via models and chambers, respectively. |
BibTeX:
@article{Jansen2020a,
author = {Jansen, Joachim and Thornton, Brett F and Wik, Martin and MacIntyre, Sally and Crill, Patrick M},
title = {Temperature Proxies as a Solution to Biased Sampling of Lake Methane Emissions},
journal = {Geophysical Research Letters},
year = {2020},
volume = {47},
number = {14},
doi = {10.1029/2020GL088647}
}
|
| Janssens-Maenhout G, Pinty B, Dowell M, Zunker H, Andersson E, Balsamo G, Bézy J-L, Brunhes T, Bösch H, Bojkov B, Brunner D, Buchwitz M, Crisp D, Ciais P, Counet P, Dee D, Denier van der Gon H, Dolman H, Drinkwater M, Dubovik O, Engelen R, Fehr T, Fernandez V, Heimann M, Holmlund K, Houweling S, Husband R, Juvyns O, Kentarchos A, Landgraf J, Lang R, Löscher A, Marshall J, Meijer Y, Nakajima M, Palmer PI, Peylin P, Rayner P, Scholze M, Sierk B, Tamminen J and Veefkind P (2020), "Towards an operational anthropogenic CO2 emissions monitoring and verification support capacity", Bulletin of the American Meteorological Society., feb, 2020. Vol. preprint(2020) |
| Abstract: Under the Paris Agreement progress of emission reduction efforts is tracked on the basis of regular updates to national Greenhouse Gas (GHG) inventories, referred to as bottom-up estimates. However, only top-down atmospheric measurements can provide observation-based evidence of emission trends. Today there is no internationally agreed, operational capacity to monitor anthropogenic GHG emission trends using atmospheric measurements to complement national bottom-up inventories. |
BibTeX:
@article{Janssens-Maenhout2020,
author = {Janssens-Maenhout, G and Pinty, B and Dowell, M and Zunker, H and Andersson, E and Balsamo, G and Bézy, J.-L. and Brunhes, T and Bösch, H and Bojkov, B and Brunner, D and Buchwitz, M and Crisp, D and Ciais, P and Counet, P and Dee, D and Denier van der Gon, H and Dolman, H and Drinkwater, M and Dubovik, O and Engelen, R and Fehr, T and Fernandez, V and Heimann, M and Holmlund, K and Houweling, S and Husband, R and Juvyns, O and Kentarchos, A and Landgraf, J and Lang, R and Löscher, A and Marshall, J and Meijer, Y and Nakajima, M and Palmer, P I and Peylin, P and Rayner, P and Scholze, M and Sierk, B and Tamminen, J and Veefkind, P},
title = {Towards an operational anthropogenic CO2 emissions monitoring and verification support capacity},
journal = {Bulletin of the American Meteorological Society},
year = {2020},
volume = {preprint},
number = {2020},
url = {https://journals.ametsoc.org/bams/article/345576/Towards-an-operational-anthropogenic-CO2-emissions},
doi = {10.1175/BAMS-D-19-0017.1}
}
|
| Jiang T, Wang D, Meng B, Chi J, Laudon H and Liu J (2020), "The concentrations and characteristics of dissolved organic matter in high-latitude lakes determine its ambient reducing capacity", Water Research. Vol. 169, pp. 115217. Elsevier Ltd. |
| Abstract: The reducing capacity (RC) of natural organic matter plays an important role in the carbon cycle and biogeochemical fates of environmental contaminants in the aquatic system. However, the electron donation potentials of dissolved organic matter (DOM) from high-latitude lakes are still uncertain. In this study, we collected DOM samples from high-latitude lakes across the Arctic and boreal regions in Sweden and Norway to investigate the effects of the DOM concentration and characteristics on its ambient reducing capacity (ARC). Mercury (Hg(II)) abiotic reduction in darkness was used to determine the ARC. The results showed that the DOM in Arctic lakes is less terrestrial-dominant than in reference sites (i.e., forest lakes). Between the two categories of Arctic lakes, tundra lakes are more terrestrial-influenced compared to mountain lakes. Additionally, terrestrial-originated DOM is a main controlling factor for enhancing the ambient reducing capacity, whereas the DOM concentration, i.e., dissolved organic carbon (DOC), resulted in variations in the Hg/DOC ratios that also cause the variations of the observed ARC values. Thus, comparisons of the ARC values can be conducted while oxidant/DOC ratios are kept the same and reported through the method using heavy metals as a chemical probe. After correction for Hg/DOC ratio interference, the ambient reducing capacity of DOM followed the order: boreal forest lakes textgreaterArctic tundra lakes textgreaterArctic mountain lakes. This study highlights that the DOM concentration should also be considered when estimating the ARC as compared to the previous that mainly focusing on the properties of DOM such as its origins. As climate change is projected to be severe in high latitudes, this study demonstrates a significant connection between aquatic DOM geochemical reactivity and terrestrial inputs, which is crucial for a better prediction of the role of DOM in high-latitude lakes in the context of climate change. |
BibTeX:
@article{Jiang2020,
author = {Jiang, Tao and Wang, Dingyong and Meng, Bo and Chi, Jinshu and Laudon, Hjalmar and Liu, Jiang},
title = {The concentrations and characteristics of dissolved organic matter in high-latitude lakes determine its ambient reducing capacity},
journal = {Water Research},
publisher = {Elsevier Ltd},
year = {2020},
volume = {169},
pages = {115217},
url = {https://doi.org/10.1016/j.watres.2019.115217},
doi = {10.1016/j.watres.2019.115217}
}
|
| Jung M, Schwalm C, Migliavacca M, Walther S, Camps-Valls G, Koirala S, Anthoni P, Besnard S, Bodesheim P, Carvalhais N, Chevallier F, Gans F, Goll DS, Haverd V, Köhler P, Ichii K, Jain AK, Liu J, Lombardozzi D, Nabel JEMS, Nelson JA, O&apos, Sullivan M, Pallandt M, Papale D, Peters W, Pongratz J, Rödenbeck C, Sitch S, Tramontana G, Walker A, Weber U and Reichstein M (2020), "Scaling carbon fluxes from eddy covariance sites to globe: synthesis and evaluation of the FLUXCOM approach", Biogeosciences., mar, 2020. Vol. 17(5), pp. 1343-1365. |
| Abstract: 0.94 at 1∘ spatial resolution) while the majority of DGVMs show, for 70 % of the land surface, values outside the FLUXCOM range. Global mean GPP magnitudes for 2008–2010 from FLUXCOM members vary within 106 and 130 PgC yrâˆ'1 with the largest uncertainty in the tropics. Seasonal variations in independent SIF estimates agree better with FLUXCOM GPP (mean global pixel-wise R2∼0.75) than with GPP from DGVMs (mean global pixel-wise R2∼0.6). Seasonal variations in FLUXCOM NEE show good consistency with atmospheric inversion-based net land carbon fluxes, particularly for temperate and boreal regions (R20.92). Interannual variability of global NEE in FLUXCOM is underestimated compared to inversions and DGVMs. The FLUXCOM version which also uses meteorological inputs shows a strong co-variation in interannual patterns with inversions (R2=0.87 for 2001–2010). Mean regional NEE from FLUXCOM shows larger uptake than inversion and DGVM-based estimates, particularly in the tropics with discrepancies of up to several hundred grammes of carbon per square metre per year. These discrepancies can only partly be reconciled by carbon loss pathways that are implicit in inversions but not captured by the flux tower measurements such as carbon emissions from fires and water bodies. We hypothesize that a combination of systematic biases in the underlying eddy covariance data, in particular in tall tropical forests, and a lack of site history effects on NEE in FLUXCOM are likely responsible for the too strong tropical carbon sink estimated by FLUXCOM. Furthermore, as FLUXCOM does not account for CO2 fertilization effects, carbon flux trends are not realistic. Overall, current FLUXCOM estimates of mean annual and seasonal cycles of GPP as well as seasonal NEE variations provide useful constraints of global carbon cycling, while interannual variability patterns from FLUXCOM are valuable but require cautious interpretation. Exploring the diversity of Earth observation data and of machine learning concepts along with improved quality and quantity of flux tower measurements will facilitate further improvements of the FLUXCOM approach overall.]] |
BibTeX:
@article{Jung2020,
author = {Jung, Martin and Schwalm, Christopher and Migliavacca, Mirco and Walther, Sophia and Camps-Valls, Gustau and Koirala, Sujan and Anthoni, Peter and Besnard, Simon and Bodesheim, Paul and Carvalhais, Nuno and Chevallier, Frédéric and Gans, Fabian and Goll, Daniel S and Haverd, Vanessa and Köhler, Philipp and Ichii, Kazuhito and Jain, Atul K and Liu, Junzhi and Lombardozzi, Danica and Nabel, Julia E M S and Nelson, Jacob A and O&apos;Sullivan, Michael and Pallandt, Martijn and Papale, Dario and Peters, Wouter and Pongratz, Julia and Rödenbeck, Christian and Sitch, Stephen and Tramontana, Gianluca and Walker, Anthony and Weber, Ulrich and Reichstein, Markus},
title = {Scaling carbon fluxes from eddy covariance sites to globe: synthesis and evaluation of the FLUXCOM approach},
journal = {Biogeosciences},
year = {2020},
volume = {17},
number = {5},
pages = {1343--1365},
url = {https://www.biogeosciences.net/17/1343/2020/},
doi = {10.5194/bg-17-1343-2020}
}
|
| Kaikkonen L, Enberg S, Blomster J, Luhtanen A-M, Autio R and Rintala J-M (2020), "Autumn to spring microbial community in the northern Baltic Sea: temporal variability in bacterial, viral and nanoflagellate abundance during the cold-water season", Polar Biology., jun, 2020. |
BibTeX:
@article{Kaikkonen2020,
author = {Kaikkonen, Laura and Enberg, Sara and Blomster, Jaanika and Luhtanen, Anne-Mari and Autio, Riitta and Rintala, Janne-Markus},
title = {Autumn to spring microbial community in the northern Baltic Sea: temporal variability in bacterial, viral and nanoflagellate abundance during the cold-water season},
journal = {Polar Biology},
year = {2020},
url = {http://link.springer.com/10.1007/s00300-020-02700-8},
doi = {10.1007/s00300-020-02700-8}
}
|
| Kammer J, Décuq C, Baisnée D, Ciuraru R, Lafouge F, Buysse P, Bsaibes S, Henderson B, Cristescu SM, Benabdallah R, Chandra V, Durand B, Fanucci O, Petit JE, Truong F, Bonnaire N, Sarda-Estève R, Gros V and Loubet B (2020), "Characterization of particulate and gaseous pollutants from a French dairy and sheep farm", Science of the Total Environment., apr, 2020. Vol. 712, pp. 135598. Elsevier BV. |
| Abstract: Agricultural activities highly contribute to atmospheric pollution, but the diversity and the magnitude of their emissions are still subject to large uncertainties. A field measurement campaign was conducted to characterize gaseous and particulate emissions from an experimental farm in France containing a sheep pen and a dairy stable. During the campaign, more than four hundred volatile organic compounds (VOCs) were characterized using an original combination of online and off-line measurements. Carbon dioxide (CO2) and ammonia (NH3) were the most concentrated compounds inside the buildings, followed by methanol, acetic acid and acetaldehyde. A CO2 mass balance model was used to estimate NH3 and VOC emission rates. To our knowledge, this study constitutes the first evaluation of emission rates for most of the identified VOCs. The measurements show that the dairy stable emitted more VOCs than the sheep pen. Despite strong VOC and NH3 emissions, the chemical composition of particles indicates that gaseous farm emissions do not affect the loading of fine particles inside the farm and is mainly explained by the low residence time inside the buildings. The experimental dataset obtained in this work will help to improve emissions inventories for agricultural activities. |
BibTeX:
@article{Kammer2020,
author = {Kammer, Julien and Décuq, Céline and Baisnée, Dominique and Ciuraru, Raluca and Lafouge, Florence and Buysse, Pauline and Bsaibes, Sandy and Henderson, Ben and Cristescu, Simona M and Benabdallah, Rachid and Chandra, Varunesh and Durand, Brigitte and Fanucci, Oliver and Petit, Jean Eudes and Truong, Francois and Bonnaire, Nicolas and Sarda-Estève, Roland and Gros, Valerie and Loubet, Benjamin},
title = {Characterization of particulate and gaseous pollutants from a French dairy and sheep farm},
journal = {Science of the Total Environment},
publisher = {Elsevier BV},
year = {2020},
volume = {712},
pages = {135598},
doi = {10.1016/j.scitotenv.2019.135598}
}
|
| Kannenberg SA, Bowling DR and Anderegg WR (2020), "Hot moments in ecosystem fluxes: High GPP anomalies exert outsized influence on the carbon cycle and are differentially driven by moisture availability across biomes", Environmental Research Letters., may, 2020. Vol. 15(5) Institute of Physics Publishing. |
| Abstract: The 'hot spot-hot moment' concept is a long-standing and popular framework often invoked to explain spatially or temporally variable rates of biogeochemical cycling. However, this concept has been rarely extended to ecosystem fluxes such as gross primary productivity (GPP), in part due to the lack of a quantitative definition of hot moments that can be applied to large flux datasets. Here, we develop a general statistical framework for quantifying hot moments in GPP and identify their spatial patterns and climatic drivers. Using 308 site-years of eddy covariance data from the FLUXNET2015 dataset spanning 32 U.S. sites, we found hot moments in GPP to comprise a disproportionate percentage of annual carbon (C) uptake relative to the frequency of their occurrence. For example, at five sites over 12% of annual C uptake occurred during the ∼2% most extreme half-hourly or hourly observations of GPP. Hot moments were most quantitatively important for the C cycle in short-stature, arid ecosystem such as grasslands, woody savannas, and open shrublands, where these positive anomalies in GPP were caused by increases in moisture availability. In contrast, hot moments were less important for annual C uptake in more mesic ecosystems, where their occurrence was largely determined by high temperature and light availability. Our results point to a need to consider how short-term spikes in environmental conditions exert an outsized influence on annual GPP, and how future shifts in these conditions could impact the terrestrial C cycle. |
BibTeX:
@article{Kannenberg2020,
author = {Kannenberg, Steven A. and Bowling, David R. and Anderegg, William R.L.},
title = {Hot moments in ecosystem fluxes: High GPP anomalies exert outsized influence on the carbon cycle and are differentially driven by moisture availability across biomes},
journal = {Environmental Research Letters},
publisher = {Institute of Physics Publishing},
year = {2020},
volume = {15},
number = {5},
doi = {10.1088/1748-9326/ab7b97}
}
|
| Kitz F, Spielmann FM, Hammerle A, Kolle O, Migliavacca M, Moreno G, Ibrom A, Krasnov D, Noe SM and Wohlfahrt G (2020), "Soil COS Exchange: A Comparison of Three European Ecosystems", Global Biogeochemical Cycles. Vol. 34(4) |
| Abstract: The potential of carbonyl sulfide (COS) flux measurements as an additional constraint for estimating the gross primary production depends, among other preconditions, on our understanding of the soil COS exchange and its contribution to the overall net ecosystem COS flux. We conducted soil chamber measurements of COS, with transparent chambers, in three different ecosystems across Europe. The in situ measurements were followed by laboratory measurements of soil samples collected at the study sites. The soil samples were exposed to UV radiation to investigate the role of photo-degradation for COS exchange. In situ and laboratory measurements revealed pronounced intersite and intrasite variability of COS exchange. In situ COS fluxes were primarily governed by radiation in the savannah-like grassland (SAV), soil temperature and intrasite heterogeneity in the deciduous broadleaf forest, and soil water content and intrasite heterogeneity in the evergreen needleleaf forest. The soil of the ecosystem with the highest light intensity incident on the soil surface, SAV, was a net source for COS, while the soils of the other two ecosystems were COS sinks. UV radiation increased COS emissions and/or reduced COS uptake from all soil samples under laboratory conditions. The impact of UV on the COS flux differed between soil samples, with a tendency toward a stronger response of the COS flux to UV radiation exposure in samples with higher soil organic matter content. Our results emphasize the importance of photo-degradation for the soil COS flux and stress the substantial spatial variability of soil COS exchange in ecosystems. |
BibTeX:
@article{Kitz2020,
author = {Kitz, Florian and Spielmann, Felix M and Hammerle, Albin and Kolle, Olaf and Migliavacca, Mirco and Moreno, Gerardo and Ibrom, Andreas and Krasnov, Dmitrii and Noe, Steffen M and Wohlfahrt, Georg},
title = {Soil COS Exchange: A Comparison of Three European Ecosystems},
journal = {Global Biogeochemical Cycles},
year = {2020},
volume = {34},
number = {4},
doi = {10.1029/2019GB006202}
}
|
| Koebsch F, Sonnentag O, Järveoja J, Peltoniemi M, Alekseychik P, Aurela M, Arslan AN, Dinsmore K, Gianelle D, Helfter C, Jackowicz-Korczynski M, Korrensalo A, Leith F, Linkosalmi M, Lohila A, Lund M, Maddison M, Mammarella I, Mander Ü, Minkkinen K, Pickard A, Pullens JWM, Tuittila ES, Nilsson MB and Peichl M (2020), "Refining the role of phenology in regulating gross ecosystem productivity across European peatlands", Global Change Biology., dec, 2020. Vol. 26(2), pp. 876-887. Wiley. |
| Abstract: The role of plant phenology as a regulator for gross ecosystem productivity (GEP) in peatlands is empirically not well constrained. This is because proxies to track vegetation development with daily coverage at the ecosystem scale have only recently become available and the lack of such data has hampered the disentangling of biotic and abiotic effects. This study aimed at unraveling the mechanisms that regulate the seasonal variation in GEP across a network of eight European peatlands. Therefore, we described phenology with canopy greenness derived from digital repeat photography and disentangled the effects of radiation, temperature and phenology on GEP with commonality analysis and structural equation modeling. The resulting relational network could not only delineate direct effects but also accounted for possible effect combinations such as interdependencies (mediation) and interactions (moderation). We found that peatland GEP was controlled by the same mechanisms across all sites: phenology constituted a key predictor for the seasonal variation in GEP and further acted as a distinct mediator for temperature and radiation effects on GEP. In particular, the effect of air temperature on GEP was fully mediated through phenology, implying that direct temperature effects representing the thermoregulation of photosynthesis were negligible. The tight coupling between temperature, phenology and GEP applied especially to high latitude and high altitude peatlands and during phenological transition phases. Our study highlights the importance of phenological effects when evaluating the future response of peatland GEP to climate change. Climate change will affect peatland GEP especially through changing temperature patterns during plant phenologically sensitive phases in high latitude and high altitude regions. |
BibTeX:
@article{Koebsch2020,
author = {Koebsch, Franziska and Sonnentag, Oliver and Järveoja, Järvi and Peltoniemi, Mikko and Alekseychik, Pavel and Aurela, Mika and Arslan, Ali Nadir and Dinsmore, Kerry and Gianelle, Damiano and Helfter, Carole and Jackowicz-Korczynski, Marcin and Korrensalo, Aino and Leith, Fraser and Linkosalmi, Maiju and Lohila, Annalea and Lund, Magnus and Maddison, Martin and Mammarella, Ivan and Mander, Ülo and Minkkinen, Kari and Pickard, Amy and Pullens, Johannes W M and Tuittila, Eeva Stiina and Nilsson, Mats B and Peichl, Matthias},
title = {Refining the role of phenology in regulating gross ecosystem productivity across European peatlands},
journal = {Global Change Biology},
publisher = {Wiley},
year = {2020},
volume = {26},
number = {2},
pages = {876--887},
doi = {10.1111/gcb.14905}
}
|
| Koebsch F, Gottschalk P, Beyer F, Wille C, Jurasinski G and Sachs T (2020), "The impact of occasional drought periods on vegetation spread and greenhouse gas exchange in rewetted fens", Philosophical Transactions of the Royal Society B: Biological Sciences., oct, 2020. Vol. 375(1810), pp. 20190685. |
| Abstract: Peatland rewetting aims at stopping the emissions of carbon dioxide (CO 2 ) and establishing net carbon sinks. However, in times of global warming, restoration projects must increasingly deal with extreme events such as drought periods. Here, we evaluate the effect of the European summer drought 2018 on vegetation development and the exchange of methane (CH 4 ) and CO 2 in two rewetted minerotrophic fens (Hütelmoor—Hte and Zarnekow—Zrk) including potential carry-over effects in the post-drought year. Drought was a major stress factor for the established vegetation but also promoted the rapid spread of new vegetation, which will likely gain a lasting foothold in Zrk. Accordingly, drought increased not only respiratory CO 2 losses but also photosynthetic CO 2 uptake. Altogether, the drought reduced the net CO 2 sink in Hte, while it stopped the persistent net CO 2 emissions of Zrk. In addition, the drought reduced CH 4 emissions in both fens, though this became most apparent in the post-drought year and suggests a lasting shift towards non-methanogenic organic matter decomposition. Occasional droughts can be beneficial for the restoration of the peatland carbon sink function if the newly grown vegetation increases CO 2 sequestration in the long term. Nonetheless, care must be taken to prevent extensive peat decay. |
BibTeX:
@article{Koebsch2020a,
author = {Koebsch, Franziska and Gottschalk, Pia and Beyer, Florian and Wille, Christian and Jurasinski, Gerald and Sachs, Torsten},
title = {The impact of occasional drought periods on vegetation spread and greenhouse gas exchange in rewetted fens},
journal = {Philosophical Transactions of the Royal Society B: Biological Sciences},
year = {2020},
volume = {375},
number = {1810},
pages = {20190685},
url = {https://royalsocietypublishing.org/doi/10.1098/rstb.2019.0685},
doi = {10.1098/rstb.2019.0685}
}
|
| Korkiakoski M, Ojanen P, Penttilä T, Minkkinen K, Sarkkola S, Rainne J, Laurila T and Lohila A (2020), "Impact of partial harvest on CH4 and N2O balances of a drained boreal peatland forest", Agricultural and Forest Meteorology. Vol. 295(March), pp. 108168. Elsevier. |
| Abstract: Rotation forestry including clearcutting is a common method of practising forestry in Fennoscandia. Clearcutting in peatland forests markedly increases environmental loading: leaching of nutrients and methane (CH4) and nitrous oxide (N2O) fluxes from soil. Continuous cover forestry has been suggested as an alternative because it does not include clearcutting but partial harvesting. However, impacts of partial harvesting on greenhouse gas fluxes are not well understood and in peatlands have not been studied at all. We conducted a partial harvest by removing 70% of the total stem volume in a mature nutrient-rich peatland forest in Southern Finland. The aim was to investigate how partial harvesting a peatland forest affects CH4 and N2O balances, and how much different surface types contribute to the balances. We used automatic and manual chamber methods to measure fluxes from both harvest and uncut control site. Fluxes were measured from the forest floor, logging trails, and ditches. Fluxes from these surface types were upscaled to obtain net ecosystem-level fluxes during two post-harvest summers (June–August 2016 and 2017). After the harvest, forest floor CH4 fluxes did not change significantly at the harvested site compared to the control site. However, fluxes at logging trails increased significantly. N2O fluxes increased at the harvest site in the post-harvest years, but so did those at the control site as well. Upscaling CH4 fluxes to ecosystem-level indicated that despite their small area (2.4%), emissions from ditches could be large on ecosystem-scale, but their uncertainty was high, while the logging trail CH4 fluxes (20% of the total area) were small. In contrast, N2O fluxes from ditches were low, but the logging trail fluxes comprised 35–38% of the total surface balance. The overall conclusion is that partial harvesting did not cause considerable changes in CH4 and N2O fluxes from a forestry-drained peatland. |
BibTeX:
@article{Korkiakoski2020,
author = {Korkiakoski, Mika and Ojanen, Paavo and Penttilä, Timo and Minkkinen, Kari and Sarkkola, Sakari and Rainne, Juuso and Laurila, Tuomas and Lohila, Annalea},
title = {Impact of partial harvest on CH4 and N2O balances of a drained boreal peatland forest},
journal = {Agricultural and Forest Meteorology},
publisher = {Elsevier},
year = {2020},
volume = {295},
number = {March},
pages = {108168},
url = {https://doi.org/10.1016/j.agrformet.2020.108168},
doi = {10.1016/j.agrformet.2020.108168}
}
|
| Korrensalo A, Mehtätalo L, Alekseychik P, Uljas S, Mammarella I, Vesala T and Tuittila ES (2020), "Varying Vegetation Composition, Respiration and Photosynthesis Decrease Temporal Variability of the CO2 Sink in a Boreal Bog", Ecosystems., jun, 2020. Vol. 23(4), pp. 842-858. Springer. |
| Abstract: We quantified the role of spatially varying vegetation composition in seasonal and interannual changes in a boreal bog's CO2 uptake. We divided the spatially heterogeneous site into six microform classes based on plant species composition and measured their net ecosystem exchange (NEE) using chamber method over the growing seasons in 2012–2014. A nonlinear mixed-effects model was applied to assess how the contributions of microforms with different vegetation change temporally, and to upscale NEE to the ecosystem level to be compared with eddy covariance (EC) measurements. Both ecosystem respiration (R) and gross photosynthesis (PG) were the largest in high hummocks, 894–964 (R) and 969–1132 (PG) g CO2 m−2 growing season−1, and decreased toward the wetter microforms. NEE had a different spatial pattern than R and PG; the highest cumulative seasonal CO2 sink was found in lawns in all years (165–353 g CO2 m−2). Microforms with similar wetness but distinct vegetation had different NEE, highlighting the importance of vegetation composition in regulating CO2 sink. Chamber-based ecosystem-level NEE was smaller and varied less interannually than the EC-derived estimate, indicating a need for further research on the error sources of both methods. Lawns contributed more to ecosystem-level NEE (55–78%) than their areal cover within the site (21.5%). In spring and autumn, lawns had the highest NEE, whereas in midsummer differences among microforms were small. The contributions of all microforms to the ecosystem-level NEE varied seasonally and interannually, suggesting that spatially heterogeneous vegetation composition could make bog CO2 uptake temporally more stable. |
BibTeX:
@article{Korrensalo2020,
author = {Korrensalo, Aino and Mehtätalo, Lauri and Alekseychik, Pavel and Uljas, Salli and Mammarella, Ivan and Vesala, Timo and Tuittila, Eeva Stiina},
title = {Varying Vegetation Composition, Respiration and Photosynthesis Decrease Temporal Variability of the CO2 Sink in a Boreal Bog},
journal = {Ecosystems},
publisher = {Springer},
year = {2020},
volume = {23},
number = {4},
pages = {842--858},
doi = {10.1007/s10021-019-00434-1}
}
|
| Kowalska N, Šigut L, Stojanović M, Fischer M, Kyselova I and Pavelka M (2020), "Analysis of floodplain forest sensitivity to drought", Philosophical Transactions of the Royal Society B: Biological Sciences., oct, 2020. Vol. 375(1810), pp. 20190518. |
| Abstract: Floodplain forests are very complex, productive ecosystems, capable of storing huge amounts of soil carbon. With the increasing occurrence of extreme events, they are today among the most threatened ecosystems. Our study's main goal was to assess the productivity of a floodplain forest located at Lanžhot in the Czech Republic from two perspectives: carbon uptake (using an eddy covariance method) and stem radius variations (using dendrometers). We aimed to determine which conditions allow for high ecosystem production and what role drought plays in reducing such production potential. Additionally, we were interested to determine the relative soil water content threshold indicating the onset and duration of this event. We hypothesized that summer drought in 2018 had the most significant negative effects on the overall annual carbon and water budgets. In contrast with our original hypothesis, we found that an exceptionally warm spring in 2018 caused a positive gross primary production (GPP) and evapotranspiration (ET) anomaly that consequently led in 2018 to the highest seasonal total GPP and ET from all of the investigated years (2015–2018). The results showed ring-porous species to be the most drought resistant. Relative soil water content threshold of approximately 0.45 was determined as indicating the onset of drought stress. |
BibTeX:
@article{Kowalska2020,
author = {Kowalska, Natalia and Šigut, Ladislav and Stojanović, Marko and Fischer, Milan and Kyselova, Ina and Pavelka, Marian},
title = {Analysis of floodplain forest sensitivity to drought},
journal = {Philosophical Transactions of the Royal Society B: Biological Sciences},
year = {2020},
volume = {375},
number = {1810},
pages = {20190518},
url = {https://royalsocietypublishing.org/doi/10.1098/rstb.2019.0518},
doi = {10.1098/rstb.2019.0518}
}
|
| Kozii N, Haahti K, Tor-Ngern P, Chi J, Maher Hasselquist E, Laudon H, Launiainen S, Oren R, Peichl M, rgen Wallerman J and Hasselquist NJ (2020), "Partitioning growing season water balance within a forested boreal catchment using sap flux, eddy covariance, and a process-based model", Hydrology and Earth System Sciences., jun, 2020. Vol. 24(6), pp. 2999-3014. Copernicus GmbH. |
| Abstract: Although it is well known that evapotranspiration (ET) represents an important water flux at local to global scales, few studies have quantified the magnitude and relative importance of ET and its individual flux components in high-latitude forests. In this study, we combined empirical sapflux, throughfall, and eddy-covariance measurements with estimates from a process-based model to partition the water balance in a northern boreal forested catchment. This study was conducted within the Krycklan catchment, which has a rich history of hydrological measurements, thereby providing us with the unique opportunity to compare the absolute and relative magnitudes of ET and its flux components to other water balance components. During the growing season, ET represented ca. 85% of the incoming precipitation. Both empirical results and model estimates suggested that tree transpiration (T) and evaporation of intercepted water from the tree canopy (IC) represented 43% and 31% of ET, respectively, and together were equal to ca. 70%of incoming precipitation during the growing season. Understory evapotranspiration (ETu) was less important than T and IC during most of the study period, except for late autumn, when ETu was the largest ET flux component. Overall, our study highlights the importance of trees in regulating the water cycle of boreal catchments, implying that forest management impacts on stand structure as well as climate change effects on tree growth are likely to have large cascading effects on the way water moves through these forested landscapes. |
BibTeX:
@article{Kozii2020,
author = {Kozii, Nataliia and Haahti, Kersti and Tor-Ngern, Pantana and Chi, Jinshu and Maher Hasselquist, Eliza and Laudon, Hjalmar and Launiainen, Samuli and Oren, Ram and Peichl, Matthias and rgen Wallerman, J. and Hasselquist, Niles J.},
title = {Partitioning growing season water balance within a forested boreal catchment using sap flux, eddy covariance, and a process-based model},
journal = {Hydrology and Earth System Sciences},
publisher = {Copernicus GmbH},
year = {2020},
volume = {24},
number = {6},
pages = {2999--3014},
doi = {10.5194/hess-24-2999-2020}
}
|
| Krich C, Runge J, Miralles DG, Migliavacca M, Perez-Priego O, El-Madany T, Carrara A and Mahecha MD (2020), "Estimating causal networks in biosphere-atmosphere interaction with the PCMCI approach", Biogeosciences., feb, 2020. Vol. 17(4), pp. 1033-1061. Copernicus GmbH. |
| Abstract: The dynamics of biochemical processes in terrestrial ecosystems are tightly coupled to local meteorological conditions. Understanding these interactions is an essential prerequisite for predicting, e.g. the response of the terrestrial carbon cycle to climate change. However, many empirical studies in this field rely on correlative approaches and only very few studies apply causal discovery methods. Here we explore the potential for a recently proposed causal graph discovery algorithm to reconstruct the causal dependency structure underlying biosphere-atmosphere interactions. Using artificial time series with known dependencies that mimic real-world biosphere-atmosphere interactions we address the influence of non-stationarities, i.e. periodicity and heteroscedasticity, on the estimation of causal networks. We then investigate the interpretability of the method in two case studies. Firstly, we analyse three replicated eddy covariance datasets from a Mediterranean ecosystem. Secondly, we explore global Normalised Difference Vegetation Index time series (GIMMS 3g), along with gridded climate data to study large-scale climatic drivers of vegetation greenness. We compare the retrieved causal graphs to simple cross-correlation-based approaches to test whether causal graphs are considerably more informative. Overall, the results confirm the capacity of the causal discovery method to extract time-lagged linear dependencies under realistic settings. For example, we find a complete decoupling of the net ecosystem exchange from meteorological variability during summer in the Mediterranean ecosystem. However, cautious interpretations are needed, as the violation of the method's assumptions due to non-stationarities increases the likelihood to detect false links. Overall, estimating directed biosphere-atmosphere networks helps unravel complex multidirectional process interactions. Other than classical correlative approaches, our findings are constrained to a few meaningful sets of relations, which can be powerful insights for the evaluation of terrestrial ecosystem models. |
BibTeX:
@article{Krich2020,
author = {Krich, Christopher and Runge, Jakob and Miralles, Diego G. and Migliavacca, Mirco and Perez-Priego, Oscar and El-Madany, Tarek and Carrara, Arnaud and Mahecha, Miguel D.},
title = {Estimating causal networks in biosphere-atmosphere interaction with the PCMCI approach},
journal = {Biogeosciences},
publisher = {Copernicus GmbH},
year = {2020},
volume = {17},
number = {4},
pages = {1033--1061},
doi = {10.5194/bg-17-1033-2020}
}
|
| Kuhry P, Barta J, Blok D, Elberling B, Faucherre S, Hugelius G, Jørgensen CJ, Richter A, ŠantrÅ̄čková H and Weiss N (2020), "Lability classification of soil organic matter in the northern permafrost region", Biogeosciences. Vol. 17(2), pp. 361-379. |
| Abstract: The large stocks of soil organic carbon (SOC) in soils and deposits of the northern permafrost region are sensitive to global warming and permafrost thawing. The potential release of this carbon (C) as greenhouse gases to the atmosphere does not only depend on the total quantity of soil organic matter (SOM) affected by warming and thawing, but it also depends on its lability (i.e., the rate at which it will decay). In this study we develop a simple and robust classification scheme of SOM lability for the main types of soils and deposits in the northern permafrost region. The classification is based on widely available soil geochemical parameters and landscape unit classes, which makes it useful for upscaling to the entire northern permafrost region. We have analyzed the relationship between C content and C-textlessspan classCombining double low line"inline-formula"textgreaterCO2textless/spantextgreaterproduction rates of soil samples in two different types of laboratory incubation experiments. In one experiment, ca. 240 soil samples from four study areas were incubated using the same protocol (at 5&thinsp;textlessspan classCombining double low line"inline-formula"textgreaterĝtextless/spantextgreaterC, aerobically) over a period of 1 year. Here we present C release rates measured on day 343 of incubation. These long-term results are compared to those obtained from short-term incubations of ca. 1000 samples (at 12&thinsp;textlessspan classCombining double low line"inline-formula"textgreaterĝtextless/spantextgreaterC, aerobically) from an additional three study areas. In these experiments, C-textlessspan classCombining double low line"inline-formula"textgreaterCO2textless/spantextgreaterproduction rates were measured over the first 4&thinsp;d of incubation. We have focused our analyses on the relationship between C-textlessspan classCombining double low line"inline-formula"textgreaterCO2textless/spantextgreaterproduction per gram dry weight per day (textlessspan classCombining double low line"inline-formula"textgreater$$textless/spantextgreatergC-textlessspan classCombining double low line"inline-formula"textgreaterCO2textless/spantextgreater&thinsp;gdwtextlessspan classCombining double low line"inline-formula"textgreater-1textless/spantextgreater&thinsp;dtextlessspan classCombining double low line"inline-formula"textgreater-1textless/spantextgreater) and C content (%C of dry weight) in the samples, but we show that relationships are consistent when using textlessspan classCombining double low line"inline-formula"textgreaterC ĝ• Ntextless/spantextgreaterratios or different production units such as textlessspan classCombining double low line"inline-formula"textgreater$$textless/spantextgreatergC per gram soil C per day (textlessspan classCombining double low line"inline-formula"textgreater$$textless/spantextgreatergC-textlessspan classCombining double low line"inline-formula"textgreaterCO2textless/spantextgreater&thinsp;gCtextlessspan classCombining double low line"inline-formula"textgreater-1textless/spantextgreater&thinsp;dtextlessspan classCombining double low line"inline-formula"textgreater-1textless/spantextgreater) or per&thinsp;cmtextlessspan classCombining double low line"inline-formula"textgreater3textless/spantextgreaterof soil per day (textlessspan classCombining double low line"inline-formula"textgreater$$textless/spantextgreatergC-textlessspan classCombining double low line"inline-formula"textgreaterCO2textless/spantextgreater&thinsp;cmtextlessspan classCombining double low line"inline-formula"textgreater-3textless/spantextgreater&thinsp;dtextlessspan classCombining double low line"inline-formula"textgreater-1textless/spantextgreater). C content of the samples is positively correlated to C-textlessspan classCombining double low line"inline-formula"textgreaterCO2textless/spantextgreaterproduction rates but explains less than 50&thinsp;% of the observed variability when the full datasets are considered. A partitioning of the data into landscape units greatly reduces variance and provides consistent results between incubation experiments. These results indicate that relative SOM lability decreases in the order of Late Holocene eolian deposits to alluvial deposits and mineral soils (including peaty wetlands) to Pleistocene yedoma deposits to C-enriched pockets in cryoturbated soils to peat deposits. Thus, three of the most important SOC storage classes in the northern permafrost region (yedoma, cryoturbated soils and peatlands) show low relative SOM lability. Previous research has suggested that SOM in these pools is relatively undecomposed, and the reasons for the observed low rates of decomposition in our experiments need urgenttextlessspan idCombining double low line"page362"/textgreaterattention if we want to better constrain the magnitude of the thawing permafrost carbon feedback on global warming. |
BibTeX:
@article{Kuhry2020,
author = {Kuhry, Peter and Barta, Jiri and Blok, Daan and Elberling, Bo and Faucherre, Samuel and Hugelius, Gustaf and Jørgensen, Christian J and Richter, Andreas and ŠantrÅ̄čková, Hana and Weiss, Niels},
title = {Lability classification of soil organic matter in the northern permafrost region},
journal = {Biogeosciences},
year = {2020},
volume = {17},
number = {2},
pages = {361--379},
doi = {10.5194/bg-17-361-2020}
}
|
| L. Tunnicliffe R, L. Ganesan A, J. Parker R, Boesch H, Gedney N, Poulter B, Zhang Z, Walter D, Rigby M, Henne S, Young D and O'Doherty S (2020), "Quantifying sources of Brazil's CH4 emissions between 2010 and 2018 from satellite data", Atmospheric Chemistry and Physics. Vol. 20(21), pp. 13041-13067. |
| Abstract: Brazil's CH4 emissions over the period 2010- 2018 were derived for the three main sectors of activity: anthropogenic, wetland and biomass burning. Our inverse modelling estimates were derived from GOSAT (Greenhouse gases Observing SATellite) satellite measurements of XCH4 combined with surface data from Ragged Point, Barbados, and the high-resolution regional atmospheric transport model NAME (Numerical Atmospheric-dispersion Modelling Environment). We find that Brazil's mean emissions over 2010- 2018 are 33:63:6Tgyr1, which are comprised of 19:0 2:6Tgyr1 from anthropogenic (primarily related to agriculture and waste), 13:01:9Tgyr1 from wetlands and 1:7 0:3Tgyr1 from biomass burning sources. In addition, between the 2011-2013 and 2014-2018 periods, Brazil's mean emissions rose by 6:95:3Tgyr1 and this increase may have contributed to the accelerated global methane growth rate observed during the latter period. We find that wetland emissions from the western Amazon increased during the start of the 2015-2016 El Nino by 3:72:7Tgyr1 and this is likely driven by increased surface temperatures. We also find that our estimates of anthropogenic emissions are consistent with those reported by Brazil to the United Framework Convention on Climate Change. We show that satellite data are beneficial for constraining national-scale CH4 emissions, and, through a series of sensitivity studies and validation experiments using data not assimilated in the inversion, we demonstrate that (a) calibrated ground-based data are important to include alongside satellite data in a regional inversion and that (b) inversions must account for any offsets between the two data streams and their representations by models. |
BibTeX:
@article{L.Tunnicliffe2020,
author = {L. Tunnicliffe, Rachel and L. Ganesan, Anita and J. Parker, Robert and Boesch, Hartmut and Gedney, Nicola and Poulter, Benjamin and Zhang, Zhen and Walter, David and Rigby, Matthew and Henne, Stephan and Young, Dickon and O'Doherty, Simon},
title = {Quantifying sources of Brazil's CH4 emissions between 2010 and 2018 from satellite data},
journal = {Atmospheric Chemistry and Physics},
year = {2020},
volume = {20},
number = {21},
pages = {13041--13067},
doi = {10.5194/acp-20-13041-2020}
}
|
| Languille B, Gros V, Petit JE, Honoré C, Baudic A, Perrussel O, Foret G, Michoud V, Truong F, Bonnaire N, Sarda-Estève R, Delmotte M, Feron A, Maisonneuve F, Gaimoz C, Formenti P, Kotthaus S, Haeffelin M and Favez O (2020), "Wood burning: A major source of Volatile Organic Compounds during wintertime in the Paris region", Science of the Total Environment., apr, 2020. Vol. 711, pp. 135055. Elsevier BV. |
| Abstract: Wood burning is widely used for domestic heating and has been identified as a ubiquitous pollution source in urban areas, especially during cold months. The present study is based on a three and a half winter months field campaign in the Paris region measuring Volatile Organic Compounds (VOCs) by Proton Transfer Reaction Mass Spectrometry (PTR-MS) in addition to Black Carbon (BC). Several VOCs were identified as strongly wood burning-influenced (e.g., acetic acid, furfural), or traffic-influenced (e.g., toluene, C8-aromatics). Methylbutenone, benzenediol and butandione were identified for the first time as wood burning-related in ambient air. A Positive Matrix Factorization (PMF) analysis highlighted that wood burning is the most important source of VOCs during the winter season. (47%). Traffic was found to account for about 22% of the measured VOCs during the same period, whereas solvent use plus background accounted altogether for the remaining fraction. The comparison with the regional emission inventory showed good consistency for benzene and xylenes but revisions of the inventory should be considered for several VOCs such as acetic acid, C9-aromatics and methanol. Finally, complementary measurements acquired simultaneously at other sites in Île-de-France (the Paris region) enabled evaluation of spatial variabilities. The influence of traffic emissions on investigated pollutants displayed a clear negative gradient from roadside to suburban stations, whereas wood burning pollution was found to be fairly homogeneous over the region. |
BibTeX:
@article{Languille2020,
author = {Languille, Baptiste and Gros, Valérie and Petit, Jean Eudes and Honoré, Cécile and Baudic, Alexia and Perrussel, Olivier and Foret, Gilles and Michoud, Vincent and Truong, François and Bonnaire, Nicolas and Sarda-Estève, Roland and Delmotte, Marc and Feron, Anaïs and Maisonneuve, Franck and Gaimoz, Cécile and Formenti, Paola and Kotthaus, Simone and Haeffelin, Martial and Favez, Olivier},
title = {Wood burning: A major source of Volatile Organic Compounds during wintertime in the Paris region},
journal = {Science of the Total Environment},
publisher = {Elsevier BV},
year = {2020},
volume = {711},
pages = {135055},
doi = {10.1016/j.scitotenv.2019.135055}
}
|
| Lansu EM, van Heerwaarden CC, Stegehuis AI and Teuling AJ (2020), "Atmospheric Aridity and Apparent Soil Moisture Drought in European Forest During Heat Waves", Geophysical Research Letters., mar, 2020. Vol. 47(6) Blackwell Publishing Ltd. |
| Abstract: Land-atmosphere feedbacks, in particular the response of land evaporation to vapor pressure deficit (VPD) or the dryness of the air, remain poorly understood. Here we investigate the VPD response by analysis of a large database of eddy covariance flux observations and simulations using a conceptual model of the atmospheric boundary layer. Data analysis reveals that under high VPD and corresponding high temperatures, forest in particular reduces evaporation and emits more sensible heat. In contrast, grass increases evaporation and emits less sensible heat. Simulations show that this VPD feedback can induce significant temperature increases over forest of up to 2 K during heat wave conditions. It is inferred from the simulations that the effect of the VPD feedback corresponds to an apparent soil moisture depletion of more than 50%. This suggests that previous studies may have incorrectly attributed the effects of atmospheric aridity on temperature to soil dryness. |
BibTeX:
@article{Lansu2020,
author = {Lansu, Eva M. and van Heerwaarden, C. C. and Stegehuis, Annemiek I. and Teuling, Adriaan J.},
title = {Atmospheric Aridity and Apparent Soil Moisture Drought in European Forest During Heat Waves},
journal = {Geophysical Research Letters},
publisher = {Blackwell Publishing Ltd},
year = {2020},
volume = {47},
number = {6},
doi = {10.1029/2020GL087091}
}
|
| Lefèvre N, Tyaquiçã P, Veleda D, Perruche C and van Gennip SJ (2020), "Amazon River propagation evidenced by a CO2 decrease at 8°N, 38°W in September 2013", Journal of Marine Systems., nov, 2020. Vol. 211 Elsevier B.V.. |
| Abstract: The surface fugacity of CO2 (fCO2) has been measured hourly at a mooring at 8°N, 38°W, using a spectrophotometric CO2 sensor, from June to October 2013. In September 2013, the fCO2 and the sea surface salinity (SSS) decrease significantly. The high precipitation due to the presence of the Intertropical Convergence Zone (ITCZ) and the propagation of low salinity waters from the Amazon River plume explain the decrease of SSS. Indeed, in fall, the retroflection of the North Brazil Current (NBC) feeds the North Equatorial Counter Current (NECC) and transports Amazon waters to the eastern part of the tropical Atlantic. Simulations from a three dimensional physical and biogeochemical model and observations at the mooring show that the Amazon plume reached the mooring in September 2013. The decrease of fCO2 is associated with a moderate peak of chlorophyll. Over the period of the CO2 observations, the site is a source of CO2 to the atmosphere of 0.65 ± 0.47 mmol m−2 day−1. Although the wind speed is at its lowest intensity in September 2013, the flux over the whole period would be about 14% higher without this month. Every month of September from 2006 to 2017, the model simulates a decrease of dissolved inorganic carbon corresponding to the SSS minimum. |
BibTeX:
@article{Lefevre2020,
author = {Lefèvre, Nathalie and Tyaquiçã, Pedro and Veleda, Doris and Perruche, Coralie and van Gennip, Simon Jan},
title = {Amazon River propagation evidenced by a CO2 decrease at 8°N, 38°W in September 2013},
journal = {Journal of Marine Systems},
publisher = {Elsevier B.V.},
year = {2020},
volume = {211},
doi = {10.1016/j.jmarsys.2020.103419}
}
|
| Legge O, Johnson M, Hicks N, Jickells T, Diesing M, Aldridge J, Andrews J, Artioli Y, Bakker DC, Burrows MT, Carr N, Cripps G, Felgate SL, Fernand L, Greenwood N, Hartman S, Kröger S, Lessin G, Mahaffey C, Mayor DJ, Parker R, Queirós AM, Shutler JD, Silva T, Stahl H, Tinker J, Underwood GJ, Van Der Molen J, Wakelin S, Weston K and Williamson P (2020), "Carbon on the Northwest European Shelf: Contemporary Budget and Future Influences", Frontiers in Marine Science., mar, 2020. Vol. 7, pp. 143. Frontiers Media S.A.. |
| Abstract: A carbon budget for the northwest European continental shelf seas (NWES) was synthesized using available estimates for coastal, pelagic and benthic carbon stocks and flows. Key uncertainties were identified and the effect of future impacts on the carbon budget were assessed. The water of the shelf seas contains between 210 and 230 Tmol of carbon and absorbs between 1.3 and 3.3 Tmol from the atmosphere annually. Off-shelf transport and burial in the sediments account for 60–100 and 0–40% of carbon outputs from the NWES, respectively. Both of these fluxes remain poorly constrained by observations and resolving their magnitudes and relative importance is a key research priority. Pelagic and benthic carbon stocks are dominated by inorganic carbon. Shelf sediments contain the largest stock of carbon, with between 520 and 1600 Tmol stored in the top 0.1 m of the sea bed. Coastal habitats such as salt marshes and mud flats contain large amounts of carbon per unit area but their total carbon stocks are small compared to pelagic and benthic stocks due to their smaller spatial extent. The large pelagic stock of carbon will continue to increase due to the rising concentration of atmospheric CO2, with associated pH decrease. Pelagic carbon stocks and flows are also likely to be significantly affected by increasing acidity and temperature, and circulation changes but the net impact is uncertain. Benthic carbon stocks will be affected by increasing temperature and acidity, and decreasing oxygen concentrations, although the net impact of these interrelated changes on carbon stocks is uncertain and a major knowledge gap. The impact of bottom trawling on benthic carbon stocks is unique amongst the impacts we consider in that it is widespread and also directly manageable, although its net effect on the carbon budget is uncertain. Coastal habitats are vulnerable to sea level rise and are strongly impacted by management decisions. Local, national and regional actions have the potential to protect or enhance carbon storage, but ultimately global governance, via controls on emissions, has the greatest potential to influence the long-term fate of carbon stocks in the northwestern European continental shelf. |
BibTeX:
@article{Legge2020,
author = {Legge, Oliver and Johnson, Martin and Hicks, Natalie and Jickells, Tim and Diesing, Markus and Aldridge, John and Andrews, Julian and Artioli, Yuri and Bakker, Dorothee C.E. and Burrows, Michael T. and Carr, Nealy and Cripps, Gemma and Felgate, Stacey L. and Fernand, Liam and Greenwood, Naomi and Hartman, Susan and Kröger, Silke and Lessin, Gennadi and Mahaffey, Claire and Mayor, Daniel J. and Parker, Ruth and Queirós, Ana M. and Shutler, Jamie D. and Silva, Tiago and Stahl, Henrik and Tinker, Jonathan and Underwood, Graham J.C. and Van Der Molen, Johan and Wakelin, Sarah and Weston, Keith and Williamson, Phillip},
title = {Carbon on the Northwest European Shelf: Contemporary Budget and Future Influences},
journal = {Frontiers in Marine Science},
publisher = {Frontiers Media S.A.},
year = {2020},
volume = {7},
pages = {143},
url = {www.frontiersin.org},
doi = {10.3389/fmars.2020.00143}
}
|
| Lembrechts JJ, Aalto J, Ashcroft MB, De Frenne P, Kopecký M, Lenoir J, Luoto M, Maclean IM, Roupsard O, Fuentes-Lillo E, García RA, Pellissier L, Pitteloud C, Alatalo JM, Smith SW, Björk RG, Muffler L, Ratier Backes A, Cesarz S, Gottschall F, Okello J, Urban J, Plichta R, Svátek M, Phartyal SS, Wipf S, Eisenhauer N, Pușcaș M, Turtureanu PD, Varlagin A, Dimarco RD, Jump AS, Randall K, Dorrepaal E, Larson K, Walz J, Vitale L, Svoboda M, Finger Higgens R, Halbritter AH, Curasi SR, Klupar I, Koontz A, Pearse WD, Simpson E, Stemkovski M, Jessen Graae B, Vedel Sørensen M, Høye TT, Fernández Calzado MR, Lorite J, Carbognani M, Tomaselli M, Forte TG, Petraglia A, Haesen S, Somers B, Van Meerbeek K, Björkman MP, Hylander K, Merinero S, Gharun M, Buchmann N, Dolezal J, Matula R, Thomas AD, Bailey JJ, Ghosn D, Kazakis G, de Pablo MA, Kemppinen J, Niittynen P, Rew L, Seipel T, Larson C, Speed JD, Ardö J, Cannone N, Guglielmin M, Malfasi F, Bader MY, Canessa R, Stanisci A, Kreyling J, Schmeddes J, Teuber L, Aschero V, Čiliak M, Máliš F, De Smedt P, Govaert S, Meeussen C, Vangansbeke P, Gigauri K, Lamprecht A, Pauli H, Steinbauer K, Winkler M, Ueyama M, Nuñez MA, Ursu TM, Haider S, Wedegärtner RE, Smiljanic M, Trouillier M, Wilmking M, Altman J, Brůna J, Hederová L, Macek M, Man M, Wild J, Vittoz P, Pärtel M, Barančok P, Kanka R, Kollár J, Palaj A, Barros A, Mazzolari AC, Bauters M, Boeckx P, Benito Alonso JL, Zong S, Di Cecco V, Sitková Z, Tielbörger K, van den Brink L, Weigel R, Homeier J, Dahlberg CJ, Medinets S, Medinets V, De Boeck HJ, Portillo-Estrada M, Verryckt LT, Milbau A, Daskalova GN, Thomas HJ, Myers-Smith IH, Blonder B, Stephan JG, Descombes P, Zellweger F, Frei ER, Heinesch B, Andrews C, Dick J, Siebicke L, Rocha A, Senior RA, Rixen C, Jimenez JJ, Boike J, Pauchard A, Scholten T, Scheffers B, Klinges D, Basham EW, Zhang J, Zhang Z, Géron C, Fazlioglu F, Candan O, Sallo Bravo J, Hrbacek F, Laska K, Cremonese E, Haase P, Moyano FE, Rossi C and Nijs I (2020), "SoilTemp: A global database of near-surface temperature", Global Change Biology. Blackwell Publishing Ltd. |
| Abstract: Current analyses and predictions of spatially explicit patterns and processes in ecology most often rely on climate data interpolated from standardized weather stations. This interpolated climate data represents long-term average thermal conditions at coarse spatial resolutions only. Hence, many climate-forcing factors that operate at fine spatiotemporal resolutions are overlooked. This is particularly important in relation to effects of observation height (e.g. vegetation, snow and soil characteristics) and in habitats varying in their exposure to radiation, moisture and wind (e.g. topography, radiative forcing or cold-air pooling). Since organisms living close to the ground relate more strongly to these microclimatic conditions than to free-air temperatures, microclimatic ground and near-surface data are needed to provide realistic forecasts of the fate of such organisms under anthropogenic climate change, as well as of the functioning of the ecosystems they live in. To fill this critical gap, we highlight a call for temperature time series submissions to SoilTemp, a geospatial database initiative compiling soil and near-surface temperature data from all over the world. Currently, this database contains time series from 7,538 temperature sensors from 51 countries across all key biomes. The database will pave the way toward an improved global understanding of microclimate and bridge the gap between the available climate data and the climate at fine spatiotemporal resolutions relevant to most organisms and ecosystem processes. |
BibTeX:
@article{Lembrechts2020,
author = {Lembrechts, Jonas J. and Aalto, Juha and Ashcroft, Michael B. and De Frenne, Pieter and Kopecký, Martin and Lenoir, Jonathan and Luoto, Miska and Maclean, Ilya M.D. and Roupsard, Olivier and Fuentes-Lillo, Eduardo and García, Rafael A. and Pellissier, Loïc and Pitteloud, Camille and Alatalo, Juha M. and Smith, Stuart W. and Björk, Robert G. and Muffler, Lena and Ratier Backes, Amanda and Cesarz, Simone and Gottschall, Felix and Okello, Joseph and Urban, Josef and Plichta, Roman and Svátek, Martin and Phartyal, Shyam S. and Wipf, Sonja and Eisenhauer, Nico and Pușcaș, Mihai and Turtureanu, Pavel D. and Varlagin, Andrej and Dimarco, Romina D. and Jump, Alistair S. and Randall, Krystal and Dorrepaal, Ellen and Larson, Keith and Walz, Josefine and Vitale, Luca and Svoboda, Miroslav and Finger Higgens, Rebecca and Halbritter, Aud H. and Curasi, Salvatore R. and Klupar, Ian and Koontz, Austin and Pearse, William D. and Simpson, Elizabeth and Stemkovski, Michael and Jessen Graae, Bente and Vedel Sørensen, Mia and Høye, Toke T. and Fernández Calzado, M. Rosa and Lorite, Juan and Carbognani, Michele and Tomaselli, Marcello and Forte, T'ai G.W. and Petraglia, Alessandro and Haesen, Stef and Somers, Ben and Van Meerbeek, Koenraad and Björkman, Mats P. and Hylander, Kristoffer and Merinero, Sonia and Gharun, Mana and Buchmann, Nina and Dolezal, Jiri and Matula, Radim and Thomas, Andrew D. and Bailey, Joseph J. and Ghosn, Dany and Kazakis, George and de Pablo, Miguel A. and Kemppinen, Julia and Niittynen, Pekka and Rew, Lisa and Seipel, Tim and Larson, Christian and Speed, James D.M. and Ardö, Jonas and Cannone, Nicoletta and Guglielmin, Mauro and Malfasi, Francesco and Bader, Maaike Y. and Canessa, Rafaella and Stanisci, Angela and Kreyling, Juergen and Schmeddes, Jonas and Teuber, Laurenz and Aschero, Valeria and Čiliak, Marek and Máliš, František and De Smedt, Pallieter and Govaert, Sanne and Meeussen, Camille and Vangansbeke, Pieter and Gigauri, Khatuna and Lamprecht, Andrea and Pauli, Harald and Steinbauer, Klaus and Winkler, Manuela and Ueyama, Masahito and Nuñez, Martin A. and Ursu, Tudor Mihai and Haider, Sylvia and Wedegärtner, Ronja E.M. and Smiljanic, Marko and Trouillier, Mario and Wilmking, Martin and Altman, Jan and Brůna, Josef and Hederová, Lucia and Macek, Martin and Man, Matěj and Wild, Jan and Vittoz, Pascal and Pärtel, Meelis and Barančok, Peter and Kanka, Róbert and Kollár, Jozef and Palaj, Andrej and Barros, Agustina and Mazzolari, Ana C. and Bauters, Marijn and Boeckx, Pascal and Benito Alonso, José Luis and Zong, Shengwei and Di Cecco, Valter and Sitková, Zuzana and Tielbörger, Katja and van den Brink, Liesbeth and Weigel, Robert and Homeier, Jürgen and Dahlberg, C. Johan and Medinets, Sergiy and Medinets, Volodymyr and De Boeck, Hans J. and Portillo-Estrada, Miguel and Verryckt, Lore T. and Milbau, Ann and Daskalova, Gergana N. and Thomas, Haydn J.D. and Myers-Smith, Isla H. and Blonder, Benjamin and Stephan, Jörg G. and Descombes, Patrice and Zellweger, Florian and Frei, Esther R. and Heinesch, Bernard and Andrews, Christopher and Dick, Jan and Siebicke, Lukas and Rocha, Adrian and Senior, Rebecca A. and Rixen, Christian and Jimenez, Juan J. and Boike, Julia and Pauchard, Aníbal and Scholten, Thomas and Scheffers, Brett and Klinges, David and Basham, Edmund W. and Zhang, Jian and Zhang, Zhaochen and Géron, Charly and Fazlioglu, Fatih and Candan, Onur and Sallo Bravo, Jhonatan and Hrbacek, Filip and Laska, Kamil and Cremonese, Edoardo and Haase, Peter and Moyano, Fernando E. and Rossi, Christian and Nijs, Ivan},
title = {SoilTemp: A global database of near-surface temperature},
journal = {Global Change Biology},
publisher = {Blackwell Publishing Ltd},
year = {2020},
doi = {10.1111/gcb.15123}
}
|
| Leppä K, Korkiakoski M, Nieminen M, Laiho R, Hotanen JP, Kieloaho AJ, Korpela L, Laurila T, Lohila A, Minkkinen K, Mäkipää R, Ojanen P, Pearson M, Penttilä T, Tuovinen JP and Launiainen S (2020), "Vegetation controls of water and energy balance of a drained peatland forest: Responses to alternative harvesting practices", Agricultural and Forest Meteorology. Vol. 295(April), pp. 108198. Elsevier. |
| Abstract: We quantified the response of peatland water table level (WTL) and energy fluxes to harvesting of a drained peatland forest. Two alternative harvests (clear-cut and partial harvest) were carried out in a mixed-species ditch-drained peatland forest in southern Finland, where water and energy balance components were monitored for six pre-treatment and three post-treatment growing seasons. To explore the responses caused by harvestings, we applied a mechanistic multi-layer soil-plant-atmosphere transfer model. At the clear-cut site, the mean growing season WTL rose by 0.18 ± 0.02 m (error estimate based on measurement uncertainty), while net radiation, and sensible and latent heat fluxes decreased after harvest. On the contrary, we observed only minor changes in energy fluxes and mean WTL (0.05 ± 0.03 m increase) at the partial harvest site, although as much as 70% of the stand basal area was removed and leaf-area index was reduced to half. The small changes were mainly explained by increased water use of spruce undergrowth and field layer vegetation, as well as increased forest floor evaporation. The rapid establishment of field layer vegetation had a significant role in energy balance recovery at the clear-cut site. At partial harvest, chlorophyll fluorescence measurements and model-data comparison suggested the shade-adapted spruce undergrowth was suffering from light stress during the first post-harvest growing season. We conclude that in addition to stand basal area, species composition and stand structure need to be considered when controlling WTL in peatland forests with partial harvesting. Our results have important implications on the operational use of continuous cover forestry on drained peatlands. A continuously maintained tree cover with significant evapotranspiration capacity could enable optimizing WTL from both tree growth and environmental perspectives. |
BibTeX:
@article{Leppae2020,
author = {Leppä, Kersti and Korkiakoski, Mika and Nieminen, Mika and Laiho, Raija and Hotanen, Juha Pekka and Kieloaho, Antti Jussi and Korpela, Leila and Laurila, Tuomas and Lohila, Annalea and Minkkinen, Kari and Mäkipää, Raisa and Ojanen, Paavo and Pearson, Meeri and Penttilä, Timo and Tuovinen, Juha Pekka and Launiainen, Samuli},
title = {Vegetation controls of water and energy balance of a drained peatland forest: Responses to alternative harvesting practices},
journal = {Agricultural and Forest Meteorology},
publisher = {Elsevier},
year = {2020},
volume = {295},
number = {April},
pages = {108198},
url = {https://doi.org/10.1016/j.agrformet.2020.108198},
doi = {10.1016/j.agrformet.2020.108198}
}
|
| Le Quéré C, Jackson RB, Jones MW, Smith AJP, Abernethy S, Andrew RM, De-Gol AJ, Willis DR, Shan Y, Canadell JG, Friedlingstein P, Creutzig F and Peters GP (2020), "Temporary reduction in daily global CO2 emissions during the COVID-19 forced confinement", Nature Climate Change., jul, 2020. Vol. 10(7), pp. 647-653. |
BibTeX:
@article{LeQuere2020,
author = {Le Quéré, Corinne and Jackson, Robert B and Jones, Matthew W and Smith, Adam J P and Abernethy, Sam and Andrew, Robbie M and De-Gol, Anthony J and Willis, David R and Shan, Yuli and Canadell, Josep G and Friedlingstein, Pierre and Creutzig, Felix and Peters, Glen P},
title = {Temporary reduction in daily global CO2 emissions during the COVID-19 forced confinement},
journal = {Nature Climate Change},
year = {2020},
volume = {10},
number = {7},
pages = {647--653},
url = {http://www.nature.com/articles/s41558-020-0797-x},
doi = {10.1038/s41558-020-0797-x}
}
|
| Leseurre C, Lo Monaco C, Reverdin G, Metzl N, Fin J, Olafsdottir S and Racapé V (2020), "Ocean carbonate system variability in the North Atlantic Subpolar surface water (1993-2017)", Biogeosciences., may, 2020. Vol. 17(9), pp. 2553-2577. Copernicus GmbH. |
| Abstract: The North Atlantic is one of the major ocean sinks for natural and anthropogenic atmospheric CO2. Given the variability of the circulation, convective processes or warming-cooling recognized in the high latitudes in this region, a better understanding of the CO2 sink temporal variability and associated acidification needs a close inspection of seasonal, interannual to multidecadal observations. In this study, we investigate the evolution of CO2 uptake and ocean acidification in the North Atlantic Subpolar Gyre (50-64_ N) using repeated observations collected over the last 3 decades in the framework of the long-term monitoring program SURATLANT (SURveillance de l'ATLANTique). Over the full period (1993-2017) pH decreases (-0:0017 yr-1) and fugacity of CO2 (fCO2) increases (C1.70 μatm yr-1). The trend of fCO2 in surface water is slightly less than the atmospheric rate (C1.96 μatm yr-1). This is mainly due to dissolved inorganic carbon (DIC) increase associated with the anthropogenic signal. However, over shorter periods (4-10 years) and depending on the season, we detect significant variability investigated in more detail in this study. Data obtained between 1993 and 1997 suggest a rapid increase in fCO2 in summer (up to C14 μatm yr-1) that was driven by a significant warming and an increase in DIC for a short period. Similar fCO2 trends are observed between 2001 and 2007 during both summer and winter, but, without significant warming detected, these trends are mainly explained by an increase in DIC and a decrease in alkalinity. This also leads to a pH decrease but with contrasting trends depending on the region and season (between -0:006 and -0:013 yr-1). Conversely, data obtained during the last decade (2008-2017) in summer show a cooling of surface waters and an increase in alkalinity, leading to a strong decrease in surface fCO2 (between -4:4 and -2:3 μatm yr-1; i.e., the ocean CO2 sink increases). Surprisingly, during summer, pH increases up to C0:0052 yr-1 in the southern subpolar gyre. Overall, our results show that, in addition to the accumulation of anthropogenic CO2, the temporal changes in the uptake of CO2 and ocean acidification in the North Atlantic Subpolar Gyre present significant multiannual variability, not clearly directly associated with the North Atlantic Oscillation (NAO). With such variability it is uncertain to predict the near-future evolution of air-sea CO2 fluxes and pH in this region. Thus, it is highly recommended to maintain long-term observations to monitor these properties in the next decade. |
BibTeX:
@article{Leseurre2020,
author = {Leseurre, Coraline and Lo Monaco, Claire and Reverdin, Gilles and Metzl, Nicolas and Fin, Jonathan and Olafsdottir, Solveig and Racapé, Virginie},
title = {Ocean carbonate system variability in the North Atlantic Subpolar surface water (1993-2017)},
journal = {Biogeosciences},
publisher = {Copernicus GmbH},
year = {2020},
volume = {17},
number = {9},
pages = {2553--2577},
doi = {10.5194/bg-17-2553-2020}
}
|
| Levin I, Karstens U, Eritt M, Maier F, Arnold S, Rzesanke D, Hammer S, Ramonet M, Vítková G, Conil S, Heliasz M, Kubistin D and Lindauer M (2020), "A dedicated flask sampling strategy developed for Integrated Carbon Observation System (ICOS) stations based on CO&lt;sub&gt;2&lt;/sub&gt; and CO measurements and Stochastic Time-Inverted Lagrangian Transport (STILT) footprint modelling", Atmospheric Chemistry and Physics., sep, 2020. Vol. 20(18), pp. 11161-11180. |
BibTeX:
@article{Levin2020,
author = {Levin, Ingeborg and Karstens, Ute and Eritt, Markus and Maier, Fabian and Arnold, Sabrina and Rzesanke, Daniel and Hammer, Samuel and Ramonet, Michel and Vítková, Gabriela and Conil, Sebastien and Heliasz, Michal and Kubistin, Dagmar and Lindauer, Matthias},
title = {A dedicated flask sampling strategy developed for Integrated Carbon Observation System (ICOS) stations based on CO&lt;sub&gt;2&lt;/sub&gt; and CO measurements and Stochastic Time-Inverted Lagrangian Transport (STILT) footprint modelling},
journal = {Atmospheric Chemistry and Physics},
year = {2020},
volume = {20},
number = {18},
pages = {11161--11180},
url = {https://acp.copernicus.org/articles/20/11161/2020/},
doi = {10.5194/acp-20-11161-2020}
}
|
| Levy P, Drewer J, Jammet M, Leeson S, Friborg T, Skiba U and van Oijen M (2020), "Inference of spatial heterogeneity in surface fluxes from eddy covariance data: A case study from a subarctic mire ecosystem", Agricultural and Forest Meteorology. Vol. 280(August 2019), pp. 107783. Elsevier. |
| Abstract: Horizontal heterogeneity causes difficulties in the eddy covariance technique for measuring surface fluxes, related to both advection and the confounding of temporal and spatial variability. Our aim here was to address this problem, using statistical modelling and footprint analysis, applied to a case study of fluxes of sensible heat and methane in a subarctic mire. We applied a new method to infer the spatial heterogeneity in fluxes of sensible heat and methane from a subarctic ecosystem in northern Sweden, where there were clear differences in surface types within the landscape. We inferred the flux from each of these surface types, using a Bayesian approach to estimate the parameters of a hierarchical model which includes coefficients for the different surface types. The approach is based on the variation in the flux observed at a single eddy covariance tower as the footprint changes over time. The method has applications wherever spatial heterogeneity is a concern in the interpretation of eddy covariance fluxes. |
BibTeX:
@article{Levy2020,
author = {Levy, Peter and Drewer, Julia and Jammet, Mathilde and Leeson, Sarah and Friborg, Thomas and Skiba, Ute and van Oijen, Marcel},
title = {Inference of spatial heterogeneity in surface fluxes from eddy covariance data: A case study from a subarctic mire ecosystem},
journal = {Agricultural and Forest Meteorology},
publisher = {Elsevier},
year = {2020},
volume = {280},
number = {August 2019},
pages = {107783},
url = {https://doi.org/10.1016/j.agrformet.2019.107783},
doi = {10.1016/j.agrformet.2019.107783}
}
|
| Li X, Wahlroos O, Haapanala S, Pumpanen J, Vasander H, Ojala A, Vesala T and Mammarella I (2020), "Carbon dioxide and methane fluxes from different surface types in a created urban wetland", Biogeosciences., jul, 2020. Vol. 17(13), pp. 3409-3425. Copernicus GmbH. |
| Abstract: Many wetlands have been drained due to urbanization, agriculture, forestry or other purposes, which has resulted in a loss of their ecosystem services. To protect receiving waters and to achieve services such as flood control and storm water quality mitigation, new wetlands are created in urbanized areas. However, our knowledge of greenhouse gas exchange in newly created wetlands in urban areas is currently limited. In this paper we present measurements carried out at a created urban wetland in Southern Finland in the boreal climate. We conducted measurements of ecosystem CO2 flux and CH4 flux (FCH4 ) at the created storm water wetland Gateway in Nummela, Vihti, Southern Finland, using the eddy covariance (EC) technique. The measurements were commenced the fourth year after construction and lasted for 1 full year and two subsequent growing seasons. Besides ecosystemscale fluxes measured by the EC tower, the diffusive CO2 and CH4 fluxes from the open-water areas (FwCO2 and FwCH4 , respectively) were modelled based on measurements of CO2 and CH4 concentration in the water. Fluxes from the vegetated areas were estimated by applying a simple mixing model using the above-mentioned fluxes and the footprintweighted fractional area. The half-hourly footprint-weighted contribution of diffusive fluxes from open water ranged from 0% to 25.5% in 2013. The annual net ecosystem exchange (NEE) of the studied wetland was 8.0 g C-CO2 m2 yr1, with the 95% confidence interval between 18:9 and 34.9 g C-CO2 m2 yr1, and FCH4 was 3.9 g C-CH4 m2 yr1, with the 95% confidence interval between 3.75 and 4.07 g C-CH4 m2 yr1. The ecosystem sequestered CO2 during summer months (June August), while the rest of the year it was a CO2 source. CH4 displayed strong seasonal dynamics, higher in summer and lower in winter, with a sporadic emission episode in the end of May 2013. Both CH4 and CO2 fluxes, especially those obtained from vegetated areas, exhibited strong diurnal cycles during summer with synchronized peaks around noon. The annual FwCO2 was 297.5 g C-CO2 m2 yr1 and FwCH4 was 1.73 g C-CH4 m2 yr1. The peak diffusive CH4 flux was 137.6 nmol C-CH4 m2 s1, which was synchronized with the FCH4 . Overall, during the monitored time period, the established storm water wetland had a climate-warming effect with 0.263 kgCO2-eqm2 yr1 of which 89% was contributed by CH4. The radiative forcing of the open-water areas exceeded that of the vegetation areas (1.194 and 0.111 kgCO2- eqm2 yr1, respectively), which implies that, when considering solely the climate impact of a created wetland over a 100-year horizon, it would be more beneficial to design and establish wetlands with large patches of emergent vegetation and to limit the areas of open water to the minimum necessitated by other desired ecosystem services. |
BibTeX:
@article{Li2020,
author = {Li, Xuefei and Wahlroos, Outi and Haapanala, Sami and Pumpanen, Jukka and Vasander, Harri and Ojala, Anne and Vesala, Timo and Mammarella, Ivan},
title = {Carbon dioxide and methane fluxes from different surface types in a created urban wetland},
journal = {Biogeosciences},
publisher = {Copernicus GmbH},
year = {2020},
volume = {17},
number = {13},
pages = {3409--3425},
doi = {10.5194/bg-17-3409-2020}
}
|
| Li X and Xiao J (2020), "Global climatic controls on interannual variability of ecosystem productivity: Similarities and differences inferred from solar-induced chlorophyll fluorescence and enhanced vegetation index", Agricultural and Forest Meteorology. Elsevier B.V.. |
| Abstract: Assessing how climate factors regulate the interannual variability (IAV) of ecosystem productivity globally is crucial for understanding the ecosystem-climate interactions and carbon-climate feedbacks under a changing climate. However, our understanding of global climatic controls on the IAV of ecosystem productivity has been limited by the lack of direct measurements of ecosystem productivity at the global scale. We used a long-term, fine-resolution solar-induced chlorophyll fluorescence (SIF) product (GOSIF) derived from SIF soundings measured by the Orbiting Carbon Observatory-2 (OCO-2) to investigate how climatic factors drive the IAV of global ecosystem productivity. We also examined how the results derived from SIF differed from those based on a satellite-derived measure of vegetation greenness and productivity - the enhanced vegetation index (EVI) derived from the Moderate Resolution Imaging Spectroradiometer (MODIS). Both productivity measures showed the dominant role of soil moisture in driving the IAV of global ecosystem productivity, particularly in arid and semi-arid areas. SIF was more sensitive to climate variability than was EVI. SIF was positively correlated with solar radiation in the humid regions, while no significant correlations were found between EVI and solar radiation. The stronger correlation of SIF with climate factors was also observed at the ecosystem level based on a number of eddy covariance flux sites, indicating that SIF had a higher ability in capturing the variations of gross primary productivity (GPP) than did EVI. The comparison between SIF and EVI also highlighted the biome-specific (depending on the tree cover) responses of ecosystem productivity to solar radiation under water stress. Our findings explicitly reveal the global climatic controls on the IAV of ecosystem productivity, and provide insight into the mechanistic differences between SIF and vegetation indices in characterizing ecosystem productivity. |
BibTeX:
@article{Li2020a,
author = {Li, Xing and Xiao, Jingfeng},
title = {Global climatic controls on interannual variability of ecosystem productivity: Similarities and differences inferred from solar-induced chlorophyll fluorescence and enhanced vegetation index},
journal = {Agricultural and Forest Meteorology},
publisher = {Elsevier B.V.},
year = {2020},
doi = {10.1016/j.agrformet.2020.108018}
}
|
| Lian X, Piao S, Li LZX, Li Y, Huntingford C, Ciais P, Cescatti A, Janssens IA, Peñuelas J, Buermann W, Chen A, Li X, Myneni RB, Wang X, Wang Y, Yang Y, Zeng Z, Zhang Y and McVicar TR (2020), "Summer soil drying exacerbated by earlier spring greening of northern vegetation", Science Advances., jan, 2020. Vol. 6(1), pp. eaax0255. American Association for the Advancement of Science (AAAS). |
| Abstract: Earlier vegetation greening under climate change raises evapotranspiration and thus lowers spring soil moisture, yet the extent and magnitude of this water deficit persistence into the following summer remain elusive. We provide observational evidence that increased foliage cover over the Northern Hemisphere, during 1982–2011, triggers an additional soil moisture deficit that is further carried over into summer. Climate model simulations independently support this and attribute the driving process to be larger increases in evapotranspiration than in precipitation. This extra soil drying is projected to amplify the frequency and intensity of summer heatwaves. Most feedbacks operate locally, except for a notable teleconnection where extra moisture transpired over Europe is transported to central Siberia. Model results illustrate that this teleconnection offsets Siberian soil moisture losses from local spring greening. Our results highlight that climate change adaptation planning must account for the extra summer water and heatwave stress inherited from warming-induced earlier greening. |
BibTeX:
@article{Lian2020,
author = {Lian, Xu and Piao, Shilong and Li, Laurent Z X and Li, Yue and Huntingford, Chris and Ciais, Philippe and Cescatti, Alessandro and Janssens, Ivan A and Peñuelas, Josep and Buermann, Wolfgang and Chen, Anping and Li, Xiangyi and Myneni, Ranga B and Wang, Xuhui and Wang, Yilong and Yang, Yuting and Zeng, Zhenzhong and Zhang, Yongqiang and McVicar, Tim R},
title = {Summer soil drying exacerbated by earlier spring greening of northern vegetation},
journal = {Science Advances},
publisher = {American Association for the Advancement of Science (AAAS)},
year = {2020},
volume = {6},
number = {1},
pages = {eaax0255},
doi = {10.1126/sciadv.aax0255}
}
|
| Lin H, Tu C, Fang J, Gioli B, Loubet B, Gruening C, Zhou G, Beringer J, Huang J, Dušek J, Liddell M, Buysse P, Shi P, Song Q, Han S, Magliulo V, Li Y and Grace J (2020), "Forests buffer thermal fluctuation better than non-forests", Agricultural and Forest Meteorology. Elsevier B.V.. |
| Abstract: With the increase in intensity and frequency of extreme climate events, interactions between vegetation and local climate are gaining more and more attention. Both the mean temperature and the temperature fluctuations of vegetation will exert thermal influence on local climate and the life of plants and animals. Many studies have focused on the pattern in the mean canopy surface temperature of vegetation, whereas there is still no systematic study of thermal buffer ability (TBA) of different vegetation types across global biomes. We developed a new method to measure TBA based on the rate of temperature increase, requiring only one radiometer. With this method, we compared TBA of ten vegetation types with contrasting structures, e.g. from grasslands to forests, using data from 133 sites globally. TBA ranged from 5.2 to 21.2 across these sites and biomes. Forests and wetlands buffer thermal fluctuation better than non-forests (grasslands, savannas, and croplands), and the TBA boundary between forests and non-forests was typically around 10. Notably, seriously disturbed and young planted forests displayed a greatly reduced TBA as low as that of non-forests at high latitudes. Canopy height was a primary controller of TBA of forests, while the TBA of grasslands and savannas were mainly determined by energy partition, water availability, and carbon sequestration rates. Our research suggests that both mean values and fluctuations in canopy surface temperature should be considered to predict the risk for plants under extreme events. Protecting mature forests, both at high and low latitudes, is critical to mitigate thermal fluctuation under extreme events. |
BibTeX:
@article{Lin2020,
author = {Lin, Hua and Tu, Chengyi and Fang, Junyong and Gioli, Beniamino and Loubet, Benjamin and Gruening, Carsten and Zhou, Guoyi and Beringer, Jason and Huang, Jianguo and Dušek, Jiří and Liddell, Michael and Buysse, Pauline and Shi, Peili and Song, Qinghai and Han, Shijie and Magliulo, Vincenzo and Li, Yingnian and Grace, John},
title = {Forests buffer thermal fluctuation better than non-forests},
journal = {Agricultural and Forest Meteorology},
publisher = {Elsevier B.V.},
year = {2020},
doi = {10.1016/j.agrformet.2020.107994}
}
|
| Lindroth A, Holst J, Linderson M-L, Aurela M, Biermann T, Heliasz M, Chi J, Ibrom A, Kolari P, Klemedtsson L, Krasnova A, Laurila T, Lehner I, Lohila A, Mammarella I, Mölder M, Löfvenius MO, Peichl M, Pilegaard K, Soosar K, Vesala T, Vestin P, Weslien P and Nilsson M (2020), "Effects of drought and meteorological forcing on carbon and water fluxes in Nordic forests during the dry summer of 2018", Philosophical Transactions of the Royal Society B: Biological Sciences., oct, 2020. Vol. 375(1810), pp. 20190516. |
| Abstract: The Nordic region was subjected to severe drought in 2018 with a particularly long-lasting and large soil water deficit in Denmark, Southern Sweden and Estonia. Here, we analyse the impact of the drought on carbon and water fluxes in 11 forest ecosystems of different composition: spruce, pine, mixed and deciduous. We assess the impact of drought on fluxes by estimating the difference (anomaly) between year 2018 and a reference year without drought. Unexpectedly, the evaporation was only slightly reduced during 2018 compared to the reference year at two sites while it increased or was nearly unchanged at all other sites. This occurred under a 40 to 60% reduction in mean surface conductance and the concurrent increase in evaporative demand due to the warm and dry weather. The anomaly in the net ecosystem productivity (NEP) was 93% explained by a multilinear regression with the anomaly in heterotrophic respiration and the relative precipitation deficit as independent variables. Most of the variation (77%) was explained by the heterotrophic component. Six out of 11 forests reduced their annual NEP with more than 50 g C m −2 yr −1 during 2018 as compared to the reference year. The NEP anomaly ranged between −389 and +74 g C m −2 yr −1 with a median value of −59 g C m −2 yr −1 . |
BibTeX:
@article{Lindroth2020,
author = {Lindroth, Anders and Holst, Jutta and Linderson, Maj-Lena and Aurela, Mika and Biermann, Tobias and Heliasz, Michal and Chi, Jinshu and Ibrom, Andreas and Kolari, Pasi and Klemedtsson, Leif and Krasnova, Alisa and Laurila, Tuomas and Lehner, Irene and Lohila, Annalea and Mammarella, Ivan and Mölder, Meelis and Löfvenius, Mikaell Ottosson and Peichl, Matthias and Pilegaard, Kim and Soosar, Kaido and Vesala, Timo and Vestin, Patrik and Weslien, Per and Nilsson, Mats},
title = {Effects of drought and meteorological forcing on carbon and water fluxes in Nordic forests during the dry summer of 2018},
journal = {Philosophical Transactions of the Royal Society B: Biological Sciences},
year = {2020},
volume = {375},
number = {1810},
pages = {20190516},
url = {https://royalsocietypublishing.org/doi/10.1098/rstb.2019.0516},
doi = {10.1098/rstb.2019.0516}
}
|
| Liu N, Michelsen A and Rinnan R (2020), "Vegetation and soil responses to added carbon and nutrients remain six years after discontinuation of long-term treatments", Science of the Total Environment. Vol. 722, pp. 137885. Elsevier B.V.. |
| Abstract: Global warming and increased nutrient availability in the Arctic have attracted wide attention. However, it is unknown how an increased supply of nitrogen (N), phosphorus (P) and/or labile carbon (C) – alone and in combinations – affects the concentrations and pools of C and nutrients in plants, soil and soil microorganisms, and whether the cessation of these additions allows the ecosystem to recover from amendments. Six treatments (control, C, N, P, NP and C + NP) were applied at a subarctic heath for 8–10 years. After being untreated for two years, amendments were re-applied to one half of the plots for four years while the other plot half received no amendments. When the plots were harvested, we could therefore compare responses in plots with nearly continuous 14–16-year amendments to those with six years with discontinued treatments. The responses to individual and combined nutrient additions were mostly similar in re-initiated and discontinued plots. Individual N addition strongly increased the C and N pools in the graminoids, thereby also increasing the C and N pools in litter and fine roots compared to the plots without added N. This contributed to the increased microbial biomass C and total C in soil. P addition alone increased C and N pools in vascular cryptogams, as well as PO43−, NH4+, dissolved organic carbon and dissolved organic nitrogen concentrations in soil compared to the plots without added P. Hence, plant functional groups showed differential responses to long-term N and P amendment, and after the initial nutrient additions for 8–10 years, the investigated subarctic tundra ecosystem had reached a new steady state that was resilient to further changes still six years after cessation of additions. |
BibTeX:
@article{Liu2020,
author = {Liu, Na and Michelsen, Anders and Rinnan, Riikka},
title = {Vegetation and soil responses to added carbon and nutrients remain six years after discontinuation of long-term treatments},
journal = {Science of the Total Environment},
publisher = {Elsevier B.V.},
year = {2020},
volume = {722},
pages = {137885},
url = {https://doi.org/10.1016/j.scitotenv.2020.137885},
doi = {10.1016/j.scitotenv.2020.137885}
}
|
| Louarn G, Chabbi A and Gastal F (2020), "Nitrogen concentration in the upper leaves of the canopy is a reliable indicator of plant N nutrition in both pure and mixed grassland swards", Grass and Forage Science., jan, 2020. Vol. 75(1), pp. 127-133. Wiley. |
| Abstract: Effective indicators of plant nitrogen (N) nutrition are needed to improve N management in grasslands. This is particularly the case for mixtures that rely on N fixation by legumes as a major N input, because no reference tool such as the nitrogen nutrition index (NNI) exists under these conditions. The aims of this study were to test the reliability of a plant-based index, the N concentration of upper leaves in the canopy (Nup), as a possible alternative for NNI in both pure and mixed grasslands. Data were gathered from four experiments covering a range of pure and mixed grasslands under different N fertilization levels. A cross-validation of Nup predictions against NNI in pure stands, and against two NNI-derived indices in mixtures, was performed. The Nup values appeared to be linearly related to NNI in pure stands of both grasses and legumes. The relationship was identical for the two groups of species and explained up to 86% of NNI variability. In mixtures, Nup also displayed a linear relationship with the two other tested indices, explaining 65% and 78% of variability. The conclusions of the three indices diverged with respect to strongly unbalanced mixtures, where the assumptions regarding the computation of NNI-derived indices were not met. Excluding these situations, the overall relationship between Nup and NNI proved to be identical for mixtures and pure stands. The results suggest that Nup is a valid criterion for plant N nutrition which applies to a broad range of grassland species and to mixture conditions. |
BibTeX:
@article{Louarn2020,
author = {Louarn, Gaëtan and Chabbi, Abad and Gastal, François},
title = {Nitrogen concentration in the upper leaves of the canopy is a reliable indicator of plant N nutrition in both pure and mixed grassland swards},
journal = {Grass and Forage Science},
publisher = {Wiley},
year = {2020},
volume = {75},
number = {1},
pages = {127--133},
doi = {10.1111/gfs.12466}
}
|
| Macovei VA, Hartman SE, Schuster U, Torres-Valdés S, Moore CM and Sanders RJ (2020), "Impact of physical and biological processes on temporal variations of the ocean carbon sink in the mid-latitude North Atlantic (2002–2016)", Progress in Oceanography., jan, 2020. Vol. 180, pp. 102223. Elsevier BV. |
| Abstract: The ocean is currently a significant net sink for anthropogenically remobilised CO2, taking up around 24% of global emissions. Numerical models predict a diversity of responses of the ocean carbon sink to increased atmospheric concentrations in a warmer world. Here, we tested the hypothesis that increased atmospheric forcing is causing a change in the ocean carbon sink using a high frequency observational dataset derived from underway pCO2 (carbon dioxide partial pressure) instruments on ships of opportunity (SOO) and a fixed-point mooring between 2002 and 2016. We calculated an average carbon flux of 0.013 Pg yrâˆ'1 into the ocean at the Porcupine Abyssal Plain (PAP) site, consistent with past estimates. In spite of the increase in atmospheric pCO2, monthly average seawater pCO2 did not show a statistically significant increasing trend, but a higher annual variability, likely due to the decreasing buffer capacity of the system. The increasing ΔpCO2 led to an increasing trend in the estimated CO2 flux into the ocean of 0.19 ± 0.03 mmol mâˆ'2 dayâˆ'1 per year across the entire 15 year time series, making the study area a stronger carbon sink. Seawater pCO2 variability is mostly influenced by temperature, alkalinity and dissolved inorganic carbon (DIC) changes, with 77% of the annual seawater pCO2 changes explained by these terms. DIC is in turn influenced by gas exchange and biological production. In an average year, the DIC drawdown by biological production, as determined from nitrate uptake, was higher than the DIC increase due to atmospheric CO2 dissolution into the surface ocean. This effect was enhanced in years with high nutrient input or shallow mixed layers. Using the rate of change of DIC and nitrate, we observed Redfieldian carbon consumption during the spring bloom at a C:N ratio of 6.2 ± 1.6. A comparison between SOO and PAP sustained observatory data revealed a strong agreement for pCO2 and DIC. This work demonstrates that the study area has continued to absorb atmospheric CO2 in recent years with this sink enhancing over time. Furthermore, the change in pCO2 per unit nitrate became larger as surface buffer capacity changed. |
BibTeX:
@article{Macovei2020,
author = {Macovei, Vlad A and Hartman, Susan E and Schuster, Ute and Torres-Valdés, Sinhué and Moore, C Mark and Sanders, Richard J},
title = {Impact of physical and biological processes on temporal variations of the ocean carbon sink in the mid-latitude North Atlantic (2002–2016)},
journal = {Progress in Oceanography},
publisher = {Elsevier BV},
year = {2020},
volume = {180},
pages = {102223},
doi = {10.1016/j.pocean.2019.102223}
}
|
| Maksyutov S, Oda T, Saito M, Janardanan R, Belikov D, Kaiser W, Zhuravlev R, Ganshin A, Valsala VK, Andrews A, Chmura L, Dlugokencky E, Haszpra L, Langenfelds RL, Machida T, Nakazawa T, Ramonet M, Sweeney C and Worthy D (2020), "Technical note: A high-resolution inverse modelling technique for estimating surface CO2 fluxes based on the NIES-TM-FLEXPART coupled transport model and its adjoint", Atmospheric Chemistry and Physics. |
| Abstract: 25 We developed a high-resolution surface flux inversion system based on the global Lagrangian-Eulerian coupled tracer transport model composed of National Institute for Environmental Studies Transport Model (NIES-TM) and FLEXible PARTicle dispersion model (FLEXPART). The inversion system is named NTFVAR (NIES-TM-FLEXPART-variational) as it applies variational optimisation to estimate surface fluxes. We tested the system by estimating optimized corrections to natural surface CO2 fluxes to achieve best fit to atmospheric CO2 data collected by the global in-situ network, as a 30 necessary step towards capability of estimating anthropogenic CO2 emissions. We employ the Lagrangian particle dispersion model (LPDM) FLEXPART to calculate the surface flux footprints of CO2 observations at a 0.1° × 0.1° spatial https://doi.org/10.5194/acp-2020-251 Preprint. Discussion started: 27 March 2020 c Author(s) 2020. CC BY 4.0 License. 2 resolution. The LPDM is coupled to a global atmospheric tracer transport model (NIES-TM). Our inversion technique uses an adjoint of the coupled transport model in an iterative optimization procedure. The flux error covariance operator is being implemented via implicit diffusion. Biweekly flux corrections to prior flux fields were estimated for the years 2010-2012 from in-situ CO2 data included in the Observation Package (ObsPack) dataset. High-resolution prior flux fields were prepared using Open-Data Inventory for Anthropogenic Carbon dioxide (ODIAC) for fossil fuel combustion, Global Fire 5 Assimilation System (GFAS) for biomass burning, the Vegetation Integrative SImulator for Trace gases (VISIT) model for terrestrial biosphere exchange and Ocean Tracer Transport Model (OTTM) for oceanic exchange. The terrestrial biospheric flux field was constructed using a vegetation mosaic map and separate simulation of CO2 fluxes at daily time step by the VISIT model for each vegetation type. The prior flux uncertainty for terrestrial biosphere was scaled proportionally to the monthly mean Gross Primary Production (GPP) by the Moderate Resolution Imaging 10 Spectroradiometer (MODIS) MOD17 product. The inverse system calculates flux corrections to the prior fluxes in the form of a relatively smooth field multiplied by high-resolution patterns of the prior flux uncertainties for land and ocean, following the coastlines and vegetation productivity gradients. The resulting flux estimates improve fit to the observations at continuous observations sites, reproducing both the seasonal variation and short-term concentration variability, including high CO2 concentration events associated with anthropogenic emissions. The use of high-resolution atmospheric transport 15 in global CO2 flux inversion has the advantage of better resolving the transport from the mix of the anthropogenic and biospheric sources in densely populated continental regions and shows potential for better separation between fluxes from terrestrial ecosystems and strong localised sources such as anthropogenic emissions and forest fires. Further improvements in the modelling system are needed as the posterior fit is better than that by the National Oceanic and Atmospheric Administration (NOAA) CarbonTracker only for a fraction of the monitoring sites, mostly at coastal and island locations 20 experiencing mix of background and local flux signals. |
BibTeX:
@article{Maksyutov,
author = {Maksyutov, Shamil and Oda, Tomohiro and Saito, Makoto and Janardanan, Rajesh and Belikov, Dmitry and Kaiser, W and Zhuravlev, Ruslan and Ganshin, Alexander and Valsala, Vinu K and Andrews, Arlyn and Chmura, Lukasz and Dlugokencky, Edward and Haszpra, László and Langenfelds, Ray L and Machida, Toshinobu and Nakazawa, Takakiyo and Ramonet, Michel and Sweeney, Colm and Worthy, Douglas},
title = {Technical note: A high-resolution inverse modelling technique for estimating surface CO2 fluxes based on the NIES-TM-FLEXPART coupled transport model and its adjoint},
journal = {Atmospheric Chemistry and Physics},
year = {2020},
url = {https://doi.org/10.5194/acp-2020-251},
doi = {10.5194/acp-2020-251}
}
|
| Martínez B, Gilabert MA, Sánchez-Ruiz S, Campos-Taberner M, García-Haro FJ, Brümmer C, Carrara A, Feig G, Grünwald T, Mammarella I and Tagesson T (2020), "Evaluation of the LSA-SAF gross primary production product derived from SEVIRI/MSG data (MGPP)", ISPRS Journal of Photogrammetry and Remote Sensing. Vol. 159(November 2019), pp. 220-236. Elsevier. |
| Abstract: The objective of this study is to describe a completely new 10-day gross primary production (GPP) product (MGPP LSA-411) based on data from the geostationary SEVIRI/MSG satellite within the LSA SAF (Land Surface Analysis SAF) as part of the SAF (Satellite Application Facility) network of EUMETSAT. The methodology relies on the Monteith approach. It considers that GPP is proportional to the absorbed photosynthetically active radiation APAR and the proportionality factor is known as the light use efficiency $$. A parameterization of this factor is proposed as the product of a $$max, corresponding to the canopy functioning under optimal conditions, and a coefficient quantifying the reduction of photosynthesis as a consequence of water stress. A three years data record (2015–2017) was used in an assessment against site-level eddy covariance (EC) tower GPP estimates and against other Earth Observation (EO) based GPP products. The site-level comparison indicated that the MGPP product performed better than the other EO based GPP products with 48% of the observations being below the optimal accuracy (absolute error textless1.0 g m−2 day−1) and 75% of these data being below the user requirement threshold (absolute error textless3.0 g m−2 day−1). The largest discrepancies between the MGPP product and the other GPP products were found for forests whereas small differences were observed for the other land cover types. The integration of this GPP product with the ensemble of LSA-SAF MSG products is conducive to meet user needs for a better understanding of ecosystem processes and for improved understanding of anthropogenic impact on ecosystem services. |
BibTeX:
@article{Martinez2020,
author = {Martínez, B and Gilabert, M A and Sánchez-Ruiz, S and Campos-Taberner, M and García-Haro, F J and Brümmer, C and Carrara, A and Feig, G and Grünwald, T and Mammarella, I and Tagesson, T},
title = {Evaluation of the LSA-SAF gross primary production product derived from SEVIRI/MSG data (MGPP)},
journal = {ISPRS Journal of Photogrammetry and Remote Sensing},
publisher = {Elsevier},
year = {2020},
volume = {159},
number = {November 2019},
pages = {220--236},
url = {https://doi.org/10.1016/j.isprsjprs.2019.11.010},
doi = {10.1016/j.isprsjprs.2019.11.010}
}
|
| McColl KA and Rigden AJ (2020), "Emergent Simplicity of Continental Evapotranspiration", Geophysical Research Letters., mar, 2020. Vol. 47(6) Blackwell Publishing Ltd. |
| Abstract: Evapotranspiration (ET) is challenging to model because it depends on heterogeneous land surface features—such as soil moisture, land cover type, and plant physiology—resulting in rising model complexity and substantial disagreement between models. We show that the evaporative fraction (ET as a proportion of available energy at the surface) can be estimated accurately across a broad range of conditions using a simple equation with no free parameters and no land surface information; only near-surface air temperature and specific humidity observations are required. The equation performs well when compared to eddy covariance measurements at 76 inland continental sites, with prediction errors comparable to errors in the eddy covariance measurements themselves, despite substantial variability in surface conditions across sites. This reveals an emergent simplicity to continental ET that has not been previously recognized, in which land-atmosphere coupling efficiently embeds land surface information in the near-surface atmospheric state on daily to monthly time scales. |
BibTeX:
@article{McColl2020,
author = {McColl, Kaighin A. and Rigden, Angela J.},
title = {Emergent Simplicity of Continental Evapotranspiration},
journal = {Geophysical Research Letters},
publisher = {Blackwell Publishing Ltd},
year = {2020},
volume = {47},
number = {6},
doi = {10.1029/2020GL087101}
}
|
| McKinley GA, Fay AR, Eddebbar YA, Gloege L and Lovenduski NS (2020), "External Forcing Explains Recent Decadal Variability of the Ocean Carbon Sink", AGU Advances., jun, 2020. Vol. 1(2) American Geophysical Union (AGU). |
| Abstract: The ocean has absorbed the equivalent of 39% of industrial‐age fossil carbon emissions, significantly modulating the growth rate of atmospheric CO2 and its associated impacts on climate. Despite the importance of the ocean carbon sink to climate, our understanding of the causes of its interannual‐to‐decadal variability remains limited. This hinders our ability to attribute its past behavior and project its future. A key period of interest is the 1990s, when the ocean carbon sink did not grow as expected. Previous explanations of this behavior have focused on variability internal to the ocean or associated with coupled atmosphere/ocean modes. Here, we use an idealized upper ocean box model to illustrate that two external forcings are sufficient to explain the pattern and magnitude of sink variability since the mid‐1980s. First, the global‐scale reduction in the decadal‐average ocean carbon sink in the 1990s is attributable to the slowed growth rate of atmospheric pCO2. The acceleration of atmospheric pCO2 growth after 2001 drove recovery of the sink. Second, the global sea surface temperature response to the 1991 eruption of Mt Pinatubo explains the timing of the global sink within the 1990s. These results are consistent with previous experiments using ocean hindcast models with variable atmospheric pCO2 and with and without climate variability. The fact that variability in the growth rate of atmospheric pCO2 directly imprints on the ocean sink implies that there will be an immediate reduction in ocean carbon uptake as atmospheric pCO2 responds to cuts in anthropogenic emissions. |
BibTeX:
@article{McKinley2020,
author = {McKinley, Galen A. and Fay, Amanda R. and Eddebbar, Yassir A. and Gloege, Lucas and Lovenduski, Nicole S.},
title = {External Forcing Explains Recent Decadal Variability of the Ocean Carbon Sink},
journal = {AGU Advances},
publisher = {American Geophysical Union (AGU)},
year = {2020},
volume = {1},
number = {2},
url = {https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2019AV000149 https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2019AV000149 https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2019AV000149},
doi = {10.1029/2019av000149}
}
|
| Melton JR, Arora VK, Wisernig-Cojoc E, Seiler C, Fortier M, Chan E and Teckentrup L (2020), "CLASSIC v1.0: The open-source community successor to the Canadian Land Surface Scheme (CLASS) and the Canadian Terrestrial Ecosystem Model (CTEM)-Part 1: Model framework and site-level performance", Geoscientific Model Development., jun, 2020. Vol. 13(6), pp. 2825-2850. Copernicus GmbH. |
| Abstract: Recent reports by the Global Carbon Project highlight large uncertainties around land surface processes such as land use change, strength of CO2 fertilization, nutrient limitation and supply, and response to variability in climate. Process-based land surface models are well suited to address these complex and emerging global change problems but will require extensive development and evaluation. The coupled Canadian Land Surface Scheme and Canadian Terrestrial Ecosystem Model (CLASS-CTEM) framework has been under continuous development by Environment and Climate Change Canada since 1987. As the open-source model of code development has revolutionized the software industry, scientific software is experiencing a similar evolution. Given the scale of the challenge facing land surface modellers, and the benefits of open-source, or community model, development, we have transitioned CLASS-CTEM from an internally developed model to an open-source community model, which we call the Canadian Land Surface Scheme including Biogeochemical Cycles (CLASSIC) v.1.0. CLASSIC contains many technical features specifically designed to encourage community use including software containerization for serial and parallel simulations, extensive benchmarking software and data (Automated Model Benchmarking; AMBER), self-documenting code, community standard formats for model inputs and outputs, amongst others. Here, we evaluate and benchmark CLASSIC against 31 FLUXNET sites where the model has been tailored to the site-level conditions and driven with observed meteorology. Future versions of CLASSIC will be developed using AMBER and these initial benchmark results to evaluate model performance over time. CLASSIC remains under active development and the code, site-level benchmarking data, software container, and AMBER are freely available for community use. |
BibTeX:
@article{Melton2020,
author = {Melton, Joe R. and Arora, Vivek K. and Wisernig-Cojoc, Eduard and Seiler, Christian and Fortier, Matthew and Chan, Ed and Teckentrup, Lina},
title = {CLASSIC v1.0: The open-source community successor to the Canadian Land Surface Scheme (CLASS) and the Canadian Terrestrial Ecosystem Model (CTEM)-Part 1: Model framework and site-level performance},
journal = {Geoscientific Model Development},
publisher = {Copernicus GmbH},
year = {2020},
volume = {13},
number = {6},
pages = {2825--2850},
doi = {10.5194/gmd-13-2825-2020}
}
|
| Miettinen H, Pumpanen J, Rantakari M and Ojala A (2020), "Carbon dynamics in a Boreal land-stream-lake continuum during the spring freshet of two hydrologically contrasting years", Biogeochemistry., mar, 2020. Vol. 148(1), pp. 91-109. Springer. |
| Abstract: We studied in 2013 and 2014 the spring carbon dynamics in a Boreal landscape consisting of a lake and 15 inflowing streams and an outlet. The first year had weather and a hydrological regime typical of past years with a distinct spring freshet connected with the thaw of the average snowpack. The latter year had higher air temperatures which did not permit snow accumulation, despite similar winter precipitation. As such, there was hardly any spring freshet in 2014, and stream discharge peaked in January, i.e., the conditions resembled those predicted in the future climate. Despite the hydrological differences between the years, there were only small interannual differences in the stream CO2 and DOC concentrations. The relationship between the concentrations and discharge was stronger in the typical year. CO2 concentrations in medium-sized streams correlated negatively with the discharge, indicating dilution effect of melting snowpacks, while in large-sized streams the correlation was positive, suggesting stronger groundwater influence. The DOC pathway to these streams was through the subsurface soil layers, not the groundwater. The total amount of carbon transported into the lake was ca. 1.5-fold higher in the typical year than in the year with warm winter. In 2013, most of the lateral inputs took place during spring freshet. In 2014, the majority of inputs occurred earlier, during the winter months. The lateral CO2 signal was visible in the lake at 1.5 m depth. DOC dominated the carbon transport, and in both years, 12% of the input C was in inorganic form. |
BibTeX:
@article{Miettinen2020,
author = {Miettinen, H. and Pumpanen, J. and Rantakari, M. and Ojala, A.},
title = {Carbon dynamics in a Boreal land-stream-lake continuum during the spring freshet of two hydrologically contrasting years},
journal = {Biogeochemistry},
publisher = {Springer},
year = {2020},
volume = {148},
number = {1},
pages = {91--109},
doi = {10.1007/s10533-020-00648-9}
}
|
| Mobilia M, Schmidt M and Longobardi A (2020), "Modelling actual evapotranspiration seasonal variability by meteorological data-based models", Hydrology. Vol. 7(3), pp. 1-27. |
| Abstract: This study aims at illustrating a methodology for predicting monthly scale actual evapotranspiration losses only based on meteorological data, which mimics the evapotranspiration intra-annual dynamic. For this purpose, micrometeorological data at the Rollesbroich and Bondone mountain sites, which are energy-limited systems, and the Sister site, a water-limited system, have been analyzed. Based on an observed intra-annual transition between dry and wet states governed by a threshold value of net radiation at each site, an approach that couples meteorological data-based potential evapotranspiration and actual evapotranspiration relationships has been proposed and validated against eddy covariance measurements, and further compared to two well-known actual evapotranspiration prediction models, namely the advection-aridity and the antecedent precipitation index models. The threshold approach improves the intra-annual actual evapotranspiration variability prediction, particularly during the wet state periods, and especially concerning the Sister site, where errors are almost four times smaller compared to the basic models. To further improve the prediction within the dry state periods, a calibration of the Priestley-Taylor advection coefficient was necessary. This led to an error reduction of about 80% in the case of the Sister site, of about 30% in the case of Rollesbroich, and close to 60% in the case of Bondone Mountain. For cases with a lack of measured data of net radiation and soil heat fluxes, which are essential for the implementation of the models, an application derived from empirical relationships is discussed. In addition, the study assessed whether this variation from meteorological data worsened the prediction performances of the models. |
BibTeX:
@article{Mobilia2020,
author = {Mobilia, Mirka and Schmidt, Marius and Longobardi, Antonia},
title = {Modelling actual evapotranspiration seasonal variability by meteorological data-based models},
journal = {Hydrology},
year = {2020},
volume = {7},
number = {3},
pages = {1--27},
doi = {10.3390/HYDROLOGY7030050}
}
|
| Montzka C, Brogi C, Mengen D, Matveeva M, Baum S, Schüttemeyer D, Bayat B, Bogena H, Coccia A, Masalias G, Graf V, Jakobi J, Jonard F, Ma Y, Mattia F, Palmisano D, Rascher U, Satalino G, Jagdhuber T, Fluhrer A, Schumacher M, Schmidt M and Vereecken H (2020), "Sarsense: A C- and L-Band SAR Rehearsal Campaign in Germany in Preparation for ROSE-L", In IGARSS 2020 - 2020 IEEE International Geoscience and Remote Sensing Symposium. , pp. 2137-2140. |
| Abstract: In summer 2019 the SARSense campaign was held in Jülich, Germany, to provide insights into the potentials and specifications of the ESA Copernicus candidate mission ROSE-L (Radar Observation System for Europe). ROSE-L will consist of two satellites that carry a polarimetric L-band SAR. Since the L-band signal can penetrate through many natural materials such as vegetation, dry snow and ice, the mission will provide additional information that cannot be gathered by the Copernicus Sentinel-1 C-band SAR mission. The overall objective of the SARSense 2019 campaign is to analyze the mission design concerning its potential for agricultural monitoring services including target applications such as soil moisture monitoring, irrigation management, crop type discrimination, food security and precision farming. The SARSense in situ measurements of soil moisture, soil temperature, vegetation properties, UAS-based multispectral and thermal mapping, as well as the airborne SAR observations are presented as well as strategies for soil moisture retrieval and first analysis. |
BibTeX:
@inproceedings{Montzka2020,
author = {Montzka, C and Brogi, C and Mengen, D and Matveeva, M and Baum, S and Schüttemeyer, D and Bayat, B and Bogena, H and Coccia, A and Masalias, G and Graf, V and Jakobi, J and Jonard, F and Ma, Y and Mattia, F and Palmisano, D and Rascher, U and Satalino, G and Jagdhuber, T and Fluhrer, A and Schumacher, M and Schmidt, M and Vereecken, H},
title = {Sarsense: A C- and L-Band SAR Rehearsal Campaign in Germany in Preparation for ROSE-L},
booktitle = {IGARSS 2020 - 2020 IEEE International Geoscience and Remote Sensing Symposium},
year = {2020},
pages = {2137--2140},
doi = {10.1109/IGARSS39084.2020.9324090}
}
|
| Moreaux V, Longdoz B, Berveiller D, Delpierre N, Dufrene E, Bonnefond J-M, Chipeaux C, Joffre R, Limousin J-M, Ourcival J-M, Klumpp K, Darsonville O, Brut A, Tallec T, Ceschia E, Panthou G and Loustau D (2020), "Environmental control of land-atmosphere CO2 fluxes from temperate ecosystems: a statistical approach based on homogenized time series from five land-use types", TELLUS SERIES B-CHEMICAL AND PHYSICAL METEOROLOGY., jun, 2020. Vol. 72(1), pp. 1-25. |
BibTeX:
@article{Moreaux2020,
author = {Moreaux, Virginie and Longdoz, Bernard and Berveiller, Daniel and Delpierre, Nicolas and Dufrene, Eric and Bonnefond, Jean-Marc and Chipeaux, Christophe and Joffre, Richard and Limousin, Jean-Marc and Ourcival, Jean-Marc and Klumpp, Katja and Darsonville, Olivier and Brut, Aurore and Tallec, Tiphaine and Ceschia, Eric and Panthou, Geremy and Loustau, Denis},
title = {Environmental control of land-atmosphere CO2 fluxes from temperate ecosystems: a statistical approach based on homogenized time series from five land-use types},
journal = {TELLUS SERIES B-CHEMICAL AND PHYSICAL METEOROLOGY},
year = {2020},
volume = {72},
number = {1},
pages = {1--25},
doi = {10.1080/16000889.2020.1784689}
}
|
| Moreaux V, Martel S, Bosc A, Picart D, Achat D, Moisy C, Aussenac R, Chipeaux C, Bonnefond J-M, Figueres S, Trichetl P, Vezy R, Badeau V, Longdoz B, Granier A, Roupsard O, Nicolas M, Pilegaard K, Matteucci G, Jolivet C, Black AT, Picard O and Loustau D (2020), "Energy, water and carbon exchanges in managed forest ecosystems: description, sensitivity analysis and evaluation of the INRAE GO plus model, version 3.0", GEOSCIENTIFIC MODEL DEVELOPMENT., dec, 2020. Vol. 13(12), pp. 5973-6009. |
BibTeX:
@article{Moreaux2020a,
author = {Moreaux, Virginie and Martel, Simon and Bosc, Alexandre and Picart, Delphine and Achat, David and Moisy, Christophe and Aussenac, Raphael and Chipeaux, Christophe and Bonnefond, Jean-Marc and Figueres, Soisick and Trichetl, Pierre and Vezy, Remi and Badeau, Vincent and Longdoz, Bernard and Granier, Andre and Roupsard, Olivier and Nicolas, Manuel and Pilegaard, Kim and Matteucci, Giorgio and Jolivet, Claudy and Black, Andrew T and Picard, Olivier and Loustau, Denis},
title = {Energy, water and carbon exchanges in managed forest ecosystems: description, sensitivity analysis and evaluation of the INRAE GO plus model, version 3.0},
journal = {GEOSCIENTIFIC MODEL DEVELOPMENT},
year = {2020},
volume = {13},
number = {12},
pages = {5973--6009},
doi = {10.5194/gmd-13-5973-2020}
}
|
| Müller M, Graf P, Meyer J, Pentina A, Brunner D, Perez-Cruz F, Hüglin C and Emmenegger L (2020), "Integration and calibration of non-dispersive infrared (NDIR) CO2 low-cost sensors and their operation in a sensor network covering Switzerland", Atmospheric Measurement Techniques., jul, 2020. Vol. 13(7), pp. 3815-3834. |
| Abstract: ∼85 %) impairs the LP8 measurements, and corresponding data filtering results in a significant loss during humid conditions. The LP8 sensors are not suitable for the detection of small regional gradients and long-term trends. However, with careful data processing, the sensors are able to resolve CO2 changes and differences with a magnitude larger than about 30 ppm. Thereby, the sensor can resolve the site-specific CO2 signal at most locations in Switzerland. A low-power network (LPN) using LoRaWAN allowed for reliable data transmission with low energy consumption and proved to be a key element of the Carbosense low-cost sensor network.]]textgreater |
BibTeX:
@article{Mueller2020,
author = {Müller, Michael and Graf, Peter and Meyer, Jonas and Pentina, Anastasia and Brunner, Dominik and Perez-Cruz, Fernando and Hüglin, Christoph and Emmenegger, Lukas},
title = {Integration and calibration of non-dispersive infrared (NDIR) CO2 low-cost sensors and their operation in a sensor network covering Switzerland},
journal = {Atmospheric Measurement Techniques},
year = {2020},
volume = {13},
number = {7},
pages = {3815--3834},
url = {https://amt.copernicus.org/articles/13/3815/2020/},
doi = {10.5194/amt-13-3815-2020}
}
|
| Mund M, Herbst M, Knohl A, Matthäus B, Schumacher J, Schall P, Siebicke L, Tamrakar R and Ammer C (2020), "It is not just a ‘trade-off': indications for sink- and source-limitation to vegetative and regenerative growth in an old-growth beech forest", New Phytologist. Vol. 226(1), pp. 111-125. |
| Abstract: Controls on tree growth are key issues in plant physiology. The hypothesis of our study was that the interannual variability of wood and fruit production are primarily controlled directly by weather conditions (sink limitation), while carbon assimilation (source limitation) plays a secondary role. We analyzed the interannual variability of weather conditions, gross primary productivity (GPP) and net primary productivity (NPP) of wood and fruits of an old-growth, unmanaged Fagus sylvatica forest over 14 yr, including six mast years. In a multiple linear regression model, c. 71% of the annual variation in wood-NPP could be explained by mean air temperature in May, precipitation from April to May (positive influence) and fruit-NPP (negative influence). GPP of June to July solely explained c. 42% of the variation in wood-NPP. Fruit-NPP was positively related to summer precipitation 2 yr before (R2 = 0.85), and negatively to precipitation in May (R2 = 0.83) in the fruit years. GPP had no influence on fruit-NPP. Our results suggest a complex system of sink and source limitations to tree growth driven by weather conditions and going beyond a simple carbon-mediated ‘trade-off' between regenerative and vegetative growth. |
BibTeX:
@article{Mund2020,
author = {Mund, Martina and Herbst, Mathias and Knohl, Alexander and Matthäus, Bertrand and Schumacher, Jens and Schall, Peter and Siebicke, Lukas and Tamrakar, Rijan and Ammer, Christian},
title = {It is not just a ‘trade-off': indications for sink- and source-limitation to vegetative and regenerative growth in an old-growth beech forest},
journal = {New Phytologist},
year = {2020},
volume = {226},
number = {1},
pages = {111--125},
doi = {10.1111/nph.16408}
}
|
| Nelson JA, Pérez-Priego O, Zhou S, Poyatos R, Zhang Y, Blanken PD, Gimeno TE, Wohlfahrt G, Desai AR, Gioli B, Limousin JM, Bonal D, Paul-Limoges E, Scott RL, Varlagin A, Fuchs K, Montagnani L, Wolf S, Delpierre N, Berveiller D, Gharun M, Belelli Marchesini L, Gianelle D, Šigut L, Mammarella I, Siebicke L, Andrew Black T, Knohl A, Hörtnagl L, Magliulo V, Besnard S, Weber U, Carvalhais N, Migliavacca M, Reichstein M and Jung M (2020), "Ecosystem transpiration and evaporation: Insights from three water flux partitioning methods across FLUXNET sites", Global Change Biology. Vol. 26(12), pp. 6916-6930. |
| Abstract: We apply and compare three widely applicable methods for estimating ecosystem transpiration (T) from eddy covariance (EC) data across 251 FLUXNET sites globally. All three methods are based on the coupled water and carbon relationship, but they differ in assumptions and parameterizations. Intercomparison of the three daily T estimates shows high correlation among methods (R between.89 and.94), but a spread in magnitudes of T/ET (evapotranspiration) from 45% to 77%. When compared at six sites with concurrent EC and sap flow measurements, all three EC-based T estimates show higher correlation to sap flow-based T than EC-based ET. The partitioning methods show expected tendencies of T/ET increasing with dryness (vapor pressure deficit and days since rain) and with leaf area index (LAI). Analysis of 140 sites with high-quality estimates for at least two continuous years shows that T/ET variability was 1.6 times higher across sites than across years. Spatial variability of T/ET was primarily driven by vegetation and soil characteristics (e.g., crop or grass designation, minimum annual LAI, soil coarse fragment volume) rather than climatic variables such as mean/standard deviation of temperature or precipitation. Overall, T and T/ET patterns are plausible and qualitatively consistent among the different water flux partitioning methods implying a significant advance made for estimating and understanding T globally, while the magnitudes remain uncertain. Our results represent the first extensive EC data-based estimates of ecosystem T permitting a data-driven perspective on the role of plants' water use for global water and carbon cycling in a changing climate. |
BibTeX:
@article{Nelson2020,
author = {Nelson, Jacob A and Pérez-Priego, Oscar and Zhou, Sha and Poyatos, Rafael and Zhang, Yao and Blanken, Peter D and Gimeno, Teresa E and Wohlfahrt, Georg and Desai, Ankur R and Gioli, Beniamino and Limousin, Jean Marc and Bonal, Damien and Paul-Limoges, Eugénie and Scott, Russell L and Varlagin, Andrej and Fuchs, Kathrin and Montagnani, Leonardo and Wolf, Sebastian and Delpierre, Nicolas and Berveiller, Daniel and Gharun, Mana and Belelli Marchesini, Luca and Gianelle, Damiano and Šigut, Ladislav and Mammarella, Ivan and Siebicke, Lukas and Andrew Black, T and Knohl, Alexander and Hörtnagl, Lukas and Magliulo, Vincenzo and Besnard, Simon and Weber, Ulrich and Carvalhais, Nuno and Migliavacca, Mirco and Reichstein, Markus and Jung, Martin},
title = {Ecosystem transpiration and evaporation: Insights from three water flux partitioning methods across FLUXNET sites},
journal = {Global Change Biology},
year = {2020},
volume = {26},
number = {12},
pages = {6916--6930},
doi = {10.1111/gcb.15314}
}
|
| Nezami S, Khoramshahi E, Nevalainen O, Pölönen I and Honkavaara E (2020), "Tree species classification of drone hyperspectral and RGB imagery with deep learning convolutional neural networks", Remote Sensing. Vol. 12(7) |
| Abstract: Interest in drone solutions in forestry applications is growing. Using drones, datasets can be captured flexibly and at high spatial and temporal resolutions when needed. In forestry applications, fundamental tasks include the detection of individual trees, tree species classification, biomass estimation, etc. Deep neural networks (DNN) have shown superior results when comparing with conventional machine learning methods such as multi-layer perceptron (MLP) in cases of huge input data. The objective of this research is to investigate 3D convolutional neural networks (3D-CNN) to classify three major tree species in a boreal forest: pine, spruce, and birch. The proposed 3D-CNN models were employed to classify tree species in a test site in Finland. The classifiers were trained with a dataset of 3039 manually labelled trees. Then the accuracies were assessed by employing independent datasets of 803 records. To find the most efficient set of feature combination, we compare the performances of 3D-CNN models trained with hyperspectral (HS) channels, Red-Green-Blue (RGB) channels, and canopy height model (CHM), separately and combined. It is demonstrated that the proposed 3D-CNN model with RGB and HS layers produces the highest classification accuracy. The producer accuracy of the best 3D-CNN classifier on the test dataset were 99.6%, 94.8%, and 97.4% for pines, spruces, and birches, respectively. The best 3D-CNN classifier produced ˜5% better classification accuracy than the MLP with all layers. Our results suggest that the proposed method provides excellent classification results with acceptable performance metrics for HS datasets. Our results show that pine class was detectable in most layers. Spruce was most detectable in RGB data, while birch was most detectable in the HS layers. Furthermore, the RGB datasets provide acceptable results for many low-accuracy applications. |
BibTeX:
@article{Nezami2020,
author = {Nezami, Somayeh and Khoramshahi, Ehsan and Nevalainen, Olli and Pölönen, Ilkka and Honkavaara, Eija},
title = {Tree species classification of drone hyperspectral and RGB imagery with deep learning convolutional neural networks},
journal = {Remote Sensing},
year = {2020},
volume = {12},
number = {7},
doi = {10.3390/rs12071070}
}
|
| Nickless A, Scholes RJ, Vermeulen A, Beck J, López-Ballesteros A, Ardö J, Karstens U, Rigby M, Kasurinen V, Pantazatou K, Jorch V and Kutsch W (2020), "Greenhouse gas observation network design for Africa", Tellus B: Chemical and Physical Meteorology. Vol. 72(1), pp. 1-30. Taylor & Francis. |
BibTeX:
@article{Nickless2020,
author = {Nickless, Alecia and Scholes, Robert J and Vermeulen, Alex and Beck, Johannes and López-Ballesteros, Ana and Ardö, Jonas and Karstens, Ute and Rigby, Matthew and Kasurinen, Ville and Pantazatou, Karolina and Jorch, Veronika and Kutsch, Werner},
title = {Greenhouse gas observation network design for Africa},
journal = {Tellus B: Chemical and Physical Meteorology},
publisher = {Taylor & Francis},
year = {2020},
volume = {72},
number = {1},
pages = {1--30},
url = {https://www.tandfonline.com/doi/abs/10.1080/16000889.2020.1824486},
doi = {10.1080/16000889.2020.1824486}
}
|
| Olid C, Klaminder J, Monteux S, Johansson M and Dorrepaal E (2020), "Decade of experimental permafrost thaw reduces turnover of young carbon and increases losses of old carbon, without affecting the net carbon balance", Global Change Biology., oct, 2020. Vol. 26(10), pp. 5886-5898. |
BibTeX:
@article{Olid2020,
author = {Olid, Carolina and Klaminder, Jonatan and Monteux, Sylvain and Johansson, Margareta and Dorrepaal, Ellen},
title = {Decade of experimental permafrost thaw reduces turnover of young carbon and increases losses of old carbon, without affecting the net carbon balance},
journal = {Global Change Biology},
year = {2020},
volume = {26},
number = {10},
pages = {5886--5898},
url = {https://onlinelibrary.wiley.com/doi/10.1111/gcb.15283},
doi = {10.1111/gcb.15283}
}
|
| Ouyang Z, Qi D, Chen L, Takahashi T, Zhong W, DeGrandpre MD, Chen B, Gao Z, Nishino S, Murata A, Sun H, Robbins LL, Jin M and Cai WJ (2020), "Sea-ice loss amplifies summertime decadal CO2 increase in the western Arctic Ocean", Nature Climate Change., jul, 2020. Vol. 10(7), pp. 678-684. Nature Research. |
| Abstract: Rapid climate warming and sea-ice loss have induced major changes in the sea surface partial pressure of CO2 (pCO2). However, the long-term trends in the western Arctic Ocean are unknown. Here we show that in 1994–2017, summer pCO2 in the Canada Basin increased at twice the rate of atmospheric increase. Warming and ice loss in the basin have strengthened the pCO2 seasonal amplitude, resulting in the rapid decadal increase. Consequently, the summer air–sea CO2 gradient has reduced rapidly, and may become near zero within two decades. In contrast, there was no significant pCO2 increase on the Chukchi Shelf, where strong and increasing biological uptake has held pCO2 low, and thus the CO2 sink has increased and may increase further due to the atmospheric CO2 increase. Our findings elucidate the contrasting physical and biological drivers controlling sea surface pCO2 variations and trends in response to climate change in the Arctic Ocean. |
BibTeX:
@article{Ouyang2020,
author = {Ouyang, Zhangxian and Qi, Di and Chen, Liqi and Takahashi, Taro and Zhong, Wenli and DeGrandpre, Michael D. and Chen, Baoshan and Gao, Zhongyong and Nishino, Shigeto and Murata, Akihiko and Sun, Heng and Robbins, Lisa L. and Jin, Meibing and Cai, Wei Jun},
title = {Sea-ice loss amplifies summertime decadal CO2 increase in the western Arctic Ocean},
journal = {Nature Climate Change},
publisher = {Nature Research},
year = {2020},
volume = {10},
number = {7},
pages = {678--684},
url = {https://www.nature.com/articles/s41558-020-0784-2},
doi = {10.1038/s41558-020-0784-2}
}
|
| Papale D (2020), "Ideas and perspectives: enhancing the impact of the FLUXNET network of eddy covariance sites", Biogeosciences. Vol. 17(22), pp. 5587-5598. |
| Abstract: In the last 20 years, the FLUXNET network provided unique measurements of CO2, energy and other greenhouse gas exchanges between ecosystems and atmosphere measured with the eddy covariance technique. These data have been widely used in different and heterogeneous applications, and FLUXNET became a reference source of information not only for ecological studies but also in modeling and remote sensing applications. The data are, in general, collected, processed and shared by regional networks or by single sites, and for this reason it is difficult for users interested in analyses involving multiple sites to easily access a coherent and standardized dataset. For this reason, periodic FLUXNET collections have been released in the last 15 years, every 5 to 10 years, with data standardized and shared under the same data use policy. However, the new tools available for data analysis and the need to constantly monitor the relations between ecosystem behavior and climate change require a reorganization of FLUXNET in order to increase the data interoperability, reduce the delay in the data sharing and facilitate the data use, all this while keeping in mind the great effort made by the site teams to collect these unique data and respecting the different regional and national network organizations and data policies. Here a proposal for a new organization of FLUXNET is presented with the aim of stimulating a discussion for the needed developments. In this new scheme, the regional and national networks become the pillars of the global initiative, organizing clusters and becoming responsible for the processing, preparation and distribution of datasets that users will be able to access in real time and with a machine-to-machine tool, obtaining always the most updated collection possible but keeping a high standardization and common data policy. This will also lead to an increase in the FAIRness (Findability, Accessibility, Interoperability and Reusability) of the FLUXNET data that will ensure a larger impact of the unique data produced and a proper data management and traceability. |
BibTeX:
@article{Papale2020,
author = {Papale, Dario},
title = {Ideas and perspectives: enhancing the impact of the FLUXNET network of eddy covariance sites},
journal = {Biogeosciences},
year = {2020},
volume = {17},
number = {22},
pages = {5587--5598},
doi = {10.5194/bg-17-5587-2020}
}
|
| Pastorello G, Trotta C, Canfora E, Chu H, Christianson D, Cheah Y-W, Poindexter C, Chen J, Elbashandy A, Humphrey M, Isaac P, Polidori D, Ribeca A, van Ingen C, Zhang L, Amiro B, Ammann C, Arain MA, Ardö J, Arkebauer T, Arndt SK, Arriga N, Aubinet M, Aurela M, Baldocchi D, Barr A, Beamesderfer E, Marchesini LB, Bergeron O, Beringer J, Bernhofer C, Berveiller D, Billesbach D, Black TA, Blanken PD, Bohrer G, Boike J, Bolstad PV, Bonal D, Bonnefond J-M, Bowling DR, Bracho R, Brodeur J, Brümmer C, Buchmann N, Burban B, Burns SP, Buysse P, Cale P, Cavagna M, Cellier P, Chen S, Chini I, Christensen TR, Cleverly J, Collalti A, Consalvo C, Cook BD, Cook D, Coursolle C, Cremonese E, Curtis PS, D'Andrea E, da Rocha H, Dai X, Davis KJ, De Cinti B, de Grandcourt A, De Ligne A, De Oliveira RC, Delpierre N, Desai AR, Di Bella CM, di Tommasi P, Dolman H, Domingo F, Dong G, Dore S, Duce P, Dufrêne E, Dunn A, Dušek J, Eamus D, Eichelmann U, ElKhidir HAM, Eugster W, Ewenz CM, Ewers B, Famulari D, Fares S, Feigenwinter I, Feitz A, Fensholt R, Filippa G, Fischer M, Frank J, Galvagno M, Gharun M, Gianelle D, Gielen B, Gioli B, Gitelson A, Goded I, Goeckede M, Goldstein AH, Gough CM, Goulden ML, Graf A, Griebel A, Gruening C, Grünwald T, Hammerle A, Han S, Han X, Hansen BU, Hanson C, Hatakka J, He Y, Hehn M, Heinesch B, Hinko-Najera N, Hörtnagl L, Hutley L, Ibrom A, Ikawa H, Jackowicz-Korczynski M, Janouš D, Jans W, Jassal R, Jiang S, Kato T, Khomik M, Klatt J, Knohl A, Knox S, Kobayashi H, Koerber G, Kolle O, Kosugi Y, Kotani A, Kowalski A, Kruijt B, Kurbatova J, Kutsch WL, Kwon H, Launiainen S, Laurila T, Law B, Leuning R, Li Y, Liddell M, Limousin J-M, Lion M, Liska AJ, Lohila A, López-Ballesteros A, López-Blanco E, Loubet B, Loustau D, Lucas-Moffat A, Lüers J, Ma S, Macfarlane C, Magliulo V, Maier R, Mammarella I, Manca G, Marcolla B, Margolis HA, Marras S, Massman W, Mastepanov M, Matamala R, Matthes JH, Mazzenga F, McCaughey H, McHugh I, McMillan AMS, Merbold L, Meyer W, Meyers T, Miller SD, Minerbi S, Moderow U, Monson RK, Montagnani L, Moore CE, Moors E, Moreaux V, Moureaux C, Munger JW, Nakai T, Neirynck J, Nesic Z, Nicolini G, Noormets A, Northwood M, Nosetto M, Nouvellon Y, Novick K, Oechel W, Olesen JE, Ourcival J-M, Papuga SA, Parmentier F-J, Paul-Limoges E, Pavelka M, Peichl M, Pendall E, Phillips RP, Pilegaard K, Pirk N, Posse G, Powell T, Prasse H, Prober SM, Rambal S, Rannik Ü, Raz-Yaseef N, Reed D, de Dios VR, Restrepo-Coupe N, Reverter BR, Roland M, Sabbatini S, Sachs T, Saleska SR, Sánchez-Cañete EP, Sanchez-Mejia ZM, Schmid HP, Schmidt M, Schneider K, Schrader F, Schroder I, Scott RL, Sedlák P, Serrano-Ortíz P, Shao C, Shi P, Shironya I, Siebicke L, Šigut L, Silberstein R, Sirca C, Spano D, Steinbrecher R, Stevens RM, Sturtevant C, Suyker A, Tagesson T, Takanashi S, Tang Y, Tapper N, Thom J, Tiedemann F, Tomassucci M, Tuovinen J-P, Urbanski S, Valentini R, van der Molen M, van Gorsel E, van Huissteden K, Varlagin A, Verfaillie J, Vesala T, Vincke C, Vitale D, Vygodskaya N, Walker JP, Walter-Shea E, Wang H, Weber R, Westermann S, Wille C, Wofsy S, Wohlfahrt G, Wolf S, Woodgate W, Li Y, Zampedri R, Zhang J, Zhou G, Zona D, Agarwal D, Biraud S, Torn M and Papale D (2020), "The FLUXNET2015 dataset and the ONEFlux processing pipeline for eddy covariance data", Scientific Data., dec, 2020. Vol. 7(1), pp. 225. |
BibTeX:
@article{Pastorello2020,
author = {Pastorello, Gilberto and Trotta, Carlo and Canfora, Eleonora and Chu, Housen and Christianson, Danielle and Cheah, You-Wei and Poindexter, Cristina and Chen, Jiquan and Elbashandy, Abdelrahman and Humphrey, Marty and Isaac, Peter and Polidori, Diego and Ribeca, Alessio and van Ingen, Catharine and Zhang, Leiming and Amiro, Brian and Ammann, Christof and Arain, M Altaf and Ardö, Jonas and Arkebauer, Timothy and Arndt, Stefan K and Arriga, Nicola and Aubinet, Marc and Aurela, Mika and Baldocchi, Dennis and Barr, Alan and Beamesderfer, Eric and Marchesini, Luca Belelli and Bergeron, Onil and Beringer, Jason and Bernhofer, Christian and Berveiller, Daniel and Billesbach, Dave and Black, Thomas Andrew and Blanken, Peter D and Bohrer, Gil and Boike, Julia and Bolstad, Paul V and Bonal, Damien and Bonnefond, Jean-Marc and Bowling, David R and Bracho, Rosvel and Brodeur, Jason and Brümmer, Christian and Buchmann, Nina and Burban, Benoit and Burns, Sean P and Buysse, Pauline and Cale, Peter and Cavagna, Mauro and Cellier, Pierre and Chen, Shiping and Chini, Isaac and Christensen, Torben R and Cleverly, James and Collalti, Alessio and Consalvo, Claudia and Cook, Bruce D and Cook, David and Coursolle, Carole and Cremonese, Edoardo and Curtis, Peter S and D'Andrea, Ettore and da Rocha, Humberto and Dai, Xiaoqin and Davis, Kenneth J and De Cinti, Bruno and de Grandcourt, Agnes and De Ligne, Anne and De Oliveira, Raimundo C and Delpierre, Nicolas and Desai, Ankur R and Di Bella, Carlos Marcelo and di Tommasi, Paul and Dolman, Han and Domingo, Francisco and Dong, Gang and Dore, Sabina and Duce, Pierpaolo and Dufrêne, Eric and Dunn, Allison and Dušek, JiÅ™í and Eamus, Derek and Eichelmann, Uwe and ElKhidir, Hatim Abdalla M and Eugster, Werner and Ewenz, Cacilia M and Ewers, Brent and Famulari, Daniela and Fares, Silvano and Feigenwinter, Iris and Feitz, Andrew and Fensholt, Rasmus and Filippa, Gianluca and Fischer, Marc and Frank, John and Galvagno, Marta and Gharun, Mana and Gianelle, Damiano and Gielen, Bert and Gioli, Beniamino and Gitelson, Anatoly and Goded, Ignacio and Goeckede, Mathias and Goldstein, Allen H and Gough, Christopher M and Goulden, Michael L and Graf, Alexander and Griebel, Anne and Gruening, Carsten and Grünwald, Thomas and Hammerle, Albin and Han, Shijie and Han, Xingguo and Hansen, Birger Ulf and Hanson, Chad and Hatakka, Juha and He, Yongtao and Hehn, Markus and Heinesch, Bernard and Hinko-Najera, Nina and Hörtnagl, Lukas and Hutley, Lindsay and Ibrom, Andreas and Ikawa, Hiroki and Jackowicz-Korczynski, Marcin and Janouš, Dalibor and Jans, Wilma and Jassal, Rachhpal and Jiang, Shicheng and Kato, Tomomichi and Khomik, Myroslava and Klatt, Janina and Knohl, Alexander and Knox, Sara and Kobayashi, Hideki and Koerber, Georgia and Kolle, Olaf and Kosugi, Yoshiko and Kotani, Ayumi and Kowalski, Andrew and Kruijt, Bart and Kurbatova, Julia and Kutsch, Werner L and Kwon, Hyojung and Launiainen, Samuli and Laurila, Tuomas and Law, Bev and Leuning, Ray and Li, Yingnian and Liddell, Michael and Limousin, Jean-Marc and Lion, Marryanna and Liska, Adam J and Lohila, Annalea and López-Ballesteros, Ana and López-Blanco, Efrén and Loubet, Benjamin and Loustau, Denis and Lucas-Moffat, Antje and Lüers, Johannes and Ma, Siyan and Macfarlane, Craig and Magliulo, Vincenzo and Maier, Regine and Mammarella, Ivan and Manca, Giovanni and Marcolla, Barbara and Margolis, Hank A and Marras, Serena and Massman, William and Mastepanov, Mikhail and Matamala, Roser and Matthes, Jaclyn Hatala and Mazzenga, Francesco and McCaughey, Harry and McHugh, Ian and McMillan, Andrew M S and Merbold, Lutz and Meyer, Wayne and Meyers, Tilden and Miller, Scott D and Minerbi, Stefano and Moderow, Uta and Monson, Russell K and Montagnani, Leonardo and Moore, Caitlin E and Moors, Eddy and Moreaux, Virginie and Moureaux, Christine and Munger, J William and Nakai, Taro and Neirynck, Johan and Nesic, Zoran and Nicolini, Giacomo and Noormets, Asko and Northwood, Matthew and Nosetto, Marcelo and Nouvellon, Yann and Novick, Kimberly and Oechel, Walter and Olesen, Jørgen Eivind and Ourcival, Jean-Marc and Papuga, Shirley A and Parmentier, Frans-Jan and Paul-Limoges, Eugenie and Pavelka, Marian and Peichl, Matthias and Pendall, Elise and Phillips, Richard P and Pilegaard, Kim and Pirk, Norbert and Posse, Gabriela and Powell, Thomas and Prasse, Heiko and Prober, Suzanne M and Rambal, Serge and Rannik, Üllar and Raz-Yaseef, Naama and Reed, David and de Dios, Victor Resco and Restrepo-Coupe, Natalia and Reverter, Borja R and Roland, Marilyn and Sabbatini, Simone and Sachs, Torsten and Saleska, Scott R and Sánchez-Cañete, Enrique P and Sanchez-Mejia, Zulia M and Schmid, Hans Peter and Schmidt, Marius and Schneider, Karl and Schrader, Frederik and Schroder, Ivan and Scott, Russell L and Sedlák, Pavel and Serrano-Ortíz, Penélope and Shao, Changliang and Shi, Peili and Shironya, Ivan and Siebicke, Lukas and Šigut, Ladislav and Silberstein, Richard and Sirca, Costantino and Spano, Donatella and Steinbrecher, Rainer and Stevens, Robert M and Sturtevant, Cove and Suyker, Andy and Tagesson, Torbern and Takanashi, Satoru and Tang, Yanhong and Tapper, Nigel and Thom, Jonathan and Tiedemann, Frank and Tomassucci, Michele and Tuovinen, Juha-Pekka and Urbanski, Shawn and Valentini, Riccardo and van der Molen, Michiel and van Gorsel, Eva and van Huissteden, Ko and Varlagin, Andrej and Verfaillie, Joseph and Vesala, Timo and Vincke, Caroline and Vitale, Domenico and Vygodskaya, Natalia and Walker, Jeffrey P and Walter-Shea, Elizabeth and Wang, Huimin and Weber, Robin and Westermann, Sebastian and Wille, Christian and Wofsy, Steven and Wohlfahrt, Georg and Wolf, Sebastian and Woodgate, William and Li, Yuelin and Zampedri, Roberto and Zhang, Junhui and Zhou, Guoyi and Zona, Donatella and Agarwal, Deb and Biraud, Sebastien and Torn, Margaret and Papale, Dario},
title = {The FLUXNET2015 dataset and the ONEFlux processing pipeline for eddy covariance data},
journal = {Scientific Data},
year = {2020},
volume = {7},
number = {1},
pages = {225},
url = {http://www.nature.com/articles/s41597-020-0534-3},
doi = {10.1038/s41597-020-0534-3}
}
|
| Patzner MS, Mueller CW, Malusova M, Baur M, Nikeleit V, Scholten T, Hoeschen C, Byrne JM, Borch T, Kappler A and Bryce C (2020), "Iron mineral dissolution releases iron and associated organic carbon during permafrost thaw", Nature Communications. Vol. 11(1), pp. 1-11. Springer US. |
| Abstract: It has been shown that reactive soil minerals, specifically iron(III) (oxyhydr)oxides, can trap organic carbon in soils overlying intact permafrost, and may limit carbon mobilization and degradation as it is observed in other environments. However, the use of iron(III)-bearing minerals as terminal electron acceptors in permafrost environments, and thus their stability and capacity to prevent carbon mobilization during permafrost thaw, is poorly understood. We have followed the dynamic interactions between iron and carbon using a space-for-time approach across a thaw gradient in Abisko (Sweden), where wetlands are expanding rapidly due to permafrost thaw. We show through bulk (selective extractions, EXAFS) and nanoscale analysis (correlative SEM and nanoSIMS) that organic carbon is bound to reactive Fe primarily in the transition between organic and mineral horizons in palsa underlain by intact permafrost (41.8 ± 10.8 mg carbon per g soil, 9.9 to 14.8% of total soil organic carbon). During permafrost thaw, water-logging and O2 limitation lead to reducing conditions and an increase in abundance of Fe(III)-reducing bacteria which favor mineral dissolution and drive mobilization of both iron and carbon along the thaw gradient. By providing a terminal electron acceptor, this rusty carbon sink is effectively destroyed along the thaw gradient and cannot prevent carbon release with thaw. |
BibTeX:
@article{Patzner2020,
author = {Patzner, Monique S and Mueller, Carsten W and Malusova, Miroslava and Baur, Moritz and Nikeleit, Verena and Scholten, Thomas and Hoeschen, Carmen and Byrne, James M and Borch, Thomas and Kappler, Andreas and Bryce, Casey},
title = {Iron mineral dissolution releases iron and associated organic carbon during permafrost thaw},
journal = {Nature Communications},
publisher = {Springer US},
year = {2020},
volume = {11},
number = {1},
pages = {1--11},
url = {http://dx.doi.org/10.1038/s41467-020-20102-6},
doi = {10.1038/s41467-020-20102-6}
}
|
| Penuelas J, Janssens IA, Ciais P, Obersteiner M and Sardans J (2020), "Anthropogenic global shifts in biospheric N and P concentrations and ratios and their impacts on biodiversity, ecosystem productivity, food security, and human health", Global Change Biology., feb, 2020. Vol. 26(4), pp. 1962-1985. Wiley. |
| Abstract: The availability of carbon (C) from high levels of atmospheric carbon dioxide (CO2 ) and anthropogenic release of nitrogen (N) is increasing, but these increases are not paralleled by increases in levels of phosphorus (P). The current unstoppable changes in the stoichiometries of C and N relative to P have no historical precedent. We describe changes in P and N fluxes over the last five decades that have led to asymmetrical increases in P and N inputs to the biosphere. We identified widespread and rapid changes in N:P ratios in air, soil, water, and organisms and important consequences to the structure, function, and biodiversity of ecosystems. A mass-balance approach found that the combined limited availability of P and N was likely to reduce C storage by natural ecosystems during the remainder of the 21st Century, and projected crop yields of the Millennium Ecosystem Assessment indicated an increase in nutrient deficiency in developing regions if access to P fertilizer is limited. Imbalances of the N:P ratio would likely negatively affect human health, food security, and global economic and geopolitical stability, with feedbacks and synergistic effects on drivers of global environmental change, such as increasing levels of CO2 , climatic warming, and increasing pollution. We summarize potential solutions for avoiding the negative impacts of global imbalances of N:P ratios on the environment, biodiversity, climate change, food security, and human health. |
BibTeX:
@article{Penuelas2020,
author = {Penuelas, Josep and Janssens, Ivan A and Ciais, Philippe and Obersteiner, Michael and Sardans, Jordi},
title = {Anthropogenic global shifts in biospheric N and P concentrations and ratios and their impacts on biodiversity, ecosystem productivity, food security, and human health},
journal = {Global Change Biology},
publisher = {Wiley},
year = {2020},
volume = {26},
number = {4},
pages = {1962--1985},
doi = {10.1111/gcb.14981}
}
|
| Perryman CR, McCalley CK, Malhotra A, Fahnestock MF, Kashi NN, Bryce JG, Giesler R and Varner RK (2020), "Thaw Transitions and Redox Conditions Drive Methane Oxidation in a Permafrost Peatland", Journal of Geophysical Research: Biogeosciences. Vol. 125(3), pp. 1-15. |
| Abstract: Permafrost peatlands are a significant source of methane (CH4) emissions to the atmosphere and could emit more CH4 with continued permafrost thaw. Aerobic methane-oxidizing bacteria may attenuate a substantial fraction of CH4 emissions in thawing permafrost peatlands; however, the impact of permafrost thaw on CH4 oxidation is uncertain. We measured potential CH4 oxidation rates (hereafter, CH4 oxidation) and their predictors using laboratory incubations and in situ porewater redox chemistry across a permafrost thaw gradient of eight thaw stages at Stordalen Mire, a permafrost peatland complex in northernmost Sweden. Methane oxidation rates increased across a gradient of permafrost thaw and differed in transitional thaw stages relative to end-member stages. Oxidation was consistently higher in submerged fens than in bogs or palsas across a range of CH4 concentrations. We also observed that CH4 oxidation increased with decreasing in situ redox potential and was highest in sites with lower redox potential (Eh textless10 mV) and high water table. Our results suggest that redox potential can be used as an important predictor of CH4 oxidation, especially in thawed permafrost peatlands. Our results also highlight the importance of considering transitional thaw stages when characterizing landscape-scale CH4 dynamics, because these transitional areas have different rates and controls of CH4 oxidation relative to intact or completely thawed permafrost areas. As permafrost thaw increases the total area of semiwet and wet thaw stages in permafrost peatlands, CH4 oxidation represents an important control on CH4 emissions to the atmosphere. |
BibTeX:
@article{Perryman2020,
author = {Perryman, Clarice R and McCalley, Carmody K and Malhotra, Avni and Fahnestock, M Florencia and Kashi, Natalie N and Bryce, Julia G and Giesler, Reiner and Varner, Ruth K},
title = {Thaw Transitions and Redox Conditions Drive Methane Oxidation in a Permafrost Peatland},
journal = {Journal of Geophysical Research: Biogeosciences},
year = {2020},
volume = {125},
number = {3},
pages = {1--15},
doi = {10.1029/2019JG005526}
}
|
| Peters W, Bastos A, Ciais P and Vermeulen A (2020), "A historical, geographical and ecological perspective on the 2018 European summer drought", Philosophical Transactions of the Royal Society B: Biological Sciences., oct, 2020. Vol. 375(1810), pp. 20190505. |
BibTeX:
@article{Peters2020,
author = {Peters, Wouter and Bastos, Ana and Ciais, Philippe and Vermeulen, Alex},
title = {A historical, geographical and ecological perspective on the 2018 European summer drought},
journal = {Philosophical Transactions of the Royal Society B: Biological Sciences},
year = {2020},
volume = {375},
number = {1810},
pages = {20190505},
url = {https://royalsocietypublishing.org/doi/10.1098/rstb.2019.0505},
doi = {10.1098/rstb.2019.0505}
}
|
| Peters RL, von Arx G, Nievergelt D, Ibrom A, Stillhard J, Trotsiuk V, Mazurkiewicz A and Babst F (2020), "Axial changes in wood functional traits have limited net effects on stem biomass increment in European beech (Fagus sylvatica)", Tree physiology. Vol. 40(4), pp. 498-510. |
| Abstract: During the growing season, trees allocate photoassimilates to increase their aboveground woody biomass in the stem (ABIstem). This 'carbon allocation' to structural growth is a dynamic process influenced by internal and external (e.g., climatic) drivers. While radial variability in wood formation and its resulting structure have been intensively studied, their variability along tree stems and subsequent impacts on ABIstem remain poorly understood. We collected wood cores from mature trees within a fixed plot in a well-studied temperate Fagus sylvatica L. forest. For a subset of trees, we performed regular interval sampling along the stem to elucidate axial variability in ring width (RW) and wood density ($$), and the resulting effects on tree- and plot-level ABIstem. Moreover, we measured wood anatomical traits to understand the anatomical basis of $$ and the coupling between changes in RW and $$ during drought. We found no significant axial variability in $$ because an increase in the vessel-to-fiber ratio with smaller RW compensated for vessel tapering towards the apex. By contrast, temporal variability in RW varied significantly along the stem axis, depending on the growing conditions. Drought caused a more severe growth decrease, and wetter summers caused a disproportionate growth increase at the stem base compared with the top. Discarding this axial variability resulted in a significant overestimation of tree-level ABIstem in wetter and cooler summers, but this bias was reduced to ˜2% when scaling ABIstem to the plot level. These results suggest that F. sylvatica prioritizes structural carbon sinks close to the canopy when conditions are unfavorable. The different axial variability in RW and $$ thereby indicates some independence of the processes that drive volume growth and wood structure along the stem. This refines our knowledge of carbon allocation dynamics in temperate diffuse-porous species and contributes to reducing uncertainties in determining forest carbon fixation. |
BibTeX:
@article{Peters2020a,
author = {Peters, Richard L and von Arx, Georg and Nievergelt, Daniel and Ibrom, Andreas and Stillhard, Jonas and Trotsiuk, Volodymyr and Mazurkiewicz, Aleksandra and Babst, Flurin},
title = {Axial changes in wood functional traits have limited net effects on stem biomass increment in European beech (Fagus sylvatica)},
journal = {Tree physiology},
year = {2020},
volume = {40},
number = {4},
pages = {498--510},
doi = {10.1093/treephys/tpaa002}
}
|
| Piao S, Wang X, Wang K, Li X, Bastos A, Canadell JG, Ciais P, Friedlingstein P and Sitch S (2020), "Interannual variation of terrestrial carbon cycle: Issues and perspectives", Global Change Biology., nov, 2020. Vol. 26(1), pp. 300-318. Wiley. |
| Abstract: With accumulation of carbon cycle observations and model developments over the past decades, exploring interannual variation (IAV) of terrestrial carbon cycle offers the opportunity to better understand climate–carbon cycle relationships. However, despite growing research interest, uncertainties remain on some fundamental issues, such as the contributions of different regions, constituent fluxes and climatic factors to carbon cycle IAV. Here we overviewed the literature on carbon cycle IAV about current understanding of these issues. Observations and models of the carbon cycle unanimously show the dominance of tropical land ecosystems to the signal of global carbon cycle IAV, where tropical semiarid ecosystems contribute as much as the combination of all other tropical ecosystems. Vegetation photosynthesis contributes more than ecosystem respiration to IAV of the global net land carbon flux, but large uncertainties remain on the contribution of fires and other disturbance fluxes. Climatic variations are the major drivers to the IAV of net land carbon flux. Although debate remains on whether the dominant driver is temperature or moisture variability, their interaction,that is, the dependence of carbon cycle sensitivity to temperature on moisture conditions, is emerging as key regulators of the carbon cycle IAV. On timescales from the interannual to the centennial, global carbon cycle variability will be increasingly contributed by northern land ecosystems and oceans. Therefore, both improving Earth system models (ESMs) with the progressive understanding on the fast processes manifested at interannual timescale and expanding carbon cycle observations at broader spatial and longer temporal scales are critical to better prediction on evolution of the carbon–climate system. |
BibTeX:
@article{Piao2020,
author = {Piao, Shilong and Wang, Xuhui and Wang, Kai and Li, Xiangyi and Bastos, Ana and Canadell, Josep G and Ciais, Philippe and Friedlingstein, Pierre and Sitch, Stephen},
title = {Interannual variation of terrestrial carbon cycle: Issues and perspectives},
journal = {Global Change Biology},
publisher = {Wiley},
year = {2020},
volume = {26},
number = {1},
pages = {300--318},
doi = {10.1111/gcb.14884}
}
|
| Piilo SR, Korhola A, Heiskanen L, Tuovinen JP, Aurela M, Juutinen S, Marttila H, Saari M, Tuittila ES, Turunen J and Väliranta MM (2020), "Spatially varying peatland initiation, Holocene development, carbon accumulation patterns and radiative forcing within a subarctic fen", Quaternary Science Reviews. Vol. 248 |
| Abstract: High latitude peatlands act as globally important carbon (C) sinks and are in constant interaction with the atmosphere. Their C storage formed during the Holocene. In the course of time, the aggregate effect of the C fluxes on radiative forcing (RF) typically changes from warming to cooling, but the timing of this shift varies among different peatlands. Here we investigated Holocene peatland development, including vegetation history, vertical peat growth and the lateral expansion of a patterned subarctic fen in northern Finland by means of multiple sampling points. We modelled the Holocene RF by combining knowledge on past vegetation communities based on plant macrofossil stratigraphies and present in situ C flux measurements. The peatland initiated at ca. 9500 calibrated years Before Present (cal yr BP), and its lateral expansion was greatest between ca. 9000 and 7000 cal yr BP. After the early expansion, vertical peat growth proceeded very differently in different parts of the peatland, regulated by internal and external factors. The pronounced surface microtopography, with high strings and wet flarks, started to form only after ca. 1000 cal yr BP. C accumulation within the peatland recorded a high degree of spatial variability throughout its history, including the recent past. We applied two flux scenarios with different interpretation of the initial peatland development phases to estimate the RF induced by C fluxes of the fen. After ca. 4000 cal yr BP, at the latest, the peatland RF has been negative (cooling), mainly driven by C uptake and biomass production, while methane emissions had a lesser role in the total RF. Interestingly, these scenarios suggest that the greatest cooling effect took place around ca. 1000 cal yr BP, after which the surface microtopography established. The study demonstrated that despite the high spatial heterogeneity and idiosyncratic behaviour of the peatland, the RF of the studied fen followed the general development pattern of more southern peatlands. Holocene climate variations and warm phases did not seem to induce any distinctive and consistent peatland-scale patterns in C accumulation, whereas our data suggests that the changes in vegetation related to autogenic succession were reflected in the C accumulation patterns and RF more clearly. |
BibTeX:
@article{Piilo2020,
author = {Piilo, Sanna R and Korhola, Atte and Heiskanen, Lauri and Tuovinen, Juha Pekka and Aurela, Mika and Juutinen, Sari and Marttila, Hannu and Saari, Markus and Tuittila, Eeva Stiina and Turunen, Jukka and Väliranta, Minna M},
title = {Spatially varying peatland initiation, Holocene development, carbon accumulation patterns and radiative forcing within a subarctic fen},
journal = {Quaternary Science Reviews},
year = {2020},
volume = {248},
doi = {10.1016/j.quascirev.2020.106596}
}
|
| Pilegaard K and Ibrom A (2020), "Net carbon ecosystem exchange during 24 years in the SorøBeech Forest–relations to phenology and climate", Tellus, Series B: Chemical and Physical Meteorology. Vol. 72(1), pp. 1-17. Taylor & Francis. |
| Abstract: The carbon sequestration of plants through photosynthesis is responsible for removal of a substantial amount of the man-made CO2 emissions to the atmosphere. In recent years this so-called land-sink has removed about 30% of the man-made emissions to the atmosphere, with forests being the most important sinks. The land-sink is, however, vulnerable to changes in the environment, such as the atmospheric composition, climate change, and extreme events like storms and droughts. It is therefore important to study the effects of such change on terrestrial ecosystems to provide the basis for predicting the future of the sink. We here report the results of continuous CO2 flux measurements over a Danish beech forest during the years 1996–2019. Over the years the forest acted as a sink of CO2 with a net carbon sequestration ranging from about zero to 400 g C m–2 yr−1. We found significant trends in net ecosystem exchange (NEE) (increasing in absolute terms with 15 g C m–2 yr2), gross ecosystem exchange (GEE) (increasing with 25 g C m–2 yr–2), and ecosystem respiration (RE) (increasing with 10 g C m–2 yr–2). A prolonged growing season explained 73% of the increase in NEE. The increasing CO2 concentration in the atmosphere and a subsequent increase in photosynthetic capacity together with warming are the most likely main causes of the increased carbon uptake. The severe drought in the summer of 2018 resulted in a reduction of the annual NEE of 25%. |
BibTeX:
@article{Pilegaard2020,
author = {Pilegaard, Kim and Ibrom, Andreas},
title = {Net carbon ecosystem exchange during 24 years in the SorøBeech Forest–relations to phenology and climate},
journal = {Tellus, Series B: Chemical and Physical Meteorology},
publisher = {Taylor & Francis},
year = {2020},
volume = {72},
number = {1},
pages = {1--17},
url = {https://doi.org/10.1080/16000889.2020.1822063},
doi = {10.1080/16000889.2020.1822063}
}
|
| Pioli S, Sarneel J, Thomas HJD, Domene X, Andrés P, Hefting M, Reitz T, Laudon H, Sandén T, Piscová V, Aurela M and Brusetti L (2020), "Linking plant litter microbial diversity to microhabitat conditions, environmental gradients and litter mass loss: Insights from a European study using standard litter bags", Soil Biology and Biochemistry. Vol. 144(November 2019) |
| Abstract: Plant litter decomposition is a key process for carbon dynamics and nutrient cycling in terrestrial ecosystems. The interaction between litter properties, climatic conditions and soil attributes, influences the activity of microorganisms responsible for litter mineralization. So far, studies using standardized litters to investigate the response of bacterial and fungal communities under different environmental conditions are scarce, especially along wide geographic ranges. We used a standardized protocol to investigate the diversity of bacteria and fungi in plant litter with the aim of: (i) comparing the microbial communities of native and exotic litters with the community of local soil along a European transect from northern Finland to southern Italy, (ii) defining whether and to what extent, litter types with different traits represent selective substrates for microbial communities, (iii) disentangling the abiotic drivers of microbial diversity, and (iv) correlating the microbial diversity and species co-occurrences patterns with litter mass loss. We buried native litter and three exotic standardized litters (Deschampsia cespitosa, rooibos tea and green tea) at 12 European study sites. We determined litter mass loss after 94 days. We used an automated molecular DNA-based fingerprinting (ARISA) to profile the bacterial and fungal communities of each litter type and soil (180 samples in total). Microbial communities in native and exotic litters differed from local soil assemblages. Green tea and D. cespitosa litter represented more selective substrates compared to native litter and rooibos. Soil moisture and soil temperature were the major drivers of microbial community structure at larger scales, though with varying patterns according to litter type. Soil attributes (i.e. moisture and C/N ratios) better explained the differences in microbial abundances than litter type. Green tea degraded faster than all other litter types and accounted for the largest number of positive co-occurrences among microbial taxa. Litter mass loss was positively correlated with fungal evenness and with the percentage of positive co-occurrences between fungi. Our findings suggest that the microbial community at larger scales reflects the complex interplay between litter type and soil attributes, with the latter exerting a major influence. Mass loss patterns are in part determined by inter- and intra-kingdom interactions and fungal diversity. |
BibTeX:
@article{Pioli2020,
author = {Pioli, Silvia and Sarneel, Judith and Thomas, Haydn J D and Domene, Xavier and Andrés, Pilar and Hefting, Mariet and Reitz, Thomas and Laudon, Hjalmar and Sandén, Taru and Piscová, Veronika and Aurela, Mika and Brusetti, Lorenzo},
title = {Linking plant litter microbial diversity to microhabitat conditions, environmental gradients and litter mass loss: Insights from a European study using standard litter bags},
journal = {Soil Biology and Biochemistry},
year = {2020},
volume = {144},
number = {November 2019},
doi = {10.1016/j.soilbio.2020.107778}
}
|
| Portillo-Estrada M, Ariza-Carricondo C and Ceulemans R (2020), "Outburst of senescence-related VOC emissions from a bioenergy poplar plantation", Plant Physiology and Biochemistry., mar, 2020. Vol. 148, pp. 324-332. Elsevier Masson SAS. |
| Abstract: Leaf senescence is a catabolic process that emits volatile organic compounds (VOCs). In densely planted monocultures these VOC emissions occur in outbursts that might be relevant for the local air quality since these VOCs are typically oxygenated. The VOC emissions of a high-density poplar (Populus) bioenergy plantation were monitored along with meteorological parameters, CO2 and H2O exchanges, canopy greenness, and leaf area index during the second half of the year 2015. The emissions of 25 VOCs peaked at the beginning of September, coinciding with the onset of senescence. Together these VOC emissions amounted to a total of 2.85 mmol m−2, translated into 98.3 mg C m−2. The emission peak was mainly composed of oxygenated VOCs as methanol, acetic acid, and lipoxygenase products that are all typical for catabolic processes. So, the senescence process of the poplar plantation was very well reflected in the peak of VOC emissions. |
BibTeX:
@article{Portillo-Estrada2020,
author = {Portillo-Estrada, Miguel and Ariza-Carricondo, Cristina and Ceulemans, Reinhart},
title = {Outburst of senescence-related VOC emissions from a bioenergy poplar plantation},
journal = {Plant Physiology and Biochemistry},
publisher = {Elsevier Masson SAS},
year = {2020},
volume = {148},
pages = {324--332},
doi = {10.1016/j.plaphy.2020.01.024}
}
|
| Prendin AL, Carrer M, Karami M, Hollesen J, Bjerregaard Pedersen N, Pividori M, Treier UA, Westergaard-Nielsen A, Elberling B and Normand S (2020), "Immediate and carry-over effects of insect outbreaks on vegetation growth in West Greenland assessed from cells to satellite", Journal of Biogeography. Vol. 47(1), pp. 87-100. |
| Abstract: Aim: Tundra ecosystems are highly vulnerable to climate change, and climate–growth responses of Arctic shrubs are variable and altered by microsite environmental conditions and biotic factors. With warming and drought during the growing season, insect-driven defoliation is expected to increase in frequency and severity with potential broad-scale impacts on tundra ecosystem functioning. Here we provide the first broad-scale reconstruction of spatio-temporal dynamics of past insect outbreaks by assessing their effects on shrub growth along a typical Greenlandic fjord climate gradient from the inland ice to the sea. Location: Nuuk Fjord (64°30′N/51°23′W) and adjacent areas, West Greenland. Taxa: Great brocade (Eurois occulta L.) and grey willow (Salix glauca L.). Methods: We combined dendro-anatomical and remote sensing analyses. Time series of ring width (RW) and wood-anatomical traits were obtained from chronologies of textgreater40 years established from 153 individuals of S. glauca collected at nine sites. We detected anomalies in satellite-based Normalized Difference Vegetation Index (NDVI) related to defoliation and reconstructed past changes in photosynthetic activity across the region. Results: We identified outbreaks as distinctive years with reduced RW, cell-wall thickness and vessel size, without being directly related to climate but matching with years of parallel reduction in NDVI. The two subsequent years after the defoliation showed a significant increase in RW. The reconstructed spatio-temporal dynamics of these events indicate substantial regional variation in outbreak intensity linked to the climate variability across the fjord system. Main conclusions: Our results highlight the ability of S. glauca to cope with severe insect defoliation by changing carbon investment and xylem conductivity leading to high resilience and rapid recovery after the disturbance. Our multiproxy approach allows us to pinpoint biotic drivers of narrow ring formation and to provide new broad-scale insight on the C-budget and vegetation productivity of shrub communities in a widespread arctic ecosystem. |
BibTeX:
@article{Prendin2020,
author = {Prendin, Angela Luisa and Carrer, Marco and Karami, Mojtaba and Hollesen, Jørgen and Bjerregaard Pedersen, Nanna and Pividori, Mario and Treier, Urs A and Westergaard-Nielsen, Andreas and Elberling, Bo and Normand, Signe},
title = {Immediate and carry-over effects of insect outbreaks on vegetation growth in West Greenland assessed from cells to satellite},
journal = {Journal of Biogeography},
year = {2020},
volume = {47},
number = {1},
pages = {87--100},
doi = {10.1111/jbi.13644}
}
|
| Räsänen M, Merbold L, Vakkari V, Aurela M, Laakso L, Beukes JP, Van Zyl PG, Josipovic M, Feig G, Pellikka P, Rinne J and Katul GG (2020), "Root-zone soil moisture variability across African savannas: From pulsed rainfall to land-cover switches", Ecohydrology. Vol. 13(5), pp. 1-20. |
| Abstract: The main source of soil moisture variability in savanna ecosystems is pulsed rainfall. Rainfall pulsing impacts water-stress durations, soil moisture switching between wet-to-dry and dry-to-wet states, and soil moisture spectra as well as derived measures from it such as soil moisture memory. Rainfall pulsing is also responsible for rapid changes in grassland leaf area and concomitant changes in evapotranspirational (ET) losses, which then impact soil moisture variability. With the use of a hierarchy of models and soil moisture measurements, temporal variability in root-zone soil moisture and water-stress periods are analysed at four African sites ranging from grass to miombo savannas. The normalized difference vegetation index (NDVI) and potential ET (PET)-adjusted ET model predict memory timescale and dry persistence in agreement with measurements. The model comparisons demonstrate that dry persistence and mean annual dry periods must account for seasonal and interannual changes in maximum ET represented by NDVI and to a lesser extent PET. Interestingly, the precipitation intensity and soil moisture memory were linearly related across three savannas with ET/infiltration ∼ 1.0. This relation and the variability of length and timing of dry periods are also discussed. |
BibTeX:
@article{Raesaenen2020,
author = {Räsänen, Matti and Merbold, Lutz and Vakkari, Ville and Aurela, Mika and Laakso, Lauri and Beukes, J Paul and Van Zyl, Pieter G and Josipovic, Miroslav and Feig, Gregor and Pellikka, Petri and Rinne, Janne and Katul, Gabriel G},
title = {Root-zone soil moisture variability across African savannas: From pulsed rainfall to land-cover switches},
journal = {Ecohydrology},
year = {2020},
volume = {13},
number = {5},
pages = {1--20},
doi = {10.1002/eco.2213}
}
|
| Rahmati M, Groh J, Graf A, Pütz T, Vanderborght J and Vereecken H (2020), "On the impact of increasing drought on the relationship between soil water content and evapotranspiration of a grassland", Vadose Zone Journal. Vol. 19(1), pp. 1-20. |
| Abstract: Weighable lysimeters were used to study the relation between soil water content (SWC) and the actual evapotranspiration (ETa) of grassland under two different climate regimes of Rollesbroich and Selhausen but for an identical soil from Rollesbroich. All components of the water balance were determined from 2012 until 2018. Budyko analysis was used to characterize the hydrological status of the studied sites. Wavelet analysis was also applied to study the power spectrum of ETa, vegetation-height-adjusted reference evapotranspiration (ETcrop), and water stress index (WSI) defined as ETa/ETcrop, as well as SWC at three different depths and the coherence between SWC and ETa and WSI. The Budyko analysis showed that 2018 resulted in a shift of both locations towards more water-limited conditions, although Rollesbroich remained an energy-limited system. Based on the power spectrum analysis, the annual timescale is the dominant scale for the temporal variability of ETa, ETcrop, and SWC. The results also showed that increasing dryness at the energy-limited site led to more temporal variability of SWC at all depths at the annual timescale. Wavelet coherence analysis showed a reduction of the phase shift between SWC and ETa at an annual scale caused by the increase in dryness during the measurement period. We found that phase shifts between SWC and ETa and SWC and WSI were stronger at the water-limited site than at the energy-limited site. The wavelet coherence analysis also showed that from 2014 to 2018, the control of ETa and WSI on SWC increased due to higher dryness of soil. |
BibTeX:
@article{Rahmati2020,
author = {Rahmati, Mehdi and Groh, Jannis and Graf, Alexander and Pütz, Thomas and Vanderborght, Jan and Vereecken, Harry},
title = {On the impact of increasing drought on the relationship between soil water content and evapotranspiration of a grassland},
journal = {Vadose Zone Journal},
year = {2020},
volume = {19},
number = {1},
pages = {1--20},
doi = {10.1002/vzj2.20029}
}
|
| Ramonet M, Ciais P, Apadula F, Bartyzel J, Bastos A, Bergamaschi P, Blanc PE, Brunner D, Caracciolo di Torchiarolo L, Calzolari F, Chen H, Chmura L, Colomb A, Conil S, Cristofanelli P, Cuevas E, Curcoll R, Delmotte M, di Sarra A, Emmenegger L, Forster G, Frumau A, Gerbig C, Gheusi F, Hammer S, Haszpra L, Hatakka J, Hazan L, Heliasz M, Henne S, Hensen A, Hermansen O, Keronen P, Kivi R, Komínková K, Kubistin D, Laurent O, Laurila T, Lavric JV, Lehner I, Lehtinen KEJ, Leskinen A, Leuenberger M, Levin I, Lindauer M, Lopez M, Myhre CL, Mammarella I, Manca G, Manning A, Marek MV, Marklund P, Martin D, Meinhardt F, Mihalopoulos N, Mölder M, Morgui JA, Necki J, O'Doherty S, O'Dowd C, Ottosson M, Philippon C, Piacentino S, Pichon JM, Plass-Duelmer C, Resovsky A, Rivier L, Rodó X, Sha MK, Scheeren HA, Sferlazzo D, Spain TG, Stanley KM, Steinbacher M, Trisolino P, Vermeulen A, Vítková G, Weyrauch D, Xueref-Remy I, Yala K and Yver Kwok C (2020), "The fingerprint of the summer 2018 drought in Europe on ground-based atmospheric CO 2 measurements", Philosophical Transactions of the Royal Society B: Biological Sciences., oct, 2020. Vol. 375(1810), pp. 20190513. |
| Abstract: During the summer of 2018, a widespread drought developed over Northern and Central Europe. The increase in temperature and the reduction of soil moisture have influenced carbon dioxide (CO 2 ) exchange between the atmosphere and terrestrial ecosystems in various ways, such as a reduction of photosynthesis, changes in ecosystem respiration, or allowing more frequent fires. In this study, we characterize the resulting perturbation of the atmospheric CO 2 seasonal cycles. 2018 has a good coverage of European regions affected by drought, allowing the investigation of how ecosystem flux anomalies impacted spatial CO 2 gradients between stations. This density of stations is unprecedented compared to previous drought events in 2003 and 2015, particularly thanks to the deployment of the Integrated Carbon Observation System (ICOS) network of atmospheric greenhouse gas monitoring stations in recent years. Seasonal CO 2 cycles from 48 European stations were available for 2017 and 2018. Earlier data were retrieved for comparison from international databases or national networks. Here, we show that the usual summer minimum in CO 2 due to the surface carbon uptake was reduced by 1.4 ppm in 2018 for the 10 stations located in the area most affected by the temperature anomaly, mostly in Northern Europe. Notwithstanding, the CO 2 transition phases before and after July were slower in 2018 compared to 2017, suggesting an extension of the growing season, with either continued CO 2 uptake by photosynthesis and/or a reduction in respiration driven by the depletion of substrate for respiration inherited from the previous months due to the drought. For stations with sufficiently long time series, the CO 2 anomaly observed in 2018 was compared to previous European droughts in 2003 and 2015. Considering the areas most affected by the temperature anomalies, we found a higher CO 2 anomaly in 2003 (+3 ppm averaged over 4 sites), and a smaller anomaly in 2015 (+1 ppm averaged over 11 sites) compared to 2018. |
BibTeX:
@article{Ramonet2020,
author = {Ramonet, M. and Ciais, P. and Apadula, F. and Bartyzel, J. and Bastos, A. and Bergamaschi, P. and Blanc, P. E. and Brunner, D. and Caracciolo di Torchiarolo, L. and Calzolari, F. and Chen, H. and Chmura, L. and Colomb, A. and Conil, S. and Cristofanelli, P. and Cuevas, E. and Curcoll, R. and Delmotte, M. and di Sarra, A. and Emmenegger, L. and Forster, G. and Frumau, A. and Gerbig, C. and Gheusi, F. and Hammer, S. and Haszpra, L. and Hatakka, J. and Hazan, L. and Heliasz, M. and Henne, S. and Hensen, A. and Hermansen, O. and Keronen, P. and Kivi, R. and Komínková, K. and Kubistin, D. and Laurent, O. and Laurila, T. and Lavric, J. V. and Lehner, I. and Lehtinen, K. E. J. and Leskinen, A. and Leuenberger, M. and Levin, I. and Lindauer, M. and Lopez, M. and Myhre, C. Lund and Mammarella, I. and Manca, G. and Manning, A. and Marek, M. V. and Marklund, P. and Martin, D. and Meinhardt, F. and Mihalopoulos, N. and Mölder, M. and Morgui, J. A. and Necki, J. and O'Doherty, S. and O'Dowd, C. and Ottosson, M. and Philippon, C. and Piacentino, S. and Pichon, J. M. and Plass-Duelmer, C. and Resovsky, A. and Rivier, L. and Rodó, X. and Sha, M. K. and Scheeren, H. A. and Sferlazzo, D. and Spain, T. G. and Stanley, K. M. and Steinbacher, M. and Trisolino, P. and Vermeulen, A. and Vítková, G. and Weyrauch, D. and Xueref-Remy, I. and Yala, K. and Yver Kwok, C.},
title = {The fingerprint of the summer 2018 drought in Europe on ground-based atmospheric CO 2 measurements},
journal = {Philosophical Transactions of the Royal Society B: Biological Sciences},
year = {2020},
volume = {375},
number = {1810},
pages = {20190513},
url = {https://royalsocietypublishing.org/doi/10.1098/rstb.2019.0513},
doi = {10.1098/rstb.2019.0513}
}
|
| Randazzo NA, Michalak AM and Desai AR (2020), "Synoptic Meteorology Explains Temperate Forest Carbon Uptake", Journal of Geophysical Research: Biogeosciences., feb, 2020. Vol. 125(2) Blackwell Publishing Ltd. |
| Abstract: While substantial attention has been paid to the effects of both global climate oscillations and local meteorological conditions on the interannual variability of ecosystem carbon exchange, the relationship between the interannual variability of synoptic meteorology and ecosystem carbon exchange has not been well studied. Here we use a clustering algorithm to identify a summertime cyclonic precipitation system northwest of the Great Lakes to determine (a) the association at a daily scale between the occurrence of this system and the local meteorology and net ecosystem exchange at three Great Lakes region forested eddy covariance sites and (b) the association between the seasonal prevalence of this system and the summertime net ecosystem exchange of these sites. We find that temperature, in addition to precipitation and cloud cover, is an important explanatory factor for the suppression of net ecosystem productivity that occurs during these cyclonic events in this region. In addition, the prevalence of this cyclonic system can explain a significant proportion of the interannual variability in summertime forest ecosystem exchange in this region. This explanatory power is not due to a simple accumulation of low-productivity days that cooccur with this meteorological event, but rather a broader association between the frequency of these events and several aspects of prevailing seasonal conditions. This work demonstrates the usefulness of conceptualizing meteorology in terms of synoptic systems for explaining the interannual variability of regional carbon fluxes. |
BibTeX:
@article{Randazzo2020,
author = {Randazzo, Nina A. and Michalak, Anna M. and Desai, Ankur R.},
title = {Synoptic Meteorology Explains Temperate Forest Carbon Uptake},
journal = {Journal of Geophysical Research: Biogeosciences},
publisher = {Blackwell Publishing Ltd},
year = {2020},
volume = {125},
number = {2},
doi = {10.1029/2019JG005476}
}
|
| Rannik Ü, Vesala T, Peltola O, Novick KA, Aurela M, Järvi L, Montagnani L, Mölder M, Peichl M, Pilegaard K and Mammarella I (2020), "Impact of coordinate rotation on eddy covariance fluxes at complex sites", Agricultural and Forest Meteorology. Vol. 287(December 2019), pp. 107940. Elsevier. |
| Abstract: The choice of coordinate system to calculate eddy covariance fluxes becomes particularly relevant at complex measurement sites. The traditional way is to perform double rotation (DR) of the coordinate system i.e., to calculate turbulent fluxes in a coordinate system that is aligned with the flow streamlines within the flux averaging period (e.g., Kaimal and Finnigan, 1994). The second approach, the so-called planar-fitted (PF) coordinate system, averages the flow over a longer period of time, in practice a month or more. The PF method allows to derive an intercept coefficient of the vertical wind speed which can be attributed to the offset of the sonic anemometer or the average vertical flow related to meteorological conditions. We evaluated the variants of the PF methods using data from a variety of sites ranging from complex urban and forest sites to nearly ideal forest and peatland sites. At complex sites, we found that the intercept of the vertical wind speed derived from the PF method is a function of wind direction, time of day and/or stability. The sector-wise PF (SPF) method frequently led to insignificant statistical relationships. We tested a continuous PF (CPF) method where the relationship establishing the coordinate frame was represented as the continuous function in the form of Fourier series. The method enabled to obtain the PF with lower uncertainty as compared to the SPF method, by selecting necessary number of harmonics for each site based on confidence intervals of estimated parameters. Therefore, we recommend to use the CPF method in cases when the number of observations in some wind direction interval is low or the obtained SPF is insignificant due to large variance in measurements. We also showed that significant systematic difference can exist in cumulative turbulent fluxes between the DR and PF methods over a longer period of time. Derived vertical advection of carbon dioxide exhibited large variability with wind direction due to topography at complex sites and therefore, without considering horizontal advection, cannot be used to improve the net ecosystem exchange estimation during nocturnal, low turbulence conditions. |
BibTeX:
@article{Rannik2020,
author = {Rannik, Üllar and Vesala, Timo and Peltola, Olli and Novick, Kimberly A and Aurela, Mika and Järvi, Leena and Montagnani, Leonardo and Mölder, Meelis and Peichl, Matthias and Pilegaard, Kim and Mammarella, Ivan},
title = {Impact of coordinate rotation on eddy covariance fluxes at complex sites},
journal = {Agricultural and Forest Meteorology},
publisher = {Elsevier},
year = {2020},
volume = {287},
number = {December 2019},
pages = {107940},
url = {https://doi.org/10.1016/j.agrformet.2020.107940},
doi = {10.1016/j.agrformet.2020.107940}
}
|
| Rasmussen LH, Michelsen A, Ladegaard-Pedersen P, Nielsen CS and Elberling B (2020), "Arctic soil water chemistry in dry and wet tundra subject to snow addition, summer warming and herbivory simulation", Soil Biology and Biochemistry. Vol. 141(May 2019), pp. 107676. Elsevier Ltd. |
| Abstract: Multiple and rapid environmental changes in the Arctic have major consequences for the entire ecosystem. Soil water chemistry is one component with important implications for understanding climate feedbacks, plant growth, microbial turnover and net greenhouse gas emissions. Here we assess the contrasting growing season soil water chemistry in a Low arctic Greenlandic mesic tundra heath and a fen, which have been subjected to factorial treatments of summer warming using open top chambers (OTCs), snow addition using snow fences, which increase soil temperature in late winter, and shrub removal mimicking herbivory attack. Dissolved Organic Carbon (DOC) and plant nutrients, including NO3−, NH4+, PO42+ and total dissolved N were measured during multiple growing seasons (2013–2016) to quantify the treatment effects on nutrient availability in two dominating, but contrasting, vegetation types. Ambient nutrient concentrations in the mesic tundra heath decreased throughout the growing season and increased during senescence, while concentrations were highest during peak growing season in the fen. The content of NH4+ and DOC were highest in the fen, whereas NO3− was highest in the mesic tundra heath. The fen had no seasonal pattern. Summer warming in the mesic tundra heath did not change the availability of nutrients, but in combination with shrub removal, both NO3− and DOC concentrations increased, likely due to reduced plant uptake. Shrub removal alone increased NO3− in one growing season, and, combined with snow addition, increased DOC. Significant effects of shrub removal were mostly found in 2016. Snow addition combined with summer warming increased DOC and total N concentrations and highlights the potential loss of dissolved C from the ecosystem. In the fen, shrub removal alone and combined with summer warming decreased DOC. Snow addition alone and in combination with summer warming similarly decreased DOC. In the mesic tundra heath, shrub removal caused higher soil water contents in all years. In the dry and warm 2016, it meant textless10% soil water content in controls and 15–20% in shrub removal plots during the peak growing season, which may have relieved soil moisture limitation on mineralization rates in the latter. We conclude that soil water chemistry is vegetation-specific, and that treatment effects are surprisingly limited when comparing multiple years with contrasting precipitation patterns. Herbivory may have larger impact in very dry, warm summers and, together with extreme weather events, exert similar or larger effects than four years of temperature manipulations. The effects of summer warming or increased winter snow depend on ecosystem type and moisture status of the soil. The combination of multi-year and multi-site studies therefore seem important for understanding future biogeochemical dynamics in Arctic landscapes. |
BibTeX:
@article{Rasmussen2020,
author = {Rasmussen, Laura H and Michelsen, Anders and Ladegaard-Pedersen, Pernille and Nielsen, Cecilie S and Elberling, Bo},
title = {Arctic soil water chemistry in dry and wet tundra subject to snow addition, summer warming and herbivory simulation},
journal = {Soil Biology and Biochemistry},
publisher = {Elsevier Ltd},
year = {2020},
volume = {141},
number = {May 2019},
pages = {107676},
url = {https://doi.org/10.1016/j.soilbio.2019.107676},
doi = {10.1016/j.soilbio.2019.107676}
}
|
| Ravn NR, Elberling B and Michelsen A (2020), "Arctic soil carbon turnover controlled by experimental snow addition, summer warming and shrub removal", Soil Biology and Biochemistry. Vol. 142(April 2019), pp. 107698. Elsevier Ltd. |
| Abstract: Northern latitude tundra heaths have accumulated large amounts of organic carbon (C) in the soil. Changes in climatic conditions such as temperature and winter precipitation might affect the C balance and potentially change these tundra ecosystems from being C sinks to sources of CO2 emitted to the atmosphere. However, studies on C fluxes with single and combined winter snow and summer warming effects are scarce. This study investigates gross ecosystem production (GEP), ecosystem respiration (ER), net ecosystem production (NEP) and carbon isotopic composition of CO2 emitted from a dry heath in arctic Greenland one and two years following field manipulations of summer temperature, shrub abundance and winter snow depth. Our aims were to quantify climatic change effects on CO2 fluxes and the growing season carbon balance of the ecosystem and to investigate shifts in $$13C of emitted CO2 potentially due changes in emission from old soil C versus recently fixed carbon. Ecosystem CO2 fluxes and $$13C-CO2 were measured using closed chambers, and soil CO2 concentrations and $$13C were measured depth-specifically using gas probes. We found a significant increase of CO2 emissions in all treatments during both years. Growing season NEP increased by 38 and 73% with 1 m enhanced winter snow depth, by 113 and 144% with summer warming and by 61 and 320% with total shrub removal in 2013 and 2014, respectively. The snow effect can be explained by the delay in the onset of growth as indicated by early season reduced vegetation greenness. The effect of warming was a result of an increase of ER by 39 and 32%, and the effect of shrub removal was mainly due to a reduction in GEP by 34 and 48%, in 2013 and 2014, respectively. Furthermore, the $$13C of the carbon source of CO2 emitted from warmed plots increased significantly two years after the experiment was initiated. This might indicate increased decomposition of 13C enriched soil organic matter and hence increased mineralization of the old carbon stock in the soil under warmed conditions. The increase of NEP, the additive response of all treatments, and the indications of increased emission of carbon from old stocks due to warming (or warming-induced drying), demonstrate the risk of a relatively fast feedback to climate warming during the snow-free season. |
BibTeX:
@article{Ravn2020,
author = {Ravn, Nynne R and Elberling, Bo and Michelsen, Anders},
title = {Arctic soil carbon turnover controlled by experimental snow addition, summer warming and shrub removal},
journal = {Soil Biology and Biochemistry},
publisher = {Elsevier Ltd},
year = {2020},
volume = {142},
number = {April 2019},
pages = {107698},
url = {https://doi.org/10.1016/j.soilbio.2019.107698},
doi = {10.1016/j.soilbio.2019.107698}
}
|
| Reichenau TG, Korres W, Schmidt M, Graf A, Welp G, Meyer N, Stadler A, Brogi C and Schneider K (2020), "A comprehensive dataset of vegetation states, fluxes of matter and energy, weather, agricultural management, and soil properties from intensively monitored crop sites in western Germany", In Earth System Science Data. Vol. 12(4), pp. 2333-2364. |
| Abstract: The development and validation of hydroecological land-surface models to simulate agricultural areas require extensive data on weather, soil properties, agricultural management, and vegetation states and fluxes. However, these comprehensive data are rarely available since measurement, quality control, documentation, and compilation of the different data types are costly in terms of time and money. Here, we present a comprehensive dataset, which was collected at four agricultural sites within the Rur catchment in western Germany in the framework of the Transregional Collaborative Research Centre 32 (TR32) "Patterns in Soil-Vegetation-Atmosphere Systems: Monitoring, Modeling and Data Assimilation". Vegetation-related data comprise fresh and dry biomass (green and brown, predominantly per organ), plant height, green and brown leaf area index, phenological development state, nitrogen and carbon content (overall textgreater17 000 entries), and masses of harvest residues and regrowth of vegetation after harvest or before planting of the main crop (textgreater250 entries). Vegetation data including LAI were collected in frequencies of 1 to 3 weeks in the years 2015 until 2017, mostly during overflights of the Sentinel 1 and Radarsat 2 satellites. In addition, fluxes of carbon, energy, and water (textgreater180 000 half-hourly records) measured using the eddy covariance technique are included. Three flux time series have simultaneous data from two different heights. Data on agricultural management include sowing and harvest dates as well as information on cultivation, fertilization, and agrochemicals (27 management periods). The dataset also includes gap-filled weather data (textgreater200 000 hourly records) and soil parameters (particle size distributions, carbon and nitrogen content; textgreater800 records). These data can also be useful for development and validation of remote-sensing products. The dataset is hosted at the TR32 database (https://www.tr32db.uni-koeln.de/data.php?dataID=1889, last access: 29 September 2020) and has the DOI https://doi.org/10.5880/TR32DB.39 (Reichenau et al., 2020). |
BibTeX:
@book{Reichenau2020,
author = {Reichenau, Tim G and Korres, Wolfgang and Schmidt, Marius and Graf, Alexander and Welp, Gerhard and Meyer, Nele and Stadler, Anja and Brogi, Cosimo and Schneider, Karl},
title = {A comprehensive dataset of vegetation states, fluxes of matter and energy, weather, agricultural management, and soil properties from intensively monitored crop sites in western Germany},
booktitle = {Earth System Science Data},
year = {2020},
volume = {12},
number = {4},
pages = {2333--2364},
doi = {10.5194/essd-12-2333-2020}
}
|
| Reichl BG and Deike L (2020), "Contribution of Sea‐State Dependent Bubbles to Air‐Sea Carbon Dioxide Fluxes", Geophysical Research Letters., may, 2020. Vol. 47(9) Blackwell Publishing Ltd. |
| Abstract: Breaking surface ocean waves produce bubbles that are important for air-sea gas exchanges, particularly during high winds. In this study we estimate air-sea CO2 fluxes globally using a new approach that considers the surface wave contribution to gas fluxes. We estimate that 40% of the net air-sea CO2 flux is via bubbles, with annual, seasonal, and regional variability. When compared to traditional gas-flux parameterization methods that consider the wind speed alone, we find high-frequency (daily to weekly) differences in the predicted gas flux using the sea-state dependent method at spatial scales related to atmospheric weather (10 to 100 km). Seasonal net differences in the air-sea CO2 flux due to the sea-state dependence can exceed 20%, with the largest values associated with North Atlantic and North Pacific winter storms. These results confirm that bubbles are important for global gas-flux dynamics and that sea-state dependent parameterizations may improve performance of global coupled models. |
BibTeX:
@article{Reichl2020,
author = {Reichl, B. G. and Deike, L.},
title = {Contribution of Sea‐State Dependent Bubbles to Air‐Sea Carbon Dioxide Fluxes},
journal = {Geophysical Research Letters},
publisher = {Blackwell Publishing Ltd},
year = {2020},
volume = {47},
number = {9},
url = {https://onlinelibrary.wiley.com/doi/abs/10.1029/2020GL087267},
doi = {10.1029/2020GL087267}
}
|
| Reyer CPO, Silveyra Gonzalez R, Dolos K, Hartig F, Hauf Y, Noack M, Lasch-Born P, Rötzer T, Pretzsch H, Meesenburg H, Fleck S, Wagner M, Bolte A, Sanders TGM, Kolari P, Mäkelä A, Vesala T, Mammarella I, Pumpanen J, Collalti A, Collalti A, Trotta C, Matteucci G, D'Andrea E, Foltýnová L, Krejza J, Ibrom A, Pilegaard K, Loustau D, Bonnefond JM, Berbigier P, Picart D, Lafont S, Dietze M, Cameron D, Vieno M, Tian H, Palacios-Orueta A, Cicuendez V, Recuero L, Wiese K, Büchner M, Lange S, Volkholz J, Kim H, Horemans JA, Bohn F, Steinkamp J, Chikalanov A, Weedon GP, Sheffield J, Babst F, Babst F, Vega Del Valle I, Suckow F, Martel S, Mahnken M, Gutsch M and Frieler K (2020), "The PROFOUND Database for evaluating vegetation models and simulating climate impacts on European forests", Earth System Science Data. Vol. 12(2), pp. 1295-1320. |
| Abstract: Process-based vegetation models are widely used to predict local and global ecosystem dynamics and climate change impacts. Due to their complexity, they require careful parameterization and evaluation to ensure that projections are accurate and reliable. The PROFOUND Database (PROFOUND DB) provides a wide range of empirical data on European forests to calibrate and evaluate vegetation models that simulate climate impacts at the forest stand scale. A particular advantage of this database is its wide coverage of multiple data sources at different hierarchical and temporal scales, together with environmental driving data as well as the latest climate scenarios. Specifically, the PROFOUND DB provides general site descriptions, soil, climate, CO2, nitrogen deposition, tree and forest stand level, and remote sensing data for nine contrasting forest stands distributed across Europe. Moreover, for a subset of five sites, time series of carbon fluxes, atmospheric heat conduction and soil water are also available. The climate and nitrogen deposition data contain several datasets for the historic period and a wide range of future climate change scenarios following the Representative Concentration Pathways (RCP2.6, RCP4.5, RCP6.0, RCP8.5). We also provide pre-industrial climate simulations that allow for model runs aimed at disentangling the contribution of climate change to observed forest productivity changes. The PROFOUND DB is available freely as a "SQLite"relational database or "ASCII"flat file version (at https://doi.org/10.5880/PIK.2020.006/; Reyer et al., 2020). The data policies of the individual contributing datasets are provided in the metadata of each data file. The PROFOUND DB can also be accessed via the ProfoundData R package (https://CRAN.R-project.org/package=ProfoundData; Silveyra Gonzalez et al., 2020), which provides basic functions to explore, plot and extract the data for model set-up, calibration and evaluation. |
BibTeX:
@article{Reyer2020,
author = {Reyer, Christopher P O and Silveyra Gonzalez, Ramiro and Dolos, Klara and Hartig, Florian and Hauf, Ylva and Noack, Matthias and Lasch-Born, Petra and Rötzer, Thomas and Pretzsch, Hans and Meesenburg, Henning and Fleck, Stefan and Wagner, Markus and Bolte, Andreas and Sanders, Tanja G M and Kolari, Pasi and Mäkelä, Annikki and Vesala, Timo and Mammarella, Ivan and Pumpanen, Jukka and Collalti, Alessio and Collalti, Alessio and Trotta, Carlo and Matteucci, Giorgio and D'Andrea, Ettore and Foltýnová, Lenka and Krejza, Jan and Ibrom, Andreas and Pilegaard, Kim and Loustau, Denis and Bonnefond, Jean Marc and Berbigier, Paul and Picart, Delphine and Lafont, Sébastien and Dietze, Michael and Cameron, David and Vieno, Massimo and Tian, Hanqin and Palacios-Orueta, Alicia and Cicuendez, Victor and Recuero, Laura and Wiese, Klaus and Büchner, Matthias and Lange, Stefan and Volkholz, Jan and Kim, Hyungjun and Horemans, Joanna A and Bohn, Friedrich and Steinkamp, Jörg and Chikalanov, Alexander and Weedon, Graham P and Sheffield, Justin and Babst, Flurin and Babst, Flurin and Vega Del Valle, Iliusi and Suckow, Felicitas and Martel, Simon and Mahnken, Mats and Gutsch, Martin and Frieler, Katja},
title = {The PROFOUND Database for evaluating vegetation models and simulating climate impacts on European forests},
journal = {Earth System Science Data},
year = {2020},
volume = {12},
number = {2},
pages = {1295--1320},
doi = {10.5194/essd-12-1295-2020}
}
|
| Rinne J, Tuovinen J-P, Klemedtsson L, Aurela M, Holst J, Lohila A, Weslien P, Vestin P, Łakomiec P, Peichl M, Tuittila E-S, Heiskanen L, Laurila T, Li X, Alekseychik P, Mammarella I, Ström L, Crill P and Nilsson MB (2020), "Effect of the 2018 European drought on methane and carbon dioxide exchange of northern mire ecosystems", Philosophical Transactions of the Royal Society B: Biological Sciences., oct, 2020. Vol. 375(1810), pp. 20190517. |
| Abstract: We analysed the effect of the 2018 European drought on greenhouse gas (GHG) exchange of five North European mire ecosystems. The low precipitation and high summer temperatures in Fennoscandia led to a lowered water table in the majority of these mires. This lowered both carbon dioxide (CO 2 ) uptake and methane (CH 4 ) emission during 2018, turning three out of the five mires from CO 2 sinks to sources. The calculated radiative forcing showed that the drought-induced changes in GHG fluxes first resulted in a cooling effect lasting 15–50 years, due to the lowered CH 4 emission, which was followed by warming due to the lower CO 2 uptake. |
BibTeX:
@article{Rinne2020,
author = {Rinne, J. and Tuovinen, J.-P. and Klemedtsson, L. and Aurela, M. and Holst, J. and Lohila, A. and Weslien, P. and Vestin, P. and Łakomiec, P. and Peichl, M. and Tuittila, E.-S. and Heiskanen, L. and Laurila, T. and Li, X. and Alekseychik, P. and Mammarella, I. and Ström, L. and Crill, P. and Nilsson, M. B.},
title = {Effect of the 2018 European drought on methane and carbon dioxide exchange of northern mire ecosystems},
journal = {Philosophical Transactions of the Royal Society B: Biological Sciences},
year = {2020},
volume = {375},
number = {1810},
pages = {20190517},
url = {https://royalsocietypublishing.org/doi/10.1098/rstb.2019.0517},
doi = {10.1098/rstb.2019.0517}
}
|
| Rocher-Ros G, Harms TK, Sponseller RA, Väisänen M, Mörth CM and Giesler R (2020), "Metabolism overrides photo-oxidation in CO2 dynamics of Arctic permafrost streams", Limnology and Oceanography. , pp. 1-13. |
| Abstract: Global warming is enhancing the mobilization of organic carbon (C) from Arctic soils into streams, where it can be mineralized to CO2 and released to the atmosphere. Abiotic photo-oxidation might drive C mineralization, but this process has not been quantitatively integrated with biological processes that also influence CO2 dynamics in aquatic ecosystems. We measured CO2 concentrations and the isotopic composition of dissolved inorganic C ($$13CDIC) at diel resolution in two Arctic streams, and coupled this with whole-system metabolism estimates to assess the effect of biotic and abiotic processes on stream C dynamics. CO2 concentrations consistently decreased from night to day, a pattern counter to the hypothesis that photo-oxidation is the dominant source of CO2. Instead, the observed decrease in CO2 during daytime was explained by photosynthetic rates, which were strongly correlated with diurnal changes in $$13CDIC values. However, on days when modeled photosynthetic rates were near zero, there was still a significant diel change in $$13CDIC values, suggesting that metabolic estimates are partly masked by O2 consumption from photo-oxidation. Our results suggest that 6–12 mmol CO2-C m−2 d−1 may be generated from photo-oxidation, a range that corresponds well to previous laboratory measurements. Moreover, ecosystem respiration rates were 10 times greater than published photo-oxidation rates for these Arctic streams, and accounted for 33–80% of total CO2 evasion. Our results suggest that metabolic activity is the dominant process for CO2 production in Arctic streams. Thus, future aquatic CO2 emissions may depend on how biotic processes respond to the ongoing environmental change. |
BibTeX:
@article{RocherRos2020,
author = {Rocher-Ros, Gerard and Harms, Tamara K and Sponseller, Ryan A and Väisänen, Maria and Mörth, Carl Magnus and Giesler, Reiner},
title = {Metabolism overrides photo-oxidation in CO2 dynamics of Arctic permafrost streams},
journal = {Limnology and Oceanography},
year = {2020},
pages = {1--13},
doi = {10.1002/lno.11564}
}
|
| Rocher-Ros G, Sponseller RA, Bergström AK, Myrstener M and Giesler R (2020), "Stream metabolism controls diel patterns and evasion of CO2 in Arctic streams", Global Change Biology. Vol. 26(3), pp. 1400-1413. |
| Abstract: Streams play an important role in the global carbon (C) cycle, accounting for a large portion of CO2 evaded from inland waters despite their small areal coverage. However, the relative importance of different terrestrial and aquatic processes driving CO2 production and evasion from streams remains poorly understood. In this study, we measured O2 and CO2 continuously in streams draining tundra-dominated catchments in northern Sweden, during the summers of 2015 and 2016. From this, we estimated daily metabolic rates and CO2 evasion simultaneously and thus provide insight into the role of stream metabolism as a driver of C dynamics in Arctic streams. Our results show that aquatic biological processes regulate CO2 concentrations and evasion at multiple timescales. Photosynthesis caused CO2 concentrations to decrease by as much as 900 ppm during the day, with the magnitude of this diel variation being strongest at the low-turbulence streams. Diel patterns in CO2 concentrations in turn influenced evasion, with up to 45% higher rates at night. Throughout the summer, CO2 evasion was sustained by aquatic ecosystem respiration, which was one order of magnitude higher than gross primary production. Furthermore, in most cases, the contribution of stream respiration exceeded CO2 evasion, suggesting that some stream reaches serve as net sources of CO2, thus creating longitudinal heterogeneity in C production and loss within this stream network. Overall, our results provide the first link between stream metabolism and CO2 evasion in the Arctic and demonstrate that stream metabolic processes are key drivers of the transformation and fate of terrestrial organic matter exported from these landscapes. |
BibTeX:
@article{RocherRos2020a,
author = {Rocher-Ros, Gerard and Sponseller, Ryan A and Bergström, Ann Kristin and Myrstener, Maria and Giesler, Reiner},
title = {Stream metabolism controls diel patterns and evasion of CO2 in Arctic streams},
journal = {Global Change Biology},
year = {2020},
volume = {26},
number = {3},
pages = {1400--1413},
doi = {10.1111/gcb.14895}
}
|
| Rödenbeck C, Zaehle S, Keeling R and Heimann M (2020), "The European carbon cycle response to heat and drought as seen from atmospheric CO 2 data for 1999–2018", Philosophical Transactions of the Royal Society B: Biological Sciences., oct, 2020. Vol. 375(1810), pp. 20190506. |
| Abstract: In 2018, central and northern parts of Europe experienced heat and drought conditions over many months from spring to autumn, strongly affecting both natural ecosystems and crops. Besides their impact on nature and society, events like this can be used to study the impact of climate variations on the terrestrial carbon cycle, which is an important determinant of the future climate trajectory. Here, variations in the regional net ecosystem exchange (NEE) of CO 2 between terrestrial ecosystems and the atmosphere were quantified from measurements of atmospheric CO 2 mole fractions. Over Europe, several observational records have been maintained since at least 1999, giving us the opportunity to assess the 2018 anomaly in the context of at least two decades of variations, including the strong climate anomaly in 2003. In addition to an atmospheric inversion with temporally explicitly estimated anomalies, we use an inversion based on empirical statistical relations between anomalies in the local NEE and anomalies in local climate conditions. For our analysis period 1999–2018, we find that higher-than-usual NEE in hot and dry summers may tend to arise in Central Europe from enhanced ecosystem respiration due to the elevated temperatures, and in Southern Europe from reduced photosynthesis due to the reduced water availability. Despite concerns in the literature, the level of agreement between regression-based NEE anomalies and temporally explicitly estimated anomalies indicates that the atmospheric CO 2 measurements from the relatively dense European station network do provide information about the year-to-year variations of Europe's carbon sources and sinks, at least in summer. |
BibTeX:
@article{Roedenbeck2020,
author = {Rödenbeck, C. and Zaehle, S. and Keeling, R. and Heimann, M.},
title = {The European carbon cycle response to heat and drought as seen from atmospheric CO 2 data for 1999–2018},
journal = {Philosophical Transactions of the Royal Society B: Biological Sciences},
year = {2020},
volume = {375},
number = {1810},
pages = {20190506},
url = {https://royalsocietypublishing.org/doi/10.1098/rstb.2019.0506},
doi = {10.1098/rstb.2019.0506}
}
|
| Saarela T, Rissanen AJ, Ojala A, Pumpanen J, Aalto SL, Tiirola M, Vesala T and Jäntti H (2020), "CH4 oxidation in a boreal lake during the development of hypolimnetic hypoxia", Aquatic Sciences., apr, 2020. Vol. 82(2) Springer. |
| Abstract: Freshwater ecosystems represent a significant natural source of methane (CH4). CH4 produced through anaerobic decomposition of organic matter (OM) in lake sediment and water column can be either oxidized to carbon dioxide (CO2) by methanotrophic microbes or emitted to the atmosphere. While the role of CH4 oxidation as a CH4 sink is widely accepted, neither the magnitude nor the drivers behind CH4 oxidation are well constrained. In this study, we aimed to gain more specific insight into CH4 oxidation in the water column of a seasonally stratified, typical boreal lake, particularly under hypoxic conditions. We used 13CH4 incubations to determine the active CH4 oxidation sites and the potential CH4 oxidation rates in the water column, and we measured environmental variables that could explain CH4 oxidation in the water column. During hypolimnetic hypoxia, 91% of available CH4 was oxidized in the active CH4 oxidation zone, where the potential CH4 oxidation rates gradually increased from the oxycline to the hypolimnion. Our results showed that in warm springs, which become more frequent, early thermal stratification with cold well-oxygenated hypolimnion delays the period of hypolimnetic hypoxia and limits CH4 production. Thus, the delayed development of hypolimnetic hypoxia may partially counteract the expected increase in the lacustrine CH4 emissions caused by the increasing organic carbon load from forested catchments. |
BibTeX:
@article{Saarela2020,
author = {Saarela, Taija and Rissanen, Antti J. and Ojala, Anne and Pumpanen, Jukka and Aalto, Sanni L. and Tiirola, Marja and Vesala, Timo and Jäntti, Helena},
title = {CH4 oxidation in a boreal lake during the development of hypolimnetic hypoxia},
journal = {Aquatic Sciences},
publisher = {Springer},
year = {2020},
volume = {82},
number = {2},
doi = {10.1007/s00027-019-0690-8}
}
|
| Saunois M, Stavert AR, Poulter B, Bousquet P, Canadell JG, Jackson RB, Raymond PA, Dlugokencky EJ, Houweling S, Patra PK, Ciais P, Arora VK, Bastviken D, Bergamaschi P, Blake DR, Brailsford G, Bruhwiler L, Carlson KM, Carrol M, Castaldi S, Chandra N, Crevoisier C, Crill PM, Covey K, Curry CL, Etiope G, Frankenberg C, Gedney N, Hegglin MI, Höglund-Isaksson L, Hugelius G, Ishizawa M, Ito A, Janssens-Maenhout G, Jensen KM, Joos F, Kleinen T, Krummel PB, Langenfelds RL, Laruelle GG, Liu L, Machida T, Maksyutov S, McDonald KC, McNorton J, Miller PA, Melton JR, Morino I, Müller J, Murguia-Flores F, Naik V, Niwa Y, Noce S, O'Doherty S, Parker RJ, Peng C, Peng S, Peters GP, Prigent C, Prinn R, Ramonet M, Regnier P, Riley WJ, Rosentreter JA, Segers A, Simpson IJ, Shi H, Smith SJ, Steele LP, Thornton BF, Tian H, Tohjima Y, Tubiello FN, Tsuruta A, Viovy N, Voulgarakis A, Weber TS, van Weele M, van der Werf GR, Weiss RF, Worthy D, Wunch D, Yin Y, Yoshida Y, Zhang W, Zhang Z, Zhao Y, Zheng B, Zhu Q, Zhu Q and Zhuang Q (2020), "The Global Methane Budget 2000–2017", Earth System Science Data., jul, 2020. Vol. 12(3), pp. 1561-1623. |
BibTeX:
@article{Saunois2020,
author = {Saunois, Marielle and Stavert, Ann R. and Poulter, Ben and Bousquet, Philippe and Canadell, Josep G. and Jackson, Robert B. and Raymond, Peter A. and Dlugokencky, Edward J. and Houweling, Sander and Patra, Prabir K. and Ciais, Philippe and Arora, Vivek K. and Bastviken, David and Bergamaschi, Peter and Blake, Donald R. and Brailsford, Gordon and Bruhwiler, Lori and Carlson, Kimberly M. and Carrol, Mark and Castaldi, Simona and Chandra, Naveen and Crevoisier, Cyril and Crill, Patrick M. and Covey, Kristofer and Curry, Charles L. and Etiope, Giuseppe and Frankenberg, Christian and Gedney, Nicola and Hegglin, Michaela I. and Höglund-Isaksson, Lena and Hugelius, Gustaf and Ishizawa, Misa and Ito, Akihiko and Janssens-Maenhout, Greet and Jensen, Katherine M. and Joos, Fortunat and Kleinen, Thomas and Krummel, Paul B. and Langenfelds, Ray L. and Laruelle, Goulven G. and Liu, Licheng and Machida, Toshinobu and Maksyutov, Shamil and McDonald, Kyle C. and McNorton, Joe and Miller, Paul A. and Melton, Joe R. and Morino, Isamu and Müller, Jurek and Murguia-Flores, Fabiola and Naik, Vaishali and Niwa, Yosuke and Noce, Sergio and O'Doherty, Simon and Parker, Robert J. and Peng, Changhui and Peng, Shushi and Peters, Glen P. and Prigent, Catherine and Prinn, Ronald and Ramonet, Michel and Regnier, Pierre and Riley, William J. and Rosentreter, Judith A. and Segers, Arjo and Simpson, Isobel J. and Shi, Hao and Smith, Steven J. and Steele, L. Paul and Thornton, Brett F. and Tian, Hanqin and Tohjima, Yasunori and Tubiello, Francesco N. and Tsuruta, Aki and Viovy, Nicolas and Voulgarakis, Apostolos and Weber, Thomas S. and van Weele, Michiel and van der Werf, Guido R. and Weiss, Ray F. and Worthy, Doug and Wunch, Debra and Yin, Yi and Yoshida, Yukio and Zhang, Wenxin and Zhang, Zhen and Zhao, Yuanhong and Zheng, Bo and Zhu, Qing and Zhu, Qiuan and Zhuang, Qianlai},
title = {The Global Methane Budget 2000–2017},
journal = {Earth System Science Data},
year = {2020},
volume = {12},
number = {3},
pages = {1561--1623},
url = {https://essd.copernicus.org/articles/12/1561/2020/},
doi = {10.5194/essd-12-1561-2020}
}
|
| Savi F, Nemitz E, Coyle M, Aitkenhead M, Frumau K, Gerosa G, Finco A, Gruening C, Goded I, Loubet B, Stella P, Ruuskanen T, Weidinger T, Horvath L, Zenone T and Fares S (2020), "Neural Network Analysis to Evaluate Ozone Damage to Vegetation Under Different Climatic Conditions", Frontiers in Forests and Global Change., apr, 2020. Vol. 3 Frontiers Media SA. |
BibTeX:
@article{Savi2020,
author = {Savi, Flavia and Nemitz, Eiko and Coyle, Mhairi and Aitkenhead, Matt and Frumau, Kfa and Gerosa, Giacomo and Finco, Angelo and Gruening, Carten and Goded, Ignacio and Loubet, Benjamin and Stella, Patrick and Ruuskanen, Taaina and Weidinger, T and Horvath, L and Zenone, Terenzio and Fares, Silvano},
title = {Neural Network Analysis to Evaluate Ozone Damage to Vegetation Under Different Climatic Conditions},
journal = {Frontiers in Forests and Global Change},
publisher = {Frontiers Media SA},
year = {2020},
volume = {3},
url = {http://dx.doi.org/10.3389/ffgc.2020.00042},
doi = {10.3389/ffgc.2020.00042}
}
|
| Schindler D and Kolbe S (2020), "Assessment of the response of a scots pine tree to effective wind loading", Forests. Vol. 11(2) |
| Abstract: The parameterization of hybrid-mechanistic storm damage models is largely based on the results of tree pulling tests. The tree pulling tests are used for imitating the quasi-static wind load associated with the mean wind speed. The combined effect of dynamic and quasi-static wind loads associated with wind load maxima is considered by either linearly increasing the quasi-static wind load by a gust factor or by using a turning moment coefficient determined from the relationship between maxima of wind-induced tree response and wind speed. To improve the joint use of information on dynamic and quasi-static wind loading, we present a new method that uses the coupled components of momentum flux time series and time series of stem orientation of a plantation-grown Scots pine tree. First, non-oscillatory tree motion components, which respond to wind excitation, are isolated from oscillatory components that are not coupled to the wind. The non-oscillatory components are detected by applying a sequence of time series decomposition methods including biorthogonal decomposition and singular spectrum analysis. Then, the wind-excited tree response components are subjected to dynamic time warping, which maximizes the coincidence between the processed data. The strong coincidence of the time-warped data allows for the estimation of the wind-induced tree response as a function of the effective wind load using simple linear regression. The slope of the regression line represents the rate of change in the tree response as the effective wind load changes. Because of the strength of the relationship, we argue that the method described is an improvement for the analysis of storm damage in forests and to individual trees. |
BibTeX:
@article{Schindler2020,
author = {Schindler, Dirk and Kolbe, Sven},
title = {Assessment of the response of a scots pine tree to effective wind loading},
journal = {Forests},
year = {2020},
volume = {11},
number = {2},
doi = {10.3390/f11020145}
}
|
| Schneuwly J and Ammann C (2020), "Large regional differences of soil water limitation effect on ozone induced yield loss for wheat and potato in Switzerland", Science of the Total Environment., may, 2020. Vol. 718 Elsevier B.V.. |
| Abstract: The accumulated stomatal ozone (O3) uptake over a threshold (Phytotoxic Ozone Dose POD6), calculated by an ozone deposition model, has been shown to be the most appropriate metric to quantify negative effects of O3 on food crops. In this study we used data of 13 sites in different regions of Switzerland with multiple years of O3 measurements to quantify the stomatal O3 uptake and the related yield loss of wheat and potato. Flux patterns for different years were calculated with the DO3SE model to disentangle the influence of contrasting seasonal environmental conditions. Regional and inter-annual differences in meteorological conditions led to considerable variations in soil water conditions and the POD6 values for wheat. Potato stomatal uptake was much less influenced by soil water and showed a more even distribution of POD6 values across sites and years. The estimated nationally and temporally average yield loss was 3.2 ± 1.2% for wheat and 2.4 ± 0.8% for potato, calculated based on an area weighting. It was found that soil water deficit, observed frequently in the western part of Switzerland, had a large attenuation effect on stomatal O3 uptake by wheat and on corresponding yield losses. This highlights the importance of including soil moisture limitation in O3 uptake modelling even in moist climatic regions. The comparison of modelled evapotranspiration with water flux measurements over a wheat field showed a reasonable agreement concerning the temporal pattern and the magnitude. But it is also concluded that the DO3SE soil moisture module will need further testing and adaptation to improve accuracy of the model in dryer conditions. |
BibTeX:
@article{Schneuwly2020,
author = {Schneuwly, Jérôme and Ammann, Christof},
title = {Large regional differences of soil water limitation effect on ozone induced yield loss for wheat and potato in Switzerland},
journal = {Science of the Total Environment},
publisher = {Elsevier B.V.},
year = {2020},
volume = {718},
doi = {10.1016/j.scitotenv.2019.135257}
}
|
| Schrader F, Erisman JW and Brümmer C (2020), "Towards a coupled paradigm of NH3-CO2 biosphere–atmosphere exchange modelling", Global Change Biology. Vol. 26(9), pp. 4654-4663. |
| Abstract: Stomatal conductance, one of the major plant physiological controls within NH3 biosphere–atmosphere exchange models, is commonly estimated from semi-empirical multiplicative schemes or simple light- and temperature-response functions. However, due to their inherent parameterization on meteorological proxy variables, instead of a direct measure of stomatal opening, they are unfit for the use in climate change scenarios and of limited value for interpreting field-scale measurements. Alternatives based on H2O flux measurements suffer from uncertainties in the partitioning of evapotranspiration at humid sites, as well as a potential decoupling of transpiration from stomatal opening in the presence of hygroscopic particles on leaf surfaces. We argue that these problems may be avoided by directly deriving stomatal conductance from CO2 fluxes instead. We reanalysed a data set of NH3 flux measurements based on CO2-derived stomatal conductance, confirming the hypothesis that the increasing relevance of stomatal exchange with the onset of vegetation activity caused a rapid decrease of observed NH3 deposition velocities. Finally, we argue that developing more mechanistic representations of NH3 biosphere–atmosphere exchange can be of great benefit in many applications. These range from model-based flux partitioning, over deposition monitoring using low-cost samplers and inferential modelling, to a direct response of NH3 exchange to climate change. |
BibTeX:
@article{Schrader2020,
author = {Schrader, Frederik and Erisman, Jan Willem and Brümmer, Christian},
title = {Towards a coupled paradigm of NH3-CO2 biosphere–atmosphere exchange modelling},
journal = {Global Change Biology},
year = {2020},
volume = {26},
number = {9},
pages = {4654--4663},
doi = {10.1111/gcb.15184}
}
|
| Schuldt B, Buras A, Arend M, Vitasse Y, Beierkuhnlein C, Damm A, Gharun M, Grams TE, Hauck M, Hajek P, Hartmann H, Hiltbrunner E, Hoch G, Holloway-Phillips M, Körner C, Larysch E, Lübbe T, Nelson DB, Rammig A, Rigling A, Rose L, Ruehr NK, Schumann K, Weiser F, Werner C, Wohlgemuth T, Zang CS and Kahmen A (2020), "A first assessment of the impact of the extreme 2018 summer drought on Central European forests", Basic and Applied Ecology., jun, 2020. Vol. 45, pp. 86-103. Elsevier GmbH. |
| Abstract: In 2018, Central Europe experienced one of the most severe and long-lasting summer drought and heat wave ever recorded. Before 2018, the 2003 millennial drought was often invoked as the example of a “hotter drought”, and was classified as the most severe event in Europe for the last 500 years. First insights now confirm that the 2018 drought event was climatically more extreme and had a greater impact on forest ecosystems of Austria, Germany and Switzerland than the 2003 drought. Across this region, mean growing season air temperature from April to October was more than 3.3°C above the long-term average, and 1.2 °C warmer than in 2003. Here, we present a first impact assessment of the severe 2018 summer drought and heatwave on Central European forests. In response to the 2018 event, most ecologically and economically important tree species in temperate forests of Austria, Germany and Switzerland showed severe signs of drought stress. These symptoms included exceptionally low foliar water potentials crossing the threshold for xylem hydraulic failure in many species and observations of widespread leaf discoloration and premature leaf shedding. As a result of the extreme drought stress, the 2018 event caused unprecedented drought-induced tree mortality in many species throughout the region. Moreover, unexpectedly strong drought-legacy effects were detected in 2019. This implies that the physiological recovery of trees was impaired after the 2018 drought event, leaving them highly vulnerable to secondary drought impacts such as insect or fungal pathogen attacks. As a consequence, mortality of trees triggered by the 2018 events is likely to continue for several years. Our assessment indicates that many common temperate European forest tree species are more vulnerable to extreme summer drought and heat waves than previously thought. As drought and heat events are likely to occur more frequently with the progression of climate change, temperate European forests might approach the point for a substantial ecological and economic transition. Our assessment also highlights the urgent need for a pan-European ground-based monitoring network suited to track individual tree mortality, supported by remote sensing products with high spatial and temporal resolution to track, analyse and forecast these transitions. |
BibTeX:
@article{Schuldt2020,
author = {Schuldt, Bernhard and Buras, Allan and Arend, Matthias and Vitasse, Yann and Beierkuhnlein, Carl and Damm, Alexander and Gharun, Mana and Grams, Thorsten E.E. and Hauck, Markus and Hajek, Peter and Hartmann, Henrik and Hiltbrunner, Erika and Hoch, Günter and Holloway-Phillips, Meisha and Körner, Christian and Larysch, Elena and Lübbe, Torben and Nelson, Daniel B. and Rammig, Anja and Rigling, Andreas and Rose, Laura and Ruehr, Nadine K. and Schumann, Katja and Weiser, Frank and Werner, Christiane and Wohlgemuth, Thomas and Zang, Christian S. and Kahmen, Ansgar},
title = {A first assessment of the impact of the extreme 2018 summer drought on Central European forests},
journal = {Basic and Applied Ecology},
publisher = {Elsevier GmbH},
year = {2020},
volume = {45},
pages = {86--103},
doi = {10.1016/j.baae.2020.04.003}
}
|
| Seco R, Holst T, Sillesen Matzen M, Westergaard-Nielsen A, Li T, Simin T, Jansen J, Crill P, Friborg T, Rinne J and Rinnan R (2020), "Volatile organic compound fluxes in a subarctic peatland and lake", Atmospheric Chemistry and Physics. Vol. 20(21), pp. 13399-13416. |
| Abstract: Ecosystems exchange climate-relevant trace gases with the atmosphere, including volatile organic compounds (VOCs) that are a small but highly reactive part of the carbon cycle. VOCs have important ecological functions and implications for atmospheric chemistry and climate.We measured the ecosystem-level surface-atmosphere VOC fluxes using the eddy covariance technique at a shallow subarctic lake and an adjacent graminoid-dominated fen in northern Sweden during two contrasting periods: the peak growing season (mid-July) and the senescent period post-growing season (September-October). In July, the fen was a net source of methanol, acetaldehyde, acetone, dimethyl sulfide, isoprene, and monoterpenes. All of these VOCs showed a diel cycle of emission with maxima around noon and isoprene dominated the fluxes (93±22 $$molm-2 d-1, mean±SE). Isoprene emission was strongly stimulated by temperature and presented a steeper response to temperature (Q10 = 14:5) than that typically assumed in biogenic emission models, supporting the high temperature sensitivity of arctic vegetation. In September, net emissions of methanol and isoprene were drastically reduced, while acetaldehyde and acetone were deposited to the fen, with rates of up to-6:7±2:8 $$molm-2 d-1 for acetaldehyde. Remarkably, the lake was a sink for acetaldehyde and acetone during both periods, with average fluxes up to -19±1:3 $$molm-2 d-1 of acetone in July and up to-8:5± 2:3 $$molm-2 d-1 of acetaldehyde in September. The deposition of both carbonyl compounds correlated with their atmospheric mixing ratios, with deposition velocities of-0:23± 0:01 and-0:68±0:03 cm s-1 for acetone and acetaldehyde, respectively. Even though these VOC fluxes represented less than 0.5%and less than 5%of the CO2 and CH4 net carbon ecosystem exchange, respectively, VOCs alter the oxidation capacity of the atmosphere. Thus, understanding the response of their emissions to climate change is important for accurate prediction of the future climatic conditions in this rapidly warming area of the planet. |
BibTeX:
@article{Seco2020,
author = {Seco, Roger and Holst, Thomas and Sillesen Matzen, Mikkel and Westergaard-Nielsen, Andreas and Li, Tao and Simin, Tihomir and Jansen, Joachim and Crill, Patrick and Friborg, Thomas and Rinne, Janne and Rinnan, Riikka},
title = {Volatile organic compound fluxes in a subarctic peatland and lake},
journal = {Atmospheric Chemistry and Physics},
year = {2020},
volume = {20},
number = {21},
pages = {13399--13416},
doi = {10.5194/acp-20-13399-2020}
}
|
| Seelmann K, Steinhoff T, Aßmann S and Körtzinger A (2020), "Enhance Ocean Carbon Observations: Successful Implementation of a Novel Autonomous Total Alkalinity Analyzer on a Ship of Opportunity", Frontiers in Marine Science. Vol. 7(December), pp. 1-18. |
| Abstract: Over recent decades, observations based on merchant vessels (Ships of Opportunity—SOOP) equipped with sensors measuring the CO2 partial pressure (pCO2) in the surface seawater formed the backbone of the global ocean carbon observation system. However, the restriction to pCO2 measurements alone is one severe shortcoming of the current SOOP observatory. Full insight into the marine inorganic carbon system requires the measurement of at least two of the four measurable variables which are pCO2, total alkalinity (TA), dissolved inorganic carbon (DIC), and pH. One workaround is to estimate TA values based on established temperature-salinity parameterizations, but this leads to higher uncertainties and the possibility of regional and/or seasonal biases. Therefore, autonomous SOOP-based TA measurements are of great interest. Our study describes the implementation of a novel autonomous analyzer for seawater TA, the CONTROS HydroFIAⓇ TA system (-4H-JENA engineering GmbH, Germany) for unattended routine TA measurements on a SOOP line operating in the North Atlantic. We present the installation in detail and address major issues encountered with autonomous measurements using this analyzer, e.g., automated cleaning and stabilization routines, and waste handling. Another issue during long-term deployments is the provision of reference seawater in large-volume containers for quality assurance measurements and drift correction. Hence, a stable large-volume seawater storage had to be found. We tested several container types with respect to their suitability to store seawater over a time period of 30 days without significant changes in TA. Only one gas sampling bag made of polyvinylidene fluoride (PVDF) satisfied the high stability requirement. In order to prove the performance of the entire setup, we compared the autonomous TA measurements with TA from discrete samples taken during the first two trans-Atlantic crossings. Although the measurement accuracy in unattended mode (about ± 5 $$mol kgˆ-1) slightly deteriorated compared to our previous system characterization, its overall uncertainty fulfilled requirements for autonomous TA measurements on SOOP lines. A comparison with predicted TA values based on an established and often used parameterization pointed at regional and seasonal limitations of such TA predictions. Consequently, TA observations with better coverage of spatiotemporal variability are needed, which is now possible with the method described here. |
BibTeX:
@article{Seelmann2020,
author = {Seelmann, Katharina and Steinhoff, Tobias and Aßmann, Steffen and Körtzinger, Arne},
title = {Enhance Ocean Carbon Observations: Successful Implementation of a Novel Autonomous Total Alkalinity Analyzer on a Ship of Opportunity},
journal = {Frontiers in Marine Science},
year = {2020},
volume = {7},
number = {December},
pages = {1--18},
doi = {10.3389/fmars.2020.571301}
}
|
| Sgrigna G, Baldacchini C, Dreveck S, Cheng Z and Calfapietra C (2020), "Relationships between air particulate matter capture efficiency and leaf traits in twelve tree species from an Italian urban-industrial environment", Science of the Total Environment., may, 2020. Vol. 718 Elsevier B.V.. |
| Abstract: Air pollution in the urban environment is widely recognized as one of the most harmful threats for human health. International organizations such as the United Nations and the European Commission are highlighting the potential role of nature in mitigating air pollution and are now funding the implementation of Nature-Based Solutions, especially at the city level. Over the past few decades, the attention of the scientific community has grown around the role of urban forest in air pollution mitigation. Nevertheless, the understanding on Particulate Matter (PM) retention mechanisms by tree leaves is still limited. In this study, twelve tree species were sampled within an urban park of an industrial city. Two techniques were used for leaf analysis: Vacuum/Filtration and Scanning Electron Microscopy coupled with Energy Dispersive X-ray spectroscopy, in order to obtain a quali-quantitative analysis of the different PM size fractions. Results showed that deposited PM loads vary significantly among species. Different leaf traits, including micro and macromorphological characteristics, were observed, measured and ranked, with the final aim to relate them with PM load. Even if no significant correlation between each single leaf characteristic and PM deposition was observed (p textgreater 0.05), multivariate analysis revealed relationships between clusters of leaf traits and deposited PM. Thus, by assigning a score to each trait, an Accumulation index (Ai) was calculated, which was significantly related to the leaf deposited PM load (p ≤ 0.05). |
BibTeX:
@article{Sgrigna2020,
author = {Sgrigna, G. and Baldacchini, C. and Dreveck, S. and Cheng, Z. and Calfapietra, C.},
title = {Relationships between air particulate matter capture efficiency and leaf traits in twelve tree species from an Italian urban-industrial environment},
journal = {Science of the Total Environment},
publisher = {Elsevier B.V.},
year = {2020},
volume = {718},
doi = {10.1016/j.scitotenv.2020.137310}
}
|
| Shapkalijevski MM, Viana S, Boone A, Rodier Q and Moigne PL (2020), "Introducing a roughness-sublayer in the vegetation-atmosphere coupling of HARMONIE-AROME" (Harman 2012), pp. 82-90.
[BibTeX] |
BibTeX:
@article{Shapkalijevski2020,
author = {Shapkalijevski, Metodija M and Viana, Samuel and Boone, Aaron and Rodier, Quentin and Moigne, Patrick Le},
title = {Introducing a roughness-sublayer in the vegetation-atmosphere coupling of HARMONIE-AROME},
year = {2020},
number = {Harman 2012},
pages = {82--90}
}
|
| Shutler JD, Wanninkhof R, Nightingale PD, Woolf DK, Bakker DC, Watson A, Ashton I, Holding T, Chapron B, Quilfen Y, Fairall C, Schuster U, Nakajima M and Donlon CJ (2020), "Satellites will address critical science priorities for quantifying ocean carbon", Frontiers in Ecology and the Environment., feb, 2020. Vol. 18(1), pp. 27-35. Wiley Blackwell. |
| Abstract: The ability to routinely quantify global carbon dioxide (CO2) absorption by the oceans has become crucial: it provides a powerful constraint for establishing global and regional carbon (C) budgets, and enables identification of the ecological impacts and risks of this uptake on the marine environment. Advances in understanding, technology, and international coordination have made it possible to measure CO2 absorption by the oceans to a greater degree of accuracy than is possible in terrestrial landscapes. These advances, combined with new satellite-based Earth observation capabilities, increasing public availability of data, and cloud computing, provide important opportunities for addressing critical knowledge gaps. Furthermore, Earth observation in synergy with in-situ monitoring can provide the large-scale ocean monitoring that is necessary to support policies to protect ocean ecosystems at risk, and motivate societal shifts toward meeting C emissions targets; however, sustained effort will be needed. |
BibTeX:
@article{Shutler2020,
author = {Shutler, Jamie D and Wanninkhof, Rik and Nightingale, Philip D and Woolf, David K and Bakker, Dorothee CE and Watson, Andy and Ashton, Ian and Holding, Thomas and Chapron, Bertrand and Quilfen, Yves and Fairall, Chris and Schuster, Ute and Nakajima, Masakatsu and Donlon, Craig J},
title = {Satellites will address critical science priorities for quantifying ocean carbon},
journal = {Frontiers in Ecology and the Environment},
publisher = {Wiley Blackwell},
year = {2020},
volume = {18},
number = {1},
pages = {27--35},
url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/fee.2129},
doi = {10.1002/fee.2129}
}
|
| Silfver T, Heiskanen L, Aurela M, Myller K, Karhu K, Meyer N, Tuovinen JP, Oksanen E, Rousi M and Mikola J (2020), "Insect herbivory dampens Subarctic birch forest C sink response to warming", Nature Communications. Vol. 11(1), pp. 1-9. Springer US. |
| Abstract: Climate warming is anticipated to make high latitude ecosystems stronger C sinks through increasing plant production. This effect might, however, be dampened by insect herbivores whose damage to plants at their background, non-outbreak densities may more than double under climate warming. Here, using an open-air warming experiment among Subarctic birch forest field layer vegetation, supplemented with birch plantlets, we show that a 2.3 °C air and 1.2 °C soil temperature increase can advance the growing season by 1–4 days, enhance soil N availability, leaf chlorophyll concentrations and plant growth up to 400%, 160% and 50% respectively, and lead up to 122% greater ecosystem CO2 uptake potential. However, comparable positive effects are also found when insect herbivory is reduced, and the effect of warming on C sink potential is intensified under reduced herbivory. Our results confirm the expected warming-induced increase in high latitude plant growth and CO2 uptake, but also reveal that herbivorous insects may significantly dampen the strengthening of the CO2 sink under climate warming. |
BibTeX:
@article{Silfver2020,
author = {Silfver, Tarja and Heiskanen, Lauri and Aurela, Mika and Myller, Kristiina and Karhu, Kristiina and Meyer, Nele and Tuovinen, Juha Pekka and Oksanen, Elina and Rousi, Matti and Mikola, Juha},
title = {Insect herbivory dampens Subarctic birch forest C sink response to warming},
journal = {Nature Communications},
publisher = {Springer US},
year = {2020},
volume = {11},
number = {1},
pages = {1--9},
url = {http://dx.doi.org/10.1038/s41467-020-16404-4},
doi = {10.1038/s41467-020-16404-4}
}
|
| Silyakova A, Jansson P, Serov P, Ferré B, Pavlov AK, Hattermann T, Graves CA, Platt SM, Myhre CL, Gründger F and Niemann H (2020), "Physical controls of dynamics of methane venting from a shallow seep area west of Svalbard", Continental Shelf Research., feb, 2020. Vol. 194, pp. 104030. Elsevier BV. |
| Abstract: We investigate methane seepage on the shallow shelf west of Svalbard during three consecutive years, using discrete sampling of the water column, echosounder-based gas flux estimates, water mass properties, and numerical dispersion modelling. The results reveal three distinct hydrographic conditions in spring and summer, showing that the methane content in the water column is controlled by a combination of free gas seepage intensity and lateral water mass movements, which disperse and displace dissolved methane horizontally away from the seeps. Horizontal dispersion and displacement of dissolved methane are promoted by eddies originating from the West Spitsbergen Current and passing over the shallow shelf, a process that is more intense in winter and spring than in the summer season. Most of the methane injected from seafloor seeps resides in the bottom layer even when the water column is well mixed, implying that the controlling effect of water column stratification on vertical methane transport is small. Only small concentrations of methane are found in surface waters, and thus the escape of methane into the atmosphere above the site of seepage is also small. The magnitude of the sea to air methane flux is controlled by wind speed, rather than by the concentration of dissolved methane in the surface ocean. |
BibTeX:
@article{Silyakova2020,
author = {Silyakova, Anna and Jansson, Pär and Serov, Pavel and Ferré, Benedicte and Pavlov, Alexey K and Hattermann, Tore and Graves, Carolyn A and Platt, Stephen M and Myhre, Cathrine Lund and Gründger, Friederike and Niemann, Helge},
title = {Physical controls of dynamics of methane venting from a shallow seep area west of Svalbard},
journal = {Continental Shelf Research},
publisher = {Elsevier BV},
year = {2020},
volume = {194},
pages = {104030},
doi = {10.1016/j.csr.2019.104030}
}
|
| Simioni G, Marie G, Davi H, Martin-St Paul N and Huc R (2020), "Natural forest dynamics have more influence than climate change on the net ecosystem production of a mixed Mediterranean forest", Ecological Modelling., jan, 2020. Vol. 416, pp. 108921. Elsevier BV. |
| Abstract: Climate models predict increased drought conditions for the Mediterranean region, putting forests under increasing risk from direct or indirect effects of droughts. On the other hand, increasing CO2 and longer growing seasons could compensate the negative impacts of more intense droughts on forest productivity and carbon sequestration. Furthermore, large areas of Mediterranean forests are relatively young and unmanaged, and maturing usually tends to decrease carbon sequestration. We conducted a simulation study to explore the interplay between climate, CO2, and maturing, on forest net primary production (NPP) and net ecosystem production (NEP) over the 2000–2100 period. We used the Not Only Tree/Grass (NOTG) model, which is individual-based, process-oriented, and spatially explicit. We applied the model to the Font-Blanche experimental site, a typical mixed Mediterranean forest dominated by Aleppo pines and holm oaks. Simulations under three climate scenarios (current, moderate change, severe change) suggest that NPP could be enhanced by climate change, both due to higher CO2 and longer growing seasons. On the other hand NEP would only be temporarily enhanced by climate change. The largest effect, however, was a decrease of NEP over time for all scenarios, due to forest maturing, with heterotrophic respiration progressively catching up with NPP. This implies that, regardless of climate change, the sink capacity of large unmanaged forest areas in southern Europe could strongly diminish during the 21st century. |
BibTeX:
@article{Simioni2020,
author = {Simioni, Guillaume and Marie, Guillaume and Davi, Hendrik and Martin-St Paul, Nicolas and Huc, Roland},
title = {Natural forest dynamics have more influence than climate change on the net ecosystem production of a mixed Mediterranean forest},
journal = {Ecological Modelling},
publisher = {Elsevier BV},
year = {2020},
volume = {416},
pages = {108921},
doi = {10.1016/j.ecolmodel.2019.108921}
}
|
| Simmonds PG, Rigby M, Manning AJ, Park S, Stanley KM, McCulloch A, Henne S, Graziosi F, Maione M, Arduini J, Reimann S, Vollmer MK, Mühle J, O'Doherty S, Young D, Krummel PB, Fraser PJ, Weiss RF, Salameh PK, Harth CM, Park M-K, Park H, Arnold T, Rennick C, Steele LP, Mitrevski B, Wang RHJ and Prinn RG (2020), "The increasing atmospheric burden of the greenhouse gas sulfur hexafluoride (SF6)", Atmospheric Chemistry and Physics., jun, 2020. Vol. 20(12), pp. 7271-7290. |
BibTeX:
@article{Simmonds2020,
author = {Simmonds, Peter G. and Rigby, Matthew and Manning, Alistair J. and Park, Sunyoung and Stanley, Kieran M. and McCulloch, Archie and Henne, Stephan and Graziosi, Francesco and Maione, Michela and Arduini, Jgor and Reimann, Stefan and Vollmer, Martin K. and Mühle, Jens and O'Doherty, Simon and Young, Dickon and Krummel, Paul B. and Fraser, Paul J. and Weiss, Ray F. and Salameh, Peter K. and Harth, Christina M. and Park, Mi-Kyung and Park, Hyeri and Arnold, Tim and Rennick, Chris and Steele, L. Paul and Mitrevski, Blagoj and Wang, Ray H. J. and Prinn, Ronald G.},
title = {The increasing atmospheric burden of the greenhouse gas sulfur hexafluoride (SF6)},
journal = {Atmospheric Chemistry and Physics},
year = {2020},
volume = {20},
number = {12},
pages = {7271--7290},
url = {https://acp.copernicus.org/articles/20/7271/2020/},
doi = {10.5194/acp-20-7271-2020}
}
|
| Smith NE, Kooijmans LMJ, Koren G, van Schaik E, van der Woude AM, Wanders N, Ramonet M, Xueref-Remy I, Siebicke L, Manca G, Brümmer C, Baker IT, Haynes KD, Luijkx IT and Peters W (2020), "Spring enhancement and summer reduction in carbon uptake during the 2018 drought in northwestern Europe", Philosophical Transactions of the Royal Society B: Biological Sciences., oct, 2020. Vol. 375(1810), pp. 20190509. |
| Abstract: We analysed gross primary productivity (GPP), total ecosystem respiration (TER) and the resulting net ecosystem exchange (NEE) of carbon dioxide (CO 2 ) by the terrestrial biosphere during the summer of 2018 through observed changes across the Integrated Carbon Observation System (ICOS) network, through biosphere and inverse modelling, and through remote sensing. Highly correlated yet independently-derived reductions in productivity from sun-induced fluorescence, vegetative near-infrared reflectance, and GPP simulated by the Simple Biosphere model version 4 (SiB4) suggest a 130–340 TgC GPP reduction in July–August–September (JAS) of 2018. This occurs over an area of 1.6 × 10 6 km 2 with anomalously low precipitation in northwestern and central Europe. In this drought-affected area, reduced GPP, TER, NEE and soil moisture at ICOS ecosystem sites are reproduced satisfactorily by the SiB4 model. We found that, in contrast to the preceding 5 years, low soil moisture is the main stress factor across the affected area. SiB4's NEE reduction by 57 TgC for JAS coincides with anomalously high atmospheric CO 2 observations in 2018, and this is closely matched by the NEE anomaly derived by CarbonTracker Europe (52 to 83 TgC). Increased NEE during the spring (May–June) of 2018 (SiB4 −52 TgC; CTE −46 to −55 TgC) largely offset this loss, as ecosystems took advantage of favourable growth conditions. |
BibTeX:
@article{Smith2020,
author = {Smith, Naomi E. and Kooijmans, Linda M. J. and Koren, Gerbrand and van Schaik, Erik and van der Woude, Auke M. and Wanders, Niko and Ramonet, Michel and Xueref-Remy, Irène and Siebicke, Lukas and Manca, Giovanni and Brümmer, Christian and Baker, Ian T. and Haynes, Katherine D. and Luijkx, Ingrid T. and Peters, Wouter},
title = {Spring enhancement and summer reduction in carbon uptake during the 2018 drought in northwestern Europe},
journal = {Philosophical Transactions of the Royal Society B: Biological Sciences},
year = {2020},
volume = {375},
number = {1810},
pages = {20190509},
url = {https://royalsocietypublishing.org/doi/10.1098/rstb.2019.0509},
doi = {10.1098/rstb.2019.0509}
}
|
| Song C, Luan J, Xu X, Ma M, Aurela M, Lohila A, Mammarella I, Alekseychik P, Tuittila ES, Gong W, Chen X, Meng X and Yuan W (2020), "A Microbial Functional Group-Based CH4 Model Integrated Into a Terrestrial Ecosystem Model: Model Structure, Site-Level Evaluation, and Sensitivity Analysis", Journal of Advances in Modeling Earth Systems. Vol. 12(4) |
| Abstract: Wetlands are one of the most important terrestrial ecosystems for land-atmosphere CH4 exchange. A new process-based, biophysical model to quantify CH4 emissions from natural wetlands was developed and integrated into a terrestrial ecosystem model (Integrated Biosphere Simulator). The new model represents a multisubstance system (CH4, O2, CO2, and H2) and describes CH4 production, oxidation, and three transport processes (diffusion, plant-mediated transport, and ebullition). The new model uses several critical microbial mechanisms to represent the interaction of anaerobic fermenters and homoacetogens, hydrogenotrophic, and acetoclastic methanogens, and methanotrophs in CH4 production and oxidation. We applied the model to 24 different wetlands globally to compare the simulated CH4 emissions to observations and conducted a sensitivity analysis. The results indicated that (1) for most sites, the model was able to capture the magnitude and variation of observed CH4 emissions under varying environmental conditions; (2) the parameters that regulate dissolved organic carbon and acetate production, and acetoclastic methanogenesis had the significant impact on simulated CH4 emissions; (3) the representation of the process components of CH4 cycling showed that CH4 oxidation was about half or more of CH4 production, and plant-mediated transport was the dominant pathway at most sites; and (4) the seasonality of simulated CH4 emissions can be controlled by soil temperature, water table position, or combinations thereof. |
BibTeX:
@article{Song2020,
author = {Song, Chaoqing and Luan, Junwei and Xu, Xiaofeng and Ma, Minna and Aurela, Mika and Lohila, Annalea and Mammarella, Ivan and Alekseychik, Pavel and Tuittila, Eeva Stiina and Gong, Wei and Chen, Xiuzhi and Meng, Xianhong and Yuan, Wenping},
title = {A Microbial Functional Group-Based CH4 Model Integrated Into a Terrestrial Ecosystem Model: Model Structure, Site-Level Evaluation, and Sensitivity Analysis},
journal = {Journal of Advances in Modeling Earth Systems},
year = {2020},
volume = {12},
number = {4},
doi = {10.1029/2019MS001867}
}
|
| Song R, Muller JP, Kharbouche S, Yin F, Woodgate W, Kitchen M, Roland M, Arriga N, Meyer W, Koerber G, Bonal D, Burban B, Knohl A, Siebicke L, Buysse P, Loubet B, Leonardo M, Lerebourg C and Gobron N (2020), "Validation of space-based albedo products from upscaled tower-based measurements over heterogeneous and homogeneous landscapes", Remote Sensing. Vol. 12(5) |
| Abstract: Surface albedo is a fundamental radiative parameter as it controls the Earth's energy budget and directly affects the Earth's climate. Satellite observations have long been used to capture the temporal and spatial variations of surface albedo because of their continuous global coverage. However, space-based albedo products are often affected by errors in the atmospheric correction, multi-angular bi-directional reflectance distribution function (BRDF) modelling, as well as spectral conversions. To validate space-based albedo products, an in situ tower albedometer is often used to provide continuous "ground truth" measurements of surface albedo over an extended area. Since space-based albedo and tower-measured albedo are produced at different spatial scales, the can be directly compared only for specific homogeneous land surfaces. However, most land surfaces are inherently heterogeneous with surface properties that vary over a wide range of spatial scales. In this work, tower-measured albedo products, including both directional hemispherical reflectance (DHR) and bi-hemispherical reflectance (BHR), are upscaled to coarse satellite spatial resolutions using a new method. This strategy uses high-resolution satellite derived surface albedos to fill the gaps between the albedometer's field-of-view (FoV) and coarse satellite scales. The high-resolution surface albedo is generated from a combination of surface reflectance retrieved from high-resolution Earth Observation (HR-EO) data and moderate resolution imaging spectroradiometer (MODIS) BRDF climatology over a larger area. We implemented a recently developed atmospheric correction method, the Sensor Invariant Atmospheric Correction (SIAC), to retrieve surface reflectance from HR-EO (e.g., Sentinel-2 and Landsat-8) top-of-atmosphere (TOA) reflectance measurements. This SIAC processing provides an estimated uncertainty for the retrieved surface spectral reflectance at the HR-EO pixel level and shows excellent agreement with the standard Landsat 8 Surface Reflectance Code (LaSRC) in retrieving Landsat-8 surface reflectance. Atmospheric correction of Sentinel-2 data is vastly improved by SIAC when compared against the use of in situ AErosol RObotic NETwork (AERONET) data. Based on this, we can trace the uncertainty of tower-measured albedo during its propagation through high-resolution EO measurements up to coarse satellite scales. These upscaled albedo products can then be compared with space-based albedo products over heterogeneous land surfaces. In this study, both tower-measured albedo and upscaled albedo products are examined at Ground Based Observation for Validation (GbOV) stations (https://land.copernicus.eu/global/gbov/), and used to compare with satellite observations, including Copernicus Global Land Service (CGLS) based on ProbaV and VEGETATION 2 data, MODIS and multi-angle imaging spectroradiometer (MISR). |
BibTeX:
@article{Song2020a,
author = {Song, Rui and Muller, Jan Peter and Kharbouche, Said and Yin, Feng and Woodgate, William and Kitchen, Mark and Roland, Marilyn and Arriga, Nicola and Meyer, Wayne and Koerber, Georgia and Bonal, Damien and Burban, Benoit and Knohl, Alexander and Siebicke, Lukas and Buysse, Pauline and Loubet, Benjamin and Leonardo, Montagnani and Lerebourg, Christophe and Gobron, Nadine},
title = {Validation of space-based albedo products from upscaled tower-based measurements over heterogeneous and homogeneous landscapes},
journal = {Remote Sensing},
year = {2020},
volume = {12},
number = {5},
doi = {10.3390/rs12050833}
}
|
| Spank U, Hehn M, Keller P, Koschorreck M and Bernhofer C (2020), "A Season of Eddy-Covariance Fluxes Above an Extensive Water Body Based on Observations from a Floating Platform", Boundary-Layer Meteorology., dec, 2020. Vol. 174(3), pp. 433-464. Springer Science and Business Media LLC. |
| Abstract: The eddy-covariance (EC) technique is used to determine mass and energy fluxes between the Earth's surface and the lower atmosphere at high temporal resolution. Despite the frequent and successful use of the EC technique at terrestrial sites, its application over water surfaces is rare. We present one season of EC measurements conducted on the Rappbode Reservoir, Germany's largest drinking water reservoir. A floating observation platform in the centre of the reservoir is used for observations of fluxes that were unaffected by surrounding land surfaces and therefore representative of the actual water–atmosphere exchange. The temporal patterns of sensible heat flux are inverted compared to land sites, since the maxima and the minima occur at night and day respectively. The latent heat flux and the evaporation are unexpectedly low for a site where evaporation is not limited by the availability of water. The daily totals in summer and autumn are only 50% and 75% of the potential evaporation assessed by the FAO grass-reference evaporation, respectively. Measurement uncertainties and the effects of the energy balance closure are ruled out as potential factors, so that low values appear to be a general feature of large water surfaces. The observed carbon dioxide fluxes are characterized by distinctive diurnal variations in a typical range for lakes and reservoirs. However, the methane fluxes are low compared to other inland waters. |
BibTeX:
@article{Spank2020,
author = {Spank, Uwe and Hehn, Markus and Keller, Philipp and Koschorreck, Matthias and Bernhofer, Christian},
title = {A Season of Eddy-Covariance Fluxes Above an Extensive Water Body Based on Observations from a Floating Platform},
journal = {Boundary-Layer Meteorology},
publisher = {Springer Science and Business Media LLC},
year = {2020},
volume = {174},
number = {3},
pages = {433--464},
doi = {10.1007/s10546-019-00490-z}
}
|
| Stanley KM, Say D, Mühle J, Harth CM, Krummel PB, Young D, O’Doherty SJ, Salameh PK, Simmonds PG, Weiss RF, Prinn RG, Fraser PJ and Rigby M (2020), "Increase in global emissions of HFC-23 despite near-total expected reductions", Nature Communications., January, 2020. Vol. 11(1) Springer Science and Business Media LLC. |
BibTeX:
@article{Stanley2020,
author = {Stanley, K. M. and Say, D. and Mühle, J. and Harth, C. M. and Krummel, P. B. and Young, D. and O’Doherty, S. J. and Salameh, P. K. and Simmonds, P. G. and Weiss, R. F. and Prinn, R. G. and Fraser, P. J. and Rigby, M.},
title = {Increase in global emissions of HFC-23 despite near-total expected reductions},
journal = {Nature Communications},
publisher = {Springer Science and Business Media LLC},
year = {2020},
volume = {11},
number = {1},
doi = {10.1038/s41467-019-13899-4}
}
|
| Stocker M, Darroch L, Krahl R, Habermann T, Devaraju A, Schwardmann U, D'Onofrio C and Häggström I (2020), "Persistent Identification of Instruments", Data Science Journal., may, 2020. Vol. 19 |
BibTeX:
@article{Stocker2020,
author = {Stocker, Markus and Darroch, Louise and Krahl, Rolf and Habermann, Ted and Devaraju, Anusuriya and Schwardmann, Ulrich and D'Onofrio, Claudio and Häggström, Ingemar},
title = {Persistent Identification of Instruments},
journal = {Data Science Journal},
year = {2020},
volume = {19},
url = {http://datascience.codata.org/articles/10.5334/dsj-2020-018/},
doi = {10.5334/dsj-2020-018}
}
|
| Sulpis O, Lauvset SK and Hagens M (2020), "Current estimates of K&lt;sub&gt;1&lt;/sub&gt;* and K&lt;sub&gt;2&lt;/sub&gt;* appear inconsistent with measured CO&lt;sub&gt;2&lt;/sub&gt; system parameters in cold oceanic regions", Ocean Science., jul, 2020. Vol. 16(4), pp. 847-862. Copernicus GmbH. |
| Abstract: textlessptextgreatertextless![CDATA[Abstract. Seawater absorption of anthropogenic atmospheric carbon dioxide (CO2) has led to a range of changes in carbonate chemistry, collectively referred to as ocean acidification. Stoichiometric dissociation constants used to convert measured carbonate system variables (pH, pCO2, dissolved inorganic carbon, total alkalinity) into globally comparable parameters are crucial for accurately quantifying these changes. The temperature and salinity coefficients of these constants have generally been experimentally derived under controlled laboratory conditions. Here, we use field measurements of carbonate system variables taken from the Global Ocean Data Analysis Project version 2 and the Surface Ocean CO2 Atlas data products to evaluate the temperature dependence of the carbonic acid stoichiometric dissociation constants. By applying a novel iterative procedure to a large dataset of 948 surface-water, quality-controlled samples where four carbonate system variables were independently measured, we show that the set of equations published by Lueker et al. (2000), currently preferred by the ocean acidification community, overestimates the stoichiometric dissociation constants at temperatures below about 8 ∘C. We apply these newly derived temperature coefficients to high-latitude Argo float and cruise data to quantify the effects on surface-water pCO2 and calcite saturation states. These findings highlight the critical implications of uncertainty in stoichiometric dissociation constants for future projections of ocean acidification in polar regions and the need to improve knowledge of what causes the CO2 system inconsistencies in cold waters.]]textgreatertextless/ptextgreater |
BibTeX:
@article{Sulpis2020,
author = {Sulpis, Olivier and Lauvset, Siv K. and Hagens, Mathilde},
title = {Current estimates of K&lt;sub&gt;1&lt;/sub&gt;* and K&lt;sub&gt;2&lt;/sub&gt;* appear inconsistent with measured CO&lt;sub&gt;2&lt;/sub&gt; system parameters in cold oceanic regions},
journal = {Ocean Science},
publisher = {Copernicus GmbH},
year = {2020},
volume = {16},
number = {4},
pages = {847--862},
url = {https://os.copernicus.org/articles/16/847/2020/},
doi = {10.5194/os-16-847-2020}
}
|
| Super I, Dellaert SNC, Visschedijk AJH and Denier van der Gon HAC (2020), "Uncertainty analysis of a European high-resolution emission inventory of CO2 and CO to support inverse modelling and network design", Atmospheric Chemistry and Physics., feb, 2020. Vol. 20(3), pp. 1795-1816. |
BibTeX:
@article{Super2020,
author = {Super, Ingrid and Dellaert, Stijn N. C. and Visschedijk, Antoon J. H. and Denier van der Gon, Hugo A. C.},
title = {Uncertainty analysis of a European high-resolution emission inventory of CO2 and CO to support inverse modelling and network design},
journal = {Atmospheric Chemistry and Physics},
year = {2020},
volume = {20},
number = {3},
pages = {1795--1816},
url = {https://acp.copernicus.org/articles/20/1795/2020/},
doi = {10.5194/acp-20-1795-2020}
}
|
| Tagesson T, Schurgers G, Horion S, Ciais P, Tian F, Brandt M, Ahlström A, Wigneron JP, Ardö J, Olin S, Fan L, Wu Z and Fensholt R (2020), "Recent divergence in the contributions of tropical and boreal forests to the terrestrial carbon sink", Nature Ecology and Evolution., jan, 2020. Vol. 4(2), pp. 202-209. Springer Science and Business Media LLC. |
| Abstract: Anthropogenic land use and land cover changes (LULCC) have a large impact on the global terrestrial carbon sink, but this effect is not well characterized according to biogeographical region. Here, using state-of-the-art Earth observation data and a dynamic global vegetation model, we estimate the impact of LULCC on the contribution of biomes to the terrestrial carbon sink between 1992 and 2015. Tropical and boreal forests contributed equally, and with the largest share of the mean global terrestrial carbon sink. CO2 fertilization was found to be the main driver increasing the terrestrial carbon sink from 1992 to 2015, but the net effect of all drivers (CO2 fertilization and nitrogen deposition, LULCC and meteorological forcing) caused a reduction and an increase, respectively, in the terrestrial carbon sink for tropical and boreal forests. These diverging trends were not observed when applying a conventional LULCC dataset, but were also evident in satellite passive microwave estimates of aboveground biomass. These datasets thereby converge on the conclusion that LULCC have had a greater impact on tropical forests than previously estimated, causing an increase and decrease of the contributions of boreal and tropical forests, respectively, to the growing terrestrial carbon sink. |
BibTeX:
@article{Tagesson2020,
author = {Tagesson, Torbern and Schurgers, Guy and Horion, Stéphanie and Ciais, Philippe and Tian, Feng and Brandt, Martin and Ahlström, Anders and Wigneron, Jean Pierre and Ardö, Jonas and Olin, Stefan and Fan, Lei and Wu, Zhendong and Fensholt, Rasmus},
title = {Recent divergence in the contributions of tropical and boreal forests to the terrestrial carbon sink},
journal = {Nature Ecology and Evolution},
publisher = {Springer Science and Business Media LLC},
year = {2020},
volume = {4},
number = {2},
pages = {202--209},
doi = {10.1038/s41559-019-1090-0}
}
|
| Thompson RL, Broquet G, Gerbig C, Koch T, Lang M, Monteil G, Munassar S, Nickless A, Scholze M, Ramonet M, Karstens U, van Schaik E, Wu Z and Rödenbeck C (2020), "Changes in net ecosystem exchange over Europe during the 2018 drought based on atmospheric observations", Philosophical Transactions of the Royal Society B: Biological Sciences., oct, 2020. Vol. 375(1810), pp. 20190512. |
| Abstract: The 2018 drought was one of the worst European droughts of the twenty-first century in terms of its severity, extent and duration. The effects of the drought could be seen in a reduction in harvest yields in parts of Europe, as well as an unprecedented browning of vegetation in summer. Here, we quantify the effect of the drought on net ecosystem exchange (NEE) using five independent regional atmospheric inversion frameworks. Using a network of atmospheric CO 2 mole fraction observations, we estimate NEE with at least monthly and 0.5° × 0.5° resolution for 2009–2018. We find that the annual NEE in 2018 was likely more positive (less CO 2 uptake) in the temperate region of Europe by 0.09 ± 0.06 Pg C yr −1 (mean ± s.d.) compared to the mean of the last 10 years of −0.08 ± 0.17 Pg C yr −1 , making the region close to carbon neutral in 2018. Similarly, we find a positive annual NEE anomaly for the northern region of Europe of 0.02 ± 0.02 Pg C yr −1 compared the 10-year mean of −0.04 ± 0.05 Pg C yr −1 . In both regions, this was largely owing to a reduction in the summer CO 2 uptake. The positive NEE anomalies coincided spatially and temporally with negative anomalies in soil water. These anomalies were exceptional for the 10-year period of our study. |
BibTeX:
@article{Thompson2020,
author = {Thompson, R. L. and Broquet, G. and Gerbig, C. and Koch, T. and Lang, M. and Monteil, G. and Munassar, S. and Nickless, A. and Scholze, M. and Ramonet, M. and Karstens, U. and van Schaik, E. and Wu, Z. and Rödenbeck, C.},
title = {Changes in net ecosystem exchange over Europe during the 2018 drought based on atmospheric observations},
journal = {Philosophical Transactions of the Royal Society B: Biological Sciences},
year = {2020},
volume = {375},
number = {1810},
pages = {20190512},
url = {https://royalsocietypublishing.org/doi/10.1098/rstb.2019.0512},
doi = {10.1098/rstb.2019.0512}
}
|
| Tian X, Minunno F, Cao T, Peltoniemi M, Kalliokoski T and Mäkelä A (2020), "Extending the range of applicability of the semi‐empirical ecosystem flux model PRELES for varying forest types and climate", Global Change Biology., may, 2020. Vol. 26(5), pp. 2923-2943. Blackwell Publishing Ltd. |
| Abstract: Applications of ecosystem flux models on large geographical scales are often limited by model complexity and data availability. Here we calibrated and evaluated a semi-empirical ecosystem flux model, PREdict Light-use efficiency, Evapotranspiration and Soil water (PRELES), for various forest types and climate conditions, based on eddy covariance data from 55 sites. A Bayesian approach was adopted for model calibration and uncertainty quantification. We applied the site-specific calibrations and multisite calibrations to nine plant functional types (PFTs) to obtain the site-specific and PFT-specific parameter vectors for PRELES. A systematically designed cross-validation was implemented to evaluate calibration strategies and the risks in extrapolation. The combination of plant physiological traits and climate patterns generated significant variation in vegetation responses and model parameters across but not within PFTs, implying that applying the model without PFT-specific parameters is risky. But within PFT, the multisite calibrations performed as accurately as the site-specific calibrations in predicting gross primary production (GPP) and evapotranspiration (ET). Moreover, the variations among sites within one PFT could be effectively simulated by simply adjusting the parameter of potential light-use efficiency (LUE), implying significant convergence of simulated vegetation processes within PFT. The hierarchical modelling of PRELES provides a compromise between satellite-driven LUE and physiologically oriented approaches for extrapolating the geographical variation of ecosystem productivity. Although measurement errors of eddy covariance and remotely sensed data propagated a substantial proportion of uncertainty or potential biases, the results illustrated that PRELES could reliably capture daily variations of GPP and ET for contrasting forest types on large geographical scales if PFT-specific parameterizations were applied. |
BibTeX:
@article{Tian2020,
author = {Tian, Xianglin and Minunno, Francesco and Cao, Tianjian and Peltoniemi, Mikko and Kalliokoski, Tuomo and Mäkelä, Annikki},
title = {Extending the range of applicability of the semi‐empirical ecosystem flux model PRELES for varying forest types and climate},
journal = {Global Change Biology},
publisher = {Blackwell Publishing Ltd},
year = {2020},
volume = {26},
number = {5},
pages = {2923--2943},
url = {https://onlinelibrary.wiley.com/doi/abs/10.1111/gcb.14992},
doi = {10.1111/gcb.14992}
}
|
| Tiemoko DT, Yoroba F, Paris J-D, Diawara A, Berchet A, Pison I, Riandet A and Ramonet M (2020), "Source–Receptor Relationships and Cluster Analysis of CO2, CH4, and CO Concentrations in West Africa: The Case of Lamto in Côte d'Ivoire", Atmosphere., aug, 2020. Vol. 11(9), pp. 903. |
| Abstract: The contribution in terms of long-range transport of CO2, CH4, and CO concentrations to measurements at Lamto (5°02′ W–6°13′ N) was analyzed for the 2014–2017 period using the FLEXPART model that calculates the retro-plumes of air masses arriving at the station. The identification of the source-receptor relationships was also studied with a clustering technique applied on those retro-plumes. This clustering technique enabled us to distinguish four categories of air mass transports arriving at Lamto site described as follows: oceanic and maritime origin (≈37% of the retro-plumes), continental origin (≈21%), and two hybrid clusters (≈42%). The results show that continental emission sources contribute significantly to the increases in concentrations of CO2, CH4, and CO and explain ≈40% of their variance. These emission sources are predominantly from north and north-east directions of the measurement point, and where densely populated and economically developed areas are located. In addition, the transport of air masses from these directions lead to the accumulation of CO2, CH4, and CO. Furthermore, the ratios ΔCO/ΔCH4 and ΔCO/ΔCO2 observed in the groups associated with Harmattan flows clearly show an influence of combustion processes on the continent. Thus, the grouping based on FLEXPART footprints shows an advantage compared to the use of simple trajectories for analyzing source–receptor relationships. |
BibTeX:
@article{Tiemoko2020,
author = {Tiemoko, Dro Touré and Yoroba, Fidèle and Paris, Jean-Daniel and Diawara, Adama and Berchet, Antoine and Pison, Isabelle and Riandet, Aurélie and Ramonet, Michel},
title = {Source–Receptor Relationships and Cluster Analysis of CO2, CH4, and CO Concentrations in West Africa: The Case of Lamto in Côte d'Ivoire},
journal = {Atmosphere},
year = {2020},
volume = {11},
number = {9},
pages = {903},
url = {https://www.mdpi.com/2073-4433/11/9/903},
doi = {10.3390/atmos11090903}
}
|
| Tramontana G, Migliavacca M, Jung M, Reichstein M, Keenan TF, Camps-Valls G, Ogee J, Verrelst J and Papale D (2020), "Partitioning net carbon dioxide fluxes into photosynthesis and respiration using neural networks", Global Change Biology. Vol. 26(9), pp. 5235-5253. |
| Abstract: The eddy covariance (EC) technique is used to measure the net ecosystem exchange (NEE) of CO2 between ecosystems and the atmosphere, offering a unique opportunity to study ecosystem responses to climate change. NEE is the difference between the total CO2 release due to all respiration processes (RECO), and the gross carbon uptake by photosynthesis (GPP). These two gross CO2 fluxes are derived from EC measurements by applying partitioning methods that rely on physiologically based functional relationships with a limited number of environmental drivers. However, the partitioning methods applied in the global FLUXNET network of EC observations do not account for the multiple co-acting factors that modulate GPP and RECO flux dynamics. To overcome this limitation, we developed a hybrid data-driven approach based on combined neural networks (NNC-part). NNC-part incorporates process knowledge by introducing a photosynthetic response based on the light-use efficiency (LUE) concept, and uses a comprehensive dataset of soil and micrometeorological variables as fluxes drivers. We applied the method to 36 sites from the FLUXNET2015 dataset and found a high consistency in the results with those derived from other standard partitioning methods for both GPP (R2 textgreater.94) and RECO (R2 textgreater.8). High consistency was also found for (a) the diurnal and seasonal patterns of fluxes and (b) the ecosystem functional responses. NNC-part performed more realistic than the traditional methods for predicting additional patterns of gross CO2 fluxes, such as: (a) the GPP response to VPD, (b) direct effects of air temperature on GPP dynamics, (c) hysteresis in the diel cycle of gross CO2 fluxes, (d) the sensitivity of LUE to the diffuse to direct radiation ratio, and (e) the post rain respiration pulse after a long dry period. In conclusion, NNC-part is a valid data-driven approach to provide GPP and RECO estimates and complementary to the existing partitioning methods. |
BibTeX:
@article{Tramontana2020,
author = {Tramontana, Gianluca and Migliavacca, Mirco and Jung, Martin and Reichstein, Markus and Keenan, Trevor F and Camps-Valls, Gustau and Ogee, Jerome and Verrelst, Jochem and Papale, Dario},
title = {Partitioning net carbon dioxide fluxes into photosynthesis and respiration using neural networks},
journal = {Global Change Biology},
year = {2020},
volume = {26},
number = {9},
pages = {5235--5253},
doi = {10.1111/gcb.15203}
}
|
| Trotsiuk V, Hartig F, Cailleret M, Babst F, Forrester DI, Baltensweiler A, Buchmann N, Bugmann H, Gessler A, Gharun M, Minunno F, Rigling A, Rohner B, Stillhard J, Thürig E, Waldner P, Ferretti M, Eugster W and Schaub M (2020), "Assessing the response of forest productivity to climate extremes in Switzerland using model–data fusion", Global Change Biology., apr, 2020. Vol. 26(4), pp. 2463-2476. |
BibTeX:
@article{Trotsiuk2020,
author = {Trotsiuk, Volodymyr and Hartig, Florian and Cailleret, Maxime and Babst, Flurin and Forrester, David I. and Baltensweiler, Andri and Buchmann, Nina and Bugmann, Harald and Gessler, Arthur and Gharun, Mana and Minunno, Francesco and Rigling, Andreas and Rohner, Brigitte and Stillhard, Jonas and Thürig, Esther and Waldner, Peter and Ferretti, Marco and Eugster, Werner and Schaub, Marcus},
title = {Assessing the response of forest productivity to climate extremes in Switzerland using model–data fusion},
journal = {Global Change Biology},
year = {2020},
volume = {26},
number = {4},
pages = {2463--2476},
url = {https://onlinelibrary.wiley.com/doi/abs/10.1111/gcb.15011},
doi = {10.1111/gcb.15011}
}
|
| Ueyama M, Ichii K, Kobayashi H, Kumagai T, Beringer J, Merbold L, Euskirchen ES, Hirano T, Belelli Marchesini L, Baldocchi D, Saitoh TM, Mizoguchi Y, Ono K, Kim J, Varlagin A, Kang M, Shimizu T, Kosugi Y, Bret-Harte MS(D, Machimura T, Matsuura Y, Ohta T, Takagi K, Takanashi S and Yasuda Y (2020), "Inferring CO2 fertilization effect based on global monitoring land-atmosphere exchange with a theoretical model", Environmental Research Letters., feb, 2020. IOP Publishing. |
| Abstract: Rising atmospheric CO2 concentration ([CO2]) enhances photosynthesis and reduces transpiration 8 70 9 at the leaf, ecosystem, and global scale via the CO2 fertilization effect. The CO2 fertilization effect 10 71 is among the most important processes for predicting the terrestrial carbon budget and future 11 72 12 climate, yet it has been elusive to quantify. For evaluating the CO2 fertilization effect on land 13 73 photosynthesis and transpiration, we developed a technique that isolated this effect from other 14 74 15 confounding effects, such as changes in climate, using a noisy time series of observed land- 16 75 atmosphere CO2 and water vapor exchange. Here, we evaluate the magnitude of this effect from 17 76 18 2000 to 2014 globally based on constraint optimization of gross primary productivity (GPP) and 19 77 evapotranspiration in a canopy photosynthesis model over 104 global eddy-covariance stations. 20 21 78 We found a consistent increase of GPP (0.138 ± 0.007 % ppm-1; percentile per rising ppm of 22 79 [CO2]) and a concomitant decrease in transpiration (-0.073 ± 0.006 % ppm-1) due to rising [CO2]. 23 80 24 Enhanced GPP from CO2 fertilization after the baseline year 2000 is, on average, 1.2% of global 25 81 GPP, 12.4 g C m-2 yr-1 or 1.8 Pg C yr-1 at the years from 2001 to 2014. Our result demonstrates 26 82 27 that the current increase in [CO2] could potentially explain the recent land CO2 sink at the global 28 83 scale |
BibTeX:
@article{Ueyama2020,
author = {Ueyama, Masahito and Ichii, Kazuhito and Kobayashi, Hideki and Kumagai, Tomo'omi and Beringer, Jason and Merbold, Lutz and Euskirchen, Eugenie S and Hirano, Takashi and Belelli Marchesini, Luca and Baldocchi, Dennis and Saitoh, Taku M. and Mizoguchi, Yasuko and Ono, Keisuke and Kim, Joon and Varlagin, Andrej and Kang, Minseok and Shimizu, Takanori and Kosugi, Yoshiko and Bret-Harte, Marion Syndonia (Donie) and Machimura, Takashi and Matsuura, Yojiro and Ohta, Takeshi and Takagi, Kentaro and Takanashi, Satoru and Yasuda, Yukio},
title = {Inferring CO2 fertilization effect based on global monitoring land-atmosphere exchange with a theoretical model},
journal = {Environmental Research Letters},
publisher = {IOP Publishing},
year = {2020},
doi = {10.1088/1748-9326/ab79e5}
}
|
| Väisänen M, Krab EJ, Monteux S, Teuber LM, Gavazov K, Weedon JT, Keuper F and Dorrepaal E (2020), "Meshes in mesocosms control solute and biota exchange in soils: A step towards disentangling (a)biotic impacts on the fate of thawing permafrost", Applied Soil Ecology. Vol. 151(February), pp. 103537. Elsevier. |
| Abstract: Environmental changes feedback to climate through their impact on soil functions such as carbon (C) and nutrient sequestration. Abiotic conditions and the interactions between above- and belowground biota drive soil responses to environmental change but these (a)biotic interactions are challenging to study. Nonetheless, better understanding of these interactions would improve predictions of future soil functioning and the soil-climate feedback and, in this context, permafrost soils are of particular interest due to their vast soil C-stores. We need new tools to isolate abiotic (microclimate, chemistry) and biotic (roots, fauna, microorganisms) components and to identify their respective roles in soil processes. We developed a new experimental setup, in which we mimic thermokarst (permafrost thaw-induced soil subsidence) by fitting thawed permafrost and vegetated active layer sods side by side into mesocosms deployed in a subarctic tundra over two growing seasons. In each mesocosm, the two sods were separated from each other by barriers with different mesh sizes to allow varying degrees of physical connection and, consequently, (a)biotic exchange between active layer and permafrost. We demonstrate that our mesh-approach succeeded in controlling 1) lateral exchange of solutes between the two soil types, 2) colonization of permafrost by microbes but not by soil fauna, and 3) ingrowth of roots into permafrost. In particular, experimental thermokarst induced a ˜60% decline in permafrost nitrogen (N) content, a shift in soil bacteria and a rapid buildup of root biomass (+33.2 g roots m−2 soil). This indicates that cascading plant-soil-microbe linkages are at the heart of biogeochemical cycling in thermokarst events. We propose that this novel setup can be used to explore the effects of (a)biotic ecosystem components on focal biogeochemical processes in permafrost soils and beyond. |
BibTeX:
@article{Vaeisaenen2020,
author = {Väisänen, Maria and Krab, Eveline J and Monteux, Sylvain and Teuber, Laurenz M and Gavazov, Konstantin and Weedon, James T and Keuper, Frida and Dorrepaal, Ellen},
title = {Meshes in mesocosms control solute and biota exchange in soils: A step towards disentangling (a)biotic impacts on the fate of thawing permafrost},
journal = {Applied Soil Ecology},
publisher = {Elsevier},
year = {2020},
volume = {151},
number = {February},
pages = {103537},
url = {https://doi.org/10.1016/j.apsoil.2020.103537},
doi = {10.1016/j.apsoil.2020.103537}
}
|
| Van Der Graaf SC, Kranenburg R, Segers AJ, Schaap M and Willem Erisman J (2020), "Satellite-derived leaf area index and roughness length information for surface-atmosphere exchange modelling: A case study for reactive nitrogen deposition in north-western Europe using LOTOS-EUROS v2.0", Geoscientific Model Development., may, 2020. Vol. 13(5), pp. 2451-2474. Copernicus GmbH. |
| Abstract: The nitrogen cycle has been continuously disrupted by human activity over the past century, resulting in almost a tripling of the total reactive nitrogen fixation in Europe. Consequently, excessive amounts of reactive nitrogen (textlessspan classCombining double low line"inline-formula"textgreaterNrtextless/spantextgreater) have manifested in the environment, leading to a cascade of adverse effects, such as acidification and eutrophication of terrestrial and aquatic ecosystems, and particulate matter formation. Chemistry transport models (CTMs) are frequently used as tools to simulate the complex chain of processes that determine atmospheric textlessspan classCombining double low line"inline-formula"textgreaterNrtextless/spantextgreater flows. In these models, the parameterization of the atmosphere-biosphere exchange of textlessspan classCombining double low line"inline-formula"textgreaterNrtextless/spantextgreater is largely based on few surface exchange measurement and is therefore known to be highly uncertain. In addition to this, the input parameters that are used here are often fixed values, only linked to specific land use classes. In an attempt to improve this, a combination of multiple satellite products is used to derive updated, time-variant leaf area index (LAI) and roughness length (textlessspan classCombining double low line"inline-formula"textgreatertextlessitextgreaterztextless/itextgreater0textless/spantextgreater) input maps. As LAI, we use the Moderate Resolution Imaging Spectroradiometer (MODIS) MCD15A2H product. The monthly textlessspan classCombining double low line"inline-formula"textgreatertextlessitextgreaterztextless/itextgreater0textless/spantextgreater input maps presented in this paper are a function of satellite-derived normalized difference vegetation index (NDVI) values (MYD13A3 product) for short vegetation types (such as grass and arable land) and a combination of satellite-derived forest canopy height and LAI for forests. The use of these growth-dependent satellite products allows us to represent the growing season more realistically. For urban areas, the textlessspan classCombining double low line"inline-formula"textgreatertextlessitextgreaterztextless/itextgreater0textless/spantextgreater values are updated, too, and linked to a population density map. The approach to derive these dynamic textlessspan classCombining double low line"inline-formula"textgreatertextlessitextgreaterztextless/itextgreater0textless/spantextgreater estimates can be linked to any land use map and is as such transferable to other models. We evaluated the sensitivity of the modelled textlessspan classCombining double low line"inline-formula"textgreaterNrtextless/spantextgreater deposition fields in LOng Term Ozone Simulation - EURopean Operational Smog (LOTOS-EUROS) v2.0 to the abovementioned changes in LAI and textlessspan classCombining double low line"inline-formula"textgreatertextlessitextgreaterztextless/itextgreater0textless/spantextgreater inputs, focusing on Germany, the Netherlands and Belgium. We computed textlessspan classCombining double low line"inline-formula"textgreatertextlessitextgreaterztextless/itextgreater0textless/spantextgreater values from FLUXNET sites and compared these to the default and updated textlessspan classCombining double low line"inline-formula"textgreatertextlessitextgreaterztextless/itextgreater0textless/spantextgreater values in LOTOS-EUROS. The root mean square difference (RMSD) for both short vegetation and forest sites improved. Comparing all sites, the RMSD decreased from 0.76 (default textlessspan classCombining double low line"inline-formula"textgreatertextlessitextgreaterztextless/itextgreater0textless/spantextgreater) to 0.60 (updated textlessspan classCombining double low line"inline-formula"textgreatertextlessitextgreaterztextless/itextgreater0textless/spantextgreater). The implementation of these updated LAI and textlessspan classCombining double low line"inline-formula"textgreatertextlessitextgreaterztextless/itextgreater0textless/spantextgreater input maps led to local changes in the total textlessspan classCombining double low line"inline-formula"textgreaterNrtextless/spantextgreater deposition of up to textlessspan classCombining double low line"inline-formula"textgreaterĝ&circ;1/430textless/spantextgreater&thinsp;% and a general shift from wet to dry deposition. The most distinct changes are observed in land-use-specific deposition fluxes. These fluxes may show relatively large deviations, locally affecting estimated critical load exceedances for specific natural ecosystems. |
BibTeX:
@article{VanDerGraaf2020,
author = {Van Der Graaf, Shelley C. and Kranenburg, Richard and Segers, Arjo J. and Schaap, Martijn and Willem Erisman, Jan},
title = {Satellite-derived leaf area index and roughness length information for surface-atmosphere exchange modelling: A case study for reactive nitrogen deposition in north-western Europe using LOTOS-EUROS v2.0},
journal = {Geoscientific Model Development},
publisher = {Copernicus GmbH},
year = {2020},
volume = {13},
number = {5},
pages = {2451--2474},
doi = {10.5194/gmd-13-2451-2020}
}
|
| Verreyken B, Amelynck C, Brioude J, Muller JF, Schoon N, Kumps N, Colomb A, Metzger JM, Lee CF, Koenig TK, Volkamer R and Stavrakou T (2020), "Characterisation of African biomass burning plumes and impacts on the atmospheric composition over the south-west Indian Ocean", Atmospheric Chemistry and Physics. Vol. 20(23), pp. 14821-14845. |
| Abstract: We present an investigation of biomass burning (BB) plumes originating from Africa and Madagascar based on measurements of a suite of volatile organic compounds (VOCs), carbon monoxide (CO), ozone (O3) and nitrogen dioxide (NO2) obtained during the dry season of 2018 and 2019 at the high-Altitude Maïdo observatory (21.1 S, 55.4 E, 2160ma:s:l:), located on the remote island of La Réunion in the south-west Indian Ocean (SWIO). Biomass burning plume episodes were identified from increased acetonitrile (CH3CN) mixing ratios. Enhancement ratios (EnRs) relative to CO were calculated from in situ measurements for CH3CN, acetone (CH3COCH3), formic acid (HCOOH), acetic acid (CH3COOH), benzene (C6H6), methanol (CH3OH) and O3. We compared the EnRs to emission ratios (ERs) relative to CO reported in the literature in order to estimate loss or production of these compounds during transport. For CH3CN and CH3COOH, the calculated EnRs are similar to the ERs. For C6H6 and CH3OH, the EnR is lower than the ER, indicating a net sink of these compounds which was found to be in line with the expected atmospheric lifetime. For CH3COCH3 and HCOOH, the calculated EnRs are larger than the ERs. The discrepancy reaches an order of magnitude for HCOOH (18 34 pptvppbv1 compared to 1.8 4.5 pptvppbv1). This points to significant secondary production of HCOOH during transport. The Copernicus Atmospheric Monitoring Service (CAMS) global model simulations reproduce the temporal variation of CO mixing ratios well at the observatory but underestimate O3 and NO2 mixing ratios in the plumes by on average 16 ppbv and 60 pptv respectively. This discrepancy between modelled and measured O3 mixing ratios was attributed to (i) large uncertainties in VOC and NOx (NOCNO2) emissions due to BB in CAMS and (ii) misrepresentation of NOx recycling in the model during transport. Finally, transport of pyrogenically emitted CO is calculated with FLEXPART in order to (i) determine the mean plume age during the intrusions at the observatory and (ii) estimate the impact of BB on the pristine marine boundary layer (MBL). By multiplying the excess CO in the MBL with inferred EnRs at the observatory, we calculated the expected impact of BB on CH3CN, CH3COCH3, CH3OH and C6H6 concentrations in the MBL. These excesses constitute increases of 20 % 150% compared to background measurements in the SWIO MBL reported in the literature. |
BibTeX:
@article{Verreyken2020,
author = {Verreyken, Bert and Amelynck, Crist and Brioude, Jerome and Muller, Jean Francois and Schoon, Niels and Kumps, Nicolas and Colomb, Aurelie and Metzger, Jean Marc and Lee, Christopher F and Koenig, Theodore K and Volkamer, Rainer and Stavrakou, Trissevgeni},
title = {Characterisation of African biomass burning plumes and impacts on the atmospheric composition over the south-west Indian Ocean},
journal = {Atmospheric Chemistry and Physics},
year = {2020},
volume = {20},
number = {23},
pages = {14821--14845},
doi = {10.5194/acp-20-14821-2020}
}
|
| Vestin P, Mölder M, Kljun N, Cai Z, Hasan A, Holst J, Klemedtsson L and Lindroth A (2020), "Impacts of Clear-Cutting of a Boreal Forest on Carbon Dioxide, Methane and Nitrous Oxide Fluxes", Forests., sep, 2020. Vol. 11(9), pp. 961. |
| Abstract: The 2015 Paris Agreement encourages stakeholders to implement sustainable forest management policies to mitigate anthropogenic emissions of greenhouse gases (GHG). The net effects of forest management on the climate and the environment are, however, still not completely understood, partially as a result of a lack of long-term measurements of GHG fluxes in managed forests. During the period 2010–2013, we simultaneously measured carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O) fluxes using the flux-gradient technique at two clear-cut plots of different degrees of wetness, located in central Sweden. The measurements started approx. one year after clear-cutting, directly following soil scarification and planting. The study focused on robust inter-plot comparisons, spatial and temporal dynamics of GHG fluxes, and the determination of the global warming potential of a clear-cut boreal forest. The clear-cutting resulted in significant emissions of GHGs at both the wet and the dry plot. The degree of wetness determined, directly or indirectly, the relative contribution of each GHG to the total budgets. Faster establishment of vegetation on the wet plot reduced total emissions of CO2 as compared to the dry plot but this was partially offset by higher CH4 emissions. Waterlogging following clear-cutting likely caused both plots to switch from sinks to sources of CH4. In addition, there were periods with N2O uptake at the wet plot, although both plots were net sources of N2O on an annual basis. We observed clear diel patters in CO2, CH4 and N2O fluxes during the growing season at both plots, with the exception of CH4 at the dry plot. The total three-year carbon budgets were 4107 gCO2-equivalent m−2 and 5274 gCO2-equivalent m−2 at the wet and the dry plots, respectively. CO2 contributed 91.8% to the total carbon budget at the wet plot and 98.2% at the dry plot. For the only full year with N2O measurements, the total GHG budgets were 1069.9 gCO2-eqvivalents m−2 and 1695.7 gCO2-eqvivalents m−2 at the wet and dry plot, respectively. At the wet plot, CH4 contributed 3.7%, while N2O contributed 7.3%. At the dry plot, CH4 and N2O contributed 1.5% and 7.6%, respectively. Our results emphasize the importance of considering the effects of the three GHGs on the climate for any forest management policy aiming at enhancing the mitigation potential of forests. |
BibTeX:
@article{Vestin2020,
author = {Vestin, Patrik and Mölder, Meelis and Kljun, Natascha and Cai, Zhanzhang and Hasan, Abdulghani and Holst, Jutta and Klemedtsson, Leif and Lindroth, Anders},
title = {Impacts of Clear-Cutting of a Boreal Forest on Carbon Dioxide, Methane and Nitrous Oxide Fluxes},
journal = {Forests},
year = {2020},
volume = {11},
number = {9},
pages = {961},
url = {https://www.mdpi.com/1999-4907/11/9/961},
doi = {10.3390/f11090961}
}
|
| Vezy R, le Maire G, Christina M, Georgiou S, Imbach P, Hidalgo HG, Alfaro EJ, Blitz-Frayret C, Charbonnier F, Lehner P, Loustau D and Roupsard O (2020), "DynACof: A process-based model to study growth, yield and ecosystem services of coffee agroforestry systems", Environmental Modelling and Software., feb, 2020. Vol. 124, pp. 104609. Elsevier BV. |
| Abstract: The DynACof model was designed to model coffee agroforestry systems and study the trade-offs to e.g. optimize the system facing climate changes. The model simulates net primary productivity (NPP), growth, yield, mortality, energy and water balance of coffee agroforestry systems according to shade tree species and management. Several plot-scale ecosystem services are simulated by the model, such as production, canopy cooling effect, or potential C sequestration. DynACof uses metamodels derived from a detailed 3D process-based model (MAESPA) to account for complex spatial effects, while running fast. It also includes a coffee flower bud and fruit cohort module to better distribute fruit carbon demand over the year, a key feature to obtain a realistic competition between sinks. The model was parameterized and evaluated using a highly comprehensive database on a coffee agroforestry experimental site in Costa Rica. The fluxes simulated by the model were close to the measurements over a 5-year period (nRMSE = 26.27 for gross primary productivity; 28.22 for actual evapo-transpiration, 53.91 for sensible heat flux and 15.26 for net radiation), and DynACof satisfactorily simulated the yield, NPP, mortality and carbon stock for each coffee organ type over a 35-year rotation. |
BibTeX:
@article{Vezy2020,
author = {Vezy, Rémi and le Maire, Guerric and Christina, Mathias and Georgiou, Selena and Imbach, Pablo and Hidalgo, Hugo G and Alfaro, Eric J and Blitz-Frayret, Céline and Charbonnier, Fabien and Lehner, Peter and Loustau, Denis and Roupsard, Olivier},
title = {DynACof: A process-based model to study growth, yield and ecosystem services of coffee agroforestry systems},
journal = {Environmental Modelling and Software},
publisher = {Elsevier BV},
year = {2020},
volume = {124},
pages = {104609},
doi = {10.1016/j.envsoft.2019.104609}
}
|
| Vitale D, Fratini G, Bilancia M, Nicolini G, Sabbatini S and Papale D (2020), "A robust data cleaning procedure for eddy covariance flux measurements", Biogeosciences., mar, 2020. Vol. 17(6), pp. 1367-1391. |
BibTeX:
@article{Vitale2020,
author = {Vitale, Domenico and Fratini, Gerardo and Bilancia, Massimo and Nicolini, Giacomo and Sabbatini, Simone and Papale, Dario},
title = {A robust data cleaning procedure for eddy covariance flux measurements},
journal = {Biogeosciences},
year = {2020},
volume = {17},
number = {6},
pages = {1367--1391},
url = {https://www.biogeosciences.net/17/1367/2020/},
doi = {10.5194/bg-17-1367-2020}
}
|
| Waliser D, Gleckler PJ, Ferraro R, Taylor KE, Ames S, Biard J, Bosilovich MG, Brown O, Chepfer H, Cinquini L, Durack PJ, Eyring V, Mathieu P-P, Lee T, Pinnock S, Potter GL, Rixen M, Saunders R, Schulz J, Thépaut J-N and Tuma M (2020), "Observations for Model Intercomparison Project (Obs4MIPs): status for CMIP6", Geoscientific Model Development., jul, 2020. Vol. 13(7), pp. 2945-2958. |
| Abstract: textlessptextgreatertextless![CDATA[Abstract. The Observations for Model Intercomparison Project (Obs4MIPs) was initiated in 2010 to facilitate the use of observations in climate model evaluation and research, with a particular target being the Coupled Model Intercomparison Project (CMIP), a major initiative of the World Climate Research Programme (WCRP). To this end, Obs4MIPs (1) targets observed variables that can be compared to CMIP model variables; (2) utilizes dataset formatting specifications and metadata requirements closely aligned with CMIP model output; (3) provides brief technical documentation for each dataset, designed for nonexperts and tailored towards relevance for model evaluation, including information on uncertainty, dataset merits, and limitations; and (4) disseminates the data through the Earth System Grid Federation (ESGF) platforms, making the observations searchable and accessible via the same portals as the model output. Taken together, these characteristics of the organization and structure of obs4MIPs should entice a more diverse community of researchers to engage in the comparison of model output with observations and to contribute to a more comprehensive evaluation of the climate models. At present, the number of obs4MIPs datasets has grown to about 80; many are undergoing updates, with another 20 or so in preparation, and more than 100 are proposed and under consideration. A partial list of current global satellite-based datasets includes humidity and temperature profiles; a wide range of cloud and aerosol observations; ocean surface wind, temperature, height, and sea ice fraction; surface and top-of-atmosphere longwave and shortwave radiation; and ozone (O3), methane (CH4), and carbon dioxide (CO2) products. A partial list of proposed products expected to be useful in analyzing CMIP6 results includes the following: alternative products for the above quantities, additional products for ocean surface flux and chlorophyll products, a number of vegetation products (e.g., FAPAR, LAI, burned area fraction), ice sheet mass and height, carbon monoxide (CO), and nitrogen dioxide (NO2). While most existing obs4MIPs datasets consist of monthly-mean gridded data over the global domain, products with higher time resolution (e.g., daily) and/or regional products are now receiving more attention. Along with an increasing number of datasets, obs4MIPs has implemented a number of capability upgrades including (1) an updated obs4MIPs data specifications document that provides additional search facets and generally improves congruence with CMIP6 specifications for model datasets, (2) a set of six easily understood indicators that help guide users as to a dataset's maturity and suitability for application, and (3) an option to supply supplemental information about a dataset beyond what can be found in the standard metadata. With the maturation of the obs4MIPs framework, the dataset inclusion process, and the dataset formatting guidelines and resources, the scope of the observations being considered is expected to grow to include gridded in situ datasets as well as datasets with a regional focus, and the ultimate intent is to judiciously expand this scope to any observation dataset that has applicability for evaluation of the types of Earth system models used in CMIP.]]textgreatertextless/ptextgreater |
BibTeX:
@article{Waliser2020,
author = {Waliser, Duane and Gleckler, Peter J. and Ferraro, Robert and Taylor, Karl E. and Ames, Sasha and Biard, James and Bosilovich, Michael G. and Brown, Otis and Chepfer, Helene and Cinquini, Luca and Durack, Paul J. and Eyring, Veronika and Mathieu, Pierre-Philippe and Lee, Tsengdar and Pinnock, Simon and Potter, Gerald L. and Rixen, Michel and Saunders, Roger and Schulz, Jörg and Thépaut, Jean-Noël and Tuma, Matthias},
title = {Observations for Model Intercomparison Project (Obs4MIPs): status for CMIP6},
journal = {Geoscientific Model Development},
year = {2020},
volume = {13},
number = {7},
pages = {2945--2958},
url = {https://gmd.copernicus.org/articles/13/2945/2020/},
doi = {10.5194/gmd-13-2945-2020}
}
|
| Walker AP, De Kauwe MG, Bastos A, Belmecheri S, Georgiou K, Keeling RF, McMahon SM, Medlyn BE, Moore DJP, Norby RJ, Zaehle S, Anderson‐Teixeira KJ, Battipaglia G, Brienen RJW, Cabugao KG, Cailleret M, Campbell E, Canadell JG, Ciais P, Craig ME, Ellsworth DS, Farquhar GD, Fatichi S, Fisher JB, Frank DC, Graven H, Gu L, Haverd V, Heilman K, Heimann M, Hungate BA, Iversen CM, Joos F, Jiang M, Keenan TF, Knauer J, Körner C, Leshyk VO, Leuzinger S, Liu Y, MacBean N, Malhi Y, McVicar TR, Penuelas J, Pongratz J, Powell AS, Riutta T, Sabot MEB, Schleucher J, Sitch S, Smith WK, Sulman B, Taylor B, Terrer C, Torn MS, Treseder KK, Trugman AT, Trumbore SE, Mantgem PJ, Voelker SL, Whelan ME and Zuidema PA (2020), "Integrating the evidence for a terrestrial carbon sink caused by increasing atmospheric CO 2", New Phytologist., oct, 2020. , pp. nph.16866. |
BibTeX:
@article{Walker2020,
author = {Walker, Anthony P. and De Kauwe, Martin G. and Bastos, Ana and Belmecheri, Soumaya and Georgiou, Katerina and Keeling, Ralph F. and McMahon, Sean M. and Medlyn, Belinda E. and Moore, David J. P. and Norby, Richard J. and Zaehle, Sönke and Anderson‐Teixeira, Kristina J. and Battipaglia, Giovanna and Brienen, Roel J. W. and Cabugao, Kristine G. and Cailleret, Maxime and Campbell, Elliott and Canadell, Josep G. and Ciais, Philippe and Craig, Matthew E. and Ellsworth, David S. and Farquhar, Graham D. and Fatichi, Simone and Fisher, Joshua B. and Frank, David C. and Graven, Heather and Gu, Lianhong and Haverd, Vanessa and Heilman, Kelly and Heimann, Martin and Hungate, Bruce A. and Iversen, Colleen M. and Joos, Fortunat and Jiang, Mingkai and Keenan, Trevor F. and Knauer, Jürgen and Körner, Christian and Leshyk, Victor O. and Leuzinger, Sebastian and Liu, Yao and MacBean, Natasha and Malhi, Yadvinder and McVicar, Tim R. and Penuelas, Josep and Pongratz, Julia and Powell, A. Shafer and Riutta, Terhi and Sabot, Manon E. B. and Schleucher, Juergen and Sitch, Stephen and Smith, William K. and Sulman, Benjamin and Taylor, Benton and Terrer, César and Torn, Margaret S. and Treseder, Kathleen K. and Trugman, Anna T. and Trumbore, Susan E. and Mantgem, Phillip J. and Voelker, Steve L. and Whelan, Mary E. and Zuidema, Pieter A.},
title = {Integrating the evidence for a terrestrial carbon sink caused by increasing atmospheric CO 2},
journal = {New Phytologist},
year = {2020},
pages = {nph.16866},
url = {https://onlinelibrary.wiley.com/doi/10.1111/nph.16866},
doi = {10.1111/nph.16866}
}
|
| Wang S, Garcia M, Ibrom A and Bauer-Gottwein P (2020), "Temporal interpolation of land surface fluxes derived from remote sensing - Results with an unmanned aerial system", Hydrology and Earth System Sciences. Vol. 24(7), pp. 3643-3661. |
| Abstract: Remote sensing imagery can provide snapshots of rapidly changing land surface variables, e.g. evapotranspiration (ET), land surface temperature (Ts), net radiation (Rn), soil moisture (-), and gross primary productivity (GPP), for the time of sensor overpass. However, discontinuous data acquisitions limit the applicability of remote sensing for water resources and ecosystem management. Methods to interpolate between remote sensing snapshot data and to upscale them from an instantaneous to a daily timescale are needed. We developed a dynamic soil-vegetation-atmosphere transfer model to interpolate land surface state variables that change rapidly between remote sensing observations. The "Soil-Vegetation, Energy, water, and CO2 traNsfer" (SVEN) model, which combines the snapshot version of the remote sensing Priestley-Taylor Jet Propulsion Laboratory ET model and light use efficiency GPP models, now incorporates a dynamic component for the ground heat flux based on the "force-restore" method and a water balance "bucket" model to estimate and canopy wetness at a half-hourly time step. A case study was conducted to demonstrate the method using optical and thermal data from an unmanned aerial system at a willow plantation flux site (Risoe, Denmark). Based on model parameter calibration with the snapshots of land surface variables at the time of flight, SVEN interpolated UAS-based snapshots to continuous records of Ts, Rn , ET, and GPP for the 2016 growing season with forcing from continuous climatic data and the normalized difference vegetation index (NDVI). Validation with eddy covariance and other in situ observations indicates that SVEN can estimate daily land surface fluxes between remote sensing acquisitions with normalized root mean square deviations of the simulated daily Ts, Rn , LE, and GPP of 11.77 %, 6.65 %, 19.53 %, 14.77 %, and 12.97% respectively. In this deciduous tree plantation, this study demonstrates that temporally sparse optical and thermal remote sensing observations can be used to calibrate soil and vegetation parameters of a simple land surface modelling scheme to estimate "lowpersistence" or rapidly changing land surface variables with the use of few forcing variables. This approach can also be applied with remotely-sensed data from other platforms to fill temporal gaps, e.g. cloud-induced data gaps in satellite observations. |
BibTeX:
@article{Wang2020,
author = {Wang, Sheng and Garcia, Monica and Ibrom, Andreas and Bauer-Gottwein, Peter},
title = {Temporal interpolation of land surface fluxes derived from remote sensing - Results with an unmanned aerial system},
journal = {Hydrology and Earth System Sciences},
year = {2020},
volume = {24},
number = {7},
pages = {3643--3661},
doi = {10.5194/hess-24-3643-2020}
}
|
| Watson AJ, Schuster U, Shutler JD, Holding T, Ashton IGC, Landschützer P, Woolf DK and Goddijn-Murphy L (2020), "Revised estimates of ocean-atmosphere CO2 flux are consistent with ocean carbon inventory", Nature Communications., dec, 2020. Vol. 11(1), pp. 4422. |
BibTeX:
@article{Watson2020,
author = {Watson, Andrew J. and Schuster, Ute and Shutler, Jamie D. and Holding, Thomas and Ashton, Ian G. C. and Landschützer, Peter and Woolf, David K. and Goddijn-Murphy, Lonneke},
title = {Revised estimates of ocean-atmosphere CO2 flux are consistent with ocean carbon inventory},
journal = {Nature Communications},
year = {2020},
volume = {11},
number = {1},
pages = {4422},
url = {http://www.nature.com/articles/s41467-020-18203-3},
doi = {10.1038/s41467-020-18203-3}
}
|
| Westergaard-Nielsen A, Balstr m T, Treier UA, Normand S and Elberling B (2020), "Estimating meltwater retention and associated nitrate redistribution during snowmelt in an Arctic tundra landscape", Environmental Research Letters. Vol. 15(3) IOP Publishing. |
| Abstract: Nitrogen availability in Arctic ecosystems is a key driver for biological activity, including plant, growth and thereby directly linked to the greening of the Arctic. Here, we model the redistribution of meltwater following spring snowmelt as well as the accumulation of meltwater and dissolved nitrate at landscape scale. By combining snow mapping with unmanned aerial systems, snow chemistry, and hydrological modelling, we argue that the majority of nitrate in the snowpack is flushed out of the landscape due to the limited storage capacity of meltwater in the early growing season frozen soil. We illustrate how landscape micro-topography is a crucial parameter to quantify storage capacity of meltwater at landscape scale and thereby the associated pool of soluble compounds such as nitrate. This pool will be available for plants and may be important for plant diversity and growth rates in the wettest part of the landscape. This study illustrates that the evenly distributed nitrate input during the Arctic winter may be redistributed during the initial snowmelt and lead to marked differences in biologically available nitrate at the onset of the growing season, but also that the majority of deposited nitrate in snow is lost from the terrestrial to the aquatic environment during snowmelt. |
BibTeX:
@article{WestergaardNielsen2020,
author = {Westergaard-Nielsen, Andreas and Balstr m, Thomas and Treier, Urs A and Normand, Signe and Elberling, Bo},
title = {Estimating meltwater retention and associated nitrate redistribution during snowmelt in an Arctic tundra landscape},
journal = {Environmental Research Letters},
publisher = {IOP Publishing},
year = {2020},
volume = {15},
number = {3},
doi = {10.1088/1748-9326/ab57b1}
}
|
| Wester-Larsen L, Kramshøj M, Albers CN and Rinnan R (2020), "Biogenic Volatile Organic Compounds in Arctic Soil: A Field Study of Concentrations and Variability With Vegetation Cover", Journal of Geophysical Research: Biogeosciences. Vol. 125(7), pp. 1-15. |
| Abstract: Soil biogenic volatile organic compounds (sBVOCs) contribute to ecosystem emissions and play an important role in the soil ecosystem. Most previous studies on sBVOCs have looked at emissions from excavated soil in the laboratory or in situ emissions from areas with bare soil, using chambers. So far, however, the actual BVOC concentrations in the soil have rarely been considered. Herein, we sought to explore the relationships between the vegetation cover in a low Arctic heath ecosystem in Western Greenland and the BVOC concentration in the soil below. In situ measurements were performed at 15-cm depth in areas dominated by Cassiope tetragona, Empetrum nigrum, Salix glauca, and Betula nana and along a 36-m-long transect with mixed vegetation cover during the growing seasons of 2015–2017. sBVOC concentrations varied between the different vegetation covers, with higher concentrations below Cassiope and Betula compared to Empetrum. Furthermore, sBVOC concentrations differed along the transect, and this variation was also partly related to differences in the vegetation cover. Moreover, we demonstrate that installation of a soil probe, for sampling soil air, changes the composition and magnitude of sBVOCs up to 1 day after the installation. |
BibTeX:
@article{WesterLarsen2020,
author = {Wester-Larsen, Lærke and Kramshøj, Magnus and Albers, Christian N and Rinnan, Riikka},
title = {Biogenic Volatile Organic Compounds in Arctic Soil: A Field Study of Concentrations and Variability With Vegetation Cover},
journal = {Journal of Geophysical Research: Biogeosciences},
year = {2020},
volume = {125},
number = {7},
pages = {1--15},
doi = {10.1029/2019JG005551}
}
|
| Western LM, Sha Z, Rigby M, Ganesan AL, Manning AJ, Stanley KM, O’Doherty SJ, Young D and Rougier J (2020), "Bayesian spatio-temporal inference of trace gas emissions using an integrated nested Laplacian approximation and Gaussian Markov random fields", Geoscientific Model Development., April, 2020. Vol. 13(4), pp. 2095-2107. Copernicus GmbH. |
BibTeX:
@article{Western2020,
author = {Western, Luke M. and Sha, Zhe and Rigby, Matthew and Ganesan, Anita L. and Manning, Alistair J. and Stanley, Kieran M. and O’Doherty, Simon J. and Young, Dickon and Rougier, Jonathan},
title = {Bayesian spatio-temporal inference of trace gas emissions using an integrated nested Laplacian approximation and Gaussian Markov random fields},
journal = {Geoscientific Model Development},
publisher = {Copernicus GmbH},
year = {2020},
volume = {13},
number = {4},
pages = {2095--2107},
doi = {10.5194/gmd-13-2095-2020}
}
|
| Wiekenkamp I, Huisman JA, Bogena HR and Vereecken H (2020), "Effects of deforestation on water flow in the vadose zone", Water (Switzerland). Vol. 12(1) |
| Abstract: The effects of land use change on the occurrence and frequency of preferential flow (fast water flow through a small fraction of the pore space) and piston flow (slower water flow through a large fraction of the pore space) are still not fully understood. In this study, we used a five year high resolution soil moisture monitoring dataset in combination with a response time analysis to identify factors that control preferential and piston flow before and after partial deforestation in a small headwater catchment. The sensor response times at 5, 20 and 50 cm depths were classified into one of four classes: (1) non-sequential preferential flow, (2) velocity based preferential flow, (3) sequential (piston) flow, and (4) no response. The results of this analysis showed that partial deforestation increased sequential flow occurrence and decreased the occurrence of no flow in the deforested area. Similar precipitation conditions (total precipitation) after deforestation caused more sequential flow in the deforested area, which was attributed to higher antecedent moisture conditions and the lack of interception. At the same time, an increase in preferential flow occurrence was also observed for events with identical total precipitation. However, as the events in the treatment period (after deforestation) generally had lower total, maximum, and mean precipitation, this effect was not observed in the overall occurrence of preferential flow. The results of this analysis demonstrate that the combination of a sensor response time analysis and a soil moisture dataset that includes pre-and post-deforestation conditions can offer new insights in preferential and sequential flow conditions after land use change. |
BibTeX:
@article{Wiekenkamp2020,
author = {Wiekenkamp, Inge and Huisman, Johan Alexander and Bogena, Heye Reemt and Vereecken, Harry},
title = {Effects of deforestation on water flow in the vadose zone},
journal = {Water (Switzerland)},
year = {2020},
volume = {12},
number = {1},
doi = {10.3390/w12010035}
}
|
| Wigneron JP, Fan L, Ciais P, Bastos A, Brandt M, Chave J, Saatchi S, Baccini A and Fensholt R (2020), "Tropical forests did not recover from the strong 2015–2016 El Niño event", Science Advances., feb, 2020. Vol. 6(6), pp. eaay4603. American Association for the Advancement of Science (AAAS). |
| Abstract: Severe drought and extreme heat associated with the 2015–2016 El Niño event have led to large carbon emissions from the tropical vegetation to the atmosphere. With the return to normal climatic conditions in 2017, tropical forest aboveground carbon (AGC) stocks are expected to partly recover due to increased productivity, but the intensity and spatial distribution of this recovery are unknown. We used low-frequency microwave satellite data (L-VOD) to feature precise monitoring of AGC changes and show that the AGC recovery of tropical ecosystems was slow and that by the end of 2017, AGC had not reached predrought levels of 2014. From 2014 to 2017, tropical AGC stocks decreased by 1.31.51.2 Pg C due to persistent AGC losses in Africa (âˆ'0.9âˆ'0.8âˆ'1.1 Pg C) and America (âˆ'0.5âˆ'0.4âˆ'0.6 Pg C). Pantropically, drylands recovered their carbon stocks to pre–El Niño levels, but African and American humid forests did not, suggesting carryover effects from enhanced forest mortality. |
BibTeX:
@article{Wigneron2020,
author = {Wigneron, Jean Pierre and Fan, Lei and Ciais, Philippe and Bastos, Ana and Brandt, Martin and Chave, Jérome and Saatchi, Sassan and Baccini, Alessandro and Fensholt, Rasmus},
title = {Tropical forests did not recover from the strong 2015–2016 El Niño event},
journal = {Science Advances},
publisher = {American Association for the Advancement of Science (AAAS)},
year = {2020},
volume = {6},
number = {6},
pages = {eaay4603},
doi = {10.1126/sciadv.aay4603}
}
|
| Wimart-Rousseau C, Lajaunie-Salla K, Marrec P, Wagener T, Raimbault P, Lagadec V, Lafont M, Garcia N, Diaz F, Pinazo C, Yohia C, Garcia F, Xueref-Remy I, Blanc P-E, Armengaud A and Lefèvre D (2020), "Temporal variability of the carbonate system and air-sea CO2 exchanges in a Mediterranean human-impacted coastal site", Estuarine, Coastal and Shelf Science., may, 2020. Vol. 236, pp. 106641. |
BibTeX:
@article{WimartRousseau2020,
author = {Wimart-Rousseau, Cathy and Lajaunie-Salla, Katixa and Marrec, Pierre and Wagener, Thibaut and Raimbault, Patrick and Lagadec, Véronique and Lafont, Michel and Garcia, Nicole and Diaz, Frédéric and Pinazo, Christel and Yohia, Christophe and Garcia, Fabrice and Xueref-Remy, Irène and Blanc, Pierre-Eric and Armengaud, Alexandre and Lefèvre, Dominique},
title = {Temporal variability of the carbonate system and air-sea CO2 exchanges in a Mediterranean human-impacted coastal site},
journal = {Estuarine, Coastal and Shelf Science},
year = {2020},
volume = {236},
pages = {106641},
url = {https://linkinghub.elsevier.com/retrieve/pii/S0272771419305542},
doi = {10.1016/j.ecss.2020.106641}
}
|
| Wintjen P, Ammann C, Schrader F and Brümmer C (2020), "Correcting high-frequency losses of reactive nitrogen flux measurements", Atmospheric Measurement Techniques. Vol. 13(6), pp. 2923-2948. |
| Abstract: Flux measurements of reactive nitrogen compounds are of increasing importance to assess the impact of unintended emissions on sensitive ecosystems and to evaluate the efficiency of mitigation strategies. Therefore, it is necessary to determine the exchange of reactive nitrogen gases with the highest possible accuracy. This study gives insight into the performance of flux correction methods and their usability for reactive nitrogen gases. The eddy-covariance (EC) technique is today widely used in experimental field studies to measure land surface-atmosphere exchange of a variety of trace gases. In recent years, applying the EC technique to reactive nitrogen compounds has become more important since atmospheric nitrogen deposition influences the productivity and biodiversity of (semi)natural ecosystems and their carbon dioxide (CO2) exchange. Fluxes, which are calculated by EC, have to be corrected for setup-specific effects like attenuation in the high-frequency range. However, common methods for correcting such flux losses are mainly optimized for inert greenhouse gases like CO2 and methane or water vapor. In this study, we applied a selection of correction methods to measurements of total reactive nitrogen ($$Nr) conducted in different ecosystems using the Total Reactive Atmospheric Nitrogen Converter (TRANC) coupled to a chemiluminescence detector (CLD). Average flux losses calculated by methods using measured cospectra and ogives were approximately 26 %-38% for a seminatural peatland and about 16 %-22% for a mixed forest. The investigation of the different methods showed that damping factors calculated with measured heat and gas flux cospectra using an empirical spectral transfer function were most reliable. Flux losses of 6Nr with this method were on the upper end of the median damping range, i.e., 38% for the peatland site and 22% for the forest site. Using modified Kaimal cospectra for damping estimation worked well for the forest site but underestimated damping for the peatland site by about 12 %. Correction factors of methods based on power spectra or on site-specific and instrumental parameters were mostly below 10 %. Power spectra of $$Nr were heavily affected-likely by white noise-and deviated substantially at lower frequencies from the respective temperature (power) spectra. Our study supports the use of an empirical method for estimating flux losses of 6Nr or any reactive nitrogen compound and the use of locally measured cospectra. |
BibTeX:
@article{Wintjen2020,
author = {Wintjen, Pascal and Ammann, Christof and Schrader, Frederik and Brümmer, Christian},
title = {Correcting high-frequency losses of reactive nitrogen flux measurements},
journal = {Atmospheric Measurement Techniques},
year = {2020},
volume = {13},
number = {6},
pages = {2923--2948},
doi = {10.5194/amt-13-2923-2020}
}
|
| Xiao M, Yu Z, Kong D, Gu X, Mammarella I, Montagnani L, Arain MA, Merbold L, Magliulo V, Lohila A, Buchmann N, Wolf S, Gharun M, Hörtnagl L, Beringer J and Gioli B (2020), "Stomatal response to decreased relative humidity constrains the acceleration of terrestrial evapotranspiration", Environmental Research Letters. Vol. 15(9) |
| Abstract: Terrestrial evapotranspiration (ET) is thermodynamically expected to increase with increasing atmospheric temperature; however, the actual constraints on the intensification of ET remain uncertain due to a lack of direct observations. Based on the FLUXNET2015 Dataset, we found that relative humidity (RH) is a more important driver of ET than temperature. While actual ET decrease at reduced RH, potential ET increases, consistently with the complementary relationship (CR) framework stating that the fraction of energy not used for actual ET is dissipated as increased sensible heat flux that in turn increases potential ET. In this study, we proposed an improved CR formulation requiring no parameter calibration and assessed its reliability in estimating ET both at site-level with the FLUXNET2015 Dataset and at basin-level. Using the ERA-Interim meteorological dataset for 1979-2017 to calculate ET, we found that the global terrestrial ET showed an increasing trend until 1998, while the trend started to decline afterwards. Such decline was largely associated with a reduced RH, inducing water stress conditions that triggered stomatal closure to conserve water. For the first time, this study quantified the global-scale implications of changes in RH on terrestrial ET, indicating that the temperature-driven acceleration of the terrestrial water cycle will be likely constrained by terrestrial vegetation feedbacks. |
BibTeX:
@article{Xiao2020,
author = {Xiao, Mingzhong and Yu, Zhongbo and Kong, Dongdong and Gu, Xihui and Mammarella, Ivan and Montagnani, Leonardo and Arain, M Altaf and Merbold, Lutz and Magliulo, Vincenzo and Lohila, Annalea and Buchmann, Nina and Wolf, Sebastian and Gharun, Mana and Hörtnagl, Lukas and Beringer, Jason and Gioli, Beniamino},
title = {Stomatal response to decreased relative humidity constrains the acceleration of terrestrial evapotranspiration},
journal = {Environmental Research Letters},
year = {2020},
volume = {15},
number = {9},
doi = {10.1088/1748-9326/ab9967}
}
|
| Yang S, Zhang J, Zhang S, Wang J, Bai Y, Yao F and Guo H (2020), "The potential of remote sensing-based models on global water-use efficiency estimation: An evaluation and intercomparison of an ecosystem model (BESS) and algorithm (MODIS) using site level and upscaled eddy covariance data", Agricultural and Forest Meteorology., jun, 2020. Vol. 287 Elsevier B.V.. |
| Abstract: Ecosystem water-use efficiency (WUE) is a critical indicator to investigate the interaction between the terrestrial ecosystem carbon and water cycles. WUE, estimated from gross primary productivity (GPP) and evapotranspiration (ET) based on remote sensing (RS)-based ecosystem models and algorithms (e.g., MODIS (MODerate resolution Imaging Spectroradiometer), BESS (Breathing Earth System Simulator)), have been used to quantify the spatiotemporal dynamics of WUE and its responses to environmental changes. However, few studies have assessed the ability of RS-based ecosystem models and algorithms on global WUE estimation. In this study, we evaluated 8-day and annual WUE from MODIS and BESS among different sites, land cover types and climate zones using the FLUXNET2015 dataset as reference, and conducted spatial intercomparisons of annual WUE between MODIS, BESS and an upscaled FLUXNET dataset (MTE). The site level evaluation results showed that BESS WUE had better performance than MODIS WUE at both 8-day and annual scales. Among different land cover types and climate zones, MODIS and BESS WUE performed unsatisfactorily, especially for MODIS WUE in open shrublands and savannas and for BESS WUE in closed shrublands. Additionally, both MODIS and BESS WUE performed poorly in the hot semi-arid climate zone. The spatial intercomparisons over 2001-2011 revealed that BESS WUE had similar spatial patterns of annual WUE and linear trends with MTE WUE over the globe, except at the high latitudes. However, the spatiotemporal patterns of MODIS WUE were different from those of MTE and BESS WUE, particularly in the (sub) tropical arid and semi-arid regions. Our evaluations results suggested that coupling carbon and water cycles into RS-based models could improve their performance on global WUE estimation. Moreover, the performance of MODIS and BESS on global WUE estimation should be further improved, especially for their performance on temporal variation and their performance at the (semi) arid areas and the high latitudes. |
BibTeX:
@article{Yang2020,
author = {Yang, Shanshan and Zhang, Jiahua and Zhang, Sha and Wang, Jingwen and Bai, Yun and Yao, Fengmei and Guo, Huadong},
title = {The potential of remote sensing-based models on global water-use efficiency estimation: An evaluation and intercomparison of an ecosystem model (BESS) and algorithm (MODIS) using site level and upscaled eddy covariance data},
journal = {Agricultural and Forest Meteorology},
publisher = {Elsevier B.V.},
year = {2020},
volume = {287},
doi = {10.1016/j.agrformet.2020.107959}
}
|
| Yu L, Harris E, Henne S, Eggleston S, Steinbacher M, Emmenegger L, Zellweger C and Mohn J (2020), "The isotopic composition of atmospheric nitrous oxide observed at the high-altitude research station Jungfraujoch, Switzerland", Atmospheric Chemistry and Physics., jun, 2020. Vol. 20(11), pp. 6495-6519. |
BibTeX:
@article{Yu2020,
author = {Yu, Longfei and Harris, Eliza and Henne, Stephan and Eggleston, Sarah and Steinbacher, Martin and Emmenegger, Lukas and Zellweger, Christoph and Mohn, Joachim},
title = {The isotopic composition of atmospheric nitrous oxide observed at the high-altitude research station Jungfraujoch, Switzerland},
journal = {Atmospheric Chemistry and Physics},
year = {2020},
volume = {20},
number = {11},
pages = {6495--6519},
url = {https://acp.copernicus.org/articles/20/6495/2020/},
doi = {10.5194/acp-20-6495-2020}
}
|
| Yu D, Yao B, Lin W, Vollmer MK, Ge B, Zhang G, Li Y, Xu H, O’Doherty S, Chen L and Reimann S (2020), "Atmospheric CH3CCl3 observations in China: Historical trends and implications", Atmospheric Research., January, 2020. Vol. 231, pp. 104658. Elsevier BV. |
BibTeX:
@article{Yu2020a,
author = {Yu, Dajiang and Yao, Bo and Lin, Weili and Vollmer, Martin K. and Ge, Baozhu and Zhang, Gen and Li, Yi and Xu, Honghui and O’Doherty, Simon and Chen, Liqu and Reimann, Stefan},
title = {Atmospheric CH3CCl3 observations in China: Historical trends and implications},
journal = {Atmospheric Research},
publisher = {Elsevier BV},
year = {2020},
volume = {231},
pages = {104658},
doi = {10.1016/j.atmosres.2019.104658}
}
|
| Zhang H, Väliranta M, Piilo S, Amesbury MJ, Aquinoâ€López MA, Roland TP, Salminenâ€Paatero S, Paatero J, Lohila A and Tuittila E (2020), "Decreased carbon accumulation feedback driven by climateâ€induced drying of two southern boreal bogs over recent centuries", Global Change Biology., feb, 2020. Vol. 26(4), pp. 2435-2448. Wiley. |
| Abstract: pNorthern boreal peatlands are important ecosystems in modulating global biogeochemical cycles, yet their biological communities and related carbon dynamics are highly sensitive to changes in climate. Despite this, the strength and recent direction of these feedbacks are still unclear. The response of boreal peatlands to climate warming has received relatively little attention compared with other northern peatland types, despite forming a large northern hemisphereâ€wide ecosystem. Here we studied the response of two ombrotrophic boreal peatlands to climate variability over the last ic/i. 200 years for which local meteorological data are available. We used remains from plants and testate amoebae to study historical changes in peatland biological communities. These data were supplemented by peat property (bulk density, carbon and nitrogen content), sup14/supC, sup210/supPb and sup137/supCs analyses and were used to infer changes in peatland hydrology and carbon dynamics. In total, six peat cores, three per study site, were studied that represent different microhabitats: low hummock, high lawn and low lawn. The data show a consistent drying trend over recent centuries, represented mainly as a change from wet habitat iSphagnum/i spp. to dry habitat iS. fuscum/i. Summer temperature and precipitation appeared to be important drivers shaping peatland community and surface moisture conditions. Data from the driest microhabitat studied, low hummock, revealed a clear and strong negative linear correlation (Rsup2/sup = 0.5031, ip/i 0.001) between carbon accumulation rate and peat surface moisture conditions: under dry conditions, less carbon was accumulated. This suggests that at the dry end of the moisture gradient, availability of water regulates carbon accumulation. It can be further linked to the decreased abundance of mixotrophic testate amoebae under drier conditions (Rsup2/sup = 0.4207, ip/i 0.001). Our study implies that if effective precipitation decreases in the future, the carbon uptake capacity of boreal bogs may be threatened./p |
BibTeX:
@article{Zhang2020,
author = {Zhang, Hui and Väliranta, Minna and Piilo, Sanna and Amesbury, Matthew J and Aquinoâ€López, Marco A and Roland, Thomas P and Salminenâ€Paatero, Susanna and Paatero, Jussi and Lohila, Annalea and Tuittila, Eevaâ€Stiina},
title = {Decreased carbon accumulation feedback driven by climateâ€induced drying of two southern boreal bogs over recent centuries},
journal = {Global Change Biology},
publisher = {Wiley},
year = {2020},
volume = {26},
number = {4},
pages = {2435--2448},
doi = {10.1111/gcb.15005}
}
|
| Zhang H, Goll DS, Wang YP, Ciais P, Wieder WR, Abramoff R, Huang Y, Guenet B, Prescher AK, Viscarra Rossel RA, Barré P, Chenu C, Zhou G and Tang X (2020), "Microbial dynamics and soil physicochemical properties explain large-scale variations in soil organic carbon", Global Change Biology., feb, 2020. Vol. 26(4), pp. 2668-2685. Wiley. |
| Abstract: First-order organic matter decomposition models are used within most Earth System Models (ESMs) to project future global carbon cycling; these models have been criticized for not accurately representing mechanisms of soil organic carbon (SOC) stabilization and SOC response to climate change. New soil biogeochemical models have been developed, but their evaluation is limited to observations from laboratory incubations or few field experiments. Given the global scope of ESMs, a comprehensive evaluation of such models is essential using in situ observations of a wide range of SOC stocks over large spatial scales before their introduction to ESMs. In this study, we collected a set of in situ observations of SOC, litterfall and soil properties from 206 sites covering different forest and soil types in Europe and China. These data were used to calibrate the model MIMICS (The MIcrobial-MIneral Carbon Stabilization model), which we compared to the widely used first-order model CENTURY. We show that, compared to CENTURY, MIMICS more accurately estimates forest SOC concentrations and the sensitivities of SOC to variation in soil temperature, clay content and litter input. The ratios of microbial biomass to total SOC predicted by MIMICS agree well with independent observations from globally distributed forest sites. By testing different hypotheses regarding (using alternative process representations) the physicochemical constraints on SOC deprotection and microbial turnover in MIMICS, the errors of simulated SOC concentrations across sites were further decreased. We show that MIMICS can resolve the dominant mechanisms of SOC decomposition and stabilization and that it can be a reliable tool for predictions of terrestrial SOC dynamics under future climate change. It also allows us to evaluate at large scale the rapidly evolving understanding of SOC formation and stabilization based on laboratory and limited filed observation. |
BibTeX:
@article{Zhang2020a,
author = {Zhang, Haicheng and Goll, Daniel S and Wang, Ying Ping and Ciais, Philippe and Wieder, William R and Abramoff, Rose and Huang, Yuanyuan and Guenet, Bertrand and Prescher, Anne Katrin and Viscarra Rossel, Raphael A and Barré, Pierre and Chenu, Claire and Zhou, Guoyi and Tang, Xuli},
title = {Microbial dynamics and soil physicochemical properties explain large-scale variations in soil organic carbon},
journal = {Global Change Biology},
publisher = {Wiley},
year = {2020},
volume = {26},
number = {4},
pages = {2668--2685},
doi = {10.1111/gcb.14994}
}
|
| Zhang W, Yu G, Chen Z, Zhang L, Wang Q, Zhang Y, He H, Han L, Chen S, Han S, Li Y, Sha L, Shi P, Wang H, Wang Y, Xiang W, Yan J, Zhang Y, Zona D, Arain MA, Maximov T, Oechel W and Kosugi Y (2020), "Attribute parameter characterized the seasonal variation of gross primary productivity (αGPP): Spatiotemporal variation and influencing factors", Agricultural and Forest Meteorology., jan, 2020. Vol. 280 Elsevier B.V.. |
| Abstract: The seasonal dynamic of gross primary productivity (GPP) has influences on the annual GPP (AGPP) of the terrestrial ecosystem. However, the spatiotemporal variation of the seasonal dynamic of GPP and its effects on spatial and temporal variations of AGPP are still poorly addressed. In this study, we developed a parameter, αGPP, defined as the ratio of mean daily GPP (GPPmean) to the maximum daily GPP (GPPmax) during the growing season, to analyze the seasonal dynamic of GPP based on Weibull function. The αGPP was a comprehensive parameter characterizing the shape, scale, and location of the seasonal dynamic curve of GPP. We calculated αGPP based on the data of GPP for 942 site-years from 115 flux sites in the Northern Hemisphere, and analyzed the spatiotemporal variation and influencing factors of the αGPP. We found that the αGPP of terrestrial ecosystems in the Northern Hemisphere ranged from 0.47 to 0.85, with an average of 0.62 ± 0.06. The αGPP varied significantly both among different climatic zones and different ecosystem types. The αGPP was stable on the interannual scale, while decreased as latitude increased, which was consistent across different ecosystem types. The spatial pattern of the seasonal dynamic of astronomical radiation was the dominating factor of the spatial pattern of αGPP, that was, the spatial pattern of the seasonal dynamic of astronomical radiation determined that of the seasonal dynamic of GPP by controlling that of seasonal dynamics of total radiation and temperature. In addition, we assessed the spatial variation of AGPP preliminarily based on αGPP and other seasonal dynamic parameters of GPP, indicating that the understanding of the spatiotemporal variation of αGPP could provide a new approach for studying the spatial and temporal variations of AGPP and estimating AGPP based on the seasonal dynamic of GPP. |
BibTeX:
@article{Zhang2020b,
author = {Zhang, Weikang and Yu, Guirui and Chen, Zhi and Zhang, Leiming and Wang, Qiufeng and Zhang, Yangjian and He, Honglin and Han, Lang and Chen, Shiping and Han, Shijie and Li, Yingnian and Sha, Liqing and Shi, Peili and Wang, Huimin and Wang, Yanfen and Xiang, Wenhua and Yan, Junhua and Zhang, Yiping and Zona, Donatella and Arain, M. Altaf and Maximov, Trofim and Oechel, Walter and Kosugi, Yoshiko},
title = {Attribute parameter characterized the seasonal variation of gross primary productivity (αGPP): Spatiotemporal variation and influencing factors},
journal = {Agricultural and Forest Meteorology},
publisher = {Elsevier B.V.},
year = {2020},
volume = {280},
doi = {10.1016/j.agrformet.2019.107774}
}
|
| Zhang Y, Commane R, Zhou S, Williams AP and Gentine P (2020), "Light limitation regulates the response of autumn terrestrial carbon uptake to warming", Nature Climate Change., aug, 2020. Nature Research. |
| Abstract: Global warming is projected to shift the phenology and increase the productivity of northern ecosystems1–6. Both changes will further feed back to climate through biophysical and biogeochemical processes and are critical for future prediction7,8. However, it remains unclear whether warming and the extended growing season, especially in autumn, would lead to increased net ecosystem carbon uptake9,10. Here we analyse satellite observations, field measurements and model simulations and show a prevalent radiation limitation on carbon uptake in northern ecosystems, especially in autumn. By comparing the start and end of the growing season estimated from vegetation indices and from solar-induced chlorophyll fluorescence (a proxy for gross primary production11,12 (GPP)), we find a greater change in greenness-based start and end of season than that from GPP, mostly caused by the radiation limitation on photosynthesis. This radiation limitation explains the contrasting responses of autumn net carbon exchanges to warming, using both eddy covariance measurements and model simulations from Coupled Model Intercomparison Project Phase 5. Regions with weak radiation limitation benefit more from warming and enhanced vegetation greenness in autumn, where GPP increases can outweigh the warming-induced respiration carbon losses. With continued warming, radiation limitation will increase and exert a strong upper bound on northern ecosystems to act as carbon sinks. |
BibTeX:
@article{Zhang2020c,
author = {Zhang, Yao and Commane, Róisín and Zhou, Sha and Williams, A. Park and Gentine, Pierre},
title = {Light limitation regulates the response of autumn terrestrial carbon uptake to warming},
journal = {Nature Climate Change},
publisher = {Nature Research},
year = {2020},
doi = {10.1038/s41558-020-0806-0}
}
|
| Zhang Z, Zhang Y, Porcar-Castell A, Joiner J, Guanter L, Yang X, Migliavacca M, Ju W, Sun Z, Chen S, Martini D, Zhang Q, Li Z, Cleverly J, Wang H and Goulas Y (2020), "Reduction of structural impacts and distinction of photosynthetic pathways in a global estimation of GPP from space-borne solar-induced chlorophyll fluorescence", Remote Sensing of Environment., apr, 2020. Vol. 240 Elsevier Inc.. |
| Abstract: Quantifying global photosynthesis remains a challenge due to a lack of accurate remote sensing proxies. Solar-induced chlorophyll fluorescence (SIF) has been shown to be a good indicator of photosynthetic activity across various spatial scales. However, a global and spatially challenging estimate of terrestrial gross primary production (GPP) based on satellite SIF remains unresolved due to the confounding effects of species-specific physical and physiological traits and external factors, such as canopy structure or photosynthetic pathway (C3 or C4). Here we analyze an ensemble of far-red SIF data from OCO-2 satellite and ground observations at multiple sites, using the spectral invariant theory to reduce the effects of canopy structure and to retrieve a structure-corrected total canopy SIF emission (SIFtotal). We find that the relationships between observed canopy-leaving SIF and ecosystem GPP vary significantly among biomes. In contrast, the relationships between SIFtotal and GPP converge around two unique models, one for C3 and one for C4 plants. We show that the two single empirical models can be used to globally scale satellite SIF observations to terrestrial GPP. We obtain an independent estimate of global terrestrial GPP of 129.56 ± 6.54 PgC/year for the 2015–2017 period, which is consistent with the state-of-the-art data- and process-oriented models. The new GPP product shows improved sensitivity to previously undetected ‘hotspots' of productivity, being able to resolve the double-peak in GPP due to rotational cropping systems. We suggest that the direct scheme to estimate GPP presented here, which is based on satellite SIF, may open up new possibilities to resolve the dynamics of global terrestrial GPP across space and time. |
BibTeX:
@article{Zhang2020d,
author = {Zhang, Zhaoying and Zhang, Yongguang and Porcar-Castell, Albert and Joiner, Joanna and Guanter, Luis and Yang, Xi and Migliavacca, Mirco and Ju, Weimin and Sun, Zhigang and Chen, Shiping and Martini, David and Zhang, Qian and Li, Zhaohui and Cleverly, James and Wang, Hezhou and Goulas, Yves},
title = {Reduction of structural impacts and distinction of photosynthetic pathways in a global estimation of GPP from space-borne solar-induced chlorophyll fluorescence},
journal = {Remote Sensing of Environment},
publisher = {Elsevier Inc.},
year = {2020},
volume = {240},
doi = {10.1016/j.rse.2020.111722}
}
|
| Zhang Y, Bastos A, Maignan F, Goll D, Boucher O, Li L, Cescatti A, Vuichard N, Chen X, Ammann C, Altaf Arain M, Andrew Black T, Chojnicki B, Kato T, Mammarella I, Montagnani L, Roupsard O, Sanz MJ, Siebicke L, Urbaniak M, Primo Vaccari F, Wohlfahrt G, Woodgate W and Ciais P (2020), "Modeling the impacts of diffuse light fraction on photosynthesis in ORCHIDEE (v5453) land surface model", Geoscientific Model Development. Vol. 13(11), pp. 5401-5423. |
| Abstract: Aerosol- and cloud-induced changes in diffuse light have important impacts on the global land carbon cycle, as they alter light distribution and photosynthesis in vegetation canopies. However, this effect remains poorly represented or evaluated in current land surface models. Here, we add a light partitioning module and a new canopy light transmission module to the ORCHIDEE (Organising Carbon and Hydrology In Dynamic Ecosystems) land surface model (trunk version, v5453) and use the revised model, ORCHIDEE- DF, to estimate the fraction of diffuse light and its effect on gross primary production (GPP) in a multilayer canopy. We evaluate the new parameterizations using flux observations from 159 eddy covariance sites over the globe. Our results show that, compared with the original model, ORCHIDEE-DF improves the GPP simulation under sunny conditions and captures the observed higher photosynthesis under cloudier conditions in most plant functional types (PFTs). Our results also indicate that the larger GPP under cloudy conditions compared with sunny conditions is mainly driven by increased diffuse light in the morning and in the afternoon as well as by a decreased vapor pressure deficit (VPD) and decreased air temperature at midday. The observations show that the strongest positive effects of diffuse light on photosynthesis are found in the range from 5 to 20 °C and at a VPDtextless1 kPa. This effect is found to decrease when the VPD becomes too large or the temperature falls outside of the abovementioned range, which is likely due to the increasing stomatal resistance to leaf CO2 uptake. ORCHIDEE-DF underestimates the diffuse light effect at low temperature in all PFTs and overestimates this effect at high temperature and at a high VPD in grasslands and croplands. The new model has the potential to better investigate the impact of large-scale aerosol changes and long-term changes in cloudiness on the terrestrial carbon budget, both in the historical period and in the context of future air quality policies and/or climate engineering. |
BibTeX:
@article{Zhang2020e,
author = {Zhang, Yuan and Bastos, Ana and Maignan, Fabienne and Goll, Daniel and Boucher, Olivier and Li, Laurent and Cescatti, Alessandro and Vuichard, Nicolas and Chen, Xiuzhi and Ammann, Christof and Altaf Arain, M and Andrew Black, T and Chojnicki, Bogdan and Kato, Tomomichi and Mammarella, Ivan and Montagnani, Leonardo and Roupsard, Olivier and Sanz, Maria J and Siebicke, Lukas and Urbaniak, Marek and Primo Vaccari, Francesco and Wohlfahrt, Georg and Woodgate, Will and Ciais, Philippe},
title = {Modeling the impacts of diffuse light fraction on photosynthesis in ORCHIDEE (v5453) land surface model},
journal = {Geoscientific Model Development},
year = {2020},
volume = {13},
number = {11},
pages = {5401--5423},
doi = {10.5194/gmd-13-5401-2020}
}
|
| Zweifel R, Etzold S, Sterck F, Gessler A, Anfodillo T, Mencuccini M, von Arx G, Lazzarin M, Haeni M, Feichtinger L, Meusburger K, Knuesel S, Walthert L, Salmon Y, Bose AK, Schoenbeck L, Hug C, De Girardi N, Giuggiola A, Schaub M and Rigling A (2020), "Determinants of legacy effects in pine trees – implications from an irrigation‐stop experiment", New Phytologist., aug, 2020. Vol. 227(4), pp. 1081-1096. |
BibTeX:
@article{Zweifel2020,
author = {Zweifel, Roman and Etzold, Sophia and Sterck, Frank and Gessler, Arthur and Anfodillo, Tommaso and Mencuccini, Maurizio and von Arx, Georg and Lazzarin, Martina and Haeni, Matthias and Feichtinger, Linda and Meusburger, Katrin and Knuesel, Simon and Walthert, Lorenz and Salmon, Yann and Bose, Arun K. and Schoenbeck, Leonie and Hug, Christian and De Girardi, Nicolas and Giuggiola, Arnaud and Schaub, Marcus and Rigling, Andreas},
title = {Determinants of legacy effects in pine trees – implications from an irrigation‐stop experiment},
journal = {New Phytologist},
year = {2020},
volume = {227},
number = {4},
pages = {1081--1096},
url = {https://onlinelibrary.wiley.com/doi/abs/10.1111/nph.16582},
doi = {10.1111/nph.16582}
}
|
| Acosta M, Dušek J, Chamizo S, Serrano-Ortiz P and Pavelka M (2019), "Autumnal fluxes of CH4 and CO2 from Mediterranean reed wetland based on eddy covariance and chamber methods", Catena., dec, 2019. Vol. 183, pp. 104191. Elsevier BV. |
| Abstract: Atmospheric methane (CH4) and carbon dioxide (CO2) concentration have been increasing during the last several centuries due to changes in agricultural practices and other anthropogenic activities. Both greenhouse gases (GHGs), have a significant impact on the Earth's radiative balance. GHG effluxes of CH4 and CO2 were measured in a warm Mediterranean wetland in south of Spain. The dominant vegetation cover at the site was by common reed (Phragmites australis) and the measurements were done during short measurement campaign in early autumn 2015. Gas-flux measurements were carried out applying two methods, the eddy covariance (EC) technique and the chamber method (CM). These two methods representing different ecosystem subsets, with EC representing the plant/ecosystem subset and CM representing the water/soil subset. In our measurement campaigns using CM, CH4 emissions ranged from 7.2 to 17.7 mg CH4-C mâˆ'2 dâˆ'1 and CO2 emissions from 0.53 to 1.27 g CO2-C mâˆ'2 dâˆ'1. When using EC, the average fluxes of CH4 and CO2 were 31.4 mg CH4-C mâˆ'2 dâˆ'1 and 1.32 g CO2-C mâˆ'2 dâˆ'1, respectively. Relationships between gas fluxes (CO2 and CH4) measured by the EC method were quite closely correlated with photosynthetically active solar radiation. Our results showed higher CO2 carbon released from the water/soil ecosystem subset in comparison to plants subset. On the other hand, the estimated CH4 carbon balance for the plant/ecosystem subset was about twice that of the water/soil ecosystem subset. Overall, we showed that EC and CM methods cover different areas making EC advantageous for integrated measurements over larger areas, while the CM approach is suitable for local and spatially well constrained flux measurements. Hence, EC and CM methods should be seen as complementary rather than fully comparable methods. |
BibTeX:
@article{Acosta2019,
author = {Acosta, Manuel and Dušek, JiÅ™í and Chamizo, S and Serrano-Ortiz, Penelope and Pavelka, Marian},
title = {Autumnal fluxes of CH4 and CO2 from Mediterranean reed wetland based on eddy covariance and chamber methods},
journal = {Catena},
publisher = {Elsevier BV},
year = {2019},
volume = {183},
pages = {104191},
doi = {10.1016/j.catena.2019.104191}
}
|
| Agustí-Panareda A, Diamantakis M, Massart S, Chevallier F, Muñoz-Sabater J, Barré J, Curcoll R, Engelen R, Langerock B, Law RM, Loh Z, Morguí JA, Parrington M, Peuch VH, Ramonet M, Roehl C, Vermeulen AT, Warneke T and Wunch D (2019), "Modelling CO2 weather-why horizontal resolution matters", Atmospheric Chemistry and Physics., jun, 2019. Vol. 19(11), pp. 7347-7376. |
| Abstract: Climate change mitigation efforts require information on the current greenhouse gas atmospheric concentrations and their sources and sinks. Carbon dioxide (CO2) is the most abundant anthropogenic greenhouse gas. Its variability in the atmosphere is modulated by the synergy between weather and CO2 surface fluxes, often referred to as CO2 weather. It is interpreted with the help of global or regional numerical transport models, with horizontal resolutions ranging from a few hundreds of kilometres to a few kilometres. Changes in the model horizontal resolution affect not only atmospheric transport but also the representation of topography and surface CO2 fluxes. This paper assesses the impact of horizontal resolution on the simulated atmospheric CO2 variability with a numerical weather prediction model. The simulations are performed using the Copernicus Atmosphere Monitoring Service (CAMS) CO2 forecasting system at different resolutions from 9 to 80 km and are evaluated using in situ atmospheric surface measurements and atmospheric column-mean observations of CO2, as well as radiosonde and SYNOP observations of the winds. The results indicate that both diurnal and day-to-day variability of atmospheric CO2 are generally better represented at high resolution, as shown by a reduction in the errors in simulated wind and CO2. Mountain stations display the largest improvements at high resolution as they directly benefit from the more realistic orography. In addition, the CO2 spatial gradients are generally improved with increasing resolution for both stations near the surface and those observing the total column, as the overall inter-station error is also reduced in magnitude. However, close to emission hotspots, the high resolution can also lead to a deterioration of the simulation skill, highlighting uncertainties in the high-resolution fluxes that are more diffuse at lower resolutions. We conclude that increasing horizontal resolution matters for modelling CO2 weather because it has the potential to bring together improvements in the surface representation of both winds and CO2 fluxes, as well as an expected reduction in numerical errors of transport. Modelling applications like atmospheric inversion systems to estimate surface fluxes will only be able to benefit fully from upgrades in horizontal resolution if the topography, winds and prior flux distribution are also upgraded accordingly. It is clear from the results that an additional increase in resolution might reduce errors even further. However, the horizontal resolution sensitivity tests indicate that the change in the CO2 and wind modelling error with resolution is not linear, making it difficult to quantify the improvement beyond the tested resolutions. Finally, we show that the high-resolution simulations are useful for the assessment of the small-scale variability of CO2 which cannot be represented in coarser-resolution models. These representativeness errors need to be considered when assimilating in situ data and high-resolution satellite data such as Greenhouse gases Observing Satellite (GOSAT), Orbiting Carbon Observatory-2 (OCO-2), the Chinese Carbon Dioxide Observation Satellite Mission (TanSat) and future missions such as the Geostationary Carbon Observatory (GeoCarb) and the Sentinel satellite constellation for CO2. For these reasons, the high-resolution CO2 simulations provided by the CAMS in real time can be useful to estimate such small-scale variability in real time, as well as providing boundary conditions for regional modelling studies and supporting field experiments. |
BibTeX:
@article{Agusti-Panareda2019,
author = {Agustí-Panareda, Anna and Diamantakis, Michail and Massart, Sébastien and Chevallier, Frédéric and Muñoz-Sabater, Joaquín and Barré, Jérôme and Curcoll, Roger and Engelen, Richard and Langerock, Bavo and Law, Rachel M and Loh, Zoë and Morguí, Josep Anton and Parrington, Mark and Peuch, Vincent Henri and Ramonet, Michel and Roehl, Coleen and Vermeulen, Alex T and Warneke, Thorsten and Wunch, Debra},
title = {Modelling CO2 weather-why horizontal resolution matters},
journal = {Atmospheric Chemistry and Physics},
year = {2019},
volume = {19},
number = {11},
pages = {7347--7376},
url = {https://www.atmos-chem-phys.net/19/7347/2019/},
doi = {10.5194/acp-19-7347-2019}
}
|
| Alice Courtois E, Stahl C, Burban B, Van Den Berge J, Berveiller D, Bréchet L, Larned Soong J, Arriga N, Peñuelas J and August Janssens I (2019), "Automatic high-frequency measurements of full soil greenhouse gas fluxes in a tropical forest", Biogeosciences., feb, 2019. Vol. 16(3), pp. 785-796. Copernicus GmbH. |
| Abstract: Measuring in situ soil fluxes of carbon dioxide (CO 2 ), methane (CH 4 ), and nitrous oxide (N 2 O) continuously at high frequency requires appropriate technology. We tested the combination of a commercial automated soil CO 2 flux chamber system (LI-8100A) with a CH 4 and N 2 O analyzer (Picarro G2308) in a tropical rainforest for 4 months. A chamber closure time of 2 min was sufficient for a reliable estimation of CO 2 and CH 4 fluxes (100% and 98.5% of fluxes were above minimum detectable flux - MDF, respectively). This closure time was generally not suitable for a reliable estimation of the low N 2 O fluxes in this ecosystem but was sufficient for detecting rare major peak events. A closure time of 25 min was more appropriate for reliable estimation of most N 2 O fluxes (85.6% of measured fluxes are above MDF±0.002 nmolm -2 s -1 ). Our study highlights the importance of adjusted closure time for each gas. |
BibTeX:
@article{AliceCourtois2019,
author = {Alice Courtois, Elodie and Stahl, Clément and Burban, Benoit and Van Den Berge, Joke and Berveiller, Daniel and Bréchet, Laëtitia and Larned Soong, Jennifer and Arriga, Nicola and Peñuelas, Josep and August Janssens, Ivan},
title = {Automatic high-frequency measurements of full soil greenhouse gas fluxes in a tropical forest},
journal = {Biogeosciences},
publisher = {Copernicus GmbH},
year = {2019},
volume = {16},
number = {3},
pages = {785--796},
doi = {10.5194/bg-16-785-2019}
}
|
| Alves M, Music B, Nadeau DF and Anctil F (2019), "Comparing the Performance of the Maximum Entropy Production Model With a Land Surface Scheme in Simulating Surface Energy Fluxes", Journal of Geophysical Research: Atmospheres., mar, 2019. Vol. 124(6), pp. 3279-3300. Blackwell Publishing Ltd. |
| Abstract: Hydrological projections under future climate change have been shown to be sensitive to the formulation of evapotranspiration. Many hydrological models still rely on empirical formulations of this flux, and hence do not take into account the surface energy budget. On the other hand, land surface schemes, which are used within the climate models to describe land hydrology and associated surface heat fluxes (SHF), rely on the energy conservation. Due to land surface schemes complexity, they are not suitable for integration in traditional hydrological models. A newly developed and relatively simple Maximum Entropy Production model, which operates under the constraint of energy conservation and allows for an appropriate partitioning of available energy into SHF, appears to be a good alternative for integration in hydrological models. However, the MEP's performances still need to be evaluated under various environmental conditions. This study aims to evaluate the SHF simulated by MEP using observations over a multiyear period from several carefully chosen snow-free sites located in low-latitude regions. Moreover, simulated fluxes were compared to those derived from the Canadian Land Surface Scheme (CLASS), which was run at the same sites. The analysis of simulated and observed fluxes associated with different water stress conditions suggests that the abilities of MEP and CLASS in estimating sensible and latent heat fluxes are comparable. It was also found that the MEP and CLASS fluxes are in a good agreement with observations. However, the simulated nocturnal fluxes show that both models are in less agreement with the observations. |
BibTeX:
@article{Alves2019,
author = {Alves, M. and Music, B. and Nadeau, D. F. and Anctil, F.},
title = {Comparing the Performance of the Maximum Entropy Production Model With a Land Surface Scheme in Simulating Surface Energy Fluxes},
journal = {Journal of Geophysical Research: Atmospheres},
publisher = {Blackwell Publishing Ltd},
year = {2019},
volume = {124},
number = {6},
pages = {3279--3300},
doi = {10.1029/2018JD029282}
}
|
| Araujo M, Noriega C, Medeiros C, Lefèvre N, Ibánhez JSP, Flores Montes M, da Silva AC and Santos MdL (2019), "On the variability in the CO2 system and water productivity in the western tropical Atlantic off North and Northeast Brazil", Journal of Marine Systems., jan, 2019. Vol. 189, pp. 62-77. Elsevier BV. |
| Abstract: A high-resolution nutrient biochemistry and carbonate system surface synoptic data set from the N-NE Brazilian continental shelf was reanalyzed to fill a gap in the time series of the carbonate system in the region and to allow us to perform a historical analysis of its evolution in recent years. We used data collected from 7 oceanographic cruises (n = 852) undertaken between March 1995 and September 2001 during the Brazilian Program “REVIZEE†in the North (N) and Northeast (NE) Economical Exclusive Zones of Brazil. Measured temperature and salinity data, which exhibited strong fluctuations (25.5 °C – 29.5 °C and 13.2–37.4 units, respectively), showed significant differences between the N and NE campaigns. The concentrations of dissolved inorganic nitrogen (DIN), PO4âˆ' and SiO2âˆ' were higher in the N region than in the NE region, mainly due to fluvial transport, and nitrogen: phosphorus (N:P) ratios of 16 and oxygen supersaturation were observed within the Amazon plume. The concentrations of riverine nutrients in the N region support primary production occurring in the offshore plume area. The calculated total alkalinity (1031–2437 μmol kgâˆ'1) values showed strong spatial variations that were mainly associated with the Amazon plume. The calculated pCO2 values reached 423 μatm offshore in the NE region during boreal winter. The calculated sea-air CO2 fluxes (average: +0.3 ± 1.7 mmol mâˆ'2 dâˆ'1; range: âˆ'1.2 to +2.0 mmol mâˆ'2 dâˆ'1) showed spatial and temporal variations, with negative values (sink) in the region of the Amazon River plume and positive values (source) offshore in the NE region (4°S to 12°S). The variability in the sea-air CO2 fluxes in the N and NE regions was explained by variations in biological activity and the thermodynamic effect of temperature, respectively. The analysis of available data, complemented with those presented here, indicated that the surface water pCO2 values showed a positive temporal trend (+1.10 ± 0.2 μatm yrâˆ'1) in the NE region during the period of 1987–2010. This rate of increase is lower than that verified to have occurred in the atmosphere (+1.72 ± 0.01 μatm yrâˆ'1) during the same period. |
BibTeX:
@article{Araujo2019,
author = {Araujo, Moacyr and Noriega, Carlos and Medeiros, Carmen and Lefèvre, Nathalie and Ibánhez, J Severino P and Flores Montes, Manuel and da Silva, Alex Costa and Santos, Maria de Lourdes},
title = {On the variability in the CO2 system and water productivity in the western tropical Atlantic off North and Northeast Brazil},
journal = {Journal of Marine Systems},
publisher = {Elsevier BV},
year = {2019},
volume = {189},
pages = {62--77},
doi = {10.1016/j.jmarsys.2018.09.008}
}
|
| Ariza-Carricondo C, Di Mauro F, De Beeck MO, Roland M, Gielen B, Vitale D, Ceulemans R and Papale D (2019), "A comparison of different methods for assessing leaf area index in four canopy types", Central European Forestry Journal., jun, 2019. Vol. 65(2), pp. 67-80. Walter de Gruyter GmbH. |
| Abstract: The agreement of Leaf Area Index (LAI) assessments from three indirect methods, i.e. the LAI-2200 Plant Canopy Analyzer, the SS1 SunScan Canopy Analysis System and Digital Hemispherical Photography (DHP) was evaluated for four canopy types, i.e. a short rotation coppice plantation (SRC) with poplar, a Scots pine stand, a Pedunculate oak stand and a maize field. In the SRC and in the maize field, the indirect measurements were compared with direct measurements (litter fall and harvesting). In the low LAI range (0 to 2) the discrepancies of the SS1 were partly explained by the inability to properly account for clumping and the uncertainty of the ellipsoidal leaf angle distribution parameter. The higher values for SS1 in the medium (2 to 6) to high (6 to 8) ranges might be explained by gap fraction saturation for LAI-2200 and DHP above certain values. Wood area index-understood as the woody light-blocking elements from the canopy with respect to diameter growth-accounted for overestimation by all indirect methods when compared to direct methods in the SRC. The inter-comparison of the three indirect methods in the four canopy types showed a general agreement for all methods in the medium LAI range (2 to 6). LAI-2200 and DHP revealed the best agreement among the indirect methods along the entire range of LAI (0 to 8) in all canopy types. SS1 showed some discrepancies with the LAI-2200 and DHP at low (0 to 2) and high ranges of LAI (6 to 8). |
BibTeX:
@article{Ariza-Carricondo2019,
author = {Ariza-Carricondo, Cristina and Di Mauro, Francesca and De Beeck, Maarten Op and Roland, Marilyn and Gielen, Bert and Vitale, Domenico and Ceulemans, Reinhart and Papale, Dario},
title = {A comparison of different methods for assessing leaf area index in four canopy types},
journal = {Central European Forestry Journal},
publisher = {Walter de Gruyter GmbH},
year = {2019},
volume = {65},
number = {2},
pages = {67--80},
doi = {10.2478/forj-2019-0011}
}
|
| Baeten L, Bruelheide H, van der Plas F, Kambach S, Ratcliffe S, Jucker T, Allan E, Ampoorter E, Barbaro L, Bastias CC, Bauhus J, Benavides R, Bonal D, Bouriaud O, Bussotti F, Carnol M, Castagneyrol B, Charbonnier Y, Chećko E, Coomes DA, Dahlgren J, Dawud SM, De Wandeler H, Domisch T, Finér L, Fischer M, Fotelli M, Gessler A, Grossiord C, Guyot V, Hättenschwiler S, Jactel H, Jaroszewicz B, Joly FX, Koricheva J, Lehtonen A, Müller S, Muys B, Nguyen D, Pollastrini M, Radoglou K, Raulund-Rasmussen K, Ruiz-Benito P, Selvi F, Stenlid J, Valladares F, Vesterdal L, Verheyen K, Wirth C, Zavala MA and Scherer-Lorenzen M (2019), "Identifying the tree species compositions that maximize ecosystem functioning in European forests", Journal of Applied Ecology., dec, 2019. Vol. 56(3), pp. 733-744. Wiley. |
| Abstract: Forest ecosystem functioning generally benefits from higher tree species richness, but variation within richness levels is typically large. This is mostly due to the contrasting performances of communities with different compositions. Evidence-based understanding of composition effects on forest productivity, as well as on multiple other functions will enable forest managers to focus on the selection of species that maximize functioning, rather than on diversity per se. We used a dataset of 30 ecosystem functions measured in stands with different species richness and composition in six European forest types. First, we quantified whether the compositions that maximize annual above-ground wood production (productivity) generally also fulfil the multiple other ecosystem functions (multifunctionality). Then, we quantified the species identity effects and strength of interspecific interactions to identify the “best†and “worst†species composition for multifunctionality. Finally, we evaluated the real-world frequency of occurrence of best and worst mixtures, using harmonized data from multiple national forest inventories. The most productive tree species combinations also tended to express relatively high multifunctionality, although we found a relatively wide range of compositions with high- or low-average multifunctionality for the same level of productivity. Monocultures were distributed among the highest as well as the lowest performing compositions. The variation in functioning between compositions was generally driven by differences in the performance of the component species and, to a lesser extent, by particular interspecific interactions. Finally, we found that the most frequent species compositions in inventory data were monospecific stands and that the most common compositions showed below-average multifunctionality and productivity. Synthesis and applications. Species identity and composition effects are essential to the development of high-performing production systems, for instance in forestry and agriculture. They therefore deserve great attention in the analysis and design of functional biodiversity studies if the aim is to inform ecosystem management. A management focus on tree productivity does not necessarily trade-off against other ecosystem functions; high productivity and multifunctionality can be combined with an informed selection of tree species and species combinations. |
BibTeX:
@article{Baeten2019,
author = {Baeten, Lander and Bruelheide, Helge and van der Plas, Fons and Kambach, Stephan and Ratcliffe, Sophia and Jucker, Tommaso and Allan, Eric and Ampoorter, Evy and Barbaro, Luc and Bastias, Cristina C and Bauhus, Jürgen and Benavides, Raquel and Bonal, Damien and Bouriaud, Olivier and Bussotti, Filippo and Carnol, Monique and Castagneyrol, Bastien and Charbonnier, Yohan and Chećko, Ewa and Coomes, David A and Dahlgren, Jonas and Dawud, Seid Muhie and De Wandeler, Hans and Domisch, Timo and Finér, Leena and Fischer, Markus and Fotelli, Mariangela and Gessler, Arthur and Grossiord, Charlotte and Guyot, Virginie and Hättenschwiler, Stephan and Jactel, Hervé and Jaroszewicz, Bogdan and Joly, François Xavier and Koricheva, Julia and Lehtonen, Aleksi and Müller, Sandra and Muys, Bart and Nguyen, Diem and Pollastrini, Martina and Radoglou, Kalliopi and Raulund-Rasmussen, Karsten and Ruiz-Benito, Paloma and Selvi, Federico and Stenlid, Jan and Valladares, Fernando and Vesterdal, Lars and Verheyen, Kris and Wirth, Christian and Zavala, Miguel A and Scherer-Lorenzen, Michael},
editor = {Mori, Akira},
title = {Identifying the tree species compositions that maximize ecosystem functioning in European forests},
journal = {Journal of Applied Ecology},
publisher = {Wiley},
year = {2019},
volume = {56},
number = {3},
pages = {733--744},
doi = {10.1111/1365-2664.13308}
}
|
| Balzarolo M, Valdameri N, Fu YH, Schepers L, Janssens IA and Campioli M (2019), "Different determinants of radiation use efficiency in cold and temperate forests", Global Ecology and Biogeography., aug, 2019. Vol. 28(11), pp. 1649-1667. Wiley. |
| Abstract: Aim: To verify which vegetation and environmental factors are the most important in determining the spatial and temporal variability of average and maximum values of radiation use efficiency (RUEann and RUEmax, respectively) of cold and temperate forests. Location: Forty-eight cold and temperate forests distributed across the Northern Hemisphere. Major taxa studied: Evergreen and deciduous trees. Time period: 2000–2011. Methods: We analysed the impact of 17 factors as potential determinants of mean RUE (at 8 days interval, annual and interannual level) and RUEmax (at annual and interannual level) in cold and temperate forests by using linear regression and random forests models. Results: Mean annual RUE (RUEann, c. 1.1 gC/MJ) and RUEmax (c. 0.8 gC/MJ) did not differ between cold and temperate forests. However, for cold forests, RUEann was affected by temperature-related variables, while for temperate forests RUEann was affected by drought-related variables. Leaf area index (LAI) was important for both forest types, while N deposition only for cold forests and cloud cover only for temperate forest. RUEmax of cold forests was mainly driven by N deposition and LAI, whereas for temperate forests only a weak relationship between RUEmax and CO2 concentration was found. Short-term variability of RUE was strongly related to the meteorological variables and varied during the season and was stronger in summer than spring or autumn. Interannual variability of RUEann and RUEmax was only weakly related to the interannual variability of the environmental drivers. Main conclusions: Cold and temperate forests show different relationships with the environment and vegetation properties. Among the RUE drivers observed, the least anticipated was N deposition. RUE is strongly related to short-term and seasonal changes in meteorological variables among seasons and among sites. Our results should be considered in the formulation of climate zone-specific tools for remote sensing and global models. |
BibTeX:
@article{Balzarolo2019,
author = {Balzarolo, Manuela and Valdameri, Nadia and Fu, Yongshuo H and Schepers, Lennert and Janssens, Ivan A and Campioli, Matteo},
editor = {Kerkhoff, Andrew},
title = {Different determinants of radiation use efficiency in cold and temperate forests},
journal = {Global Ecology and Biogeography},
publisher = {Wiley},
year = {2019},
volume = {28},
number = {11},
pages = {1649--1667},
doi = {10.1111/geb.12985}
}
|
| Bange HW, Arévalo-Martínez DL, de la Paz M, Farías L, Kaiser J, Kock A, Law CS, Rees AP, Rehder G, Tortell PD, Upstill-Goddard RC and Wilson ST (2019), "A harmonized nitrous oxide (N 2 O) ocean observation network for the 21st century", Frontiers in Marine Science., apr, 2019. Vol. 6(APR) Frontiers Media SA. |
| Abstract: Nitrous oxide (N 2 O) is an important atmospheric trace gas involved in tropospheric warming and stratospheric ozone depletion. Estimates of the global ocean contribution to N 2 O emissions average 21% (range: 10 to 53%). Ongoing environmental changes such as warming, deoxygenation and acidification are affecting oceanic N 2 O cycling and emissions to the atmosphere. International activities over the last decades aimed at improving estimates of global N 2 O emissions, including (i) the MarinE MethanE and NiTrous Oxide database (MEMENTO) for archiving of quality-controlled data, and (ii) a recent large-scale inter-laboratory comparison by Working Group 143 of the Scientific Committee on Ocean Research (SCOR). To reduce uncertainties in oceanic N 2 O emission estimates and to characterize the spatial and temporal variability in N 2 O distributions in a changing ocean, we propose the establishment of a harmonized N 2 O Observation Network (N 2 O-ON) combining discrete and continuous data from various platforms. The network will integrate observations obtained by calibrated techniques, using time series measurements at fixed stations and repeated hydrographic sections on voluntary observing ships and research vessels. In addition to exploiting existing oceanographic infrastructure, we propose the establishment of central calibration facilities in selected international laboratories to improve accuracy, and ensure standardization and comparability of N 2 O measurements. Final data products will include a harmonized global N 2 O concentration and emission fields for use in model validation and projections of future oceanic N 2 O emissions, to inform the global research community and policy makers. |
BibTeX:
@article{Bange2019,
author = {Bange, Hermann W and Arévalo-Martínez, Damian L and de la Paz, Mercedes and Farías, Laura and Kaiser, Jan and Kock, Annette and Law, Cliff S and Rees, Andrew P and Rehder, Gregor and Tortell, Philippe D and Upstill-Goddard, Robert C and Wilson, Samuel T},
title = {A harmonized nitrous oxide (N 2 O) ocean observation network for the 21st century},
journal = {Frontiers in Marine Science},
publisher = {Frontiers Media SA},
year = {2019},
volume = {6},
number = {APR},
doi = {10.3389/fmars.2019.00157}
}
|
| Bastos A, Ciais P, Chevallier F, Rödenbeck C, Ballantyne AP, Maignan F, Yin Y, Fernández-Martínez M, Friedlingstein P, Peñuelas J, Piao SL, Sitch S, Smith WK, Wang X, Zhu Z, Haverd V, Kato E, Jain AK, Lienert S, Lombardozzi D, Nabel JEMS, Peylin P, Poulter B and Zhu D (2019), "Contrasting effects of CO2 fertilization, land-use change and warming on seasonal amplitude of Northern Hemisphere CO2 exchange", Atmospheric Chemistry and Physics., oct, 2019. Vol. 19(19), pp. 12361-12375. Copernicus GmbH. |
| Abstract: Continuous atmospheric CO2 monitoring data indicate an increase in the amplitude of seasonal CO2-cycle exchange (SCANBP) in northern high latitudes. The major drivers of enhanced SCANBP remain unclear and intensely debated, with land-use change, CO2 fertilization and warming being identified as likely contributors. We integrated CO2-flux data from two atmospheric inversions (consistent with atmospheric records) and from 11 state-of-the-art land-surface models (LSMs) to evaluate the relative importance of individual contributors to trends and drivers of the SCANBP of CO2 fluxes for 1980-2015. The LSMs generally reproduce the latitudinal increase in SCANBP trends within the inversions range. Inversions and LSMs attribute SCANBP increase to boreal Asia and Europe due to enhanced vegetation productivity (in LSMs) and point to contrasting effects of CO2 fertilization (positive) and warming (negative) on SCANBP. Our results do not support land-use change as a key contributor to the increase in SCANBP. The sensitivity of simulated microbial respiration to temperature in LSMs explained biases in SCANBP trends, which suggests that SCANBP could help to constrain model turnover times. |
BibTeX:
@article{Bastos2019,
author = {Bastos, Ana and Ciais, Philippe and Chevallier, Frédéric and Rödenbeck, Christian and Ballantyne, Ashley P and Maignan, Fabienne and Yin, Yi and Fernández-Martínez, Marcos and Friedlingstein, Pierre and Peñuelas, Josep and Piao, Shilong L and Sitch, Stephen and Smith, William K and Wang, Xuhui and Zhu, Zaichun and Haverd, Vanessa and Kato, Etsushi and Jain, Atul K and Lienert, Sebastian and Lombardozzi, Danica and Nabel, Julia E M S and Peylin, Philippe and Poulter, Benjamin and Zhu, Dan},
title = {Contrasting effects of CO2 fertilization, land-use change and warming on seasonal amplitude of Northern Hemisphere CO2 exchange},
journal = {Atmospheric Chemistry and Physics},
publisher = {Copernicus GmbH},
year = {2019},
volume = {19},
number = {19},
pages = {12361--12375},
doi = {10.5194/acp-19-12361-2019}
}
|
| Bechtold M, De Lannoy GJM, Koster RD, Reichle RH, Mahanama SP, Bleuten W, Bourgault MA, Brümmer C, Burdun I, Desai AR, Devito K, Grünwald T, Grygoruk M, Humphreys ER, Klatt J, Kurbatova J, Lohila A, Munir TM, Nilsson MB, Price JS, Röhl M, Schneider A and Tiemeyer B (2019), "PEAT-CLSM: A Specific Treatment of Peatland Hydrology in the NASA Catchment Land Surface Model", Journal of Advances in Modeling Earth Systems., jul, 2019. Vol. 11(7), pp. 2130-2162. |
| Abstract: Peatlands are poorly represented in global Earth system modeling frameworks. Here we add a peatland-specific land surface hydrology module (PEAT-CLSM) to the Catchment Land Surface Model (CLSM) of the NASA Goddard Earth Observing System (GEOS) framework. The amended TOPMODEL approach of the original CLSM that uses topography characteristics to model catchment processes is discarded, and a peatland-specific model concept is realized in its place. To facilitate its utilization in operational GEOS efforts, PEAT-CLSM uses the basic structure of CLSM and the same global input data. Parameters used in PEAT-CLSM are based on literature data. A suite of CLSM and PEAT-CLSM simulations for peatland areas between 40°N and 75°N is presented and evaluated against a newly compiled data set of groundwater table depth and eddy covariance observations of latent and sensible heat fluxes in natural and seminatural peatlands. CLSM's simulated groundwater tables are too deep and variable, whereas PEAT-CLSM simulates a mean groundwater table depth of âˆ'0.20 m (snow-free unfrozen period) with moderate temporal fluctuations (standard deviation of 0.10 m), in significantly better agreement with in situ observations. Relative to an operational CLSM version that simply includes peat as a soil class, the temporal correlation coefficient is increased on average by 0.16 and reaches 0.64 for bogs and 0.66 for fens when driven with global atmospheric forcing data. In PEAT-CLSM, runoff is increased on average by 38% and evapotranspiration is reduced by 19%. The evapotranspiration reduction constitutes a significant improvement relative to eddy covariance measurements. |
BibTeX:
@article{Bechtold2019,
author = {Bechtold, M and De Lannoy, G J M and Koster, R D and Reichle, R H and Mahanama, S P and Bleuten, W and Bourgault, M A and Brümmer, C and Burdun, I and Desai, A R and Devito, K and Grünwald, T and Grygoruk, M and Humphreys, E R and Klatt, J and Kurbatova, J and Lohila, A and Munir, T M and Nilsson, M B and Price, J S and Röhl, M and Schneider, A and Tiemeyer, B},
title = {PEAT-CLSM: A Specific Treatment of Peatland Hydrology in the NASA Catchment Land Surface Model},
journal = {Journal of Advances in Modeling Earth Systems},
year = {2019},
volume = {11},
number = {7},
pages = {2130--2162},
url = {https://onlinelibrary.wiley.com/doi/abs/10.1029/2018MS001574},
doi = {10.1029/2018MS001574}
}
|
| Berger C, Bieri M, Bradshaw K, Brümmer C, Clemen T, Hickler T, Kutsch WL, Lenfers UA, Martens C, Midgley GF, Mukwashi K, Odipo V, Scheiter S, Schmullius C, Baade J, du Toit JCO, Scholes RJ, Smit IPJ, Stevens N and Twine W (2019), "Linking scales and disciplines: an interdisciplinary cross-scale approach to supporting climate-relevant ecosystem management", Climatic Change. Vol. 156(1), pp. 139-150. |
| Abstract: Southern Africa is particularly sensitive to climate change, due to both ecological and socio-economic factors, with rural land users among the most vulnerable groups. The provision of information to support climate-relevant decision-making requires an understanding of the projected impacts of change and complex feedbacks within the local ecosystems, as well as local demands on ecosystem services. In this paper, we address the limitation of current approaches for developing management relevant socio-ecological information on the projected impacts of climate change and human activities. We emphasise the need for linking disciplines and approaches by expounding the methodology followed in our two consecutive projects. These projects combine disciplines and levels of measurements from the leaf level (ecophysiology) to the local landscape level (flux measurements) and from the local household level (socio-economic surveys) to the regional level (remote sensing), feeding into a variety of models at multiple scales. Interdisciplinary, multi-scaled, and integrated socio-ecological approaches, as proposed here, are needed to compliment reductionist and linear, scale-specific approaches. Decision support systems are used to integrate and communicate the data and models to the local decision-makers. |
BibTeX:
@article{Berger2019,
author = {Berger, Christian and Bieri, Mari and Bradshaw, Karen and Brümmer, Christian and Clemen, Thomas and Hickler, Thomas and Kutsch, Werner Leo and Lenfers, Ulfia A and Martens, Carola and Midgley, Guy F and Mukwashi, Kanisios and Odipo, Victor and Scheiter, Simon and Schmullius, Christiane and Baade, Jussi and du Toit, Justin C O and Scholes, Robert J and Smit, Izak P J and Stevens, Nicola and Twine, Wayne},
title = {Linking scales and disciplines: an interdisciplinary cross-scale approach to supporting climate-relevant ecosystem management},
journal = {Climatic Change},
year = {2019},
volume = {156},
number = {1},
pages = {139--150},
url = {https://doi.org/10.1007/s10584-019-02544-0}
}
|
| Berhanu TA, Hoffnagle J, Rella C, Kimhak D, Nyfeler P and Leuenberger M (2019), "High-precision atmospheric oxygen measurement comparisons between a newly built CRDS analyzer and existing measurement techniques", Atmospheric Measurement Techniques., dec, 2019. Vol. 12(12), pp. 6803-6826. Copernicus GmbH. |
| Abstract: Carbon dioxide and oxygen are tightly coupled in land biosphere CO2-O2 exchange processes, whereas they are not coupled in oceanic exchange. For this reason, atmospheric oxygen measurements can be used to constrain the global carbon cycle, especially oceanic uptake. However, accurately quantifying small (∼ 1-100 ppm) variations in O2 is analytically challenging due to the very large atmospheric background which constitutes about 20.9%(209500 ppm) of atmospheric air. Here we present a detailed description of a newly developed high-precision oxygen mixing ratio and isotopic composition analyzer (Picarro G2207) that is based on cavity ring-down spectroscopy (CRDS) as well as to its operating principles; we also demonstrate comprehensive laboratory and field studies using the abovementioned instrument. From the laboratory tests, we calculated a shortterm precision (standard error of 1 min O2 mixing ratio measurements) of 1 ppm for this analyzer based on measurements of eight standard gases analyzed for 2 h, respectively. In contrast to the currently existing techniques, the instrument has an excellent long-term stability; therefore, calibration every 12 h is sufficient to get an overall uncertainty of 5 ppm. Measurements of ambient air were also conducted at the Jungfraujoch high-altitude research station and the Beromünster tall tower in Switzerland. At both sites, we observed opposing and diurnally varying CO2 and O2 profiles due to different processes such as combustion, photosynthesis, and respiration. Based on the combined measurements at Beromünster tower, we determined height-dependent O2 V CO2 oxidation ratios varying between -0:98 and -1:60; these ratios increased with the height of the tower inlet, possibly due to different source contributions such as natural gas combustion, which has a high oxidation ratio, and biological processes, which have oxidation ratios that are relatively lower. |
BibTeX:
@article{Berhanu2019,
author = {Berhanu, Tesfaye A and Hoffnagle, John and Rella, Chris and Kimhak, David and Nyfeler, Peter and Leuenberger, Markus},
title = {High-precision atmospheric oxygen measurement comparisons between a newly built CRDS analyzer and existing measurement techniques},
journal = {Atmospheric Measurement Techniques},
publisher = {Copernicus GmbH},
year = {2019},
volume = {12},
number = {12},
pages = {6803--6826},
doi = {10.5194/amt-12-6803-2019}
}
|
| Berhongaray G, Cotrufo FM, Janssens IA and Ceulemans R (2019), "Below-ground carbon inputs contribute more than above-ground inputs to soil carbon accrual in a bioenergy poplar plantation", Plant and Soil., oct, 2019. Vol. 434(1-2), pp. 363-378. Springer Science and Business Media LLC. |
| Abstract: Background and aims: Soil organic carbon (SOC) accrual is central to the discussion on active atmospheric CO 2 removal strategies, but it requires a clear understanding of the mechanisms driving new SOC formation. SOC is formed from the decomposition of above- and below-ground plant inputs, yet their accurate quantification remains a major challenge. In the current study the in-growth soil core and δ 13 C methods were combined to quantify the net C input from single or combined above- and below-ground parts of a poplar (Populus) bioenergy plantation. Methods: Three different mesh sizes were used for the in-growth cores in four different treatments designed to estimate the relative contributions of above-ground litter fall, fine roots and mycorrhizae (C3 input from the poplar) to the new C formation in cores filled with a C4 soil, by applying a mass balance equation. Results: Soil C formation was higher in the treatments with roots as compared to the treatments with above-ground C inputs only (29 vs 16 g C m âˆ'2 ), despite the disproportionally lower root inputs as compared to above-ground C inputs (34 vs 175 g C m âˆ'2 y âˆ'1 ). Soil C formation from different sources (above- and below-ground) was additive; i.e. the observed soil C formation in the combined treatment was the sum of those in the single soil C input treatments. As a result, below-ground C-inputs had a high conversion efficiency to SOC of 76%. Above-ground plant inputs had a very low SOC formation efficiency of 9%, and were presumably mainly mineralized by microorganisms. Conclusion: The higher soil C accumulation rates from below-ground C inputs are particularly important in bioenergy plantations where the above-ground biomass is frequently removed for biomass and energy production. |
BibTeX:
@article{Berhongaray2019,
author = {Berhongaray, Gonzalo and Cotrufo, Francesca M and Janssens, Ivan A and Ceulemans, Reinhart},
title = {Below-ground carbon inputs contribute more than above-ground inputs to soil carbon accrual in a bioenergy poplar plantation},
journal = {Plant and Soil},
publisher = {Springer Science and Business Media LLC},
year = {2019},
volume = {434},
number = {1-2},
pages = {363--378},
doi = {10.1007/s11104-018-3850-z}
}
|
| Besnard S, Carvalhais N, Altaf Arain M, Black A, Brede B, Buchmann N, Chen J, Clevers JGPW, Dutrieux LP, Gans F, Herold M, Jung M, Kosugi Y, Knohl A, Law BE, Paul-Limoges E, Lohila A, Merbold L, Roupsard O, Valentini R, Wolf S, Zhang X and Reichstein M (2019), "Memory effects of climate and vegetation affecting net ecosystem CO2 fluxes in global forests", PLoS ONE., feb, 2019. Vol. 14(2), pp. e0211510. Public Library of Science (PLoS). |
| Abstract: Forests play a crucial role in the global carbon (C) cycle by storing and sequestering a substantial amount of C in the terrestrial biosphere. Due to temporal dynamics in climate and vegetation activity, there are significant regional variations in carbon dioxide (CO2) fluxes between the biosphere and atmosphere in forests that are affecting the global C cycle. Current forest CO2 flux dynamics are controlled by instantaneous climate, soil, and vegetation conditions, which carry legacy effects from disturbances and extreme climate events. Our level of understanding from the legacies of these processes on net CO2 fluxes is still limited due to their complexities and their long-term effects. Here, we combined remote sensing, climate, and eddy-covariance flux data to study net ecosystem CO2 exchange (NEE) at 185 forest sites globally. Instead of commonly used non-dynamic statistical methods, we employed a type of recurrent neural network (RNN), called Long Short-Term Memory network (LSTM) that captures information from the vegetation and climate's temporal dynamics. The resulting data-driven model integrates interannual and seasonal variations of climate and vegetation by using Landsat and climate data at each site. The presented LSTM algorithm was able to effectively describe the overall seasonal variability (Nash-Sutcliffe efficiency, NSE = 0.66) and across-site (NSE = 0.42) variations in NEE, while it had less success in predicting specific seasonal and interannual anomalies (NSE = 0.07). This analysis demonstrated that an LSTM approach with embedded climate and vegetation memory effects outperformed a non-dynamic statistical model (i.e. Random Forest) for estimating NEE. Additionally, it is shown that the vegetation mean seasonal cycle embeds most of the information content to realistically explain the spatial and seasonal variations in NEE. These findings show the relevance of capturing memory effects from both climate and vegetation in quantifying spatio-temporal variations in forest NEE. |
BibTeX:
@article{Besnard2019,
author = {Besnard, Simon and Carvalhais, Nuno and Altaf Arain, M and Black, Andrew and Brede, Benjamin and Buchmann, Nina and Chen, Jiquan and Clevers, Jan G P W and Dutrieux, Loïc P and Gans, Fabian and Herold, Martin and Jung, Martin and Kosugi, Yoshiko and Knohl, Alexander and Law, Beverly E and Paul-Limoges, Eugénie and Lohila, Annalea and Merbold, Lutz and Roupsard, Olivier and Valentini, Riccardo and Wolf, Sebastian and Zhang, Xudong and Reichstein, Markus},
editor = {Hui, Dafeng},
title = {Memory effects of climate and vegetation affecting net ecosystem CO2 fluxes in global forests},
journal = {PLoS ONE},
publisher = {Public Library of Science (PLoS)},
year = {2019},
volume = {14},
number = {2},
pages = {e0211510},
doi = {10.1371/journal.pone.0211510}
}
|
| Bigeard G, Coudert B, Chirouze J, Er-Raki S, Boulet G, Ceschia E and Jarlan L (2019), "Ability of a soil-vegetation-atmosphere transfer model and a two-source energy balance model to predict evapotranspiration for several crops and climate conditions", Hydrology and Earth System Sciences., dec, 2019. Vol. 23(12), pp. 5033-5058. Copernicus GmbH. |
| Abstract: The heterogeneity of Agroecosystems, in terms of hydric conditions, crop types and states, and meteorological forcing, is difficult to characterize precisely at the field scale over an agricultural landscape. This study aims to perform a sensitivity study with respect to the uncertain model inputs of two classical approaches used to map the evapotranspiration of agroecosystems: (1) a surface energy balance (SEB) model, the Two-Source Energy Balance (TSEB) model, forced with thermal infrared (TIR) data as a proxy for the crop hydric conditions, and (2) a soil-vegetation-atmosphere transfer (SVAT) model, the SEtHyS model, where hydric conditions are computed from a soil water budget. To this end, the models skill was compared using a large and unique in situ database covering different crops and climate conditions, which was acquired over three experimental sites in southern France and Morocco. On average, the models provide 30 min estimations of latent heat flux (LE) with a RMSE of around 55Wm-2 for TSEB and 47Wm-2 for SEtHyS, and estimations of sensible heat flux (H) with a RMSE of around 29Wm-2 for TSEB and 38Wm-2 for SEtHyS. A sensitivity analysis based on realistic errors aimed to estimate the potential decrease in performance induced by the spatialization process. For the SVAT model, the multi-objective calibration iterative procedure (MCIP) is used to determine and test different sets of parameters. TSEB is run with only one set of parameters and provides acceptable performance for all crop stages apart from the early growing season (LAI0.2m2 m-2) and when hydric stress occurs. An in-depth study on the Priestley- Taylor key parameter highlights its marked diurnal cycle and the need to adjust its value to improve flux partitioning between the sensible and latent heat fluxes (1.5 and 1.25 for France and Morocco, respectively). Optimal values of 1.8-2 were highlighted under cloudy conditions, which is of particular interest due to the emergence of low-altitude drone acquisition. Under developed vegetation (LAI0.8m2 m-2) and unstressed conditions, using sets of parameters that only differentiate crop types is a valuable trade-off for SEtHyS. This study provides some scientific elements regarding the joint use of both approaches and TIR imagery, via the development of new data assimilation and calibration strategies.. |
BibTeX:
@article{Bigeard2019,
author = {Bigeard, Guillaume and Coudert, Benoit and Chirouze, Jonas and Er-Raki, Salah and Boulet, Gilles and Ceschia, Eric and Jarlan, Lionel},
title = {Ability of a soil-vegetation-atmosphere transfer model and a two-source energy balance model to predict evapotranspiration for several crops and climate conditions},
journal = {Hydrology and Earth System Sciences},
publisher = {Copernicus GmbH},
year = {2019},
volume = {23},
number = {12},
pages = {5033--5058},
doi = {10.5194/hess-23-5033-2019}
}
|
| Billesbach DP, Chan SW, Cook DR, Papale D, Bracho-Garrillo R, Verfallie J, Vargas R and Biraud SC (2019), "Effects of the Gill-Solent WindMaster-Pro “w-boost†firmware bug on eddy covariance fluxes and some simple recovery strategies", Agricultural and Forest Meteorology., feb, 2019. Vol. 265, pp. 145-151. Elsevier BV. |
| Abstract: In late 2015 and early 2016, work done by the AmeriFlux Management Project Technical Team (amerilfux.lbl.gov) helped to uncover an issue with Gill WindMaster and WindMaster Pro sonic anemometers used by many researchers for eddy covariance flux measurements. Gill has addressed this issue and has since sent out a notice that the vertical wind speed component (a critical piece of all eddy covariance fluxes) was being erroneously computed and reported. The problem (known as the “w-boost†bug) resulted in positive (upward) wind speeds being under-reported by 16.6% and negative (downward) wind speeds being under-reported by 28.9%. This has the potential to cause similar under estimates in fluxes derived from measurements using these instruments. Additionally, the bug affects corrections for angle of attack as derived by Nakai and Shimoyama, rendering them invalid. While the manufacturer has offered a firmware upgrade for existing instruments that will fix this issue, many existing data sets have been affected by it and are currently in use by the scientific community. To address the issue of affected data, currently in use, we analyzed multi-year and short-term data sets from a variety of ecosystems to assess methods of correcting existing flux data. We found that simple multiplicative correction factors (∼1.18) may be used to remove most of the “w-boost†bias from fluxes in existing data sets that do not include angle of attack corrections. |
BibTeX:
@article{Billesbach2019,
author = {Billesbach, D P and Chan, S W and Cook, D R and Papale, D and Bracho-Garrillo, R and Verfallie, J and Vargas, R and Biraud, S C},
title = {Effects of the Gill-Solent WindMaster-Pro “w-boost†firmware bug on eddy covariance fluxes and some simple recovery strategies},
journal = {Agricultural and Forest Meteorology},
publisher = {Elsevier BV},
year = {2019},
volume = {265},
pages = {145--151},
doi = {10.1016/j.agrformet.2018.11.010}
}
|
| Bowring SPK, Lauerwald R, Guenet B, Zhu D, Guimberteau M, Tootchi A, Ducharne A and Ciais P (2019), "ORCHIDEE MICT-LEAK (r5459), a global model for the production, transport, and transformation of dissolved organic carbon from Arctic permafrost regions - Part 1: Rationale, model description, and simulation protocol", Geoscientific Model Development., aug, 2019. Vol. 12(8), pp. 3503-3521. Copernicus GmbH. |
| Abstract: Few Earth system models adequately represent the unique permafrost soil biogeochemistry and its respective processes; this significantly contributes to uncertainty in estimating their responses, and that of the planet at large, to warming. Likewise, the riverine component of what is known as the "boundless carbon cycle" is seldom recognised in Earth system modelling. The hydrological mobilisation of organic material from a ∼ 1330-1580 PgC carbon stock to the river network results in either sedimentary settling or atmospheric "evasion", processes widely expected to increase with amplified Arctic climate warming. Here, the production, transport, and atmospheric release of dissolved organic carbon (DOC) from high-latitude permafrost soils into inland waters and the ocean are explicitly represented for the first time in the land surface component (ORCHIDEE) of a CMIP6 global climate model (Institut Pierre Simon Laplace - IPSL). The model, ORCHIDEE MICT-LEAK, which represents the merger of previously described ORCHIDEE versions MICT and LEAK, mechanistically represents (a) vegetation and soil physical processes for high-latitude snow, ice, and soil phenomena and (b) the cycling of DOC and CO2, including atmospheric evasion, along the terrestrial-aquatic continuum from soils through the river network to the coast at 0.5 to 2° resolution. This paper, the first in a two-part study, presents the rationale for including these processes in a high-latitude-specific land surface model, then describes the model with a focus on novel process implementations, followed by a summary of the model configuration and simulation protocol. The results of these simulation runs, conducted for the Lena River basin, are evaluated against observational data in the second part of this study. |
BibTeX:
@article{Bowring2019,
author = {Bowring, Simon P K and Lauerwald, Ronny and Guenet, Bertrand and Zhu, Dan and Guimberteau, Matthieu and Tootchi, Ardalan and Ducharne, Agnès and Ciais, Philippe},
title = {ORCHIDEE MICT-LEAK (r5459), a global model for the production, transport, and transformation of dissolved organic carbon from Arctic permafrost regions - Part 1: Rationale, model description, and simulation protocol},
journal = {Geoscientific Model Development},
publisher = {Copernicus GmbH},
year = {2019},
volume = {12},
number = {8},
pages = {3503--3521},
doi = {10.5194/gmd-12-3503-2019}
}
|
| Box JE, Colgan WT, Christensen TR, Schmidt NM, Lund M, Parmentier FJW, Brown R, Bhatt US, Euskirchen ES, Romanovsky VE, Walsh JE, Overland JE, Wang M, Corell RW, Meier WN, Wouters B, Mernild S, Mård J, Pawlak J and Olsen MS (2019), "Key indicators of Arctic climate change: 1971-2017", Environmental Research Letters., apr, 2019. Vol. 14(4), pp. 45010. IOP Publishing. |
| Abstract: Key observational indicators of climate change in the Arctic, most spanning a 47 year period (1971-2017) demonstrate fundamental changes among nine key elements of the Arctic system. We find that, coherent with increasing air temperature, there is an intensification of the hydrological cycle, evident from increases in humidity, precipitation, river discharge, glacier equilibrium line altitude and land ice wastage. Downward trends continue in sea ice thickness (and extent) and spring snow cover extent and duration, while near-surface permafrost continues to warm. Several of the climate indicators exhibit a significant statistical correlation with air temperature or precipitation, reinforcing the notion that increasing air temperatures and precipitation are drivers of major changes in various components of the Arctic system. To progress beyond a presentation of the Arctic physical climate changes, we find a correspondence between air temperature and biophysical indicators such as tundra biomass and identify numerous biophysical disruptions with cascading effects throughout the trophic levels. These include: increased delivery of organic matter and nutrients to Arctic near-coastal zones; condensed flowering and pollination plant species periods; timing mismatch between plant flowering and pollinators; increased plant vulnerability to insect disturbance; increased shrub biomass; increased ignition of wildfires; increased growing season CO2 uptake, with counterbalancing increases in shoulder season and winter CO2 emissions; increased carbon cycling, regulated by local hydrology and permafrost thaw; conversion between terrestrial and aquatic ecosystems; and shifting animal distribution and demographics. The Arctic biophysical system is now clearly trending away from its 20th Century state and into an unprecedented state, with implications not only within but beyond the Arctic. The indicator time series of this study are freely downloadable at AMAP.no. |
BibTeX:
@article{Box2019,
author = {Box, Jason E and Colgan, William T and Christensen, Torben Røjle and Schmidt, Niels Martin and Lund, Magnus and Parmentier, Frans Jan W and Brown, Ross and Bhatt, Uma S and Euskirchen, Eugénie S and Romanovsky, Vladimir E and Walsh, John E and Overland, James E and Wang, Muyin and Corell, Robert W and Meier, Walter N and Wouters, Bert and Mernild, Sebastian and Mård, Johanna and Pawlak, Janet and Olsen, Morten Skovgård},
title = {Key indicators of Arctic climate change: 1971-2017},
journal = {Environmental Research Letters},
publisher = {IOP Publishing},
year = {2019},
volume = {14},
number = {4},
pages = {45010},
doi = {10.1088/1748-9326/aafc1b}
}
|
| Brændholt A, Ibrom A, Ambus P, Larsen KS and Pilegaard K (2019), "Combining a quantum cascade laser spectrometer with an automated closed-chamber system for δ13C measurements of forest soil, tree stem and tree root CO2 fluxess", Forests., may, 2019. Vol. 10(5), pp. 432. MDPI AG. |
| Abstract: Recent advances in laser spectroscopy have allowed for real-time measurements of the 13C/12C isotopic ratio in CO2, thereby providing new ways to investigate carbon cycling in natural ecosystems. In this study, we combined an Aerodyne quantum cascade laser spectrometer for CO2 isotopes with a LI-COR LI-8100A/8150 automated chamber system to measure the δ13C of CO2 during automated closed-chamber measurements. The isotopic composition of the CO2 flux was determined for each chamber measurement by applying the Keeling plot method. We found that the δ13C measured by the laser spectrometer was influenced by water vapour and CO2 concentration of the sample air and we developed a method to correct for these effects to yield accurate measurements of δ13C. Overall, correcting for the CO2 concentration increased the δ13C determined from the Keeling plots by 3.4%‰ compared to 2.1%‰ for the water vapour correction. We used the combined system to measure δ13C of the CO2 fluxes automatically every two hours from intact soil, trenched soil, tree stems and coarse roots during a two-month campaign in a Danish beech forest. The mean δ13C was -29.8 ± 0.32%‰ for the intact soil plots, which was similar to the mean δ13C of -29.8 ± 1.2%‰ for the trenched soil plots. The lowest δ13C was found for the root plots with a mean of -32.6 ± 0.78%‰. The mean δ13C of the stems was -30.2 ± 0.74%‰, similar to the mean δ13C of the soil plots. In conclusion, the study showed the potential of using a quantum cascade laser spectrometer to measure δ13C of CO2 during automated closed-chamber measurements, thereby allowing for measurements of isotopic ecosystem CO2 fluxes at a high temporal resolution. It also highlighted the importance of proper correction for cross-sensitivity with water vapour and CO2 concentration of the sample air to get accurate measurements of δ13C. |
BibTeX:
@article{Brændholt2019,
author = {Brændholt, Andreas and Ibrom, Andreas and Ambus, Per and Larsen, Klaus Steenberg and Pilegaard, Kim},
title = {Combining a quantum cascade laser spectrometer with an automated closed-chamber system for δ13C measurements of forest soil, tree stem and tree root CO2 fluxess},
journal = {Forests},
publisher = {MDPI AG},
year = {2019},
volume = {10},
number = {5},
pages = {432},
doi = {10.3390/f10050432}
}
|
| Brown MS, Munro DR, Feehan CJ, Sweeney C, Ducklow HW and Schofield OM (2019), "Enhanced oceanic CO2 uptake along the rapidly changing West Antarctic Peninsula". sep, 2019. |
| Abstract: The global ocean is an important sink for anthropogenic CO2 (ref. 1). Nearly half of the oceanic CO2 uptake occurs in the Southern Ocean2. Although the role of the Southern Ocean CO2 sink in the global carbon cycle is recognized, there are uncertainties regarding its contemporary trend3,4, with a need for improved mechanistic understanding, especially in productive Antarctic coastal regions experiencing substantial changes in temperature and sea ice5. Here, we demonstrate strong coupling between summer upper ocean stability, phytoplankton dynamics and oceanic CO2 uptake along the rapidly changing West Antarctic Peninsula using a 25-year dataset (1993–2017). Greater upper ocean stability drives enhanced biological production and biological dissolved inorganic carbon drawdown, resulting in greater oceanic CO2 uptake. Diatoms achieve higher biomass, oceanic CO2 uptake and uptake efficiency than other phytoplankton. Over the past 25 years, changes in sea ice dynamics have driven an increase in upper ocean stability, phytoplankton biomass and biological dissolved inorganic carbon drawdown, resulting in a nearly fivefold increase in summer oceanic CO2 uptake. We hypothesize that continued warming and declines in sea ice will lead to a decrease in biological dissolved inorganic carbon drawdown, negatively impacting summer oceanic CO2 uptake. These results from the West Antarctic Peninsula provide a framework to understand how oceanic CO2 uptake in other Antarctic coastal regions may be altered due to climate change. |
BibTeX:
@misc{Brown2019,
author = {Brown, Michael S. and Munro, David R. and Feehan, Colette J. and Sweeney, Colm and Ducklow, Hugh W. and Schofield, Oscar M.},
title = {Enhanced oceanic CO2 uptake along the rapidly changing West Antarctic Peninsula},
booktitle = {Nature Climate Change},
publisher = {Nature Publishing Group},
year = {2019},
volume = {9},
number = {9},
pages = {678--683},
url = {https://doi.org/10.1038/s41558-019-0552-3},
doi = {10.1038/s41558-019-0552-3}
}
|
| Buchen C, Roobroeck D, Augustin J, Behrendt U, Boeckx P and Ulrich A (2019), "High N2O consumption potential of weakly disturbed fen mires with dissimilar denitrifier community structure", Soil Biology and Biochemistry., mar, 2019. Vol. 130, pp. 63-72. |
BibTeX:
@article{Buchen2019,
author = {Buchen, C and Roobroeck, D and Augustin, J and Behrendt, U and Boeckx, P and Ulrich, A},
title = {High N2O consumption potential of weakly disturbed fen mires with dissimilar denitrifier community structure},
journal = {Soil Biology and Biochemistry},
year = {2019},
volume = {130},
pages = {63--72},
url = {https://linkinghub.elsevier.com/retrieve/pii/S0038071718304115},
doi = {10.1016/j.soilbio.2018.12.001}
}
|
| Burri S, Haeler E, Eugster W, Haeni M, Etzold S, Walthert L, Braun S and Zweifel R (2019), "How did Swiss forest trees respond to the hot summer 2015?", Erde., dec, 2019. Vol. 150(4), pp. 214-229. Gesellschaft fur Erdkunde zu Berlin. |
| Abstract: Central Europe experienced an exceptionally hot summer in 2015. The area of investigation in the Central Alps in Switzerland faced the second warmest summer since the beginning of measurements in 1864. As a consequence, agriculture suffered from considerable production losses. But how were forests affected by the hot summer? We analyzed stem growth data, measured by automated point dendrometers,from 50 trees across nine sites covering the four main Swiss tree species spruce (Picea abies),fir (Abies alba), beech (Fagus sylvatica) and oak (Quercus spp.) in the years 2014 (relatively wet and cool) and 2015 (hot and dry). Annual growth and environmental conditions were determined by, and related to, the growing period based on daily resolved growth data. Our multi-species approach revealed a wide range of responses. Radial growth of spruce was largely reduced during the hot summer 2015 for sites located below 1500 m a.s.l. Growth of beech responded even positively at several sites on the Swiss Plateau. Fir and oak did not significantly deviate from their respective average growth rate. We conclude that one hot summer actually matters for stem growth, but its effect is not a priori negative. The timing of the heat wave is of highest importance. A relatively wet previous year, a wet spring and the relatively late occurrence of the heat wave in the wood growth period led to a less strong growth reduction than what could have been expected from agricultural plants. Endogenous effects like mast fruiting and legacy effects from past conditions are suggested to further play an important role for stem growth. |
BibTeX:
@article{Burri2019,
author = {Burri, Susanne and Haeler, Elena and Eugster, Werner and Haeni, Matthias and Etzold, Sophia and Walthert, Lorenz and Braun, Sabine and Zweifel, Roman},
title = {How did Swiss forest trees respond to the hot summer 2015?},
journal = {Erde},
publisher = {Gesellschaft fur Erdkunde zu Berlin},
year = {2019},
volume = {150},
number = {4},
pages = {214--229},
doi = {10.12854/erde-2019-420}
}
|
| Bushinsky SM, Landschützer P, Rödenbeck C, Gray AR, Baker D, Mazloff MR, Resplandy L, Johnson KS and Sarmiento JL (2019), "Reassessing Southern Ocean Air‐Sea CO textlesssubtextgreater2textless/subtextgreater Flux Estimates With the Addition of Biogeochemical Float Observations", Global Biogeochemical Cycles., nov, 2019. Vol. 33(11), pp. 1370-1388. Blackwell Publishing Ltd. |
| Abstract: New estimates of pCO2 from profiling floats deployed by the Southern Ocean Carbon and Climate Observations and Modeling (SOCCOM) project have demonstrated the importance of wintertime outgassing south of the Polar Front, challenging the accepted magnitude of Southern Ocean carbon uptake (Gray et al., 2018, https://doi:10.1029/2018GL078013). Here, we put 3.5 years of SOCCOM observations into broader context with the global surface carbon dioxide database (Surface Ocean CO2 Atlas, SOCAT) by using the two interpolation methods currently used to assess the ocean models in the Global Carbon Budget (Le Quéré et al., 2018, https://doi:10.5194/essd-10-2141-2018) to create a ship-only, a float-weighted, and a combined estimate of Southern Ocean carbon fluxes (textless35°S). In our ship-only estimate, we calculate a mean uptake of −1.14 ± 0.19 Pg C/yr for 2015–2017, consistent with prior studies. The float-weighted estimate yields a significantly lower Southern Ocean uptake of −0.35 ± 0.19 Pg C/yr. Subsampling of high-resolution ocean biogeochemical process models indicates that some of the differences between float and ship-only estimates of the Southern Ocean carbon flux can be explained by spatial and temporal sampling differences. The combined ship and float estimate minimizes the root-mean-square pCO2 difference between the mapped product and both data sets, giving a new Southern Ocean uptake of −0.75 ± 0.22 Pg C/yr, though with uncertainties that overlap the ship-only estimate. An atmospheric inversion reveals that a shift of this magnitude in the contemporary Southern Ocean carbon flux must be compensated for by ocean or land sinks within the Southern Hemisphere. |
BibTeX:
@article{Bushinsky2019,
author = {Bushinsky, Seth M. and Landschützer, Peter and Rödenbeck, Christian and Gray, Alison R. and Baker, David and Mazloff, Matthew R. and Resplandy, Laure and Johnson, Kenneth S. and Sarmiento, Jorge L.},
title = {Reassessing Southern Ocean Air‐Sea CO textlesssubtextgreater2textless/subtextgreater Flux Estimates With the Addition of Biogeochemical Float Observations},
journal = {Global Biogeochemical Cycles},
publisher = {Blackwell Publishing Ltd},
year = {2019},
volume = {33},
number = {11},
pages = {1370--1388},
url = {https://onlinelibrary.wiley.com/doi/abs/10.1029/2019GB006176},
doi = {10.1029/2019GB006176}
}
|
| Bushinsky SM, Takeshita Y and Williams NL (2019), "Observing Changes in Ocean Carbonate Chemistry: Our Autonomous Future". sep, 2019. |
| Abstract: Purpose of Review: We summarize recent progress on autonomous observations of ocean carbonate chemistry and the development of a network of sensors capable of observing carbonate processes at multiple temporal and spatial scales. Recent Findings: The development of versatile pH sensors suitable for both deployment on autonomous vehicles and in compact, fixed ecosystem observatories has been a major development in the field. The initial large-scale deployment of profiling floats equipped with these new pH sensors in the Southern Ocean has demonstrated the feasibility of a global autonomous open-ocean carbonate observing system. Summary: Our developing network of autonomous carbonate observations is currently targeted at surface ocean CO2 fluxes and compact ecosystem observatories. New integration of developed sensors on gliders and surface vehicles will increase our coastal and regional observational capability. Most autonomous platforms observe a single carbonate parameter, which leaves us reliant on the use of empirical relationships to constrain the rest of the carbonate system. Sensors now in development promise the ability to observe multiple carbonate system parameters from a range of vehicles in the near future. |
BibTeX:
@misc{Bushinsky2019a,
author = {Bushinsky, Seth M. and Takeshita, Yuichiro and Williams, Nancy L.},
title = {Observing Changes in Ocean Carbonate Chemistry: Our Autonomous Future},
booktitle = {Current Climate Change Reports},
publisher = {Springer},
year = {2019},
volume = {5},
number = {3},
pages = {207--220},
url = {https://doi.org/10.1007/s40641-019-00129-8},
doi = {10.1007/s40641-019-00129-8}
}
|
| Byrne A, Jones B, Strong D, Journal A, Byrne B, Jones DBA, Strong K, Polavarapu SM, Harper AB, Baker DF and Maksyutov S (2019), "On what scales can GOSAT flux inversions constrain anomalies in terrestrial ecosystems? A NOTE ON VERSIONS On what scales can GOSAT flux inversions constrain anomalies in terrestrial ecosystems?", Atmos. Chem. Phys. Vol. 19, pp. 13017-13035. |
| Abstract: Interannual variations in temperature and precipitation impact the carbon balance of terrestrial ecosystems , leaving an imprint in atmospheric CO 2. Quantifying the impact of climate anomalies on the net ecosystem exchange (NEE) of terrestrial ecosystems can provide a constraint to evaluate terrestrial biosphere models against and may provide an emergent constraint on the response of terrestrial ecosystems to climate change. We investigate the spatial scales over which interannual variability in NEE can be constrained using atmospheric CO 2 observations from the Greenhouse Gases Observing Satellite (GOSAT). NEE anomalies are calculated by performing a series of inversion analyses using the GEOS-Chem adjoint model to assimilate GOSAT observations. Monthly NEE anomalies are compared to "proxies", variables that are associated with anomalies in the terrestrial carbon cycle, and to upscaled NEE estimates from FLUXCOM. Statistically significant correlations (P textless 0.05) are obtained between posterior NEE anomalies and anomalies in soil temperature and FLUXCOM NEE on continental and larger scales in the tropics, as well as in the northern extratropics on subcontinental scales during the summer (R 2 ≥ 0.49), suggesting that GOSAT measurements provide a constraint on NEE interannual variability (IAV) on these spatial scales. Furthermore, we show that GOSAT flux inversions are generally better correlated with the environmental proxies and FLUXCOM NEE than NEE anomalies produced by a set of terrestrial biosphere models (TBMs), suggesting that GOSAT flux inversions could be used to evaluate TBM NEE fluxes. |
BibTeX:
@article{Byrne2019,
author = {Byrne, Authors and Jones, B ; and Strong, Dba ; and Journal, Al and Byrne, Brendan and Jones, Dylan B A and Strong, Kimberly and Polavarapu, Saroja M and Harper, Anna B and Baker, David F and Maksyutov, Shamil},
title = {On what scales can GOSAT flux inversions constrain anomalies in terrestrial ecosystems? A NOTE ON VERSIONS On what scales can GOSAT flux inversions constrain anomalies in terrestrial ecosystems?},
journal = {Atmos. Chem. Phys},
year = {2019},
volume = {19},
pages = {13017--13035},
url = {http://hdl.handle.net/10871/39986},
doi = {10.5194/acp-19-13017-2019}
}
|
| Campbell JL and Laudon H (2019), "Carbon response to changing winter conditions in northern regions: Current understanding and emerging research needs", Environmental Reviews., dec, 2019. Vol. 27(4), pp. 545-566. |
| Abstract: Winter is an important period for ecological processes in northern regions; however, compared to other seasons, the impacts of winter climate on ecosystems are poorly understood. In this review we evaluate the influence of winter climate on carbon dynamics based on the current state of knowledge and highlight emerging topics and future research challenges. Studies that have addressed this topic include plot-scale snow cover manipulation experiments that alter soil temperatures, empirical investigations along natural climatic gradients, laboratory temperature incubation experiments aimed at isolating influential factors in controlled environments, and time series of climate and carbon data that evaluate long-term natural variation and trends. Combined, these studies have demonstrated how winter climate can influence carbon in complex ways that in some cases are consistent across studies and in other cases are difficult to predict. Despite advances in our understanding, there is a great need for studies that further explore: (i) carry-over effects from one season to another, (ii) ecosystem processes in the fall–winter and winter–spring shoulder seasons, (iii) the impacts of extreme events, (iv) novel experimental approaches, and (v) improvements to models to include ecological effects of winter climate. We also call for the establishment of an international winter climate change research network that enhances collaboration and coordination among studies, which could provide a more thorough understanding of how the snow-covered period influences carbon cycling, thereby improving our ability to predict future responses to climate change. |
BibTeX:
@article{Campbell2019,
author = {Campbell, John L and Laudon, Hjalmar},
title = {Carbon response to changing winter conditions in northern regions: Current understanding and emerging research needs},
journal = {Environmental Reviews},
year = {2019},
volume = {27},
number = {4},
pages = {545--566},
url = {http://www.nrcresearchpress.com/doi/10.1139/er-2018-0097},
doi = {10.1139/er-2018-0097}
}
|
| Campeau A, Bishop K, Amvrosiadi N, Billett MF, Garnett MH, Laudon H, Öquist MG and Wallin MB (2019), "Current forest carbon fixation fuels stream CO 2 emissions", Nature Communications., dec, 2019. Vol. 10(1), pp. 1876. |
| Abstract: Stream CO 2 emissions contribute significantly to atmospheric climate forcing. While there are strong indications that groundwater inputs sustain these emissions, the specific biogeochemical pathways and timescales involved in this lateral CO 2 export are still obscure. Here, via an extensive radiocarbon ( 14 C) characterisation of CO 2 and DOC in stream water and its groundwater sources in an old-growth boreal forest, we demonstrate that the 14 C-CO 2 is consistently in tune with the current atmospheric 14 C-CO 2 level and shows little association with the 14 C-DOC in the same waters. Our findings thus indicate that stream CO 2 emissions act as a shortcut that returns CO 2 recently fixed by the forest vegetation to the atmosphere. Our results expose a positive feedback mechanism within the C budget of forested catchments, where stream CO 2 emissions will be highly sensitive to changes in forest C allocation patterns associated with climate and land-use changes. |
BibTeX:
@article{Campeau2019,
author = {Campeau, A and Bishop, K and Amvrosiadi, N and Billett, M F and Garnett, M H and Laudon, H and Öquist, M G and Wallin, M B},
title = {Current forest carbon fixation fuels stream CO 2 emissions},
journal = {Nature Communications},
year = {2019},
volume = {10},
number = {1},
pages = {1876},
url = {http://www.nature.com/articles/s41467-019-09922-3},
doi = {10.1038/s41467-019-09922-3}
}
|
| Capotondi A, Jacox M, Bowler C, Kavanaugh M, Lehodey P, Barrie D, Brodie S, Chaffron S, Cheng W, Dias DF, Eveillard D, Guidi L, Iudicone D, Lovenduski NS, Nye JA, Ortiz I, Pirhalla D, Pozo Buil M, Saba V, Sheridan S, Siedlecki S, Subramanian A, de Vargas C, Di Lorenzo E, Doney SC, Hermann AJ, Joyce T, Merrifield M, Miller AJ, Not F and Pesant S (2019), "Observational Needs Supporting Marine Ecosystems Modeling and Forecasting: From the Global Ocean to Regional and Coastal Systems". oct, 2019. |
| Abstract: Many coastal areas host rich marine ecosystems and are also centers of economic activities, including fishing, shipping and recreation. Due to the socioeconomic and ecological importance of these areas, predicting relevant indicators of the ecosystem state on sub-seasonal to interannual timescales is gaining increasing attention. Depending on the application, forecasts may be sought for variables and indicators spanning physics (e.g., sea level, temperature, currents), chemistry (e.g., nutrients, oxygen, pH), and biology (from viruses to top predators). Many components of the marine ecosystem are known to be influenced by leading modes of climate variability, which provide a physical basis for predictability. However, prediction capabilities remain limited by the lack of a clear understanding of the physical and biological processes involved, as well as by insufficient observations for forecast initialization and verification. The situation is further complicated by the influence of climate change on ocean conditions along coastal areas, including sea level rise, increased stratification, and shoaling of oxygen minimum zones. Observations are thus vital to all aspects of marine forecasting: statistical and/or dynamical model development, forecast initialization, and forecast validation, each of which has different observational requirements, which may be also specific to the study region. Here, we use examples from United States (U.S.) coastal applications to identify and describe the key requirements for an observational network that is needed to facilitate improved process understanding, as well as for sustaining operational ecosystem forecasting. We also describe new holistic observational approaches, e.g., approaches based on acoustics, inspired by Tara Oceans or by landscape ecology, which have the potential to support and expand ecosystem modeling and forecasting activities by bridging global and local observations. |
BibTeX:
@misc{Capotondi2019,
author = {Capotondi, Antonietta and Jacox, Michael and Bowler, Chris and Kavanaugh, Maria and Lehodey, Patrick and Barrie, Daniel and Brodie, Stephanie and Chaffron, Samuel and Cheng, Wei and Dias, Daniela F. and Eveillard, Damien and Guidi, Lionel and Iudicone, Daniele and Lovenduski, Nicole S. and Nye, Janet A. and Ortiz, Ivonne and Pirhalla, Douglas and Pozo Buil, Mercedes and Saba, Vincent and Sheridan, Scott and Siedlecki, Samantha and Subramanian, Aneesh and de Vargas, Colomban and Di Lorenzo, Emanuele and Doney, Scott C. and Hermann, Albert J. and Joyce, Terrence and Merrifield, Mark and Miller, Arthur J. and Not, Fabrice and Pesant, Stephane},
title = {Observational Needs Supporting Marine Ecosystems Modeling and Forecasting: From the Global Ocean to Regional and Coastal Systems},
booktitle = {Frontiers in Marine Science},
publisher = {Frontiers Media S.A.},
year = {2019},
volume = {6},
pages = {623},
url = {https://ec.europa.eu/maritimeaffairs/},
doi = {10.3389/fmars.2019.00623}
}
|
| Carter BR, Williams NL, Evans W, Fassbender AJ, Barbero L, Hauri C, Feely RA and Sutton AJ (2019), "Time of Detection as a Metric for Prioritizing Between Climate Observation Quality, Frequency, and Duration", Geophysical Research Letters., apr, 2019. Vol. 46(7), pp. 3853-3861. Blackwell Publishing Ltd. |
| Abstract: We advance a simple framework based on “time of detection” for estimating the observational needs of studies assessing climate changes amidst natural variability and apply it to several examples related to ocean acidification. This approach aims to connect the Global Ocean Acidification Observing Network “weather” and “climate” data quality thresholds with a single dynamic threshold appropriate for a range of potential ocean signals and environments. A key implication of the framework is that measurement frequency can be as important as measurement accuracy, particularly in highly variable environments. Pragmatic cost-benefit analyses based on this framework can be performed to quantitatively determine which observing strategy will accomplish a given detection goal soonest and resolve a signal with the greatest confidence and to assess how the trade-offs between measurement frequency and accuracy vary regionally. |
BibTeX:
@article{Carter2019,
author = {Carter, B. R. and Williams, N. L. and Evans, W. and Fassbender, A. J. and Barbero, L. and Hauri, C. and Feely, R. A. and Sutton, A. J.},
title = {Time of Detection as a Metric for Prioritizing Between Climate Observation Quality, Frequency, and Duration},
journal = {Geophysical Research Letters},
publisher = {Blackwell Publishing Ltd},
year = {2019},
volume = {46},
number = {7},
pages = {3853--3861},
url = {https://onlinelibrary.wiley.com/doi/abs/10.1029/2018GL080773},
doi = {10.1029/2018GL080773}
}
|
| Cernusak LA, Haverd V, Brendel O, Le Thiec D, Guehl JM and Cuntz M (2019), "Robust Response of Terrestrial Plants to Rising CO2", Trends in Plant Science., jul, 2019. Vol. 24(7), pp. 578-586. Elsevier BV. |
| Abstract: Human-caused CO2 emissions over the past century have caused the climate of the Earth to warm and have directly impacted on the functioning of terrestrial plants. We examine the global response of terrestrial gross primary production (GPP) to the historic change in atmospheric CO2. The GPP of the terrestrial biosphere has increased steadily, keeping pace remarkably in proportion to the rise in atmospheric CO2. Water-use efficiency, namely the ratio of CO2 uptake by photosynthesis to water loss by transpiration, has increased as a direct leaf-level effect of rising CO2. This has allowed an increase in global leaf area, which has conspired with stimulation of photosynthesis per unit leaf area to produce a maximal response of the terrestrial biosphere to rising atmospheric CO2 and contemporary climate change. |
BibTeX:
@article{Cernusak2019,
author = {Cernusak, Lucas A and Haverd, Vanessa and Brendel, Oliver and Le Thiec, Didier and Guehl, Jean Marc and Cuntz, Matthias},
title = {Robust Response of Terrestrial Plants to Rising CO2},
journal = {Trends in Plant Science},
publisher = {Elsevier BV},
year = {2019},
volume = {24},
number = {7},
pages = {578--586},
doi = {10.1016/j.tplants.2019.04.003}
}
|
| Chen JM, Ju W, Ciais P, Viovy N, Liu R, Liu Y and Lu X (2019), "Vegetation structural change since 1981 significantly enhanced the terrestrial carbon sink", Nature Communications., sep, 2019. Vol. 10(1) Springer Science and Business Media LLC. |
| Abstract: Satellite observations show that leaf area index (LAI) has increased globally since 1981, but the impact of this vegetation structural change on the global terrestrial carbon cycle has not been systematically evaluated. Through process-based diagnostic ecosystem modeling, we find that the increase in LAI alone was responsible for 12.4% of the accumulated terrestrial carbon sink (95 ± 5 Pg C) from 1981 to 2016, whereas other drivers of CO2 fertilization, nitrogen deposition, and climate change (temperature, radiation, and precipitation) contributed to 47.0%, 1.1%, and âˆ'28.6% of the sink, respectively. The legacy effects of past changes in these drivers prior to 1981 are responsible for the remaining 65.5% of the accumulated sink from 1981 to 2016. These results refine the attribution of the land sink to the various drivers and would help constrain prognostic models that often have large uncertainties in simulating changes in vegetation and their impacts on the global carbon cycle. |
BibTeX:
@article{Chen2019,
author = {Chen, Jing M and Ju, Weimin and Ciais, Philippe and Viovy, Nicolas and Liu, Ronggao and Liu, Yang and Lu, Xuehe},
title = {Vegetation structural change since 1981 significantly enhanced the terrestrial carbon sink},
journal = {Nature Communications},
publisher = {Springer Science and Business Media LLC},
year = {2019},
volume = {10},
number = {1},
doi = {10.1038/s41467-019-12257-8}
}
|
| Chen Y, Shen W, Gao S, Zhang K, Wang J and Huang N (2019), "Estimating deciduous broadleaf forest gross primary productivity by remote sensing data using a random forest regression model", Journal of Applied Remote Sensing., aug, 2019. Vol. 13(3), pp. 1-17. |
BibTeX:
@article{Chen2019a,
author = {Chen, Yue and Shen, Wei and Gao, Shuai and Zhang, Kun and Wang, Jian and Huang, Ni},
title = {Estimating deciduous broadleaf forest gross primary productivity by remote sensing data using a random forest regression model},
journal = {Journal of Applied Remote Sensing},
year = {2019},
volume = {13},
number = {3},
pages = {1--17},
url = {https://doi.org/10.1117/1.JRS.13.038502},
doi = {10.1117/1.JRS.13.038502}
}
|
| Chi J, Nilsson MB, Kljun N, Wallerman J, Fransson JES, Laudon H, Lundmark T and Peichl M (2019), "The carbon balance of a managed boreal landscape measured from a tall tower in northern Sweden", Agricultural and Forest Meteorology., aug, 2019. Vol. 274, pp. 29-41. |
| Abstract: Boreal forests exchange large amounts of carbon dioxide (CO2) with the atmosphere. A managed boreal landscape usually comprises various potential CO2 sinks and sources across forest stands of varying age classes, clear-cut areas, mires, and lakes. Due to this heterogeneity and complexity, large uncertainties exist regarding the net CO2 balance at the landscape scale. In this study, we present the first estimate of the net CO2 exchange over a managed boreal landscape (∼68 km2) in northern Sweden, based on tall tower eddy covariance measurements. Our results suggest that from March 1, 2016 to February 28, 2018, the heterogeneous landscape was a net CO2 sink with a 2-year mean uptake of âˆ'87 ± 6 g C mâˆ'2 yrâˆ'1. Due to an earlier and warmer spring and sunnier autumn, the landscape was a stronger CO2 sink during the first year (âˆ'122 ± 8 g C mâˆ'2) compared to the second year (âˆ'52 ± 9 g C mâˆ'2). Footprint analysis shows that 87% of the CO2 flux measurements originated from forests, whereas mires, clear-cuts, lakes, and grassland contributed 11%, 1%, 0.7%, and 0.2%, respectively. Altogether, the CO2 sink strength of the heterogeneous landscape was up to 38% lower compared to the sink strength of a mature stand surrounding the tower. Overall, this study suggests that the managed boreal landscape acted as a CO2 sink and advocates tall tower eddy covariance measurements to improve regional carbon budget estimates. |
BibTeX:
@article{Chi2019,
author = {Chi, Jinshu and Nilsson, Mats B and Kljun, Natascha and Wallerman, Jörgen and Fransson, Johan E S and Laudon, Hjalmar and Lundmark, Tomas and Peichl, Matthias},
title = {The carbon balance of a managed boreal landscape measured from a tall tower in northern Sweden},
journal = {Agricultural and Forest Meteorology},
year = {2019},
volume = {274},
pages = {29--41},
url = {https://linkinghub.elsevier.com/retrieve/pii/S0168192319301509},
doi = {10.1016/j.agrformet.2019.04.010}
}
|
| Chiesa M, Bignotti L, Finco A, Marzuoli R and Gerosa G (2019), "Size-resolved aerosol fluxes above a broadleaved deciduous forest", Agricultural and Forest Meteorology., dec, 2019. Vol. 279, pp. 107757. Elsevier BV. |
| Abstract: In order to understand the aerosol exchange dynamics between the atmosphere and a peri-urban forest ecosystem located in the Po Valley, a region characterized by high PM concentrations, eddy covariance (EC) aerosol fluxes were measured between September and December 2017. The aerosol sampling, performed with an Electrical Low Pressure Impactor (ELPI +, DEKATI), involved a wide range of particle sizes including both ultrafine and fine aerosol. The monitoring campaign comprised a period with leaves (PL) and a period without leaves (PNL) to assess their influence on the emission and deposition fluxes. The diurnal profiles of particle number (PN) fluxes associated to the geometric mean diameters (GMD) of 0.02 µm and 0.48 µm were chosen as representative of the behaviour of ultrafine and fine particles, respectively. Fluxes of ultrafine particles showed a net emission pattern both in PL and PNL assuming values up to 5.6 106 mâˆ'2 sâˆ'1 and 4.5textperiodcentered106 mâˆ'2 sâˆ'1, respectively. Instead, fine particles fluxes showed a net deposition pattern in PL, assuming values up to âˆ'1.1 textperiodcentered 106 mâˆ'2 sâˆ'1, while in PNL a slight emission up to 4.1 textperiodcentered105 mâˆ'2 sâˆ'1 occurred. The behaviour of the fluxes of the cumulative classes PM0.1 and PM1 was similar to the one of the PN fluxes of ultrafine and fine aerosol, respectively. Deposition velocities were calculated for PL and PNL depending on the atmospheric stability class. The values emerged from this study (from âˆ'0.25 cm sâˆ'1 up to 0.12 cm sâˆ'1) evidenced that under stable and very stable atmospheric conditions all size classes presented negative or slightly positive deposition velocities both in PL and PNL. Instead under unstable conditions fine particles showed deposition velocities whose direction changed in the two periods (PL and PNL). |
BibTeX:
@article{Chiesa2019,
author = {Chiesa, M and Bignotti, L and Finco, A and Marzuoli, R and Gerosa, G},
title = {Size-resolved aerosol fluxes above a broadleaved deciduous forest},
journal = {Agricultural and Forest Meteorology},
publisher = {Elsevier BV},
year = {2019},
volume = {279},
pages = {107757},
doi = {10.1016/j.agrformet.2019.107757}
}
|
| Ciais P, Tan J, Wang X, Roedenbeck C, Chevallier F, Piao SL, Moriarty R, Broquet G, Le Quéré C, Canadell JG, Peng S, Poulter B, Liu Z and Tans P (2019), "Five decades of northern land carbon uptake revealed by the interhemispheric CO2 gradient", Nature., apr, 2019. Vol. 568(7751), pp. 221-225. Nature Publishing Group. |
| Abstract: The global land and ocean carbon sinks have increased proportionally with increasing carbon dioxide emissions during the past decades1. It is thought that Northern Hemisphere lands make a dominant contribution to the global land carbon sink2–7; however, the long-term trend of the northern land sink remains uncertain. Here, using measurements of the interhemispheric gradient of atmospheric carbon dioxide from 1958 to 2016, we show that the northern land sink remained stable between the 1960s and the late 1980s, then increased by 0.5 ± 0.4 petagrams of carbon per year during the 1990s and by 0.6 ± 0.5 petagrams of carbon per year during the 2000s. The increase of the northern land sink in the 1990s accounts for 65% of the increase in the global land carbon flux during that period. The subsequent increase in the 2000s is larger than the increase in the global land carbon flux, suggesting a coincident decrease of carbon uptake in the Southern Hemisphere. Comparison of our findings with the simulations of an ensemble of terrestrial carbon models5,8 over the same period suggests that the decadal change in the northern land sink between the 1960s and the 1990s can be explained by a combination of increasing concentrations of atmospheric carbon dioxide, climate variability and changes in land cover. However, the increase during the 2000s is underestimated by all models, which suggests the need for improved consideration of changes in drivers such as nitrogen deposition, diffuse light and land-use change. Overall, our findings underscore the importance of Northern Hemispheric land as a carbon sink. |
BibTeX:
@article{Ciais2019,
author = {Ciais, P. and Tan, J. and Wang, X. and Roedenbeck, C. and Chevallier, F. and Piao, S. L. and Moriarty, R. and Broquet, G. and Le Quéré, C. and Canadell, J. G. and Peng, S. and Poulter, B. and Liu, Z. and Tans, P.},
title = {Five decades of northern land carbon uptake revealed by the interhemispheric CO2 gradient},
journal = {Nature},
publisher = {Nature Publishing Group},
year = {2019},
volume = {568},
number = {7751},
pages = {221--225},
url = {https://www.nature.com/articles/s41586-019-1078-6},
doi = {10.1038/s41586-019-1078-6}
}
|
| Collalti A, Thornton PE, Cescatti A, Rita A, Borghetti M, Nolè A, Trotta C, Ciais P and Matteucci G (2019), "The sensitivity of the forest carbon budget shifts across processes along with stand development and climate change", Ecological Applications., feb, 2019. Vol. 29(2) Wiley. |
| Abstract: The future trajectory of atmospheric CO2 concentration depends on the development of the terrestrial carbon sink, which in turn is influenced by forest dynamics under changing environmental conditions. An in-depth understanding of model sensitivities and uncertainties in non-steady-state conditions is necessary for reliable and robust projections of forest development and under scenarios of global warming and CO2 enrichment. Here, we systematically assessed if a biogeochemical process-based model (3D-CMCC-CNR), which embeds similarities with many other vegetation models, applied in simulating net primary productivity (NPP) and standing woody biomass (SWB), maintained a consistent sensitivity to its 55 input parameters through time, during forest ageing and structuring as well as under climate change scenarios. Overall, the model applied at three contrasting European forests showed low sensitivity to the majority of its parameters. Interestingly, model sensitivity to parameters varied through the course of 100 yr of simulations. In particular, the model showed a large responsiveness to the allometric parameters used for initialize forest carbon and nitrogen pools early in forest simulation (i.e., for NPP up to ˜37%, 256 g Ctextperiodcenteredmâˆ'2textperiodcenteredyrâˆ'1 and for SWB up to ˜90%, 65 Mg C/ha, when compared to standard simulation), with this sensitivity decreasing sharply during forest development. At medium to longer time scales, and under climate change scenarios, the model became increasingly more sensitive to additional and/or different parameters controlling biomass accumulation and autotrophic respiration (i.e., for NPP up to ˜30%, 167 g Ctextperiodcenteredmâˆ'2textperiodcenteredyrâˆ'1 and for SWB up to ˜24%, 64 Mg C/ha, when compared to standard simulation). Interestingly, model outputs were shown to be more sensitive to parameters and processes controlling stand development rather than to climate change (i.e., warming and changes in atmospheric CO2 concentration) itself although model sensitivities were generally higher under climate change scenarios. Our results suggest the need for sensitivity and uncertainty analyses that cover multiple temporal scales along forest developmental stages to better assess the potential of future forests to act as a global terrestrial carbon sink. |
BibTeX:
@article{Collalti2019,
author = {Collalti, Alessio and Thornton, Peter E and Cescatti, Alessandro and Rita, Angelo and Borghetti, Marco and Nolè, Angelo and Trotta, Carlo and Ciais, Philippe and Matteucci, Giorgio},
title = {The sensitivity of the forest carbon budget shifts across processes along with stand development and climate change},
journal = {Ecological Applications},
publisher = {Wiley},
year = {2019},
volume = {29},
number = {2},
doi = {10.1002/eap.1837}
}
|
| Conil S, Helle J, Langrene L, Laurent O, Delmotte M and Ramonet M (2019), "Continuous atmospheric CO2, CH4 and CO measurements at the Observatoire Pérenne de l'Environnement (OPE) station in France from 2011 to 2018", Atmospheric Measurement Techniques., dec, 2019. Vol. 12(12), pp. 6361-6383. Copernicus GmbH. |
| Abstract: Located in north-east France, the Observatoire Pérenne de l'Environnement (OPE) station was built during the Integrated Carbon Observation System (ICOS) Demonstration Experiment to monitor the greenhouse gases mole fraction. Its continental rural background setting fills the gaps between oceanic or mountain stations and urban stations within the ICOS network. Continuous measurements of several greenhouse gases using high-precision spectrometers started in 2011 on a tall tower with three sampling inlets at 10, 50 and 120 m above ground level (a.g.l.). Measurement quality is regularly assessed using several complementary approaches based on reference high-pressure cylinders, audits using travelling instruments and sets of travelling cylinders ("cucumber" intercomparison programme). Thanks to the quality assurance strategy recommended by ICOS, measurement uncertainties are within the World Meteorological Organisation compatibility goals for carbon dioxide (CO2), methane (CH4) and carbon monoxide (CO). The time series of mixing ratios from 2011 to the end of 2018 are used to analyse trends and diurnal and seasonal cycles. The CO2 and CH4 annual growth rates are 2.4 ppm yr-1 and 8.8 ppb yr-1 respectively for measurements at 120 m a.g.l. over the investigated period. However, no significant trend has been recorded for CO mixing ratios. The afternoon mean residuals (defined as the differences between midday observations and a smooth fitted curve) of these three compounds are significantly stronger during the cold period when inter-species correlations are high, compared to the warm period. The variabilities of residuals show a close link with air mass backtrajectories. |
BibTeX:
@article{Conil2019,
author = {Conil, Sébastien and Helle, Julie and Langrene, Laurent and Laurent, Olivier and Delmotte, Marc and Ramonet, Michel},
title = {Continuous atmospheric CO2, CH4 and CO measurements at the Observatoire Pérenne de l'Environnement (OPE) station in France from 2011 to 2018},
journal = {Atmospheric Measurement Techniques},
publisher = {Copernicus GmbH},
year = {2019},
volume = {12},
number = {12},
pages = {6361--6383},
doi = {10.5194/amt-12-6361-2019}
}
|
| Conte A, Fares S, Salvati L, Savi F, Matteucci G, Mazzenga F, Spano D, Sirca C, Marras S, Galvagno M, Cremonese E and Montagnani L (2019), "Ecophysiological Responses to Rainfall Variability in Grassland and Forests Along a Latitudinal Gradient in Italy", Frontiers in Forests and Global Change., may, 2019. Vol. 2 Frontiers Media SA. |
| Abstract: In the Mediterranean region, ecosystems are severely affected by climate variability. The Italian Peninsula is a hot spot for biodiversity thanks to heterogeneous landscape and Mediterranean, Continental, and Alpine climates hosting a broad range of plant functional types along a limited latitudinal range from 40' to 46' N. In this study we applied a comparative approach integrating descriptive statistics, time series analysis, and multivariate techniques to answer the following questions: (i) do the climatic variables affect GPP, Reco, WUE and ET to a similar extent among different sites? (ii) Does a common response pattern exist among ecosystems along a latitudinal gradient in Italy? And, finally (iii) do these ecosystems respond synchronically to meteorological conditions or does a delayed response exists? Six sites along a latitudinal, altitudinal and vegetational gradient from semi-arid (southern Italy) to a mountainous Mediterranean site (central Italy) and sub-humid wet Alpine sites (northern Italy) were considered. For each site, carbon and water fluxes and meteorological data collected during two hydrologically-contrasting years (i.e. a dry and a wet year) were analysed. Principal Component Analysis was adopted to identify temporal and spatial variations in Gross Primary Productivity (GPP), Ecosystem Respiration (Reco), Water Use Efficiency (WUE) and Evapotranspiration (ET). The model outlined differences among Mediterranean semi-arid, Mediterranean mountainous, and Alpine sites in response to contrasting precipitation regimes. GPP, Reco, WUE and ET increased up to 16, 19, 25 and 28 %, respectively in semi-arid Mediterranean sites and up to 15, 32, 15 and 11%, respectively in Alpine sites in the wet year compared to the dry year. Air temperature was revealed to be one of the most important variables affecting GPP, Reco, WUE and ET in all the study sites. While relative air humidity was more important in southern Mediterranean sites, global radiation was more significant in northern Italy. Our work suggests that a realistic prediction of the main responses of Italian forests under climate change should also take in account delayed responses due to acclimation to abiotic stress or changing environmental conditions. |
BibTeX:
@article{Conte2019,
author = {Conte, Adriano and Fares, Silvano and Salvati, Luca and Savi, Flavia and Matteucci, Giorgio and Mazzenga, Francesco and Spano, Donatella and Sirca, Costantino and Marras, Serena and Galvagno, Marta and Cremonese, Edoardo and Montagnani, Leonardo},
title = {Ecophysiological Responses to Rainfall Variability in Grassland and Forests Along a Latitudinal Gradient in Italy},
journal = {Frontiers in Forests and Global Change},
publisher = {Frontiers Media SA},
year = {2019},
volume = {2},
doi = {10.3389/ffgc.2019.00016}
}
|
| Couldrey MP, Oliver KIC, Yool A, Halloran PR and Achterberg EP (2019), "Drivers of 21textlesssuptextgreatersttextless/suptextgreater Century carbon cycle variability in the North Atlantic Ocean", Biogeosciences Discussions., jan, 2019. , pp. 1-33. Copernicus GmbH. |
| Abstract: textlessptextgreatertextlessstrongtextgreaterAbstract.textless/strongtextgreater The North Atlantic carbon sink is a prominent component of global climate, storing large amounts of atmospheric carbon dioxide (COtextlesssubtextgreater2textless/subtextgreater), but this basin's COtextlesssubtextgreater2textless/subtextgreater uptake variability presents challenges for future climate prediction. A comprehensive mechanistic understanding of the processes that give rise to year-to-year (interannual) and decade-to-decade (decadal) variability in the North Atlantic's dissolved inorganic carbon (DIC) inventory is lacking. Here, we numerically simulate the oceanic response to human-induced (anthropogenic) climate change from the industrial era to the year 2100. The model distinguishes how different physical, chemical, and biological processes modify the basin's DIC inventory; the saturation, soft tissue, and carbonate pumps, anthropogenic emissions, and other processes causing air-sea disequilibria. There are four ‘natural' pools (saturation, soft tissue, carbonate, and disequilibrium), and an ‘anthropogenic' pool. Interannual variability of the North Atlantic DIC inventory arises primarily due to temperature- and alkalinity-induced changes in carbon solubility (saturation concentrations). A mixture of saturation and anthropogenic drivers cause decadal variability. Multidecadal variability results from the opposing effects of saturation versus soft tissue carbon, and anthropogenic carbon uptake. By the year 2100, the North Atlantic gains 66&thinsp;Pg (1&thinsp;Pg = 10textlesssuptextgreater15textless/suptextgreater grams) of anthropogenic carbon, and the natural carbon pools collectively decline by 4.8&thinsp;Pg. The first order controls on interannual variability of the North Atlantic carbon sink size are therefore largely physical, and the biological pump emerges as an important driver of change on multidecadal timescales. Further work should identify specifically which physical processes underlie the interannual saturation-dominated DIC variability documented here.textless/ptextgreater |
BibTeX:
@article{Couldrey2019,
author = {Couldrey, Matthew P. and Oliver, Kevin I. C. and Yool, Andrew and Halloran, Paul R. and Achterberg, Eric P.},
title = {Drivers of 21textlesssuptextgreatersttextless/suptextgreater Century carbon cycle variability in the North Atlantic Ocean},
journal = {Biogeosciences Discussions},
publisher = {Copernicus GmbH},
year = {2019},
pages = {1--33},
doi = {10.5194/bg-2019-16}
}
|
| Crabbe RA, Janouš D, DaÅ™enová E and Pavelka M (2019), "Exploring the potential of LANDSAT-8 for estimation of forest soil CO 2 efflux", International Journal of Applied Earth Observation and Geoinformation., may, 2019. Vol. 77, pp. 42-52. Elsevier BV. |
| Abstract: Monitoring forest soil carbon dioxide efflux (FCO 2 ) is important as it contributes significantly to terrestrial ecosystem respiration and is hence a major factor in global carbon cycle. FCO 2 monitoring is usually conducted by the use of soil chambers to sample various point positions, but this method is difficult to replicate at spatially large research sites. Satellite remote sensing is accustomed to monitoring environmental phenomenon at large spatial scale, however its utilisation in FCO 2 monitoring is under-explored. To this end, this study explored the potential of LANDSAT-8 to estimate FCO 2 with the specific aims of deriving land surface temperature (LST) from LANDSAT-8 and then develop FCO 2 model on the basis of LANDSAT-8 LST to account for seasonal and inter-annual variations of FCO 2 . The study was conducted over an old European beech forest (Fagus sylvatica) in Czech Republic. In the end, two kinds of linear mixed effect models were built; Model-1 (inter-annual variations of FCO 2 ) and Model-2 (seasonal variations of FCO 2 ). The difference between Model-1 and Model-2 lies in their random factors; while Model-1 has ‘year' of FCO 2 measurement as a random factor, Model-2 has ‘season' of FCO 2 measurement as a random factor. When modelling without random factors, LANDSAT-8 LST as the fixed predictor in both models was able to account for 26% (marginal R 2 = 0.26) of FCO 2 variability in Model-1 whereas it accounted for 29% in Model-2. However, the parameterisation of random effects improved the performance of both models. Model-1 was the best in that it explained 65% (conditional R 2 = 0.65) of variability in FCO 2 and produced the least deviation from observed FCO 2 (RMSE = 0.38 μmol/m 2 /s). This study adds to the limited number of previous similar studies with the aim of encouraging satellite remote sensing integration in FCO 2 observation. |
BibTeX:
@article{Crabbe2019,
author = {Crabbe, Richard A and Janouš, Dalibor and DaÅ™enová, Eva and Pavelka, Marian},
title = {Exploring the potential of LANDSAT-8 for estimation of forest soil CO 2 efflux},
journal = {International Journal of Applied Earth Observation and Geoinformation},
publisher = {Elsevier BV},
year = {2019},
volume = {77},
pages = {42--52},
doi = {10.1016/j.jag.2018.12.007}
}
|
| Creamean JM, Mignani C, Bukowiecki N and Conen F (2019), "Using freezing spectra characteristics to identify ice-nucleating particle populations during the winter in the Alps", Atmospheric Chemistry and Physics., jun, 2019. Vol. 19(12), pp. 8123-8140. |
BibTeX:
@article{Creamean2019,
author = {Creamean, Jessie M. and Mignani, Claudia and Bukowiecki, Nicolas and Conen, Franz},
title = {Using freezing spectra characteristics to identify ice-nucleating particle populations during the winter in the Alps},
journal = {Atmospheric Chemistry and Physics},
year = {2019},
volume = {19},
number = {12},
pages = {8123--8140},
url = {https://acp.copernicus.org/articles/19/8123/2019/},
doi = {10.5194/acp-19-8123-2019}
}
|
| Crowell S, Baker D, Schuh A, Basu S, Jacobson AR, Chevallier F, Liu J, Deng F, Feng L, Mckain K, Chatterjee A, Miller JB, Stephens BB, Eldering A, Crisp D, Schimel D, Nassar R, O'dell CW, Oda T, Sweeney C, Palmer PI and Jones DBA (2019), "The 2015-2016 carbon cycle as seen from OCO-2 and the global in situ network", Atmos. Chem. Phys. Vol. 19, pp. 9797-9831. |
| Abstract: The Orbiting Carbon Observatory-2 has been on orbit since 2014, and its global coverage holds the potential to reveal new information about the carbon cycle through the use of top-down atmospheric inversion methods combined with column average CO 2 retrievals. We employ a large ensemble of atmospheric inversions utilizing different transport models, data assimilation techniques, and prior flux distributions in order to quantify the satellite-informed fluxes from OCO-2 Version 7r land observations and their uncertainties at continental scales. Additionally, we use in situ measurements to provide a baseline against which to compare the satellite-constrained results. We find that within the ensemble spread, in situ observations, and satellite retrievals constrain a similar global total carbon sink of 3.7 ± 0.5 PgC yr −1 , and 1.5±0.6 PgC yr −1 for global land, for the 2015-2016 annual mean. This agreement breaks down in smaller regions, and we discuss the differences between the experiments. Of particular interest is the difference between the different assimilation constraints in the tropics, with the largest differences occurring in tropical Africa, which could be an indication of the global perturbation from the 2015-2016 El Niño. Evaluation of posterior concentrations using TCCON and aircraft observations gives some limited insight into the quality of the different assimilation constraints, but the lack of such data in the tropics inhibits our ability to make strong conclusions there. Copyright statement. The works published in this journal are distributed under the Creative Commons Attribution 4.0 License. This license does not affect the Crown copyright work, which is re-usable under the Open Government Licence (OGL). The Creative Commons Attribution 4.0 License and the OGL are interoperable and do not conflict with, reduce or limit each other. Published by Copernicus Publications on behalf of the European Geosciences Union. 9798 S. Crowell et al.: The 2015-2016 carbon cycle as seen from OCO-2 and the global in situ network |
BibTeX:
@article{Crowell2019,
author = {Crowell, Sean and Baker, David and Schuh, Andrew and Basu, Sourish and Jacobson, Andrew R and Chevallier, Frederic and Liu, Junjie and Deng, Feng and Feng, Liang and Mckain, Kathryn and Chatterjee, Abhishek and Miller, John B and Stephens, Britton B and Eldering, Annmarie and Crisp, David and Schimel, David and Nassar, Ray and O'dell, Christopher W and Oda, Tomohiro and Sweeney, Colm and Palmer, Paul I and Jones, Dylan B A},
title = {The 2015-2016 carbon cycle as seen from OCO-2 and the global in situ network},
journal = {Atmos. Chem. Phys},
year = {2019},
volume = {19},
pages = {9797--9831},
url = {https://doi.org/10.5194/acp-19-9797-2019},
doi = {10.5194/acp-19-9797-2019}
}
|
| Cui W and Chui TFM (2019), "Temporal and spatial variations of energy balance closure across FLUXNET research sites", Agricultural and Forest Meteorology., jun, 2019. Vol. 271, pp. 12-21. Elsevier B.V.. |
| Abstract: There is always a discrepancy between available energy and output energy in the surface energy budget of FLUXNET research sites. Using the daily data retrieved from the FLUXNET database, the energy balance closure (EBC) of around 150 sites covering nine land covers and five Köppen climate zones [i.e. tropical area (A), dry area (B), mild temperate area (C), snow area (D) and polar area (E)] was analyzed. The temporal and spatial variations of EBC in different land covers and climate zones were summarized, and the relationships between EBC and environmental variables were explored. The possible differences in the EBCs of sites with open path (OP) and closed path (CP) gas analyzers were also examined at different precipitation levels in various climate zones. The results showed that EBC was positively related to air temperature (Ta) and vapor pressure deficit (VPD) below certain thresholds. Better EBCs were observed in land covers with stable evaporative fraction (i.e. the ratio of latent heat flux to the sum of latent and sensible heat fluxes). For land covers with seasonal varying evaporative fraction, the larger evaporative fraction in summer corresponded with better EBCs. OP systems resulted in better EBCs at various precipitation levels, and EBCs decreased with increasing precipitation for both OP and CP systems. In addition, the relationship between EBC and CO 2 fluxes was different among the different land covers. There was a positive relationship for most land covers but not for savannah, shrub land, and evergreen broadleaf forest. The relationships between EBC and CO 2 as well as EBC and other environmental variables are cross-influenced, which could be related to the stomata aperture and metabolism of the vegetation. Overall, this study summarized patterns of EBCs that could be used to correct eddy covariance data and energy balance closure related models. It further enhanced our understanding of the potential link between EBC and vegetation physiology that could facilitate the modeling and prediction of biophysical processes related to water, energy, and carbon fluxes from the leaf to ecosystem levels. |
BibTeX:
@article{Cui2019,
author = {Cui, Wenhui and Chui, Ting Fong May},
title = {Temporal and spatial variations of energy balance closure across FLUXNET research sites},
journal = {Agricultural and Forest Meteorology},
publisher = {Elsevier B.V.},
year = {2019},
volume = {271},
pages = {12--21},
doi = {10.1016/j.agrformet.2019.02.026}
}
|
| Dangal SRS, Tian H, Xu R, Chang J, Canadell JG, Ciais P, Pan S, Yang J and Zhang B (2019), "Global Nitrous Oxide Emissions From Pasturelands and Rangelands: Magnitude, Spatiotemporal Patterns, and Attribution", Global Biogeochemical Cycles., feb, 2019. Vol. 33(2), pp. 200-222. American Geophysical Union (AGU). |
| Abstract: The application of manure and mineral nitrogen (N) fertilizer, and livestock excreta deposition are the main drivers of nitrous oxide (N 2 O) emissions in agricultural systems. However, the magnitude and spatiotemporal variations of N 2 O emissions due to different management practices (excreta deposition and manure/fertilizer application) from grassland ecosystems remain unclear. In this study, we used the Dynamic Land Ecosystem Model to simulate the spatiotemporal variation in global N 2 O emissions and their attribution to different sources from both intensively managed (pasturelands) and extensively managed (rangelands) grasslands during 1961–2014. Over the study period, pasturelands and rangelands experienced a significant increase in N 2 O emissions from 1.74 Tg N 2 O-N in 1961 to 3.11 Tg N 2 O-N in 2014 (p  0.05). Globally, pasturelands and rangelands were responsible for 54% (2.2 Tg N 2 O-N) of the total agricultural N 2 O emissions (4.1 Tg N 2 O-N) in 2006. Natural and anthropogenic sources contributed 26% (0.64 Tg N 2 O-N/year) and 74% (1.78 Tg N 2 O-N/year) of the net emissions, respectively. Across different biomes, pasturelands (i.e., C3 and C4) were the single largest contributor to N 2 O fluxes, accounting for 86% of the net global emissions from grasslands. Among different sources, livestock excreta deposition contributed 54% of the net emissions, followed by manure N (13%) and mineral N (7%) application. Regionally, southern Asia contributed 38% of the total emissions, followed by Europe (29%) and North America (16%). Our modeling study demonstrates that livestock excreta deposition and manure/fertilizer application have dramatically altered the N cycle in pasturelands, with a substantial impact on the climate system. |
BibTeX:
@article{Dangal2019,
author = {Dangal, Shree R S and Tian, Hanqin and Xu, Rongting and Chang, Jinfeng and Canadell, Josep G and Ciais, Philippe and Pan, Shufen and Yang, Jia and Zhang, Bowen},
title = {Global Nitrous Oxide Emissions From Pasturelands and Rangelands: Magnitude, Spatiotemporal Patterns, and Attribution},
journal = {Global Biogeochemical Cycles},
publisher = {American Geophysical Union (AGU)},
year = {2019},
volume = {33},
number = {2},
pages = {200--222},
doi = {10.1029/2018GB006091}
}
|
| Darenova E, Dušek J and Mžourková-Macalková L (2019), "Are the hydrophobic membrane tubes suitable for instantaneous soil CO 2 concentration measurements?", In Indian Journal of Geo Marine Sciences. Vol. 48(02), pp. 223-227.
[BibTeX] |
BibTeX:
@techreport{Darenova2019,
author = {Darenova, Eva and Dušek, Jiří and Mžourková-Macalková, Lenka},
title = {Are the hydrophobic membrane tubes suitable for instantaneous soil CO 2 concentration measurements?},
booktitle = {Indian Journal of Geo Marine Sciences},
year = {2019},
volume = {48},
number = {02},
pages = {223--227}
}
|
| Darenova E, Szatniewska J, Acosta M and Pavelka M (2019), "Variability of stem CO2 efflux response to temperature over the diel period", Tree Physiology., dec, 2019. Vol. 39(5), pp. 877-887. Oxford University Press (OUP). |
| Abstract: This study presents results from continuous measurements of stem CO2 efflux carried out for seven growing seasons in a young Norway spruce forest. The objective of the study was to determine differences in temperature sensitivity of stem CO2 efflux (Q10) during night (when sap flow is zero or nearly zero), during early afternoon (when the maximum rate of sap flow occurs) and during two transition periods between the aforementioned periods. The highest Q10 was recorded during the period of zero sap flow, while the lowest Q10 was observed in period of the highest sap flow. Calculating Q10 using only data from the period of zero sap flow resulted in a Q10 that was higher by as much as 19% compared with Q10 calculated using 24 h data. On the other hand, basing the calculation on data from the period of the highest sap flow yielded 5.6% lower Q10 than if 24 h data were used. Considering that change in CO2 efflux lagged in time behind changing stem temperature, there was only a small effect on calculated Q10 for periods with zero and the highest sap flow. A larger effect of the time lag (by as much as 15%) was observed for the two transition periods. Stem CO2 efflux was modelled based on the night CO2 efflux response to temperature. This model had a tendency to overestimate CO2 efflux during daytime, thus indicating potential daytime depression of stem CO2 efflux compared with the values predicated on the basis of temperature caused by CO2 transport upward in the sap flow. This view was supported by our results inasmuch as the overestimation grew with sap flow that was modelled on the basis of photosynthetically active radiation and vapour pressure deficit. |
BibTeX:
@article{Darenova2019a,
author = {Darenova, Eva and Szatniewska, Justyna and Acosta, Manuel and Pavelka, Marian},
editor = {Ryan, Michael},
title = {Variability of stem CO2 efflux response to temperature over the diel period},
journal = {Tree Physiology},
publisher = {Oxford University Press (OUP)},
year = {2019},
volume = {39},
number = {5},
pages = {877--887},
doi = {10.1093/treephys/tpy134}
}
|
| Davis RE, Talley LD, Roemmich D, Owens WB, Rudnick DL, Toole J, Weller R, McPhaden MJ and Barth JA (2019), "100 Years of Progress in Ocean Observing Systems", Meteorological Monographs., jan, 2019. Vol. 59, pp. 3.1-3.46. American Meteorological Society. |
| Abstract: The history of over 100 years of observing the ocean is reviewed. The evolution of particular classes of ocean measurements (e.g., shipboard hydrography, moorings, and drifting floats) are summarized along with some of the discoveries and dynamical understanding they made possible. By the 1970s, isolated and “expedition” observational approaches were evolving into experimental campaigns that covered large ocean areas and addressed multiscale phenomena using diverse instrumental suites and associated modeling and analysis teams. The Mid-Ocean Dynamics Experiment (MODE) addressed mesoscale “eddies” and their interaction with larger-scale currents using new ocean modeling and experiment design techniques and a suite of developing observational methods. Following MODE, new instrument networks were established to study processes that dominated ocean behavior in different regions. The Tropical Ocean Global Atmosphere program gathered multiyear time series in the tropical Pacific to understand, and eventually predict, evolution of coupled ocean–atmosphere phenomena like El Niño–Southern Oscillation (ENSO). The World Ocean Circulation Experiment (WOCE) sought to quantify ocean transport throughout the global ocean using temperature, salinity, and other tracer measurements along with fewer direct velocity measurements with floats and moorings. Western and eastern boundary currents attracted comprehensive measurements, and various coastal regions, each with its unique scientific and societally important phenomena, became home to regional observing systems. Today, the trend toward networked observing arrays of many instrument types continues to be a productive way to understand and predict large-scale ocean phenomena. |
BibTeX:
@article{Davis2019,
author = {Davis, Russ E. and Talley, Lynne D. and Roemmich, Dean and Owens, W. Brechner and Rudnick, Daniel L. and Toole, John and Weller, Robert and McPhaden, Michael J. and Barth, John A.},
title = {100 Years of Progress in Ocean Observing Systems},
journal = {Meteorological Monographs},
publisher = {American Meteorological Society},
year = {2019},
volume = {59},
pages = {3.1--3.46},
url = {http://journals.ametsoc.org/mono/article-pdf/doi/10.1175/AMSMONOGRAPHS-D-18-0014.1/4941360/amsmonographs-d-18-0014_1.pdf},
doi = {10.1175/amsmonographs-d-18-0014.1}
}
|
| DeCola P, Tarasova O, Brunner D, Maksyutov S, Manning A, Vogel F, Gurney K, Turnbull J, Zavala-Araiza D, Kort E, Robinson R, Canadell P, Ciais P, Vladu F, Houweling S, Lauvaux T, Mueller K, Vermeulen A(LU and Al. E (2019), "An Integrated Global Greenhouse Gas Information System (IG3IS) Science Implementation Plane - GAW Report No. 245". Thesis at: WMO. Geneva , pp. 62. |
| Abstract: The implementation of the Paris Agreement will require countries and sub-national entities to take actions to reduce emissions of greenhouse gases in an optimal way. To assist the countries in meeting their commitments the World Meteorological Organization (WMO) and its partners have initiated the development of an Integrated Global Greenhouse Gas Information System (IG3IS). IG3IS looks to serve users (decision-makers) who are able and willing to take actions to reduce emissions of greenhouse gases and pollutants that reduce air quality. This service is based on existing and successful methods and use-cases for which the scientific and technical skill is proven or emerging. The Science Implementation Plan presents the suite of the technical solutions that are available to address articulated user needs on different scales (from national to facility). It also paves the way for the development of future solutions where additional research is required. This document presents the main principles of the IG3IS Science Implementation Plan. The choice of the objective to be implemented has to be made by the countries or sub-national implementation bodies/practitioners. For each individual objective, the plan presents the available and proven tools based on measurements and model analyses. It summarizes key elements required to implement individual solutions. The plan describes the approach to the modelling coordination activities to ensure harmonized and quality assured global implementation and compatibility of the products delivered on different scales. The measure of success of the IG3IS implementation is the use of the provided information for valuable and additional emission reduction actions, building user confidence and practitioner skills in the value of atmospheric composition measurements as an essential part of the climate change mitigation and pollution remediation tool kits. The IG3IS team defined four implementation objectives: 1) improve knowledge of national emissions (including reduction of uncertainties of inventory reporting to the United Nations Framework Convention on Climate Change (UNFCCC)); 2) locate and quantify previously unknown emission reduction opportunities such as fugitive methane emissions from industrial sources; 3) provide sub-national entities such as large urban source regions (for example, megacities) with timely and quantified information on the amounts, trends and attribution by sector of their greenhouse gas (GHG) emissions to evaluate and guide progress towards emission reduction goals; and 4) support for the Paris Agreement's global stocktake through the integration of these objectives. This Science Implementation Plan documents the “good-practice†methodological guidelines for how atmospheric measurements and analysis methods can deliver valuable information under each objective area. This plan and the team that prepared it, will serve to guide WMO Members and their partners in the definition and implementation of new IG3IS projects that apply and advance these “good-practice†capabilities. The plan will evolve overtime to respond to new policy challenges and to capture emerging capabilities. Successful application of IG3IS methods depends on intimate dialogue between scientists and users in order to ensure that user requirements are met, and so that users are introduced to previously unknown capabilities that may drive them to address challenges in new ways. IG3IS takes a highly collaborative “Translation Atmospheric Sciences†approach to deliver science-based services to potential stakeholders/users and is well in line with the implementation plan of the Global Atmosphere Watch (GAW) Programme. The plan directly supports implementation of the WMO Strategic Plan for 2020-2023, Objective 3.2 “Advance policy-relevant scienceâ€. |
BibTeX:
@techreport{DeCola2019,
author = {DeCola, Phil and Tarasova, Oksana and Brunner, Dominik and Maksyutov, Shamil and Manning, Alistair and Vogel, Felix and Gurney, Kevin and Turnbull, Jocelyn and Zavala-Araiza, Daniel and Kort, Eric and Robinson, Rod and Canadell, Pep and Ciais, Philippe and Vladu, Florin and Houweling, Sander and Lauvaux, Thomas and Mueller, Kim and Vermeulen, Alex (Lund University) and Al., Et},
title = {An Integrated Global Greenhouse Gas Information System (IG3IS) Science Implementation Plane - GAW Report No. 245},
school = {WMO},
year = {2019},
pages = {62},
url = {https://library.wmo.int/index.php?lvl=etagere_see&id=144#.WK2TTBiZNB}
}
|
| Deirmendjian L, Anschutz P, Morel C, Mollier A, Augusto L, Loustau D, Cotovicz LC, Buquet D, Lajaunie K, Chaillou G, Voltz B, Charbonnier C, Poirier D and Abril G (2019), "Importance of the vegetation-groundwater-stream continuum to understand transformation of biogenic carbon in aquatic systems – A case study based on a pine-maize comparison in a lowland sandy watershed (Landes de Gascogne, SW France)", Science of the Total Environment., apr, 2019. Vol. 661, pp. 613-629. Elsevier BV. |
| Abstract: During land-aquatic transfer, carbon (C) and inorganic nutrients (IN) are transformed in soils, groundwater, and at the groundwater-surface water interface as well as in stream channels and stream sediments. However, processes and factors controlling these transfers and transformations are not well constrained, particularly with respect to land use effect. We compared C and IN concentrations in shallow groundwater and first-order streams of a sandy lowland catchment dominated by two types of land use: pine forest and maize cropland. Contrary to forest groundwater, crop groundwater exhibited oxic conditions all-year round as a result of higher evapotranspiration and better lateral drainage that decreased the water table below the organic-rich soil horizon, prevented the leaching of soil-generated dissolved organic carbon (DOC) in groundwater, and thus limited consumption of dissolved oxygen (O 2 ). In crop groundwater, oxic conditions inhibited denitrification and methanogenesis resulting in high nitrate (NO 3âˆ' ; on average 1140 ± 485 μmol L âˆ'1 ) and low methane (CH 4 ; 40 ± 25 nmol L âˆ'1 ) concentrations. Conversely, anoxic conditions in forest groundwater led to lower NO 3âˆ' (25 ± 40 μmol L âˆ' 1) and higher CH 4 (1770 ± 1830 nmol L âˆ'1 ) concentrations. The partial pressure of carbon dioxide (pCO 2 ; 30,650 ± 11,590 ppmv) in crop groundwater was significantly lower than in forest groundwater (50,630 ± 26,070 ppmv), and was apparently caused by the deeper water table delaying downward diffusion of soil CO 2 to the water table. In contrast, pCO 2 was not significantly different in crop (4480 ± 2680 ppmv) and forest (4900 ± 4500 ppmv) streams, suggesting faster degassing in forest streams resulting from greater water turbulence. Although NO 3âˆ' concentrations indicated that denitrification occurred in riparian-forest groundwater, crop streams nevertheless exhibited important signs of spring and summer eutrophication such as the development of macrophytes. Stream eutrophication favored development of anaerobic conditions in crop stream sediments, as evidenced by increased ammonia (NH 4+ ) and CH 4 in stream waters and concomitant decreased in NO 3âˆ' concentrations as a result of sediment denitrification. In crop streams, dredging and erosion of streambed sediments during winter sustained high concentration of particulate organic C, NH 4+ and CH 4 . In forest streams, dissolved iron (Fe 2+ ), NH 4+ and CH 4 were negatively correlated with O 2 reflecting the gradual oxygenation of stream water and associated oxidations of Fe 2+ , NH 4+ and CH 4 . The results overall showed that forest groundwater behaved as source of CO 2 and CH 4 to streams, the intensity depending on the hydrological connectivity among soils, groundwater, and streams. CH 4 production was prevented in cropland in soils and groundwater, however crop groundwater acted as a source of CO 2 to streams (but less so than forest groundwater). Conversely, in streams, pCO 2 was not significantly affected by land use while CH 4 production was enhanced by cropland. At the catchment scale, this study found substantial biogeochemical heterogeneity in C and IN concentrations between forest and crop waters, demonstrating the importance of including the full vegetation-groundwater-stream continuum when estimating land-water fluxes of C (and nitrogen) and attempting to understand their spatial and temporal dynamics. |
BibTeX:
@article{Deirmendjian2019,
author = {Deirmendjian, Loris and Anschutz, Pierre and Morel, Christian and Mollier, Alain and Augusto, Laurent and Loustau, Denis and Cotovicz, Luiz Carlos and Buquet, Damien and Lajaunie, Katixa and Chaillou, Gwenaëlle and Voltz, Baptiste and Charbonnier, Céline and Poirier, Dominique and Abril, Gwenaël},
title = {Importance of the vegetation-groundwater-stream continuum to understand transformation of biogenic carbon in aquatic systems – A case study based on a pine-maize comparison in a lowland sandy watershed (Landes de Gascogne, SW France)},
journal = {Science of the Total Environment},
publisher = {Elsevier BV},
year = {2019},
volume = {661},
pages = {613--629},
doi = {10.1016/j.scitotenv.2019.01.152}
}
|
| Delon C, Galy-Lacaux C, Serça D, Personne E, Mougin E, Adon M, Le Dantec V, Loubet B, Fensholt R and Tagesson T (2019), "Modelling land-atmosphere daily exchanges of NO, NH3, and CO2 in a semi-arid grazed ecosystem in Senegal", Biogeosciences., may, 2019. Vol. 16(9), pp. 2049-2077. Copernicus GmbH. |
| Abstract: Three different models (STEP-GENDEC-NOflux, Zhang2010, and Surfatm) are used to simulate NO, CO2, and NH3 fluxes at the daily scale for 2 years (2012-2013) in a semi-arid grazed ecosystem at Dahra (15°24′10′ ′ N, 15°25′56′ ′W, Senegal, Sahel). Model results are evaluated against experimental results acquired during three field campaigns. At the end of the dry season, when the first rains re-wet the dry soils, the model STEP-GENDEC-NOflux simulates the sudden mineralization of buried litter, leading to pulses in soil respiration and NO fluxes. The contribution of wet season fluxes of NO and CO2 to the annual mean is respectively 51% and 57 %. NH3 fluxes are simulated by two models: Surfatm and Zhang2010. During the wet season, air humidity and soil moisture increase, leading to a transition between low soil NH3 emissions (which dominate during the dry months) and large NH3 deposition on vegetation during wet months. Results show a great impact of the soil emission potential, a difference in the deposition processes on the soil and the vegetation between the two models with however a close agreement of the total fluxes. The order of magnitude of NO, NH3, and CO2 fluxes is correctly represented by the models, as well as the sharp transitions between seasons, specific to the Sahel region. The role of soil moisture in flux magnitude is highlighted, whereas the role of soil temperature is less obvious. The simultaneous increase in NO and CO2 emissions and NH3 deposition at the beginning of the wet season is attributed to the availability of mineral nitrogen in the soil and also to microbial processes, which distribute the roles between respiration (CO2 emissions), nitrification (NO emissions), volatilization, and deposition (NH3 emission/deposition). The objectives of this study are to understand the origin of carbon and nitrogen compounds exchanges between the soil and the atmosphere and to quantify these exchanges on a longer timescale when only a few measurements have been performed. |
BibTeX:
@article{Delon2019,
author = {Delon, Claire and Galy-Lacaux, Corinne and Serça, Dominique and Personne, Erwan and Mougin, Eric and Adon, Marcellin and Le Dantec, Valérie and Loubet, Benjamin and Fensholt, Rasmus and Tagesson, Torbern},
title = {Modelling land-atmosphere daily exchanges of NO, NH3, and CO2 in a semi-arid grazed ecosystem in Senegal},
journal = {Biogeosciences},
publisher = {Copernicus GmbH},
year = {2019},
volume = {16},
number = {9},
pages = {2049--2077},
doi = {10.5194/bg-16-2049-2019}
}
|
| De Marco A, Proietti C, Anav A, Ciancarella L, D'Elia I, Fares S, Fornasier MF, Fusaro L, Gualtieri M, Manes F, Marchetto A, Mircea M, Paoletti E, Piersanti A, Rogora M, Salvati L, Salvatori E, Screpanti A, Vialetto G, Vitale M and Leonardi C (2019), "Impacts of air pollution on human and ecosystem health, and implications for the National Emission Ceilings Directive: Insights from Italy", Environment International., apr, 2019. Vol. 125, pp. 320-333. Elsevier BV. |
| Abstract: Across the 28 EU member states there were nearly half a million premature deaths in 2015 as a result of exposure to PM2.5, O3 and NO2. To set the target for air quality levels and avoid negative impacts for human and ecosystems health, the National Emission Ceilings Directive (NECD, 2016/2284/EU) sets objectives for emission reduction for SO2, NOx, NMVOCs, NH3 and PM2.5 for each Member State as percentages of reduction to be reached in 2020 and 2030 compared to the emission levels into 2005. One of the innovations of NECD is Article 9, that mentions the issue of “monitoring air pollution impacts†on ecosystems. We provide a clear picture of what is available in term of monitoring network for air pollution impacts on Italian ecosystems, summarizing what has been done to control air pollution and its effects on different ecosystems in Italy. We provide an overview of the impacts of air pollution on health of the Italian population and evaluate opportunities and implementation of Article 9 in the Italian context, as a case study beneficial for all Member States. The results showed that SO42âˆ' deposition strongly decreased in all monitoring sites in Italy over the period 1999–2017, while NO3âˆ' and NH4+ decreased more slightly. As a consequence, most of the acid-sensitive sites which underwent acidification in the 1980s partially recovered. The O3 concentration at forest sites showed a decreasing trend. Consequently, AOT40 (the metric identified to protect vegetation from ozone pollution) showed a decrease, even if values were still above the limit for forest protection (5000 ppb hâˆ'1), while PODy (flux-based metric under discussion as new European legislative standard for forest protection) showed an increase. National scale studies pointed out that PM10 and NO2 induced about 58,000 premature deaths (year 2005), due to cardiovascular and respiratory diseases. The network identified for Italy contains a good number of monitoring sites (6 for terrestrial ecosystem monitoring, 4 for water bodies monitoring and 11 for ozone impact monitoring) distributed over the territory and will produce a high number of monitored parameters for the implementation of the NECD. |
BibTeX:
@article{DeMarco2019,
author = {De Marco, Alessandra and Proietti, Chiara and Anav, Alessandro and Ciancarella, Luisella and D'Elia, Ilaria and Fares, Silvano and Fornasier, Maria Francesca and Fusaro, Lina and Gualtieri, Maurizio and Manes, Fausto and Marchetto, Aldo and Mircea, Mihaela and Paoletti, Elena and Piersanti, Antonio and Rogora, Michela and Salvati, Luca and Salvatori, Elisabetta and Screpanti, Augusto and Vialetto, Giovanni and Vitale, Marcello and Leonardi, Cristina},
title = {Impacts of air pollution on human and ecosystem health, and implications for the National Emission Ceilings Directive: Insights from Italy},
journal = {Environment International},
publisher = {Elsevier BV},
year = {2019},
volume = {125},
pages = {320--333},
doi = {10.1016/j.envint.2019.01.064}
}
|
| Denvil-Sommer A, Gehlen M, Vrac M and Mejia C (2019), "LSCE-FFNN-v1: a two-step neural network model for the reconstruction of surface ocean &lt;i&gt;p&lt;/i&gt;CO&lt;sub&gt;2&lt;/sub&gt; over the global ocean", Geoscientific Model Development., may, 2019. Vol. 12(5), pp. 2091-2105. Copernicus GmbH. |
| Abstract: textlessptextgreatertextless![CDATA[Abstract. A new feed-forward neural network (FFNN) model is presented to reconstruct surface ocean partial pressure of carbon dioxide (pCO2) over the global ocean. The model consists of two steps: (1) the reconstruction of pCO2 climatology, and (2) the reconstruction of pCO2 anomalies with respect to the climatology. For the first step, a gridded climatology was used as the target, along with sea surface salinity (SSS), sea surface temperature (SST), sea surface height (SSH), chlorophyll a (Chl a), mixed layer depth (MLD), as well as latitude and longitude as predictors. For the second step, data from the Surface Ocean CO2 Atlas (SOCAT) provided the target. The same set of predictors was used during step (2) augmented by their anomalies. During each step, the FFNN model reconstructs the nonlinear relationships between pCO2 and the ocean predictors. It provides monthly surface ocean pCO2 distributions on a 1∘×1∘ grid for the period from 2001 to 2016. Global ocean pCO2 was reconstructed with satisfying accuracy compared with independent observational data from SOCAT. However, errors were larger in regions with poor data coverage (e.g., the Indian Ocean, the Southern Ocean and the subpolar Pacific). The model captured the strong interannual variability of surface ocean pCO2 with reasonable skill over the equatorial Pacific associated with ENSO (the El Niño–Southern Oscillation). Our model was compared to three pCO2 mapping methods that participated in the Surface Ocean pCO2 Mapping intercomparison (SOCOM) initiative. We found a good agreement in seasonal and interannual variability between the models over the global ocean. However, important differences still exist at the regional scale, especially in the Southern Hemisphere and, in particular, in the southern Pacific and the Indian Ocean, as these regions suffer from poor data coverage. Large regional uncertainties in reconstructed surface ocean pCO2 and sea–air CO2 fluxes have a strong influence on global estimates of CO2 fluxes and trends.]]textgreatertextless/ptextgreater |
BibTeX:
@article{Denvil-Sommer2019,
author = {Denvil-Sommer, Anna and Gehlen, Marion and Vrac, Mathieu and Mejia, Carlos},
title = {LSCE-FFNN-v1: a two-step neural network model for the reconstruction of surface ocean &lt;i&gt;p&lt;/i&gt;CO&lt;sub&gt;2&lt;/sub&gt; over the global ocean},
journal = {Geoscientific Model Development},
publisher = {Copernicus GmbH},
year = {2019},
volume = {12},
number = {5},
pages = {2091--2105},
url = {https://gmd.copernicus.org/articles/12/2091/2019/},
doi = {10.5194/gmd-12-2091-2019}
}
|
| DeVries T, Le Quéré C, Andrews O, Berthet S, Hauck J, Ilyina T, Landschützer P, Lenton A, Lima ID, Nowicki M, Schwinger J and Séférian R (2019), "Decadal trends in the ocean carbon sink", Proceedings of the National Academy of Sciences of the United States of America., jun, 2019. Vol. 116(24), pp. 11646-11651. National Academy of Sciences. |
| Abstract: Measurements show large decadal variability in the rate of CO2 accumulation in the atmosphere that is not driven by CO2 emissions. The decade of the 1990s experienced enhanced carbon accumulation in the atmosphere relative to emissions, while in the 2000s, the atmospheric growth rate slowed, even though emissions grew rapidly. These variations are driven by natural sources and sinks of CO2 due to the ocean and the terrestrial biosphere. In this study, we compare three independent methods for estimating oceanic CO2 uptake and find that the ocean carbon sink could be responsible for up to 40% of the observed decadal variability in atmospheric CO2 accumulation. Data-based estimates of the ocean carbon sink from pCO2 mapping methods and decadal ocean inverse models generally agree on the magnitude and sign of decadal variability in the ocean CO2 sink at both global and regional scales. Simulations with ocean biogeochemical models confirm that climate variability drove the observed decadal trends in ocean CO2 uptake, but also demonstrate that the sensitivity of ocean CO2 uptake to climate variability may be too weak in models. Furthermore, all estimates point toward coherent decadal variability in the oceanic and terrestrial CO2 sinks, and this variability is not well-matched by current global vegetation models. Reconciling these differences will help to constrain the sensitivity of oceanic and terrestrial CO2 uptake to climate variability and lead to improved climate projections and decadal climate predictions. |
BibTeX:
@article{DeVries2019,
author = {DeVries, Tim and Le Quéré, Corinne and Andrews, Oliver and Berthet, Sarah and Hauck, Judith and Ilyina, Tatiana and Landschützer, Peter and Lenton, Andrew and Lima, Ivan D. and Nowicki, Michael and Schwinger, Jörg and Séférian, Roland},
title = {Decadal trends in the ocean carbon sink},
journal = {Proceedings of the National Academy of Sciences of the United States of America},
publisher = {National Academy of Sciences},
year = {2019},
volume = {116},
number = {24},
pages = {11646--11651},
url = {https://www.pnas.org/content/116/24/11646 https://www.pnas.org/content/116/24/11646.abstract},
doi = {10.1073/pnas.1900371116}
}
|
| Djomo SN, De Groote T, Gobin A, Ceulemans R and Janssens IA (2019), "Combining a land surface model with life cycle assessment for identifying the optimal management of short rotation coppice in Belgium", Biomass and Bioenergy., feb, 2019. Vol. 121, pp. 78-88. Elsevier BV. |
| Abstract: Poplar (Populus spp.) and willow (Salix spp.) short rotation coppice (SRC) are attractive feedstock for conversion to renewable electricity. Site managers typically optimize biomass production at their sites. However, maximum biomass production does not necessarily equate an optimal CO2 balance, water use and energy production. This is because many operational actions consume water and energy and emit CO2, either on-site or off-site. Coupling a land surface model (ORCHIDEE-SRC) with life cycle assessment enabled us to determine the optimal management for SRC in Belgium. We simulated 120 different management scenarios for each of two well-studied Belgian SRC sites (i.e. Boom and Lochristi). Simulated soil carbon changes suggested substantial carbon losses of 20–30 Mg haâˆ'1 over a time period of 20 years, which were within observation-based uncertainty bounds. Results showed that in Belgium, which has a temperate maritime climate, optimal management of SRC has a rotation cycle of two years without irrigation. Energy inputs for this optimal management were 5.2 GJ haâˆ'1 yrâˆ'1 for the Boom site and 5.3 GJ haâˆ'1 yrâˆ'1 for the Lochristi site, while the biomass yields at Boom and Lochristi were 9.0 Mg haâˆ'1 yrâˆ'1 and 9.4 Mg haâˆ'1 yrâˆ'1, respectively. The energy ratio (i.e., ratio of bioelectricity output to cumulative energy input) for this optimal management was 12, on average. Planting density turned out to be unimportant, while rotation length turned out to be most important to obtain the highest energy ratio and still maintain high biomass yield. Scenarios with high energy-input generated more bioenergy outputs, but the energy gains did not compensate for the increased energy inputs. Reductions in energy consumption per unit of bioenergy output should target the agricultural stage since it accounted for the largest energy share in the production chain. |
BibTeX:
@article{Djomo2019,
author = {Djomo, S Njakou and De Groote, T and Gobin, A and Ceulemans, R and Janssens, I A},
title = {Combining a land surface model with life cycle assessment for identifying the optimal management of short rotation coppice in Belgium},
journal = {Biomass and Bioenergy},
publisher = {Elsevier BV},
year = {2019},
volume = {121},
pages = {78--88},
doi = {10.1016/j.biombioe.2018.12.010}
}
|
| Draper C and Reichle RH (2019), "Assimilation of satellite soil moisture for improved atmospheric reanalyses", Monthly Weather Review., jun, 2019. Vol. 147(6), pp. 2163-2188. American Meteorological Society. |
| Abstract: A newly developed, weakly coupled land and atmosphere data assimilation system for NASA's Global Earth Observing System model is presented, and used to demonstrate the benefit of assimilating satellite soil moisture into an atmospheric reanalysis. Specifically, Advanced Scatterometer and Soil Moisture Ocean Salinity soil moisture retrievals are assimilated into a system that uses the same model, atmospheric assimilation system, and atmospheric observations as the Modern-Era Retrospective Analysis for Research and Applications, version 2 (MERRA-2). The atmosphere is sensitive to soil moisture only under certain conditions. Hence, while the globally averaged model improvements were small, regionally, the soil moisture assimilation induced some substantial improvements. For example, in a large region spanning from western Europe across southern Russia, the soil moisture assimilation decreased the RMSE against independent station observations of daily maximum 2-m temperature (Tmax2m ) by up to 0.4 K, and of 2-m specific humidity (q2m) by up to 0.5 g kg-1. Over all available stations, the mean Tmax2m RMSE was reduced from 2.82 to 2.79 K, while the mean q2m RMSE was reduced from 1.25 to 1.20 g kg-1. The soil moisture assimilation also reduced the mean RMSE across 29 flux tower sites from 34.2 to 32.6Wm-2 for latent heating, and from 37.7 to 36.5Wm-2 for sensible heating. For all variables evaluated, the soil moisture assimilation improved the model at monthly to seasonal, rather than daily, time scales. Based on the above experiments, it is recommended that satellite soil moisture be assimilated into future reanalyses, including the follow-on to MERRA-2. |
BibTeX:
@article{Draper2019,
author = {Draper, Clara and Reichle, Rolf H.},
title = {Assimilation of satellite soil moisture for improved atmospheric reanalyses},
journal = {Monthly Weather Review},
publisher = {American Meteorological Society},
year = {2019},
volume = {147},
number = {6},
pages = {2163--2188},
doi = {10.1175/MWR-D-18-0393.1}
}
|
| Druel A, Ciais P, Krinner G and Peylin P (2019), "Modeling the Vegetation Dynamics of Northern Shrubs and Mosses in the ORCHIDEE Land Surface Model", Journal of Advances in Modeling Earth Systems., jul, 2019. Vol. 11(7), pp. 2020-2035. American Geophysical Union (AGU). |
| Abstract: Parameterizations of plant competition processes involving shrubs, mosses, grasses, and trees were introduced with the recently implemented shrubs and mosses plant functional types in the ORCHIDEE dynamic global vegetation model in order to improve the representation of high latitude vegetation dynamics. Competition is based on light capture for growth, net primary productivity, and survival to cold-induced mortality during winter. Trees are assumed to outcompete shrubs and grasses for light, and shrubs outcompete grasses. Shrubs are modeled to have a higher survival than trees to extremely cold winters because of thermic protection by snow. The fractional coverage of each plant type is based on their respective net primary productivity and winter mortality of trees and shrubs. Gridded simulations were carried out for the historical period and the 21st century following the RCP4.5 and 8.5 scenarios. We evaluate the simulated present-day vegetation with an observation-based distribution map and literature data of boreal shrubs. The simulation produces a realistic present-day boreal vegetation distribution, with shrubs, mosses north of trees and grasses. Nevertheless, the model underestimated local shrub expansion compared to observations from selected sites in the Arctic during the last 30 years suggesting missing processes (nutrients and microscale effects). The RCP4.5 and RCP8.5 projections show a substantial decrease of bare soil, an increase in tree and moss cover and an increase of shrub net primary productivity. Finally, the impact of new vegetation types and associated processes is discussed in the context of climate feedbacks. |
BibTeX:
@article{Druel2019,
author = {Druel, Arsène and Ciais, Philippe and Krinner, Gerhard and Peylin, Philippe},
title = {Modeling the Vegetation Dynamics of Northern Shrubs and Mosses in the ORCHIDEE Land Surface Model},
journal = {Journal of Advances in Modeling Earth Systems},
publisher = {American Geophysical Union (AGU)},
year = {2019},
volume = {11},
number = {7},
pages = {2020--2035},
doi = {10.1029/2018MS001531}
}
|
| Drushka K, Asher WE, Sprintall J, Gille ST and Hoang C (2019), "Global patterns of submesoscale surface salinity variability", Journal of Physical Oceanography., jul, 2019. Vol. 49(7), pp. 1669-1685. American Meteorological Society. |
| Abstract: Surface salinity variability on O(1–10) km lateral scales (the submesoscale) generates density variability and thus has implications for submesoscale dynamics. Satellite salinity measurements represent a spatial average over horizontal scales of approximately 40–100 km but are compared to point measurements for validation, so submesoscale salinity variability also complicates validation of satellite salinities. Here, we combine several databases of historical thermosalinograph (TSG) measurements made from ships to globally characterize surface submesoscale salinity, temperature, and density variability. In river plumes; regions affected by ice melt or upwelling; and the Gulf Stream, South Atlantic, and Agulhas Currents, submesoscale surface salinity variability is large. In these regions, horizontal salinity variability appears to explain some of the differences between surface salinities from the Aquarius and SMOS satellites and salinities measured with Argo floats. In other words, apparent satellite errors in highly variable regions in fact arise because Argo point measurements do not represent spatially averaged satellite data. Salinity dominates over temperature in generating submesoscale surface density variability throughout the tropical rainbands, in river plumes, and in polar regions. Horizontal density fronts on 10-km scales tend to be compensated (salinity and temperature have opposing effects on density) throughout most of the global oceans, with the exception of the south Indian and southwest Pacific Oceans between 20° and 30°S, where fronts tend to be anticompensated. |
BibTeX:
@article{Drushka2019,
author = {Drushka, Kyla and Asher, William E. and Sprintall, Janet and Gille, Sarah T. and Hoang, Clifford},
title = {Global patterns of submesoscale surface salinity variability},
journal = {Journal of Physical Oceanography},
publisher = {American Meteorological Society},
year = {2019},
volume = {49},
number = {7},
pages = {1669--1685},
url = {http://www.legos.obs-mip.fr},
doi = {10.1175/JPO-D-19-0018.1}
}
|
| Dumortier P, Aubinet M, Lebeau F, Naiken A and Heinesch B (2019), "Point source emission estimation using eddy covariance: Validation using an artificial source experiment", Agricultural and Forest Meteorology. Vol. 266-267, pp. 148-156. Elsevier BV. |
| Abstract: Eddy covariance is increasingly used to monitor cattle emissions. However, the turbulent flux calculation method and the footprint models upon which calculations are based are insufficiently validated. In addition, available footprint models presume the source to be placed at soil height, which is obviously not the case for cattle. The present study uses a single known artificial point source placed at cow's muzzle height in order to assess the impact of the flux calculation method (averaging method, averaging period, quality filters) and of the footprint model on the emission estimates. The optimal calculation method and footprint model combination (running mean, 15 min averaging periods, no application of the Foken and Wichura (1996) stationarity filter, and the use of the Kormann and Meixner (2001) footprint function) led to estimated emissions between 90 and 113% of the true emission, leading to the conclusion that the use of eddy-covariance for point-source emission estimation is feasible provided an adequate calculation method is selected. |
BibTeX:
@article{Dumortier2019,
author = {Dumortier, Pierre and Aubinet, Marc and Lebeau, Frédéric and Naiken, Alwin and Heinesch, Bernard},
title = {Point source emission estimation using eddy covariance: Validation using an artificial source experiment},
journal = {Agricultural and Forest Meteorology},
publisher = {Elsevier BV},
year = {2019},
volume = {266-267},
pages = {148--156},
url = {https://doi.org/10.1016%2Fj.agrformet.2018.12.012},
doi = {10.1016/j.agrformet.2018.12.012}
}
|
| Efren LB, Exbrayat JF, Lund M, Christensen TR, Tamstorf MP, Slevin D, Hugelius G, Bloom AA and Williams M (2019), "Evaluation of terrestrial pan-Arctic carbon cycling using a data-assimilation system", Earth System Dynamics., apr, 2019. Vol. 10(2), pp. 233-255. Copernicus GmbH. |
| Abstract: There is a significant knowledge gap in the current state of the terrestrial carbon (C) budget. Recent studies have highlighted a poor understanding particularly of C pool transit times and of whether productivity or biomass dominate these biases. The Arctic, accounting for approximately 50% of the global soil organic C stocks, has an important role in the global C cycle. Here, we use the CARbon DAta MOdel (CARDAMOM) data-assimilation system to produce pan-Arctic terrestrial C cycle analyses for 2000-2015. This approach avoids using traditional plant functional type or steady-state assumptions. We integrate a range of data (soil organic C, leaf area index, biomass, and climate) to determine the most likely state of the high-latitude C cycle at a 11 resolution and also to provide general guidance about the controlling biases in transit times. On average, CARDAMOM estimates regional mean rates of photosynthesis of 565 gCm2 yr1 (90% confidence interval between the 5th and 95th percentiles: 428, 741), autotrophic respiration of 270 g Cm2 yr1 (182, 397) and heterotrophic respiration of 219 g Cm2 yr1 (31, 1458), suggesting a pan-Arctic sink of 67 (287, 1160) gCm2 yr1, weaker in tundra and stronger in taiga. However, our confidence intervals remain large (and so the region could be a source of C), reflecting uncertainty assigned to the regional data products. We show a clear spatial and temporal agreement between CARDAMOM analyses and different sources of assimilated and independent data at both pan-Arctic and local scales but also identify consistent biases between CARDAMOM and validation data. The assimilation process requires clearer error quantification for leaf area index (LAI) and biomass products to resolve these biases. Mapping of vegetation C stocks and change over time and soil C ages linked to soil C stocks is required for better analytical constraint. Comparing CARDAMOM analyses to global vegetation models (GVMs) for the same period, we conclude that transit times of vegetation C are inconsistently simulated in GVMs due to a combination of uncertainties from productivity and biomass calculations. Our findings highlight that GVMs need to focus on constraining both current vegetation C stocks and net primary production to improve a process-based understanding of C cycledynamics in the Arctic. |
BibTeX:
@article{Efren2019,
author = {Efren, Lopez Blanco and Exbrayat, Jean Francois and Lund, Magnus and Christensen, Torben R and Tamstorf, Mikkel P and Slevin, Darren and Hugelius, Gustaf and Bloom, Anthony A and Williams, Mathew},
title = {Evaluation of terrestrial pan-Arctic carbon cycling using a data-assimilation system},
journal = {Earth System Dynamics},
publisher = {Copernicus GmbH},
year = {2019},
volume = {10},
number = {2},
pages = {233--255},
doi = {10.5194/esd-10-233-2019}
}
|
| Esquivel-Muelbert A, Baker TR, Dexter KG, Lewis SL, Brienen RJW, Feldpausch TR, Lloyd J, Monteagudo-Mendoza A, Arroyo L, Álvarez-Dávila E, Higuchi N, Marimon BS, Marimon-Junior BH, Silveira M, Vilanova E, Gloor E, Malhi Y, Chave J, Barlow J, Bonal D, Davila Cardozo N, Erwin T, Fauset S, Hérault B, Laurance S, Poorter L, Qie L, Stahl C, Sullivan MJP, ter Steege H, Vos VA, Zuidema PA, Almeida E, Almeida de Oliveira E, Andrade A, Vieira SA, Aragão L, Araujo-Murakami A, Arets E, Aymard C GA, Baraloto C, Camargo PB, Barroso JG, Bongers F, Boot R, Camargo JL, Castro W, Chama Moscoso V, Comiskey J, Cornejo Valverde F, Lola da Costa AC, del Aguila Pasquel J, Di Fiore A, Fernanda Duque L, Elias F, Engel J, Flores Llampazo G, Galbraith D, Herrera Fernández R, Honorio Coronado E, Hubau W, Jimenez-Rojas E, Lima AJN, Umetsu RK, Laurance W, Lopez-Gonzalez G, Lovejoy T, Aurelio Melo Cruz O, Morandi PS, Neill D, Núñez Vargas P, Pallqui Camacho NC, Parada Gutierrez A, Pardo G, Peacock J, Peña-Claros M, Peñuela-Mora MC, Petronelli P, Pickavance GC, Pitman N, Prieto A, Quesada C, Ramírez-Angulo H, Réjou-Méchain M, Restrepo Correa Z, Roopsind A, Rudas A, Salomão R, Silva N, Silva Espejo J, Singh J, Stropp J, Terborgh J, Thomas R, Toledo M, Torres-Lezama A, Valenzuela Gamarra L, van de Meer PJ, van der Heijden G, van der Hout P, Vasquez Martinez R, Vela C, Vieira ICG and Phillips OL (2019), "Compositional response of Amazon forests to climate change", Global Change Biology., nov, 2019. Vol. 25(1), pp. 39-56. Wiley. |
| Abstract: Most of the planet's diversity is concentrated in the tropics, which includes many regions undergoing rapid climate change. Yet, while climate-induced biodiversity changes are widely documented elsewhere, few studies have addressed this issue for lowland tropical ecosystems. Here we investigate whether the floristic and functional composition of intact lowland Amazonian forests have been changing by evaluating records from 106 long-term inventory plots spanning 30Â years. We analyse three traits that have been hypothesized to respond to different environmental drivers (increase in moisture stress and atmospheric CO 2 concentrations): maximum tree size, biogeographic water-deficit affiliation and wood density. Tree communities have become increasingly dominated by large-statured taxa, but to date there has been no detectable change in mean wood density or water deficit affiliation at the community level, despite most forest plots having experienced an intensification of the dry season. However, among newly recruited trees, dry-affiliated genera have become more abundant, while the mortality of wet-affiliated genera has increased in those plots where the dry season has intensified most. Thus, a slow shift to a more dry-affiliated Amazonia is underway, with changes in compositional dynamics (recruits and mortality) consistent with climate-change drivers, but yet to significantly impact whole-community composition. The Amazon observational record suggests that the increase in atmospheric CO 2 is driving a shift within tree communities to large-statured species and that climate changes to date will impact forest composition, but long generation times of tropical trees mean that biodiversity change is lagging behind climate change. |
BibTeX:
@article{Esquivel-Muelbert2019,
author = {Esquivel-Muelbert, Adriane and Baker, Timothy R and Dexter, Kyle G and Lewis, Simon L and Brienen, Roel J W and Feldpausch, Ted R and Lloyd, Jon and Monteagudo-Mendoza, Abel and Arroyo, Luzmila and Álvarez-Dávila, Esteban and Higuchi, Niro and Marimon, Beatriz S and Marimon-Junior, Ben Hur and Silveira, Marcos and Vilanova, Emilio and Gloor, Emanuel and Malhi, Yadvinder and Chave, Jerôme and Barlow, Jos and Bonal, Damien and Davila Cardozo, Nallaret and Erwin, Terry and Fauset, Sophie and Hérault, Bruno and Laurance, Susan and Poorter, Lourens and Qie, Lan and Stahl, Clement and Sullivan, Martin J P and ter Steege, Hans and Vos, Vincent Antoine and Zuidema, Pieter A and Almeida, Everton and Almeida de Oliveira, Edmar and Andrade, Ana and Vieira, Simone Aparecida and Aragão, Luiz and Araujo-Murakami, Alejandro and Arets, Eric and Aymard C, Gerardo A and Baraloto, Christopher and Camargo, Plínio Barbosa and Barroso, Jorcely G and Bongers, Frans and Boot, Rene and Camargo, José Luís and Castro, Wendeson and Chama Moscoso, Victor and Comiskey, James and Cornejo Valverde, Fernando and Lola da Costa, Antonio Carlos and del Aguila Pasquel, Jhon and Di Fiore, Anthony and Fernanda Duque, Luisa and Elias, Fernando and Engel, Julien and Flores Llampazo, Gerardo and Galbraith, David and Herrera Fernández, Rafael and Honorio Coronado, Eurídice and Hubau, Wannes and Jimenez-Rojas, Eliana and Lima, Adriano José Nogueira and Umetsu, Ricardo Keichi and Laurance, William and Lopez-Gonzalez, Gabriela and Lovejoy, Thomas and Aurelio Melo Cruz, Omar and Morandi, Paulo S and Neill, David and Núñez Vargas, Percy and Pallqui Camacho, Nadir C and Parada Gutierrez, Alexander and Pardo, Guido and Peacock, Julie and Peña-Claros, Marielos and Peñuela-Mora, Maria Cristina and Petronelli, Pascal and Pickavance, Georgia C and Pitman, Nigel and Prieto, Adriana and Quesada, Carlos and Ramírez-Angulo, Hirma and Réjou-Méchain, Maxime and Restrepo Correa, Zorayda and Roopsind, Anand and Rudas, Agustín and Salomão, Rafael and Silva, Natalino and Silva Espejo, Javier and Singh, James and Stropp, Juliana and Terborgh, John and Thomas, Raquel and Toledo, Marisol and Torres-Lezama, Armando and Valenzuela Gamarra, Luis and van de Meer, Peter J and van der Heijden, Geertje and van der Hout, Peter and Vasquez Martinez, Rodolfo and Vela, Cesar and Vieira, Ima Célia Guimarães and Phillips, Oliver L},
title = {Compositional response of Amazon forests to climate change},
journal = {Global Change Biology},
publisher = {Wiley},
year = {2019},
volume = {25},
number = {1},
pages = {39--56},
doi = {10.1111/gcb.14413}
}
|
| Fan L, Wigneron JP, Ciais P, Chave J, Brandt M, Fensholt R, Saatchi SS, Bastos A, Al-Yaari A, Hufkens K, Qin Y, Xiao X, Chen C, Myneni RB, Fernandez-Moran R, Mialon A, Rodriguez-Fernandez NJ, Kerr Y, Tian F and Peñuelas J (2019), "Satellite-observed pantropical carbon dynamics", Nature Plants., jul, 2019. Vol. 5(9), pp. 944-951. Springer Science and Business Media LLC. |
| Abstract: Changes in terrestrial tropical carbon stocks have an important role in the global carbon budget. However, current observational tools do not allow accurate and large-scale monitoring of the spatial distribution and dynamics of carbon stocks1. Here, we used low-frequency L-band passive microwave observations to compute a direct and spatially explicit quantification of annual aboveground carbon (AGC) fluxes and show that the tropical net AGC budget was approximately in balance during 2010 to 2017, the net budget being composed of gross losses of âˆ'2.86 PgC yrâˆ'1 offset by gross gains of âˆ'2.97 PgC yrâˆ'1 between continents. Large interannual and spatial fluctuations of tropical AGC were quantified during the wet 2011 La Niña year and throughout the extreme dry and warm 2015–2016 El Niño episode. These interannual fluctuations, controlled predominantly by semiarid biomes, were shown to be closely related to independent global atmospheric CO2 growth-rate anomalies (Pearson's r = 0.86), highlighting the pivotal role of tropical AGC in the global carbon budget. |
BibTeX:
@article{Fan2019,
author = {Fan, Lei and Wigneron, Jean Pierre and Ciais, Philippe and Chave, Jérôme and Brandt, Martin and Fensholt, Rasmus and Saatchi, Sassan S and Bastos, Ana and Al-Yaari, Amen and Hufkens, Koen and Qin, Yuanwei and Xiao, Xiangming and Chen, Chi and Myneni, Ranga B and Fernandez-Moran, Roberto and Mialon, Arnaud and Rodriguez-Fernandez, N J and Kerr, Yann and Tian, Feng and Peñuelas, Josep},
title = {Satellite-observed pantropical carbon dynamics},
journal = {Nature Plants},
publisher = {Springer Science and Business Media LLC},
year = {2019},
volume = {5},
number = {9},
pages = {944--951},
doi = {10.1038/s41477-019-0478-9}
}
|
| Fares S, Alivernini A, Conte A and Maggi F (2019), "Ozone and particle fluxes in a Mediterranean forest predicted by the AIRTREE model", Science of the Total Environment., sep, 2019. Vol. 682, pp. 494-504. Elsevier BV. |
| Abstract: Mediterranean forests are among the most threatened ecosystems by the concurrent effects of climate change and atmospheric pollution. In this work we parameterized the AIRTREE multi-layer model to predict CO2, water, ozone, and fine particles exchanges between leaves and the atmosphere. AIRTREE consists of four different modules: (1) a canopy environmental module determines the leaf temperature and radiative fluxes at different levels from above to the bottom of the canopy; (2) a hydrological module predicts soil water flow and water availability to the plant's photosynthetic apparatus; (3) a photosynthesis module estimates the net photosynthesis and stomatal conductance, and (4) a deposition module estimates ozone and PM deposition sinks as a function of the resistances to gas diffusion in the atmosphere, and within the canopy and leaf boundary layer. We describe the AIRTREE model framework, accuracy and sensitivity by comparing modeling results against long-term continuous Eddy Covariance measurements of ozone, water, and CO2 fluxes in a Mediterranean Holm oak forest, and we discuss potential application of AIRTREE for ozone-risk assessment in view of availability of a large observational database from ecosystems distributed worldwide. |
BibTeX:
@article{Fares2019,
author = {Fares, Silvano and Alivernini, Alessandro and Conte, Adriano and Maggi, Federico},
title = {Ozone and particle fluxes in a Mediterranean forest predicted by the AIRTREE model},
journal = {Science of the Total Environment},
publisher = {Elsevier BV},
year = {2019},
volume = {682},
pages = {494--504},
doi = {10.1016/j.scitotenv.2019.05.109}
}
|
| Fennel K, Alin S, Barbero L, Evans W, Bourgeois T, Cooley S, Dunne J, Feely RA, Hernandez-Ayon JM, Hu X, Lohrenz S, Muller-Karger F, Najjar R, Robbins L, Shadwick E, Siedlecki S, Steiner N, Sutton A, Turk D, Vlahos P and Wang ZA (2019), "Carbon cycling in the North American coastal ocean: a synthesis", Biogeosciences., mar, 2019. Vol. 16(6), pp. 1281-1304. Copernicus GmbH. |
| Abstract: textlessptextgreatertextless![CDATA[Abstract. A quantification of carbon fluxes in the coastal ocean and across its boundaries with the atmosphere, land, and the open ocean is important for assessing the current state and projecting future trends in ocean carbon uptake and coastal ocean acidification, but this is currently a missing component of global carbon budgeting. This synthesis reviews recent progress in characterizing these carbon fluxes for the North American coastal ocean. Several observing networks and high-resolution regional models are now available. Recent efforts have focused primarily on quantifying the net air–sea exchange of carbon dioxide (CO2). Some studies have estimated other key fluxes, such as the exchange of organic and inorganic carbon between shelves and the open ocean. Available estimates of air–sea CO2 flux, informed by more than a decade of observations, indicate that the North American Exclusive Economic Zone (EEZ) acts as a sink of 160±80 Tg C yr−1, although this flux is not well constrained. The Arctic and sub-Arctic, mid-latitude Atlantic, and mid-latitude Pacific portions of the EEZ account for 104, 62, and −3.7 Tg C yr−1, respectively, while making up 51 %, 25 %, and 24 % of the total area, respectively. Combining the net uptake of 160±80 Tg C yr−1 with an estimated carbon input from land of 106±30 Tg C yr−1 minus an estimated burial of 65±55 Tg C yr−1 and an estimated accumulation of dissolved carbon in EEZ waters of 50±25 Tg C yr−1 implies a carbon export of 151±105 Tg C yr−1 to the open ocean. The increasing concentration of inorganic carbon in coastal and open-ocean waters leads to ocean acidification. As a result, conditions favoring the dissolution of calcium carbonate occur regularly in subsurface coastal waters in the Arctic, which are naturally prone to low pH, and the North Pacific, where upwelling of deep, carbon-rich waters has intensified. Expanded monitoring and extension of existing model capabilities are required to provide more reliable coastal carbon budgets, projections of future states of the coastal ocean, and quantification of anthropogenic carbon contributions.]]textgreatertextless/ptextgreater |
BibTeX:
@article{Fennel2019,
author = {Fennel, Katja and Alin, Simone and Barbero, Leticia and Evans, Wiley and Bourgeois, Timothée and Cooley, Sarah and Dunne, John and Feely, Richard A. and Hernandez-Ayon, Jose Martin and Hu, Xinping and Lohrenz, Steven and Muller-Karger, Frank and Najjar, Raymond and Robbins, Lisa and Shadwick, Elizabeth and Siedlecki, Samantha and Steiner, Nadja and Sutton, Adrienne and Turk, Daniela and Vlahos, Penny and Wang, Zhaohui Aleck},
title = {Carbon cycling in the North American coastal ocean: a synthesis},
journal = {Biogeosciences},
publisher = {Copernicus GmbH},
year = {2019},
volume = {16},
number = {6},
pages = {1281--1304},
url = {https://bg.copernicus.org/articles/16/1281/2019/},
doi = {10.5194/bg-16-1281-2019}
}
|
| Fernández-Martínez M, Sardans J, Chevallier F, Ciais P, Obersteiner M, Vicca S, Canadell JG, Bastos A, Friedlingstein P, Sitch S, Piao SL, Janssens IA and Peñuelas J (2019), "Global trends in carbon sinks and their relationships with CO2 and temperature", Nature Climate Change., dec, 2019. Vol. 9(1), pp. 73-79. Springer Science and Business Media LLC. |
| Abstract: Elevated CO2 concentrations increase photosynthesis and, potentially, net ecosystem production (NEP), meaning a greater CO2 uptake. Climate, nutrients and ecosystem structure, however, influence the effect of increasing CO2. Here we analysed global NEP from MACC-II and Jena CarboScope atmospheric inversions and ten dynamic global vegetation models (TRENDY), using statistical models to attribute the trends in NEP to its potential drivers: CO2, climatic variables and land-use change. We found that an increased CO2 was consistently associated with an increased NEP (1995–2014). Conversely, increased temperatures were negatively associated with NEP. Using the two atmospheric inversions and TRENDY, the estimated global sensitivities for CO2 were 6.0 ± 0.1, 8.1 ± 0.3 and 3.1 ± 0.1 PgC per 100 ppm (˜1 °C increase), and âˆ'0.5 ± 0.2, âˆ'0.9 ± 0.4 and âˆ'1.1 ± 0.1 PgC °Câˆ'1 for temperature. These results indicate a positive CO2 effect on terrestrial C sinks that is constrained by climate warming. |
BibTeX:
@article{Fernandez-Martinez2019,
author = {Fernández-Martínez, M and Sardans, J and Chevallier, F and Ciais, P and Obersteiner, M and Vicca, S and Canadell, J G and Bastos, A and Friedlingstein, P and Sitch, S and Piao, S L and Janssens, I A and Peñuelas, J},
title = {Global trends in carbon sinks and their relationships with CO2 and temperature},
journal = {Nature Climate Change},
publisher = {Springer Science and Business Media LLC},
year = {2019},
volume = {9},
number = {1},
pages = {73--79},
doi = {10.1038/s41558-018-0367-7}
}
|
| Fischer FJ, Maréchaux I and Chave J (2019), "Improving plant allometry by fusing forest models and remote sensing", New Phytologist., apr, 2019. Vol. 223(3), pp. 1159-1165. Wiley. |
| Abstract: Allometry determines how tree shape and function scale with each other, related through size. Allometric relationships help scale processes from the individual to the global scale and constitute a core component of vegetation models. Allometric relationships have been expected to emerge from optimisation theory, yet this does not suitably predict empirical data. Here we argue that the fusion of high-resolution data, such as those derived from airborne laser scanning, with individual-based forest modelling offers insight into how plant size contributes to large-scale biogeochemical processes. We review the challenges in allometric scaling, how they can be tackled by advances in data-model fusion, and how individual-based models can serve as data integrators for dynamic global vegetation models. |
BibTeX:
@article{Fischer2019,
author = {Fischer, Fabian Jörg and Maréchaux, Isabelle and Chave, Jérôme},
title = {Improving plant allometry by fusing forest models and remote sensing},
journal = {New Phytologist},
publisher = {Wiley},
year = {2019},
volume = {223},
number = {3},
pages = {1159--1165},
doi = {10.1111/nph.15810}
}
|
| Fitzky AC, Sandén H, Karl T, Fares S, Calfapietra C, Grote R, Saunier A and Rewald B (2019), "The Interplay Between Ozone and Urban Vegetation—BVOC Emissions, Ozone Deposition, and Tree Ecophysiology", Frontiers in Forests and Global Change., sep, 2019. Vol. 2 Frontiers Media SA. |
| Abstract: Tropospheric ozone (Osub3/sub) is one of the most prominent air pollution problems in Europe and other countries worldwide. Human health is affected by Osub3/sub via the respiratory as well the cardiovascular systems. Even though trees are present in relatively low numbers in urban areas, they can be a dominant factor in the regulation of urban Osub3/sub concentrations. Trees affect the Osub3/sub concentration via emission of biogenic volatile organic compounds (BVOC), which can act as a precursor of Osub3/sub, and by Osub3/sub deposition on leaves. The role of urban trees with regard to Osub3/sub will gain further importance as NOsubx/sub concentrations continue declining and climate warming is progressing—rendering especially the urban ozone chemistry more sensitive to BVOC emissions. However, the role of urban vegetation on the local regulation of tropospheric Osub3/sub concentrations is complex and largely influenced by species-specific emission rates of BVOCs and Osub3/sub deposition rates, both highly modified by tree physiological status. In this review, we shed light on processes related to trees that affect tropospheric ozone concentrations in metropolitan areas from rural settings to urban centers, and discuss their importance under present and future conditions. After a brief overview on the mechanisms regulating Osub3/sub concentrations in urban settings, we focus on effects of tree identity and tree physiological status, as affected by multiple stressors, influencing both BVOC emission and Osub3/sub deposition rates. In addition, we highlight differences along the rural-urban gradient affecting tropospheric Osub3/sub concentrations and current knowledge gaps with the potential to improve future models on tropospheric Osub3/sub formation in metropolitan areas. |
BibTeX:
@article{Fitzky2019,
author = {Fitzky, Anne Charlott and Sandén, Hans and Karl, Thomas and Fares, Silvano and Calfapietra, Carlo and Grote, Rüdiger and Saunier, Amélie and Rewald, Boris},
title = {The Interplay Between Ozone and Urban Vegetation—BVOC Emissions, Ozone Deposition, and Tree Ecophysiology},
journal = {Frontiers in Forests and Global Change},
publisher = {Frontiers Media SA},
year = {2019},
volume = {2},
doi = {10.3389/ffgc.2019.00050}
}
|
| Freeman NM, Munro DR, Sprintall J, Mazloff MR, Purkey S, Rosso I, DeRanek CA and Sweeney C (2019), "The Observed Seasonal Cycle of Macronutrients in Drake Passage: Relationship to Fronts and Utility as a Model Metric", Journal of Geophysical Research: Oceans., jul, 2019. Vol. 124(7), pp. 4763-4783. Blackwell Publishing Ltd. |
| Abstract: The Drake Passage Time-series (DPT) is used to quantify the spatial and seasonal variability of historically undersampled, biogeochemically relevant properties across the Drake Passage. From 2004–2017, discrete ship-based observations of surface macronutrients (silicate, nitrate, and phosphate), temperature, and salinity have been collected 5–8 times per year as part of the DPT program. Using the DPT and Antarctic Circumpolar Current (ACC) front locations derived from concurrent expendable bathythermograph data, the distinct physical and biogeochemical characteristics of ACC frontal zones are characterized. Biogeochemical-Argo floats in the region confirm that the near-surface sampling scheme of the DPT robustly captures mixed-layer biogeochemistry. While macronutrient concentrations consistently increase toward the Antarctic continent, their meridional distribution, variability, and biogeochemical gradients are unique across physical ACC fronts, suggesting a combination of physical and biological processes controlling nutrient availability and nutrient front location. The Polar Front is associated with the northern expression of the Silicate Front, marking the biogeographically relevant location between silicate-poor and silicate-rich waters. South of the northern Silicate Front, the silicate-to-nitrate ratio increases, with the sharpest gradient in silicate associated with the Southern ACC Front (i.e., the southern expression of the Silicate Front). Nutrient cycling is an important control on variability in the surface ocean partial pressure of carbon dioxide (pCO2). The robust characterization of the spatiotemporal variability of nutrients presented here highlights the utility of biogeochemical time series for diagnosing and potentially reducing biases in modeling Southern Ocean pCO2 variability, and by inference, air-sea CO2 flux. |
BibTeX:
@article{Freeman2019,
author = {Freeman, Natalie M. and Munro, David R. and Sprintall, Janet and Mazloff, Matthew R. and Purkey, Sarah and Rosso, Isabella and DeRanek, Carissa A. and Sweeney, Colm},
title = {The Observed Seasonal Cycle of Macronutrients in Drake Passage: Relationship to Fronts and Utility as a Model Metric},
journal = {Journal of Geophysical Research: Oceans},
publisher = {Blackwell Publishing Ltd},
year = {2019},
volume = {124},
number = {7},
pages = {4763--4783},
url = {https://onlinelibrary.wiley.com/doi/abs/10.1029/2019JC015052},
doi = {10.1029/2019JC015052}
}
|
| Frey M, Sha MK, Hase F, Kiel M, Blumenstock T, Harig R, Surawicz G, Deutscher NM, Shiomi K, Franklin JE, Bösch H, Chen J, Grutter M, Ohyama H, Sun Y, Butz A, Mengistu Tsidu G, Ene D, Wunch D, Cao Z, Garcia O, Ramonet M, Vogel F and Orphal J (2019), "Building the COllaborative Carbon Column Observing Network (COCCON): Long-term stability and ensemble performance of the EM27/SUN Fourier transform spectrometer", Atmospheric Measurement Techniques., mar, 2019. Vol. 12(3), pp. 1513-1530. Copernicus GmbH. |
| Abstract: In a 3.5-year long study, the long-term performance of a mobile, solar absorption Bruker EM27/SUN spectrometer, used for greenhouse gas observations, is checked with respect to a co-located reference Bruker IFS 125HR spectrometer, which is part of the Total Carbon Column Observing Network (TCCON). We find that the EM27/SUN is stable on timescales of several years; the drift per year between the EM27/SUN and the official TCCON product is 0.02 ppmv for XCO2 and 0.9 ppbv for XCH4, which is within the 1σ precision of the comparison, 0.6 ppmv for XCO2 and 4.3 ppbv for XCH4. The bias between the two data sets is 3.9 ppmv for XCO2 and 13.0 ppbv for XCH4. In order to avoid sensitivity-dependent artifacts, the EM27/SUN is also compared to a truncated IFS 125HR data set derived from full-resolution TCCON interferograms. The drift is 0.02 ppmv for XCO2 and 0.2 ppbv for XCH4 per year, with 1σ precisions of 0.4 ppmv for XCO2 and 1.4 ppbv for XCH4, respectively. The bias between the two data sets is 0.6 ppmv for XCO2 and 0.5 ppbv for XCH4. With the presented long-term stability, the EM27/SUN qualifies as an useful supplement to the existing TCCON network in remote areas. To achieve consistent performance, such an extension requires careful testing of any spectrometers involved by application of common quality assurance measures. One major aim of the COllaborative Carbon Column Observing Network (COCCON) infrastructure is to provide these services to all EM27/SUN operators. In the framework of COCCON development, the performance of an ensemble of 30 EM27/SUN spectrometers was tested and found to be very uniform, enhanced by the centralized inspection performed at the Karlsruhe Institute of Technology prior to deployment. Taking into account measured instrumental line shape parameters for each spectrometer, the resulting average bias across the ensemble with respect to the reference EM27/SUN used in the long-term study in XCO2 is 0.20 ppmv, while it is 0.8 ppbv for XCH4. The average standard deviation of the ensemble is 0.13 ppmv for XCO2 and 0.6 ppbv for XCH4. In addition to the robust metric based on absolute differences, we calculate the standard deviation among the empirical calibration factors. The resulting 2σ uncertainty is 0.6 ppmv for XCO2 and 2.2 ppbv for XCH4. As indicated by the executed long-term study on one device presented here, the remaining empirical calibration factor deduced for each individual instrument can be assumed constant over time. Therefore the application of these empirical factors is expected to further improve the EM27/SUN network conformity beyond the scatter among the empirical calibration factors reported above. |
BibTeX:
@article{Frey2019,
author = {Frey, Matthias and Sha, Mahesh K and Hase, Frank and Kiel, Matthäus and Blumenstock, Thomas and Harig, Roland and Surawicz, Gregor and Deutscher, Nicholas M and Shiomi, Kei and Franklin, Jonathan E and Bösch, Hartmut and Chen, Jia and Grutter, Michel and Ohyama, Hirofumi and Sun, Youwen and Butz, André and Mengistu Tsidu, Gizaw and Ene, Dragos and Wunch, Debra and Cao, Zhensong and Garcia, Omaira and Ramonet, Michel and Vogel, Felix and Orphal, Johannes},
title = {Building the COllaborative Carbon Column Observing Network (COCCON): Long-term stability and ensemble performance of the EM27/SUN Fourier transform spectrometer},
journal = {Atmospheric Measurement Techniques},
publisher = {Copernicus GmbH},
year = {2019},
volume = {12},
number = {3},
pages = {1513--1530},
doi = {10.5194/amt-12-1513-2019}
}
|
| Friedlingstein P, Jones MW, O'Sullivan M, Andrew RM, Hauck J, Peters GP, Peters W, Pongratz J, Sitch S, Le Quéré C, DBakker OCE, Canadell1 JG, Ciais1 P, Jackson RB, Anthoni1 P, Barbero L, Bastos A, Bastrikov V, Becker M, Bopp L, Buitenhuis E, Chandra N, Chevallier F, Chini LP, Currie KI, Feely RA, Gehlen M, Gilfillan D, Gkritzalis T, Goll DS, Gruber N, Gutekunst S, Harris I, Haverd V, Houghton RA, Hurtt G, Ilyina T, Jain AK, Joetzjer E, Kaplan JO, Kato E, Goldewijk KK, Korsbakken JI, Landschützer P, Lauvset SK, Lefèvre N, Lenton A, Lienert S, Lombardozzi D, Marland G, McGuire PC, Melton JR, Metzl N, Munro DR, Nabel JEMS, Nakaoka SI, Neill C, Omar AM, Ono T, Peregon A, Pierrot D, Poulter B, Rehder G, Resplandy L, Robertson E, Rödenbeck C, Séférian R, Schwinger J, Smith N, Tans PP, Tian H, Tilbrook B, Tubiello FN, Van Der Werf GR, Wiltshire AJ and Zaehle S (2019), "Global carbon budget 2019", Earth System Science Data., dec, 2019. Vol. 11(4), pp. 1783-1838. |
| Abstract: Accurate assessment of anthropogenic carbon dioxide (CO2) emissions and their redistribution among the atmosphere, ocean, and terrestrial biosphere-the "global carbon budget"-is important to better understand the global carbon cycle, support the development of climate policies, and project future climate change. Here we describe data sets and methodology to quantify the five major components of the global carbon budget and their uncertainties. Fossil CO2 emissions (EFF) are based on energy statistics and cement production data, while emissions from land use change (ELUC), mainly deforestation, are based on land use and land use change data and bookkeeping models. Atmospheric CO2 concentration is measured directly and its growth rate (GATM) is computed from the annual changes in concentration. The ocean CO2 sink (SOCEAN) and terrestrial CO2 sink (SLAND) are estimated with global process models constrained by observations. The resulting carbon budget imbalance (BIM), the difference between the estimated total emissions and the estimated changes in the atmosphere, ocean, and terrestrial biosphere, is a measure of imperfect data and understanding of the contemporary carbon cycle. All uncertainties are reported as ±1σ. For the last decade available (2009-2018), EFF was 9:5±0:5 GtC yr-1, ELUC 1:5±0:7 GtC yr-1, GATM 4:9±0:02 GtC yr-1 (2:3±0:01 ppm yr-1), SOCEAN 2:5±0:6 GtC yr-1, and SLAND 3:2±0:6 GtC yr-1, with a budget imbalance BIM of 0.4 GtC yr-1 indicating overestimated emissions and/or underestimated sinks. For the year 2018 alone, the growth in EFF was about 2.1% and fossil emissions increased to 10:0±0:5 GtC yr-1, reaching 10 GtC yr-1 for the first time in history, ELUC was 1:5±0:7 GtC yr-1, for total anthropogenic CO2 emissions of 11:5±0:9 GtC yr-1 (42:5±3:3 GtCO2). Also for 2018, GATM was 5:1±0:2 GtC yr-1 (2:4±0:1 ppm yr-1), SOCEAN was 2:6±0:6 GtC yr-1, and SLAND was 3:5±0:7 GtC yr-1, with a BIM of 0.3 GtC. The global atmospheric CO2 concentration reached 407:38±0:1 ppm averaged over 2018. For 2019, preliminary data for the first 6-10 months indicate a reduced growth in EFF of C0:6% (range of.0:2% to 1.5 %) based on national emissions projections for China, the USA, the EU, and India and projections of gross domestic product corrected for recent changes in the carbon intensity of the economy for the rest of the world. Overall, the mean and trend in the five components of the global carbon budget are consistently estimated over the period 1959-2018, but discrepancies of up to 1 GtC yr-1 persist for the representation of semi-decadal variability in CO2 fluxes. A detailed comparison among individual estimates and the introduction of a broad range of observations shows (1) no consensus in the mean and trend in land use change emissions over the last decade, (2) a persistent low agreement between the different methods on the magnitude of the land CO2 flux in the northern extra-tropics, and (3) an apparent underestimation of the CO2 variability by ocean models outside the tropics. This living data update documents changes in the methods and data sets used in this new global carbon budget and the progress in understanding of the global carbon cycle compared with previous publications of this data set (Le Quéré et al., 2018a, b, 2016, 2015a, b, 2014, 2013). The data generated by this work are available at https://doi.org/10.18160/gcp-2019 (Friedlingstein et al., 2019). |
BibTeX:
@article{Friedlingstein2019,
author = {Friedlingstein, Pierre and Jones, Matthew W and O'Sullivan, Michael and Andrew, Robbie M and Hauck, Judith and Peters, Glen P and Peters, Wouter and Pongratz, Julia and Sitch, Stephen and Le Quéré, Corinne and DBakker, Orothee C E and Canadell1, Josep G and Ciais1, Philippe and Jackson, Robert B and Anthoni1, Peter and Barbero, Leticia and Bastos, Ana and Bastrikov, Vladislav and Becker, Meike and Bopp, Laurent and Buitenhuis, Erik and Chandra, Naveen and Chevallier, Frédéric and Chini, Louise P and Currie, Kim I and Feely, Richard A and Gehlen, Marion and Gilfillan, Dennis and Gkritzalis, Thanos and Goll, Daniel S and Gruber, Nicolas and Gutekunst, Sören and Harris, Ian and Haverd, Vanessa and Houghton, Richard A and Hurtt, George and Ilyina, Tatiana and Jain, Atul K and Joetzjer, Emilie and Kaplan, Jed O and Kato, Etsushi and Goldewijk, Kees Klein and Korsbakken, Jan Ivar and Landschützer, Peter and Lauvset, Siv K and Lefèvre, Nathalie and Lenton, Andrew and Lienert, Sebastian and Lombardozzi, Danica and Marland, Gregg and McGuire, Patrick C and Melton, Joe R and Metzl, Nicolas and Munro, David R and Nabel, Julia E M S and Nakaoka, Shin Ichiro and Neill, Craig and Omar, Abdirahman M and Ono, Tsuneo and Peregon, Anna and Pierrot, Denis and Poulter, Benjamin and Rehder, Gregor and Resplandy, Laure and Robertson, Eddy and Rödenbeck, Christian and Séférian, Roland and Schwinger, Jörg and Smith, Naomi and Tans, Pieter P and Tian, Hanqin and Tilbrook, Bronte and Tubiello, Francesco N and Van Der Werf, Guido R and Wiltshire, Andrew J and Zaehle, Sönke},
title = {Global carbon budget 2019},
journal = {Earth System Science Data},
year = {2019},
volume = {11},
number = {4},
pages = {1783--1838},
url = {https://www.earth-syst-sci-data.net/11/1783/2019/},
doi = {10.5194/essd-11-1783-2019}
}
|
| Fröb F, Olsen A, Becker M, Chafik L, Johannessen T, Reverdin G and Omar A (2019), "Wintertime fCO 2 Variability in the Subpolar North Atlantic Since 2004", Geophysical Research Letters., feb, 2019. Vol. 46(3), pp. 1580-1590. |
| Abstract: Winter data of surface ocean temperature (SST), salinity (SSS) and CO 2 fugacity (fCO 2 ) collected on the VOS M/V Nuka Arctica in the subpolar North Atlantic between 2004 and 2017 are used to establish trends, drivers, and interannual variability. Over the period, waters cooled and freshened, and the fCO 2 increased at a rate similar to the atmospheric CO 2 growth rate. When accounting for the freshening, the inferred increase in dissolved inorganic carbon (DIC) was found to be approximately twice that expected from atmospheric CO 2 alone. This is attributed to the cooling. In the Irminger Sea, fCO 2 exhibited additional interannual variations driven by atmospheric forcing through winter mixing. As winter fCO 2 in the region is close to the atmospheric, the subpolar North Atlantic has varied between being slightly supersaturated and slightly undersaturated over the investigated period. |
BibTeX:
@article{Frob2019,
author = {Fröb, F and Olsen, A and Becker, M and Chafik, L and Johannessen, T and Reverdin, G and Omar, A},
title = {Wintertime fCO 2 Variability in the Subpolar North Atlantic Since 2004},
journal = {Geophysical Research Letters},
year = {2019},
volume = {46},
number = {3},
pages = {1580--1590},
url = {http://doi.wiley.com/10.1029/2018GL080554},
doi = {10.1029/2018GL080554}
}
|
| Geng MS, Christensen JH and Christensen TR (2019), "Potential future methane emission hot spots in Greenland", Environmental Research Letters., mar, 2019. Vol. 14(3), pp. 35001. IOP Publishing. |
| Abstract: Climate models have been making significant progress encompassing an increasing number of complex feedback mechanisms from natural ecosystems. Permafrost thaw and subsequent induced greenhouse gas emissions, however, remain a challenge for climate models at large. Deducing permafrost conditions and associated greenhouse gas emissions from parameters that are simulated in climate models would be a helpful step towards estimating emission budgets from permafrost regions. Here we use a regional climate model with a 5 km horizontal resolution to assess future potential methane (CH4) emissions over presently unglaciated areas in Greenland under an RCP8.5 scenario. A simple frost index is applied to estimate permafrost conditions from the model output. CH4 flux measurements from two stations in Greenland; Nuuk representing sub-Arctic and Zackenberg high-Arctic climate, are used to establish a relationship between emissions and near surface air temperature. Permafrost conditions in Greenland change drastically by the end of the 21st century in an RCP8.5 climate. Continuous permafrost remains stable only in North Greenland, the north-west coast, the northern tip of Disko Island, and Nuussuaq. Southern Greenland conditions only sustain sporadic permafrost conditions and largely at high elevations, whereas former permafrost in other regions thaws. The increasing thawed soil leads to increasing CH4 emissions. Especially the area surrounding Kangerlussuaq, Scoresby Land, and the southern coast of Greenland exhibit potentially high emissions during the longer growing season. The constructed maps and budgets combining modelled permafrost conditions with observed CH4 fluxes from CH4 promoting sites represent a useful tool to identify areas in need of additional monitoring as they highlight potential CH4 hot spots. |
BibTeX:
@article{Geng2019,
author = {Geng, Marilena Sophie and Christensen, Jens Hesselbjerg and Christensen, Torben Røjle},
title = {Potential future methane emission hot spots in Greenland},
journal = {Environmental Research Letters},
publisher = {IOP Publishing},
year = {2019},
volume = {14},
number = {3},
pages = {35001},
doi = {10.1088/1748-9326/aaf34b}
}
|
| Giemsa E, Jacobeit J, Ries L and Hachinger S (2019), "Investigating regional source and sink patterns of Alpine CO2 and CH4 concentrations based on a back trajectory receptor model", Environmental Sciences Europe., dec, 2019. Vol. 31(1), pp. 49. |
BibTeX:
@article{Giemsa2019,
author = {Giemsa, Esther and Jacobeit, Jucundus and Ries, Ludwig and Hachinger, Stephan},
title = {Investigating regional source and sink patterns of Alpine CO2 and CH4 concentrations based on a back trajectory receptor model},
journal = {Environmental Sciences Europe},
year = {2019},
volume = {31},
number = {1},
pages = {49},
url = {https://enveurope.springeropen.com/articles/10.1186/s12302-019-0233-x},
doi = {10.1186/s12302-019-0233-x}
}
|
| Gonzaga Gomez L, Loubet B, Lafouge F, Ciuraru R, Buysse P, Durand B, Gueudet JC, Fanucci O, Fortineau A, Zurfluh O, Decuq C, Kammer J, Duprix P, Bsaibes S, Truong F, Gros V and Boissard C (2019), "Comparative study of biogenic volatile organic compounds fluxes by wheat, maize and rapeseed with dynamic chambers over a short period in northern France", Atmospheric Environment., oct, 2019. Vol. 214, pp. 116855. Elsevier BV. |
| Abstract: Biogenic volatile organic compounds (BVOC) are mainly emitted from vegetation. However there is still little information on BVOC exchanges with crops. In this study we measured fluxes of BVOC from wheat, maize and rapeseed crops near Paris at the plant level during a full-week period for each species. We used dynamic automated chambers coupled to a Proton Transfer Reaction, Quadrupole ion guide, Time of Flight mass spectrometer (PTR-Qi-Tof-MS) instrument for online measurements of BVOC. Our results confirm the hypothesis that many unexplored compounds contribute to BVOC exchanges between crops and the atmosphere, although for all plant species methanol was dominating the emissions (55–85% of the sum of the BVOC exchanges fluxes on a mass basis) followed by acetone and acetaldehyde. The 10 most exchanged compounds, excluding methanol, contributed more than 50% of the summed fluxes and the 100 most exchanged contributed to more than 90%. The summed BVOC emission and deposition presented large interspecies variations, but limited intra-species variability, with a summed net flux of 0.11 ± 0.02 μgBVOC gDWâˆ'1 hâˆ'1 for maize, 1.5 ± 0.7 μgBVOC gDWâˆ'1 hâˆ'1 for wheat, and 9.1 ± 2.4 μgBVOC gDWâˆ'1 hâˆ'1 for rapeseed. The 10 most emitted compounds were mostly emitted during the day and were correlated with both photosynthetically active radiation and temperature and anti-correlated with relative humidity. This study provides the first evaluation so far of the biosphere-atmosphere fluxes for several BVOC. In particular we provide a first evaluation of standard emission factor for isoprene and monoterpene for wheat and rapeseed at their respective growth stages. This study is however limited to a week period at a given stage for each species and at the plant level. |
BibTeX:
@article{GonzagaGomez2019,
author = {Gonzaga Gomez, Lais and Loubet, Benjamin and Lafouge, Florence and Ciuraru, Raluca and Buysse, Pauline and Durand, Brigitte and Gueudet, Jean Christophe and Fanucci, Olivier and Fortineau, A and Zurfluh, Olivier and Decuq, Céline and Kammer, Julien and Duprix, Pascal and Bsaibes, S and Truong, François and Gros, Valérie and Boissard, Christophe},
title = {Comparative study of biogenic volatile organic compounds fluxes by wheat, maize and rapeseed with dynamic chambers over a short period in northern France},
journal = {Atmospheric Environment},
publisher = {Elsevier BV},
year = {2019},
volume = {214},
pages = {116855},
doi = {10.1016/j.atmosenv.2019.116855}
}
|
| Gourlez de la Motte L, Dumortier P, Beckers Y, Bodson B, Heinesch B and Aubinet M (2019), "Herd position habits can bias net CO 2 ecosystem exchange estimates in free range grazed pastures", Agricultural and Forest Meteorology., apr, 2019. Vol. 268, pp. 156-168. Elsevier BV. |
| Abstract: The eddy covariance (EC) technique has been widely used to quantify the net CO 2 ecosystem exchange (NEE) of grasslands, which is an important component of grassland carbon and greenhouse gas budgets. In free range grazed pastures, NEE estimations are supposed to also include cattle respiration. However, cattle respiration measurement by an EC system is challenging as animals act as moving points emitting CO 2 that are more or less captured by the EC tower depending on their presence in the footprint. Often it is supposed that, over the long term, cattle distribution in the pasture is homogeneous so that fluctuations due to moving sources are averaged and NEE estimates are reasonably representative of cattle respiration. In this study, we test this hypothesis by comparing daily cow respiration rate per livestock unit (LU) estimated by postulating a homogeneous cow repartition over the whole pasture with three other estimates based on animal localization data, animal scale carbon budget and confinement experiments. We applied these methods to an intensively managed free range grassland and showed that the NEE estimate based on a homogeneous cow repartition was systematically lower than the three other estimates. The bias was about 60 g C m –2 yr –1 , which corresponded to around 40% of the annual NEE. The sign and the importance of this bias is site specific, as it depends on cow location habits in relation to the footprint of the EC measurements which highlight the importance of testing the hypothesis of homogeneity of cattle distribution on each site. Consequently, in order to allow estimating the validity of this hypothesis but also to improve inter site comparisons, we advocate to compute separately pasture NEE and grazer's respiration. For the former we propose a method based on cattle presence detection using CH 4 fluxes, elimination of data with cattle and gap filling on the basis of data without cattle. For the second we present and discuss three independent methods (animal localization with GPS, animal scale carbon budget, confinement experiments) to estimate the cattle respiration rate. |
BibTeX:
@article{GourlezdelaMotte2019,
author = {Gourlez de la Motte, Louis and Dumortier, Pierre and Beckers, Yves and Bodson, Bernard and Heinesch, Bernard and Aubinet, Marc},
title = {Herd position habits can bias net CO 2 ecosystem exchange estimates in free range grazed pastures},
journal = {Agricultural and Forest Meteorology},
publisher = {Elsevier BV},
year = {2019},
volume = {268},
pages = {156--168},
doi = {10.1016/j.agrformet.2019.01.015}
}
|
| Gregor L, Lebehot AD, Kok S and Scheel Monteiro PM (2019), "A comparative assessment of the uncertainties of global surface ocean CO&lt;sub&gt;2&lt;/sub&gt; estimates using a machine-learning ensemble (CSIR-ML6 version 2019a) – have we hit the wall?", Geoscientific Model Development., dec, 2019. Vol. 12(12), pp. 5113-5136. Copernicus GmbH. |
| Abstract: textlessptextgreatertextless![CDATA[Abstract. Over the last decade, advanced statistical inference and machine learning have been used to fill the gaps in sparse surface ocean CO2 measurements (Rödenbeck et al., 2015). The estimates from these methods have been used to constrain seasonal, interannual and decadal variability in sea–air CO2 fluxes and the drivers of these changes (Landschützer et al., 2015, 2016; Gregor et al., 2018). However, it is also becoming clear that these methods are converging towards a common bias and root mean square error (RMSE) boundary: “the wall”, which suggests that pCO2 estimates are now limited by both data gaps and scale-sensitive observations. Here, we analyse this problem by introducing a new gap-filling method, an ensemble average of six machine-learning models (CSIR-ML6 version 2019a, Council for Scientific and Industrial Research – Machine Learning ensemble with Six members), where each model is constructed with a two-step clustering-regression approach. The ensemble average is then statistically compared to well-established methods. The ensemble average, CSIR-ML6, has an RMSE of 17.16 µatm and bias of 0.89 µatm when compared to a test dataset kept separate from training procedures. However, when validating our estimates with independent datasets, we find that our method improves only incrementally on other gap-filling methods. We investigate the differences between the methods to understand the extent of the limitations of gap-filling estimates of pCO2. We show that disagreement between methods in the South Atlantic, southeastern Pacific and parts of the Southern Ocean is too large to interpret the interannual variability with confidence. We conclude that improvements in surface ocean pCO2 estimates will likely be incremental with the optimisation of gap-filling methods by (1) the inclusion of additional clustering and regression variables (e.g. eddy kinetic energy), (2) increasing the sampling resolution and (3) successfully incorporating pCO2 estimates from alternate platforms (e.g. floats, gliders) into existing machine-learning approaches.]]textgreatertextless/ptextgreater |
BibTeX:
@article{Gregor2019,
author = {Gregor, Luke and Lebehot, Alice D. and Kok, Schalk and Scheel Monteiro, Pedro M.},
title = {A comparative assessment of the uncertainties of global surface ocean CO&lt;sub&gt;2&lt;/sub&gt; estimates using a machine-learning ensemble (CSIR-ML6 version 2019a) – have we hit the wall?},
journal = {Geoscientific Model Development},
publisher = {Copernicus GmbH},
year = {2019},
volume = {12},
number = {12},
pages = {5113--5136},
url = {https://gmd.copernicus.org/articles/12/5113/2019/},
doi = {10.5194/gmd-12-5113-2019}
}
|
| Grossiord C, Christoffersen B, Alonso-Rodríguez AM, Anderson-Teixeira K, Asbjornsen H, Aparecido LMT, Carter Berry Z, Baraloto C, Bonal D, Borrego I, Burban B, Chambers JQ, Christianson DS, Detto M, Faybishenko B, Fontes CG, Fortunel C, Gimenez BO, Jardine KJ, Kueppers L, Miller GR, Moore GW, Negron-Juarez R, Stahl C, Swenson NG, Trotsiuk V, Varadharajan C, Warren JM, Wolfe BT, Wei L, Wood TE, Xu C and McDowell NG (2019), "Precipitation mediates sap flux sensitivity to evaporative demand in the neotropics", Oecologia., sep, 2019. Vol. 191(3), pp. 519-530. Springer Science and Business Media LLC. |
| Abstract: Transpiration in humid tropical forests modulates the global water cycle and is a key driver of climate regulation. Yet, our understanding of how tropical trees regulate sap flux in response to climate variability remains elusive. With a progressively warming climate, atmospheric evaporative demand [i.e., vapor pressure deficit (VPD)] will be increasingly important for plant functioning, becoming the major control of plant water use in the twenty-first century. Using measurements in 34 tree species at seven sites across a precipitation gradient in the neotropics, we determined how the maximum sap flux velocity (vmax) and the VPD threshold at which vmax is reached (VPDmax) vary with precipitation regime [mean annual precipitation (MAP); seasonal drought intensity (PDRY)] and two functional traits related to foliar and wood economics spectra [leaf mass per area (LMA); wood specific gravity (WSG)]. We show that, even though vmax is highly variable within sites, it follows a negative trend in response to increasing MAP and PDRY across sites. LMA and WSG exerted little effect on vmax and VPDmax, suggesting that these widely used functional traits provide limited explanatory power of dynamic plant responses to environmental variation within hyper-diverse forests. This study demonstrates that long-term precipitation plays an important role in the sap flux response of humid tropical forests to VPD. Our findings suggest that under higher evaporative demand, trees growing in wetter environments in humid tropical regions may be subjected to reduced water exchange with the atmosphere relative to trees growing in drier climates. |
BibTeX:
@article{Grossiord2019,
author = {Grossiord, Charlotte and Christoffersen, Bradley and Alonso-Rodríguez, Aura M and Anderson-Teixeira, Kristina and Asbjornsen, Heidi and Aparecido, Luiza Maria T and Carter Berry, Z and Baraloto, Christopher and Bonal, Damien and Borrego, Isaac and Burban, Benoit and Chambers, Jeffrey Q and Christianson, Danielle S and Detto, Matteo and Faybishenko, Boris and Fontes, Clarissa G and Fortunel, Claire and Gimenez, Bruno O and Jardine, Kolby J and Kueppers, Lara and Miller, Gretchen R and Moore, Georgianne W and Negron-Juarez, Robinson and Stahl, Clément and Swenson, Nathan G and Trotsiuk, Volodymyr and Varadharajan, Charu and Warren, Jeffrey M and Wolfe, Brett T and Wei, Liang and Wood, Tana E and Xu, Chonggang and McDowell, Nate G},
title = {Precipitation mediates sap flux sensitivity to evaporative demand in the neotropics},
journal = {Oecologia},
publisher = {Springer Science and Business Media LLC},
year = {2019},
volume = {191},
number = {3},
pages = {519--530},
doi = {10.1007/s00442-019-04513-x}
}
|
| Gruber N, Landschützer P and Lovenduski NS (2019), "The Variable Southern Ocean Carbon Sink", Annual Review of Marine Science., jan, 2019. Vol. 11(1), pp. 159-186. Annual Reviews Inc.. |
| Abstract: textlessptextgreater The CO textlesssubtextgreater2textless/subtextgreater uptake by the Southern Ocean (textless35°S) varies substantially on all timescales and is a major determinant of the variations of the global ocean carbon sink. Particularly strong are the decadal changes characterized by a weakening period of the Southern Ocean carbon sink in the 1990s and a rebound after 2000. The weakening in the 1990s resulted primarily from a southward shift of the westerlies that enhanced the upwelling and outgassing of respired (i.e., natural) CO textlesssubtextgreater2textless/subtextgreater . The concurrent reduction in the storage rate of anthropogenic CO textlesssubtextgreater2textless/subtextgreater in the mode and intermediate waters south of 35°S suggests that this shift also decreased the uptake of anthropogenic CO textlesssubtextgreater2textless/subtextgreater . The rebound and the subsequent strong, decade-long reinvigoration of the carbon sink appear to have been driven by cooling in the Pacific Ocean, enhanced stratification in the Atlantic and Indian Ocean sectors, and a reduced overturning. Current-generation ocean models generally do not reproduce these variations and are poorly skilled at making decadal predictions in this region. textless/ptextgreater |
BibTeX:
@article{Gruber2019,
author = {Gruber, Nicolas and Landschützer, Peter and Lovenduski, Nicole S.},
title = {The Variable Southern Ocean Carbon Sink},
journal = {Annual Review of Marine Science},
publisher = {Annual Reviews Inc.},
year = {2019},
volume = {11},
number = {1},
pages = {159--186},
url = {https://www.annualreviews.org/doi/10.1146/annurev-marine-121916-063407},
doi = {10.1146/annurev-marine-121916-063407}
}
|
| Haro K, Ouarma I, Nana B, Bere A, Tubreoumya GC, Kam SZ, Laville P, Loubet B and Koulidiati J (2019), "Assessment of CH4 and CO2 surface emissions from Polesgo's landfill (Ouagadougou, Burkina Faso) based on static chamber method", Advances in Climate Change Research., sep, 2019. Vol. 10(3), pp. 181-191. Elsevier BV. |
| Abstract: Methane (CH4) and carbon dioxide (CO2) surface emissions from Polesgo's landfill (Ouagadougou, Burkina Faso) were measured using the static chamber technique in 2017 and 2018. The Polesgo's landfill was composed of four zones: Phase I, II, Phase III, and SP. The surface of Phase I was fully covered and its conditions are better for surface emission measurements. As results concerning the Phase I zone, the geospatial means flux rates of CH4 (657 mg mâˆ'2 hâˆ'1 in 2017 and 1210 mg mâˆ'2 hâˆ'1 in 2018, respectively) are measured higher than the tolerable value reported in literature. The emitted CH4 or CO2 have permitted to locate higher surface emissions which are related to the cover state. The calculated gas collection efficiency (27.4% in 2017 and 23.0% in 2018) is low compared to those reported for landfills integrating landfill gas (LFG) extraction system. The carbon footprint calculations (24,966 tCO2-eq 2017 and 40,025 tCO2-eq in 2018, respectively) shown that Polesgo's landfill is a significant source of greenhouse gases (GHG) and its important potential for organic recovery can contribute to reduce the carbon footprint. |
BibTeX:
@article{Haro2019,
author = {Haro, Kayaba and Ouarma, Issoufou and Nana, Bernard and Bere, Antoine and Tubreoumya, Guy Christian and Kam, Sié Zacharie and Laville, Patricia and Loubet, Benjamin and Koulidiati, Jean},
title = {Assessment of CH4 and CO2 surface emissions from Polesgo's landfill (Ouagadougou, Burkina Faso) based on static chamber method},
journal = {Advances in Climate Change Research},
publisher = {Elsevier BV},
year = {2019},
volume = {10},
number = {3},
pages = {181--191},
doi = {10.1016/j.accre.2019.09.002}
}
|
| Hartman SE, Humphreys MP, Kivimäe C, Woodward EMS, Kitidis V, McGrath T, Hydes DJ, Greenwood N, Hull T, Ostle C, Pearce DJ, Sivyer D, Stewart BM, Walsham P, Painter SC, McGovern E, Harris C, Griffiths A, Smilenova A, Clarke J, Davis C, Sanders R and Nightingale P (2019), "Seasonality and spatial heterogeneity of the surface ocean carbonate system in the northwest European continental shelf", Progress in Oceanography., oct, 2019. Vol. 177, pp. 101909. Elsevier BV. |
| Abstract: In 2014–5 the UK NERC sponsored an 18 month long Shelf Sea Biogeochemistry research programme which collected over 1500 nutrient and carbonate system samples across the NW European Continental shelf, one of the largest continental shelves on the planet. This involved the cooperation of 10 different Institutes and Universities, using 6 different vessels. Additional carbon dioxide (CO2) data were obtained from the underway systems on three of the research vessels. Here, we present and discuss these data across 9 ecohydrodynamic regions, adapted from those used by the EU Marine Strategy Framework Directive (MSFD). We observed strong seasonal and regional variability in carbonate chemistry around the shelf in relation to nutrient biogeochemistry. Whilst salinity increased (and alkalinity decreased) out from the near-shore coastal waters offshore throughout the year nutrient concentrations varied with season. Spatial and seasonal variations in the ratio of DIC to nitrate concentration were seen that could impact carbon cycling. A decrease in nutrient concentrations and a pronounced under-saturation of surface pCO2 was evident in the spring in most regions, especially in the Celtic Sea. This decrease was less pronounced in Liverpool Bay and to the North of Scotland, where nutrient concentrations remained measurable throughout the year. The near-shore and relatively shallow ecosystems such as the eastern English Channel and southern North Sea were associated with a thermally driven increase in pCO2 to above atmospheric levels in summer and an associated decrease in pH. Non-thermal processes (such as mixing and the remineralisation of organic material) dominated in winter in most regions but especially in the northwest of Scotland and in Liverpool Bay. The large database collected will improve understanding of carbonate chemistry over the North-Western European Shelf in relation to nutrient biogeochemistry, particularly in the context of climate change and ocean acidification. |
BibTeX:
@article{Hartman2019,
author = {Hartman, S E and Humphreys, M P and Kivimäe, C and Woodward, E M S and Kitidis, V and McGrath, T and Hydes, D J and Greenwood, N and Hull, T and Ostle, C and Pearce, D J and Sivyer, D and Stewart, B M and Walsham, P and Painter, S C and McGovern, E and Harris, C and Griffiths, A and Smilenova, A and Clarke, J and Davis, C and Sanders, R and Nightingale, P},
title = {Seasonality and spatial heterogeneity of the surface ocean carbonate system in the northwest European continental shelf},
journal = {Progress in Oceanography},
publisher = {Elsevier BV},
year = {2019},
volume = {177},
pages = {101909},
doi = {10.1016/j.pocean.2018.02.005}
}
|
| Hastie A, Lauerwald R, Ciais P and Regnier P (2019), "Aquatic carbon fluxes dampen the overall variation of net ecosystem productivity in the Amazon basin: An analysis of the interannual variability in the boundless carbon cycle", Global Change Biology., apr, 2019. Vol. 25(6), pp. 2094-2111. Wiley. |
| Abstract: The river–floodplain network plays an important role in the carbon (C) cycle of the Amazon basin, as it transports and processes a significant fraction of the C fixed by terrestrial vegetation, most of which evades as CO 2 from rivers and floodplains back to the atmosphere. There is empirical evidence that exceptionally dry or wet years have an impact on the net C balance in the Amazon. While seasonal and interannual variations in hydrology have a direct impact on the amounts of C transferred through the river–floodplain system, it is not known how far the variation of these fluxes affects the overall Amazon C balance. Here, we introduce a new wetland forcing file for the ORCHILEAK model, which improves the representation of floodplain dynamics and allows us to closely reproduce data-driven estimates of net C exports through the river–floodplain network. Based on this new wetland forcing and two climate forcing datasets, we show that across the Amazon, the percentage of net primary productivity lost to the river–floodplain system is highly variable at the interannual timescale, and wet years fuel aquatic CO 2 evasion. However, at the same time overall net ecosystem productivity (NEP) and C sequestration are highest during wet years, partly due to reduced decomposition rates in water-logged floodplain soils. It is years with the lowest discharge and floodplain inundation, often associated with El Nino events, that have the lowest NEP and the highest total (terrestrial plus aquatic) CO 2 emissions back to atmosphere. Furthermore, we find that aquatic C fluxes display greater variation than terrestrial C fluxes, and that this variation significantly dampens the interannual variability in NEP of the Amazon basin. These results call for a more integrative view of the C fluxes through the vegetation-soil-river-floodplain continuum, which directly places aquatic C fluxes into the overall C budget of the Amazon basin. |
BibTeX:
@article{Hastie2019,
author = {Hastie, Adam and Lauerwald, Ronny and Ciais, Philippe and Regnier, Pierre},
title = {Aquatic carbon fluxes dampen the overall variation of net ecosystem productivity in the Amazon basin: An analysis of the interannual variability in the boundless carbon cycle},
journal = {Global Change Biology},
publisher = {Wiley},
year = {2019},
volume = {25},
number = {6},
pages = {2094--2111},
doi = {10.1111/gcb.14620}
}
|
| Hayes F, Mills G, Alonso R, González-Fernández I, Coyle M, Grünhage L, Gerosa G, Karlsson PE and Marzuoli R (2019), "A Site-Specific Analysis of the Implications of a Changing Ozone Profile and Climate for Stomatal Ozone Fluxes in Europe", Water, Air, and Soil Pollution., dec, 2019. Vol. 230(1) Springer Science and Business Media LLC. |
| Abstract: In this study, we used eight sites from across Europe to investigate the implications of a future climate (2 °C warmer and 20% drier) and a changing ozone profile (increased background concentrations and reduced peaks) on stomatal ozone fluxes of three widely occurring plant species. A changing ozone profile with small increases in background ozone concentrations over the course of a growing season could have significant impacts on the annual accumulated stomatal ozone uptake, even if peak concentrations of ozone are reduced. Predicted increases in stomatal ozone uptake showed a strong relationship with latitude and were larger at sites from northern and mid-Europe than those from southern Europe. At the sites from central and northern regions of Europe, including the UK and Sweden, climatic conditions were highly conducive to stomatal ozone uptake by vegetation during the summer months and therefore an increase in daily mean ozone concentration of 3–16% during this time of year (from increased background concentrations, reduced peaks) would have a large impact on stomatal ozone uptake. In contrast, during spring and autumn, the climatic conditions can limit ozone uptake for many species. Although small increases in ozone concentration during these seasons could cause a modest increase in ozone uptake, for those species that are active at low temperatures, a 2 °C increase in temperature would increase stomatal ozone uptake even in the absence of further increases in ozone concentration. Predicted changes in climate could alter ozone uptake even with no change in ozone profile. For some southern regions of Europe, where temperatures are close to or above optimum for stomatal opening, an increase in temperature of 2 °C could limit stomatal ozone uptake by enhancing stomatal closure during the summer months, whereas during the spring, when many plants are actively growing, a small increase in temperature would increase stomatal ozone uptake. |
BibTeX:
@article{Hayes2019,
author = {Hayes, Felicity and Mills, Gina and Alonso, Rocio and González-Fernández, Ignacio and Coyle, Mhairi and Grünhage, Ludger and Gerosa, Giacomo and Karlsson, Per Erik and Marzuoli, Riccardo},
title = {A Site-Specific Analysis of the Implications of a Changing Ozone Profile and Climate for Stomatal Ozone Fluxes in Europe},
journal = {Water, Air, and Soil Pollution},
publisher = {Springer Science and Business Media LLC},
year = {2019},
volume = {230},
number = {1},
doi = {10.1007/s11270-018-4057-x}
}
|
| Haynes KD, Baker IT, Denning AS, Wolf S, Wohlfahrt G, Kiely G, Minaya RC and Haynes JM (2019), "Representing Grasslands Using Dynamic Prognostic Phenology Based on Biological Growth Stages: Part 2. Carbon Cycling", Journal of Advances in Modeling Earth Systems., dec, 2019. Vol. 11(12), pp. 4440-4465. Blackwell Publishing Ltd. |
| Abstract: Grasslands are one of the most widely distributed and abundant vegetation types globally, and land surface models struggle to accurately simulate grassland carbon dioxide, energy, and water fluxes. Here we hypothesize that this is due to land surface models having difficulties in reproducing grassland phenology, in particular in response to the seasonal and interannual variability of precipitation. Using leaf area index (LAI), net primary productivity, and flux data at 55 sites spanning climate zones, the aim of this study is to evaluate a novel prognostic phenology model (Simple Biosphere Model, SiB4) while simultaneously illustrating grassland relationships across precipitation gradients. Evaluating from 2000 to 2014, SiB4 predicts daily LAI, carbon, and energy fluxes with root-mean-square errors textless 15% and individual biases textless10%; however, not including management likely reduces its performance. Grassland mean annual LAI increases linearly with mean annual precipitation, with both SiB4 and the Moderate Resolution Imaging Spectroradiometer (MODIS) showing a 0.13 increase in LAI per 100-mm increase in precipitation. Both gross primary production and ecosystem respiration increase with growing season length by ∼8.5 g C m−2 per day, with SiB4 and Fluxnet estimates within 18%. Despite differences in mean annual precipitation and growing season length, all grassland sites shift to seasonal carbon sinks one month prior to peak uptake. During a U.S. drought, MODIS and SiB4 had nearly identical LAI responses, and the LAI change due to drought was less than the LAI change across the precipitation gradient, indicating that grassland drought response is not as strong as the overlying climate response. |
BibTeX:
@article{Haynes2019,
author = {Haynes, Katherine D. and Baker, Ian T. and Denning, A. Scott and Wolf, Sebastian and Wohlfahrt, Georg and Kiely, Gerard and Minaya, Renee C. and Haynes, John M.},
title = {Representing Grasslands Using Dynamic Prognostic Phenology Based on Biological Growth Stages: Part 2. Carbon Cycling},
journal = {Journal of Advances in Modeling Earth Systems},
publisher = {Blackwell Publishing Ltd},
year = {2019},
volume = {11},
number = {12},
pages = {4440--4465},
doi = {10.1029/2018MS001541}
}
|
| He Y, Peng S, Liu Y, Li X, Wang K, Ciais P, Arain MA, Fang Y, Fisher JB, Goll D, Hayes D, Huntzinger DN, Ito A, Jain AK, Janssens IA, Mao J, Matteo C, Michalak AM, Peng C, Peñuelas J, Poulter B, Qin D, Ricciuto DM, Schaefer K, Schwalm CR, Shi X, Tian H, Vicca S, Wei Y, Zeng N and Zhu Q (2019), "Global vegetation biomass production efficiency constrained by models and observations", Global Change Biology., sep, 2019. Vol. 26(3), pp. 1474-1484. Wiley. |
| Abstract: Plants use only a fraction of their photosynthetically derived carbon for biomass production (BP). The biomass production efficiency (BPE), defined as the ratio of BP to photosynthesis, and its variation across and within vegetation types is poorly understood, which hinders our capacity to accurately estimate carbon turnover times and carbon sinks. Here, we present a new global estimation of BPE obtained by combining field measurements from 113 sites with 14 carbon cycle models. Our best estimate of global BPE is 0.41 ± 0.05, excluding cropland. The largest BPE is found in boreal forests (0.48 ± 0.06) and the lowest in tropical forests (0.40 ± 0.04). Carbon cycle models overestimate BPE, although models with carbon–nitrogen interactions tend to be more realistic. Using observation-based estimates of global photosynthesis, we quantify the global BP of non-cropland ecosystems of 41 ± 6 Pg C/year. This flux is less than net primary production as it does not contain carbon allocated to symbionts, used for exudates or volatile carbon compound emissions to the atmosphere. Our study reveals a positive bias of 24 ± 11% in the model-estimated BP (10 of 14 models). When correcting models for this bias while leaving modeled carbon turnover times unchanged, we found that the global ecosystem carbon storage change during the last century is decreased by 67% (or 58 Pg C). |
BibTeX:
@article{He2019,
author = {He, Yue and Peng, Shushi and Liu, Yongwen and Li, Xiangyi and Wang, Kai and Ciais, Philippe and Arain, M Altaf and Fang, Yuanyuan and Fisher, Joshua B and Goll, Daniel and Hayes, Daniel and Huntzinger, Deborah N and Ito, Akihiko and Jain, Atul K and Janssens, Ivan A and Mao, Jiafu and Matteo, Campioli and Michalak, Anna M and Peng, Changhui and Peñuelas, Josep and Poulter, Benjamin and Qin, Dahe and Ricciuto, Daniel M and Schaefer, Kevin and Schwalm, Christopher R and Shi, Xiaoying and Tian, Hanqin and Vicca, Sara and Wei, Yaxing and Zeng, Ning and Zhu, Qiuan},
title = {Global vegetation biomass production efficiency constrained by models and observations},
journal = {Global Change Biology},
publisher = {Wiley},
year = {2019},
volume = {26},
number = {3},
pages = {1474--1484},
doi = {10.1111/gcb.14816}
}
|
| Helfter C, Mullinger N, Vieno M, O'Doherty S, Ramonet M, Palmer PI and Nemitz E (2019), "Country-scale greenhouse gas budgets using shipborne measurements: A case study for the UK and Ireland", Atmospheric Chemistry and Physics., mar, 2019. Vol. 19(5), pp. 3043-3063. Copernicus GmbH. |
| Abstract: We present a mass balance approach to estimate the seasonal and annual budgets of carbon dioxide (CO2) and methane (CH4) of the United Kingdom (excluding Scotland) and the Republic of Ireland from concentration measurements taken on a ferry along the east coast of the United Kingdom over a 3-year period (2015-2017). We estimate the annual emissions of CH4 to be 2.55±0.48 Tg, which is consistent with the combined 2.29 Tg reported to the United Nations Framework Convention on Climate Change by the individual countries. The net CO2 budget (i.e. including all anthropogenic and biogenic sources and sinks of CO2) is estimated at 881.0±125.8 Tg, with a net biogenic contribution of 458.7 Tg (taken as the difference between the estimated net emissions and the inventory value, which accounts for anthropogenic emissions only). The largest emissions for both gases were observed in a broad latitudinal band (52.5-54°N), which coincides with densely populated areas. The emissions of both gases were seasonal (maxima in winter and minima in summer), strongly correlated with natural gas usage and, to a lesser extent, also anti-correlated with mean air temperature. Methane emissions exhibited a statistically significant anti-correlation with air temperature at the seasonal timescale in the central region spanning 52.8-54.2°N, which hosts a relatively high density of waste treatment facilities. Methane emissions from landfills have been shown to sometimes increase with decreasing air temperature due to changes in the CH4-oxidising potential of the topsoil, and we speculate that the waste sector contributes significantly to the CH4 budget of this central region. This study brings independent verification of the emission budgets estimated using alternative products (e.g. mass balance budgets by aircraft measurements, inverse modelling, inventorying) and offers an opportunity to investigate the seasonality of these emissions, which is usually not possible. |
BibTeX:
@article{Helfter2019,
author = {Helfter, Carole and Mullinger, Neil and Vieno, Massimo and O'Doherty, Simon and Ramonet, Michel and Palmer, Paul I and Nemitz, Eiko},
title = {Country-scale greenhouse gas budgets using shipborne measurements: A case study for the UK and Ireland},
journal = {Atmospheric Chemistry and Physics},
publisher = {Copernicus GmbH},
year = {2019},
volume = {19},
number = {5},
pages = {3043--3063},
doi = {10.5194/acp-19-3043-2019}
}
|
| Hemes KS, Chamberlain SD, Eichelmann E, Anthony T, Valach A, Kasak K, Szutu D, Verfaillie J, Silver WL and Baldocchi DD (2019), "Assessing the carbon and climate benefit of restoring degraded agricultural peat soils to managed wetlands", Agricultural and Forest Meteorology., apr, 2019. Vol. 268, pp. 202-214. Elsevier B.V.. |
| Abstract: Restoring degraded peat soils presents an attractive, but largely untested, climate change mitigation approach. Drained peat soils used for agriculture can be large greenhouse gas sources. By restoring subsided peat soils to managed, impounded wetlands, significant agricultural emissions are avoided, and soil carbon can be sequestered and protected. Here, we synthesize 36 site-years of continuous carbon dioxide and methane flux data from a mesonetwork of eddy covariance towers in the Sacramento-San Joaquin Delta in California, USA to compute carbon and greenhouse gas budgets for drained agricultural land uses and compare these to restored deltaic wetlands. We found that restored wetlands effectively sequestered carbon and halted soil carbon loss associated with drained agricultural land uses. Depending on the age and disturbance regime of the restored wetland, many land use conversions from agriculture to restored wetland resulted in emission reductions over a 100-year timescale. With a simple model of radiative forcing and atmospheric lifetimes, we showed that restored wetlands do not begin to accrue greenhouse gas benefits until nearly a half century, and become net sinks from the atmosphere after a century. Due to substantial interannual variability and uncertainty about the multi-decadal successional trajectory of managed, restored wetlands, ongoing ecosystem flux measurements are critical for understanding the long-term impacts of wetland restoration for climate change mitigation. |
BibTeX:
@article{Hemes2019,
author = {Hemes, Kyle S. and Chamberlain, Samuel D. and Eichelmann, Elke and Anthony, Tyler and Valach, Amy and Kasak, Kuno and Szutu, Daphne and Verfaillie, Joe and Silver, Whendee L. and Baldocchi, Dennis D.},
title = {Assessing the carbon and climate benefit of restoring degraded agricultural peat soils to managed wetlands},
journal = {Agricultural and Forest Meteorology},
publisher = {Elsevier B.V.},
year = {2019},
volume = {268},
pages = {202--214},
doi = {10.1016/j.agrformet.2019.01.017}
}
|
| Holding T, Ashton IG, Shutler JD, Land PE, Nightingale PD, Rees AP, Brown I, Piolle JF, Kock A, Bange HW, Woolf DK, Goddijn-Murphy L, Pereira R, Paul F, Girard-Ardhuin F, Chapron B, Rehder G, Ardhuin F and Donlon CJ (2019), "The fluxengine air-sea gas flux toolbox: Simplified interface and extensions for in situ analyses and multiple sparingly soluble gases", Ocean Science., dec, 2019. Vol. 15(6), pp. 1707-1728. Copernicus GmbH. |
| Abstract: The flow (flux) of climate-critical gases, such as carbon dioxide (span classCombining double low line"inline-formula"CO2/span), between the ocean and the atmosphere is a fundamental component of our climate and an important driver of the biogeochemical systems within the oceans. Therefore, the accurate calculation of these air-sea gas fluxes is critical if we are to monitor the oceans and assess the impact that these gases are having on Earth's climate and ecosystems. FluxEngine is an open-source software toolbox that allows users to easily perform calculations of air-sea gas fluxes from model, in situ, and Earth observation data. The original development and verification of the toolbox was described in a previous publication. The toolbox has now been considerably updated to allow for its use as a Python library, to enable simplified installation, to ensure verification of its installation, to enable the handling of multiple sparingly soluble gases, and to enable the greatly expanded functionality for supporting in situ dataset analyses. This new functionality for supporting in situ analyses includes user-defined grids, time periods and projections, the ability to reanalyse in situ span classCombining double low line"inline-formula"CO2/span data to a common temperature dataset, and the ability to easily calculate gas fluxes using in situ data from drifting buoys, fixed moorings, and research cruises. Here we describe these new capabilities and demonstrate their application through illustrative case studies. The first case study demonstrates the workflow for accurately calculating span classCombining double low line"inline-formula"CO2/span fluxes using in situ data from four research cruises from the Surface Ocean span classCombining double low line"inline-formula"CO2/span ATlas (SOCAT) database. The second case study calculates air-sea span classCombining double low line"inline-formula"CO2/span fluxes using in situ data from a fixed monitoring station in the Baltic Sea. The third case study focuses on nitrous oxide (span classCombining double low line"inline-formula"N2O/span) and, through a user-defined gas transfer parameterisation, identifies that biological surfactants in the North Atlantic could suppress individual span classCombining double low line"inline-formula"N2O/span sea-air gas fluxes by up to 13&thinsp;%. The fourth and final case study illustrates how a dissipation-based gas transfer parameterisation can be implemented and used. The updated version of the toolbox (version 3) and all documentation is now freely available. |
BibTeX:
@article{Holding2019,
author = {Holding, Thomas and Ashton, Ian G and Shutler, Jamie D and Land, Peter E and Nightingale, Philip D and Rees, Andrew P and Brown, Ian and Piolle, Jean Francois and Kock, Annette and Bange, Hermann W and Woolf, David K and Goddijn-Murphy, Lonneke and Pereira, Ryan and Paul, Frederic and Girard-Ardhuin, Fanny and Chapron, Bertrand and Rehder, Gregor and Ardhuin, Fabrice and Donlon, Craig J},
title = {The fluxengine air-sea gas flux toolbox: Simplified interface and extensions for in situ analyses and multiple sparingly soluble gases},
journal = {Ocean Science},
publisher = {Copernicus GmbH},
year = {2019},
volume = {15},
number = {6},
pages = {1707--1728},
doi = {10.5194/os-15-1707-2019}
}
|
| Horemans JA, Arriga N and Ceulemans R (2019), "Greenhouse gas budget of a poplar bioenergy plantation in Belgium: CO2 uptake outweighs CH4 and N2O emissions", GCB Bioenergy., oct, 2019. Vol. 11(12), pp. 1435-1443. Wiley. |
| Abstract: Biomass from short-rotation coppice (SRC) of woody perennials is being increasingly used as a bioenergy source to replace fossil fuels, but accurate assessments of the long-term greenhouse gas (GHG) balance of SRC are lacking. To evaluate its mitigation potential, we monitored the GHG balance of a poplar (Populus) SRC in Flanders, Belgium, over 7 years comprising three rotations (i.e., two 2 year rotations and one 3 year rotation). In the beginning—that is, during the establishment year and during each year immediately following coppicing—the SRC plantation was a net source of GHGs. Later on—that is, during each second or third year after coppicing—the site shifted to a net sink. From the sixth year onward, there was a net cumulative GHG uptake reaching âˆ'35.8 Mg CO2 eq/ha during the seventh year. Over the three rotations, the total CO2 uptake was âˆ'51.2 Mg CO2/ha, while the emissions of CH4 and N2O amounted to 8.9 and 6.5 Mg CO2 eq/ha, respectively. As the site was non-fertilized, non-irrigated, and only occasionally flooded, CO2 fluxes dominated the GHG budget. Soil disturbance after land conversion and after coppicing were the main drivers for CO2 losses. One single N2O pulse shortly after SRC establishment contributed significantly to the N2O release. The results prove the potential of SRC biomass plantations to reduce GHG emissions and demonstrate that, for the poplar plantation under study, the high CO2 uptake outweighs the emissions of non-CO2 greenhouse gases. |
BibTeX:
@article{Horemans2019,
author = {Horemans, Joanna A and Arriga, Nicola and Ceulemans, Reinhart},
title = {Greenhouse gas budget of a poplar bioenergy plantation in Belgium: CO2 uptake outweighs CH4 and N2O emissions},
journal = {GCB Bioenergy},
publisher = {Wiley},
year = {2019},
volume = {11},
number = {12},
pages = {1435--1443},
doi = {10.1111/gcbb.12648}
}
|
| Huang X, Xiao J and Ma M (2019), "Evaluating the Performance of Satellite-Derived Vegetation Indices for Estimating Gross Primary Productivity Using FLUXNET Observations across the Globe", Remote Sensing., aug, 2019. Vol. 11(15), pp. 1823. |
| Abstract: Satellite-derived vegetation indices (VIs) have been widely used to approximate or estimate gross primary productivity (GPP). However, it remains unclear how the VI-GPP relationship varies with indices, biomes, timescales, and the bidirectional reflectance distribution function (BRDF) effect. We examined the relationship between VIs and GPP for 121 FLUXNET sites across the globe and assessed how the VI-GPP relationship varied among a variety of biomes at both monthly and annual timescales. We used three widely-used VIs: normalized difference vegetation index (NDVI), enhanced vegetation index (EVI), and 2-band EVI (EVI2) as well as a new VI - NIRV and used surface reflectance both with and without BRDF correction from the moderate resolution imaging spectroradiometer (MODIS) to calculate these indices. The resulting traditional (NDVI, EVI, EVI2, and NIRV) and BRDF-corrected (NDVIBRDF, EVIBRDF, EVI2BRDF, and NIRV, BRDF) VIs were used to examine the VI-GPP relationship. At the monthly scale, all VIs were moderate or strong predictors of GPP, and the BRDF correction improved their performance. EVI2BRDF and NIRV, BRDF had similar performance in capturing the variations in tower GPP as did the MODIS GPP product. The VIs explained lower variance in tower GPP at the annual scale than at the monthly scale. The BRDF-correction of surface reflectance did not improve the VI-GPP relationship at the annual scale. The VIs had similar capability in capturing the interannual variability in tower GPP as MODIS GPP. VIs were influenced by temperature and water stresses and were more sensitive to temperature stress than to water stress. VIs in combination with environmental factors could improve the prediction of GPP than VIs alone. Our findings can help us better understand how the VI-GPP relationship varies among indices, biomes, and timescales and how the BRDF effect influences the VI-GPP relationship. |
BibTeX:
@article{Huang2019,
author = {Huang, Xiaojuan and Xiao, Jingfeng and Ma, Mingguo},
title = {Evaluating the Performance of Satellite-Derived Vegetation Indices for Estimating Gross Primary Productivity Using FLUXNET Observations across the Globe},
journal = {Remote Sensing},
year = {2019},
volume = {11},
number = {15},
pages = {1823},
url = {https://www.mdpi.com/2072-4292/11/15/1823},
doi = {10.3390/rs11151823}
}
|
| Huang M, Piao S, Ciais P, Peñuelas J, Wang X, Keenan TF, Peng S, Berry JA, Wang K, Mao J, Alkama R, Cescatti A, Cuntz M, De Deurwaerder H, Gao M, He Y, Liu Y, Luo Y, Myneni RB, Niu S, Shi X, Yuan W, Verbeeck H, Wang T, Wu J and Janssens IA (2019), "Air temperature optima of vegetation productivity across global biomes", Nature Ecology and Evolution., mar, 2019. Vol. 3(5), pp. 772-779. Springer Science and Business Media LLC. |
| Abstract: The global distribution of the optimum air temperature for ecosystem-level gross primary productivity (Topteco) is poorly understood, despite its importance for ecosystem carbon uptake under future warming. We provide empirical evidence for the existence of such an optimum, using measurements of in situ eddy covariance and satellite-derived proxies, and report its global distribution. Topteco is consistently lower than the physiological optimum temperature of leaf-level photosynthetic capacity, which typically exceeds 30 °C. The global average Topteco is estimated to be 23 ± 6 °C, with warmer regions having higher Topteco values than colder regions. In tropical forests in particular, Topteco is close to growing-season air temperature and is projected to fall below it under all scenarios of future climate, suggesting a limited safe operating space for these ecosystems under future warming. |
BibTeX:
@article{Huang2019a,
author = {Huang, Mengtian and Piao, Shilong and Ciais, Philippe and Peñuelas, Josep and Wang, Xuhui and Keenan, Trevor F and Peng, Shushi and Berry, Joseph A and Wang, Kai and Mao, Jiafu and Alkama, Ramdane and Cescatti, Alessandro and Cuntz, Matthias and De Deurwaerder, Hannes and Gao, Mengdi and He, Yue and Liu, Yongwen and Luo, Yiqi and Myneni, Ranga B and Niu, Shuli and Shi, Xiaoying and Yuan, Wenping and Verbeeck, Hans and Wang, Tao and Wu, Jin and Janssens, Ivan A},
title = {Air temperature optima of vegetation productivity across global biomes},
journal = {Nature Ecology and Evolution},
publisher = {Springer Science and Business Media LLC},
year = {2019},
volume = {3},
number = {5},
pages = {772--779},
doi = {10.1038/s41559-019-0838-x}
}
|
| Huang W, Raza SA, Mirzov O and Harrie L (2019), "Assessment and Benchmarking of Spatially Enabled RDF Stores for the Next Generation of Spatial Data Infrastructure", ISPRS International Journal of Geo-Information., jul, 2019. Vol. 8(7), pp. 310. MDPI AG. |
| Abstract: textlessptextgreaterGeospatial information is indispensable for various real-world applications and is thus a prominent part of today's data science landscape. Geospatial data is primarily maintained and disseminated through spatial data infrastructures (SDIs). However, current SDIs are facing challenges in terms of data integration and semantic heterogeneity because of their partially siloed data organization. In this context, linked data provides a promising means to unravel these challenges, and it is seen as one of the key factors moving SDIs toward the next generation. In this study, we investigate the technical environment of the support for geospatial linked data by assessing and benchmarking some popular and well-known spatially enabled RDF stores (RDF4J, GeoSPARQL-Jena, Virtuoso, Stardog, and GraphDB), with a focus on GeoSPARQL compliance and query performance. The tests were performed in two different scenarios. In the first scenario, geospatial data forms a part of a large-scale data infrastructure and is integrated with other types of data. In this scenario, we used ICOS Carbon Portal's metadata—a real-world Earth Science linked data infrastructure. In the second scenario, we benchmarked the RDF stores in a dedicated SDI environment that contains purely geospatial data, and we used geospatial datasets with both crowd-sourced and authoritative data (the same test data used in a previous benchmark study, the Geographica benchmark). The assessment and benchmarking results demonstrate that the GeoSPARQL compliance of the RDF stores has encouragingly advanced in the last several years. The query performances are generally acceptable, and spatial indexing is imperative when handling a large number of geospatial objects. Nevertheless, query correctness remains a challenge for cross-database interoperability. In conclusion, the results indicate that the spatial capacity of the RDF stores has become increasingly mature, which could benefit the development of future SDIs.textless/ptextgreater |
BibTeX:
@article{Huang2019b,
author = {Huang, Weiming and Raza, Syed Amir and Mirzov, Oleg and Harrie, Lars},
title = {Assessment and Benchmarking of Spatially Enabled RDF Stores for the Next Generation of Spatial Data Infrastructure},
journal = {ISPRS International Journal of Geo-Information},
publisher = {MDPI AG},
year = {2019},
volume = {8},
number = {7},
pages = {310},
url = {https://www.mdpi.com/2220-9964/8/7/310},
doi = {10.3390/ijgi8070310}
}
|
| Hurdebise Q, Aubinet M, Heinesch B and Vincke C (2019), "Increasing temperatures over an 18-year period shortens growing season length in a beech (Fagus sylvatica L.)-dominated forest", Annals of Forest Science., jul, 2019. Vol. 76(3) Springer Science and Business Media LLC. |
| Abstract: Key message: Using long-term measurements in a mature beech (Fagus sylvatica L.)-dominated forest located in east Belgium, this paper showed that spring and autumn temperature increases during the last two decades led to an earlier end and a shortening of the growing season. These phenological shifts impact negatively but not significantly the forest annual net ecosystem productivity. Context: The mechanisms controlling temperate forest phenology are not fully understood nor are the impacts of climate change and the consequences for forest productivity. Aims: The aim of this paper is to contribute to the understanding of how temperate forest phenology and net ecosystem productivity (NEP) interplay and respond to temperature and its evolution. Methods: Indicators of leaf phenology and productivity dynamics at the start and the end of the growing season, as well as combinations of these indicators (length of the growing season), were derived from a long-term (1997–2014) dataset of eddy covariance and light transmission measurements taken over a mature beech-dominated temperate forest. Results: The start and the end of the growing season were correlated to spring (and autumn, for the end) temperatures. Despite no trends in annual average temperatures being detected during the observation period, April and November temperatures significantly increased. As a result, an earlier but slower start and an earlier end, inducing a shorter length of the growing season, were observed over the studied period. The first shift positively impacts the mixed forest NEP but is mainly related to the presence of conifers in the subplot. The earlier end of the growing season, more related to beech phenology, negatively impacts the forest NEP. Overall, these two effects partially compensate each other, leading to a non-significant impact on NEP. Conclusion: Increasing temperatures over the 18-year studied period shortened the growing season length, without affecting significantly the mixed forest NEP. However, as beeches are only affected by the earlier end of the growing season, this suggests a phenologically driven beech productivity reduction in the forest. |
BibTeX:
@article{Hurdebise2019,
author = {Hurdebise, Quentin and Aubinet, Marc and Heinesch, Bernard and Vincke, Caroline},
title = {Increasing temperatures over an 18-year period shortens growing season length in a beech (Fagus sylvatica L.)-dominated forest},
journal = {Annals of Forest Science},
publisher = {Springer Science and Business Media LLC},
year = {2019},
volume = {76},
number = {3},
doi = {10.1007/s13595-019-0861-8}
}
|
| Ivakhov VM, Paramonova NN, Privalov VI, Zinchenko AV, Loskutova MA, Makshtas AP, Kustov VY, Laurila T, Aurela M and Asmi E (2019), "Atmospheric Concentration of Carbon Dioxide at Tiksi and Cape Baranov Stations in 2010–2017", Russian Meteorology and Hydrology., apr, 2019. Vol. 44(4), pp. 291-299. Allerton Press. |
| Abstract: The study presents the results of continuous measurements of carbon dioxide concentration in the atmospheric surface layer at Tiksi and Cape Baranov Arctic stations over the period of August 2010–May 2017 and over the whole 2016, respectively. The amplitude of diurnal variations in the CO2 concentration in Tiksi from June to September is 1.1 ± 1.3, 2.4 ± 2.0, 4.1 ± 2.3, and 2.0 ± 2.4 ppm. Diurnal variations in CO2 at Cape Baranov station are absent. The observed seasonal variations in the CO2 concentration are compared with the data of the MBL empirical model for the marine atmospheric boundary layer of the Arctic region. In 2016, the difference between the observed and model concentrations at Tiksi and Cape Baranov stations amounted to 1.7 and 0.5 ppm, respectively, in winter and âˆ'3.0 and âˆ'1.9 ppm, respectively, in summer. It is shown that wildfires in Siberia caused a long synchronous increase in the CO2 concentration by 20 ppm in Tiksi and by 15 ppm at Cape Baranov station. |
BibTeX:
@article{Ivakhov2019,
author = {Ivakhov, V M and Paramonova, N N and Privalov, V I and Zinchenko, A V and Loskutova, M A and Makshtas, A P and Kustov, V Y and Laurila, T and Aurela, M and Asmi, E},
title = {Atmospheric Concentration of Carbon Dioxide at Tiksi and Cape Baranov Stations in 2010–2017},
journal = {Russian Meteorology and Hydrology},
publisher = {Allerton Press},
year = {2019},
volume = {44},
number = {4},
pages = {291--299},
doi = {10.3103/S1068373919040095}
}
|
| Jakovljević T, Marchetto A, Lovreškov L, Potočić N, Seletković I, Indir K, Jelić G, Butorac L, Zgrablić Ž, De Marco A, Simioni G, Ognjenović M and Jurinjak Tušek A (2019), "Assessment of Atmospheric Deposition and Vitality Indicators in Mediterranean Forest Ecosystems", Sustainability., nov, 2019. Vol. 11(23), pp. 6805. MDPI AG. |
| Abstract: Considering the fragility of the Mediterranean environment, there is an increasing need to improve the knowledge of this forest environment. The aim of this study was to examine the effects of air pollution on the forest ecosystem's condition by analyzing tree vitality. The study area was chosen to represent the most important and the most common species in Mediterranean forest ecosystems of the Eastern Adriatic coast. Quercus pubescens, Quercus ilex, Pinus halepensis, and Pinus nigra plots were equipped with rain collectors and dendrometer bands. Sampling, measurements, and analyses of atmospheric deposition, foliar nutrient, defoliation, and growth were all carried out. Results showed that actual N deposition loads were the lowest in Aleppo pine forest and the highest in holm oak forests. This, however, did not have an effect on the concentrations of N in foliage. Most elements' concentrations were in the plausible range. No relevant differences in mean defoliation between the plots were observed. The plots with a lower percentage of basal area increment (BAI%) were found to have lower defoliation. The research was conducted to bridge the gap in the knowledge of air pollutants and vitality indicators in different forest types. These findings are a valuable contribution to the sustainable forest management of Mediterranean forest. |
BibTeX:
@article{Jakovljevic2019,
author = {Jakovljević, Tamara and Marchetto, Aldo and Lovreškov, Lucija and Potočić, Nenad and Seletković, Ivan and Indir, Krunoslav and Jelić, Goran and Butorac, Lukrecija and Zgrablić, Željko and De Marco, Alessandra and Simioni, Guillaume and Ognjenović, Mladen and Jurinjak Tušek, Ana},
title = {Assessment of Atmospheric Deposition and Vitality Indicators in Mediterranean Forest Ecosystems},
journal = {Sustainability},
publisher = {MDPI AG},
year = {2019},
volume = {11},
number = {23},
pages = {6805},
doi = {10.3390/su11236805}
}
|
| Järvi L, Havu M, Ward HC, Bellucco V, McFadden JP, Toivonen T, Heikinheimo V, Kolari P, Riikonen A and Grimmond CSB (2019), "Spatial Modeling of Local-Scale Biogenic and Anthropogenic Carbon Dioxide Emissions in Helsinki", Journal of Geophysical Research: Atmospheres., aug, 2019. Vol. 124(15), pp. 8363-8384. American Geophysical Union (AGU). |
| Abstract: There is a growing need to simulate the effect of urban planning on both local climate and greenhouse gas emissions. Here, a new urban surface carbon dioxide (CO2) flux module for the Surface Urban Energy and Water Balance Scheme is described and evaluated using eddy covariance observations at two sites in Helsinki in 2012. The spatial variability and magnitude of local-scale anthropogenic and biogenic CO2 flux components at high spatial (250 m × 250 m) and temporal (hourly) resolution are examined by combining high-resolution (down to 2 m) airborne lidar-derived land use data and mobility data to account for people's movement. Urban effects are included in the biogenic components parameterized using urban eddy covariance and chamber observations. Surface Urban Energy and Water Balance Scheme reproduces the seasonal and diurnal variability of the CO2 flux well. Annual totals deviate 3% from observations in the city center and 2% in a suburban location. In the latter, traffic is the dominant CO2 source but summertime vegetation partly offsets traffic-related emissions. In the city center, emissions from traffic and human metabolism dominate and the vegetation effect is minor due to the low proportion of vegetation surface cover (22%). Within central Helsinki, human metabolism accounts for 39% of the net local-scale emissions and together with road traffic is to a large extent responsible for the spatial variability of the emissions. Annually, the biogenic emissions and sinks are in near balance and thus the effect of vegetation on the carbon balance is small in this high-latitude city. |
BibTeX:
@article{Jarvi2019,
author = {Järvi, Leena and Havu, Minttu and Ward, Helen C and Bellucco, Veronica and McFadden, Joseph P and Toivonen, Tuuli and Heikinheimo, Vuokko and Kolari, Pasi and Riikonen, Anu and Grimmond, C Sue B},
title = {Spatial Modeling of Local-Scale Biogenic and Anthropogenic Carbon Dioxide Emissions in Helsinki},
journal = {Journal of Geophysical Research: Atmospheres},
publisher = {American Geophysical Union (AGU)},
year = {2019},
volume = {124},
number = {15},
pages = {8363--8384},
doi = {10.1029/2018JD029576}
}
|
| Jauhiainen J, Alm J, Bjarnadottir B, Callesen I, Christiansen JR, Clarke N, Dalsgaard L, He H, Jordan S, Kazanavičiute V, Klemedtsson L, Lauren A, Lazdins A, Lehtonen A, Lohila A, Lupikis A, Mander Ü, Minkkinen K, Kasimir Å, Olsson M, Ojanen P, Óskarsson H, Sigurdsson BD, Søgaard G, Soosaar K, Vesterdal L and Laiho R (2019), "Reviews and syntheses: Greenhouse gas exchange data from drained organic forest soils-A review of current approaches and recommendations for future research", Biogeosciences., dec, 2019. Vol. 16(23), pp. 4687-4703. Copernicus GmbH. |
| Abstract: Drained organic forest soils in boreal and temperate climate zones are believed to be significant sources of the greenhouse gases (GHGs) carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O), but the annual fluxes are still highly uncertain. Drained organic soils exemplify systems where many studies are still carried out with relatively small resources, several methodologies and manually operated systems, which further involve different options for the detailed design of the measurement and data analysis protocols for deriving the annual flux. It would be beneficial to set certain guidelines for how to measure and report the data, so that data from individual studies could also be used in synthesis work based on data collation and modelling. Such synthesis work is necessary for deciphering general patterns and trends related to, e.g., site types, climate, and management, and the development of corresponding emission factors, i.e. estimates of the net annual soil GHG emission and removal, which can be used in GHG inventories. Development of specific emission factors also sets prerequisites for the background or environmental data to be reported in individual studies. We argue that wide applicability greatly increases the value of individual studies. An overall objective of this paper is to support future monitoring campaigns in obtaining high-value data.We analysed peer-reviewed public cations presenting CO2, CH4 and N2O flux data for drained organic forest soils in boreal and temperate climate zones, focusing on data that have been used, or have the potential to be used, for estimating net annual soil GHG emissions and removals. We evaluated the methods used in data collection and identified major gaps in background or environmental data. Based on these, we formulated recommendations for future research. |
BibTeX:
@article{Jauhiainen2019,
author = {Jauhiainen, Jyrki and Alm, Jukka and Bjarnadottir, Brynhildur and Callesen, Ingeborg and Christiansen, Jesper R and Clarke, Nicholas and Dalsgaard, Lise and He, Hongxing and Jordan, Sabine and Kazanavičiute, Vaiva and Klemedtsson, Leif and Lauren, Ari and Lazdins, Andis and Lehtonen, Aleksi and Lohila, Annalea and Lupikis, Ainars and Mander, Ülo and Minkkinen, Kari and Kasimir, Åsa and Olsson, Mats and Ojanen, Paavo and Óskarsson, Hlynur and Sigurdsson, Bjarni D and Søgaard, Gunnhild and Soosaar, Kaido and Vesterdal, Lars and Laiho, Raija},
title = {Reviews and syntheses: Greenhouse gas exchange data from drained organic forest soils-A review of current approaches and recommendations for future research},
journal = {Biogeosciences},
publisher = {Copernicus GmbH},
year = {2019},
volume = {16},
number = {23},
pages = {4687--4703},
doi = {10.5194/bg-16-4687-2019}
}
|
| Jiang ZP, Yuan J, Hartman SE and Fan W (2019), "Enhancing the observing capacity for the surface ocean by the use of Volunteer Observing Ship", Acta Oceanologica Sinica., jul, 2019. Vol. 38(7), pp. 114-120. Springer Verlag. |
| Abstract: Knowledge of the surface ocean dynamics and the underlying controlling mechanisms is critical to understand the natural variability of the ocean and to predict its future response to climate change. In this paper, we highlight the potential use of Volunteer Observing Ship (VOS), as carrier for automatic underway measuring system and as platform for sample collection, to enhance the observing capacity for the surface ocean. We review the concept, history, present status and future development of the VOS-based in situ surface ocean observation. The successes of various VOS projects demonstrate that, along with the rapid advancing sensor techniques, VOS is able to improve the temporal resolution and spatial coverage of the surface ocean observation in a highly cost-effective manner. A sustained and efficient marine monitoring system in the future should integrate the advantages of various observing platforms including VOS. |
BibTeX:
@article{Jiang2019,
author = {Jiang, Zong Pei and Yuan, Jiajun and Hartman, Susan E. and Fan, Wei},
title = {Enhancing the observing capacity for the surface ocean by the use of Volunteer Observing Ship},
journal = {Acta Oceanologica Sinica},
publisher = {Springer Verlag},
year = {2019},
volume = {38},
number = {7},
pages = {114--120},
url = {https://link.springer.com/article/10.1007/s13131-019-1463-3},
doi = {10.1007/s13131-019-1463-3}
}
|
| Jiang P, Liu H, Piao S, Ciais P, Wu X, Yin Y and Wang H (2019), "Enhanced growth after extreme wetness compensates for post-drought carbon loss in dry forests", Nature Communications., jan, 2019. Vol. 10(1) Springer Science and Business Media LLC. |
| Abstract: While many studies have reported that drought events have substantial negative legacy effects on forest growth, it remains unclear whether wetness events conversely have positive growth legacy effects. Here, we report pervasive and substantial growth enhancement after extreme wetness by examining tree radial growth at 1929 forest sites, satellite-derived vegetation greenness, and land surface model simulations. Enhanced growth after extreme wetness lasts for 1 to 5 years and compensates for 93 ± 8% of the growth deficit after extreme drought across global water-limited regions. Remarkable wetness-enhanced growths are observed in dry forests and gymnosperms, whereas the enhanced growths after extreme wetness are much smaller in wet forests and angiosperms. Limited or no enhanced growths are simulated by the land surface models after extreme wetness. These findings provide new evidence for improving climate-vegetation models to include the legacy effects of both drought and wet climate extremes. |
BibTeX:
@article{Jiang2019a,
author = {Jiang, Peng and Liu, Hongyan and Piao, Shilong and Ciais, Philippe and Wu, Xiuchen and Yin, Yi and Wang, Hongya},
title = {Enhanced growth after extreme wetness compensates for post-drought carbon loss in dry forests},
journal = {Nature Communications},
publisher = {Springer Science and Business Media LLC},
year = {2019},
volume = {10},
number = {1},
doi = {10.1038/s41467-018-08229-z}
}
|
| Jiang LQ, Carter BR, Feely RA, Lauvset SK and Olsen A (2019), "Surface ocean pH and buffer capacity: past, present and future", Scientific Reports., dec, 2019. Vol. 9(1) Springer Science and Business Media LLC. |
| Abstract: The ocean's chemistry is changing due to the uptake of anthropogenic carbon dioxide (CO2). This phenomenon, commonly referred to as “Ocean Acidificationâ€, is endangering coral reefs and the broader marine ecosystems. In this study, we combine a recent observational seawater CO2 data product, i.e., the 6th version of the Surface Ocean CO2 Atlas (1991–2018, ˜23 million observations), with temporal trends at individual locations of the global ocean from a robust Earth System Model to provide a high-resolution regionally varying view of global surface ocean pH and the Revelle Factor. The climatology extends from the pre-Industrial era (1750 C.E.) to the end of this century under historical atmospheric CO2 concentrations (pre-2005) and the Representative Concentrations Pathways (post-2005) of the Intergovernmental Panel on Climate Change (IPCC)'s 5th Assessment Report. By linking the modeled pH trends to the observed modern pH distribution, the climatology benefits from recent improvements in both model design and observational data coverage, and is likely to provide improved regional OA trajectories than the model output could alone, therefore, will help guide the regional OA adaptation strategies. We show that air-sea CO2 disequilibrium is the dominant mode of spatial variability for surface pH, and discuss why pH and calcium carbonate mineral saturation states, two important metrics for OA, show contrasting spatial variability. |
BibTeX:
@article{Jiang2019b,
author = {Jiang, Li Qing and Carter, Brendan R and Feely, Richard A and Lauvset, Siv K and Olsen, Are},
title = {Surface ocean pH and buffer capacity: past, present and future},
journal = {Scientific Reports},
publisher = {Springer Science and Business Media LLC},
year = {2019},
volume = {9},
number = {1},
doi = {10.1038/s41598-019-55039-4}
}
|
| Jung M, Koirala S, Weber U, Ichii K, Gans F, Camps-Valls G, Papale D, Schwalm C, Tramontana G and Reichstein M (2019), "The FLUXCOM ensemble of global land-atmosphere energy fluxes", Scientific Data., dec, 2019. Vol. 6(1), pp. 74. |
BibTeX:
@article{Jung2019,
author = {Jung, Martin and Koirala, Sujan and Weber, Ulrich and Ichii, Kazuhito and Gans, Fabian and Camps-Valls, Gustau and Papale, Dario and Schwalm, Christopher and Tramontana, Gianluca and Reichstein, Markus},
title = {The FLUXCOM ensemble of global land-atmosphere energy fluxes},
journal = {Scientific Data},
year = {2019},
volume = {6},
number = {1},
pages = {74},
url = {http://www.nature.com/articles/s41597-019-0076-8},
doi = {10.1038/s41597-019-0076-8}
}
|
| Juráň S, Šigut L, Holub P, Fares S, Klem K, Grace J and Urban O (2019), "Ozone flux and ozone deposition in a mountain spruce forest are modulated by sky conditions", Science of the Total Environment., jul, 2019. Vol. 672, pp. 296-304. Elsevier BV. |
| Abstract: In order to understand the main driving factors of ozone (O 3 ) deposition we tested the hypothesis that sky conditions (cloudy, partly cloudy, and clear sky) modulate O 3 flux in forest ecosystems via stomatal regulation. The hypothesis is based on the fact that complex microclimate conditions under cloudy sky usually stimulate stomatal conductance. O 3 fluxes were inferred from a concentration gradient in a mountainous Norway spruce forest in the Czech Republic (Central Europe) for years 2012–2016 and measured directly by eddy-covariance during the summer of 2017. Daily and seasonal O 3 depositions were calculated separately for days with cloudy, partly cloudy, and clear sky conditions. The data show unequivocally that more O 3 is taken up under cloudy and partially cloudy skies. Moreover, we found significant interactive effects of sky conditions and season on O 3 flux. Though there are other mechanisms and pathways involved in the transport of O 3 to the plant-soil system, the highest O 3 deposition was associated to the highest stomatal conductance during partly cloudy and cloudy sky conditions in all seasons, while lower O 3 ecosystem fluxes were observed under clear sky conditions despite the highest O 3 concentrations at this time. These findings suggest that forests growing at sites where conditions are predominantly cloudy are expected to deposit higher extent of O 3 than less-cloudy forests being thus more threatened by phytotoxic O 3 . |
BibTeX:
@article{JuraA2019,
author = {Juráň, Stanislav and Šigut, Ladislav and Holub, Petr and Fares, Silvano and Klem, Karel and Grace, John and Urban, Otmar},
title = {Ozone flux and ozone deposition in a mountain spruce forest are modulated by sky conditions},
journal = {Science of the Total Environment},
publisher = {Elsevier BV},
year = {2019},
volume = {672},
pages = {296--304},
doi = {10.1016/j.scitotenv.2019.03.491}
}
|
| Kadavý J, Adamec Z, Uherková B, Kneifl M, Knott R, Kučera A, Friedl M, DaÅ™enová E, Skládanka J and Drápela K (2019), "Growth response of sessile oak and European hornbeam to traditional coppice-with-standards management", Forests., jun, 2019. Vol. 10(6), pp. 515. MDPI AG. |
| Abstract: Research Highlights: The influence of litter raking and livestock grazing on the development of juvenile sessile oak and European hornbeam sprouts as well as on sessile oak standards were studied. Such experiments are very rare, especially in central Europe where these activities have been prohibited for several decades. Little is known on how these ancient management activities affect tree growth. Background and Objectives: Traditional management practices in coppice forests such as grazing and litter raking have been abandoned, but have recently been studied as to whether these practices can substantially contribute to an increase in the species diversity of coppices. The important question is, however, how these practices influence the growth of coppice-with-standards. Therefore, this study focused on the effect of grazing, litter raking, and their combination on both sprouts and adult trees in a coppice-with-standards system one year after harvest. Materials and Methods: The experiment was carried out in the area of the Training Forest Enterprise Masaryk Forest Křtiny, Czech Republic, in a forest stand dominated by sessile oak and European hornbeam. We analyzed 132 oak polycormons, 132 hornbeam polycormons, and 163 oak standards. Results: The number of sprouts per stump was affected by the stump size and management practice: (A) coppice-with-standards, litter raking, and sheep grazing; (B) coppice-with-standards and sheep grazing; (C) coppice-with-standards and litter raking; and (D) coppice-with-standards), but not by tree species. The number of the sprouts as well as their height increased with the stump size. In contrast, grazing resulted in a smaller height of the sprouts while thinner sprouts were found under a combination of grazing and raking. When comparing the species, the oak sprouts were higher and thicker when compared to the hornbeam sprouts. The increment of standards increased after stand harvest. This, however, was not the result of grazing or raking, but the response to the reduction of tree number and thus of competition between neighboring trees. Conclusions: The results showed that there were rather negative impacts from the implemented traditional management practices on the growth of sprouts. This may lead to the question of whether ecological diversity resulting from the traditional practices may prevail their negative effect on the growth of the coppices. |
BibTeX:
@article{Kadavy2019,
author = {Kadavý, Jan and Adamec, Zdeněk and Uherková, Barbora and Kneifl, Michal and Knott, Robert and Kučera, Aleš and Friedl, Michal and DaÅ™enová, Eva and Skládanka, JiÅ™í and Drápela, Karel},
title = {Growth response of sessile oak and European hornbeam to traditional coppice-with-standards management},
journal = {Forests},
publisher = {MDPI AG},
year = {2019},
volume = {10},
number = {6},
pages = {515},
doi = {10.3390/f10060515}
}
|
| Keenan TF, Migliavacca M, Papale D, Baldocchi D, Reichstein M, Torn M and Wutzler T (2019), "Widespread inhibition of daytime ecosystem respiration", Nature Ecology and Evolution., feb, 2019. Vol. 3(3), pp. 407-415. |
| Abstract: The global land surface absorbs about a third of anthropogenic emissions each year, due to the difference between two key processes: ecosystem photosynthesis and respiration. Despite the importance of these two processes, it is not possible to measure either at the ecosystem scale during the daytime. Eddy-covariance measurements are widely used as the closest ‘quasi-direct' ecosystem-scale observation from which to estimate ecosystem photosynthesis and respiration. Recent research, however, suggests that current estimates may be biased by up to 25%, due to a previously unaccounted for process: the inhibition of leaf respiration in the light. Yet the extent of inhibition remains debated, and implications for estimates of ecosystem-scale respiration and photosynthesis remain unquantified. Here, we quantify an apparent inhibition of daytime ecosystem respiration across the global FLUXNET eddy-covariance network and identify a pervasive influence that varies by season and ecosystem type. We develop partitioning methods that can detect an apparent ecosystem-scale inhibition of daytime respiration and find that diurnal patterns of ecosystem respiration might be markedly different than previously thought. The results call for the re-evaluation of global terrestrial carbon cycle models and also suggest that current global estimates of photosynthesis and respiration may be biased, some on the order of magnitude of anthropogenic fossil fuel emissions. |
BibTeX:
@article{Keenan2019,
author = {Keenan, Trevor F and Migliavacca, Mirco and Papale, Dario and Baldocchi, Dennis and Reichstein, Markus and Torn, Margaret and Wutzler, Thomas},
title = {Widespread inhibition of daytime ecosystem respiration},
journal = {Nature Ecology and Evolution},
year = {2019},
volume = {3},
number = {3},
pages = {407--415},
url = {http://www.nature.com/articles/s41559-019-0809-2},
doi = {10.1038/s41559-019-0809-2}
}
|
| Keppler L and Landschützer P (2019), "Regional Wind Variability Modulates the Southern Ocean Carbon Sink", Scientific Reports., dec, 2019. Vol. 9(1), pp. 1-10. Nature Publishing Group. |
| Abstract: The Southern Ocean south of 35°S accounts for approximately half of the annual oceanic carbon uptake, thereby substantially mitigating the effects of anthropogenic carbon dioxide (CO 2 ) emissions. The intensity of this important carbon sink varies considerably on inter-annual to decadal timescales. However, the drivers of this variability are still debated, challenging our ability to accurately predict the future role of the Southern Ocean in absorbing atmospheric carbon. Analysing mapped sea-air CO 2 fluxes, estimated from upscaled surface ocean CO 2 measurements, we find that the overall Southern Ocean carbon sink has weakened since ˜2011, reversing the trend of the reinvigoration period of the 2000s. Although we find significant regional positive and negative responses of the Southern Ocean carbon uptake to changes in the Southern Annular Mode (SAM) over the past 35 years, the net effect of the SAM on the Southern Ocean carbon sink variability is approximately zero, due to the opposing effects of enhanced outgassing in upwelling regions and enhanced carbon uptake elsewhere. Instead, regional shifts in sea level pressure, linked to zonal wavenumber 3 (ZW3) and related changes in surface winds substantially contribute to the inter-annual to decadal variability of the Southern Ocean carbon sink. |
BibTeX:
@article{Keppler2019,
author = {Keppler, Lydia and Landschützer, Peter},
title = {Regional Wind Variability Modulates the Southern Ocean Carbon Sink},
journal = {Scientific Reports},
publisher = {Nature Publishing Group},
year = {2019},
volume = {9},
number = {1},
pages = {1--10},
url = {www.nature.com/scientificreports},
doi = {10.1038/s41598-019-43826-y}
}
|
| Khatiwala S, Schmittner A and Muglia J (2019), "Air-sea disequilibrium enhances ocean carbon storage during glacial periods", Science Advances., jun, 2019. Vol. 5(6), pp. eaaw4981. American Association for the Advancement of Science. |
| Abstract: The prevailing hypothesis for lower atmospheric carbon dioxide (CO2) concentrations during glacial periods is an increased efficiency of the ocean's biological pump. However, tests of this and other hypotheses have been hampered by the difficulty to accurately quantify ocean carbon components. Here, we use an observationally constrained earth system model to precisely quantify these components and the role that different processes play in simulated glacial-interglacial CO2 variations. We find that air-sea disequilibrium greatly amplifies the effects of cooler temperatures and iron fertilization on glacial ocean carbon storage even as the efficiency of the soft-tissue biological pump decreases. These two processes, which have previously been regarded as minor, explain most of our simulated glacial CO2 drawdown, while ocean circulation and sea ice extent, hitherto considered dominant, emerge as relatively small contributors. |
BibTeX:
@article{Khatiwala2019,
author = {Khatiwala, S. and Schmittner, A. and Muglia, J.},
title = {Air-sea disequilibrium enhances ocean carbon storage during glacial periods},
journal = {Science Advances},
publisher = {American Association for the Advancement of Science},
year = {2019},
volume = {5},
number = {6},
pages = {eaaw4981},
url = {http://advances.sciencemag.org/},
doi = {10.1126/sciadv.aaw4981}
}
|
| Kitidis V, Shutler JD, Ashton I, Warren M, Brown I, Findlay H, Hartman SE, Sanders R, Humphreys M, Kivimäe C, Greenwood N, Hull T, Pearce D, McGrath T, Stewart BM, Walsham P, McGovern E, Bozec Y, Gac JP, van Heuven SMAC, Hoppema M, Schuster U, Johannessen T, Omar A, Lauvset SK, Skjelvan I, Olsen A, Steinhoff T, Körtzinger A, Becker M, Lefevre N, Diverrès D, Gkritzalis T, Cattrijsse A, Petersen W, Voynova YG, Chapron B, Grouazel A, Land PE, Sharples J and Nightingale PD (2019), "Winter weather controls net influx of atmospheric CO2 on the north-west European shelf", Scientific Reports., dec, 2019. Vol. 9(1) Springer Science and Business Media LLC. |
| Abstract: Shelf seas play an important role in the global carbon cycle, absorbing atmospheric carbon dioxide (CO2) and exporting carbon (C) to the open ocean and sediments. The magnitude of these processes is poorly constrained, because observations are typically interpolated over multiple years. Here, we used 298500 observations of CO2 fugacity (fCO2) from a single year (2015), to estimate the net influx of atmospheric CO2 as 26.2 ± 4.7 Tg C yrâˆ'1 over the open NW European shelf. CO2 influx from the atmosphere was dominated by influx during winter as a consequence of high winds, despite a smaller, thermally-driven, air-sea fCO2 gradient compared to the larger, biologically-driven summer gradient. In order to understand this climate regulation service, we constructed a carbon-budget supplemented by data from the literature, where the NW European shelf is treated as a box with carbon entering and leaving the box. This budget showed that net C-burial was a small sink of 1.3 ± 3.1 Tg C yrâˆ'1, while CO2 efflux from estuaries to the atmosphere, removed the majority of river C-inputs. In contrast, the input from the Baltic Sea likely contributes to net export via the continental shelf pump and advection (34.4 ± 6.0 Tg C yrâˆ'1). |
BibTeX:
@article{Kitidis2019,
author = {Kitidis, Vassilis and Shutler, Jamie D and Ashton, Ian and Warren, Mark and Brown, Ian and Findlay, Helen and Hartman, Sue E and Sanders, Richard and Humphreys, Matthew and Kivimäe, Caroline and Greenwood, Naomi and Hull, Tom and Pearce, David and McGrath, Triona and Stewart, Brian M and Walsham, Pamela and McGovern, Evin and Bozec, Yann and Gac, Jean Philippe and van Heuven, Steven M A C and Hoppema, Mario and Schuster, Ute and Johannessen, Truls and Omar, Abdirahman and Lauvset, Siv K and Skjelvan, Ingunn and Olsen, Are and Steinhoff, Tobias and Körtzinger, Arne and Becker, Meike and Lefevre, Nathalie and Diverrès, Denis and Gkritzalis, Thanos and Cattrijsse, André and Petersen, Wilhelm and Voynova, Yoana G and Chapron, Bertrand and Grouazel, Antoine and Land, Peter E and Sharples, Jonathan and Nightingale, Philip D},
title = {Winter weather controls net influx of atmospheric CO2 on the north-west European shelf},
journal = {Scientific Reports},
publisher = {Springer Science and Business Media LLC},
year = {2019},
volume = {9},
number = {1},
doi = {10.1038/s41598-019-56363-5}
}
|
| Kiuru P, Ojala A, Mammarella I, Heiskanen J, Erkkilä KM, Miettinen H, Vesala T and Huttula T (2019), "Applicability and consequences of the integration of alternative models for CO2 transfer velocity into a process-based lake model", Biogeosciences., sep, 2019. Vol. 16(17), pp. 3297-3317. Copernicus GmbH. |
| Abstract: Freshwater lakes are important in carbon cycling, especially in the boreal zone where many lakes are supersaturated with the greenhouse gas carbon dioxide (CO2) and emit it to the atmosphere, thus ventilating carbon originally fixed by the terrestrial system. The exchange of CO2 between water and the atmosphere is commonly estimated using simple wind-based parameterizations or models of gas transfer velocity (k). More complex surface renewal models, however, have been shown to yield more correct estimates of k in comparison with direct CO2 flux measurements. We incorporated four gas exchange models with different complexity into a vertical process-based physico-biochemical lake model, MyLake C, and assessed the performance and applicability of the alternative lake model versions to simulate air-water CO2 fluxes over a small boreal lake. None of the incorporated gas exchange models significantly outperformed the other models in the simulations in comparison to the measured near-surface CO2 concentrations or respective air-water CO2 fluxes calculated directly with the gas exchange models using measurement data as input. The use of more complex gas exchange models in the simulation, on the contrary, led to difficulties in obtaining a sufficient gain of CO2 in the water column and thus resulted in lower CO2 fluxes and water column CO2 concentrations compared to the respective measurement-based values. The inclusion of sophisticated and more correct models for air-water CO2 exchange in process-based lake models is crucial in efforts to properly assess lacustrine carbon budgets through model simulations in both single lakes and on a larger scale. However, finding higher estimates for both the internal and external sources of inorganic carbon in boreal lakes is important if improved knowledge of the magnitude of CO2 evasion from lakes is included in future studies on lake carbon budgets. |
BibTeX:
@article{Kiuru2019,
author = {Kiuru, Petri and Ojala, Anne and Mammarella, Ivan and Heiskanen, Jouni and Erkkilä, Kukka Maaria and Miettinen, Heli and Vesala, Timo and Huttula, Timo},
title = {Applicability and consequences of the integration of alternative models for CO2 transfer velocity into a process-based lake model},
journal = {Biogeosciences},
publisher = {Copernicus GmbH},
year = {2019},
volume = {16},
number = {17},
pages = {3297--3317},
doi = {10.5194/bg-16-3297-2019}
}
|
| Kivimäki E, Lindqvist H, Hakkarainen J, Laine M, Sussmann R, Tsuruta A, Detmers R, Deutscher NM, Dlugokencky EJ, Hase F, Hasekamp O, Kivi R, Morino I, Notholt J, Pollard DF, Roehl C, Schneider M, Sha MK, Velazco VA, Warneke T, Wunch D, Yoshida Y and Tamminen J (2019), "Evaluation and analysis of the seasonal cycle and variability of the trend from GOSAT methane retrievals", Remote Sensing., apr, 2019. Vol. 11(7) MDPI AG. |
| Abstract: Methane (CH4) is a potent greenhouse gas with a large temporal variability. To increase the spatial coverage, methane observations are increasingly made from satellites that retrieve the column-averaged dry air mole fraction of methane (XCH4). To understand and quantify the spatial differences of the seasonal cycle and trend of XCH4 in more detail, and to ultimately help reduce uncertainties in methane emissions and sinks, we evaluated and analyzed the average XCH4 seasonal cycle and trend from three Greenhouse Gases Observing Satellite (GOSAT) retrieval algorithms: National Institute for Environmental Studies algorithm version 02.75, RemoTeC CH4 Proxy algorithm version 2.3.8 and RemoTeC CH4 Full Physics algorithm version 2.3.8. Evaluations were made against the Total Carbon Column Observing Network (TCCON) retrievals at 15 TCCON sites for 2009-2015, and the analysis was performed, in addition to the TCCON sites, at 31 latitude bands between latitudes 44.43°S and 53.13°N. At latitude bands, we also compared the trend of GOSAT XCH4retrievals to the NOAA's Marine Boundary Layer reference data. The average seasonal cycle and the non-linear trend were, for the first time for methane, modeled with a dynamic regression method called Dynamic Linear Model that quantifies the trend and the seasonal cycle, and provides reliable uncertainties for the parameters. Our results show that, if the number of co-located soundings is sufficiently large throughout the year, the seasonal cycle and trend of the three GOSAT retrievals agree well, mostly within the uncertainty ranges, with the TCCON retrievals. Especially estimates of the maximum day of XCH4 agree well, both between the GOSAT and TCCON retrievals, and between the three GOSAT retrievals at the latitude bands. In our analysis, we showed that there are large spatial differences in the trend and seasonal cycle of XCH4. These differences are linked to the regional CH4 sources and sinks, and call for further research. |
BibTeX:
@article{Kivimaki2019,
author = {Kivimäki, Ella and Lindqvist, Hannakaisa and Hakkarainen, Janne and Laine, Marko and Sussmann, Ralf and Tsuruta, Aki and Detmers, Rob and Deutscher, Nicholas M. and Dlugokencky, Edward J. and Hase, Frank and Hasekamp, Otto and Kivi, Rigel and Morino, Isamu and Notholt, Justus and Pollard, David F. and Roehl, Coleen and Schneider, Matthias and Sha, Mahesh Kumar and Velazco, Voltaire A. and Warneke, Thorsten and Wunch, Debra and Yoshida, Yukio and Tamminen, Johanna},
title = {Evaluation and analysis of the seasonal cycle and variability of the trend from GOSAT methane retrievals},
journal = {Remote Sensing},
publisher = {MDPI AG},
year = {2019},
volume = {11},
number = {7},
doi = {10.3390/RS11070882}
}
|
| Klosterhalfen A, Graf A, Brüggemann N, Drüe C, Esser O, González-Dugo MP, Heinemann G, Jacobs CMJ, Mauder M, Moene AF, Ney P, Pütz T, Rebmann C, Rodríguez MR, Scanlon TM, Schmidt M, Steinbrecher R, Thomas CK, Valler V, Zeeman MJ and Vereecken H (2019), "Source partitioning of H2O and CO2 fluxes based on high-frequency eddy covariance data: A comparison between study sites", Biogeosciences., mar, 2019. Vol. 16(6), pp. 1111-1132. Copernicus GmbH. |
| Abstract: For an assessment of the roles of soil and vegetation in the climate system, a further understanding of the flux components of H2O and CO2 (e.g., transpiration, soil respiration) and their interaction with physical conditions and physiological functioning of plants and ecosystems is necessary. To obtain magnitudes of these flux components, we applied source partitioning approaches after Scanlon and Kustas (2010; SK10) and after Thomas et al. (2008; TH08) to high-frequency eddy covariance measurements of 12 study sites covering different ecosystems (croplands, grasslands, and forests) in different climatic regions. Both partitioning methods are based on higher-order statistics of the H2O and CO2 fluctuations, but proceed differently to estimate transpiration, evaporation, net primary production, and soil respiration. We compared and evaluated the partitioning results obtained with SK10 and TH08, including slight modifications of both approaches. Further, we analyzed the interrelations among the performance of the partitioning methods, turbulence characteristics, and site characteristics (such as plant cover type, canopy height, canopy density, and measurement height). We were able to identify characteristics of a data set that are prerequisites for adequate performance of the partitioning methods. SK10 had the tendency to overestimate and TH08 to underestimate soil flux components. For both methods, the partitioning of CO2 fluxes was less robust than for H2O fluxes. Results derived with SK10 showed relatively large dependencies on estimated water use efficiency (WUE) at the leaf level, which is a required input. Measurements of outgoing longwave radiation used for the estimation of foliage temperature (used in WUE) could slightly increase the quality of the partitioning results. A modification of the TH08 approach, by applying a cluster analysis for the conditional sampling of respiration-evaporation events, performed satisfactorily, but did not result in significant advantages compared to the original method versions developed by Thomas et al. (2008). The performance of each partitioning approach was dependent on meteorological conditions, plant development, canopy height, canopy density, and measurement height. Foremost, the performance of SK10 correlated page1112 negatively with the ratio between measurement height and canopy height. The performance of TH08 was more dependent on canopy height and leaf area index. In general, all site characteristics that increase dissimilarities between scalars appeared to enhance partitioning performance for SK10 and TH08. |
BibTeX:
@article{Klosterhalfen2019,
author = {Klosterhalfen, Anne and Graf, Alexander and Brüggemann, Nicolas and Drüe, Clemens and Esser, Odilia and González-Dugo, María P and Heinemann, Günther and Jacobs, Cor M J and Mauder, Matthias and Moene, Arnold F and Ney, Patrizia and Pütz, Thomas and Rebmann, Corinna and Rodríguez, Mario Ramos and Scanlon, Todd M and Schmidt, Marius and Steinbrecher, Rainer and Thomas, Christoph K and Valler, Veronika and Zeeman, Matthias J and Vereecken, Harry},
title = {Source partitioning of H2O and CO2 fluxes based on high-frequency eddy covariance data: A comparison between study sites},
journal = {Biogeosciences},
publisher = {Copernicus GmbH},
year = {2019},
volume = {16},
number = {6},
pages = {1111--1132},
doi = {10.5194/bg-16-1111-2019}
}
|
| Klosterhalfen A, Moene AF, Schmidt M, Scanlon TM, Vereecken H and Graf A (2019), "Sensitivity analysis of a source partitioning method for H2O and CO2 fluxes based on high frequency eddy covariance data: Findings from field data and large eddy simulations", Agricultural and Forest Meteorology., feb, 2019. Vol. 265, pp. 152-170. Elsevier BV. |
| Abstract: Scanlon and Sahu (2008) and Scanlon and Kustas (2010) proposed a source partitioning method (SK10 in the following) to estimate contributions of transpiration, evaporation, photosynthesis, and respiration to H2O and CO2 fluxes obtained by the eddy covariance method. High frequency eddy covariance raw data time series are needed, and the source partitioning is estimated based on separate application of the flux-variance similarity theory to stomatal and non-stomatal components of the regarded fluxes, as well as on additional assumptions on leaf-level water use efficiency (WUE). We applied SK10 to data from two test sites (forest and cropland) and analyzed partitioning results depending on various ways to estimate WUE from available data. Also, we conducted large eddy simulations (LES), simulating the turbulent transport of H2O and CO2 for contrasting vertical distributions of the canopy sinks/sources, as well as for varying relative magnitudes of soil sources and canopy sinks/sources. SK10 was applied to the synthetic high frequency data generated by LES and the effects of canopy type, measurement height, given sink-source-distributions, and input of varying WUEs were tested regarding the partitioning performance. SK10 requires that the correlation coefficient between stomatal and non-stomatal scalar fluctuations is determined by the ratio of the transfer efficiencies of these scalar components, an assumption (transfer assumption in the following) that could be tested with the generated LES data. The partitioning results of the field sites yielded satisfactory flux fractions, when fair-weather conditions (no precipitation) and a high productive state of the vegetation were present. Further, partitioning performance with regard to soil fluxes increased with crop maturity. Results also showed relatively large dependencies on WUE, where the partitioning factors (median) changed by around -57% and +36%. Measurements of outgoing longwave radiation used for the estimation of foliage temperature and WUE could slightly increase the plausibility of the partitioning results in comparison to soil respiration measurements by decreasing the partitioning factor by up to 42%. The LES-based analysis revealed that for a satisfying performance of SK10, a certain degree of decorrelation of the H2O and CO2 fluctuations (here, |ρq'c'| 0.975) was needed. This decorrelation is enhanced by a clear separation between soil sources and canopy sinks/sources, and for observations within the roughness sublayer. The expected dependence of the partitioning results on the WUE input could be observed. However, due to violation of the abovementioned transfer assumption, the known true input WUE did not yield the known true input partitioning. This could only be achieved after introducing correction factors for the transfer assumption, which were known however only in the special case of the LES experiments. |
BibTeX:
@article{Klosterhalfen2019a,
author = {Klosterhalfen, A and Moene, A F and Schmidt, M and Scanlon, T M and Vereecken, H and Graf, A},
title = {Sensitivity analysis of a source partitioning method for H2O and CO2 fluxes based on high frequency eddy covariance data: Findings from field data and large eddy simulations},
journal = {Agricultural and Forest Meteorology},
publisher = {Elsevier BV},
year = {2019},
volume = {265},
pages = {152--170},
doi = {10.1016/j.agrformet.2018.11.003}
}
|
| Knox SH, Jackson RB, Poulter B, McNicol G, Fluet-Chouinard E, Zhang Z, Hugelius G, Bousquet P, Canadell JG, Saunois M, Papale D, Chu H, Keenan TF, Baldocchi D, Torn MS, Mammarella I, Trotta C, Aurela M, Bohrer G, Campbell DI, Cescatti A, Chamberlain S, Chen J, Chen W, Dengel S, Desai AR, Euskirchen E, Friborg T, Gasbarra D, Goded I, Goeckede M, Heimann M, Helbig M, Hirano T, Hollinger DY, Iwata H, Kang M, Klatt J, Krauss KW, Kutzbach L, Lohila A, Mitra B, Morin TH, Nilsson MB, Niu S, Noormets A, Oechel WC, Peichl M, Peltola O, Reba ML, Richardson AD, Runkle BRK, Ryu Y, Sachs T, Schäfer KVR, Schmid HP, Shurpali N, Sonnentag O, Tang ACI, Ueyama M, Vargas R, Vesala T, Ward EJ, Windham-Myers L, Wohlfahrt G and Zona D (2019), "FluXNET-CH4 synthesis activity objectives, observations, and future directions", Bulletin of the American Meteorological Society., dec, 2019. Vol. 100(12), pp. 2607-2632. |
| Abstract: We describe a new coordination activity and initial results for a global synthesis of eddy covariance CH4 flux measurements. |
BibTeX:
@article{Knox2019,
author = {Knox, Sara H and Jackson, Robert B and Poulter, Benjamin and McNicol, Gavin and Fluet-Chouinard, Etienne and Zhang, Zhen and Hugelius, Gustaf and Bousquet, Philippe and Canadell, Josep G and Saunois, Marielle and Papale, Dario and Chu, Housen and Keenan, Trevor F and Baldocchi, Dennis and Torn, Margaret S and Mammarella, Ivan and Trotta, Carlo and Aurela, Mika and Bohrer, Gil and Campbell, David I and Cescatti, Alessandro and Chamberlain, Samuel and Chen, Jiquan and Chen, Weinan and Dengel, Sigrid and Desai, Ankur R and Euskirchen, Eugenie and Friborg, Thomas and Gasbarra, Daniele and Goded, Ignacio and Goeckede, Mathias and Heimann, Martin and Helbig, Manuel and Hirano, Takashi and Hollinger, David Y and Iwata, Hiroki and Kang, Minseok and Klatt, Janina and Krauss, Ken W and Kutzbach, Lars and Lohila, Annalea and Mitra, Bhaskar and Morin, Timothy H and Nilsson, Mats B and Niu, Shuli and Noormets, Asko and Oechel, Walter C and Peichl, Matthias and Peltola, Olli and Reba, Michele L and Richardson, Andrew D and Runkle, Benjamin R K and Ryu, Youngryel and Sachs, Torsten and Schäfer, Karina V R and Schmid, Hans Peter and Shurpali, Narasinha and Sonnentag, Oliver and Tang, Angela C I and Ueyama, Masahito and Vargas, Rodrigo and Vesala, Timo and Ward, Eric J and Windham-Myers, Lisamarie and Wohlfahrt, Georg and Zona, Donatella},
title = {FluXNET-CH4 synthesis activity objectives, observations, and future directions},
journal = {Bulletin of the American Meteorological Society},
year = {2019},
volume = {100},
number = {12},
pages = {2607--2632},
url = {http://journals.ametsoc.org/doi/10.1175/BAMS-D-18-0268.1},
doi = {10.1175/BAMS-D-18-0268.1}
}
|
| Kohonen K-M, Kolari P, Kooijmans LM, Chen H, Seibt U, Sun W and Mammarella I (2019), "Towards standardized processing of eddy covariance flux measurements of carbonyl sulfide", Atmospheric Measurement Techniques Discussions., oct, 2019. , pp. 1-30. Copernicus GmbH. |
| Abstract: Carbonyl sulfide (COS) flux measurements with the eddy covariance (EC) technique are growing in popularity with the recent development in using COS to estimate gross photosynthesis at the ecosystem scale. Flux data intercomparison would benefit from standardized protocols for COS flux data processing. In this study, we analyze how various data processing steps affect the final flux and provide a method for gap-filling COS fluxes. Different methods for determining the lag time between COS mixing ratio and the vertical wind velocity (w) resulted in a maximum of 12 % difference in the cumulative COS flux. Due to limited COS measurement precision, small COS fluxes (below approximately 3 pmol mâˆ'2 sâˆ'1) could not be detected when the lag time was determined from maximizing the covariance between COS and w. We recommend using a combination of COS and carbon dioxide (CO2) lag times in determining the COS flux, depending on the flux magnitude compared to the detection limit of each averaging period. Different high frequency spectral corrections had a maximum effect of 10 % on COS flux calculations and different detrending methods only 1.2 %. Relative total uncertainty was more than five times higher for low COS fluxes (absolute flux lower than 3 pmol mâˆ'2 sâˆ'1) than for low CO2 fluxes (lower than 1.5 μmol mâˆ'2 sâˆ'1), indicating a low signal-to-noise ratio of COS fluxes. Due to similarities in ecosystem COS and CO2 exchange, and the low signal-to-noise ratio of COS fluxes that is similar to methane, we recommend a combination of CO2 and methane flux processing protocols for COS EC fluxes. [ABSTRACT FROM AUTHOR] |
BibTeX:
@article{Kohonen2019,
author = {Kohonen, Kukka-Maaria and Kolari, Pasi and Kooijmans, Linda M and Chen, Huilin and Seibt, Ulli and Sun, Wu and Mammarella, Ivan},
title = {Towards standardized processing of eddy covariance flux measurements of carbonyl sulfide},
journal = {Atmospheric Measurement Techniques Discussions},
publisher = {Copernicus GmbH},
year = {2019},
pages = {1--30},
doi = {10.5194/amt-2019-313}
}
|
| Kondo M, Patra PK, Sitch S, Friedlingstein P, Poulter B, Chevallier F, Ciais P, Canadell JG, Bastos A, Lauerwald R, Calle L, Ichii K, Anthoni P, Arneth A, Haverd V, Jain AK, Kato E, Kautz M, Law RM, Lienert S, Lombardozzi D, Maki T, Nakamura T, Peylin P, Rödenbeck C, Zhuravlev R, Saeki T, Tian H, Zhu D and Ziehn T (2019), "State of the science in reconciling top-down and bottom-up approaches for terrestrial CO2 budget", Global Change Biology., mar, 2019. Vol. 26(3), pp. 1068-1084. Wiley. |
| Abstract: Robust estimates of CO2 budget, CO2 exchanged between the atmosphere and terrestrial biosphere, are necessary to better understand the role of the terrestrial biosphere in mitigating anthropogenic CO2 emissions. Over the past decade, this field of research has advanced through understanding of the differences and similarities of two fundamentally different approaches: “top-down†atmospheric inversions and “bottom-up†biosphere models. Since the first studies were undertaken, these approaches have shown an increasing level of agreement, but disagreements in some regions still persist, in part because they do not estimate the same quantity of atmosphere–biosphere CO2 exchange. Here, we conducted a thorough comparison of CO2 budgets at multiple scales and from multiple methods to assess the current state of the science in estimating CO2 budgets. Our set of atmospheric inversions and biosphere models, which were adjusted for a consistent flux definition, showed a high level of agreement for global and hemispheric CO2 budgets in the 2000s. Regionally, improved agreement in CO2 budgets was notable for North America and Southeast Asia. However, large gaps between the two methods remained in East Asia and South America. In other regions, Europe, boreal Asia, Africa, South Asia, and Oceania, it was difficult to determine whether those regions act as a net sink or source because of the large spread in estimates from atmospheric inversions. These results highlight two research directions to improve the robustness of CO2 budgets: (a) to increase representation of processes in biosphere models that could contribute to fill the budget gaps, such as forest regrowth and forest degradation; and (b) to reduce sink–source compensation between regions (dipoles) in atmospheric inversion so that their estimates become more comparable. Advancements on both research areas will increase the level of agreement between the top-down and bottom-up approaches and yield more robust knowledge of regional CO2 budgets. |
BibTeX:
@article{Kondo2019,
author = {Kondo, Masayuki and Patra, Prabir K and Sitch, Stephen and Friedlingstein, Pierre and Poulter, Benjamin and Chevallier, Frederic and Ciais, Philippe and Canadell, Josep G and Bastos, Ana and Lauerwald, Ronny and Calle, Leonardo and Ichii, Kazuhito and Anthoni, Peter and Arneth, Almut and Haverd, Vanessa and Jain, Atul K and Kato, Etsushi and Kautz, Markus and Law, Rachel M and Lienert, Sebastian and Lombardozzi, Danica and Maki, Takashi and Nakamura, Takashi and Peylin, Philippe and Rödenbeck, Christian and Zhuravlev, Ruslan and Saeki, Tazu and Tian, Hanqin and Zhu, Dan and Ziehn, Tilo},
title = {State of the science in reconciling top-down and bottom-up approaches for terrestrial CO2 budget},
journal = {Global Change Biology},
publisher = {Wiley},
year = {2019},
volume = {26},
number = {3},
pages = {1068--1084},
doi = {10.1111/gcb.14917}
}
|
| Kondrik D, Kazakov E and Pozdnyakov D (2019), "A synthetic satellite dataset of the spatio-temporal distributions of &lt;i&gt;Emiliania huxleyi&lt;/i&gt; blooms and their impacts on Arctic and sub-Arctic marine environments (1998–2016)", Earth System Science Data., jan, 2019. Vol. 11(1), pp. 119-128. Copernicus GmbH. |
| Abstract: textlessptextgreatertextless![CDATA[Abstract. A 19-year (1998–2016) continuous dataset is presented of coccolithophore Emiliania huxleyi distributions and activity, i.e. the release of CaCO3 in water and the decrease of uptake of dissolved CO2 by Emiliania huxleyi cells (e.g. Kondrik et al., 2018a), in Arctic and sub-Arctic seas. The dataset is based on optical remote-sensing data (mostly OC CCI data) with assimilation of different relevant in situ observations, preprocessed with authorial algorithms. Alongside bloom locations, we provide both detailed information on E. huxleyi impacts on carbon balance and the sub-datasets of quantified coccolith concentrations, particulate inorganic carbon content and CO2 partial pressure in water driven by coccolithophores. All data are presented on a regular 4×4 km grid at a temporal resolution of 8 days. The paper describes the theoretical and methodological basis for all processing and modelling steps. The data are available on Zenodo: https://doi.org/10.5281/zenodo.1402033.]]textgreatertextless/ptextgreater |
BibTeX:
@article{Kondrik2019,
author = {Kondrik, Dmitry and Kazakov, Eduard and Pozdnyakov, Dmitry},
title = {A synthetic satellite dataset of the spatio-temporal distributions of &lt;i&gt;Emiliania huxleyi&lt;/i&gt; blooms and their impacts on Arctic and sub-Arctic marine environments (1998–2016)},
journal = {Earth System Science Data},
publisher = {Copernicus GmbH},
year = {2019},
volume = {11},
number = {1},
pages = {119--128},
url = {https://essd.copernicus.org/articles/11/119/2019/},
doi = {10.5194/essd-11-119-2019}
}
|
| Kooijmans LMJ, Sun W, Aalto J, Erkkilä KM, Maseyk K, Seibt U, Vesala T, Mammarella I and Chen H (2019), "Influences of light and humidity on carbonyl sulfide-based estimates of photosynthesis", Proceedings of the National Academy of Sciences of the United States of America., jan, 2019. Vol. 116(7), pp. 2470-2475. Proceedings of the National Academy of Sciences. |
| Abstract: Understanding climate controls on gross primary productivity (GPP) is crucial for accurate projections of the future land carbon cycle. Major uncertainties exist due to the challenge in separating GPP and respiration from observations of the carbon dioxide (CO 2 ) flux. Carbonyl sulfide (COS) has a dominant vegetative sink, and plant COS uptake is used to infer GPP through the leaf relative uptake (LRU) ratio of COS to CO 2 fluxes. However, little is known about variations of LRU under changing environmental conditions and in different phenological stages. We present COS and CO 2 fluxes and LRU of Scots pine branches measured in a boreal forest in Finland during the spring recovery and summer. We find that the diurnal dynamics of COS uptake is mainly controlled by stomatal conductance, but the leaf internal conductance could significantly limit the COS uptake during the daytime and early in the season. LRU varies with light due to the differential light responses of COS and CO 2 uptake, and with vapor pressure deficit (VPD) in the peak growing season, indicating a humidity-induced stomatal control. Our COS-based GPP estimates show that it is essential to incorporate the variability of LRU with environmental variables for accurate estimation of GPP on ecosystem, regional, and global scales. |
BibTeX:
@article{Kooijmans2019,
author = {Kooijmans, Linda M J and Sun, Wu and Aalto, Juho and Erkkilä, Kukka Maaria and Maseyk, Kadmiel and Seibt, Ulrike and Vesala, Timo and Mammarella, Ivan and Chen, Huilin},
title = {Influences of light and humidity on carbonyl sulfide-based estimates of photosynthesis},
journal = {Proceedings of the National Academy of Sciences of the United States of America},
publisher = {Proceedings of the National Academy of Sciences},
year = {2019},
volume = {116},
number = {7},
pages = {2470--2475},
doi = {10.1073/pnas.1807600116}
}
|
| Koren G, Schneider L, van der Velde IR, van Schaik E, Gromov SS, Adnew GA, Mrozek Martino DJ, Hofmann MEG, Liang M-C, Mahata S, Bergamaschi P, van der Laan-Luijkx IT, Krol MC, Röckmann T and Peters W (2019), "Global 3-D Simulations of the Triple Oxygen Isotope Signature Δ textlesssuptextgreater17textless/suptextgreater O in Atmospheric CO textlesssubtextgreater2textless/subtextgreater", Journal of Geophysical Research: Atmospheres., aug, 2019. Vol. 124(15), pp. 8808-8836. Blackwell Publishing Ltd. |
| Abstract: The triple oxygen isotope signature Δ17O in atmospheric CO2, also known as its “17O excess,” has been proposed as a tracer for gross primary production (the gross uptake of CO2 by vegetation through photosynthesis). We present the first global 3-D model simulations for Δ17O in atmospheric CO2 together with a detailed model description and sensitivity analyses. In our 3-D model framework we include the stratospheric source of Δ17O in CO2 and the surface sinks from vegetation, soils, ocean, biomass burning, and fossil fuel combustion. The effect of oxidation of atmospheric CO on Δ17O in CO2 is also included in our model. We estimate that the global mean Δ17O (defined as Δ17O = ln(δ17O+1)−𝜆λRL textperiodcentered ln(δ18O+1) with λRL = 0.5229) of CO2 in the lowest 500 m of the atmosphere is 39.6 per meg, which is ∼20 per meg lower than estimates from existing box models. We compare our model results with a measured stratospheric Δ17O in CO2 profile from Sodankylä (Finland), which shows good agreement. In addition, we compare our model results with tropospheric measurements of Δ17O in CO2 from Göttingen (Germany) and Taipei (Taiwan), which shows some agreement but we also find substantial discrepancies that are subsequently discussed. Finally, we show model results for Zotino (Russia), Mauna Loa (United States), Manaus (Brazil), and South Pole, which we propose as possible locations for future measurements of Δ17O in tropospheric CO2 that can help to further increase our understanding of the global budget of Δ17O in atmospheric CO2. |
BibTeX:
@article{Koren2019,
author = {Koren, Gerbrand and Schneider, Linda and van der Velde, Ivar R. and van Schaik, Erik and Gromov, Sergey S. and Adnew, Getachew A. and Mrozek Martino, Dorota J. and Hofmann, Magdalena E. G. and Liang, Mao-Chang and Mahata, Sasadhar and Bergamaschi, Peter and van der Laan-Luijkx, Ingrid T. and Krol, Maarten C. and Röckmann, Thomas and Peters, Wouter},
title = {Global 3-D Simulations of the Triple Oxygen Isotope Signature Δ textlesssuptextgreater17textless/suptextgreater O in Atmospheric CO textlesssubtextgreater2textless/subtextgreater},
journal = {Journal of Geophysical Research: Atmospheres},
publisher = {Blackwell Publishing Ltd},
year = {2019},
volume = {124},
number = {15},
pages = {8808--8836},
url = {http://doi.wiley.com/10.1029/2019JD030387},
doi = {10.1029/2019JD030387}
}
|
| Korkiakoski M, Tuovinen JP, Penttilä T, Sarkkola S, Ojanen P, Minkkinen K, Rainne J, Laurila T and Lohila A (2019), "Greenhouse gas and energy fluxes in a boreal peatland forest after clear-cutting", Biogeosciences., sep, 2019. Vol. 16(19), pp. 3703-3723. Copernicus GmbH. |
| Abstract: The most common forest management method in Fennoscandia is rotation forestry, including clear-cutting and forest regeneration. In clear-cutting, stem wood is removed and the logging residues are either removed or left on site. Clear-cutting changes the microclimate and vegetation structure at the site, both of which affect the site's carbon balance. Peat soils with poor aeration and high carbon densities are especially prone to such changes, and significant changes in greenhouse gas exchange can be expected. We measured carbon dioxide (CO2) and energy fluxes with the eddy covariance method for 2 years (April 2016-March 2018) after clear-cutting a drained peatland forest. We observed a significant rise (23 cm) in the water table level and a large CO2 source (first year: 3086 ± 148 g CO2 m-2 yr-1; second year: 2072 ± 124 g CO2 m-2 yr-1). These large CO2 emissions resulted from the very low gross primary production (GPP) following the removal of photosynthesizing trees and the decline of ground vegetation, unable to compensate for the decomposition of logging residues and peat. During the second summer (June-August) after the clear-cutting, GPP had already increased by 96 % and total ecosystem respiration decreased by 14 % from the previous summer. The mean daytime ratio of sensible to latent heat flux decreased after harvesting from 2.6 in May 2016 to 1.0 in August 2016, and in 2017 it varied mostly within 0.6-1.0. In April-September, the mean daytime sensible heat flux was 33 % lower and latent heat flux 40 % higher in 2017, probably due to the recovery of ground vegetation that increased evapotranspiration and albedo of the site. In addition to CO2 and energy fluxes, we measured methane (CH4) and nitrous oxide (N2O) fluxes with manual chambers. After the clear-cutting, the site turned from a small CH4 sink into a small source and from N2O neutral to a significant N2O source. Compared to the large CO2 emissions, the 100-year global warming potential (GWP100) of the CH4 emissions was negligible. Also, the GWP100 due to increased N2O emissions was less than 10 % of that of the CO2 emission change. |
BibTeX:
@article{Korkiakoski2019,
author = {Korkiakoski, Mika and Tuovinen, Juha Pekka and Penttilä, Timo and Sarkkola, Sakari and Ojanen, Paavo and Minkkinen, Kari and Rainne, Juuso and Laurila, Tuomas and Lohila, Annalea},
title = {Greenhouse gas and energy fluxes in a boreal peatland forest after clear-cutting},
journal = {Biogeosciences},
publisher = {Copernicus GmbH},
year = {2019},
volume = {16},
number = {19},
pages = {3703--3723},
doi = {10.5194/bg-16-3703-2019}
}
|
| Kosonen Z, Schnyder E, Hiltbrunner E, Thimonier A, Schmitt M, Seitler E and Thöni L (2019), "Current atmospheric nitrogen deposition still exceeds critical loads for sensitive, semi-natural ecosystems in Switzerland", Atmospheric Environment., aug, 2019. Vol. 211, pp. 214-225. Elsevier BV. |
| Abstract: Increased atmospheric nitrogen (N) deposition is driving nutrient imbalances, soil acidification, biodiversity losses and the long-term reduction in stability of sensitive ecosystems which previously had limited N. In this study, we analysed the concentrations of seven different N compounds in precipitation and in the air at 34 sites across Switzerland. We calculated the N deposition by precipitation (bulk deposition) and applied the inferential method to derive dry deposition (gases, aerosols) from air concentrations. We then quantified the total inorganic N deposition by adding together the bulk and dry deposition. Finally, the total inorganic N input into the sensitive ecosystems of the 34 sites was compared to the critical loads of these ecosystems. N deposition by precipitation was the main contributor to the total N load in 16 out of 34 sites, especially into open ecosystems such as alpine/subalpine grassland, mountain hay meadows, and raised bogs. Dry deposition of ammonia (NH3) was the second most important pathway, in particular for forests close to agricultural activities, due to high NH3 concentrations and the higher deposition velocity. The N deposition exceeded the lower limit of the Critical Load of Nitrogen (CLN) range at most sites, and at many sites even surpassed the upper limit of the CLN range. No, or minor, exceedances of the critical loads for N were found only at remote sites at higher elevation in the Central Alps. Annual inorganic N deposition between 2000 and 2017 revealed a significant decline in oxidised N compounds at four of five sites (âˆ'1.6–1.8% per year), but reduced compounds only decreased at two sites (âˆ'1% and âˆ'1.4% per year) and even increased at one site (+1.2% per year), despite adopted abatement strategies for agricultural practices. This emphasises that most sensitive ecosystems in Switzerland continue to be exposed to excessive N loads through atmospheric deposition, with detrimental consequences for the biodiversity and stability of these ecosystems. |
BibTeX:
@article{Kosonen2019,
author = {Kosonen, Zaida and Schnyder, Elvira and Hiltbrunner, Erika and Thimonier, Anne and Schmitt, Maria and Seitler, Eva and Thöni, Lotti},
title = {Current atmospheric nitrogen deposition still exceeds critical loads for sensitive, semi-natural ecosystems in Switzerland},
journal = {Atmospheric Environment},
publisher = {Elsevier BV},
year = {2019},
volume = {211},
pages = {214--225},
doi = {10.1016/j.atmosenv.2019.05.005}
}
|
| Kozii N, Haahti K, Tor-ngern P, Chi J, Hasselquist EM, Laudon H, Launiainen S, Oren R, Peichl M, Wallerman J and Hasselquist N (2019), "Partitioning the forest water balance within a boreal catchment using sapflux, eddy covariance and process-based model", Hydrology and Earth System Sciences Discussions., oct, 2019. , pp. 1-50. Copernicus GmbH. |
| Abstract: Predicting the binding mode of flexible polypeptides to proteins is an important task that falls outside the domain of applicability of most small molecule and proteinâˆ'protein docking tools. Here, we test the small molecule flexible ligand docking program Glide on a set of 19 non-α-helical peptides and systematically improve pose prediction accuracy by enhancing Glide sampling for flexible polypeptides. In addition, scoring of the poses was improved by post-processing with physics-based implicit solvent MM- GBSA calculations. Using the best RMSD among the top 10 scoring poses as a metric, the success rate (RMSD ≤ 2.0 Å for the interface backbone atoms) increased from 21% with default Glide SP settings to 58% with the enhanced peptide sampling and scoring protocol in the case of redocking to the native protein structure. This approaches the accuracy of the recently developed Rosetta FlexPepDock method (63% success for these 19 peptides) while being over 100 times faster. Cross-docking was performed for a subset of cases where an unbound receptor structure was available, and in that case, 40% of peptides were docked successfully. We analyze the results and find that the optimized polypeptide protocol is most accurate for extended peptides of limited size and number of formal charges, defining a domain of applicability for this approach. |
BibTeX:
@article{Kozii2019,
author = {Kozii, Natalia and Haahti, Kersti and Tor-ngern, Pantana and Chi, Jinshu and Hasselquist, Eliza Maher and Laudon, Hjalmar and Launiainen, Samuli and Oren, Ram and Peichl, Matthias and Wallerman, Jörgen and Hasselquist, Niles},
title = {Partitioning the forest water balance within a boreal catchment using sapflux, eddy covariance and process-based model},
journal = {Hydrology and Earth System Sciences Discussions},
publisher = {Copernicus GmbH},
year = {2019},
pages = {1--50},
doi = {10.5194/hess-2019-541}
}
|
| Krupková L, Havránková K, Krejza J, Sedlák P and Marek MV (2019), "Impact of water scarcity on spruce and beech forests", Journal of Forestry Research. Vol. 30(3), pp. 899-909. |
| Abstract: One of the greatest threats posed by ongoing climate change may be regarded the drought caused by changes in precipitation distribution. The aim of presented study was to characterize reactions to dry conditions and conditions without drought stress on gross primary production (GPP) and net ecosystem production (NEP) of spruce and beech forests, as these two species dominate within the European continent. Daily courses of GPP and NEP of these two species were evaluated in relation to an expected decrease in CO2 uptake during dry days. The occurrence of CO2 uptake hysteresis in daily production was also investigated. Our study was performed at Bílý KÅ™íž (spruce) and Štítná (beech) mountain forest sites during 2010–2012 period. We applied eddy covariance technique for the estimation of carbon fluxes, vapor pressure deficit and precipitation characteristics together with the SoilClim model for the determination of drought conditions, and the inverse of the Penman–Monteith equation to compute canopy conductance. Significant differences were found in response to reduced water supply for both species. Spruce reacts by closing its stomata before noon and maintaining a reduced photosynthetic activity for the rest of the day, while beech keeps its stomata open as long as possible and slightly reduces photosynthetic activity evenly throughout the entire day. In the spruce forest, we found substantial hysteresis in the light response curve of GPP. In the beech forest, the shape of this curve was different: evening values exceeded morning values. |
BibTeX:
@article{Krupkova2019,
author = {Krupková, Lenka and Havránková, KateÅ™ina and Krejza, Jan and Sedlák, Pavel and Marek, Michal V},
title = {Impact of water scarcity on spruce and beech forests},
journal = {Journal of Forestry Research},
year = {2019},
volume = {30},
number = {3},
pages = {899--909},
doi = {10.1007/s11676-018-0642-5}
}
|
| Kulmala L, Pumpanen J, Kolari P, Dengel S, Berninger F, Köster K, Matkala L, Vanhatalo A, Vesala T and Bäck J (2019), "Inter- and intra-annual dynamics of photosynthesis differ between forest floor vegetation and tree canopy in a subarctic Scots pine stand", Agricultural and Forest Meteorology., jun, 2019. Vol. 271, pp. 1-11. Elsevier BV. |
| Abstract: We studied the inter- and intra-annual dynamics of the photosynthesis of forest floor vegetation and tree canopy in a subarctic Scots pine stand at the northern timberline in Finland. We tackled the issue using three different approaches: 1) measuring carbon dioxide exchange above and below canopy with the eddy covariance technique, 2) modelling the photosynthesis of the tree canopy based on shoot chamber measurements, and 3) upscaling the forest floor photosynthesis using biomass estimates and available information on the annual cycle of photosynthetic capacity of those species. The studied ecosystem was generally a weak sink of carbon but the sink strength showed notable year-to-year variation. Total ecosystem respiration and photosynthesis indicated a clear temperature limitation for the carbon exchange. However, the increase in photosynthetic production was steeper than the increase in respiration with temperature, indicating that warm temperatures increase the sink strength and do not stimulate the total ecosystem respiration as much in the 4-year window studied. The interannual variation in the photosynthetic production of the forest stand mainly resulted from the forest floor vegetation, whereas the photosynthesis of the tree canopy seemed to be more stable from year to year. Tree canopy photosynthesis increased earlier in the spring, whereas that of the forest floor increased after snowmelt, highlighting that models for photosynthesis in the northern area should also include snow cover in order to accurately estimate the seasonal dynamics of photosynthesis in these forests. |
BibTeX:
@article{Kulmala2019,
author = {Kulmala, Liisa and Pumpanen, Jukka and Kolari, Pasi and Dengel, Sigrid and Berninger, Frank and Köster, Kajar and Matkala, Laura and Vanhatalo, Anni and Vesala, Timo and Bäck, Jaana},
title = {Inter- and intra-annual dynamics of photosynthesis differ between forest floor vegetation and tree canopy in a subarctic Scots pine stand},
journal = {Agricultural and Forest Meteorology},
publisher = {Elsevier BV},
year = {2019},
volume = {271},
pages = {1--11},
doi = {10.1016/j.agrformet.2019.02.029}
}
|
| Kuyper B, Wingrove H, Lesch T, Labuschagne C, Say D, Martin D, Young D, Khan MAH, O’Doherty S, Davies-Coleman MT and Shallcross DE (2019), "Atmospheric Toluene and Benzene Mole Fractions at Cape Town and Cape Point and an Estimation of the Hydroxyl Radical Concentrations in the Air above the Cape Peninsula, South Africa", ACS Earth and Space Chemistry., December, 2019. Vol. 4(1), pp. 24-34. American Chemical Society (ACS). |
BibTeX:
@article{Kuyper2019,
author = {Kuyper, Brett and Wingrove, Haithum and Lesch, Timothy and Labuschagne, Casper and Say, Daniel and Martin, Damien and Young, Dickon and Khan, M. Anwar H. and O’Doherty, Simon and Davies-Coleman, Michael T. and Shallcross, Dudley E.},
title = {Atmospheric Toluene and Benzene Mole Fractions at Cape Town and Cape Point and an Estimation of the Hydroxyl Radical Concentrations in the Air above the Cape Peninsula, South Africa},
journal = {ACS Earth and Space Chemistry},
publisher = {American Chemical Society (ACS)},
year = {2019},
volume = {4},
number = {1},
pages = {24--34},
doi = {10.1021/acsearthspacechem.9b00207}
}
|
| Lagergren F, Jönsson AM, Linderson H and Lindroth A (2019), "Time shift between net and gross CO2 uptake and growth derived from tree rings in pine and spruce", Trees - Structure and Function., jun, 2019. Vol. 33(3), pp. 765-776. |
| Abstract: Key message: A 6–9 month backward time shift of the carbon uptake gave the highest correlation between annual biomass increment and carbon uptake in this old even aged forest. Abstract: Plants' carbon uptake and allocation to different biomass compartments is an important process for both wood production and climate mitigation. Measurements of the net ecosystem carbon dioxide exchange between ecosystems and the atmosphere provide insights into the processes of photosynthesis, respiration and accumulation of carbon over time, and the increase in woody biomass can be assessed by allometric functions based on stem diameter measurements. The fraction of carbon allocated to radial stem growth varies over time, and a lag between carbon uptake and growth can be expected. The dynamics of non-structural carbohydrates and autotrophic and heterotrophic respiration are key mechanisms for understanding this lag effect. In this study, a 9-year record of carbon flux and tree-ring data from Norunda, Sweden was used to investigate the relationship between net and gross carbon uptake and carbon allocated to growth. The flux data were aggregated to monthly sums. When full 12-month periods of accumulated carbon exchange were successively shifted backwards in time, the highest correlation was found with a 6–9 month shift, showing that a large part of the previous growing season was important for explaining the biomass increment of the following year. |
BibTeX:
@article{Lagergren2019,
author = {Lagergren, Fredrik and Jönsson, Anna Maria and Linderson, Hans and Lindroth, Anders},
title = {Time shift between net and gross CO2 uptake and growth derived from tree rings in pine and spruce},
journal = {Trees - Structure and Function},
year = {2019},
volume = {33},
number = {3},
pages = {765--776},
url = {http://link.springer.com/10.1007/s00468-019-01814-9},
doi = {10.1007/s00468-019-01814-9}
}
|
| Landschützer P, Ilyina T and Lovenduski NS (2019), "Detecting Regional Modes of Variability in Observation‐Based Surface Ocean textlessitextgreaterptextless/itextgreater CO textlesssubtextgreater2textless/subtextgreater", Geophysical Research Letters., mar, 2019. Vol. 46(5), pp. 2670-2679. Blackwell Publishing Ltd. |
| Abstract: We use a neural network-based estimate of the sea surface partial pressure of CO2 (pCO2) derived from measurements assembled within the Surface Ocean CO2 Atlas to investigate the dominant modes of pCO2 variability from 1982 through 2015. Our analysis shows that detrended and deseasonalized sea surface pCO2 varies substantially by region and the respective frequencies match those from the major modes of climate variability (Atlantic Multidecadal Oscillation, Pacific Decadal Oscillation, multivariate ENSO index, Southern Annular Mode), suggesting a climate modulated air-sea exchange of CO2. We find that most of the regional pCO2 variability is driven by changes in the ocean circulation and/or changes in biology, whereas the North Atlantic variability is tightly linked to temperature variations in the surface ocean and the resulting changes in solubility. Despite the 34-year time series, our analysis reveals that we can currently only detect one to two periods of slow frequency oscillations, challenging our ability to robustly link pCO2 variations to climate variability. |
BibTeX:
@article{Landschutzer2019,
author = {Landschützer, Peter and Ilyina, Tatiana and Lovenduski, Nicole S.},
title = {Detecting Regional Modes of Variability in Observation‐Based Surface Ocean textlessitextgreaterptextless/itextgreater CO textlesssubtextgreater2textless/subtextgreater},
journal = {Geophysical Research Letters},
publisher = {Blackwell Publishing Ltd},
year = {2019},
volume = {46},
number = {5},
pages = {2670--2679},
url = {https://onlinelibrary.wiley.com/doi/abs/10.1029/2018GL081756},
doi = {10.1029/2018GL081756}
}
|
| Langvall O and Ottosson Löfvenius M (2019), "Long-term standardized forest phenology in Sweden: a climate change indicator", International Journal of Biometeorology., oct, 2019. |
| Abstract: Because climate change alters patterns of vegetative growth, long-term phenological measurements and observations can provide important data for analyzing its impact. Phenological assessments are usually made as records of calendar dates when specific phase changes occur. Such assessments have benefits and are used in Citizen Science monitoring. However, these kinds of data often have low statistical precision when describing gradual changes. Frequent monitoring of the phenological traits of forest trees and berries as they undergo gradual change is needed to acquire good temporal resolution of transitions relative to other factors, such as susceptibility to frosts, insects, and fungi, and the use of berries as a food resource. Intensive weekly monitoring of the growth of apical and branch buds and the elongation of shoots and leaves on four tree species, and the abundance of flowers and berries of bilberry and lingonberry, has been performed in Sweden since 2006. Here, we present quantitative methods for interpolating such data, which detail the gradual changes between assessments in order to describe average rates of development and amount of interannual variation. Our analysis has shown the active growth period of trees to differ with latitude. We also observed a change in the timing of the maximum numbers of ripening berries and their successive decline. Data from tree phenology assessments can be used to recommend best forestry practice and to model tree growth, while berry data can be used to estimate when food resources for animals are most available. |
BibTeX:
@article{Langvall2019,
author = {Langvall, Ola and Ottosson Löfvenius, Mikaell},
title = {Long-term standardized forest phenology in Sweden: a climate change indicator},
journal = {International Journal of Biometeorology},
year = {2019},
url = {http://link.springer.com/10.1007/s00484-019-01817-8},
doi = {10.1007/s00484-019-01817-8}
}
|
| Lebehot AD, Halloran PR, Watson AJ, McNeall D, Ford DA, Landschützer P, Lauvset SK and Schuster U (2019), "Reconciling Observation and Model Trends in North Atlantic Surface CO2", Global Biogeochemical Cycles., oct, 2019. Vol. 33(10), pp. 1204-1222. American Geophysical Union (AGU). |
| Abstract: The North Atlantic Ocean is a region of intense uptake of atmospheric CO2. To assess how this CO2 sink has evolved over recent decades, various approaches have been used to estimate basin-wide uptake from the irregularly sampled in situ CO2 observations. Until now, the lack of robust uncertainties associated with observation-based gap-filling methods required to produce these estimates has limited the capacity to validate climate model simulated surface ocean CO2 concentrations. After robustly quantifying basin-wide and annually varying interpolation uncertainties using both observational and model data, we show that the North Atlantic surface ocean fugacity of CO2 (fCO2âˆ'ocean) increased at a significantly slower rate than that simulated by the latest generation of Earth System Models during the period 1992–2014. We further show, with initialized model simulations, that the inability of these models to capture the observed trend in surface fCO2âˆ'ocean is primarily due to biases in the models' ocean biogeochemistry. Our results imply that current projections may underestimate the contribution of the North Atlantic to mitigating increasing future atmospheric CO2 concentrations. |
BibTeX:
@article{Lebehot2019,
author = {Lebehot, Alice D and Halloran, Paul R and Watson, Andrew J and McNeall, Doug and Ford, David A and Landschützer, Peter and Lauvset, Siv K and Schuster, Ute},
title = {Reconciling Observation and Model Trends in North Atlantic Surface CO2},
journal = {Global Biogeochemical Cycles},
publisher = {American Geophysical Union (AGU)},
year = {2019},
volume = {33},
number = {10},
pages = {1204--1222},
doi = {10.1029/2019GB006186}
}
|
| Lefèvre N, Veleda D, Tyaquiçã P, Perruche C, Diverrès D and Ibánhez JSP (2019), "Basin-Scale Estimate of the Sea-Air CO2 Flux During the 2010 Warm Event in the Tropical North Atlantic", Journal of Geophysical Research: Biogeosciences., apr, 2019. Vol. 124(4), pp. 973-986. American Geophysical Union (AGU). |
| Abstract: Following the anomalous warming event occurring in the tropical North Atlantic in 2010, higher than usual surface fugacity of CO2 (fCO2) was observed. To evaluate the spatial extent of these anomalies and their drivers, and to quantify the sea-air CO2 flux at basin scale, the Mercator-Ocean model is used from 2006 to 2014 within the region 0–30°N, 70–15°W. Model outputs are generally in accordance with underway sea surface temperature, sea surface salinity, and surface fCO2 recorded by two merchant ships. The anomalous warming of 2010 is well reproduced by the model and is the main driver of fCO2 anomalies. The first coupled Empirical Orthogonal Function mode, between sea surface temperature and fCO2, captures more than 70% of the total variance and is characterized by a basin-scale warming associated to positive fCO2 anomalies. The corresponding principal components are correlated to the Tropical North Atlantic Index and identify 2010 as the year with the highest positive anomaly over 2006–2014. Exceptions to this general pattern are located near the African coast, where the weakening of the coastal upwelling causes negative inorganic carbon anomalies, and close to the Amazon River plume, where fCO2 anomalies are primarily associated with sea surface salinity anomalies. Although the fCO2 anomalies of 2010 appear mostly in spring, they affect the annual CO2 budget and lead to an increased CO2 outgassing twice as large (46.2 Tg C per year) as the mean annual flux over the 2006–2014 period (23.3 Tg C per year). |
BibTeX:
@article{Lefevre2019,
author = {Lefèvre, Nathalie and Veleda, Doris and Tyaquiçã, Pedro and Perruche, Coralie and Diverrès, Denis and Ibánhez, J Severino P},
title = {Basin-Scale Estimate of the Sea-Air CO2 Flux During the 2010 Warm Event in the Tropical North Atlantic},
journal = {Journal of Geophysical Research: Biogeosciences},
publisher = {American Geophysical Union (AGU)},
year = {2019},
volume = {124},
number = {4},
pages = {973--986},
doi = {10.1029/2018JG004840}
}
|
| Le Traon PY, Reppucci A, Alvarez Fanjul E, Aouf L, Behrens A, Belmonte M, Bentamy A, Bertino L, Brando VE, Kreiner MB, Benkiran M, Carval T, Ciliberti SA, Claustre H, Clementi E, Coppini G, Cossarini G, De Alfonso Alonso-Muñoyerro M, Delamarche A, Dibarboure G, Dinessen F, Drevillon M, Drillet Y, Faugere Y, Fernández V, Fleming A, Garcia-Hermosa MI, Sotillo MG, Garric G, Gasparin F, Giordan C, Gehlen M, Gregoire ML, Guinehut S, Hamon M, Harris C, Hernandez F, Hinkler JB, Hoyer J, Karvonen J, Kay S, King R, Lavergne T, Lemieux-Dudon B, Lima L, Mao C, Martin MJ, Masina S, Melet A, Buongiorno Nardelli B, Nolan G, Pascual A, Pistoia J, Palazov A, Piolle JF, Pujol MI, Pequignet AC, Peneva E, Pérez Gómez B, Petit de la Villeon L, Pinardi N, Pisano A, Pouliquen S, Reid R, Remy E, Santoleri R, Siddorn J, She J, Staneva J, Stoffelen A, Tonani M, Vandenbulcke L, von Schuckmann K, Volpe G, Wettre C and Zacharioudaki A (2019), "From Observation to Information and Users: The Copernicus Marine Service Perspective", Frontiers in Marine Science., may, 2019. Vol. 6, pp. 234. Frontiers Media SA. |
| Abstract: The Copernicus Marine Environment Monitoring Service (CMEMS) provides regular and systematic reference information on the physical and biogeochemical ocean and sea-ice state for the global ocean and the European regional seas. CMEMS serves a wide range of users (more than 15,000 users are now registered to the service) and applications. Observations are a fundamental pillar of the CMEMS value-added chain that goes from observation to information and users. Observations are used by CMEMS Thematic Assembly Centres (TACs) to derive high-level data products and by CMEMS Monitoring and Forecasting Centres (MFCs) to validate and constrain their global and regional ocean analysis and forecasting systems. This paper presents an overview of CMEMS, its evolution, and how the value of in situ and satellite observations is increased through the generation of high-level products ready to be used by downstream applications and services. The complementary nature of satellite and in situ observations is highlighted. Long-term perspectives for the development of CMEMS are described and implications for the evolution of the in situ and satellite observing systems are outlined. Results from Observing System Evaluations (OSEs) and Observing System Simulation Experiments (OSSEs) illustrate the high dependencies of CMEMS systems on observations. Finally future CMEMS requirements for both satellite and in situ observations are detailed. |
BibTeX:
@article{LeTraon2019,
author = {Le Traon, Pierre Yves and Reppucci, Antonio and Alvarez Fanjul, Enrique and Aouf, Lotfi and Behrens, Arno and Belmonte, Maria and Bentamy, Abderrahim and Bertino, Laurent and Brando, Vittorio Ernesto and Kreiner, Matilde Brandt and Benkiran, Mounir and Carval, Thierry and Ciliberti, Stefania A. and Claustre, Hervé and Clementi, Emanuela and Coppini, Giovanni and Cossarini, Gianpiero and De Alfonso Alonso-Muñoyerro, Marta and Delamarche, Anne and Dibarboure, Gerald and Dinessen, Frode and Drevillon, Marie and Drillet, Yann and Faugere, Yannice and Fernández, Vicente and Fleming, Andrew and Garcia-Hermosa, M. Isabel and Sotillo, Marcos García and Garric, Gilles and Gasparin, Florent and Giordan, Cedric and Gehlen, Marion and Gregoire, Marilaure L. and Guinehut, Stephanie and Hamon, Mathieu and Harris, Chris and Hernandez, Fabrice and Hinkler, Jørgen B. and Hoyer, Jacob and Karvonen, Juha and Kay, Susan and King, Robert and Lavergne, Thomas and Lemieux-Dudon, Benedicte and Lima, Leonardo and Mao, Chongyuan and Martin, Matthew J. and Masina, Simona and Melet, Angelique and Buongiorno Nardelli, Bruno and Nolan, Glenn and Pascual, Ananda and Pistoia, Jenny and Palazov, Atanas and Piolle, Jean Francois and Pujol, Marie Isabelle and Pequignet, Anne Christine and Peneva, Elisaveta and Pérez Gómez, Begoña and Petit de la Villeon, Loic and Pinardi, Nadia and Pisano, Andrea and Pouliquen, Sylvie and Reid, Rebecca and Remy, Elisabeth and Santoleri, Rosalia and Siddorn, John and She, Jun and Staneva, Joanna and Stoffelen, Ad and Tonani, Marina and Vandenbulcke, Luc and von Schuckmann, Karina and Volpe, Gianluca and Wettre, Cecilie and Zacharioudaki, Anna},
title = {From Observation to Information and Users: The Copernicus Marine Service Perspective},
journal = {Frontiers in Marine Science},
publisher = {Frontiers Media SA},
year = {2019},
volume = {6},
pages = {234},
url = {https://www.frontiersin.org/article/10.3389/fmars.2019.00234/full},
doi = {10.3389/fmars.2019.00234}
}
|
| Leufen LH and Schädler G (2019), "Calculating the turbulent fluxes in the atmospheric surface layer with neural networks", Geoscientific Model Development., may, 2019. Vol. 12(5), pp. 2033-2047. |
| Abstract: The turbulent fluxes of momentum, heat and water vapour link the Earth's surface with the atmosphere. Therefore, the correct modelling of the flux interactions between these two systems with very different timescales is vital for climate and weather forecast models. Conventionally, these fluxes are modelled using Monin-Obukhov similarity theory (MOST) with stability functions derived from a small number of field experiments. This results in a range of formulations of these functions and thus also in differences in the flux calculations; furthermore, the underlying equations are non-linear and have to be solved iteratively at each time step of the model. In this study, we tried a different and more flexible approach, namely using an artificial neural network (ANN) to calculate the scaling quantities uand(used to parameterise the fluxes), thereby avoiding function fitting and iteration. The network was trained and validated with multi-year data sets from seven grassland, forest and wetland sites worldwide using the Broyden-Fletcher-Goldfarb-Shanno (BFGS) quasi-Newton backpropagation algorithm and six-fold cross validation. Extensive sensitivity tests showed that an ANN with six input variables and one hidden layer gave results comparable to (and in some cases even slightly better than) the standard method; moreover, this ANN performed considerably better than a multivariate linear regression model. Similar satisfying results were obtained when the ANN routine was implemented in a one-dimensional stand-alone land surface model (LSM), paving the way for implementation in three-dimensional climate models. In the case of the one-dimensional LSM, no CPU time was saved when using the ANN version, as the small time step of the standard version required only one iteration in most cases. This may be different in models with longer time steps, e.g. global climate models. |
BibTeX:
@article{Leufen2019,
author = {Leufen, Lukas Hubert and Schädler, Gerd},
title = {Calculating the turbulent fluxes in the atmospheric surface layer with neural networks},
journal = {Geoscientific Model Development},
year = {2019},
volume = {12},
number = {5},
pages = {2033--2047},
url = {https://www.geosci-model-dev.net/12/2033/2019/},
doi = {10.5194/gmd-12-2033-2019}
}
|
| Li H, Ilyina T, Müller WA and Landschützer P (2019), "Predicting the variable ocean carbon sink", Science Advances., apr, 2019. Vol. 5(4), pp. eaav6471. American Association for the Advancement of Science. |
| Abstract: Strong decadal variations in the oceanic uptake of carbon dioxide (CO2) observed over the past three decades challenge our ability to predict the strength of the ocean carbon sink. By assimilating atmospheric and oceanic observational data products into an Earth system model-based decadal prediction system, we can reproduce the observed variations of the ocean carbon uptake globally. We find that variations of the ocean CO2 uptake are predictable up to 2 years in advance globally, albeit there is evidence for a higher predictive skill up to 5 years regionally.We further suggest that while temperature variations largely determine shorter-term (textless3 years) predictability, nonthermal drivers are responsible for longer-term (textgreater3 years) predictability, especially at high latitudes. |
BibTeX:
@article{Li2019,
author = {Li, H. and Ilyina, T. and Müller, W. A. and Landschützer, P.},
title = {Predicting the variable ocean carbon sink},
journal = {Science Advances},
publisher = {American Association for the Advancement of Science},
year = {2019},
volume = {5},
number = {4},
pages = {eaav6471},
url = {http://advances.sciencemag.org/},
doi = {10.1126/sciadv.aav6471}
}
|
| Li X and Xiao J (2019), "Mapping photosynthesis solely from solar-induced chlorophyll fluorescence: A global, fine-resolution dataset of gross primary production derived from OCO-2", Remote Sensing., oct, 2019. Vol. 11(21), pp. 2563. |
| Abstract: Accurately quantifying gross primary production (GPP) globally is critical for assessing plant productivity, carbon balance, and carbon-climate feedbacks, while current GPP estimates exhibit substantial uncertainty. Solar-induced chlorophyll fluorescence (SIF) observed by the Orbiting Carbon Observatory-2 (OCO-2) has offered unprecedented opportunities for monitoring land photosynthesis, while its sparse coverage remains a bottleneck for mapping finer-resolution GPP globally. Here, we used the global, OCO-2-based SIF product (GOSIF) and linear relationships between SIF and GPP to map GPP globally at a 0.05° spatial resolution and 8-day time step for the period from 2000 to 2017. To account for the uncertainty of GPP estimates resulting from the SIF-GPP relationship, we used a total of eight SIF-GPP relationships with different forms (universal and biome-specific, with and without intercept) at both site and grid cell levels to estimate GPP. Our results showed that all of the eight SIF-GPP relationships performed well in estimating GPP globally. The ensemble mean 8-day GPP was generally highly correlated with flux tower GPP for 91 eddy covariance flux sites across the globe (R2 = 0.74, Root Mean Square Error = 1.92 g C m-2 d-1). Our fine-resolution GPP estimates showed reasonable spatial and seasonal variations across the globe and fully captured both seasonal cycles and spatial patterns present in our coarse-resolution (1°) GPP estimates based on coarse-resolution SIF data directly aggregated from discrete OCO-2 soundings. SIF-GPP relationships with different forms could lead to significant differences in annual GPP particularly in the tropics. Our ensemble global annual GPP estimate (135.5 ± 8.8 Pg C yr-1) is between the median estimate of non-process based methods and the median estimate of process-based models. Our GPP estimates showed interannual variability in many regions and exhibited increasing trends in many parts of the globe particularly in the Northern Hemisphere. With the availability of high-quality, gridded SIF observations from space (e.g., TROPOMI, FLEX), our novel approach does not rely on any other input data (e.g., climate data, soil properties) and therefore can map GPP solely based on satellite SIF observations and potentially lead to more accurate GPP estimates at regional to global scales. The use of a universal SIF-GPP relationship versus biome-specific relationships can also avoid the uncertainty associated with land cover maps. Our novel, independent GPP product (GOSIF GPP), freely available at our data repository, will be valuable for studying photosynthesis, carbon cycle, agricultural production, and ecosystem responses to climate change and disturbances, informing ecosystem management, and benchmarking terrestrial biosphere and Earth system models. |
BibTeX:
@article{Li2019a,
author = {Li, Xing and Xiao, Jingfeng},
title = {Mapping photosynthesis solely from solar-induced chlorophyll fluorescence: A global, fine-resolution dataset of gross primary production derived from OCO-2},
journal = {Remote Sensing},
year = {2019},
volume = {11},
number = {21},
pages = {2563},
url = {https://www.mdpi.com/2072-4292/11/21/2563},
doi = {10.3390/rs11212563}
}
|
| Li S, Yuan W, Ciais P, Viovy N, Ito A, Jia B and Zhu D (2019), "Benchmark estimates for aboveground litterfall data derived from ecosystem models", Environmental Research Letters., jul, 2019. Vol. 14(8), pp. 84020. IOP Publishing. |
| Abstract: Litter production is a fundamental ecosystem process, which plays an important role in regulating terrestrial carbon and nitrogen cycles. However, there are substantial differences in the litter production simulations among ecosystem models, and a global benchmarking evaluation to measure the performance of these models is still lacking. In this study, we generated a global dataset of aboveground litterfall production (i.e. cLitter), a benchmark as the defined reference to test model performance, by combining systematic measurements taken from a substantial number of surveys (1079 sites) with a machine learning technique (i.e. random forest, RF). Our study demonstrated that the RF model is an effective tool for upscaling local litterfall production observations to the global scale. On average, the model predicted 23.15 Pg C yr-1 of aboveground litterfall production. Our results revealed substantial differences in the aboveground litterfall production simulations among the five investigated ecosystem models. Compared to the reference data at the global scale, most of models could reproduce the spatial patterns of aboveground litterfall production, but the magnitude of simulations differed substantially from the reference data. Overall, ORCHIDEE-MICT performed the best among the five investigated ecosystem models. |
BibTeX:
@article{Li2019b,
author = {Li, Shihua and Yuan, Wenping and Ciais, Philippe and Viovy, Nicolas and Ito, Akihiko and Jia, Bingrui and Zhu, Dan},
title = {Benchmark estimates for aboveground litterfall data derived from ecosystem models},
journal = {Environmental Research Letters},
publisher = {IOP Publishing},
year = {2019},
volume = {14},
number = {8},
pages = {84020},
doi = {10.1088/1748-9326/ab2ee4}
}
|
| Lian J, Bréon FM, Broquet G, Scott Zaccheo T, Dobler J, Ramonet M, Staufer J, Santaren D, Xueref-Remy I and Ciais P (2019), "Analysis of temporal and spatial variability of atmospheric CO2 concentration within Paris from the GreenLITEâ„¢ laser imaging experiment", Atmospheric Chemistry and Physics., nov, 2019. Vol. 19(22), pp. 13809-13825. Copernicus GmbH. |
| Abstract: In 2015, the Greenhouse gas Laser Imaging Tomography Experiment (GreenLITEâ„¢) measurement system was deployed for a long-duration experiment in the center of Paris, France. The system measures near-surface atmospheric CO2 concentrations integrated along 30 horizontal chords ranging in length from 2.3 to 5.2 km and covering an area of 25 km2 over the complex urban environment. In this study, we use this observing system together with six conventional in situ point measurements and the Weather Research and Forecasting model coupled with Chemistry (WRF-Chem) and two urban canopy schemes (Urban Canopy Model-UCM; Building Effect Parameterization-BEP) at a horizontal resolution of 1 km to analyze the temporal and spatial variations in CO2 concentrations within the city of Paris and its vicinity for the 1-year period spanning December 2015 to November 2016. Such an analysis aims at supporting the development of CO2 atmospheric inversion systems at the city scale. Results show that both urban canopy schemes in the WRF-Chem model are capable of reproducing the seasonal cycle and most of the synoptic variations in the atmospheric CO2 point measurements over the suburban areas as well as the general corresponding spatial differences in CO2 concentration that span the urban area. However, within the city, there are larger discrepancies between the observations and the model results with very distinct features during winter and summer. During winter, the GreenLITEâ„¢ measurements clearly demonstrate that one urban canopy scheme (BEP) provides a much better description of temporal variations and horizontal differences in CO2 concentrations than the other (UCM) does. During summer, much larger CO2 horizontal differences are indicated by the GreenLITEâ„¢ system than both the in situ measurements and the model results, with systematic east-west variations. |
BibTeX:
@article{Lian2019,
author = {Lian, Jinghui and Bréon, François Marie and Broquet, Grégoire and Scott Zaccheo, T and Dobler, Jeremy and Ramonet, Michel and Staufer, Johannes and Santaren, Diego and Xueref-Remy, Irène and Ciais, Philippe},
title = {Analysis of temporal and spatial variability of atmospheric CO2 concentration within Paris from the GreenLITEâ„¢ laser imaging experiment},
journal = {Atmospheric Chemistry and Physics},
publisher = {Copernicus GmbH},
year = {2019},
volume = {19},
number = {22},
pages = {13809--13825},
doi = {10.5194/acp-19-13809-2019}
}
|
| Lin M, Malyshev S, Shevliakova E, Paulot F, Horowitz LW, Fares S, Mikkelsen TN and Zhang L (2019), "Sensitivity of Ozone Dry Deposition to Ecosystem-Atmosphere Interactions: A Critical Appraisal of Observations and Simulations", Global Biogeochemical Cycles., oct, 2019. Vol. 33(10), pp. 1264-1288. American Geophysical Union (AGU). |
| Abstract: The response of ozone (O3) dry deposition to ecosystem-atmosphere interactions is poorly understood but is central to determining the potential for extreme pollution events under current and future climate conditions. Using observations and an interactive dry deposition scheme within two dynamic vegetation land models (Geophysical Fluid Dynamics Laboratory LM3.0/LM4.0) driven by observation-based meteorological forcings over 1948–2014, we investigate the factors controlling seasonal and interannual variability (IAV) in O3 deposition velocities (Vd,O3). Stomatal activity in this scheme is determined mechanistically, depending on phenology, soil moisture, vapor pressure deficit, and CO2 concentration. Soil moisture plays a key role in modulating the observed and simulated Vd,O3 seasonal changes over evergreen forests in Mediterranean Europe, South Asia, and the Amazon. Analysis of multiyear observations at forest sites in Europe and North America reveals drought stress to reduce Vd,O3 by ˜50%. Both LM3.0 and LM4.0 capture the observed Vd,O3 decreases due to drought; however, IAV is weaker by a factor of 2 in LM3.0 coupled to atmospheric models, particularly in regions with large precipitation biases. IAV in summertime Vd,O3 to forests, driven primarily by the stomatal pathway, is largest (15–35%) in semiarid regions of western Europe, eastern North America, and northeastern China. Monthly mean Vd,O3 for the highest year is 2 to 4 times that of the lowest, with significant implications for surface O3 variability and extreme events. Using Vd,O3 from LM4.0 in an atmospheric chemistry model improves the simulation of surface O3 abundance and spatial variability (reduces mean biases by ˜10 ppb) relative to the widely used Wesely scheme. |
BibTeX:
@article{Lin2019,
author = {Lin, Meiyun and Malyshev, Sergey and Shevliakova, Elena and Paulot, Fabien and Horowitz, Larry W and Fares, Silvano and Mikkelsen, Teis N and Zhang, Leiming},
title = {Sensitivity of Ozone Dry Deposition to Ecosystem-Atmosphere Interactions: A Critical Appraisal of Observations and Simulations},
journal = {Global Biogeochemical Cycles},
publisher = {American Geophysical Union (AGU)},
year = {2019},
volume = {33},
number = {10},
pages = {1264--1288},
doi = {10.1029/2018GB006157}
}
|
| Lin C, Gentine P, Frankenberg C, Zhou S, Kennedy D and Li X (2019), "Evaluation and mechanism exploration of the diurnal hysteresis of ecosystem fluxes", Agricultural and Forest Meteorology., nov, 2019. Vol. 278 Elsevier B.V.. |
| Abstract: Diurnal environmental variations can be dynamically strong (driven by solar radiation) and can lead to hysteretic plant responses. The diurnal hysteresis patterns of ecosystem fluxes and meteorological variables are important to understand the relations and interactions between vegetation and its surrounding environment. To provide new insights on hysteresis at the ecosystem scale, we systematically evaluated the differences in ecosystem fluxes between morning (time of day before the highest potential shortwave incoming) and afternoon (time of day after the highest potential shortwave incoming), as well as both biotic and abiotic driving mechanisms, using half-hourly and hourly data from 82 eddy-covariance sites in the FLUXNET2015 Tier 1 dataset. Results show that gross primary production (GPP) is slightly higher in the morning for most plant functional types (PFTs), with less water stress, yet with higher, compensating, CO2 concentration. Conversely, evapotranspiration (ET) is larger in the afternoon, with higher atmospheric vapor pressure deficit (VPD) and a tendency for decreased stomatal opening, in response to daytime boundary layer warming and drying. The higher ET reduces the afternoon increase of the leaf-scale VPD compared to the atmospheric VPD. A GPP decomposition analysis suggests that changes in light use efficiency (LUE) are the main factor explaining the difference in GPP between the morning and afternoon. Additionally, simulations from an ecosystem conductance model show that plant responses to VPD are higher and interactions with the atmosphere are stronger in the afternoon. Both evaluations of LUE and responses to VPD along a soil-plant-atmosphere continuum model suggest a systematic drop in leaf water potential in the afternoon affecting ecosystem stress responses. Accordingly, the hysteresis effects ultimately result in daytime variations in ET and GPP, through changes in ecosystem conductance coupled to the atmosphere. |
BibTeX:
@article{Lin2019a,
author = {Lin, Changjie and Gentine, Pierre and Frankenberg, Christian and Zhou, Sha and Kennedy, Daniel and Li, Xi},
title = {Evaluation and mechanism exploration of the diurnal hysteresis of ecosystem fluxes},
journal = {Agricultural and Forest Meteorology},
publisher = {Elsevier B.V.},
year = {2019},
volume = {278},
doi = {10.1016/j.agrformet.2019.107642}
}
|
| Liu Z, Chen L, Smith NG, Yuan W, Chen X, Zhou G, Alam SA, Lin K, Zhao T, Zhou P, Chu C, Ma H and Liu J (2019), "Global divergent responses of primary productivity to water, energy, and co2", Environmental Research Letters., dec, 2019. Vol. 14(12) Institute of Physics Publishing. |
| Abstract: The directionality of the response of gross primary productivity (GPP) to climate has been shown to vary across the globe. This effect has been hypothesized to be the result of the interaction between multiple bioclimatic factors, including environmental energy (i.e. temperature and radiation) and water availability. This is due to the tight coupling between water and carbon cycling in plants and the fact that temperature often drives plant water demand. Using GPP data extracted from 188 sites of FLUXNET2015 and observation-driven terrestrial biosphere models (TBMs), we disentangled the confounding effects of temperature, precipitation and carbon dioxide on GPP, and examined their long-term effects on productivity across the globe. Based on the FLUXNET2015 data, we observed a decline in the positive effect of temperature on GPP, while the positive effects of precipitation and CO2 were becoming stronger during 2000-2014. Using data derived from TBMs between 1980 and 2010 we found similar effects globally. The modeled data allowed us to investigate these effects more thoroughly over space and time. In arid regions, the modeled response to precipitation increased since 1950, approximately 30 years earlier than in humid regions. We further observed the negative effects of summer temperature on GPP in arid regions, suggesting greater aridity stress on productivity under global warming. Our results imply that aridity stress, triggered by rising temperatures, has reduced the positive influence of temperature on GPP, while increased precipitation and elevated CO2 may alleviate negative aridity impacts. |
BibTeX:
@article{Liu2019,
author = {Liu, Zhiyong and Chen, Lei and Smith, Nicholas G. and Yuan, Wenping and Chen, Xiaohong and Zhou, Guoyi and Alam, Syed Ashraful and Lin, Kairong and Zhao, Tongtiegang and Zhou, Ping and Chu, Chengjin and Ma, Hanqing and Liu, Jianquan},
title = {Global divergent responses of primary productivity to water, energy, and co2},
journal = {Environmental Research Letters},
publisher = {Institute of Physics Publishing},
year = {2019},
volume = {14},
number = {12},
doi = {10.1088/1748-9326/ab57c5}
}
|
| Liu Y, Piao S, Gasser T, Ciais P, Yang H, Wang H, Keenan TF, Huang M, Wan S, Song J, Wang K, Janssens IA, Peñuelas J, Huntingford C, Wang X, Altaf Arain M, Fang Y, Fisher JB, Huang M, Huntzinger DN, Ito A, Jain AK, Mao J, Michalak AM, Peng C, Poulter B, Schwalm C, Shi X, Tian H, Wei Y, Zeng N, Zhu Q and Wang T (2019), "Field-experiment constraints on the enhancement of the terrestrial carbon sink by CO2 fertilization", Nature Geoscience., sep, 2019. Vol. 12(10), pp. 809-814. Springer Science and Business Media LLC. |
| Abstract: Clarifying how increased atmospheric CO2 concentration (eCO2) contributes to accelerated land carbon sequestration remains important since this process is the largest negative feedback in the coupled carbon–climate system. Here, we constrain the sensitivity of the terrestrial carbon sink to eCO2 over the temperate Northern Hemisphere for the past five decades, using 12 terrestrial ecosystem models and data from seven CO2 enrichment experiments. This constraint uses the heuristic finding that the northern temperate carbon sink sensitivity to eCO2 is linearly related to the site-scale sensitivity across the models. The emerging data-constrained eCO2 sensitivity is 0.64 ± 0.28 PgC yrâˆ'1 per hundred ppm of eCO2. Extrapolating worldwide, this northern temperate sensitivity projects the global terrestrial carbon sink to increase by 3.5 ± 1.9 PgC yrâˆ'1 for an increase in CO2 of 100 ppm. This value suggests that CO2 fertilization alone explains most of the observed increase in global land carbon sink since the 1960s. More CO2 enrichment experiments, particularly in boreal, arctic and tropical ecosystems, are required to explain further the responsible processes. |
BibTeX:
@article{Liu2019a,
author = {Liu, Yongwen and Piao, Shilong and Gasser, Thomas and Ciais, Philippe and Yang, Hui and Wang, Han and Keenan, Trevor F and Huang, Mengtian and Wan, Shiqiang and Song, Jian and Wang, Kai and Janssens, Ivan A and Peñuelas, Josep and Huntingford, Chris and Wang, Xuhui and Altaf Arain, Muhammad and Fang, Yuanyuan and Fisher, Joshua B and Huang, Maoyi and Huntzinger, Deborah N and Ito, Akihiko and Jain, Atul K and Mao, Jiafu and Michalak, Anna M and Peng, Changhui and Poulter, Benjamin and Schwalm, Christopher and Shi, Xiaoying and Tian, Hanqin and Wei, Yaxing and Zeng, Ning and Zhu, Qiuan and Wang, Tao},
title = {Field-experiment constraints on the enhancement of the terrestrial carbon sink by CO2 fertilization},
journal = {Nature Geoscience},
publisher = {Springer Science and Business Media LLC},
year = {2019},
volume = {12},
number = {10},
pages = {809--814},
doi = {10.1038/s41561-019-0436-1}
}
|
| Lognoul M, Debacq A, De Ligne A, Dumont B, Manise T, Bodson B, Heinesch B and Aubinet M (2019), "N 2 O flux short-term response to temperature and topsoil disturbance in a fertilized crop: An eddy covariance campaign", Agricultural and Forest Meteorology., jun, 2019. Vol. 271, pp. 193-206. Elsevier BV. |
| Abstract: Using the eddy covariance technique, half-hourly N 2 O fluxes were measured over a sugar beet crop (ICOS Station, Lonzée, BE) from fertilization to harvest. Several parameters of the data quality control tests were adapted to suit the characteristics of N 2 O. No u* filtering threshold could be seen for N 2 O fluxes; therefore, it was determined based on CO 2 data. The uncertainty of N 2 O fluxes was assessed for several aspects of data treatment (total random uncertainty, spectral correction, u* filtering, gap-filling), which were combined to determine the uncertainty of the N 2 O budget. Between fertilization and harvest, the crop emitted 1.83 (± 0.21) kg N 2 O-N ha âˆ'1 corresponding to 1.2% of N supplies. Flux variability was characterized by three episodes of high emissions across the experiment, interspersed with lower background fluxes. These peak events were driven by soil moisture and temperature, dependent on the time-scale. Soil water content at 5 cm was identified as the single trigger for N 2 O emission peaks given sufficient N availability, while intraday oscillations were positively correlated to the variations in surface temperature rather than deeper soil temperatures. For the first time, an inhibiting and short-term effect of topsoil disturbance (seed-bed preparation) on N 2 O fluxes was recorded, which interrupted the peak that followed fertilization, and delayed the start of the next high emission episode. This observation, along with the synchronicity found between surface temperature and diel oscillations of N 2 O fluxes, supports the hypothesis of a N 2 O-producing microbial community located in the topmost soil layer. Given that a third of the overall N 2 O emissions during the measurement campaign occurred between fertilization and seed-bed preparation, further investigation into the timing of farming operations as mitigation strategies is needed. The contribution of N 2 O emissions to the net greenhouse gas balance (which comprises CO 2 and N 2 O fluxes) was estimated at between 20 and 66%. Our results stress the importance of including nitrous oxide when measuring gas exchanges in fertilized crops, and to do so at high temporal resolution for improved estimates. |
BibTeX:
@article{Lognoul2019,
author = {Lognoul, M and Debacq, A and De Ligne, A and Dumont, B and Manise, T and Bodson, B and Heinesch, B and Aubinet, M},
title = {N 2 O flux short-term response to temperature and topsoil disturbance in a fertilized crop: An eddy covariance campaign},
journal = {Agricultural and Forest Meteorology},
publisher = {Elsevier BV},
year = {2019},
volume = {271},
pages = {193--206},
doi = {10.1016/j.agrformet.2019.02.033}
}
|
| Lovenduski NS, Yeager SG, Lindsay K and Long MC (2019), "Predicting near-term variability in ocean carbon uptake", Earth System Dynamics., jan, 2019. Vol. 10(1), pp. 45-57. Copernicus GmbH. |
| Abstract: textlessptextgreatertextless![CDATA[Abstract. Interannual variations in air–sea fluxes of carbon dioxide (CO2) impact the global carbon cycle and climate system, and previous studies suggest that these variations may be predictable in the near term (from a year to a decade in advance). Here, we quantify and understand the sources of near-term predictability and predictive skill in air–sea CO2 flux on global and regional scales by analyzing output from a novel set of retrospective decadal forecasts of an Earth system model. These forecasts exhibit the potential to predict year-to-year variations in the globally integrated air–sea CO2 flux several years in advance, as indicated by the high correlation of the forecasts with a model reconstruction of past CO2 flux evolution. This potential predictability exceeds that obtained solely from foreknowledge of variations in external forcing or a simple persistence forecast, with the longest-lasting forecast enhancement in the subantarctic Southern Ocean and the northern North Atlantic. Potential predictability in CO2 flux variations is largely driven by predictability in the surface ocean partial pressure of CO2, which itself is a function of predictability in surface ocean dissolved inorganic carbon and alkalinity. The potential predictability, however, is not realized as predictive skill, as indicated by the moderate to low correlation of the forecasts with an observationally based CO2 flux product. Nevertheless, our results suggest that year-to-year variations in ocean carbon uptake have the potential to be predicted well in advance and establish a precedent for forecasting air–sea CO2 flux in the near future.]]textgreatertextless/ptextgreater |
BibTeX:
@article{Lovenduski2019,
author = {Lovenduski, Nicole S. and Yeager, Stephen G. and Lindsay, Keith and Long, Matthew C.},
title = {Predicting near-term variability in ocean carbon uptake},
journal = {Earth System Dynamics},
publisher = {Copernicus GmbH},
year = {2019},
volume = {10},
number = {1},
pages = {45--57},
url = {https://esd.copernicus.org/articles/10/45/2019/},
doi = {10.5194/esd-10-45-2019}
}
|
| Lupon A, Denfeld BA, Laudon H, Leach J, Karlsson J and Sponseller RA (2019), "Groundwater inflows control patterns and sources of greenhouse gas emissions from streams", Limnology and Oceanography., jul, 2019. Vol. 64(4), pp. 1545-1557. |
| Abstract: Headwater streams can be important sources of carbon dioxide (CO2) and methane (CH4) to the atmosphere. However, the influence of groundwater–stream connectivity on the patterns and sources of carbon (C) gas evasion is still poorly understood. We explored these connections in the boreal landscape through a detailed study of a 1.4 km lake outlet stream that is hydrologically fed by multiple topographically driven groundwater input zones. We measured stream and groundwater dissolved organic C (DOC), CO2, and CH4 concentrations every 50 m biweekly during the ice-free period and estimated in-stream C gas production through a mass balance model and independent estimates of aquatic metabolism. The spatial pattern of C gas concentrations was consistent over time, with peaks of both CH4 and CO2 concentrations occurring after each groundwater input zone. Moreover, lateral C gas inputs from riparian soils were the major source of CO2 and CH4 to the stream. DOC mineralization and CH4 oxidation within the stream accounted for 17–51% of stream CO2 emissions, and this contribution was the greatest during relatively higher flows. Overall, our results illustrate how the nature and arrangement of groundwater flowpaths can organize patterns of stream C concentrations, transformations, and emissions by acting as a direct source of gases and by supplying organic substrates that fuel aquatic metabolism. Hence, refined assessments of how catchment structure influences the timing and magnitude of groundwater–stream connections are crucial for mechanistically understanding and scaling C evasion rates from headwaters. |
BibTeX:
@article{Lupon2019,
author = {Lupon, Anna and Denfeld, Blaize A and Laudon, Hjalmar and Leach, Jason and Karlsson, Jan and Sponseller, Ryan A},
title = {Groundwater inflows control patterns and sources of greenhouse gas emissions from streams},
journal = {Limnology and Oceanography},
year = {2019},
volume = {64},
number = {4},
pages = {1545--1557},
url = {http://doi.wiley.com/10.1002/lno.11134},
doi = {10.1002/lno.11134}
}
|
| Machacova K, Vainio E, Urban O and Pihlatie M (2019), "Seasonal dynamics of stem N2O exchange follow the physiological activity of boreal trees", Nature Communications., dec, 2019. Vol. 10(1) Nature Publishing Group. |
| Abstract: The role of trees in the nitrous oxide (N2O) balance of boreal forests has been neglected despite evidence suggesting their substantial contribution. We measured seasonal changes in N2O fluxes from soil and stems of boreal trees in Finland, showing clear seasonality in stem N2O flux following tree physiological activity, particularly processes of CO2 uptake and release. Stem N2O emissions peak during the vegetation season, decrease rapidly in October, and remain low but significant to the annual totals during winter dormancy. Trees growing on dry soils even turn to consumption of N2O from the atmosphere during dormancy, thereby reducing their overall N2O emissions. At an annual scale, pine, spruce and birch are net N2O sources, with spruce being the strongest emitter. Boreal trees thus markedly contribute to the seasonal dynamics of ecosystem N2O exchange, and their species-specific contribution should be included into forest emission inventories. |
BibTeX:
@article{Machacova2019,
author = {Machacova, Katerina and Vainio, Elisa and Urban, Otmar and Pihlatie, Mari},
title = {Seasonal dynamics of stem N2O exchange follow the physiological activity of boreal trees},
journal = {Nature Communications},
publisher = {Nature Publishing Group},
year = {2019},
volume = {10},
number = {1},
doi = {10.1038/s41467-019-12976-y}
}
|
| Macovei VA, Torres-Valdés S, Hartman SE, Schuster U, Moore CM, Brown PJ, Hydes DJ and Sanders RJ (2019), "Temporal Variability in the Nutrient Biogeochemistry of the Surface North Atlantic: 15 Years of Ship of Opportunity Data", Global Biogeochemical Cycles., dec, 2019. Vol. 33(12), pp. 1674-1692. American Geophysical Union (AGU). |
| Abstract: Ocean biological processes play an important role in the global carbon cycle via the production of organic matter and its subsequent export. Often, this flux is assumed to be in steady state; however, it is dependent on nutrients introduced to surface waters via multiple mechanisms, some of which are likely to exhibit both intra-annual and interannual variability leading to comparable variability in ocean carbon uptake. Here we test this variability using surface (5 m) inorganic nutrient concentrations from voluntary observing ships and satellite-derived estimates of chlorophyll and net primary production. At lower latitudes, the seasonality is small, and the monthly averages of nitrate:phosphate are lower than the canonical 16:1 Redfield ratio, implying nitrogen limitation, a situation confirmed via a series of nutrient limitation experiments conducted between Bermuda and Puerto Rico. The nutrient seasonal cycle is more pronounced at higher latitudes, with clear interannual variability. Over a large area of the midlatitude North Atlantic, the winters of 2009/2010 and 2010/2011 had nitrate values more than 1μmol Lâˆ'1 higher than the 2002–2017 average, suggesting that during this period, the system may have shifted to phosphorus limitation. This nitrate increase meant that, in the region between 31° and 39° N, new production calculated from nitrate uptake was 20.5g C mâˆ'2 in 2010, more than four times higher than the median value of the whole observing period. Overall, we suggest that substantial variability in nutrient concentrations and biological carbon uptake occurs in the North Atlantic with interannual variability apparent over a number of different time scales. |
BibTeX:
@article{Macovei2019,
author = {Macovei, V A and Torres-Valdés, S and Hartman, S E and Schuster, U and Moore, C M and Brown, P J and Hydes, D J and Sanders, R J},
title = {Temporal Variability in the Nutrient Biogeochemistry of the Surface North Atlantic: 15 Years of Ship of Opportunity Data},
journal = {Global Biogeochemical Cycles},
publisher = {American Geophysical Union (AGU)},
year = {2019},
volume = {33},
number = {12},
pages = {1674--1692},
doi = {10.1029/2018GB006132}
}
|
| Mader S (2019), "Plant trees for the planet: the potential of forests for climate change mitigation and the major drivers of national forest area", Mitigation and Adaptation Strategies for Global Change. Springer Netherlands. |
| Abstract: Forests are one of the most cost-effective ways to sequester carbon today. Here, I estimate the world's land share under forests required to prevent dangerous climate change. For this, I combine newest longitudinal data of FLUXNET on forests' net ecosystem exchange of carbon (NEE) from 78 forest sites (N = 607) with countries' mean temperature and forest area. This straightforward approach indicates that the world's forests sequester 8.3 GtCO2year−1. For the 2 °C climate target, the current forest land share has to be doubled to 60.0% to sequester an additional 7.8 GtCO2year−1, which demands less red meat consumption. This afforestation/reforestation (AR) challenge is achievable, as the estimated global biophysical potential of AR is 8.0 GtCO2year−1 safeguarding food supply for 10 billion people. Climate-responsible countries have the highest AR potential. For effective climate policies, knowledge on the major drivers of forest area is crucial. Enhancing information here, I analyze forest land share data of 98 countries from 1990 to 2015 applying causal inference (N = 2494). The results highlight that population growth, industrialization, and increasing temperature reduce forest land share, while more protected forest and economic growth generally increase it. In all, this study confirms the potential of AR for climate change mitigation with a straightforward approach based on the direct measurement of NEE. This might provide a more valid picture given the shortcomings of indirect carbon stock-based inventories. The analysis identifies future regional hotspots for the AR potential and informs the need for fast and forceful action to prevent dangerous climate change. |
BibTeX:
@article{Mader2019,
author = {Mader, Sebastian},
title = {Plant trees for the planet: the potential of forests for climate change mitigation and the major drivers of national forest area},
journal = {Mitigation and Adaptation Strategies for Global Change},
publisher = {Springer Netherlands},
year = {2019},
doi = {10.1007/s11027-019-09875-4}
}
|
| Maes WH, Gentine P, Verhoest NE and Miralles DG (2019), "Potential evaporation at eddy-covariance sites across the globe", Hydrology and Earth System Sciences., feb, 2019. Vol. 23(2), pp. 925-948. Copernicus GmbH. |
| Abstract: Potential evaporation (textlessspan classCombining double low line"inline-formula"textgreatertextlessitextgreaterEtextless/itextgreaterptextless/spantextgreater) is a crucial variable for hydrological forecasting and drought monitoring. However, multiple interpretations of textlessspan classCombining double low line"inline-formula"textgreatertextlessitextgreaterEtextless/itextgreaterptextless/spantextgreater exist, which reflect a diverse range of methods to calculate it. A comparison of the performance of these methods against field observations in different global ecosystems is urgently needed. In this study, potential evaporation was defined as the rate of terrestrial evaporation (or textlessitextgreaterevapotranspirationtextless/itextgreater) that the actual ecosystem would attain if it were to evaporate at maximal rate for the given atmospheric conditions. We use eddy-covariance measurements from the FLUXNET2015 database, covering 11 different biomes, to parameterise and inter-compare the most widely used textlessspan classCombining double low line"inline-formula"textgreatertextlessitextgreaterEtextless/itextgreaterptextless/spantextgreater methods and to uncover their relative performance. For each of the 107 sites, we isolate days for which ecosystems can be considered unstressed, based on both an energy balance and a soil water content approach. Evaporation measurements during these days are used as reference to calibrate and validate the different methods to estimate textlessspan classCombining double low line"inline-formula"textgreatertextlessitextgreaterEtextless/itextgreaterptextless/spantextgreater. Our results indicate that a simple radiation-driven method, calibrated per biome, consistently performs best against in situ measurements (mean correlation of 0.93; unbiased RMSE of 0.56&thinsp;mm&thinsp;daytextlessspan classCombining double low line"inline-formula"textgreaterĝ'1textless/spantextgreater; and bias of textlessspan classCombining double low line"inline-formula"textgreaterĝ'0.02textless/spantextgreater&thinsp;mm&thinsp;daytextlessspan classCombining double low line"inline-formula"textgreaterĝ'1textless/spantextgreater). A Priestley and Taylor method, calibrated per biome, performed just slightly worse, yet substantially and consistently better than more complex Penman-based, Penman-Monteith-based or temperature-driven approaches. We show that the poor performance of Penman-Monteith-based approaches largely relates to the fact that the unstressed stomatal conductance cannot be assumed to be constant in time at the ecosystem scale. On the contrary, the biome-specific parameters required by simpler radiation-driven methods are relatively constant in time and per biome type. This makes these methods a robust way to estimate textlessspan classCombining double low line"inline-formula"textgreatertextlessitextgreaterEtextless/itextgreaterptextless/spantextgreater and a suitable tool to investigate the impact of water use and demand, drought severity and biome productivity. |
BibTeX:
@article{Maes2019,
author = {Maes, Wouter H. and Gentine, Pierre and Verhoest, Niko E.C. and Miralles, Diego G.},
title = {Potential evaporation at eddy-covariance sites across the globe},
journal = {Hydrology and Earth System Sciences},
publisher = {Copernicus GmbH},
year = {2019},
volume = {23},
number = {2},
pages = {925--948},
doi = {10.5194/hess-23-925-2019}
}
|
| Mäkelä J, Knauer J, Aurela M, Black A, Heimann M, Kobayashi H, Lohila A, Mammarella I, Margolis H, Markkanen T, Susiluoto J, Thum T, Viskari T, Zaehle S and Aalto T (2019), "Parameter calibration and stomatal conductance formulation comparison for boreal forests with adaptive population importance sampler in the land surface model JSBACH", Geoscientific Model Development., sep, 2019. Vol. 12(9), pp. 4075-4098. Copernicus GmbH. |
| Abstract: We calibrated the JSBACH model with six different stomatal conductance formulations using measurements from 10 FLUXNET coniferous evergreen sites in the boreal zone. The parameter posterior distributions were generated by the adaptive population importance sampler (APIS); then the optimal values were estimated by a simple stochastic optimisation algorithm. The model was constrained with in situ observations of evapotranspiration (ET) and gross primary production (GPP). We identified the key parameters in the calibration process. These parameters control the soil moisture stress function and the overall rate of carbon fixation. The JSBACH model was also modified to use a delayed effect of temperature for photosynthetic activity in spring. This modification enabled the model to correctly reproduce the springtime increase in GPP for all conifer sites used in this study. Overall, the calibration and model modifications improved the coefficient of determination and the model bias for GPP with all stomatal conductance formulations. However, only the coefficient of determination was clearly improved for ET. The optimisation resulted in best performance by the Bethy, Ball-Berry, and the Friend and Kiang stomatal conductance models. We also optimised the model during a drought event at a Finnish Scots pine forest site. This optimisation improved the model behaviour but resulted in significant changes to the parameter values except for the unified stomatal optimisation model (USO). Interestingly, the USO demonstrated the best performance during this event. |
BibTeX:
@article{Makela2019,
author = {Mäkelä, Jarmo and Knauer, Jürgen and Aurela, Mika and Black, Andrew and Heimann, Martin and Kobayashi, Hideki and Lohila, Annalea and Mammarella, Ivan and Margolis, Hank and Markkanen, Tiina and Susiluoto, Jouni and Thum, Tea and Viskari, Toni and Zaehle, Sönke and Aalto, Tuula},
title = {Parameter calibration and stomatal conductance formulation comparison for boreal forests with adaptive population importance sampler in the land surface model JSBACH},
journal = {Geoscientific Model Development},
publisher = {Copernicus GmbH},
year = {2019},
volume = {12},
number = {9},
pages = {4075--4098},
doi = {10.5194/gmd-12-4075-2019}
}
|
| Mäki M, Aaltonen H, Heinonsalo J, Hellén H, Pumpanen J and Bäck J (2019), "Boreal forest soil is a significant and diverse source of volatile organic compounds", Plant and Soil., may, 2019. Vol. 441(1-2), pp. 89-110. Springer Science and Business Media LLC. |
| Abstract: Aims: Vegetation emissions of volatile organic compounds (VOCs) are intensively studied world-wide, because oxidation products of VOCs contribute to atmospheric processes. The overall aim of this study was to identify and quantify the VOCs that originate from boreal podzolized forest soil at different depths, in addition to studying the association of VOC concentrations with VOC and CO2 fluxes from the boreal forest floor. Methods: This is the first published study that measures belowground VOC concentrations at different depths in a podzol soil combined with simultaneous flux measurements from the boreal forest floor. The VOC concentrations were determined by sampling VOCs from air inside soil layers using the gas collectors and adsorbent tubes. Forest floor VOC fluxes were determined using a dynamic enclosure technique. All the VOC samples were analysed using a thermal desorption-gas chromatograph-mass spectrometer. Results: More than 50 VOCs, dominated by monoterpenes and sesquiterpenes, were detected in the air space in the soil during two measurement campaigns. The O-horizon was a significant monoterpene source, because it contained fresh isoprenoid-rich litter. Belowground monoterpene concentrations were largely decoupled from forest floor monoterpene fluxes; thus, it seems that production processes and storages of VOCs partly differ from those VOCs that are simultaneously released from the forest floor. Both fluxes and concentrations of the monoterpenes and sesquiterpenes correlated with the CO2 fluxes in autumn, indicating that VOC release was driven by microbial activity. Conclusions: This is the first study where below-ground VOC concentrations were quantified in situ, and for this reason, this study provides valuable insights to the VOC sources present in soils. |
BibTeX:
@article{Maki2019,
author = {Mäki, Mari and Aaltonen, Hermanni and Heinonsalo, Jussi and Hellén, Heidi and Pumpanen, Jukka and Bäck, Jaana},
title = {Boreal forest soil is a significant and diverse source of volatile organic compounds},
journal = {Plant and Soil},
publisher = {Springer Science and Business Media LLC},
year = {2019},
volume = {441},
number = {1-2},
pages = {89--110},
doi = {10.1007/s11104-019-04092-z}
}
|
| Männistö E, Korrensalo A, Alekseychik P, Mammarella I, Peltola O, Vesala T and Tuittila ES (2019), "Multi-year methane ebullition measurements from water and bare peat surfaces of a patterned boreal bog", Biogeosciences., jun, 2019. Vol. 16(11), pp. 2409-2421. Copernicus GmbH. |
| Abstract: We measured methane ebullition from a patterned boreal bog situated in the Siikaneva wetland complex in southern Finland. Measurements were conducted on water (W) and bare peat surfaces (BP) in three growing seasons (2014-2016) using floating gas traps. The volume of the trapped gas was measured weekly, and methane and carbon dioxide (CO2) concentrations of bubbles were analysed from fresh bubble samples that were collected separately. We applied a mixed-effect model to quantify the effect of the environmental controlling factors on the ebullition. Ebullition was higher from W than from BP, and more bubbles were released from open water (OW) than from the water's edge (EW). On average, ebullition rate was the highest in the wettest year (2016) and ranged between 0 and 253 mgm-2 d-1 with a median of 2 mg m-2 d-1, 0 and 147 mgm-2 d-1 with a median of 3 mgm-2 d-1, and 0 and 186 mgm-2 d-1 with a median of 28 mgm-2 d-1 in 2014, 2015, and 2016, respectively. Ebullition increased together with increasing peat temperature, weekly air temperature sum and atmospheric pressure, and decreasing water table (WT). Methane concentration in the bubbles released from W was 15-20 times higher than the CO2 concentration, and from BP it was 10 times higher. The proportion of ebullition fluxes upscaled to ecosystem level for the peak season was 2 %-8% and 2 %-5% of the total flux measured with eddy covariance technique and with chambers and gas traps, respectively. Thus, the contribution of methane ebullition from wet non-vegetated surfaces of the bog to the total ecosystemscale methane emission appeared to be small. |
BibTeX:
@article{Mannisto2019,
author = {Männistö, Elisa and Korrensalo, Aino and Alekseychik, Pavel and Mammarella, Ivan and Peltola, Olli and Vesala, Timo and Tuittila, Eeva Stiina},
title = {Multi-year methane ebullition measurements from water and bare peat surfaces of a patterned boreal bog},
journal = {Biogeosciences},
publisher = {Copernicus GmbH},
year = {2019},
volume = {16},
number = {11},
pages = {2409--2421},
doi = {10.5194/bg-16-2409-2019}
}
|
| Martinez MA, Woodcroft BJ, Ignacio Espinoza JC, Zayed AA, Singleton CM, Boyd JA, Li YF, Purvine S, Maughan H, Hodgkins SB, Anderson D, Sederholm M, Temperton B, Bolduc B, Saleska SR, Tyson GW and Rich VI (2019), "Discovery and ecogenomic context of a global Caldiserica-related phylum active in thawing permafrost, Candidatus Cryosericota phylum nov., Ca. Cryosericia class nov., Ca. Cryosericales ord. nov., Ca. Cryosericaceae fam. nov., comprising the four species Cryosericum septentrionale gen. nov. sp. nov., Ca. C. hinesii sp. nov., Ca. C. odellii sp. nov., Ca. C. terrychapinii sp. nov.", Systematic and Applied Microbiology., jan, 2019. Vol. 42(1), pp. 54-66. Elsevier BV. |
| Abstract: The phylum Caldiserica was identified from the hot spring 16S rRNA gene lineage ‘OP5' and named for the sole isolate Caldisericum exile, a hot spring sulfur-reducing chemoheterotroph. Here we characterize 7 Caldiserica metagenome-assembled genomes (MAGs) from a thawing permafrost site in Stordalen Mire, Arctic Sweden. By 16S rRNA and marker gene phylogenies, and average nucleotide and amino acid identities, these Stordalen Mire Caldiserica (SMC) MAGs form part of a divergent clade from C. exile. Genome and meta-transcriptome and proteome analyses suggest that unlike Caldisericum, the SMCs (i) are carbohydrate- and possibly amino acid fermenters that can use labile plant compounds and peptides, and (ii) encode adaptations to low temperature. The SMC clade rose to community dominance within permafrost, with a peak metagenome-based relative abundance of ∼60%. It was also physiologically active in the upper seasonally-thawed soil. Beyond Stordalen Mire, analysis of 16S rRNA gene surveys indicated a global distribution of this clade, predominantly in anaerobic, carbon-rich and cold environments. These findings establish the SMCs as four novel phenotypically and ecologically distinct species within a single novel genus, distinct from C. exile clade at the phylum level. The SMCs are thus part of a novel cold-habitat phylum for an understudied, globally-distributed superphylum encompassing the Caldiserica. We propose the names Candidatus Cryosericota phylum nov., Ca. Cryosericia class nov., Ca. Cryosericales ord. nov., Ca. Cryosericaceae fam. nov., Ca. Cryosericum gen. nov., Ca. Cryosericum septentrionale sp. nov., Ca. C. hinesii sp. nov., Ca. C. odellii sp. nov., and Ca. C. terrychapinii sp. nov. |
BibTeX:
@article{Martinez2019,
author = {Martinez, Miguel A and Woodcroft, Ben J and Ignacio Espinoza, Julio C and Zayed, Ahmed A and Singleton, Caitlin M and Boyd, Joel A and Li, Yueh Fen and Purvine, Samuel and Maughan, Heather and Hodgkins, Suzanne B and Anderson, Darya and Sederholm, Maya and Temperton, Ben and Bolduc, Benjamin and Saleska, Scott R and Tyson, Gene W and Rich, Virginia I},
title = {Discovery and ecogenomic context of a global Caldiserica-related phylum active in thawing permafrost, Candidatus Cryosericota phylum nov., Ca. Cryosericia class nov., Ca. Cryosericales ord. nov., Ca. Cryosericaceae fam. nov., comprising the four species Cryosericum septentrionale gen. nov. sp. nov., Ca. C. hinesii sp. nov., Ca. C. odellii sp. nov., Ca. C. terrychapinii sp. nov.},
journal = {Systematic and Applied Microbiology},
publisher = {Elsevier BV},
year = {2019},
volume = {42},
number = {1},
pages = {54--66},
doi = {10.1016/j.syapm.2018.12.003}
}
|
| Marzuoli R, Gerosa G, Bussotti F and Pollastrini M (2019), "Assessing the Impact of Ozone on Forest Trees in An Integrative Perspective: Are Foliar Visible Symptoms Suitable Predictors for Growth Reduction? A Critical Review", Forests., dec, 2019. Vol. 10(12), pp. 1144. MDPI AG. |
BibTeX:
@article{Marzuoli2019,
author = {Marzuoli, Riccardo and Gerosa, Giacomo and Bussotti, Filippo and Pollastrini, Martina},
title = {Assessing the Impact of Ozone on Forest Trees in An Integrative Perspective: Are Foliar Visible Symptoms Suitable Predictors for Growth Reduction? A Critical Review},
journal = {Forests},
publisher = {MDPI AG},
year = {2019},
volume = {10},
number = {12},
pages = {1144},
url = {http://dx.doi.org/10.3390/f10121144},
doi = {10.3390/f10121144}
}
|
| Massmann A, Gentine P and Lin C (2019), "When Does Vapor Pressure Deficit Drive or Reduce Evapotranspiration?", Journal of Advances in Modeling Earth Systems., oct, 2019. Vol. 11(10), pp. 3305-3320. Blackwell Publishing Ltd. |
| Abstract: Increasing vapor pressure deficit (VPD) increases atmospheric demand for water. While increased evapotranspiration (ET) in response to increased atmospheric demand seems intuitive, plants are capable of reducing ET in response to increased VPD by closing their stomata. We examine which effect dominates the response to increasing VPD: atmospheric demand and increases in ET or plant response (stomata closure) and decreases in ET. We use Penman-Monteith, combined with semiempirical optimal stomatal regulation theory and underlying water use efficiency, to develop a theoretical framework for assessing ET response to VPD. The theory suggests that depending on the environment and plant characteristics, ET response to increasing VPD can vary from strongly decreasing to increasing, highlighting the diversity of plant water regulation strategies. The ET response varies due to (1) climate, with tropical and temperate climates more likely to exhibit a positive ET response to increasing VPD than boreal and arctic climates; (2) photosynthesis strategy, with C3 plants more likely to exhibit a positive ET response than C4 plants; and (3) plant type, with crops more likely to exhibit a positive ET response, and shrubs and gymniosperm trees more likely to exhibit a negative ET response. These results, derived from previous literature connecting plant parameters to plant and climate characteristics, highlight the utility of our simplified framework for understanding complex land-atmosphere systems in terms of idealized scenarios in which ET responds to VPD only. This response is otherwise challenging to assess in an environment where many processes coevolve together. |
BibTeX:
@article{Massmann2019,
author = {Massmann, Adam and Gentine, Pierre and Lin, Changjie},
title = {When Does Vapor Pressure Deficit Drive or Reduce Evapotranspiration?},
journal = {Journal of Advances in Modeling Earth Systems},
publisher = {Blackwell Publishing Ltd},
year = {2019},
volume = {11},
number = {10},
pages = {3305--3320},
doi = {10.1029/2019MS001790}
}
|
| McGloin R, Šigut L, Fischer M, Foltýnová L, Chawla S, Trnka M, Pavelka M and Marek MV (2019), "Available Energy Partitioning During Drought at Two Norway Spruce Forests and a European Beech Forest in Central Europe", Journal of Geophysical Research: Atmospheres., apr, 2019. Vol. 124(7), pp. 3726-3742. American Geophysical Union (AGU). |
| Abstract: Partitioning of the available energy at the Earth's surface into the latent heat (LE) and sensible heat (H) fluxes has important climatological, hydrological, and physiological implications. With the prediction of more frequent droughts in central Europe in the near future, there is a particular need to understand variability in available energy partitioning under drought stress conditions at forest ecosystems that are common in the region, such as Norway spruce and European beech. Using eddy covariance measurements from two Norway spruce sites with contrasting wet and dry climates and one European beech site in the Czech Republic, it was found that the proportion of energy partitioned into H was greater at the spruce sites than at the beech site in all conditions during the growing season. The difference between the mean midday (09:00–15:00) β values for low stress conditions and drought stress conditions was much smaller at the European beech site (β = 1.04 vs. 1.11) than at the wet (β = 1.52 vs. 2.50) and dry Norway spruce (β = 1.80 vs. 2.70) sites, indicating that β was not as sensitive to drought stress at the European beech site as at the Norway spruce sites. The high β values and enhancement of drought conditions through positive feedback processes at Norway spruce stands mean that the potential substitution of Norway spruce monocultures with mixed broadleaf-coniferous stands in central Europe will likely lessen the severity of droughts and heat waves in the region. |
BibTeX:
@article{McGloin2019,
author = {McGloin, Ryan and Šigut, Ladislav and Fischer, Milan and Foltýnová, Lenka and Chawla, Shilpi and Trnka, Miroslav and Pavelka, Marian and Marek, Michal V},
title = {Available Energy Partitioning During Drought at Two Norway Spruce Forests and a European Beech Forest in Central Europe},
journal = {Journal of Geophysical Research: Atmospheres},
publisher = {American Geophysical Union (AGU)},
year = {2019},
volume = {124},
number = {7},
pages = {3726--3742},
doi = {10.1029/2018JD029490}
}
|
| Metzl N (2019), "A canary in the Southern Ocean". sep, 2019. |
| Abstract: The Southern Ocean is a major carbon sink, but knowledge of its variability is limited, especially in the coastal Antarctic. Now, results based on 25 years of observations in the West Antarctic Peninsula show that the carbon sink is increasing rapidly, driven by summertime biological production linked to sea ice dynamics. |
BibTeX:
@misc{Metzl2019,
author = {Metzl, Nicolas},
title = {A canary in the Southern Ocean},
booktitle = {Nature Climate Change},
publisher = {Nature Publishing Group},
year = {2019},
volume = {9},
number = {9},
pages = {651--652},
url = {https://www.nature.com/articles/s41558-019-0562-1},
doi = {10.1038/s41558-019-0562-1}
}
|
| Monteil G, Broquet G, Scholze M, Lang M, Karstens U, Gerbig C, Koch F-T, Smith N, Thompson R, White E, Meesters A, Ciais P, Ganesan A, Manning A, Mischurow M, Peters W, Peylin P, Tarniewicz J, Rigby M, Rödenbeck C, Vermeulen A and Walton E (2019), "The regional EUROpean atmospheric transport inversion COMparison, EUROCOM: first results on European wide terrestrial carbon fluxes for the period 2006–2015", Atmospheric Chemistry and Physics Discussions., dec, 2019. , pp. 1-40. Copernicus GmbH. |
| Abstract: Atmospheric inversions have been used for the past two decades to derive large scale constraints on the sources and sinks of CO 2 into the atmosphere. The development of high density in-situ surface observation networks, such as ICOS in Europe, enables in theory inversions at a resolution close to the country scale in Europe. This has led to the development of many regional inversion systems capable of assimilating these high-resolution data, in Europe and elsewhere. The EURO-COM project (EUROpean atmospheric transport inversion COMparison) is a collaboration between seven European research 5 institutes, which aims at producing a collective assessment of the net carbon flux between the terrestrial ecosystems and the atmosphere in Europe for the period 2006-2015. It aims in particular at investigating the capacity of the inversions to deliver consistent flux estimates from the country scale up to the continental scale. The project participants were provided with a common database of in-situ observed CO 2 concentrations (including the observation sites that are now part of the ICOS network), and were tasked with providing their best estimate of the net terrestrial 10 carbon flux for that period, and for a large domain covering the entire European Union. The inversion systems differ by the transport model, the inversion approach and the choice of observation and prior constraints, enabling us to widely explore the space of uncertainties. This paper describes the intercomparison protocol and the participating systems, and it presents the first results from a reference set of inversions, at the continental scale and in four large regions. At the continental scale, the regional inversions 15 1 https://doi. support the assumption that European ecosystems are a relatively small sink (-0.21±0.2 PgC/year). We find that the convergence of the regional inversions at this scale is not better than that obtained in state-of-the-art global inversions. However, more robust results are obtained for sub-regions within Europe, and in these areas with dense observational coverage, the objective of delivering robust country scale flux estimates appears achievable in the near future. |
BibTeX:
@article{Monteil2019,
author = {Monteil, Guillaume and Broquet, Grégoire and Scholze, Marko and Lang, Matthew and Karstens, Ute and Gerbig, Christof and Koch, Frank-Thomas and Smith, Naomi and Thompson, Rona and White, Emily and Meesters, Antoon and Ciais, Philippe and Ganesan, Anita and Manning, Alistair and Mischurow, Michael and Peters, Wouter and Peylin, Philippe and Tarniewicz, Jerôme and Rigby, Matt and Rödenbeck, Christian and Vermeulen, Alex and Walton, Evie},
title = {The regional EUROpean atmospheric transport inversion COMparison, EUROCOM: first results on European wide terrestrial carbon fluxes for the period 2006–2015},
journal = {Atmospheric Chemistry and Physics Discussions},
publisher = {Copernicus GmbH},
year = {2019},
pages = {1--40},
doi = {10.5194/acp-2019-1008}
}
|
| Morel X, Decharme B, Delire C, Krinner G, Lund M, Hansen BU and Mastepanov M (2019), "A New Process-Based Soil Methane Scheme: Evaluation Over Arctic Field Sites With the ISBA Land Surface Model", Journal of Advances in Modeling Earth Systems., jan, 2019. Vol. 11(1), pp. 293-326. American Geophysical Union (AGU). |
| Abstract: Permafrost soils and arctic wetlands methane emissions represent an important challenge for modeling the future climate. Here we present a process-based model designed to correctly represent the main thermal, hydrological, and biogeochemical processes related to these emissions for general land surface modeling. We propose a new multilayer soil carbon and gas module within the Interaction Soil-Biosphere-Atmosphere (ISBA) land-surface model (LSM). This module represents carbon pools, vertical carbon dynamics, and both oxic and anoxic organic matter decomposition. It also represents the soil gas processes for CH 4 , CO 2 , and O 2 through the soil column. We base CH 4 production and oxydation on an O 2 control instead of the classical water table level strata approach used in state-of-the-art soil CH 4 models. We propose a new parametrization of CH 4 oxydation using recent field experiments and use an explicit O 2 limitation for soil carbon decomposition. Soil gas transport is computed explicitly, using a revisited formulation of plant-mediated transport, a new representation of gas bulk diffusivity in porous media closer to experimental observations, and an innovative advection term for ebullition. We evaluate this advanced model on three climatically distinct sites : two in Greenland (Nuuk and Zackenberg) and one in Siberia (Chokurdakh). The model realistically reproduces methane and carbon dioxide emissions from both permafrosted and nonpermafrosted sites. The evolution and vertical characteristics of the underground processes leading to these fluxes are consistent with current knowledge. Results also show that physics is the main driver of methane fluxes, and the main source of variability appears to be the water table depth. |
BibTeX:
@article{Morel2019,
author = {Morel, X and Decharme, B and Delire, C and Krinner, G and Lund, M and Hansen, B U and Mastepanov, M},
title = {A New Process-Based Soil Methane Scheme: Evaluation Over Arctic Field Sites With the ISBA Land Surface Model},
journal = {Journal of Advances in Modeling Earth Systems},
publisher = {American Geophysical Union (AGU)},
year = {2019},
volume = {11},
number = {1},
pages = {293--326},
doi = {10.1029/2018MS001329}
}
|
| Morgan EJ, Lavric JV, Arévalo-Martínez DL, Bange HW, Steinhoff T, Seifert T and Heimann M (2019), "Air–sea fluxes of greenhouse gases and oxygen in the northern Benguela Current region during upwelling events", Biogeosciences., oct, 2019. Vol. 16(20), pp. 4065-4084. Copernicus GmbH. |
| Abstract: textlessptextgreatertextless![CDATA[Abstract. Ground-based atmospheric observations of CO2, δ(O2∕N2), N2O, and CH4 were used to make estimates of the air–sea fluxes of these species from the Lüderitz and Walvis Bay upwelling cells in the northern Benguela region, during upwelling events. Average flux densities (±1σ) were 0.65±0.4 µmol m−2 s−1 for CO2, -5.1±2.5 µmol m−2 s−1 for O2 (as APO), 0.61±0.5 nmol m−2 s−1 for N2O, and 4.8±6.3 nmol m−2 s−1 for CH4. A comparison of our top-down (i.e., inferred from atmospheric anomalies) flux estimates with shipboard-based measurements showed that the two approaches agreed within ±55 % on average, though the degree of agreement varied by species and was best for CO2. Since the top-down method overestimated the flux density relative to the shipboard-based approach for all species, we also present flux density estimates that have been tuned to best match the shipboard fluxes. During the study, upwelling events were sources of CO2, N2O, and CH4 to the atmosphere. N2O fluxes were fairly low, in accordance with previous work suggesting that the evasion of this gas from the Benguela is smaller than for other eastern boundary upwelling systems (EBUS). Conversely, CH4 release was quite high for the marine environment, a result that supports studies that indicated a large sedimentary source of CH4 in the Walvis Bay area. These results demonstrate the suitability of atmospheric time series for characterizing the temporal variability of upwelling events and their influence on the overall marine greenhouse gas (GHG) emissions from the northern Benguela region.]]textgreatertextless/ptextgreater |
BibTeX:
@article{Morgan2019,
author = {Morgan, Eric J. and Lavric, Jost V. and Arévalo-Martínez, Damian L. and Bange, Hermann W. and Steinhoff, Tobias and Seifert, Thomas and Heimann, Martin},
title = {Air–sea fluxes of greenhouse gases and oxygen in the northern Benguela Current region during upwelling events},
journal = {Biogeosciences},
publisher = {Copernicus GmbH},
year = {2019},
volume = {16},
number = {20},
pages = {4065--4084},
url = {https://bg.copernicus.org/articles/16/4065/2019/},
doi = {10.5194/bg-16-4065-2019}
}
|
| Mortelmans J, Deneudt K, Cattrijsse A, Beauchard O, Daveloose I, Vyverman W, Vanaverbeke J, Timmermans K, Peene J, Roose P, Knockaert M, Chou L, Sanders R, Stinchcombe M, Kimpe P, Lammens S, Theetaert H, Gkritzalis T, Hernandez F and Mees J (2019), "Nutrient, pigment, suspended matter and turbidity measurements in the Belgian part of the North Sea", Scientific Data., dec, 2019. Vol. 6(1) Nature Research. |
| Abstract: Through regular sampling surveys, the Flanders Marine Institute is generating long term data series for the Belgian coastal water and sand bank systems, a designated site in the Long Term Ecological Research (LTER) network. The data series is built on sampling activities initiated in 2002, but gradually upgraded and extended in the framework of the LifeWatch marine observatory and the Integrated Carbon Observation System (ICOS) participation. Nine nearshore stations are sampled monthly, with additional seasonal sampling of eight offshore stations. This paper presents the generated data series for nutrients, pigments, suspended matter and turbidity. The collection, methodology and processing of the 2002–2018 dataset is described, along with its data curation, integration and quality control. Yearly versions of the data are published online in a standardized format, accompanied with extensive metadata description and labelled with digital identifiers for traceability. Data is published under a CC-BY license, allowing use of the data under the condition of providing reference to the original source. |
BibTeX:
@article{Mortelmans2019,
author = {Mortelmans, Jonas and Deneudt, Klaas and Cattrijsse, André and Beauchard, Olivier and Daveloose, Ilse and Vyverman, Wim and Vanaverbeke, Jan and Timmermans, Klaas and Peene, Jan and Roose, Patrick and Knockaert, Mark and Chou, Lei and Sanders, Richard and Stinchcombe, Marc and Kimpe, Philippe and Lammens, Saskia and Theetaert, Hannelore and Gkritzalis, Thanos and Hernandez, Francisco and Mees, Jan},
title = {Nutrient, pigment, suspended matter and turbidity measurements in the Belgian part of the North Sea},
journal = {Scientific Data},
publisher = {Nature Research},
year = {2019},
volume = {6},
number = {1},
doi = {10.1038/s41597-019-0032-7}
}
|
| Nangini C, Peregon A, Ciais P, Weddige U, Vogel F, Wang J, Bréon FM, Bachra S, Wang Y, Gurney K, Yamagata Y, Appleby K, Telahoun S, Canadell JG, Grübler A, Dhakal S and Creutzig F (2019), "A global dataset of co2 emissions and ancillary data related to emissions for 343 cities", Scientific Data., jan, 2019. Vol. 6(1) Springer Science and Business Media LLC. |
| Abstract: We present a global dataset of anthropogenic carbon dioxide (CO2) emissions for 343 cities. The dataset builds upon data from CDP (187 cities, few in developing countries), the Bonn Center for Local Climate Action and Reporting (73 cities, mainly in developing countries), and data collected by Peking University (83 cities in China). The CDP data being self-reported by cities, we applied quality control procedures, documented the type of emissions and reporting method used, and made a correction to separate CO2 emissions from those of other greenhouse gases. Further, a set of ancillary data that have a direct or potentially indirect impact on CO2 emissions were collected from other datasets (e.g. socio-economic and traffic indices) or calculated (climate indices, urban area expansion), then combined with the emission data. We applied several quality controls and validation comparisons with independent datasets. The dataset presented here is not intended to be comprehensive or a representative sample of cities in general, as the choice of cities is based on self-reporting not a designed sampling procedure. |
BibTeX:
@article{Nangini2019,
author = {Nangini, Cathy and Peregon, Anna and Ciais, Philippe and Weddige, Ulf and Vogel, Felix and Wang, Jun and Bréon, François Marie and Bachra, Simeran and Wang, Yilong and Gurney, Kevin and Yamagata, Yoshiki and Appleby, Kyra and Telahoun, Sara and Canadell, Josep G and Grübler, Arnulf and Dhakal, Shobhakar and Creutzig, Felix},
title = {A global dataset of co2 emissions and ancillary data related to emissions for 343 cities},
journal = {Scientific Data},
publisher = {Springer Science and Business Media LLC},
year = {2019},
volume = {6},
number = {1},
doi = {10.1038/sdata.2018.280}
}
|
| Natali SM, Watts JD, Rogers BM, Potter S, Ludwig SM, Selbmann AK, Sullivan PF, Abbott BW, Arndt KA, Birch L, Björkman MP, Bloom AA, Celis G, Christensen TR, Christiansen CT, Commane R, Cooper EJ, Crill P, Czimczik C, Davydov S, Du J, Egan JE, Elberling B, Euskirchen ES, Friborg T, Genet H, Göckede M, Goodrich JP, Grogan P, Helbig M, Jafarov EE, Jastrow JD, Kalhori AAM, Kim Y, Kimball JS, Kutzbach L, Lara MJ, Larsen KS, Lee BY, Liu Z, Loranty MM, Lund M, Lupascu M, Madani N, Malhotra A, Matamala R, McFarland J, McGuire AD, Michelsen A, Minions C, Oechel WC, Olefeldt D, Parmentier FJW, Pirk N, Poulter B, Quinton W, Rezanezhad F, Risk D, Sachs T, Schaefer K, Schmidt NM, Schuur EAG, Semenchuk PR, Shaver G, Sonnentag O, Starr G, Treat CC, Waldrop MP, Wang Y, Welker J, Wille C, Xu X, Zhang Z, Zhuang Q and Zona D (2019), "Large loss of CO2 in winter observed across the northern permafrost region", Nature Climate Change., oct, 2019. Vol. 9(11), pp. 852-857. Springer Science and Business Media LLC. |
| Abstract: Recent warming in the Arctic, which has been amplified during the winter1–3, greatly enhances microbial decomposition of soil organic matter and subsequent release of carbon dioxide (CO2)4. However, the amount of CO2 released in winter is not known and has not been well represented by ecosystem models or empirically based estimates5,6. Here we synthesize regional in situ observations of CO2 flux from Arctic and boreal soils to assess current and future winter carbon losses from the northern permafrost domain. We estimate a contemporary loss of 1,662 TgC per year from the permafrost region during the winter season (October–April). This loss is greater than the average growing season carbon uptake for this region estimated from process models (âˆ'1,032 TgC per year). Extending model predictions to warmer conditions up to 2100 indicates that winter CO2 emissions will increase 17% under a moderate mitigation scenario—Representative Concentration Pathway 4.5—and 41% under business-as-usual emissions scenario—Representative Concentration Pathway 8.5. Our results provide a baseline for winter CO2 emissions from northern terrestrial regions and indicate that enhanced soil CO2 loss due to winter warming may offset growing season carbon uptake under future climatic conditions. |
BibTeX:
@article{Natali2019,
author = {Natali, Susan M and Watts, Jennifer D and Rogers, Brendan M and Potter, Stefano and Ludwig, Sarah M and Selbmann, Anne Katrin and Sullivan, Patrick F and Abbott, Benjamin W and Arndt, Kyle A and Birch, Leah and Björkman, Mats P and Bloom, A Anthony and Celis, Gerardo and Christensen, Torben R and Christiansen, Casper T and Commane, Roisin and Cooper, Elisabeth J and Crill, Patrick and Czimczik, Claudia and Davydov, Sergey and Du, Jinyang and Egan, Jocelyn E and Elberling, Bo and Euskirchen, Eugenie S and Friborg, Thomas and Genet, Hélène and Göckede, Mathias and Goodrich, Jordan P and Grogan, Paul and Helbig, Manuel and Jafarov, Elchin E and Jastrow, Julie D and Kalhori, Aram A M and Kim, Yongwon and Kimball, John S and Kutzbach, Lars and Lara, Mark J and Larsen, Klaus S and Lee, Bang Yong and Liu, Zhihua and Loranty, Michael M and Lund, Magnus and Lupascu, Massimo and Madani, Nima and Malhotra, Avni and Matamala, Roser and McFarland, Jack and McGuire, A David and Michelsen, Anders and Minions, Christina and Oechel, Walter C and Olefeldt, David and Parmentier, Frans Jan W and Pirk, Norbert and Poulter, Ben and Quinton, William and Rezanezhad, Fereidoun and Risk, David and Sachs, Torsten and Schaefer, Kevin and Schmidt, Niels M and Schuur, Edward A G and Semenchuk, Philipp R and Shaver, Gaius and Sonnentag, Oliver and Starr, Gregory and Treat, Claire C and Waldrop, Mark P and Wang, Yihui and Welker, Jeffrey and Wille, Christian and Xu, Xiaofeng and Zhang, Zhen and Zhuang, Qianlai and Zona, Donatella},
title = {Large loss of CO2 in winter observed across the northern permafrost region},
journal = {Nature Climate Change},
publisher = {Springer Science and Business Media LLC},
year = {2019},
volume = {9},
number = {11},
pages = {852--857},
doi = {10.1038/s41558-019-0592-8}
}
|
| Nelson RR and O'Dell CW (2019), "The impact of improved aerosol priors on near-infrared measurements of carbon dioxide", Atmospheric Measurement Techniques., mar, 2019. Vol. 12(3), pp. 1495-1512. Copernicus GmbH. |
| Abstract: The Orbiting Carbon Observatory-2 (OCO-2) was launched in 2014 with the goal of measuring the columnaveraged dry-air mole fraction of carbon dioxide (XCO2 ) with sufficient precision and accuracy to infer regional carbon sources and sinks. One of the primary sources of error in near-infrared measurements of XCO2 is the scattering effects of cloud and aerosol layers. In this work, we study the impact of ingesting better informed aerosol priors from the Goddard Earth Observing System Model, Version 5 (GEOS-5) into the OCO-2 ACOS V8 retrieval algorithm with the objective of reducing the error in XCO2 from real measurements. Multiple levels of both aerosol setup complexity and uncertainty on the aerosol priors were tested, ranging from a mostly unconstrained aerosol optical depth (AOD) setup to ingesting full aerosol profiles with high confidence. We find that using co-located GEOS-5 aerosol types and AODs with low uncertainty results in a small improvement in the retrieved XCO2 against the Total Carbon Column Observing Network relative to V8. In contrast, attempting to use modeled vertical information in the aerosol prior to improve the XCO2 retrieval generally gives poor results, as aerosol models struggle with the vertical placement of aerosol layers. To assess regional differences in XCO2 , we compare our results to a global CO2 model validation suite. We find that the GEOS-5 setup performs better than V8 over northern Africa and central Asia, with the standard deviation of the XCO2 error reduced from 2.12 to 1.83 ppm, due to a combination of smaller prior AODs and lower prior uncertainty. In general, the use of better informed aerosol priors shows promise but may be restricted by the current accuracy of aerosol models. |
BibTeX:
@article{Nelson2019,
author = {Nelson, Robert R. and O'Dell, Christopher W.},
title = {The impact of improved aerosol priors on near-infrared measurements of carbon dioxide},
journal = {Atmospheric Measurement Techniques},
publisher = {Copernicus GmbH},
year = {2019},
volume = {12},
number = {3},
pages = {1495--1512},
doi = {10.5194/amt-12-1495-2019}
}
|
| Ney P, Graf A, Bogena H, Diekkrüger B, Drüe C, Esser O, Heinemann G, Klosterhalfen A, Pick K, Pütz T, Schmidt M, Valler V and Vereecken H (2019), "CO2 fluxes before and after partial deforestation of a Central European spruce forest", Agricultural and Forest Meteorology., aug, 2019. Vol. 274, pp. 61-74. Elsevier BV. |
| Abstract: A seven year CO2-flux dataset measured in a 70 year old spruce monoculture is presented, of which 22% was deforested three years after the start of the measurements to accelerate regeneration towards natural deciduous vegetation. An eddy covariance (EC) system, mounted on top of a tower within the spruce forest, continuously sampled fluxes of momentum, sensible heat, latent heat and CO2. After clear-cutting, a second EC station with an identical set of instruments was installed inside the deforested area. In total, we examined an EC dataset including three years before (forest) and four years after partial deforestation (forest and deforested). Full time series and annual carbon budgets of the net ecosystem exchange (NEE) and its components gross primary production (GPP) and total ecosystem respiration (Reco) were calculated for both EC sites. Soil respiration was measured with manual chambers on average every month after the deforestation at 75 measurement points in the forest and deforested area. Annual sums of NEE measured above the forest indicated a strong carbon sink of -660 (-535) g C m-2 y-1 with small interannual variability ±78 (72) g C m-2 y-1 (values in brackets including correction for self-heating of the open-path gas analyzer). In the first year after partial deforestation, regrowth on the clearcut consisted mainly of grasses, with beginning of the second year shrubs and young trees became increasingly important. The regrowth of vegetation is reflected in the annual sums of NEE, which decreased from a carbon source of 521 (548) g C m-2 y-1 towards 82 (236) g C m-2 y-1 over the past four years, due to an increase in the magnitude of GPP from 385 (447) to 892 (1036) g C m-2 y-1. |
BibTeX:
@article{Ney2019,
author = {Ney, Patrizia and Graf, Alexander and Bogena, Heye and Diekkrüger, Bernd and Drüe, Clemens and Esser, Odilia and Heinemann, Günther and Klosterhalfen, Anne and Pick, Katharina and Pütz, Thomas and Schmidt, Marius and Valler, Veronika and Vereecken, Harry},
title = {CO2 fluxes before and after partial deforestation of a Central European spruce forest},
journal = {Agricultural and Forest Meteorology},
publisher = {Elsevier BV},
year = {2019},
volume = {274},
pages = {61--74},
doi = {10.1016/j.agrformet.2019.04.009}
}
|
| Nichol CJ, Drolet G, Porcar-Castell A, Wade T, Sabater N, Middleton EM, MacLellan C, Levula J, Mammarella I, Vesala T and Atherton J (2019), "Diurnal and seasonal solar induced chlorophyll fluorescence and photosynthesis in a boreal scots pine canopy", Remote Sensing., feb, 2019. Vol. 11(3) MDPI AG. |
| Abstract: Solar induced chlorophyll fluorescence has been shown to be increasingly an useful proxy for the estimation of gross primary productivity (GPP), at a range of spatial scales. Here, we explore the seasonality in a continuous time series of canopy solar induced fluorescence (hereafter SiF) and its relation to canopy gross primary production (GPP), canopy light use efficiency (LUE), and direct estimates of leaf level photochemical efficiency in an evergreen canopy. SiF was calculated using infilling in two bands from the incoming and reflected radiance using a pair of Ocean Optics USB2000+ spectrometers operated in a dual field of view mode, sampling at a 30 min time step using custom written automated software, from early spring through until autumn in 2011. The optical system was mounted on a tower of 18 m height adjacent to an eddy covariance system, to observe a boreal forest ecosystem dominated by Scots pine. (Pinus sylvestris) AWalz MONITORING-PAM, multi fluorimeter system, was simultaneously mounted within the canopy adjacent to the footprint sampled by the optical system. Following correction of the SiF data for O 2 and structural effects, SiF, SiF yield, LUE, the photochemicsl reflectance index (PRI), and the normalized difference vegetation index (NDVI) exhibited a seasonal pattern that followed GPP sampled by the eddy covariance system. Due to the complexities of solar azimuth and zenith angle (SZA) over the season on the SiF signal, correlations between SiF, SiF yield, GPP, and LUE were assessed on SZA textless 50° and under strictly clear sky conditions. Correlations found, even under these screened scenarios, resulted around ˜r 2 = 0.3. The diurnal responses of SiF, SiF yield, PAM estimates of effective quantum yield (ΔF/F m '), and meteorological parameters demonstrated some agreement over the diurnal cycle. The challenges inherent in SiF retrievals in boreal evergreen ecosystems are discussed. |
BibTeX:
@article{Nichol2019,
author = {Nichol, Caroline J. and Drolet, Guillaume and Porcar-Castell, Albert and Wade, Tom and Sabater, Neus and Middleton, Elizabeth M. and MacLellan, Chris and Levula, Janne and Mammarella, Ivan and Vesala, Timo and Atherton, Jon},
title = {Diurnal and seasonal solar induced chlorophyll fluorescence and photosynthesis in a boreal scots pine canopy},
journal = {Remote Sensing},
publisher = {MDPI AG},
year = {2019},
volume = {11},
number = {3},
doi = {10.3390/rs11030273}
}
|
| Nijp JJ, Metselaar K, Limpens J, Bartholomeus HM, Nilsson MB, Berendse F and van der Zee SE (2019), "High-resolution peat volume change in a northern peatland: Spatial variability, main drivers, and impact on ecohydrology", Ecohydrology., aug, 2019. Vol. 12(6) Wiley. |
| Abstract: The depth of the groundwater table below the surface and its spatiotemporal variability are major controls on all major biogeophysical processes in northern peatlands, including ecohydrology, carbon balance, and greenhouse gas exchange. In these ecosystems, water table fluctuations are buffered by compression and expansion of peat. Controls on peat volume change and its spatial variability, however, remain elusive, hampering accurate assessment of climate change impact on functioning of peatlands. We therefore (1) analysed patterning of seasonal surface elevation change at high spatial resolution (0.5 m); (2) assessed its relationship with vegetation, geohydrology, and position within the peatland; and (3) quantified the consequences for peatland surface topography and ecohydrology. Changes in surface elevation were monitored using digital close-range photogrammetry along a transect in a northern peatland from after snowmelt up to midgrowing season (May–July). Surface elevation change was substantial and varied spatially from âˆ'0.062 to +0.012 m over the measurement period. Spatial patterns of peat volume change were correlated up to 40.8 m. Spatial variation of peat volume change was mainly controlled by changes in water table, and to a lesser extent to vegetation, with peat volume change magnitude increasing from lawn ' hollow ' flark. Our observations suggest that patchiness and vertical variability of peatland surface topography are a function of the groundwater table. In dry conditions, the variability of surface elevation increases and more localized groundwater flows may develop. Consequently, spatially variable peat volume change may enhance peatland water retention and thereby sustain carbon uptake during drought. |
BibTeX:
@article{Nijp2019,
author = {Nijp, Jelmer J and Metselaar, Klaas and Limpens, Juul and Bartholomeus, Harm M and Nilsson, Mats B and Berendse, Frank and van der Zee, Sjoerd E.A.T.M.},
title = {High-resolution peat volume change in a northern peatland: Spatial variability, main drivers, and impact on ecohydrology},
journal = {Ecohydrology},
publisher = {Wiley},
year = {2019},
volume = {12},
number = {6},
doi = {10.1002/eco.2114}
}
|
| Nilsson E, Rutgersson A, Dingwell A, Björkqvist JV, Pettersson H, Axell L, Nyberg J and Strömstedt E (2019), "Characterization of wave energy potential for the Baltic Sea with focus on the Swedish exclusive economic zone", Energies., feb, 2019. Vol. 12(5), pp. 793. |
| Abstract: In this study, a third-generation wave model is used to examine the wave power resource for the Baltic Sea region at an unprecedented one-kilometer-scale resolution for the years 1998 to 2013. Special focus is given to the evaluation and description of wave field characteristics for the Swedish Exclusive Economic Zone (SEEZ). It is carried out to provide a more detailed assessment of the potential of waves as a renewable energy resource for the region. The wave energy potential is largely controlled by the distance from the coast and the fetch associated with the prevailing dominant wave direction. The ice cover is also shown to significantly influence the wave power resource, especially in the most northern basins of the SEEZ. For the areas in focus here, the potential annual average wave energy flux reaches 45 MWh/m/year in the two sub-basins with the highest wave energies, but local variations are up to 65 MWh/m/year. The assessment provides the basis for a further detailed identification of potential sites for wave energy converters. An outlook is given for additional aspects studied within a broad multi-disciplinary project to assess the conditions for offshore wave energy conversion within the SEEZ. |
BibTeX:
@article{Nilsson2019,
author = {Nilsson, Erik and Rutgersson, Anna and Dingwell, Adam and Björkqvist, Jan Victor and Pettersson, Heidi and Axell, Lars and Nyberg, Johan and Strömstedt, Erland},
title = {Characterization of wave energy potential for the Baltic Sea with focus on the Swedish exclusive economic zone},
journal = {Energies},
year = {2019},
volume = {12},
number = {5},
pages = {793},
url = {http://www.mdpi.com/1996-1073/12/5/793},
doi = {10.3390/en12050793}
}
|
| Nisbet EG, Manning MR, Dlugokencky EJ, Fisher RE, Lowry D, Michel SE, Myhre CL, Platt SM, Allen G, Bousquet P, Brownlow R, Cain M, France JL, Hermansen O, Hossaini R, Jones AE, Levin I, Manning AC, Myhre G, Pyle JA, Vaughn BH, Warwick NJ and White JWC (2019), "Very Strong Atmospheric Methane Growth in the 4 Years 2014–2017: Implications for the Paris Agreement", Global Biogeochemical Cycles., mar, 2019. Vol. 33(3), pp. 318-342. American Geophysical Union (AGU). |
| Abstract: Atmospheric methane grew very rapidly in 2014 (12.7 ± 0.5 ppb/year), 2015 (10.1 ± 0.7 ppb/year), 2016 (7.0 ± 0.7 ppb/year), and 2017 (7.7 ± 0.7 ppb/year), at rates not observed since the 1980s. The increase in the methane burden began in 2007, with the mean global mole fraction in remote surface background air rising from about 1,775 ppb in 2006 to 1,850 ppb in 2017. Simultaneously the 13C/12C isotopic ratio (expressed as δ13CCH4) has shifted, has shifted, now trending negative for more than a decade. The causes of methane's recent mole fraction increase are therefore either a change in the relative proportions (and totals) of emissions from biogenic and thermogenic and pyrogenic sources, especially in the tropics and subtropics, or a decline in the atmospheric sink of methane, or both. Unfortunately, with limited measurement data sets, it is not currently possible to be more definitive. The climate warming impact of the observed methane increase over the past decade, if continued at 5 ppb/year in the coming decades, is sufficient to challenge the Paris Agreement, which requires sharp cuts in the atmospheric methane burden. However, anthropogenic methane emissions are relatively very large and thus offer attractive targets for rapid reduction, which are essential if the Paris Agreement aims are to be attained. |
BibTeX:
@article{Nisbet2019,
author = {Nisbet, E G and Manning, M R and Dlugokencky, E J and Fisher, R E and Lowry, D and Michel, S E and Myhre, C Lund and Platt, S M and Allen, G and Bousquet, P and Brownlow, R and Cain, M and France, J L and Hermansen, O and Hossaini, R and Jones, A E and Levin, I and Manning, A C and Myhre, G and Pyle, J A and Vaughn, B H and Warwick, N J and White, J W C},
title = {Very Strong Atmospheric Methane Growth in the 4 Years 2014–2017: Implications for the Paris Agreement},
journal = {Global Biogeochemical Cycles},
publisher = {American Geophysical Union (AGU)},
year = {2019},
volume = {33},
number = {3},
pages = {318--342},
doi = {10.1029/2018GB006009}
}
|
| Omar AM, Thomas H, Olsen A, Becker M, Skjelvan I and Reverdin G (2019), "Trends of Ocean Acidification and pCO2 in the Northern North Sea, 2003–2015", Journal of Geophysical Research: Biogeosciences., oct, 2019. Vol. 124(10), pp. 3088-3103. American Geophysical Union (AGU). |
| Abstract: For continental shelf regions, the long-term trend in sea surface carbon dioxide (CO2) partial pressure (pCO2) and rates of ocean acidification are not accurately known. Here, we investigate the decadal trend of observed wintertime pCO2 as well as computed wintertime pH and aragonite saturation state (Ωar) in the northern North Sea, using the first decade long monthly underway data from a voluntary observing ship covering the period 2004–2015. We also evaluate how seawater CO2 chemistry, in response to physical and biological processes, drives variations in the above parameters on seasonal and interannual timescales. In the northern North Sea, pCO2, pH, and Ωar are subject to strong seasonal variations with mean wintertime values of 375 ± 11 μatm, 8.17 ± 0.01, and 1.96 ± 0.05. Dissolved inorganic carbon is found to be the primary driver of both seasonal and interannual changes while total alkalinity and sea surface temperature have secondary effects that reduce the changes produced by dissolved inorganic carbon. Average interannual variations during winter are around 3%, 0.1%, and 2% for pCO2, pH, and Ωar, respectively and slightly larger in the eastern part of the study area (Skagerrak region) than in the western part (North Atlantic Water region). Statistically significant long-term trends were found only in the North Atlantic Water region with mean annual rates of 2.39 ± 0.58 μatm/year, âˆ'0.0024 ± 0.001 year-1, and âˆ'0.010 ± 0.003 year-1 for pCO2, pH, and Ωar, respectively. The drivers of the observed trends as well as reasons for the lack of statistically significant trends in the Skagerrak region are discussed. |
BibTeX:
@article{Omar2019,
author = {Omar, A M and Thomas, H and Olsen, A and Becker, M and Skjelvan, I and Reverdin, G},
title = {Trends of Ocean Acidification and pCO2 in the Northern North Sea, 2003–2015},
journal = {Journal of Geophysical Research: Biogeosciences},
publisher = {American Geophysical Union (AGU)},
year = {2019},
volume = {124},
number = {10},
pages = {3088--3103},
doi = {10.1029/2018JG004992}
}
|
| Othoniel B, Rugani B, Heijungs R, Beyer M, Machwitz M and Post P (2019), "An improved life cycle impact assessment principle for assessing the impact of land use on ecosystem services", Science of the Total Environment., nov, 2019. Vol. 693 Elsevier B.V.. |
| Abstract: In order to consider the effects of land use, and the land cover changes it causes, on ecosystem services in life cycle assessment (LCA), a new methodology is proposed and applied to calculate midpoint and endpoint characterization factors. To do this, a cause-effect chain was established in line with conceptual models of ecosystem services to describe the impacts of land use and related land cover changes. A high-resolution, spatially explicit and temporally dynamic modeling framework that integrates land use and ecosystem services models was developed and used as an impact characterization model to simulate that cause-effect chain. Characterization factors (CFs) were calculated and regionalized at the scales of Luxembourg and its municipalities, taken as a case to show the advantages of the modeling approach. More specifically, the calculated CFs enable the impact assessment of six land cover types on six ecosystem functions and two final ecosystem services. A mapping and comparison exercise of these CFs allowed us to identify spatial trade-offs and synergies between ecosystem services due to possible land cover changes. Ultimately, the proposed methodology can offer a solution to overcome a number of methodological limitations that still exist in the characterization of impacts on ecosystem services in LCA, implying a rethinking of the modeling of land use in life cycle inventory. |
BibTeX:
@article{Othoniel2019,
author = {Othoniel, Benoit and Rugani, Benedetto and Heijungs, Reinout and Beyer, M. and Machwitz, Miriam and Post, Pim},
title = {An improved life cycle impact assessment principle for assessing the impact of land use on ecosystem services},
journal = {Science of the Total Environment},
publisher = {Elsevier B.V.},
year = {2019},
volume = {693},
doi = {10.1016/j.scitotenv.2019.07.180}
}
|
| Palacz A, Telszewski M, Rehder G and Bittig H (2019), "Training the Next Generation of Marine Biogeochemists", Eos., nov, 2019. Vol. 100 American Geophysical Union (AGU). |
| Abstract: Early-career scientists came together recently to learn to use a suite of ocean biogeochemical sensors, with the goal of closing the knowledge gap between ocean technology and potential end users. |
BibTeX:
@article{Palacz2019,
author = {Palacz, Artur and Telszewski, Maciej and Rehder, Gregor and Bittig, Henry},
title = {Training the Next Generation of Marine Biogeochemists},
journal = {Eos},
publisher = {American Geophysical Union (AGU)},
year = {2019},
volume = {100},
doi = {10.1029/2019eo136334}
}
|
| Palmer PI, Wilson EL, L. Villanueva G, Liuzzi G, Feng L, DiGregorio AJ, Mao J, Ott L and Duncan B (2019), "Potential improvements in global carbon flux estimates from a network of laser heterodyne radiometer measurements of column carbon dioxide", Atmospheric Measurement Techniques., may, 2019. Vol. 12(4), pp. 2579-2594. |
BibTeX:
@article{Palmer2019,
author = {Palmer, Paul I. and Wilson, Emily L. and L. Villanueva, Geronimo and Liuzzi, Giuliano and Feng, Liang and DiGregorio, Anthony J. and Mao, Jianping and Ott, Lesley and Duncan, Bryan},
title = {Potential improvements in global carbon flux estimates from a network of laser heterodyne radiometer measurements of column carbon dioxide},
journal = {Atmospheric Measurement Techniques},
year = {2019},
volume = {12},
number = {4},
pages = {2579--2594},
url = {https://amt.copernicus.org/articles/12/2579/2019/},
doi = {10.5194/amt-12-2579-2019}
}
|
| Pandey S, Houweling S, Krol M, Aben I, Nechitaâ€Banda N, Thoning K, Röckmann T, Yin Y, Segers A and Dlugokencky EJ (2019), "Influence of Atmospheric Transport on Estimates of Variability in the Global Methane Burden", Geophysical Research Letters., feb, 2019. Vol. 46(4), pp. 2302-2311. |
BibTeX:
@article{Pandey2019,
author = {Pandey, Sudhanshu and Houweling, Sander and Krol, Maarten and Aben, Ilse and Nechitaâ€Banda, Narcisa and Thoning, Kirk and Röckmann, Thomas and Yin, Yi and Segers, Arjo and Dlugokencky, Edward J},
title = {Influence of Atmospheric Transport on Estimates of Variability in the Global Methane Burden},
journal = {Geophysical Research Letters},
year = {2019},
volume = {46},
number = {4},
pages = {2302--2311},
url = {https://onlinelibrary.wiley.com/doi/abs/10.1029/2018GL081092},
doi = {10.1029/2018GL081092}
}
|
| Peaucelle M, Janssens IA, Stocker BD, Descals Ferrando A, Fu YH, Molowny-Horas R, Ciais P and Peñuelas J (2019), "Spatial variance of spring phenology in temperate deciduous forests is constrained by background climatic conditions", Nature Communications., nov, 2019. Vol. 10(1) Springer Science and Business Media LLC. |
| Abstract: Leaf unfolding in temperate forests is driven by spring temperature, but little is known about the spatial variance of that temperature dependency. Here we use in situ leaf unfolding observations for eight deciduous tree species to show that the two factors that control chilling (number of cold days) and heat requirement (growing degree days at leaf unfolding, GDDreq) only explain 30% of the spatial variance of leaf unfolding. Radiation and aridity differences among sites together explain 10% of the spatial variance of leaf unfolding date, and 40% of the variation in GDDreq. Radiation intensity is positively correlated with GDDreq and aridity is negatively correlated with GDDreq spatial variance. These results suggest that leaf unfolding of temperate deciduous trees is adapted to local mean climate, including water and light availability, through altered sensitivity to spring temperature. Such adaptation of heat requirement to background climate would imply that models using constant temperature response are inherently inaccurate at local scale. |
BibTeX:
@article{Peaucelle2019,
author = {Peaucelle, Marc and Janssens, Ivan A and Stocker, Benjamin D and Descals Ferrando, Adrià and Fu, Yongshuo H and Molowny-Horas, Roberto and Ciais, Philippe and Peñuelas, Josep},
title = {Spatial variance of spring phenology in temperate deciduous forests is constrained by background climatic conditions},
journal = {Nature Communications},
publisher = {Springer Science and Business Media LLC},
year = {2019},
volume = {10},
number = {1},
doi = {10.1038/s41467-019-13365-1}
}
|
| Peaucelle M, Bacour C, Ciais P, Vuichard N, Kuppel S, Peñuelas J, Belelli Marchesini L, Blanken PD, Buchmann N, Chen J, Delpierre N, Desai AR, Dufrene E, Gianelle D, Gimeno-Colera C, Gruening C, Helfter C, Hörtnagl L, Ibrom A, Joffre R, Kato T, Kolb TE, Law B, Lindroth A, Mammarella I, Merbold L, Minerbi S, Montagnani L, Šigut L, Sutton M, Varlagin A, Vesala T, Wohlfahrt G, Wolf S, Yakir D and Viovy N (2019), "Covariations between plant functional traits emerge from constraining parameterization of a terrestrial biosphere model", Global Ecology and Biogeography., jun, 2019. Vol. 28(9), pp. 1351-1365. Wiley. |
| Abstract: Aim: The mechanisms of plant trait adaptation and acclimation are still poorly understood and, consequently, lack a consistent representation in terrestrial biosphere models (TBMs). Despite the increasing availability of geo-referenced trait observations, current databases are still insufficient to cover all vegetation types and environmental conditions. In parallel, the growing number of continuous eddy-covariance observations of energy and CO2 fluxes has enabled modellers to optimize TBMs with these data. Past attempts to optimize TBM parameters mostly focused on model performance, overlooking the ecological properties of ecosystems. The aim of this study was to assess the ecological consistency of optimized trait-related parameters while improving the model performances for gross primary productivity (GPP) at sites. Location: Worldwide. Time period: 1992–2012. Major taxa studied: Trees and C3 grasses. Methods: We optimized parameters of the ORCHIDEE model against 371 site-years of GPP estimates from the FLUXNET network, and we looked at global covariation among parameters and with climate. Results: The optimized parameter values were shown to be consistent with leaf-scale traits, in particular, with well-known trade-offs observed at the leaf level, echoing the leaf economic spectrum theory. Results showed a marked sensitivity of trait-related parameters to local bioclimatic variables and reproduced the observed relationships between traits and climate. Main conclusions: Our approach validates some biological processes implemented in the model and enables us to study ecological properties of vegetation at the canopy level, in addition to some traits that are difficult to observe experimentally. This study stresses the need for: (a) implementing explicit trade-offs and acclimation processes in TBMs; (b) improving the representation of processes to avoid model-specific parameterization; and (c) performing systematic measurements of traits at FLUXNET sites in order to gather information on plant ecophysiology and plant diversity, together with micro-meteorological conditions. |
BibTeX:
@article{Peaucelle2019a,
author = {Peaucelle, Marc and Bacour, Cédric and Ciais, Philippe and Vuichard, Nicolas and Kuppel, Sylvain and Peñuelas, Josep and Belelli Marchesini, Luca and Blanken, Peter D and Buchmann, Nina and Chen, Jiquan and Delpierre, Nicolas and Desai, Ankur R and Dufrene, Eric and Gianelle, Damiano and Gimeno-Colera, Cristina and Gruening, Carsten and Helfter, Carole and Hörtnagl, Lukas and Ibrom, Andreas and Joffre, Richard and Kato, Tomomichi and Kolb, Thomas E and Law, Beverly and Lindroth, Anders and Mammarella, Ivan and Merbold, Lutz and Minerbi, Stefano and Montagnani, Leonardo and Šigut, Ladislav and Sutton, Mark and Varlagin, Andrej and Vesala, Timo and Wohlfahrt, Georg and Wolf, Sebastian and Yakir, Dan and Viovy, Nicolas},
editor = {Lenoir, Jonathan},
title = {Covariations between plant functional traits emerge from constraining parameterization of a terrestrial biosphere model},
journal = {Global Ecology and Biogeography},
publisher = {Wiley},
year = {2019},
volume = {28},
number = {9},
pages = {1351--1365},
doi = {10.1111/geb.12937}
}
|
| Peaucelle M, Ciais P, Maignan F, Nicolas M, Cecchini S and Viovy N (2019), "Representing explicit budburst and senescence processes for evergreen conifers in global models", Agricultural and Forest Meteorology., mar, 2019. Vol. 266-267, pp. 97-108. Elsevier BV. |
| Abstract: Global ecosystem models lack an explicit representation of budburst and senescence for evergreen conifers despite their primordial role in the carbon cycle. In this study we evaluated eight different budburst models, combining forcing, chilling and photoperiod, for their ability to describe spring budburst, and one model of needle senescence for temperate evergreen coniferous forests. The models' parameters were optimized against field observations from a national forest monitoring network in France. The best fitting budburst model was determined according to a new metrics which accounts for both temporal and spatial variabilities of budburst events across sites. The best model could reproduce observed budburst dates both at the site scale (±5 days) and at regional scale (±12 days). We also showed that the budburst models parameterized at site scale lose some predictive capability when applied at coarser spatial resolution, e.g., in grid-based simulations. The selected budburst model was then coupled to a senescence function defined from needle survivorship observations in order to describe the full phenology cycle of coniferous forests. Implemented in the process-driven ecosystem model ORCHIDEE, this new conifer phenology module represented accurately the intra and inter-annual dynamics of leaf area index at both the local and regional scales when compared against MODIS remote sensing observations. A sensitivity analysis showed only a small impact of the new budburst model on the timing of the seasonal cycle of photosynthesis (GPP). Yet, due to the faster renewal of needles compared to the standard version of ORCHIDEE, we simulated an increase in the GPP by on average 15% over France, while the simulated needle turnover was doubled. Compared to 1970–2000, projections indicated an advancement of the budburst date of 10.3 ± 2.8 and 12.3 ± 4.1 days in average over the period 2060–2100 with the best forcing and chilling-forcing models respectively. Our study suggests that including an explicit simulation of needle budburst and senescence for evergreen conifers in global terrestrial ecosystem models may significantly impact future projections of carbon budgets. |
BibTeX:
@article{Peaucelle2019b,
author = {Peaucelle, Marc and Ciais, Philippe and Maignan, Fabienne and Nicolas, Manuel and Cecchini, Sébastien and Viovy, Nicolas},
title = {Representing explicit budburst and senescence processes for evergreen conifers in global models},
journal = {Agricultural and Forest Meteorology},
publisher = {Elsevier BV},
year = {2019},
volume = {266-267},
pages = {97--108},
doi = {10.1016/j.agrformet.2018.12.008}
}
|
| Peltola O, Vesala T, Gao Y, Räty O, Alekseychik P, Aurela M, Chojnicki B, Desai AR, Dolman AJ, Euskirchen ES, Friborg T, Göckede M, Helbig M, Humphreys E, Jackson RB, Jocher G, Joos F, Klatt J, Knox SH, Kowalska N, Kutzbach L, Lienert S, Lohila A, Mammarella I, Nadeau DF, Nilsson MB, Oechel WC, Peichl M, Pypker T, Quinton W, Rinne J, Sachs T, Samson M, Schmid HP, Sonnentag O, Wille C, Zona D and Aalto T (2019), "Monthly gridded data product of northern wetland methane emissions based on upscaling eddy covariance observations", Earth System Science Data., aug, 2019. Vol. 11(3), pp. 1263-1289. |
| Abstract: Natural wetlands constitute the largest and most uncertain source of methane (CH4) to the atmosphere and a large fraction of them are found in the northern latitudes. These emissions are typically estimated using process ("bottom-up") or inversion ("top-down") models. However, estimates from these two types of models are not independent of each other since the top-down estimates usually rely on the a priori estimation of these emissions obtained with process models. Hence, independent spatially explicit validation data are needed. Here we utilize a random forest (RF) machine-learning technique to upscale CH4 eddy covariance flux measurements from 25 sites to estimate CH4 wetland emissions from the northern latitudes (north of 45° N). Eddy covariance data from 2005 to 2016 are used for model development. The model is then used to predict emissions during 2013 and 2014. The predictive performance of the RF model is evaluated using a leave-one-site-out cross-validation scheme. The performance (Nash-Sutcliffe model efficiency D 0:47) is comparable to previous studies upscaling net ecosystem exchange of carbon dioxide and studies comparing process model output against site-level CH4 emission data. The global distribution of wetlands is one major source of uncertainty for upscaling CH4. Thus, three wetland distribution maps are utilized in the upscaling. Depending on the wetland distribution map, the annual emissions for the northern wetlands yield 32 (22.3-41.2, 95 % confidence interval calculated from a RF model ensemble), 31 (21.4-39.9) or 38 (25.9-49.5) Tg(CH4) yr-1. To further evaluate the uncertainties of the upscaled CH4 flux data products we also compared them against output from two process models (LPX-Bern and WetCHARTs), and methodological issues related to CH4 flux upscaling are discussed. The monthly upscaled CH4 flux data products are available at https://doi.org/10.5281/zenodo.2560163 (Peltola et al., 2019). |
BibTeX:
@article{Peltola2019,
author = {Peltola, Olli and Vesala, Timo and Gao, Yao and Räty, Olle and Alekseychik, Pavel and Aurela, Mika and Chojnicki, Bogdan and Desai, Ankur R and Dolman, Albertus J and Euskirchen, Eugenie S and Friborg, Thomas and Göckede, Mathias and Helbig, Manuel and Humphreys, Elyn and Jackson, Robert B and Jocher, Georg and Joos, Fortunat and Klatt, Janina and Knox, Sara H and Kowalska, Natalia and Kutzbach, Lars and Lienert, Sebastian and Lohila, Annalea and Mammarella, Ivan and Nadeau, Daniel F and Nilsson, Mats B and Oechel, Walter C and Peichl, Matthias and Pypker, Thomas and Quinton, William and Rinne, Janne and Sachs, Torsten and Samson, Mateusz and Schmid, Hans Peter and Sonnentag, Oliver and Wille, Christian and Zona, Donatella and Aalto, Tuula},
title = {Monthly gridded data product of northern wetland methane emissions based on upscaling eddy covariance observations},
journal = {Earth System Science Data},
year = {2019},
volume = {11},
number = {3},
pages = {1263--1289},
url = {https://www.earth-syst-sci-data.net/11/1263/2019/},
doi = {10.5194/essd-11-1263-2019}
}
|
| Petzold A, Asmi A, Vermeulen A, Pappalardo G, Bailo D, Schaap D, Glaves HM, Bundke U and Zhao Z (2019), "ENVRI-FAIR - Interoperable Environmental FAIR Data and Services for Society, Innovation and Research", In 2019 15th International Conference on eScience (eScience)., sep, 2019. , pp. 277-280. IEEE. |
BibTeX:
@inproceedings{Petzold2019,
author = {Petzold, Andreas and Asmi, Ari and Vermeulen, Alex and Pappalardo, Gelsomina and Bailo, Daniele and Schaap, Dick and Glaves, Helen M and Bundke, Ulrich and Zhao, Zhiming},
title = {ENVRI-FAIR - Interoperable Environmental FAIR Data and Services for Society, Innovation and Research},
booktitle = {2019 15th International Conference on eScience (eScience)},
publisher = {IEEE},
year = {2019},
pages = {277--280},
url = {https://ieeexplore.ieee.org/document/9041704/},
doi = {10.1109/eScience.2019.00038}
}
|
| Pierrot D, Steinhoff T and Oceanographic A (2019), "Installation of Autonomous Underway pCO2 Instruments onboard Ships of Opportunity". |
BibTeX:
@misc{Pierrot2019,
author = {Pierrot, D and Steinhoff, T and Oceanographic, Atlantic},
title = {Installation of Autonomous Underway pCO2 Instruments onboard Ships of Opportunity},
booktitle = {NOAA Technical Report},
publisher = {Atlantic Oceanographic and Meteorological Laboratory},
year = {2019},
volume = {OAR-AOML-5},
number = {April},
pages = {31},
doi = {10.25923/ffz6-0x48}
}
|
| Pisso I, Sollum E, Grythe H, Kristiansen NI, Cassiani M, Eckhardt S, Arnold D, Morton D, Thompson RL, Groot Zwaaftink CD, Evangeliou N, Sodemann H, Haimberger L, Henne S, Brunner D, Burkhart JF, Fouilloux A, Brioude J, Philipp A, Seibert P and Stohl A (2019), "The Lagrangian particle dispersion model FLEXPART version 10.4", Geoscientific Model Development., dec, 2019. Vol. 12(12), pp. 4955-4997. |
| Abstract: The Lagrangian particle dispersion model FLEXPART in its original version in the mid-1990s was designed for calculating the long-range and mesoscale dispersion of hazardous substances from point sources, such as those released after an accident in a nuclear power plant. Over the past decades, the model has evolved into a comprehensive tool for multi-scale atmospheric transport modeling and analysis and has attracted a global user community. Its application fields have been extended to a large range of atmospheric gases and aerosols, e.g., greenhouse gases, short-lived climate forcers like black carbon and volcanic ash, and it has also been used to study the atmospheric branch of the water cycle. Given suitable meteorological input data, it can be used for scales from dozens of meters to global. In particular, inverse modeling based on source-receptor relationships from FLEXPART has become widely used. In this paper, we present FLEXPART version 10.4, which works with meteorological input data from the European Centre for Medium-Range Weather Forecasts (ECMWF) Integrated Forecast System (IFS) and data from the United States National Centers of Environmental Prediction (NCEP) Global Forecast System (GFS). Since the last publication of a detailed FLEXPART description (version 6.2), the model has been improved in different aspects such as performance, physicochemical parameterizations, input/output formats, and available preprocessing and post-processing software. The model code has also been parallelized using the Message Passing Interface (MPI). We demonstrate that the model scales well up to using 256 processors, with a parallel efficiency greater than 75&thinsp;% for up to 64 processes on multiple nodes in runs with very large numbers of particles. The deviation from 100&thinsp;% efficiency is almost entirely due to the remaining nonparallelized parts of the code, suggesting large potential for further speedup. A new turbulence scheme for the convective boundary layer has been developed that considers the skewness in the vertical velocity distribution (updrafts and downdrafts) and vertical gradients in air density. FLEXPART is the only model available considering both effects, making it highly accurate for small-scale applications, e.g., to quantify dispersion in the vicinity of a point source. The wetspan idCombining double low line"page4956"/ deposition scheme for aerosols has been completely rewritten and a new, more detailed gravitational settling parameterization for aerosols has also been implemented. FLEXPART has had the option of running backward in time from atmospheric concentrations at receptor locations for many years, but this has now been extended to also work for deposition values and may become useful, for instance, for the interpretation of ice core measurements. To our knowledge, to date FLEXPART is the only model with that capability. Furthermore, the temporal variation and temperature dependence of chemical reactions with the OH radical have been included, allowing for more accurate simulations for species with intermediate lifetimes against the reaction with OH, such as ethane. Finally, user settings can now be specified in a more flexible namelist format, and output files can be produced in NetCDF format instead of FLEXPART's customary binary format. In this paper, we describe these new developments. Moreover, we present some tools for the preparation of the meteorological input data and for processing FLEXPART output data, and we briefly report on alternative FLEXPART versions. |
BibTeX:
@article{Pisso2019,
author = {Pisso, Ignacio and Sollum, Espen and Grythe, Henrik and Kristiansen, Nina I and Cassiani, Massimo and Eckhardt, Sabine and Arnold, Delia and Morton, Don and Thompson, Rona L and Groot Zwaaftink, Christine D and Evangeliou, Nikolaos and Sodemann, Harald and Haimberger, Leopold and Henne, Stephan and Brunner, Dominik and Burkhart, John F and Fouilloux, Anne and Brioude, Jerome and Philipp, Anne and Seibert, Petra and Stohl, Andreas},
title = {The Lagrangian particle dispersion model FLEXPART version 10.4},
journal = {Geoscientific Model Development},
year = {2019},
volume = {12},
number = {12},
pages = {4955--4997},
url = {https://www.geosci-model-dev.net/12/4955/2019/},
doi = {10.5194/gmd-12-4955-2019}
}
|
| Proietti C, Anav A, Vitale M, Fares S, Fornasier MF, Screpanti A, Salvati L, Paoletti E, Sicard P and De Marco A (2019), "A new wetness index to evaluate the soil water availability influence on gross primary production of european forests", Climate., mar, 2019. Vol. 7(3), pp. 42. MDPI AG. |
| Abstract: Rising temperature, drought and more-frequent extreme climatic events have been predicted for the next decades in many regions around the globe. In this framework, soil water availability plays a pivotal role in affecting vegetation productivity, especially in arid or semi-arid environments. However, direct measurements of soil moisture are scarce, and modeling estimations are still subject to biases. Further investigation on the effect of soil moisture on plant productivity is required. This study aims at analyzing spatio-temporal variations of a modified temperature vegetation wetness index (mTVWI), a proxy of soil moisture, and evaluating its effect on gross primary production (GPP) in forests. The study was carried out in Europe on 19 representative tree species during the 2000-2010 time period. Results outline a north-south gradient of mTVWI with minimum values (low soil water availability) in Southern Europe and maximum values (high soil water availability) in Northeastern Europe. A low soil water availability negatively affected GPP from 20 to 80%, as a function of site location, tree species, and weather conditions. Such a wetness index improves our understanding of water stress impacts, which is crucial for predicting the response of forest carbon cycling to drought and aridity. |
BibTeX:
@article{Proietti2019,
author = {Proietti, Chiara and Anav, Alessandro and Vitale, Marcello and Fares, Silvano and Fornasier, Maria Francesca and Screpanti, Augusto and Salvati, Luca and Paoletti, Elena and Sicard, Pierre and De Marco, Alessandra},
title = {A new wetness index to evaluate the soil water availability influence on gross primary production of european forests},
journal = {Climate},
publisher = {MDPI AG},
year = {2019},
volume = {7},
number = {3},
pages = {42},
doi = {10.3390/cli7030042}
}
|
| Puche N, Senapati N, Flechard CR, Klumpp K, Kirschbaum MUF and Chabbi A (2019), "Modeling carbon and water fluxes of managed grasslands: Comparing flux variability and net carbon budgets between grazed and mowed systems", Agronomy., apr, 2019. Vol. 9(4), pp. 183. MDPI AG. |
| Abstract: The CenW ecosystem model simulates carbon, water, and nitrogen cycles following ecophysiological processes and management practices on a daily basis. We tested and evaluated the model using five years eddy covariance measurements from two adjacent but differently managed grasslands in France. The data were used to independently parameterize CenW for the two grassland sites. Very good agreements, i.e., high model efficiencies and correlations, between observed and modeled fluxes were achieved. We showed that the CenW model captured dayâ€toâ€day, seasonal, and interannual variability observed in measured CO2 and water fluxes. We also showed that following typical management practices (i.e., mowing and grazing), carbon gain was severely curtailed through a sharp and severe reduction in photosynthesizing biomass. We also identified large model/data discrepancies for carbon fluxes during grazing events caused by the noncapture by the eddy covariance system of large respiratory losses of C from dairy cows when they were present in the paddocks. The missing component of grazing animal respiration in the net carbon budget of the grazed grassland can be quantitatively important and can turn sites from being C sinks to being neutral or C sources. It means that extra care is needed in the processing of eddy covariance data from grazed pastures to correctly calculate their annual CO2 balances and carbon budgets. |
BibTeX:
@article{Puche2019,
author = {Puche, Nicolas and Senapati, Nimai and Flechard, Christophe R and Klumpp, Katia and Kirschbaum, Miko U F and Chabbi, Abad},
title = {Modeling carbon and water fluxes of managed grasslands: Comparing flux variability and net carbon budgets between grazed and mowed systems},
journal = {Agronomy},
publisher = {MDPI AG},
year = {2019},
volume = {9},
number = {4},
pages = {183},
doi = {10.3390/agronomy9040183}
}
|
| Räsänen A, Juutinen S, Tuittila ES, Aurela M and Virtanen T (2019), "Comparing ultra-high spatial resolution remote-sensing methods in mapping peatland vegetation", Journal of Vegetation Science., jul, 2019. Vol. 30(5), pp. 1016-1026. Wiley. |
| Abstract: Questions: How to map floristic variation in a patterned fen in an ecologically meaningfully way? Can plant communities be delineated with species data generalized into plant functional types? What are the benefits and drawbacks of the two selected remote-sensing approaches in mapping vegetation patterns, namely: (a) regression models of floristically defined fuzzy plant community clusters and (b) classification of predefined habitat types that combine vegetation and land cover information?. Location: Treeless 0.4 km2 mesotrophic string–flark fen in Kaamanen, northern Finland. Methods: We delineated plant community clusters with fuzzy c-means clustering based on two different inventories of plant species and functional type distribution. We used multiple optical remote-sensing data sets, digital elevation models and vegetation height models derived from drone, aerial and satellite platforms from ultra-high to very high spatial resolution (0.05–3 m) in an object-based approach. We mapped spatial patterns for fuzzy and crisp plant community clusters using boosted regression trees, and fuzzy and crisp habitat types using supervised random forest classification. Results: Clusters delineated with species-specific data or plant functional type data produced comparable results. However, species-specific data for graminoids and mosses improved the accuracy of clustering in the case of flarks and string margins. Mapping accuracy was higher for habitat types (overall accuracy 0.72) than for fuzzy plant community clusters (R2 values between 0.27 and 0.67). Conclusions: For ecologically meaningful mapping of a patterned fen vegetation, plant functional types provide enough information. However, if the aim is to capture floristic variation in vegetation as realistically as possible, species-specific data should be used. Maps of plant community clusters and habitat types complement each other. While fuzzy plant communities appear to be floristically most accurate, crisp habitat types are easiest to interpret and apply to different landscape and biogeochemical cycle analyses and modeling. |
BibTeX:
@article{Rasanen2019,
author = {Räsänen, Aleksi and Juutinen, Sari and Tuittila, Eeva Stiina and Aurela, Mika and Virtanen, Tarmo},
editor = {Rocchini, Duccio},
title = {Comparing ultra-high spatial resolution remote-sensing methods in mapping peatland vegetation},
journal = {Journal of Vegetation Science},
publisher = {Wiley},
year = {2019},
volume = {30},
number = {5},
pages = {1016--1026},
doi = {10.1111/jvs.12769}
}
|
| Räsänen A, Juutinen S, Aurela M and Virtanen T (2019), "Predicting aboveground biomass in Arctic landscapes using very high spatial resolution satellite imagery and field sampling", International Journal of Remote Sensing., nov, 2019. Vol. 40(3), pp. 1175-1199. Informa UK Limited. |
| Abstract: Remote sensing based biomass estimates in Arctic areas are usually produced using coarse spatial resolution satellite imagery, which is incapable of capturing the fragmented nature of tundra vegetation communities. We mapped aboveground biomass using field sampling and very high spatial resolution (VHSR) satellite images (QuickBird, WorldView-2 and WorldView-3) in four different Arctic tundra or peatland sites with low vegetation located in Russia, Canada, and Finland. We compared site-specific and cross-site empirical regressions. First, we classified species into plant functional types and estimated biomass using easy, non-destructive field measurements (cover, height). Second, we used the cover/height-based biomass as the response variable and used combinations of single bands and vegetation indices in predicting total biomass. We found that plant functional type biomass could be predicted reasonably well in most cases using cover and height as the explanatory variables (adjusted R 2 0.21–0.92), and there was considerable variation in the model fit when the total biomass was predicted with satellite spectra (adjusted R 2 0.33–0.75). There were dissimilarities between cross-site and site-specific regression estimates in satellite spectra based regressions suggesting that the same regression should be used only in areas with similar kinds of vegetation. We discuss the considerable variation in biomass and plant functional type composition within and between different Arctic landscapes and how well this variation can be reproduced using VHSR satellite images. Overall, the usage of VHSR images creates new possibilities but to utilize them to full potential requires similarly more detailed in-situ data related to biomass inventories and other ecosystem change studies and modelling. |
BibTeX:
@article{Rasanen2019a,
author = {Räsänen, Aleksi and Juutinen, Sari and Aurela, Mika and Virtanen, Tarmo},
title = {Predicting aboveground biomass in Arctic landscapes using very high spatial resolution satellite imagery and field sampling},
journal = {International Journal of Remote Sensing},
publisher = {Informa UK Limited},
year = {2019},
volume = {40},
number = {3},
pages = {1175--1199},
doi = {10.1080/01431161.2018.1524176}
}
|
| Räsänen A, Aurela M, Juutinen S, Kumpula T, Lohila A, Penttilä T and Virtanen T (2019), "Detecting northern peatland vegetation patterns at ultra-high spatial resolution", Remote Sensing in Ecology and Conservation., dec, 2019. Wiley. |
| Abstract: Within northern peatlands, landscape elements such as vegetation and topography are spatially heterogenic from ultra-high (centimeter level) to coarse scale. In addition to within-site spatial heterogeneity, there is evident between-site heterogeneity, but there is a lack of studies assessing whether different combinations of remotely sensed features and mapping approaches are needed in different types of landscapes. We evaluated the value of different mapping methods and remote sensing datasets and analyzed the kinds of differences present in vegetation patterns and their mappability between three northern boreal peatland landscapes in northern Finland. We utilized field-inventoried vegetation plots together with spectral, textural, topography and vegetation height remote sensing data from 0.02- to 3-m pixel size. Remote sensing data included true-color unmanned aerial vehicle images, aerial images with four spectral bands, aerial lidar data and multiple PlanetScope satellite images. We used random forest regressions for tracking plant functional type (PFT) coverage, non-metric multidimensional scaling ordination axes and fuzzy k-medoid plant community clusters. PFT regressions had variable performance for different study sites (R2 âˆ'0.03 to 0.69). Spatial patterns of some spectrally or structurally distinctive PFTs could be predicted relatively well. The first ordination axis represented wetness gradient and was well predicted using remotely sensed data (R2 0.64 to 0.82), but the other three axes had a less straightforward explanation and lower mapping performance (R2 âˆ'0.09 to 0.53). Plant community clusters were predicted most accurately in the sites with clear string-flark topography but less accurately in the flatter site (R2 0.16–0.82). The most important remote sensing features differed between dependent variables and study sites: different topographic, spectral and textural features; and coarse-scale and fine-scale datasets were the most important in different tasks. We suggest that multiple different mapping approaches should be tested and several remote sensing datasets used when maps of vegetation are produced. |
BibTeX:
@article{Rasanen2019b,
author = {Räsänen, Aleksi and Aurela, Mika and Juutinen, Sari and Kumpula, Timo and Lohila, Annalea and Penttilä, Timo and Virtanen, Tarmo},
editor = {Horning, Ned and Zhang, Jian},
title = {Detecting northern peatland vegetation patterns at ultra-high spatial resolution},
journal = {Remote Sensing in Ecology and Conservation},
publisher = {Wiley},
year = {2019},
doi = {10.1002/rse2.140}
}
|
| Réjou-Méchain M, Barbier N, Couteron P, Ploton P, Vincent G, Herold M, Mermoz S, Saatchi S, Chave J, de Boissieu F, Féret JB, Takoudjou SM and Pélissier R (2019), "Upscaling Forest Biomass from Field to Satellite Measurements: Sources of Errors and Ways to Reduce Them", Surveys in Geophysics., may, 2019. Vol. 40(4), pp. 881-911. Springer Science and Business Media LLC. |
| Abstract: Forest biomass monitoring is at the core of the research agenda due to the critical importance of forest dynamics in the carbon cycle. However, forest biomass is never directly measured; thus, upscaling it from trees to stand or larger scales (e.g., countries, regions) relies on a series of statistical models that may propagate large errors. Here, we review the main steps usually adopted in forest aboveground biomass mapping, highlighting the major challenges and perspectives. We show that there is room for improvement along the scaling-up chain from field data collection to satellite-based large-scale mapping, which should lead to the adoption of effective practices to better control the propagation of errors. We specifically illustrate how the increasing use of emerging technologies to collect massive amounts of high-quality data may significantly improve the accuracy of forest carbon maps. Furthermore, we discuss how sources of spatially structured biases that directly propagate into remote sensing models need to be better identified and accounted for when extrapolating forest carbon estimates, e.g., through a stratification design. We finally discuss the increasing realism of 3D simulated stands, which, through radiative transfer modelling, may contribute to a better understanding of remote sensing signals and open avenues for the direct calibration of large-scale products, thereby circumventing several current difficulties. |
BibTeX:
@article{Rejou-Mechain2019,
author = {Réjou-Méchain, Maxime and Barbier, Nicolas and Couteron, Pierre and Ploton, Pierre and Vincent, Grégoire and Herold, Martin and Mermoz, Stéphane and Saatchi, Sassan and Chave, Jérôme and de Boissieu, Florian and Féret, Jean Baptiste and Takoudjou, Stéphane Momo and Pélissier, Raphaël},
title = {Upscaling Forest Biomass from Field to Satellite Measurements: Sources of Errors and Ways to Reduce Them},
journal = {Surveys in Geophysics},
publisher = {Springer Science and Business Media LLC},
year = {2019},
volume = {40},
number = {4},
pages = {881--911},
doi = {10.1007/s10712-019-09532-0}
}
|
| Ribas-Ribas M, Battaglia G, Humphreys MP and Wurl O (2019), "Impact of Nonzero Intercept Gas Transfer Velocity Parameterizations on Global and Regional Ocean–Atmosphere CO2 Fluxes", Geosciences., may, 2019. Vol. 9(5), pp. 230. MDPI AG. |
| Abstract: textlessptextgreaterCarbon dioxide (CO2) fluxes between the ocean and atmosphere (FCO2) are commonly computed from differences between their partial pressures of CO2 (ΔpCO2) and the gas transfer velocity (k). Commonly used wind-based parameterizations for k imply a zero intercept, although in situ field data below 4 m s−1 are scarce. Considering a global average wind speed over the ocean of 6.6 m s−1, a nonzero intercept might have a significant impact on global FCO2. Here, we present a database of 245 in situ measurements of k obtained with the floating chamber technique (Sniffle), 190 of which have wind speeds lower than 4 m s−1. A quadratic parameterization with wind speed and a nonzero intercept resulted in the best fit for k. We further tested FCO2 calculated with a different parameterization with a complementary pCO2 observation-based product. Furthermore, we ran a simulation in a well-tested ocean model of intermediate complexity to test the implications of different gas transfer velocity parameterizations for the natural carbon cycle. The global ocean observation-based analysis suggests that ignoring a nonzero intercept results in an ocean-sink increase of 0.73 Gt C yr−1. This corresponds to a 28% higher uptake of CO2 compared with the flux calculated from a parameterization with a nonzero intercept. The differences in FCO2 were higher in the case of low wind conditions and large ΔpCO2 between the ocean and atmosphere. Such conditions occur frequently in the Tropics.textless/ptextgreater |
BibTeX:
@article{Ribas-Ribas2019,
author = {Ribas-Ribas, Mariana and Battaglia, Gianna and Humphreys, Matthew P. and Wurl, Oliver},
title = {Impact of Nonzero Intercept Gas Transfer Velocity Parameterizations on Global and Regional Ocean–Atmosphere CO2 Fluxes},
journal = {Geosciences},
publisher = {MDPI AG},
year = {2019},
volume = {9},
number = {5},
pages = {230},
url = {https://www.mdpi.com/2076-3263/9/5/230},
doi = {10.3390/geosciences9050230}
}
|
| Riihimäki H, Luoto M and Heiskanen J (2019), "Estimating fractional cover of tundra vegetation at multiple scales using unmanned aerial systems and optical satellite data", Remote Sensing of Environment., apr, 2019. Vol. 224, pp. 119-132. |
| Abstract: Fractional cover of green vegetation (FCover) is a key variable when observing Arctic vegetation under a changing climate. Vegetation changes over large areas are traditionally monitored by linking plot-scale measurements to satellite data. However, integrating field and satellite data is not straightforward. Typically, the satellite data are at a much coarser scale in comparison to field measurements. Here, we studied how Unmanned Aerial Systems (UASs) can be used to bridge this gap. We covered three 250 m × 250 m sites in Fennoscandian tundra with varying productivity and FCover, ranging from barren vegetation to shrub tundra. The UAS sites were then used to train satellite data-based FCover models. First, we created a binary vegetation classification (absent, present) by using UAS-derived RGB-orthomosaics and logistic regression. Secondly, we used the classification to calculate FCover to Planet CubeSat (3 m), Sentinel-2A MSI (10 m, 20 m), and Landsat 8 OLI (30 m) grids, and examined how well FCover is explained by various spectral vegetation indices (VI) derived from satellite data. The overall classification accuracies for the UAS sites were ≥90%. The UAS-FCover were strongly related to the tested VIs (D 2 89% at best). The explained deviance was generally higher for coarser resolution data, indicating that the effect of data resolution should be taken into account when comparing results from different sensors. VIs based on red-edge (at 740 nm, 783 nm), or near-infrared and shortwave infrared (SWIR) had the highest performance. We recommend wider inspection of red-edge and SWIR bands for future Arctic vegetation research. Our results demonstrate that UASs can be used for observing FCover at multiple scales. Individual UAS sites can serve as focus areas, which provide information at the finest resolution (e.g. individual plants), whereas a sample of several UAS sites can be used to train satellite data and examine vegetation over larger extents. |
BibTeX:
@article{Riihimaki2019,
author = {Riihimäki, Henri and Luoto, Miska and Heiskanen, Janne},
title = {Estimating fractional cover of tundra vegetation at multiple scales using unmanned aerial systems and optical satellite data},
journal = {Remote Sensing of Environment},
year = {2019},
volume = {224},
pages = {119--132},
url = {https://linkinghub.elsevier.com/retrieve/pii/S0034425719300367},
doi = {10.1016/j.rse.2019.01.030}
}
|
| Rineau F, Malina R, Beenaerts N, Arnauts N, Bardgett RD, Berg MP, Boerema A, Bruckers L, Clerinx J, Davin EL, De Boeck HJ, De Dobbelaer T, Dondini M, De Laender F, Ellers J, Franken O, Gilbert L, Gudmundsson L, Janssens IA, Johnson D, Lizin S, Longdoz B, Meire P, Meremans D, Milbau A, Moretti M, Nijs I, Nobel A, Pop IS, Puetz T, Reyns W, Roy J, Schuetz J, Seneviratne SI, Smith P, Solmi F, Staes J, Thiery W, Thijs S, Vanderkelen I, Van Landuyt W, Verbruggen E, Witters N, Zscheischler J and Vangronsveld J (2019), "Towards more predictive and interdisciplinary climate change ecosystem experiments", Nature Climate Change., oct, 2019. Vol. 9(11), pp. 809-816. Springer Science and Business Media LLC. |
| Abstract: Despite great advances, experiments concerning the response of ecosystems to climate change still face considerable challenges, including the high complexity of climate change in terms of environmental variables, constraints in the number and amplitude of climate treatment levels, and the limited scope of responses and interactions covered. Drawing on the expertise of researchers from a variety of disciplines, this Perspective outlines how computational and technological advances can help in designing experiments that can contribute to overcoming these challenges, and also outlines a first application of such an experimental design. |
BibTeX:
@article{Rineau2019,
author = {Rineau, Francois and Malina, Robert and Beenaerts, Natalie and Arnauts, Natascha and Bardgett, Richard D and Berg, Matty P and Boerema, Annelies and Bruckers, Liesbeth and Clerinx, Jan and Davin, Edouard L and De Boeck, Hans J and De Dobbelaer, Tom and Dondini, Marta and De Laender, Frederik and Ellers, Jacintha and Franken, Oscar and Gilbert, Lucy and Gudmundsson, Lukas and Janssens, Ivan A and Johnson, David and Lizin, Sebastien and Longdoz, Bernard and Meire, Patrick and Meremans, Dominique and Milbau, Ann and Moretti, Michele and Nijs, Ivan and Nobel, Anne and Pop, Iuliu Sorin and Puetz, Thomas and Reyns, Wouter and Roy, Jacques and Schuetz, Jochen and Seneviratne, Sonia I and Smith, Pete and Solmi, Francesca and Staes, Jan and Thiery, Wim and Thijs, Sofie and Vanderkelen, Inne and Van Landuyt, Wouter and Verbruggen, Erik and Witters, Nele and Zscheischler, Jakob and Vangronsveld, Jaco},
title = {Towards more predictive and interdisciplinary climate change ecosystem experiments},
journal = {Nature Climate Change},
publisher = {Springer Science and Business Media LLC},
year = {2019},
volume = {9},
number = {11},
pages = {809--816},
doi = {10.1038/s41558-019-0609-3}
}
|
| Rosíková J, Darenova E, Kučera A, VolaÅ™ík D and Vranová V (2019), "Effect of different dolomitic limestone dosages on soil respiration in a mid-altitudinal Norway spruce stand", IForest., aug, 2019. Vol. 12(4), pp. 357-365. Italian Society of Sivilculture and Forest Ecology (SISEF). |
| Abstract: The study focuses on the effect of chemical amelioration of dolomitic limestone (doses of 0, 2, 3, 4, 6, 9 and 26 t ha-1) on soil respiration in a Norway spruce monoculture in mid-altitudinal elevation during one-year period after application. Firstly, the soil respiration was measured in situ as monthly CO2 efflux from the soil surface horizon in the period May to October 2016. Secondly, basal respiration, microbial biomass carbon and metabolic quotient of the organic H and organo-mineral A horizons were assessed under laboratory conditions within one year after the treatment. Soil CO2 efflux increased by 3 to 31% and by 29 to 98% for the ameliorant of 2 and 26 t ha-1, respectively, compared to the unlimed control treatment. The CO2 efflux was significantly driven by external conditions such as soil moisture and temperature, especially in the last seasonal months. Basal respiration of the H horizon increased up to a dose of 9 t ha-1 but decreased at 26 t ha-1. In the A horizon, microbial activity increased in all the limed variants compared to the non-limed variant. A similar trend was observed in microbial carbon and the metabolic quotient of the soil. Our results prove that the ameliorant doses commonly used in the forestry sector (3-4 t ha-1) substantially increase the soil microbial activity during (soil CO2 efflux) and after (laboratory data) the first year after application. This results in the accelerated mineralization of soil organic material and subsequent loss from the forest ecosystem. |
BibTeX:
@article{Rosikova2019,
author = {Rosíková, Jana and Darenova, Eva and Kučera, Aleš and VolaÅ™ík, Daniel and Vranová, Valerie},
title = {Effect of different dolomitic limestone dosages on soil respiration in a mid-altitudinal Norway spruce stand},
journal = {IForest},
publisher = {Italian Society of Sivilculture and Forest Ecology (SISEF)},
year = {2019},
volume = {12},
number = {4},
pages = {357--365},
doi = {10.3832/ifor2894-012}
}
|
| Šálek M and Szabó-Takács B (2019), "Comparison of SAFNWC/MSG satellite cloud type with Vaisala CL51 ceilometer-detected cloud base layer using the sky condition algorithm and Vaisala BL-View software", Atmosphere., jun, 2019. Vol. 10(6), pp. 316. MDPI AG. |
| Abstract: Ceilometer detection can be used to determine cloud type based on cloud layer height. Satellite observations provide images of clouds' physical properties. During the summer and winter of 2017, Satellite Application Facility on support to Nowcasting/Very Short-Range Forecasting Meteosat Second Generation (SAFNWC/MSG) cloud type was compared to cloud base layers based upon a sky condition algorithm of Vaisala CL51 ceilometer and the BL-View applied range-variant smoothing backscatter profile at the National Atmospheric Observatory in Košetice, Czech Republic. This study investigated whether the larger measurement range of CL51 improved high cloud base detection and the effect of the range-variant smoothing on cloud base detection. The comparison utilized a multi-category contingency table wherein hit rate, false alarm ratio, frequency of bias, and proportion correct were evaluated. The accuracy of low-level and high cloud type detection by satellite was almost identical in both seasons compared to that using the sky condition algorithm. The occurrence of satellite high cloud detection was greatest when the ceilometer detected high cloud base above low and/or medium cloud base. The hit rate of high cloud detection increased significantly when the BL-View-produced cloud base layer was applied as a reference. We conclude that BL-View produces more accurate high cloud base detection. |
BibTeX:
@article{Salek2019,
author = {Šálek, Milan and Szabó-Takács, Beáta},
title = {Comparison of SAFNWC/MSG satellite cloud type with Vaisala CL51 ceilometer-detected cloud base layer using the sky condition algorithm and Vaisala BL-View software},
journal = {Atmosphere},
publisher = {MDPI AG},
year = {2019},
volume = {10},
number = {6},
pages = {316},
doi = {10.3390/atmos10060316}
}
|
| Sastri AR, Christian JR, Achterberg EP, Atamanchuk D, Buck JJH, Bresnahan P, Duke PJ, Evans W, Gonski SF, Johnson B, Juniper SK, Mihaly S, Miller LA, Morley M, Murphy D, Nakaoka S-i, Ono T, Parker G, Simpson K and Tsunoda T (2019), "Perspectives on in situ Sensors for Ocean Acidification Research", Frontiers in Marine Science., oct, 2019. Vol. 6, pp. 653. Frontiers Media S.A.. |
| Abstract: As ocean acidification (OA) sensor technology develops and improves, in situ deployment of such sensors is becoming more widespread. However, the scientific value of these data depends on the development and application of best practices for calibration, validation, and quality assurance as well as on further development and optimization of the measurement technologies themselves. Here, we summarize the results of a 2-day workshop on OA sensor best practices held in February 2018, in Victoria, British Columbia, Canada, drawing on the collective experience and perspectives of the participants. The workshop on in situ Sensors for OA Research was organized around three basic questions: 1) What are the factors limiting the precision, accuracy and reliability of sensor data? 2) What can we do to facilitate the quality assurance/quality control (QA/QC) process and optimize the utility of these data? and 3) What sort of data or metadata are needed for these data to be most useful to future users? A synthesis of the discussion of these questions among workshop participants and conclusions drawn is presented in this paper. |
BibTeX:
@article{Sastri2019,
author = {Sastri, Akash R. and Christian, James R. and Achterberg, Eric P. and Atamanchuk, Dariia and Buck, Justin J. H. and Bresnahan, Philip and Duke, Patrick J. and Evans, Wiley and Gonski, Stephen F. and Johnson, Bruce and Juniper, S. Kim and Mihaly, Steve and Miller, Lisa A. and Morley, Mike and Murphy, Dave and Nakaoka, Shin-ichiro and Ono, Tsuneo and Parker, George and Simpson, Kyle and Tsunoda, Tomohiko},
title = {Perspectives on in situ Sensors for Ocean Acidification Research},
journal = {Frontiers in Marine Science},
publisher = {Frontiers Media S.A.},
year = {2019},
volume = {6},
pages = {653},
url = {https://www.frontiersin.org/article/10.3389/fmars.2019.00653/full},
doi = {10.3389/fmars.2019.00653}
}
|
| Schepaschenko D, Chave J, Phillips OL, Lewis SL, Davies SJ, Réjou-Méchain M, Sist P, Scipal K, Perger C, Herault B, Labrière N, Hofhansl F, Affum-Baffoe K, Aleinikov A, Alonso A, Amani C, Araujo-Murakami A, Armston J, Arroyo L, Ascarrunz N, Azevedo C, Baker T, Bałazy R, Bedeau C, Berry N, Bilous AM, Bilous SY, Bissiengou P, Blanc L, Bobkova KS, Braslavskaya T, Brienen R, Burslem DFRP, Condit R, Cuni-Sanchez A, Danilina D, Del Castillo Torres D, Derroire G, Descroix L, Sotta ED, D'Oliveira MVN, Dresel C, Erwin T, Evdokimenko MD, Falck J, Feldpausch TR, Foli EG, Foster R, Fritz S, Garcia-Abril AD, Gornov A, Gornova M, Gothard-Bassébé E, Gourlet-Fleury S, Guedes M, Hamer KC, Susanty FH, Higuchi N, Coronado EN, Hubau W, Hubbell S, Ilstedt U, Ivanov VV, Kanashiro M, Karlsson A, Karminov VN, Killeen T, Koffi JCK, Konovalova M, Kraxner F, Krejza J, Krisnawati H, Krivobokov LV, Kuznetsov MA, Lakyda I, Lakyda PI, Licona JC, Lucas RM, Lukina N, Lussetti D, Malhi Y, Manzanera JA, Marimon B, Junior BHM, Martinez RV, Martynenko OV, Matsala M, Matyashuk RK, Mazzei L, Memiaghe H, Mendoza C, Mendoza AM, Moroziuk OV, Mukhortova L, Musa S, Nazimova DI, Okuda T, Oliveira LC, Ontikov PV, Osipov AF, Pietsch S, Playfair M, Poulsen J, Radchenko VG, Rodney K, Rozak AH, Ruschel A, Rutishauser E, See L, Shchepashchenko M, Shevchenko N, Shvidenko A, Silveira M, Singh J, Sonké B, Souza C, Stereʼnczak K, Stonozhenko L, Sullivan MJP, Szatniewska J, Taedoumg H, Ter Steege H, Tikhonova E, Toledo M, Trefilova OV, Valbuena R, Gamarra LV, Vasiliev S, Vedrova EF, Verhovets SV, Vidal E, Vladimirova NA, Vleminckx J, Vos VA, Vozmitel FK, Wanek W, West TAP, Woell H, Woods JT, Wortel V, Yamada T, Nur Hajar ZS and Zo-Bi IC (2019), "The Forest Observation System, building a global reference dataset for remote sensing of forest biomass", Scientific data., oct, 2019. Vol. 6(1), pp. 198. Springer Science and Business Media LLC. |
| Abstract: Forest biomass is an essential indicator for monitoring the Earth's ecosystems and climate. It is a critical input to greenhouse gas accounting, estimation of carbon losses and forest degradation, assessment of renewable energy potential, and for developing climate change mitigation policies such as REDD+, among others. Wall-to-wall mapping of aboveground biomass (AGB) is now possible with satellite remote sensing (RS). However, RS methods require extant, up-to-date, reliable, representative and comparable in situ data for calibration and validation. Here, we present the Forest Observation System (FOS) initiative, an international cooperation to establish and maintain a global in situ forest biomass database. AGB and canopy height estimates with their associated uncertainties are derived at a 0.25 ha scale from field measurements made in permanent research plots across the world's forests. All plot estimates are geolocated and have a size that allows for direct comparison with many RS measurements. The FOS offers the potential to improve the accuracy of RS-based biomass products while developing new synergies between the RS and ground-based ecosystem research communities. |
BibTeX:
@article{Schepaschenko2019,
author = {Schepaschenko, Dmitry and Chave, Jérôme and Phillips, Oliver L and Lewis, Simon L and Davies, Stuart J and Réjou-Méchain, Maxime and Sist, Plinio and Scipal, Klaus and Perger, Christoph and Herault, Bruno and Labrière, Nicolas and Hofhansl, Florian and Affum-Baffoe, Kofi and Aleinikov, Alexei and Alonso, Alfonso and Amani, Christian and Araujo-Murakami, Alejandro and Armston, John and Arroyo, Luzmila and Ascarrunz, Nataly and Azevedo, Celso and Baker, Timothy and Bałazy, Radomir and Bedeau, Caroline and Berry, Nicholas and Bilous, Andrii M and Bilous, Svitlana Yu and Bissiengou, Pulchérie and Blanc, Lilian and Bobkova, Kapitolina S and Braslavskaya, Tatyana and Brienen, Roel and Burslem, David F R P and Condit, Richard and Cuni-Sanchez, Aida and Danilina, Dilshad and Del Castillo Torres, Dennis and Derroire, Géraldine and Descroix, Laurent and Sotta, Eleneide Doff and D'Oliveira, Marcus V N and Dresel, Christopher and Erwin, Terry and Evdokimenko, Mikhail D and Falck, Jan and Feldpausch, Ted R and Foli, Ernest G and Foster, Robin and Fritz, Steffen and Garcia-Abril, Antonio Damian and Gornov, Aleksey and Gornova, Maria and Gothard-Bassébé, Ernest and Gourlet-Fleury, Sylvie and Guedes, Marcelino and Hamer, Keith C and Susanty, Farida Herry and Higuchi, Niro and Coronado, Eurídice N.Honorio and Hubau, Wannes and Hubbell, Stephen and Ilstedt, Ulrik and Ivanov, Viktor V and Kanashiro, Milton and Karlsson, Anders and Karminov, Viktor N and Killeen, Timothy and Koffi, Jean Claude Konan and Konovalova, Maria and Kraxner, Florian and Krejza, Jan and Krisnawati, Haruni and Krivobokov, Leonid V and Kuznetsov, Mikhail A and Lakyda, Ivan and Lakyda, Petro I and Licona, Juan Carlos and Lucas, Richard M and Lukina, Natalia and Lussetti, Daniel and Malhi, Yadvinder and Manzanera, José Antonio and Marimon, Beatriz and Junior, Ben Hur Marimon and Martinez, Rodolfo Vasquez and Martynenko, Olga V and Matsala, Maksym and Matyashuk, Raisa K and Mazzei, Lucas and Memiaghe, Hervé and Mendoza, Casimiro and Mendoza, Abel Monteagudo and Moroziuk, Olga V and Mukhortova, Liudmila and Musa, Samsudin and Nazimova, Dina I and Okuda, Toshinori and Oliveira, Luis Claudio and Ontikov, Petr V and Osipov, Andrey F and Pietsch, Stephan and Playfair, Maureen and Poulsen, John and Radchenko, Vladimir G and Rodney, Kenneth and Rozak, Andes H and Ruschel, Ademir and Rutishauser, Ervan and See, Linda and Shchepashchenko, Maria and Shevchenko, Nikolay and Shvidenko, Anatoly and Silveira, Marcos and Singh, James and Sonké, Bonaventure and Souza, Cintia and Stereʼnczak, Krzysztof and Stonozhenko, Leonid and Sullivan, Martin J P and Szatniewska, Justyna and Taedoumg, Hermann and Ter Steege, Hans and Tikhonova, Elena and Toledo, Marisol and Trefilova, Olga V and Valbuena, Ruben and Gamarra, Luis Valenzuela and Vasiliev, Sergey and Vedrova, Estella F and Verhovets, Sergey V and Vidal, Edson and Vladimirova, Nadezhda A and Vleminckx, Jason and Vos, Vincent A and Vozmitel, Foma K and Wanek, Wolfgang and West, Thales A P and Woell, Hannsjorg and Woods, John T and Wortel, Verginia and Yamada, Toshihiro and Nur Hajar, Zamah Shari and Zo-Bi, Irié Casimir},
title = {The Forest Observation System, building a global reference dataset for remote sensing of forest biomass},
journal = {Scientific data},
publisher = {Springer Science and Business Media LLC},
year = {2019},
volume = {6},
number = {1},
pages = {198},
doi = {10.1038/s41597-019-0196-1}
}
|
| Scholze M, Kaminski T, Knorr W, Voßbeck M, Wu M, Ferrazzoli P, Kerr Y, Mialon A, Richaume P, Rodríguez-Fernández N, Vittucci C, Wigneron J, Mecklenburg S and Drusch M (2019), "Mean European Carbon Sink Over 2010–2015 Estimated by Simultaneous Assimilation of Atmospheric CO 2 , Soil Moisture, and Vegetation Optical Depth", Geophysical Research Letters., dec, 2019. Vol. 46(23), pp. 13796-13803. |
BibTeX:
@article{Scholze2019,
author = {Scholze, M. and Kaminski, T. and Knorr, W. and Voßbeck, M. and Wu, M. and Ferrazzoli, P. and Kerr, Y. and Mialon, A. and Richaume, P. and Rodríguez-Fernández, N. and Vittucci, C. and Wigneron, J.‐P. and Mecklenburg, S. and Drusch, M.},
title = {Mean European Carbon Sink Over 2010–2015 Estimated by Simultaneous Assimilation of Atmospheric CO 2 , Soil Moisture, and Vegetation Optical Depth},
journal = {Geophysical Research Letters},
year = {2019},
volume = {46},
number = {23},
pages = {13796--13803},
url = {https://onlinelibrary.wiley.com/doi/abs/10.1029/2019GL085725},
doi = {10.1029/2019GL085725}
}
|
| Silva BJ, Gaspar FL, Tyaquiçã P, Lefèvre N and Flores Montes MJ (2019), "Carbon chemistry variability around a tropical archipelago", Marine and Freshwater Research. Vol. 70(6), pp. 767-780. CSIRO Publishing. |
| Abstract: Oceanic islands affect the surrounding oceanic circulation by producing upwelling or vortices, resulting in the rising of a richer and colder subsurface water mass. This process increases primary production and can change some biogeochemical processes, such as carbon chemistry and the biological pump. The aim of this study was to describe the vertical variability of carbon chemistry around Fernando de Noronha Archipelago (FNA) and to verify how the island mass effect (IME) can affect carbon distribution. Two transects on opposite sides of the FNA were established according to the direction of the central South Equatorial Current, and samples were collected in July 2010, September 2012 and July 2014 from the surface down to a depth of 500 m. The results showed strong stratification, with an uplift of the thermohaline structure, which resulted in an increase of chlorophyll- A concentration downstream of the island during the 2010 and 2014 cruises. Carbon chemistry parameters were strongly correlated with temperature, salinity and dissolved oxygen along the water column and did not change between sides of the island in the periods studied. We conclude that the IME did not significantly affect carbon chemistry, which was more correlated with thermohaline gradient. |
BibTeX:
@article{Silva2019,
author = {Silva, Brenno J and Gaspar, Felipe L and Tyaquiçã, Pedro and Lefèvre, Nathalie and Flores Montes, Manuel J},
title = {Carbon chemistry variability around a tropical archipelago},
journal = {Marine and Freshwater Research},
publisher = {CSIRO Publishing},
year = {2019},
volume = {70},
number = {6},
pages = {767--780},
doi = {10.1071/MF18011}
}
|
| Smith SR, Alory G, Andersson A, Asher W, Baker A, Berry DI, Drushka K, Figurskey D, Freeman E, Holthus P, Jickells T, Kleta H, Kent EC, Kolodziejczyk N, Kramp M, Loh Z, Poli P, Schuster U, Steventon E, Swart S, Tarasova O, De La Villéon LP and Shiffer NV (2019), "Ship-based contributions to global ocean, weather, and climate observing systems". aug, 2019. |
| Abstract: The role ships play in atmospheric, oceanic, and biogeochemical observations is described with a focus on measurements made within 100 m of the ocean surface. Ships include merchant and research vessels, cruise liners and ferries, fishing vessels, coast guard, military, and other government-operated ships, yachts, and a growing fleet of automated surface vessels. The present capabilities of ships to measure essential climate/ocean variables and the requirements from a broad community to address operational, commercial, and scientific needs are described. Following the guidance from the OceanObs'19 organizing committee, the authors provide a vision to expand observations needed from ships to understand and forecast the exchanges across the ocean-atmosphere interface. The vision addresses (1) recruiting vessels to improve both spatial and temporal sampling, (2) conducting multi-variate sampling on ships, (3) raising technology readiness levels of automated shipboard sensors and ship-to-shore data communications, (4) advancing quality evaluation of observations, and (5) developing a unified data management approach for observations and metadata that meets the needs of a diverse user community. Recommendations are made focusing on integrating private and autonomous vessels into the observing system, investing in sensor and communications technology development, developing an integrated data management structure that includes all types of ships, and moving towards a quality evaluation process that will result in a subset of ships being defined as mobile reference ships that will support climate studies. We envision a future where commercial, research, and privately-owned vessels are making multivariate observations using a combination of automated and human-observed measurements. All data and metadata will be documented, tracked, evaluated, distributed, and archived to benefit users of marine data. This vision looks at ships as a holistic network, not a set of disparate commercial, research, and/or third-party activities working in isolation, to bring these communities together for the mutual benefit of all. |
BibTeX:
@misc{Smith2019,
author = {Smith, Shawn R. and Alory, Gael and Andersson, Axel and Asher, Wiliam and Baker, Alex and Berry, David I. and Drushka, Kyla and Figurskey, Darin and Freeman, Eric and Holthus, Paul and Jickells, Tim and Kleta, Henry and Kent, Elizabeth C. and Kolodziejczyk, Nicolas and Kramp, Martin and Loh, Zoe and Poli, Paul and Schuster, Ute and Steventon, Emma and Swart, Sebastiaan and Tarasova, Oksana and De La Villéon, Loic Petit and Shiffer, Nadya Vinogradova},
title = {Ship-based contributions to global ocean, weather, and climate observing systems},
booktitle = {Frontiers in Marine Science},
publisher = {Frontiers Media S.A.},
year = {2019},
volume = {6},
number = {JUL},
pages = {434},
url = {www.frontiersin.org},
doi = {10.3389/fmars.2019.00434}
}
|
| Sofie Lansø A, Luke Smallman T, Heile Christensen J, Williams M, Pilegaard K, Sorensen LL and Geels C (2019), "Simulating the atmospheric CO2 concentration across the heterogeneous landscape of Denmark using a coupled atmosphere-biosphere mesoscale model system", Biogeosciences., apr, 2019. Vol. 16(7), pp. 1505-1524. Copernicus GmbH. |
| Abstract: Although coastal regions only amount to 7% of the global oceans, their contribution to the global oceanic air-sea CO2 exchange is proportionally larger, with fluxes in some estuaries being similar in magnitude to terrestrial surface fluxes of CO2. Across a heterogeneous surface consisting of a coastal marginal sea with estuarine properties and varied land mosaics, the surface fluxes of CO2 from both marine areas and terrestrial surfaces were investigated in this study together with their impact in atmospheric CO2 concentrations by the usage of a high-resolution modelling framework. The simulated terrestrial fluxes across the study region of Denmark experienced an east-west gradient corresponding to the distribution of the land cover classification, their biological activity and the urbanised areas. Annually, the Danish terrestrial surface had an uptake of approximately 7000 GgC yr1. While the marine fluxes from the North Sea and the Danish inner waters were smaller annually, with about 1800 and 1300 GgC yr1, their sizes are comparable to annual terrestrial fluxes from individual land cover classifications in the study region and hence are not negligible. The contribution of terrestrial surfaces fluxes was easily detectable in both simulated and measured concentrations of atmospheric CO2 at the only tall tower site in the study region. Although, the tower is positioned next to Roskilde Fjord, the local marine impact was not distinguishable in the simulated concentrations. But the regional impact from the Danish inner waters and the Baltic Sea increased the atmospheric concentration by up to 0.5 ppm during the winter months. |
BibTeX:
@article{SofieLansø2019,
author = {Sofie Lansø, Anne and Luke Smallman, Thomas and Heile Christensen, Jesper and Williams, Mathew and Pilegaard, Kim and Sorensen, Lise Lotte and Geels, Camilla},
title = {Simulating the atmospheric CO2 concentration across the heterogeneous landscape of Denmark using a coupled atmosphere-biosphere mesoscale model system},
journal = {Biogeosciences},
publisher = {Copernicus GmbH},
year = {2019},
volume = {16},
number = {7},
pages = {1505--1524},
doi = {10.5194/bg-16-1505-2019}
}
|
| Song J, Wan S, Piao S, Hui D, Hovenden MJ, Ciais P, Liu Y, Liu Y, Zhong M, Zheng M, Ma G, Zhou Z and Ru J (2019), "Elevated CO 2 does not stimulate carbon sink in a semi-arid grassland", Ecology Letters., jan, 2019. Vol. 22(3), pp. 458-468. Wiley. |
| Abstract: Elevated CO 2 is widely accepted to enhance terrestrial carbon sink, especially in arid and semi-arid regions. However, great uncertainties exist for the CO 2 fertilisation effects, particularly when its interactions with other global change factors are considered. A four-factor (CO 2 , temperature, precipitation and nitrogen) experiment revealed that elevated CO 2 did not affect either gross ecosystem productivity or ecosystem respiration, and consequently resulted in no changes of net ecosystem productivity in a semi-arid grassland despite whether temperature, precipitation and nitrogen were elevated or not. The observations could be primarily attributable to the offset of ecosystem carbon uptake by enhanced soil carbon release under CO 2 enrichment. Our findings indicate that arid and semi-arid ecosystems may not be sensitive to CO 2 enrichment as previously expected and highlight the urgent need to incorporate this mechanism into most IPCC carbon-cycle models for convincing projection of terrestrial carbon sink and its feedback to climate change. |
BibTeX:
@article{Song2019,
author = {Song, Jian and Wan, Shiqiang and Piao, Shilong and Hui, Dafeng and Hovenden, Mark J and Ciais, Philippe and Liu, Yongwen and Liu, Yinzhan and Zhong, Mingxing and Zheng, Mengmei and Ma, Gaigai and Zhou, Zhenxing and Ru, Jingyi},
editor = {Knops, Johannes},
title = {Elevated CO 2 does not stimulate carbon sink in a semi-arid grassland},
journal = {Ecology Letters},
publisher = {Wiley},
year = {2019},
volume = {22},
number = {3},
pages = {458--468},
doi = {10.1111/ele.13202}
}
|
| Soussana JF, Lutfalla S, Ehrhardt F, Rosenstock T, Lamanna C, Havlík P, Richards M, Wollenberg E(L, Chotte JL, Torquebiau E, Ciais P, Smith P and Lal R (2019), "Matching policy and science: Rationale for the ‘4 per 1000 - soils for food security and climate' initiative", Soil and Tillage Research., may, 2019. Vol. 188, pp. 3-15. Elsevier BV. |
| Abstract: At the 21st session of the United Nations Framework Convention on Climate Change (UNFCCC, COP21), a voluntary action plan, the ‘4 per 1000 Initiative: Soils for Food Security and Climate' was proposed under the Agenda for Action. The Initiative underlines the role of soil organic matter (SOM) in addressing the three-fold challenge of food and nutritional security, adaptation to climate change and mitigation of human-induced greenhouse gases (GHGs) emissions. It sets an ambitious aspirational target of a 4 per 1000 (i.e. 0.4%) rate of annual increase in global soil organic carbon (SOC) stocks, with a focus on agricultural lands where farmers would ensure the carbon stewardship of soils, like they manage day-to-day multipurpose production systems in a changing environment. In this paper, the opportunities and challenges for the 4 per 1000 initiative are discussed. We show that the 4 per 1000 target, calculated relative to global top soil SOC stocks, is consistent with literature estimates of the technical potential for SOC sequestration, though the achievable potential is likely to be substantially lower given socio-economic constraints. We calculate that land-based negative emissions from additional SOC sequestration could significantly contribute to reducing the anthropogenic CO 2 equivalent emission gap identified from Nationally Determined Contributions pledged by countries to stabilize global warming levels below 2 °C or even 1.5 °C under the Paris agreement on climate. The 4 per 1000 target could be implemented by taking into account differentiated SOC stock baselines, reversing the current trend of huge soil CO 2 losses, e.g. from agriculture encroaching peatland soils. We further discuss the potential benefits of SOC stewardship for both degraded and healthy soils along contrasting spatial scales (field, farm, landscape and country) and temporal (year to century) horizons. Last, we present some of the implications relative to non-CO 2 GHGs emissions, water and nutrients use as well as co-benefits for crop yields and climate change adaptation. We underline the considerable challenges associated with the non-permanence of SOC stocks and show how the rates of adoption and the duration of improved soil management practices could alter the global impacts of practices under the 4 per 1000 initiative. We conclude that the 4 per 1000 initiative has potential to support multiple sustainable development goals (SDGs) of the 2030 Agenda. It can be regarded as no-regret since increasing SOC in agricultural soils will contribute to food security benefits that will enhance resilience to climate change. However, social, economic and environmental safeguards will be needed to ensure an equitable and sustainable implementation of the 4 per 1000 target. |
BibTeX:
@article{Soussana2019,
author = {Soussana, Jean François and Lutfalla, Suzanne and Ehrhardt, Fiona and Rosenstock, Todd and Lamanna, Christine and Havlík, Petr and Richards, Meryl and Wollenberg, Eva (Lini) and Chotte, Jean Luc and Torquebiau, Emmanuel and Ciais, Philippe and Smith, Pete and Lal, Rattan},
title = {Matching policy and science: Rationale for the ‘4 per 1000 - soils for food security and climate' initiative},
journal = {Soil and Tillage Research},
publisher = {Elsevier BV},
year = {2019},
volume = {188},
pages = {3--15},
doi = {10.1016/j.still.2017.12.002}
}
|
| Spielmann FM, Wohlfahrt G, Hammerle A, Kitz F, Migliavacca M, Alberti G, Ibrom A, El-Madany TS, Gerdel K, Moreno G, Kolle O, Karl T, Peressotti A and Delle Vedove G (2019), "Gross Primary Productivity of Four European Ecosystems Constrained by Joint CO2 and COS Flux Measurements", Geophysical Research Letters., may, 2019. Vol. 46(10), pp. 5284-5293. American Geophysical Union (AGU). |
| Abstract: Gross primary productivity (GPP), the gross uptake of carbon dioxide (CO2) by plant photosynthesis, is the primary driver of the land carbon sink, which presently removes around one quarter of the anthropogenic CO2 emissions each year. GPP, however, cannot be measured directly and the resulting uncertainty undermines our ability to project the magnitude of the future land carbon sink. Carbonyl sulfide (COS) has been proposed as an independent proxy for GPP as it diffuses into leaves in a fashion very similar to CO2, but in contrast to the latter is generally not emitted. Here we use concurrent ecosystem-scale flux measurements of CO2 and COS at four European biomes for a joint constraint on CO2 flux partitioning. The resulting GPP estimates generally agree with classical approaches relying exclusively on CO2 fluxes but indicate a systematic underestimation under low light conditions, demonstrating the importance of using multiple approaches for constraining present-day GPP. |
BibTeX:
@article{Spielmann2019,
author = {Spielmann, F M and Wohlfahrt, G and Hammerle, A and Kitz, F and Migliavacca, M and Alberti, G and Ibrom, A and El-Madany, T S and Gerdel, K and Moreno, G and Kolle, O and Karl, T and Peressotti, A and Delle Vedove, G},
title = {Gross Primary Productivity of Four European Ecosystems Constrained by Joint CO2 and COS Flux Measurements},
journal = {Geophysical Research Letters},
publisher = {American Geophysical Union (AGU)},
year = {2019},
volume = {46},
number = {10},
pages = {5284--5293},
doi = {10.1029/2019GL082006}
}
|
| Steinhoff T, Gkritzalis T, Lauvset SK, Jones S, Schuster U, Olsen A, Becker M, Bozzano R, Brunetti F, Cantoni C, Cardin V, Diverrès D, Fiedler B, Fransson A, Giani M, Hartman S, Hoppema M, Jeansson E, Johannessen T, Kitidis V, Körtzinger A, Landa C, Lefèvre N, Luchetta A, Naudts L, Nightingale PD, Omar AM, Pensieri S, Pfeil B, Castaño-Primo R, Rehder G, Rutgersson A, Sanders R, Schewe I, Siena G, Skjelvan I, Soltwedel T, van Heuven S and Watson A (2019), "Constraining the Oceanic Uptake and Fluxes of Greenhouse Gases by Building an Ocean Network of Certified Stations: The Ocean Component of the Integrated Carbon Observation System, ICOS-Oceans", Frontiers in Marine Science., sep, 2019. Vol. 6 |
| Abstract: The European Research Infrastructure Consortium “Integrated Carbon Observation System†(ICOS) aims at delivering high quality greenhouse gas (GHG) observations and derived data products (e.g., regional GHG-flux maps) for constraining the GHG balance on a European level, on a sustained long-term basis. The marine domain (ICOS-Oceans) currently consists of 11 Ship of Opportunity lines (SOOP – Ship of Opportunity Program) and 10 Fixed Ocean Stations (FOSs) spread across European waters, including the North Atlantic and Arctic Oceans and the Barents, North, Baltic, and Mediterranean Seas. The stations operate in a harmonized and standardized way based on community-proven protocols and methods for ocean GHG observations, improving operational conformity as well as quality control and assurance of the data. This enables the network to focus on long term research into the marine carbon cycle and the anthropogenic carbon sink, while preparing the network to include other GHG fluxes. ICOS data are processed on a near real-time basis and will be published on the ICOS Carbon Portal (CP), allowing monthly estimates of CO2 air-sea exchange to be quantified for European waters. ICOS establishes transparent operational data management routines following the FAIR (Findable, Accessible, Interoperable, and Reusable) guiding principles allowing amongst others reproducibility, interoperability, and traceability. The ICOS-Oceans network is actively integrating with the atmospheric (e.g., improved atmospheric measurements onboard SOOP lines) and ecosystem (e.g., oceanic direct gas flux measurements) domains of ICOS, and utilizes techniques developed by the ICOS Central Facilities and the CP. There is a strong interaction with the international ocean carbon cycle community to enhance interoperability and harmonize data flow. The future vision of ICOS-Oceans includes ship-based ocean survey sections to obtain a three-dimensional understanding of marine carbon cycle processes and optimize the existing network design. |
BibTeX:
@article{Steinhoff2019,
author = {Steinhoff, Tobias and Gkritzalis, Thanos and Lauvset, Siv K and Jones, Steve and Schuster, Ute and Olsen, Are and Becker, Meike and Bozzano, Roberto and Brunetti, Fabio and Cantoni, Carolina and Cardin, Vanessa and Diverrès, Denis and Fiedler, Björn and Fransson, Agneta and Giani, Michele and Hartman, Sue and Hoppema, Mario and Jeansson, Emil and Johannessen, Truls and Kitidis, Vassilis and Körtzinger, Arne and Landa, Camilla and Lefèvre, Nathalie and Luchetta, Anna and Naudts, Lieven and Nightingale, Philip D and Omar, Abdirahman M and Pensieri, Sara and Pfeil, Benjamin and Castaño-Primo, Rocío and Rehder, Gregor and Rutgersson, Anna and Sanders, Richard and Schewe, Ingo and Siena, Giuseppe and Skjelvan, Ingunn and Soltwedel, Thomas and van Heuven, Steven and Watson, Andrew},
title = {Constraining the Oceanic Uptake and Fluxes of Greenhouse Gases by Building an Ocean Network of Certified Stations: The Ocean Component of the Integrated Carbon Observation System, ICOS-Oceans},
journal = {Frontiers in Marine Science},
year = {2019},
volume = {6},
url = {https://www.frontiersin.org/article/10.3389/fmars.2019.00544/full},
doi = {10.3389/fmars.2019.00544}
}
|
| Stella P, Loubet B, de Berranger C, Charrier X, Ceschia E, Gerosa G, Finco A, Lamaud E, Serça D, George C and Ciuraru R (2019), "Soil ozone deposition: Dependence of soil resistance to soil texture", Atmospheric Environment., feb, 2019. Vol. 199, pp. 202-209. Elsevier BV. |
| Abstract: Soil deposition is an essential pathway for tropospheric ozone (O3) removal, but its controlling factors remain unclear. Here, we explored the variability of soil O3 resistance in response to soil texture. To this aim, data of O3 deposition over bare soil obtained from micrometeorological measurements under contrasted meteorological conditions for five sites were used. The results obtained are twofold: (i) soil resistance (Rsoil) increased with soil surface relative humidity (RHsurf), but (ii) this relationship exhibited large site-by-site variability. Further analysis showed that the minimum soil resistance (corresponding to completely dry soil surface or RHsurf = 0%) and the increase of Rsoil with RHsurf are both linked to soil clay content. These results can be explained by (i) the soil surface available for O3 deposition at a microscopic scale which is a function of the soil specific surface area, and (ii) the capacity of a soil to adsorb water according to its clay content and therefore to reduce the surface active for O3 deposition. From these results, a new parameterization has been established to estimate Rsoil as a function of RHsurf and soil clay fraction. |
BibTeX:
@article{Stella2019,
author = {Stella, P and Loubet, B and de Berranger, C and Charrier, X and Ceschia, E and Gerosa, G and Finco, A and Lamaud, E and Serça, D and George, C and Ciuraru, R},
title = {Soil ozone deposition: Dependence of soil resistance to soil texture},
journal = {Atmospheric Environment},
publisher = {Elsevier BV},
year = {2019},
volume = {199},
pages = {202--209},
doi = {10.1016/j.atmosenv.2018.11.036}
}
|
| Stocker BD, Zscheischler J, Keenan TF, Prentice IC, Seneviratne SI and Peñuelas J (2019), "Drought impacts on terrestrial primary production underestimated by satellite monitoring", Nature Geoscience., apr, 2019. Vol. 12(4), pp. 264-270. Nature Research. |
| Abstract: Satellite retrievals of information about the Earth's surface are widely used to monitor global terrestrial photosynthesis and primary production and to examine the ecological impacts of droughts. Methods for estimating photosynthesis from space commonly combine information on vegetation greenness, incoming radiation, temperature and atmospheric demand for water (vapour-pressure deficit), but do not account for the direct effects of low soil moisture. They instead rely on vapour-pressure deficit as a proxy for dryness, despite widespread evidence that soil moisture deficits have a direct impact on vegetation, independent of vapour-pressure deficit. Here, we use a globally distributed measurement network to assess the effect of soil moisture on photosynthesis, and identify a common bias in an ensemble of satellite-based estimates of photosynthesis that is governed by the magnitude of soil moisture effects on photosynthetic light-use efficiency. We develop methods to account for the influence of soil moisture and estimate that soil moisture effects reduce global annual photosynthesis by ˜15%, increase interannual variability by more than 100% across 25% of the global vegetated land surface, and amplify the impacts of extreme events on primary production. These results demonstrate the importance of soil moisture effects for monitoring carbon-cycle variability and drought impacts on vegetation productivity from space. |
BibTeX:
@article{Stocker2019,
author = {Stocker, Benjamin D. and Zscheischler, Jakob and Keenan, Trevor F. and Prentice, I. Colin and Seneviratne, Sonia I. and Peñuelas, Josep},
title = {Drought impacts on terrestrial primary production underestimated by satellite monitoring},
journal = {Nature Geoscience},
publisher = {Nature Research},
year = {2019},
volume = {12},
number = {4},
pages = {264--270},
doi = {10.1038/s41561-019-0318-6}
}
|
| Stoy PC, El-Madany TS, Fisher JB, Gentine P, Gerken T, Good SP, Klosterhalfen A, Liu S, Miralles DG, Perez-Priego O, Rigden AJ, Skaggs TH, Wohlfahrt G, Anderson RG, Coenders-Gerrits AMJ, Jung M, Maes WH, Mammarella I, Mauder M, Migliavacca M, Nelson JA, Poyatos R, Reichstein M, Scott RL and Wolf S (2019), "Reviews and syntheses: Turning the challenges of partitioning ecosystem evaporation and transpiration into opportunities", Biogeosciences., oct, 2019. Vol. 16(19), pp. 3747-3775. Copernicus GmbH. |
| Abstract: Evaporation (E) and transpiration (T) respond differently to ongoing changes in climate, atmospheric composition, and land use. It is difficult to partition ecosystem-scale evapotranspiration (ET) measurements into E and T, which makes it difficult to validate satellite data and land surface models. Here, we review current progress in partitioning E and T and provide a prospectus for how to improve theory and observations going forward. Recent advancements in analytical techniques create new opportunities for partitioning E and T at the ecosystem scale, but their assumptions have yet to be fully tested. For example, many approaches to partition E and T rely on the notion that plant canopy conductance and ecosystem water use efficiency exhibit optimal responses to atmospheric vapor pressure deficit (D). We use observations from 240 eddy covariance flux towers to demonstrate that optimal ecosystem response to D is a reasonable assumption, in agreement with recent studies, but more analysis is necessary to determine the conditions for which this assumption holds. Another critical assumption for many partitioning approaches is that ET can be approximated as T during ideal transpiring conditions, which has been challenged by observational studies. We demonstrate that T can exceed 95 % of ET from certain ecosystems, but other ecosystems do not appear to reach this value, which suggests that this assumption is ecosystem-dependent with implications for partitioning. It is important to further improve approaches for partitioning E and T, yet few multi-method comparisons have been undertaken to date. Advances in our understanding of carbon-water coupling at the stomatal, leaf, and canopy level open new perspectives on how to quantify T via its strong coupling with photosynthesis. Photosynthesis can be constrained at the ecosystem and global scales with emerging data sources including solar-induced fluorescence, carbonyl sulfide flux measurements, thermography, and more. Such comparisons would improve our mechanistic understanding of ecosystem water fluxes and provide the observations necessary to validate remote sensing algorithms and land surface models to understand the changing global water cycle. |
BibTeX:
@article{Stoy2019,
author = {Stoy, Paul C and El-Madany, Tarek S and Fisher, Joshua B and Gentine, Pierre and Gerken, Tobias and Good, Stephen P and Klosterhalfen, Anne and Liu, Shuguang and Miralles, Diego G and Perez-Priego, Oscar and Rigden, Angela J and Skaggs, Todd H and Wohlfahrt, Georg and Anderson, Ray G and Coenders-Gerrits, A Miriam J and Jung, Martin and Maes, Wouter H and Mammarella, Ivan and Mauder, Matthias and Migliavacca, Mirco and Nelson, Jacob A and Poyatos, Rafael and Reichstein, Markus and Scott, Russell L and Wolf, Sebastian},
title = {Reviews and syntheses: Turning the challenges of partitioning ecosystem evaporation and transpiration into opportunities},
journal = {Biogeosciences},
publisher = {Copernicus GmbH},
year = {2019},
volume = {16},
number = {19},
pages = {3747--3775},
doi = {10.5194/bg-16-3747-2019}
}
|
| Su Y, Liu L, Wu J, Chen X, Shang J, Ciais P, Zhou G, Lafortezza R, Wang Y, Yuan W, Wang Y, Zhang H, Huang G and Huang N (2019), "Quantifying the biophysical effects of forests on local air temperature using a novel three-layered land surface energy balance model", Environment International., nov, 2019. Vol. 132, pp. 105080. Elsevier BV. |
| Abstract: The well-documented energy balance dynamics within forest ecosystems are poorly implemented in studies of the biophysical effects of forests. This results in limitations to the accurate quantification of forest cooling/warming on local air temperature. Taking into consideration the forest air space, this study proposes a three-layered (canopy, forest air space and soil [CAS]) land surface energy balance model to simulate air temperature within forest spaces (Taf) and subsequently to evaluate its biophysical effects on forest cooling/warming, i.e., the air temperature gradient (∆Ta) between the Taf and air temperature of open spaces (Tao) (∆Ta = Taf âˆ' Tao). We test the model using field data for 23 sites across 10 cities worldwide; the model shows satisfactory performance with the test data. High-latitude forests show greater seasonal dynamics of ∆Ta, generating considerable cooling of local air temperatures in warm seasons but minimal cooling or even warming effects during cool seasons, while low-latitude tropical forests always exert cooling effects with less interannual variability. The interannual dynamics of ∆Ta are significantly related to the seasonality of solar geometry and canopy leaf phenology. The differences between forest canopy temperature (Tc) and Tao, which are the two most important terms attributed by the CAS model in impacting Taf, explain a large part of forest cooling and warming (May–July: R2 = 0.35; November–January: R2 = 0.51). The novel CAS model provides a feasible way to represent the energy balance within forest ecosystems and to assess its impacts on local air temperatures globally. |
BibTeX:
@article{Su2019,
author = {Su, Yongxian and Liu, Liyang and Wu, Jianping and Chen, Xiuzhi and Shang, Jiali and Ciais, Philippe and Zhou, Guoyi and Lafortezza, Raffaele and Wang, Yingping and Yuan, Wenping and Wang, Yilong and Zhang, Hongou and Huang, Guangqing and Huang, Ningsheng},
title = {Quantifying the biophysical effects of forests on local air temperature using a novel three-layered land surface energy balance model},
journal = {Environment International},
publisher = {Elsevier BV},
year = {2019},
volume = {132},
pages = {105080},
doi = {10.1016/j.envint.2019.105080}
}
|
| Super I, Denier van der Gon HA, Dellaert SN and Peters W (2019), "Optimizing a dynamic fossil fuel CO2 emission model with CTDAS (v1.0) for an urban area using atmospheric observations of CO2, CO, NOx, and SO2", Geoscientific Model Development Discussions., nov, 2019. , pp. 1-38. Copernicus GmbH. |
BibTeX:
@article{Super2019,
author = {Super, Ingrid and Denier van der Gon, Hugo A and Dellaert, Stijn N and Peters, Wouter},
title = {Optimizing a dynamic fossil fuel CO2 emission model with CTDAS (v1.0) for an urban area using atmospheric observations of CO2, CO, NOx, and SO2},
journal = {Geoscientific Model Development Discussions},
publisher = {Copernicus GmbH},
year = {2019},
pages = {1--38},
doi = {10.5194/gmd-2019-283}
}
|
| Svensson N, Arnqvist J, Bergström H, Rutgersson A and Sahlée E (2019), "Measurements and modelling of offshorewind profiles in a Semi-Enclosed Sea", Atmosphere. Vol. 10(4) MDPI AG. |
| Abstract: A conically scanning, continuous-wave LIDAR is placed on an island in the central Baltic Sea with large open-water fetch, providing wind and turbulence profiles up to 300 m height. LIDAR and Weather Research and Forecasting (WRF) profiles from one year are used to characterize the marine boundary layer, at the same time performing an evaluation of the WRF model against LIDAR measurements with a focus on low-level jet representation. A good agreement is found between the average wind speed profile in WRF and LIDAR, with the largest bias occurring during stable conditions. The LLJ frequency is highest in May with frequency of occurrence ranging between 18% and 27% depending on the method of detection. Most of the LLJs occur during nighttime, indicating that most of them do not have local origin. For cases with simultaneous LLJs in both data sets the WRF agrees well with the LIDAR. In many cases, however, the LLJ is misplaced in time or space in the WRF simulations compared to the LIDAR. This shows that models still must be improved to capture mesoscale effects in the coastal zone. |
BibTeX:
@article{Svensson2019,
author = {Svensson, Nina and Arnqvist, Johan and Bergström, Hans and Rutgersson, Anna and Sahlée, Erik},
title = {Measurements and modelling of offshorewind profiles in a Semi-Enclosed Sea},
journal = {Atmosphere},
publisher = {MDPI AG},
year = {2019},
volume = {10},
number = {4},
doi = {10.3390/ATMOS10040194}
}
|
| Svensson N, Bergström H, Rutgersson A and Sahlée E (2019), "Modification of the Baltic Sea wind field by land-sea interaction", Wind Energy., jun, 2019. Vol. 22(6), pp. 764-779. |
| Abstract: The wind and turbulence fields over a small, high-latitude sea are investigated. These fields are highly influenced by the proximity to the coast, which is never more than 200 km away. Simulations with the WRF model over the Baltic Sea are compared with a simplified, stationary wind model driven by the synoptic forcing. The difference between the models is therefore representative of the mesoscale influence. The results show that the largest wind-field modifications compared with a neutral atmosphere occur during spring and summer, with a mean monthly increase of up to approximately 1 msâˆ'1 at typical hub heights and upper rotor area (120-170 m height) in the WRF model. The main reason for this is large-scale low-level jets caused by the land-sea temperature differences, likely increasing in strength due to inertial oscillations. These kind of events can be persistent for approximately 12 hours and cover almost the entire basin, causing wind speed and wind shear to increase considerably. The strongest effect is around 2000 to 2300 local time. Sea breezes and coastal low-level jets are of less importance, but while sea breezes are mostly detected near the coastline, other types of coastal jets can extend large distances off the coast. During autumn and winter, there are fewer low-level jet occurrences, but the wind profile cannot be explained by the classical theory of the one-dimensional model. This indicates that the coastal environment is complex and may be affected by advection from land surfaces to a large degree even when unstable conditions dominate. |
BibTeX:
@article{Svensson2019b,
author = {Svensson, Nina and Bergström, Hans and Rutgersson, Anna and Sahlée, Erik},
title = {Modification of the Baltic Sea wind field by land-sea interaction},
journal = {Wind Energy},
year = {2019},
volume = {22},
number = {6},
pages = {764--779},
url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/we.2320},
doi = {10.1002/we.2320}
}
|
| Tallec T, Brut A, Joly L, Dumelié N, Serça D, Mordelet P, Claverie N, Legain D, Barrié J, Decarpenterie T, Cousin J, Zawilski B, Ceschia E, Guérin F and Le Dantec V (2019), "N2O flux measurements over an irrigated maize crop: A comparison of three methods", Agricultural and Forest Meteorology., jan, 2019. Vol. 264, pp. 56-72. Elsevier B.V.. |
| Abstract: This paper presents the NitroCOSMES campaign, aimed at testing and evaluating the performance of three methods for monitoring N2O fluxes over an agricultural field. The experiment was conducted from May to August 2012 at a site located in the south-west of France. N2O fluxes from a 24 ha irrigated maize field were measured using eddy covariance (EC), automated chamber (AC) and static chamber (SC) methodologies. Uncertainties were calculated according to the specificities of each set-up. Measurements were performed over a large range of water-filled pore spaces (WFPS), soil temperatures, and mineral nitrogen availability, and offered the opportunity to compare methodologies over a wide range of N2O emission intensities. The average N2O fluxes were compared among the three methodologies during the same periods of measurement and for different intensities of emissions (low, moderate and high). Periods of comparison were determined according to the AC results. On average, the three methods gave comparable results for the low (SC: 14.7 ± 2.2, EC: 15.7 ± 10.1, AC: 17.5 ± 1.6 ng N2O-N m−² s−1) and the high (SC: 131.7 ± 22.1, EC: 125.3 ± 8, AC: 125.1 ± 8.9 ng N2O-N m−² s−1) N2O emission ranges. For the moderate N2O emission range, AC measurements gave higher emissions (57.2 ± 3.9 ng N2O-N m−² s−1) on average than both the SC (41.6 ± 6.6 ng N2O-N m−² s−1) and EC (33.8 ± 3.9 ng N2O-N m−² s−1) methods, which agreed better with each other. The relative standard deviation coefficient (RSD) indicated that EC methodology gave highly variable values during periods of low N2O emissions, from -52.2 ± 88.1 to 62.2 ± 50.7 ng N2O-N m−² s−1, with a mean RSD of 151%. Water vapour effects (dilution and spectroscopic cross-sensitivity) were discussed in an attempt to explain the high variability in low N2O emission measurements. Even after applying the Webb term correction, there could still be a spectroscopic cross-sensitivity effect of water vapour on the N2O trace gas signal because of the layout of the analysers, which was not determined during the experiment. This study underlined that EC methodology is a promising way to estimate and refine N2O budgets at the field scale and to analyse the effects of different agricultural practices more finely with continuous flux monitoring. It also highlighted the need to continue the effort to assess and develop chambers and EC methodologies, especially for the low N2O emission measurement range, for which values and systematic uncertainties remain high and highly variable. |
BibTeX:
@article{Tallec2019,
author = {Tallec, T. and Brut, A. and Joly, L. and Dumelié, N. and Serça, D. and Mordelet, P. and Claverie, N. and Legain, D. and Barrié, J. and Decarpenterie, T. and Cousin, J. and Zawilski, B. and Ceschia, E. and Guérin, F. and Le Dantec, V.},
title = {N2O flux measurements over an irrigated maize crop: A comparison of three methods},
journal = {Agricultural and Forest Meteorology},
publisher = {Elsevier B.V.},
year = {2019},
volume = {264},
pages = {56--72},
doi = {10.1016/j.agrformet.2018.09.017}
}
|
| Tang AC, Stoy PC, Hirata R, Musin KK, Aeries EB, Wenceslaus J, Shimizu M and Melling L (2019), "The exchange of water and energy between a tropical peat forest and the atmosphere: Seasonal trends and comparison against other tropical rainforests", Science of the Total Environment., sep, 2019. Vol. 683, pp. 166-174. Elsevier B.V.. |
| Abstract: Tropical rainforests control the exchange of water and energy between the land surface and the atmosphere near the equator and thus play an important role in the global climate system. Measurements of latent (LE) and sensible heat exchange (H) have not been synthesized across global tropical rainforests to date, which can help place observations from individual tropical forests in a global context. We measured LE and H for four years in a tropical peat forest ecosystem in Sarawak, Malaysian Borneo using eddy covariance, and hypothesize that the study ecosystem will exhibit less seasonal variability in turbulent fluxes than other tropical ecosystems as soil water is not expected to be limiting in a tropical forested wetland. LE and H show little variability across seasons in the study ecosystem, with LE values on the order of 11 MJ m−2 day and H on the order of 3 MJ m−2 day−1. Annual evapotranspiration (ET) did not differ among years and averaged 1579 ± 47 mm year−1. LE exceeded characteristic values from other tropical rainforest ecosystems in the FLUXNET2015 database with the exception of GF-Guy near coastal French Guyana, which averaged 8–11 MJ m−2 day−1. The Bowen ratio (Bo) in tropical rainforests in the FLUXNET2015 database either exhibited little seasonal trend, one seasonal peak, or two peaks. Volumetric water content (VWC) and VPD explained a trivial amount of the variability of LE and Bo in some of the tropical rainforests including the study ecosystem, but were strong controls in others, suggesting differences in stomatal regulation and/or the partitioning between evaporation and transpiration. Results demonstrate important differences in the seasonal patterns in water and energy exchange across different tropical rainforest ecosystems that need to be understood to quantify how ongoing changes in tropical rainforest extent will impact the global climate system. |
BibTeX:
@article{Tang2019,
author = {Tang, Angela C.I. and Stoy, Paul C. and Hirata, Ryuichi and Musin, Kevin K. and Aeries, Edward B. and Wenceslaus, Joseph and Shimizu, Mariko and Melling, Lulie},
title = {The exchange of water and energy between a tropical peat forest and the atmosphere: Seasonal trends and comparison against other tropical rainforests},
journal = {Science of the Total Environment},
publisher = {Elsevier B.V.},
year = {2019},
volume = {683},
pages = {166--174},
doi = {10.1016/j.scitotenv.2019.05.217}
}
|
| Tanhua T, Pouliquen S, Hausman J, O'Brien KM, Bricher P, de Bruin T, Buck JJ, Burger EF, Carval T, Casey KS, Diggs S, Giorgetti A, Glaves H, Harscoat V, Kinkade D, Muelbert JH, Novellino A, Pfeil BG, Pulsifer P, Van de Putte AP, Robinson E, Shaap D, Smirnov A, Smith N, Snowden DP, Spears T, Stall S, Tacoma M, Thijsse P, Tronstad S, Vandenberghe T, Wengren M, Wyborn L and Zhao Z (2019), "Ocean FAIR data services", Frontiers in Marine Science., aug, 2019. Vol. 6(JUL) Frontiers Media SA. |
| Abstract: Well-founded data management systems are of vital importance for ocean observing systems as they ensure that essential data are not only collected but also retained and made accessible for analysis and application by current and future users. Effective data management requires collaboration across activities including observations, metadata and data assembly, quality assurance and control (QA/QC), and data publication that enables local and interoperable discovery and access, and secure archiving that guarantees long-term preservation. To achieve this, data should be Findable, Accessible, Interoperable, and Reusable (FAIR). Here, we outline how these principles apply to ocean data, and illustrate them with a few examples. In recent decades, ocean data managers, in close collaboration with international organizations, have played an active role in the improvement of environmental data standardization, accessibility and interoperability through different projects, enhancing access to observation data at all stages of the data life cycle and fostering the development of integrated services targeted to research, regulatory and operational users. As ocean observing systems evolve and an increasing number of autonomous platforms and sensors are deployed, the volume and variety of data increases dramatically. For instance, there are more than 70 data catalogues that contain metadata records for the polar oceans, a situation that makes comprehensive data discovery beyond the capacity of most researchers. To better serve research, operational, and commercial users, more efficient turnaround of quality data in known formats and made available through web services is necessary. In particular, automation of data workflows will be critical to reduce friction throughout the data value chain. Adhering to the FAIR principles with free, timely and unrestricted access to ocean observation data is beneficial for the originators, has obvious benefits for users and is an essential foundation for the development of new services made possible with big data technologies. |
BibTeX:
@article{Tanhua2019,
author = {Tanhua, Toste and Pouliquen, Sylvie and Hausman, Jessica and O'Brien, Kevin M and Bricher, Pip and de Bruin, Taco and Buck, Justin J and Burger, Eugene F and Carval, Thierry and Casey, Kenneth S and Diggs, Steve and Giorgetti, Alessandra and Glaves, Helen and Harscoat, Valerie and Kinkade, Danie and Muelbert, Jose H and Novellino, Antonio and Pfeil, Benjamin G and Pulsifer, Peter and Van de Putte, Anton P and Robinson, Erin and Shaap, Dick and Smirnov, Alexander and Smith, Neville and Snowden, Derrick P and Spears, Tobias and Stall, Shelley and Tacoma, Marten and Thijsse, Peter and Tronstad, Stein and Vandenberghe, Thomas and Wengren, Micha and Wyborn, Lesley and Zhao, Zhiming},
title = {Ocean FAIR data services},
journal = {Frontiers in Marine Science},
publisher = {Frontiers Media SA},
year = {2019},
volume = {6},
number = {JUL},
doi = {10.3389/fmars.2019.00440}
}
|
| Tebaldini S, Ho Tong Minh D, Mariotti d'Alessandro M, Villard L, Le Toan T and Chave J (2019), "The Status of Technologies to Measure Forest Biomass and Structural Properties: State of the Art in SAR Tomography of Tropical Forests", Surveys in Geophysics., may, 2019. Vol. 40(4), pp. 779-801. Springer Science and Business Media LLC. |
| Abstract: Synthetic aperture radar (SAR) tomography (TomoSAR) is an emerging technology to image the 3D structure of the illuminated media. TomoSAR exploits the key feature of microwaves to penetrate into vegetation, snow, and ice, hence providing the possibility to see features that are hidden to optical and hyper-spectral systems. The research on the use of P-band waves, in particular, has been largely propelled since 2007 in experimental studies supporting the future spaceborne Mission BIOMASS, to be launched in 2022 with the aim of mapping forest aboveground biomass (AGB) accurately and globally. The results obtained in the frame of these studies demonstrated that TomoSAR can be used for accurate retrieval of geophysical variables such as forest height and terrain topography and, especially in the case of dense tropical forests, to provide a more direct link to AGB. This paper aims at providing the reader with a comprehensive understanding of TomoSAR and its application for remote sensing of forested areas, with special attention to the case of tropical forests. We will introduce the basic physical principles behind TomoSAR, present the most relevant experimental results of the last decade, and discuss the potentials of BIOMASS tomography. |
BibTeX:
@article{Tebaldini2019,
author = {Tebaldini, Stefano and Ho Tong Minh, Dinh and Mariotti d'Alessandro, Mauro and Villard, Ludovic and Le Toan, Thuy and Chave, Jerome},
title = {The Status of Technologies to Measure Forest Biomass and Structural Properties: State of the Art in SAR Tomography of Tropical Forests},
journal = {Surveys in Geophysics},
publisher = {Springer Science and Business Media LLC},
year = {2019},
volume = {40},
number = {4},
pages = {779--801},
doi = {10.1007/s10712-019-09539-7}
}
|
| Thanh Duc N, Silverstein S, Wik M, Crill P, Bastviken D and Varner RK (2019), "Greenhouse gas flux studies: An automated online system for gas emission measurements in aquatic environments", Hydrology and Earth System Sciences Discussions. , pp. 1-18. |
| Abstract: textlessptextgreatertextlessstrongtextgreaterAbstract.textless/strongtextgreaterAquatic ecosystems are major sources of greenhouse gases (GHG). Robust measurements of natural GHG emissions are vital for evaluating regional to global carbon budgets and for assessing climate feedbacks on natural emissions to improve climate models. Diffusive and ebullitive (bubble) transport are two major pathways of gas release from surface waters. To capture the high temporal variability of these fluxes in a well-defined footprint, we designed and built an inexpensive device that includes an easily mobile diffusive flux chamber and a bubble counter, all in one. In addition to automatically collecting gas samples for subsequent various analyses in the laboratory, this device also utilizes a low cost carbon dioxide (COtextlesssubtextgreater2textless/subtextgreater) sensor (SenseAir, Sweden) and methane (CHtextlesssubtextgreater4textless/subtextgreater) sensor (Figaro, Japan) to measure GHG fluxes. Each of the devices were equipped with an XBee module to enable a local radio communication (DigiMesh network) for time synchronization, and data readout at a server-controller station on the lakeshore. Software of this server-controller is operated on a low-cost computer (Raspberry Pi) which has a 3G connection for remote control and monitor functions from anywhere in the world. This study shows the potential of a low cost automatic sensor network system to study GHG fluxes on lakes in remote locations.textless/ptextgreater |
BibTeX:
@article{ThanhDuc2019,
author = {Thanh Duc, Nguyen and Silverstein, Samuel and Wik, Martin and Crill, Patrick and Bastviken, David and Varner, Ruth K},
title = {Greenhouse gas flux studies: An automated online system for gas emission measurements in aquatic environments},
journal = {Hydrology and Earth System Sciences Discussions},
year = {2019},
pages = {1--18},
doi = {10.5194/hess-2019-83}
}
|
| Tian H, Yang J, Xu R, Lu C, Canadell JG, Davidson EA, Jackson RB, Arneth A, Chang J, Ciais P, Gerber S, Ito A, Joos F, Lienert S, Messina P, Olin S, Pan S, Peng C, Saikawa E, Thompson RL, Vuichard N, Winiwarter W, Zaehle S and Zhang B (2019), "Global soil nitrous oxide emissions since the preindustrial era estimated by an ensemble of terrestrial biosphere models: Magnitude, attribution, and uncertainty", Global Change Biology., dec, 2019. Vol. 25(2), pp. 640-659. Wiley. |
| Abstract: Our understanding and quantification of global soil nitrous oxide (N 2 O) emissions and the underlying processes remain largely uncertain. Here, we assessed the effects of multiple anthropogenic and natural factors, including nitrogen fertilizer (N) application, atmospheric N deposition, manure N application, land cover change, climate change, and rising atmospheric CO 2 concentration, on global soil N 2 O emissions for the period 1861–2016 using a standard simulation protocol with seven process-based terrestrial biosphere models. Results suggest global soil N 2 O emissions have increased from 6.3 ± 1.1 Tg N 2 O-N/year in the preindustrial period (the 1860s) to 10.0 ± 2.0 Tg N 2 O-N/year in the recent decade (2007–2016). Cropland soil emissions increased from 0.3 Tg N 2 O-N/year to 3.3 Tg N 2 O-N/year over the same period, accounting for 82% of the total increase. Regionally, China, South Asia, and Southeast Asia underwent rapid increases in cropland N 2 O emissions since the 1970s. However, US cropland N 2 O emissions had been relatively flat in magnitude since the 1980s, and EU cropland N 2 O emissions appear to have decreased by 14%. Soil N 2 O emissions from predominantly natural ecosystems accounted for 67% of the global soil emissions in the recent decade but showed only a relatively small increase of 0.7 ± 0.5 Tg N 2 O-N/year (11%) since the 1860s. In the recent decade, N fertilizer application, N deposition, manure N application, and climate change contributed 54%, 26%, 15%, and 24%, respectively, to the total increase. Rising atmospheric CO 2 concentration reduced soil N 2 O emissions by 10% through the enhanced plant N uptake, while land cover change played a minor role. Our estimation here does not account for indirect emissions from soils and the directed emissions from excreta of grazing livestock. To address uncertainties in estimating regional and global soil N 2 O emissions, this study recommends several critical strategies for improving the process-based simulations. |
BibTeX:
@article{Tian2019,
author = {Tian, Hanqin and Yang, Jia and Xu, Rongting and Lu, Chaoqun and Canadell, Josep G and Davidson, Eric A and Jackson, Robert B and Arneth, Almut and Chang, Jinfeng and Ciais, Philippe and Gerber, Stefan and Ito, Akihiko and Joos, Fortunat and Lienert, Sebastian and Messina, Palmira and Olin, Stefan and Pan, Shufen and Peng, Changhui and Saikawa, Eri and Thompson, Rona L and Vuichard, Nicolas and Winiwarter, Wilfried and Zaehle, Sönke and Zhang, Bowen},
title = {Global soil nitrous oxide emissions since the preindustrial era estimated by an ensemble of terrestrial biosphere models: Magnitude, attribution, and uncertainty},
journal = {Global Change Biology},
publisher = {Wiley},
year = {2019},
volume = {25},
number = {2},
pages = {640--659},
doi = {10.1111/gcb.14514}
}
|
| Tilbrook B, Jewett EB, DeGrandpre MD, Hernandez-Ayon JM, Feely RA, Gledhill DK, Hansson L, Isensee K, Kurz ML, Newton JA, Siedlecki SA, Chai F, Dupont S, Graco M, Calvo E, Greeley D, Kapsenberg L, Lebrec M, Pelejero C, Schoo KL and Telszewski M (2019), "An Enhanced Ocean Acidification Observing Network: From People to Technology to Data Synthesis and Information Exchange", Frontiers in Marine Science., jun, 2019. Vol. 6(JUN), pp. 337. Frontiers Media S.A.. |
| Abstract: A successful integrated ocean acidification (OA) observing network must include (1) scientists and technicians from a range of disciplines from physics to chemistry to biology to technology development; (2) government, private, and intergovernmental support; (3) regional cohorts working together on regionally specific issues; (4) publicly accessible data from the open ocean to coastal to estuarine systems; (5) close integration with other networks focusing on related measurements or issues including the social and economic consequences of OA; and (6) observation-based informational products useful for decision making such as management of fisheries and aquaculture. The Global Ocean Acidification Observing Network (GOA-ON), a key player in this vision, seeks to expand and enhance geographic extent and availability of coastal and open ocean observing data to ultimately inform adaptive measures and policy action, especially in support of the United Nations 2030 Agenda for Sustainable Development. GOA-ON works to empower and support regional collaborative networks such as the Latin American Ocean Acidification Network, supports new scientists entering the field with training, mentorship, and equipment, refines approaches for tracking biological impacts, and stimulates development of lower-cost methodology and technologies allowing for wider participation of scientists. GOA-ON seeks to collaborate with and complement work done by other observing networks such as those focused on carbon flux into the ocean, tracking of carbon and oxygen in the ocean, observing biological diversity, and determining short- and long-term variability in these and other ocean parameters through space and time. |
BibTeX:
@article{Tilbrook2019,
author = {Tilbrook, Bronte and Jewett, Elizabeth B. and DeGrandpre, Michael D. and Hernandez-Ayon, Jose Martin and Feely, Richard A. and Gledhill, Dwight K. and Hansson, Lina and Isensee, Kirsten and Kurz, Meredith L. and Newton, Janet A. and Siedlecki, Samantha A. and Chai, Fei and Dupont, Sam and Graco, Michelle and Calvo, Eva and Greeley, Dana and Kapsenberg, Lydia and Lebrec, Marine and Pelejero, Carles and Schoo, Katherina L. and Telszewski, Maciej},
title = {An Enhanced Ocean Acidification Observing Network: From People to Technology to Data Synthesis and Information Exchange},
journal = {Frontiers in Marine Science},
publisher = {Frontiers Media S.A.},
year = {2019},
volume = {6},
number = {JUN},
pages = {337},
url = {https://www.frontiersin.org/article/10.3389/fmars.2019.00337/full},
doi = {10.3389/fmars.2019.00337}
}
|
| Tiralla N, Panferov O, Kreilein H, Olchev A, Ali AA and Knohl A (2019), "Quantification of leaf emisivities of forest species: Effects on modeled energy and matter fluxes in forest ecosystems", Geography, Environment, Sustainability., jul, 2019. Vol. 12(2), pp. 245-258. Faculty of Geography Lomonosov Moscow State University. |
| Abstract: Climate change has distinct regional and local differences in its impacts on the land surface. One of the important parameters determining the climate change signal is the emissivity (𝜖) of the surface. In forest-climate interactions, the leaf surface emissivity plays a decisive role. The accurate determination of leaf emissivities is crucial for the appropriate interpretation of measured energy and matter fluxes between the forest and the atmosphere. In this study, we quantified the emissivity of the five broadleaf tree species Acer pseudoplatanus, Fagus sylvatica, Fraxinus excelsior, Populus simonii and Populus candicans. Measurements of leaf surface temperatures were conducted under laboratory conditions in a controlled-climate chamber within the temperature range of +8 °C and +32 °C. Based on these measurements, broadband leaf emissivities 𝜖 (𝜖 for the spectral range of 8-14 µm) were calculated. Average 𝜖8-14 µm was 0.958±0.002 for all species with very little variation among species. In a second step, the soil-vegetation-atmosphere transfer model ‘MixFor-SVAT' was applied to examine the effects of e changes on radiative, sensible and latent energy fluxes of the Hainich forest in Central Germany. Model experiments were driven by meteorological data measured at the Hainich site. The simulations were forced with the calculated 𝜖 value as well as with minimum and maximum values obtained from the literature. Significant effects of 𝜖 changes were detected. The strongest effect was identified for the sensible heat flux with a sensitivity of 20.7 % per 1 % 𝜖 change. Thus, the variability of 𝜖 should be considered in climate change studies. |
BibTeX:
@article{Tiralla2019,
author = {Tiralla, Nina and Panferov, Oleg and Kreilein, Heinrich and Olchev, Alexander and Ali, Ashehad A and Knohl, Alexander},
title = {Quantification of leaf emisivities of forest species: Effects on modeled energy and matter fluxes in forest ecosystems},
journal = {Geography, Environment, Sustainability},
publisher = {Faculty of Geography Lomonosov Moscow State University},
year = {2019},
volume = {12},
number = {2},
pages = {245--258},
doi = {10.24057/2071-9388-2018-86}
}
|
| Tsuruta A, Aalto T, Backman L, Krol MC, Peters W, Lienert S, Joos F, Miller PA, Zhang W, Laurila T, Hatakka J, Leskinen A, Lehtinen KEJ, Peltola O, Vesala T, Levula J, Dlugokencky E, Heimann M, Kozlova E, Aurela M, Lohila A, Kauhaniemi M and Gomez-Pelaez AJ (2019), "Methane budget estimates in Finland from the CarbonTracker Europe-CH4 data assimilation system", Tellus, Series B: Chemical and Physical Meteorology., jan, 2019. Vol. 71(1), pp. 1-20. Informa UK Limited. |
| Abstract: We estimated the CH4 budget in Finland for 2004–2014 using the CTE-CH4 data assimilation system with an extended atmospheric CH4 observation network of seven sites from Finland to surrounding regions (Hyytiälä, Kjølnes, Kumpula, Pallas, Puijo, Sodankylä, and Utö). The estimated average annual total emission for Finland is 0.6 ± 0.5 Tg CH4 yrâˆ'1. Sensitivity experiments show that the posterior biospheric emission estimates for Finland are between 0.3 and 0.9 Tg CH4 yrâˆ'1, which lies between the LPX-Bern-DYPTOP (0.2 Tg CH4 yrâˆ'1) and LPJG-WHyMe (2.2 Tg CH4 yrâˆ'1) process-based model estimates. For anthropogenic emissions, we found that the EDGAR v4.2 FT2010 inventory (0.4 Tg CH4 yrâˆ'1) is likely to overestimate emissions in southernmost Finland, but the extent of overestimation and possible relocation of emissions are difficult to derive from the current observation network. The posterior emission estimates were especially reliant on prior information in central Finland. However, based on analysis of posterior atmospheric CH4, we found that the anthropogenic emission distribution based on a national inventory is more reliable than the one based on EDGAR v4.2 FT2010. The contribution of total emissions in Finland to global total emissions is only about 0.13%, and the derived total emissions in Finland showed no trend during 2004–2014. The model using optimized emissions was able to reproduce observed atmospheric CH4 at the sites in Finland and surrounding regions fairly well (correlation 0.75, bias (Formula presented.) ppb), supporting adequacy of the observations to be used in atmospheric inversion studies. In addition to global budget estimates, we found that CTE-CH4 is also applicable for regional budget estimates, where small scale (1º × 1º in this case) optimization is possible with a dense observation network. |
BibTeX:
@article{Tsuruta2019,
author = {Tsuruta, Aki and Aalto, Tuula and Backman, Leif and Krol, Maarten C and Peters, Wouter and Lienert, Sebastian and Joos, Fortunat and Miller, Paul A and Zhang, Wenxin and Laurila, Tuomas and Hatakka, Juha and Leskinen, Ari and Lehtinen, Kari E J and Peltola, Olli and Vesala, Timo and Levula, Janne and Dlugokencky, Ed and Heimann, Martin and Kozlova, Elena and Aurela, Mika and Lohila, Annalea and Kauhaniemi, Mari and Gomez-Pelaez, Angel J},
title = {Methane budget estimates in Finland from the CarbonTracker Europe-CH4 data assimilation system},
journal = {Tellus, Series B: Chemical and Physical Meteorology},
publisher = {Informa UK Limited},
year = {2019},
volume = {71},
number = {1},
pages = {1--20},
doi = {10.1080/16000889.2018.1565030}
}
|
| Tuovinen JP, Aurela M, Hatakka J, Räsänen A, Virtanen T, Mikola J, Ivakhov V, Kondratyev V and Laurila T (2019), "Interpreting eddy covariance data from heterogeneous Siberian tundra: Land-cover-specific methane fluxes and spatial representativeness", Biogeosciences., jan, 2019. Vol. 16(2), pp. 255-274. Copernicus GmbH. |
| Abstract: The non-uniform spatial integration, an inherent feature of the eddy covariance (EC) method, creates a challenge for flux data interpretation in a heterogeneous environment, where the contribution of different land cover types varies with flow conditions, potentially resulting in biased estimates in comparison to the areally averaged fluxes and land cover attributes. We modelled flux footprints and characterized the spatial scale of our EC measurements in Tiksi, a tundra site in northern Siberia. We used leaf area index (LAI) and land cover class (LCC) data, derived from very-high-spatial-resolution satellite imagery and field surveys, and quantified the sensor location bias. We found that methane (CH 4 ) fluxes varied strongly with wind direction (-0:09 to 0.59 μgCH 4 m -2 s -1 on average) during summer 2014, reflecting the distribution of different LCCs. Other environmental factors had only a minor effect on short-term flux variations but influenced the seasonal trend. Using footprint weights of grouped LCCs as explanatory variables for the measured CH 4 flux, we developed a multiple regression model to estimate LCC group-specific fluxes. This model showed that wet fen and graminoid tundra patches in locations with topography-enhanced wetness acted as strong sources (1.0 μgCH 4 m -2 s -1 during the peak emission period), while mineral soils were significant sinks (-0:13 μgCH 4 m -2 s -1 ). To assess the representativeness of measurements, we upscaled the LCC group-specific fluxes to different spatial scales. Despite the landscape heterogeneity and rather poor representativeness of EC data with respect to the areally averaged LAI and coverage of some LCCs, the mean flux was close to the CH 4 balance upscaled to an area of 6.3 km 2 , with a location bias of 14 %. We recommend that EC site descriptions in a heterogeneous environment should be complemented with footprint-weighted highresolution data on vegetation and other site characteristics. |
BibTeX:
@article{Tuovinen2019,
author = {Tuovinen, Juha Pekka and Aurela, Mika and Hatakka, Juha and Räsänen, Aleksi and Virtanen, Tarmo and Mikola, Juha and Ivakhov, Viktor and Kondratyev, Vladimir and Laurila, Tuomas},
title = {Interpreting eddy covariance data from heterogeneous Siberian tundra: Land-cover-specific methane fluxes and spatial representativeness},
journal = {Biogeosciences},
publisher = {Copernicus GmbH},
year = {2019},
volume = {16},
number = {2},
pages = {255--274},
doi = {10.5194/bg-16-255-2019}
}
|
| van der Horst SVJ, Pitman AJ, De Kauwe MG, Ukkola A, Abramowitz G and Isaac P (2019), "How representative are FLUXNET measurements of surface fluxes during temperature extremes?", Biogeosciences., apr, 2019. Vol. 16(8), pp. 1829-1844. |
BibTeX:
@article{VanderHorst2019,
author = {van der Horst, Sophie V J and Pitman, Andrew J and De Kauwe, Martin G and Ukkola, Anna and Abramowitz, Gab and Isaac, Peter},
title = {How representative are FLUXNET measurements of surface fluxes during temperature extremes?},
journal = {Biogeosciences},
year = {2019},
volume = {16},
number = {8},
pages = {1829--1844},
url = {https://www.biogeosciences.net/16/1829/2019/},
doi = {10.5194/bg-16-1829-2019}
}
|
| Vernet M, Geibert W, Hoppema M, Brown PJ, Haas C, Hellmer HH, Jokat W, Jullion L, Mazloff M, Bakker DCE, Brearley JA, Croot P, Hattermann T, Hauck J, Hillenbrand CD, Hoppe CJM, Huhn O, Koch BP, Lechtenfeld OJ, Meredith MP, Naveira Garabato AC, Nöthig EM, Peeken I, Rutgers van der Loeff MM, Schmidtko S, Schröder M, Strass VH, Torres-Valdés S and Verdy A (2019), "The Weddell Gyre, Southern Ocean: Present Knowledge and Future Challenges", Reviews of Geophysics., jul, 2019. Vol. 57(3), pp. 623-708. American Geophysical Union (AGU). |
| Abstract: The Weddell Gyre (WG) is one of the main oceanographic features of the Southern Ocean south of the Antarctic Circumpolar Current which plays an influential role in global ocean circulation as well as gas exchange with the atmosphere. We review the state-of-the art knowledge concerning the WG from an interdisciplinary perspective, uncovering critical aspects needed to understand this system's role in shaping the future evolution of oceanic heat and carbon uptake over the next decades. The main limitations in our knowledge are related to the conditions in this extreme and remote environment, where the polar night, very low air temperatures, and presence of sea ice year-round hamper field and remotely sensed measurements. We highlight the importance of winter and under-ice conditions in the southern WG, the role that new technology will play to overcome present-day sampling limitations, the importance of the WG connectivity to the low-latitude oceans and atmosphere, and the expected intensification of the WG circulation as the westerly winds intensify. Greater international cooperation is needed to define key sampling locations that can be visited by any research vessel in the region. Existing transects sampled since the 1980s along the Prime Meridian and along an East-West section at ˜62°S should be maintained with regularity to provide answers to the relevant questions. This approach will provide long-term data to determine trends and will improve representation of processes for regional, Antarctic-wide, and global modeling efforts—thereby enhancing predictions of the WG in global ocean circulation and climate. |
BibTeX:
@article{Vernet2019,
author = {Vernet, M and Geibert, W and Hoppema, M and Brown, P J and Haas, C and Hellmer, H H and Jokat, W and Jullion, L and Mazloff, M and Bakker, D C E and Brearley, J A and Croot, P and Hattermann, T and Hauck, J and Hillenbrand, C D and Hoppe, C J M and Huhn, O and Koch, B P and Lechtenfeld, O J and Meredith, M P and Naveira Garabato, A C and Nöthig, E M and Peeken, I and Rutgers van der Loeff, M M and Schmidtko, S and Schröder, M and Strass, V H and Torres-Valdés, S and Verdy, A},
title = {The Weddell Gyre, Southern Ocean: Present Knowledge and Future Challenges},
journal = {Reviews of Geophysics},
publisher = {American Geophysical Union (AGU)},
year = {2019},
volume = {57},
number = {3},
pages = {623--708},
doi = {10.1029/2018RG000604}
}
|
| Vincent-Barbaroux C, Berveiller D, Lelarge-Trouverie C, Maia R, Máguas C, Pereira J, Chaves MM and Damesin C (2019), "Carbon-use strategies in stem radial growth of two oak species, one Temperate deciduous and one Mediterranean evergreen: what can be inferred from seasonal variations in the δ13C of the current year ring?", Tree physiology., may, 2019. Vol. 39(8), pp. 1329-1341. Oxford University Press (OUP). |
| Abstract: Tree ring synthesis is a key process in wood production; however, little is known of the origin and fate of the carbon involved. We used natural 13C abundance to investigate the carbon-use process for the ring development in a temperate deciduous (Quercus petraea (Matt.) Liebl.) and a Mediterranean evergreen (Quercus ilex L.) oak. The sapwood carbon reserves, phloem sucrose contents, stem respired CO2 efflux and their respective carbon isotope compositions (δ13C) were recorded over 1 year, in the native area of each species. The seasonal δ13C variation of the current year ring was determined in the total ring throughout the seasons, as well as in slices from the fully mature ring after the growth season (intra-ring pattern). Although the budburst dates of the two oaks were similar, the growth of Quercus ilex began 50Â days later. Both species exhibited growth cessation during the hot and dry summer but only Q. ilex resumed in the autumn. In the deciduous oak, xylem starch storage showed clear variations during the radial growth. The intra-ring δ13C variations of the two species exhibited similar ranges, but contrasting patterns, with an early increase for Q. petraea. Comparison between δ13C of starch and total ring suggested that Q. petraea (but not Q. ilex) builds its rings using reserves during the first month of growth. Shifts in ring and soluble sugars δ13C suggested an interspecific difference in either the phloem unloading or the use of fresh assimilate inside the ring. A decrease in ring δ13C for both oaks between the end of the radial growth and the winter is attributed to a lignification of ring cell walls after stem increment. This study highlighted the differences in carbon-use during ring growth for evergreen and deciduous oaks, as well as the benefits of exploring the process using natural 13C abundance. |
BibTeX:
@article{Vincent-Barbaroux2019,
author = {Vincent-Barbaroux, Cécile and Berveiller, Daniel and Lelarge-Trouverie, Caroline and Maia, Rodrigo and Máguas, Cristina and Pereira, João and Chaves, Manuela M and Damesin, Claire},
title = {Carbon-use strategies in stem radial growth of two oak species, one Temperate deciduous and one Mediterranean evergreen: what can be inferred from seasonal variations in the δ13C of the current year ring?},
journal = {Tree physiology},
publisher = {Oxford University Press (OUP)},
year = {2019},
volume = {39},
number = {8},
pages = {1329--1341},
doi = {10.1093/treephys/tpz043}
}
|
| Vitale D, Bilancia M and Papale D (2019), "Modelling random uncertainty of eddy covariance flux measurements", Stochastic Environmental Research and Risk Assessment., mar, 2019. Vol. 33(3), pp. 725-746. Springer Science and Business Media LLC. |
| Abstract: The eddy-covariance (EC) technique is considered the most direct and reliable method to calculate flux exchanges of the main greenhouse gases over natural ecosystems and agricultural fields. The resulting measurements are extremely important to characterize ecosystem exchanges of carbon, water, energy and other trace gases, and are widely used to validate or constrain parameter of land surface models via data assimilation techniques. For this purpose, the availability of both complete half-hourly flux time series and its associated uncertainty is mandatory. However, uncertainty estimation for EC data is challenging because the standard procedures based on repeated sampling are not suitable for this kind of measurements, and the presence of missing data makes it difficult to build any sensible time series model with time-varying second-order moments that can provide estimates of total random uncertainty. To overcome such limitations, this paper describes a new method in the context of the strategy based on the model residual approach proposed by Richardson et al. (Agric For Meteorol 148(1): 38–50, 2008). The proposed approach consists in (1) estimating the conditional mean process as representative of the true signal underlying observed data and (2) estimating the conditional variance process as representative of the total random uncertainty affecting EC data. The conditional mean process is estimated through the multiple imputation algorithm recently proposed by Vitale et al. (J Environ Inform https://doi.org/10.3808/jei.201800391, 2018). The conditional variance process is estimated through the stochastic volatility model introduced by Beltratti and Morana (Econ Notes 30(2): 205–234, 2001). This strategy is applied to ten sites that are part of FLUXNET2015 dataset, selected in such a way to cover various ecosystem types under different climatic regimes around the world. The estimated uncertainty is compared with estimates by other well-established methods, and it is demonstrated that the scaling relationship between uncertainty and flux magnitude is preserved. Additionally, the proposed strategy allows obtaining a complete half-hourly time series of uncertainty estimates, which are expected to be useful for many users of EC flux data. |
BibTeX:
@article{Vitale2019,
author = {Vitale, Domenico and Bilancia, Massimo and Papale, Dario},
title = {Modelling random uncertainty of eddy covariance flux measurements},
journal = {Stochastic Environmental Research and Risk Assessment},
publisher = {Springer Science and Business Media LLC},
year = {2019},
volume = {33},
number = {3},
pages = {725--746},
doi = {10.1007/s00477-019-01664-4}
}
|
| Vitale D, Bilancia M and Papale D (2019), "A multiple imputation strategy for eddy covariance data", Journal of Environmental Informatics., jul, 2019. Vol. 34(2), pp. 68-87. International Society for Environmental Information Science (ISEIS). |
| Abstract: Half-hourly time series of net ecosystem exchange (NEE) of CO2, latent heat flux (LE) and sensible heat flux (H) measured through the micro-meteorological eddy covariance (EC) technique are noisy and show a high percentage of missing data. By using EC measurements that are part of the FLUXNET2015 dataset, we evaluate the performance of a multiple imputation (MI) strategy based on an efficient computational strategy introduced in Honaker and King (2010), combining the classic Expectation-Maximization (EM) algorithm with a bootstrap approach, in order to take draws from a suitable approximation of posterior distribution of model parameters. Armed with these instruments, we are able to introduce three new multiple imputation models, characterized by an increasing level of complexity, and built on top of multivariate normality assumption: 1) MLR, which imputes EC missing values using a static multiple linear regression of observed values of suitable input variables; 2) ADL, which enriches with dynamic properties the static specification of MLR, by considering an autoregressive distributed lag specification; 3) PADL, which adds further complexity by embedding the ADL model in a panel-data perspective. Under several artificial gap scenarios, we show that PADL has a better ability in modeling the complex dynamics of ecosystem fluxes and reconstructing missing data points, thus providing unbiased imputations and preserving the original sampling distribution. The added flexibility arising from the time series cross section structure of PADL warrants improved performances, outperforming those of other imputation methods, as well as of the marginal distribution sampling algorithm (MDS), a widely used gap-filling approach introduced by Reichstein et al. (2005), especially in the case of nighttime flux data. It is expected that the strategy proposed in this paper will become useful in creating multiple imputations for a variety of EC datasets, providing valid inferences for a broad range of scientific estimands (such as annual budgets). |
BibTeX:
@article{Vitale2019a,
author = {Vitale, D and Bilancia, M and Papale, D},
title = {A multiple imputation strategy for eddy covariance data},
journal = {Journal of Environmental Informatics},
publisher = {International Society for Environmental Information Science (ISEIS)},
year = {2019},
volume = {34},
number = {2},
pages = {68--87},
doi = {10.3808/jei.201800391}
}
|
| Vogel FR, Frey M, Staufer J, Hase F, Broquet G, Xueref-Remy I, Chevallier F, Ciais P, Sha MK, Chelin P, Jeseck P, Janssen C, Té Y, Groß J, Blumenstock T, Tu Q and Orphal J (2019), "XCO2 in an emission hot-spot region: The COCCON Paris campaign 2015", Atmospheric Chemistry and Physics., mar, 2019. Vol. 19(5), pp. 3271-3285. Copernicus GmbH. |
| Abstract: Providing timely information on urban greenhouse gas (GHG) emissions and their trends to stakeholders relies on reliable measurements of atmospheric concentrations and the understanding of how local emissions and atmospheric transport influence these observations. Portable Fourier transform infrared (FTIR) spectrometers were deployed at five stations in the Paris metropolitan area to provide column-averaged concentrations of CO2 (XCO2) during a field campaign in spring of 2015, as part of the Collaborative Carbon Column Observing Network (COCCON). Here, we describe and analyze the variations of XCO2 observed at different sites and how they changed over time. We find that observations upwind and downwind of the city centre differ significantly in their XCO2 concentrations, while the overall variability of the daily cycle is similar, i.e. increasing during night-time with a strong decrease (typically 2-3 ppm) during the afternoon. An atmospheric transport model framework (CHIMERECAMS) was used to simulate XCO2 and predict the same behaviour seen in the observations, which supports key findings, e.g. that even in a densely populated region like Paris (over 12 million people), biospheric uptake of CO2 can be of major influence on daily XCO2 variations. Despite a general offset between modelled and observed XCO2, the model correctly predicts the impact of the meteorological parameters (e.g. wind direction and speed) on the concentration gradients between different stations. When analyzing local gradients of XCO2 for upwind and downwind station pairs, those local gradients are found to be less sensitive to changes in XCO2 boundary conditions and biogenic fluxes within the domain and we find the model-data agreement further improves. Our modelling framework indicates that the local XCO2 gradient between the stations is dominated by the fossil fuel CO2 signal of the Paris metropolitan area. This furtherhighlights the potential usefulness of XCO2 observations to help optimize future urban GHG emission estimates. |
BibTeX:
@article{Vogel2019,
author = {Vogel, Felix R and Frey, Matthias and Staufer, Johannes and Hase, Frank and Broquet, Grégoire and Xueref-Remy, Irène and Chevallier, Frédéric and Ciais, Philippe and Sha, Mahesh Kumar and Chelin, Pascale and Jeseck, Pascal and Janssen, Christof and Té, Yao and Groß, Jochen and Blumenstock, Thomas and Tu, Qiansi and Orphal, Johannes},
title = {XCO2 in an emission hot-spot region: The COCCON Paris campaign 2015},
journal = {Atmospheric Chemistry and Physics},
publisher = {Copernicus GmbH},
year = {2019},
volume = {19},
number = {5},
pages = {3271--3285},
doi = {10.5194/acp-19-3271-2019}
}
|
| Voigt C, Marushchak ME, Mastepanov M, Lamprecht RE, Christensen TR, Dorodnikov M, Jackowicz-Korczyʼnski M, Lindgren A, Lohila A, Nykänen H, Oinonen M, Oksanen T, Palonen V, Treat CC, Martikainen PJ and Biasi C (2019), "Ecosystem carbon response of an Arctic peatland to simulated permafrost thaw", Global Change Biology., feb, 2019. Vol. 25(5), pp. 1746-1764. Wiley. |
| Abstract: Permafrost peatlands are biogeochemical hot spots in the Arctic as they store vast amounts of carbon. Permafrost thaw could release part of these long-term immobile carbon stocks as the greenhouse gases (GHGs) carbon dioxide (CO 2 ) and methane (CH 4 ) to the atmosphere, but how much, at which time-span and as which gaseous carbon species is still highly uncertain. Here we assess the effect of permafrost thaw on GHG dynamics under different moisture and vegetation scenarios in a permafrost peatland. A novel experimental approach using intact plant–soil systems (mesocosms) allowed us to simulate permafrost thaw under near-natural conditions. We monitored GHG flux dynamics via high-resolution flow-through gas measurements, combined with detailed monitoring of soil GHG concentration dynamics, yielding insights into GHG production and consumption potential of individual soil layers. Thawing the upper 10–15 cm of permafrost under dry conditions increased CO 2 emissions to the atmosphere (without vegetation: 0.74 ± 0.49 vs. 0.84 ± 0.60 g CO 2 –C m âˆ'2 day âˆ'1 ; with vegetation: 1.20 ± 0.50 vs. 1.32 ± 0.60 g CO 2 –C m âˆ'2 day âˆ'1 , mean ± SD, pre- and post-thaw, respectively). Radiocarbon dating ( 14 C) of respired CO 2 , supported by an independent curve-fitting approach, showed a clear contribution (9%–27%) of old carbon to this enhanced post-thaw CO 2 flux. Elevated concentrations of CO 2 , CH 4 , and dissolved organic carbon at depth indicated not just pulse emissions during the thawing process, but sustained decomposition and GHG production from thawed permafrost. Oxidation of CH 4 in the peat column, however, prevented CH 4 release to the atmosphere. Importantly, we show here that, under dry conditions, peatlands strengthen the permafrost–carbon feedback by adding to the atmospheric CO 2 burden post-thaw. However, as long as the water table remains low, our results reveal a strong CH 4 sink capacity in these types of Arctic ecosystems pre- and post-thaw, with the potential to compensate part of the permafrost CO 2 losses over longer timescales. |
BibTeX:
@article{Voigt2019,
author = {Voigt, Carolina and Marushchak, Maija E and Mastepanov, Mikhail and Lamprecht, Richard E and Christensen, Torben R and Dorodnikov, Maxim and Jackowicz-Korczyʼnski, Marcin and Lindgren, Amelie and Lohila, Annalea and Nykänen, Hannu and Oinonen, Markku and Oksanen, Timo and Palonen, Vesa and Treat, Claire C and Martikainen, Pertti J and Biasi, Christina},
title = {Ecosystem carbon response of an Arctic peatland to simulated permafrost thaw},
journal = {Global Change Biology},
publisher = {Wiley},
year = {2019},
volume = {25},
number = {5},
pages = {1746--1764},
doi = {10.1111/gcb.14574}
}
|
| Wang Y, Ciais P, Broquet G, Bréon FM, Oda T, Lespinas F, Meijer Y, Loescher A, Janssens-Maenhout G, Zheng B, Xu H, Tao S, Gurney KR, Roest G, Santaren D and Su Y (2019), "A global map of emission clumps for future monitoring of fossil fuel CO2 emissions from space", Earth System Science Data., may, 2019. Vol. 11(2), pp. 687-703. Copernicus GmbH. |
| Abstract: A large fraction of fossil fuel CO 2 emissions emanate from "hotspots", such as cities (where direct CO 2 emissions related to fossil fuel combustion in transport, residential, commercial sectors, etc., excluding emissions from electricity-producing power plants, occur), isolated power plants, and manufacturing facilities, which cover a small fraction of the land surface. The coverage of all high-emitting cities and point sources across the globe by bottom-up inventories is far from complete, and for most of those covered, the uncertainties in CO 2 emission estimates in bottom-up inventories are too large to allow continuous and rigorous assessment of emission changes (Gurney et al., 2019). Space-borne imagery of atmospheric CO 2 has the potential to provide independent estimates of CO 2 emissions from hotspots. But first, what a hotspot is needs to be defined for the purpose of satellite observations. The proposed space-borne imagers with global coverage planned for the coming decade have a pixel size on the order of a few square kilometers and a XCO 2 accuracy and precision of 1 ppm for individual measurements of vertically integrated columns of dry-air mole fractions of CO 2 (XCO 2 ). This resolution and precision is insufficient to provide a cartography of emissions for each individual pixel. Rather, the integrated emission of diffuse emitting areas and intense point sources is sought. In this study, we characterize area and point fossil fuel CO 2 emitting sources which generate coherent XCO 2 plumes that may be observed from space. We characterize these emitting sources around the globe and they are referred to as "emission clumps" hereafter. An algorithm is proposed to identify emission clumps worldwide, based on the ODIAC global high-resolution 1 km fossil fuel emission data product. The clump algorithm selects the major urban areas from a GIS (geographic information system) file and two emission thresholds. The selected urban areas and a high emission threshold are used to identify clump cores such as inner city areas or large power plants. A low threshold and a random walker (RW) scheme are then used to aggregate all grid cells contiguous to cores in order to define a single clump. With our definition of the thresholds, which are appropriate for a space imagery with 0.5 ppm precision for a single XCO 2 measurement, a total of 11 314 individual clumps, with 5088 area clumps, and 6226 point-source clumps (power plants) are identified. These clumps contribute 72% of the global fossil fuel CO 2 emissions according to the ODIAC inventory. The emission clumps is a new tool for comparing fossil fuel CO 2 emissions from different inventories and objectively identifying emitting areas that have a potential to be detected by future global satellite imagery of XCO 2 . The emission clump data product is distributed from https://doi.org/10.6084/m9.figshare.7217726.v1. |
BibTeX:
@article{Wang2019,
author = {Wang, Yilong and Ciais, Philippe and Broquet, Grégoire and Bréon, François Marie and Oda, Tomohiro and Lespinas, Franck and Meijer, Yasjka and Loescher, Armin and Janssens-Maenhout, Greet and Zheng, Bo and Xu, Haoran and Tao, Shu and Gurney, Kevin R and Roest, Geoffrey and Santaren, Diego and Su, Yongxian},
title = {A global map of emission clumps for future monitoring of fossil fuel CO2 emissions from space},
journal = {Earth System Science Data},
publisher = {Copernicus GmbH},
year = {2019},
volume = {11},
number = {2},
pages = {687--703},
doi = {10.5194/essd-11-687-2019}
}
|
| Wang S, Garcia M, Bauer-Gottwein P, Jakobsen J, Zarco-Tejada PJ, Bandini F, Paz VS and Ibrom A (2019), "High spatial resolution monitoring land surface energy, water and CO2 fluxes from an Unmanned Aerial System", Remote Sensing of Environment., aug, 2019. Vol. 229, pp. 14-31. Elsevier BV. |
| Abstract: High spatial resolution maps of land surface energy, water and CO2 fluxes, e.g. evapotranspiration (ET)and gross primary productivity (GPP), are important for agricultural monitoring, ecosystem and water resources management. However, it is not clear which is the optimal (e.g. coarsest possible)spatial resolution to capture those fluxes accurately. Unmanned Aerial Systems (UAS)can address this by collecting very high spatial resolution (1 m, VHR)imagery. The objective of this study is to model ET and GPP dynamics using VHR optical and thermal imagery and quantify the influence of the spatial heterogeneity in the flux simulations and validations. The study was conducted at a deciduous willow bioenergy eddy covariance (EC)flux site in Denmark. Flight campaigns were conducted during the growing seasons of 2016 and 2017 with a hexacopter equipped with RGB, multispectral and thermal infrared cameras. A ‘top-down' modeling approach consisting of the Priestley–Taylor Jet Propulsion Laboratory model and a light use efficiency model sharing the same canopy biophysical constraints was used to estimate ET and GPP. Model outputs were benchmarked by EC flux observations with the source weighted footprint. Our results indicate that our model can well estimate the instantaneous net radiation, ET, GPP, evaporative fraction, light use efficiency and water use efficiency with root-mean-square deviations (RMSD)of 31.6 Wtextperiodcenteredmâˆ'2, 41.2 Wtextperiodcenteredmâˆ'2, 3.12 μmoltextperiodcenteredCtextperiodcenteredmâˆ'2textperiodcenteredsâˆ'1, 0.08, 0.16 gtextperiodcenteredCtextperiodcenteredMJâˆ'1 and 0.35 gtextperiodcenteredCtextperiodcenteredkgâˆ'1, respectively. Further, it is found that using a footprint model to sample different areas of VHR imagery can be a tool to provide better diurnal estimates to benchmark with EC data. Moreover, these VHR maps (0.3 m)allowed us to quantify metrics of spatial heterogeneity by using semivariogram analysis and by aggregating model inputs into different spatial resolutions. For instance, we find that in this site, the aggregation of simulated GPP using the source weighted mean of the EC footprint was about 30% lower in RMSD than using the arithmetic mean of the footprint. This demonstrates the accuracy of the modeled VHR spatial patterns. Nevertheless, we also find that imagery resolution consistent with the canopy size (around 1.5 m in our study)is sufficient to capture the spatial heterogeneity of the fluxes as transpiration and canopy assimilation of CO2 are processes regulated at the tree crown level. Our results highlight the importance of considering the land surface heterogeneity for flux modeling and the source contribution within the EC footprint for model benchmarking at appropriate spatial resolutions. |
BibTeX:
@article{Wang2019a,
author = {Wang, Sheng and Garcia, Monica and Bauer-Gottwein, Peter and Jakobsen, Jakob and Zarco-Tejada, Pablo J and Bandini, Filippo and Paz, Verónica Sobejano and Ibrom, Andreas},
title = {High spatial resolution monitoring land surface energy, water and CO2 fluxes from an Unmanned Aerial System},
journal = {Remote Sensing of Environment},
publisher = {Elsevier BV},
year = {2019},
volume = {229},
pages = {14--31},
doi = {10.1016/j.rse.2019.03.040}
}
|
| Wanninkhof R, Triñanes J, Park G, Gledhill D and Olsen A (2019), "Large Decadal Changes in Air‐Sea CO textlesssubtextgreater2textless/subtextgreater Fluxes in the Caribbean Sea", Journal of Geophysical Research: Oceans., oct, 2019. Vol. 124(10), pp. 6960-6982. Blackwell Publishing Ltd. |
| Abstract: Sixteen years of surface water CO2 data from autonomous systems on cruise ships sailing in the Caribbean Sea and Western North Atlantic show marked changes on interannual timescales. The measured changes in fugacity (≈partial pressure) of CO2 in surface water, fCO2w, are based on over a million observations. Seasonally the patterns are similar to other oligotrophic subtropical regions with an amplitude of fCO2w of ≈40 μatm with low wintertime values, causing the area to be a sink, and high summertime values making it a source of CO2 to the atmosphere. On annual scales there was negligible increase of fCO2w from 2002 to 2010 and a rapid increase from 2010 to 2018. Correspondingly, the trend of air-sea CO2 flux from 2002 to 2010 was strongly negative (increasing uptake or sink) at −0.05 ± 0.01 (mol m−2 year−1) year−1 and positive (decreasing uptake) at 0.02 ± 0.02 (mol m−2 year−1) year−1 from 2010-2018. For the whole period from 2002 to 2018, the fCO2w lagged the atmospheric CO2 increase by 24 %, causing an increase in CO2 uptake. The average flux into the ocean for the 16 years is −0.20 ± 0.16 mol m−2 year−1 with the uncertainty reflecting the standard deviation in annual means. The change in multiannual trend in fCO2w is modulated by several factors, notably changes in sea surface temperature and ocean mixed layer depth that, in turn, affected the physical and biological processes controlling fCO2w. |
BibTeX:
@article{Wanninkhof2019,
author = {Wanninkhof, Rik and Triñanes, Joaquin and Park, Geun‐Ha and Gledhill, Dwight and Olsen, Are},
title = {Large Decadal Changes in Air‐Sea CO textlesssubtextgreater2textless/subtextgreater Fluxes in the Caribbean Sea},
journal = {Journal of Geophysical Research: Oceans},
publisher = {Blackwell Publishing Ltd},
year = {2019},
volume = {124},
number = {10},
pages = {6960--6982},
url = {https://onlinelibrary.wiley.com/doi/abs/10.1029/2019JC015366},
doi = {10.1029/2019JC015366}
}
|
| Wanninkhof R, Pickers PA, Omar AM, Sutton A, Murata A, Olsen A, Stephens BB, Tilbrook B, Munro D, Pierrot D, Rehder G, Santana-Casiano JM, Müller JD, Trinanes J, Tedesco K, O'Brien K, Currie K, Barbero L, Telszewski M, Hoppema M, Ishii M, González-Dávila M, Bates NR, Metzl N, Suntharalingam P, Feely RA, ichiro Nakaoka S, Lauvset SK, Takahashi T, Steinhoff T and Schuster U (2019), "A surface ocean CO2 reference network, SOCONET and associated marine boundary layer CO2 measurements", Frontiers in Marine Science., jul, 2019. Vol. 6(JUL) Frontiers Media SA. |
| Abstract: The Surface Ocean CO2 NETwork (SOCONET) and atmospheric Marine Boundary Layer (MBL) CO2 measurements from ships and buoys focus on the operational aspects of measurements of CO2 in both the ocean surface and atmospheric MBLs. The goal is to provide accurate pCO2 data to within 2 micro atmosphere (μatm) for surface ocean and 0.2 parts per million (ppm) for MBL measurements following rigorous best practices, calibration and intercomparison procedures. Platforms and data will be tracked in near real-time and final quality-controlled data will be provided to the community within a year. The network, involving partners worldwide, will aid in production of important products such as maps of monthly resolved surface ocean CO2 and air-sea CO2 flux measurements. These products and other derivatives using surface ocean and MBL CO2 data, such as surface ocean pH maps and MBL CO2 maps, will be of high value for policy assessments and socio-economic decisions regarding the role of the ocean in sequestering anthropogenic CO2 and how this uptake is impacting ocean health by ocean acidification. SOCONET has an open ocean emphasis but will work with regional (coastal) networks. It will liaise with intergovernmental science organizations such as Global Atmosphere Watch (GAW), and the joint committee for and ocean and marine meteorology (JCOMM). Here we describe the details of this emerging network and its proposed operations and practices. |
BibTeX:
@article{Wanninkhof2019a,
author = {Wanninkhof, Rik and Pickers, Penelope A and Omar, Abdirahman M and Sutton, Adrienne and Murata, Akihiko and Olsen, Are and Stephens, Britton B and Tilbrook, Bronte and Munro, David and Pierrot, Denis and Rehder, Gregor and Santana-Casiano, J Magdalena and Müller, Jens D and Trinanes, Joaquin and Tedesco, Kathy and O'Brien, Kevin and Currie, Kim and Barbero, Leticia and Telszewski, Maciej and Hoppema, Mario and Ishii, Masao and González-Dávila, Melchor and Bates, Nicholas R and Metzl, Nicolas and Suntharalingam, Parvadha and Feely, Richard A and ichiro Nakaoka, Shin and Lauvset, Siv K and Takahashi, Taro and Steinhoff, Tobias and Schuster, Ute},
title = {A surface ocean CO2 reference network, SOCONET and associated marine boundary layer CO2 measurements},
journal = {Frontiers in Marine Science},
publisher = {Frontiers Media SA},
year = {2019},
volume = {6},
number = {JUL},
doi = {10.3389/fmars.2019.00400}
}
|
| White ED, Rigby M, Lunt MF, Luke Smallman T, Comyn-Platt E, Manning AJ, Ganesan AL, O'Doherty S, Stavert AR, Stanley K, Williams M, Levy P, Ramonet M, Forster GL, Manning AC and Palmer PI (2019), "Quantifying the UK's carbon dioxide flux: An atmospheric inverse modelling approach using a regional measurement network", Atmospheric Chemistry and Physics., apr, 2019. Vol. 19(7), pp. 4345-4365. Copernicus GmbH. |
| Abstract: We present a method to derive atmosphericobservation-based estimates of carbon dioxide (CO2) fluxes at the national scale, demonstrated using data from a network of surface tall-tower sites across the UK and Ireland over the period 2013-2014. The inversion is carried out using simulations from a Lagrangian chemical transport model and an innovative hierarchical Bayesian Markov chain Monte Carlo (MCMC) framework, which addresses some of the traditional problems faced by inverse modelling studies, such as subjectivity in the specification of model and prior uncertainties. Biospheric fluxes related to gross primary productivity and terrestrial ecosystem respiration are solved separately in the inversion and then combined a posteriori to determine net ecosystem exchange of CO2. Two different models, Data Assimilation Linked Ecosystem Carbon (DALEC) and Joint UK Land Environment Simulator (JULES), provide prior estimates for these fluxes. We carry out separate inversions to assess the impact of these different priors on the posterior flux estimates and evaluate the differences between the prior and posterior estimates in terms of missing model components. The Numerical Atmospheric dispersion Modelling Environment (NAME) is used to relate fluxes to the measurements taken across the regional network. Posterior CO2 estimates from the two inversions agree within estimated uncertainties, despite large differences in the prior fluxes from the different models. With our method, averaging results from 2013 and 2014, we find a total annual net biospheric flux for the UK of 8±79 TgCO2 yr-1 (DALEC prior) and 64±85 TgCO2 yr-1 (JULES prior), where negative values represent an uptake of CO2. These biospheric CO2 estimates show that annual UK biospheric sources and sinks are roughly in balance. These annual mean estimates consistently indicate a greater net release of CO2 than the prior estimates, which show much more pronounced uptake in summer months. |
BibTeX:
@article{White2019,
author = {White, Emily D and Rigby, Matthew and Lunt, Mark F and Luke Smallman, T and Comyn-Platt, Edward and Manning, Alistair J and Ganesan, Anita L and O'Doherty, Simon and Stavert, Ann R and Stanley, Kieran and Williams, Mathew and Levy, Peter and Ramonet, Michel and Forster, Grant L and Manning, Andrew C and Palmer, Paul I},
title = {Quantifying the UK's carbon dioxide flux: An atmospheric inverse modelling approach using a regional measurement network},
journal = {Atmospheric Chemistry and Physics},
publisher = {Copernicus GmbH},
year = {2019},
volume = {19},
number = {7},
pages = {4345--4365},
doi = {10.5194/acp-19-4345-2019}
}
|
| Woolf D, Shutler J, Goddijn‐Murphy L, Watson A, Chapron B, Nightingale P, Donlon C, Piskozub J, Yelland M, Ashton I, Holding T, Schuster U, Girard‐Ardhuin F, Grouazel A, Piolle J, Warren M, Wrobel‐Niedzwiecka I, Land P, Torres R, Prytherch J, Moat B, Hanafin J, Ardhuin F and Paul F (2019), "Key Uncertainties in the Recent Air‐Sea Flux of CO textlesssubtextgreater2textless/subtextgreater", Global Biogeochemical Cycles., dec, 2019. Vol. 33(12), pp. 1548-1563. Blackwell Publishing Ltd. |
| Abstract: The contemporary air-sea flux of CO2 is investigated by the use of an air-sea flux equation, with particular attention to the uncertainties in global values and their origin with respect to that equation. In particular, uncertainties deriving from the transfer velocity and from sparse upper ocean sampling are investigated. Eight formulations of air-sea gas transfer velocity are used to evaluate the combined standard uncertainty resulting from several sources of error. Depending on expert opinion, a standard uncertainty in transfer velocity of either ˜5% or ˜10% can be argued and that will contribute a proportional error in air-sea flux. The limited sampling of upper ocean fCO2 is readily apparent in the Surface Ocean CO2 Atlas databases. The effect of sparse sampling on the calculated fluxes was investigated by a bootstrap method, that is, treating each ship cruise to an oceanic region as a random episode and creating 10 synthetic data sets by randomly selecting episodes with replacement. Convincing values of global net air-sea flux can only be achieved using upper ocean data collected over several decades but referenced to a standard year. The global annual referenced values are robust to sparse sampling, but seasonal and regional values exhibit more sampling uncertainty. Additional uncertainties are related to thermal and haline effects and to aspects of air-sea gas exchange not captured by standard models. An estimate of global net CO2 exchange referenced to 2010 of −3.0 ± 0.6 Pg C/year is proposed, where the uncertainty derives primarily from uncertainty in the transfer velocity. |
BibTeX:
@article{Woolf2019,
author = {Woolf, D.K. and Shutler, J.D. and Goddijn‐Murphy, L. and Watson, A.J. and Chapron, B. and Nightingale, P.D. and Donlon, C.J. and Piskozub, J. and Yelland, M.J. and Ashton, I. and Holding, T. and Schuster, U. and Girard‐Ardhuin, F. and Grouazel, A. and Piolle, J.‐F. and Warren, M. and Wrobel‐Niedzwiecka, I. and Land, P.E. and Torres, R. and Prytherch, J. and Moat, B. and Hanafin, J. and Ardhuin, F. and Paul, F.},
title = {Key Uncertainties in the Recent Air‐Sea Flux of CO textlesssubtextgreater2textless/subtextgreater},
journal = {Global Biogeochemical Cycles},
publisher = {Blackwell Publishing Ltd},
year = {2019},
volume = {33},
number = {12},
pages = {1548--1563},
url = {https://onlinelibrary.wiley.com/doi/abs/10.1029/2018GB006041},
doi = {10.1029/2018GB006041}
}
|
| Wu W, Gong C, Li X, Guo H and Zhang L (2019), "An online deep convolutional model of gross primary productivity and net ecosystem exchange estimation for global forests", IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing., dec, 2019. Vol. 12(12), pp. 5178-5188. Institute of Electrical and Electronics Engineers. |
| Abstract: In this article, we propose a universal data-driven model to acquire FLUXNET-consistent annual forest gross primary productivity and net ecosystem exchange globally. The model is developed based on a deep-learning network with a time series of seven ecological and climatic parameters as inputs. To avoid tedious data downloading for large-Area studies, we build this model on the Google earth engine platform with all of the input data available online. A multidimensional convolutional block is adopted to detect meaningful variation patterns between forest growth and the environment. The patterns are then encoded and adjusted with forest attributes to obtain the final estimation through a multilayer perceptron. This special working mechanism enables the model to understand and adapt to different modes of forest carbon dynamics. The new model behaves more like a human than conventional machine-learning models, which directly retrieve estimations from raw input variables. Multistep transfer learning is implemented to make the model robust to a large portion of data gaps and to obtain a balanced performance for different climates and ecological zones. The experimental results demonstrate that the model can achieve estimations that are highly consistent with the FLUXNET records. By visualizing the activation outputs of intermediate layers in the convolutional block, we show that the model can reasonably reflect key influence factors in different periods of a year for various forest types. This result means that we may be able to better understand forest carbon absorption by learning how this model works to obtain correct estimations. |
BibTeX:
@article{Wu2019,
author = {Wu, Wenjin and Gong, Chen and Li, Xinwu and Guo, Huadong and Zhang, Lu},
title = {An online deep convolutional model of gross primary productivity and net ecosystem exchange estimation for global forests},
journal = {IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing},
publisher = {Institute of Electrical and Electronics Engineers},
year = {2019},
volume = {12},
number = {12},
pages = {5178--5188},
doi = {10.1109/JSTARS.2019.2954556}
}
|
| Xia J, Yuan W, Lienert S, Joos F, Ciais P, Viovy N, ping Wang Y, Wang X, Zhang H, Chen Y and Tian X (2019), "Global Patterns in Net Primary Production Allocation Regulated by Environmental Conditions and Forest Stand Age: A Model-Data Comparison", Journal of Geophysical Research: Biogeosciences., jul, 2019. Vol. 124(7), pp. 2039-2059. American Geophysical Union (AGU). |
| Abstract: The allocation of net primary production (NPP) to different plant structures, such as leaves, wood, and fine roots, plays an important role in the terrestrial carbon cycle. However, the biogeographical patterns of NPP allocation are not well understood. We constructed a global database of forest NPP to investigate the observed spatial patterns of forest NPP allocation, as influenced by environmental drivers and forest stand age. We then examined whether dynamic global vegetation models (DGVMs) could capture these allocation patterns. The NPP allocation response to variations in temperature or precipitation was often opposite in leaves and fine roots, a finding consistent with the functional balance theory for allocation. The observed allocation to fine roots decreased with increasing temperature and precipitation. The observed allocation to wood and leaves decreased with forest stand age. The simulated allocation with five DGVMs was compared with the observations. The five models captured the spatial gradient of lower allocation to fine roots with increasing temperature and precipitation but did not capture coincident gradients in allocation to wood and leaves. None of the five models adequately represented the changes in allocation with forest stand age. Specifically, the models did not reproduce the decrease in allocation to wood and leaves and the increase in allocation to fine roots with increasing forest stand age. An accurate simulation of NPP allocation requires more realistic representation of multiple processes that are closely related to allocation. The NPP allocation database can be used to develop DGVMs. |
BibTeX:
@article{Xia2019,
author = {Xia, Jiangzhou and Yuan, Wenping and Lienert, Sebastian and Joos, Fortunat and Ciais, Philippe and Viovy, Nicolas and ping Wang, Ying and Wang, Xufeng and Zhang, Haicheng and Chen, Yang and Tian, Xiangjun},
title = {Global Patterns in Net Primary Production Allocation Regulated by Environmental Conditions and Forest Stand Age: A Model-Data Comparison},
journal = {Journal of Geophysical Research: Biogeosciences},
publisher = {American Geophysical Union (AGU)},
year = {2019},
volume = {124},
number = {7},
pages = {2039--2059},
doi = {10.1029/2018JG004777}
}
|
| Xu X, Du H, Fan W, Hu J, Mao F and Dong H (2019), "Long-term trend in vegetation gross primary production, phenology and their relationships inferred from the FLUXNET data", Journal of Environmental Management., sep, 2019. Vol. 246, pp. 605-616. |
BibTeX:
@article{Xu2019,
author = {Xu, Xiaojun and Du, Huaqiang and Fan, Weiliang and Hu, Junguo and Mao, Fangjie and Dong, Hao},
title = {Long-term trend in vegetation gross primary production, phenology and their relationships inferred from the FLUXNET data},
journal = {Journal of Environmental Management},
year = {2019},
volume = {246},
pages = {605--616},
url = {https://linkinghub.elsevier.com/retrieve/pii/S0301479719308242},
doi = {10.1016/j.jenvman.2019.06.023}
}
|
| Yang W, Kobayashi H, Wang C, Shen M, Chen J, Matsushita B, Tang Y, Kim Y, Bret-Harte MS, Zona D, Oechel W and Kondoh A (2019), "A semi-analytical snow-free vegetation index for improving estimation of plant phenology in tundra and grassland ecosystems", Remote Sensing of Environment., jul, 2019. Vol. 228, pp. 31-44. Elsevier Inc.. |
| Abstract: Satellite monitoring of plant phenology in tundra and grassland ecosystems using conventional vegetation indices (VIs), such as the normalized difference vegetation index (NDVI), can be biased by effects of snow. Snow-free VIs that take advantage of the shortwave infrared (SWIR) band have been proposed to overcome this problem, viz., the phenology index (PI) and the normalized difference phenology index (NDPI). However, the PI cannot properly capture the presence of sparse vegetation, and the NDPI does not account for the influence of dry vegetation. Here, we propose a novel snow-free VI, designated the normalized difference greenness index (NDGI), that uses reflectance in the green, red, and near-infrared (NIR) bands. The NDGI is a semi-analytical index based on a linear spectral mixture model and the spectral characteristics of vegetation, snow, soil, and dry grass. Its performance at estimating the start and end of the growing season (SOS and EOS) was evaluated using simulation datasets, time-lapse camera data at tundra sites, and flux tower gross primary production (GPP) data at grassland sites. Simulation results demonstrated that the NDGI can exclude the influence of snow on estimates of SOS and EOS. At the tundra sites, the NDGI markedly outperformed the NDVI, PI, NDPI, NIRv (near-infrared reflectance of vegetation), EVI2 (two-band enhanced vegetation index), PPI (plant phenology index), and DVI+ (difference vegetation index plus) for SOS estimation, with a root mean square error (RMSE) of 6.5 days and a Bias of −1.3 days, and for EOS estimation, with an RMSE of 8.3 days and a Bias of 0.11 days. At the grassland sites, the NDGI also outperformed the other VIs at SOS estimation, with an RMSE of 10.3 days and a Bias of −4.9 days. Although its performance was poorer at monitoring EOS than SOS at grassland (GPP) sites, its performance was comparable to that of the PI and superior to that of the other VIs at estimating EOS. These results indicate the potential of the NDGI for operational monitoring of plant phenology in tundra and grassland ecosystems based on satellite observations. |
BibTeX:
@article{Yang2019,
author = {Yang, Wei and Kobayashi, Hideki and Wang, Cong and Shen, Miaogen and Chen, Jin and Matsushita, Bunkei and Tang, Yanhong and Kim, Yongwon and Bret-Harte, M. Syndonia and Zona, Donatella and Oechel, Walter and Kondoh, Akihiko},
title = {A semi-analytical snow-free vegetation index for improving estimation of plant phenology in tundra and grassland ecosystems},
journal = {Remote Sensing of Environment},
publisher = {Elsevier Inc.},
year = {2019},
volume = {228},
pages = {31--44},
doi = {10.1016/j.rse.2019.03.028}
}
|
| Yuan W, Zheng Y, Piao S, Ciais P, Lombardozzi D, Wang Y, Ryu Y, Chen G, Dong W, Hu Z, Jain AK, Jiang C, Kato E, Li S, Lienert S, Liu S, Nabel JEMS, Qin Z, Quine T, Sitch S, Smith WK, Wang F, Wu C, Xiao Z and Yang S (2019), "Increased atmospheric vapor pressure deficit reduces global vegetation growth", Science Advances., aug, 2019. Vol. 5(8), pp. eaax1396. American Association for the Advancement of Science (AAAS). |
| Abstract: Atmospheric vapor pressure deficit (VPD) is a critical variable in determining plant photosynthesis. Synthesis of four global climate datasets reveals a sharp increase of VPD after the late 1990s. In response, the vegetation greening trend indicated by a satellite-derived vegetation index (GIMMS3g), which was evident before the late 1990s, was subsequently stalled or reversed. Terrestrial gross primary production derived from two satellite-based models (revised EC-LUE and MODIS) exhibits persistent and widespread decreases after the late 1990s due to increased VPD, which offset the positive CO2 fertilization effect. Six Earth system models have consistently projected continuous increases of VPD throughout the current century. Our results highlight that the impacts of VPD on vegetation growth should be adequately considered to assess ecosystem responses to future climate conditions. |
BibTeX:
@article{Yuan2019,
author = {Yuan, Wenping and Zheng, Yi and Piao, Shilong and Ciais, Philippe and Lombardozzi, Danica and Wang, Yingping and Ryu, Youngryel and Chen, Guixing and Dong, Wenjie and Hu, Zhongming and Jain, Atul K and Jiang, Chongya and Kato, Etsushi and Li, Shihua and Lienert, Sebastian and Liu, Shuguang and Nabel, Julia E M S and Qin, Zhangcai and Quine, Timothy and Sitch, Stephen and Smith, William K and Wang, Fan and Wu, Chaoyang and Xiao, Zhiqiang and Yang, Song},
title = {Increased atmospheric vapor pressure deficit reduces global vegetation growth},
journal = {Science Advances},
publisher = {American Association for the Advancement of Science (AAAS)},
year = {2019},
volume = {5},
number = {8},
pages = {eaax1396},
doi = {10.1126/sciadv.aax1396}
}
|
| Zeeman MJ, Shupe H, Baessler C and Ruehr NK (2019), "Productivity and vegetation structure of three differently managed temperate grasslands", Agriculture, Ecosystems and Environment., feb, 2019. Vol. 270-271, pp. 129-148. Elsevier BV. |
| Abstract: An improved regional assessment of the productivity of grasslands depends on comprehensive knowledge of the interactions between climatic drivers, vegetation properties and human activity. Managed grasslands in Europe display highly dynamic responses, which contribute to the challenge in making representative model simulations. Therefore, we investigated the relationships between vegetation state changes and productivity of meadow grasslands by comparing three study sites in Southern Germany (DE-Fen, DE-RbW, DE-Gwg), which are characterised by different management intensities and elevations. Weekly observations of vegetation height, leaf area, above-ground biomass and plant functional types were compared to estimates of the gross ecosystem productivity (GEP) determined from atmospheric surface exchange of carbon dioxide. We found that the cumulative GEP of these grasslands correlated positively with management intensity and negatively with elevation at the seasonal scale. The differences in above-ground vegetation properties among the three sites were most pronounced during spring and contributed to significant differences in annual carbon (200%) and nitrogen (4%) biomass yields. Nevertheless, when periods between harvests were considered individually, the relationship between GEP and above-ground biomass, leaf area and vegetation height appeared to follow unified patterns for all sites. In addition, our study highlights a substantial potential for systematic error based on the techniques used to quantify vegetation properties and a mitigating approach was evaluated that includes continuous automated observations of vegetation height. These outcomes can serve as a reference for modelling studies on the seasonal allocation of carbon and vegetation properties in managed humid temperate grassland systems. |
BibTeX:
@article{Zeeman2019,
author = {Zeeman, Matthias J and Shupe, Heather and Baessler, Cornelia and Ruehr, Nadine K},
title = {Productivity and vegetation structure of three differently managed temperate grasslands},
journal = {Agriculture, Ecosystems and Environment},
publisher = {Elsevier BV},
year = {2019},
volume = {270-271},
pages = {129--148},
doi = {10.1016/j.agee.2018.10.003}
}
|
| Zellweger C, Steinbrecher R, Laurent O, Lee H, Kim S, Emmenegger L, Steinbacher M and Buchmann B (2019), "Recent advances in measurement techniques for atmospheric carbon monoxide and nitrous oxide observations", Atmospheric Measurement Techniques., nov, 2019. Vol. 12(11), pp. 5863-5878. Copernicus GmbH. |
| Abstract: Carbon monoxide (CO) and nitrous oxide (span classCombining double low line inline-formula N2O/span) are two key parameters in the observation of the atmosphere, relevant to air quality and climate change, respectively. For CO, various analytical techniques have been in use over the last few decades. In contrast, span classCombining double low line inline-formula N2O/span was mainly measured using gas chromatography (GC) with an electron capture detector (ECD). In recent years, new spectroscopic methods have become available which are suitable for both CO and span classCombining double low line inline-formula N2O/span. These include infrared (IR) spectroscopic techniques such as cavity ring-down spectroscopy (CRDS), off-axis integrated cavity output spectroscopy (OA-ICOS) and Fourier transform infrared spectroscopy (FTIR). Corresponding instruments became recently commercially available and are increasingly used at atmospheric monitoring stations. We analysed results obtained through performance audits conducted within the framework of the Global Atmosphere Watch (GAW) quality management system of the World Meteorology Organization (WMO). These results reveal that current spectroscopic measurement techniques have clear advantages with respect to data quality objectives compared to more traditional methods for measuring CO and span classCombining double low line inline-formula N2O/span. Further, they allow for a smooth continuation of historic CO and span classCombining double low line inline-formula N2O/span time series. However, special care is required concerning potential water vapour interference on the CO amount fraction reported by near-IR CRDS instruments. This is reflected in the results of parallel measurement campaigns, which clearly indicate that drying the sample air leads to an improved accuracy of CO measurements with such near-IR CRDS instruments. |
BibTeX:
@article{Zellweger2019,
author = {Zellweger, Christoph and Steinbrecher, Rainer and Laurent, Olivier and Lee, Haeyoung and Kim, Sumin and Emmenegger, Lukas and Steinbacher, Martin and Buchmann, Brigitte},
title = {Recent advances in measurement techniques for atmospheric carbon monoxide and nitrous oxide observations},
journal = {Atmospheric Measurement Techniques},
publisher = {Copernicus GmbH},
year = {2019},
volume = {12},
number = {11},
pages = {5863--5878},
doi = {10.5194/amt-12-5863-2019}
}
|
| Zhang Y, Goll D, Bastos A, Balkanski Y, Boucher O, Cescatti A, Collier M, Gasser T, Ghattas J, Li L, Piao S, Viovy N, Zhu D and Ciais P (2019), "Increased Global Land Carbon Sink Due to Aerosol-Induced Cooling", Global Biogeochemical Cycles., mar, 2019. Vol. 33(3), pp. 439-457. American Geophysical Union (AGU). |
| Abstract: Anthropogenic aerosols have contributed to historical climate change through their interactions with radiation and clouds. In turn, climate change due to aerosols has impacted the C cycle. Here we use a set of offline simulations made with the Organising Carbon and Hydrology In Dynamic Ecosystems (ORCHIDEE) land surface model driven by bias-corrected climate fields from simulations of three Coupled Model Intercomparison Project Phase 5 (CMIP5) Earth system models (ESMs; IPSL-CM5A-LR, CSIRO-Mk3.6.0, and GISS-E2-R) to quantify the climate-related impacts of aerosols on land carbon fluxes during 1860–2005. We found that climate change from anthropogenic aerosols (CCAA) globally cooled the climate, and increased land carbon storage, or cumulative net biome production (NBP), by 11.6–41.8 PgC between 1860 and 2005. The increase in NBP from CCAA mainly occurs in the tropics and northern midlatitudes, primarily due to aerosol-induced cooling. At high latitudes, cooling caused stronger decrease in gross primary production (GPP) than in total ecosystem respiration (TER), leading to lower NBP. At midlatitudes, cooling-induced decrease in TER is stronger than that of GPP, resulting in NBP increase. At low latitudes, NBP was also enhanced due to the cooling-induced GPP increase, but precipitation decline from CCAA may negate the effect of temperature. The three ESMs show large divergence in low-latitude CCAA precipitation response to aerosols, which results in considerable uncertainties in regional estimations of CCAA effects on carbon fluxes. Our results suggest that better understanding and simulation of how anthropogenic aerosols affect precipitation in ESMs is required for a more accurate attribution of aerosol effects on the terrestrial carbon cycle. |
BibTeX:
@article{Zhang2019,
author = {Zhang, Yuan and Goll, Daniel and Bastos, Ana and Balkanski, Yves and Boucher, Olivier and Cescatti, Alessandro and Collier, Mark and Gasser, Thomas and Ghattas, Josefine and Li, Laurent and Piao, Shilong and Viovy, Nicolas and Zhu, Dan and Ciais, Philippe},
title = {Increased Global Land Carbon Sink Due to Aerosol-Induced Cooling},
journal = {Global Biogeochemical Cycles},
publisher = {American Geophysical Union (AGU)},
year = {2019},
volume = {33},
number = {3},
pages = {439--457},
doi = {10.1029/2018GB006051}
}
|
| Zhang W, Jansson PE, Sigsgaard C, McConnell A, Jammet MM, Westergaard-Nielsen A, Lund M, Friborg T, Michelsen A and Elberling B (2019), "Model-data fusion to assess year-round CO2 fluxes for an arctic heath ecosystem in West Greenland (69°N)", Agricultural and Forest Meteorology., jul, 2019. Vol. 272-273, pp. 176-186. Elsevier BV. |
| Abstract: Quantifying net CO2 exchange (NEE)of arctic terrestrial ecosystems in response to changes in climatic and environmental conditions is central to understanding ecosystem functioning and assessing potential feedbacks of the carbon cycle to future climate changes. However, annual CO2 budgets for arctic tundra are rare due to the difficulties of performing measurements during non-growing seasons. It is still unclear to what extent arctic tundra ecosystems currently act as a CO2 source, sink or are in balance. This study presents year-round eddy-covariance (EC)measurements of CO2 fluxes for an arctic heath ecosystem on Disko Island, West Greenland (69 °N)over five years. Based on a fusion of year-round EC-derived CO2 fluxes, soil temperature and moisture, the process-oriented model (CoupModel)has been constrained to quantify an annual budget and characterize seasonal patterns of CO2 fluxes. The results show that total photosynthesis corresponds to -202 ± 20 g C mâˆ'2 yr-1 with ecosystem respiration of 167 ± 28 g C m-2 yr-1, resulting in NEE of -35 ± 15 g C m-2 yr-1. The respiration loss is mainly described as decomposition of near-surface litter. A year with an anomalously deep snowpack shows a threefold increase in the rate of ecosystem respiration compared to other years. Due to the high CO2 emissions during that winter, the annual budget results in a marked reduction in the CO2 sink. The seasonal patterns of photosynthesis and soil respiration were described using response functions of the forcing atmosphere and soil conditions. Snow depth, topography-related soil moisture, and growing season warmth are identified as important environmental characteristics which most influence seasonal rates of gas exchange. |
BibTeX:
@article{Zhang2019a,
author = {Zhang, Wenxin and Jansson, Per Erik and Sigsgaard, Charlotte and McConnell, Alistair and Jammet, Mathilde Manon and Westergaard-Nielsen, Andreas and Lund, Magnus and Friborg, Thomas and Michelsen, Anders and Elberling, Bo},
title = {Model-data fusion to assess year-round CO2 fluxes for an arctic heath ecosystem in West Greenland (69°N)},
journal = {Agricultural and Forest Meteorology},
publisher = {Elsevier BV},
year = {2019},
volume = {272-273},
pages = {176--186},
doi = {10.1016/j.agrformet.2019.02.021}
}
|
| Zhao WL, Gentine P, Reichstein M, Zhang Y, Zhou S, Wen Y, Lin C, Li X and Qiu GY (2019), "Physics-Constrained Machine Learning of Evapotranspiration", Geophysical Research Letters., dec, 2019. Vol. 46(24), pp. 14496-14507. Blackwell Publishing Ltd. |
| Abstract: Estimating ecosystem evapotranspiration (ET) is important to understanding the global water cycle and to study land-atmosphere interactions. We developed a physics constrained machine learning (ML) model (hybrid model) to estimate latent heat flux (LE), which conserves the surface energy budget. By comparing model predictions with observations at 82 eddy covariance tower sites, our hybrid model shows similar performance to the pure ML model in terms of mean metrics (e.g., mean absolute percent errors) but, importantly, the hybrid model conserves the surface energy balance, while the pure ML model does not. A second key result is that the hybrid model extrapolates much better than the pure ML model, emphasizing the benefits of combining physics with ML for increased generalizations. The hybrid model allows inferring the structural dependence of ET and surface resistance (rs), and we find that vegetation height and soil moisture are the main regulators of ET and rs. |
BibTeX:
@article{Zhao2019,
author = {Zhao, Wen Li and Gentine, Pierre and Reichstein, Markus and Zhang, Yao and Zhou, Sha and Wen, Yeqiang and Lin, Changjie and Li, Xi and Qiu, Guo Yu},
title = {Physics-Constrained Machine Learning of Evapotranspiration},
journal = {Geophysical Research Letters},
publisher = {Blackwell Publishing Ltd},
year = {2019},
volume = {46},
number = {24},
pages = {14496--14507},
doi = {10.1029/2019GL085291}
}
|
| Zhao Y, Saunois M, Bousquet P, Lin X, Berchet A, Hegglin MI, Canadell JG, Jackson RB, Hauglustaine DA, Szopa S, Stavert AR, Abraham NL, Archibald AT, Bekki S, Deushi M, Jöckel P, Josse B, Kinnison D, Kirner O, Marécal V, O'connor FM, Plummer DA, Revell LE, Rozanov E, Stenke A, Strode S, Tilmes S, Dlugokencky EJ and Zheng B (2019), "Inter-model comparison of global hydroxyl radical (OH) distributions and their impact on atmospheric methane over the 2000-2016 period", Atmos. Chem. Phys. Vol. 19, pp. 13701-13723. |
| Abstract: The modeling study presented here aims to estimate how uncertainties in global hydroxyl radical (OH) distributions , variability, and trends may contribute to resolving discrepancies between simulated and observed methane (CH 4) changes since 2000. A multi-model ensemble of 14 OH fields was analyzed and aggregated into 64 scenarios to force the offline atmospheric chemistry transport model LMDz (Laboratoire de Meteorologie Dynamique) with a standard CH 4 emission scenario over the period 2000-2016. The multi-model simulated global volume-weighted tropo-spheric mean OH concentration ([OH]) averaged over 2000-2010 ranges between 8.7 × 10 5 and 12.8 × 10 5 molec cm −3. The inter-model differences in tropospheric OH burden and vertical distributions are mainly determined by the differences in the nitrogen oxide (NO) distributions, while the spatial discrepancies between OH fields are mostly due to differences in natural emissions and volatile organic compound (VOC) chemistry. From 2000 to 2010, most simulated OH fields show an increase of 0.1-0.3 × 10 5 molec cm −3 in the tropospheric mean [OH], with year-to-year variations much smaller than during the historical period 1960-2000. Once ingested into the LMDz model, these OH changes translated into a 5 to 15 ppbv reduction in the CH 4 mixing ratio in 2010, which represents 7 %-20 % of the model-simulated CH 4 increase due to surface emissions. Between 2010 and 2016, the ensemble of simulations showed that OH changes could lead to a CH 4 mixing ratio uncertainty of textgreater ±30 ppbv. Over the full 2000-2016 time period, using a common state-of-the-art but nonoptimized emission scenario, the impact of [OH] changes tested here can explain up to 54 % of the gap between model simulations and observations. This result emphasizes the importance of better representing OH abundance and variations in CH 4 forward simulations and emission optimizations performed by atmospheric inversions. |
BibTeX:
@article{Zhao2019a,
author = {Zhao, Yuanhong and Saunois, Marielle and Bousquet, Philippe and Lin, Xin and Berchet, Antoine and Hegglin, Michaela I and Canadell, Josep G and Jackson, Robert B and Hauglustaine, Didier A and Szopa, Sophie and Stavert, Ann R and Abraham, Nathan Luke and Archibald, Alex T and Bekki, Slimane and Deushi, Makoto and Jöckel, Patrick and Josse, Béatrice and Kinnison, Douglas and Kirner, Ole and Marécal, Virginie and O'connor, Fiona M and Plummer, David A and Revell, Laura E and Rozanov, Eugene and Stenke, Andrea and Strode, Sarah and Tilmes, Simone and Dlugokencky, Edward J and Zheng, Bo},
title = {Inter-model comparison of global hydroxyl radical (OH) distributions and their impact on atmospheric methane over the 2000-2016 period},
journal = {Atmos. Chem. Phys},
year = {2019},
volume = {19},
pages = {13701--13723},
url = {https://doi.org/10.5194/acp-19-13701-2019},
doi = {10.5194/acp-19-13701-2019}
}
|
| Zheng B, Chevallier F, Yin Y, Ciais P, Fortems-Cheiney A, Deeter MN, Parker RJ, Wang Y, Worden HM and Zhao Y (2019), "Global atmospheric carbon monoxide budget 2000-2017 inferred from multi-species atmospheric inversions", Earth System Science Data., sep, 2019. Vol. 11(3), pp. 1411-1436. Copernicus GmbH. |
| Abstract: Atmospheric carbon monoxide (CO) concentrations have been decreasing since 2000, as observed by both satellite-and ground-based instruments, but global bottom-up emission inventories estimate increasing anthropogenic CO emissions concurrently. In this study, we use a multi-species atmospheric Bayesian inversion approach to attribute satellite-observed atmospheric CO variations to its sources and sinks in order to achieve a full closure of the global CO budget during 2000-2017. Our observation constraints include satellite retrievals of the total column mole fraction of CO, formaldehyde (HCHO), and methane (CH4) that are all major components of the atmospheric CO cycle. Three inversions (i.e., 2000-2017, 2005-2017, and 2010-2017) are performed to use the observation data to the maximum extent possible as they become available and assess the consistency of inversion results to the assimilation of more trace gas species. We identify a declining trend in the global CO budget since 2000 (three inversions are broadly consistent during overlapping periods), driven by reduced anthropogenic emissions in the US and Europe (both likely from the transport sector), and in China (likely from industry and residential sectors), as well as by reduced biomass burning emissions globally, especially in equatorial Africa (associated with reduced burned areas). We show that the trends and drivers of the inversionbased CO budget are not affected by the inter-annual variation assumed for prior CO fluxes. All three inversions contradict the global bottom-up inventories in the world's top two emitters: for the sign of anthropogenic emission trends in China (e.g., here-0:8 ± 0:5 % yr-1 since 2000, while the prior gives 1:3 ± 0:4 % yr-1) and for the rate of anthropogenic emission increase in South Asia (e.g., here 1:0 ± 0:6 % yr-1 since 2000, smaller than 3:5 ± 0:4 % yr-1 in the prior inventory). The posterior model CO concentrations and trends agree well with independent ground-based observations and correct the prior model bias. The comparison of the three inversions with different observation constraints further suggests that the most complete constrained inversion that assimilates CO, HCHO, and CH4 has a good representation of the global CO budget, and therefore matches best with independent observations, while the inversion only assimilating CO tends to underestimate both the decrease in anthropogenic CO emissions and the increase in the CO chemical production. The global CO budget data from all three inversions in this study can be accessed from https://doi.org/10.6084/m9.figshare.c.4454453.v1 (Zheng et al., 2019). |
BibTeX:
@article{Zheng2019,
author = {Zheng, Bo and Chevallier, Frederic and Yin, Yi and Ciais, Philippe and Fortems-Cheiney, Audrey and Deeter, Merritt N and Parker, Robert J and Wang, Yilong and Worden, Helen M and Zhao, Yuanhong},
title = {Global atmospheric carbon monoxide budget 2000-2017 inferred from multi-species atmospheric inversions},
journal = {Earth System Science Data},
publisher = {Copernicus GmbH},
year = {2019},
volume = {11},
number = {3},
pages = {1411--1436},
doi = {10.5194/essd-11-1411-2019}
}
|
| Zhou M, Langerock B, Vigouroux C, Kumar Sha M, Hermans C, Metzger JM, Chen H, Ramonet M, Kivi R, Heikkinen P, Smale D, Pollard DF, Jones N, Velazco VA, García OE, Schneider M, Palm M, Warneke T and De Mazière M (2019), "TCCON and NDACC XCO measurements: Difference, discussion and application", Atmospheric Measurement Techniques., nov, 2019. Vol. 12(11), pp. 5979-5995. Copernicus GmbH. |
| Abstract: Column-averaged dry-air mole fraction of CO (XCO) measurements are obtained from two ground-based Fourier transform infrared (FTIR) spectrometer networks: the Total Carbon Column Observing Network (TCCON) and the Network for the Detection of Atmospheric Composition Change (NDACC). In this study, the differences between the TCCON and NDACC XCO measurements are investigated and discussed based on six NDACC-TCCON sites using data over the period 2007-2017. A direct comparison shows that the NDACC XCO measurements are about 5.5 % larger than the TCCON data at Ny-Ålesund, Bremen, and Izaña (Northern Hemisphere), and the absolute bias between the NDACC and TCCON data is within 2 % at Saint-Denis, Wollongong and Lauder (Southern Hemisphere). The hemispheric dependence of the bias is mainly attributed to their smoothing errors. The systematic smoothing error of the TCCON XCO data varies in the range between 0.2 % (Bremen) and 7.9 % (Lauder), and the random smoothing error varies in the range between 2.0 % and 3.6 %. The systematic smoothing error of NDACC data is between 0.1 % and 0.8 %, and the random smoothing error of NDACC data is about 0.3 %. For TCCON data, the smoothing error is significant because it is higher than the reported uncertainty, particularly at Southern Hemisphere sites. To reduce the influence from the a priori profiles and different vertical sensitivities, the scaled NDACC a priori profiles are used as the common a priori profiles for comparing TCCON and NDACC retrievals. As a result, the biases between TCCON and NDACC XCO measurements become more consistent (5.6 %-8.5 %) with a mean value of 6.8 % at these sites. To determine the sources of the remaining bias, regular AirCore measurements at Orléans and Sodankylä are compared to co-located TCCON measurements. It is found that TCCON XCO measurements are 6.1 ± 1.6 % and 8.0 ± 3.2 % smaller than the AirCore measurements at Orléans and Sodankylä, respectively, indicating that the scaling factor of TCCON XCO data should be around 1.0000 instead of 1.0672. Further investigations should be carried out in the TCCON community to determine the correct scaling factor to be applied to the TCCON XCO data. This paper also demonstrates that the smoothing error must be taken into account when comparing FTIR XCO data, and especially TCCON XCO data, with model or satellite data. |
BibTeX:
@article{Zhou2019,
author = {Zhou, Minqiang and Langerock, Bavo and Vigouroux, Corinne and Kumar Sha, Mahesh and Hermans, Christian and Metzger, Jean Marc and Chen, Huilin and Ramonet, Michel and Kivi, Rigel and Heikkinen, Pauli and Smale, Dan and Pollard, David F and Jones, Nicholas and Velazco, Voltaire A and García, Omaira E and Schneider, Matthias and Palm, Mathias and Warneke, Thorsten and De Mazière, Martine},
title = {TCCON and NDACC XCO measurements: Difference, discussion and application},
journal = {Atmospheric Measurement Techniques},
publisher = {Copernicus GmbH},
year = {2019},
volume = {12},
number = {11},
pages = {5979--5995},
doi = {10.5194/amt-12-5979-2019}
}
|
| Zhou M, Langerock B, Sha MK, Kumps N, Hermans C, Petri C, Warneke T, Chen H, Metzger JM, Kivi R, Heikkinen P, Ramonet M and De Mazière M (2019), "Retrieval of atmospheric CH4 vertical information from ground-based FTS near-infrared spectra", Atmospheric Measurement Techniques., nov, 2019. Vol. 12(11), pp. 6125-6141. Copernicus GmbH. |
| Abstract: The Total Carbon Column Observing Network (TCCON) column-averaged dry air mole fraction of CH4 (XCH4) measurements have been widely used to validate satellite observations and to estimate model simulations. The GGG2014 code is the standard TCCON retrieval software used in performing a profile scaling retrieval. In order to obtain several vertical pieces of information in addition to the total column, in this study, the SFIT4 retrieval code is applied to retrieve the CH4 mole fraction vertical profile from the Fourier transform spectrometer (FTS) spectrum at six sites (Ny-Ålesund, Sodankylä, Bialystok, Bremen, Orléans and St Denis) during the time period of 2016-2017. The retrieval strategy of the CH4 profile retrieval from groundbased FTS near-infrared (NIR) spectra using the SFIT4 code (SFIT4NIR) is investigated. The degree of freedom for signal (DOFS) of the SFIT4NIR retrieval is about 2.4, with two distinct pieces of information in the troposphere and in the stratosphere. The averaging kernel and error budget of the SFIT4NIR retrieval are presented. The data accuracy and precision of the SFIT4NIR retrievals, including the total column and two partial columns (in the troposphere and stratosphere), are estimated by TCCON standard retrievals, ground-based in situ measurements, Atmospheric Chemistry Experiment - Fourier Transform Spectrometer (ACE-FTS) satellite observations, TCCON proxy data and AirCore and aircraft measurements. By comparison against TCCON standard retrievals, it is found that the retrieval uncertainty of SFIT4NIR XCH4 is similar to that of TCCON standard retrievals with systematic uncertainty within 0.35 % and random uncertainty of about 0.5 %. The tropospheric and stratospheric XCH4 from SFIT4NIR retrievals are assessed by comparison with AirCore and aircraft measurements, and there is a 1.0 ± 0.3 % overestimation in the SFIT4NIR tropospheric XCH4 and a 4.0 ± 2.0 % underestimation in the SFIT4NIR stratospheric XCH4, which are within the systematic uncertainties of SFIT4NIR-retrieved partial columns in the troposphere and stratosphere respectively. |
BibTeX:
@article{Zhou2019a,
author = {Zhou, Minqiang and Langerock, Bavo and Sha, Mahesh Kumar and Kumps, Nicolas and Hermans, Christian and Petri, Christof and Warneke, Thorsten and Chen, Huilin and Metzger, Jean Marc and Kivi, Rigel and Heikkinen, Pauli and Ramonet, Michel and De Mazière, Martine},
title = {Retrieval of atmospheric CH4 vertical information from ground-based FTS near-infrared spectra},
journal = {Atmospheric Measurement Techniques},
publisher = {Copernicus GmbH},
year = {2019},
volume = {12},
number = {11},
pages = {6125--6141},
doi = {10.5194/amt-12-6125-2019}
}
|
| Zhu P, Zhuang Q, Welp L, Ciais P, Heimann M, Peng B, Li W, Bernacchi C, Roedenbeck C and Keenan TF (2019), "Recent warming has resulted in smaller gains in net carbon uptake in northern high latitudes", Journal of Climate., sep, 2019. Vol. 32(18), pp. 5849-5863. American Meteorological Society. |
| Abstract: Carbon balance of terrestrial ecosystems in the northern high latitudes (NHL) is sensitive to climate change. It remains uncertain whether current regional carbon uptake capacity can be sustained under future warming. Here the atmospheric CO2 drawdown rate (CDR) between 1974 and 2014, defined as the CO2 decrease in ppm over the number of days in spring or summer, is estimated using atmospheric CO2 observations at Barrow (now known as Utqiaġvik), Alaska. We found that the sensitivity of CDR to interannual seasonal air temperature anomalies has trended toward less carbon uptake for a given amount of warming over this period. Changes in interannual temperature sensitivity of CDR suggest that relatively warm springs now result in less of a carbon uptake enhancement. Similarly, relatively warm summers now result in greater carbon release. These results generally agree with the sensitivity of net carbon exchange (NCE) estimated by atmospheric CO2 inversion. When NCE was aggregated over North America (NA) and Eurasia (EA), separately, the temperature sensitivity of NCE in NA has changed more than in EA. To explore potential mechanisms of this signal, we also examine trends in interannual variability of other climate variables (soil temperature and precipitation), satellite-derived gross primary production (GPP), and Trends in Net Land–Atmosphere Carbon Exchanges (TRENDY) model ensemble results. Our analysis suggests that the weakened spring sensitivity of CDR may be related to the slowdown in seasonal soil thawing rate, while the summer sensitivity change may be caused by the temporally coincident decrease in temperature sensitivity of photosynthesis. This study suggests that the current NHL carbon sink may become unsustainable as temperatures warm further. We also found that current carbon cycle models do not represent the decrease in temperature sensitivity of net carbon flux. We argue that current carbon–climate models misrepresent important aspect of the carbon–climate feedback and bias the estimation of warming influence on NHL carbon balance. |
BibTeX:
@article{Zhu2019,
author = {Zhu, Peng and Zhuang, Qianlai and Welp, Lisa and Ciais, Philippe and Heimann, Martin and Peng, Bin and Li, Wenyu and Bernacchi, Carl and Roedenbeck, Christian and Keenan, Trevor F},
title = {Recent warming has resulted in smaller gains in net carbon uptake in northern high latitudes},
journal = {Journal of Climate},
publisher = {American Meteorological Society},
year = {2019},
volume = {32},
number = {18},
pages = {5849--5863},
doi = {10.1175/JCLI-D-18-0653.1}
}
|
| Zhu G, Zhang K, Chen H, Wang Y, Su Y, Zhang Y and Ma J (2019), "Development and evaluation of a simple hydrologically based model for terrestrial evapotranspiration simulations", Journal of Hydrology., oct, 2019. Vol. 577 Elsevier B.V.. |
| Abstract: Following the scheme of the groundwater-soil-plant-atmosphere continuum (GSPAC), a simple process-based model (SiTH; Simple Terrestrial Hydrosphere) was developed to estimate the dynamics of terrestrial evapotranspiration (ET) at the daily step. The input data include net radiation, air temperature, precipitation, leaf area index, vegetation type and soil data, most of which are readily available. Locally, the model performed well in simulating the dynamics of ET and soil moisture over selected FLUXNET sites. Globally, the daily 0.25° ET and groundwater table depth estimations in year 2005 were determined using available gridded datasets. The spatial pattern was reasonable and the range of values corresponded well with other global ET and groundwater table depth products. In future studies, we will produce a long-term daily 0.25° global ET and groundwater table depth products that spans from 1984 to present by using different input datasets. |
BibTeX:
@article{Zhu2019a,
author = {Zhu, Gaofeng and Zhang, Kun and Chen, Huiling and Wang, Yunquan and Su, Yonghong and Zhang, Yang and Ma, Jinzhu},
title = {Development and evaluation of a simple hydrologically based model for terrestrial evapotranspiration simulations},
journal = {Journal of Hydrology},
publisher = {Elsevier B.V.},
year = {2019},
volume = {577},
doi = {10.1016/j.jhydrol.2019.123928}
}
|
| Ziegler C, Coste S, Stahl C, Delzon S, Levionnois S, Cazal J, Cochard H, Esquivel-Muelbert A, Goret JY, Heuret P, Jaouen G, Santiago LS and Bonal D (2019), "Large hydraulic safety margins protect Neotropical canopy rainforest tree species against hydraulic failure during drought", Annals of Forest Science., dec, 2019. Vol. 76(4) Springer Science and Business Media LLC. |
| Abstract: Key message: Abundant Neotropical canopy-tree species are more resistant to drought-induced branch embolism than what is currently admitted. Large hydraulic safety margins protect them from hydraulic failure under actual drought conditions. Context: Xylem vulnerability to embolism, which is associated to survival under extreme drought conditions, is being increasingly studied in the tropics, but data on the risk of hydraulic failure for lowland Neotropical rainforest canopy-tree species, thought to be highly vulnerable, are lacking. Aims: The purpose of this study was to gain more knowledge on species drought-resistance characteristics in branches and leaves and the risk of hydraulic failure of abundant rainforest canopy-tree species during the dry season. Methods: We first assessed the range of branch xylem vulnerability to embolism using the flow-centrifuge technique on 1-m-long sun-exposed branches and evaluated hydraulic safety margins with leaf turgor loss point and midday water potential during normal- and severe-intensity dry seasons for a large set of Amazonian rainforest canopy-tree species. Results: Tree species exhibited a broad range of embolism resistance, with the pressure threshold inducing 50% loss of branch hydraulic conductivity varying from âˆ' 1.86 to âˆ' 7.63 MPa. Conversely, we found low variability in leaf turgor loss point and dry season midday leaf water potential, and mostly large, positive hydraulic safety margins. Conclusions: Rainforest canopy-tree species growing under elevated mean annual precipitation can have high resistance to embolism and are more resistant than what was previously thought. Thanks to early leaf turgor loss and high embolism resistance, most species have a low risk of hydraulic failure and are well able to withstand normal and even severe dry seasons. |
BibTeX:
@article{Ziegler2019,
author = {Ziegler, Camille and Coste, Sabrina and Stahl, Clément and Delzon, Sylvain and Levionnois, Sébastien and Cazal, Jocelyn and Cochard, Hervé and Esquivel-Muelbert, Adriane and Goret, Jean Yves and Heuret, Patrick and Jaouen, Gaëlle and Santiago, Louis S and Bonal, Damien},
title = {Large hydraulic safety margins protect Neotropical canopy rainforest tree species against hydraulic failure during drought},
journal = {Annals of Forest Science},
publisher = {Springer Science and Business Media LLC},
year = {2019},
volume = {76},
number = {4},
doi = {10.1007/s13595-019-0905-0}
}
|
| Ziembliʼnska K, Urbaniak M, Dukat P and Olejnik J (2019), "Measurements of co2 fluxes at non-ideal eddy covariance sites", Journal of Visualized Experiments., jun, 2019. Vol. 2019(148) MyJove Corporation. |
| Abstract: This protocol is an example of utilizing the eddy covariance (EC) technique to investigate spatially and temporally averaged net CO2 fluxes (net ecosystem production, NEP), in non-typical ecosystems, on a currently reforested windthrow area in Poland. After a tornado event, a relatively narrow “corridor†was created within surviving forest stands, which complicates such kind of experiments. The application of other measuring techniques, such as the chamber method, is even more difficult under these circumstances, because especially at the beginning, fallen trees and in general great heterogeneity of the site provide a challenging platform to perform flux measurements and then to properly upscale obtained results. In comparison with standard EC measurements carried out in untouched forests, the case of windthrow areas requires special consideration when it comes to the site location and data analysis in order to ensure their representativeness. Therefore, here we present a protocol of real-time, continuous CO2 flux measurements at a dynamically changing, non-ideal EC site, which includes (1) site location and instrumentation setup, (2) flux computation, (3) rigorous data filtering and quality control, and (4) gap filling and net fluxes partitioning into CO2 respiration and absorption. The main advantage of the described methodology is that it provides a detailed description of the experimental setup and measurement performance from scratch, which can be applied to other spatially limited ecosystems. It can also be viewed as a list of recommendations on how to deal with unconventional site operation, providing a description for non-specialists. Obtained quality-checked, gap filled, half-hour values of net CO2, as well as absorption and respiration fluxes, can be finally aggregated into daily, monthly, seasonal or annual totals. |
BibTeX:
@article{Ziemblinska2019,
author = {Ziembliʼnska, Klaudia and Urbaniak, Marek and Dukat, Paulina and Olejnik, Janusz},
title = {Measurements of co2 fluxes at non-ideal eddy covariance sites},
journal = {Journal of Visualized Experiments},
publisher = {MyJove Corporation},
year = {2019},
volume = {2019},
number = {148},
doi = {10.3791/59525}
}
|
| Zöll U, Lucas-Moffat AM, Wintjen P, Schrader F, Beudert B and Brümmer C (2019), "Is the biosphere-atmosphere exchange of total reactive nitrogen above forest driven by the same factors as carbon dioxide? An analysis using artificial neural networks", Atmospheric Environment., jun, 2019. Vol. 206, pp. 108-118. Elsevier BV. |
| Abstract: Phase and amplitude of ecosystem-atmosphere fluxes of reactive nitrogen compounds are poorly understood due to a lack of suitable observation methods. Understanding the biophysical controls of the surface nitrogen exchange is essential for the parameterization of process-based and chemical transport models that can be used for the determination of regional or national nitrogen budgets. In this study, we investigated similarities in time series of net total reactive nitrogen (ΣNr) and carbon dioxide (CO2) fluxes above forest with regard to their variability and driving factors. We found corresponding shapes of the mean diurnal summertime patterns of ΣNr and CO2. While ecosystem respiration leads to a net CO2 release at night, ΣNr was on average deposited throughout the entire observation period. Using artificial neural network analysis, global radiation (Rg) was identified to be the main control for both ΣNr and CO2. While the concentration of ΣNr substantially improved the coefficient of determination for ΣNr fluxes when used as a secondary driver, only minor improvements of 2–3% were found for CO2 fluxes when using for example temperature or vapour pressure deficit (VPD) as secondary driver. Considering two dominant drivers, 41 and 66% of the variability in ΣNr and CO2 fluxes, respectively, could be explained. Further data stratification for ΣNr revealed that higher concentrations, higher temperature, and higher VPD as well as dry leaf surfaces tend to favour higher deposition of ΣNr, whereas lower concentrations, lower temperature, and lower VPD as well as wet leaf surfaces mainly correspond to situations when less ΣNr was deposited or even emitted. Our results support the understanding of biosphere-atmosphere interactions, their driving factors, and establish a link between ΣNr and CO2 exchange, which may be beneficial for future developments in state-of-the-art exchange modelling. |
BibTeX:
@article{Zoll2019,
author = {Zöll, Undine and Lucas-Moffat, Antje M and Wintjen, Pascal and Schrader, Frederik and Beudert, Burkhard and Brümmer, Christian},
title = {Is the biosphere-atmosphere exchange of total reactive nitrogen above forest driven by the same factors as carbon dioxide? An analysis using artificial neural networks},
journal = {Atmospheric Environment},
publisher = {Elsevier BV},
year = {2019},
volume = {206},
pages = {108--118},
doi = {10.1016/j.atmosenv.2019.02.042}
}
|
| Achat DL, Martel S, Picart D, Moisy C, Augusto L, Bakker MR and Loustau D (2018), "Modelling the nutrient cost of biomass harvesting under different silvicultural and climate scenarios in production forests", Forest Ecology and Management., dec, 2018. Vol. 429, pp. 642-653. Elsevier BV. |
| Abstract: Intensifying the use of forest biomass to produce fuelwood, through the removal of harvest residues or reductions in rotation length, increases nutrient outputs and can ultimately lead to reduced soil fertility. We developed a modelling approach for the evaluation of different forest management options under future climate scenarios. This approach allows management systems to be evaluated in terms of their nutrient costs by quantifying several variables: nutrient outputs (N, P, K, Ca and Mg) resulting from harvesting, ecosystem N and P balances, and changes in organic C, N and P stocks in the soil. In addition, we calculated a “nutrient cost index†(in kg-harvested-biomass g-exported-nutrientsâˆ'1). As part of this study, we looked at the effects of harvesting branches, foliage and stumps in addition to tree stems, as well as the effects of changing rotation length in Pinus pinaster, Pseudotsuga menziesii and Fagus sylvatica forest stands, under contrasting Representative Concentration Pathway climate scenarios (RCPs). Comparably to previous studies, our simulations showed that removing harvest residues and, to a lesser extent, reducing rotation length have high nutrient costs. Climate was also found to have an impact, mainly caused by larger amounts of standing tree biomass, and therefore larger biomass harvests and increased nutrient outputs in the scenario which involved elevated atmospheric CO2. Using contrasting forest management systems and climates, we showed that our modelling approach can be used to guide forest managers in their choice of future silvicultural practices (rotation length, conventional stem-only harvest versus intensive harvest, thinning regime) based on future climate scenarios. Finally, our approach can be used to determine, more accurately than simple allometric relationships, the amounts of nutrients that would need to be applied in order to compensate for losses. |
BibTeX:
@article{Achat2018,
author = {Achat, David L and Martel, Simon and Picart, Delphine and Moisy, Christophe and Augusto, Laurent and Bakker, Mark R and Loustau, Denis},
title = {Modelling the nutrient cost of biomass harvesting under different silvicultural and climate scenarios in production forests},
journal = {Forest Ecology and Management},
publisher = {Elsevier BV},
year = {2018},
volume = {429},
pages = {642--653},
doi = {10.1016/j.foreco.2018.06.047}
}
|
| Acosta M, Darenova E, Krupková L and Pavelka M (2018), "Seasonal and inter-annual variability of soil CO2 efflux in a Norway spruce forest over an eight-year study", Agricultural and Forest Meteorology., jun, 2018. Vol. 256-257, pp. 93-103. Elsevier BV. |
| Abstract: Automated soil CO2 efflux chamber measurements were carried out over a period of eight years in a young Norway spruce forest in the northeast region of the Czech Republic to determine seasonal and inter-annual variables affecting this flux. The data obtained was summarized and analysed with the aims of estimating long-term carbon losses from the soil and comparing selected models to determine the model best describing soil CO2 efflux. Our results show that seasonal variation in soil CO2 efflux was driven mainly by soil temperature, while inter-annual variation showed the closest relationship with precipitation. The total amount of carbon released from the soil into the atmosphere per season varied from 6.4 to 11.2 tC haâˆ'1 over the eight-year record. One of the variables used in the CO2 efflux models, beside environmental variables, was day of year (DOY). Incorporating this variable into models improved the estimation of soil CO2 efflux dynamics. Therefore, we assume that models incorporating DOY could be used effectively to gap-fill measured soil chamber data. These models could also be appropriate for filling longer gaps on a scale from days to weeks, because DOY, as a single parameter, covers up to 80% of variability in the data. This study also demonstrated the different levels of correlation between investigated climate variables and soil CO2 efflux at seasonal and inter-annual time scales. This highlights the importance of different environmental variables in interpreting long-term soil CO2 efflux data and also modelling the complexity of the processes connected with soil CO2 efflux in Norway spruce forest. |
BibTeX:
@article{Acosta2018,
author = {Acosta, Manuel and Darenova, Eva and Krupková, Lenka and Pavelka, Marian},
title = {Seasonal and inter-annual variability of soil CO2 efflux in a Norway spruce forest over an eight-year study},
journal = {Agricultural and Forest Meteorology},
publisher = {Elsevier BV},
year = {2018},
volume = {256-257},
pages = {93--103},
doi = {10.1016/j.agrformet.2018.03.005}
}
|
| Aguilos M, Stahl C, Burban B, Hérault B, Courtois E, Coste S, Wagner F, Ziegler C, Takagi K and Bonal D (2018), "Interannual and seasonal variations in ecosystem transpiration and water use efficiency in a tropical rainforest", Forests., dec, 2018. Vol. 10(1), pp. 14. MDPI AG. |
| Abstract: Warmer and drier climates over Amazonia have been predicted for the next century with expected changes in regional water and carbon cycles. We examined the impact of interannual and seasonal variations in climate conditions on ecosystem-level evapotranspiration (ET) and water use efficiency (WUE) to determine key climatic drivers and anticipate the response of these ecosystems to climate change. We used daily climate and eddyflux data recorded at the Guyaflux site in French Guiana from 2004 to 2014. ET and WUE exhibited weak interannual variability. The main climatic driver of ET and WUE was global radiation (Rg), but relative extractable water (REW) and soil temperature (Ts) did also contribute. At the seasonal scale, ET and WUE showed a modal pattern driven by Rg, with maximum values for ET in July and August and for WUE at the beginning of the year. By removing radiation effects during water depleted periods, we showed that soil water stress strongly reduced ET. In contrast, drought conditions enhanced radiation-normalized WUE in almost all the years, suggesting that the lack of soil water had a more severe effect on ecosystem evapotranspiration than on photosynthesis. Our results are of major concern for tropical ecosystem modeling because they suggest that under future climate conditions, tropical forest ecosystems will be able to simultaneously adjust CO 2 and H 2 O fluxes. Yet, for tropical forests under future conditions, the direction of change in WUE at the ecosystem scale is hard to predict, since the impact of radiation on WUE is counterbalanced by adjustments to soil water limitations. Developing mechanistic models that fully integrate the processes associated with CO 2 and H 2 O flux control should help researchers understand and simulate future functional adjustments in these ecosystems. |
BibTeX:
@article{Aguilos2018,
author = {Aguilos, Maricar and Stahl, Clément and Burban, Benoit and Hérault, Bruno and Courtois, Elodie and Coste, Sabrina and Wagner, Fabien and Ziegler, Camille and Takagi, Kentaro and Bonal, Damien},
title = {Interannual and seasonal variations in ecosystem transpiration and water use efficiency in a tropical rainforest},
journal = {Forests},
publisher = {MDPI AG},
year = {2018},
volume = {10},
number = {1},
pages = {14},
doi = {10.3390/f10010014}
}
|
| Aguilos M, Hérault B, Burban B, Wagner F and Bonal D (2018), "What drives long-term variations in carbon flux and balance in a tropical rainforest in French Guiana?", Agricultural and Forest Meteorology. Vol. 253-254, pp. 114-123. Elsevier BV. |
| Abstract: A thorough understanding of how tropical forests respond to climate is important to improve ecosystem process models and to reduce uncertainties in current and future global carbon balance calculations. The Amazon rainforest, a major contributor to the global carbon cycle, is subject to strong intra- and interannual variations in climate conditions. Understanding their effect on carbon fluxes between the ecosystem and the atmosphere and on the resulting carbon balance is still incomplete. We examined the long-term (over a 12-year period; 2004–2015) variations in gross primary productivity (GPP), ecosystem respiration (RE) and net ecosystem exchange (NEE) in a tropical rainforest in French Guiana and identified key climatic drivers influencing the changes. The study period was characterized by strong differences in climatic conditions among years, particularly differences in the intensity of the dry and wet seasons, as well as differences in annual carbon fluxes and balance. Annual average GPP varied from 3384.9 g C mâˆ'2 yrâ€'1 (95% CI [3320.7, 3445.9]) to 4061.2 g C mâˆ'2 yrâ€'1 (95% CI [3980.1, 4145.0]). RE varied even more than GPP, with a difference of 933.1 C mâˆ'2 yrâ€'1 between the minimum (3020.6 g C mâˆ'2 yrâ€'1; 95% CI [2889.4, 3051.3]) and maximum (3953.7 g C mâˆ'2 yrâ€'1; 95% CI [3887.6, 4019.6]) values. Although NEE showed large interannual variability (nine-fold), from â€'65.6 g C mâˆ'2 yrâ€'1 (95% CI [â€'4.4, â€'126.0]) to â€'590.5 g C mâˆ'2 yrâ€'1 (95% CI [â€'532.3, â€'651.6]), the forest remained a carbon sink over the 12-year period. A combination of global radiation (Rg), relative extractable water (REW) and soil temperature (Ts) explained 51% of the daily variations for GPP, 30% for RE and 39% for NEE. Global radiation was always the best predictor of these variations, but soil water content and temperature did also influence carbon fluxes and balance. Seasonally, Rg was the major controlling factor for GPP, RE and NEE during the wet season. During the dry season, variations in carbon fluxes and balance were poorly explained by climate factors. Yet, REW was the key driver of variations in NEE during the dry season. This study highlights that, over the long-term, carbon fluxes and balance in such tropical rainforest ecosystems are largely controlled by both radiation and water limitation. Even though variations in Rg have a greater impact on these fluxes, water limitation during seasonal droughts is enough to reduce ecosystem productivity, respiration and carbon uptake. The reduced precipitation expected in tropical rainforest areas under future climatic conditions will therefore strongly influence carbon fluxes and carbon uptake. This study also highlights the importance for land surface or dynamic global vegetation models to consider the main drivers of carbon fluxes and balance separately for dry and wet seasons. |
BibTeX:
@article{Aguilos2018a,
author = {Aguilos, Maricar and Hérault, Bruno and Burban, Benoit and Wagner, Fabien and Bonal, Damien},
title = {What drives long-term variations in carbon flux and balance in a tropical rainforest in French Guiana?},
journal = {Agricultural and Forest Meteorology},
publisher = {Elsevier BV},
year = {2018},
volume = {253-254},
pages = {114--123},
doi = {10.1016/j.agrformet.2018.02.009}
}
|
| Alekseychik P, Mammarella I, Lindroth A, Lohila A, Aurela M, Laurila T, Kasurinen V, Lund M, Rinne J, Nilsson MB, Peichl M, Minkkinen K, Shurpali NJ, Tuittila ES, Martikainen PJ, Tuovinen JP and Vesala T (2018), "Surface energy exchange in pristine and managed boreal peatlands", Mires and Peat. Vol. 21 IMCG and IPS. |
| Abstract: Surface–atmosphere energy exchange is strongly ecosystem-specific. At the same time, as the energy balance constitutes responses of an ecosystem to environmental stressors including precipitation, humidity and solar radiation, it results in feedbacks of potential importance for the regional climate. Northern peatlands represent a diverse class of ecosystems that cover nearly 6 × 106 km2 in the Boreal region, which makes the inter-comparison of their energy balances an important objective. With this in mind we studied energy exchange across a broad spectrum of peatlands from pristine fens and bogs to forested and agriculturally managed peatlands, which represent a large fraction of the landscape in Finland and Sweden. The effects of management activities on the energy balance were extensively examined from the micrometeorological point of view, using eddy covariance data from eight sites in these two countries (56º 12'–62º 11' N, 13º 03'–30º 05' E). It appears that the surface energy balance varies widely amongst the different peatland types. Generally, energy exchange features including the Bowen ratio, surface conductance, coupling to the atmosphere, responses to water table fluctuations and vapour pressure deficit could be associated directly with the peatland type. The relative constancy of the Bowen ratio in natural open mires contrasted with its variation in tree-covered and agricultural peatlands. We conclude that the impacts of management and the consequences of land-use change in peatlands for the local and regional climate might be substantial. |
BibTeX:
@article{Alekseychik2018,
author = {Alekseychik, Pavel and Mammarella, I. and Lindroth, A. and Lohila, A. and Aurela, M. and Laurila, T. and Kasurinen, V. and Lund, M. and Rinne, J. and Nilsson, M. B. and Peichl, M. and Minkkinen, K. and Shurpali, N. J. and Tuittila, E. S. and Martikainen, P. J. and Tuovinen, J. P. and Vesala, T.},
title = {Surface energy exchange in pristine and managed boreal peatlands},
journal = {Mires and Peat},
publisher = {IMCG and IPS},
year = {2018},
volume = {21},
doi = {10.19189/MaP.2018.OMB.333}
}
|
| Alivernini A, Fares S, Ferrara C and Chianucci F (2018), "An objective image analysis method for estimation of canopy attributes from digital cover photography", Trees - Structure and Function., feb, 2018. Vol. 32(3), pp. 713-723. Springer Nature. |
| Abstract: Key message: A method was proposed to remove the subjectivity of gap size analyses approaches implemented by default in cover photography. The method yielded robust and replicable measurements of forest canopy attributes. Abstract: Digital cover photography (DCP) is an increasingly popular method to estimate canopy attributes of forest canopies. Compared with other canopy photographic methods, DCP is fast, simple, and less sensitive to image acquisition and processing. However, the image processing steps used by default in DCP have a large substantial subjective component, particularly regarding the separation of canopy gaps into large gaps and small gaps. In this study, we proposed an objective procedure to analyse DCP based on the statistical distribution of gaps occurring in any image. The new method was tested in 11 deciduous forest stands in central Italy, with different tree composition, stand density, and structure, which is representative of the natural variation of these forest types. Results indicated that the new method removed the subjectivity of manual and semi-automated gap size classifications performed so far in cover photography. A comparison with direct LAI measurements demonstrated that the new method outperformed the previous approaches and increased the precision of LAI estimates. Results have important implications in forestry, because the simplicity of the method allowed objective, reliable, and highly reproducible estimates of canopy attributes, which are largely suitable in forest monitoring, where measures are routinely repeated. In addition, the use of a restricted field of view enables implementation of this photographic method in many devices, including smartphones, downward-looking cameras, and unmanned aerial vehicles. |
BibTeX:
@article{Alivernini2018,
author = {Alivernini, Alessandro and Fares, Silvano and Ferrara, Carlotta and Chianucci, Francesco},
title = {An objective image analysis method for estimation of canopy attributes from digital cover photography},
journal = {Trees - Structure and Function},
publisher = {Springer Nature},
year = {2018},
volume = {32},
number = {3},
pages = {713--723},
doi = {10.1007/s00468-018-1666-3}
}
|
| Al-Yaari A, Dayau S, Chipeaux C, Aluome C, Kruszewski A, Loustau D and Wigneron JP (2018), "The AQUI soil moisture network for satellite microwave remote sensing validation in South-Western France", Remote Sensing., nov, 2018. Vol. 10(11), pp. 1839. MDPI AG. |
| Abstract: Global soil moisture (SM) products are currently available thanks to microwave remote sensing techniques. Validation of these satellite-based SM products over different vegetation and climate conditions is a crucial step. INRA (National Institute of Agricultural Research) has set up the AQUI SM and soil temperature in situ network (composed of three main sites Bouron, Bilos, and Hermitage), over a flat area of dense pine forests, in South-Western France (the Bordeaux-Aquitaine region) to validate the Soil Moisture and Ocean salinity (SMOS) satellite SM products. SMOS was launched in 2009 by the European Space Agency (ESA). The aims of this study are to present the AQUI network and to evaluate the SMOS SM product (in the new SMOS-IC version) along with other microwave SM products such as the active ASCAT (Advanced Scatterometer) and the ESA combined (passive and active) CCI (Climate Change Initiative) SM retrievals. A first comparison, using Pearson correlation, Bias, RMSE (Root Mean Square Error), and Un biased RMSE (ubRMSE) scores, between the 0-5 cm AQUI network and ASCAT, CCI, and SMOS SM products was conducted. In general all the three products were able to reproduce the annual cycle of the AQUI in situ observations. CCI and ASCAT had best and similar correlations (R˜0.72) over the Bouron and Bilos sites. All had comparable correlations over the Hermitage sites with overall average values of 0.74, 0.68, and 0.69 for CCI, SMOS-IC, and ASCAT, respectively. Considering anomalies, correlation values decreased for all products with best ability to capture day to day variations obtained by ASCAT. CCI (followed by SMOS-IC) had the best ubRMSE values (mostly 0.04 m3/m3) over most of the stations. Although the region is highly impacted by radio frequency interferences, SMOS-IC followed correctly the in situ SM dynamics. All the three remotely-sensed SM products (except SMOS-IC over some stations) overestimated the AQUI in situ SM observations. These results demonstrate that the AQUI network is likely to be well-suited for satellite microwave remote sensing evaluations/validations. |
BibTeX:
@article{Al-Yaari2018,
author = {Al-Yaari, A and Dayau, S and Chipeaux, C and Aluome, C and Kruszewski, A and Loustau, D and Wigneron, J P},
title = {The AQUI soil moisture network for satellite microwave remote sensing validation in South-Western France},
journal = {Remote Sensing},
publisher = {MDPI AG},
year = {2018},
volume = {10},
number = {11},
pages = {1839},
doi = {10.3390/rs10111839}
}
|
| Ameli AA and Craig JR (2018), "Semi-analytical 3D solution for assessing radial collector well pumping impacts on groundwater-surface water interaction", Hydrology Research., apr, 2018. Vol. 49(1), pp. 17-26. IWA Publishing. |
| Abstract: We present a new semi-analytical flow and transport model for the simulation of 3D steady-state flow and particle movement between groundwater, a surface water body and a radial collector well in geometrically complex unconfined aquifers. This precise and grid-free Series Solution-analytic element method approach handles the irregular configurations of radial wells more efficiently than grid-based methods. This method is then used to explore how pumping well location and river shape interact and together influence (1) transit time distribution (TTD) of captured water in a radial collector well and TTD of groundwater discharged into the river and (2) the percentage of well waters captured from different sources. Results show that meandering river shape plays a significant role in controlling the aforementioned metrics and that increasing the pumping rate has different consequences in different situations. This approach can also inform the design of water remediation and groundwater protection systems (e.g., river bank filtration and well head protection area). |
BibTeX:
@article{Ameli2018,
author = {Ameli, Ali A and Craig, James R},
title = {Semi-analytical 3D solution for assessing radial collector well pumping impacts on groundwater-surface water interaction},
journal = {Hydrology Research},
publisher = {IWA Publishing},
year = {2018},
volume = {49},
number = {1},
pages = {17--26},
doi = {10.2166/nh.2017.201}
}
|
| Andersen T, Scheeren B, Peters W and Chen H (2018), "A UAV-based active AirCore system for measurements of greenhouse gases", Atmospheric Measurement Techniques. Vol. 11(5), pp. 2683-2699. Copernicus GmbH. |
| Abstract: We developed and field-tested an unmanned aerial vehicle (UAV)-based active AirCore for atmospheric mole fraction measurements of CO2, CH4, and CO. The system applies an alternative way of using the AirCore technique invented by NOAA. As opposed to the conventional concept of passively sampling air using the atmospheric pressure gradient during descent, the active AirCore collects atmospheric air samples using a pump to pull the air through the tube during flight, which opens up the possibility to spatially sample atmospheric air. The active AirCore system used for this study weighs ∼-1.1-kg. It consists of a ∼-50-m long stainless-steel tube, a small stainless-steel tube filled with magnesium perchlorate, a KNF micropump, and a 45-μm orifice working together to form a critical flow of dried atmospheric air through the active AirCore. A cavity ring-down spectrometer (CRDS) was used to analyze the air samples on site not more than 7-min after landing for mole fraction measurements of CO2, CH4, and CO. We flew the active AirCore system on a UAV near the atmospheric measurement station at Lutjewad, located in the northwest of the city of Groningen in the Netherlands. Five consecutive flights took place over a 5-h period on the same morning, from sunrise until noon. We validated the measurements of CO2 and CH4 from the active AirCore against those from the Lutjewad station at 60-m. The results show a good agreement between the measurements from the active AirCore and the atmospheric station (N-Combining double low line-146; R2CO2: 0.97 and R2CH4: 0.94; and mean differences: CO2: 0.18-ppm and CH4: 5.13-ppb). The vertical and horizontal resolution (for CH4) at typical UAV speeds of 1.5 and 2.5-m-s-1 were determined to be ±24.7 to 29.3 and ±41.2 to 48.9-m, respectively, depending on the storage time. The collapse of the nocturnal boundary layer and the buildup of the mixed layer were clearly observed with three consecutive vertical profile measurements in the early morning hours. Besides this, we furthermore detected a CH4 hotspot in the coastal wetlands from a horizontal flight north to the dike, which demonstrates the potential of this new active AirCore method to measure at locations where other techniques have no practical access. |
BibTeX:
@article{Andersen2018,
author = {Andersen, Truls and Scheeren, Bert and Peters, Wouter and Chen, Huilin},
title = {A UAV-based active AirCore system for measurements of greenhouse gases},
journal = {Atmospheric Measurement Techniques},
publisher = {Copernicus GmbH},
year = {2018},
volume = {11},
number = {5},
pages = {2683--2699},
doi = {10.5194/amt-11-2683-2018}
}
|
| Arrouays D, Saby NPA, Boukir H, Jolivet C, Ratié C, Schrumpf M, Merbold L, Gielen B, Gogo S, Delpierre N, Vincent G, Klumpp K and Loustau D (2018), "Soil sampling and preparation for monitoring soil carbon", International Agrophysics., dec, 2018. Vol. 32(4), pp. 633-643. |
| Abstract: There is an urgent need for standardized monitoring of existing soil organic carbon stocks in order to accurately quantify potential negative or positive feedbacks with climate change on carbon fluxes. Given the uncertainty of flux measurements at the ecosystem scale, obtaining precise estimates of changes in soil organic carbon stocks is essential to provide an independent assessment of long-Term net ecosystem carbon exchange. Here we describe the standard procedure to monitor the soil organic carbon stocks within the footprint of an eddy covariance flux tower, as applied at ecosystem stations of the Integrated Carbon Observation System. The objectives are i) to ensure comparability between sites and to be able to draw general conclusions from the results obtained across many ecosystems and ii) to optimize the sampling design in order to be able to prove changes in time using a reduced number of samples. When sampling a given site at two periods, the objective is generally to assess if changes occurred in time. The changes that can be detected (i.e., demonstrated as statistically significant) depend on several parameters such as the number of samples, the spatial sampling design, and the inherent within-site soil variability. Depending on these parameters, one can define the 'minimum detectable change' which is the minimum value of changed that can be statistically proved. Using simulation studies, we address the trade-off between increasing the number of samples and getting lower minimum detectable changes of soil organic carbon stocks. |
BibTeX:
@article{Arrouays2018,
author = {Arrouays, Dominique and Saby, Nicolas P A and Boukir, Hakima and Jolivet, Claudy and Ratié, Céline and Schrumpf, Marion and Merbold, Lutz and Gielen, Bert and Gogo, Sébastien and Delpierre, Nicolas and Vincent, Gaëlle and Klumpp, Katja and Loustau, Denis},
title = {Soil sampling and preparation for monitoring soil carbon},
journal = {International Agrophysics},
year = {2018},
volume = {32},
number = {4},
pages = {633--643},
url = {https://content.sciendo.com/view/journals/intag/32/4/article-p633.xml},
doi = {10.1515/intag-2017-0047}
}
|
| Arzoumanian E, Vogel FR, Bastos A, Gaynullin B, Laurent O, Ramonet M and Ciais P (2018), "Characterization of lower-cost medium precision atmospheric COsub2/sub monitoring systems for urban areas using commercial NDIR sensors", Atmospheric Measurement Techniques Discussions. , pp. 1-22. Copernicus GmbH. |
| Abstract: pstrongAbstract./strong COsub2/sub emission estimates from urban areas can be obtained with a network of in-situ instruments measuring atmospheric COsub2/sub combined with high-resolution (inverse) transport modeling. The distribution of COsub2/sub emissions being highly heterogeneous in space and variable in time in urban areas, gradients of atmospheric COsub2/sub need to be measured by numerous instruments placed at multiple locations around and possibly within these urban areas, which calls for the development of lower-cost medium precision sensors to allow a deployment at required densities. Medium precision is here set to be a random error (uncertainty) on hourly measurements of ±1 ppm or less, a precision requirement based on previous studies of network design in urban areas. Here we present tests of a HPP commercial NDIR sensors manufactured by Senseair AB performed in the laboratory and at actual field stations, the latter for COsub2/sub concentration in the Paris area. The lower-cost medium precision sensors are shown to be sensitive to atmospheric pressure and temperature conditions. The sensors respond linearly to COsub2/sub when measuring calibration tanks, but the regression slope between measured and true COsub2/sub differs between individual sensors and changes with time. In addition to pressure and temperature variations, humidity impacts the measurement of COsub2/sub, all causing systematic errors. In the field, an empirical calibration strategy is proposed based on parallel measurements with the lower-cost medium precision sensors and a high-precision instrument cavity ring-down instrument during 6 month. This empirical calibration method consists of using a multiple regression approach to create a model of the errors defined as the difference of COsub2/sub measured by the lower-cost medium precision sensors relative to a calibrated high-precision instrument, based on predictors of air temperature, pressure and humidity. This error model shows good performances to explain the observed drifts of the lower-cost medium precision sensors on time scales of up to 1&ndash;2 months when trained against 1&ndash;2 weeks of high-precision instrument time series. Residual errors are contained within the ±1 ppm target, showing the feasibility to use networks of HPP instruments for urban COsub2/sub networks, provided that they could be regularly calibrated against one anchor reference high-precision instrument./p |
BibTeX:
@article{Arzoumanian2018,
author = {Arzoumanian, Emmanuel and Vogel, Felix R and Bastos, Ana and Gaynullin, Bakhram and Laurent, Olivier and Ramonet, Michel and Ciais, Philippe},
title = {Characterization of lower-cost medium precision atmospheric COsub2/sub monitoring systems for urban areas using commercial NDIR sensors},
journal = {Atmospheric Measurement Techniques Discussions},
publisher = {Copernicus GmbH},
year = {2018},
pages = {1--22},
doi = {10.5194/amt-2018-329}
}
|
| Assan S, Vogel FR, Gros V, Baudic A, Staufer J and Ciais P (2018), "Can we separate industrial CH4 emission sources from atmospheric observations? - A test case for carbon isotopes, PMF and enhanced APCA", Atmospheric Environment., aug, 2018. Vol. 187, pp. 317-327. Elsevier BV. |
| Abstract: A large factor contributing to the uncertainties associated with sector specific anthropogenic methane emissions is the lack of available methods and data to reliably discriminate the different production processes. In this study, a variety of source apportionment techniques were investigated and developed to improve CH4 apportionment for co-located CH4 sources. The goal was to distinguish emissions from different systems at a mid-stream natural gas (NG) site (compressor station). Continuous measurements of atmospheric CH4 and co-emitted volatile organic compounds (VOCs) were analysed using Principle Component Analysis (PCA) and Positive Matrix Factorisation (PMF) receptor models. After sensitivity studies, significant extensions were made to the classical PCA, (Monte Carlo Absolute PCA ‘MC-APCA' and Monte Carlo moving Absolute PCA ‘MC-mAPCA') to better suit this application. Results from the receptor models are compared and combined with isotopic analysis, examining both long and short-term temporal variations. This work determined MC-APCA and PMF to be the most appropriate techniques for the long-term analysis of dominant sources; according to MC-mAPCA, this was identified to be 77.5 ± 0.6% natural gas, while 66% of the remaining variability was associated with traffic-related proxies. Techniques such as the moving Miller-Tans method for isotopic source identification and MC-mAPCA gave an insight into the short-term variability of source composition. During most CH4 enhancement periods, δ13CH4 sources range from âˆ'40‰ to âˆ'45‰ while MC-mAPCA typically show methane to ethane ratios of 4%–8%, confirming the prevalence of NG emissions. Both techniques identified CH4 enhancements from intermittently contributing sources (in this case a ruminant source characterised by δ13CH4 -62 ± 3‰ and 0% C2H6:CH4), and differentiate small fluctuations in NG source composition. Overall, the best method to identify CH4 sources from atmospheric local measurements remains strongly dependant on the characteristics of said source. The campaign investigated here required sensitive analysis as it was predominantly single sourced, and focussed on the identification of two gas streams. In such a case, it was found that a combination of old and novel techniques provide the greatest information on the characteristics of CH4 sources and gives confidence in the results. |
BibTeX:
@article{Assan2018,
author = {Assan, Sabina and Vogel, F R and Gros, V and Baudic, A and Staufer, J and Ciais, P},
title = {Can we separate industrial CH4 emission sources from atmospheric observations? - A test case for carbon isotopes, PMF and enhanced APCA},
journal = {Atmospheric Environment},
publisher = {Elsevier BV},
year = {2018},
volume = {187},
pages = {317--327},
doi = {10.1016/j.atmosenv.2018.05.004}
}
|
| Aubinet M, Hurdebise Q, Chopin H, Debacq A, De Ligne A, Heinesch B, Manise T and Vincke C (2018), "Inter-annual variability of Net Ecosystem Productivity for a temperate mixed forest: A predominance of carry-over effects?", Agricultural and Forest Meteorology., nov, 2018. Vol. 262, pp. 340-353. Elsevier B.V.. |
| Abstract: This study presents twenty years of Net Ecosystem Productivity estimations obtained using eddy covariance in a mixed forest, dominated by beech with sparse conifers, at the Vielsalm station, in the Belgian Ardennes. First the quality and reliability of the data set is discussed. An uncertainty analysis showed that if, on one hand, the site heterogeneity and set-up changes may strongly affect yearly NEP estimates, questioning thus the total carbon budget relevance, on the other hand, robust inter-annual anomalies may be obtained as long as a site dedicated data treatment is carefully applied. A validation of the anomalies by comparison with a growth index derived from tree ring measurements is given. The resulting anomalies (range: [−206; + 123] g C m−2 yr−1, standard deviation: 93 g C m−2 yr−1) being larger than their own uncertainty (∼30 g C m−2 yr−1), an inter-annual variability analysis is possible. This analysis shows that the sources of NEP inter-annual variability at the Vielsalm station are multiple but the most prominent causes are biotic processes driven by carry-over effects of preceding meteorological events. The lowest observed NEP, in 2000, resulted from a bark beetle attack probably prompted by an early frost event in 1998. Besides, the robust lagged correlation between NEP anomalies and mean vapor pressure deficit during the preceding vegetation season also suggests a carry-over effect of water limitation during the previous year on the beech NEP. Mechanisms driving this carry-over effect are supposedly linked to tree physiology, which is confirmed by a dependency of canopy photosynthetic capacity to previous year water limitation. Some hypotheses, involving biomass allocation and bud formation, are proposed to explain its lagged impact on canopy photosynthetic capacity. Other causes of NEP inter-annual variability are the radiation during the current vegetation season and the temperature at the end of the winter but the latter variable rather indicates an effect on the conifers interspersed in the plot. Overall, the photosynthetic capacity combined with these two factors explained about 75% of NEP inter-annual variability. |
BibTeX:
@article{Aubinet2018,
author = {Aubinet, Marc and Hurdebise, Quentin and Chopin, Henri and Debacq, Alain and De Ligne, Anne and Heinesch, Bernard and Manise, Tanguy and Vincke, Caroline},
title = {Inter-annual variability of Net Ecosystem Productivity for a temperate mixed forest: A predominance of carry-over effects?},
journal = {Agricultural and Forest Meteorology},
publisher = {Elsevier B.V.},
year = {2018},
volume = {262},
pages = {340--353},
doi = {10.1016/j.agrformet.2018.07.024}
}
|
| Bachy A, Aubinet M, Amelynck C, Schoon N, Bodson B, Moureaux C, Delaplace P, De Ligne A and Heinesch B (2018), "Methanol exchange dynamics between a temperate cropland soil and the atmosphere", Atmospheric Environment., mar, 2018. Vol. 176, pp. 229-239. |
| Abstract: Soil methanol (CH3OH) exchange is often considered as several orders of magnitude smaller than plant methanol exchange. However, for some ecosystems, it is significant in regard with plant exchange and worth thus better consideration. Our study sought to gain a better understanding of soil exchange. Methanol flux was measured at the ecosystem scale on a bare agricultural soil over two contrasted periods using the disjunct eddy covariance by mass scanning technique. A proton-transfer-reaction mass spectrometer was used for the methanol ambient mixing ratio measurements. Bi-directional exchange dynamics were observed. Methanol emission occurred under dry and warm conditions and correlated best with soil surface temperature, whereas methanol uptake occurred under wet and mild conditions and correlated well with the methanol ambient concentration. After having tested a physical adsorption-desorption model and by confronting our data with the literature, we propose that the exchange was ruled by both a physical adsorption/desorption mechanism and by a methanol source, which still needs to be identified. The soil emission decreased when the vegetation developed. The reasons for the decrease still need to be determined. Overall, the dynamics observed at our site were similar to those reported by other studies for both cropland and forest ecosystems. The mechanism proposed in our work can thus be possibly applied to other sites or ecosystems. In addition, the methanol exchange rate was in the upper range of the exchange rates reported by other soil studies, suggesting that cropland soils are more important methanol exchangers than those in other ecosystems and should therefore be further investigated. |
BibTeX:
@article{Bachy2018,
author = {Bachy, A and Aubinet, M and Amelynck, C and Schoon, N and Bodson, B and Moureaux, C and Delaplace, P and De Ligne, A and Heinesch, B},
title = {Methanol exchange dynamics between a temperate cropland soil and the atmosphere},
journal = {Atmospheric Environment},
year = {2018},
volume = {176},
pages = {229--239},
url = {http://linkinghub.elsevier.com/retrieve/pii/S1352231017308579},
doi = {10.1016/j.atmosenv.2017.12.016}
}
|
| Ballantyne AP, Ciais P and Miller JB (2018), "Cautious Optimism and Incremental Goals Toward Stabilizing Atmospheric CO2", Earth's Future., dec, 2018. Vol. 6(12), pp. 1632-1637. American Geophysical Union (AGU). |
| Abstract: Fossil fuel emissions of CO2 to the atmosphere appear to have leveled off in recent years; however, atmospheric CO2 concentrations continue to rise. Our simple analysis shows that peaks in the growth rates of human population and fossil fuel emissions have been observed, but the growth rate of atmospheric CO2 has reached record levels and shows no indication of peaking. Before atmospheric CO2 concentrations can be stabilized at safe levels, a peak in the CO2 growth rate must be achieved. |
BibTeX:
@article{Ballantyne2018,
author = {Ballantyne, A P and Ciais, P and Miller, J B},
title = {Cautious Optimism and Incremental Goals Toward Stabilizing Atmospheric CO2},
journal = {Earth's Future},
publisher = {American Geophysical Union (AGU)},
year = {2018},
volume = {6},
number = {12},
pages = {1632--1637},
doi = {10.1029/2018EF001012}
}
|
| Balsamo G, Agusti-Panareda A, Albergel C, Arduini G, Beljaars A, Bidlot J, Bousserez N, Boussetta S, Brown A, Buizza R, Buontempo C, Chevallier F, Choulga M, Cloke H, Cronin MF, Dahoui M, Rosnay PD, Dirmeyer PA, Drusch M, Dutra E, Ek MB, Gentine P, Hewitt H, Keeley SPE, Kerr Y, Kumar S, Lupu C, Mahfouf JF, McNorton J, Mecklenburg S, Mogensen K, Muñoz-Sabater J, Orth R, Rabier F, Reichle R, Ruston B, Pappenberger F, Sandu I, Seneviratne SI, Tietsche S, Trigo IF, Uijlenhoet R, Wedi N, Woolway RI and Zeng X (2018), "Satellite and in situ observations for advancing global earth surface modelling: A review", Remote Sensing., dec, 2018. Vol. 10(12), pp. 2038. MDPI AG. |
| Abstract: In this paper, we review the use of satellite-based remote sensing in combination with in situ data to inform Earth surface modelling. This involves verification and optimization methods that can handle both random and systematic errors and result in effective model improvement for both surface monitoring and prediction applications. The reasons for diverse remote sensing data and products include (i) their complementary areal and temporal coverage, (ii) their diverse and covariant information content, and (iii) their ability to complement in situ observations, which are often sparse and only locally representative. To improve our understanding of the complex behavior of the Earth system at the surface and sub-surface, we need large volumes of data from high-resolution modelling and remote sensing, since the Earth surface exhibits a high degree of heterogeneity and discontinuities in space and time. The spatial and temporal variability of the biosphere, hydrosphere, cryosphere and anthroposphere calls for an increased use of Earth observation (EO) data attaining volumes previously considered prohibitive. We review data availability and discuss recent examples where satellite remote sensing is used to infer observable surface quantities directly or indirectly, with particular emphasis on key parameters necessary for weather and climate prediction. Coordinated high-resolution remote-sensing and modelling/assimilation capabilities for the Earth surface are required to support an international application-focused effort. |
BibTeX:
@article{Balsamo2018,
author = {Balsamo, Gianpaolo and Agusti-Panareda, Anna and Albergel, Clement and Arduini, Gabriele and Beljaars, Anton and Bidlot, Jean and Bousserez, Nicolas and Boussetta, Souhail and Brown, Andy and Buizza, Roberto and Buontempo, Carlo and Chevallier, Frederic and Choulga, Margarita and Cloke, Hannah and Cronin, Meghan F and Dahoui, Mohamed and Rosnay, Patricia De and Dirmeyer, Paul A and Drusch, Matthias and Dutra, Emanuel and Ek, Michael B and Gentine, Pierre and Hewitt, Helene and Keeley, Sarah P E and Kerr, Yann and Kumar, Sujay and Lupu, Cristina and Mahfouf, Jean Francois and McNorton, Joe and Mecklenburg, Susanne and Mogensen, Kristian and Muñoz-Sabater, Joaquín and Orth, Rene and Rabier, Florence and Reichle, Rolf and Ruston, Ben and Pappenberger, Florian and Sandu, Irina and Seneviratne, Sonia I and Tietsche, Steffen and Trigo, Isabel F and Uijlenhoet, Remko and Wedi, Nils and Woolway, R Iestyn and Zeng, Xubin},
title = {Satellite and in situ observations for advancing global earth surface modelling: A review},
journal = {Remote Sensing},
publisher = {MDPI AG},
year = {2018},
volume = {10},
number = {12},
pages = {2038},
doi = {10.3390/rs10122038}
}
|
| Barba J, Cueva A, Bahn M, Barron-Gafford GA, Bond-Lamberty B, Hanson PJ, Jaimes A, Kulmala L, Pumpanen J, Scott RL, Wohlfahrt G and Vargas R (2018), "Comparing ecosystem and soil respiration: Review and key challenges of tower-based and soil measurements", Agricultural and Forest Meteorology. Vol. 249, pp. 434-443. |
| Abstract: The net ecosystem exchange (NEE) is the difference between ecosystem CO2 assimilation and CO2 losses to the atmosphere. Ecosystem respiration (Reco), the efflux of CO2 from the ecosystem to the atmosphere, includes the soil-to-atmosphere carbon flux (i.e., soil respiration; Rsoil) and aboveground plant respiration. Therefore, Rsoil is a fraction of Reco and theoretically has to be smaller than Reco at daily, seasonal, and annual scales. However, several studies estimating Reco with the eddy covariance technique and measuring Rsoil within the footprint of the tower have reported higher Rsoil than Reco at different time scales. Here, we compare four different and contrasting ecosystems (from forest to grasslands, and from boreal to semiarid) to test if measurements of Reco are consistently higher than Rsoil. In general, both fluxes showed similar temporal patterns, but Reco was not consistently higher than Rsoil from daily to annual scales across sites. We identified several issues that apply for measuring NEE and measuring/upscaling Rsoil that could result in an underestimation of Reco and/or an overestimation of Rsoil. These issues are discussed based on (a) nighttime measurements of NEE, (b) Rsoil measurements, and (c) the interpretation of the functional relationships of these fluxes with temperature (i.e., Q10). We highlight that there is still a need for better integration of Rsoil with eddy covariance measurements to address challenges related to the spatial and temporal variability of Reco and Rsoil. |
BibTeX:
@article{Barba2018,
author = {Barba, Josep and Cueva, Alejandro and Bahn, Michael and Barron-Gafford, Greg A and Bond-Lamberty, Benjamin and Hanson, Paul J and Jaimes, Aline and Kulmala, Liisa and Pumpanen, Jukka and Scott, Russell L and Wohlfahrt, Georg and Vargas, Rodrigo},
title = {Comparing ecosystem and soil respiration: Review and key challenges of tower-based and soil measurements},
journal = {Agricultural and Forest Meteorology},
year = {2018},
volume = {249},
pages = {434--443},
doi = {10.1016/j.agrformet.2017.10.028}
}
|
| Barskov KV, Glazunov AV, Repina IA, Stepanenko VM, Lykossov VN and Mammarella I (2018), "On the Applicability of Similarity Theory for the Stable Atmospheric Boundary Layer over Complex Terrain", Izvestiya - Atmospheric and Ocean Physics., sep, 2018. Vol. 54(5), pp. 462-471. Pleiades Publishing Ltd. |
| Abstract: Micrometeorological measurements in the atmospheric boundary layer over a hilly forest terrain have been made on a meteorological tower at several levels from the forest canopy top to a height that exceeds the height of trees almost seven times. A semiempirical length scale depending on the local topography features and the underlying surface type has been proposed and calculated. This scale has been shown to allow the universal functions of the Monin–Obukhov similarity theory to be corrected for a stable atmospheric boundary layer over complex terrain without substantial modification when compared to the universal functions over a homogeneous surface with small roughness elements. This approach can be used to refine the methods for calculating turbulent momentum fluxes from profile measurements over spatially inhomogeneous landscapes. |
BibTeX:
@article{Barskov2018,
author = {Barskov, K V and Glazunov, A V and Repina, I A and Stepanenko, V M and Lykossov, V N and Mammarella, I},
title = {On the Applicability of Similarity Theory for the Stable Atmospheric Boundary Layer over Complex Terrain},
journal = {Izvestiya - Atmospheric and Ocean Physics},
publisher = {Pleiades Publishing Ltd},
year = {2018},
volume = {54},
number = {5},
pages = {462--471},
doi = {10.1134/S0001433818050031}
}
|
| Bastos A, Peregon A, Gani ÉA, Khudyaev S, Yue C, Li W, Gouveia CM and Ciais P (2018), "Influence of high-latitude warming and land-use changes in the early 20th century northern Eurasian CO2 sink", Environmental Research Letters., jun, 2018. Vol. 13(6), pp. 65014. IOP Publishing. |
| Abstract: While the global carbon budget (GCB) is relatively well constrained over the last decades of the 20th century [1], observations and reconstructions of atmospheric CO2 growth rate present large discrepancies during the earlier periods [2]. The large uncertainty in GCB has been attributed to the land biosphere, although it is not clear whether the gaps between observations and reconstructions are mainly because land-surface models (LSMs) underestimate inter-annual to decadal variability in natural ecosystems, or due to inaccuracies in land-use change reconstructions. As Eurasia encompasses about 15% of the terrestrial surface, 20% of the global soil organic carbon pool and constitutes a large CO2 sink, we evaluate the potential contribution of natural and human-driven processes to induce large anomalies in the biospheric CO2 fluxes in the early 20th century. We use an LSM specifically developed for high-latitudes, that correctly simulates Eurasian C-stocks and fluxes from observational records [3], in order to evaluate the sensitivity of the Eurasian sink to the strong high-latitude warming occurring between 1930 and 1950. We show that the LSM with improved high-latitude phenology, hydrology and soil processes, contrary to the group of LSMs in [2], is able to represent enhanced vegetation growth linked to boreal spring warming, consistent with tree-ring time-series [4]. By compiling a dataset of annual agricultural area in the Former Soviet Union that better reflects changes in cropland area linked with socio-economic fluctuations during the early 20th century, we show that land-abadonment during periods of crisis and war may result in reduced CO2 emissions from land-use change (44%-78% lower) detectable at decadal time-scales. Our study points to key processes that may need to be improved in LSMs and LUC datasets in order to better represent decadal variability in the land CO2 sink, and to better constrain the GCB during the pre-observational record. |
BibTeX:
@article{Bastos2018,
author = {Bastos, Ana and Peregon, Anna and Gani, Érico A and Khudyaev, Sergey and Yue, Chao and Li, Wei and Gouveia, Célia M and Ciais, Philippe},
title = {Influence of high-latitude warming and land-use changes in the early 20th century northern Eurasian CO2 sink},
journal = {Environmental Research Letters},
publisher = {IOP Publishing},
year = {2018},
volume = {13},
number = {6},
pages = {65014},
doi = {10.1088/1748-9326/aac4d3}
}
|
| Basu S, Baker DF, Chevallier F, Patra PK, Liu J and Miller JB (2018), "The impact of transport model differences on CO2 surface flux estimates from OCO-2 retrievals of column average CO2", Atmospheric Chemistry and Physics. Vol. 18(10), pp. 7189-7215. Copernicus GmbH. |
| Abstract: We estimate the uncertainty of CO2 flux estimates in atmospheric inversions stemming from differences between different global transport models. Using a set of observing system simulation experiments (OSSEs), we estimate this uncertainty as represented by the spread between five different state-of-the-art global transport models (ACTM, LMDZ, GEOS-Chem, PCTM and TM5), for both traditional in situ CO2 inversions and inversions of XCO2 estimates from the Orbiting Carbon Observatory 2 (OCO-2). We find that, in the absence of relative biases between in situ CO2 and OCO-2 XCO2, OCO-2 estimates of terrestrial flux for TRANSCOM-scale land regions can be more robust to transport model differences than corresponding in situ CO2 inversions. This is due to a combination of the increased spatial coverage of OCO-2 samples and the total column nature of OCO-2 estimates. We separate the two effects by constructing hypothetical in situ networks with the coverage of OCO-2 but with only near-surface samples. We also find that the transport-driven uncertainty in fluxes is comparable between well-sampled northern temperate regions and poorly sampled tropical regions. Furthermore, we find that spatiotemporal differences in sampling, such as between OCO-2 land and ocean soundings, coupled with imperfect transport, can produce differences in flux estimates that are larger than flux uncertainties due to transport model differences. This highlights the need for sampling with as complete a spatial and temporal coverage as possible (e.g., using both land and ocean retrievals together for span styleCombining double low line"" classCombining double low line"text"OCO-2/span) to minimize the impact of selective sampling. Finally, our annual and monthly estimates of transport-driven uncertainties can be used to evaluate the robustness of conclusions drawn from real OCO-2 and in situ CO2 inversions. |
BibTeX:
@article{Basu2018,
author = {Basu, Sourish and Baker, David F and Chevallier, Frédéric and Patra, Prabir K and Liu, Junjie and Miller, John B},
title = {The impact of transport model differences on CO2 surface flux estimates from OCO-2 retrievals of column average CO2},
journal = {Atmospheric Chemistry and Physics},
publisher = {Copernicus GmbH},
year = {2018},
volume = {18},
number = {10},
pages = {7189--7215},
doi = {10.5194/acp-18-7189-2018}
}
|
| Beaudoin N, Gallois N, Viennot P, Le Bas C, Puech T, Schott C, Buis S and Mary B (2018), "Evaluation of a spatialized agronomic model in predicting yield and N leaching at the scale of the Seine-Normandie Basin", Environmental Science and Pollution Research., sep, 2018. Vol. 25(24), pp. 23529-23558. Springer Nature. |
| Abstract: The EU directive has addressed ambitious targets concerning the quality of water bodies. Predicting water quality as affected by land use and management requires using dynamic agro-hydrogeological models. In this study, an agronomic model (STICS) and a hydrogeological model (MODCOU) have been associated in order to simulate nitrogen fluxes in the Seine-Normandie Basin, which is affected by nitrate pollution of groundwater due to intensive farming systems. This modeling platform was used to predict and understand the spatial and temporal evolution of water quality over the 1971–2013 period. A quality assurance protocol (Refsgaard et al. Environ Model Softw 20: 1201–1215, 2005) was used to qualify the reliability of STICS outputs. Four iterative runs of the model were carried out with improved parameterization of soils and crop management without any change in the model. Improving model inputs changed much more the spatial distribution of simulated N losses than their mean values. STICS slightly underestimated the crop yields compared to the observed values at the administrative district scale. The platform also slightly underestimated the nitrate concentration at the outlet level with a mean difference ranging from âˆ'1.4 to âˆ'9.2 mg NO3 Lâˆ'1 according to the aquifer during the last decade. This outcome should help the stakeholders in decision-making to prevent nitrate pollution and provide new specifications for STICS development. |
BibTeX:
@article{Beaudoin2018,
author = {Beaudoin, N and Gallois, N and Viennot, P and Le Bas, C and Puech, T and Schott, C and Buis, S and Mary, B},
title = {Evaluation of a spatialized agronomic model in predicting yield and N leaching at the scale of the Seine-Normandie Basin},
journal = {Environmental Science and Pollution Research},
publisher = {Springer Nature},
year = {2018},
volume = {25},
number = {24},
pages = {23529--23558},
doi = {10.1007/s11356-016-7478-3}
}
|
| Bergamaschi P, Karstens U, Manning AJ, Saunois M, Tsuruta A, Berchet A, Vermeulen AT, Arnold T, Janssens-Maenhout G, Hammer S, Levin I, Schmidt M, Ramonet M, Lopez M, Lavric J, Aalto T, Chen H, Feist DG, Gerbig C, Haszpra L, Hermansen O, Manca G, Moncrieff J, Meinhardt F, Necki J, Galkowski M, O'Doherty S, Paramonova N, Scheeren HA, Steinbacher M and Dlugokencky E (2018), "Inverse modelling of European CH4 emissions during 2006-2012 using different inverse models and reassessed atmospheric observations", Atmospheric Chemistry and Physics., jan, 2018. Vol. 18(2), pp. 901-920. Copernicus GmbH. |
| Abstract: We present inverse modelling (top down) estimates of European methane (CH4) emissions for 2006-2012 based on a new quality-controlled and harmonised in situ data set from 18 European atmospheric monitoring stations. We applied an ensemble of seven inverse models and performed four inversion experiments, investigating the impact of different sets of stations and the use of a priori information on emissions. The inverse models infer total CH4 emissions of 26.8 (20.2-29.7) Tg CH4 yr-1 (mean, 10th and 90th percentiles from all inversions) for the EU-28 for 2006-2012 from the four inversion experiments. For comparison, total anthropogenic CH4 emissions reported to UNFCCC (bottom up, based on statistical data and emissions factors) amount to only 21.3 Tg CH4 yr-1 (2006) to 18.8 Tg CH4 yr-1 (2012). A potential explanation for the higher range of top-down estimates compared to bottom-up inventories could be the contribution from natural sources, such as peatlands, wetlands, and wet soils. Based on seven different wetland inventories from the Wetland and Wetland CH4 Inter-comparison of Models Project (WETCHIMP), total wetland emissions of 4.3 (2.3-8.2) Tg CH4 yr-1 from the EU-28 are estimated. The hypothesis of significant natural emissions is supported by the finding that several inverse models yield significant seasonal cycles of derived CH4 emissions with maxima in summer, while anthropogenic CH4 emissions are assumed to have much lower seasonal variability. Taking into account the wetland emissions from the WETCHIMP ensemble, the top-down estimates are broadly consistent with the sum of anthropogenic and natural bottom-up inventories. However, the contribution of natural sources and their regional distribution remain rather uncertain. Furthermore, we investigate potential biases in the inverse models by comparison with regular aircraft profiles at four European sites and with vertical profiles obtained during the Infrastructure for Measurement of the European Carbon Cycle (IMECC) aircraft campaign. We present a novel approach to estimate the biases in the derived emissions, based on the comparison of simulated and measured enhancements of CH4 compared to the background, integrated over the entire boundary layer and over the lower troposphere. The estimated average regional biases range between -40 and 20 % at the aircraft profile sites in France, Hungary and Poland. |
BibTeX:
@article{Bergamaschi2018,
author = {Bergamaschi, Peter and Karstens, Ute and Manning, Alistair J and Saunois, Marielle and Tsuruta, Aki and Berchet, Antoine and Vermeulen, Alexander T and Arnold, Tim and Janssens-Maenhout, Greet and Hammer, Samuel and Levin, Ingeborg and Schmidt, Martina and Ramonet, Michel and Lopez, Morgan and Lavric, Jost and Aalto, Tuula and Chen, Huilin and Feist, Dietrich G and Gerbig, Christoph and Haszpra, László and Hermansen, Ove and Manca, Giovanni and Moncrieff, John and Meinhardt, Frank and Necki, Jaroslaw and Galkowski, Michal and O'Doherty, Simon and Paramonova, Nina and Scheeren, Hubertus A and Steinbacher, Martin and Dlugokencky, Ed},
title = {Inverse modelling of European CH4 emissions during 2006-2012 using different inverse models and reassessed atmospheric observations},
journal = {Atmospheric Chemistry and Physics},
publisher = {Copernicus GmbH},
year = {2018},
volume = {18},
number = {2},
pages = {901--920},
doi = {10.5194/acp-18-901-2018}
}
|
| Besnard S, Carvalhais N, Arain MA, Black A, De Bruin S, Buchmann N, Cescatti A, Chen J, Clevers JGPW, Desai AR, Gough CM, Havrankova K, Herold M, Hörtnagl L, Jung M, Knohl A, Kruijt B, Krupkova L, Law BE, Lindroth A, Noormets A, Roupsard O, Steinbrecher R, Varlagin A, Vincke C and Reichstein M (2018), "Quantifying the effect of forest age in annual net forest carbon balance", Environmental Research Letters., dec, 2018. Vol. 13(12), pp. 124018. IOP Publishing. |
| Abstract: Forests dominate carbon (C) exchanges between the terrestrial biosphere and the atmosphere on land. In the long term, the net carbon flux between forests and the atmosphere has been significantly impacted by changes in forest cover area and structure due to ecological disturbances and management activities. Current empirical approaches for estimating net ecosystem productivity (NEP) rarely consider forest age as a predictor, which represents variation in physiological processes that can respond differently to environmental drivers, and regrowth following disturbance. Here, we conduct an observational synthesis to empirically determine to what extent climate, soil properties, nitrogen deposition, forest age and management influence the spatial and interannual variability of forest NEP across 126 forest eddy-covariance flux sites worldwide. The empirical models explained up to 62% and 71% of spatio-temporal and across-site variability of annual NEP, respectively. An investigation of model structures revealed that forest age was a dominant factor of NEP spatio-temporal variability in both space and time at the global scale as compared to abiotic factors, such as nutrient availability, soil characteristics and climate. These findings emphasize the importance of forest age in quantifying spatio-temporal variation in NEP using empirical approaches. |
BibTeX:
@article{Besnard2018,
author = {Besnard, Simon and Carvalhais, Nuno and Arain, M Altaf and Black, Andrew and De Bruin, Sytze and Buchmann, Nina and Cescatti, Alessandro and Chen, Jiquan and Clevers, Jan G P W and Desai, Ankur R and Gough, Christopher M and Havrankova, Katerina and Herold, Martin and Hörtnagl, Lukas and Jung, Martin and Knohl, Alexander and Kruijt, Bart and Krupkova, Lenka and Law, Beverly E and Lindroth, Anders and Noormets, Asko and Roupsard, Olivier and Steinbrecher, Rainer and Varlagin, Andrej and Vincke, Caroline and Reichstein, Markus},
title = {Quantifying the effect of forest age in annual net forest carbon balance},
journal = {Environmental Research Letters},
publisher = {IOP Publishing},
year = {2018},
volume = {13},
number = {12},
pages = {124018},
doi = {10.1088/1748-9326/aaeaeb}
}
|
| Bodesheim P, Jung M, Gans F, Mahecha MD and Reichstein M (2018), "Upscaled diurnal cycles of land–atmosphere fluxes: a new global half-hourly data product", Earth System Science Data., jul, 2018. Vol. 10(3), pp. 1327-1365. |
| Abstract: Abstract. Interactions between the biosphere and the atmosphere can be well characterized by fluxes between the two. In particular, carbon and energy fluxes play a major role in understanding biogeochemical processes on an ecosystem level or global scale. However, the fluxes can only be measured at individual sites, e.g., by eddy covariance towers, and an upscaling of these local observations is required to analyze global patterns. Previous work focused on upscaling monthly, 8-day, or daily average values, and global maps for each flux have been provided accordingly. In this paper, we raise the upscaling of carbon and energy fluxes between land and atmosphere to the next level by increasing the temporal resolution to subdaily timescales. We provide continuous half-hourly fluxes for the period from 2001 to 2014 at 0.5° spatial resolution, which allows for analyzing diurnal cycles globally. The data set contains four fluxes: gross primary production (GPP), net ecosystem exchange (NEE), latent heat (LE), and sensible heat (H). We propose two prediction approaches for the diurnal cycles based on large-scale regression models and compare them in extensive cross-validation experiments using different sets of predictor variables. We analyze the results for a set of FLUXNET tower sites showing the suitability of our approaches for this upscaling task. Finally, we have selected one approach to calculate the global half-hourly data products based on predictor variables from remote sensing and meteorology at daily resolution as well as half-hourly potential radiation. In addition, we provide a derived product that only contains monthly average diurnal cycles, which is a lightweight version in terms of data storage that still allows studying the important characteristics of diurnal patterns globally. We recommend to primarily use these monthly average diurnal cycles, because they are less affected by the impacts of day-to-day variation, observation noise, and short-term fluctuations on subdaily timescales compared to the full half-hourly flux products. The global half-hourly data products are available at https://doi.org/10.17871/BACI.224. |
BibTeX:
@article{Bodesheim2018,
author = {Bodesheim, Paul and Jung, Martin and Gans, Fabian and Mahecha, Miguel D. and Reichstein, Markus},
title = {Upscaled diurnal cycles of land–atmosphere fluxes: a new global half-hourly data product},
journal = {Earth System Science Data},
year = {2018},
volume = {10},
number = {3},
pages = {1327--1365},
url = {https://essd.copernicus.org/articles/10/1327/2018/},
doi = {10.5194/essd-10-1327-2018}
}
|
| Bogena HR, Montzka C, Huisman JA, Graf A, Schmidt M, Stockinger M, von Hebel C, Hendricks-Franssen HJ, van der Kruk J, Tappe W, Lücke A, Baatz R, Bol R, Groh J, Pütz T, Jakobi J, Kunkel R, Sorg J and Vereecken H (2018), "The TERENO-Rur Hydrological Observatory: A Multiscale Multi-Compartment Research Platform for the Advancement of Hydrological Science", Vadose Zone Journal. Vol. 17(1), pp. 180055. Soil Science Society of America. |
| Abstract: We provide an overview of the Rur hydrological observatory, which is the main observational platform of the TERENO (TERrestrial ENvironmental Observatories) Eifel/Lower Rhine Valley Observatory. The Rur catchment area exhibits distinct gradients in altitude, climate, land use, soil properties, and geology. The Eifel National Park is situated in the southern part of the Rur catchment and serves as a reference site for the hydrological observatory. We present information on general physical characteristics of the Rur catchment and describe the main features of the multi-scale and multi-compartment monitoring framework. In addition, we also present some examples of the ongoing interdisciplinary research that aims to advance the understanding of complex hydrological processes and interactions within the Rur catchment. |
BibTeX:
@article{Bogena2018,
author = {Bogena, H R and Montzka, C and Huisman, J A and Graf, A and Schmidt, M and Stockinger, M and von Hebel, C and Hendricks-Franssen, H J and van der Kruk, J and Tappe, W and Lücke, A and Baatz, R and Bol, R and Groh, J and Pütz, T and Jakobi, J and Kunkel, R and Sorg, J and Vereecken, H},
title = {The TERENO-Rur Hydrological Observatory: A Multiscale Multi-Compartment Research Platform for the Advancement of Hydrological Science},
journal = {Vadose Zone Journal},
publisher = {Soil Science Society of America},
year = {2018},
volume = {17},
number = {1},
pages = {180055},
doi = {10.2136/vzj2018.03.0055}
}
|
| Borsdorff T, Aan De Brugh J, Hu H, Hasekamp O, Sussmann R, Rettinger M, Hase F, Gross J, Schneider M, Garcia O, Stremme W, Grutter M, Feist DG, Arnold SG, De Mazière M, Kumar Sha M, Pollard DF, Kiel M, Roehl C, Wennberg PO, Toon GC and Landgraf J (2018), "Mapping carbon monoxide pollution from space down to city scales with daily global coverage", Atmospheric Measurement Techniques., oct, 2018. Vol. 11(10), pp. 5507-5518. Copernicus GmbH. |
| Abstract: On 13 October 2017, the European Space Agency (ESA) successfully launched the Sentinel-5 Precursor satellite with the Tropospheric Monitoring Instrument (TROPOMI) as its single payload. TROPOMI is the first of ESA's atmospheric composition Sentinel missions, which will provide complete long-term records of atmospheric trace gases for the coming 30 years as a contribution to the European Union's Earth Observing program Copernicus. One of TROPOMI's primary products is atmospheric carbon monoxide (CO). It is observed with daily global coverage and a high spatial resolution of 7×7km2. The moderate atmospheric resistance time and the low background concentration leads to localized pollution hotspots of CO and allows the tracking of the atmospheric transport of pollution on regional to global scales. In this contribution, we demonstrate the groundbreaking performance of the TROPOMI CO product, sensing CO enhancements above cities and industrial areas and tracking, with daily coverage, the atmospheric transport of pollution from biomass burning regions. The CO data product is validated with two months of Fourier-transform spectroscopy (FTS) measurements at nine ground-based stations operated by the Total Carbon Column Observing Network (TCCON). We found a good agreement between both datasets with a mean bias of 6ppb (average of individual station biases) for both clear-sky and cloudy TROPOMI CO retrievals. Together with the corresponding standard deviation of the individual station biases of 3.8ppb for clear-sky and 4.0ppb for cloudy sky, it indicates that the CO data product is already well within the mission requirement. |
BibTeX:
@article{Borsdorff2018,
author = {Borsdorff, Tobias and Aan De Brugh, Joost and Hu, Haili and Hasekamp, Otto and Sussmann, Ralf and Rettinger, Markus and Hase, Frank and Gross, Jochen and Schneider, Matthias and Garcia, Omaira and Stremme, Wolfgang and Grutter, Michel and Feist, DIetrich G. and Arnold, Sabrina G. and De Mazière, Martine and Kumar Sha, Mahesh and Pollard, David F. and Kiel, Matthäus and Roehl, Coleen and Wennberg, Paul O. and Toon, Geoffrey C. and Landgraf, Jochen},
title = {Mapping carbon monoxide pollution from space down to city scales with daily global coverage},
journal = {Atmospheric Measurement Techniques},
publisher = {Copernicus GmbH},
year = {2018},
volume = {11},
number = {10},
pages = {5507--5518},
doi = {10.5194/amt-11-5507-2018}
}
|
| Brændholt A, Ibrom A, Larsen KS and Pilegaard K (2018), "Partitioning of ecosystem respiration in a beech forest", Agricultural and Forest Meteorology., apr, 2018. Vol. 252, pp. 88-98. Elsevier BV. |
| Abstract: Terrestrial ecosystem respiration (Reco) represents a major component of the global carbon cycle. It consists of many sub-components, such as aboveground plant respiration and belowground root and microbial respiration, each of which may respond differently to abiotic factors, and thus to global climate change. To correctly predict future carbon cycles in forest ecosystems, Reco must therefore be partitioned and understood for each of its various components. In this study we used the eddy covariance technique together with manual and automated closed-chambers to quantify the individual components of Reco in a temperate beech forest at diel, seasonal and annual time scales. Reco was measured by eddy covariance while respiration rates from soil, tree stems and isolated coarse tree roots were measured bi-hourly by an automated closed-chamber system. Soil respiration (Rsoil) was measured in intact plots, and heterotrophic Rsoil was measured in trenched plots. Tree stem (Rstem) and coarse root (Rroot) respiration were measured by custom made closed-chambers. We found that the contribution of Rstem to total Reco varied across the year, by only accounting for 6% of Reco during winter and 16% during the summer growing season. In contrast Rsoil was approximately half of Reco during winter (52%), spring (45%) and summer (49%), while the contribution increased to 79% during autumn. Based on observed fluxes in the trenched and intact soil plots, we found that autotrophic Rsoil accounted for 34% of Rsoil during summer, i.e. a relatively low fractional estimate compared to findings from other studies. It is likely that dead roots were still decomposing in the trenched soil plots thus causing overestimation of heterotrophic Rsoil. Diel Rstem and Rroot measurements showed a distinct pattern during summer with the highest respiration rates around 13:00-15:00 CET for Rstem, and the highest respiration seen from 9:00–15:00 for Rroot. In contrast, Rsoil showed the lowest respiration during daytime with no clear difference in the diel pattern between the intact and trenched soil plots. Finally, we calculated annual Rsoil for different transects, and found that annual Rsoil estimated from the previously used transect at the site was underestimated due to Rsoil of the transect not being representative for the spatial heterogeneity of Rsoil at the site. This highlights the importance of performing a sufficient number of chamber measurements at a site to adequately capture the spatial variation and estimate Rsoil correctly. |
BibTeX:
@article{Brændholt2018,
author = {Brændholt, Andreas and Ibrom, Andreas and Larsen, Klaus Steenberg and Pilegaard, Kim},
title = {Partitioning of ecosystem respiration in a beech forest},
journal = {Agricultural and Forest Meteorology},
publisher = {Elsevier BV},
year = {2018},
volume = {252},
pages = {88--98},
doi = {10.1016/j.agrformet.2018.01.012}
}
|
| Buermann W, Forkel M, O'Sullivan M, Sitch S, Friedlingstein P, Haverd V, Jain AK, Kato E, Kautz M, Lienert S, Lombardozzi D, Nabel JE, Tian H, Wiltshire AJ, Zhu D, Smith WK and Richardson AD (2018), "Widespread seasonal compensation effects of spring warming on northern plant productivity", Nature., oct, 2018. Vol. 562(7725), pp. 110-114. Nature Publishing Group. |
| Abstract: Climate change is shifting the phenological cycles of plants1, thereby altering the functioning of ecosystems, which in turn induces feedbacks to the climate system2. In northern (north of 30° N) ecosystems, warmer springs lead generally to an earlier onset of the growing season3,4 and increased ecosystem productivity early in the season5. In situ6 and regional7–9 studies also provide evidence for lagged effects of spring warmth on plant productivity during the subsequent summer and autumn. However, our current understanding of these lagged effects, including their direction (beneficial or adverse) and geographic distribution, is still very limited. Here we analyse satellite, field-based and modelled data for the period 1982–2011 and show that there are widespread and contrasting lagged productivity responses to spring warmth across northern ecosystems. On the basis of the observational data, we find that roughly 15 per cent of the total study area of about 41 million square kilometres exhibits adverse lagged effects and that roughly 5 per cent of the total study area exhibits beneficial lagged effects. By contrast, current-generation terrestrial carbon-cycle models predict much lower areal fractions of adverse lagged effects (ranging from 1 to 14 per cent) and much higher areal fractions of beneficial lagged effects (ranging from 9 to 54 per cent). We find that elevation and seasonal precipitation patterns largely dictate the geographic pattern and direction of the lagged effects. Inadequate consideration in current models of the effects of the seasonal build-up of water stress on seasonal vegetation growth may therefore be able to explain the differences that we found between our observation-constrained estimates and the model-constrained estimates of lagged effects associated with spring warming. Overall, our results suggest that for many northern ecosystems the benefits of warmer springs on growing-season ecosystem productivity are effectively compensated for by the accumulation of seasonal water deficits, despite the fact that northern ecosystems are thought to be largely temperature- and radiation-limited10. |
BibTeX:
@article{Buermann2018,
author = {Buermann, Wolfgang and Forkel, Matthias and O'Sullivan, Michael and Sitch, Stephen and Friedlingstein, Pierre and Haverd, Vanessa and Jain, Atul K. and Kato, Etsushi and Kautz, Markus and Lienert, Sebastian and Lombardozzi, Danica and Nabel, Julia E.M.S. and Tian, Hanqin and Wiltshire, Andrew J. and Zhu, Dan and Smith, William K. and Richardson, Andrew D.},
title = {Widespread seasonal compensation effects of spring warming on northern plant productivity},
journal = {Nature},
publisher = {Nature Publishing Group},
year = {2018},
volume = {562},
number = {7725},
pages = {110--114},
doi = {10.1038/s41586-018-0555-7}
}
|
| Byrne B, Wunch D, Jones DBA, Strong K, Deng F, Baker I, Köhler P, Frankenberg C, Joiner J, Arora VK, Badawy B, Harper AB, Warneke T, Petri C, Kivi R and Roehl CM (2018), "Evaluating GPP and Respiration Estimates Over Northern Midlatitude Ecosystems Using Solar-Induced Fluorescence and Atmospheric CO textlesssubtextgreater2textless/subtextgreater Measurements", Journal of Geophysical Research: Biogeosciences., sep, 2018. Vol. 123(9), pp. 2976-2997. Blackwell Publishing Ltd. |
| Abstract: On regional to global scales, few constraints exist on gross primary productivity (GPP) and ecosystem respiration (Re) fluxes. Yet constraints on these fluxes are critical for evaluating and improving terrestrial biosphere models. In this study, we evaluate the seasonal cycle of GPP, Re, and net ecosystem exchange (NEE) produced by four terrestrial biosphere models and FLUXCOM, a data-driven model, over northern midlatitude ecosystems. We evaluate the seasonal cycle of GPP and NEE using solar-induced fluorescence retrieved from the Global Ozone Monitoring Experiment-2 and column-averaged dry-air mole fractions of CO2 (XCO2) from the Total Carbon Column Observing Network, respectively. We then infer Re by combining constraints on GPP with constraints on NEE from two flux inversions. An ensemble of optimized Re seasonal cycles is generated using five GPP estimates and two NEE estimates. The optimized Re curves generally show high consistency with each other, with the largest differences due to the magnitude of GPP. We find optimized Re exhibits a systematically broader summer maximum than modeled Re, with values lower during June–July and higher during the fall than Re. Further analysis suggests that the differences could be due to seasonal variations in the carbon use efficiency (possibly due to an ecosystem-scale Kok effect) and to seasonal variations in the leaf litter and fine root carbon pool. The results suggest that the inclusion of variable carbon use efficiency for autotrophic respiration and carbon pool dependence for heterotrophic respiration is important for accurately simulating Re. |
BibTeX:
@article{Byrne2018,
author = {Byrne, B. and Wunch, D. and Jones, D. B. A. and Strong, K. and Deng, F. and Baker, I. and Köhler, P. and Frankenberg, C. and Joiner, J. and Arora, V. K. and Badawy, B. and Harper, A. B. and Warneke, T. and Petri, C. and Kivi, R. and Roehl, C. M.},
title = {Evaluating GPP and Respiration Estimates Over Northern Midlatitude Ecosystems Using Solar-Induced Fluorescence and Atmospheric CO textlesssubtextgreater2textless/subtextgreater Measurements},
journal = {Journal of Geophysical Research: Biogeosciences},
publisher = {Blackwell Publishing Ltd},
year = {2018},
volume = {123},
number = {9},
pages = {2976--2997},
url = {http://doi.wiley.com/10.1029/2018JG004472},
doi = {10.1029/2018JG004472}
}
|
| Cameron D, Flechard C and Van Oijen M (2018), "Calibrating a process-based forest model with a rich observational dataset at 22 European forest sites", Biogeosciences Discussions., apr, 2018. , pp. 1-42. |
| Abstract: ppstrongAbstract./strong In recent years model-data interaction has improved through use of probabilistic techniques to inform and reduce the uncertainty of model parameters, while also taking into account observational uncertainty. This study builds on previous work, through access to a richer representation of the plant-soil ecosystem at multiple European forest sites, than was previously available. Given this rich dataset, we asked which observational datasets were most effective in reducing uncertainty in model predictions and model-data differences. Also, since there is a lack of consensus about whether it is more beneficial to calibrate forest sites separately or together we revisited this question with a particular emphasis on which is most effective in reducing model-data differences and uncertainty. We performed single dataset Bayesian calibrations (BC) and compared the results with a calibration with all the observations included. We also compared calibrations where each pine forest site was calibrated separately with a calibration where all the pine sites were calibrated together. While measurements of plant and soil carbon stocks were more sparse, their inclusion in the BC were more important for reducing model-data differences and uncertainty in the above and belowground carbon pools than the greater numbers of carbon and water flux data. Our results suggest that use of calibration data representing just a few aspects of the ecosystem could be problematic, since improved model-data fits for the parts of the system represented by the data could be at the expense of other part of the system, where the model-data fit worsened. The single dataset calibrations helped to diagnose where there may be inconsistencies between different datasets or between the model and data or both. These inconsistencies hampered the reduction in model-data differences in the calibration with all the observations present. As expected, we found a strong relationship between the quantity of data included in the calibration and the uncertainty reduction after BC, finding the largest reduction in uncertainty when all the observations were included. For some ecosystem variables uncertainty reduced after calibration but model-data differences increased. This would suggest that there were deficiencies in the model or systematic errors in the data or both. These results advocate the use of calibration datasets which represent the rich diversity of the ecosystem under investigation but where model discrepancies and data systematic errors are explicitly represented in the BC. While separate calibrations at each forest site generally reduced model-data differences more than calibrating at all the sites together, parts of the ecosystem that were sparsely observed benefited more from the multi-site calibration. Multi-site calibration led to larger and more consistent reductions in uncertainty than separate calibrations at each site, especially for ecosystem variables with fewer observations. These results support the use of Bayesian hierarchical calibration which allows variation in model parameters between different sites while allowing information to be shared across sites for sparsely observed ecosystem variables./p/p |
BibTeX:
@article{Cameron2018,
author = {Cameron, David and Flechard, Christophe and Van Oijen, Marcel},
title = {Calibrating a process-based forest model with a rich observational dataset at 22 European forest sites},
journal = {Biogeosciences Discussions},
year = {2018},
pages = {1--42},
url = {https://www.biogeosciences-discuss.net/bg-2018-156/},
doi = {10.5194/bg-2018-156}
}
|
| Camino-Serrano M, Guenet B, Luyssaert S, Ciais P, Bastrikov V, De Vos B, Gielen B, Gleixner G, Jornet-Puig A, Kaiser K, Kothawala D, Lauerwald R, Peñuelas J, Schrumpf M, Vicca S, Vuichard N, Walmsley D and Janssens IA (2018), "ORCHIDEE-SOM: Modeling soil organic carbon (SOC) and dissolved organic carbon (DOC) dynamics along vertical soil profiles in Europe", Geoscientific Model Development., mar, 2018. Vol. 11(3), pp. 937-957. Copernicus GmbH. |
| Abstract: Current land surface models (LSMs) typically represent soils in a very simplistic way, assuming soil organic carbon (SOC) as a bulk, and thus impeding a correct representation of deep soil carbon dynamics. Moreover, LSMs generally neglect the production and export of dissolved organic carbon (DOC) from soils to rivers, leading to overestimations of the potential carbon sequestration on land. This common oversimplified processing of SOC in LSMs is partly responsible for the large uncertainty in the predictions of the soil carbon response to climate change. In this study, we present a new soil carbon module called ORCHIDEE-SOM, embedded within the land surface model ORCHIDEE, which is able to reproduce the DOC and SOC dynamics in a vertically discretized soil to 2gm. The model includes processes of biological production and consumption of SOC and DOC, DOC adsorption on and desorption from soil minerals, diffusion of SOC and DOC, and DOC transport with water through and out of the soils to rivers. We evaluated ORCHIDEE-SOM against observations of DOC concentrations and SOC stocks from four European sites with different vegetation covers: A coniferous forest, a deciduous forest, a grassland, and a cropland. The model was able to reproduce the SOC stocks along their vertical profiles at the four sites and the DOC concentrations within the range of measurements, with the exception of the DOC concentrations in the upper soil horizon at the coniferous forest. However, the model was not able to fully capture the temporal dynamics of DOC concentrations. Further model improvements should focus on a plant- A nd depth-dependent parameterization of the new input model parameters, such as the turnover times of DOC and the microbial carbon use efficiency. We suggest that this new soil module, when parameterized for global simulations, will improve the representation of the global carbon cycle in LSMs, thus helping to constrain the predictions of the future SOC response to global warming. |
BibTeX:
@article{Camino-Serrano2018,
author = {Camino-Serrano, Marta and Guenet, Bertrand and Luyssaert, Sebastiaan and Ciais, Philippe and Bastrikov, Vladislav and De Vos, Bruno and Gielen, Bert and Gleixner, Gerd and Jornet-Puig, Albert and Kaiser, Klaus and Kothawala, Dolly and Lauerwald, Ronny and Peñuelas, Josep and Schrumpf, Marion and Vicca, Sara and Vuichard, Nicolas and Walmsley, David and Janssens, Ivan A.},
title = {ORCHIDEE-SOM: Modeling soil organic carbon (SOC) and dissolved organic carbon (DOC) dynamics along vertical soil profiles in Europe},
journal = {Geoscientific Model Development},
publisher = {Copernicus GmbH},
year = {2018},
volume = {11},
number = {3},
pages = {937--957},
doi = {10.5194/gmd-11-937-2018}
}
|
| Campeau A, Bishop K, Nilsson MB, Klemedtsson L, Laudon H, Leith FI, Öquist M and Wallin MB (2018), "Stable Carbon Isotopes Reveal Soil-Stream DIC Linkages in Contrasting Headwater Catchments", Journal of Geophysical Research: Biogeosciences., jan, 2018. Vol. 123(1), pp. 149-167. |
| Abstract: Large CO2 evasion to the atmosphere occurs as dissolved inorganic carbon (DIC) is transported from soils to streams. While this physical process has been the focus of multiple studies, less is known about the underlying biogeochemical transformations that accompany this transfer of C from soils to streams. Here we used patterns in stream water and groundwater δ13C-DIC values within three headwater catchments with contrasting land cover to identify the sources and processes regulating DIC during its transport. We found that although considerable CO2 evasion occurs as DIC is transported from soils to streams, there were also other processes affecting the DIC pool. Methane production and mixing of C sources, associated with different types and spatial distribution of peat-rich areas within each catchment, had a significant influence on the δ13C-DIC values in both soils and streams. These processes represent an additional control on δ13C-DIC values and the catchment-scale cycling of DIC across different northern landscape types. The results from this study demonstrate that the transport of DIC from soils to streams results in more than just rapid CO2 evasion to the atmosphere but also represents a channel of C transformation, which questions some of our current conceptualizations of C cycling at the landscape scale. |
BibTeX:
@article{Campeau2018,
author = {Campeau, A and Bishop, K and Nilsson, M B and Klemedtsson, L and Laudon, H and Leith, F I and Öquist, M and Wallin, M B},
title = {Stable Carbon Isotopes Reveal Soil-Stream DIC Linkages in Contrasting Headwater Catchments},
journal = {Journal of Geophysical Research: Biogeosciences},
year = {2018},
volume = {123},
number = {1},
pages = {149--167},
url = {http://doi.wiley.com/10.1002/2017JG004083},
doi = {10.1002/2017JG004083}
}
|
| Carrara A, Kolari P, De Beeck MO, Arriga N, Berveiller D, Dengel S, Ibrom A, Merbold L, Rebmann C, Sabbatini S, Serrano-Ortíz P and Biraud SC (2018), "Radiation measurements at ICOS ecosystem stations", International Agrophysics., dec, 2018. Vol. 32(4), pp. 589-605. |
| Abstract: Solar radiation is a key driver of energy and carbon fluxes in natural ecosystems. Radiation measurements are essential for interpreting ecosystem scale greenhouse gases and energy fluxes as well as many other observations performed at ecosystem stations of the Integrated Carbon Observation System (ICOS). We describe and explain the relevance of the radiation variables that are monitored continuously at ICOS ecosystem stations and define recommendations to perform these measurements with consistent and comparable accuracy. The measurement methodology and instruments are described including detailed technical specifications. Guidelines for instrumental set up as well as for operation, maintenance and data collection are defined considering both ICOS scientific objectives and practical operational constraints. For measurements of short-wave (solar) and long wave (infrared) radiation components, requirements for the ICOS network are based on available well-defined state-of-The art standards (World Meteorological Organization, International Organization for Standardization). For photosynthetically active radiation measurements, some basic instrumental requirements are based on the performance of commercially available sensors. Since site specific conditions and practical constraints at individual ICOS ecosystem stations may hamper the applicability of standard requirements, we recommend that ICOS develops mid-Term coordinated actions to assess the effective level of uncertainties in radiation measurements at the network scale. |
BibTeX:
@article{Carrara2018,
author = {Carrara, Arnaud and Kolari, Pasi and De Beeck, Maarten Op and Arriga, Nicola and Berveiller, Daniel and Dengel, Sigrid and Ibrom, Andreas and Merbold, Lutz and Rebmann, Corinna and Sabbatini, Simone and Serrano-Ortíz, Penelope and Biraud, Sébastien C},
title = {Radiation measurements at ICOS ecosystem stations},
journal = {International Agrophysics},
year = {2018},
volume = {32},
number = {4},
pages = {589--605},
url = {https://content.sciendo.com/view/journals/intag/32/4/article-p589.xml},
doi = {10.1515/intag-2017-0049}
}
|
| Chen L, Dirmeyer PA, Guo Z and Schultz NM (2018), "Pairing FLUXNET sites to validate model representations of land-use/land-cover change", Hydrology and Earth System Sciences., jan, 2018. Vol. 22(1), pp. 111-125. Copernicus GmbH. |
| Abstract: Land surface energy and water fluxes play an important role in land-atmosphere interactions, especially for the climatic feedback effects driven by land-use/landcover change (LULCC). These have long been documented in model-based studies, but the performance of land surface models in representing LULCC-induced responses has not been investigated well. In this study, measurements from proximate paired (open versus forest) flux tower sites are used to represent observed deforestation-induced changes in surface fluxes, which are compared with simulations from the Community Land Model (CLM) and the Noah Multi-Parameterization (Noah-MP) land model. Point-scale simulations suggest the CLM can represent the observed diurnal and seasonal changes in net radiation (Rnet) and ground heat flux (G), but difficulties remain in the energy partitioning between latent (LE) and sensible (H) heat flux. The CLM does not capture the observed decreased daytime LE, and overestimates the increased H during summer. These deficiencies are mainly associated with models' greater biases over forest land-cover types and the parameterization of soil evaporation. Global gridded simulations with the CLM show uncertainties in the estimation of LE and H at the grid level for regional and global simulations. Noah-MP exhibits a similar ability to simulate the surface flux changes, but with larger biases in H, G, and Rnet change during late winter and early spring, which are related to a deficiency in estimating albedo. Differences in meteorological conditions between paired sites is not a factor in these results. Attention needs to be devoted to improving the representation of surface heat flux processes in land models to increase confidence in LULCC simulations. |
BibTeX:
@article{Chen2018,
author = {Chen, Liang and Dirmeyer, Paul A. and Guo, Zhichang and Schultz, Natalie M.},
title = {Pairing FLUXNET sites to validate model representations of land-use/land-cover change},
journal = {Hydrology and Earth System Sciences},
publisher = {Copernicus GmbH},
year = {2018},
volume = {22},
number = {1},
pages = {111--125},
doi = {10.5194/hess-22-111-2018}
}
|
| Ciavatta S, Brewin RJW, Skákala J, Polimene L, de Mora L, Artioli Y and Allen JI (2018), "Assimilation of Ocean-Color Plankton Functional Types to Improve Marine Ecosystem Simulations", Journal of Geophysical Research: Oceans., feb, 2018. Vol. 123(2), pp. 834-854. American Geophysical Union (AGU). |
| Abstract: We assimilated phytoplankton functional types (PFTs) derived from ocean color into a marine ecosystem model, to improve the simulation of biogeochemical indicators and emerging properties in a shelf sea. Error-characterized chlorophyll concentrations of four PFTs (diatoms, dinoflagellates, nanoplankton, and picoplankton), as well as total chlorophyll for comparison, were assimilated into a physical-biogeochemical model of the North East Atlantic, applying a localized Ensemble Kalman filter. The reanalysis simulations spanned the years 1998–2003. The skill of the reference and reanalysis simulations in estimating ocean color and in situ biogeochemical data were compared by using robust statistics. The reanalysis outperformed both the reference and the assimilation of total chlorophyll in estimating the ocean-color PFTs (except nanoplankton), as well as the not-assimilated total chlorophyll, leading the model to simulate better the plankton community structure. Crucially, the reanalysis improved the estimates of not-assimilated in situ data of PFTs, as well as of phosphate and pCO2, impacting the simulation of the air-sea carbon flux. However, the reanalysis increased further the model overestimation of nitrate, in spite of increases in plankton nitrate uptake. The method proposed here is easily adaptable for use with other ecosystem models that simulate PFTs, for, e.g., reanalysis of carbon fluxes in the global ocean and for operational forecasts of biogeochemical indicators in shelf-sea ecosystems. |
BibTeX:
@article{Ciavatta2018,
author = {Ciavatta, S and Brewin, R J W and Skákala, J and Polimene, L and de Mora, L and Artioli, Y and Allen, J I},
title = {Assimilation of Ocean-Color Plankton Functional Types to Improve Marine Ecosystem Simulations},
journal = {Journal of Geophysical Research: Oceans},
publisher = {American Geophysical Union (AGU)},
year = {2018},
volume = {123},
number = {2},
pages = {834--854},
doi = {10.1002/2017JC013490}
}
|
| Collalti A, Trotta C, Keenan TF, Ibrom A, Bond-Lamberty B, Grote R, Vicca S, Reyer CPO, Migliavacca M, Veroustraete F, Anav A, Campioli M, Scoccimarro E, Šigut L, Grieco E, Cescatti A and Matteucci G (2018), "Thinning Can Reduce Losses in Carbon Use Efficiency and Carbon Stocks in Managed Forests Under Warmer Climate", Journal of Advances in Modeling Earth Systems. Vol. 10(10), pp. 2427-2452. American Geophysical Union (AGU). |
| Abstract: Forest carbon use efficiency (CUE, the ratio of net to gross primary productivity) represents the fraction of photosynthesis that is not used for plant respiration. Although important, it is often neglected in climate change impact analyses. Here we assess the potential impact of thinning on projected carbon cycle dynamics and implications for forest CUE and its components (i.e., gross and net primary productivity and plant respiration), as well as on forest biomass production. Using a detailed process-based forest ecosystem model forced by climate outputs of five Earth System Models under four representative climate scenarios, we investigate the sensitivity of the projected future changes in the autotrophic carbon budget of three representative European forests. We focus on changes in CUE and carbon stocks as a result of warming, rising atmospheric CO2 concentration, and forest thinning. Results show that autotrophic carbon sequestration decreases with forest development, and the decrease is faster with warming and in unthinned forests. This suggests that the combined impacts of climate change and changing CO2 concentrations lead the forests to grow faster, mature earlier, and also die younger. In addition, we show that under future climate conditions, forest thinning could mitigate the decrease in CUE, increase carbon allocation into more recalcitrant woody pools, and reduce physiological-climate-induced mortality risks. Altogether, our results show that thinning can improve the efficacy of forest-based mitigation strategies and should be carefully considered within a portfolio of mitigation options. |
BibTeX:
@article{Collalti2018,
author = {Collalti, Alessio and Trotta, Carlo and Keenan, Trevor F and Ibrom, Andreas and Bond-Lamberty, Ben and Grote, Ruediger and Vicca, Sara and Reyer, Christopher P O and Migliavacca, Mirco and Veroustraete, Frank and Anav, Alessandro and Campioli, Matteo and Scoccimarro, Enrico and Šigut, Ladislav and Grieco, Elisa and Cescatti, Alessandro and Matteucci, Giorgio},
title = {Thinning Can Reduce Losses in Carbon Use Efficiency and Carbon Stocks in Managed Forests Under Warmer Climate},
journal = {Journal of Advances in Modeling Earth Systems},
publisher = {American Geophysical Union (AGU)},
year = {2018},
volume = {10},
number = {10},
pages = {2427--2452},
doi = {10.1029/2018MS001275}
}
|
| Colomb A. CSDMHMHOHJ…Y-KC (2018), "ICOS Atmospheric Greenhouse Gas Mole Fractions of CO2, CH4, CO, 14CO2 and Meteorological Observations 2016-2018, final quality controlled Level 2 data.". |
BibTeX:
@misc{ColombA.2018,
author = {Colomb A., Conil S Delmotte M Heliasz M Hermannsen O Holst J … Yver-Kwok C},
title = {ICOS Atmospheric Greenhouse Gas Mole Fractions of CO2, CH4, CO, 14CO2 and Meteorological Observations 2016-2018, final quality controlled Level 2 data.},
booktitle = {Icos Eric},
publisher = {ICOS ERIC},
year = {2018},
doi = {doi.org/10.18160/RHKC-VP22}
}
|
| Conen F, Bukowiecki N, Gysel M, Steinbacher M, Fischer A and Reimann S (2018), "Low number concentration of ice nucleating particles in an aged smoke plume", Quarterly Journal of the Royal Meteorological Society., jul, 2018. Vol. 144(715), pp. 1991-1994. Wiley. |
| Abstract: Smoke from forest fires in the western part of North America reached the High Altitude Research Station Jungfraujoch, Switzerland, at the beginning of September 2017. Number concentration of ice nucleating particles (INPs) active at âˆ'15 °C or warmer decreased by about half during its passage. This is different to observations of enhanced INP concentrations in fresh plumes from forest fires. We hypothesise that INPs initially present in a smoke plume are lost or deactivated during long-range transport, while components of smoke capable of deactivating INPs originally present or mixed later into the plume continue to remain active across a longer distance. |
BibTeX:
@article{Conen2018,
author = {Conen, Franz and Bukowiecki, Nicolas and Gysel, Martin and Steinbacher, Martin and Fischer, Andrea and Reimann, Stefan},
title = {Low number concentration of ice nucleating particles in an aged smoke plume},
journal = {Quarterly Journal of the Royal Meteorological Society},
publisher = {Wiley},
year = {2018},
volume = {144},
number = {715},
pages = {1991--1994},
doi = {10.1002/qj.3312}
}
|
| Darenova E, Acosta M, Pokorny R and Pavelka M (2018), "Variability in temperature dependence of stem CO 2 efflux from Norway spruce trees", Tree Physiology., feb, 2018. Vol. 38(9), pp. 1333-1344. Oxford University Press (OUP). |
| Abstract: This study presents results from continuous measurements of stem CO 2 efflux carried out for seven experimental seasons (from May to October) in a young Norway spruce forest. The objectives of the study were to determine variability in the response of stem CO 2 efflux to stem temperature over the season and to observe differences in the calculated relationship between stem temperature and CO 2 efflux based on full growing season data or on data divided into periods according to stem growth rate. Temperature sensitivity of stem CO 2 efflux (Q 10 ) calculated for the established periods ranged between 1.61 and 3.46 and varied over the season, with the lowest values occurring in July and August. Q 10 calculated using data from the full growing seasons ranged between 2.30 and 2.94 and was often significantly higher than Q 10 calculated for the individual periods. Temperature-normalized stem CO 2 efflux (R 10 ) determined using Q 10 from growing season data was overestimated when the temperature was below 10 °C and underestimated when the temperature was above 10 °C, compared with R 10 calculated using Q 10 established for the individual periods. The differences in daily mean R 10 calculated by these two approaches ranged between âˆ'0.9 and 0.2 μmol CO 2 m âˆ'2 s âˆ'1 . The results of this study confirm that long periods for determining the temperature dependence of stem CO 2 efflux encompass different statuses of the wood (especially in relation to stem growth). This may cause bias in models using this relationship for estimating stem CO 2 efflux as a function of temperature. |
BibTeX:
@article{Darenova2018,
author = {Darenova, Eva and Acosta, Manuel and Pokorny, Radek and Pavelka, Marian},
editor = {Ryan, Michael},
title = {Variability in temperature dependence of stem CO 2 efflux from Norway spruce trees},
journal = {Tree Physiology},
publisher = {Oxford University Press (OUP)},
year = {2018},
volume = {38},
number = {9},
pages = {1333--1344},
doi = {10.1093/treephys/tpy006}
}
|
| Dayalu A, William Munger J, Wofsy SC, Wang Y, Nehrkorn T, Zhao Y, McElroy MB, Nielsen CP and Luus K (2018), "Assessing biotic contributions to CO2 fluxes in northern China using the Vegetation, Photosynthesis and Respiration Model (VPRM-China) and observations from 2005 to 2009", Biogeosciences., nov, 2018. Vol. 15(21), pp. 6713-6729. Copernicus GmbH. |
| Abstract: Accurately quantifying the spatiotemporal distribution of the biological component of CO2 surface-atmosphere exchange is necessary to improve top-down constraints on China's anthropogenic CO2 emissions. We provide hourly fluxes of CO2 as net ecosystem exchange (NEE; μmol&thinsp;CO2&thinsp;mĝ'2&thinsp;sĝ'1) on a 0.25° × 0.25° grid by adapting the Vegetation, Photosynthesis, and Respiration Model (VPRM) to the eastern half of China for the time period from 2005 to 2009; the minimal empirical parameterization of the VPRM-China makes it well suited for inverse modeling approaches. This study diverges from previous VPRM applications in that it is applied at a large scale to China's ecosystems for the first time, incorporating a novel processing framework not previously applied to existing VPRM versions. In addition, the VPRM-China model prescribes methods for addressing dual-cropping regions that have two separate growing-season modes applied to the same model grid cell. We evaluate the VPRM-China performance during the growing season and compare to other biospheric models. We calibrate the VPRM-China with ChinaFlux and FluxNet data and scale up regionally using Weather Research and Forecasting (WRF) Model v3.6.1 meteorology and MODIS surface reflectances. When combined with an anthropogenic emissions model in a Lagrangian particle transport framework, we compare the ability of VPRM-China relative to an ensemble mean of global hourly flux models (NASA CMS - Carbon Monitoring System) to reproduce observations made at a site in northern China. The measurements are heavily influenced by the northern China administrative region. Modeled hourly time series using vegetation fluxes prescribed by VPRM-China exhibit low bias relative to measurements during the May-September growing season. Compared to NASA CMS subset over the study region, VPRM-China agrees significantly better with measurements. NASA CMS consistently underestimates regional uptake in the growing season. We find that during the peak growing season, when the heavily cropped North China Plain significantly influences measurements, VPRM-China models a CO2 uptake signal comparable in magnitude to the modeled anthropogenic signal. In addition to demonstrating efficacy as a low-bias prior for top-down CO2 inventory optimization studies using ground-based measurements, high spatiotemporal resolution models such as the VPRM are critical for interpreting retrievals from global CO2 remote-sensing platforms such as OCO-2 and OCO-3 (planned). Depending on the satellite time of day and season of crossover, efforts to interpret the relative contribution of the vegetation and anthropogenic components to the measured signal are critical in key emitting regions such as northern China - where the magnitude of the vegetation CO2 signal is shown to be equivalent to the anthropogenic signal. |
BibTeX:
@article{Dayalu2018,
author = {Dayalu, Archana and William Munger, J. and Wofsy, Steven C. and Wang, Yuxuan and Nehrkorn, Thomas and Zhao, Yu and McElroy, Michael B. and Nielsen, Chris P. and Luus, Kristina},
title = {Assessing biotic contributions to CO2 fluxes in northern China using the Vegetation, Photosynthesis and Respiration Model (VPRM-China) and observations from 2005 to 2009},
journal = {Biogeosciences},
publisher = {Copernicus GmbH},
year = {2018},
volume = {15},
number = {21},
pages = {6713--6729},
doi = {10.5194/bg-15-6713-2018}
}
|
| De Beeck MO, Gielen B, Merbold L, Ayres E, Serrano-Ortiz P, Acosta M, Pavelka M, Montagnani L, Nilsson M, Klemedtsson L, Vincke C, De Ligne A, Moureaux C, Maraʼnon-Jimenez S, Saunders M, Mereu S and Hörtnagl L (2018), "Soil-meteorological measurements at ICOS monitoring stations in terrestrial ecosystems", International Agrophysics., dec, 2018. Vol. 32(4), pp. 619-631. |
| Abstract: The Integrated Carbon Observation System is a pan-European research infrastructure providing standardized, long-Term observations of greenhouse gas concentrations and earth-Atmosphere greenhouse gas interactions. The terrestrial component of Integrated Carbon Observation System comprises a network of monitoring stations in terrestrial ecosystems where the principal activity is the measurement of ecosystem-Atmosphere fluxes of greenhouse gases and energy by means of the eddy covariance technique. At each station a large set of ancillary variables needed for the interpretation of observed fluxes and for process studies is additionally monitored. This set includes a subset of variables that describe the thermal and moisture conditions of the soil and which are here conveniently referred to as soil-meteorological variables: soil temperature, volumetric soil water content, water table depth, and soil heat flux density. This paper describes the standard methodology that has been developped for the monitoring of these variables at the ecosystem stations. |
BibTeX:
@article{DeBeeck2018,
author = {De Beeck, Maarten Op and Gielen, Bert and Merbold, Lutz and Ayres, Edward and Serrano-Ortiz, Penelope and Acosta, Manuel and Pavelka, Marian and Montagnani, Leonardo and Nilsson, Mats and Klemedtsson, Leif and Vincke, Caroline and De Ligne, Anne and Moureaux, Christine and Maraʼnon-Jimenez, Sara and Saunders, Matthew and Mereu, Simone and Hörtnagl, Lukas},
title = {Soil-meteorological measurements at ICOS monitoring stations in terrestrial ecosystems},
journal = {International Agrophysics},
year = {2018},
volume = {32},
number = {4},
pages = {619--631},
url = {https://content.sciendo.com/view/journals/intag/32/4/article-p619.xml},
doi = {10.1515/intag-2017-0041}
}
|
| Denfeld BA, Klaus M, Laudon H, Sponseller RA and Karlsson J (2018), "Carbon Dioxide and Methane Dynamics in a Small Boreal Lake During Winter and Spring Melt Events", Journal of Geophysical Research: Biogeosciences., aug, 2018. Vol. 123(8), pp. 2527-2540. American Geophysical Union (AGU). |
| Abstract: In seasonally ice-covered lakes, carbon dioxide (CO2) and methane (CH4) emission at ice-off can account for a significant fraction of the annual budget. Yet knowledge of the mechanisms controlling below lake-ice carbon (C) dynamics and subsequent CO2 and CH4 emissions at ice-off is limited. To understand the control of below ice C dynamics, and C emissions in spring, we measured spatial variation in CO2, CH4, and dissolved inorganic and organic carbon from ice-on to ice-off, in a small boreal lake during a winter with sporadic melting events. Winter melt events were associated with decreased surface water DOC in the forest-dominated basin and increased surface water CH4 in the mire-dominated basin. At the whole-lake scale, CH4 accumulated below ice throughout the winter, whereas CO2 accumulation was greatest in early winter. Mass-balance estimates suggest that, in addition to the CO2 and CH4 accumulated during winter, external inputs of CO2 and CH4 and internal processing during ice-melt could represent significant sources of C gas emissions during ice-off. Moreover, internal processing of CO2 and CH4 worked in opposition, with production of CO2 and oxidation of CH4 dominating at ice-off. These findings have important implications for how small boreal lakes will respond to warmer winters in the future; increased winter melt events will likely increase external inputs below ice and thus alter the extent and timing of CO2 and CH4 emissions to the atmosphere at ice-off. |
BibTeX:
@article{Denfeld2018,
author = {Denfeld, B A and Klaus, M and Laudon, H and Sponseller, R A and Karlsson, J},
title = {Carbon Dioxide and Methane Dynamics in a Small Boreal Lake During Winter and Spring Melt Events},
journal = {Journal of Geophysical Research: Biogeosciences},
publisher = {American Geophysical Union (AGU)},
year = {2018},
volume = {123},
number = {8},
pages = {2527--2540},
doi = {10.1029/2018JG004622}
}
|
| Dengel S, Graf A, Grünwald T, Hehn M, Kolari P, Löfvenius MO, Merbold L, Nicolini G and Pavelka M (2018), "Standardized precipitation measurements within ICOS: Rain, snowfall and snow depth: A review", International Agrophysics., dec, 2018. Vol. 32(4), pp. 607-617. |
| Abstract: Precipitation is one of the most important abiotic variables related to plant growth. Using standardised measurements improves the comparability and quality of precipitation data as well as all other data within the Integrated Carbon Observation System network. Despite the spatial and temporal variation of some types of precipitation, a single point measurement satisfies the requirement as an ancillary variable for eddy covariance measurements. Here the term precipitation includes: rain, snowfall (liquid water equivalent) and snow depth, with the latter two being of interest only where occurring. Weighing gauges defined as Integrated Carbon Observation System standard with the capacity of continuously measuring liquid and solid precipitation are installed free-standing, away from obstacles obstructing rain or snowfall. In order to minimise wind-induced errors, gauges are shielded either naturally or artificially to reduce the adverse effect of wind speed on the measurements. Following standardised methods strengthens the compatibility and comparability of data with other standardised environmental observation networks while opening the possibility for synthesis studies of different precipitation measurement methodologies and types including a wide range of ecosystems and geolocations across Europe. |
BibTeX:
@article{Dengel2018,
author = {Dengel, Sigrid and Graf, Alexander and Grünwald, Thomas and Hehn, Markus and Kolari, Pasi and Löfvenius, Mikaell Ottosson and Merbold, Lutz and Nicolini, Giacomo and Pavelka, Marian},
title = {Standardized precipitation measurements within ICOS: Rain, snowfall and snow depth: A review},
journal = {International Agrophysics},
year = {2018},
volume = {32},
number = {4},
pages = {607--617},
url = {https://content.sciendo.com/view/journals/intag/32/4/article-p607.xml},
doi = {10.1515/intag-2017-0046}
}
|
| Denvil-Sommer A, Gehlen M, Vrac M and Mejia C (2018), "FFNN-LSCE: A two-step neural network model for the reconstruction of surface ocean pCOsub2/sub over the Global Ocean", Geoscientific Model Development Discussions., nov, 2018. , pp. 1-27. Copernicus GmbH. |
| Abstract: pstrongAbstract./strong A new Feed-Forward Neural Network (FFNN) model is presented to reconstruct surface ocean partial pressure of carbon dioxide (pCOsub2/sub) over the global ocean. The model consists of two steps: (1) reconstruction of pCOsub2/sub climatology and (2) reconstruction of pCOsub2/sub anomalies with respect to the climatology. For the first step, a gridded climatology was used as the target, along with sea surface salinity and temperature (SSS and SST), sea surface height (SSH), chlorophyll ia/i (Chl), mixed layer depth (MLD), as well as latitude and longitude as predictors. For the second step, data from the Surface Ocean COsub2/sub Atlas (SOCAT) provided the target. The same set of predictors was used during step 2 augmented by their anomalies. During each step, the FFNN model reconstructs the non-linear relations between pCOsub2/sub and the ocean predictors. It provides monthly surface ocean pCOsub2/sub distributions on a 1º&thinsp;x&thinsp;1º grid for the period 2001&ndash;2016. Global ocean pCOsub2/sub was reconstructed with a satisfying accuracy compared to independent observational data from SOCAT. However, errors are larger in regions with poor data coverage (e.g. Indian Ocean, Southern Ocean, subpolar Pacific). The model captured the strong interannual variability of surface ocean pCO2 with reasonable skills over the Equatorial Pacific associated with ENSO (El Niño Southern Oscillation). Our model was compared to three pCOsub2/sub mapping methods that participated in the Surface Ocean pCOsub2/sub Mapping intercomparison (SOCOM) initiative. We found a good agreement in seasonal and interannual variabilty between the models over the global ocean. However, important differences still exist at the regional scale, especially in the Southern hemisphere and in particular, the Southern Pacific and the Indian Ocean, as these regions suffer from poor data-coverage. Large regional uncertainties in reconstructed surface ocean pCOsub2/sub and sea-air COsub2/sub fluxes have a strong influence on global estimates of COsub2/sub fluxes and trends./p |
BibTeX:
@article{Denvil-Sommer2018,
author = {Denvil-Sommer, Anna and Gehlen, Marion and Vrac, Mathieu and Mejia, Carlos},
title = {FFNN-LSCE: A two-step neural network model for the reconstruction of surface ocean pCOsub2/sub over the Global Ocean},
journal = {Geoscientific Model Development Discussions},
publisher = {Copernicus GmbH},
year = {2018},
pages = {1--27},
doi = {10.5194/gmd-2018-247}
}
|
| Digrado A, De La Motte LG, Bachy A, Mozaffar A, Schoon N, Bussotti F, Amelynck C, Dalcq AC, Fauconnier ML, Aubinet M, Heinesch B, Du Jardin P and Delaplace P (2018), "Decrease in the photosynthetic performance of temperate grassland species does not lead to a decline in the gross primary production of the ecosystem", Frontiers in Plant Science., feb, 2018. Vol. 9 |
| Abstract: Plants, under stressful conditions, can proceed to photosynthetic adjustments in order to acclimatize and alleviate the detrimental impacts on the photosynthetic apparatus. However, it is currently unclear how adjustment of photosynthetic processes under environmental constraints by plants influences CO2 gas exchange at the ecosystem-scale. Over a 2-year period, photosynthetic performance of a temperate grassland ecosystemwas characterized by conducting frequent chlorophyll fluorescence (ChlF) measurements on three primary grassland species (Loliumperenne L., Taraxacum sp., and Trifolium repens L.). Ecosystem photosynthetic performance was estimated frommeasurements performed on the three dominant grassland species weighed based on their relative abundance. In addition, monitoring CO2 fluxes was performed by eddy covariance. The highest decrease in photosynthetic performance was detected in summer, when environmental constraints were combined. Dicot species (Taraxacum sp. and T. repens) presented the strongest capacity to up-regulate PSI and exhibited the highest electron transport efficiency under stressful environmental conditions compared with L. perenne. The decline in ecosystem photosynthetic performance did not lead to a reduction in gross primary productivity, likely because increased light energy was available under these conditions. The carbon amounts fixed at light saturation were not influenced by alterations in photosynthetic processes, suggesting photosynthesis was not impaired. Decreased photosynthetic performance was associated with high respiration flux, but both were influenced by temperature. Our study revealed variation in photosynthetic performance of a grassland ecosystem responded to environmental constraints, but alterations in photosynthetic processes appeared to exhibit a negligible influence on ecosystem CO2 fluxes. |
BibTeX:
@article{Digrado2018,
author = {Digrado, Anthony and De La Motte, Louis G and Bachy, Aurélie and Mozaffar, Ahsan and Schoon, Niels and Bussotti, Filippo and Amelynck, Crist and Dalcq, Anne Catherine and Fauconnier, Marie Laure and Aubinet, Marc and Heinesch, Bernard and Du Jardin, Patrick and Delaplace, Pierre},
title = {Decrease in the photosynthetic performance of temperate grassland species does not lead to a decline in the gross primary production of the ecosystem},
journal = {Frontiers in Plant Science},
year = {2018},
volume = {9},
url = {http://journal.frontiersin.org/article/10.3389/fpls.2018.00067/full},
doi = {10.3389/fpls.2018.00067}
}
|
| Dirmeyer PA, Chen L, Wu J, Shin C-S, Huang B, Cash BA, Bosilovich MG, Mahanama S, Koster RD, Santanello JA, Ek MB, Balsamo G, Dutra E and Lawrence DM (2018), "Verification of Land–Atmosphere Coupling in Forecast Models, Reanalyses, and Land Surface Models Using Flux Site Observations", Journal of Hydrometeorology., feb, 2018. Vol. 19(2), pp. 375-392. |
| Abstract: This study compares four model systems in three configurations (LSM, LSM + GCM, and reanalysis) with global flux tower observations to validate states, surface fluxes, and coupling indices between land and atmosphere. Models clearly underrepresent the feedback of surface fluxes on boundary layer properties (the atmospheric leg of land–atmosphere coupling) and may overrepresent the connection between soil moisture and surface fluxes (the terrestrial leg). Models generally underrepresent spatial and temporal variability relative to observations, which is at least partially an artifact of the differences in spatial scale between model grid boxes and flux tower footprints. All models bias high in near-surface humidity and downward shortwave radiation, struggle to represent precipitation accurately, and show serious problems in reproducing surface albedos. These errors create challenges for models to partition surface energy properly, and errors are traceable through the surface energy and water cycles. The spatial distribution of the amplitude and phase of annual cycles (first harmonic) are generally well reproduced, but the biases in means tend to reflect in these amplitudes. Interannual variability is also a challenge for models to reproduce. Although the models validate better against Bowen-ratio-corrected surface flux observations, which allow for closure of surface energy balances at flux tower sites, it is not clear whether the corrected fluxes are more representative of actual fluxes. The analysis illuminates targets for coupled land–atmosphere model development, as well as the value of long-term globally distributed observational monitoring. |
BibTeX:
@article{Dirmeyer2018,
author = {Dirmeyer, Paul A. and Chen, Liang and Wu, Jiexia and Shin, Chul-Su and Huang, Bohua and Cash, Benjamin A. and Bosilovich, Michael G. and Mahanama, Sarith and Koster, Randal D. and Santanello, Joseph A. and Ek, Michael B. and Balsamo, Gianpaolo and Dutra, Emanuel and Lawrence, David M.},
title = {Verification of Land–Atmosphere Coupling in Forecast Models, Reanalyses, and Land Surface Models Using Flux Site Observations},
journal = {Journal of Hydrometeorology},
year = {2018},
volume = {19},
number = {2},
pages = {375--392},
url = {https://journals.ametsoc.org/jhm/article/19/2/375/69573/Verification-of-LandAtmosphere-Coupling-in},
doi = {10.1175/JHM-D-17-0152.1}
}
|
| Draper CS, Reichle RH and Koster RD (2018), "Assessment of MERRA-2 Land Surface Energy Flux Estimates", Journal of Climate., jan, 2018. Vol. 31(2), pp. 671-691. |
| Abstract: In the Modern-Era Retrospective Analysis for Research and Applications version 2 (MERRA-2) system the land is forced by replacing the model-generated precipitation with observed precipitation before it reaches the surface. This approach is motivated by the expectation that the resultant improvements in soil moisture will lead to improved land surface latent heating (LH). Here aspects of the MERRA-2 land surface energy budget and 2-m air temperatures [Formula: see text] are assessed. For global land annual averages, MERRA-2 appears to overestimate the LH (by 5 W m −2 ), the sensible heating (by 6 W m −2 ), and the downwelling shortwave radiation (by 14 W m −2 ) while underestimating the downwelling and upwelling (absolute) longwave radiation (by 10–15 W m −2 each). These results differ only slightly from those for NASA's previous reanalysis, MERRA. Comparison to various gridded reference datasets over boreal summer (June–August) suggests that MERRA-2 has particularly large positive biases (textgreater20 W m −2 ) where LH is energy limited and that these biases are associated with evaporative fraction biases rather than radiation biases. For time series of monthly means during boreal summer, the globally averaged anomaly correlations [Formula: see text] with reference data were improved from MERRA to MERRA-2, for LH (from 0.39 to 0.48 vs Global Land Evaporation Amsterdam Model data) and the daily maximum T 2m (from 0.69 to 0.75 vs Climatic Research Unit data). In regions where [Formula: see text] is particularly sensitive to the precipitation corrections (including the central United States, the Sahel, and parts of South Asia), the changes in the [Formula: see text] [Formula: see text] are relatively large, suggesting that the observed precipitation influenced the [Formula: see text] performance. |
BibTeX:
@article{Draper2018,
author = {Draper, Clara S. and Reichle, Rolf H. and Koster, Randal D.},
title = {Assessment of MERRA-2 Land Surface Energy Flux Estimates},
journal = {Journal of Climate},
year = {2018},
volume = {31},
number = {2},
pages = {671--691},
url = {http://journals.ametsoc.org/doi/10.1175/JCLI-D-17-0121.1},
doi = {10.1175/JCLI-D-17-0121.1}
}
|
| Du E and de Vries W (2018), "Nitrogen-induced new net primary production and carbon sequestration in global forests", Environmental Pollution., nov, 2018. Vol. 242, pp. 1476-1487. |
BibTeX:
@article{Du2018,
author = {Du, Enzai and de Vries, Wim},
title = {Nitrogen-induced new net primary production and carbon sequestration in global forests},
journal = {Environmental Pollution},
year = {2018},
volume = {242},
pages = {1476--1487},
url = {https://linkinghub.elsevier.com/retrieve/pii/S0269749118325090},
doi = {10.1016/j.envpol.2018.08.041}
}
|
| Ducker JA, Holmes CD, Keenan TF, Fares S, Goldstein AH, Mammarella I, William Munger J and Schnell J (2018), "Synthetic ozone deposition and stomatal uptake at flux tower sites", Biogeosciences., sep, 2018. Vol. 15(17), pp. 5395-5413. Copernicus GmbH. |
| Abstract: We develop and evaluate a method to estimate O3 deposition and stomatal O3 uptake across networks of eddy covariance flux tower sites where O3 concentrations and O3 fluxes have not been measured. The method combines standard micrometeorological flux measurements, which constrain O3 deposition velocity and stomatal conductance, with a gridded dataset of observed surface O3 concentrations. Measurement errors are propagated through all calculations to quantify O3 flux uncertainties. We evaluate the method at three sites with O3 flux measurements: Harvard Forest, Blodgett Forest, and Hyytiälä Forest. The method reproduces 83% or more of the variability in daily stomatal uptake at these sites with modest mean bias (21% or less). At least 95% of daily average values agree with measurements within a factor of 2 and, according to the error analysis, the residual differences from measured O3 fluxes are consistent with the uncertainty in the underlying measurements. The product, called synthetic O3 flux or SynFlux, includes 43 FLUXNET sites in the United States and 60 sites in Europe, totaling 926 site years of data. This dataset, which is now public, dramatically expands the number and types of sites where O3 fluxes can be used for ecosystem impact studies and evaluation of air quality and climate models. Across these sites, the mean stomatal conductance and O3 deposition velocity is 0.03-1.0cms-1. The stomatal O3 flux during the growing season (typically April-September) is 0.5-11.0nmol O3m-2s-1 with a mean of 4.5nmol O3m-2s-1 and the largest fluxes generally occur where stomatal conductance is high, rather than where O3 concentrations are high. The conductance differences across sites can be explained by atmospheric humidity, soil moisture, vegetation type, irrigation, and land management. These stomatal fluxes suggest that ambient O3 degrades biomass production and CO2 sequestration by 20%-24% at crop sites, 6%-29% at deciduous broadleaf forests, and 4%-20% at evergreen needleleaf forests in the United States and Europe. |
BibTeX:
@article{Ducker2018,
author = {Ducker, Jason A and Holmes, Christopher D and Keenan, Trevor F and Fares, Silvano and Goldstein, Allen H and Mammarella, Ivan and William Munger, J and Schnell, Jordan},
title = {Synthetic ozone deposition and stomatal uptake at flux tower sites},
journal = {Biogeosciences},
publisher = {Copernicus GmbH},
year = {2018},
volume = {15},
number = {17},
pages = {5395--5413},
doi = {10.5194/bg-15-5395-2018}
}
|
| Dušek J, Acosta M, Stellner S, Šigut L and Pavelka M (2018), "Consumption of atmospheric methane by soil in a lowland broadleaf mixed forest", Plant, Soil and Environment., aug, 2018. Vol. 64(8), pp. 400-406. Czech Academy of Agricultural Sciences. |
| Abstract: Soils of forest ecosystems can release or consume methane (CH4) depending on their specific hydrological regime. Our study reported the consumption of CH4 by soil in a lowland broadleaf mixed temperate forest in the Czech Republic (Central Europe). The motivation of our study was to determine the importance of CH4 fluxes in context of carbon dioxide (CO2) fluxes of a broadleaf mixed forest. CH4 and CO2 emissions from the soil were measured during the 2016 vegetation season on a long transect applying the chamber technique. The average daily consumption of atmospheric CH4 by the forest soil ranged from 0.83 to 1.15 mg CH4-C/m2/day. This consumption of CH4 during summer and autumn periods was not significantly affected by soil temperature and soil moisture. However, during spring period the consumption of CH4 was positively significantly affected by soil temperature and moisture. Estimated amount of carbon (CH4-C) consumed by the forest soil makes up a very small part of carbon (CO2-C) participated in the ecosystem carbon cycle. |
BibTeX:
@article{Dusek2018,
author = {Dušek, JiÅ™í and Acosta, Manuel and Stellner, Stanislav and Šigut, Ladislav and Pavelka, Marian},
title = {Consumption of atmospheric methane by soil in a lowland broadleaf mixed forest},
journal = {Plant, Soil and Environment},
publisher = {Czech Academy of Agricultural Sciences},
year = {2018},
volume = {64},
number = {8},
pages = {400--406},
doi = {10.17221/183/2018-PSE}
}
|
| Du Toit A (2018), "Permafrost thawing and carbon metabolism", Nature Reviews Microbiology., jul, 2018. Vol. 16(9), pp. 519. Springer Nature. |
| Abstract: Three studies provide insights into the microbial lineages involved in carbon processing in thawing permafrost, the role of viruses in soil carbon cycling, and the pattern, extent and scientific implications of sampling bias in environmental field research across the Arctic. |
BibTeX:
@article{DuToit2018,
author = {Du Toit, Andrea},
title = {Permafrost thawing and carbon metabolism},
journal = {Nature Reviews Microbiology},
publisher = {Springer Nature},
year = {2018},
volume = {16},
number = {9},
pages = {519},
doi = {10.1038/s41579-018-0066-4}
}
|
| Duveiller G, Hooker J and Cescatti A (2018), "A dataset mapping the potential biophysical effects of vegetation cover change", Scientific Data., feb, 2018. Vol. 5 Nature Publishing Groups. |
| Abstract: Changing the vegetation cover of the Earth has impacts on the biophysical properties of the surface and ultimately on the local climate. Depending on the specific type of vegetation change and on the background climate, the resulting competing biophysical processes can have a net warming or cooling effect, which can further vary both spatially and seasonally. Due to uncertain climate impacts and the lack of robust observations, biophysical effects are not yet considered in land-based climate policies. Here we present a dataset based on satellite remote sensing observations that provides the potential changes i) of the full surface energy balance, ii) at global scale, and iii) for multiple vegetation transitions, as would now be required for the comprehensive evaluation of land based mitigation plans. We anticipate that this dataset will provide valuable information to benchmark Earth system models, to assess future scenarios of land cover change and to develop the monitoring, reporting and verification guidelines required for the implementation of mitigation plans that account for biophysical land processes. |
BibTeX:
@article{Duveiller2018,
author = {Duveiller, Gregory and Hooker, Josh and Cescatti, Alessandro},
title = {A dataset mapping the potential biophysical effects of vegetation cover change},
journal = {Scientific Data},
publisher = {Nature Publishing Groups},
year = {2018},
volume = {5},
doi = {10.1038/sdata.2018.14}
}
|
| Ehrhardt F, Soussana JF, Bellocchi G, Grace P, McAuliffe R, Recous S, Sándor R, Smith P, Snow V, de Antoni Migliorati M, Basso B, Bhatia A, Brilli L, Doltra J, Dorich CD, Doro L, Fitton N, Giacomini SJ, Grant B, Harrison MT, Jones SK, Kirschbaum MUF, Klumpp K, Laville P, Léonard J, Liebig M, Lieffering M, Martin R, Massad RS, Meier E, Merbold L, Moore AD, Myrgiotis V, Newton P, Pattey E, Rolinski S, Sharp J, Smith WN, Wu L and Zhang Q (2018), "Assessing uncertainties in crop and pasture ensemble model simulations of productivity and N2O emissions", Global Change Biology., feb, 2018. Vol. 24(2), pp. e603-e616. |
| Abstract: Simulation models are extensively used to predict agricultural productivity and greenhouse gas emissions. However, the uncertainties of (reduced) model ensemble simulations have not been assessed systematically for variables affecting food security and climate change mitigation, within multi-species agricultural contexts. We report an international model comparison and benchmarking exercise, showing the potential of multi-model ensembles to predict productivity and nitrous oxide (N2O) emissions for wheat, maize, rice and temperate grasslands. Using a multi-stage modelling protocol, from blind simulations (stage 1) to partial (stages 2–4) and full calibration (stage 5), 24 process-based biogeochemical models were assessed individually or as an ensemble against long-term experimental data from four temperate grassland and five arable crop rotation sites spanning four continents. Comparisons were performed by reference to the experimental uncertainties of observed yields and N2O emissions. Results showed that across sites and crop/grassland types, 23%–40% of the uncalibrated individual models were within two standard deviations (SD) of observed yields, while 42 (rice) to 96% (grasslands) of the models were within 1 SD of observed N2O emissions. At stage 1, ensembles formed by the three lowest prediction model errors predicted both yields and N2O emissions within experimental uncertainties for 44% and 33% of the crop and grassland growth cycles, respectively. Partial model calibration (stages 2–4) markedly reduced prediction errors of the full model ensemble E-median for crop grain yields (from 36% at stage 1 down to 4% on average) and grassland productivity (from 44% to 27%) and to a lesser and more variable extent for N2O emissions. Yield-scaled N2O emissions (N2O emissions divided by crop yields) were ranked accurately by three-model ensembles across crop species and field sites. The potential of using process-based model ensembles to predict jointly productivity and N2O emissions at field scale is discussed. |
BibTeX:
@article{Ehrhardt2018,
author = {Ehrhardt, Fiona and Soussana, Jean François and Bellocchi, Gianni and Grace, Peter and McAuliffe, Russel and Recous, Sylvie and Sándor, Renáta and Smith, Pete and Snow, Val and de Antoni Migliorati, Massimiliano and Basso, Bruno and Bhatia, Arti and Brilli, Lorenzo and Doltra, Jordi and Dorich, Christopher D and Doro, Luca and Fitton, Nuala and Giacomini, Sandro J and Grant, Brian and Harrison, Matthew T and Jones, Stephanie K and Kirschbaum, Miko U F and Klumpp, Katja and Laville, Patricia and Léonard, Joël and Liebig, Mark and Lieffering, Mark and Martin, Raphaël and Massad, Raia S and Meier, Elizabeth and Merbold, Lutz and Moore, Andrew D and Myrgiotis, Vasileios and Newton, Paul and Pattey, Elizabeth and Rolinski, Susanne and Sharp, Joanna and Smith, Ward N and Wu, Lianhai and Zhang, Qing},
title = {Assessing uncertainties in crop and pasture ensemble model simulations of productivity and N2O emissions},
journal = {Global Change Biology},
year = {2018},
volume = {24},
number = {2},
pages = {e603--e616},
url = {http://doi.wiley.com/10.1111/gcb.13965},
doi = {10.1111/gcb.13965}
}
|
| Emerson JB, Roux S, Brum JR, Bolduc B, Woodcroft BJ, Jang HB, Singleton CM, Solden LM, Naas AE, Boyd JA, Hodgkins SB, Wilson RM, Trubl G, Li C, Frolking S, Pope PB, Wrighton KC, Crill PM, Chanton JP, Saleska SR, Tyson GW, Rich VI and Sullivan MB (2018), "Host-linked soil viral ecology along a permafrost thaw gradient", Nature Microbiology., jul, 2018. Vol. 3(8), pp. 870-880. Springer Nature. |
| Abstract: Climate change threatens to release abundant carbon that is sequestered at high latitudes, but the constraints on microbial metabolisms that mediate the release of methane and carbon dioxide are poorly understood 1–7 . The role of viruses, which are known to affect microbial dynamics, metabolism and biogeochemistry in the oceans 8–10 , remains largely unexplored in soil. Here, we aimed to investigate how viruses influence microbial ecology and carbon metabolism in peatland soils along a permafrost thaw gradient in Sweden. We recovered 1,907 viral populations (genomes and large genome fragments) from 197 bulk soil and size-fractionated metagenomes, 58% of which were detected in metatranscriptomes and presumed to be active. In silico predictions linked 35% of the viruses to microbial host populations, highlighting likely viral predators of key carbon-cycling microorganisms, including methanogens and methanotrophs. Lineage-specific virus/host ratios varied, suggesting that viral infection dynamics may differentially impact microbial responses to a changing climate. Virus-encoded glycoside hydrolases, including an endomannanase with confirmed functional activity, indicated that viruses influence complex carbon degradation and that viral abundances were significant predictors of methane dynamics. These findings suggest that viruses may impact ecosystem function in climate-critical, terrestrial habitats and identify multiple potential viral contributions to soil carbon cycling. |
BibTeX:
@article{Emerson2018,
author = {Emerson, Joanne B and Roux, Simon and Brum, Jennifer R and Bolduc, Benjamin and Woodcroft, Ben J and Jang, Ho Bin and Singleton, Caitlin M and Solden, Lindsey M and Naas, Adrian E and Boyd, Joel A and Hodgkins, Suzanne B and Wilson, Rachel M and Trubl, Gareth and Li, Changsheng and Frolking, Steve and Pope, Phillip B and Wrighton, Kelly C and Crill, Patrick M and Chanton, Jeffrey P and Saleska, Scott R and Tyson, Gene W and Rich, Virginia I and Sullivan, Matthew B},
title = {Host-linked soil viral ecology along a permafrost thaw gradient},
journal = {Nature Microbiology},
publisher = {Springer Nature},
year = {2018},
volume = {3},
number = {8},
pages = {870--880},
doi = {10.1038/s41564-018-0190-y}
}
|
| Ericson Y, Falck E, Chierici M, Fransson A, Kristiansen S, Platt SM, Hermansen O and Myhre CL (2018), "Temporal Variability in Surface Water pCO2 in Adventfjorden (West Spitsbergen) With Emphasis on Physical and Biogeochemical Drivers", Journal of Geophysical Research: Oceans., jul, 2018. Vol. 123(7), pp. 4888-4905. American Geophysical Union (AGU). |
| Abstract: Seasonal and interannual variability in surface water partial pressure of CO2 (pCO2) and air-sea CO2 fluxes from a West Spitsbergen fjord (IsA Station, Adventfjorden) are presented, and the associated driving forces are evaluated. Marine CO2 system data together with temperature, salinity, and nutrients, were collected at the IsA Station between March 2015 and June 2017. The surface waters were undersaturated in pCO2 with respect to atmospheric pCO2 all year round. The effects of biological activity (primary production/respiration) followed by thermal forcing on pCO2 were the most important drivers on a seasonal scale. The ocean was a sink for atmospheric CO2 with annual air-sea CO2 fluxes of âˆ'36 ± 2 and âˆ'31 ± 2 g Ctextperiodcenteredmâˆ'2textperiodcenteredyearâˆ'1 for 2015–2016 and 2016–2017, respectively, as estimated from the month of April. Waters of an Arctic origin dominated in 2015 and were replaced in 2016 by waters of a transformed Atlantic source. The CO2 uptake rates over the period of Arctic origin waters were significantly higher (2 mmol Ctextperiodcenteredmâˆ'2textperiodcentereddayâˆ'1) than the rates of the Atlantic origin waters of the following year. |
BibTeX:
@article{Ericson2018,
author = {Ericson, Y and Falck, E and Chierici, M and Fransson, A and Kristiansen, S and Platt, S M and Hermansen, O and Myhre, C L},
title = {Temporal Variability in Surface Water pCO2 in Adventfjorden (West Spitsbergen) With Emphasis on Physical and Biogeochemical Drivers},
journal = {Journal of Geophysical Research: Oceans},
publisher = {American Geophysical Union (AGU)},
year = {2018},
volume = {123},
number = {7},
pages = {4888--4905},
doi = {10.1029/2018JC014073}
}
|
| Erkkilä KM, Ojala A, Bastviken D, Biermann T, Heiskanen J, Lindroth A, Peltola O, Rantakari M, Vesala T and Mammarella I (2018), "Methane and carbon dioxide fluxes over a lake: Comparison between eddy covariance, floating chambers and boundary layer method", Biogeosciences., jan, 2018. Vol. 15(2), pp. 429-445. |
| Abstract: Freshwaters bring a notable contribution to the global carbon budget by emitting both carbon dioxide (CO2) and methane (CH4) to the atmosphere. Global estimates of freshwater emissions traditionally use a wind-speed-based gas transfer velocity, kCC (introduced by Cole and Caraco, 1998), for calculating diffusive flux with the boundary layer method (BLM). We compared CH4 and CO2 fluxes from BLM with kCC and two other gas transfer velocities (kTE and kHE), which include the effects of water-side cooling to the gas transfer besides shear-induced turbulence, with simultaneous eddy covariance (EC) and floating chamber (FC) fluxes during a 16-day measurement campaign in September 2014 at Lake Kuivajärvi in Finland. The measurements included both lake stratification and water column mixing periods. Results show that BLM fluxes were mainly lower than EC, with the more recent model kTE giving the best fit with EC fluxes, whereas FC measurements resulted in higher fluxes than simultaneous EC measurements. We highly recommend using up-to-date gas transfer models, instead of kCC, for better flux estimates. brbr BLM CO2 flux measurements had clear differences between daytime and night-time fluxes with all gas transfer models during both stratified and mixing periods, whereas EC measurements did not show a diurnal behaviour in CO2 flux. CH4 flux had higher values in daytime than night-time during lake mixing period according to EC measurements, with highest fluxes detected just before sunset. In addition, we found clear differences in daytime and night-time concentration difference between the air and surface water for both CH4 and CO2. This might lead to biased flux estimates, if only daytime values are used in BLM upscaling and flux measurements in general. brbr FC measurements did not detect spatial variation in either CH4 or CO2 flux over Lake Kuivajärvi. EC measurements, on the other hand, did not show any spatial variation in CH4 fluxes but did show a clear difference between CO2 fluxes from shallower and deeper areas. We highlight that while all flux measurement methods have their pros and cons, it is important to carefully think about the chosen method and measurement interval, as well as their effects on the resulting flux. |
BibTeX:
@article{Erkkila2018,
author = {Erkkilä, Kukka Maaria and Ojala, Anne and Bastviken, David and Biermann, Tobias and Heiskanen, Jouni and Lindroth, Anders and Peltola, Olli and Rantakari, Miitta and Vesala, Timo and Mammarella, Ivan},
title = {Methane and carbon dioxide fluxes over a lake: Comparison between eddy covariance, floating chambers and boundary layer method},
journal = {Biogeosciences},
year = {2018},
volume = {15},
number = {2},
pages = {429--445},
url = {https://www.biogeosciences.net/15/429/2018/},
doi = {10.5194/bg-15-429-2018}
}
|
| Faiola CL, Buchholz A, Kari E, Yli-Pirilä P, Holopainen JK, Kivimäenpää M, Miettinen P, Worsnop DR, Lehtinen KEJ, Guenther AB and Virtanen A (2018), "Terpene Composition Complexity Controls Secondary Organic Aerosol Yields from Scots Pine Volatile Emissions", Scientific Reports., feb, 2018. Vol. 8(1) Springer Nature. |
| Abstract: Secondary organic aerosol (SOA) impact climate by scattering and absorbing radiation and contributing to cloud formation. SOA models are based on studies of simplified chemical systems that do not account for the chemical complexity in the atmosphere. This study investigated SOA formation from a mixture of real Scots pine (Pinus sylvestris) emissions including a variety of monoterpenes and sesquiterpenes. SOA generation was characterized from different combinations of volatile compounds as the plant emissions were altered with an herbivore stress treatment. During active herbivore feeding, monoterpene and sesquiterpene emissions increased, but SOA mass yields decreased after accounting for absorption effects. SOA mass yields were controlled by sesquiterpene emissions in healthy plants. In contrast, SOA mass yields from stressed plant emissions were controlled by the specific blend of monoterpene emissions. Conservative estimates using a box model approach showed a 1.5- to 2.3-fold aerosol enhancement when the terpene complexity was taken into account. This enhancement was relative to the commonly used model monoterpene, "α-pinene". These results suggest that simplifying terpene complexity in SOA models could lead to underpredictions in aerosol mass loading. |
BibTeX:
@article{Faiola2018,
author = {Faiola, C L and Buchholz, A and Kari, E and Yli-Pirilä, P and Holopainen, J K and Kivimäenpää, M and Miettinen, P and Worsnop, D R and Lehtinen, K E J and Guenther, A B and Virtanen, A},
title = {Terpene Composition Complexity Controls Secondary Organic Aerosol Yields from Scots Pine Volatile Emissions},
journal = {Scientific Reports},
publisher = {Springer Nature},
year = {2018},
volume = {8},
number = {1},
doi = {10.1038/s41598-018-21045-1}
}
|
| Famiglietti CA, Fisher JB, Halverson G and Borbas EE (2018), "Global Validation of MODIS Near-Surface Air and Dew Point Temperatures", Geophysical Research Letters., aug, 2018. Vol. 45(15), pp. 7772-7780. Blackwell Publishing Ltd. |
| Abstract: This analysis is the first global validation of the Moderate Resolution Imaging Spectroradiometer (MODIS)-derived near-surface air temperature and dew point estimates, which both serve as crucial input data in models of energy, water, and carbon exchange between terrestrial ecosystems and the atmosphere. By hypsometrically interpolating the MOD07 Level-2 atmospheric profile product to surface pressure level, we obtained near-surface air temperature and dew point observations at 5 km pixel resolution. We compared these daily data, retrieved over a 14-year record, to corresponding measurements from 109 ground meteorological stations (FLUXNET). Our results show strong agreement between satellite and in situ near-surface air temperature measurements (R2 = 0.89, root-mean-square error = 3.47°C, and bias = −0.19°C) and dew point observations (R2 = 0.76, root-mean-square error = 5.04°C, and bias = 0.79°C) with insignificant differences in error across climate zones. This validation is among the earliest assessments of the reprocessed, crosstalk-corrected Collection 6.1 Terra MODIS data and provides support for widespread applications of near-surface atmospheric data. |
BibTeX:
@article{Famiglietti2018,
author = {Famiglietti, Caroline A. and Fisher, Joshua B. and Halverson, Gregory and Borbas, Eva E.},
title = {Global Validation of MODIS Near-Surface Air and Dew Point Temperatures},
journal = {Geophysical Research Letters},
publisher = {Blackwell Publishing Ltd},
year = {2018},
volume = {45},
number = {15},
pages = {7772--7780},
doi = {10.1029/2018GL077813}
}
|
| Fares S, Conte A and Chabbi A (2018), "Ozone flux in plant ecosystems: new opportunities for long-term monitoring networks to deliver ozone-risk assessments", Environmental Science and Pollution Research. Vol. 25(9), pp. 8240-8248. Springer Nature. |
| Abstract: Ozone (O3) is a photochemically formed reactive gas responsible for a decreasing carbon assimilation in plant ecosystems. Present in the atmosphere in trace concentrations (less than 100 ppbv), this molecule is capable of inhibiting carbon assimilation in agricultural and forest ecosystems. Ozone-risk assessments are typically based on manipulative experiments. Present regulations regarding critical ozone levels are mostly based on an estimated accumulated exposure over a given threshold concentration. There is however a scientific consensus over flux estimates being more accurate, because they include plant physiology analyses and different environmental parameters that control the uptake—that is, not just the exposure—of O3. While O3 is a lot more difficult to measure than other non-reactive greenhouse gases, UV-based and chemiluminescence sensors enable precise and fast measurements and are therefore highly desirable for eddy covariance studies. Using micrometeorological techniques in association with latent heat flux measurements in the field allows for the partition of ozone fluxes into the stomatal and non-stomatal sinks along the soil-plant continuum. Long-term eddy covariance measurements represent a key opportunity in estimating carbon assimilation at high-temporal resolutions, in an effort to study the effect of climate change on photosynthetic mechanisms. Our aim in this work is to describe potential of O3 flux measurement at the canopy level for ozone-risk assessment in established long-term monitoring networks. |
BibTeX:
@article{Fares2018,
author = {Fares, Silvano and Conte, Adriano and Chabbi, Abad},
title = {Ozone flux in plant ecosystems: new opportunities for long-term monitoring networks to deliver ozone-risk assessments},
journal = {Environmental Science and Pollution Research},
publisher = {Springer Nature},
year = {2018},
volume = {25},
number = {9},
pages = {8240--8248},
doi = {10.1007/s11356-017-0352-0}
}
|
| Fassbender AJ, Rodgers KB, Palevsky HI and Sabine CL (2018), "Seasonal Asymmetry in the Evolution of Surface Ocean pCO2 and pH Thermodynamic Drivers and the Influence on Sea-Air CO2 Flux", Global Biogeochemical Cycles. Vol. 32(10), pp. 1476-1497. American Geophysical Union (AGU). |
| Abstract: It has become clear that anthropogenic carbon invasion into the surface ocean drives changes in the seasonal cycles of carbon dioxide partial pressure (pCO2) and pH. However, it is not yet known whether the resulting sea-air CO2 fluxes are symmetric in their seasonal expression. Here we consider a novel application of observational constraints and modeling inferences to test the hypothesis that changes in the ocean's Revelle factor facilitate a seasonally asymmetric response in pCO2 and the sea-air CO2 flux. We use an analytical framework that builds on observed sea surface pCO2 variability for the modern era and incorporates transient dissolved inorganic carbon concentrations from an Earth system model. Our findings reveal asymmetric amplification of pCO2 and pH seasonal cycles by a factor of two (or more) above preindustrial levels under Representative Concentration Pathway 8.5. These changes are significantly larger than observed modes of interannual variability and are relevant to climate feedbacks associated with Revelle factor perturbations. Notably, this response occurs in the absence of changes to the seasonal cycle amplitudes of dissolved inorganic carbon, total alkalinity, salinity, and temperature, indicating that significant alteration of surface pCO2 can occur without modifying the physical or biological ocean state. This result challenges the historical paradigm that if the same amount of carbon and nutrients is entrained and subsequently exported, there is no impact on anthropogenic carbon uptake. Anticipation of seasonal asymmetries in the sea surface pCO2 and CO2 flux response to ocean carbon uptake over the 21st century may have important implications for carbon cycle feedbacks. |
BibTeX:
@article{Fassbender2018,
author = {Fassbender, Andrea J and Rodgers, Keith B and Palevsky, Hilary I and Sabine, Christopher L},
title = {Seasonal Asymmetry in the Evolution of Surface Ocean pCO2 and pH Thermodynamic Drivers and the Influence on Sea-Air CO2 Flux},
journal = {Global Biogeochemical Cycles},
publisher = {American Geophysical Union (AGU)},
year = {2018},
volume = {32},
number = {10},
pages = {1476--1497},
doi = {10.1029/2017GB005855}
}
|
| Fay AR, Lovenduski NS, Mckinley GA, Munro DR, Sweeney C, Gray AR, Landschützer P, Stephens BB, Takahashi T and Williams N (2018), "Utilizing the Drake Passage Time-series to understand variability and change in subpolar Southern Ocean pCO 2", Biogeosciences. Vol. 15, pp. 3841-3855. |
| Abstract: The Southern Ocean is highly under-sampled for the purpose of assessing total carbon uptake and its variability. Since this region dominates the mean global ocean sink for anthropogenic carbon, understanding temporal change is critical. |
BibTeX:
@article{Fay2018,
author = {Fay, Amanda R and Lovenduski, Nicole S and Mckinley, Galen A and Munro, David R and Sweeney, Colm and Gray, Alison R and Landschützer, Peter and Stephens, Britton B and Takahashi, Taro and Williams, Nancy},
title = {Utilizing the Drake Passage Time-series to understand variability and change in subpolar Southern Ocean pCO 2},
journal = {Biogeosciences},
year = {2018},
volume = {15},
pages = {3841--3855},
url = {https://doi.org/10.5194/bg-15-3841-2018},
doi = {10.5194/bg-15-3841-2018}
}
|
| Finco A, Coyle M, Nemitz E, Marzuoli R, Chiesa M, Loubet B, Fares S, Diaz-Pines E, Gasche R and Gerosa G (2018), "Characterization of ozone deposition to a mixed oak-hornbeam forest - Flux measurements at five levels above and inside the canopy and their interactions with nitric oxide", Atmospheric Chemistry and Physics., dec, 2018. Vol. 18(24), pp. 17945-17961. Copernicus GmbH. |
| Abstract: A 1-month field campaign of ozone (span classCombining double low line"inline-formula"O3/span) flux measurements along a five-level vertical profile above, inside and below the canopy was run in a mature broadleaf forest of the Po Valley, northern Italy. The study aimed to characterize span classCombining double low line"inline-formula"O3/span flux dynamics and their interactions with nitrogen oxides (span classCombining double low line"inline-formula"NOix/i/span) fluxes from the forest soil and the atmosphere above the canopy. Ozone fluxes measured at the levels above the canopy were in good agreement, thus confirming the validity of the constant flux hypothesis, while below-canopy span classCombining double low line"inline-formula"O3/span fluxes were lower than above. However, at the upper canopy edge span classCombining double low line"inline-formula"O3/span fluxes were surprisingly higher than above during the morning hours. This was attributed to a chemical span classCombining double low line"inline-formula"O3/span sink due to a reaction with the nitric oxide (NO) emitted from soil and deposited from the atmosphere, thus converging at the top of the canopy. Moreover, this mechanism was favored by the morning coupling between the forest and the atmosphere, while in the afternoon the fluxes at the upper canopy edge became similar to those of the levels above as a consequence of the in-canopy stratification. Nearly 80&thinsp;% of the span classCombining double low line"inline-formula"O3/span deposited to the forest ecosystem was removed by the canopy by stomatal deposition, dry deposition on physical surfaces and by ambient chemistry reactions (33.3&thinsp;% by the upper canopy layer and 46.3&thinsp;% by the lower canopy layer). Only a minor part of span classCombining double low line"inline-formula"O3/span was removed by the understorey vegetation and the soil surface (2&thinsp;%), while the remaining 18.2&thinsp;% was consumed by chemical reaction with NO emitted from soil. The collected data could be used to improve the span classCombining double low line"inline-formula"O3/span risk assessment for forests and to test the predicting capability of span classCombining double low line"inline-formula"O3/span deposition models. Moreover, these data could help multilayer canopy models to separate the influence of ambient chemistry vs. span classCombining double low line"inline-formula"O3/span dry deposition on the observed fluxes. |
BibTeX:
@article{Finco2018,
author = {Finco, Angelo and Coyle, Mhairi and Nemitz, Eiko and Marzuoli, Riccardo and Chiesa, Maria and Loubet, Benjamin and Fares, Silvano and Diaz-Pines, Eugenio and Gasche, Rainer and Gerosa, Giacomo},
title = {Characterization of ozone deposition to a mixed oak-hornbeam forest - Flux measurements at five levels above and inside the canopy and their interactions with nitric oxide},
journal = {Atmospheric Chemistry and Physics},
publisher = {Copernicus GmbH},
year = {2018},
volume = {18},
number = {24},
pages = {17945--17961},
doi = {10.5194/acp-18-17945-2018}
}
|
| Fischer M, Zenone T, Trnka M, Orság M, Montagnani L, Ward EJ, Tripathi AM, Hlavinka P, Seufert G, Žalud Z, King JS and Ceulemans R (2018), "Water requirements of short rotation poplar coppice: Experimental and modelling analyses across Europe", Agricultural and Forest Meteorology., mar, 2018. Vol. 250-251, pp. 343-360. |
| Abstract: Poplars are among the most widely used short rotation woody coppice (SRWC) species but due to their assumed high water use, concerns have been raised with respect to large-scale exploitation and potentially detrimental effects on water resources. Here we present a quantitative analysis of the water requirements of poplar SRWC using experimental data and a soil water balance modelling approach at three different sites across Europe. We used (i) eddy covariance (EC) measurements (2004–2006) at an irrigated SRWC grown on a previous rice paddy in northern Italy, (ii) Bowen ratio and energy balance (BREB) measurements (2008–2015) and EC (2011–2015) at a SRWC in rain-fed uplands in the Czech Republic, and (iii) EC measurements (2010–2013) at a SRWC on a previous agricultural land with a shallow water table in Belgium. Without any calibration against water balance component measurements, simulations by the newly developed soil water balance model R-4ET were compared with evapotranspiration (ET) measurements by EC and BREB with a resulting mean root mean square error (RMSE) of 0.75 mm dayâˆ'1. In general, there was better agreement between EC and the model (RMSE = 0.66 mm dayâˆ'1) when EC data were adjusted for lack of energy balance closure. A comparison of the simulated and measured soil water content yielded a mean RMSE of 0.03 m3 mâˆ'3. The mean annual crop coefficient, i.e. the ratio between actual and reference ET, was 0.82 (ranging from 0.65 to 0.95) while the monthly maxima reached 1.16. These values indicated that ET of poplar SRWC was significantly lower than ET of a well-watered grass cover at the annual time scale, but exceeded ET of the reference cover at shorter time scales during the growing season. We show that the model R-4ET is a simple, yet reliable tool for the assessment of water requirements of existing or planned SRWC. For very simple assessments on an annual basis, using a crop coefficient of 0.86 (adjusted to a sub-humid climate), representing an average value across the three sites in years with no evident drought stress, is supported by this analysis. |
BibTeX:
@article{Fischer2018,
author = {Fischer, Milan and Zenone, Terenzio and Trnka, Miroslav and Orság, Matěj and Montagnani, Leonardo and Ward, Eric J and Tripathi, Abhishek Mani and Hlavinka, Petr and Seufert, Günther and Žalud, Zdeněk and King, John S and Ceulemans, Reinhart},
title = {Water requirements of short rotation poplar coppice: Experimental and modelling analyses across Europe},
journal = {Agricultural and Forest Meteorology},
year = {2018},
volume = {250-251},
pages = {343--360},
url = {http://linkinghub.elsevier.com/retrieve/pii/S0168192317304860},
doi = {10.1016/j.agrformet.2017.12.079}
}
|
| Franz D, Acosta M, Altimir N, Arriga N, Arrouays D, Aubinet M, Aurela M, Ayres E, López-Ballesteros A, Barbaste M, Berveiller D, Biraud S, Boukir H, Brown T, Brömmer C, Buchmann N, Burba G, Carrara A, Cescatti A, Ceschia E, Clement R, Cremonese E, Crill P, Darenova E, Dengel S, D'Odorico P, Filippa G, Fleck S, Fratini G, Fuß R, Gielen B, Gogo S, Grace J, Graf A, Grelle A, Gross P, Grönwald T, Haapanala S, Hehn M, Heinesch B, Heiskanen J, Herbst M, Herschlein C, Hörtnagl L, Hufkens K, Ibrom A, Jolivet C, Joly L, Jones M, Kiese R, Klemedtsson L, Kljun N, Klumpp K, Kolari P, Kolle O, Kowalski A, Kutsch W, Laurila T, De Ligne A, Linder S, Lindroth A, Lohila A, Longdoz B, Mammarella I, Manise T, Jiménez SM, Matteucci G, Mauder M, Meier P, Merbold L, Mereu S, Metzger S, Migliavacca M, Mölder M, Montagnani L, Moureaux C, Nelson D, Nemitz E, Nicolini G, Nilsson MB, De Beeck MOM, Osborne B, Löfvenius MO, Pavelka M, Peichl M, Peltola O, Pihlatie M, Pitacco A, Pokorný R, Pumpanen J, Ratié C, Rebmann C, Roland M, Sabbatini S, Saby NPA, Saunders M, Schmid HP, Schrumpf M, Sedlák P, Ortiz PS, Siebicke L, Šigut L, Silvennoinen H, Simioni G, Skiba U, Sonnentag O, Soudani K, Soulé P, Steinbrecher R, Tallec T, Thimonier A, Tuittila ES, Tuovinen JP, Vestin P, Vincent G, Vincke C, Vitale D, Waldner P, Weslien P, Wingate L, Wohlfahrt G, Zahniser M and Vesala T (2018), "Towards long-Term standardised carbon and greenhouse gas observations for monitoring Europe's terrestrial ecosystems: A review", International Agrophysics., dec, 2018. Vol. 32(4), pp. 439-455. |
| Abstract: Research infrastructures play a key role in launching a new generation of integrated long-Term, geographically distributed observation programmes designed to monitor climate change, better understand its impacts on global ecosystems, and evaluate possible mitigation and adaptation strategies. The pan-European Integrated Carbon Observation System combines carbon and greenhouse gas (GHG; CO 2 , CH 4 , N 2 O, H 2 O) observations within the atmosphere, terrestrial ecosystems and oceans. High-precision measurements are obtained using standardised methodologies, are centrally processed and openly available in a traceable and verifiable fashion in combination with detailed metadata. The Integrated Carbon Observation System ecosystem station network aims to sample climate and land-cover variability across Europe. In addition to GHG flux measurements, a large set of complementary data (including management practices, vegetation and soil characteristics) is collected to support the interpretation, spatial upscaling and modelling of observed ecosystem carbon and GHG dynamics. The applied sampling design was developed and formulated in protocols by the scientific community, representing a trade-off between an ideal dataset and practical feasibility. The use of open-Access, high-quality and multi-level data products by different user communities is crucial for the Integrated Carbon Observation System in order to achieve its scientific potential and societal value. |
BibTeX:
@article{Franz2018,
author = {Franz, Daniela and Acosta, Manuel and Altimir, Núria and Arriga, Nicola and Arrouays, Dominique and Aubinet, Marc and Aurela, Mika and Ayres, Edward and López-Ballesteros, Ana and Barbaste, Mireille and Berveiller, Daniel and Biraud, Sébastien and Boukir, Hakima and Brown, Timothy and Brömmer, Christian and Buchmann, Nina and Burba, George and Carrara, Arnaud and Cescatti, Allessandro and Ceschia, Eric and Clement, Robert and Cremonese, Edoardo and Crill, Patrick and Darenova, Eva and Dengel, Sigrid and D'Odorico, Petra and Filippa, Gianluca and Fleck, Stefan and Fratini, Gerardo and Fuß, Roland and Gielen, Bert and Gogo, Sébastien and Grace, John and Graf, Alexander and Grelle, Achim and Gross, Patrick and Grönwald, Thomas and Haapanala, Sami and Hehn, Markus and Heinesch, Bernard and Heiskanen, Jouni and Herbst, Mathias and Herschlein, Christine and Hörtnagl, Lukas and Hufkens, Koen and Ibrom, Andreas and Jolivet, Claudy and Joly, Lilian and Jones, Michael and Kiese, Ralf and Klemedtsson, Leif and Kljun, Natascha and Klumpp, Katja and Kolari, Pasi and Kolle, Olaf and Kowalski, Andrew and Kutsch, Werner and Laurila, Tuomas and De Ligne, Anne and Linder, Sune and Lindroth, Anders and Lohila, Annalea and Longdoz, Bernhard and Mammarella, Ivan and Manise, Tanguy and Jiménez, Sara Maraón and Matteucci, Giorgio and Mauder, Matthias and Meier, Philip and Merbold, Lutz and Mereu, Simone and Metzger, Stefan and Migliavacca, Mirco and Mölder, Meelis and Montagnani, Leonardo and Moureaux, Christine and Nelson, David and Nemitz, Eiko and Nicolini, Giacomo and Nilsson, Mats B and De Beeck, M O M and Osborne, Bruce and Löfvenius, Mikaell Ottosson and Pavelka, Marian and Peichl, Matthias and Peltola, Olli and Pihlatie, Mari and Pitacco, Andrea and Pokorný, Radek and Pumpanen, Jukka and Ratié, Céline and Rebmann, Corinna and Roland, Marilyn and Sabbatini, Simone and Saby, Nicolas P A and Saunders, Matthew and Schmid, Hans Peter and Schrumpf, Marion and Sedlák, Pavel and Ortiz, Penelope Serrano and Siebicke, Lukas and Šigut, Ladislav and Silvennoinen, Hanna and Simioni, Guillaume and Skiba, Ute and Sonnentag, Oliver and Soudani, Kamel and Soulé, Patrice and Steinbrecher, Rainer and Tallec, Tiphaine and Thimonier, Anne and Tuittila, Eeva Stiina and Tuovinen, Juha Pekka and Vestin, Patrik and Vincent, Gaëlle and Vincke, Caroline and Vitale, Domenico and Waldner, Peter and Weslien, Per and Wingate, Lisa and Wohlfahrt, Georg and Zahniser, Mark and Vesala, Timo},
title = {Towards long-Term standardised carbon and greenhouse gas observations for monitoring Europe's terrestrial ecosystems: A review},
journal = {International Agrophysics},
year = {2018},
volume = {32},
number = {4},
pages = {439--455},
url = {https://content.sciendo.com/view/journals/intag/32/4/article-p439.xml},
doi = {10.1515/intag-2017-0039}
}
|
| Fratini G, Sabbatini S, Ediger K, Riensche B, Burba G, Nicolini G, Vitale D and Papale D (2018), "Eddy covariance flux errors due to random and systematic timing errors during data acquisition", Biogeosciences., sep, 2018. Vol. 15(17), pp. 5473-5487. Copernicus GmbH. |
| Abstract: Modern eddy covariance (EC) systems collect high-frequency data (10-20Hz) via digital outputs of instruments. This is an important evolution with respect to the traditional and widely used mixed analog/digital systems, as fully digital systems help overcome the traditional limitations of transmission reliability, data quality, and completeness of the datasets. However, fully digital acquisition introduces a new problem for guaranteeing data synchronicity when the clocks of the involved devices themselves cannot be synchronized, which is often the case with instruments providing data via serial or Ethernet connectivity in a streaming mode. In this paper, we suggest that, when assembling EC systems qin-house/q, aspects related to timing issues need to be carefully considered to avoid significant flux biases. By means of a simulation study, we found that, in most cases, random timing errors can safely be neglected, as they do not impact fluxes significantly. At the same time, systematic timing errors potentially arising in asynchronous systems can effectively act as filters leading to significant flux underestimations, as large as 10%, by means of attenuation of high-frequency flux contributions. We characterized the transfer function of such qfilters/q as a function of the error magnitude and found cutoff frequencies as low as 1Hz, implying that synchronization errors can dominate high-frequency attenuations in open- and enclosed-path EC systems. In most cases, such timing errors neither be detected nor characterized a posteriori. Therefore, it is important to test the ability of traditional and prospective EC data logging systems to assure the required synchronicity and propose a procedure to implement such a test relying on readily available equipment. |
BibTeX:
@article{Fratini2018,
author = {Fratini, Gerardo and Sabbatini, Simone and Ediger, Kevin and Riensche, Brad and Burba, George and Nicolini, Giacomo and Vitale, Domenico and Papale, Dario},
title = {Eddy covariance flux errors due to random and systematic timing errors during data acquisition},
journal = {Biogeosciences},
publisher = {Copernicus GmbH},
year = {2018},
volume = {15},
number = {17},
pages = {5473--5487},
doi = {10.5194/bg-15-5473-2018}
}
|
| Fusaro L, Mereu S, Salvatori E, Agliari E, Fares S and Manes F (2018), "Modeling ozone uptake by urban and peri-urban forest: a case study in the Metropolitan City of Rome", Environmental Science and Pollution Research. Vol. 25(9), pp. 8190-8205. Springer Nature. |
| Abstract: Urban and peri-urban forests are green infrastructures (GI) that play a substantial role in delivering ecosystem services such as the amelioration of air quality by the removal of air pollutants, among which is ozone (O3), which is the most harmful pollutant in Mediterranean metropolitan areas. Models may provide a reliable estimate of gas exchanges between vegetation and atmosphere and are thus a powerful tool to quantify and compare O3 removal in different contexts. The present study modeled the O3 stomatal uptake at canopy level of an urban and a peri-urban forest in the Metropolitan City of Rome in two different years. Results show different rates of O3 fluxes between the two forests, due to different exposure to the pollutant, management practice effects on forest structure and functionality, and environmental conditions, namely, different stressors affecting the gas exchange rates of the two GIs. The periodic components of the time series calculated by means of the spectral analysis show that seasonal variation of modeled canopy transpiration is driven by precipitation in peri-urban forests, whereas in the urban forest seasonal variations are driven by vapor pressure deficit of ambient air. Moreover, in the urban forest high water availability during summer months, owing to irrigation practice, leads to an increase in O3 uptake, thus suggesting that irrigation may enhance air phytoremediation in urban areas. |
BibTeX:
@article{Fusaro2018,
author = {Fusaro, Lina and Mereu, Simone and Salvatori, Elisabetta and Agliari, Elena and Fares, Silvano and Manes, Fausto},
title = {Modeling ozone uptake by urban and peri-urban forest: a case study in the Metropolitan City of Rome},
journal = {Environmental Science and Pollution Research},
publisher = {Springer Nature},
year = {2018},
volume = {25},
number = {9},
pages = {8190--8205},
doi = {10.1007/s11356-017-0474-4}
}
|
| García OE, Schneider M, Ertl B, Sepúlveda E, Borger C, Diekmann C, Wiegele A, Hase F, Barthlott S, Blumenstock T, Raffalski U, Gómez-Peláez A, Steinbacher M, Ries L and De Frutos AM (2018), "The MUSICA IASI CH4 and N2O products and their comparison to HIPPO, GAW and NDACC FTIR references", Atmospheric Measurement Techniques., jul, 2018. Vol. 11(7), pp. 4171-4215. Copernicus GmbH. |
| Abstract: This work presents the methane (CH4) and nitrous oxide (N2O) products as generated by the IASI (Infrared Atmospheric Sounding Interferometer) processor developed during the project MUSICA (MUlti-platform remote Sensing of Isotopologues for investigating the Cycle of Atmospheric water). The processor retrieves CH4 and N2O with different water vapour and water vapour isotopologues (as well as HNO3) and uses a single a priori data set for all the retrievals (no variation in space and time). Firstly, the characteristics and errors of the products are analytically described. Secondly, the products are comprehensively evaluated by comparisons to the following reference data measured by different techniques and from different platforms as follows: (1) aircraft CH4 and N2O profiles from the five HIAPER Pole-to-Pole Observation (HIPPO) missions; (2) continuous in situ CH4 and N2O observations performed between 2007 and 2017 at subtropical and mid-latitude highmountain observatories (Izaña Atmospheric Observatory and Jungfraujoch, respectively) in the framework of the WMO-GAW (World Meteorological Organization-Global Atmosphere Watch) programme; (3) ground-based FTIR (Fouriertransform infrared spectrometer) measurements made between 2007 and 2017 in the framework of the NDACC (Network for the Detection of Atmospheric Composition Change) at the subtropical Izaña Atmospheric Observatory, the mid-latitude station of Karlsruhe and the Kiruna polar site. The theoretical estimations and the comparison studies suggest a precision for the N2O and CH4 retrieval products of about 1.5-3% and systematic errors due to spectroscopic parameters of about 2 %. The MUSICA IASI CH4 data offer a better sensitivity than N2O data. While for the latter the sensitivity is mainly limited to the UTLS (upper troposphere- lower stratosphere) region, for CH4 we are able to prove that at low latitudes the MUSICA IASI processor can detect variations that take place in the free troposphere independently from the variations in the UTLS region.We demonstrate that the MUSICA IASI data qualitatively capture the CH4 gradients between low and high latitudes and between the Southern Hemisphere and Northern Hemisphere; however, we also find an inconsistency between low- and high-latitude CH4 data of up to 5 %. The N2O latitudinal gradients are very weak and cannot be detected. We make comparisons over a 10-year time period and analyse the agreement with the reference data on different timescales. The MUSICA IASI data can detect day-to-day signals (only in the UTLS), seasonal cycles and long-term evolution (in the UTLS and for CH4 also in the free troposphere) similar to the reference data; however, there are also inconsistencies in the long-term evolution connected to inconsistencies in the used atmospheric temperature a priori data. Moreover, we present a method for analytically describing the a posteriori-calculated logarithmic-scale difference of the CH4 and N2O retrieval estimates. By correcting errors that are common in the CH4 and N2O retrieval products, the a posteriori-calculated difference can be used for generating an a posteriori-corrected CH4 product with a theoretically better precision than the original CH4 retrieval products. We discuss and evaluate two different approaches for such a posteriori corrections. It is shown that the correction removes the inconsistencies between low and high latitudes and enables the detection of day-to-day signals also in the free troposphere. Furthermore, they reduce the impact of short-term atmospheric dynamics, which is an advantage, because respective signals are presumably hardly comparable to model data. The approach that affects the correction solely on the scales on which the errors dominate is identified as the most efficient, because it reduces the inconsistencies and errors without removing measurable real atmospheric signals. We give a brief outlook on a possible usage of this a posterioricorrected MUSICA IASI CH4 product in combination with inverse modelling. |
BibTeX:
@article{Garcia2018,
author = {García, Omaira E and Schneider, Matthias and Ertl, Benjamin and Sepúlveda, Eliezer and Borger, Christian and Diekmann, Christopher and Wiegele, Andreas and Hase, Frank and Barthlott, Sabine and Blumenstock, Thomas and Raffalski, Uwe and Gómez-Peláez, Angel and Steinbacher, Martin and Ries, Ludwig and De Frutos, Angel M},
title = {The MUSICA IASI CH4 and N2O products and their comparison to HIPPO, GAW and NDACC FTIR references},
journal = {Atmospheric Measurement Techniques},
publisher = {Copernicus GmbH},
year = {2018},
volume = {11},
number = {7},
pages = {4171--4215},
doi = {10.5194/amt-11-4171-2018}
}
|
| Gevaert AI, Miralles DG, de Jeu RA, Schellekens J and Dolman AJ (2018), "Soil Moisture-Temperature Coupling in a Set of Land Surface Models", Journal of Geophysical Research: Atmospheres., feb, 2018. Vol. 123(3), pp. 1481-1498. Blackwell Publishing Ltd. |
| Abstract: The land surface controls the partitioning of water and energy fluxes and therefore plays a crucial role in the climate system. The coupling between soil moisture and air temperature, in particular, has been shown to affect the severity and occurrence of temperature extremes and heat waves. Here we study soil moisture-temperature coupling in five land surface models, focusing on the terrestrial segment of the coupling in the warm season. All models are run off-line over a common period with identical atmospheric forcing data, in order to allow differences in the results to be attributed to the models' partitioning of energy and water fluxes. Coupling is calculated according to two semiempirical metrics, and results are compared to observational flux tower data. Results show that the locations of the global hot spots of soil moisture-temperature coupling are similar across all models and for both metrics. In agreement with previous studies, these areas are located in transitional climate regimes. The magnitude and local patterns of model coupling, however, can vary considerably. Model coupling fields are compared to tower data, bearing in mind the limitations in the geographical distribution of flux towers and the differences in representative area of models and in situ data. Nevertheless, model coupling correlates in space with the tower-based results (r = 0.5–0.7), with the multimodel mean performing similarly to the best-performing model. Intermodel differences are also found in the evaporative fractions and may relate to errors in model parameterizations and ancillary data of soil and vegetation characteristics. |
BibTeX:
@article{Gevaert2018,
author = {Gevaert, A. I. and Miralles, D. G. and de Jeu, R. A.M. and Schellekens, J. and Dolman, A. J.},
title = {Soil Moisture-Temperature Coupling in a Set of Land Surface Models},
journal = {Journal of Geophysical Research: Atmospheres},
publisher = {Blackwell Publishing Ltd},
year = {2018},
volume = {123},
number = {3},
pages = {1481--1498},
doi = {10.1002/2017JD027346}
}
|
| Gielen B, Acosta M, Altimir N, Buchmann N, Cescatti A, Ceschia E, Fleck S, Hörtnagl L, Klumpp K, Kolari P, Lohila A, Loustau D, Maraʼnon-Jimenez S, Manise T, Matteucci G, Merbold L, Metzger C, Moureaux C, Montagnani L, Nilsson MB, Osborne B, Papale D, Pavelka M, Saunders M, Simioni G, Soudani K, Sonnentag O, Tallec T, Tuittila ES, Peichl M, Pokorny R, Vincke C and Wohlfahrt G (2018), "Ancillary vegetation measurements at ICOS ecosystem stations", International Agrophysics., dec, 2018. Vol. 32(4), pp. 645-664. |
| Abstract: The Integrated Carbon Observation System is a Pan-European distributed research infrastructure that has as its main goal to monitor the greenhouse gas balance of Europe. The ecosystem component of Integrated Carbon Observation System consists of a multitude of stations where the net greenhouse gas exchange is monitored continuously by eddy covariance measurements while, in addition many other measurements are carried out that are a key to an understanding of the greenhouse gas balance. Amongst them are the continuous meteorological measurements and a set of non-continuous measurements related to vegetation. The latter include Green Area Index, aboveground biomass and litter biomass. The standardized methodology that is used at the Integrated Carbon Observation System ecosystem stations to monitor these vegetation related variables differs between the ecosystem types that are represented within the network, whereby in this paper we focus on forests, grasslands, croplands and mires. For each of the variables and ecosystems a spatial and temporal sampling design was developed so that the variables can be monitored in a consistent way within the ICOS network. The standardisation of the methodology to collect Green Area Index, above ground biomass and litter biomass and the methods to evaluate the quality of the collected data ensures that all stations within the ICOS ecosystem network produce data sets with small and similar errors, which allows for inter-comparison comparisons across the Integrated Carbon Observation System ecosystem network. |
BibTeX:
@article{Gielen2018,
author = {Gielen, Bert and Acosta, Manuel and Altimir, Nuria and Buchmann, Nina and Cescatti, Alessandro and Ceschia, Eric and Fleck, Stefan and Hörtnagl, Lukas and Klumpp, Katja and Kolari, Pasi and Lohila, Annalea and Loustau, Denis and Maraʼnon-Jimenez, Sara and Manise, Tanguy and Matteucci, Giorgio and Merbold, Lutz and Metzger, Christine and Moureaux, Christine and Montagnani, Leonardo and Nilsson, Mats B and Osborne, Bruce and Papale, Dario and Pavelka, Marian and Saunders, Matthew and Simioni, Guillaume and Soudani, Kamel and Sonnentag, Oliver and Tallec, Tiphaine and Tuittila, Eeva Stiina and Peichl, Matthias and Pokorny, Radek and Vincke, Caroline and Wohlfahrt, Georg},
title = {Ancillary vegetation measurements at ICOS ecosystem stations},
journal = {International Agrophysics},
year = {2018},
volume = {32},
number = {4},
pages = {645--664},
url = {https://content.sciendo.com/view/journals/intag/32/4/article-p645.xml},
doi = {10.1515/intag-2017-0048}
}
|
| Goris N, Tjiputra JF, Olsen A, Schwinger J, Lauvset SK and Jeansson E (2018), "Constraining projection-based estimates of the future North Atlantic carbon uptake", Journal of Climate., may, 2018. Vol. 31(10), pp. 3959-3978. American Meteorological Society. |
| Abstract: The North Atlantic is one of the major sinks for anthropogenic carbon in the global ocean. Improved understanding of the underlying mechanisms is vital for constraining future projections, which presently have high uncertainties. To identify some of the causes behind this uncertainty, this study investigates the North Atlantic's anthropogenically altered carbon uptake and inventory, that is, changes in carbon uptake and inventory due to rising atmospheric CO2 and climate change (abbreviated as Cant*-uptake and Cant*-inventory). Focus is set on an ensemble of 11 Earth system models and their simulations of a future with high atmospheric CO2. Results show that the model spread in the Cant*-uptake originates in middle and high latitudes. Here, the annual cycle of oceanic pCO2 reveals inherent model mechanisms that are responsible for different model behavior: while it is SST-dominated for models with a low future Cant* -uptake, it is dominated by deep winter mixing and biological production for models with a high future Cant*-uptake. Models with a high future Cant*-uptake show an efficient carbon sequestration and hence store a large fraction of their contemporary North Atlantic Cant*-inventory below 1000-m depth, while the opposite is true for models with a low future Cant*-uptake. Constraining the model ensemble with observation-based estimates of carbon sequestration and summer oceanic pCO2 anomalies yields later flattening of the Cant*-uptake than previously estimated. This result highlights the need to depart from the concept of unconstrained model ensembles in order to reduce uncertainties associated with future projections. |
BibTeX:
@article{Goris2018,
author = {Goris, Nadine and Tjiputra, Jerry F. and Olsen, Are and Schwinger, Jörg and Lauvset, Siv K. and Jeansson, Emil},
title = {Constraining projection-based estimates of the future North Atlantic carbon uptake},
journal = {Journal of Climate},
publisher = {American Meteorological Society},
year = {2018},
volume = {31},
number = {10},
pages = {3959--3978},
url = {www.ametsoc.org/PUBSReuseLicenses},
doi = {10.1175/JCLI-D-17-0564.1}
}
|
| Gourlez de la Motte L, Mamadou O, Beckers Y, Bodson B, Heinesch B and Aubinet M (2018), "Rotational and continuous grazing does not affect the total net ecosystem exchange of a pasture grazed by cattle but modifies CO2 exchange dynamics", Agriculture, Ecosystems and Environment., feb, 2018. Vol. 253, pp. 157-165. Elsevier BV. |
| Abstract: Grassland carbon budgets are known to be greatly dependent on management. In particular, grazing is known to directly affect CO2 exchange through consumption by plants, cattle respiration, natural fertilisation through excreta, and soil compaction. This study investigates the impact of two grazing methods on the net ecosystem exchange (NEE) dynamics and carbon balance, by measuring CO2 fluxes using eddy covariance in two adjacent pastures located in southern Belgium during a complete grazing season. Rotational (RG) grazing consists of an alternation of rest periods and short high stock density grazing periods. Continuous grazing (CG) consists of uninterrupted grazing with variable stocking rates. To our knowledge, this is the first study to assess the impact of these grazing methods on total net ecosystem exchange and CO2 exchange dynamics using eddy covariance. The results showed that NEE dynamics were greatly impacted by the grazing method. Following grazing events on the RG parcel, net CO2 uptake on the RG parcel was reduced compared to the CG parcel. During the following rest periods, this phenomenon progressively shifted towards a higher assimilation for the RG treatment. This behaviour was attributed to sharp biomass changes in the RG treatment and therefore sharp changes in plant photosynthetic capacity. We found that differences in gross primary productivity at high radiation were strongly correlated to differences in standing biomass. In terms of carbon budgets, no significant difference was observed between the two treatments, neither in cumulative NEE, or in terms of estimated biomass production. The results of our study suggest that we should not expect major benefits in terms of CO2 uptake from rotational grazing management when compared to continuous grazing management in intensively managed temperate pastures. |
BibTeX:
@article{GourlezdelaMotte2018,
author = {Gourlez de la Motte, Louis and Mamadou, Ossénatou and Beckers, Yves and Bodson, Bernard and Heinesch, Bernard and Aubinet, Marc},
title = {Rotational and continuous grazing does not affect the total net ecosystem exchange of a pasture grazed by cattle but modifies CO2 exchange dynamics},
journal = {Agriculture, Ecosystems and Environment},
publisher = {Elsevier BV},
year = {2018},
volume = {253},
pages = {157--165},
url = {http://linkinghub.elsevier.com/retrieve/pii/S0167880917305017 https://doi.org/10.1016/j.agee.2017.11.011},
doi = {10.1016/j.agee.2017.11.011}
}
|
| Gregor L, Kok S and Monteiro PMS (2018), "Interannual drivers of the seasonal cycle of CO&lt;sub&gt;2&lt;/sub&gt; in the Southern Ocean", Biogeosciences., apr, 2018. Vol. 15(8), pp. 2361-2378. Copernicus GmbH. |
| Abstract: textlessptextgreaterAbstract. Resolving and understanding the drivers of variability of CO2 in the Southern Ocean and its potential climate feedback is one of the major scientific challenges of the ocean-climate community. Here we use a regional approach on empirical estimates of pCO2 to understand the role that seasonal variability has in long-term CO2 changes in the Southern Ocean. Machine learning has become the preferred empirical modelling tool to interpolate time- and location-restricted ship measurements of pCO2. In this study we use an ensemble of three machine-learning products: support vector regression (SVR) and random forest regression (RFR) from Gregor et al. (2017), and the self-organising-map feed-forward neural network (SOM-FFN) method from Landschützer et al. (2016). The interpolated estimates of ΔpCO2 are separated into nine regions in the Southern Ocean defined by basin (Indian, Pacific, and Atlantic) and biomes (as defined by Fay and McKinley, 2014a). The regional approach shows that, while there is good agreement in the overall trend of the products, there are periods and regions where the confidence in estimated ΔpCO2 is low due to disagreement between the products. The regional breakdown of the data highlighted the seasonal decoupling of the modes for summer and winter interannual variability. Winter interannual variability had a longer mode of variability compared to summer, which varied on a 4–6-year timescale. We separate the analysis of the ΔpCO2 and its drivers into summer and winter. We find that understanding the variability of ΔpCO2 and its drivers on shorter timescales is critical to resolving the long-term variability of ΔpCO2. Results show that ΔpCO2 is rarely driven by thermodynamics during winter, but rather by mixing and stratification due to the stronger correlation of ΔpCO2 variability with mixed layer depth. Summer pCO2 variability is consistent with chlorophyll a variability, where higher concentrations of chlorophyll a correspond with lower pCO2 concentrations. In regions of low chlorophyll a concentrations, wind stress and sea surface temperature emerged as stronger drivers of ΔpCO2. In summary we propose that sub-decadal variability is explained by summer drivers, while winter variability contributes to the long-term changes associated with the SAM. This approach is a useful framework to assess the drivers of ΔpCO2 but would greatly benefit from improved estimates of ΔpCO2 and a longer time series.textless/ptextgreater |
BibTeX:
@article{Gregor2018,
author = {Gregor, Luke and Kok, Schalk and Monteiro, Pedro M. S.},
title = {Interannual drivers of the seasonal cycle of CO&lt;sub&gt;2&lt;/sub&gt; in the Southern Ocean},
journal = {Biogeosciences},
publisher = {Copernicus GmbH},
year = {2018},
volume = {15},
number = {8},
pages = {2361--2378},
url = {https://bg.copernicus.org/articles/15/2361/2018/},
doi = {10.5194/bg-15-2361-2018}
}
|
| Groh J, Slawitsch V, Herndl M, Graf A, Vereecken H and Pütz T (2018), "Determining dew and hoar frost formation for a low mountain range and alpine grassland site by weighable lysimeter", Journal of Hydrology., aug, 2018. Vol. 563, pp. 372-381. Elsevier BV. |
| Abstract: Non-rainfall events like dew or hoar frost formation are often neglected in the water budget, because either assumed to be too small or their determination requires time consuming and difficult measurements. These events supply in many dryland ecosystems a substantial amount of water, but their role for northern humid ecosystems is largely unknown. There is a general need to quantify the ecological relevance for ecosystems of the water amount from dew and hoar frost formation. Weighable precision lysimeters were used to determine dew and hoar frost formation for a low mountain range and alpine grassland site for the hydrological years 2013–2015. Together dew and hoar frost formation ranged on a yearly basis between 42.1 and 67.7 mm, which corresponds to 4.2–6% of the total annual amount of precipitation. In drier months dew and hoar frost contributed up to 16.1% of total monthly precipitation amount. In winter months dew and hoar frost formation contributed up to 38% to the total monthly precipitation amount. Our investigation suggests, that dew and hoar frost formation are of ecological importance during droughts as well as cold periods. The amounts and seasonal patterns of dew and hoar frost formation could be predicted relatively well, based on standard meteorological variables with the Penman-Monteith equation. However, our results also showed, that the surface energy balance model from Penman-Monteith underestimated the amount of dew and hoar frost during colder periods and specific meteorological site conditions (i.e. high wind speeds at night). The mean underestimation between calculated and measured dew and hoar frost on a yearly scale were 63.2% and 16.6% at Rollesbroich and Gumpenstein, respectively. Dew and hoar frost formation contributes substantially to the water budgets of a low mountain range and alpine grassland. |
BibTeX:
@article{Groh2018,
author = {Groh, Jannis and Slawitsch, Veronika and Herndl, Markus and Graf, Alexander and Vereecken, Harry and Pütz, Thomas},
title = {Determining dew and hoar frost formation for a low mountain range and alpine grassland site by weighable lysimeter},
journal = {Journal of Hydrology},
publisher = {Elsevier BV},
year = {2018},
volume = {563},
pages = {372--381},
doi = {10.1016/j.jhydrol.2018.06.009}
}
|
| Groot Zwaaftink CD, Henne S, Thompson RL, Dlugokencky EJ, Machida T, Paris JD, Sasakawa M, Segers A, Sweeney C and Stohl A (2018), "Three-dimensional methane distribution simulated with FLEXPART 8-CTM-1.1 constrained with observation data", Geoscientific Model Development., nov, 2018. Vol. 11(11), pp. 4469-4487. Copernicus GmbH. |
| Abstract: A Lagrangian particle dispersion model, the FLEXible PARTicle dispersion chemical transport model (FLEXPART CTM), is used to simulate global three-dimensional fields of trace gas abundance. These fields are constrained with surface observation data through nudging, a data assimilation method, which relaxes model fields to observed values. Such fields are of interest to a variety of applications, such as inverse modelling, satellite retrievals, radiative forcing models and estimating global growth rates of greenhouse gases. Here, we apply this method to methane using 6 million model particles filling the global model domain. For each particle, methane mass tendencies due to emissions (based on several inventories) and loss by reaction with OH, Cl and O(1D), as well as observation data nudging were calculated. Model particles were transported by mean, turbulent and convective transport driven by 1° × 1° ERA-Interim meteorology. Nudging is applied at 79 surface stations, which are mostly included in the World Data Centre for Greenhouse Gases (WDCGG) database or the Japan-Russia Siberian Tall Tower Inland Observation Network (JR-STATION) in Siberia. For simulations of 1 year (2013), we perform a sensitivity analysis to show how nudging settings affect modelled concentration fields. These are evaluated with a set of independent surface observations and with vertical profiles in North America from the National Oceanic and Atmospheric Administration (NOAA) Earth System Research Laboratory (ESRL), and in Siberia from the Airborne Extensive Regional Observations in SIBeria (YAK-AEROSIB) and the National Institute for Environmental Studies (NIES). FLEXPART CTM results are also compared to simulations from the global Eulerian chemistry Transport Model version 5 (TM5) based on optimized fluxes. Results show that nudging strongly improves modelled methane near the surface, not only at the nudging locations but also at independent stations. Mean bias at all surface locations could be reduced from over 20 to less than 5 ppb through nudging. Near the surface, FLEXPART CTM, including nudging, appears better able to capture methane molar mixing ratios than TM5 with optimized fluxes, based on a larger bias of over 13 ppb in TM5 simulations. The vertical profiles indicate that nudging affects model methane at high altitudes, yet leads to little improvement in the model results there. Averaged from 19 aircraft profile locations in North America and Siberia, root mean square error (RMSE) changes only from 16.3 to 15.7 ppb through nudging, while the mean absolute bias increases from 5.3 to 8.2 ppb. The performance for vertical profiles is thereby similar to TM5 simulations based on TM5 optimized fluxes where we found a bias of 5 ppb and RMSE of 15.9 ppb. With this rather simple model setup, we thus provide three-dimensional methane fields suitable for use as boundary conditions in regional inverse modelling as a priori information for satellite retrievals and for more accurate estimation of mean mixing ratios and growth rates. The method is also applicable to other long-lived trace gases. |
BibTeX:
@article{GrootZwaaftink2018,
author = {Groot Zwaaftink, Christine D and Henne, Stephan and Thompson, Rona L and Dlugokencky, Edward J and Machida, Toshinobu and Paris, Jean Daniel and Sasakawa, Motoki and Segers, Arjo and Sweeney, Colm and Stohl, Andreas},
title = {Three-dimensional methane distribution simulated with FLEXPART 8-CTM-1.1 constrained with observation data},
journal = {Geoscientific Model Development},
publisher = {Copernicus GmbH},
year = {2018},
volume = {11},
number = {11},
pages = {4469--4487},
doi = {10.5194/gmd-11-4469-2018}
}
|
| Grossiord C, Sevanto S, Bonal D, Borrego I, Dawson TE, Ryan M, Wang W and McDowell NG (2018), "Prolonged warming and drought modify belowground interactions for water among coexisting plants", Tree Physiology., sep, 2018. Vol. 39(1), pp. 55-63. Oxford University Press (OUP). |
| Abstract: Understanding how climate alters plant-soil water dynamics, and its impact on physiological functions, is critical to improved predictions of vegetation responses to climate change. Here we analyzed how belowground interactions for water shift under warming and drought, and associated impacts on plant functions. In a semi-arid woodland, adult trees (piñon and juniper) and perennial grasses (blue grama) were exposed to warming and precipitation reduction. After 6 years of continuous treatment exposure, soil and plant water isotopic composition was measured to assess plant water uptake depths and community-level water source partitioning. Warming and drought modified plant water uptake depths. Under warming, contrasting changes in water sources between grasses and trees reduced belowground water source partitioning, resulting in higher interspecific competition for water. Under drought, shifts in trees and grass water sources to deeper soil layers resulted in the maintenance of the naturally occurring water source partitioning among species. Trees showed higher water stress, and reduced water use and photosynthesis in response to warming and drought. This case study demonstrates that neighboring plants shift their competitive interactions for water under prolonged warming and drought, but regardless of whether changes in moisture sources will result in increased competition among species or maintained partitioning of water resources, these competitive adaptations may easily be overridden by climate extremes. |
BibTeX:
@article{Grossiord2018,
author = {Grossiord, Charlotte and Sevanto, Sanna and Bonal, Damien and Borrego, Isaac and Dawson, Todd E and Ryan, Max and Wang, Wenzhi and McDowell, Nate G},
editor = {Whitehead, David},
title = {Prolonged warming and drought modify belowground interactions for water among coexisting plants},
journal = {Tree Physiology},
publisher = {Oxford University Press (OUP)},
year = {2018},
volume = {39},
number = {1},
pages = {55--63},
doi = {10.1093/treephys/tpy080}
}
|
| Gu C, Ma J, Zhu G, Yang H, Zhang K, Wang Y and Gu C (2018), "Partitioning evapotranspiration using an optimized satellite-based ET model across biomes", Agricultural and Forest Meteorology., sep, 2018. Vol. 259, pp. 355-363. Elsevier B.V.. |
| Abstract: The partitioning of evapotranspiration (ET) is a critical factor in the terrestrial water balance and global water cycle, and understanding the partitioning across terrestrial biomes and the relationships between ET partitions and potential influencing factors is critical for predicting future ecosystem feedbacks. Based on an optimized Priestly-Taylor Jet Propulsion Laboratory model, we partitioned ET into three components transpiration (T), canopy interception evaporation (EI), and soil evaporation (ES). We found the components of EI to be significant with the ratio of EI to precipitation ranging from 0.02 to 0.29 across different biomes. The T/ET ratio ranged from 0.29 to 0.72 with obvious differences across biomes and with ratios generally lower than in previous studies with isotope-based methods. The (T + EI)/ET ratio was limited to a relatively narrow band from 0.57 to 0.86. The T/ET values show an obvious decreasing trend with increasing annual precipitation, but there was no significant correlation between T/ET and annual leaf area index. |
BibTeX:
@article{Gu2018,
author = {Gu, Chunjie and Ma, Jinzhu and Zhu, Gaofeng and Yang, Huan and Zhang, Kun and Wang, Yunquan and Gu, Chunli},
title = {Partitioning evapotranspiration using an optimized satellite-based ET model across biomes},
journal = {Agricultural and Forest Meteorology},
publisher = {Elsevier B.V.},
year = {2018},
volume = {259},
pages = {355--363},
doi = {10.1016/j.agrformet.2018.05.023}
}
|
| Hari P, Noe S, Dengel S, Elbers J, Gielen B, Kerminen VM, Kruijt B, Kulmala L, Lindroth A, Mammarella I, Petäjä T, Schurgers G, Vanhatalo A, Kulmala M and Bäck J (2018), "Prediction of photosynthesis in Scots pine ecosystems across Europe by a needle-level theory", Atmospheric Chemistry and Physics., sep, 2018. Vol. 18(18), pp. 13321-13328. Copernicus GmbH. |
| Abstract: Photosynthesis provides carbon for the synthesis of macromolecules to construct cells during growth. This is the basis for the key role of photosynthesis in the carbon dynamics of ecosystems and in the biogenic CO2 assimilation. The development of eddy-covariance (EC) measurements for ecosystem CO2 fluxes started a new era in the field studies of photosynthesis. However, the interpretation of the very variable CO2 fluxes in evergreen forests has been problematic especially in transition times such as the spring and autumn. We apply two theoretical needle-level equations that connect the variation in the light intensity, stomatal action and the annual metabolic cycle of photosynthesis. We then use these equations to predict the photosynthetic CO2 flux in five Scots pine stands located from the northern timberline to Central Europe. Our result has strong implications for our conceptual understanding of the effects of the global change on the processes in boreal forests, especially of the changes in the metabolic annual cycle of photosynthesis. |
BibTeX:
@article{Hari2018,
author = {Hari, Pertti and Noe, Steffen and Dengel, Sigrid and Elbers, Jan and Gielen, Bert and Kerminen, Veli Matti and Kruijt, Bart and Kulmala, Liisa and Lindroth, Anders and Mammarella, Ivan and Petäjä, Tuukka and Schurgers, Guy and Vanhatalo, Anni and Kulmala, Markku and Bäck, Jaana},
title = {Prediction of photosynthesis in Scots pine ecosystems across Europe by a needle-level theory},
journal = {Atmospheric Chemistry and Physics},
publisher = {Copernicus GmbH},
year = {2018},
volume = {18},
number = {18},
pages = {13321--13328},
doi = {10.5194/acp-18-13321-2018}
}
|
| Hauck J (2018), "Unsteady seasons in the sea", Nature Climate Change., jan, 2018. Vol. 8(2), pp. 97-98. Springer Nature. |
| Abstract: Ocean uptake of CO2 slows the rate of anthropogenic climate change but comes at the cost of ocean acidification. Observations now show that the seasonal cycle of CO2 in the ocean also changes, leading to earlier occurrence of detrimental conditions for ocean biota. |
BibTeX:
@article{Hauck2018,
author = {Hauck, Judith},
title = {Unsteady seasons in the sea},
journal = {Nature Climate Change},
publisher = {Springer Nature},
year = {2018},
volume = {8},
number = {2},
pages = {97--98},
doi = {10.1038/s41558-018-0069-1}
}
|
| He YC, Tjiputra J, Langehaug HR, Jeansson E, Gao Y, Schwinger J and Olsen A (2018), "A Model-Based Evaluation of the Inverse Gaussian Transit-Time Distribution Method for Inferring Anthropogenic Carbon Storage in the Ocean", Journal of Geophysical Research: Oceans. Vol. 123(3), pp. 1777-1800. American Geophysical Union (AGU). |
| Abstract: The Inverse Gaussian approximation of transit time distribution method (IG-TTD) is widely used to infer the anthropogenic carbon (Cant) concentration in the ocean from measurements of transient tracers such as chlorofluorocarbons (CFCs) and sulfur hexafluoride (SF6). Its accuracy relies on the validity of several assumptions, notably (i) a steady state ocean circulation, (ii) a prescribed age tracer saturation history, e.g., a constant 100% saturation, (iii) a prescribed constant degree of mixing in the ocean, (iv) a constant surface ocean air-sea CO2 disequilibrium with time, and (v) that preformed alkalinity can be sufficiently estimated by salinity or salinity and temperature. Here, these assumptions are evaluated using simulated “model-truth†of Cant. The results give the IG-TTD method a range of uncertainty from 7.8% to 13.6% (11.4 Pg C to 19.8 Pg C) due to above assumptions, which is about half of the uncertainty derived in previous model studies. Assumptions (ii), (iv) and (iii) are the three largest sources of uncertainties, accounting for 5.5%, 3.8% and 3.0%, respectively, while assumptions (i) and (v) only contribute about 0.6% and 0.7%. Regionally, the Southern Ocean contributes the largest uncertainty, of 7.8%, while the North Atlantic contributes about 1.3%. Our findings demonstrate that spatial-dependency of Δ/Г, and temporal changes in tracer saturation and air-sea CO2 disequilibrium have strong compensating effect on the estimated Cant. The values of these parameters should be quantified to reduce the uncertainty of IG-TTD; this is increasingly important under a changing ocean climate. |
BibTeX:
@article{He2018,
author = {He, Yan Chun and Tjiputra, Jerry and Langehaug, Helene R and Jeansson, Emil and Gao, Yongqi and Schwinger, Jörg and Olsen, Are},
title = {A Model-Based Evaluation of the Inverse Gaussian Transit-Time Distribution Method for Inferring Anthropogenic Carbon Storage in the Ocean},
journal = {Journal of Geophysical Research: Oceans},
publisher = {American Geophysical Union (AGU)},
year = {2018},
volume = {123},
number = {3},
pages = {1777--1800},
doi = {10.1002/2017JC013504}
}
|
| Henson SA, Humphreys MP, Land PE, Shutler JD, Goddijn-Murphy L and Warren M (2018), "Controls on Open-Ocean North Atlantic ΔpCO2 at Seasonal and Interannual Time Scales Are Different", Geophysical Research Letters., sep, 2018. Vol. 45(17), pp. 9067-9076. American Geophysical Union (AGU). |
| Abstract: The North Atlantic is a substantial sink for anthropogenic CO2. Understanding the mechanisms driving the sink's variability is key to assessing its current state and predicting its potential response to global climate change. Here we apply a time series decomposition technique to satellite and in situ data to examine separately the factors (both biological and nonbiological) that affect the sea-air CO2 difference (ΔpCO2) on seasonal and interannual time scales. We demonstrate that on seasonal time scales, the subpolar North Atlantic ΔpCO2 signal is predominantly correlated with biological processes, whereas seawater temperature dominates in the subtropics. However, the same factors do not necessarily control ΔpCO2 on interannual time scales. Our results imply that the mechanisms driving seasonal variability in ΔpCO2 cannot necessarily be extrapolated to predict how ΔpCO2, and thus the North Atlantic CO2 sink, may respond to increases in anthropogenic CO2 over longer time scales. |
BibTeX:
@article{Henson2018,
author = {Henson, Stephanie A and Humphreys, Matthew P and Land, Peter E and Shutler, Jamie D and Goddijn-Murphy, Lonneke and Warren, Mark},
title = {Controls on Open-Ocean North Atlantic ΔpCO2 at Seasonal and Interannual Time Scales Are Different},
journal = {Geophysical Research Letters},
publisher = {American Geophysical Union (AGU)},
year = {2018},
volume = {45},
number = {17},
pages = {9067--9076},
doi = {10.1029/2018GL078797}
}
|
| Hobeichi S, Abramowitz G, Evans J and Ukkola A (2018), "Derived Optimal Linear Combination Evapotranspiration (DOLCE): A global gridded synthesis et estimate", Hydrology and Earth System Sciences., feb, 2018. Vol. 22(2), pp. 1317-1336. Copernicus GmbH. |
| Abstract: Accurate global gridded estimates of evapotranspiration (ET) are key to understanding water and energy budgets, in addition to being required for model evaluation. Several gridded ET products have already been developed which differ in their data requirements, the approaches used to derive them and their estimates, yet it is not clear which provides the most reliable estimates. This paper presents a new global ET dataset and associated uncertainty with monthly temporal resolution for 2000-2009. Six existing gridded ET products are combined using a weighting approach trained by observational datasets from 159 FLUXNET sites. The weighting method is based on a technique that provides an analytically optimal linear combination of ET products compared to site data and accounts for both the performance differences and error covariance between the participating ET products. We examine the performance of the weighting approach in several in-sample and out-of-sample tests that confirm that point-based estimates of flux towers provide information on the grid scale of these products. We also provide evidence that the weighted product performs better than its six constituent ET product members in four common metrics. Uncertainty in the ET estimate is derived by rescaling the spread of participating ET products so that their spread reflects the ability of the weighted mean estimate to match flux tower data. While issues in observational data and any common biases in participating ET datasets are limitations to the success of this approach, future datasets can easily be incorporated and enhance the derived product. |
BibTeX:
@article{Hobeichi2018,
author = {Hobeichi, Sanaa and Abramowitz, Gab and Evans, Jason and Ukkola, Anna},
title = {Derived Optimal Linear Combination Evapotranspiration (DOLCE): A global gridded synthesis et estimate},
journal = {Hydrology and Earth System Sciences},
publisher = {Copernicus GmbH},
year = {2018},
volume = {22},
number = {2},
pages = {1317--1336},
doi = {10.5194/hess-22-1317-2018}
}
|
| Hodgkins SB, Richardson CJ, Dommain R, Wang H, Glaser PH, Verbeke B, Winkler BR, Cobb AR, Rich VI, Missilmani M, Flanagan N, Ho M, Hoyt AM, Harvey CF, Vining SR, Hough MA, Moore TR, Richard PJH, De La Cruz FB, Toufaily J, Hamdan R, Cooper WT and Chanton JP (2018), "Tropical peatland carbon storage linked to global latitudinal trends in peat recalcitrance", Nature Communications., sep, 2018. Vol. 9(1) Springer Nature. |
| Abstract: Peatlands represent large terrestrial carbon banks. Given that most peat accumulates in boreal regions, where low temperatures and water saturation preserve organic matter, the existence of peat in (sub)tropical regions remains enigmatic. Here we examined peat and plant chemistry across a latitudinal transect from the Arctic to the tropics. Near-surface low-latitude peat has lower carbohydrate and greater aromatic content than near-surface high-latitude peat, creating a reduced oxidation state and resulting recalcitrance. This recalcitrance allows peat to persist in the (sub)tropics despite warm temperatures. Because we observed similar declines in carbohydrate content with depth in high-latitude peat, our data explain recent field-scale deep peat warming experiments in which catotelm (deeper) peat remained stable despite temperature increases up to 9 °C. We suggest that high-latitude deep peat reservoirs may be stabilized in the face of climate change by their ultimately lower carbohydrate and higher aromatic composition, similar to tropical peats. |
BibTeX:
@article{Hodgkins2018,
author = {Hodgkins, Suzanne B and Richardson, Curtis J and Dommain, René and Wang, Hongjun and Glaser, Paul H and Verbeke, Brittany and Winkler, B Rose and Cobb, Alexander R and Rich, Virginia I and Missilmani, Malak and Flanagan, Neal and Ho, Mengchi and Hoyt, Alison M and Harvey, Charles F and Vining, S Rose and Hough, Moira A and Moore, Tim R and Richard, Pierre J H and De La Cruz, Florentino B and Toufaily, Joumana and Hamdan, Rasha and Cooper, William T and Chanton, Jeffrey P},
title = {Tropical peatland carbon storage linked to global latitudinal trends in peat recalcitrance},
journal = {Nature Communications},
publisher = {Springer Nature},
year = {2018},
volume = {9},
number = {1},
doi = {10.1038/s41467-018-06050-2}
}
|
| Honkanen M, Tuovinen JP, Laurila T, Mäkelä T, Hatakka J, Kielosto S and Laakso L (2018), "Measuring turbulent CO2 fluxes with a closed-path gas analyzer in a marine environment", Atmospheric Measurement Techniques., sep, 2018. Vol. 11(9), pp. 5335-5350. Copernicus GmbH. |
| Abstract: In this study, we introduce new observations of sea-air fluxes of carbon dioxide using the eddy covariance method. The measurements took place at the Utö Atmospheric and Marine Research Station on the island of Utö in the Baltic Sea in July-October 2017. The flux measurement system is based on a closed-path infrared gas analyzer (LI-7000, LI-COR) requiring only occasional maintenance, making the station capable of continuous monitoring. However, such infrared gas analyzers are prone to significant water vapor interference in a marine environment, where CO2 fluxes are small. Two LI-7000 analyzers were run in parallel to test the effect of a sample air drier which dampens water vapor fluctuations and a virtual impactor, included to remove liquid sea spray, both of which were attached to the sample air tubing of one of the analyzers. The systems showed closely similar (R2 Combining double low line 0.99) sea-air CO2 fluxes when the latent heat flux was low, which proved that neither the drier nor the virtual impactor perturbed the CO2 flux measurement. However, the undried measurement had a positive bias that increased with increasing latent heat flux, suggesting water vapor interference. For both systems, cospectral densities between vertical wind speed and CO2 molar fraction were distributed within the expected frequency range, with a moderate attenuation of high-frequency fluctuations. While the setup equipped with a drier and a virtual impactor generated a slightly higher flux loss, we opt for this alternative for its reduced water vapor cross-sensitivity and better protection against sea spray. The integral turbulence characteristics were found to agree with the universal stability dependence observed over land. Nonstationary conditions caused unphysical results, which resulted in a high percentage (65&thinsp;%) of discarded measurements. After removing the nonstationary cases, the direction of the sea-air CO2 fluxes was in good accordance with independently measured CO2 partial pressure difference between the sea and the atmosphere. Atmospheric CO2 concentration changes larger than 2&thinsp;ppm during a 30&thinsp;min averaging period were found to be associated with the nonstationarity of CO2 fluxes. |
BibTeX:
@article{Honkanen2018,
author = {Honkanen, Martti and Tuovinen, Juha Pekka and Laurila, Tuomas and Mäkelä, Timo and Hatakka, Juha and Kielosto, Sami and Laakso, Lauri},
title = {Measuring turbulent CO2 fluxes with a closed-path gas analyzer in a marine environment},
journal = {Atmospheric Measurement Techniques},
publisher = {Copernicus GmbH},
year = {2018},
volume = {11},
number = {9},
pages = {5335--5350},
doi = {10.5194/amt-11-5335-2018}
}
|
| Hooghiem JJD, De Vries M, Been HA, Heikkinen P, Kivi R and Chen H (2018), "LISA: A lightweight stratospheric air sampler", Atmospheric Measurement Techniques., dec, 2018. Vol. 11(12), pp. 6785-6801. Copernicus GmbH. |
| Abstract: We developed a new lightweight stratospheric air sampler (LISA). The LISA sampler is designed to collect four bag samples in the stratosphere during a balloon flight for CO 2 , CH 4 and CO mole fraction measurements. It consists of four multi-layer foil (MLF) sampling bags, a custommade manifold, and a diaphragm pump, with a total weight of ∼ 2.5kg. A series of laboratory storage tests were performed to assess the stability of CO 2 , CH 4 and CO mole fractions in both MLF and Tedlar bags. The MLF bag was chosen due to its better overall performance than the Tedlar bag for the three species CO 2 , CH 4 and CO. Furthermore, we evaluated the performance of the pump under low pressure conditions to optimize a trade-off between the vertical resolution and the sample size. The LISA sampler was flown on the same balloon flight with an AirCore in Sodankylä, Finland (67.368° N, 26.633° E, 179ma.s.l.), on 26 April and 4-7 September 2017. A total of 15 stratospheric air samples were obtained during the ascent of four flights. The sample size ranges between 800 and 180mL for the altitude between 12 and 25 km, with the corresponding vertical resolution ranging from 0.5 to 1.5 km. The collected air samples were analysed for CO 2 , CH 4 and CO mole fractions, and evaluated against AirCore retrieved profiles, showing mean differences of 0.84 ppm for CO 2 , 1.8 ppb for CH 4 and 6.3 ppb for CO, respectively. High-accuracy stratospheric measurements of greenhouse gas mole fractions are useful to validate remote sensing measurements from ground and from space, which has been performed primarily by comparison with collocated aircraft measurements (0.15-13 km), and more recently with Air- Core observations (0-30 km). While AirCore is capable of achieving high-accuracy greenhouse gas mole fraction measurements, it is challenging to obtain accurate altitude registration for AirCore measurements. The LISA sampler provides a viable low-cost tool for retrieving stratospheric air samples for greenhouse gas measurements that is complementary to AirCore. Furthermore, the LISA sampler is advantageous in both the vertical resolution and sample size for performing routine stratospheric measurements of the isotopic composition of trace gases. |
BibTeX:
@article{Hooghiem2018,
author = {Hooghiem, Joram J D and De Vries, Marcel and Been, Henk A and Heikkinen, Pauli and Kivi, Rigel and Chen, Huilin},
title = {LISA: A lightweight stratospheric air sampler},
journal = {Atmospheric Measurement Techniques},
publisher = {Copernicus GmbH},
year = {2018},
volume = {11},
number = {12},
pages = {6785--6801},
doi = {10.5194/amt-11-6785-2018}
}
|
| Hufkens K, Filippa G, Cremonese E, Migliavacca M, D'Odorico P, Peichl M, Gielen B, Hörtnagl L, Soudani K, Papale D, Rebmann C, Brown T and Wingate L (2018), "Assimilating phenology datasets automatically across ICOS ecosystem stations", International Agrophysics., dec, 2018. Vol. 32(4), pp. 677-687. |
| Abstract: The presence or absence of leaves within plant canopies exert a strong influence on the carbon, water and energy balance of ecosystems. Identifying key changes in the timing of leaf elongation and senescence during the year can help to understand the sensitivity of different plant functional types to changes in temperature. When recorded over many years these data can provide information on the response of ecosystems to long-Term changes in climate. The installation of digital cameras that take images at regular intervals of plant canopies across the Integrated Carbon Observation System ecosystem stations will provide a reliable and important record of variations in canopy state, colour and the timing of key phenological events. Here, we detail the procedure for the implementation of cameras on Integrated Carbon Observation System flux towers and how these images will help us understand the impact of leaf phenology and ecosystem function, distinguish changes in canopy structure from leaf physiology and at larger scales will assist in the validation of (future) remote sensing products. These data will help us improve the representation of phenological responses to climatic variability across Integrated Carbon Observation System stations and the terrestrial biosphere through the improvement of model algorithms and the provision of validation datasets. |
BibTeX:
@article{Hufkens2018,
author = {Hufkens, Koen and Filippa, Gianluca and Cremonese, Edoardo and Migliavacca, Mirco and D'Odorico, Petra and Peichl, Matthias and Gielen, Bert and Hörtnagl, Lukas and Soudani, Kamel and Papale, Dario and Rebmann, Corinna and Brown, Tim and Wingate, Lisa},
title = {Assimilating phenology datasets automatically across ICOS ecosystem stations},
journal = {International Agrophysics},
year = {2018},
volume = {32},
number = {4},
pages = {677--687},
url = {https://content.sciendo.com/view/journals/intag/32/4/article-p677.xml},
doi = {10.1515/intag-2017-0050}
}
|
| Ibraim E, Wolf B, Harris E, Gasche R, Wei J, Yu L, Kiese R, Eggleston S, Butterbach-Bahl K, Zeeman M, Tuzson B, Emmenegger L, Six J, Henne S and Mohn J (2018), "Attribution of Nsub2/subO sources in a grassland soil with laser spectroscopy based isotopocule analysis", Biogeosciences Discussions. , pp. 1-27. Copernicus GmbH. |
| Abstract: pstrongAbstract./strong Nitrous oxide (Nsub2/subO) is the primary atmospheric constituent involved in stratospheric ozone depletion and contributes strongly to changes in the climate system through a positive radiative forcing mechanism. The atmospheric abundance of Nsub2/subO has increased from 270&thinsp;ppb during the pre-industrial era to approx. 330&thinsp;ppb in 2018. Even though it is well known that microbial processes in agricultural and natural soils are the major Nsub2/subO source, the contribution of specific soil processes is still uncertain. The relative abundance of Nsub2/subO isotopocules (sup14/supNsup14/supNsup16/supN, sup14/supNsup15/supNsup16/supO, sup15/supNsup14/supNsup16/supO and sup14/supNsup14/supNsup18/supO) carries process-specific in-formation and thus can be used to trace production and consumption pathways. While isotope ratio mass spectroscopy (IRMS) was traditionally used for high-precision measurement of the isotopic composition of Nsub2/subO, quantum cascade laser absorption spectroscopy (QCLAS) has been put forward as a complementary technique with the potential for on-site analysis. In recent years, preconcentration combined with QCLAS has been presented as a technique to resolve subtle changes in ambient Nsub2/subO isotopic composition./p pFrom the end of May until the beginning of August 2016, we investigated Nsub2/subO emissions from an intensively managed grassland at the study site Fendt in Southern Germany. In total, 612 measurements of ambient Nsub2/subO were taken by combining preconcentration with QCLAS analyses, yielding δsup15/supNsupα/sup, δsup15/supNsupβ/sup, δsup18/supO and Nsub2/subO concentration with a temporal resolution of approximately one hour and precisions of 0.46&thinsp;‰, 0.36&thinsp;‰, 0.59&thinsp;‰ and 1.24&thinsp;ppb, respectively. Soil δsup15/supN-NOsub3/subsup&minus;/sup values and concentrations of NOsub3/subsup&minus;/sup and NHsub4/subsup+/sup were measured to further constrain possible Nsub2/subO-emitting source processes. Furthermore, the concentration footprint area of measured Nsub2/subO was determined with a Lagrangian particle dispersion model (FLEXPART-COSMO) using local wind and turbulence observations. These simulations indicated that night-time concentration observations were largely sensitive to local fluxes. While bacterial denitrification and nitrifier denitrification were identified as the primary Nsub2/subO-emitting processes, Nsub2/subO reduction to Nsub2/sub largely dictated the isotopic composition of measured Nsub2/subO. Fungal denitrification and nitrification-derived Nsub2/subO accounted for 34&ndash;42&thinsp;% of total Nsub2/subO emissions and had a clear effect on the measured isotopic source signatures. This study presents the suitability of on-site Nsub2/subO isotopocule analysis for disentangling source and sink processes in-situ and found that at the Fendt site bacterial denitrification/nitrifier denitrification is the major source for Nsub2/subO, while Nsub2/subO reduction acted as a major sink./p |
BibTeX:
@article{Ibraim2018,
author = {Ibraim, Erkan and Wolf, Benjamin and Harris, Eliza and Gasche, Rainer and Wei, Jing and Yu, Longfei and Kiese, Ralf and Eggleston, Sarah and Butterbach-Bahl, Klaus and Zeeman, Matthias and Tuzson, Béla and Emmenegger, Lukas and Six, Johan and Henne, Stephan and Mohn, Joachim},
title = {Attribution of Nsub2/subO sources in a grassland soil with laser spectroscopy based isotopocule analysis},
journal = {Biogeosciences Discussions},
publisher = {Copernicus GmbH},
year = {2018},
pages = {1--27},
doi = {10.5194/bg-2018-426}
}
|
| Järveoja J, Nilsson MB, Gažovič M, Crill PM and Peichl M (2018), "Partitioning of the net CO2 exchange using an automated chamber system reveals plant phenology as key control of production and respiration fluxes in a boreal peatland", Global Change Biology. Vol. 24(8), pp. 3436-3451. Wiley. |
| Abstract: The net ecosystem CO2 exchange (NEE) drives the carbon (C) sink–source strength of northern peatlands. Since NEE represents a balance between various production and respiration fluxes, accurate predictions of its response to global changes require an in depth understanding of these underlying processes. Currently, however, detailed information of the temporal dynamics as well as the separate biotic and abiotic controls of the NEE component fluxes is lacking in peatland ecosystems. In this study, we address this knowledge gap by using an automated chamber system established across natural and trenching/vegetation removal plots to partition NEE into its production (i.e., gross and net primary production; GPP and NPP) and respiration (i.e., ecosystem, heterotrophic and autotrophic respiration; ER, Rh and Ra) fluxes in a boreal peatland in northern Sweden. Our results showed that daily NEE patterns were driven by GPP while variations in ER were governed by Ra rather than Rh. Moreover, we observed pronounced seasonal shifts in the Ra/Rh and above/belowground NPP ratios throughout the main phenological phases. Generalized linear model analysis revealed that the greenness index derived from digital images (as a proxy for plant phenology) was the strongest control of NEE, GPP and NPP while explaining considerable fractions also in the variations of ER and Ra. In addition, our data exposed greater temperature sensitivity of NPP compared to Rh resulting in enhanced C sequestration with increasing temperature. Overall, our study suggests that the temporal patterns in NEE and its component fluxes are tightly coupled to vegetation dynamics in boreal peatlands and thus challenges previous studies that commonly identify abiotic factors as key drivers. These findings further emphasize the need for integrating detailed information on plant phenology into process-based models to improve predictions of global change impacts on the peatland C cycle. |
BibTeX:
@article{Jarveoja2018,
author = {Järveoja, Järvi and Nilsson, Mats B and Gažovič, Michal and Crill, Patrick M and Peichl, Matthias},
title = {Partitioning of the net CO2 exchange using an automated chamber system reveals plant phenology as key control of production and respiration fluxes in a boreal peatland},
journal = {Global Change Biology},
publisher = {Wiley},
year = {2018},
volume = {24},
number = {8},
pages = {3436--3451},
doi = {10.1111/gcb.14292}
}
|
| Järvi L, Rannik U, Kokkonen TV, Kurppa M, Karppinen A, Kouznetsov RD, Rantala P, Vesala T and Wood CR (2018), "Uncertainty of eddy covariance flux measurements over an urban area based on two towers", Atmospheric Measurement Techniques. Vol. 11(10), pp. 5421-5438. Copernicus GmbH. |
| Abstract: The eddy covariance (EC) technique is the most direct method for measuring the exchange between the surface and the atmosphere in different ecosystems. Thus, it is commonly used to get information on air pollutant and greenhouse gas emissions, and on turbulent heat transfer. Typically an ecosystem is monitored by only one single EC measurement station at a time, making the ecosystem-level flux values subject to random and systematic uncertainties. Furthermore, in urban ecosystems we often have no choice but to conduct the single-point measurements in non-ideal locations such as close to buildings and/or in the roughness sublayer, bringing further complications to data analysis and flux estimations. In order to tackle the question of how representative a single EC measurement point in an urban area can be, two identical EC systems - measuring momentum, sensible and latent heat, and carbon dioxide fluxes - were installed on each side of the same building structure in central Helsinki, Finland, during July 2013-September 2015. The main interests were to understand the sensitivity of the vertical fluxes on the single measurement point and to estimate the systematic uncertainty in annual cumulative values due to missing data if certain, relatively wide, flow-distorted wind sectors are disregarded.The momentum and measured scalar fluxes respond very differently to the distortion caused by the building structure. The momentum flux is the most sensitive to the measurement location, whereas scalar fluxes are less impacted. The flow distortion areas of the two EC systems (40-150 and 230-340°) are best detected from the mean-wind-normalised turbulent kinetic energy, and outside these areas the median relative random uncertainties of the studied fluxes measured by one system are between 12% and 28%. Different gap-filling methods with which to yield annual cumulative fluxes show how using data from a single EC measurement point can cause up to a 12% (480Cm 2) underestimation in the cumulative carbon fluxes as compared to combined data from the two systems. Combining the data from two EC systems also increases the fraction of usable half-hourly carbon fluxes from 45% to 69% at the annual level. For sensible and latent heat, the respective underestimations are up to 5% and 8% (0.094 and 0.069TJm 2). The obtained random and systematic uncertainties are in the same range as observed in vegetated ecosystems. We also show how the commonly used data flagging criteria in natural ecosystems, kurtosis and skewness, are not necessarily suitable for filtering out data in a densely built urban environment. The results show how the single measurement system can be used to derive representative flux values for central Helsinki, but the addition of second system to other side of the building structure decreases the systematic uncertainties. Comparable results can be expected in similarly dense city locations where no large directional deviations in the source area are seen. In general, the obtained results will aid the scientific community by providing information about the sensitivity of EC measurements and their quality flagging in urban areas. |
BibTeX:
@article{Jarvi2018,
author = {Järvi, Leena and Rannik, Ullar and Kokkonen, Tom V and Kurppa, Mona and Karppinen, Ari and Kouznetsov, Rostislav D and Rantala, Pekka and Vesala, Timo and Wood, Curtis R},
title = {Uncertainty of eddy covariance flux measurements over an urban area based on two towers},
journal = {Atmospheric Measurement Techniques},
publisher = {Copernicus GmbH},
year = {2018},
volume = {11},
number = {10},
pages = {5421--5438},
doi = {10.5194/amt-11-5421-2018}
}
|
| Jiskra M, Sonke JE, Obrist D, Bieser J, Ebinghaus R, Myhre CL, Pfaffhuber KA, Wängberg I, Kyllönen K, Worthy D, Martin LG, Labuschagne C, Mkololo T, Ramonet M, Magand O and Dommergue A (2018), "A vegetation control on seasonal variations in global atmospheric mercury concentrations", Nature Geoscience., apr, 2018. Vol. 11(4), pp. 244-250. Springer Nature. |
| Abstract: Anthropogenic mercury emissions are transported through the atmosphere as gaseous elemental mercury (Hg(0)) before they are deposited to Earth's surface. Strong seasonality in atmospheric Hg(0) concentrations in the Northern Hemisphere has been explained by two factors: anthropogenic Hg(0) emissions are thought to peak in winter due to higher energy consumption, and atmospheric oxidation rates of Hg(0) are faster in summer. Oxidation-driven Hg(0) seasonality should be equally pronounced in the Southern Hemisphere, which is inconsistent with observations of constant year-round Hg(0) levels. Here, we assess the role of Hg(0) uptake by vegetation as an alternative mechanism for driving Hg(0) seasonality. We find that at terrestrial sites in the Northern Hemisphere, Hg(0) co-varies with CO2, which is known to exhibit a minimum in summer when CO2 is assimilated by vegetation. The amplitude of seasonal oscillations in the atmospheric Hg(0) concentration increases with latitude and is larger at inland terrestrial sites than coastal sites. Using satellite data, we find that the photosynthetic activity of vegetation correlates with Hg(0) levels at individual sites and across continents. We suggest that terrestrial vegetation acts as a global Hg(0) pump, which can contribute to seasonal variations of atmospheric Hg(0), and that decreasing Hg(0) levels in the Northern Hemisphere over the past 20 years can be partly attributed to increased terrestrial net primary production. |
BibTeX:
@article{Jiskra2018,
author = {Jiskra, Martin and Sonke, Jeroen E and Obrist, Daniel and Bieser, Johannes and Ebinghaus, Ralf and Myhre, Cathrine Lund and Pfaffhuber, Katrine Aspmo and Wängberg, Ingvar and Kyllönen, Katriina and Worthy, Doug and Martin, Lynwill G and Labuschagne, Casper and Mkololo, Thumeka and Ramonet, Michel and Magand, Olivier and Dommergue, Aurélien},
title = {A vegetation control on seasonal variations in global atmospheric mercury concentrations},
journal = {Nature Geoscience},
publisher = {Springer Nature},
year = {2018},
volume = {11},
number = {4},
pages = {244--250},
doi = {10.1038/s41561-018-0078-8}
}
|
| Jocher G, Marshall J, Nilsson MB, Linder S, De Simon G, Hörnlund T, Lundmark T, Näsholm T, Ottosson Löfvenius M, Tarvainen L, Wallin G and Peichl M (2018), "Impact of Canopy Decoupling and Subcanopy Advection on the Annual Carbon Balance of a Boreal Scots Pine Forest as Derived From Eddy Covariance", Journal of Geophysical Research: Biogeosciences., feb, 2018. Vol. 123(2), pp. 303-325. |
| Abstract: Apparent net uptake of carbon dioxide (CO2) during wintertime by an ∼ 90 year old Scots pine stand in northern Sweden led us to conduct canopy decoupling and subcanopy advection investigations over an entire year. Eddy covariance (EC) measurements ran simultaneously above and within the forest canopy for that purpose. We used the correlation of above- and below-canopy standard deviation of vertical wind speed (σw) as decoupling indicator. We identified 0.33 m sâˆ'1 and 0.06 m sâˆ'1 as site-specific σw thresholds for above- and below-canopy coupling during nighttime (global radiation 20 W mâˆ'2) and 0.23 m sâˆ'1 and 0.06 m sâˆ'1 as daytime (global radiation 20 W mâˆ'2) σw thresholds. Decoupling occurred in 53% of the annual nighttime and 14% of the annual daytime. The annual net ecosystem exchange (NEE), gross ecosystem exchange (GEE), and ecosystem respiration (Reco) derived via two-level filtered EC data were âˆ'357 g C mâˆ'2, âˆ'1,138 g C mâˆ'2, and 781 g C mâˆ'2, respectively. In comparison, both single-level friction velocity (u*) and quality filtering resulted in ˜ 22% higher NEE, mainly caused by ˜ 16% lower Reco. GEE remained similar among filtering regimes. Accounting for changes of CO2 storage across the canopy in the single-level filtered data could only marginally decrease these discrepancies. Consequently, advection appears to be responsible for the major part of this divergence. We conclude that the two-level filter is necessary to adequately address decoupling and subcanopy advection at our site, and we recommend this filter for all forested EC sites. |
BibTeX:
@article{Jocher2018,
author = {Jocher, Georg and Marshall, John and Nilsson, Mats B and Linder, Sune and De Simon, Giuseppe and Hörnlund, Thomas and Lundmark, Tomas and Näsholm, Torgny and Ottosson Löfvenius, Mikaell and Tarvainen, Lasse and Wallin, Göran and Peichl, Matthias},
title = {Impact of Canopy Decoupling and Subcanopy Advection on the Annual Carbon Balance of a Boreal Scots Pine Forest as Derived From Eddy Covariance},
journal = {Journal of Geophysical Research: Biogeosciences},
year = {2018},
volume = {123},
number = {2},
pages = {303--325},
url = {http://doi.wiley.com/10.1002/2017JG003988},
doi = {10.1002/2017JG003988}
}
|
| Juráň S, Edwards-Jonášová M, Cudlín P, Zapletal M, Šigut L, Grace J and Urban O (2018), "Prediction of ozone effects on net ecosystem production of Norway spruce forest", IForest., dec, 2018. Vol. 11(6), pp. 743-750. Italian Society of Sivilculture and Forest Ecology (SISEF). |
| Abstract: Future ground-level concentrations of phytotoxic ozone are projected to grow in the Northern Hemisphere, at a rate depending on emission scenarios. We explored the likely changes in net ecosystem production (NEP) due to the increasing concentration of tropospheric ozone by applying a Generalized Additive Mixed Model based on measurements of ozone concentration ([O 3 ]) and stomatal ozone flux (FsO 3 ), at a mountainous Norway spruce forest in the Czech Republic, Central Europe. A dataset covering the growing period (May-August 2009) was examined in this case study. A predictive model based on FsO 3 was found to be marginally more accurate than a model using [O 3 ] alone for prediction of the course of NEP when compared to NEP measured by the eddy covariance technique. Both higher [O 3 ] and FsO 3 were found to reduce NEP. NEP simulated at low, pre-industrial FsO 3 (0.5 nmol m -2 s -1 ) was higher by 24.8% as compared to NEP assessed at current rates of FsO 3 (8.32 nmol m -2 s -1 ). However, NEP simulated at high FsO 3 (17 nmol m -2 s -1 ), likely in the future, was reduced by 14.1% as compared to NEP values at current FsO 3 . The interaction between environmental factors and stomatal conductance is discussed in this paper. |
BibTeX:
@article{JuraA2018,
author = {Juráň, Stanislav and Edwards-Jonášová, Magda and Cudlín, Pavel and Zapletal, Miloš and Šigut, Ladislav and Grace, John and Urban, Otmar},
title = {Prediction of ozone effects on net ecosystem production of Norway spruce forest},
journal = {IForest},
publisher = {Italian Society of Sivilculture and Forest Ecology (SISEF)},
year = {2018},
volume = {11},
number = {6},
pages = {743--750},
doi = {10.3832/ifor2805-011}
}
|
| Jurevics A, Peichl M and Egnell G (2018), "Stand volume production in the subsequent stand during three decades remains unaffected by slash and stump harvest in Nordic forests", Forests., dec, 2018. Vol. 9(12), pp. 770. MDPI AG. |
| Abstract: The renewable energy policies of the European Union rely on forest biomass in achieving climate mitigation targets. In Sweden, where secondary residues from the forest industries are fully utilized, primary residues following harvest such as stumps and slash offer a potential as an additional biomass source. Stump and slash harvest may, however, have adverse effects on site productivity due to increased nutrient loss from the site which could negatively impact the stand volume production of the subsequent stand. Stand volume production is also affected by seedling survival, seedling input from natural regeneration and management of the regenerated stand. In this study, we evaluate the effects of stump and slash harvest on stand volume production of the subsequent stand based on data from eight experimental sites across Sweden planted with Scots pine (Pinus sylvestris L.) or Norway spruce (Picea abies (L.) Karst.) over period of 31-34 years after clearcut with (1) traditional stem-only harvest; (2) stem and stump harvest; (3) stem and slash harvest; and (4) stem, stump and slash harvest. With the goal to explain treatment differences in stand volume production, treatment effects on site productivity estimated through initial height growth (10-19 years after planting), seedling survival, and input of seedlings through natural regeneration were also analyzed. We found that stand volume production was higher following stump harvest as compared to slash harvest, but stand volume production for the more intense harvest treatments (2)-(4) did not differ from stem-only harvest (1). Initial height growth (i.e., site productivity) did not differ between treatments, but followed the trend in stand volume production with (2) (4) (3) (1). Survival of planted seedlings was not affected by the treatments, whereas natural regeneration after 5 years was significantly increased after both treatments including slash harvest (3) and (4) in comparison to stem-only harvest. However, since most of that natural regeneration was removed in subsequent pre-commercial thinnings, this initial increase did not affect stand volume production. The absence of a significant interaction between treatment and species planted for all independent variables tested suggests that there were no species related response differences. Since the experimental design did not allow for site-level analyses, we cannot exclude the possibility that site-specific harvest treatment effects might have masked general effects across all sites. Thus, slash and stump harvest effects at the site level need to be further studied. These results suggest, at least over a 3-decade perspective, that logging residues like stumps and slash can provide an additional renewable energy source to help achieving climate change mitigation goals in the Nordic countries without depleting the future forest biomass resource. |
BibTeX:
@article{Jurevics2018,
author = {Jurevics, Arnis and Peichl, Matthias and Egnell, Gustaf},
title = {Stand volume production in the subsequent stand during three decades remains unaffected by slash and stump harvest in Nordic forests},
journal = {Forests},
publisher = {MDPI AG},
year = {2018},
volume = {9},
number = {12},
pages = {770},
doi = {10.3390/f9120770}
}
|
| Kaisermann A, Ogée J, Sauze J, Wohl S, Jones SP, Gutierrez A and Wingate L (2018), "Disentangling the rates of carbonyl sulfide (COS) production and consumption and their dependency on soil properties across biomes and land use types", Atmospheric Chemistry and Physics., jul, 2018. Vol. 18(13), pp. 9425-9440. Copernicus GmbH. |
| Abstract: Soils both emit and consume the trace gas carbonyl sulfide (COS) leading to a soil-air COS exchange rate that is the net result of two opposing fluxes. Partitioning these two gross fluxes and understanding their drivers are necessary to estimate the contribution of soils to the current and future atmospheric COS budget. Previous efforts to disentangle the gross COS fluxes from soils have used flux measurements on air-dried soils as a proxy for the COS emission rates of moist soils. However, this method implicitly assumes that COS uptake becomes negligible and that COS emission remains steady while soils are drying. We tested this assumption by simultaneously estimating the soil COS sources and sinks and their temperature sensitivity (Q10); these estimates were based on soil-air COS flux measurements on fresh soils at different COS concentrations and two soil temperatures. Measurements were performed on 27 European soils from different biomes and land use types in order to obtain a large range of physical-chemical properties and identify the drivers of COS consumption and production rates. We found that COS production rates from moist and airdried soils were not significantly different for a given soil and that the COS production rates had Q10 values (3.96±3.94) that were larger and more variable than the Q10 for COS consumption (1.17±0.27). COS production generally contributed less to the net flux at lower temperatures but this contribution of COS production increased rapidly at higher temperatures, lower soil moisture contents and lower COS concentrations. Consequently, measurements at higher COS concentrations (viz. 1000 ppt) always increased the robustness of COS consumption estimates. Across the range of biomes and land use types COS production rates co-varied with total soil nitrogen concentrations (r =0.52, P 0.05) and mean annual precipitation (r = 0.53, P 0.05), whilst the gross COS uptake rate and the first-order COS hydrolysis rate constant co-varied significantly with the microbial biomass nitrogen (N) content of the soils (r = -0.74 and 0.64, P 0.05 and P 0.05, respectively). Collectively our findings suggest a strong interaction between soil nitrogen and water cycling on COS production and uptake, providing new insights into how to upscale the contribution of soils to the global atmospheric COS budget. |
BibTeX:
@article{Kaisermann2018,
author = {Kaisermann, Aurore and Ogée, Jérôme and Sauze, Joana and Wohl, Steven and Jones, Sam P and Gutierrez, Ana and Wingate, Lisa},
title = {Disentangling the rates of carbonyl sulfide (COS) production and consumption and their dependency on soil properties across biomes and land use types},
journal = {Atmospheric Chemistry and Physics},
publisher = {Copernicus GmbH},
year = {2018},
volume = {18},
number = {13},
pages = {9425--9440},
doi = {10.5194/acp-18-9425-2018}
}
|
| Kamp J, Skov H, Jensen B and Sørensen LL (2018), "Fluxes of gaseous elemental mercury (GEM) in the High Arctic during atmospheric mercury depletion events (AMDEs)", Atmospheric Chemistry and Physics., may, 2018. Vol. 18(9), pp. 6923-6938. Copernicus GmbH. |
| Abstract: Measurements of gaseous elemental mercury (GEM) fluxes over snow surfaces using a relaxed eddy accumulation (REA) system are carried out at the High Arctic site at the Villum Research Station, Station Nord, in North Greenland. Simultaneously, CO2 fluxes are determined using the eddy covariance (EC) technique. The REA system with dual inlets and dual analyzers is used to measure fluxes directly over the snow. The measurements were carried out from 23 April to 12 May during spring 2016, where atmospheric mercury depletion events (AMDEs) took place. The measurements showed a net emission of 8.9 ng m-2 min-1, with only a few minor episodes of net depositional fluxes, from a maximum deposition of 8.1 ng m-2 min-1 to a maximum emission of 179.2 ng m-2 min-1. The data support the theory that gaseous oxidized mercury (GOM) is deposited during AMDEs followed by formation of GEM on surface snow and is re-emitted as GEM shortly after the AMDEs. Furthermore, observation of the relation between GEM fluxes and atmospheric temperature suggests that GEM emission partly could be affected by surface heating. However, it is also clear that the GEM emissions are affected by many parameters. |
BibTeX:
@article{Kamp2018,
author = {Kamp, Jesper and Skov, Henrik and Jensen, Bjarne and Sørensen, Lise Lotte},
title = {Fluxes of gaseous elemental mercury (GEM) in the High Arctic during atmospheric mercury depletion events (AMDEs)},
journal = {Atmospheric Chemistry and Physics},
publisher = {Copernicus GmbH},
year = {2018},
volume = {18},
number = {9},
pages = {6923--6938},
doi = {10.5194/acp-18-6923-2018}
}
|
| Katul G, Mammarella I, Grönholm T and Vesala T (2018), "A Structure Function Model Recovers the Many Formulations for Air-Water Gas Transfer Velocity", Water Resources Research., sep, 2018. Vol. 54(9), pp. 5905-5920. Blackwell Publishing Ltd. |
| Abstract: Two ideas regarding the structure of turbulence near a clear air-water interface are used to derive a waterside gas transfer velocity kL for sparingly and slightly soluble gases. The first is that kL is proportional to the turnover velocity described by the vertical velocity structure function Dww(r), where r is separation distance between two points. The second is that the scalar exchange between the air-water interface and the waterside turbulence can be suitably described by a length scale proportional to the Batchelor scale lB=ηSc−1/2, where Sc is the molecular Schmidt number and η is the Kolmogorov microscale defining the smallest scale of turbulent eddies impacted by fluid viscosity. Using an approximate solution to the von Kármán-Howarth equation predicting Dww(r) in the inertial and viscous regimes, prior formulations for kL are recovered including (i) kL = √2/15Sc-12, vK is the Kolmogorov velocity defined by the Reynolds number vKη/ν = 1 and ν is the kinematic viscosity of water; (ii) surface divergence formulations; (iii) kL ∝ Sc−1/2u∗, where u∗ is the waterside friction velocity; (iv) kL ∝ Sc−1/2√gν/u∗ for Keulegan numbers exceeding a threshold needed for long-wave generation, where the proportionality constant varies with wave age, g is the gravitational acceleration; and (v) kL = ‚2/15Sc−1/2(νgβoqo)1/4 in free convection, where qo is the surface heat flux and βo is the thermal expansion of water. The work demonstrates that the aforementioned kL formulations can be recovered from a single structure function model derived for locally homogeneous and isotropic turbulence. |
BibTeX:
@article{Katul2018,
author = {Katul, Gabriel and Mammarella, Ivan and Grönholm, Tiia and Vesala, Timo},
title = {A Structure Function Model Recovers the Many Formulations for Air-Water Gas Transfer Velocity},
journal = {Water Resources Research},
publisher = {Blackwell Publishing Ltd},
year = {2018},
volume = {54},
number = {9},
pages = {5905--5920},
doi = {10.1029/2018WR022731}
}
|
| Katul G, Peltola O, Grönholm T, Launiainen S, Mammarella I and Vesala T (2018), "Ejective and Sweeping Motions Above a Peatland and Their Role in Relaxed-Eddy-Accumulation Measurements and Turbulent Transport Modelling", Boundary-Layer Meteorology., jul, 2018. Vol. 169(2), pp. 163-184. Springer Nature. |
| Abstract: The three turbulent velocity components, water vapour (H 2O ), carbon dioxide (CO 2), and methane (CH 4) concentration fluctuations are measured above a boreal peatland and analyzed using conditional sampling and quadrant analysis. The overarching question to be addressed is to what degree lower-order cumulant expansion methods describe transport efficiency and the relative importance of ejections and sweeps to momentum, CH 4, CO 2 and H 2O fluxes across a range of atmospheric flow regimes. The patchy peatland surface creates distinctly different source and sink distributions for the three scalars in space and time thereby adding to the uniqueness of the set-up. The measured and modelled fractional contributions to the momentum flux show that sweep events dominate over ejections in agreement with prior studies conducted in the roughness sublayer. For scalar fluxes, ejections dominate the turbulent fluxes over sweeps. While ejective motions persist longer for momentum transport, sweeping events persist longer for all three scalars. Third-order cumulant expansions describe many of the results detailed above, and the results are surprising given the highly non-Gaussian distribution of CH 4 turbulent fluctuations. Connections between the asymmetric contributions of sweeps and ejections and the flux-transport term arising in scalar turbulent-flux-budget closure are derived and shown to agree reasonably well with measurements. The proposed model derived here is much simpler than prior structural models used to describe laboratory experiments. Implications of such asymmetric contributions on, (i) the usage of the now proliferating relaxed-eddy-accumulation method in turbulent flux measurements, (ii) the constant-flux assumption, and (iii) gradient-diffusion closure models are presented. |
BibTeX:
@article{Katul2018a,
author = {Katul, Gabriel and Peltola, Olli and Grönholm, Tiia and Launiainen, Samuli and Mammarella, Ivan and Vesala, Timo},
title = {Ejective and Sweeping Motions Above a Peatland and Their Role in Relaxed-Eddy-Accumulation Measurements and Turbulent Transport Modelling},
journal = {Boundary-Layer Meteorology},
publisher = {Springer Nature},
year = {2018},
volume = {169},
number = {2},
pages = {163--184},
doi = {10.1007/s10546-018-0372-4}
}
|
| Kiese R, Fersch B, Baessler C, Brosy C, Butterbach-Bahl K, Chwala C, Dannenmann M, Fu J, Gasche R, Grote R, Jahn C, Klatt J, Kunstmann H, Mauder M, Rödiger T, Smiatek G, Soltani M, Steinbrecher R, Völksch I, Werhahn J, Wolf B, Zeeman M and Schmid HP (2018), "The TERENO Pre-Alpine Observatory: Integrating Meteorological, Hydrological, and Biogeochemical Measurements and Modeling", Vadose Zone Journal. Vol. 17(1), pp. 180060. Soil Science Society of America. |
| Abstract: textcopyright Soil Science Society of America. Global change has triggered several transformations, such as alterations in climate, land productivity, water resources, and atmospheric chemistry, with far reaching impacts on ecosystem functions and services. Finding solutions to climate and land cover change-driven impacts on our terrestrial environment is one of the most important scientific challenges of the 21st century, with far-reaching interlinkages to the socio-economy. The setup of the German Terrestrial Environmental Observatories (TERENO) Pre-Alpine Observatory was motivated by the fact that mountain areas, such as the pre-alpine region in southern Germany, have been exposed to more intense warming compared with the global average trend and to higher frequencies of extreme hydrological events, such as droughts and intense rainfall. Scientific research questions in the TERENO Pre-Alpine Observatory focus on improved process understanding and closing of combined energy, water, C, and N cycles at site to regional scales. The main long-term objectives of the TERENO Pre-Alpine Observatory include the characterization and quantification of climate change and land cover–manage-ment effects on terrestrial hydrology and biogeochemical processes at site and regional scales by joint measuring and modeling approaches. Here we present a detailed climatic and biogeophysical characterization of the TERENO Pre-Alpine Observatory and a summary of novel scientific findings from observations and projects. Finally, we reflect on future directions of climate impact research in this particularly vulnerable region of Germany. |
BibTeX:
@article{Kiese2018,
author = {Kiese, R and Fersch, B and Baessler, C and Brosy, C and Butterbach-Bahl, K and Chwala, C and Dannenmann, M and Fu, J and Gasche, R and Grote, R and Jahn, C and Klatt, J and Kunstmann, H and Mauder, M and Rödiger, T and Smiatek, G and Soltani, M and Steinbrecher, R and Völksch, I and Werhahn, J and Wolf, B and Zeeman, M and Schmid, H P},
title = {The TERENO Pre-Alpine Observatory: Integrating Meteorological, Hydrological, and Biogeochemical Measurements and Modeling},
journal = {Vadose Zone Journal},
publisher = {Soil Science Society of America},
year = {2018},
volume = {17},
number = {1},
pages = {180060},
doi = {10.2136/vzj2018.03.0060}
}
|
| Kisel'Ák J, Dušek J and Stehlík M (2018), "Recurrence of CH 4 and CO 2 emissions measured by a non-steady state flow-through chamber system", In AIP Conference Proceedings. Vol. 2046 Author(s). |
| Abstract: Raw data of methane and carbon dioxide emissions from the sedge-grass marsh ecosystem measured by the non-steady state flow-through chamber system were analyzed using a recurrence plots of a time trajectory returns. The recurrence plots can help to understand process of gases emission and optionally can exploited to characterize the system's behavior. According to recurrence plots we can to state that behavior of system is mostly stochastic with determination parts with chaos transitions. |
BibTeX:
@inproceedings{KiselAk2018,
author = {Kisel'Ák, Jozef and Dušek, JiÅ™í and Stehlík, Milan},
title = {Recurrence of CH 4 and CO 2 emissions measured by a non-steady state flow-through chamber system},
booktitle = {AIP Conference Proceedings},
publisher = {Author(s)},
year = {2018},
volume = {2046},
doi = {10.1063/1.5081566}
}
|
| Kiuru P, Ojala A, Mammarella I, Heiskanen J, Kämäräinen M, Vesala T and Huttula T (2018), "Effects of Climate Change on CO2 Concentration and Efflux in a Humic Boreal Lake: A Modeling Study", Journal of Geophysical Research: Biogeosciences., jul, 2018. Vol. 123(7), pp. 2212-2233. American Geophysical Union (AGU). |
| Abstract: Climate change may have notable impacts on carbon cycling in freshwater ecosystems, especially in the boreal zone. Higher atmospheric temperature and changes in annual discharge patterns and carbon loading from the catchment affect the thermal and biogeochemical conditions in a lake. We developed an extension of a one-dimensional process-based lake model MyLake for simulating carbon dioxide (CO2) dynamics of a boreal lake. We calibrated the model for Lake Kuivajärvi, a small humic boreal lake, for the years 2013–2014, using the extensive data available on carbon inflow and concentrations of water column CO2 and dissolved organic carbon. The lake is a constant source of CO2 to the atmosphere in the present climate. We studied the potential effects of climate change-induced warming on lake CO2 concentration and air-water flux using downscaled air temperature data from three recent-generation global climate models with two alternative representative concentration pathway forcing scenarios. Literature estimates were used for climate change impacts on the lake inflow. The scenario simulations showed a 20–35% increase in the CO2 flux from the lake to the atmosphere in the scenario period 2070–2099 compared to the control period 1980–2009. In addition, we estimated possible implications of different changes in terrestrial inorganic and organic carbon loadings to the lake. The scenarios with plausible increases of 10% and 20% in CO2 and dissolved organic carbon loadings, respectively, produced increases of 2.1–2.5% and 2.2–2.3% in the annual CO2 flux. |
BibTeX:
@article{Kiuru2018,
author = {Kiuru, Petri and Ojala, Anne and Mammarella, Ivan and Heiskanen, Jouni and Kämäräinen, Matti and Vesala, Timo and Huttula, Timo},
title = {Effects of Climate Change on CO2 Concentration and Efflux in a Humic Boreal Lake: A Modeling Study},
journal = {Journal of Geophysical Research: Biogeosciences},
publisher = {American Geophysical Union (AGU)},
year = {2018},
volume = {123},
number = {7},
pages = {2212--2233},
doi = {10.1029/2018JG004585}
}
|
| Knauer J, El-Madany TS, Zaehle S and Migliavacca M (2018), "Bigleaf—An R package for the calculation of physical and physiological ecosystem properties from eddy covariance data", PLoS ONE., aug, 2018. Vol. 13(8) Public Library of Science. |
| Abstract: We present the R package bigleaf (version 0.6.5), an open source toolset for the derivation of meteorological, aerodynamic, and physiological ecosystem properties from eddy covariance (EC) flux observations and concurrent meteorological measurements. A ‘bigleaf' framework, in which vegetation is represented as a single, uniform layer, is employed to infer bulk ecosystem characteristics top-down from the measured fluxes. Central to the package is the calculation of a bulk surface/canopy conductance (Gs/Gc) and a bulk aerodynamic conductance (Ga), with the latter including formulations for the turbulent and canopy boundary layer components. The derivation of physical land surface characteristics such as surface roughness parameters, wind profile, aerodynamic and radiometric surface temperature, surface vapor pressure deficit (VPD), potential evapotranspiration (ET), imposed and equilibrium ET, as well as vegetation-atmosphere decoupling coefficients, is described. The package further provides calculation routines for physiological ecosytem properties (stomatal slope parameters, stomatal sensitivity to VPD, bulk intercellular CO2 concentration, canopy photosynthetic capacity), energy balance characteristics (closure, biochemical energy), ancillary meteorological variables (psychrometric constant, saturation vapor pressure, air density, etc.), customary unit interconversions and data filtering. The target variables can be calculated with a different degree of complexity, depending on the amount of available site-specific information. The utilities of the package are demonstrated for three single-level (above-canopy) eddy covariance sites representing a temperate grassland, a temperate needle-leaf forest, and a Mediterranean evergreen broadleaf forest. The routines are further tested for a two-level EC site (tree and grass layer) located in a Mediterranean oak savanna. The limitations and the ecophysiological interpretation of the derived ecosystem properties are discussed and practical guidelines are given. The package provides the basis for a consistent, physically sound, and reproducible characterization of biometeorological conditions and ecosystem physiology, and is applicable to EC sites across vegetation types and climatic conditions with minimal ancillary data requirements. |
BibTeX:
@article{Knauer2018,
author = {Knauer, Jürgen and El-Madany, Tarek S. and Zaehle, Sönke and Migliavacca, Mirco},
title = {Bigleaf—An R package for the calculation of physical and physiological ecosystem properties from eddy covariance data},
journal = {PLoS ONE},
publisher = {Public Library of Science},
year = {2018},
volume = {13},
number = {8},
doi = {10.1371/journal.pone.0201114}
}
|
| Knauer J, Zaehle S, Medlyn BE, Reichstein M, Williams CA, Migliavacca M, De Kauwe MG, Werner C, Keitel C, Kolari P, Limousin J and Linderson M (2018), "Towards physiologically meaningful waterâ€use efficiency estimates from eddy covariance data", Global Change Biology., feb, 2018. Vol. 24(2), pp. 694-710. |
BibTeX:
@article{Knauer2018a,
author = {Knauer, Jürgen and Zaehle, Sönke and Medlyn, Belinda E and Reichstein, Markus and Williams, Christopher A and Migliavacca, Mirco and De Kauwe, Martin G and Werner, Christiane and Keitel, Claudia and Kolari, Pasi and Limousin, Jeanâ€Marc and Linderson, Majâ€Lena},
title = {Towards physiologically meaningful waterâ€use efficiency estimates from eddy covariance data},
journal = {Global Change Biology},
year = {2018},
volume = {24},
number = {2},
pages = {694--710},
url = {https://onlinelibrary.wiley.com/doi/abs/10.1111/gcb.13893},
doi = {10.1111/gcb.13893}
}
|
| Kokkonen TV, Grimmond CS, Räty O, Ward HC, Christen A, Oke TR, Kotthaus S and Järvi L (2018), "Sensitivity of Surface Urban Energy and Water Balance Scheme (SUEWS) to downscaling of reanalysis forcing data", Urban Climate., mar, 2018. Vol. 23, pp. 36-52. Elsevier B.V.. |
| Abstract: Often the meteorological forcing data required for urban hydrological models are unavailable at the required temporal resolution or for the desired period. Although reanalysis data can provide this information, the spatial resolution is often coarse relative to cities, so downscaling is required prior to use as realistic forcing. In this study, WATCH WFDEI reanalysis data are used to force the Surface Urban Energy and Water Balance Scheme (SUEWS). From sensitivity tests in two cities, Vancouver and London with different orography, we conclude precipitation is the most important meteorological variable to be properly downscaled to obtain reliable surface hydrology results, with relative humidity being the second most important. Overestimation of precipitation in reanalysis data at the three sites gives 6–21% higher annual modelled evaporation, 26–39% higher runoff at one site and 4% lower value at one site when compared to modelled values using observed forcing data. Application of a bias correction method to the reanalysis precipitation reduces the model bias compared to using observed forcing data, when evaluated using eddy covariance evaporation measurements. |
BibTeX:
@article{Kokkonen2018,
author = {Kokkonen, T. V. and Grimmond, C. S.B. and Räty, O. and Ward, H. C. and Christen, A. and Oke, T. R. and Kotthaus, S. and Järvi, L.},
title = {Sensitivity of Surface Urban Energy and Water Balance Scheme (SUEWS) to downscaling of reanalysis forcing data},
journal = {Urban Climate},
publisher = {Elsevier B.V.},
year = {2018},
volume = {23},
pages = {36--52},
doi = {10.1016/j.uclim.2017.05.001}
}
|
| Kokkonen TV, Grimmond CS, Christen A, Oke TR and Järvi L (2018), "Changes to the Water Balance Over a Century of Urban Development in Two Neighborhoods: Vancouver, Canada", Water Resources Research., sep, 2018. Vol. 54(9), pp. 6625-6642. Blackwell Publishing Ltd. |
| Abstract: Hydrological cycles of two suburban neighborhoods in Vancouver, BC, during initial urban development and subsequent urban densification (1920–2010) are examined using the Surface Urban Energy and Water Balance Scheme. The two neighborhoods have different surface characteristics (as determined from aerial photographs) which impact the hydrological processes. Unlike previous studies of the effect of urbanization on the local hydrology, densification of already built lots is explored with a focus on the neighborhood scale. Human behavioral changes to irrigation are accounted for in the simulations. Irrigation is the dominant factor, accounting for up to 56% of the water input on an annual basis in the study areas. This may surpass garden needs and go to runoff. Irrigating once a week would provide sufficient water for the garden. Without irrigation, evaporation would have decreased over the 91 years at a rate of up to 1.4 mm/year and runoff increased at 4.0 mm/year with the increase in impervious cover. Similarly without irrigation, the ratio of sensible heat flux to the available energy would have increased over the 91 years at a rate of up to 0.003 per year. Urbanization and densification cause an increase in runoff and increase risk of surface flooding. Small daily runoff events with short return periods have increased over the century, whereas the occurrence of heavy daily runoff events (return period textgreater 52 days) are not affected. The results can help us to understand the dominant factors in the suburban hydrological cycle and can inform urban planning. |
BibTeX:
@article{Kokkonen2018a,
author = {Kokkonen, T. V. and Grimmond, C. S.B. and Christen, A. and Oke, T. R. and Järvi, L.},
title = {Changes to the Water Balance Over a Century of Urban Development in Two Neighborhoods: Vancouver, Canada},
journal = {Water Resources Research},
publisher = {Blackwell Publishing Ltd},
year = {2018},
volume = {54},
number = {9},
pages = {6625--6642},
doi = {10.1029/2017WR022445}
}
|
| Kondrik D, Kazakov E and Pozdnyakov D (2018), "A synthetic satellite dataset of iE. huxleyi/i spatio-temporal distributions and their impacts on Arctic and Subarctic marine environments (1998&ndash;2016)", Earth System Science Data Discussions., oct, 2018. , pp. 1-17. Copernicus GmbH. |
| Abstract: pstrongAbstract./strong A 19-year (1998&ndash;2016) continuous dataset of coccolithophore iE. huxleyi/i distributions and activity in Arctic and Subarctic seas is presented. The dataset is based on optical remote sensing data (mostly OC CCI data) with assimilation of different relevant in-situ observations, preprocessed with authorial algorithms. Alongside with bloom locations, we also provide both detailed information on iE. huxleyi/i impacts within the bloom area on marine environments and the subdatasets of quantified coccolith concentrations, particulate inorganic carbon content and COsub2/sub partial pressure in water driven by coccolithophores. All data are presented on a regular 4&times;4span class="thinspace"/spankm grid at a temporal resolution of 8 days. The paper describes the theoretical and methodological basis for all processing and modeling steps. The data are available on Zenodo: a href="https://doi.org/10.5281/zenodo.1402033" target="_blank"https://doi.org/10.5281/zenodo.1402033/a./p |
BibTeX:
@article{Kondrik2018,
author = {Kondrik, Dmitry and Kazakov, Eduard and Pozdnyakov, Dmitry},
title = {A synthetic satellite dataset of iE. huxleyi/i spatio-temporal distributions and their impacts on Arctic and Subarctic marine environments (1998&ndash;2016)},
journal = {Earth System Science Data Discussions},
publisher = {Copernicus GmbH},
year = {2018},
pages = {1--17},
doi = {10.5194/essd-2018-101}
}
|
| Korrensalo A, Männistö E, Alekseychik P, Mammarella I, Rinne J, Vesala T and Tuittila ES (2018), "Small spatial variability in methane emission measured from a wet patterned boreal bog", Biogeosciences. Vol. 15(6), pp. 1749-1761. Copernicus GmbH. |
| Abstract: We measured methane fluxes of a patterned bog situated in Siikaneva in southern Finland from six different plant community types in three growing seasons (2012-2014) using the static chamber method with chamber exposure of 35 min. A mixed-effects model was applied to quantify the effect of the controlling factors on the methane flux.The plant community types differed from each other in their water level, species composition, total leaf area (LAITOT) and leaf area of aerenchymatous plant species (LAIAER). Methane emissions ranged from-309 to 1254 mg m-2 d-1. Although methane fluxes increased with increasing peat temperature, LAITOT and LAIAER, they had no correlation with water table or with plant community type. The only exception was higher fluxes from hummocks and high lawns than from high hummocks and bare peat surfaces in 2013 and from bare peat surfaces than from high hummocks in 2014. Chamber fluxes upscaled to ecosystem level for the peak season were of the same magnitude as the fluxes measured with the eddy covariance (EC) technique. In 2012 and in August 2014 there was a good agreement between the two methods; in 2013 and in July 2014, the chamber fluxes were higher than the EC fluxes.Net fluxes to soil, indicating higher methane oxidation than production, were detected every year and in all community types. Our results underline the importance of both LAIAER and LAITOT in controlling methane fluxes and indicate the need for automatized chambers to reliably capture localized events to support the more robust EC method. |
BibTeX:
@article{Korrensalo2018,
author = {Korrensalo, Aino and Männistö, Elisa and Alekseychik, Pavel and Mammarella, Ivan and Rinne, Janne and Vesala, Timo and Tuittila, Eeva Stiina},
title = {Small spatial variability in methane emission measured from a wet patterned boreal bog},
journal = {Biogeosciences},
publisher = {Copernicus GmbH},
year = {2018},
volume = {15},
number = {6},
pages = {1749--1761},
doi = {10.5194/bg-15-1749-2018}
}
|
| Korrensalo A, Kettunen L, Laiho R, Alekseychik P, Vesala T, Mammarella I and Tuittila ES (2018), "Boreal bog plant communities along a water table gradient differ in their standing biomass but not their biomass production", Journal of Vegetation Science., feb, 2018. Vol. 29(2), pp. 136-146. Wiley. |
| Abstract: Question: Peatlands are globally important for carbon storage due to the imbalance between plant biomass production and decomposition. Distribution of both live standing biomass (BM, dry mass g/m2) and biomass production (BMP, dry mass g mâˆ'2 growing seasonâˆ'1) are known to be dependent on the water table (WT). However, the relations of BM and BMP to WT variation are poorly known. Here we investigated, how the above- and below-ground BM and BMP of three different plant functional types (PFTs), dwarf shrubs, sedges and Sphagnum mosses, relate to natural WT variation within an ombrotrophic boreal bog. In addition, we estimated ecosystem-level BMP and compared that with ecosystem net primary production (NPP) derived from eddy covariance (EC) measurements. Location: Siikaneva bog, Ruovesi, Finland. Methods: We quantified above- and below-ground BM and BMP of PFTs along the WT gradient, divided into six plant community types. Plant community scale BM and BMP were up-scaled to the ecosystem level. NPP was derived from EC measurements using a literature-based ratio of heterotrophic respiration to total ecosystem respiration. Results: BM varied from 211 to 979 g/m2 among the plant community types, decreasing gradually from dry to wet community types. In contrast, BMP was similar between plant community types (162–216 g/m2), except on nearly vegetation-free bare peat surfaces where it was low (38 g/m2). Vascular plant BM turnover rate (BMP:BM, per year) varied from 0.14 to 0.30 among the plant community types, being highest in sedge-dominated hollows. On average 56% of the vascular BM was produced below ground. Mosses, when present, produced on average 31% of the total BM, ranging from 16% to 53% depending on community type. EC-derived NPP was higher than measured BMP due to underestimation of certain components. Conclusions: We found that the diversity of PFTs decreases the spatial variability in productivity of a boreal bog ecosystem. The observed even distribution of BMP resulted from different WT optima and BMP:BM of dwarf shrubs, sedges and Sphagnum species. These differences in biomass turnover rate and species responses to environmental conditions may provide a resilience mechanism for bog ecosystems in changing conditions. |
BibTeX:
@article{Korrensalo2018a,
author = {Korrensalo, Aino and Kettunen, Laura and Laiho, Raija and Alekseychik, Pavel and Vesala, Timo and Mammarella, Ivan and Tuittila, Eeva Stiina},
editor = {Roxburgh, Stephen},
title = {Boreal bog plant communities along a water table gradient differ in their standing biomass but not their biomass production},
journal = {Journal of Vegetation Science},
publisher = {Wiley},
year = {2018},
volume = {29},
number = {2},
pages = {136--146},
doi = {10.1111/jvs.12602}
}
|
| Köster K, Köster E, Berninger F, Heinonsalo J and Pumpanen J (2018), "Contrasting effects of reindeer grazing on CO2, CH4, and N2O fluxes originating from the northern boreal forest floor", Land Degradation and Development., feb, 2018. Vol. 29(2), pp. 374-381. John Wiley and Sons Ltd. |
| Abstract: Reindeer (Rangifer tarandus L.) is considered to be an important mammalian herbivore, strongly influencing Arctic lichen-dominated ecosystems. There is no wide knowledge about the effect of reindeer on greenhouse gas (GHG) fluxes in northern boreal forests. Ground vegetation plays an important role in absorbing nitrogen (N) and carbon dioxide (CO2) from the atmosphere. Lately, it has also been found to be a significant source of nitrous oxide (N2O) and a small source of methane (CH4). We investigated the influence of reindeer grazing on field layer GHG (CO2, CH4, and N2O) fluxes, ground vegetation coverage and biomass, and soil physical properties (temperature and moisture) in a northern boreal forest. At our study site, the reindeer-induced replacement of lichen by mosses had contrasting effects on the GHG fluxes originating from the field layer. Field layer CO2 efflux was significantly higher in grazed areas. The field layer was a CH4 sink in all areas, but grazed areas absorbed more CH4 compared to non-grazed areas. Although total N2O fluxes remained around 0 in grazed areas, a small N2O sink occurred in non-grazed areas with lower moss biomass. Our results indicated that grazing by reindeer in northern boreal forests affects GHG fluxes from the forest field layer both positively and negatively, and these emissions largely depend on grazing-induced changes in vegetation composition. |
BibTeX:
@article{Koster2018,
author = {Köster, Kajar and Köster, Egle and Berninger, Frank and Heinonsalo, Jussi and Pumpanen, Jukka},
title = {Contrasting effects of reindeer grazing on CO2, CH4, and N2O fluxes originating from the northern boreal forest floor},
journal = {Land Degradation and Development},
publisher = {John Wiley and Sons Ltd},
year = {2018},
volume = {29},
number = {2},
pages = {374--381},
doi = {10.1002/ldr.2868}
}
|
| Köster E, Köster K, Berninger F, Prokushkin A, Aaltonen H, Zhou X and Pumpanen J (2018), "Changes in fluxes of carbon dioxide and methane caused by fire in Siberian boreal forest with continuous permafrost", Journal of Environmental Management., dec, 2018. Vol. 228, pp. 405-415. Academic Press. |
| Abstract: Rising air temperatures and changes in precipitation patterns in boreal ecosystems are changing the fire occurrence regimes (intervals, severity, intensity, etc.). The main impacts of fires are reported to be changes in soil physical and chemical characteristics, vegetation stress, degradation of permafrost, and increased depth of the active layer. Changes in these characteristics influence the dynamics of carbon dioxide (CO2) and methane (CH4) fluxes. We have studied the changes in CO2 and CH4 fluxes from the soil in boreal forest areas in central Siberia underlain by continuous permafrost and the possible impacts of the aforementioned environmental factors on the emissions of these greenhouse gases. We have used a fire chronosequence of areas, with the last fire occurring 1, 23, 56, and more than 100 years ago. The soils in our study acted as a source of CO2. Emissions of CO2 were lowest at the most recently burned area and increased with forest age throughout the fire chronosequence. The CO2 flux was influenced by the pH of the top 5 cm of the soil, the biomass of the birch (Betula) and alder (Duschekia) trees, and by the biomass of vascular plants in the ground vegetation. Soils were found to be a CH4 sink in all our study areas. The uptake of CH4 was highest in the most recently burned area (forest fire one year ago) and the lowest in the area burned 56 years ago, but the difference between fire chronosequence areas was not significant. According to the linear mixed effect model, none of the tested factors explained the CH4 flux. The results confirm that the impact of a forest fire on CO2 flux is long-lasting in Siberian boreal forests, continuing for more than 50 years, but the impact of forest fire on CH4 flux is minimal. |
BibTeX:
@article{Koster2018a,
author = {Köster, Egle and Köster, Kajar and Berninger, Frank and Prokushkin, Anatoly and Aaltonen, Heidi and Zhou, Xuan and Pumpanen, Jukka},
title = {Changes in fluxes of carbon dioxide and methane caused by fire in Siberian boreal forest with continuous permafrost},
journal = {Journal of Environmental Management},
publisher = {Academic Press},
year = {2018},
volume = {228},
pages = {405--415},
doi = {10.1016/j.jenvman.2018.09.051}
}
|
| Kountouris P, Gerbig C, Rödenbeck C, Karstens U, Frank Koch T and Heimann M (2018), "Technical Note: Atmospheric CO2 inversions on the mesoscale using data-driven prior uncertainties: Methodology and system evaluation", Atmospheric Chemistry and Physics., mar, 2018. Vol. 18(4), pp. 3027-3045. Copernicus GmbH. |
| Abstract: Atmospheric inversions are widely used in the optimization of surface carbon fluxes on a regional scale using information from atmospheric CO2 dry mole fractions. In many studies the prior flux uncertainty applied to the inversion schemes does not directly reflect the true flux uncertainties but is used to regularize the inverse problem. Here, we aim to implement an inversion scheme using the Jena inversion system and applying a prior flux error structure derived from a model-data residual analysis using high spatial and temporal resolution over a full year period in the European domain. We analyzed the performance of the inversion system with a synthetic experiment, in which the flux constraint is derived following the same residual analysis but applied to the model-model mismatch. The synthetic study showed a quite good agreement between posterior and "true" fluxes on European, country, annual and monthly scales. Posterior monthly and country-aggregated fluxes improved their correlation coefficient with the "known truth" by 7% compared to the prior estimates when compared to the reference, with a mean correlation of 0.92. The ratio of the SD between the posterior and reference and between the prior and reference was also reduced by 33% with a mean value of 1.15. We identified temporal and spatial scales on which the inversion system maximizes the derived information; monthly temporal scales at around 200km spatial resolution seem to maximize the information gain. |
BibTeX:
@article{Kountouris2018,
author = {Kountouris, Panagiotis and Gerbig, Christoph and Rödenbeck, Christian and Karstens, Ute and Frank Koch, Thomas and Heimann, Martin},
title = {Technical Note: Atmospheric CO2 inversions on the mesoscale using data-driven prior uncertainties: Methodology and system evaluation},
journal = {Atmospheric Chemistry and Physics},
publisher = {Copernicus GmbH},
year = {2018},
volume = {18},
number = {4},
pages = {3027--3045},
doi = {10.5194/acp-18-3027-2018}
}
|
| Kountouris P, Gerbig C, Rödenbeck C, Karstens U, Koch TF and Heimann M (2018), "Atmospheric CO2 inversions on the mesoscale using data-driven prior uncertainties: Quantification of the European terrestrial CO2 fluxes", Atmospheric Chemistry and Physics. Vol. 18(4), pp. 3047-3064. |
| Abstract: Optimized biogenic carbon fluxes for Europe were estimated from high-resolution regional-scale inversions, utilizing atmospheric CO2 measurements at 16 stations for the year 2007. Additional sensitivity tests with different data-driven error structures were performed. As the atmospheric network is rather sparse and consequently contains large spatial gaps, we use a priori biospheric fluxes to further constrain the inversions. The biospheric fluxes were simulated by the Vegetation Photosynthesis and Respiration Model (VPRM) at a resolution of 0.1° and optimized against eddy covariance data. Overall we estimate an a priori uncertainty of 0.54 GtC yr-1 related to the poor spatial representation between the biospheric model and the ecosystem sites. The sink estimated from the atmospheric inversions for the area of Europe (as represented in the model domain) ranges between 0.23 and 0.38 GtC yr-1 (0.39 and 0.71 GtC yr-1 up-scaled to geographical Europe). This is within the range of posterior flux uncertainty estimates of previous studies using ground-based observations. |
BibTeX:
@article{Kountouris2018a,
author = {Kountouris, Panagiotis and Gerbig, Christoph and Rödenbeck, Christian and Karstens, Ute and Koch, Thomas F and Heimann, Martin},
title = {Atmospheric CO2 inversions on the mesoscale using data-driven prior uncertainties: Quantification of the European terrestrial CO2 fluxes},
journal = {Atmospheric Chemistry and Physics},
year = {2018},
volume = {18},
number = {4},
pages = {3047--3064},
url = {https://www.atmos-chem-phys.net/18/3047/2018/},
doi = {10.5194/acp-18-3047-2018}
}
|
| Kovalets I, Avila R, Mölder M, Kovalets S and Lindroth A (2018), "Verification of a One-Dimensional Model of CO 2 Atmospheric Transport Inside and Above a Forest Canopy Using Observations at the Norunda Research Station", Boundary-Layer Meteorology., feb, 2018. Vol. 168(1), pp. 103-126. Springer Nature. |
| Abstract: A model of CO 2 atmospheric transport in vegetated canopies is tested against measurements of the flow, as well as CO 2 concentrations at the Norunda research station located inside a mixed pine–spruce forest. We present the results of simulations of wind-speed profiles and CO 2 concentrations inside and above the forest canopy with a one-dimensional model of profiles of the turbulent diffusion coefficient above the canopy accounting for the influence of the roughness sub-layer on turbulent mixing according to Harman and Finnigan (Boundary-Layer Meteorol 129:323–351, 2008; hereafter HF08). Different modelling approaches are used to define the turbulent exchange coefficients for momentum and concentration inside the canopy: (1) the modified HF08 theory—numerical solution of the momentum and concentration equations with a non-constant distribution of leaf area per unit volume; (2) empirical parametrization of the turbulent diffusion coefficient using empirical data concerning the vertical profiles of the Lagrangian time scale and root-mean-square deviation of the vertical velocity component. For neutral, daytime conditions, the second-order turbulence model is also used. The flexibility of the empirical model enables the best fit of the simulated CO 2 concentrations inside the canopy to the observations, with the results of simulations for daytime conditions inside the canopy layer only successful provided the respiration fluxes are properly considered. The application of the developed model for radiocarbon atmospheric transport released in the form of 14CO 2 is presented and discussed. |
BibTeX:
@article{Kovalets2018,
author = {Kovalets, Ivan and Avila, Rodolfo and Mölder, Meelis and Kovalets, Sophia and Lindroth, Anders},
title = {Verification of a One-Dimensional Model of CO 2 Atmospheric Transport Inside and Above a Forest Canopy Using Observations at the Norunda Research Station},
journal = {Boundary-Layer Meteorology},
publisher = {Springer Nature},
year = {2018},
volume = {168},
number = {1},
pages = {103--126},
doi = {10.1007/s10546-018-0340-z}
}
|
| Kuhn M, Lundin EJ, Giesler R, Johansson M and Karlsson J (2018), "Emissions from thaw ponds largely offset the carbon sink of northern permafrost wetlands", Scientific Reports., jun, 2018. Vol. 8(1) Springer Nature. |
| Abstract: Northern regions have received considerable attention not only because the effects of climate change are amplified at high latitudes but also because this region holds vast amounts of carbon (C) stored in permafrost. These carbon stocks are vulnerable to warming temperatures and increased permafrost thaw and the breakdown and release of soil C in the form of carbon dioxide (CO2) and methane (CH4). The majority of research has focused on quantifying and upscaling the effects of thaw on CO2 and CH4 emissions from terrestrial systems. However, small ponds formed in permafrost wetlands following thawing have been recognized as hotspots for C emissions. Here, we examined the importance of small ponds for C fluxes in two permafrost wetland ecosystems in northern Sweden. Detailed flux estimates of thaw ponds during the growing season show that ponds emit, on average (±SD), 279 ± 415 and 7 ± 11 mmol C m-2 d-1 of CO2 and CH4, respectively. Importantly, addition of pond emissions to the total C budget of the wetland decreases the C sink by ˜39%. Our results emphasize the need for integrated research linking C cycling on land and in water in order to make correct assessments of contemporary C balances. |
BibTeX:
@article{Kuhn2018,
author = {Kuhn, McKenzie and Lundin, Erik J and Giesler, Reiner and Johansson, Margareta and Karlsson, Jan},
title = {Emissions from thaw ponds largely offset the carbon sink of northern permafrost wetlands},
journal = {Scientific Reports},
publisher = {Springer Nature},
year = {2018},
volume = {8},
number = {1},
doi = {10.1038/s41598-018-27770-x}
}
|
| Kunz M, Lavric J, Gerbig C, Tans P, Neff D, Hummelgärd C, Martin H, Rödjegärd H, Wrenger B and Heimann M (2018), "COCAP: A carbon dioxide analyser for small unmanned aircraft systems", Atmospheric Measurement Techniques. Vol. 11(3), pp. 1833-1849. Copernicus GmbH. |
| Abstract: Unmanned aircraft systems (UASs) could provide a cost-effective way to close gaps in the observation of the carbon cycle, provided that small yet accurate analysers are available. We have developed a COmpact Carbon dioxide analyser for Airborne Platforms (COCAP). The accuracy of COCAP's carbon dioxide (CO2) measurements is ensured by calibration in an environmental chamber, regular calibration in the field and by chemical drying of sampled air. In addition, the package contains a lightweight thermal stabilisation system that reduces the influence of ambient temperature changes on the CO2 sensor by 2 orders of magnitude. During validation of COCAP's CO2 measurements in simulated and real flights we found a measurement error of 1.2gmolgmolg'1 or better with no indication of bias. COCAP is a self-contained package that has proven well suited for the operation on board small UASs. Besides carbon dioxide dry air mole fraction it also measures air temperature, humidity and pressure. We describe the measurement system and our calibration strategy in detail to support others in tapping the potential of UASs for atmospheric trace gas measurements. |
BibTeX:
@article{Kunz2018,
author = {Kunz, Martin and Lavric, Jost and Gerbig, Christoph and Tans, Pieter and Neff, Don and Hummelgärd, Christine and Martin, Hans and Rödjegärd, Henrik and Wrenger, Burkhard and Heimann, Martin},
title = {COCAP: A carbon dioxide analyser for small unmanned aircraft systems},
journal = {Atmospheric Measurement Techniques},
publisher = {Copernicus GmbH},
year = {2018},
volume = {11},
number = {3},
pages = {1833--1849},
doi = {10.5194/amt-11-1833-2018}
}
|
| Landschützer P, Gruber N, Bakker DC, Stemmler I and Six KD (2018), "Strengthening seasonal marine CO2 variations due to increasing atmospheric CO2", Nature Climate Change., feb, 2018. Vol. 8(2), pp. 146-150. Nature Publishing Group. |
| Abstract: The increase of atmospheric CO2 (ref. 1 ) has been predicted to impact the seasonal cycle of inorganic carbon in the global ocean 2,3, yet the observational evidence to verify this prediction has been missing. Here, using an observation-based product of the oceanic partial pressure of CO2 (p CO2) covering the past 34 years, we find that the winter-to-summer difference of the p CO2 has increased on average by 2.2 ± 0.4 μatm per decade from 1982 to 2015 poleward of 10° latitude. This is largely in agreement with the trend expected from thermodynamic considerations. Most of the increase stems from the seasonality of the drivers acting on an increasing oceanic p CO2 caused by the uptake of anthropogenic CO2 from the atmosphere. In the high latitudes, the concurrent ocean-acidification-induced changes in the buffer capacity of the ocean enhance this effect. This strengthening of the seasonal winter-to-summer difference pushes the global ocean towards critical thresholds earlier, inducing stress to ocean ecosystems and fisheries 4 . Our study provides observational evidence for this strengthening seasonal difference in the oceanic carbon cycle on a global scale, illustrating the inevitable consequences of anthropogenic CO2 emissions. |
BibTeX:
@article{Landschutzer2018,
author = {Landschützer, Peter and Gruber, Nicolas and Bakker, Dorothee C.E. and Stemmler, Irene and Six, Katharina D.},
title = {Strengthening seasonal marine CO2 variations due to increasing atmospheric CO2},
journal = {Nature Climate Change},
publisher = {Nature Publishing Group},
year = {2018},
volume = {8},
number = {2},
pages = {146--150},
url = {https://www.nature.com/articles/s41558-017-0057-x},
doi = {10.1038/s41558-017-0057-x}
}
|
| Laruelle GG, Cai WJ, Hu X, Gruber N, Mackenzie FT and Regnier P (2018), "Continental shelves as a variable but increasing global sink for atmospheric carbon dioxide", Nature Communications., jan, 2018. Vol. 9(1) Springer Nature. |
| Abstract: It has been speculated that the partial pressure of carbon dioxide (pCO2) in shelf waters may lag the rise in atmospheric CO2. Here, we show that this is the case across many shelf regions, implying a tendency for enhanced shelf uptake of atmospheric CO2. This result is based on analysis of long-term trends in the air-sea pCO2 gradient (ΔpCO2) using a global surface ocean pCO2 database spanning a period of up to 35 years. Using wintertime data only, we find that ΔpCO2 increased in 653 of the 825 0.5° cells for which a trend could be calculated, with 325 of these cells showing a significant increase in excess of +0.5 μatm yr-1 (p 0.05). Although noisier, the deseasonalized annual data suggest similar results. If this were a global trend, it would support the idea that shelves might have switched from a source to a sink of CO2 during the last century. |
BibTeX:
@article{Laruelle2018,
author = {Laruelle, Goulven G and Cai, Wei Jun and Hu, Xinping and Gruber, Nicolas and Mackenzie, Fred T and Regnier, Pierre},
title = {Continental shelves as a variable but increasing global sink for atmospheric carbon dioxide},
journal = {Nature Communications},
publisher = {Springer Nature},
year = {2018},
volume = {9},
number = {1},
doi = {10.1038/s41467-017-02738-z}
}
|
| Laudon H and Sponseller RA (2018), "How landscape organization and scale shape catchment hydrology and biogeochemistry: insights from a long-term catchment study", Wiley Interdisciplinary Reviews: Water., nov, 2018. Vol. 5(2), pp. e1265. Wiley. |
| Abstract: Catchment science plays a critical role in the protection of water resources in the face of ongoing changes in climate, long-range transport of air pollutants, and land use. Addressing these challenges, however, requires improved understand- ing of how, when, and where changes in water quantity and quality occur within river networks. To reach these goals, we must recognize how different catchment features are organized to regulate surface chemistry at multiple scales, from pro- cesses controlling headwaters, to the downstream mixing of water from multiple landscape sources and deep aquifers. Here we synthesize 30-years of hydrologi- cal and biogeochemical research from the Krycklan catchment study (KCS) in northern Sweden to demonstrate the benefits of coupling long-term monitoring with multi-scale research to advance our understanding of catchment function- ing across space and time. We show that the regulation of hydrological and bio- geochemical patterns in the KCS can be decomposed into four, hierarchically structured landscape features that include: (1) transmissivity and reactivity of dominant source layers within riparian soils, (2) spatial arrangement of groundwater input zones that govern water and solute fluxes at reach- to segment-scales, (3) landscape scale heterogeneity (forests, mires, and lakes) that generates unique biogeochemical signals downstream, and (4) broad-scale mixing of surface streams with deep groundwater contributions. While this set of features are perhaps specific to the study region, analogous hierarchical controls are likely to be wide- spread. Resolving these scale dependent processes is important for predicting how, when, and where different environmental changes may influence patterns of surface water chemistry within river networks. |
BibTeX:
@article{Laudon2018,
author = {Laudon, Hjalmar and Sponseller, Ryan A},
title = {How landscape organization and scale shape catchment hydrology and biogeochemistry: insights from a long-term catchment study},
journal = {Wiley Interdisciplinary Reviews: Water},
publisher = {Wiley},
year = {2018},
volume = {5},
number = {2},
pages = {e1265},
doi = {10.1002/wat2.1265}
}
|
| Ledesma JLJ, Futter MN, Blackburn M, Lidman F, Grabs T, Sponseller RA, Laudon H, Bishop KH and Köhler SJ (2018), "Towards an Improved Conceptualization of Riparian Zones in Boreal Forest Headwaters", Ecosystems., apr, 2018. Vol. 21(2), pp. 297-315. Springer Nature. |
| Abstract: The boreal ecoregion supports about one-third of the world's forest. Over 90% of boreal forest streams are found in headwaters, where terrestrial–aquatic interfaces are dominated by organic matter (OM)-rich riparian zones (RZs). Because these transition zones are key features controlling catchment biogeochemistry, appropriate RZ conceptualizations are needed to sustainably manage surface water quality in the face of a changing climate and increased demands for forest biomass. Here we present a simple, yet comprehensive, conceptualization of RZ function based on hydrological connectivity, biogeochemical processes, and spatial heterogeneity. We consider four dimensions of hydrological connectivity: (1) laterally along hillslopes, (2) longitudinally along the stream, (3) vertically down the riparian profile, and (4) temporally through event-based and seasonal changes in hydrology. Of particular importance is the vertical dimension, characterized by a ‘Dominant Source Layer' that has the highest contribution to solute and water fluxes to streams. In addition to serving as the primary source of OM to boreal streams, RZs shape water chemistry through two sets of OM-dependent biogeochemical processes: (1) transport and retention of OM-associated material and (2) redox-mediated transformations controlled by RZ water residence time and availability of labile OM. These processes can lead to both retention and release of pollutants. Variations in width, hydrological connectivity, and OM storage drive spatial heterogeneity in RZ biogeochemical function. This conceptualization provides a useful theoretical framework for environmental scientists and ecologically sustainable and economically effective forest management in the boreal region and elsewhere, where forest headwaters are dominated by low-gradient, OM-rich RZs. |
BibTeX:
@article{Ledesma2018,
author = {Ledesma, José L J and Futter, Martyn N and Blackburn, M and Lidman, Fredrik and Grabs, Thomas and Sponseller, Ryan A and Laudon, Hjalmar and Bishop, Kevin H and Köhler, Stephan J},
title = {Towards an Improved Conceptualization of Riparian Zones in Boreal Forest Headwaters},
journal = {Ecosystems},
publisher = {Springer Nature},
year = {2018},
volume = {21},
number = {2},
pages = {297--315},
doi = {10.1007/s10021-017-0149-5}
}
|
| Leip A, Skiba U, Vermeulen A and Thompson RL (2018), "A complete rethink is needed on how greenhouse gas emissions are quantified for national reporting", Atmospheric Environment., feb, 2018. Vol. 174, pp. 237-240. |
BibTeX:
@article{Leip2018,
author = {Leip, Adrian and Skiba, Ute and Vermeulen, Alex and Thompson, Rona L},
title = {A complete rethink is needed on how greenhouse gas emissions are quantified for national reporting},
journal = {Atmospheric Environment},
year = {2018},
volume = {174},
pages = {237--240},
url = {http://linkinghub.elsevier.com/retrieve/pii/S1352231017308300},
doi = {10.1016/j.atmosenv.2017.12.006}
}
|
| Le Quéré C, Andrew RM, Friedlingstein P, Sitch S, Pongratz J, Manning AC, Ivar Korsbakken J, Peters GP, Canadell JG, Jackson RB, Boden TA, Tans PP, Andrews OD, Arora VK, Bakker DCE, Barbero L, Becker M, Betts RA, Bopp L, Chevallier F, Chini LP, Ciais P, Cosca CE, Cross J, Currie K, Gasser T, Harris I, Hauck J, Haverd V, Houghton RA, Hunt CW, Hurtt G, Ilyina T, Jain AK, Kato E, Kautz M, Keeling RF, Klein Goldewijk K, Körtzinger A, Landschützer P, Lefèvre N, Lenton A, Lienert S, Lima I, Lombardozzi D, Metzl N, Millero F, Monteiro PMS, Munro DR, Nabel JEMS, Nakaoka SI, Nojiri Y, Antonio Padin X, Peregon A, Pfeil B, Pierrot D, Poulter B, Rehder G, Reimer J, Rödenbeck C, Schwinger J, Séférian R, Skjelvan I, Stocker BD, Tian H, Tilbrook B, Tubiello FN, Laan-Luijkx IT, Werf GR, Van Heuven S, Viovy N, Vuichard N, Walker AP, Watson AJ, Wiltshire AJ, Zaehle S and Zhu D (2018), "Global Carbon Budget 2017", Earth System Science Data., mar, 2018. Vol. 10(1), pp. 405-448. Copernicus GmbH. |
| Abstract: Accurate assessment of anthropogenic carbon dioxide (CO2) emissions and their redistribution among the atmosphere, ocean, and terrestrial biosphere-the "global carbon budget"-is important to better understand the global carbon cycle, support the development of climate policies, and project future climate change. Here we describe data sets and methodology to quantify the five major components of the global carbon budget and their uncertainties. CO2 emissions from fossil fuels and industry (EFF) are based on energy statistics and cement production data, respectively, while emissions from land-use change (ELUC), mainly deforestation, are based on land-cover change data and bookkeeping models. The global atmospheric CO2 concentration is measured directly and its rate of growth (GATM) is computed from the annual changes in concentration. The ocean CO2 sink (SOCEAN) and terrestrial CO2 sink (SLAND) are estimated with global process models constrained by observations. The resulting carbon budget imbalance (BIM), the difference between the estimated total emissions and the estimated changes in the atmosphere, ocean, and terrestrial biosphere, is a measure of imperfect data and understanding of the contemporary carbon cycle. All uncertainties are reported as ±1δ. For the last decade available (2007-2016), EFF was 9.4±0.5 GtC yr-1, ELUC 1.3±0.7 GtC yr-1, GATM 4.7±0.1 GtC yr-1, SOCEAN 2.4±0.5 GtC yr-1, and SLAND 3.0±0.8 GtC yr-1, with a budget imbalance BIM of 0.6 GtC yr-1 indicating overestimated emissions and/or underestimated sinks. For year 2016 alone, the growth in EFF was approximately zero and emissions remained at 9.9±0.5 GtC yr-1. Also for 2016, ELUC was 1.3±0.7 GtC yr-1, GATM was 6.1±0.2 GtC yr-1, SOCEAN was 2.6±0.5 GtC yr-1, and SLAND was 2.7±1.0 GtC yr-1, with a small BIM of-0.3 GtC. GATM continued to be higher in 2016 compared to the past decade (2007-2016), reflecting in part the high fossil emissions and the small SLAND consistent with El Ninbackslash˜o conditions. The global atmospheric CO2 concentration reached 402.8±0.1 ppm averaged over 2016. For 2017, preliminary data for the first 6-9 months indicate a renewed growth in EFF of C2.0% (range of 0.8 to 3.0 %) based on national emissions projections for China, USA, and India, and projections of gross domestic product (GDP) corrected for recent changes in the carbon intensity of the economy for the rest of the world. This living data update documents changes in the methods and data sets used in this new global carbon budget compared with previous publications of this data set (Le Quéré et al., 2016, 2015b, a, 2014, 2013). All results presented here can be downloaded from https://doi.org/10.18160/GCP-2017 (GCP, 2017). |
BibTeX:
@article{LeQuere2018,
author = {Le Quéré, Corinne and Andrew, Robbie M and Friedlingstein, Pierre and Sitch, Stephen and Pongratz, Julia and Manning, Andrew C and Ivar Korsbakken, Jan and Peters, Glen P and Canadell, Josep G and Jackson, Robert B and Boden, Thomas A and Tans, Pieter P and Andrews, Oliver D and Arora, Vivek K and Bakker, Dorothee C E and Barbero, Leticia and Becker, Meike and Betts, Richard A and Bopp, Laurent and Chevallier, Frédéric and Chini, Louise P and Ciais, Philippe and Cosca, Catherine E and Cross, Jessica and Currie, Kim and Gasser, Thomas and Harris, Ian and Hauck, Judith and Haverd, Vanessa and Houghton, Richard A and Hunt, Christopher W and Hurtt, George and Ilyina, Tatiana and Jain, Atul K and Kato, Etsushi and Kautz, Markus and Keeling, Ralph F and Klein Goldewijk, Kees and Körtzinger, Arne and Landschützer, Peter and Lefèvre, Nathalie and Lenton, Andrew and Lienert, Sebastian and Lima, Ivan and Lombardozzi, Danica and Metzl, Nicolas and Millero, Frank and Monteiro, Pedro M S and Munro, David R and Nabel, Julia E M S and Nakaoka, Shin Ichiro and Nojiri, Yukihiro and Antonio Padin, X and Peregon, Anna and Pfeil, Benjamin and Pierrot, Denis and Poulter, Benjamin and Rehder, Gregor and Reimer, Janet and Rödenbeck, Christian and Schwinger, Jörg and Séférian, Roland and Skjelvan, Ingunn and Stocker, Benjamin D and Tian, Hanqin and Tilbrook, Bronte and Tubiello, Francesco N and Laan-Luijkx, Ingrid T.Vander and Werf, Guido R.Vander and Van Heuven, Steven and Viovy, Nicolas and Vuichard, Nicolas and Walker, Anthony P and Watson, Andrew J and Wiltshire, Andrew J and Zaehle, Sönke and Zhu, Dan},
title = {Global Carbon Budget 2017},
journal = {Earth System Science Data},
publisher = {Copernicus GmbH},
year = {2018},
volume = {10},
number = {1},
pages = {405--448},
url = {https://doi.org/10.5194/essd-10-405-2018 https://www.earth-syst-sci-data.net/10/405/2018/},
doi = {10.5194/essd-10-405-2018}
}
|
| Leufen LH and Schädler G (2018), "Calculating the turbulent fluxes in the atmospheric surface layer with neural networks", Geoscientific Model Development Discussions., nov, 2018. , pp. 1-22. Copernicus GmbH. |
| Abstract: pstrongAbstract./strong The turbulent fluxes of momentum, heat and water vapour link the Earth's surface with the atmosphere. The correct modelling of the flux interactions between these two systems with very different time scales is therefore vital for climate (resp. Earth system) models. Conventionally, these fluxes are modelled using Monin&ndash;Obukhov similarity theory (MOST) with stability functions derived from a small number of field experiments; this results in a range of formulations of these functions and thus also in the flux calculations; furthermore, the underlying equations are non-linear and have to be solved iteratively at each time step of the model. For these reasons, we tried here a different approach, namely using an artificial neural network (ANN) to calculate the fluxes resp. the scaling quantities iu/isub*/sub and i&theta;/isub*/sub, thus avoiding explicit formulas for the stability functions. The network was trained and validated with multi-year datasets from seven grassland, forest and wetland sites worldwide using the Broyden&ndash;Fletcher&ndash;Goldfarb&ndash;Shanno (BFGS) quasi-Newton backpropagation algorithm and six-fold cross validation. Extensive sensitivity tests showed that an ANN with six input variables and one hidden layer gave results comparable to (and in some cases even slightly better than) the standard method. Similar satisfying results were obtained when the ANN routine was implemented in a one-dimensional stand alone land surface model (LSM), opening the way to implementation in three-dimensional climate models. In case of the one-dimensional LSM, no CPU time was saved when using the ANN version, since the small time step of the standard version required only one iteration in most cases. This could be different in models with longer time steps, e.g. global climate models./p |
BibTeX:
@article{Leufen2018,
author = {Leufen, Lukas Hubert and Schädler, Gerd},
title = {Calculating the turbulent fluxes in the atmospheric surface layer with neural networks},
journal = {Geoscientific Model Development Discussions},
publisher = {Copernicus GmbH},
year = {2018},
pages = {1--22},
doi = {10.5194/gmd-2018-263}
}
|
| Li H and Ilyina T (2018), "Current and Future Decadal Trends in the Oceanic Carbon Uptake Are Dominated by Internal Variability", Geophysical Research Letters., jan, 2018. Vol. 45(2), pp. 916-925. American Geophysical Union (AGU). |
| Abstract: We investigate the internal decadal variability of the ocean carbon uptake using 100 ensemble simulations based on the Max Planck Institute Earth system model (MPI-ESM). We find that on decadal time scales, internal variability (ensemble spread) is as large as the forced temporal variability (ensemble mean), and the largest internal variability is found in major carbon sink regions, that is, the 50–65°S band of the Southern Ocean, the North Pacific, and the North Atlantic. The MPI-ESM ensemble produces both positive and negative 10 year trends in the ocean carbon uptake in agreement with observational estimates. Negative decadal trends are projected to occur in the future under RCP4.5 scenario. Due to the large internal variability, the Southern Ocean and the North Pacific require the most ensemble members (more than 53 and 46, respectively) to reproduce the forced decadal trends. This number increases up to 79 in future decades as CO2 emission trajectory changes. |
BibTeX:
@article{Li2018,
author = {Li, Hongmei and Ilyina, Tatiana},
title = {Current and Future Decadal Trends in the Oceanic Carbon Uptake Are Dominated by Internal Variability},
journal = {Geophysical Research Letters},
publisher = {American Geophysical Union (AGU)},
year = {2018},
volume = {45},
number = {2},
pages = {916--925},
doi = {10.1002/2017GL075370}
}
|
| Lin C, Gentine P, Huang Y, Guan K, Kimm H and Zhou S (2018), "Diel ecosystem conductance response to vapor pressure deficit is suboptimal and independent of soil moisture", Agricultural and Forest Meteorology., mar, 2018. Vol. 250-251, pp. 24-34. Elsevier B.V.. |
| Abstract: Ecosystem conductance, which describes ecosystem regulation of water and carbon exchange and links plant functions with the environment, is a critical component in ecosystem and earth system models. However, the behaviors of ecosystem conductance at the ecosystem level and its responses to environmental conditions are still largely unclear. In this study, half-hourly data of 77 eddy-covariance sites from the FLUXNET2015 dataset were used to compare four ecosystem conductance models at the ecosystem level and determine the most consistent vapor pressure deficit (VPD) dependence across plant functional types for varying soil moisture stress levels at the subdaily time scale. We used leaf-level VPD (VPDl), a better indicator of atmospheric dryness at the leaf level, for canopy-level analysis instead of measured atmospheric VPD. Detection of the best-fitted exponent of VPDl indicates that ecosystem conductance responds to VPD between optimality-theory (i.e., VPD−0.5 dependence) and Leuning's (i.e., VPD−1 dependence) models. Accounting for different soil moisture stress levels only affected minimum ecosystem conductance and did not affect the exponent and factor of VPDl, indicating limited diurnal soil moisture-VPDl interactions. These results indicate limited interaction between xylem and stomata at subdaily time scales and that soil moisture effects can be simplified as a regulation of minimum (soil plus canopy) conductance. |
BibTeX:
@article{Lin2018,
author = {Lin, Changjie and Gentine, Pierre and Huang, Yuefei and Guan, Kaiyu and Kimm, Hyungsuk and Zhou, Sha},
title = {Diel ecosystem conductance response to vapor pressure deficit is suboptimal and independent of soil moisture},
journal = {Agricultural and Forest Meteorology},
publisher = {Elsevier B.V.},
year = {2018},
volume = {250-251},
pages = {24--34},
doi = {10.1016/j.agrformet.2017.12.078}
}
|
| Lindroth A, Holst J, Heliasz M, Vestin P, Lagergren F, Biermann T, Cai Z and Mölder M (2018), "Effects of low thinning on carbon dioxide fluxes in a mixed hemiboreal forest", Agricultural and Forest Meteorology., nov, 2018. Vol. 262, pp. 59-70. Elsevier BV. |
| Abstract: We used eddy-covariance (EC) measurements of net ecosystem exchange (NEE) above canopy to assess the effects of thinning on CO2 fluxes at the ICOS Sweden site Norunda in central Sweden. This forest site consists of mixed pine and spruce stands approx. 100 years old. The thinning during late autumn 2008, performed in a semi-circle from the mast extending 200 m outwards harvested about 25% of the volume. Measurements were conducted from 2007 to 2016 and thus, above canopy fluxes were recorded two years before and eight years after the thinning. We also measured the net flux from the forest floor with automatic chambers in three locations and with below-canopy EC during shorter periods before and after thinning. The chamber measurements during the first part of the growing season after thinning showed strongly enhanced effluxes in the order of 150–250% of the pre-thinning values. These chamber measurements were made on drier places within the thinned area because waterlogging made it impossible to use chambers at all available locations. The below-canopy EC measurements, which had a larger footprint as compared to the chambers, showed less enhanced fluxes (in the order of 35%). This footprint included also wetter areas. The above canopy EC measurements showed a reduction of daytime net flux by approx. 30% during the first summer after thinning. The median growing season fluxes then slowly increased but were not restored to the pre-thinning levels eight years after thinning. There was also a small decrease in growing season ecosystem respiration during the first summer after thinning and with a continued decreasing trend over time. It was concluded that this decrease in respiration was caused by successively decreasing decomposition of coarse organic substrates resulting from the thinning. This respiration decrease over time persisted even under gradual biomass increase, which otherwise would indicate increasing autotrophic respiration. The light-response and respiration models fitted to all data did not show any trends in daytime or nighttime fluxes so the conclusion was that the trends were caused by the thinning and not because of trends in meteorological drivers. The annual values contrasted with the summertime results since only a minor effect was observed on the annual NEE. Both ecosystem respiration and gross primary productivity were reduced as an effect of thinning. We explained the different summertime versus annual effects to be caused by the decrease in ecosystem respiration since respiration is dominating the NEE during non-growing season periods when photosynthesis is very low or even zero. Our results are a strong indication that the NEE of a forest could be maintained over time with harvesting practices that avoids clear-cutting and thereby enhance the total carbon uptake of forests. |
BibTeX:
@article{Lindroth2018,
author = {Lindroth, Anders and Holst, Jutta and Heliasz, Michal and Vestin, Patrik and Lagergren, Fredrik and Biermann, Tobias and Cai, Zhanzhang and Mölder, Meelis},
title = {Effects of low thinning on carbon dioxide fluxes in a mixed hemiboreal forest},
journal = {Agricultural and Forest Meteorology},
publisher = {Elsevier BV},
year = {2018},
volume = {262},
pages = {59--70},
doi = {10.1016/j.agrformet.2018.06.021}
}
|
| López-Ballesteros A, Oyonarte C, Kowalski AS, Serrano-Ortiz P, Sánchez-Cañete EP, Moya MR and Domingo F (2018), "Can land degradation drive differences in the C exchange of two similar semiarid ecosystems?", Biogeosciences., jan, 2018. Vol. 15(1), pp. 263-278. Copernicus GmbH. |
| Abstract: Currently, drylands occupy more than one-third of the global terrestrial surface and are recognized as areas vulnerable to land degradation. The concept of land degradation stems from the loss of an ecosystem's biological productivity due to long-term loss of natural vegetation or depletion of soil nutrients. Drylands' key role in the global carbon (C) balance has been recently demonstrated, but the effects of land degradation on C sequestration by these ecosystems still need to be investigated. In the present study, we compared net C and water vapor fluxes, together with satellite, meteorological and vadose zone (CO2, water content and temperature) measurements, between two nearby (∼23 km) experimental sites representing "natural" (i.e., site of reference) and "degraded" grazed semiarid grasslands. We utilized data acquired over 6 years from two eddy covariance stations located in southeastern Spain with highly variable precipitation magnitude and distribution. Results show a striking difference in the annual C balances with an average net CO2 exchange of 196±40 (C release) and-23±2 gCm-2 yr-1 (C fixation) for the degraded and natural sites, respectively. At the seasonal scale, differing patterns in net CO2 fluxes were detected over both growing and dry seasons. As expected, during the growing seasons, greater net C uptake over longer periods was observed at the natural site. However, a much greater net C release, probably derived from subterranean ventilation, was measured at the degraded site during drought periods. After subtracting the nonbiological CO2 flux from net CO2 exchange, flux partitioning results point out that, during the 6 years of study, gross primary production, ecosystem respiration and water use efficiency were, on average, 9, 2 and 10 times higher, respectively, at the natural site versus the degraded site. We also tested differences in all monitored meteorological and soil variables and CO2 at 1.50m belowground was the variable showing the greatest intersite difference, with ∼1000 ppm higher at the degraded site. Thus, we believe that subterranean ventilation of this vadose zone CO2, previously observed at both sites, partly drives the differences in C dynamics between them, especially during the dry season. It may be due to enhanced subsoil-atmosphere interconnectivity at the degraded site. |
BibTeX:
@article{Lopez-Ballesteros2018,
author = {López-Ballesteros, Ana and Oyonarte, Cecilio and Kowalski, Andrew S. and Serrano-Ortiz, Penélope and Sánchez-Cañete, Enrique P. and Moya, M. Rosario and Domingo, Francisco},
title = {Can land degradation drive differences in the C exchange of two similar semiarid ecosystems?},
journal = {Biogeosciences},
publisher = {Copernicus GmbH},
year = {2018},
volume = {15},
number = {1},
pages = {263--278},
doi = {10.5194/bg-15-263-2018}
}
|
| López-Ballesteros A, Beck J, Bombelli A, Grieco E, Lorencová EK, Merbold L, Brümmer C, Hugo W, Scholes R, VačkáÅ™ D, Vermeulen A, Acosta M, Butterbach-Bahl K, Helmschrot J, Kim DG, Jones M, Jorch V, Pavelka M, Skjelvan I and Saunders M (2018), "Towards a feasible and representative pan-African research infrastructure network for GHG observations", Environmental Research Letters., jul, 2018. Vol. 13(8) |
| Abstract: There is currently a lack of representative, systematic and harmonised greenhouse gas (GHG) observations covering the variety of natural and human-altered biomes that occur in Africa. This impedes the long-term assessment of the drivers of climate change, in addition to their impacts and feedback loops at the continental scale, but also limits our understanding of the contribution of the African continent to the global carbon (C) cycle. Given the current and projected transformation of socio-economic conditions in Africa (i.e. the increasing trend of urbanisation and population growth) and the adverse impacts of climate change, the development of a GHG research infrastructure (RI) is needed to support the design of suitable mitigation and adaptation strategies required to assure food, fuel, nutrition and economic security for the African population. This paper presents the initial results of the EU-African SEACRIFOG project, which aims to design a GHG observation RI for Africa. The first stages of this project included the identification and engagement of key stakeholders, the definition of the conceptual monitoring framework and an assessment of existing infrastructural capacity. Feedback from stakeholder sectors was obtained through three Stakeholder Consultation Workshops held in Kenya, Ghana and Zambia. Main concerns identified were data quality and accessibility, the need for capacity building and networking among the scientific community, and adaptation to climate change, which was confirmed to be a priority for Africa. This feedback in addition to input from experts in the atmospheric, terrestrial and oceanic thematic areas, facilitated the selection of a set of 'essential variables' that need to be measured in the future environmental RI. An inventory of 47 existing and planned networks across the continent allowed for an assessment of the current RIs needs and gaps in Africa. Overall, the development of a harmonised and standardised pan-African RI will serve to address the continent's primary societal and scientific challenges through a potential cross-domain synergy among existing and planned networks at regional, continental and global scales. |
BibTeX:
@article{Lopez-Ballesteros2018a,
author = {López-Ballesteros, Ana and Beck, Johannes and Bombelli, Antonio and Grieco, Elisa and Lorencová, Eliška Krkoška and Merbold, Lutz and Brümmer, Christian and Hugo, Wim and Scholes, Robert and VačkáÅ™, David and Vermeulen, Alex and Acosta, Manuel and Butterbach-Bahl, Klaus and Helmschrot, Jörg and Kim, Dong Gill and Jones, Michael and Jorch, Veronika and Pavelka, Marian and Skjelvan, Ingunn and Saunders, Matthew},
title = {Towards a feasible and representative pan-African research infrastructure network for GHG observations},
journal = {Environmental Research Letters},
year = {2018},
volume = {13},
number = {8},
url = {http://iopscience.iop.org/article/10.1088/1748-9326/aad66c},
doi = {10.1088/1748-9326/aad66c}
}
|
| López-Blanco E, Lund M, Christensen TR, Tamstorf MP, Smallman TL, Slevin D, Westergaard-Nielsen A, Hansen BU, Abermann J and Williams M (2018), "Plant Traits are Key Determinants in Buffering the Meteorological Sensitivity of Net Carbon Exchanges of Arctic Tundra", Journal of Geophysical Research: Biogeosciences., sep, 2018. Vol. 123(9), pp. 2675-2694. American Geophysical Union (AGU). |
| Abstract: The climate sensitivity of carbon (C) cycling in Arctic terrestrial ecosystems is a major unknown in the Earth system. There is a lack of knowledge about the mechanisms that drive the interactions between photosynthesis, respiration, and changes in C stocks across full annual cycles in Arctic tundra. We use a calibrated and validated model (soil-plant-atmosphere; SPA) to estimate net ecosystem exchange (NEE), gross primary production (GPP), ecosystem respiration (Reco), and internal C processing across eight full years. SPA's carbon flux estimates are validated with observational data obtained from the Greenland Ecosystem Monitoring program in West Greenland tundra. Overall, the model explained 73%, 73%, and 50% of the variance in NEE, GPP, and Reco, respectively, and 85% of the plant greenness variation. Flux data highlighted the insensitivity of growing season NEE to interannual meteorological variability, due to compensatory responses of photosynthesis and ecosystem respiration. In this modelling study, we show that this NEE buffering is the case also for full annual cycles. We show through a sensitivity analysis that plant traits related to nitrogen are likely key determinants in the compensatory response, through simulated links to photosynthesis and plant respiration. Interestingly, we found a similar temperature sensitivity of the trait-flux couplings for GPP and Reco, suggesting that plant traits drive the stabilization of NEE. Further, model analysis indicated that wintertime periods decreased the C sink by 60%, mostly driven by litter heterotrophic respiration. This result emphasizes the importance of wintertime periods and allows a more comprehensive understanding of full annual C dynamics. |
BibTeX:
@article{Lopez-Blanco2018,
author = {López-Blanco, Efrén and Lund, Magnus and Christensen, Torben R and Tamstorf, Mikkel P and Smallman, Thomas L and Slevin, Darren and Westergaard-Nielsen, Andreas and Hansen, Birger U and Abermann, Jakob and Williams, Mathew},
title = {Plant Traits are Key Determinants in Buffering the Meteorological Sensitivity of Net Carbon Exchanges of Arctic Tundra},
journal = {Journal of Geophysical Research: Biogeosciences},
publisher = {American Geophysical Union (AGU)},
year = {2018},
volume = {123},
number = {9},
pages = {2675--2694},
doi = {10.1029/2018JG004386}
}
|
| Loustau D, Altimir N, Barbaste M, Gielen B, Jiménez SM, Klumpp K, Linder S, Matteucci G, Merbold L, De Beek MO, Soulé P, Thimonier A, Vincke C and Waldner P (2018), "Sampling and collecting foliage elements for the determination of the foliar nutrients in ICOS ecosystem stations", International Agrophysics., dec, 2018. Vol. 32(4), pp. 665-676. |
| Abstract: The nutritional status of plant canopies in terms of nutrients (C, N, P, K, Ca, Mg, Mn, Fe, Cu, Zn) exerts a strong influence on the carbon cycle and energy balance of terrestrial ecosystems. Therefore, in order to account for the spatial and temporal variations in nutritional status of the plant species composing the canopy, we detail the methodology applied to achieve consistent time-series of leaf mass to area ratio and nutrient content of the foliage within the footprint of the Integrated Carbon Observation System Ecosystem stations. The guidelines and defi-nitions apply to most terrestrial ecosystems. |
BibTeX:
@article{Loustau2018,
author = {Loustau, Denis and Altimir, Nuria and Barbaste, Mireille and Gielen, Bert and Jiménez, Sara Maraʼnón and Klumpp, Katja and Linder, Sune and Matteucci, Giorgio and Merbold, Lutz and De Beek, Marteen Op and Soulé, Patrice and Thimonier, Anne and Vincke, Caroline and Waldner, Peter},
title = {Sampling and collecting foliage elements for the determination of the foliar nutrients in ICOS ecosystem stations},
journal = {International Agrophysics},
year = {2018},
volume = {32},
number = {4},
pages = {665--676},
url = {https://content.sciendo.com/view/journals/intag/32/4/article-p665.xml},
doi = {10.1515/intag-2017-0038}
}
|
| Lucas-Moffat AM, Huth V, Augustin J, Brümmer C, Herbst M and Kutsch WL (2018), "Towards pairing plot and field scale measurements in managed ecosystems: Using eddy covariance to cross-validate CO2 fluxes modeled from manual chamber campaigns", Agricultural and Forest Meteorology. Vol. 256-257, pp. 362-378. |
| Abstract: Manual chamber campaigns are a versatile method to study management effects at plot scale in factorial experiments. The eddy covariance technique has the advantage of continuous measurements but it requires large homogeneous areas. By pairing the two techniques, the uncertainties of the CO2 fluxes modeled from the chamber campaigns can be quantified through cross-validation with the continuous eddy covariance data. This is particularly important in managed ecosystems with high temporal dynamics. At our agricultural site in Northern Germany, we installed both techniques in parallel for two crop cultivation periods, winter oilseed rape in 2012/13 and winter wheat in 2013/14. First, we compared measured net CO2 exchange (NEE) obtained from the closed chambers with the corresponding half-hourly fluxes from the eddy covariance technique. Despite largely different footprints and measurement windows, the measured fluxes were highly correlated (R2 = 0.83 in 2012/13 und R2 = 0.93 in 2013/14). Interpolating from chamber campaigns to the entire measurement period is commonly performed by modeling half-hourly fluxes based on non-linear regressions for photosynthesis and respiration. These modeled fluxes were compared to the fluxes measured with the eddy covariance technique. To understand the observed differences, we performed five modeling setups: 1) Non-linear regressions based algorithm with default settings, 2) non-linear regressions with expert settings, 3) purely empirical modeling with artificial neural networks, 4) cross-validation using eddy covariance measurements as campaign fluxes on original campaign days, and 5) cross-validation on weekly campaign days. The modeled seasonal course of daily NEE agreed well with the eddy covariance measurements for all five setups (R2 from 0.77 to 0.92) but with periods of systematic offsets in the range of ±5 g C mâˆ'2 dayâˆ'1. Though the pattern of the offsets was different, all setups had comparable root mean square errors around 1.5 g C mâˆ'2 day-1 despite having opposite limitations. Cross-validation by simulating campaigns with artificial gaps from the continuous eddy dataset in setup 4) and 5) resulted in bias errors of around 0.4 g C mâˆ'2 dayâˆ'1. This translates to a total uncertainty on annual NEE of around ±175 g C mâˆ'2 aâˆ'1 purely from the modeling, i.e. the interpolation in-between campaigns. By leave-one-campaign-out scenarios, the sensitivity to single campaigns was examined. The mean effect on the annual total was higher for setup 4 (30 g C mâˆ'2) with the original number of campaigns than for setup 5 (9 g C mâˆ'2) with four times more campaigns. Furthermore, the interpolation in-between the campaigns can be improved by deriving vegetation proxies from the continuous eddy covariance measurements, such as an effective green area index (GAI) presented herein. |
BibTeX:
@article{Lucas-Moffat2018,
author = {Lucas-Moffat, Antje M and Huth, Vytas and Augustin, Jürgen and Brümmer, Christian and Herbst, Mathias and Kutsch, Werner L},
title = {Towards pairing plot and field scale measurements in managed ecosystems: Using eddy covariance to cross-validate CO2 fluxes modeled from manual chamber campaigns},
journal = {Agricultural and Forest Meteorology},
year = {2018},
volume = {256-257},
pages = {362--378},
doi = {10.1016/j.agrformet.2018.01.023}
}
|
| Lund M (2018), "Uncovering the unknown - Climate interactions in a changing arctic tundra", Environmental Research Letters., jun, 2018. Vol. 13(6), pp. 61001. IOP Publishing. |
BibTeX:
@article{Lund2018,
author = {Lund, Magnus},
title = {Uncovering the unknown - Climate interactions in a changing arctic tundra},
journal = {Environmental Research Letters},
publisher = {IOP Publishing},
year = {2018},
volume = {13},
number = {6},
pages = {61001},
doi = {10.1088/1748-9326/aac63f}
}
|
| Lundström J, Öhman K and Laudon H (2018), "Comparing buffer zone alternatives in forest planning using a decision support system", Scandinavian Journal of Forest Research., feb, 2018. Vol. 33(5), pp. 493-501. Informa UK Limited. |
| Abstract: Increased awareness of the connection between forest management activities and negative effects on water quality means that forestry needs to consider its potential impact on the aquatic environment when planning operations. Protective buffer zones are effective, but their design can vary. To be able to incorporate up-to-date scientific theory into practical applications easy-to-use planning tools are needed. In this study, we evaluate different buffer zone alternatives by using the freely available decision support system Heureka. The consequences on both economic and ecological values over a time period of 100 years were evaluated for two buffer zone approaches and three management alternatives within the buffer zones. Results indicated that there is a trade-off between economic and ecological values when managing the buffer zones. To be able to perform the analyses within Heureka, a new tool was developed. This software development provides access to a forest planning tool that can help improve nature conservation. |
BibTeX:
@article{Lundstrom2018,
author = {Lundström, Johanna and Öhman, Karin and Laudon, Hjalmar},
title = {Comparing buffer zone alternatives in forest planning using a decision support system},
journal = {Scandinavian Journal of Forest Research},
publisher = {Informa UK Limited},
year = {2018},
volume = {33},
number = {5},
pages = {493--501},
doi = {10.1080/02827581.2018.1441900}
}
|
| Malhotra A, Moore TR, Limpens J and Roulet NT (2018), "Post-thaw variability in litter decomposition best explained by microtopography at an ice-rich permafrost peatland", Arctic, Antarctic, and Alpine Research., jan, 2018. Vol. 50(1), pp. e1415622. Informa UK Limited. |
| Abstract: Litter decomposition, a key process by which recently fixed carbon is lost from ecosystems, is a function of environmental conditions and plant community characteristics. In ice-rich peatlands, permafrost thaw introduces high variability in both abiotic and biotic factors, both of which may affect litter decomposition rates in different ways. Can the existing conceptual frameworks of litter decomposition and its controls be applied across a structurally heterogeneous thaw gradient? We investigated the variability in litter decomposition and its predictors at the Stordalen subarctic peatland in northern Sweden. We measured in situ decomposition of representative litter and environments using litter bags throughout two years. We found highly variable litter decomposition rates with turnover times ranging from five months to four years. Surface elevation was a strong correlate of litter decomposition across the landscape, likely as it integrates multiple environmental and plant community changes brought about by thaw. There was faster decomposition but also more mass remaining after two years in thawed areas relative to permafrost areas, suggesting faster initial loss of carbon but more storage into the slow-decomposing carbon pool. Our results highlight mechanisms and predictors of carbon cycle changes in ice-rich peatlands following permafrost thaw. |
BibTeX:
@article{Malhotra2018,
author = {Malhotra, Avni and Moore, Tim R and Limpens, Juul and Roulet, Nigel T},
title = {Post-thaw variability in litter decomposition best explained by microtopography at an ice-rich permafrost peatland},
journal = {Arctic, Antarctic, and Alpine Research},
publisher = {Informa UK Limited},
year = {2018},
volume = {50},
number = {1},
pages = {e1415622},
doi = {10.1080/15230430.2017.1415622}
}
|
| Martínez B, Sanchez-Ruiz S, Gilabert MA, Moreno A, Campos-Taberner M, García-Haro FJ, Trigo IF, Aurela M, Brümmer C, Carrara A, De Ligne A, Gianelle D, Grünwald T, Limousin JM, Lohila A, Mammarella I, Sottocornola M, Steinbrecher R and Tagesson T (2018), "Retrieval of daily gross primary production over Europe and Africa from an ensemble of SEVIRI/MSG products", International Journal of Applied Earth Observation and Geoinformation., mar, 2018. Vol. 65, pp. 124-136. Elsevier BV. |
| Abstract: The main goal of this paper is to derive a method for a daily gross primary production (GPP) product over Europe and Africa taking the full advantage of the SEVIRI/MSG satellite products from the European Organization for the Exploitation of Meteorological Satellites (EUMETSAT) sensors delivered from the Satellite Application Facility for Land Surface Analysis (LSA SAF) system. Special attention is paid to model the daily GPP response from an optimized Montheith's light use efficiency model under dry conditions by controlling water shortage limitations from the actual evapotranspiration and the potential evapotranspiration (PET). The PET was parameterized using the mean daily air temperature at 2 m (Ta) from ERA-Interim data. The GPP product (MSG GPP) was produced for 2012 and assessed by direct site-level comparison with GPP from eddy covariance data (EC GPP). MSG GPP presents relative bias errors lower than 40% for the most forest vegetation types with a high agreement (r 0.7) when compared with EC GPP. For drylands, MSG GPP reproduces the seasonal variations related to water limitation in a good agreement with site level GPP estimates (RMSE = 2.11 g mâˆ'2 dayâˆ'1; MBE = âˆ'0.63 g mâˆ'2 dayâˆ'1), especially for the dry season. A consistency analysis against other GPP satellite products (MOD17A2 and FLUXCOM) reveals a high consistency among products (RMSD 1.5 g mâˆ'2 dayâˆ'1) over Europe, North and South Africa. The major GPP disagreement arises over moist biomes in central Africa (RMSD 3.0 g mâˆ'2 dayâˆ'1) and over dry biomes with MSG GPP estimates lower than FLUXCOM (MBD up to âˆ'3.0 g mâˆ'2 dayâˆ'1). This newly derived product has the potential for analysing spatial patterns and temporal dynamics of GPP at the MSG spatial resolutions on a daily basis allowing to better capture the GPP dynamics and magnitude. |
BibTeX:
@article{Martinez2018,
author = {Martínez, B and Sanchez-Ruiz, S and Gilabert, M A and Moreno, A and Campos-Taberner, M and García-Haro, F J and Trigo, I F and Aurela, M and Brümmer, C and Carrara, A and De Ligne, A and Gianelle, D and Grünwald, T and Limousin, J M and Lohila, A and Mammarella, I and Sottocornola, M and Steinbrecher, R and Tagesson, T},
title = {Retrieval of daily gross primary production over Europe and Africa from an ensemble of SEVIRI/MSG products},
journal = {International Journal of Applied Earth Observation and Geoinformation},
publisher = {Elsevier BV},
year = {2018},
volume = {65},
pages = {124--136},
url = {https://doi.org/10.1016/j.jag.2017.10.011 http://linkinghub.elsevier.com/retrieve/pii/S0303243417302301},
doi = {10.1016/j.jag.2017.10.011}
}
|
| Mauder M and Zeeman MJ (2018), "Field intercomparison of prevailing sonic anemometers", Atmospheric Measurement Techniques., jan, 2018. Vol. 11(1), pp. 249-263. |
| Abstract: Three-dimensional sonic anemometers are the core component of eddy covariance systems, which are widely used for micrometeorological and ecological research. In order to characterize the measurement uncertainty of these instruments we present and analyse the results from a field intercomparison experiment of six commonly used sonic anemometer models from four major manufacturers. These models include Campbell CSAT3, Gill HS-50 and R3, METEK uSonic-3 Omni, R. M. Young 81000 and 81000RE. The experiment was conducted over a meadow at the TERENO/ICOS site DE-Fen in southern Germany over a period of 16 days in June of 2016 as part of the ScaleX campaign. The measurement height was 3 m for all sensors, which were separated by 9 m from each other, each on its own tripod, in order to limit contamination of the turbulence measurements by adjacent structures as much as possible. Moreover, the high-frequency data from all instruments were treated with the same post-processing algorithm. In this study, we compare the results for various turbulence statistics, which include mean horizontal wind speed, standard deviations of vertical wind velocity and sonic temperature, friction velocity, and the buoyancy flux. Quantitative measures of uncertainty, such as bias and comparability, are derived from these results. We find that biases are generally very small for all sensors and all computed variables, except for the sonic temperature measurements of the two Gill sonic anemometers (HS and R3), confirming a known transducer-temperature dependence of the sonic temperature measurement. The best overall agreement between the different instruments was found for the mean wind speed and the buoyancy flux. |
BibTeX:
@article{Mauder2018,
author = {Mauder, Matthias and Zeeman, Matthias J},
title = {Field intercomparison of prevailing sonic anemometers},
journal = {Atmospheric Measurement Techniques},
year = {2018},
volume = {11},
number = {1},
pages = {249--263},
url = {https://www.atmos-meas-tech.net/11/249/2018/},
doi = {10.5194/amt-11-249-2018}
}
|
| Mauder M, Genzel S, Fu J, Kiese R, Soltani M, Steinbrecher R, Zeeman M, Banerjee T, De Roo F and Kunstmann H (2018), "Evaluation of energy balance closure adjustment methods by independent evapotranspiration estimates from lysimeters and hydrological simulations", Hydrological Processes., dec, 2018. Vol. 32(1), pp. 39-50. Wiley. |
| Abstract: Non-closure of the surface energy balance is a frequently observed phenomenon of hydrometeorological field measurements, when using the eddy-covariance method, which can be ascribed to an underestimation of the turbulent fluxes. Several approaches have been proposed in order to adjust the measured fluxes for this apparent systematic error. However, there are uncertainties about partitioning of the energy balance residual between the sensible and latent heat flux and whether such a correction should be applied on 30-min data or longer time scales. The data for this study originate from two grassland sites in southern Germany, where measurements from weighable lysimeters are available as reference. The adjusted evapotranspiration rates are also compared with joint energy and water balance simulations using a physically based distributed hydrological model. We evaluate two adjustment methods: the first one preserves the Bowen ratio and the correction factor is determined on a daily basis. The second one attributes a smaller portion of the residual energy to the latent heat flux than to the sensible heat flux for closing the energy balance for every 30-min flux integration interval. Both methods lead to an improved agreement of the eddy-covariance based fluxes with the independent lysimeter estimates and the physically based model simulations. The first method results in a better comparability of evapotranspiration rates, and the second method leads to a smaller overall bias. These results are similar between both sites despite considerable differences in terrain complexity and grassland management. Moreover, we found that a daily adjustment factor leads to less scatter than a complete partitioning of the residual for every half-hour time interval. The vertical temperature gradient in the surface layer and friction velocity were identified as important predictors for a potential future parameterisation of the energy balance residual. |
BibTeX:
@article{Mauder2018a,
author = {Mauder, Matthias and Genzel, Sandra and Fu, Jin and Kiese, Ralf and Soltani, Mohsen and Steinbrecher, Rainer and Zeeman, Matthias and Banerjee, Tirtha and De Roo, Frederik and Kunstmann, Harald},
title = {Evaluation of energy balance closure adjustment methods by independent evapotranspiration estimates from lysimeters and hydrological simulations},
journal = {Hydrological Processes},
publisher = {Wiley},
year = {2018},
volume = {32},
number = {1},
pages = {39--50},
doi = {10.1002/hyp.11397}
}
|
| McGloin R, Šigut L, Havránková K, Dušek J, Pavelka M and Sedlák P (2018), "Energy balance closure at a variety of ecosystems in Central Europe with contrasting topographies", Agricultural and Forest Meteorology., jan, 2018. Vol. 248, pp. 418-431. |
| Abstract: A long-standing problem in micrometeorology is that at most eddy covariance sites around the world, the sum of the sensible and latent heat flux measurements is less than the available energy, resulting in the so-called energy balance closure problem. This study utilised the national network of eddy covariance towers in the Czech Republic to examine the degree of energy balance closure at sites covering a wide variety of vegetation types and terrain complexities. The degree of energy balance closure at each site varied depending on the method used to calculate the closure fraction. When the closure was computed using linear regressions of half-hourly sums of turbulent heat fluxes against half-hourly available energy values, closure ranged from 0.68 (beech forest) to 0.81 (spruce forest). However, when closure was computed using the bulk energy balance ratio method, values ranged from 0.61 to 0.73. Highest closure occurred in moderately unstable atmospheric conditions, while closure also increased with increases in the correlation coefficients for vertical wind velocity and water vapour, and vertical wind velocity and sonic temperature. Lowest closure was found at a beech forest in the Carpathian Mountains, where evidence suggested that the complex topography to the south of the eddy covariance tower was influencing the airflow and resulting in poor energy balance closure results. Energy balance closure was also particularly low at a rapeseed cropland, and this was attributed to the low frequency of moderately unstable to strongly unstable conditions at the site. |
BibTeX:
@article{McGloin2018,
author = {McGloin, Ryan and Šigut, Ladislav and Havránková, KateÅ™ina and Dušek, JiÅ™í and Pavelka, Marian and Sedlák, Pavel},
title = {Energy balance closure at a variety of ecosystems in Central Europe with contrasting topographies},
journal = {Agricultural and Forest Meteorology},
year = {2018},
volume = {248},
pages = {418--431},
url = {http://linkinghub.elsevier.com/retrieve/pii/S0168192317303234},
doi = {10.1016/j.agrformet.2017.10.003}
}
|
| Menegat A, Milberg P, Nilsson ATS, Andersson L and Vico G (2018), "Soil water potential and temperature sum during reproductive growth control seed dormancy in Alopecurus myosuroides Huds.", Ecology and Evolution., jun, 2018. Vol. 8(14), pp. 7186-7194. Wiley. |
| Abstract: The sustainable management of unwanted vegetation in agricultural fields through integrated weed control strategies requires detailed knowledge about the maternal formation of primary seed dormancy, to support the prediction of seedling emergence dynamics. This knowledge is decisive for the timing of crop sowing and nonchemical weed control measures. Studies in controlled environments have already demonstrated that thermal conditions and, to some extent, water availability during seed set and maturation has an impact on the level of dormancy. However, it is still unclear if this applies also under field conditions, where environmental stressors and their timing are more variable. We address this question for Alopecurus myosuroides in south-western Sweden. We quantified the effects of cumulated temperature and precipitation as well as soil water potential during the reproductive growth phase of A myosuroides on primary seed dormancy under field conditions. Empirical models differing in focal time intervals and, in case of soil water potential, focal soil depths were compared regarding their predictive power. The highest predictive power for the level of primary dormancy of A. myosuroides seeds was found for a two-factorial linear model containing air temperature sum between 0 and 7 days before peak seed shedding as well as the number of days with soil water potential below field capacity between 7 and 35 days before peak seed shedding. For soil water potential, it was found that only the top 10 cm soil layer is of relevance, which is in line with the shallow root architecture of A. myosuroides. We conclude that for this species the level of dormancy depends on the magnitude and timing of temperature and water availability during the reproductive growth phase. Water availability appears to be more important during maternal environmental perception and temperature during zygotic environmental perception. |
BibTeX:
@article{Menegat2018,
author = {Menegat, Alexander and Milberg, Per and Nilsson, Anders T S and Andersson, Lars and Vico, Giulia},
title = {Soil water potential and temperature sum during reproductive growth control seed dormancy in Alopecurus myosuroides Huds.},
journal = {Ecology and Evolution},
publisher = {Wiley},
year = {2018},
volume = {8},
number = {14},
pages = {7186--7194},
doi = {10.1002/ece3.4249}
}
|
| Meredith LK, Boye K, Youngerman C, Whelan M, Ogée J, Sauze J and Wingate L (2018), "Coupled Biological and Abiotic Mechanisms Driving Carbonyl Sulfide Production in Soils", Soil Systems., jun, 2018. Vol. 2(3), pp. 37. MDPI AG. |
| Abstract: Understanding soil production of the trace gas carbonyl sulfide (OCS) is key to its use as a tracer of ecosystem function. Underlying its application is the observation that vascular plants consume atmospheric OCS via their stomatal pores in proportion with CO2 photosynthesis and that soil fluxes of OCS are negligible in comparison. Recent soil-centered studies demonstrate that soils can produce OCS and contribute as much as a quarter of the atmospheric terrestrial flux. Despite the potential widespread importance of soil OCS emissions, insufficient data exist to predict variations in OCS production across ecosystems, and the chemical and biological drivers of OCS production are virtually unknown. In this study, we address this knowledge gap by investigating variables controlling OCS soil production including soil physical and chemical properties, microbial community composition, and sulfur speciation in two independent surveys. We found that soil OCS production was nearly ubiquitous across the 58 sites, increased exponentially with temperature, and was insensitive to visible light conditioning. Soil pH, N, and C/N were predictors of OCS soil production rates in both soil surveys. Patterns in soil S speciation and predicted microbial S-cycling pathways both pointed to S-containing amino acids such as cysteine and methionine and their derivatives as potential precursors for OCS production. Elevated sulfate levels were associated with OCS production in some soils. This study provides new mechanistic insight into OCS production in soils and presents strategies to represent soil OCS fluxes that facilitate the use of OCS as a tracer for leaf-level processes related to carbon and water cycling. |
BibTeX:
@article{Meredith2018,
author = {Meredith, Laura K and Boye, Kristin and Youngerman, Connor and Whelan, Mary and Ogée, Jérôme and Sauze, Joana and Wingate, Lisa},
title = {Coupled Biological and Abiotic Mechanisms Driving Carbonyl Sulfide Production in Soils},
journal = {Soil Systems},
publisher = {MDPI AG},
year = {2018},
volume = {2},
number = {3},
pages = {37},
doi = {10.3390/soilsystems2030037}
}
|
| Mongwe NP, Vichi M and Monteiro PMS (2018), "The seasonal cycle of &lt;i&gt;p&lt;/i&gt;CO&lt;sub&gt;2&lt;/sub&gt; and CO&lt;sub&gt;2&lt;/sub&gt; fluxes in the Southern Ocean: diagnosing anomalies in CMIP5 Earth system models", Biogeosciences., may, 2018. Vol. 15(9), pp. 2851-2872. Copernicus GmbH. |
| Abstract: textlessptextgreatertextless![CDATA[Abstract. The Southern Ocean forms an important component of the Earth system as a major sink of CO2 and heat. Recent studies based on the Coupled Model Intercomparison Project version 5 (CMIP5) Earth system models (ESMs) show that CMIP5 models disagree on the phasing of the seasonal cycle of the CO2 flux (FCO2) and compare poorly with available observation products for the Southern Ocean. Because the seasonal cycle is the dominant mode of CO2 variability in the Southern Ocean, its simulation is a rigorous test for models and their long-term projections. Here we examine the competing roles of temperature and dissolved inorganic carbon (DIC) as drivers of the seasonal cycle of pCO2 in the Southern Ocean to explain the mechanistic basis for the seasonal biases in CMIP5 models. We find that despite significant differences in the spatial characteristics of the mean annual fluxes, the intra-model homogeneity in the seasonal cycle of FCO2 is greater than observational products. FCO2 biases in CMIP5 models can be grouped into two main categories, i.e., group-SST and group-DIC. Group-SST models show an exaggeration of the seasonal rates of change of sea surface temperature (SST) in autumn and spring during the cooling and warming peaks. These higher-than-observed rates of change of SST tip the control of the seasonal cycle of pCO2 and FCO2 towards SST and result in a divergence between the observed and modeled seasonal cycles, particularly in the Sub-Antarctic Zone. While almost all analyzed models (9 out of 10) show these SST-driven biases, 3 out of 10 (namely NorESM1-ME, HadGEM-ES and MPI-ESM, collectively the group-DIC models) compensate for the solubility bias because of their overly exaggerated primary production, such that biologically driven DIC changes mainly regulate the seasonal cycle of FCO2.]]textgreatertextless/ptextgreater |
BibTeX:
@article{Mongwe2018,
author = {Mongwe, N. Precious and Vichi, Marcello and Monteiro, Pedro M. S.},
title = {The seasonal cycle of &lt;i&gt;p&lt;/i&gt;CO&lt;sub&gt;2&lt;/sub&gt; and CO&lt;sub&gt;2&lt;/sub&gt; fluxes in the Southern Ocean: diagnosing anomalies in CMIP5 Earth system models},
journal = {Biogeosciences},
publisher = {Copernicus GmbH},
year = {2018},
volume = {15},
number = {9},
pages = {2851--2872},
url = {https://bg.copernicus.org/articles/15/2851/2018/},
doi = {10.5194/bg-15-2851-2018}
}
|
| Montagnani L, Grünwald T, Kowalski A, Mammarella I, Merbold L, Metzger S, Sedlák P and Siebicke L (2018), "Estimating the storage term in eddy covariance measurements: The ICOS methodology", International Agrophysics., dec, 2018. Vol. 32(4), pp. 551-567. |
| Abstract: In eddy covariance measurements, the storage flux represents the variation in time of the dry molar fraction of a given gas in the control volume representative of turbulent flux. Depending on the time scale considered, and on the height above ground of the measurements, it can either be a major component of the overall net ecosystem exchange or nearly negligible. Instrumental configuration and computational procedures must be optimized to measure this change at the time step used for the turbulent flux measurement. Three different configurations are suitable within the Integrated Carbon Observation System infrastructure for the storage flux determination: separate sampling, subsequent sampling and mixed sampling. These configurations have their own advantages and disadvantages, and must be carefully selected based on the specific features of the considered station. In this paper, guidelines about number and distribution of vertical and horizontal sampling points are given. Details about suitable instruments, sampling devices, and computational procedures for the quantification of the storage flux of different GHG gases are also provided. |
BibTeX:
@article{Montagnani2018,
author = {Montagnani, Leonardo and Grünwald, Thomas and Kowalski, Andrew and Mammarella, Ivan and Merbold, Lutz and Metzger, Stefan and Sedlák, Pavel and Siebicke, Lukas},
title = {Estimating the storage term in eddy covariance measurements: The ICOS methodology},
journal = {International Agrophysics},
year = {2018},
volume = {32},
number = {4},
pages = {551--567},
url = {https://content.sciendo.com/view/journals/intag/32/4/article-p551.xml},
doi = {10.1515/intag-2017-0037}
}
|
| Mozaffar A, Schoon N, Bachy A, Digrado A, Heinesch B, Aubinet M, Fauconnier ML, Delaplace P, du Jardin P and Amelynck C (2018), "Biogenic volatile organic compound emissions from senescent maize leaves and a comparison with other leaf developmental stages", Atmospheric Environment., mar, 2018. Vol. 176, pp. 71-81. |
| Abstract: Plants are the major source of Biogenic Volatile Organic Compounds (BVOCs) which have a large influence on atmospheric chemistry and the climate system. Therefore, understanding of BVOC emissions from all abundant plant species at all developmental stages is very important. Nevertheless, investigations on BVOC emissions from even the most widespread agricultural crop species are rare and mainly confined to the healthy green leaves. Senescent leaves of grain crop species could be an important source of BVOCs as almost all the leaves senesce on the field before being harvested. For these reasons, BVOC emission measurements have been performed on maize (Zea mays L.), one of the most cultivated crop species in the world, at all the leaf developmental stages. The measurements were performed in controlled environmental conditions using dynamic enclosures and proton transfer reaction mass spectrometry (PTR-MS). The main compounds emitted by senescent maize leaves were methanol (31% of the total cumulative BVOC emission on a mass of compound basis) and acetic acid (30%), followed by acetaldehyde (11%), hexenals (9%) and m/z 59 compounds (acetone/propanal) (7%). Important differences were observed in the temporal emission profiles of the compounds, and both yellow leaves during chlorosis and dry brown leaves after chlorosis were identified as important senescence-related BVOC sources. Total cumulative BVOC emissions from senescent maize leaves were found to be among the highest for senescent Poaceae plant species. BVOC emission rates varied strongly among the different leaf developmental stages, and senescent leaves showed a larger diversity of emitted compounds than leaves at earlier stages. Methanol was the compound with the highest emissions for all the leaf developmental stages and the contribution from the young-growing, mature, and senescent stages to the total methanol emission by a typical maize leaf was 61, 13, and 26%, respectively. This study shows that BVOC emissions from senescent maize leaves cannot be neglected and further investigations in field conditions are recommended to further constrain the BVOC emissions from this important C4 crop species. |
BibTeX:
@article{Mozaffar2018,
author = {Mozaffar, A and Schoon, N and Bachy, A and Digrado, A and Heinesch, B and Aubinet, M and Fauconnier, M L and Delaplace, P and du Jardin, P and Amelynck, C},
title = {Biogenic volatile organic compound emissions from senescent maize leaves and a comparison with other leaf developmental stages},
journal = {Atmospheric Environment},
year = {2018},
volume = {176},
pages = {71--81},
url = {http://linkinghub.elsevier.com/retrieve/pii/S1352231017308658},
doi = {10.1016/j.atmosenv.2017.12.020}
}
|
| Munier S and Aires F (2018), "A new global method of satellite dataset merging and quality characterization constrained by the terrestrial water budget", Remote Sensing of Environment., feb, 2018. Vol. 205, pp. 119-130. Elsevier Inc.. |
| Abstract: During the last decades, satellite observations have increasingly been used to study the global water cycle over land. Although their value is now appreciated by the hydrological community, they are still limited by their uncertainties and their inability to close the water budget. In a previous study, we optimally integrated several datasets for each component (precipitation, evapotranspiration, storage change and discharge) to close this budget at a basin scale. Furthermore, an independent and simple calibration of each satellite dataset was designed to reduce the budget residual. In this paper, we extend the calibration procedure to the global scale. Pixels are first classified into surface types characterized by their NDVI and net precipitation values. We show that the global calibration transforms the original datasets towards a consensus that is hydrologically more coherent, with a budget residual reduced by 26%. The calibrated datasets are compared to ground-based observations, showing an improvement for more than 65% of the sites tested. This opens new perspectives to generate long-term datasets at global scale based purely on all available satellites observations, which describe all the terrestrial water components useful for climate purposes. Beyond the simple calibration presented here, inconsistencies among the various satellite datasets can be used as a proxy for satellite observation uncertainties. The quality of our calibration procedure is constrained by the availability of discharge measurements, and could therefore be improved in the future, as discharge measurement networks become more extensive. |
BibTeX:
@article{Munier2018,
author = {Munier, S. and Aires, F.},
title = {A new global method of satellite dataset merging and quality characterization constrained by the terrestrial water budget},
journal = {Remote Sensing of Environment},
publisher = {Elsevier Inc.},
year = {2018},
volume = {205},
pages = {119--130},
doi = {10.1016/j.rse.2017.11.008}
}
|
| Mzobe P, Berggren M, Pilesjö P, Lundin E, Olefeldt D, Roulet NT and Persson A (2018), "Dissolved organic carbon in streams within a subarctic catchment analysed using a GIS/ remote sensing approach", PLoS ONE., jul, 2018. Vol. 13(7), pp. e0199608. Public Library of Science (PLoS). |
| Abstract: Climate change projections show that temperature and precipitation increases can alter the exchange of greenhouse gases between the atmosphere and high latitude landscapes, including their freshwaters. Dissolved organic carbon (DOC) plays an important role in greenhouse gas emissions, but the impact of catchment productivity on DOC release to subarctic waters remains poorly known, especially at regional scales. We test the hypothesis that increased terrestrial productivity, as indicated by the normalized difference vegetation index (NDVI), generates higher stream DOC concentrations in the Stordalen catchment in subarctic Sweden. Furthermore, we aimed to determine the degree to which other generic catchment properties (elevation, slope) explain DOC concentration, and whether or not land cover variables representing the local vegetation type (e.g., mire, forest) need to be included to obtain adequate predictive models for DOC delivered into rivers. We show that the land cover type, especially the proportion of mire, played a dominant role in the catchment's release of DOC, while NDVI, slope, and elevation were supporting predictor variables. The NDVI as a single predictor showed weak and inconsistent relationships to DOC concentrations in recipient waters, yet NDVI was a significant positive regulator of DOC in multiple regression models that included land cover variables. Our study illustrates that vegetation type exerts primary control in DOC regulation in Stordalen, while productivity (NDVI) is of secondary importance. Thus, predictive multiple linear regression models for DOC can be utilized combining these different types of explanatory variables. |
BibTeX:
@article{Mzobe2018,
author = {Mzobe, Pearl and Berggren, Martin and Pilesjö, Petter and Lundin, Erik and Olefeldt, David and Roulet, Nigel T and Persson, Andreas},
editor = {Viña, Andrés},
title = {Dissolved organic carbon in streams within a subarctic catchment analysed using a GIS/ remote sensing approach},
journal = {PLoS ONE},
publisher = {Public Library of Science (PLoS)},
year = {2018},
volume = {13},
number = {7},
pages = {e0199608},
doi = {10.1371/journal.pone.0199608}
}
|
| Nemitz E, Mammarella I, Ibrom A, Aurela M, Burba GG, Dengel S, Gielen B, Grelle A, Heinesch B, Herbst M, Hörtnagl L, Klemedtsson L, Lindroth A, Lohila A, McDermitt DK, Meier P, Merbold L, Nelson D, Nicolini G, Nilsson MB, Peltola O, Rinne J and Zahniser M (2018), "Standardisation of eddy-covariance flux measurements of methane and nitrous oxide", International Agrophysics., dec, 2018. Vol. 32(4), pp. 517-549. |
| Abstract: Commercially available fast-response analysers for methane (CH 4 ) and nitrous oxide (N 2 O) have recently become more sensitive, more robust and easier to operate. This has made their application for long-Term flux measurements with the eddy-covariance method more feasible. Unlike for carbon dioxide (CO 2 ) and water vapour (H 2 O), there have so far been no guidelines on how to optimise and standardise the measurements. This paper reviews the state-of-The-Art of the various steps of the measurements and discusses aspects such as instrument selection, setup and maintenance, data processing as well as the additional measurements needed to aid interpretation and gap-filling. It presents the methodological protocol for eddy covariance measurements of CH 4 and N 2 O fluxes as agreed for the ecosystem station network of the pan-European Research Infrastructure Integrated Carbon Observation System and provides a first international standard that is suggested to be adopted more widely. Fluxes can be episodic and the processes controlling the fluxes are complex, preventing simple mechanistic gap-filling strategies. Fluxes are often near or below the detection limit, requiring additional care during data processing. The protocol sets out the best practice for these conditions to avoid biasing the results and long-Term budgets. It summarises the current approach to gap-filling. |
BibTeX:
@article{Nemitz2018,
author = {Nemitz, Eiko and Mammarella, Ivan and Ibrom, Andreas and Aurela, Mika and Burba, George G and Dengel, Sigrid and Gielen, Bert and Grelle, Achim and Heinesch, Bernard and Herbst, Mathias and Hörtnagl, Lukas and Klemedtsson, Leif and Lindroth, Anders and Lohila, Annalea and McDermitt, Dayle K and Meier, Philip and Merbold, Lutz and Nelson, David and Nicolini, Giacomo and Nilsson, Mats B and Peltola, Olli and Rinne, Janne and Zahniser, Mark},
title = {Standardisation of eddy-covariance flux measurements of methane and nitrous oxide},
journal = {International Agrophysics},
year = {2018},
volume = {32},
number = {4},
pages = {517--549},
url = {https://content.sciendo.com/view/journals/intag/32/4/article-p517.xml},
doi = {10.1515/intag-2017-0042}
}
|
| Ney P and Graf A (2018), "High-Resolution Vertical Profile Measurements for Carbon Dioxide and Water Vapour Concentrations Within and Above Crop Canopies", Boundary-Layer Meteorology. Vol. 166(3), pp. 449-473. Springer Nature. |
| Abstract: We present a portable elevator-based facility for measuring CO 2, water vapour, temperature and wind-speed profiles between the soil surface and the atmospheric surface layer above crop canopies. The end of a tube connected to a closed-path gas analyzer is continuously moved up and down over the profile range (in our case, approximately 2 m) while concentrations are logged at a frequency of 20s-1. Using campaign measurements in winter wheat, winter barley and a catch crop mixture (spring 2015 to autumn 2016) during different stages of crop development and different times of the day, we demonstrate a simple approach to correct for time lags, and the resulting profiles of 30-min mean mole fractions of CO 2 and H 2O over height increments of 0.025 m. The profiles clearly show the effects of soil respiration and photosynthetic carbon assimilation, varying both during the diurnal cycle and during the growing season. Profiles of temperature and wind speed are based on a ventilated finewire thermocouple and a hot-wire anemometer, respectively. Measurements over bare soil and a short plant canopy were analyzed in the framework of Monin–Obukhov similarity theory to check the validity of the measurements and raw-data-processing approach. Derived fluxes of CO 2, latent and sensible heat and momentum show good agreement with eddy-covariance measurements. |
BibTeX:
@article{Ney2018,
author = {Ney, Patrizia and Graf, Alexander},
title = {High-Resolution Vertical Profile Measurements for Carbon Dioxide and Water Vapour Concentrations Within and Above Crop Canopies},
journal = {Boundary-Layer Meteorology},
publisher = {Springer Nature},
year = {2018},
volume = {166},
number = {3},
pages = {449--473},
doi = {10.1007/s10546-017-0316-4}
}
|
| Nicolini G, Aubinet M, Feigenwinter C, Heinesch B, Lindroth A, Mamadou O, Moderow U, Mölder M, Montagnani L, Rebmann C and Papale D (2018), "Impact of CO2 storage flux sampling uncertainty on net ecosystem exchange measured by eddy covariance", Agricultural and Forest Meteorology., jan, 2018. Vol. 248, pp. 228-239. |
| Abstract: Complying with several assumption and simplifications, most of the carbon budget studies based on eddy covariance (EC) measurements quantify the net ecosystem exchange (NEE) by summing the flux obtained by EC (FC) and the storage flux (SC). SC is the rate of change of a scalar, CO2 molar fraction in this case, within the control volume underneath the EC measurement level. It is given by the difference in the quasi-instantaneous profiles of concentration at the beginning and end of the EC averaging period, divided by the averaging period. The approaches used to estimate SC largely vary, from measurements based on a single sampling point usually located at the EC measurement height, to measurements based on profile sampling. Generally a single profile is used, although multiple profiles can be positioned within the control volume. Measurement accuracy reasonably increases with the spatial sampling intensity, however limited resources often prevent more elaborated measurement systems. In this study we use the experimental dataset collected during the ADVEX campaign in which turbulent and non-turbulent fluxes were measured in three forest sites by the simultaneous use of five towers/profiles. Our main objectives are to evaluate both the uncertainty of SC that derives from an insufficient sampling of CO2 variability, and its impact on concurrent NEE estimates.Results show that different measurement methods may produce substantially different SC flux estimates which in some cases involve a significant underestimation of the actual SC at a half-hourly time scales. A proper measuring system, that uses a single vertical profile of which the CO2 sampled at 3 points (the two closest to the ground and the one at the lower fringe of the canopy layer) is averaged with CO2 sampled at a certain distance and at the same height, improves the horizontal representativeness and reduces this (proportional) bias to 2–10% in such ecosystems. While the effect of this error is minor on long term NEE estimates, it can produce significant uncertainty on half-hourly NEE fluxes. |
BibTeX:
@article{Nicolini2018,
author = {Nicolini, Giacomo and Aubinet, Marc and Feigenwinter, Christian and Heinesch, Bernard and Lindroth, Anders and Mamadou, Ossénatou and Moderow, Uta and Mölder, Meelis and Montagnani, Leonardo and Rebmann, Corinna and Papale, Dario},
title = {Impact of CO2 storage flux sampling uncertainty on net ecosystem exchange measured by eddy covariance},
journal = {Agricultural and Forest Meteorology},
year = {2018},
volume = {248},
pages = {228--239},
url = {http://linkinghub.elsevier.com/retrieve/pii/S0168192317303209},
doi = {10.1016/j.agrformet.2017.09.025}
}
|
| Nielsen CS, Hasselquist NJ, Nilsson MB, Öquist M, Järveoja J and Peichl M (2018), "A Novel Approach for High-Frequency in-situ Quantification of Methane Oxidation in Peatlands", Soil Systems., dec, 2018. Vol. 3(1), pp. 4. |
| Abstract: Methane (CH4) oxidation is an important process for regulating CH4 emissions from peatlands as it oxidizes CH4 to carbon dioxide (CO2). Our current knowledge about its temporal dynamics and contribution to ecosystem CO2 fluxes is, however, limited due to methodological constraints. Here, we present the first results from a novel method for quantifying in-situ CH4 oxidation at high temporal resolution. Using an automated chamber system, we measured the isotopic signature of heterotrophic respiration (CO2 emissions from vegetation-free plots) at a boreal mire in northern Sweden. Based on these data we calculated CH4 oxidation rates using a two-source isotope mixing model. During the measurement campaign, 74 % of potential CH4 fluxes from vegetation-free plots were oxidized to CO2, and CH4 oxidation contributed 20 ± 2.5 % to heterotrophic respiration corresponding to 10 ± 0.5 % of ecosystem respiration. Furthermore, the contribution of CH4 oxidation to heterotrophic respiration showed a distinct diurnal cycle being negligible during nighttime while contributing up to 35 ± 3.0 % during the daytime. Our results show that CH4 oxidation may represent an important component of the peatland ecosystem respiration and highlight the value of our method for measuring in-situ CH4 oxidation to better understand carbon dynamics in peatlands. |
BibTeX:
@article{Nielsen2018,
author = {Nielsen, Cecilie Skov and Hasselquist, Niles J and Nilsson, Mats B and Öquist, Mats and Järveoja, Järvi and Peichl, Matthias},
title = {A Novel Approach for High-Frequency in-situ Quantification of Methane Oxidation in Peatlands},
journal = {Soil Systems},
year = {2018},
volume = {3},
number = {1},
pages = {4},
url = {http://www.mdpi.com/2571-8789/3/1/4},
doi = {10.3390/soilsystems3010004}
}
|
| Nilsson E, Bergström H, Rutgersson A, Podgrajsek E, Wallin MB, Bergström G, Dellwik E, Landwehr S and Ward B (2018), "Evaluating humidity and sea salt disturbances on CO2 flux measurements", Journal of Atmospheric and Oceanic Technology., apr, 2018. Vol. 35(4), pp. 859-875. American Meteorological Society. |
| Abstract: Global oceans are an important sink of atmospheric carbon dioxide (CO2). Therefore, understanding the air-sea flux of CO2 is a vital part in describing the global carbon balance. Eddy covariance (EC) measurements are often used to study CO2 fluxes from both land and ocean. Values of CO2 are usually measured with infrared absorption sensors, which at the same time measure water vapor. Studies have shown that the presence of water vapor fluctuations in the sampling air potentially results in erroneousCO2 flux measurements resulting from the cross sensitivity of the sensor. Here measured CO2 fluxes from both enclosed-path Li-Cor 7200 sensors and open-path Li-Cor 7500 instruments from an inland measurement site are compared with a marine site. Also, new quality control criteria based on a relative signal strength indicator (RSSI) are introduced. The sampling gas in one of the Li-Cor 7200 instruments was dried by means of a multitube diffusion dryer so that the water vapor fluxes were close to zero. With this setup the effect that cross sensitivity of the CO2 signal to water vapor can have on the CO2 fluxes was investigated. The dryer had no significant effect on the CO2 fluxes. The study tested the hypothesis that the cross-sensitivity effect is caused by hygroscopic particles such as sea salt by spraying a saline solution on the windows of the Li-Cor 7200 instruments during the inland field test. The results confirm earlier findings that sea salt contamination can affect CO2 fluxes significantly and that drying the sampling air for the gas analyzer is an effective method for reducing this signal contamination. |
BibTeX:
@article{Nilsson2018,
author = {Nilsson, Erik and Bergström, Hans and Rutgersson, Anna and Podgrajsek, Eva and Wallin, Marcus B and Bergström, Gunnar and Dellwik, Ebba and Landwehr, Sebastian and Ward, Brian},
title = {Evaluating humidity and sea salt disturbances on CO2 flux measurements},
journal = {Journal of Atmospheric and Oceanic Technology},
publisher = {American Meteorological Society},
year = {2018},
volume = {35},
number = {4},
pages = {859--875},
doi = {10.1175/JTECH-D-17-0072.1}
}
|
| Oosterwijk A, Henzing B and Järvi L (2018), "On the application of spectral corrections to particle flux measurements", Environmental Science: Nano. Vol. 5(10), pp. 2315-2324. Royal Society of Chemistry (RSC). |
| Abstract: To study the environmental fate of nanoparticles, reliable measurements of particle fluxes in the atmosphere are of importance. The eddy-covariance (EC) technique can be used to calculate surface fluxes. In this study, the EC technique has been applied to calculate particle fluxes in Helsinki (Finland) and Cabauw (the Netherlands). For reliable estimations of the surface fluxes, particle flux measurements need to be corrected for attenuation at the highest frequencies. This attenuation is caused by the relatively long response time of scalar sensors and measurement set-up. The attenuation can be estimated using a theoretical or an empirical approach. Horst [Horst, Boundary-Layer Meteorology, 1997, 82(2)] developed a simple formula to estimate the attenuation, based on the empirical approach. The empirical approach relies on the assumption of spectral similarity between two scalars. In this paper the effect of the spectral similarity assumption is investigated. It is shown that in order to apply the Horst formula reliably, a decent estimate of the sensor response time is required. Furthermore, it is shown that in order to apply the empirical method, a fast sensor response is required. It is concluded that theory does not predict the position of the peak in the cospectrum well, which means that for measurement set-ups not yet operational, this requirement is not easily evaluated. The assumption of spectral similarity seems reasonable for particle fluxes and heat fluxes, when compared to similarity between fluxes of other scalars. An altered assumption of spectral similarity has been applied, where similarity is assumed only at frequencies higher than the peak frequency in the cospectrum. This assumption leads to a better estimate for the attenuation, when applied to the Helsinki data. It does not lead to an improvement for the Cabauw data set, due to the large response time of the measurement set-up. |
BibTeX:
@article{Oosterwijk2018,
author = {Oosterwijk, Aleid and Henzing, Bas and Järvi, Leena},
title = {On the application of spectral corrections to particle flux measurements},
journal = {Environmental Science: Nano},
publisher = {Royal Society of Chemistry (RSC)},
year = {2018},
volume = {5},
number = {10},
pages = {2315--2324},
doi = {10.1039/c8en00501j}
}
|
| Osterwalder S, Sommar J, Åkerblom S, Jocher G, Fritsche J, Nilsson MB, Bishop K and Alewell C (2018), "Comparative study of elemental mercury flux measurement techniques over a Fennoscandian boreal peatland", Atmospheric Environment., jan, 2018. Vol. 172, pp. 16-25. Elsevier BV. |
| Abstract: Quantitative estimates of the land-atmosphere exchange of gaseous elemental mercury (GEM) are biased by the measurement technique employed, because no standard method or scale in space and time are agreed upon. Here we present concurrent GEM exchange measurements over a boreal peatland using a novel relaxed eddy accumulation (REA) system, a rectangular Teflon® dynamic flux chamber (DFC) and a DFC designed according to aerodynamic considerations (Aero-DFC). During four consecutive days the DFCs were placed alternately on two measurement plots in every cardinal direction around the REA sampling mast. Spatial heterogeneity in peat surface characteristics (0–34 cm) was identified by measuring total mercury in eight peat cores (57 ± 8 ng gâˆ'1, average ± SE), vascular plant coverage (32–52%), water table level (4.5–14.1 cm) and dissolved gaseous elemental mercury concentrations (28–51 pg Lâˆ'1) in the peat water. The GEM fluxes measured by the DFCs showed a distinct diel pattern, but no spatial difference in the average fluxes was detected (ANOVA, α = 0.05). Even though the correlation between the Teflon® DFC and Aero-DFC was significant (r = 0.76, p 0.05) the cumulative flux of the Aero-DFC was a factor of three larger. The average flux of the Aero-DFC (1.9 ng mâˆ'2 hâˆ'1) and REA (2 ng mâˆ'2 hâˆ'1) were in good agreement. The results indicate that the novel REA design is in agreement for cumulative flux estimates with the Aero-DFC, which incorporates the effect of atmospheric turbulence. The comparison was performed over a fetch with spatially rather homogenous GEM flux dynamics under fairly consistent weather conditions, minimizing the effect of weather influence on the data from the three measurement systems. However, in complex biomes with heterogeneous surface characteristics where there can be large spatial variability in GEM gas exchange, the small footprint of chambers (0.2 m2) makes for large coefficients of variation. Thus many chamber measurement replications are needed to establish a credible biome GEM flux estimate, even for a single point in time. Dynamic flux chambers will, however, be able to resolve systematic differences between small scale features, such as experimentally manipulated plots or small scale spatial heterogeneity. |
BibTeX:
@article{Osterwalder2018,
author = {Osterwalder, S and Sommar, J and Åkerblom, S and Jocher, G and Fritsche, J and Nilsson, M B and Bishop, K and Alewell, C},
title = {Comparative study of elemental mercury flux measurement techniques over a Fennoscandian boreal peatland},
journal = {Atmospheric Environment},
publisher = {Elsevier BV},
year = {2018},
volume = {172},
pages = {16--25},
doi = {10.1016/j.atmosenv.2017.10.025}
}
|
| Palace M, Herrick C, DelGreco J, Finnell D, Garnello AJ, McCalley C, McArthur K, Sullivan F and Varner RK (2018), "Determining subarctic peatland vegetation using an unmanned aerial system (UAS)", Remote Sensing., sep, 2018. Vol. 10(9), pp. 1498. MDPI AG. |
| Abstract: Rising global temperatures tied to increases in greenhouse gas emissions are impacting high latitude regions, leading to changes in vegetation composition and feedbacks to climate through increased methane (CH4) emissions. In subarctic peatlands, permafrost collapse has led to shifts in vegetation species on landscape scales with high spatial heterogeneity. Our goal was to provide a baseline for vegetation distribution related to permafrost collapse and changes in biogeochemical processes. We collected unmanned aerial system (UAS) imagery at Stordalen Mire, Abisko, Sweden to classify vegetation cover types. A series of digital image processing routines were used to generate texture attributes within the image for the purpose of characterizing vegetative cover types. An artificial neural network (ANN) was developed to classify the image. The ANN used all texture variables and color bands (three spectral bands and six metrics) to generate a probability map for each of the eight cover classes. We used the highest probability for a class at each pixel to designate the cover type in the final map. Our overall misclassification rate was 32%, while omission and commission error by class ranged from 0% to 50%. We found that within our area of interest, cover classes most indicative of underlying permafrost (hummock and tall shrub) comprised 43.9% percent of the landscape. Our effort showed the capability of an ANN applied to UAS high-resolution imagery to develop a classification that focuses on vegetation types associated with permafrost status and therefore potentially changes in greenhouse gas exchange. We also used a method to examine the multiple probabilities representing cover class prediction at the pixel level to examine model confusion. UAS image collection can be inexpensive and a repeatable avenue to determine vegetation change at high latitudes, which can further be used to estimate and scale corresponding changes in CH4 emissions. |
BibTeX:
@article{Palace2018,
author = {Palace, Michael and Herrick, Christina and DelGreco, Jessica and Finnell, Daniel and Garnello, Anthony John and McCalley, Carmody and McArthur, Kellen and Sullivan, Franklin and Varner, Ruth K},
title = {Determining subarctic peatland vegetation using an unmanned aerial system (UAS)},
journal = {Remote Sensing},
publisher = {MDPI AG},
year = {2018},
volume = {10},
number = {9},
pages = {1498},
doi = {10.3390/rs10091498}
}
|
| Palmer PI, O&apos, Doherty S, Allen G, Bower K, Bösch H, Chipperfield MP, Connors S, Dhomse S, Feng L, Finch DP, Gallagher MW, Gloor E, Gonzi S, Harris NRP, Helfter C, Humpage N, Kerridge B, Knappett D, Jones RL, Le Breton M, Lunt MF, Manning AJ, Matthiesen S, Muller JBA, Mullinger N, Nemiitz E, O&apos, Shea S, Parker RJ, Percival CJ, Pitt J, Riddick SN, Rigby M, Sembhi H, Siddans R, Skelton RL, Smith P, Sonderfeld H, Stanley K, Stavert AR, Wenger A, White E, Wilson C and Young D (2018), "A measurement-based verification framework for UK greenhouse gas emissions: an overview of the Greenhouse gAs Uk and Global Emissions (GAUGE) project", Atmospheric Chemistry and Physics Discussions., feb, 2018. , pp. 1-52. |
| Abstract: We describe the motivation, design, and execution of the Greenhouse gAs Uk and Global Emissions (GAUGE) project. The overarching scientific objective of GAUGE was to use atmospheric data to estimate the magnitude, distribution, and uncertainty of the UK greenhouse gas (GHG, defined here as COsub2/sub, CHsub4/sub, and Nsub2/subO) budget, 2013&ndash;2015. To address this objective we established a multi-year and interlinked measurement and data analysis programme, building on an established tall tower GHG measurement network. The inter-calibrated measurement network comprises ground-based, airborne, ship-borne, balloon-borne, and space-borne GHG sensors. Our choice of measurement technologies and measurement locations reflects the heterogeneity of UK GHG sources that range from small point sources such as landfills to large, diffuse sources such as agriculture. Atmospheric mole fraction data collected at the tall towers and on the ships provide information on sub-continental fluxes, representing the backbone to the GAUGE network. Additional spatial and temporal details of GHG fluxes over East Anglia were inferred from data collected by a regional network. Data collected during aircraft flights were used to study the transport of GHGs on local and regional scales. We purposely integrated new sensor and platform technologies into the GAUGE network, allowing us to lay the foundations of a strengthened UK capability to verify national GHG emissions beyond the project lifetime. For example, current satellites provide sparse and seasonally uneven sampling over the UK mainly because of its geographical size and cloud cover. This situation will improve with new and future satellite instruments, e.g. measurements of CHsub4/sub from the TROPOMI instrument aboard Sentinel-5P. We use global, nested, and regional atmospheric transport models and inverse methods to infer geographically resolved COsub2/sub and CHsub4/sub fluxes. This multi-model approach allows us to study model spread in ia posteriori/i flux estimates. These models are used to determine the relative importance of different measurements to infer the UK GHG budget. Attributing observed GHG variations to specific sources is a major challenge. Within a UK-wide spatial context we used two approaches: 1) Δsup14/supCOsub2/sub and other relevant isotopologues (e.g. δsup13/supCsubCHsub4/sub/sub) from collected air samples to quantify the contribution from fossil fuel combustion and other sources; 2) geographical separation of individual sources, e.g. agriculture, using a high-density measurement network. Neither of these represents a definitive approach, but they will provide invaluable information about GHG source attribution when they are adopted as part of a more comprehensive, long-term national GHG measurement programme. We also conducted a number of case studies, including an instrumented landfill experiment that provided a test-bed for new technologies and flux estimation methods. We anticipate that results from the GAUGE project will help inform other countries on how to use atmospheric data to quantify their nationally determined contributions to the Paris Agreement. |
BibTeX:
@article{Palmer2018,
author = {Palmer, Paul I and O&apos;Doherty, Simon and Allen, Grant and Bower, Keith and Bösch, Hartmut and Chipperfield, Martyn P and Connors, Sarah and Dhomse, Sandip and Feng, Liang and Finch, Douglas P and Gallagher, Martin W and Gloor, Emanuel and Gonzi, Siegfried and Harris, Neil R P and Helfter, Carole and Humpage, Neil and Kerridge, Brian and Knappett, Diane and Jones, Roderic L and Le Breton, Michael and Lunt, Mark F and Manning, Alistair J and Matthiesen, Stephan and Muller, Jennifer B A and Mullinger, Neil and Nemiitz, Eiko and O&apos;Shea, Sebastian and Parker, Robert J and Percival, Carl J and Pitt, Joseph and Riddick, Stuart N and Rigby, Matthew and Sembhi, Harjinder and Siddans, Richard and Skelton, Robert L and Smith, Paul and Sonderfeld, Hannah and Stanley, Kieron and Stavert, Ann R and Wenger, Angelina and White, Emily and Wilson, Christopher and Young, Dickon},
title = {A measurement-based verification framework for UK greenhouse gas emissions: an overview of the Greenhouse gAs Uk and Global Emissions (GAUGE) project},
journal = {Atmospheric Chemistry and Physics Discussions},
year = {2018},
pages = {1--52},
url = {https://www.atmos-chem-phys-discuss.net/acp-2018-135/},
doi = {10.5194/acp-2018-135}
}
|
| Palonen V, Pumpanen J, Kulmala L, Levin I, Heinonsalo J and Vesala T (2018), "Seasonal and diurnal variations in atmospheric and soil air 14CO2 in a boreal scots pine forest". feb, 2018. |
| Abstract: We present a radiocarbon (14C) dataset of tropospheric air CO2, forest soil air CO2, and soil CO2 emissions over the course of one growing season in a Scots pine forest in southern Finland. The CO2 collection for 14C accelerator mass spectrometry (AMS) analysis was done with a portable, suitcase-sized system, using molecular sieve cartridges to selectively trap CO2. The piloting measurements aimed to quantify the spatial, seasonal and diurnal changes in the 14C content of CO2 in a northern forest site. The atmospheric samples collected above the canopy showed a large seasonal variation and an 11‰ difference between day and nighttime profiles in August. The higher Δ14C values during night are partly explained by a higher contribution of14C-elevated soil CO2, accumulating in the nocturnal boundary layer when vertical mixing is weak. We observed significant seasonal trends in Δ14C-CO2 at different soil depths that reflected changes in the shares of autotrophic and heterotrophic respiration. Also the observed diurnal variation in the Δ14C values in soil CO2 highlighted the changes in the origin of CO2, with root activity decreasing more for the night than decomposition. |
BibTeX:
@misc{Palonen2018,
author = {Palonen, V. and Pumpanen, J. and Kulmala, L. and Levin, I. and Heinonsalo, J. and Vesala, T.},
title = {Seasonal and diurnal variations in atmospheric and soil air 14CO2 in a boreal scots pine forest},
booktitle = {Radiocarbon},
publisher = {Cambridge University Press},
year = {2018},
volume = {60},
number = {1},
pages = {283--297},
doi = {10.1017/RDC.2017.95}
}
|
| Pavelka M, Acosta M, Kiese R, Altimir N, Brümmer C, Crill P, Darenova E, Fuß R, Gielen B, Graf A, Klemedtsson L, Lohila A, Longdoz B, Lindroth A, Nilsson M, Jiménez SM, Merbold L, Montagnani L, Peichl M, Pihlatie M, Pumpanen J, Ortiz PS, Silvennoinen H, Skiba U, Vestin P, Weslien P, Janous D and Kutsch W (2018), "Standardisation of chamber technique for CO 2 , N 2 O and CH 4 fluxes measurements from terrestrial ecosystems", International Agrophysics., dec, 2018. Vol. 32(4), pp. 569-587. |
| Abstract: Chamber measurements of trace gas fluxes between the land surface and the atmosphere have been conducted for almost a century. Different chamber techniques, including static and dynamic, have been used with varying degrees of success in estimating greenhouse gases (CO 2 , CH 4 , N 2 O) fluxes. However, all of these have certain disadvantages which have either prevented them from providing an adequate estimate of greenhouse gas exchange or restricted them to be used under limited conditions. Generally, chamber methods are relatively low in cost and simple to operate. In combination with the appropriate sample allocations, chamber methods are adaptable for a wide variety of studies from local to global spatial scales, and they are particularly well suited for in situ and laboratory-based studies. Consequently, chamber measurements will play an important role in the portfolio of the Pan-European long-Term research infrastructure Integrated Carbon Observation System. The respective working group of the Integrated Carbon Observation System Ecosystem Monitoring Station Assembly has decided to ascertain standards and quality checks for automated and manual chamber systems instead of defining one or several standard systems provided by commercial manufacturers in order to define minimum requirements for chamber measurements. The defined requirements and recommendations related to chamber measurements are described here. |
BibTeX:
@article{Pavelka2018,
author = {Pavelka, Marian and Acosta, Manuel and Kiese, Ralf and Altimir, Núria and Brümmer, Christian and Crill, Patrick and Darenova, Eva and Fuß, Roland and Gielen, Bert and Graf, Alexander and Klemedtsson, Leif and Lohila, Annalea and Longdoz, Bernhard and Lindroth, Anders and Nilsson, Mats and Jiménez, Sara Maraňón and Merbold, Lutz and Montagnani, Leonardo and Peichl, Matthias and Pihlatie, Mari and Pumpanen, Jukka and Ortiz, Penelope Serrano and Silvennoinen, Hanna and Skiba, Ute and Vestin, Patrik and Weslien, Per and Janous, Dalibor and Kutsch, Werner},
title = {Standardisation of chamber technique for CO 2 , N 2 O and CH 4 fluxes measurements from terrestrial ecosystems},
journal = {International Agrophysics},
year = {2018},
volume = {32},
number = {4},
pages = {569--587},
url = {https://content.sciendo.com/view/journals/intag/32/4/article-p569.xml},
doi = {10.1515/intag-2017-0045}
}
|
| Peichl M, Gažovič M, Vermeij I, De Goede E, Sonnentag O, Limpens J and Nilsson MB (2018), "Peatland vegetation composition and phenology drive the seasonal trajectory of maximum gross primary production", Scientific Reports. Vol. 8(1) Springer Nature. |
| Abstract: Gross primary production (GPP) is a key driver of the peatland carbon cycle. Although many studies have explored the apparent GPP under natural light conditions, knowledge of the maximum GPP at light-saturation (GPPmax) and its spatio-temporal variation is limited. This information, however, is crucial since GPPmax essentially constrains the upper boundary for apparent GPP. Using chamber measurements combined with an external light source across experimental plots where vegetation composition was altered through long-term (20-year) nitrogen addition and artificial warming, we could quantify GPPmax in-situ and disentangle its biotic and abiotic controls in a boreal peatland. We found large spatial and temporal variations in the magnitudes of GPPmax which were related to vegetation species composition and phenology rather than abiotic factors. Specifically, we identified vegetation phenology as the main driver of the seasonal GPPmax trajectory. Abiotic anomalies (i.e. in air temperature and water table level), however, caused species-specific divergence between the trajectories of GPPmax and plant development. Our study demonstrates that photosynthetically active biomass constrains the potential peatland photosynthesis while abiotic factors act as secondary modifiers. This further calls for a better representation of species-specific vegetation phenology in process-based peatland models to improve predictions of global change impacts on the peatland carbon cycle. |
BibTeX:
@article{Peichl2018,
author = {Peichl, Matthias and Gažovič, Michal and Vermeij, Ilse and De Goede, Eefje and Sonnentag, Oliver and Limpens, Juul and Nilsson, Mats B},
title = {Peatland vegetation composition and phenology drive the seasonal trajectory of maximum gross primary production},
journal = {Scientific Reports},
publisher = {Springer Nature},
year = {2018},
volume = {8},
number = {1},
doi = {10.1038/s41598-018-26147-4}
}
|
| Peltola O, Raivonen M, Li X and Vesala T (2018), "Technical note: Comparison of methane ebullition modelling approaches used in terrestrial wetland models", Biogeosciences., feb, 2018. Vol. 15(3), pp. 937-951. Copernicus GmbH. |
| Abstract: Emission via bubbling, i.e. ebullition, is one of the main methane (CH4) emission pathways from wetlands to the atmosphere. Direct measurement of gas bubble formation, growth and release in the peat-water matrix is challenging and in consequence these processes are relatively unknown and are coarsely represented in current wetland CH4 emission models. In this study we aimed to evaluate three ebullition modelling approaches and their effect on model performance. This was achieved by implementing the three approaches in one process-based CH4 emission model. All the approaches were based on some kind of threshold: either on CH4 pore water concentration (ECT), pressure (EPT) or free-phase gas volume (EBG) threshold. The model was run using 4 years of data from a boreal sedge fen and the results were compared with eddy covariance measurements of CH4 fluxes. Modelled annual CH4 emissions were largely unaffected by the different ebullition modelling approaches; however, temporal variability in CH4 emissions varied an order of magnitude between the approaches. Hence the ebullition modelling approach drives the temporal variability in modelled CH4 emissions and therefore significantly impacts, for instance, high-frequency (daily scale) model comparison and calibration against measurements. The modelling approach based on the most recent knowledge of the ebullition process (volume threshold, EBG) agreed the best with the measured fluxes (R2 D 0:63) and hence produced the most reasonable results, although there was a scale mismatch between the measurements (ecosystem scale with heterogeneous ebullition locations) and model results (single horizontally homogeneous peat column). The approach should be favoured over the two other more widely used ebullition modelling approaches and researchers are encouraged to implement it into their CH4 emission models. |
BibTeX:
@article{Peltola2018,
author = {Peltola, Olli and Raivonen, Maarit and Li, Xuefei and Vesala, Timo},
title = {Technical note: Comparison of methane ebullition modelling approaches used in terrestrial wetland models},
journal = {Biogeosciences},
publisher = {Copernicus GmbH},
year = {2018},
volume = {15},
number = {3},
pages = {937--951},
doi = {10.5194/bg-15-937-2018}
}
|
| Peltoniemi M, Aurela M, Böttcher K, Kolari P, Loehr J, Karhu J, Linkosalmi M, Tanis CM, Tuovinen JP and Arslan AN (2018), "Webcam network and image database for studies of phenological changes of vegetation and snow cover in Finland, image time series from 2014 to 2016", Earth System Science Data., jan, 2018. Vol. 10(1), pp. 173-184. Copernicus GmbH. |
| Abstract: In recent years, monitoring of the status of ecosystems using low-cost web (IP) or time lapse cameras has received wide interest. With broad spatial coverage and high temporal resolution, networked cameras can provide information about snow cover and vegetation status, serve as ground truths to Earth observations and be useful for gap-filling of cloudy areas in Earth observation time series. Networked cameras can also play an important role in supplementing laborious phenological field surveys and citizen science projects, which also suffer from observer-dependent observation bias. We established a network of digital surveillance cameras for automated monitoring of phenological activity of vegetation and snow cover in the boreal ecosystems of Finland. Cameras were mounted at 14 sites, each site having 1-3 cameras. Here, we document the network, basic camera information and access to images in the permanent data repository (http://www.zenodo.org/communities/phenology-camera/). Individual DOI-referenced image time series consist of half-hourly images collected between 2014 and 2016 (https://doi.org/10.5281/zenodo.1066862). Additionally, we present an example of a colour index time series derived from images from two contrasting sites. |
BibTeX:
@article{Peltoniemi2018,
author = {Peltoniemi, Mikko and Aurela, Mika and Böttcher, Kristin and Kolari, Pasi and Loehr, John and Karhu, Jouni and Linkosalmi, Maiju and Tanis, Cemal Melih and Tuovinen, Juha Pekka and Arslan, Ali Nadir},
title = {Webcam network and image database for studies of phenological changes of vegetation and snow cover in Finland, image time series from 2014 to 2016},
journal = {Earth System Science Data},
publisher = {Copernicus GmbH},
year = {2018},
volume = {10},
number = {1},
pages = {173--184},
doi = {10.5194/essd-10-173-2018}
}
|
| Peltoniemi M, Aurela M, Böttcher K, Kolari P, Loehr J, Hokkanen T, Karhu J, Linkosalmi M, Tanis CM, Metsämäki S, Tuovinen JP, Vesala T and Arslan AN (2018), "Networked web-cameras monitor congruent seasonal development of birches with phenological field observations", Agricultural and Forest Meteorology., feb, 2018. Vol. 249, pp. 335-347. Elsevier BV. |
| Abstract: Ecosystems' potential to provide services, e.g. to sequester carbon, is largely driven by the phenological cycle of vegetation. Timing of phenological events is required for understanding and predicting the influence of climate change on ecosystems and to support analyses of ecosystem functioning. Analyses of conventional camera time series mounted near vegetation has been suggested as a means of monitoring phenological events and supporting wider monitoring of phenological cycle of biomes that is frequently done with satellite earth observation (EO). Especially in the boreal biome, sparsely scattered deciduous trees amongst conifer-dominant forests pose a problem for EO techniques as species phenological signal mix, and render EO data difficult to interpret. Therefore, deriving phenological information from on the ground measurements would provide valuable reference data for earth observed phenology products in a larger scale. Keeping this in mind, we established a network of digital cameras for automated monitoring of phenological activity of vegetation in the boreal ecosystems of Finland. Cameras were mounted at 14 sites, each site having 1–3 cameras. In this study, we used data from 12 sites to investigate how well networked cameras can detect the phenological development of birches (Betula spp.) along a latitudinal gradient. Birches typically appear in small quantities within the dominant species. We tested whether the small, scattered birch image elements allow a reliable extraction of colour indices and the temporal changes therein. We compared automatically derived phenological dates from these birch image elements both to visually determined dates from the same image time series and to independent observations recorded in the phenological monitoring network covering the same region. Automatically extracted season start dates, which were based on the change of green colour fraction in spring, corresponded well with the visually interpreted start of the season, and also to the budburst dates observed in the field. Red colour fraction turned out to be superior to the green colour-based indices in predicting leaf yellowing and fall. The latitudinal gradients derived using automated phenological date extraction corresponded well with the gradients estimated from the phenological field observations. We conclude that small and scattered birch image elements allow reliable extraction of key phenological dates for the season start and end of deciduous species studied here, thus providing important species-specific data for model validation and for explaining the temporal variation in EO phenology products. |
BibTeX:
@article{Peltoniemi2018a,
author = {Peltoniemi, Mikko and Aurela, Mika and Böttcher, Kristin and Kolari, Pasi and Loehr, John and Hokkanen, Tatu and Karhu, Jouni and Linkosalmi, Maiju and Tanis, Cemal Melih and Metsämäki, Sari and Tuovinen, Juha Pekka and Vesala, Timo and Arslan, Ali Nadir},
title = {Networked web-cameras monitor congruent seasonal development of birches with phenological field observations},
journal = {Agricultural and Forest Meteorology},
publisher = {Elsevier BV},
year = {2018},
volume = {249},
pages = {335--347},
doi = {10.1016/j.agrformet.2017.10.008}
}
|
| Pereira R, Ashton I, Sabbaghzadeh B, Shutler JD and Upstill-Goddard RC (2018), "Reduced air-sea CO2 exchange in the Atlantic Ocean due to biological surfactants", Nature Geoscience., jul, 2018. Vol. 11(7), pp. 492-496. Nature Publishing Group. |
| Abstract: Ocean CO2 uptake accounts for 20-40% of the post-industrial sink for anthropogenic CO2. The uptake rate is the product of the CO2 interfacial concentration gradient and its transfer velocity, which is controlled by spatial and temporal variability in near-surface turbulence. This variability complicates CO2 flux estimates and in large part reflects variable sea surface microlayer enrichments in biologically derived surfactants that cause turbulence suppression. Here we present a direct estimate of this surfactant effect on CO2 exchange at the ocean basin scale, with derived relationships between its transfer velocity determined experimentally and total surfactant activity for Atlantic Ocean surface seawaters. We found up to 32% reduction in CO2 exchange relative to surfactant-free water. Applying a relationship between sea surface temperature and total surfactant activity to our results gives monthly estimates of spatially resolved 'surfactant suppression' of CO2 exchange. Large areas of reduced CO2 uptake resulted, notably around 20° N, and the magnitude of the Atlantic Ocean CO2 sink for 2014 was decreased by 9%. This direct quantification of the surfactant effect on CO2 uptake at the ocean basin scale offers a framework for further refining estimates of air-sea gas exchange up to the global scale. |
BibTeX:
@article{Pereira2018,
author = {Pereira, Ryan and Ashton, Ian and Sabbaghzadeh, Bita and Shutler, Jamie D. and Upstill-Goddard, Robert C.},
title = {Reduced air-sea CO2 exchange in the Atlantic Ocean due to biological surfactants},
journal = {Nature Geoscience},
publisher = {Nature Publishing Group},
year = {2018},
volume = {11},
number = {7},
pages = {492--496},
url = {https://www.nature.com/articles/s41561-018-0136-2},
doi = {10.1038/s41561-018-0136-2}
}
|
| Perretti AR, de Albergaria-Barbosa ACR, Kerr R and da Cunha LC (2018), "Ocean acidification studies and the uncertainties relevance on measurements of marine carbonate system properties". apr, 2018. |
BibTeX:
@misc{Perretti2018,
author = {Perretti, Adriana Rodrigues and de Albergaria-Barbosa, Ana Cecília Rizzatti and Kerr, Rodrigo and da Cunha, Leticia Cotrim},
title = {Ocean acidification studies and the uncertainties relevance on measurements of marine carbonate system properties},
booktitle = {Brazilian Journal of Oceanography},
publisher = {Universidade de Sao Paulo},
year = {2018},
volume = {66},
number = {2},
pages = {234--242},
url = {http://dx.doi.org/10.1590/S1679-87592018000706602},
doi = {10.1590/s1679-87592018000706602}
}
|
| Person R, Aumont O and Lévy M (2018), "The biological pump and seasonal variability of pCO 2 in the southern ocean: Exploring the role of diatom adaptation to Low Iron", Journal of Geophysical Research: Oceans., may, 2018. Vol. 123(5), pp. 3204-3226. Blackwell Publishing Ltd. |
| Abstract: Iron is known to limit primary production in the Southern Ocean (SO). To cope with the lack of this micronutrient, diatoms, a dominant phytoplankton group in this oceanic region, have been shown in cultures to have developed an original adaptation strategy to maintain efficient growth rates despite very low cellular iron quotas, even in low light conditions. Using a global ocean biogeochemical model, we explored the consequences of this physiological adaptation for the biological pump and the seasonal variability of both surface chlorophyll concentrations and surface partial pressure of carbon dioxide (pCO 2 ) in this key region for global climate. In the model, we implemented a low intracellular Fe:C requirement in the SO for diatoms uniquely. This results in an increase of 10% in the relative contribution of diatoms to total SO primary production. The biological pump is also strengthened, which increases the biological contribution to the seasonal evolution of pCO 2 relative to the thermodynamic component. Therefore, the seasonal evolution of both surface chlorophyll and surface pCO2 is significantly impacted, with a marked improvement, in our model, in the SO polar zone compared to the observations. Our model study underscores the potentially important consequences that this adaptive physiological behavior of diatoms could have on marine biogeochemistry in the SO. It is thus critical to improve our understanding of the physiology of this key phytoplankton group, in particular in the SO. |
BibTeX:
@article{Person2018,
author = {Person, R. and Aumont, O. and Lévy, M.},
title = {The biological pump and seasonal variability of pCO 2 in the southern ocean: Exploring the role of diatom adaptation to Low Iron},
journal = {Journal of Geophysical Research: Oceans},
publisher = {Blackwell Publishing Ltd},
year = {2018},
volume = {123},
number = {5},
pages = {3204--3226},
url = {https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2018JC013775 https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2018JC013775 https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2018JC013775},
doi = {10.1029/2018JC013775}
}
|
| Peters W, van der Velde IR, van Schaik E, Miller JB, Ciais P, Duarte HF, van der Laan-Luijkx IT, van der Molen MK, Scholze M, Schaefer K, Vidale PL, Verhoef A, WÃ¥rlind D, Zhu D, Tans PP, Vaughn B and White JWC (2018), "Increased water-use efficiency and reduced CO2 uptake by plants during droughts at a continental scale", Nature Geoscience. Vol. 11(10), pp. 744-748. |
| Abstract: Severe droughts in the Northern Hemisphere cause a widespread decline of agricultural yield, the reduction of forest carbon uptake, and increased CO2 growth rates in the atmosphere. Plants respond to droughts by partially closing their stomata to limit their evaporative water loss, at the expense of carbon uptake by photosynthesis. This trade-off maximizes their water-use efficiency (WUE), as measured for many individual plants under laboratory conditions and field experiments. Here we analyse the 13C/12C stable isotope ratio in atmospheric CO2 to provide new observational evidence of the impact of droughts on the WUE across areas of millions of square kilometres and spanning one decade of recent climate variability. We find strong and spatially coherent increases in WUE along with widespread reductions of net carbon uptake over the Northern Hemisphere during severe droughts that affected Europe, Russia and the United States in 2001-2011. The impact of those droughts on WUE and carbon uptake by vegetation is substantially larger than simulated by the land-surface schemes of six state-of-the-art climate models. This suggests that drought-induced carbon-climate feedbacks may be too small in these models and improvements to their vegetation dynamics using stable isotope observations can help to improve their drought response. |
BibTeX:
@article{Peters2018,
author = {Peters, Wouter and van der Velde, Ivar R and van Schaik, Erik and Miller, John B and Ciais, Philippe and Duarte, Henrique F and van der Laan-Luijkx, Ingrid T and van der Molen, Michiel K and Scholze, Marko and Schaefer, Kevin and Vidale, Pier Luigi and Verhoef, Anne and WÃ¥rlind, David and Zhu, Dan and Tans, Pieter P and Vaughn, Bruce and White, James W C},
title = {Increased water-use efficiency and reduced CO2 uptake by plants during droughts at a continental scale},
journal = {Nature Geoscience},
year = {2018},
volume = {11},
number = {10},
pages = {744--748},
url = {https://doi.org/10.1038/s41561-018-0212-7}
}
|
| Pison I, Berchet A, Saunois M, Bousquet P, Broquet G, Conil S, Delmotte M, Ganesan A, Laurent O, Martin D, O'Doherty S, Ramonet M, Spain TG, Vermeulen A and Kwok CY (2018), "How a European network may help with estimating methane emissions on the French national scale", Atmospheric Chemistry and Physics., mar, 2018. Vol. 18(5), pp. 3779-3798. Copernicus GmbH. |
| Abstract: Methane emissions on the national scale in France in 2012 are inferred by assimilating continuous atmospheric mixing ratio measurements from nine stations of the European network ICOS located in France and surrounding countries. To assess the robustness of the fluxes deduced by our inversion system based on an objectified quantification of uncertainties, two complementary inversion set-ups are computed and analysed: (i) a regional run correcting for the spatial distribution of fluxes in France and (ii) a sectorial run correcting fluxes for activity sectors on the national scale. In addition, our results for the two set-ups are compared with fluxes produced in the framework of the inversion intercomparison exercise of the InGOS project. The seasonal variability in fluxes is consistent between different set-ups, with maximum emissions in summer, likely due to agricultural activity. However, very high monthly posterior uncertainties (up to ≈65 to 74% in the sectorial run in May and June) make it difficult to attribute maximum emissions to a specific sector. On the yearly and national scales, the two inversions range from 3835 to 4050 GgCH4 and from 3570 to 4190 GgCH4 for the regional and sectorial runs, respectively, consistently with the InGOS products. These estimates are 25 to 55% higher than the total national emissions from bottom-up approaches (biogeochemical models from natural emissions, plus inventories for anthropogenic ones), consistently pointing at missing or underestimated sources in the inventories and/or in natural sources. More specifically, in the sectorial set-up, agricultural emissions are inferred as 66% larger than estimates reported to the UNFCCC. Uncertainties in the total annual national budget are 108 and 312 GgCH4, i.e, 3 to 8 %, for the regional and sectorial runs respectively, smaller than uncertainties in available bottom-up products, proving the added value of top-down atmospheric inversions. Therefore, even though the surface network used in 2012 does not allow us to fully constrain all regions in France accurately, a regional inversion set-up makes it possible to provide estimates of French methane fluxes with an uncertainty in the total budget of less than 10% on the yearly timescale. Additional sites deployed since 2012 would help to constrain French emissions on finer spatial and temporal scales and attributing missing emissions to specific sectors. |
BibTeX:
@article{Pison2018,
author = {Pison, Isabelle and Berchet, Antoine and Saunois, Marielle and Bousquet, Philippe and Broquet, Grégoire and Conil, Sébastien and Delmotte, Marc and Ganesan, Anita and Laurent, Olivier and Martin, Damien and O'Doherty, Simon and Ramonet, Michel and Spain, T Gerard and Vermeulen, Alex and Kwok, Camille Yver},
title = {How a European network may help with estimating methane emissions on the French national scale},
journal = {Atmospheric Chemistry and Physics},
publisher = {Copernicus GmbH},
year = {2018},
volume = {18},
number = {5},
pages = {3779--3798},
doi = {10.5194/acp-18-3779-2018}
}
|
| Platt S, Eckhardt S, Ferré B, Fisher R, Hermansen O, Jansson P, Lowry D, Nisbet E, Pisso I, Schmidbauer N, Silyakova A, Stohl A, Svendby T, Vadakkepuliyambatta S, Mienert J and Lund Myhre C (2018), "Methane at svalbard and over the european arctic ocean", Atmospheric Chemistry and Physics., dec, 2018. Vol. 18(23), pp. 17207-17224. Copernicus GmbH. |
| Abstract: Methane ( classCombining double low line"inline-formula"CH4) is a powerful greenhouse gas. Its atmospheric mixing ratios have been increasing since 2005. Therefore, quantification of classCombining double low line"inline-formula"CH4 sources is essential for effective climate change mitigation. Here we report observations of the classCombining double low line"inline-formula"CH4 mixing ratios measured at the Zeppelin Observatory (Svalbard) in the Arctic and aboard the research vessel (RV) iHelmer Hanssen/i over the Arctic Ocean from June 2014 to December 2016, as well as the long-term classCombining double low line"inline-formula"CH4 trend measured at the Zeppelin Observatory from 2001 to 2017. We investigated areas over the European Arctic Ocean to identify possible hotspot regions emitting classCombining double low line"inline-formula"CH4 from the ocean to the atmosphere, and used state-of-the-art modelling (FLEXPART) combined with updated emission inventories to identify classCombining double low line"inline-formula"CH4 sources. Furthermore, we collected air samples in the region as well as samples of gas hydrates, obtained from the sea floor, which we analysed using a new technique whereby hydrate gases are sampled directly into evacuated canisters. Using this new methodology, we evaluated the suitability of ethane and isotopic signatures ( classCombining double low line"inline-formula"iδ/i13C in classCombining double low line"inline-formula"CH4) as tracers for ocean-to-atmosphere classCombining double low line"inline-formula"CH4 emission. We found that the average methane&thinsp;/&thinsp;light hydrocarbon (ethane and propane) ratio is an order of magnitude higher for the same sediment samples using our new methodology compared to previously reported values, 2379.95 vs. 460.06, respectively. Meanwhile, we show that the mean atmospheric classCombining double low line"inline-formula"CH4 mixing ratio in the Arctic increased by classCombining double low line"inline-formula"5.9±0.38 parts per billion by volume (ppb) per year (yr classCombining double low line"inline-formula"Ä'1) from 2001 to 2017 and classCombining double low line"inline-formula"Ä1/48&thinsp;pbb&thinsp;yr classCombining double low line"inline-formula"Ä'1 since 2008, similar to the global trend of classCombining double low line"inline-formula"Ä1/4&thinsp;7-8&thinsp;ppb&thinsp;yr classCombining double low line"inline-formula"Ä'1. Most large excursions from the baseline classCombining double low line"inline-formula"CH4 mixing ratio over the European Arctic Ocean are due to long-range transport from land-based sources, lending confidence to the present inventories for high-latitude classCombining double low line"inline-formula"CH4 emissions. However, we also identify a potential hotspot region with ocean-atmosphere classCombining double low line"inline-formula"CH4 flux north of Svalbard (80.4 classCombining double low line"inline-formula"Ä&thinsp;N, 12.8 classCombining double low line"inline-formula"Ä&thinsp;E) of up to 26&thinsp;nmol&thinsp;m classCombining double low line"inline-formula"Ä'2&thinsp;s classCombining double low line"inline-formula"Ä'1 from a large mixing ratio increase at the location of 30&thinsp;ppb. Since this flux is consistent with previous constraints (both spatially and temporally), there is no evidence that the area of interest north of Svalbard is unique in the context of the wider Arctic. Rather, because the meteorology at the time of the observation was unique in the context of the measurement time series, we obtained over the short course of the episode measurements highly sensitive to emissions over an active seep site, without sensitivity to land-based emissions. |
BibTeX:
@article{Platt2018,
author = {Platt, Stephen and Eckhardt, Sabine and Ferré, Benedicte and Fisher, Rebecca and Hermansen, Ove and Jansson, Par and Lowry, David and Nisbet, Euan and Pisso, Ignacio and Schmidbauer, Norbert and Silyakova, Anna and Stohl, Andreas and Svendby, Tove and Vadakkepuliyambatta, Sunil and Mienert, Jurgen and Lund Myhre, Cathrine},
title = {Methane at svalbard and over the european arctic ocean},
journal = {Atmospheric Chemistry and Physics},
publisher = {Copernicus GmbH},
year = {2018},
volume = {18},
number = {23},
pages = {17207--17224},
doi = {10.5194/acp-18-17207-2018}
}
|
| Portillo-Estrada M, Zenone T, Arriga N and Ceulemans R (2018), "Contribution of volatile organic compound fluxes to the ecosystem carbon budget of a poplar short-rotation plantation", GCB Bioenergy., jun, 2018. Vol. 10(6), pp. 405-414. Blackwell Publishing Ltd. |
| Abstract: Biogenic volatile organic compounds (BVOCs) are major precursors of both ozone and secondary organic aerosols (SOA) in the troposphere and represent a non-negligible portion of the carbon fixed by primary producers, but long-term ecosystem-scale measurements of their exchanges with the atmosphere are lacking. In this study, the fluxes of 46 ions corresponding to 36 BVOCs were continuously monitored along with the exchanges of mass (carbon dioxide and water vapor) and energy (sensible and latent heat) for an entire year in a poplar (Populus) short-rotation crop (SRC), using the eddy covariance methodology. BVOC emissions mainly consisted of isoprene, acetic acid, and methanol. Total net BVOC emissions were 19.20 kg C ha−1 yr−1, which represented 0.63% of the net ecosystem exchange (NEE), resulting from −23.59 Mg C ha−1 yr−1 fixed as CO2 and 20.55 Mg C ha−1 yr−1 respired as CO2 from the ecosystem. Isoprene emissions represented 0.293% of NEE, being emitted at a ratio of 1 : 1709 mol isoprene per mol of CO2 fixed. Based on annual ecosystem-scale measurements, this study quantified for the first time that BVOC carbon emissions were lower than previously estimated in other studies (0.5–2% of NEE) on poplar trees. Furthermore, the seasonal and diurnal emission patterns of isoprene, methanol, and other BVOCs provided a better interpretation of the relationships with ecosystem CO2 and water vapor fluxes, with air temperature, vapor pressure deficit, and photosynthetic photon flux density. |
BibTeX:
@article{Portillo-Estrada2018,
author = {Portillo-Estrada, Miguel and Zenone, Terenzio and Arriga, Nicola and Ceulemans, Reinhart},
title = {Contribution of volatile organic compound fluxes to the ecosystem carbon budget of a poplar short-rotation plantation},
journal = {GCB Bioenergy},
publisher = {Blackwell Publishing Ltd},
year = {2018},
volume = {10},
number = {6},
pages = {405--414},
doi = {10.1111/gcbb.12506}
}
|
| Post H, Franssen HJH, Han X, Baatz R, Montzka C, Schmidt M and Vereecken H (2018), "Evaluation and uncertainty analysis of regional-scale CLM4.5 net carbon flux estimates", Biogeosciences., jan, 2018. Vol. 15(1), pp. 187-208. |
| Abstract: Modeling net ecosystem exchange (NEE) at the regional scale with land surface models (LSMs) is relevant for the estimation of regional carbon balances, but studies on it are very limited. Furthermore, it is essential to better understand and quantify the uncertainty of LSMs in order to improve them. An important key variable in this respect is the prognostic leaf area index (LAI), which is very sensitive to forcing data and strongly affects the modeled NEE. We applied the Community Land Model (CLM4.5-BGC) to the Rur catchment in western Germany and compared estimated and default ecological key parameters for modeling carbon fluxes and LAI. The parameter estimates were previously estimated with the Markov chain Monte Carlo (MCMC) approach DREAM(zs) for four of the most widespread plant functional types in the catchment. It was found that the catchment-scale annual NEE was strongly positive with default parameter values but negative (and closer to observations) with the estimated values. Thus, the estimation of CLM parameters with local NEE observations can be highly relevant when determining regional carbon balances. To obtain a more comprehensive picture of model uncertainty, CLM ensembles were set up with perturbed meteorological input and uncertain initial states in addition to uncertain parameters. C3 grass and C3 crops were particularly sensitive to the perturbed meteorological input, which resulted in a strong increase in the standard deviation of the annual NEE sum (δΣNEE) for the different ensemble members from ∼ 2 to 3 g C m-2 yr-1 (with uncertain parameters) to ∼ 45 g C m-2 yr-1 (C3 grass) and ∼ 75 g C m-2 yr-1 (C3 crops) with perturbed forcings. This increase in uncertainty is related to the impact of the meteorological forcings on leaf onset and senescence, and enhanced/reduced drought stress related to perturbation of precipitation. The NEE uncertainty for the forest plant functional type (PFT) was considerably lower (σ NEE ∼ 4.0-13.5 g C m-2 yr-1 with perturbed parameters, meteorological forcings and initial states). We conclude that LAI and NEE uncertainty with CLM is clearly underestimated if uncertain meteorological forcings and initial states are not taken into account. |
BibTeX:
@article{Post2018,
author = {Post, Hanna and Franssen, Harrie Jan Hendricks and Han, Xujun and Baatz, Roland and Montzka, Carsten and Schmidt, Marius and Vereecken, Harry},
title = {Evaluation and uncertainty analysis of regional-scale CLM4.5 net carbon flux estimates},
journal = {Biogeosciences},
year = {2018},
volume = {15},
number = {1},
pages = {187--208},
url = {https://www.biogeosciences.net/15/187/2018/},
doi = {10.5194/bg-15-187-2018}
}
|
| Prinn RG, Weiss RF, Arduini J, Arnold T, Langley Dewitt H, Fraser PJ, Ganesan AL, Gasore J, Harth CM, Hermansen O, Kim J, Krummel PB, Li S, Loh ZM, Lunder CR, Maione M, Manning AJ, Miller BR, Mitrevski B, Mühle J, O'Doherty S, Park S, Reimann S, Rigby M, Saito T, Salameh PK, Schmidt R, Simmonds PG, Paul Steele L, Vollmer MK, Wang RH, Yao B, Yokouchi Y, Young D and Zhou L (2018), "History of chemically and radiatively important atmospheric gases from the Advanced Global Atmospheric Gases Experiment (AGAGE)", Earth System Science Data., jun, 2018. Vol. 10(2), pp. 985-1018. Copernicus GmbH. |
| Abstract: We present the organization, instrumentation, datasets, data interpretation, modeling, and accomplishments of the multinational global atmospheric measurement program AGAGE (Advanced Global Atmospheric Gases Experiment). AGAGE is distinguished by its capability to measure globally, at high frequency, and at multiple sites all the important species in the Montreal Protocol and all the important non-carbon-dioxide (non-CO2) gases assessed by the Intergovernmental Panel on Climate Change (CO2 is also measured at several sites). The scientific objectives of AGAGE are important in furthering our understanding of global chemical and climatic phenomena. They are the following: (1) to accurately measure the temporal and spatial distributions of anthropogenic gases that contribute the majority of reactive halogen to the stratosphere and/or are strong infrared absorbers (chlorocarbons, chlorofluorocarbons - CFCs, bromocarbons, hydrochlorofluorocarbons - HCFCs, hydrofluorocarbons - HFCs and polyfluorinated compounds (perfluorocarbons - PFCs), nitrogen trifluoride - NF3, sulfuryl fluoride - SO2F2, and sulfur hexafluoride - SF6) and use these measurements to determine the global rates of their emission and/or destruction (i.e., lifetimes); (2) to accurately measure the global distributions and temporal behaviors and determine the sources and sinks of non-CO2 biogenic-anthropogenic gases important to climate change and/or ozone depletion (methane - CH4, nitrous oxide - N2O, carbon monoxide - CO, molecular hydrogen - H2, methyl chloride - CH3Cl, and methyl bromide - CH3Br); (3) to identify new long-lived greenhouse and ozone-depleting gases (e.g., SO2F2, NF3, heavy PFCs (C4F10, C5F12, C6F14, C7F16, and C8F18) and hydrofluoroolefins (HFOs; e.g., CH2=CFCF3) have been identified in AGAGE), initiate the real-time monitoring of these new gases, and reconstruct their past histories from AGAGE, air archive, and firn air measurements; (4) to determine the average concentrations and trends of tropospheric hydroxyl radicals (OH) from the rates of destruction of atmospheric trichloroethane (CH3CCl3), HFCs, and HCFCs and estimates of their emissions; (5) to determine from atmospheric observations and estimates of their destruction rates the magnitudes and distributions by region of surface sources and sinks of all measured gases; (6) to provide accurate data on the global accumulation of many of these trace gases that are used to test the synoptic-, regional-, and global-scale circulations predicted by three-dimensional models; and (7) to provide global and regional measurements of methane, carbon monoxide, and molecular hydrogen and estimates of hydroxyl levels to test primary atmospheric oxidation pathways at midlatitudes and the tropics. Network Information and Data Repository: http://agage.mit.edu/data or http://cdiac.ess-dive.lbl.gov/ndps/alegage.html (https://doi.org/10.3334/CDIAC/atg.db1001). |
BibTeX:
@article{Prinn2018,
author = {Prinn, Ronald G and Weiss, Ray F and Arduini, Jgor and Arnold, Tim and Langley Dewitt, H and Fraser, Paul J and Ganesan, Anita L and Gasore, Jimmy and Harth, Christina M and Hermansen, Ove and Kim, Jooil and Krummel, Paul B and Li, Shanlan and Loh, Zoë M and Lunder, Chris R and Maione, Michela and Manning, Alistair J and Miller, Ben R and Mitrevski, Blagoj and Mühle, Jens and O'Doherty, Simon and Park, Sunyoung and Reimann, Stefan and Rigby, Matt and Saito, Takuya and Salameh, Peter K and Schmidt, Roland and Simmonds, Peter G and Paul Steele, L and Vollmer, Martin K and Wang, Ray H and Yao, Bo and Yokouchi, Yoko and Young, Dickon and Zhou, Lingxi},
title = {History of chemically and radiatively important atmospheric gases from the Advanced Global Atmospheric Gases Experiment (AGAGE)},
journal = {Earth System Science Data},
publisher = {Copernicus GmbH},
year = {2018},
volume = {10},
number = {2},
pages = {985--1018},
doi = {10.5194/essd-10-985-2018}
}
|
| Provenzale M, Ojala A, Heiskanen J, Erkkilä KM, Mammarella I, Hari P and Vesala T (2018), "High-frequency productivity estimates for a lake from free-water CO2 concentration measurements", Biogeosciences., apr, 2018. Vol. 15(7), pp. 2021-2032. Copernicus GmbH. |
| Abstract: Lakes are important actors in biogeochemical cycles and a powerful natural source of CO2. However, they are not yet fully integrated in carbon global budgets, and the carbon cycle in the water is still poorly understood. In freshwater ecosystems, productivity studies have usually been carried out with traditional methods (bottle incubations, 14C technique), which are imprecise and have a poor temporal resolution. Consequently, our ability to quantify and predict the net ecosystem productivity (NEP) is limited: the estimates are prone to errors and the NEP cannot be parameterised from environmental variables. Here we expand the testing of a free-water method based on the direct measurement of the CO2 concentration in the water. The approach was first proposed in 2008, but was tested on a very short data set (3 days) under specific conditions (autumn turnover); despite showing promising results, this method has been neglected by the scientific community. We tested the method under different conditions (summer stratification, typical summer conditions for boreal dark-water lakes) and on a much longer data set (40 days), and quantitatively validated it comparing our data and productivity models. We were able to evaluate the NEP with a high temporal resolution (minutes) and found a very good agreement (R2 ≥ 0.71) with the models. We also estimated the parameters of the productivity-irradiance (PI) curves that allow the calculation of the NEP from irradiance and water temperature. Overall, our work shows that the approach is suitable for productivity studies under a wider range of conditions, and is an important step towards developing this method so that it becomes more widely used. |
BibTeX:
@article{Provenzale2018,
author = {Provenzale, Maria and Ojala, Anne and Heiskanen, Jouni and Erkkilä, Kukka Maaria and Mammarella, Ivan and Hari, Pertti and Vesala, Timo},
title = {High-frequency productivity estimates for a lake from free-water CO2 concentration measurements},
journal = {Biogeosciences},
publisher = {Copernicus GmbH},
year = {2018},
volume = {15},
number = {7},
pages = {2021--2032},
doi = {10.5194/bg-15-2021-2018}
}
|
| Qiu C, Zhu D, Ciais P, Guenet B, Krinner G, Peng S, Aurela M, Bernhofer C, Brümmer C, Bret-Harte S, Chu H, Chen J, Desai AR, Dušek J, Euskirchen ES, Fortuniak K, Flanagan LB, Friborg T, Grygoruk M, Gogo S, Grünwald T, Hansen BU, Holl D, Humphreys E, Hurkuck M, Kiely G, Klatt J, Kutzbach L, Largeron C, Laggoun-Défarge F, Lund M, Lafleur PM, Li X, Mammarella I, Merbold L, Nilsson MB, Olejnik J, Ottosson-Löfvenius M, Oechel W, Parmentier FJW, Peichl M, Pirk N, Peltola O, Pawlak W, Rasse D, Rinne J, Shaver G, Peter Schmid H, Sottocornola M, Steinbrecher R, Sachs T, Urbaniak M, Zona D and Ziemblinska K (2018), "ORCHIDEE-PEAT (revision 4596), a model for northern peatland CO2, water, and energy fluxes on daily to annual scales", Geoscientific Model Development., feb, 2018. Vol. 11(2), pp. 497-519. |
| Abstract: Peatlands store substantial amounts of carbon and are vulnerable to climate change. We present a modified version of the Organising Carbon and Hydrology In Dynamic Ecosystems (ORCHIDEE) land surface model for simulating the hydrology, surface energy, and CO2 fluxes of peatlands on daily to annual timescales. The model includes a separate soil tile in each 0.5° grid cell, defined from a global peatland map and identified with peat-specific soil hydraulic properties. Runoff from non-peat vegetation within a grid cell containing a fraction of peat is routed to this peat soil tile, which maintains shallow water tables. The water table position separates oxic from anoxic decomposition. The model was evaluated against eddy-covariance (EC) observations from 30 northern peatland sites, with the maximum rate of carboxylation (Vcmax) being optimized at each site. Regarding short-term day-to-day variations, the model performance was good for gross primary production (GPP) (r2 Combining double low line 0.76; Nash-Sutcliffe modeling efficiency, MEF Combining double low line 0.76) and ecosystem respiration (ER, r2 Combining double low line 0.78, MEF Combining double low line 0.75), with lesser accuracy for latent heat fluxes (LE, r2 Combining double low line 0.42, MEF Combining double low line 0.14) and and net ecosystem CO2 exchange (NEE, r2 Combining double low line 0.38, MEF Combining double low line 0.26). Seasonal variations in GPP, ER, NEE, and energy fluxes on monthly scales showed moderate to high r2 values (0.57-0.86). For spatial across-site gradients of annual mean GPP, ER, NEE, and LE, r2 values of 0.93, 0.89, 0.27, and 0.71 were achieved, respectively. Water table (WT) variation was not well predicted (r20.1), likely due to the uncertain water input to the peat from surrounding areas. However, the poor performance of WT simulation did not greatly affect predictions of ER and NEE. We found a significant relationship between optimized Vcmax and latitude (temperature), which better reflects the spatial gradients of annual NEE than using an average Vcmax value. |
BibTeX:
@article{Qiu2018,
author = {Qiu, Chunjing and Zhu, Dan and Ciais, Philippe and Guenet, Bertrand and Krinner, Gerhard and Peng, Shushi and Aurela, Mika and Bernhofer, Christian and Brümmer, Christian and Bret-Harte, Syndonia and Chu, Housen and Chen, Jiquan and Desai, Ankur R and Dušek, JÇrí and Euskirchen, Eugénie S and Fortuniak, Krzysztof and Flanagan, Lawrence B and Friborg, Thomas and Grygoruk, Mateusz and Gogo, Sébastien and Grünwald, Thomas and Hansen, Birger U and Holl, David and Humphreys, Elyn and Hurkuck, Miriam and Kiely, Gerard and Klatt, Janina and Kutzbach, Lars and Largeron, Chloé and Laggoun-Défarge, Fatima and Lund, Magnus and Lafleur, Peter M and Li, Xuefei and Mammarella, Ivan and Merbold, Lutz and Nilsson, Mats B and Olejnik, Janusz and Ottosson-Löfvenius, Mikaell and Oechel, Walter and Parmentier, Frans Jan W and Peichl, Matthias and Pirk, Norbert and Peltola, Olli and Pawlak, Włodzimierz and Rasse, Daniel and Rinne, Janne and Shaver, Gaius and Peter Schmid, Hans and Sottocornola, Matteo and Steinbrecher, Rainer and Sachs, Torsten and Urbaniak, Marek and Zona, Donatella and Ziemblinska, Klaudia},
title = {ORCHIDEE-PEAT (revision 4596), a model for northern peatland CO2, water, and energy fluxes on daily to annual scales},
journal = {Geoscientific Model Development},
year = {2018},
volume = {11},
number = {2},
pages = {497--519},
url = {https://www.geosci-model-dev.net/11/497/2018/},
doi = {10.5194/gmd-11-497-2018}
}
|
| Quade M, Brüggemann N, Graf A, Vanderborght J, Vereecken H and Rothfuss Y (2018), "Investigation of Kinetic Isotopic Fractionation of Water During Bare Soil Evaporation", Water Resources Research., sep, 2018. Vol. 54(9), pp. 6909-6928. American Geophysical Union (AGU). |
| Abstract: The kinetic fractionation factor (αK) controls to a large extent the isotopic enrichment of surface waters during evaporation (E). In contrast to the well-known vapor-to-liquid isotopic equilibrium fractionation factor, αK has still not yet been properly characterized for soil water evaporation. In this study, we investigated the αK daily dynamics during a series of three laboratory experiments differing in soil water availability and aerodynamic conditions. For this, we applied a commonly used isotopic evaporation model and tested it in two different approaches. First, a two-end-member mixing model (Keeling plot) was fitted to the measured isotopic composition of the laboratory air water vapor to obtain αK. In a second approach, αK was obtained from the slope of the evaporation line in a dual isotopic coordinate system. For both methods, the isotopic composition of the soil water was determined nondestructively and online by sampling the soil water vapor with gas-permeable microporous tubing. Results highlighted the limitation of the first approach, as the determination of the isotopic composition of E with the Keeling plot was challenging with the laboratory setup. The second approach provided αK values within the range ((Formula presented.) = 1.0132 ± 0.0013; (Formula presented.) = 1.0149 ± 0.0012) reported in the literature and pointed to the prevalence of turbulent water vapor transport under water-saturated soil conditions but also at soil water content significantly lower than the saturated value. In a third experiment, temporal dynamics of the atmospheric water vapor intrusion in the topmost soil layer could be observed during an isotopic labeling pulse. |
BibTeX:
@article{Quade2018,
author = {Quade, Maria and Brüggemann, Nicolas and Graf, Alexander and Vanderborght, Jan and Vereecken, Harry and Rothfuss, Youri},
title = {Investigation of Kinetic Isotopic Fractionation of Water During Bare Soil Evaporation},
journal = {Water Resources Research},
publisher = {American Geophysical Union (AGU)},
year = {2018},
volume = {54},
number = {9},
pages = {6909--6928},
doi = {10.1029/2018WR023159}
}
|
| Quéré C, Andrew R, Friedlingstein P, Sitch S, Hauck J, Pongratz J, Pickers P, Ivar Korsbakken J, Peters G, Canadell J, Arneth A, Arora V, Barbero L, Bastos A, Bopp L, Ciais P, Chini L, Ciais P, Doney S, Gkritzalis T, Goll D, Harris I, Haverd V, Hoffman F, Hoppema M, Houghton R, Hurtt G, Ilyina T, Jain A, Johannessen T, Jones C, Kato E, Keeling R, Klein Goldewijk K, Landschützer P, Lefèvre N, Lienert S, Liu Z, Lombardozzi D, Metzl N, Munro D, Nabel J, Nakaoka SI, Neill C, Olsen A, Ono T, Patra P, Peregon A, Peters W, Peylin P, Pfeil B, Pierrot D, Poulter B, Rehder G, Resplandy L, Robertson E, Rocher M, Rödenbeck C, Schuster U, Skjelvan I, Séférian R, Skjelvan I, Steinhoff T, Sutton A, Tans P, Tian H, Tilbrook B, Tubiello F, Van Der Laan-Luijkx I, Van Der Werf G, Viovy N, Walker A, Wiltshire A, Wright R, Zaehle S and Zheng B (2018), "Global Carbon Budget 2018", Earth System Science Data., dec, 2018. Vol. 10(4), pp. 2141-2194. Copernicus GmbH. |
| Abstract: Accurate assessment of anthropogenic carbon dioxide (span classCombining double low line"inline-formula"CO2/span) emissions and their redistribution among the atmosphere, ocean, and terrestrial biosphere - the "global carbon budget" - is important to better understand the global carbon cycle, support the development of climate policies, and project future climate change. Here we describe data sets and methodology to quantify the five major components of the global carbon budget and their uncertainties. Fossil span classCombining double low line"inline-formula"CO2/span emissions (span classCombining double low line"inline-formula"iE/iFF/span) are based on energy statistics and cement production data, while emissions from land use and land-use change (span classCombining double low line"inline-formula"iE/iLUC/span), mainly deforestation, are based on land use and land-use change data and bookkeeping models. Atmospheric span classCombining double low line"inline-formula"CO2/span concentration is measured directly and its growth rate (span classCombining double low line"inline-formula"iG/iATM/span) is computed from the annual changes in concentration. The ocean span classCombining double low line"inline-formula"CO2/span sink (span classCombining double low line"inline-formula"iS/iOCEAN/span) and terrestrial span classCombining double low line"inline-formula"CO2/span sink (span classCombining double low line"inline-formula"iS/iLAND/span) are estimated with global process models constrained by observations. The resulting carbon budget imbalance (span classCombining double low line"inline-formula"iB/iIM/span), the difference between the estimated total emissions and the estimated changes in the atmosphere, ocean, and terrestrial biosphere, is a measure of imperfect data and understanding of the contemporary carbon cycle. All uncertainties are reported as span classCombining double low line"inline-formula"±1iσ/i/span. For the last decade available (2008-2017), span classCombining double low line"inline-formula"iE/iFF/span was span classCombining double low line"inline-formula"9.4±0.5/span&thinsp;GtC&thinsp;yrspan classCombining double low line"inline-formula"Ä'1/span, span classCombining double low line"inline-formula"iE/iLUC/span span classCombining double low line"inline-formula"1.5±0.7/span&thinsp;GtC&thinsp;yrspan classCombining double low line"inline-formula"Ä'1/span, span classCombining double low line"inline-formula"iG/iATM/span span classCombining double low line"inline-formula"4.7±0.02/span&thinsp;GtC&thinsp;yrspan classCombining double low line"inline-formula"Ä'1/span, span classCombining double low line"inline-formula"iS/iOCEAN/span span classCombining double low line"inline-formula"2.4±0.5/span&thinsp;GtC&thinsp;yrspan classCombining double low line"inline-formula"Ä'1/span, and span classCombining double low line"inline-formula"iS/iLAND/span span classCombining double low line"inline-formula"3.2±0.8/span&thinsp;GtC&thinsp;yrspan classCombining double low line"inline-formula"Ä'1/span, with a budget imbalance span classCombining double low line"inline-formula"iB/iIM/span of 0.5&thinsp;GtC&thinsp;yrspan classCombining double low line"inline-formula"Ä'1/span indicating overestimated emissions and/or underestimated sinks. For the year 2017 alone, the growth in span classCombining double low line"inline-formula"iE/iFF/span was about 1.6&thinsp;% and emissions increased to span classCombining double low line"inline-formula"9.9±0.5/span&thinsp;GtC&thinsp;yrspan classCombining double low line"inline-formula"Ä'1/span. Also for 2017, span classCombining double low line"inline-formula"iE/iLUC/span was span classCombining double low line"inline-formula"1.4±0.7/span&thinsp;GtC&thinsp;yrspan classCombining double low line"inline-formula"Ä'1/span, span classCombining double low line"inline-formula"iG/iATM/span was span classCombining double low line"inline-formula"4.6±0.2/span&thinsp;GtC&thinsp;yrspan classCombining double low line"inline-formula"Ä'1/span, span classCombining double low line"inline-formula"iS/iOCEAN/span was span classCombining double low line"inline-formula"2.5±0.5/span&thinsp;GtC&thinsp;yrspan classCombining double low line"inline-formula"Ä'1/span, and span classCombining double low line"inline-formula"iS/iLAND/span was span classCombining double low line"inline-formula"3.8±0.8/span&thinsp;GtC&thinsp;yrspan classCombining double low line"inline-formula"Ä'1/span, with a span classCombining double low line"inline-formula"iB/iIM/span of 0.3&thinsp;GtC. The global atmospheric span classCombining double low line"inline-formula"CO2/span concentration reached span classCombining double low line"inline-formula"405.0±0.1/span&thinsp;ppm averaged over 2017. For 2018, preliminary data for the first 6-9 months indicate a renewed growth in span classCombining double low line"inline-formula"iE/iFF/span of span classCombining double low line"inline-formula"+/span2.7&thinsp;% (range of 1.8&thinsp;% to 3.7&thinsp;%) based on national emission projections for China, the US, the EU, and India and projections of gross domestic product corrected for recent changes in the carbon intensity of the economy for the rest of the world. The analysis presented here shows that the mean and trend in the five components of the global carbon budget are consistently estimated over the period of 1959-2017, but discrepancies of up to 1&thinsp;GtC&thinsp;yrspan classCombining double low line"inline-formula"Ä'1/span persist for the representation of semi-decadal variability in span classCombining double low line"inline-formula"CO2/span fluxes. A detailed comparison among individual estimates and the introduction of a broad range of observations show (1) no consensus in the mean and trend in land-use change emissions, (2) a persistent low agreement among the different methods on the magnitude of the land span classCombining double low line"inline-formula"CO2/span flux in the northern extra-tropics, and (3) an apparent underestimation of the span classCombining double low line"inline-formula"CO2/span variability by ocean models, originating outside the tropics. This living data update documents changes in the methods and data sets used in this new global carbon budget and the progress in understanding the global carbon cycle compared with previous publications of this data set (Le Quéré et al., 2018, 2016, 2015a, b, 2014, 2013). |
BibTeX:
@article{Quere2018,
author = {Quéré, Corinne and Andrew, Robbie and Friedlingstein, Pierre and Sitch, Stephen and Hauck, Judith and Pongratz, Julia and Pickers, Penelope and Ivar Korsbakken, Jan and Peters, Glen and Canadell, Josep and Arneth, Almut and Arora, Vivek and Barbero, Leticia and Bastos, Ana and Bopp, Laurent and Ciais, Philippe and Chini, Louise and Ciais, Philippe and Doney, Scott and Gkritzalis, Thanos and Goll, Daniel and Harris, Ian and Haverd, Vanessa and Hoffman, Forrest and Hoppema, Mario and Houghton, Richard and Hurtt, George and Ilyina, Tatiana and Jain, Atul and Johannessen, Truls and Jones, Chris and Kato, Etsushi and Keeling, Ralph and Klein Goldewijk, Kees and Landschützer, Peter and Lefèvre, Nathalie and Lienert, Sebastian and Liu, Zhu and Lombardozzi, Danica and Metzl, Nicolas and Munro, David and Nabel, Julia and Nakaoka, Shin Ichiro and Neill, Craig and Olsen, Are and Ono, Tsueno and Patra, Prabir and Peregon, Anna and Peters, Wouter and Peylin, Philippe and Pfeil, Benjamin and Pierrot, Denis and Poulter, Benjamin and Rehder, Gregor and Resplandy, Laure and Robertson, Eddy and Rocher, Matthias and Rödenbeck, Christian and Schuster, Ute and Skjelvan, Ingunn and Séférian, Roland and Skjelvan, Ingunn and Steinhoff, Tobias and Sutton, Adrienne and Tans, Pieter and Tian, Hanqin and Tilbrook, Bronte and Tubiello, Francesco and Van Der Laan-Luijkx, Ingrid and Van Der Werf, Guido and Viovy, Nicolas and Walker, Anthony and Wiltshire, Andrew and Wright, Rebecca and Zaehle, Sönke and Zheng, Bo},
title = {Global Carbon Budget 2018},
journal = {Earth System Science Data},
publisher = {Copernicus GmbH},
year = {2018},
volume = {10},
number = {4},
pages = {2141--2194},
doi = {10.5194/essd-10-2141-2018}
}
|
| Racapé V, Zunino P, Mercier H, Lherminier P, Bopp L, Pérèz FF and Gehlen M (2018), "Transport and storage of anthropogenic C in the North Atlantic Subpolar Ocean", Biogeosciences., jul, 2018. Vol. 15(14), pp. 4661-4682. Copernicus GmbH. |
| Abstract: The North Atlantic Ocean is a major sink region for atmospheric CO2 and contributes to the storage of anthropogenic carbon (Cant). While there is general agreement that the intensity of the meridional overturning circulation (MOC) modulates uptake, transport and storage of Cant in the North Atlantic Subpolar Ocean, processes controlling their recent variability and evolution over the 21st century remain uncertain. This study investigates the relationship between transport, air-sea flux and storage rate of Cant in the North Atlantic Subpolar Ocean over the past 53 years. Its relies on the combined analysis of a multiannual in situ data set and outputs from a global biogeochemical ocean general circulation model (NEMO-PISCES) at 1 2° spatial resolution forced by an atmospheric reanalysis. Despite an underestimation of Cant transport and an overestimation of anthropogenic air-sea CO2 flux in the model, the interannual variability of the regional Cant storage rate and its driving processes were well simulated by the model. Analysis of the multi-decadal simulation revealed that the MOC intensity variability was the major driver of the Cant transport variability at 25 and 36° N, but not at OVIDE. At the subpolar OVIDE section, the interannual variability of Cant transport was controlled by the accumulation of Cant in the MOC upper limb. At multi-decadal timescales, long-term changes in the North Atlantic storage rate of Cant were driven by the increase in air-sea fluxes of anthropogenic CO2. North Atlantic Central Water played a key role for storing Cant in the upper layer of the subtropical region and for supplying Cant to Intermediate Water and North Atlantic Deep Water. The transfer of Cant from surface to deep waters occurred mainly north of the OVIDE section. Most of the Cant transferred to the deep ocean was stored in the subpolar region, while the remainder was exported to the subtropical gyre within the lower MOC. |
BibTeX:
@article{Racape2018,
author = {Racapé, Virginie and Zunino, Patricia and Mercier, Herlé and Lherminier, Pascale and Bopp, Laurent and Pérèz, Fiz F and Gehlen, Marion},
title = {Transport and storage of anthropogenic C in the North Atlantic Subpolar Ocean},
journal = {Biogeosciences},
publisher = {Copernicus GmbH},
year = {2018},
volume = {15},
number = {14},
pages = {4661--4682},
doi = {10.5194/bg-15-4661-2018}
}
|
| Rebmann C, Aubinet M, Schmid H, Arriga N, Aurela M, Burba G, Clement R, De Ligne A, Fratini G, Gielen B, Grace J, Graf A, Gross P, Haapanala S, Herbst M, Hörtnagl L, Ibrom A, Joly L, Kljun N, Kolle O, Kowalski A, Lindroth A, Loustau D, Mammarella I, Mauder M, Merbold L, Metzger S, Mölder M, Montagnani L, Papale D, Pavelka M, Peichl M, Roland M, Serrano-Ortiz P, Siebicke L, Steinbrecher R, Tuovinen JP, Vesala T, Wohlfahrt G and Franz D (2018), "ICOS eddy covariance flux-station site setup: A review", International Agrophysics., dec, 2018. Vol. 32(4), pp. 471-494. |
| Abstract: The Integrated Carbon Observation System Research Infrastructure aims to provide long-Term, continuous observations of sources and sinks of greenhouse gases such as carbon dioxide, methane, nitrous oxide, and water vapour. At ICOS ecosystem stations, the principal technique for measurements of ecosystem-Atmosphere exchange of GHGs is the eddy-covariance technique. The establishment and setup of an eddy-covariance tower have to be carefully reasoned to ensure high quality flux measurements being representative of the investigated ecosystem and comparable to measurements at other stations. To fulfill the requirements needed for flux determination with the eddy-covariance technique, variations in GHG concentrations have to be measured at high frequency, simultaneously with the wind velocity, in order to fully capture turbulent fluctuations. This requires the use of high-frequency gas analysers and ultrasonic anemometers. In addition, to analyse flux data with respect to environmental conditions but also to enable corrections in the post-processing procedures, it is necessary to measure additional abiotic variables in close vicinity to the flux measurements. Here we describe the standards the ICOS ecosystem station network has adopted for GHG flux measurements with respect to the setup of instrumentation on towers to maximize measurement precision and accuracy while allowing for flexibility in order to observe specific ecosystem features. |
BibTeX:
@article{Rebmann2018,
author = {Rebmann, Corinna and Aubinet, Marc and Schmid, Hape and Arriga, Nicola and Aurela, Mika and Burba, George and Clement, Robert and De Ligne, Anne and Fratini, Gerardo and Gielen, Bert and Grace, John and Graf, Alexander and Gross, Patrick and Haapanala, Sami and Herbst, Mathias and Hörtnagl, Lukas and Ibrom, Andreas and Joly, Lilian and Kljun, Natascha and Kolle, Olaf and Kowalski, Andrew and Lindroth, Anders and Loustau, Denis and Mammarella, Ivan and Mauder, Matthias and Merbold, Lutz and Metzger, Stefan and Mölder, Meelis and Montagnani, Leonardo and Papale, Dario and Pavelka, Marian and Peichl, Matthias and Roland, Marilyn and Serrano-Ortiz, Penélope and Siebicke, Lukas and Steinbrecher, Rainer and Tuovinen, Juha Pekka and Vesala, Timo and Wohlfahrt, Georg and Franz, Daniela},
title = {ICOS eddy covariance flux-station site setup: A review},
journal = {International Agrophysics},
year = {2018},
volume = {32},
number = {4},
pages = {471--494},
url = {https://content.sciendo.com/view/journals/intag/32/4/article-p471.xml},
doi = {10.1515/intag-2017-0044}
}
|
| Ricaud P, Zbinden R, Catoire V, Brocchi V, Dulac F, Hamonou E, Canonici JC, El Amraoui L, Massart S, Piguet B, Dayan U, Nabat P, Sciare J, Ramonet M, Delmotte M, Di Sarra A, Sferlazzo D, Di Iorio T, Piacentino S, Cristofanelli P, Mihalopoulos N, Kouvarakis G, Pikridas M, Savvides C, Mamouri RE, Nisantzi A, Hadjimitsis D, Attié JL, Ferré H, Kangah Y, Jaidan N, Guth J, Jacquet P, Chevrier S, Robert C, Bourdon A, Bourdinot JF, Etienne JC, Krysztofiak G and Theron P (2018), "The GLAM airborne campaign across the Mediterranean Basin", Bulletin of the American Meteorological Society., feb, 2018. Vol. 99(2), pp. 361-380. |
| Abstract: The Gradient in Longitude of Atmospheric Constituents above the Mediterranean Basin (GLAM) 2014 airborne campaign performed original in situ observations of gases and aerosols across the Mediterranean troposphere, which, combined with satellite measurements and model outputs, highlight their summertime variability. |
BibTeX:
@article{Ricaud2018,
author = {Ricaud, Philippe and Zbinden, Régina and Catoire, Valéry and Brocchi, Vanessa and Dulac, François and Hamonou, Eric and Canonici, Jean Christophe and El Amraoui, Laaziz and Massart, Sébastien and Piguet, Bruno and Dayan, Uri and Nabat, Pierre and Sciare, Jean and Ramonet, Michel and Delmotte, Marc and Di Sarra, Alcide and Sferlazzo, Damiano and Di Iorio, Tatiana and Piacentino, Salvatore and Cristofanelli, Paolo and Mihalopoulos, Nikos and Kouvarakis, Giorgos and Pikridas, Michael and Savvides, Chrysanthos and Mamouri, Rodanthi Elisavet and Nisantzi, Argyro and Hadjimitsis, Diofantos and Attié, Jean Luc and Ferré, Hélène and Kangah, Yannick and Jaidan, Nizar and Guth, Jonathan and Jacquet, Patrick and Chevrier, Stéphane and Robert, Claude and Bourdon, Aurélien and Bourdinot, Jean François and Etienne, Jean Claude and Krysztofiak, Gisèle and Theron, Pierre},
title = {The GLAM airborne campaign across the Mediterranean Basin},
journal = {Bulletin of the American Meteorological Society},
year = {2018},
volume = {99},
number = {2},
pages = {361--380},
url = {http://journals.ametsoc.org/doi/10.1175/BAMS-D-16-0226.1},
doi = {10.1175/BAMS-D-16-0226.1}
}
|
| Rinne J, Tuittila ES, Peltola O, Li X, Raivonen M, Alekseychik P, Haapanala S, Pihlatie M, Aurela M, Mammarella I and Vesala T (2018), "Temporal Variation of Ecosystem Scale Methane Emission From a Boreal Fen in Relation to Temperature, Water Table Position, and Carbon Dioxide Fluxes", Global Biogeochemical Cycles., jul, 2018. Vol. 32(7), pp. 1087-1106. American Geophysical Union (AGU). |
| Abstract: We have analyzed decade-long methane flux data set from a boreal fen, Siikaneva, together with data on environmental parameters and carbon dioxide exchange. The methane flux showed seasonal cycle but no systematic diel cycle. The highest fluxes were observed in July–August with average value of 73 nmol mâˆ'2 sâˆ'1. Wintertime fluxes were small but positive, with January–March average of 6.7 nmol mâˆ'2 sâˆ'1. Daily average methane emission correlated best with peat temperatures at 20–35 cm depths. The second highest correlation was with gross primary production (GPP). The best correspondence between emission algorithm and measured fluxes was found for a variable-slope generalized linear model (r2 = 0.89) with peat temperature at 35 cm depth and GPP as explanatory variables, slopes varying between years. The homogeneity of slope approach indicated that seasonal variation explained 79% of the sum of squares variation of daily average methane emission, the interannual variation in explanatory factors 7.0%, functional change 5.3%, and random variation 9.1%. Significant correlation between interannual variability of growing season methane emission and that of GPP indicates that on interannual time scales GPP controls methane emission variability, crucially for development of process-based methane emission models. Annual methane emission ranged from 6.0 to 14 gC mâˆ'2 and was 2.7 ± 0.4% of annual GPP. Over 10-year period methane emission was 18% of net ecosystem exchange as carbon. The weak relation of methane emission to water table position indicates that space-to-time analogy, used to extrapolate spatial chamber data in time, may not be applicable in seasonal time scales. |
BibTeX:
@article{Rinne2018,
author = {Rinne, Janne and Tuittila, Eeva Stiina and Peltola, Olli and Li, Xuefei and Raivonen, Maarit and Alekseychik, Pavel and Haapanala, Sami and Pihlatie, Mari and Aurela, Mika and Mammarella, Ivan and Vesala, Timo},
title = {Temporal Variation of Ecosystem Scale Methane Emission From a Boreal Fen in Relation to Temperature, Water Table Position, and Carbon Dioxide Fluxes},
journal = {Global Biogeochemical Cycles},
publisher = {American Geophysical Union (AGU)},
year = {2018},
volume = {32},
number = {7},
pages = {1087--1106},
doi = {10.1029/2017GB005747}
}
|
| Robinson NP, Allred BW, Smith WK, Jones MO, Moreno A, Erickson TA, Naugle DE and Running SW (2018), "Terrestrial primary production for the conterminous United States derived from Landsat 30 m and MODIS 250 m", Remote Sensing in Ecology and Conservation., sep, 2018. Vol. 4(3), pp. 264-280. Wiley-Blackwell. |
| Abstract: Terrestrial primary production is a fundamental ecological process and a crucial component in understanding the flow of energy through trophic levels. The global MODIS gross primary production (GPP) and net primary production (NPP) products (MOD17) are widely used for monitoring GPP and NPP at coarse resolutions across broad spatial extents. The coarse input datasets and global biome-level parameters, however, are well-known limitations to the applicability of the MOD17 product at finer scales. We addressed these limitations and created two improved products for the conterminous United States (CONUS) that capture the spatiotemporal variability in terrestrial production. The MOD17 algorithm was utilized with medium resolution land cover classifications and improved meteorological data specific to CONUS in order to produce: (a) Landsat derived 16-day GPP and annual NPP at 30 m resolution from 1986 to 2016 (GPPL30 and NPPL30, respectively); and (b) MODIS derived 8-day GPP and annual NPP at 250 m resolution from 2001 to 2016 (GPPM250 and NPPM250 respectively). Biome-specific input parameters were optimized based on eddy covariance flux tower-derived GPP data from the FLUXNET2015 database. We evaluated GPPL30 and GPPM250 products against the standard MODIS GPP product utilizing a select subset of representative flux tower sites, and found improvement across all land cover classes except croplands. We also found consistent interannual variability and trends across NPPL30, NPPM250, and the standard MODIS NPP product. We highlight the application potential of the production products, demonstrating their improved capacity for monitoring terrestrial production at higher levels of spatial detail across broad spatiotemporal scales. |
BibTeX:
@article{Robinson2018,
author = {Robinson, Nathaniel P. and Allred, Brady W. and Smith, William K. and Jones, Matthew O. and Moreno, Alvaro and Erickson, Tyler A. and Naugle, David E. and Running, Steven W.},
title = {Terrestrial primary production for the conterminous United States derived from Landsat 30 m and MODIS 250 m},
journal = {Remote Sensing in Ecology and Conservation},
publisher = {Wiley-Blackwell},
year = {2018},
volume = {4},
number = {3},
pages = {264--280},
doi = {10.1002/rse2.74}
}
|
| Rödenbeck C, Zaehle S, Keeling R and Heimann M (2018), "How does the terrestrial carbon exchange respond to inter-Annual climatic variations? A quantification based on atmospheric CO2 data", Biogeosciences., apr, 2018. Vol. 15(8), pp. 2481-2498. Copernicus GmbH. |
| Abstract: The response of the terrestrial net ecosystem exchange (NEE) of CO2 to climate variations and trends may crucially determine the future climate trajectory. Here we directly quantify this response on inter-Annual timescales by building a linear regression of inter-Annual NEE anomalies against observed air temperature anomalies into an atmospheric inverse calculation based on long-Term atmospheric CO2 observations. This allows us to estimate the sensitivity of NEE to inter-Annual variations in temperature (seen as a climate proxy) resolved in space and with season. As this sensitivity comprises both direct temperature effects and the effects of other climate variables co-varying with temperature, we interpret it as qinter-Annual climate sensitivity/q. We find distinct seasonal patterns of this sensitivity in the northern extratropics that are consistent with the expected seasonal responses of photosynthesis, respiration, and fire. Within uncertainties, these sensitivity patterns are consistent with independent inferences from eddy covariance data. On large spatial scales, northern extratropical and tropical inter-Annual NEE variations inferred from the NEE-iT/i regression are very similar to the estimates of an atmospheric inversion with explicit inter-Annual degrees of freedom. The results of this study offer a way to benchmark ecosystem process models in more detail than existing effective global climate sensitivities. The results can also be used to gap-fill or extrapolate observational records or to separate inter-Annual variations from longer-Term trends. |
BibTeX:
@article{Rodenbeck2018,
author = {Rödenbeck, Christian and Zaehle, Sönke and Keeling, Ralph and Heimann, Martin},
title = {How does the terrestrial carbon exchange respond to inter-Annual climatic variations? A quantification based on atmospheric CO2 data},
journal = {Biogeosciences},
publisher = {Copernicus GmbH},
year = {2018},
volume = {15},
number = {8},
pages = {2481--2498},
doi = {10.5194/bg-15-2481-2018}
}
|
| Roobaert A, Laruelle GG, Landschützer P and Regnier P (2018), "Uncertainty in the global oceanic CO2 uptake induced by wind forcing: Quantification and spatial analysis", Biogeosciences. Vol. 15(6), pp. 1701-1720. Copernicus GmbH. |
| Abstract: The calculation of the air-water CO2 exchange (FCO2) in the ocean not only depends on the gradient in CO2 partial pressure at the air-water interface but also on the parameterization of the gas exchange transfer velocity (k) and the choice of wind product. Here, we present regional and global-scale quantifications of the uncertainty in FCO2 induced by several widely used k formulations and four wind speed data products (CCMP, ERA, NCEP1 and NCEP2). The analysis is performed at a 1° × 1° resolution using the sea surface pCO2 climatology generated by Landschützer et al. (2015a) for the 1991-2011 period, while the regional assessment relies on the segmentation proposed by the Regional Carbon Cycle Assessment and Processes (RECCAP) project. First, we use k formulations derived from the global 14C inventory relying on a quadratic relationship between k and wind speed (k Combining double low line c g U102; Sweeney et al., 2007; Takahashi et al., 2009; Wanninkhof, 2014), where c is a calibration coefficient and U10 is the wind speed measured 10 m above the surface. Our results show that the range of global FCO2, calculated with these k relationships, diverge by 12 % when using CCMP, ERA or NCEP1. Due to differences in the regional wind patterns, regional discrepancies in FCO2 are more pronounced than global. These global and regional differences significantly increase when using NCEP2 or other k formulations which include earlier relationships (i.e., Wanninkhof, 1992; Wanninkhof et al., 2009) as well as numerous local and regional parameterizations derived experimentally. To minimize uncertainties associated with the choice of wind product, it is possible to recalculate the coefficient c globally (hereafter called c-) for a given wind product and its spatio-temporal resolution, in order to match the last evaluation of the global k value. We thus performed these recalculations for each wind product at the resolution and time period of our study but the resulting global FCO2 estimates still diverge by 10 %. These results also reveal that the Equatorial Pacific, the North Atlantic and the Southern Ocean are the regions in which the choice of wind product will most strongly affect the estimation of the FCO2, even when using c-. |
BibTeX:
@article{Roobaert2018,
author = {Roobaert, Alizée and Laruelle, Goulven G and Landschützer, Peter and Regnier, Pierre},
title = {Uncertainty in the global oceanic CO2 uptake induced by wind forcing: Quantification and spatial analysis},
journal = {Biogeosciences},
publisher = {Copernicus GmbH},
year = {2018},
volume = {15},
number = {6},
pages = {1701--1720},
doi = {10.5194/bg-15-1701-2018}
}
|
| Sabbatini S, Mammarella I, Arriga N, Fratini G, Graf A, Hörtnagl L, Ibrom A, Longdoz B, Mauder M, Merbold L, Metzger S, Montagnani L, Pitacco A, Rebmann C, Sedlák P, Šigut L, Vitale D and Papale D (2018), "Eddy covariance raw data processing for CO 2 and energy fluxes calculation at ICOS ecosystem stations", International Agrophysics., dec, 2018. Vol. 32(4), pp. 495-515. |
| Abstract: The eddy covariance is a powerful technique to estimate the surface-Atmosphere exchange of different scalars at the ecosystem scale. The EC method is central to the ecosystem component of the Integrated Carbon Observation System, a monitoring network for greenhouse gases across the European Continent. The data processing sequence applied to the collected raw data is complex, and multiple robust options for the different steps are often available. For Integrated Carbon Observation System and similar networks, the standardisation of methods is essential to avoid methodological biases and improve comparability of the results. We introduce here the steps of the processing chain applied to the eddy covariance data of Integrated Carbon Observation System stations for the estimation of final CO 2 , water and energy fluxes, including the calculation of their uncertainties. The selected methods are discussed against valid alternative options in terms of suitability and respective drawbacks and advantages. The main challenge is to warrant standardised processing for all stations in spite of the large differences in e.g. ecosystem traits and site conditions. The main achievement of the Integrated Carbon Observation System eddy covariance data processing is making CO 2 and energy flux results as comparable and reliable as possible, given the current micrometeorological understanding and the generally accepted state-of-The-Art processing methods. |
BibTeX:
@article{Sabbatini2018,
author = {Sabbatini, Simone and Mammarella, Ivan and Arriga, Nicola and Fratini, Gerardo and Graf, Alexander and Hörtnagl, Lukas and Ibrom, Andreas and Longdoz, Bernard and Mauder, Matthias and Merbold, Lutz and Metzger, Stefan and Montagnani, Leonardo and Pitacco, Andrea and Rebmann, Corinna and Sedlák, Pavel and Šigut, Ladislav and Vitale, Domenico and Papale, Dario},
title = {Eddy covariance raw data processing for CO 2 and energy fluxes calculation at ICOS ecosystem stations},
journal = {International Agrophysics},
year = {2018},
volume = {32},
number = {4},
pages = {495--515},
url = {https://content.sciendo.com/view/journals/intag/32/4/article-p495.xml},
doi = {10.1515/intag-2017-0043}
}
|
| Santalahti M, Sun H, Sietiö OM, Köster K, Berninger F, Laurila T, Pumpanen J and Heinonsalo J (2018), "Reindeer grazing alter soil fungal community structure and litter decomposition related enzyme activities in boreal coniferous forests in Finnish Lapland", Applied Soil Ecology., dec, 2018. Vol. 132, pp. 74-82. Elsevier BV. |
| Abstract: Reindeer grazing in northern boreal zone affects forest floor vegetation heavily and alters the vegetation structure. However, the effect of grazing on soil fungal communities, which are intimately linked to plants, is not currently known. Therefore, our objectives were to investigate changes caused by reindeer grazing on soil fungal communities, litter decomposition rate and litter degrading extracellular enzyme activities. The study was conducted in four areas divided into grazed and non-grazed sites (all together 38 sample plots) in northern boreal forests in Finnish Lapland. Fungal communities were analyzed from humus with high-throughput sequencing technology (454-pyrosequencing), and litter mass loss and extracellular enzyme activities were analyzed after a one-year litterbag experiment. The results showed that grazing significantly affected the fungal community structure and the abundance of certain fungal genera and species. Grazing also decreased laccase and enhanced cellobiohydrolase I activities from the litterbags. Our study is one of the first to describe detailed fungal community composition in sites with long-term history of reindeer grazing and exclusion. Our results indicate that reindeer grazing alter fungal community structure and litter degradation related enzyme activities in the northern boreal forest soils. |
BibTeX:
@article{Santalahti2018,
author = {Santalahti, Minna and Sun, Hui and Sietiö, Outi Maaria and Köster, Kajar and Berninger, Frank and Laurila, Tuomas and Pumpanen, Jukka and Heinonsalo, Jussi},
title = {Reindeer grazing alter soil fungal community structure and litter decomposition related enzyme activities in boreal coniferous forests in Finnish Lapland},
journal = {Applied Soil Ecology},
publisher = {Elsevier BV},
year = {2018},
volume = {132},
pages = {74--82},
doi = {10.1016/j.apsoil.2018.08.013}
}
|
| Saunders M, Dengel S, Kolari P, Moureaux C, Montagnani L, Ceschia E, Altimir N, López-Ballesteros A, Maraʼnon-Jimenez S, Acosta M, Klumpp K, Gielen B, De Beeck MO, Hörtnagl L, Merbold L, Osborne B, Grünwald T, Arrouays D, Boukir H, Saby N, Nicolini G, Papale D and Jones M (2018), "Importance of reporting ancillary site characteristics, and management and disturbance information at ICOS stations", International Agrophysics., dec, 2018. Vol. 32(4), pp. 457-469. |
| Abstract: There are many factors that influence ecosystem scale carbon, nitrogen and greenhouse gas dynamics, including the inherent heterogeneity of soils and vegetation, anthropogenic management interventions, and biotic and abiotic disturbance events. It is important therefore, to document the characteristics of the soils and vegetation and to accurately report all management activities, and disturbance events to aid the interpretation of collected data, and to determine whether the ecosystem either amplifies or mitigates climate change. This paper outlines the importance of assessing both the spatial and temporal variability of soils and vegetation and to report all management events, the import or export of C or N from the ecosystem, and the occurrence of biotic/abiotic disturbances at ecosystem stations of the Integrated Carbon Observation System, a pan-European research infrastructure. |
BibTeX:
@article{Saunders2018,
author = {Saunders, Matthew and Dengel, Sigrid and Kolari, Pasi and Moureaux, Christine and Montagnani, Leonardo and Ceschia, Eric and Altimir, Nuria and López-Ballesteros, Ana and Maraʼnon-Jimenez, Sara and Acosta, Manuel and Klumpp, Katja and Gielen, Bert and De Beeck, Maarten Op and Hörtnagl, Lukas and Merbold, Lutz and Osborne, Bruce and Grünwald, Thomas and Arrouays, Dominique and Boukir, Hakima and Saby, Nicolas and Nicolini, Giacomo and Papale, Dario and Jones, Michael},
title = {Importance of reporting ancillary site characteristics, and management and disturbance information at ICOS stations},
journal = {International Agrophysics},
year = {2018},
volume = {32},
number = {4},
pages = {457--469},
url = {https://content.sciendo.com/view/journals/intag/32/4/article-p457.xml},
doi = {10.1515/intag-2017-0040}
}
|
| Siewert MB (2018), "High-resolution digital mapping of soil organic carbon in permafrost terrain using machine learning: A case study in a sub-Arctic peatland environment", Biogeosciences. Vol. 15(6), pp. 1663-1682. Copernicus GmbH. |
| Abstract: Soil organic carbon (SOC) stored in northern peatlands and permafrost-affected soils are key components in the global carbon cycle. This article quantifies SOC stocks in a sub-Arctic mountainous peatland environment in the discontinuous permafrost zone in Abisko, northern Sweden. Four machine-learning techniques are evaluated for SOC quantification: multiple linear regression, artificial neural networks, support vector machine and random forest. The random forest model performed best and was used to predict SOC for several depth increments at a spatial resolution of 1 m (1×1 m). A high-resolution (1 m) land cover classification generated for this study is the most relevant predictive variable. The landscape mean SOC storage (0-150 cm) is estimated to be 8.3 ± 8.0 kg C mg-2 and the SOC stored in the top meter (0-100 cm) to be 7.7 ± 6.2 kg C mg-2. The predictive modeling highlights the relative importance of wetland areas and in particular peat plateaus for the landscape's SOC storage. The total SOC was also predicted at reduced spatial resolutions of 2, 10, 30, 100, 250 and 1000 m and shows a significant drop in land cover class detail and a tendency to underestimate the SOC at resolutions 30 m. This is associated with the occurrence of many small-scale wetlands forming local hot-spots of SOC storage that are omitted at coarse resolutions. Sharp transitions in SOC storage associated with land cover and permafrost distribution are the most challenging methodological aspect. However, in this study, at local, regional and circum-Arctic scales, the main factor limiting robust SOC mapping efforts is the scarcity of soil pedon data from across the entire environmental space. For the Abisko region, past SOC and permafrost dynamics indicate that most of the SOC is barely 2000 years old and very dynamic. Future research needs to investigate the geomorphic response of permafrost degradation and the fate of SOC across all landscape compartments in post-permafrost landscapes. |
BibTeX:
@article{Siewert2018,
author = {Siewert, Matthias B},
title = {High-resolution digital mapping of soil organic carbon in permafrost terrain using machine learning: A case study in a sub-Arctic peatland environment},
journal = {Biogeosciences},
publisher = {Copernicus GmbH},
year = {2018},
volume = {15},
number = {6},
pages = {1663--1682},
doi = {10.5194/bg-15-1663-2018}
}
|
| Singleton CM, McCalley CK, Woodcroft BJ, Boyd JA, Evans PN, Hodgkins SB, Chanton JP, Frolking S, Crill PM, Saleska SR, Rich VI and Tyson GW (2018), "Methanotrophy across a natural permafrost thaw environment", ISME Journal., jun, 2018. Vol. 12(10), pp. 2544-2558. Springer Nature. |
| Abstract: The fate of carbon sequestered in permafrost is a key concern for future global warming as this large carbon stock is rapidly becoming a net methane source due to widespread thaw. Methane release from permafrost is moderated by methanotrophs, which oxidise 20–60% of this methane before emission to the atmosphere. Despite the importance of methanotrophs to carbon cycling, these microorganisms are under-characterised and have not been studied across a natural permafrost thaw gradient. Here, we examine methanotroph communities from the active layer of a permafrost thaw gradient in Stordalen Mire (Abisko, Sweden) spanning three years, analysing 188 metagenomes and 24 metatranscriptomes paired with in situ biogeochemical data. Methanotroph community composition and activity varied significantly as thaw progressed from intact permafrost palsa, to partially thawed bog and fully thawed fen. Thirteen methanotroph population genomes were recovered, including two novel genomes belonging to the uncultivated upland soil cluster alpha (USCα) group and a novel potentially methanotrophic Hyphomicrobiaceae. Combined analysis of porewater δ13C-CH4 isotopes and methanotroph abundances showed methane oxidation was greatest below the oxic–anoxic interface in the bog. These results detail the direct effect of thaw on autochthonous methanotroph communities, and their consequent changes in population structure, activity and methane moderation potential. |
BibTeX:
@article{Singleton2018,
author = {Singleton, Caitlin M and McCalley, Carmody K and Woodcroft, Ben J and Boyd, Joel A and Evans, Paul N and Hodgkins, Suzanne B and Chanton, Jeffrey P and Frolking, Steve and Crill, Patrick M and Saleska, Scott R and Rich, Virginia I and Tyson, Gene W},
title = {Methanotrophy across a natural permafrost thaw environment},
journal = {ISME Journal},
publisher = {Springer Nature},
year = {2018},
volume = {12},
number = {10},
pages = {2544--2558},
doi = {10.1038/s41396-018-0065-5}
}
|
| Skogen MD, Hjøllo SS, Sandø AB and Tjiputra J (2018), "Future ecosystem changes in the Northeast Atlantic: a comparison between a global and a regional model system", ICES Journal of Marine Science., jul, 2018. Vol. 75(7), pp. 2355-2369. Oxford University Press (OUP). |
| Abstract: The biogeochemistry from a global climate model (Norwegian Earth System Model) has been compared with results from a regional model (NORWECOM.E2E), where the regional model is forced by downscaled physics from the global model. The study should both be regarded as a direct comparison between a regional and its driving global model to investigate at what extent a global climate model can be used for regional studies, and a study of the future climate change in the Nordic and Barents Seas. The study concludes that the global and regional model compare well on trends, but many details are lost when a coarse resolution global model is used to assess climate impact on regional scale. The main difference between the two models is the timing of the spring bloom, and a non-exhaustive nutrient consumption in the global model in summer. The global model has a cold (in summer) and saline bias compared with climatology. This is both due to poorly resolved physical processes and oversimplified ecosystem parameterization. Through the downscaling the regional model is to some extent able to alleviate the bias in the physical fields, and the timing of the spring bloom is close to observations. The summer nutrient minimum is one month early. There is no trend in future primary production in any of the models, and the trends in modelled pH and X Ar are also the same in both models. The largest discrepancy in the future projection is in the development of the CO 2 uptake, where the regional suggests a slightly reduced uptake in the future. |
BibTeX:
@article{Skogen2018,
author = {Skogen, Morten D and Hjøllo, Solfrid S and Sandø, Anne Britt and Tjiputra, Jerry},
title = {Future ecosystem changes in the Northeast Atlantic: a comparison between a global and a regional model system},
journal = {ICES Journal of Marine Science},
publisher = {Oxford University Press (OUP)},
year = {2018},
volume = {75},
number = {7},
pages = {2355--2369},
doi = {10.1093/icesjms/fsy088}
}
|
| Sponseller RA, Blackburn M, Nilsson MB and Laudon H (2018), "Headwater Mires Constitute a Major Source of Nitrogen (N) to Surface Waters in the Boreal Landscape", Ecosystems., jan, 2018. Vol. 21(1), pp. 31-44. Springer Nature. |
| Abstract: Nutrient exports from soils have important implications for long-term patterns of nutrient limitation on land and resource delivery to aquatic environments. While plant–soil systems are notably efficient at retaining limiting nutrients, spatial and temporal mismatches in resource supply and demand may create opportunities for hydrologic losses to occur. Spatial mismatches may be particularly important in peat-forming landscapes, where the development of a two-layer vertical structure can isolate plant communities on the surface from resource pools that accumulate at depth. Our objectives were to test this idea in northern Sweden, where nitrogen (N) limitation of terrestrial plants is widespread, and where peat-forming, mire ecosystems are dominant features of the landscape. We quantified vertical patterns of N chemistry in a minerogenic mire, estimated the seasonal and annual hydrologic export of organic and inorganic N from this system, and evaluated the broader influence of mire cover on N chemistry across a stream network. Relatively high concentrations of ammonium (up to 2 mg lâˆ'1) were observed in groundwater several meters below the peat surface, and N was routed to the outlet stream along deep, preferential flowpaths. Areal estimates of inorganic N export from the mire were several times greater than from an adjacent, forested catchment, with markedly higher loss rates during the growing season, when plant N demand is ostensibly greatest. At broader scales, mire cover was positively correlated with long-term concentrations of inorganic and organic N in streams across the drainage network. This study provides an example of how mire formation and peat accumulation can create broad-scale heterogeneity in nutrient supply and demand across boreal landscapes. This mismatch allows for hydrologic losses of reactive N that are independent of annual plant demand and potentially important to receiving lakes and streams. |
BibTeX:
@article{Sponseller2018,
author = {Sponseller, Ryan A and Blackburn, M and Nilsson, M B and Laudon, H},
title = {Headwater Mires Constitute a Major Source of Nitrogen (N) to Surface Waters in the Boreal Landscape},
journal = {Ecosystems},
publisher = {Springer Nature},
year = {2018},
volume = {21},
number = {1},
pages = {31--44},
doi = {10.1007/s10021-017-0133-0}
}
|
| Sprenger M, Tetzlaff D, Buttle J, Laudon H, Leistert H, Mitchell CPJ, Snelgrove J, Weiler M and Soulsby C (2018), "Measuring and Modeling Stable Isotopes of Mobile and Bulk Soil Water", Vadose Zone Journal. Vol. 17(1), pp. 170149. Soil Science Society of America. |
| Abstract: textcopyright Soil Science Society of America. Recent findings from stable isotope studies have opened up new questions about differences in the isotopic composition (d2H and d18O) of mobile (MW) and bulk water (BW) in soils. We sampled the isotopic compositions of MW using suction lysimeters and BW with the direct-equilibration method. The study was conducted at two landscape units in each of three catchments: the Bruntland Burn (Scotland), Dorset (Canada), and Krycklan (Sweden). We further used the numerical one-dimensional flow model SWIS (Soil Water Isotope Simulator) to simulate the hydrometric and isotopic dynamics. The model included evaporation fractionation, allowed differentiation between a fast and a slow flow domain, and included isotopic exchange via water vapor. Our measurements showed that MW plots along the local meteoric water lines, whereas BW plots below, which is indicative of evaporation fractionation. We suggest that the relative volume of MW to BW is relevant for explaining these isotopic differences because MW volumes are usually relatively low during periods of high evaporation. Under this condition, differences between MW and plant water isotopes are not paradoxical but rather related to the water that cannot be sampled with suction lysimeters but is still available for plant water uptake. The simulations accounting for fast and slow flow supported the conceptualization of the two soil pore domains with isotopic exchange via vapor exchange because this model setup resulted in the best model performance. Overall, these findings are of high relevance for current understanding related to the source and isotopic composition of water taken up by plants. |
BibTeX:
@article{Sprenger2018,
author = {Sprenger, Matthias and Tetzlaff, Doerthe and Buttle, Jim and Laudon, Hjalmar and Leistert, Hannes and Mitchell, Carl P J and Snelgrove, Jenna and Weiler, Markus and Soulsby, Chris},
title = {Measuring and Modeling Stable Isotopes of Mobile and Bulk Soil Water},
journal = {Vadose Zone Journal},
publisher = {Soil Science Society of America},
year = {2018},
volume = {17},
number = {1},
pages = {170149},
doi = {10.2136/vzj2017.08.0149}
}
|
| Sprenger M, Tetzlaff D, Buttle J, Carey SK, McNamara JP, Laudon H, Shatilla NJ and Soulsby C (2018), "Storage, mixing, and fluxes of water in the critical zone across northern environments inferred by stable isotopes of soil water", Hydrological Processes., jun, 2018. Vol. 32(12), pp. 1720-1737. Wiley. |
| Abstract: Quantifying soil water storage, mixing, and release via recharge, transpiration, and evaporation is essential for a better understanding of critical zone processes. Here, we integrate stable isotope (2H and 18O of soil water, precipitation, and groundwater) and hydrometric (soil moisture) data from 5 long-term experimental catchments along a hydroclimatic gradient across northern latitudes: Dry Creek (USA), Bruntland Burn (Scotland), Dorset (Canada), Krycklan (Sweden), and Wolf Creek (Canada). Within each catchment, 6 to 11 isotope sampling campaigns occurred at 2 to 4 sampling locations over at least 1Â year. Analysis for 2H and 18O in the bulk pore water was done for 2,500 soil samples either by cryogenic extraction (Dry Creek) or by direct equilibration (other sites). The results showed a similar general pattern that soil water isotope variability reflected the seasonality of the precipitation input signal. However, pronounced differences among sampling locations occurred regarding the isotopic fractionation due to evaporation. We found that antecedent precipitation volumes mainly governed the fractionation signal, temperature and evaporation rates were of secondary importance, and soil moisture played only a minor role in the variability of soil water evaporation fractionation across the hydroclimatic gradient. We further observed that soil waters beneath conifer trees were more fractionated than beneath heather shrubs or red oak trees, indicating higher soil evaporation rates in coniferous forests. Sampling locations closer to streams were more damped and depleted in their stable isotopic composition than hillslope sites, revealing increased subsurface mixing towards the saturated zone and a preferential recharge of winter precipitation. Bulk soil waters generally comprised a high share of waters older than 14Â days, which indicates that the water in soil pores are usually not fully replaced by recent infiltration events. The presented stable isotope data of soil water were, thus, a useful tool to track the spatial variability of water fluxes within and from the critical zone. Such data provide invaluable information to improve the representation of critical zone processes in spatially distributed hydrological models. |
BibTeX:
@article{Sprenger2018a,
author = {Sprenger, Matthias and Tetzlaff, Doerthe and Buttle, Jim and Carey, Sean K and McNamara, James P and Laudon, Hjalmar and Shatilla, Nadine J and Soulsby, Chris},
title = {Storage, mixing, and fluxes of water in the critical zone across northern environments inferred by stable isotopes of soil water},
journal = {Hydrological Processes},
publisher = {Wiley},
year = {2018},
volume = {32},
number = {12},
pages = {1720--1737},
doi = {10.1002/hyp.13135}
}
|
| Stocker M, Paasonen P, Fiebig M, Zaidan MA and Hardisty A (2018), "Curating Scientific Information in Knowledge Infrastructures" |
| Abstract: Interpreting observational data is a fundamental task in the sciences, specifically in earth and environmental science where observational data are increasingly acquired, curated, and published systematically by environmental research infrastructures. Typically subject to substantial processing, observational data are used by research communities, their research groups and individual scientists, who interpret such primary data for their meaning in the context of research investigations. The result of interpretation is information-meaningful secondary or derived data-about the observed environment. Research infrastructures and research communities are thus essential to evolving uninterpreted observational data to information. In digital form, the classical bearer of information are the commonly known "(elaborated) data products," for instance maps. In such form, meaning is generally implicit e.g., in map colour coding, and thus largely inaccessible to machines. The systematic acquisition, curation, possible publishing and further processing of information gained in observational data interpretation-as machine readable data and their machine readable meaning-is not common practice among environmental research infrastructures. For a use case in aerosol science, we elucidate these problems and present a Jupyter based prototype infrastructure that exploits a machine learning approach to interpretation and could support a research community in interpreting observational data and, more importantly, in curating and further using resulting information about a studied natural phenomenon. |
BibTeX:
@article{Stocker2018,
author = {Stocker, Markus and Paasonen, Pauli and Fiebig, Markus and Zaidan, Martha A and Hardisty, Alex},
title = {Curating Scientific Information in Knowledge Infrastructures},
year = {2018},
url = {https://doi.org/10.5334/dsj-2018-021},
doi = {10.5334/dsj-2018-021}
}
|
| Sun W, Kooijmans LM, Maseyk K, Chen H, Mammarella I, Vesala T, Levula J, Keskinen H and Seibt U (2018), "Soil fluxes of carbonyl sulfide (COS), carbon monoxide, and carbon dioxide in a boreal forest in southern Finland", Atmospheric Chemistry and Physics., feb, 2018. Vol. 18(2), pp. 1363-1378. Copernicus GmbH. |
| Abstract: Soil is a major contributor to the biosphere - atmosphere exchange of carbonyl sulfide (COS) and carbon monoxide (CO). COS is a tracer with which to quantify terrestrial photosynthesis based on the coupled leaf uptake of COS and CO2, but such use requires separating soil COS flux, which is unrelated to photosynthesis, from ecosystem COS uptake. For CO, soil is a significant natural sink that influences the tropospheric CO budget. In the boreal forest, magnitudes and variabilities of soil COS and CO fluxes remain poorly understood. We measured hourly soil fluxes of COS, CO, and CO2 over the 2015 late growing season (July to November) in a Scots pine forest in Hyytiälä, Finland. The soil acted as a net sink of COS and CO, with average uptake rates around 3 pmolm-2 s-1 for COS and 1 nmolm-2 s-1 for CO. Soil respiration showed seasonal dynamics controlled by soil temperature, peaking at around 4 μmolm-2 s-1 in late August and September and dropping to 1-2 μmolm-2 s-1 in October. In contrast, seasonal variations of COS and CO fluxes were weak and mainly driven by soil moisture changes through diffusion limitation. COS and CO fluxes did not appear to respond to temperature variation, although they both correlated well with soil respiration in specific temperature bins. However, COS V CO2 and CO V CO2 flux ratios increased with temperature, suggesting possible shifts in active COS- and CO-consuming microbial groups. Our results show that soil COS and CO fluxes do not have strong variations over the late growing season in this boreal forest and can be represented with the fluxes during the photosynthetically most active period. Well-characterized and relatively invariant soil COS fluxes strengthen the case for using COS as a photosynthetic tracer in boreal forests. |
BibTeX:
@article{Sun2018,
author = {Sun, Wu and Kooijmans, Linda M.J. and Maseyk, Kadmiel and Chen, Huilin and Mammarella, Ivan and Vesala, Timo and Levula, Janne and Keskinen, Helmi and Seibt, Ulli},
title = {Soil fluxes of carbonyl sulfide (COS), carbon monoxide, and carbon dioxide in a boreal forest in southern Finland},
journal = {Atmospheric Chemistry and Physics},
publisher = {Copernicus GmbH},
year = {2018},
volume = {18},
number = {2},
pages = {1363--1378},
doi = {10.5194/acp-18-1363-2018}
}
|
| Sun Z, Wang X, Yamamoto H, Tani H, Zhong G and Yin S (2018), "An attempt to introduce atmospheric CO2 concentration data to estimate the gross primary production by the terrestrial biosphere and analyze its effects", Ecological Indicators., jan, 2018. Vol. 84, pp. 218-234. Elsevier B.V.. |
| Abstract: Quantitative estimations of the GPP (gross primary production) and its variations at spatial scales are important issues with future significance due to the increasing atmospheric CO2 levels. However, the effects of the spatiotemporal variability in the atmospheric CO2 concentrations on GPP estimations are challenging with respect to the terrestrial ecosystem due to land cover component characteristics and difficulties associated with measuring CO2 concentrations over large spatial areas. The development of remote sensing offer a means to routinely monitor CO2 concentrations both spatially and temporally from space. To introduce continuous spatial CO2 data as an indicator for the estimation of the terrestrial biosphere GPP, we used the decoupling coefficients to evaluate the canopy CO2 concentrations, photosynthetic biochemical models to calculate the photosynthetic rate, and Big-leaf model to scale up to a global scale. The GPPs estimated by this method are relatively consistent with the GPP derived from Flux tower sites. Thus, the method proposed in this study utilizing continuous spatial CO2 data to estimate the GPP is practicable and feasible. Finally, we compared the GPPs under different atmospheric CO2 concentrations conditions between 2000 and 2014 and analyzed the effects of the spatiotemporal variability in the atmospheric CO2 concentrations on the GPP estimates. The results show that, in general, the terrestrial GPP increases as atmospheric CO2 concentrations increase, and the increases in the lower latitudes are more significant than those in the middle and high latitudes; by comparing the annual GPP estimates in 2000 with those in 2014, it was observed that the increases in forest GPP is greater than that of other functional types. The effects of the variations in the spatial distribution of atmospheric CO2 concentrations on the terrestrial GPP distribution vary based on time and location. Regarding the annual GPP estimates, without considering the CO2 spatial distribution, the estimates overestimate the GPP in the lower latitudes and underestimate those in the middle and high latitudes. Regarding the monthly GPP estimates, using the annual averages caused the GPP estimates of the Northern Hemisphere to be overestimated during the first half of the year, while those during the second half of the year were underestimated; the GPP estimates for the Southern Hemisphere were underestimated each month. However, using monthly averages caused the GPP estimates for the Northern Hemisphere to be overestimated in summer and underestimated in spring and autumn, which are opposite to the estimates for the Southern Hemisphere. |
BibTeX:
@article{Sun2018a,
author = {Sun, Zhongyi and Wang, Xiufeng and Yamamoto, Haruhiko and Tani, Hiroshi and Zhong, Guosheng and Yin, Shuai},
title = {An attempt to introduce atmospheric CO2 concentration data to estimate the gross primary production by the terrestrial biosphere and analyze its effects},
journal = {Ecological Indicators},
publisher = {Elsevier B.V.},
year = {2018},
volume = {84},
pages = {218--234},
doi = {10.1016/j.ecolind.2017.08.057}
}
|
| Susiluoto J, Raivonen M, Backman L, Laine M, Makela J, Peltola O, Vesala T and Aalto T (2018), "Calibrating the sqHIMMELI v1.0 wetland methane emission model with hierarchical modeling and adaptive MCMC", Geoscientific Model Development. Vol. 11(3), pp. 1199-1228. Copernicus GmbH. |
| Abstract: Estimating methane (CH4) emissions from natural wetlands is complex, and the estimates contain large uncertainties. The models used for the task are typically heavily parameterized and the parameter values are not well known. In this study, we perform a Bayesian model calibration for a new wetland CH4 emission model to improve the quality of the predictions and to understand the limitations of such models. The detailed process model that we analyze contains descriptions for CH4 production from anaerobic respiration, CH4 oxidation, and gas transportation by diffusion, ebullition, and the aerenchyma cells of vascular plants. The processes are controlled by several tunable parameters. We use a hierarchical statistical model to describe the parameters and obtain the posterior distributions of the parameters and uncertainties in the processes with adaptive Markov chain Monte Carlo (MCMC), importance resampling, and time series analysis techniques. For the estimation, the analysis utilizes measurement data from the Siikaneva flux measurement site in southern Finland. The uncertainties related to the parameters and the modeled processes are described quantitatively. At the process level, the flux measurement data are able to constrain the CH4 production processes, methane oxidation, and the different gas transport processes. The posterior covariance structures explain how the parameters and the processes are related. Additionally, the flux and flux component uncertainties are analyzed both at the annual and daily levels. The parameter posterior densities obtained provide information regarding importance of the different processes, which is also useful for development of wetland methane emission models other than the square root HelsinkI Model of MEthane buiLd-up and emIssion for peatlands (sqHIMMELI). The hierarchical modeling allows us to assess the effects of some of the parameters on an annual basis. The results of the calibration and the cross validation suggest that the early spring net primary production could be used to predict parameters affecting the annual methane production. Even though the calibration is specific to the Siikaneva site, the hierarchical modeling approach is well suited for larger-scale studies and the results of the estimation pave way for a regional or global-scale Bayesian calibration of wetland emission models. |
BibTeX:
@article{Susiluoto2018,
author = {Susiluoto, Jouni and Raivonen, Maarit and Backman, Leif and Laine, Marko and Makela, Jarmo and Peltola, Olli and Vesala, Timo and Aalto, Tuula},
title = {Calibrating the sqHIMMELI v1.0 wetland methane emission model with hierarchical modeling and adaptive MCMC},
journal = {Geoscientific Model Development},
publisher = {Copernicus GmbH},
year = {2018},
volume = {11},
number = {3},
pages = {1199--1228},
doi = {10.5194/gmd-11-1199-2018}
}
|
| Tamrakar R, Rayment MB, Moyano F, Mund M and Knohl A (2018), "Implications of structural diversity for seasonal and annual carbon dioxide fluxes in two temperate deciduous forests", Agricultural and Forest Meteorology., dec, 2018. Vol. 263, pp. 465-476. Elsevier BV. |
| Abstract: The effects of structural diversity on the carbon dioxide exchange (CO2) of forests has become an important area of research for improving the predictability of future CO2 budgets. We report the results of a paired eddy covariance tower study with 11 years of data on two forest sites of similar mean stand age, near-identical site conditions, and dominated by beech trees (Fagus sylvatica), but with a very different stand structure (incl. age, diameter distribution, stocks of dead wood and species composition) because of different management regimes. Here we address the question of how management and related structural diversity may affect CO2 fluxes, and tested the hypothesis that more structurally diverse stands are less sensitive to variations in abiotic and biotic drivers. Higher annual net ecosystem productivity (NEP) was observed in the managed, even-aged, and homogenous forest (585 ± 57.8 g C mâˆ'2 yrâˆ'1), than in the unmanaged, uneven-aged, and structurally diverse forest (487 ± 144 g C mâˆ'2 yrâˆ'1). About two-third of the difference in NEP between the sites was contributed by a higher annual gross primary productivity (GPP, 1627 ± 164 vs 1558 ± 118 g C mâˆ'2 yrâˆ'1) and one-third by a lower annual ecosystem respiration (Reco, 1042 ± 60 vs 1071 ± 96 g C mâˆ'2 yrâˆ'1) in the homogenous forest. Spring (April – May) and summer (June – July) were the two main seasons contributing to the overall annual differences between the sites, also, the sensitivities of seasonal NEP and GPP to environmental variables were stronger in the homogenous forest during those periods. Inter-annual variation of NEP was higher in the homogenous forest (coefficient of variation (CV) = 25%) compared to the heterogeneous forest (CV = 12%). At annual time scale, the higher variability of NEP in the homogenous forest is attributed to biotic factors such as fruit production and a time-dependent growth trend, outweighing differences in environmental sensitivities. |
BibTeX:
@article{Tamrakar2018,
author = {Tamrakar, Rijan and Rayment, Mark B and Moyano, Fernando and Mund, Martina and Knohl, Alexander},
title = {Implications of structural diversity for seasonal and annual carbon dioxide fluxes in two temperate deciduous forests},
journal = {Agricultural and Forest Meteorology},
publisher = {Elsevier BV},
year = {2018},
volume = {263},
pages = {465--476},
doi = {10.1016/j.agrformet.2018.08.027}
}
|
| Tang J, Yurova AY, Schurgers G, Miller PA, Olin S, Smith B, Siewert MB, Olefeldt D, Pilesjö P and Poska A (2018), "Drivers of dissolved organic carbon export in a subarctic catchment: Importance of microbial decomposition, sorption-desorption, peatland and lateral flow", Science of the Total Environment. Vol. 622-623, pp. 260-274. Elsevier BV. |
| Abstract: Tundra soils account for 50% of global stocks of soil organic carbon (SOC), and it is expected that the amplified climate warming in high latitude could cause loss of this SOC through decomposition. Decomposed SOC could become hydrologically accessible, which increase downstream dissolved organic carbon (DOC) export and subsequent carbon release to the atmosphere, constituting a positive feedback to climate warming. However, DOC export is often neglected in ecosystem models. In this paper, we incorporate processes related to DOC production, mineralization, diffusion, sorption-desorption, and leaching into a customized arctic version of the dynamic ecosystem model LPJ-GUESS in order to mechanistically model catchment DOC export, and to link this flux to other ecosystem processes. The extended LPJ-GUESS is compared to observed DOC export at Stordalen catchment in northern Sweden. Vegetation communities include flood-tolerant graminoids (Eriophorum) and Sphagnum moss, birch forest and dwarf shrub communities. The processes, sorption-desorption and microbial decomposition (DOC production and mineralization) are found to contribute most to the variance in DOC export based on a detailed variance-based Sobol sensitivity analysis (SA) at grid cell-level. Catchment-level SA shows that the highest mean DOC exports come from the Eriophorum peatland (fen). A comparison with observations shows that the model captures the seasonality of DOC fluxes. Two catchment simulations, one without water lateral routing and one without peatland processes, were compared with the catchment simulations with all processes. The comparison showed that the current implementation of catchment lateral flow and peatland processes in LPJ-GUESS are essential to capture catchment-level DOC dynamics and indicate the model is at an appropriate level of complexity to represent the main mechanism of DOC dynamics in soils. The extended model provides a new tool to investigate potential interactions among climate change, vegetation dynamics, soil hydrology and DOC dynamics at both stand-alone to catchment scales. |
BibTeX:
@article{Tang2018,
author = {Tang, Jing and Yurova, Alla Y and Schurgers, Guy and Miller, Paul A and Olin, Stefan and Smith, Benjamin and Siewert, Matthias B and Olefeldt, David and Pilesjö, Petter and Poska, Anneli},
title = {Drivers of dissolved organic carbon export in a subarctic catchment: Importance of microbial decomposition, sorption-desorption, peatland and lateral flow},
journal = {Science of the Total Environment},
publisher = {Elsevier BV},
year = {2018},
volume = {622-623},
pages = {260--274},
doi = {10.1016/j.scitotenv.2017.11.252}
}
|
| Tiwari T, Sponseller RA and Laudon H (2018), "Extreme Climate Effects on Dissolved Organic Carbon Concentrations During Snowmelt", Journal of Geophysical Research: Biogeosciences., apr, 2018. Vol. 123(4), pp. 1277-1288. Wiley. |
| Abstract: Extreme weather and climate events are predicted to increase in frequency and severity in the near future, which could have detrimental consequences for water quality in northern latitudes. Key processes that regulate the production and transport of solutes, like dissolved organic carbon (DOC), from soils to streams can be potentially altered by episodes of extreme temperature and/or precipitation. Here we use an intensively studied research catchment in northern Sweden with 23Â years of data to ask how extreme antecedent climate events influence DOC concentration during snowmelt. Specifically, we used a combination of principal components analysis, cluster analysis, and multivariate partial least square analysis to show that almost every year provides some combination of extreme conditions in terms of intensity, duration, or frequency of temperature and/or rainfall. However, in terms of DOC responses to these events, variations in peak concentrations were most closely related to cold winter conditions, winter precipitation (snow), and temperature during the previous autumn. Specifically, years with most severe frost and icing during winter, but low winter precipitation, previous summer precipitation, and warmer autumns, showed the highest peaks in concentrations. In contrast, the lowest peak DOC concentrations were observed during spring snowmelt following high summer precipitation, colder autumns, and high winter precipitation. While this research highlights the importance of winter climate for influencing the DOC concentration during the spring, it also points to the potential importance of lag effects from preceding seasons on responses observed during the snowmelt season. |
BibTeX:
@article{Tiwari2018,
author = {Tiwari, Tejshree and Sponseller, Ryan A and Laudon, Hjalmar},
title = {Extreme Climate Effects on Dissolved Organic Carbon Concentrations During Snowmelt},
journal = {Journal of Geophysical Research: Biogeosciences},
publisher = {Wiley},
year = {2018},
volume = {123},
number = {4},
pages = {1277--1288},
doi = {10.1002/2017JG004272}
}
|
| Trubl G, Jang HB, Roux S, Emerson JB, Solonenko N, Vik DR, Solden L, Ellenbogen J, Runyon AT, Bolduc B, Woodcroft BJ, Saleska SR, Tyson GW, Wrighton KC, Sullivan MB and Rich VI (2018), "Soil Viruses Are Underexplored Players in Ecosystem Carbon Processing", mSystems. Vol. 3(5) American Society for Microbiology. |
| Abstract: Rapidly thawing permafrost harbors ∼30 to 50% of global soil carbon, and the fate of this carbon remains unknown. Microorganisms will play a central role in its fate, and their viruses could modulate that impact via induced mortality and metabolic controls. Because of the challenges of recovering viruses from soils, little is known about soil viruses or their role(s) in microbial biogeochemical cycling. Here, we describe 53 viral populations (viral operational taxonomic units [vOTUs]) recovered from seven quantitatively derived (i.e., not multiple-displacement-amplified) viral-particle metagenomes (viromes) along a permafrost thaw gradient at the Stordalen Mire field site in northern Sweden. Only 15% of these vOTUs had genetic similarity to publicly available viruses in the RefSeq database, and ∼30% of the genes could be annotated, supporting the concept of soils as reservoirs of substantial undescribed viral genetic diversity. The vOTUs exhibited distinct ecology, with different distributions along the thaw gradient habitats, and a shift from soil-virus-like assemblages in the dry palsas to aquatic-virus-like assemblages in the inundated fen. Seventeen vOTUs were linked to microbial hosts ( in silico ), implicating viruses in infecting abundant microbial lineages from Acidobacteria , Verrucomicrobia , and Deltaproteobacteria , including those encoding key biogeochemical functions such as organic matter degradation. Thirty auxiliary metabolic genes (AMGs) were identified and suggested virus-mediated modulation of central carbon metabolism, soil organic matter degradation, polysaccharide binding, and regulation of sporulation. Together, these findings suggest that these soil viruses have distinct ecology, impact host-mediated biogeochemistry, and likely impact ecosystem function in the rapidly changing Arctic. IMPORTANCE This work is part of a 10-year project to examine thawing permafrost peatlands and is the first virome-particle-based approach to characterize viruses in these systems. This method yielded 2-fold-more viral populations (vOTUs) per gigabase of metagenome than vOTUs derived from bulk-soil metagenomes from the same site (J. B. Emerson, S. Roux, J. R. Brum, B. Bolduc, et al., Nat Microbiol 3:870–880, 2018, https://doi.org/10.1038/s41564-018-0190-y). We compared the ecology of the recovered vOTUs along a permafrost thaw gradient and found (i) habitat specificity, (ii) a shift in viral community identity from soil-like to aquatic-like viruses, (iii) infection of dominant microbial hosts, and (iv) carriage of host metabolic genes. These vOTUs can impact ecosystem carbon processing via top-down (inferred from lysing dominant microbial hosts) and bottom-up (inferred from carriage of auxiliary metabolic genes) controls. This work serves as a foundation which future studies can build upon to increase our understanding of the soil virosphere and how viruses affect soil ecosystem services. |
BibTeX:
@article{Trubl2018,
author = {Trubl, Gareth and Jang, Ho Bin and Roux, Simon and Emerson, Joanne B and Solonenko, Natalie and Vik, Dean R and Solden, Lindsey and Ellenbogen, Jared and Runyon, Alexander T and Bolduc, Benjamin and Woodcroft, Ben J and Saleska, Scott R and Tyson, Gene W and Wrighton, Kelly C and Sullivan, Matthew B and Rich, Virginia I},
editor = {Bordenstein, Seth},
title = {Soil Viruses Are Underexplored Players in Ecosystem Carbon Processing},
journal = {mSystems},
publisher = {American Society for Microbiology},
year = {2018},
volume = {3},
number = {5},
doi = {10.1128/msystems.00076-18}
}
|
| Tudoroiu M, Genesio L, Gioli B, Schume H, Knohl A, Brümmer C and Miglietta F (2018), "Solar dimming above temperate forests and its impact on local climate", Environmental Research Letters., jun, 2018. Vol. 13(6) Institute of Physics Publishing. |
| Abstract: Vegetation has a substantial impact on the local climate. Land cover changes through afforestation or deforestation can amplify or mitigate climate warming by changes in biophysical and biogeochemical mechanisms. In the montane to subalpine area of the Eastern Alps in Europe, where forests have constantly expanded in the last four decades, data of meteorological stations show a consistent reduction in incoming global radiation for the period 2000-2015. To assess the potential role of forests in contributing to such a reduction, three site pairs in Central Europe with neighbouring forest and non-forest sites were analysed. In all the pairs, a lower amount of incoming radiation was recorded at the forest site. When biophysical mechanisms such as albedo, surface roughness and Bowen ratio changes were modelled together with changes in global radiation, the total radiative forcing accounted for a rate of change in air temperature was equal to 0.032 °C ± 0.01 °C per Wm-2. These results suggest that local climate is influenced by land cover change through afforestation both via albedo and radiation feedbacks but also by means of indirect biophysical and species-dependent mechanisms. The data obtained for the site pairs in Central Europe are finally discussed to infer the occurrence of similar forest-driven effects in the Eastern Alps which may explain part of the solar dimming observed in high elevation weather stations. |
BibTeX:
@article{Tudoroiu2018,
author = {Tudoroiu, M. and Genesio, L. and Gioli, B. and Schume, H. and Knohl, A. and Brümmer, C. and Miglietta, F.},
title = {Solar dimming above temperate forests and its impact on local climate},
journal = {Environmental Research Letters},
publisher = {Institute of Physics Publishing},
year = {2018},
volume = {13},
number = {6},
doi = {10.1088/1748-9326/aac4e0}
}
|
| Ukkola AM, Pitman AJ, Donat MG, De Kauwe MG and Angélil O (2018), "Evaluating the Contribution of Land-Atmosphere Coupling to Heat Extremes in CMIP5 Models", Geophysical Research Letters., sep, 2018. Vol. 45(17), pp. 9003-9012. Blackwell Publishing Ltd. |
| Abstract: Land-atmosphere coupling can amplify heat extremes under declining soil moisture. Here we evaluate this coupling in 25 Coupled Model Intercomparison Project Phase 5 models using flux tower observations over Europe and North America. We compared heat extremes (2.5% of the hottest days of the year) and the evaporative fraction (EF; a measure of land surface dryness) on the day the heat extremes occurred. We found a negative relationship between the magnitude of heat extremes and EF in both models and observations in transitional regions, with the hottest temperatures occurring during the driest days, with a similar but less certain relationship in dry regions. Surprisingly, many models also showed an amplification of heat extremes by low EF in wet regions, a finding not supported by observations. Many models may therefore overamplify heat extremes over wet regions by overestimating the strength of land-atmosphere coupling, with consequences for future projections of heat extremes. |
BibTeX:
@article{Ukkola2018,
author = {Ukkola, A. M. and Pitman, A. J. and Donat, M. G. and De Kauwe, M. G. and Angélil, O.},
title = {Evaluating the Contribution of Land-Atmosphere Coupling to Heat Extremes in CMIP5 Models},
journal = {Geophysical Research Letters},
publisher = {Blackwell Publishing Ltd},
year = {2018},
volume = {45},
number = {17},
pages = {9003--9012},
doi = {10.1029/2018GL079102}
}
|
| Vanbeveren SPP, De Francesco F, Ceulemans R and Spinelli R (2018), "Productivity of mechanized whip harvesting with the Stemster MkIII in a short-rotation coppice established on farmland", Biomass and Bioenergy., jan, 2018. Vol. 108, pp. 323-329. |
| Abstract: The success of short-rotation coppice (SRC) will rise with increasing biomass prices. One of the main constraints for establishing SRC today is the unpredictable cost of (whip) harvesting. Therefore, the harvest of a 9 ha SRC in Belgium was monitored, in order to develop a whip harvesting cost model to estimate harvesting productivity and costs as a function of various input data. The harvest was executed in February 2017 with a Stemster MkIII, after a three-year rotation of SRC with poplar. A biomass inventory was combined with a time-motion study and an economic analysis. The field stocking (fresh weight basis) ranged from 40 to 100 Mg haâˆ'1. The average load of 2.4 Mg was obtained from a 220 m long double row and took 6.4 min, resulting in an average productivity of 26 Mg hâˆ'1 (excluding delays). Genotype, field stocking and their interaction significantly affected the harvester's productivity. Border limited headlands (8 m width) had a significant impact on turning time and, thus, increased the total harvesting cost by 6%. The offload time was stable at 23 s Mgâˆ'1, while the harvesting cost varied from 7 to 22 € Mgâˆ'1, depending on work conditions and costing assumptions. Even though the Stemster MkIII produces whips instead of wood chips, its productivity is still lower than the modified foragers' productivity, but the Stemster MkIII is lighter and may offer better mobility. Optimal performance can be obtained with a high field stocking, appropriate spacing and adequate headlands. |
BibTeX:
@article{Vanbeveren2018,
author = {Vanbeveren, Stefan P P and De Francesco, Fabio and Ceulemans, Reinhart and Spinelli, Raffaele},
title = {Productivity of mechanized whip harvesting with the Stemster MkIII in a short-rotation coppice established on farmland},
journal = {Biomass and Bioenergy},
year = {2018},
volume = {108},
pages = {323--329},
url = {http://linkinghub.elsevier.com/retrieve/pii/S0961953417303987},
doi = {10.1016/j.biombioe.2017.11.024}
}
|
| Van Der Velde IR, Miller JB, Van Der Molen MK, Tans PP, Vaughn BH, White JWC, Schaefer K and Peters W (2018), "The CarbonTracker Data Assimilation System for CO 2 and δ 13 C (CTDAS-C13 v1.0): retrieving information on land-atmosphere exchange processes", Geosci. Model Dev. Vol. 11, pp. 283-304. |
| Abstract: To improve our understanding of the global carbon balance and its representation in terrestrial biosphere models, we present here a first dual-species application of the CarbonTracker Data Assimilation System (CTDAS). The system's modular design allows for assimilating multiple atmospheric trace gases simultaneously to infer exchange fluxes at the Earth surface. In the prototype discussed here, we interpret signals recorded in observed carbon dioxide (CO 2) along with observed ratios of its stable isotopologues 13 CO 2 / 12 CO 2 (δ 13 C). The latter is in particular a valuable tracer to untangle CO 2 exchange from land and oceans. Potentially, it can also be used as a proxy for continent-wide drought stress in plants, largely because the ratio of 13 CO 2 and 12 CO 2 molecules removed from the atmosphere by plants is dependent on moisture conditions. The dual-species CTDAS system varies the net exchange fluxes of both 13 CO 2 and CO 2 in ocean and terrestrial bio-sphere models to create an ensemble of 13 CO 2 and CO 2 fluxes that propagates through an atmospheric transport model. Based on differences between observed and simulated 13 CO 2 and CO 2 mole fractions (and thus δ 13 C) our Bayesian minimization approach solves for weekly adjustments to both net fluxes and isotopic terrestrial discrimination that minimizes the difference between observed and estimated mole fractions. With this system, we are able to estimate changes in terrestrial δ 13 C exchange on seasonal and continental scales in the Northern Hemisphere where the observational network is most dense. Our results indicate a decrease in stomatal con-ductance on a continent-wide scale during a severe drought. These changes could only be detected after applying combined atmospheric CO 2 and δ 13 C constraints as done in this work. The additional constraints on surface CO 2 exchange from δ 13 C observations neither affected the estimated carbon fluxes nor compromised our ability to match observed CO 2 variations. The prototype presented here can be of great benefit not only to study the global carbon balance but also to potentially function as a data-driven diagnostic to assess multiple leaf-level exchange parameterizations in carbon-climate models that influence the CO 2 , water, isotope, and energy balance. |
BibTeX:
@article{VanDerVelde2018,
author = {Van Der Velde, Ivar R and Miller, John B and Van Der Molen, Michiel K and Tans, Pieter P and Vaughn, Bruce H and White, James W C and Schaefer, Kevin and Peters, Wouter},
title = {The CarbonTracker Data Assimilation System for CO 2 and δ 13 C (CTDAS-C13 v1.0): retrieving information on land-atmosphere exchange processes},
journal = {Geosci. Model Dev},
year = {2018},
volume = {11},
pages = {283--304},
url = {https://doi.org/10.5194/gmd-11-283-2018},
doi = {10.5194/gmd-11-283-2018}
}
|
| Vezy R, Christina M, Roupsard O, Nouvellon Y, Duursma R, Medlyn B, Soma M, Charbonnier F, Blitz-Frayret C, Stape JL, Laclau JP, de Melo Virginio Filho E, Bonnefond JM, Rapidel B, Do FC, Rocheteau A, Picart D, Borgonovo C, Loustau D and le Maire G (2018), "Measuring and modelling energy partitioning in canopies of varying complexity using MAESPA model", Agricultural and Forest Meteorology. Vol. 253-254, pp. 203-217. Elsevier BV. |
| Abstract: Evapotranspiration and energy partitioning are complex to estimate because they result from the interaction of many different processes, especially in multi-species and multi-strata ecosystems. We used MAESPA model, a mechanistic, 3D model of coupled radiative transfer, photosynthesis, and balances of energy and water, to simulate the partitioning of energy and evapotranspiration in homogeneous tree plantations, as well as in heterogeneous multi-species, multi-strata agroforests with diverse spatial scales and management schemes. The MAESPA model was modified to add (1) calculation of foliage surface water evaporation at the voxel scale; (2) computation of an average within-canopy air temperature and vapour pressure; and (3) use of (1) and (2) in iterative calculations of soil and leaf temperatures to close ecosystem-level energy balances. We tested MAESPA model simulations on a simple monospecific Eucalyptus stand in Brazil, and also in two complex, heterogeneous Coffea agroforests in Costa Rica. MAESPA satisfactorily simulated the daily and seasonal dynamics of net radiation (RMSE = 29.6 and 28.4 W mâˆ'2; R2 = 0.99 and 0.99 for Eucalyptus and Coffea sites respectively) and its partitioning between latent-(RMSE = 68.1 and 37.2 W mâˆ'2; R2 = 0.87 and 0.85) and sensible-energy (RMSE = 54.6 and 45.8 W mâˆ'2; R2 = 0.57 and 0.88) over a one-year simulation at half-hourly time-step. After validation, we use the modified MAESPA to calculate partitioning of evapotranspiration and energy between plants and soil in the above-mentioned agro-ecosystems. In the Eucalyptus plantation, 95% of the outgoing energy was emitted as latent-heat, while the Coffea agroforestry system's partitioning between sensible and latent-heat fluxes was roughly equal. We conclude that MAESPA process-based model has an appropriate balance of detail, accuracy, and computational speed to be applicable to simple or complex forest ecosystems and at different scales for energy and evapotranspiration partitioning. |
BibTeX:
@article{Vezy2018,
author = {Vezy, Rémi and Christina, Mathias and Roupsard, Olivier and Nouvellon, Yann and Duursma, Remko and Medlyn, Belinda and Soma, Maxime and Charbonnier, Fabien and Blitz-Frayret, Céline and Stape, José Luiz and Laclau, Jean Paul and de Melo Virginio Filho, Elias and Bonnefond, Jean Marc and Rapidel, Bruno and Do, Frédéric C and Rocheteau, Alain and Picart, Delphine and Borgonovo, Carlos and Loustau, Denis and le Maire, Guerric},
title = {Measuring and modelling energy partitioning in canopies of varying complexity using MAESPA model},
journal = {Agricultural and Forest Meteorology},
publisher = {Elsevier BV},
year = {2018},
volume = {253-254},
pages = {203--217},
doi = {10.1016/j.agrformet.2018.02.005}
}
|
| Von Buttlar J, Zscheischler J, Rammig A, Sippel S, Reichstein M, Knohl A, Jung M, Menzer O, Altaf Arain M, Buchmann N, Cescatti A, Gianelle D, Kiely G, Law BE, Magliulo V, Margolis H, McCaughey H, Merbold L, Migliavacca M, Montagnani L, Oechel W, Pavelka M, Peichl M, Rambal S, Raschi A, Scott RL, Vaccari FP, Van Gorsel E, Varlagin A, Wohlfahrt G and Mahecha MD (2018), "Impacts of droughts and extreme-temperature events on gross primary production and ecosystem respiration: A systematic assessment across ecosystems and climate zones", Biogeosciences., mar, 2018. Vol. 15(5), pp. 1293-1318. |
| Abstract: Extreme climatic events, such as droughts and heat stress, induce anomalies in ecosystem-atmosphere CO2 fluxes, such as gross primary production (GPP) and ecosystem respiration (Reco), and, hence, can change the net ecosystem carbon balance. However, despite our increasing understanding of the underlying mechanisms, the magnitudes of the impacts of different types of extremes on GPP and Reco within and between ecosystems remain poorly predicted. Here we aim to identify the major factors controlling the amplitude of extreme-event impacts on GPP, Reco, and the resulting net ecosystem production (NEP). We focus on the impacts of heat and drought and their combination. We identified hydrometeorological extreme events in consistently downscaled water availability and temperature measurements over a 30-year time period. We then used FLUXNET eddy covariance flux measurements to estimate the CO2 flux anomalies during these extreme events across dominant vegetation types and climate zones. Overall, our results indicate that short-term heat extremes increased respiration more strongly than they downregulated GPP, resulting in a moderate reduction in the ecosystem's carbon sink potential. In the absence of heat stress, droughts tended to have smaller and similarly dampening effects on both GPP and Reco and, hence, often resulted in neutral NEP responses. The combination of drought and heat typically led to a strong decrease in GPP, whereas heat and drought impacts on respiration partially offset each other. Taken together, compound heat and drought events led to the strongest C sink reduction compared to any single-factor extreme. A key insight of this paper, however, is that duration matters most: for heat stress during droughts, the magnitude of impacts systematically increased with duration, whereas under heat stress without drought, the response of Reco over time turned from an initial increase to a downregulation after about 2 weeks. This confirms earlier theories that not only the magnitude but also the duration of an extreme event determines its impact. Our study corroborates the results of several local sitelevel case studies but as a novelty generalizes these findings on the global scale. Specifically, we find that the different response functions of the two antipodal land-atmosphere fluxes GPP and Reco can also result in increasing NEP during certain extreme conditions. Apparently counterintuitive findings of this kind bear great potential for scrutinizing the mechanisms implemented in state-of-the-art terrestrial biosphere models and provide a benchmark for future model development and testing. |
BibTeX:
@article{VonButtlar2018,
author = {Von Buttlar, Jannis and Zscheischler, Jakob and Rammig, Anja and Sippel, Sebastian and Reichstein, Markus and Knohl, Alexander and Jung, Martin and Menzer, Olaf and Altaf Arain, M and Buchmann, Nina and Cescatti, Alessandro and Gianelle, Damiano and Kiely, Gerard and Law, Beverly E and Magliulo, Vincenzo and Margolis, Hank and McCaughey, Harry and Merbold, Lutz and Migliavacca, Mirco and Montagnani, Leonardo and Oechel, Walter and Pavelka, Marian and Peichl, Matthias and Rambal, Serge and Raschi, Antonio and Scott, Russell L and Vaccari, Francesco P and Van Gorsel, Eva and Varlagin, Andrej and Wohlfahrt, Georg and Mahecha, Miguel D},
title = {Impacts of droughts and extreme-temperature events on gross primary production and ecosystem respiration: A systematic assessment across ecosystems and climate zones},
journal = {Biogeosciences},
year = {2018},
volume = {15},
number = {5},
pages = {1293--1318},
url = {https://www.biogeosciences.net/15/1293/2018/},
doi = {10.5194/bg-15-1293-2018}
}
|
| Walther S, Guanter L, Heim B, Jung M, Duveiller G, Wolanin A and Sachs T (2018), "Assessing the dynamics of vegetation productivity in circumpolar regions with different satellite indicators of greenness and photosynthesis", Biogeosciences., oct, 2018. Vol. 15(20), pp. 6221-6256. Copernicus GmbH. |
| Abstract: High-latitude treeless ecosystems represent spatially highly heterogeneous landscapes with small net carbon fluxes and a short growing season. Reliable observations and process understanding are critical for projections of the carbon balance of the climate-sensitive tundra. Space-borne remote sensing is the only tool to obtain spatially continuous and temporally resolved information on vegetation greenness and activity in remote circumpolar areas. However, confounding effects from persistent clouds, low sun elevation angles, numerous lakes, widespread surface inundation, and the sparseness of the vegetation render it highly challenging. Here, we conduct an extensive analysis of the timing of peak vegetation productivity as shown by satellite observations of complementary indicators of plant greenness and photosynthesis. We choose to focus on productivity during the peak of the growing season, as it importantly affects the total annual carbon uptake. The suite of indicators are as follows: (1) MODIS-based vegetation indices (VIs) as proxies for the fraction of incident photosynthetically active radiation (PAR) that is absorbed (fPAR), (2) VIs combined with estimates of PAR as a proxy of the total absorbed radiation (APAR), (3) sun-induced chlorophyll fluorescence (SIF) serving as a proxy for photosynthesis, (4) vegetation optical depth (VOD), indicative of total water content and (5) empirically upscaled modelled gross primary productivity (GPP). Averaged over the pan-Arctic we find a clear order of the annual peak as APAR≥ GPP textless SIF textless VIs/VOD. SIF as an indicator of photosynthesis is maximised around the time of highest annual temperatures. The modelled GPP peaks at a similar time to APAR. The time lag of the annual peak between APAR and instantaneous SIF fluxes indicates that the SIF data do contain information on light-use efficiency of tundra vegetation, but further detailed studies are necessary to verify this. Delayed peak greenness compared to peak photosynthesis is consistently found across years and land-cover classes. A particularly late peak of the normalised difference vegetation index (NDVI) in regions with very small seasonality in greenness and a high amount of lakes probably originates from artefacts. Given the very short growing season in circumpolar areas, the average time difference in maximum annual photosynthetic activity and greenness or growth of 3 to 25 days (depending on the data sets chosen) is important and needs to be considered when using satellite observations as drivers in vegetation models. |
BibTeX:
@article{Walther2018,
author = {Walther, Sophia and Guanter, Luis and Heim, Birgit and Jung, Martin and Duveiller, Gregory and Wolanin, Aleksandra and Sachs, Torsten},
title = {Assessing the dynamics of vegetation productivity in circumpolar regions with different satellite indicators of greenness and photosynthesis},
journal = {Biogeosciences},
publisher = {Copernicus GmbH},
year = {2018},
volume = {15},
number = {20},
pages = {6221--6256},
doi = {10.5194/bg-15-6221-2018}
}
|
| Wang C, Chen J, Tang Y, Black TA and Zhu K (2018), "A Novel Method for Removing Snow Melting-Induced Fluctuation in GIMMS NDVI3g Data for Vegetation Phenology Monitoring: A Case Study in Deciduous Forests of North America", IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing., mar, 2018. Vol. 11(3), pp. 800-807. Institute of Electrical and Electronics Engineers. |
| Abstract: The normalized difference vegetation index (NDVI) has been widely used in recent decades to monitor vegetation phenology. However, interference from snow cover introduces a high degree of uncertainty in interpreting NDVI fluctuation, because snow melting increases NDVI value in a manner similar to vegetation growth, leading to false detection. In this study, we present a novel methodology to smooth out data noise caused by snow in the third generation NDVI dataset from Global Inventory Modeling and Mapping Studies (GIMMS NDVI3g). This method is developed to replace small values with a pixel-specific snow-free background NDVI estimate, based on the assumption that the existence of snow decrease NDVI value and the patterns of NDVI fluctuation after snow melting and that after initiation of vegetation growth are different. Using the daily gross primary production (GPP) data of 111 site-years from FLUXNET in nine North American sites and the GIMMS NDVI3g dataset, we found that the green-up onset day (GUD) derived from raw NDVI is 42.2 days earlier than that of GPP, on average. This difference decreases to 4.7 days when applying the newly developed method. Additionally, the root mean square error and Spearman's correlation coefficient between NDVI-derived GUD and GPP-derived GUD are improved from 46.8 to 12.8 days and 0.22 to 0.64, respectively. Our results indicate that this method could effectively improve the ability to monitor the vegetation phenology by NDVI time series in areas with seasonal snow cover. |
BibTeX:
@article{Wang2018,
author = {Wang, Cong and Chen, Jin and Tang, Yanhong and Black, T. Andrew and Zhu, Kai},
title = {A Novel Method for Removing Snow Melting-Induced Fluctuation in GIMMS NDVI3g Data for Vegetation Phenology Monitoring: A Case Study in Deciduous Forests of North America},
journal = {IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing},
publisher = {Institute of Electrical and Electronics Engineers},
year = {2018},
volume = {11},
number = {3},
pages = {800--807},
doi = {10.1109/JSTARS.2017.2778076}
}
|
| Wang M, Chen Y, Wu X and Bai Y (2018), "Forest-Type-Dependent Water Use Efficiency Trends Across the Northern Hemisphere", Geophysical Research Letters., aug, 2018. Vol. 45(16), pp. 8283-8293. Blackwell Publishing Ltd. |
| Abstract: Changing climate and increasing atmospheric CO2 significantly regulate forest water use efficiency (WUE). However, magnitudes of the WUE trends and underlying processes driving these patterns in two major forest types, deciduous broadleaf forests (DBFs) and evergreen needleleaf forests (ENFs), across the Northern Hemisphere remain poorly understood. We investigated the WUE trends over the past two decades using eddy covariance observations from 26 forest sites from the FLUXNET2015 data set. Our analyses revealed a greater increase in WUE in DBFs than that in ENFs. The decreased stomatal conductance (Gs) mostly contributed to the increase in WUE in the DBFs, whereas the increased gross ecosystem productivity acted as the main trigger for the increase in WUE in the ENFs. The vapor pressure deficit substantially increased in the DBFs, triggering the decrease in Gs. In contrast, the slight CO2 fertilization and the limited stomatal constraint contributed to the increased gross ecosystem productivity in the ENFs. |
BibTeX:
@article{Wang2018a,
author = {Wang, Mengjie and Chen, Yunhao and Wu, Xiuchen and Bai, Yan},
title = {Forest-Type-Dependent Water Use Efficiency Trends Across the Northern Hemisphere},
journal = {Geophysical Research Letters},
publisher = {Blackwell Publishing Ltd},
year = {2018},
volume = {45},
number = {16},
pages = {8283--8293},
doi = {10.1029/2018GL079093}
}
|
| Wang Y, Broquet G, Ciais P, Chevallier F, Vogel F, Wu L, Yin Y, Wang R and Tao S (2018), "Potential of European 14CO2 observation network to estimate the fossil fuel CO2 emissions via atmospheric inversions", Atmospheric Chemistry and Physics. Vol. 18(6), pp. 4229-4250. |
| Abstract: Combining measurements of atmospheric CO2 and its radiocarbon (14CO2) fraction and transport modeling in atmospheric inversions offers a way to derive improved estimates of CO2 emitted from fossil fuel (FFCO2). In this study, we solve for the monthly FFCO2 emission budgets at regional scale (i.e., the size of a medium-sized country in Europe) and investigate the performance of different observation networks and sampling strategies across Europe. The inversion system is built on the LMDZv4 global transport model at 3.75° × 2.5° resolution. We conduct Observing System Simulation Experiments (OSSEs) and use two types of diagnostics to assess the potential of the observation and inverse modeling frameworks. The first one relies on the theoretical computation of the uncertainty in the estimate of emissions from the inversion, known as "posterior uncertainty", and on the uncertainty reduction compared to the uncertainty in the inventories of these emissions, which are used as a prior knowledge by the inversion (called "prior uncertainty"). The second one is based on comparisons of prior and posterior estimates of the emission to synthetic "true" emissions when these true emissions are used beforehand to generate the synthetic fossil fuel CO2 mixing ratio measurements that are assimilated in the inversion. With 17 stations currently measuring 14CO2 across Europe using 2-week integrated sampling, the uncertainty reduction for monthly FFCO2 emissions in a country where the network is rather dense like Germany, is larger than 30%. With the 43 14CO2 measurement stations planned in Europe, the uncertainty reduction for monthly FFCO2 emissions is increased for the UK, France, Italy, eastern Europe and the Balkans, depending on the configuration of prior uncertainty. Further increasing the number of stations or the sampling frequency improves the uncertainty reduction (up to 40 to 70%) in high emitting regions, but the performance of the inversion remains limited over low-emitting regions, even assuming a dense observation network covering the whole of Europe. This study also shows that both the theoretical uncertainty reduction (and resulting posterior uncertainty) from the inversion and the posterior estimate of emissions itself, for a given prior and "true" estimate of the emissions, are highly sensitive to the choice between two configurations of the prior uncertainty derived from the general estimate by inventory compilers or computations on existing inventories. In particular, when the configuration of the prior uncertainty statistics in the inversion system does not match the difference between these prior and true estimates, the posterior estimate of emissions deviates significantly from the truth. This highlights the difficulty of filtering the targeted signal in the model-data misfit for this specific inversion framework, the need to strongly rely on the prior uncertainty characterization for this and, consequently, the need for improved estimates of the uncertainties in current emission inventories for real applications with actual data. We apply the posterior uncertainty in annual emissions to the problem of detecting a trend of FFCO2, showing that increasing the monitoring period (e.g., more than 20 years) is more efficient than reducing uncertainty in annual emissions by adding stations. The coarse spatial resolution of the atmospheric transport model used in this OSSE (typical of models used for global inversions of natural CO2 fluxes) leads to large representation errors (related to the inability of the transport model to capture the spatial variability of the actual fluxes and mixing ratios at subgrid scales), which is a key limitation of our OSSE setup to improve the accuracy of the monitoring of FFCO2 emissions in European regions. Using a high-resolution transport model should improve the potential to retrieve FFCO2 emissions, and this needs to be investigated. |
BibTeX:
@article{Wang2018b,
author = {Wang, Yilong and Broquet, Grégoire and Ciais, Philippe and Chevallier, Frédéric and Vogel, Felix and Wu, Lin and Yin, Yi and Wang, Rong and Tao, Shu},
title = {Potential of European 14CO2 observation network to estimate the fossil fuel CO2 emissions via atmospheric inversions},
journal = {Atmospheric Chemistry and Physics},
year = {2018},
volume = {18},
number = {6},
pages = {4229--4250},
doi = {10.5194/acp-18-4229-2018}
}
|
| Wang S, Lu X, Cheng X, Li X, Peichl M and Mammarella I (2018), "Limitations and challenges of MODIS-derived phenological metrics across different landscapes in pan-Arctic regions", Remote Sensing., nov, 2018. Vol. 10(11), pp. 1784. MDPI AG. |
| Abstract: Recent efforts have been made to monitor the seasonal metrics of plant canopy variations globally from space, using optical remote sensing. However, phenological estimations based on vegetation indices (VIs) in high-latitude regions such as the pan-Arctic remain challenging and are rarely validated. Nevertheless, pan-Arctic ecosystems are vulnerable and also crucial in the context of climate change. We reported the limitations and challenges of using MODerate-resolution Imaging Spectroradiometer (MODIS) measurements, a widely exploited set of satellite measurements, to estimate phenological transition dates in pan-Arctic regions. Four indices including normalized vegetation difference index (NDVI), enhanced vegetation index (EVI), phenology index (PI), plant phenological index (PPI) and a MODIS Land Cover Dynamics Product MCD12Q2, were evaluated and compared against eddy covariance (EC) estimates at 11 flux sites of 102 site-years during the period from 2000 to 2014. All the indices were influenced by snow cover and soil moisture during the transition dates. While relationships existed between VI-based and EC-estimated phenological transition dates, the R2 values were generally low (0.01-0.68). Among the VIs, PPI-estimated metrics showed an inter-annual pattern that was mostly closely related to the EC-based estimations. Thus, further studies are needed to develop region-specific indices to provide more reliable estimates of phenological transition dates. |
BibTeX:
@article{Wang2018c,
author = {Wang, Siyu and Lu, Xinchen and Cheng, Xiao and Li, Xianglan and Peichl, Matthias and Mammarella, Ivan},
title = {Limitations and challenges of MODIS-derived phenological metrics across different landscapes in pan-Arctic regions},
journal = {Remote Sensing},
publisher = {MDPI AG},
year = {2018},
volume = {10},
number = {11},
pages = {1784},
doi = {10.3390/rs10111784}
}
|
| Wang S, Ibrom A, Bauer-Gottwein P and Garcia M (2018), "Incorporating diffuse radiation into a light use efficiency and evapotranspiration model: An 11-year study in a high latitude deciduous forest", Agricultural and Forest Meteorology., jan, 2018. Vol. 248, pp. 479-493. Elsevier BV. |
| Abstract: The fraction of diffuse photosynthetic active radiation (PAR) reaching the land surface is one of the biophysical factors regulating carbon and water exchange between terrestrial ecosystems and the atmosphere. This is especially relevant for high latitude ecosystems, where cloudy days are prevalent. Without considering impacts of diffuse PAR, traditional ‘top-down' models of ecosystem gross primary productivity (GPP) and evapotranspiration (ET), which use satellite remote sensing observations, are biased towards clear sky conditions. This study incorporated a cloudiness index (CI), an index for the fraction of diffuse PAR, into a joint ‘top-down' model that uses the same set of biophysical constraints to simulate GPP and ET for a high latitude temperate deciduous forest. To quantify the diffuse PAR effects, CI along with other environmental variables derived from an eleven-year eddy covariance data set were used to statistically explore the independent and joint effects of diffuse PAR on GPP, ET, incident light use efficiency (LUE), evaporative fraction (EF) and ecosystem water use efficiency (WUE). The independent and joint effects of CI were compared from global sensitivity analysis of the ‘top-down' models. Results indicate that for independent effects, CI increased GPP, LUE, ET, EF and WUE. Analysis of joint effects shows that CI mainly interacted with the radiation intercepted in the canopy (PAR, net radiation and leaf area index) to influence GPP, ET and WUE. Moreover, Ta and vapor pressure saturation deficit played a major role for the joint influence of CI on LUE and EF. In the growing season from May to October, variation in CI accounts for 11.9%, 3.0% and 7.8% of the total variation of GPP, ET and transpiration, respectively. As the influence of CI on GPP is larger than that on ET, this leads to an increase in WUE with CI. Joint GPP and ET model results showed that when including CI, the root mean square errors (RMSE) of daily GPP decreased from 1.64 to 1.45 g C mâˆ'2 dâˆ'1 (11.7% reduction) and ET from 15.79 to 14.50 W mâˆ'2 (8.2% reduction). Due to the interaction of diffuse PAR with plant canopies, the largest model improvements using CI for GPP and ET occurred during the growing season and for the transpiration component, as suggested by comparisons to sap flow measurements. Furthermore, our study suggests a potential biophysical mechanism, not considered in other studies: under high diffuse PAR conditions, due to the increased longwave emission from clouds, canopy temperature gets higher and enhances GPP and transpiration in this temperature-limited high latitude ecosystem. |
BibTeX:
@article{Wang2018d,
author = {Wang, Sheng and Ibrom, Andreas and Bauer-Gottwein, Peter and Garcia, Monica},
title = {Incorporating diffuse radiation into a light use efficiency and evapotranspiration model: An 11-year study in a high latitude deciduous forest},
journal = {Agricultural and Forest Meteorology},
publisher = {Elsevier BV},
year = {2018},
volume = {248},
pages = {479--493},
doi = {10.1016/j.agrformet.2017.10.023}
}
|
| Webster C and Jonas T (2018), "Influence of canopy shading and snow coverage on effective albedo in a snow-dominated evergreen needleleaf forest", Remote Sensing of Environment., sep, 2018. Vol. 214, pp. 48-58. Elsevier Inc.. |
| Abstract: The presence of a forest canopy above highly reflective snow results in overall lower surface albedo, even when snow is intercepted by the forest canopy. The effective forest snow albedo (FSA) explains the overall upwelling radiation from the forest relative to the incoming radiation. FSA is strongly influenced by the complex pathways of radiation as it travels through the 3D canopy structure. Current errors in calculations of FSA arise due to uncertainties in how models should treat masking of snow by vegetation. Improvement of distributed models is currently limited by a lack of measurements that demonstrate both spatial and temporal variability over forests. We present above-canopy measurements of winter-time effective forest snow albedo using up- and down-looking radiometers mounted on an octocopter UAV for a total of fifteen flights on eight different days. Ground-view fractions across the flight path were between 0.12 and 0.81. Correlations between FSA and both ground-view fraction and maximum canopy height were statistically significant during 14 out of 15 flights, but correlation strength varied between flights as a function of solar angle and snow cover. Measured effective albedo across the flight path differed by up to 0.33 during snow-on canopy conditions. A subsequent comparison between maximum interception and no interception showed effective albedo differed by up 0.27. A similar variation (0.26) in effective FSA was measured during low (44°) and high (67°) solar zenith angles. This study therefore demonstrates that temporal and spatial variations in effective albedo caused by canopy shading of the snow surface are therefore as important as temporal variations caused by interception of snow by the canopy. Calculation of effective albedo of forested areas requires careful consideration of canopy height, canopy coverage, solar angle and interception coverage. The results of this study should be used to inform snow albedo and canopy structure parametrizations in local and larger scale land surface models. |
BibTeX:
@article{Webster2018,
author = {Webster, Clare and Jonas, Tobias},
title = {Influence of canopy shading and snow coverage on effective albedo in a snow-dominated evergreen needleleaf forest},
journal = {Remote Sensing of Environment},
publisher = {Elsevier Inc.},
year = {2018},
volume = {214},
pages = {48--58},
doi = {10.1016/j.rse.2018.05.023}
}
|
| Weiss RF, Levin I and Meijer YJ (2018), "Atmospheric monitoring and inverse modelling for verification of greenhouse gas inventories Tracking biosphere C emissions with radiocarbon measurements in northern Wisconsin View project Modelling and Informing Low-Emission Strategies View project". Thesis at: Publications Office of the European Union, Luxembourg. Luxembourg |
| Abstract: The Paris Agreement requires accurate accounting of greenhouse gases (GHGs) by all countries. Complementary to bottom-up emission inventories, global, regional and national GHG emissions can be estimated using atmospheric measurements and atmospheric models (the "top-down" approach). This report provides an overview of current capabilities, potential, and further perspectives to use the "top-down" approach to evaluate and improve estimates of greenhouse gas emissions in support of the Paris Agreement. |
BibTeX:
@techreport{Weiss2018,
author = {Weiss, Ray F and Levin, Ingeborg and Meijer, Y J},
title = {Atmospheric monitoring and inverse modelling for verification of greenhouse gas inventories Tracking biosphere C emissions with radiocarbon measurements in northern Wisconsin View project Modelling and Informing Low-Emission Strategies View project},
school = {Publications Office of the European Union, Luxembourg},
year = {2018},
url = {https://ec.europa.eu/jrc},
doi = {10.2760/759928}
}
|
| Woodcroft BJ, Singleton CM, Boyd JA, Evans PN, Emerson JB, Zayed AAF, Hoelzle RD, Lamberton TO, McCalley CK, Hodgkins SB, Wilson RM, Purvine SO, Nicora CD, Li C, Frolking S, Chanton JP, Crill PM, Saleska SR, Rich VI and Tyson GW (2018), "Genome-centric view of carbon processing in thawing permafrost", Nature., jul, 2018. Vol. 560(7716), pp. 49-54. Springer Nature. |
| Abstract: As global temperatures rise, large amounts of carbon sequestered in permafrost are becoming available for microbial degradation. Accurate prediction of carbon gas emissions from thawing permafrost is limited by our understanding of these microbial communities. Here we use metagenomic sequencing of 214 samples from a permafrost thaw gradient to recover 1,529 metagenome-assembled genomes, including many from phyla with poor genomic representation. These genomes reflect the diversity of this complex ecosystem, with genus-level representatives for more than sixty per cent of the community. Meta-omic analysis revealed key populations involved in the degradation of organic matter, including bacteria whose genomes encode a previously undescribed fungal pathway for xylose degradation. Microbial and geochemical data highlight lineages that correlate with the production of greenhouse gases and indicate novel syntrophic relationships. Our findings link changing biogeochemistry to specific microbial lineages involved in carbon processing, and provide key information for predicting the effects of climate change on permafrost systems. |
BibTeX:
@article{Woodcroft2018,
author = {Woodcroft, Ben J and Singleton, Caitlin M and Boyd, Joel A and Evans, Paul N and Emerson, Joanne B and Zayed, Ahmed A F and Hoelzle, Robert D and Lamberton, Timothy O and McCalley, Carmody K and Hodgkins, Suzanne B and Wilson, Rachel M and Purvine, Samuel O and Nicora, Carrie D and Li, Changsheng and Frolking, Steve and Chanton, Jeffrey P and Crill, Patrick M and Saleska, Scott R and Rich, Virginia I and Tyson, Gene W},
title = {Genome-centric view of carbon processing in thawing permafrost},
journal = {Nature},
publisher = {Springer Nature},
year = {2018},
volume = {560},
number = {7716},
pages = {49--54},
doi = {10.1038/s41586-018-0338-1}
}
|
| Wu K, Lauvaux T, Davis KJ, Deng A, Lopez Coto I, Gurney KR and Patarasuk R (2018), "Joint inverse estimation of fossil fuel and biogenic CO2 fluxes in an urban environment: An observing system simulation experiment to assess the impact of multiple uncertainties", Elem Sci Anth., feb, 2018. Vol. 6(1), pp. 17. |
| Abstract: The Indianapolis Flux Experiment aims to utilize a variety of atmospheric measurements and a high-resolution inversion system to estimate the temporal and spatial variation of anthropogenic greenhouse gas emissions from an urban environment. We present a Bayesian inversion system solving for fossil fuel and biogenic CO 2 fluxes over the city of Indianapolis, IN. Both components were described at 1 km resolution to represent point sources and fine-scale structures such as highways in the a priori fluxes. With a series of Observing System Simulation Experiments, we evaluate the sensitivity of inverse flux estimates to various measurement deployment strategies and errors. We also test the impacts of flux error structures, biogenic CO 2 fluxes and atmospheric transport errors on estimating fossil fuel CO 2 emissions and their uncertainties. The results indicate that high-accuracy and high-precision measurements produce significant improvement in fossil fuel CO 2 flux estimates. Systematic measurement errors of 1 ppm produce significantly biased inverse solutions, degrading the accuracy of retrieved emissions by about 1 μ mol m –2 s –1 compared to the spatially averaged anthropogenic CO 2 emissions of 5 μ mol m –2 s –1 . The presence of biogenic CO 2 fluxes (similar magnitude to the anthropogenic fluxes) limits our ability to correct for random and systematic emission errors. However, assimilating continuous fossil fuel CO 2 measurements with 1 ppm random error in addition to total CO 2 measurements can partially compensate for the interference from biogenic CO 2 fluxes. Moreover, systematic and random flux errors can be further reduced by reducing model-data mismatch errors caused by atmospheric transport uncertainty. Finally, the precision of the inverse flux estimate is highly sensitive to the correlation length scale in the prior emission errors. This work suggests that improved fossil fuel CO 2 measurement technology, and better understanding of both prior flux and atmospheric transport errors are essential to improve the accuracy and precision of high-resolution urban CO 2 flux estimates. |
BibTeX:
@article{Wu2018,
author = {Wu, Kai and Lauvaux, Thomas and Davis, Kenneth J and Deng, Aijun and Lopez Coto, Israel and Gurney, Kevin R and Patarasuk, Risa},
title = {Joint inverse estimation of fossil fuel and biogenic CO2 fluxes in an urban environment: An observing system simulation experiment to assess the impact of multiple uncertainties},
journal = {Elem Sci Anth},
year = {2018},
volume = {6},
number = {1},
pages = {17},
url = {https://www.elementascience.org/article/10.1525/elementa.138/},
doi = {10.1525/elementa.138}
}
|
| Wu X, Liu H, Li X, Ciais P, Babst F, Guo W, Zhang C, Magliulo V, Pavelka M, Liu S, Huang Y, Wang P, Shi C and Ma Y (2018), "Differentiating drought legacy effects on vegetation growth over the temperate Northern Hemisphere", Global Change Biology., jan, 2018. Vol. 24(1), pp. 504-516. |
| Abstract: In view of future changes in climate, it is important to better understand how different plant functional groups (PFGs) respond to warmer and drier conditions, particularly in temperate regions where an increase in both the frequency and severity of drought is expected. The patterns and mechanisms of immediate and delayed impacts of extreme drought on vegetation growth remain poorly quantified. Using satellite measurements of vegetation greenness, in-situ tree-ring records, eddy-covariance CO2 and water flux measurements, and meta-analyses of source water of plant use among PFGs, we show that drought legacy effects on vegetation growth differ markedly between forests, shrubs and grass across diverse bioclimatic conditions over the temperate Northern Hemisphere. Deepâˆ'rooted forests exhibit a drought legacy response with reduced growth during up to 4 years after an extreme drought, whereas shrubs and grass have drought legacy effects of approximately 2 years and 1 year, respectively. Statistical analyses partly attribute the differences in drought legacy effects among PFGs to plant eco-hydrological properties (related to traits), including plant water use and hydraulic responses. These results can be used to improve the representation of drought response of different PFGs in land surface models, and assess their biogeochemical and biophysical feedbacks in response to a warmer and drier climate. |
BibTeX:
@article{Wu2018a,
author = {Wu, Xiuchen and Liu, Hongyan and Li, Xiaoyan and Ciais, Philippe and Babst, Flurin and Guo, Weichao and Zhang, Cicheng and Magliulo, Vincenzo and Pavelka, Marian and Liu, Shaomin and Huang, Yongmei and Wang, Pei and Shi, Chunming and Ma, Yujun},
title = {Differentiating drought legacy effects on vegetation growth over the temperate Northern Hemisphere},
journal = {Global Change Biology},
year = {2018},
volume = {24},
number = {1},
pages = {504--516},
url = {http://doi.wiley.com/10.1111/gcb.13920},
doi = {10.1111/gcb.13920}
}
|
| Wu L, Hristov T and Rutgersson A (2018), "Vertical profiles of wave-coherent momentum flux and velocity variances in the marine atmospheric boundary layer", Journal of Physical Oceanography. Vol. 48(3), pp. 625-641. American Meteorological Society. |
| Abstract: The wave-coherent momentum flux and velocity variances are investigated using a theoretical model and openocean measurements. The spectrum-integrated wave-coherent (SIWC) momentum flux and velocity variances decay roughly exponentially with height. The exponential decay coefficients of the SIWC momentum flux and velocity variances decrease with increasing peak wavenumber. The phases of the wave-coherent horizontal (vertical) velocity fluctuations are approximately 1808 (908) under waves with wind-wave angle ja1j , 908. In general, the ratio of the SIWCmomentumflux to the total momentum flux under swell conditions is higher than that under wind-wave conditions at the same height. At a height of 9.9 m, the SIWCvertical (horizontal) velocity variances can exceed 30% (10%) of the total vertical (horizontal) velocity variances at high wave ages. The impact of SIWC momentum flux on wind profiles is determined mainly by the surface SIWC momentum flux ratio, the decay coefficient of the SIWC momentum flux, and the sea surface roughness length, with the first two factors being dominant. The results of this study suggest a methodology for parameterizing the SIWC momentum flux and the total momentum flux over the ocean. These results are important for simulating the marine atmospheric boundary layer and should be used in model development. |
BibTeX:
@article{Wu2018b,
author = {Wu, Lichuan and Hristov, Tihomir and Rutgersson, Anna},
title = {Vertical profiles of wave-coherent momentum flux and velocity variances in the marine atmospheric boundary layer},
journal = {Journal of Physical Oceanography},
publisher = {American Meteorological Society},
year = {2018},
volume = {48},
number = {3},
pages = {625--641},
doi = {10.1175/JPO-D-17-0052.1}
}
|
| Wutzler T, Lucas-Moffat A, Migliavacca M, Knauer J, Sickel K, Šigut L, Menzer O and Reichstein M (2018), "Basic and extensible post-processing of eddy covariance flux data with REddyProc", Biogeosciences., aug, 2018. Vol. 15(16), pp. 5015-5030. Copernicus GmbH. |
| Abstract: With the eddy covariance (EC) technique, net fluxes of carbon dioxide (CO2) and other trace gases as well as water and energy fluxes can be measured at the ecosystem level. These flux measurements are a main source for understanding biosphere-atmosphere interactions and feedbacks through cross-site analysis, model-data integration, and upscaling. The raw fluxes measured with the EC technique require extensive and laborious data processing. While there are standard tools1 available in an open-source environment for processing high-frequency (10 or 20&thinsp;Hz) data into half-hourly quality-checked fluxes, there is a need for more usable and extensible tools for the subsequent post-processing steps. We tackled this need by developing the span styleCombining double low line classCombining double low linetext typewriter package in the cross-platform language R that provides standard CO2-focused post-processing routines for reading (half-)hourly data from different formats, estimating the threshold, as well as gap-filling, flux-partitioning, and visualizing the results. In addition to basic processing, the functions are extensible and allow easier integration in extended analysis than current tools. New features include cross-year processing and a better treatment of uncertainties. A comparison of span styleCombining double low line classCombining double low linetext typewriter routines with other state-of-the-art tools resulted in no significant differences in monthly and annual fluxes across sites. Lower uncertainty estimates of both and resulting gap-filled fluxes by 50&thinsp;% with the presented tool were achieved by an improved treatment of seasons during the bootstrap analysis. Higher estimates of uncertainty in daytime partitioning (about twice as high) resulted from a better accounting for the uncertainty in estimates of temperature sensitivity of respiration. The provided routines can be easily installed, configured, and used. Hence, the eddy covariance community will benefit from the span styleCombining double low line classCombining double low linetext typewriterREddyProc/span package, allowing easier integration of standard post-processing with extended analysis. |
BibTeX:
@article{Wutzler2018,
author = {Wutzler, Thomas and Lucas-Moffat, Antje and Migliavacca, Mirco and Knauer, Jürgen and Sickel, Kerstin and Šigut, Ladislav and Menzer, Olaf and Reichstein, Markus},
title = {Basic and extensible post-processing of eddy covariance flux data with REddyProc},
journal = {Biogeosciences},
publisher = {Copernicus GmbH},
year = {2018},
volume = {15},
number = {16},
pages = {5015--5030},
doi = {10.5194/bg-15-5015-2018}
}
|
| Xueref-Remy I, Dieudonné E, Vuillemin C, Lopez M, Lac C, Schmidt M, Delmotte M, Chevallier F, Ravetta F, Perrussel O, Ciais P, Bréon FM, Broquet G, Ramonet M, Gerard Spain T and Ampe C (2018), "Diurnal, synoptic and seasonal variability of atmospheric CO2 in the Paris megacity area", Atmospheric Chemistry and Physics., mar, 2018. Vol. 18(5), pp. 3335-3362. |
| Abstract: Most of the global fossil fuel CO2 emissions arise from urbanized and industrialized areas. Bottom-up inventories quantify them but with large uncertainties. In 2010-2011, the first atmospheric in situ CO2 measurement network for Paris, the capital of France, began operating with the aim of monitoring the regional atmospheric impact of the emissions coming from this megacity. Five stations sampled air along a northeast-southwest axis that corresponds to the direction of the dominant winds. Two stations are classified as rural (Traînou-TRN; Montgé-en-Goële-MON), two are peri-urban (Gonesse-GON; Gif-sur-Yvette-GIF) and one is urban (EIF, located on top of the Eiffel Tower). In this study, we analyze the diurnal, synoptic and seasonal variability of the in situ CO2 measurements over nearly 1 year (8 August 2010-13 July 2011). We compare these datasets with remote CO2 measurements made at Mace Head (MHD) on the Atlantic coast of Ireland and support our analysis with atmospheric boundary layer height (ABLH) observations made in the center of Paris and with both modeled and observed meteorological fields. The average hourly CO2 diurnal cycles observed at the regional stations are mostly driven by the CO2 biospheric cycle, the ABLH cycle and the proximity to urban CO2 emissions. Differences of several μmolÄ€molÄ'1 (ppm) can be observed from one regional site to the other. The more the site is surrounded by urban sources (mostly residential and commercial heating, and traffic), the more the CO2 concentration is elevated, as is the associated variability which reflects the variability of the urban sources. Furthermore, two sites with inlets high above ground level (EIF and TRN) show a phase shift of the CO2 diurnal cycle of a few hours compared to lower sites due to a strong coupling with the boundary layer diurnal cycle. As a consequence, the existence of a CO2 vertical gradient above Paris can be inferred, whose amplitude depends on the time of the day and on the season, ranging from a few tenths of ppm during daytime to several ppm during nighttime. The CO2 seasonal cycle inferred from monthly means at our regional sites is driven by the biospheric and anthropogenic CO2 flux seasonal cycles, the ABLH seasonal cycle and also synoptic variations. Enhancements of several ppm are observed at peri-urban stations compared to rural ones, mostly from the influence of urban emissions that are in the footprint of the peri-urban station. The seasonal cycle observed at the urban station (EIF) is specific and very sensitive to the ABLH cycle. At both the diurnal and the seasonal scales, noticeable differences of several ppm are observed between the measurements made at regional rural stations and the remote measurements made at MHD, that are shown not to define background concentrations appropriately for quantifying the regional ( Ä1/4 Ä€100Ä€km) atmospheric impact of urban CO2 emissions. For wind speeds less than 3Ä€mÄ€sÄ'1, the accumulation of local CO2 emissions in the urban atmosphere forms a dome of several tens of ppm at the peri-urban stations, mostly under the influence of relatively local emissions including those from the Charles de Gaulle (CDG) Airport facility and from aircraft in flight. When wind speed increases, ventilation transforms the CO2 dome into a plume. Higher CO2 background concentrations of several ppm are advected from the remote Benelux-Ruhr and London regions, impacting concentrations at the five stations of the network even at wind speeds higher than 9Ä€mÄ€sÄ'1. For wind speeds ranging between 3 and 8Ä€mÄ€sÄ'1, the impact of Paris emissions can be detected in the peri-urban stations when they are downwind of the city, while the rural stations often seem disconnected from the city emission plume. As a conclusion, our study highlights a high sensitivity of the stations to wind speed and direction, to their distance from the city, but also to the ABLH cycle depending on their elevation. We learn some lessons regarding the design of an urban CO2 network: (1) careful attention should be paid to properly setting regional (Ä1/4 100Ä€km) background sites that will be representative of the different wind sectors; (2) the downwind stations should be positioned as symmetrically as possible in relation to the city center, at the peri-urban/rural border; (3) the stations should be installed at ventilated sites (away from strong local sources) and the air inlet set up above the building or biospheric canopy layer, whichever is the highest; and (4) high-resolution wind information should be available with the CO2 measurements. |
BibTeX:
@article{Xueref-Remy2018,
author = {Xueref-Remy, Irène and Dieudonné, Elsa and Vuillemin, Cyrille and Lopez, Morgan and Lac, Christine and Schmidt, Martina and Delmotte, Marc and Chevallier, Frédéric and Ravetta, François and Perrussel, Olivier and Ciais, Philippe and Bréon, François Marie and Broquet, Grégoire and Ramonet, Michel and Gerard Spain, T and Ampe, Christophe},
title = {Diurnal, synoptic and seasonal variability of atmospheric CO2 in the Paris megacity area},
journal = {Atmospheric Chemistry and Physics},
year = {2018},
volume = {18},
number = {5},
pages = {3335--3362},
url = {https://www.atmos-chem-phys.net/18/3335/2018/},
doi = {10.5194/acp-18-3335-2018}
}
|
| Yasunaka S, Siswanto E, Olsen A, Hoppema M, Watanabe E, Fransson A, Chierici M, Murata A, Lauvset SK, Wanninkhof R, Takahashi T, Kosugi N, Omar AM, Van Heuven S and Mathis JT (2018), "Arctic Ocean CO2 uptake: An improved multiyear estimate of the air-sea CO2 flux incorporating chlorophyll a concentrations", Biogeosciences., mar, 2018. Vol. 15(6), pp. 1643-1661. Copernicus GmbH. |
| Abstract: We estimated monthly air-sea CO2 fluxes in the Arctic Ocean and its adjacent seas north of 60° N from 1997 to 2014. This was done by mapping partial pressure of CO2 in the surface water (pCO2w) using a self-organizing map (SOM) technique incorporating chlorophyll a concentration (Chl a), sea surface temperature, sea surface salinity, sea ice concentration, atmospheric CO2 mixing ratio, and geographical position. We applied new algorithms for extracting Chl a from satellite remote sensing reflectance with close examination of uncertainty of the obtained Chl a values. The overall relationship between pCO2w and Chl a was negative, whereas the relationship varied among seasons and regions. The addition of Chl a as a parameter in the SOM process enabled us to improve the estimate of pCO2w, particularly via better representation of its decline in spring, which resulted from biologically mediated pCO2w reduction. As a result of the inclusion of Chl a, the uncertainty in the CO2 flux estimate was reduced, with a net annual Arctic Ocean CO2 uptake of 180 ± 130 Tgyr-1. Seasonal to interannual variation in the CO2 influx was also calculated. |
BibTeX:
@article{Yasunaka2018,
author = {Yasunaka, Sayaka and Siswanto, Eko and Olsen, Are and Hoppema, Mario and Watanabe, Eiji and Fransson, Agneta and Chierici, Melissa and Murata, Akihiko and Lauvset, Siv K. and Wanninkhof, Rik and Takahashi, Taro and Kosugi, Naohiro and Omar, Abdirahman M. and Van Heuven, Steven and Mathis, Jeremy T.},
title = {Arctic Ocean CO2 uptake: An improved multiyear estimate of the air-sea CO2 flux incorporating chlorophyll a concentrations},
journal = {Biogeosciences},
publisher = {Copernicus GmbH},
year = {2018},
volume = {15},
number = {6},
pages = {1643--1661},
doi = {10.5194/bg-15-1643-2018}
}
|
| Yazidi AE, Ramonet M, Ciais P, Broquet G, Pison I, Abbaris A, Brunner D, Conil S, Delmotte M, Gheusi F, Guerin F, Hazan L, Kachroudi N, Kouvarakis G, Mihalopoulos N, Rivier L and Serça D (2018), "Identification of spikes associated with local sources in continuous time series of atmospheric CO, CO2 and CH4", Atmospheric Measurement Techniques. Vol. 11(3), pp. 1599-1614. |
| Abstract: This study deals with the problem of identifying atmospheric data influenced by local emissions that can result in spikes in time series of greenhouse gases and long-lived tracer measurements. We considered three spike detection methods known as coefficient of variation (COV), robust extraction of baseline signal (REBS) and standard deviation of the background (SD) to detect and filter positive spikes in continuous greenhouse gas time series from four monitoring stations representative of the European ICOS (Integrated Carbon Observation System) Research Infrastructure network. The results of the different methods are compared to each other and against a manual detection performed by station managers. Four stations were selected as test cases to apply the spike detection methods: A continental rural tower of 100Ä€m height in eastern France (OPE), a high-mountain observatory in the south-west of France (PDM), a regional marine background site in Crete (FKL) and a marine clean-Air background site in the Southern Hemisphere on Amsterdam Island (AMS). This selection allows us to address spike detection problems in time series with different variability. Two years of continuous measurements of CO2, CH4 and CO were analysed. All methods were found to be able to detect short-Term spikes (lasting from a few seconds to a few minutes) in the time series. Analysis of the results of each method leads us to exclude the COV method due to the requirement to arbitrarily specify an a priori percentage of rejected data in the time series, which may over-or underestimate the actual number of spikes. The two other methods freely determine the number of spikes for a given set of parameters, and the values of these parameters were calibrated to provide the best match with spikes known to reflect local emissions episodes that are well documented by the station managers. More than 96Ä€% of the spikes manually identified by station managers were successfully detected both in the SD and the REBS methods after the best adjustment of parameter values. At PDM, measurements made by two analyzers located 200Ä€m from each other allow us to confirm that the CH4 spikes identified in one of the time series but not in the other correspond to a local source from a sewage treatment facility in one of the observatory buildings. From this experiment, we also found that the REBS method underestimates the number of positive anomalies in the CH4 data caused by local sewage emissions. As a conclusion, we recommend the use of the SD method, which also appears to be the easiest one to implement in automatic data processing, used for the operational filtering of spikes in greenhouse gases time series at global and regional monitoring stations of networks like that of the ICOS atmosphere network. |
BibTeX:
@article{Yazidi2018,
author = {Yazidi, Abdelhadi El and Ramonet, Michel and Ciais, Philippe and Broquet, Gregoire and Pison, Isabelle and Abbaris, Amara and Brunner, Dominik and Conil, Sebastien and Delmotte, Marc and Gheusi, Francois and Guerin, Frederic and Hazan, Lynn and Kachroudi, Nesrine and Kouvarakis, Giorgos and Mihalopoulos, Nikolaos and Rivier, Leonard and Serça, Dominique},
title = {Identification of spikes associated with local sources in continuous time series of atmospheric CO, CO2 and CH4},
journal = {Atmospheric Measurement Techniques},
year = {2018},
volume = {11},
number = {3},
pages = {1599--1614},
doi = {10.5194/amt-11-1599-2018}
}
|
| Yuan Y, Ries L, Petermeier H, Steinbacher M, Gómez-Pelaéz AJ, Leuenberger MC, Schumacher M, Trickl T, Couret C, Meinhardt F and Menzel A (2018), "Adaptive selection of diurnal minimum variation: A statistical strategy to obtain representative atmospheric CO2 data and its application to European elevated mountain stations", Atmospheric Measurement Techniques. Vol. 11(3), pp. 1501-1514. Copernicus GmbH. |
| Abstract: Critical data selection is essential for determining representative baseline levels of atmospheric trace gases even at remote measurement sites. Different data selection techniques have been used around the world, which could potentially lead to reduced compatibility when comparing data from different stations. This paper presents a novel statistical data selection method named adaptive diurnal minimum variation selection (ADVS) based on CO2 diurnal patterns typically occurring at elevated mountain stations. Its capability and applicability were studied on records of atmospheric CO2 observations at six Global Atmosphere Watch stations in Europe, namely, Zugspitze-Schneefernerhaus (Germany), Sonnblick (Austria), Jungfraujoch (Switzerland), Izanã (Spain), Schauinsland (Germany), and Hohenpeissenberg (Germany). Three other frequently applied statistical data selection methods were included for comparison. Among the studied methods, our ADVS method resulted in a lower fraction of data selected as a baseline with lower maxima during winter and higher minima during summer in the selected data. The measured time series were analyzed for long-term trends and seasonality by a seasonal-trend decomposition technique. In contrast to unselected data, mean annual growth rates of all selected datasets were not significantly different among the sites, except for the data recorded at Schauinsland. However, clear differences were found in the annual amplitudes as well as the seasonal time structure. Based on a pairwise analysis of correlations between stations on the seasonal-trend decomposed components by statistical data selection, we conclude that the baseline identified by the ADVS method is a better representation of lower free tropospheric (LFT) conditions than baselines identified by the other methods. |
BibTeX:
@article{Yuan2018,
author = {Yuan, Ye and Ries, Ludwig and Petermeier, Hannes and Steinbacher, Martin and Gómez-Pelaéz, Angel J and Leuenberger, Markus C and Schumacher, Marcus and Trickl, Thomas and Couret, Cedric and Meinhardt, Frank and Menzel, Annette},
title = {Adaptive selection of diurnal minimum variation: A statistical strategy to obtain representative atmospheric CO2 data and its application to European elevated mountain stations},
journal = {Atmospheric Measurement Techniques},
publisher = {Copernicus GmbH},
year = {2018},
volume = {11},
number = {3},
pages = {1501--1514},
doi = {10.5194/amt-11-1501-2018}
}
|
| Zhang Y, Joiner J, Hamed Alemohammad S, Zhou S and Gentine P (2018), "A global spatially contiguous solar-induced fluorescence (CSIF) dataset using neural networks", Biogeosciences., oct, 2018. Vol. 15(19), pp. 5779-5800. Copernicus GmbH. |
| Abstract: Satellite-retrieved solar-induced chlorophyll fluorescence (SIF) has shown great potential to monitor the photosynthetic activity of terrestrial ecosystems. However, several issues, including low spatial and temporal resolution of the gridded datasets and high uncertainty of the individual retrievals, limit the applications of SIF. In addition, inconsistency in measurement footprints also hinders the direct comparison between gross primary production (GPP) from eddy covariance (EC) flux towers and satellite-retrieved SIF. In this study, by training a neural network (NN) with surface reflectance from the MODerate-resolution Imaging Spectroradiometer (MODIS) and SIF from Orbiting Carbon Observatory-2 (OCO-2), we generated two global spatially contiguous SIF (CSIF) datasets at moderate spatiotemporal (0.05° 4-day) resolutions during the MODIS era, one for clear-sky conditions (2000-2017) and the other one in all-sky conditions (2000-2016). The clear-sky instantaneous CSIF (CSIFclear-inst) shows high accuracy against the clear-sky OCO-2 SIF and little bias across biome types. The all-sky daily average CSIF (CSIFall-daily) dataset exhibits strong spatial, seasonal and interannual dynamics that are consistent with daily SIF from OCO-2 and the Global Ozone Monitoring Experiment-2 (GOME-2). An increasing trend (0.39 %) of annual average CSIFall-daily is also found, confirming the greening of Earth in most regions. Since the difference between satellite-observed SIF and CSIF is mostly caused by the environmental down-regulation on SIFyield, the ratio between OCO-2 SIF and CSIFclear-inst can be an effective indicator of drought stress that is more sensitive than the normalized difference vegetation index and enhanced vegetation index. By comparing CSIFall-daily with GPP estimates from 40 EC flux towers across the globe, we find a large cross-site variation (c.v. Combining double low line 0.36) of the GPP-SIF relationship with the highest regression slopes for evergreen needleleaf forest. However, the cross-biome variation is relatively limited (c.v. Combining double low line 0.15). These two contiguous SIF datasets and the derived GPP-SIF relationship enable a better understanding of the spatial and temporal variations of the GPP across biomes and climate. |
BibTeX:
@article{Zhang2018,
author = {Zhang, Yao and Joiner, Joanna and Hamed Alemohammad, Seyed and Zhou, Sha and Gentine, Pierre},
title = {A global spatially contiguous solar-induced fluorescence (CSIF) dataset using neural networks},
journal = {Biogeosciences},
publisher = {Copernicus GmbH},
year = {2018},
volume = {15},
number = {19},
pages = {5779--5800},
doi = {10.5194/bg-15-5779-2018}
}
|
| Zhang Y, Xiao X, Zhang Y, Wolf S, Zhou S, Joiner J, Guanter L, Verma M, Sun Y, Yang X, Paul-Limoges E, Gough CM, Wohlfahrt G, Gioli B, van der Tol C, Yann N, Lund M and de Grandcourt A (2018), "On the relationship between sub-daily instantaneous and daily total gross primary production: Implications for interpreting satellite-based SIF retrievals", Remote Sensing of Environment., feb, 2018. Vol. 205, pp. 276-289. Elsevier BV. |
| Abstract: Spatially and temporally continuous estimation of plant photosynthetic carbon fixation (or gross primary production, GPP) is crucial to our understanding of the global carbon cycle and the impact of climate change. Besides spatial, seasonal and interannual variations, GPP also exhibits strong diurnal variations. Satellite retrieved solar-induced chlorophyll fluorescence (SIF) provides a spatially continuous, but temporally discrete measurement of plant photosynthesis, and has the potential to be used to estimate GPP at global scale. However, it remains unclear whether the seasonal time series of SIF snapshots taken at a fixed time of the day can be used to infer daily total GPP variation at spatial and seasonal scales. In this study, we first used GPP estimates from 135 eddy covariance flux sites, covering a wide range of geographic locations and biome types, to investigate the relationship between the instantaneous GPP (GPPinst) and daily GPP (GPPdaily) on the seasonal course for different times of the day. Latitudinal and diurnal patterns were found to correspond to variations in photosynthetically active radiation (PAR) and light use efficiency (LUE), respectively. We then used the Soil-Canopy Observation Photosynthesis and Energy Balance (SCOPE) model and the FluxCom GPP product to investigate the instantaneous and daily SIF-GPP relationships at five flux tower sites along a latitudinal gradient and at a global scale for different biome types. The results showed that daily SIF had a stronger linear correlation with daily GPP than instantaneous SIF at the seasonal scale, with an instantaneous to daily SIF conversion factor following the latitudinal and seasonal pattern driven by PAR. Our study highlights the necessity to take the latitudinal and diurnal factors into consideration for SIF-GPP relationship analyses or for physiological phenology analyses based on SIF. |
BibTeX:
@article{Zhang2018a,
author = {Zhang, Yao and Xiao, Xiangming and Zhang, Yongguang and Wolf, Sebastian and Zhou, Sha and Joiner, Joanna and Guanter, Luis and Verma, Manish and Sun, Ying and Yang, Xi and Paul-Limoges, Eugénie and Gough, Christopher M and Wohlfahrt, Georg and Gioli, Beniamino and van der Tol, Christiaan and Yann, Nouvellon and Lund, Magnus and de Grandcourt, Agnès},
title = {On the relationship between sub-daily instantaneous and daily total gross primary production: Implications for interpreting satellite-based SIF retrievals},
journal = {Remote Sensing of Environment},
publisher = {Elsevier BV},
year = {2018},
volume = {205},
pages = {276--289},
doi = {10.1016/j.rse.2017.12.009}
}
|
| Zhang W, Jansson PE, Schurgers G, Hollesen J, Lund M, Abermann J and Elberling B (2018), "Process-Oriented Modeling of a High Arctic Tundra Ecosystem: Long-Term Carbon Budget and Ecosystem Responses to Interannual Variations of Climate", Journal of Geophysical Research: Biogeosciences., apr, 2018. Vol. 123(4), pp. 1178-1196. Wiley. |
| Abstract: Terrestrial carbon (C) cycling in high Arctic tundra depends on ecosystem responses to climatic warming and concurrent changes in environmental conditions. There are very few studies to quantify long-term C budget in high Arctic tundra due to lack of sufficient measurements. Here based on well-established multiyear measurements, we calibrated a process-oriented model (CoupModel) to quantify various components of the C budget at a Cassiope tetragona heath ecosystem in northeast Greenland. Net ecosystem exchange of CO2 (NEE) for 2000–2014 was estimated at âˆ'15 ± 10 g C mâˆ'2 yrâˆ'1. Ecosystem respiration (ER) for nongrowing seasons was estimated at 10.3 ± 5.3 g C mâˆ'2 yrâˆ'1, representing around 13% of the annual ER. Significant trends for interannual variations of aboveground and belowground C fluxes and stocks were found for the subperiods (i.e., 2000–2008 and 2008–2014) but not for the entire period. Interannual variations of NEE largely relied on the response of gross primary production (GPP) and ER to seasonal changes in climate. Moreover, the model showed that interannual variations of GPP, ER, and NEE had a much higher linear correlation with July temperature and annual maximum thawing depth (ALDmax) than other climatic and site characteristics. ALDmax had the highest correlation with the decomposition rate of humus C. Overall, this modeling study suggests that a sink-source transition of the studied ecosystem depends on ecosystem responses to interannual variations of climate and that the net C balance may be sensitive to summer warmth and active layer thickness. |
BibTeX:
@article{Zhang2018b,
author = {Zhang, Wenxin and Jansson, Per Erik and Schurgers, Guy and Hollesen, Jørgen and Lund, Magnus and Abermann, Jakob and Elberling, Bo},
title = {Process-Oriented Modeling of a High Arctic Tundra Ecosystem: Long-Term Carbon Budget and Ecosystem Responses to Interannual Variations of Climate},
journal = {Journal of Geophysical Research: Biogeosciences},
publisher = {Wiley},
year = {2018},
volume = {123},
number = {4},
pages = {1178--1196},
doi = {10.1002/2017JG003956}
}
|
| Zhou M, Langerock B, Vigouroux C, Sha MK, Ramonet M, Delmotte M, Mahieu E, Bader W, Hermans C, Kumps N, Metzger JM, Duflot V, Wang Z, Palm M and De Mazière M (2018), "Atmospheric CO and CH4 time series and seasonal variations on Reunion Island from ground-based in situ and FTIR (NDACC and TCCON) measurements", Atmospheric Chemistry and Physics. Vol. 18(19), pp. 13881-13901. Copernicus GmbH. |
| Abstract: Atmospheric carbon monoxide (CO) and methane (CH4) mole fractions are measured by ground-based in situ cavity ring-down spectroscopy (CRDS) analyzers and Fourier transform infrared (FTIR) spectrometers at two sites (St Denis and Maïdo) on Reunion Island (21° S, 55° E) in the Indian Ocean. Currently, the FTIR Bruker IFS 125HR at St Denis records the direct solar spectra in the near-infrared range, contributing to the Total Carbon Column Observing Network (TCCON). The FTIR Bruker IFS 125HR at Maïdo records the direct solar spectra in the mid-infrared (MIR) range, contributing to the Network for the Detection of Atmospheric Composition Change (NDACC). In order to understand the atmospheric CO and CH4 variability on Reunion Island, the time series and seasonal cycles of CO and CH4 from in situ and FTIR (NDACC and TCCON) measurements are analyzed. Meanwhile, the difference between the in situ and FTIR measurements are discussed. The CO seasonal cycles observed from the in situ measurements at Maïdo and FTIR retrievals at both St Denis and Maïdo are in good agreement with a peak in September-November, primarily driven by the emissions from biomass burning in Africa and South America. The dry-air column averaged mole fraction of CO (XCO) derived from the FTIR MIR spectra (NDACC) is about 15.7 ppb larger than the CO mole fraction near the surface at Maïdo, because the air in the lower troposphere mainly comes from the Indian Ocean while the air in the middle and upper troposphere mainly comes from Africa and South America. The trend for CO on Reunion Island is unclear during the 2011-2017 period, and more data need to be collected to get a robust result. A very good agreement is observed in the tropospheric and stratospheric CH4 seasonal cycles between FTIR (NDACC and TCCON) measurements, and in situ and the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) satellite measurements, respectively. In the troposphere, the CH4 mole fraction is high in August-September and low in December-January, which is due to the OH seasonal variation. In the stratosphere, the CH4 mole fraction has its maximum in March-April and its minimum in August-October, which is dominated by vertical transport. In addition, the different CH4 mole fractions between the in situ, NDACC and TCCON CH4 measurements in the troposphere are discussed, and all measurements are in good agreement with the GEOS-Chem model simulation. The trend of XCH4 is 7.6±0.4 ppb yr-1 from the TCCON measurements over the 2011 to 2017 time period, which is consistent with the CH4 trend of 7.4±0.5 ppb yr-1 from the in situ measurements for the same time period at St Denis. |
BibTeX:
@article{Zhou2018,
author = {Zhou, Minqiang and Langerock, Bavo and Vigouroux, Corinne and Sha, Mahesh Kumar and Ramonet, Michel and Delmotte, Marc and Mahieu, Emmanuel and Bader, Whitney and Hermans, Christian and Kumps, Nicolas and Metzger, Jean Marc and Duflot, Valentin and Wang, Zhiting and Palm, Mathias and De Mazière, Martine},
title = {Atmospheric CO and CH4 time series and seasonal variations on Reunion Island from ground-based in situ and FTIR (NDACC and TCCON) measurements},
journal = {Atmospheric Chemistry and Physics},
publisher = {Copernicus GmbH},
year = {2018},
volume = {18},
number = {19},
pages = {13881--13901},
doi = {10.5194/acp-18-13881-2018}
}
|
| Zweifel R and Sterck F (2018), "A Conceptual Tree Model Explaining Legacy Effects on Stem Growth", Frontiers in Forests and Global Change., nov, 2018. Vol. 1 Frontiers Media SA. |
BibTeX:
@article{Zweifel2018,
author = {Zweifel, Roman and Sterck, Frank},
title = {A Conceptual Tree Model Explaining Legacy Effects on Stem Growth},
journal = {Frontiers in Forests and Global Change},
publisher = {Frontiers Media SA},
year = {2018},
volume = {1},
doi = {10.3389/ffgc.2018.00009}
}
|
| Acosta M, Juszczak R, Chojnicki B, Pavelka M, Havránková K, Lesny J, Krupková L, Urbaniak M, Machačová K and Olejnik J (2017), "CO2 Fluxes from Different Vegetation Communities on a Peatland Ecosystem", Wetlands. Vol. 37(3), pp. 423-435. |
| Abstract: Although most studies find temperature, soil moisture and water table to be important environmental factors that affect peatland carbon dynamics, the role of vegetation communities has been investigated less. Therefore, this study investigates whether peatland ecosystems produce heterogeneous CO2 fluxes due to differences in vegetation community. In addition, the study also examines which major environmental factors influence this vegetation. To achieve the aims of this study, four sites with different vegetation communities were established in a semi-natural peatland ecosystem in Poland. CO2 flux measurements were carried out using a closed dynamic chamber system. Measurement campaigns were carried out from April until December 2008, every 2–3 weeks. Measured ecosystem respiration (Reco) and net ecosystem exchange (NEE) rates showed daily and seasonal variation at all investigated sites. Reco presented a strong dependence on soil temperature at the 5 cm depth, while NEE showed a strong dependence on solar radiation. The mean temperature sensitivity (Q10) for the four sites ranged between 3.17 and 8.3. The highest NEE and Reco values were obtained at the site represented by Caricetum elatae and the lowest NEE and Reco at the site represented by Calamagrostietum neglectae. |
BibTeX:
@article{Acosta2017,
author = {Acosta, Manuel and Juszczak, Radek and Chojnicki, Bogdan and Pavelka, Marian and Havránková, KateÅ™ina and Lesny, Jacek and Krupková, Lenka and Urbaniak, Marek and Machačová, KateÅ™ina and Olejnik, Janusz},
title = {CO2 Fluxes from Different Vegetation Communities on a Peatland Ecosystem},
journal = {Wetlands},
year = {2017},
volume = {37},
number = {3},
pages = {423--435},
doi = {10.1007/s13157-017-0878-4}
}
|
| Acosta M, Darenova E, Dušek J and Pavelka M (2017), "Soil carbon dioxide fluxes in a mixed floodplain forest in the Czech Republic", European Journal of Soil Biology., sep, 2017. Vol. 82, pp. 35-42. |
| Abstract: Floodplain forests belong among the most productive, dynamic and diverse ecosystems on Earth. Only few studies have focused on the carbon dioxide fluxes of these ecosystems. Therefore, this study investigated the spatial heterogeneity in soil CO2 efflux in a floodplain forest located in the southeast of the Czech Republic. The study also examined which environmental parameters influence soil CO2 efflux. Moreover, using these obtained measurements a soil CO2 efflux model was applied. To achieve the aims of this study, soil CO2 efflux on 30 positions in 16 campaigns was measured from May to November during the growing season 2016. The efflux during the experiment period ranged from 1.59 to 8.54 μmolCO2 mâˆ'2 sâˆ'1. The highest soil CO2 effluxes were observed during the summer period while the lowest values were measured during the autumn. A strong relationship between soil CO2 efflux and soil temperature was found (R2 = 0.79). The estimated mean Q10 for the whole 30 positions was of 2.23. We determined that the spatial heterogeneity of soil CO2 efflux was 20% during our study. The cumulative amount of carbon forest floor released from our experimental forest site calculated from our model was 7.4 (±1.1) tC haâˆ'1 yâˆ'1 for 2016. Such data are important for developing our knowledge and understanding about carbon dynamics and to improve carbon models for these ecosystems types. |
BibTeX:
@article{Acosta2017a,
author = {Acosta, Manuel and Darenova, Eva and Dušek, JiÅ™í and Pavelka, Marian},
title = {Soil carbon dioxide fluxes in a mixed floodplain forest in the Czech Republic},
journal = {European Journal of Soil Biology},
year = {2017},
volume = {82},
pages = {35--42},
url = {http://linkinghub.elsevier.com/retrieve/pii/S1164556317301607},
doi = {10.1016/j.ejsobi.2017.08.006}
}
|
| Ala-aho P, Tetzlaff D, McNamara JP, Laudon H, Kormos P and Soulsby C (2017), "Modeling the isotopic evolution of snowpack and snowmelt: Testing a spatially distributed parsimonious approach", Water Resources Research., jul, 2017. Vol. 53(7), pp. 5813-5830. |
| Abstract: Use of stable water isotopes has become increasingly popular in quantifying water flow paths and travel times in hydrological systems using tracer-aided modeling. In snow-influenced catchments, snowmelt produces a traceable isotopic signal, which differs from original snowfall isotopic composition because of isotopic fractionation in the snowpack. These fractionation processes in snow are relatively well understood, but representing their spatiotemporal variability in tracer-aided studies remains a challenge. We present a novel, parsimonious modeling method to account for the snowpack isotope fractionation and estimate isotope ratios in snowmelt water in a fully spatially distributed manner. Our model introduces two calibration parameters that alone account for the isotopic fractionation caused by sublimation from interception and ground snow storage, and snowmelt fractionation progressively enriching the snowmelt runoff. The isotope routines are linked to a generic process-based snow interception-accumulation-melt model facilitating simulation of spatially distributed snowmelt runoff. We use a synthetic modeling experiment to demonstrate the functionality of the model algorithms in different landscape locations and under different canopy characteristics. We also provide a proof-of-concept model test and successfully reproduce isotopic ratios in snowmelt runoff sampled with snowmelt lysimeters in two long-term experimental catchment with contrasting winter conditions. To our knowledge, the method is the first such tool to allow estimation of the spatially distributed nature of isotopic fractionation in snowpacks and the resulting isotope ratios in snowmelt runoff. The method can thus provide a useful tool for tracer-aided modeling to better understand the integrated nature of flow, mixing, and transport processes in snow-influenced catchments. |
BibTeX:
@article{Ala-aho2017,
author = {Ala-aho, Pertti and Tetzlaff, Doerthe and McNamara, James P and Laudon, Hjalmar and Kormos, Patrick and Soulsby, Chris},
title = {Modeling the isotopic evolution of snowpack and snowmelt: Testing a spatially distributed parsimonious approach},
journal = {Water Resources Research},
year = {2017},
volume = {53},
number = {7},
pages = {5813--5830},
url = {http://doi.wiley.com/10.1002/2017WR020650},
doi = {10.1002/2017WR020650}
}
|
| Alam SA, Huang JG, Stadt KJ, Comeau PG, Dawson A, Gea-Izquierdo G, Aakala T, Hölttä T, Vesala T, Mäkelä A and Berninger F (2017), "Effects of competition, drought stress and photosynthetic productivity on the radial growth of white spruce in western Canada", Frontiers in Plant Science., nov, 2017. Vol. 8 Frontiers Media S.A.. |
| Abstract: Understanding the complex interactions of competition, climate warming-induced drought stress, and photosynthetic productivity on the radial growth of trees is central to linking climate change impacts on tree growth, stand structure and in general, forest productivity. Using a mixed modeling approach, a stand-level photosynthetic production model, climate, stand competition and tree-ring data from mixedwood stands in western Canada, we investigated the radial growth response of white spruce [Picea glauca (Moench.) Voss] to simulated annual photosynthetic production, simulated drought stress, and tree and stand level competition. The long-term (˜80-year) radial growth of white spruce was constrained mostly by competition, as measured by total basal area, with minor effects from drought. There was no relation of competition and drought on tree growth but dominant trees increased their growth more strongly to increases in modeled photosynthetic productivity, indicating asymmetric competition. Our results indicate a co-limitation of drought and climatic factors inhibiting photosynthetic productivity for radial growth of white spruce in western Canada. These results illustrate how a modeling approach can separate the complex factors regulating both multi-decadal average radial growth and interannual radial growth variations of white spruce, and contribute to advance our understanding on sustainable management of mixedwood boreal forests in western Canada. |
BibTeX:
@article{Alam2017,
author = {Alam, Syed A. and Huang, Jian Guo and Stadt, Kenneth J. and Comeau, Philip G. and Dawson, Andria and Gea-Izquierdo, Guillermo and Aakala, Tuomas and Hölttä, Teemu and Vesala, Timo and Mäkelä, Annikki and Berninger, Frank},
title = {Effects of competition, drought stress and photosynthetic productivity on the radial growth of white spruce in western Canada},
journal = {Frontiers in Plant Science},
publisher = {Frontiers Media S.A.},
year = {2017},
volume = {8},
doi = {10.3389/fpls.2017.01915}
}
|
| Alekseychik P, Mammarella I, Karpov D, Dengel S, Terentieva I, Sabrekov A, Glagolev M and Lapshina E (2017), "Net ecosystem exchange and energy fluxes measured with the eddy covariance technique in a western Siberian bog", Atmospheric Chemistry and Physics., aug, 2017. Vol. 17(15), pp. 9333-9345. Copernicus GmbH. |
| Abstract: Very few studies of ecosystem-atmosphere exchange involving eddy covariance data have been conducted in Siberia, with none in the western Siberian middle taiga. This work provides the first estimates of carbon dioxide (CO2) and energy budgets in a typical bog of the western Siberian middle taiga based on May-August measurements in 2015. The footprint of measured fluxes consisted of a homogeneous mixture of tree-covered ridges and hollows with the vegetation represented by typical sedges and shrubs. Generally, the surface exchange rates resembled those of pine-covered bogs elsewhere. The surface energy balance closure approached 100ĝ€%. Net CO2 uptake was comparatively high, summing up to 202ĝ€gCĝ€mĝ'2 for the four measurement months, while the Bowen ratio was seasonally stable at 28ĝ€%. The ecosystem turned into a net CO2 source during several front passage events in June and July. The periods of heavy rain helped keep the water table at a sustainably high level, preventing a usual drawdown in summer. However, because of the cloudy and rainy weather, the observed fluxes might rather represent the special weather conditions of 2015 than their typical magnitudes. |
BibTeX:
@article{Alekseychik2017,
author = {Alekseychik, Pavel and Mammarella, Ivan and Karpov, Dmitry and Dengel, Sigrid and Terentieva, Irina and Sabrekov, Alexander and Glagolev, Mikhail and Lapshina, Elena},
title = {Net ecosystem exchange and energy fluxes measured with the eddy covariance technique in a western Siberian bog},
journal = {Atmospheric Chemistry and Physics},
publisher = {Copernicus GmbH},
year = {2017},
volume = {17},
number = {15},
pages = {9333--9345},
doi = {10.5194/acp-17-9333-2017}
}
|
| Alekseychik PK, Korrensalo A, Mammarella I, Vesala T and Tuittila ES (2017), "Relationship between aerodynamic roughness length and bulk sedge leaf area index in a mixed-species boreal mire complex", Geophysical Research Letters., jun, 2017. Vol. 44(11), pp. 5836-5843. |
| Abstract: Leaf area index (LAI) is an important parameter in natural ecosystems, representing the seasonal development of vegetation and photosynthetic potential. However, direct measurement techniques require labor-intensive field campaigns that are usually limited in time, while remote sensing approaches often do not yield reliable estimates. Here we propose that the bulk LAI of sedges (LAIs) can be estimated alternatively from a micrometeorological parameter, the aerodynamic roughness length for momentum (z0). z0 can be readily calculated from high-response turbulence and other meteorological data, typically measured continuously and routinely available at ecosystem research sites. The regressions of LAI versus z0 were obtained using the data from two Finnish natural sites representative of boreal fen and bog ecosystems. LAIs was found to be well correlated with z0 and sedge canopy height. Superior method performance was demonstrated in the fen ecosystem where the sedges make a bigger contribution to overall surface roughness than in bogs. |
BibTeX:
@article{Alekseychik2017a,
author = {Alekseychik, P K and Korrensalo, A and Mammarella, I and Vesala, T and Tuittila, E S},
title = {Relationship between aerodynamic roughness length and bulk sedge leaf area index in a mixed-species boreal mire complex},
journal = {Geophysical Research Letters},
year = {2017},
volume = {44},
number = {11},
pages = {5836--5843},
url = {http://doi.wiley.com/10.1002/2017GL073884},
doi = {10.1002/2017GL073884}
}
|
| Ameli AA, Beven K, Erlandsson M, Creed IF, McDonnell JJ and Bishop K (2017), "Primary weathering rates, water transit times, and concentration-discharge relations: A theoretical analysis for the critical zone", Water Resources Research., jan, 2017. Vol. 53(1), pp. 942-960. |
| Abstract: The permeability architecture of the critical zone exerts a major influence on the hydrogeochemistry of the critical zone. Water flow path dynamics drive the spatiotemporal pattern of geochemical evolution and resulting streamflow concentration-discharge (C-Q) relation, but these flow paths are complex and difficult to map quantitatively. Here we couple a new integrated flow and particle tracking transport model with a general reversible Transition State Theory style dissolution rate law to explore theoretically how C-Q relations and concentration in the critical zone respond to decline in saturated hydraulic conductivity (Ks) with soil depth. We do this for a range of flow rates and mineral reaction kinetics. Our results show that for minerals with a high ratio of equilibrium concentration (Ceq) to intrinsic weathering rate (Rmax), vertical heterogeneity in Ks enhances the gradient of weathering-derived solute concentration in the critical zone and strengthens the inverse stream C-Q relation. As Ceq/Rmax decreases, the spatial distribution of concentration in the critical zone becomes more uniform for a wide range of flow rates, and stream C-Q relation approaches chemostatic behavior, regardless of the degree of vertical heterogeneity in Ks. These findings suggest that the transport-controlled mechanisms in the hillslope can lead to chemostatic C-Q relations in the stream while the hillslope surface reaction-controlled mechanisms are associated with an inverse stream C-Q relation. In addition, as Ceq/Rmax decreases, the concentration in the critical zone and stream become less dependent on groundwater age (or transit time). |
BibTeX:
@article{Ameli2017,
author = {Ameli, Ali A and Beven, Keith and Erlandsson, Martin and Creed, Irena F and McDonnell, Jeffrey J and Bishop, Kevin},
title = {Primary weathering rates, water transit times, and concentration-discharge relations: A theoretical analysis for the critical zone},
journal = {Water Resources Research},
year = {2017},
volume = {53},
number = {1},
pages = {942--960},
url = {http://doi.wiley.com/10.1002/2016WR019448},
doi = {10.1002/2016WR019448}
}
|
| Ameli AA (2017), "Controls on subsurface transport of sorbing contaminant", Hydrology Research., oct, 2017. Vol. 48(5), pp. 1226-1239. |
| Abstract: Subsurface transport of a sorbing contaminant is poorly understood and characterized. Here, a new semi-analytical saturated–unsaturated flow and transport model is coupled to a kinetic sorption algorithm to assess the impact of changes in the subsurface permeability architecture and flow rate on sorption characteristics. The model outputs reveal the pronounced effect of the rate of vertical decline in Ks on the frequency of occurrence and spatial distribution of subsurface sorption as well as the timing and rate of sorbing contaminants discharged into stream. Sorption potential is weakened with infiltration rate. The impact of infiltration rate on the decline in sorption potential becomes more accentuated as the degree of subsurface vertical heterogeneity in saturated hydraulic conductivity increases. Porosity pattern also impacts sorption characteristics; but its effects highly depend upon the degree of vertical heterogeneity in Ks. The results and methodology presented in this paper have potential implications for assessing water quality in integrated groundwater–surface water systems as well as designing remediation systems. |
BibTeX:
@article{Ameli2017a,
author = {Ameli, Ali A},
title = {Controls on subsurface transport of sorbing contaminant},
journal = {Hydrology Research},
year = {2017},
volume = {48},
number = {5},
pages = {1226--1239},
url = {http://hr.iwaponline.com/lookup/doi/10.2166/nh.2016.170},
doi = {10.2166/nh.2016.170}
}
|
| Amvrosiadi N, Seibert J, Grabs T and Bishop K (2017), "Water storage dynamics in a till hillslope: the foundation for modeling flows and turnover times", Hydrological Processes., jan, 2017. Vol. 31(1), pp. 4-14. |
| Abstract: Studies on hydrology, biogeochemistry, or mineral weathering often rely on assumptions about flow paths, water storage dynamics, and transit times. Testing these assumptions requires detailed hydrometric data that are usually unavailable at the catchment scale. Hillslope studies provide an alternative for obtaining a better understanding, but even on such well-defined and delimited scales, it is rare to have a comprehensive set of hydrometric observations from the water divide down to the stream that can constrain efforts to quantify water storage, movement, and turnover time. Here, we quantified water storage with daily resolution in a hillslope during the course of almost an entire year using hydrological measurements at the study site and an extended version of the vertical equilibrium model. We used an exponential function to simulate the relationship between hillslope discharge and water table; this was used to derive transmissivity profiles along the hillslope and map mean pore water velocities in the saturated zone. Based on the transmissivity profiles, the soil layer transmitting 99% of lateral flow to the stream had a depth that ranged from 8.9Â m at the water divide to under 1Â m closer to the stream. During the study period, the total storage of this layer varied from 1189 to 1485Â mm, resulting in a turnover time of 2172Â days. From the pore water velocities, we mapped the time it would take a water particle situated at any point of the saturated zone anywhere along the hillslope to exit as runoff. Our calculations point to the strengths as well as limitations of simple hydrometric data for inferring hydrological properties and water travel times in the subsurface. |
BibTeX:
@article{Amvrosiadi2017,
author = {Amvrosiadi, Nino and Seibert, Jan and Grabs, Thomas and Bishop, Kevin},
title = {Water storage dynamics in a till hillslope: the foundation for modeling flows and turnover times},
journal = {Hydrological Processes},
year = {2017},
volume = {31},
number = {1},
pages = {4--14},
url = {http://doi.wiley.com/10.1002/hyp.11046},
doi = {10.1002/hyp.11046}
}
|
| Amvrosiadi N, Bishop K and Seibert J (2017), "Soil moisture storage estimation based on steady vertical fluxes under equilibrium", Journal of Hydrology., oct, 2017. Vol. 553, pp. 798-804. |
| Abstract: Soil moisture is an important variable for hillslope and catchment hydrology. There are various computational methods to estimate soil moisture and their complexity varies greatly: from one box with vertically constant volumetric soil water content to fully saturated-unsaturated coupled physically-based models. Different complexity levels are applicable depending on the simulation scale, computational time limitations, input data and knowledge about the parameters. The Vertical Equilibrium Model (VEM) is a simple approach to estimate the catchment-wide soil water storage at a daily time-scale on the basis of water table level observations, soil properties and an assumption of hydrological equilibrium without vertical fluxes above the water table. In this study VEM was extended by considering vertical fluxes, which allows conditions with evaporation and infiltration to be represented. The aim was to test the hypothesis that the simulated volumetric soil water content significantly depends on vertical fluxes. The water content difference between the no-flux, equilibrium approach and the new constant-flux approach greatly depended on the soil textural class, ranging between ∼1% for silty clay and ∼44% for sand at an evapotranspiration rate of 5 mmtextperiodcentereddâˆ'1. The two approaches gave a mean volumetric soil water content difference of ∼1 mm for two case studies (sandy loam and organic rich soils). The results showed that for many soil types the differences in estimated storage between the no-flux and the constant flux approaches were relatively small. |
BibTeX:
@article{Amvrosiadi2017a,
author = {Amvrosiadi, Nino and Bishop, Kevin and Seibert, Jan},
title = {Soil moisture storage estimation based on steady vertical fluxes under equilibrium},
journal = {Journal of Hydrology},
year = {2017},
volume = {553},
pages = {798--804},
url = {http://linkinghub.elsevier.com/retrieve/pii/S0022169417305784},
doi = {10.1016/j.jhydrol.2017.08.042}
}
|
| Andriamandroso ALH, Lebeau F, Beckers Y, Froidmont E, Dufrasne I, Heinesch B, Dumortier P, Blanchy G, Blaise Y and Bindelle J (2017), "Development of an open-source algorithm based on inertial measurement units (IMU) of a smartphone to detect cattle grass intake and ruminating behaviors", Computers and Electronics in Agriculture., jun, 2017. Vol. 139, pp. 126-137. |
| Abstract: In this paper, an open algorithm was developed for the detection of cattle's grass intake and rumination activities. This was done using the widely available inertial measurement unit (IMU) from a smartphone, which contains an accelerometer, a gyroscope, a magnetometer and location sensors signals sampled at 100Â Hz. This equipment was mounted on 19 grazing cows of different breeds and daily video sequences were recorded on pasture of different forage allowances. After visually analyzing the cows' movements on a calibration database, signal combinations were selected and thresholds were determined based on 1-s time windows, since increasing the time window did not increase the accuracy of detection. The final algorithm uses the average value and standard deviation of two signals in a two-step discrimination tree: the gravitational acceleration on x-axis (Gx) expressing the cows' head movements and the rotation rate on the same x-axis (Rx) expressing jaw movements. Threshold values encompassing 95% of the normalized calibrated data gave the best results. Validation on an independent database resulted in an average detection accuracy of 92% with a better detection for rumination (95%) than for grass intake (91%). The detection algorithm also allows for characterization of the diurnal feeding activities of cattle at pasture. Any user can make further improvements, for data collected at the same way as the iPhone's IMU has done, since the algorithm codes are open and provided as supplementary data. |
BibTeX:
@article{Andriamandroso2017,
author = {Andriamandroso, Andriamasinoro Lalaina Herinaina and Lebeau, Frédéric and Beckers, Yves and Froidmont, Eric and Dufrasne, Isabelle and Heinesch, Bernard and Dumortier, Pierre and Blanchy, Guillaume and Blaise, Yannick and Bindelle, Jérôme},
title = {Development of an open-source algorithm based on inertial measurement units (IMU) of a smartphone to detect cattle grass intake and ruminating behaviors},
journal = {Computers and Electronics in Agriculture},
year = {2017},
volume = {139},
pages = {126--137},
url = {http://linkinghub.elsevier.com/retrieve/pii/S0168169916305567},
doi = {10.1016/j.compag.2017.05.020}
}
|
| Arnone V, González-Dávila M and Magdalena Santana-Casiano J (2017), "CO2 fluxes in the South African coastal region", Marine Chemistry., oct, 2017. Vol. 195, pp. 41-49. Elsevier B.V.. |
| Abstract: The air-sea exchange of CO2, its distribution and trends in the South African continental shelf over 8 years (2005–2012) has been studied using data from 28 journeys of a volunteer observing ship (VOS). Sea water properties, strongly controlled by the oceanographic dynamic, showed a complex distribution pattern between Cape Town and Durban. Three different upwelling cells were identified, which dominated the regional variability, together with the presence of eddies, filaments and the core of the Agulhas Current. From west to east the variation in CO2 fugacity (fCO2) followed the temperature increase, resulting in oversaturated (textgreater 600 μatm) or undersaturated (˜ 215 μatm) waters. After removing seasonality, seawater fCO2 decreased while sea surface temperature (SST) and salinity did not show a clear trend. From 18°25′E to 20°00′E (the west region), surface water was undersaturated and presented an averaged flux of − 4.27 ± 0.07 mol m− 2 year− 1. The south region (20°00′E-25°30′E) reached a value of − 4.39 ± 0.08 mol m− 2 year− 1, while between 25°30′E and 28°30′E (the south-east region) the averaged flux was − 5.03 ± 0.11 mol m− 2 year− 1. Between 28°30′E and 31°15′E (the east region) the flux was the lowest (− 1.65 ± 0.04 mol m− 2 year− 1). The full studied area acted as a sink with a mean value of − 3.83 ± 0.04 mol m− 2 year− 1, decreasing at an annual rate of 0.13 ± 0.16 mol m− 2 year− 1 from 2005 to 2012 related to the highest rate of increase in fCO2,sw over that in fCO2,atm. The estimated carbon uptake by the coastal region with a surface area of 99 × 109 m2 was − 4.6 ± 0.1 TgC year− 1. |
BibTeX:
@article{Arnone2017,
author = {Arnone, Verónica and González-Dávila, Melchor and Magdalena Santana-Casiano, J.},
title = {CO2 fluxes in the South African coastal region},
journal = {Marine Chemistry},
publisher = {Elsevier B.V.},
year = {2017},
volume = {195},
pages = {41--49},
doi = {10.1016/j.marchem.2017.07.008}
}
|
| Arriga N, Rannik Ü, Aubinet M, Carrara A, Vesala T and Papale D (2017), "Experimental validation of footprint models for eddy covariance CO2 flux measurements above grassland by means of natural and artificial tracers", Agricultural and Forest Meteorology., aug, 2017. Vol. 242, pp. 75-84. |
| Abstract: Footprint models, which simulate source area for scalar fluxes, are fundamental tools for a correct interpretation of micromoeteorological flux measurements and ecosystem exchange inferred from such data. Over the last two decades models of varying complexity have been developed, but all of them suffer from a significant lack of experimental validation. In this study two different experimental tests have been conducted with the aim of offering validation: a manipulation of the vegetation cover and an artificial tracer emission. In the first case the extension of the flux source has been changed progressively by successive cuts of vegetation, while in the second case by varying the distance of a tracer emission line respect to the measurement point. Results have been used to validate two analytical and a numerical footprint models. The experimental data show a good agreement with footprint models and indicate a limited extension of the flux source area, with approximately 75% of the sources confined within a range of 10–20 times the effective measurement height, i.e. the measurement height above the zero plane displacement. Another interesting result was the strong dependence on the surface roughness of both experimental estimates and numerical simulations of footprint. The effect of surface roughness on experimental results and models outputs was comparable to the effect of atmospheric stability. This indicates that surface roughness and turbulence conditions may play a significant role in source area location, in particular above inhomogeneous surfaces with change in roughness, as in the case of the manipulation experiment. Consequently a careful site specific quantification of these parameters seems to be fundamental to obtain realistic footprint estimates and significantly improve eddy covariance flux interpretation at complex sites. |
BibTeX:
@article{Arriga2017,
author = {Arriga, Nicola and Rannik, Üllar and Aubinet, Marc and Carrara, Arnaud and Vesala, Timo and Papale, Dario},
title = {Experimental validation of footprint models for eddy covariance CO2 flux measurements above grassland by means of natural and artificial tracers},
journal = {Agricultural and Forest Meteorology},
year = {2017},
volume = {242},
pages = {75--84},
url = {http://linkinghub.elsevier.com/retrieve/pii/S0168192317301417},
doi = {10.1016/j.agrformet.2017.04.006}
}
|
| Arslan AN, Tanis CM, Metsämäki S, Aurela M, Böttcher K, Linkosalmi M and Peltoniemi M (2017), "Automated webcam monitoring of fractional snow cover in northern boreal conditions", Geosciences (Switzerland)., jul, 2017. Vol. 7(3), pp. 55. |
| Abstract: Fractional snow cover (FSC) is an important parameter to estimate snow water equivalent (SWE) and surface albedo important to climatic and hydrological applications. The presence of forest creates challenges to retrieve FSC accurately from satellite data, as forest canopy can block the sensor's view of snow cover. In addition to the challenge related to presence of forest, in situ data of FSC—necessary for algorithm development and validation—are very limited. This paper investigates the estimation of FSC using digital imagery to overcome the obstacle caused by forest canopy, and the possibility to use this imagery in the validation of FSC derived from satellite data. FSC is calculated here using an algorithm based on defining a threshold value according to the histogram of an image, to classify a pixel as snow-covered or snow-free. Images from the MONIMET camera network, producing a continuous image series in Finland, are used in the analysis of FSC. The results obtained from automated image analysis of snow cover are compared with reference data estimated by visual inspection of same images. The results show the applicability and usefulness of digital imagery in the estimation of fractional snow cover in forested areas, with a Root Mean Squared Error (RMSE) in the range of 0.1–0.3 (with the full range of 0–1). |
BibTeX:
@article{Arslan2017,
author = {Arslan, Ali Nadir and Tanis, Cemal Melih and Metsämäki, Sari and Aurela, Mika and Böttcher, Kristin and Linkosalmi, Maiju and Peltoniemi, Mikko},
title = {Automated webcam monitoring of fractional snow cover in northern boreal conditions},
journal = {Geosciences (Switzerland)},
year = {2017},
volume = {7},
number = {3},
pages = {55},
url = {http://www.mdpi.com/2076-3263/7/3/55},
doi = {10.3390/geosciences7030055}
}
|
| Askne JIH, Soja MJ and Ulander LMH (2017), "Biomass estimation in a boreal forest from TanDEM-X data, lidar DTM, and the interferometric water cloud model", Remote Sensing of Environment., jul, 2017. Vol. 196, pp. 265-278. |
| Abstract: The semi-empirical Interferometric Water Cloud Model, IWCM, is used to estimate above ground forest biomass, AGB, in northern Sweden, Krycklan (64°N 20°E). The results are based on separate analysis of 14 TanDEM-X acquisitions from 2011 to 2014 and a Lidar digital terrain model (DTM). 29 stands covering 272 ha and with AGB  183 Mg/ha, and 619 stands with area  1 ha covering 3166 ha and with AGB  291 Mg/ha have been analyzed. In situ and airborne lidar scanning, ALS, data from the BioSAR 2008 experiment are used as reference. AGB and forest height are estimated using a new optimization method for determining IWCM parameters. Allometric equations are used to describe the inter-dependency between forest height, biomass, area-fill factor, and stem volume. No local training data from the investigated area are used to determine model parameters. For the 29 stands, the relative RMSE for biomass estimated using the proposed method varied between 15.8% and 21.2% (r2 between 0.82 and 0.88) and between 9.9% and 16.0% for height (r2 between 0.84 and 0.89). Dependence of model parameters on temperature and precipitation as well as height of ambiguity are investigated. A method based on look-up table for biomass estimation from phase height is proposed. The method is used over an area of 68 km2 for one TanDEM-X acquisition from 2011-06-04 and the results are compared with an ALS biomass map from August 2008. Good agreement is observed, as well as high potential for clear-cut detection. |
BibTeX:
@article{Askne2017,
author = {Askne, Jan I H and Soja, Maciej J and Ulander, Lars M H},
title = {Biomass estimation in a boreal forest from TanDEM-X data, lidar DTM, and the interferometric water cloud model},
journal = {Remote Sensing of Environment},
year = {2017},
volume = {196},
pages = {265--278},
url = {http://linkinghub.elsevier.com/retrieve/pii/S0034425717301979},
doi = {10.1016/j.rse.2017.05.010}
}
|
| Auvinen M, Järvi L, Hellsten A, Rannik Ü and Vesala T (2017), "Numerical framework for the computation of urban flux footprints employing large-eddy simulation and Lagrangian stochastic modeling", Geoscientific Model Development., nov, 2017. Vol. 10(11), pp. 4187-4205. |
| Abstract: Conventional footprint models cannot account for the heterogeneity of the urban landscape imposing a pronounced uncertainty on the spatial interpretation of eddy-covariance (EC) flux measurements in urban studies. This work introduces a computational methodology that enables the generation of detailed footprints in arbitrarily complex urban flux measurements sites. The methodology is based on conducting high-resolution large-eddy simulation (LES) and Lagrangian stochastic (LS) particle analysis on a model that features a detailed topographic description of a real urban environment. The approach utilizes an arbitrarily sized target volume set around the sensor in the LES domain, to collect a dataset of LS particles which are seeded from the potential source area of the measurement and captured at the sensor site. The urban footprint is generated from this dataset through a piecewise postprocessing procedure, which divides the footprint evaluation into multiple independent processes that each yield an intermediate result. These results are ultimately selectively combined to produce the final footprint. The strategy reduces the computational cost of the LES-LS simulation and incorporates techniques to account for the complications that arise when the EC sensor is mounted on a building instead of a conventional flux tower. The presented computational framework also introduces a result assessment strategy which utilizes the obtained urban footprint together with a detailed land cover type dataset to estimate the potential error that may arise if analytically derived footprint models were employed instead. The methodology is demonstrated with a case study that concentrates on generating the footprint for a building-mounted EC measurement station in downtown Helsinki, Finland, under the neutrally stratified atmospheric boundary layer. |
BibTeX:
@article{Auvinen2017,
author = {Auvinen, Mikko and Järvi, Leena and Hellsten, Antti and Rannik, Üllar and Vesala, Timo},
title = {Numerical framework for the computation of urban flux footprints employing large-eddy simulation and Lagrangian stochastic modeling},
journal = {Geoscientific Model Development},
year = {2017},
volume = {10},
number = {11},
pages = {4187--4205},
url = {https://www.geosci-model-dev.net/10/4187/2017/},
doi = {10.5194/gmd-10-4187-2017}
}
|
| Baccini A, Walker W, Carvalho L, Farina M, Sulla-Menashe D and Houghton RA (2017), "Tropical forests are a net carbon source based on aboveground measurements of gain and loss", Science., oct, 2017. Vol. 358(6360), pp. 230-234. |
BibTeX:
@article{Baccini2017,
author = {Baccini, A and Walker, W and Carvalho, L and Farina, M and Sulla-Menashe, D and Houghton, R A},
title = {Tropical forests are a net carbon source based on aboveground measurements of gain and loss},
journal = {Science},
year = {2017},
volume = {358},
number = {6360},
pages = {230--234},
url = {https://www.sciencemag.org/lookup/doi/10.1126/science.aam5962},
doi = {10.1126/science.aam5962}
}
|
| Bamberger I, Oney B, Brunner D, Henne S, Leuenberger M, Buchmann N and Eugster W (2017), "Observations of Atmospheric Methane and Carbon Dioxide Mixing Ratios: Tall-Tower or Mountain-Top Stations?", Boundary-Layer Meteorology., jul, 2017. Vol. 164(1), pp. 135-159. |
| Abstract: Mountain-top observations of greenhouse gas mixing ratios may be an alternative to tall-tower measurements for regional scale source and sink estimation. To investigate the equivalence or limitations of a mountain-top site as compared to a tall-tower site, we used the unique opportunity of comparing in situ measurements of methane (CH 4) and carbon dioxide (CO 2) mixing ratios at a mountain top (986 m above sea level, a.s.l.) with measurements from a nearby (distance 28.4 km) tall tower, sampled at almost the same elevation (1009 m a.s.l.). Special attention was given to, (i) how local wind statistics and greenhouse gas sources and sinks at the mountain top influence the observations, and (ii) whether mountain-top observations can be used as for those from a tall tower for constraining regional greenhouse gas emissions. Wind statistics at the mountain-top site are clearly more influenced by local flow systems than those at the tall-tower site. Differences in temporal patterns of the greenhouse gas mixing ratios observed at the two sites are mostly related to the influence of local sources and sinks at the mountain-top site. Major influences of local sources can be removed by applying a statistical filter (5 th percentile) or a filter that removes periods with unfavourable flow conditions. In the best case, the bias in mixing ratios between the mountain-top and the tall-tower sites after the application of the wind filter was - 0.0005 ± 0.0010 ppm for methane (September, 0000–0400 UTC) and 0.11 ± 0.18 ppm for CO 2 (February, 1200–1600 UTC). Temporal fluctuations of atmospheric CH 4 and CO 2 mixing ratios at both stations also showed good agreement (apart from CO 2 during summertime) as determined by moving bi-weekly Pearson correlation coefficients (up to 0.96 for CO 2 and 0.97 for CH 4). When only comparing mixing ratios minimally influenced by local sources (low bias and high correlation coefficients), our measurements indicate that mountain-top observations are comparable to tall-tower observations. |
BibTeX:
@article{Bamberger2017,
author = {Bamberger, Ines and Oney, Brian and Brunner, Dominik and Henne, Stephan and Leuenberger, Markus and Buchmann, Nina and Eugster, Werner},
title = {Observations of Atmospheric Methane and Carbon Dioxide Mixing Ratios: Tall-Tower or Mountain-Top Stations?},
journal = {Boundary-Layer Meteorology},
year = {2017},
volume = {164},
number = {1},
pages = {135--159},
url = {http://link.springer.com/10.1007/s10546-017-0236-3},
doi = {10.1007/s10546-017-0236-3}
}
|
| Barnes AD, Allen K, Kreft H, Corre MD, Jochum M, Veldkamp E, Clough Y, Daniel R, Darras K, Denmead LH, Farikhah Haneda N, Hertel D, Knohl A, Kotowska MM, Kurniawan S, Meijide A, Rembold K, Edho Prabowo W, Schneider D, Tscharntke T and Brose U (2017), "Direct and cascading impacts of tropical land-use change on multi-trophic biodiversity", Nature Ecology and Evolution., aug, 2017. Vol. 1(10), pp. 1511-1519. Springer Nature. |
| Abstract: The conversion of tropical rainforest to agricultural systems such as oil palm alters biodiversity across a large range of interacting taxa and trophic levels. Yet, it remains unclear how direct and cascading effects of land-use change simultaneously drive ecological shifts. Combining data from a multi-taxon research initiative in Sumatra, Indonesia, we show that direct and cascading land-use effects alter biomass and species richness of taxa across trophic levels ranging from microorganisms to birds. Tropical land use resulted in increases in biomass and species richness via bottom-up cascading effects, but reductions via direct effects. When considering direct and cascading effects together, land use was found to reduce biomass and species richness, with increasing magnitude at higher trophic levels. Our analyses disentangle the multifaceted effects of land-use change on tropical ecosystems, revealing that biotic interactions on broad taxonomic scales influence the ecological outcome of anthropogenic perturbations to natural ecosystems. |
BibTeX:
@article{Barnes2017,
author = {Barnes, Andrew D and Allen, Kara and Kreft, Holger and Corre, Marife D and Jochum, Malte and Veldkamp, Edzo and Clough, Yann and Daniel, Rolf and Darras, Kevin and Denmead, Lisa H and Farikhah Haneda, Noor and Hertel, Dietrich and Knohl, Alexander and Kotowska, Martyna M and Kurniawan, Syahrul and Meijide, Ana and Rembold, Katja and Edho Prabowo, Walesa and Schneider, Dominik and Tscharntke, Teja and Brose, Ulrich},
title = {Direct and cascading impacts of tropical land-use change on multi-trophic biodiversity},
journal = {Nature Ecology and Evolution},
publisher = {Springer Nature},
year = {2017},
volume = {1},
number = {10},
pages = {1511--1519},
doi = {10.1038/s41559-017-0275-7}
}
|
| Berhanu TA, Szidat S, Brunner D, Satar E, Schanda R, Nyfeler P, Battaglia M, Steinbacher M, Hammer S and Leuenberger M (2017), "Estimation of the fossil fuel component in atmospheric CO2 based on radiocarbon measurements at the Beromünster tall tower, Switzerland", Atmospheric Chemistry and Physics., sep, 2017. Vol. 17(17), pp. 10753-10766. |
| Abstract: Fossil fuel CO2 (CO2ff) is the major contributor of anthropogenic CO2 in the atmosphere, and accurate quantification is essential to better understand the carbon cycle. Since October 2012, we have been continuously measuring the mixing ratios of CO, CO2, CH4, and H2O at five different heights at the Beromünster tall tower, Switzerland. Air samples for radiocarbon (14CO2) analysis have also been collected from the highest sampling inlet (212.5 m) of the tower on a biweekly basis. A correction was applied for 14CO2 emissions from nearby nuclear power plants (NPPs), which have been simulated with the Lagrangian transport model FLEXPART-COSMO. The 14CO2 emissions from NPPs offset the depletion in 14C by fossil fuel emissions, resulting in an underestimation of the fossil fuel component in atmospheric CO2 by about 16 %. An average observed ratio (RCO) of 13.4 ± 1.3 mmol -1 was calculated from the enhancements in CO mixing ratios relative to the clean-air reference site Jungfraujoch (CO) and the radiocarbon-based fossil fuel CO2 mole fractions. The wintertime R CO estimate of 12.5 ± 3.3 is about 30 % higher than the wintertime ratio between in situ measured CO and CO2 enhancements at Beromünster over the Jungfraujoch background (8.7 mmol -1) corrected for non-fossil contributions due to strong biospheric contribution despite the strong correlation between CO andCO2 in winter. By combining the ratio derived using the radiocarbon measurements and the in situ measured CO mixing ratios, a high-resolution time series of CO2ff was calculated exhibiting a clear seasonality driven by seasonal variability in emissions and vertical mixing. By subtracting the fossil fuel component and the large-scale background, we have determined the regional biospheric CO2 component that is characterized by seasonal variations ranging between g-15 and +30 ppm. A pronounced diurnal variation was observed during summer modulated by biospheric exchange and vertical mixing, while no consistent pattern was found during winter. |
BibTeX:
@article{Berhanu2017,
author = {Berhanu, Tesfaye A and Szidat, Sonke and Brunner, Dominik and Satar, Ece and Schanda, Rudiger and Nyfeler, Peter and Battaglia, Michael and Steinbacher, Martin and Hammer, Samuel and Leuenberger, Markus},
title = {Estimation of the fossil fuel component in atmospheric CO2 based on radiocarbon measurements at the Beromünster tall tower, Switzerland},
journal = {Atmospheric Chemistry and Physics},
year = {2017},
volume = {17},
number = {17},
pages = {10753--10766},
url = {https://www.atmos-chem-phys.net/17/10753/2017/},
doi = {10.5194/acp-17-10753-2017}
}
|
| Berhongaray G, Verlinden MS, Broeckx LS, Janssens IA and Ceulemans R (2017), "Soil carbon and belowground carbon balance of a short-rotation coppice: assessments from three different approaches", GCB Bioenergy., feb, 2017. Vol. 9(2), pp. 299-313. |
| Abstract: Uncertainty in soil carbon (C) fluxes across different land-use transitions is an issue that needs to be addressed for the further deployment of perennial bioenergy crops. A large-scale short-rotation coppice (SRC) site with poplar (Populus) and willow (Salix) was established to examine the land-use transitions of arable and pasture to bioenergy. Soil C pools, output fluxes of soil CO2, CH4, dissolved organic carbon (DOC) and volatile organic compounds, as well as input fluxes from litter fall and from roots, were measured over a 4-year period, along with environmental parameters. Three approaches were used to estimate changes in the soil C. The largest C pool in the soil was the soil organic carbon (SOC) pool and increased after four years of SRC from 10.9 to 13.9 kg C mâˆ'2. The belowground woody biomass (coarse roots) represented the second largest C pool, followed by the fine roots (Fr). The annual leaf fall represented the largest C input to the soil, followed by weeds and Fr. After the first harvest, we observed a very large C input into the soil from high Fr mortality. The weed inputs decreased as trees grew older and bigger. Soil respiration averaged 568.9 g C mâˆ'2 yrâˆ'1. Leaching of DOC increased over the three years from 7.9 to 14.5 g C mâˆ'2. The pool-based approach indicated an increase of 3360 g C mâˆ'2 in the SOC pool over the 4-year period, which was high when compared with the âˆ'27 g C mâˆ'2 estimated by the flux-based approach and the âˆ'956 g C mâˆ'2 of the combined eddy-covariance + biometric approach. High uncertainties were associated to the pool-based approach. Our results suggest using the C flux approach for the assessment of the short-/medium-term SOC balance at our site, while SOC pool changes can only be used for long-term C balance assessments. |
BibTeX:
@article{Berhongaray2017,
author = {Berhongaray, Gonzalo and Verlinden, Melanie S and Broeckx, Laura S and Janssens, Ivan A and Ceulemans, Reinhart},
title = {Soil carbon and belowground carbon balance of a short-rotation coppice: assessments from three different approaches},
journal = {GCB Bioenergy},
year = {2017},
volume = {9},
number = {2},
pages = {299--313},
url = {http://doi.wiley.com/10.1111/gcbb.12369},
doi = {10.1111/gcbb.12369}
}
|
| Bidleman TF, Laudon H, Nygren O, Svanberg S and Tysklind M (2017), "Chlorinated pesticides and natural brominated anisoles in air at three northern Baltic stations", Environmental Pollution., jun, 2017. Vol. 225, pp. 381-389. |
| Abstract: Polyurethane foam (PUF) disk passive samplers were deployed at one inland and two island locations in the Bothnian Bay region of the northern Baltic Sea. Uptake was linear over 81–147 d and a temperature range of âˆ'2.6 to 14.2 °C for organochlorine pesticides (OCPs) and current-use pesticides (CUPs) having log KOA ≥9 at ambient temperatures. Partial saturation of the PUF disks occurred for the more volatile OCPs hexachlorocyclohexanes (HCHs) and hexachlorobenzene (HCB), and for bromoanisoles (BAs), which are products of bromophenols released by natural and anthropogenic sources. Correction for nonlinear uptake of these was made using experimentally measured PUF-air partition coefficients. Passive-derived air concentrations of pesticides were uniform over the bay and agreed within a factor of 2 or better with levels determined by active (pumped) sampling at one of the island stations. Levels of OCPs were similar to those reported at background sites in the European and Canadian Arctic and at monitoring stations in the central Baltic and southern Scandinavia, indicating long-range transport. The insecticide chlorpyrifos was 10 times lower at bay stations than in the Canadian Arctic. Insight to sources and processes was gained by examining compound profiles. Fractions Falpha = α-HCH/(α-HCH + γ-HCH) and FTC = trans-chlordane/(trans-chlordane + cis-chlordane) at bay stations were higher than in the Norwegian and Finnish Arctic and similar to those at the southern monitoring stations. Volatilization of chlordanes from Baltic seawater may also modify FTC. Higher FTriBA = 2,4,6-TriBA/(2,4,6-TriBA + 2,4-DiBA) distinguished local volatilization from the Baltic Sea versus lower FTriBA found at the inland site and reported in air on the Norwegian coast, suggesting westerly transport from the Atlantic across Norway and Sweden. |
BibTeX:
@article{Bidleman2017,
author = {Bidleman, Terry F and Laudon, Hjalmar and Nygren, Olle and Svanberg, Staffan and Tysklind, Mats},
title = {Chlorinated pesticides and natural brominated anisoles in air at three northern Baltic stations},
journal = {Environmental Pollution},
year = {2017},
volume = {225},
pages = {381--389},
url = {http://linkinghub.elsevier.com/retrieve/pii/S0269749116321297},
doi = {10.1016/j.envpol.2017.02.064}
}
|
| Bidleman TF, Brorström-Lundén E, Hansson K, Laudon H, Nygren O and Tysklind M (2017), "Atmospheric Transport and Deposition of Bromoanisoles Along a Temperate to Arctic Gradient", Environmental Science and Technology., oct, 2017. Vol. 51(19), pp. 10974-10982. |
| Abstract: Bromoanisoles (BAs) arise from O-methylation of bromophenols, produced by marine algae and invertebrates. BAs undergo sea-air exchange and are transported over the oceans. Here we report 2,4-DiBA and 2,4,6-TriBA in air and deposition on the Swedish west coast (RaÌŠö) and the interior of arctic Finland (Pallas). Results are discussed in perspective with previous measurements in the northern Baltic region in 2011-2013. BAs in air decreased from south to north in the order RaÌŠö northern Baltic Pallas. Geometric mean concentrations at Pallas increased significantly (p 0.05) between 2002 and 2015 for 2,4-DiBA but not for 2,4,6-TriBA. The logarithm of BA partial pressures correlated significantly to reciprocal air temperature at the coastal station RaÌŠö and over the Baltic, but only weakly (2,4-DiBA) or not significantly (2,4,6-TriBA) at inland Pallas. Deposition fluxes of BAs were similar at both sites despite lower air concentrations at Pallas, due to greater precipitation scavenging at lower temperatures. Proportions of the two BAs in air and deposition were related to Henry's law partitioning and source regions. Precipitation concentrations were 10-40% of those in surface water of Bothnian Bay, northern Baltic Sea. BAs deposited in the bay catchment likely enter rivers and provide an unexpected source to northern estuaries. BAs may be precursors to higher molecular weight compounds identified by others in Swedish inland lakes. |
BibTeX:
@article{Bidleman2017a,
author = {Bidleman, Terry F and Brorström-Lundén, Eva and Hansson, Katarina and Laudon, Hjalmar and Nygren, Olle and Tysklind, Mats},
title = {Atmospheric Transport and Deposition of Bromoanisoles Along a Temperate to Arctic Gradient},
journal = {Environmental Science and Technology},
year = {2017},
volume = {51},
number = {19},
pages = {10974--10982},
url = {http://pubs.acs.org/doi/10.1021/acs.est.7b03218},
doi = {10.1021/acs.est.7b03218}
}
|
| Blackburn M, Ledesma JLJ, Näsholm T, Laudon H and Sponseller RA (2017), "Evaluating hillslope and riparian contributions to dissolved nitrogen (N) export from a boreal forest catchment", Journal of Geophysical Research: Biogeosciences., feb, 2017. Vol. 122(2), pp. 324-339. |
| Abstract: Catchment science has long held that the chemistry of small streams reflects the landscapes they drain. However, understanding the contribution of different landscape units to stream chemistry remains a challenge which frequently limits our understanding of export dynamics. For limiting nutrients such as nitrogen (N), an implicit assumption is that the most spatially extensive landscape units (e.g., uplands) act as the primary sources to surface waters, while near-stream zones function more often as sinks. These assumptions, based largely on studies in high-gradient systems or in regions with elevated inputs of anthropogenic N, may not apply to low-gradient, nutrient-poor, and peat-rich catchments characteristic of many northern ecosystems. We quantified patterns of N mobilization along a hillslope transect in a northern boreal catchment to assess the extent to which organic matter-rich riparian soils regulate the flux of N to streams. Contrary to the prevailing view of riparian functioning, we found that near-stream, organic soils supported concentrations and fluxes of ammonium (NH4+) and dissolved organic nitrogen that were much higher than the contributing upslope forest soils. These results suggest that stream N chemistry is connected to N mobilization and mineralization within the riparian zone rather than the wider landscape. Results further suggest that water table fluctuation in near-surface riparian soils may promote elevated rates of net N mineralization in these landscapes. |
BibTeX:
@article{Blackburn2017,
author = {Blackburn, M and Ledesma, José L J and Näsholm, Torgny and Laudon, Hjalmar and Sponseller, Ryan A},
title = {Evaluating hillslope and riparian contributions to dissolved nitrogen (N) export from a boreal forest catchment},
journal = {Journal of Geophysical Research: Biogeosciences},
year = {2017},
volume = {122},
number = {2},
pages = {324--339},
url = {http://doi.wiley.com/10.1002/2016JG003535},
doi = {10.1002/2016JG003535}
}
|
| Bloemen J, Fichot R, Horemans JA, Broeckx LS, Verlinden MS, Zenone T and Ceulemans R (2017), "Water use of a multigenotype poplar short-rotation coppice from tree to stand scale", GCB Bioenergy., feb, 2017. Vol. 9(2), pp. 370-384. |
| Abstract: Short-rotation coppice (SRC) has great potential for supplying biomass-based heat and energy, but little is known about SRC's ecological footprint, particularly its impact on the water cycle. To this end, we quantified the water use of a commercial scale poplar (Populus) SRC plantation in East Flanders (Belgium) at tree and stand level, focusing primarily on the transpiration component. First, we used the AquaCrop model and eddy covariance flux data to analyse the different components of the stand-level water balance for one entire growing season. Transpiration represented 59% of evapotranspiration (ET) at stand scale over the whole year. Measured ET and modelled ET were lower as compared to the ET of reference grassland, suggesting that the SRC only used a limited amount of water. Secondly, we compared leaf area scaled and sapwood area scaled sap flow (Fs) measurements on individual plants vs. stand scale eddy covariance flux data during a 39-day intensive field campaign in late summer 2011. Daily stem diameter variation (∆D) was monitored simultaneously with Fs to understand water use strategies for three poplar genotypes. Canopy transpiration based on sapwood area or leaf area scaling was 43.5 and 50.3 mm, respectively, and accounted for 74%, respectively, 86%, of total ecosystem ET measured during the intensive field campaign. Besides differences in growth, the significant intergenotypic differences in daily ∆D (due to stem shrinkage and swelling) suggested different water use strategies among the three genotypes which were confirmed by the sap flow measurements. Future studies on the prediction of SRC water use, or efforts to enhance the biomass yield of SRC genotypes, should consider intergenotypic differences in transpiration water losses at tree level as well as the SRC water balance at stand level. |
BibTeX:
@article{Bloemen2017,
author = {Bloemen, Jasper and Fichot, Régis and Horemans, Joanna A and Broeckx, Laura S and Verlinden, Melanie S and Zenone, Terenzio and Ceulemans, Reinhart},
title = {Water use of a multigenotype poplar short-rotation coppice from tree to stand scale},
journal = {GCB Bioenergy},
year = {2017},
volume = {9},
number = {2},
pages = {370--384},
url = {http://doi.wiley.com/10.1111/gcbb.12345},
doi = {10.1111/gcbb.12345}
}
|
| Blomquist BW, Brumer SE, Fairall CW, Huebert BJ, Zappa CJ, Brooks IM, Yang M, Bariteau L, Prytherch J, Hare JE, Czerski H, Matei A and Pascal RW (2017), "Wind Speed and Sea State Dependencies of Air-Sea Gas Transfer: Results From the High Wind Speed Gas Exchange Study (HiWinGS)", Journal of Geophysical Research: Oceans., oct, 2017. Vol. 122(10), pp. 8034-8062. Blackwell Publishing Ltd. |
| Abstract: A variety of physical mechanisms are jointly responsible for facilitating air-sea gas transfer through turbulent processes at the atmosphere-ocean interface. The nature and relative importance of these mechanisms evolves with increasing wind speed. Theoretical and modeling approaches are advancing, but the limited quantity of observational data at high wind speeds hinders the assessment of these efforts. The HiWinGS project successfully measured gas transfer coefficients (k660) with coincident wave statistics under conditions with hourly mean wind speeds up to 24 m s−1 and significant wave heights to 8 m. Measurements of k660 for carbon dioxide (CO2) and dimethylsulfide (DMS) show an increasing trend with respect to 10 m neutral wind speed (U10N), following a power law relationship of the form: (Formula presented.) and (Formula presented.). Among seven high wind speed events, CO2 transfer responded to the intensity of wave breaking, which depended on both wind speed and sea state in a complex manner, with (Formula presented.) increasing as the wind sea approaches full development. A similar response is not observed for DMS. These results confirm the importance of breaking waves and bubble injection mechanisms in facilitating CO2 transfer. A modified version of the Coupled Ocean-Atmosphere Response Experiment Gas transfer algorithm (COAREG ver. 3.5), incorporating a sea state-dependent calculation of bubble-mediated transfer, successfully reproduces the mean trend in observed k660 with wind speed for both gases. Significant suppression of gas transfer by large waves was not observed during HiWinGS, in contrast to results from two prior field programs. |
BibTeX:
@article{Blomquist2017,
author = {Blomquist, B. W. and Brumer, S. E. and Fairall, C. W. and Huebert, B. J. and Zappa, C. J. and Brooks, I. M. and Yang, M. and Bariteau, L. and Prytherch, J. and Hare, J. E. and Czerski, H. and Matei, A. and Pascal, R. W.},
title = {Wind Speed and Sea State Dependencies of Air-Sea Gas Transfer: Results From the High Wind Speed Gas Exchange Study (HiWinGS)},
journal = {Journal of Geophysical Research: Oceans},
publisher = {Blackwell Publishing Ltd},
year = {2017},
volume = {122},
number = {10},
pages = {8034--8062},
url = {https://agupubs.onlinelibrary.wiley.com/doi/full/10.1002/2017JC013181 https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1002/2017JC013181 https://agupubs.onlinelibrary.wiley.com/doi/10.1002/2017JC013181},
doi = {10.1002/2017JC013181}
}
|
| Boese S, Jung M, Carvalhais N and Reichstein M (2017), "The importance of radiation for semiempirical water-use efficiency models", Biogeosciences., jun, 2017. Vol. 14(12), pp. 3015-3026. |
| Abstract: Water-use efficiency (WUE) is a fundamental property for the coupling of carbon and water cycles in plants and ecosystems. Existing model formulations predicting this variable differ in the type of response of WUE to the atmospheric vapor pressure deficit of water (VPD). We tested a representative WUE model on the ecosystem scale at 110 eddy covariance sites of the FLUXNET initiative by predicting evapotranspiration (ET) based on gross primary productivity (GPP) and VPD. We found that introducing an intercept term in the formulation increases model performance considerably, indicating that an additional factor needs to be considered. We demonstrate that this intercept term varies seasonally and we subsequently associate it with radiation. Replacing the constant intercept term with a linear function of global radiation was found to further improve model predictions of ET. Our new semiempirical ecosystem WUE formulation indicates that, averaged over all sites, this radiation term accounts for up to half (39-47g%) of transpiration. These empirical findings challenge the current understanding of water-use efficiency on the ecosystem scale. |
BibTeX:
@article{Boese2017,
author = {Boese, Sven and Jung, Martin and Carvalhais, Nuno and Reichstein, Markus},
title = {The importance of radiation for semiempirical water-use efficiency models},
journal = {Biogeosciences},
year = {2017},
volume = {14},
number = {12},
pages = {3015--3026},
url = {https://www.biogeosciences.net/14/3015/2017/},
doi = {10.5194/bg-14-3015-2017}
}
|
| Bogena H, Franssen H-JH, Montzka C and Vereecken H (2017), "A Blueprint for a Distributed Terrestrial Ecosystem Research Infrastructure", In Terrestrial Ecosystem Research Infrastructures. , pp. 279-303. CRS Press, Taylor & Francis Group. |
BibTeX:
@incollection{Bogena2017,
author = {Bogena, Heye and Franssen, Harrie-Jan Hendricks and Montzka, Carsten and Vereecken, Harry},
editor = {H, Chabbi A and Loescher},
title = {A Blueprint for a Distributed Terrestrial Ecosystem Research Infrastructure},
booktitle = {Terrestrial Ecosystem Research Infrastructures},
publisher = {CRS Press, Taylor & Francis Group},
year = {2017},
pages = {279--303},
doi = {10.1201/9781315368252-14}
}
|
| Bréchet L, Le Dantec V, Ponton S, Goret JY, Sayer E, Bonal D, Freycon V, Roy J and Epron D (2017), "Short- and Long-term Influence of Litter Quality and Quantity on Simulated Heterotrophic Soil Respiration in a Lowland Tropical Forest", Ecosystems., sep, 2017. Vol. 20(6), pp. 1190-1204. |
| Abstract: Heterotrophic soil respiration (SRH) alone can contribute up to 50% of total ecosystem respiration in tropical forests. Whereas the abiotic controls of SRH have been extensively studied, the influence of plant traits is less well characterised. We used field experiments and a modelling approach to test the relative influence of plant traits on SRH in lowland tropical forest in French Guiana. We measured leaf- and root litter traits for five common tree species and conducted a root decomposition experiment to evaluate the influence of root chemistry on decay rates. We measured SRH in trenched plots and used our field measurements to parameterize and test the Century model of soil C dynamics. Overall, the Century model performed well in simulating SRH, and species-specific root decomposition in Century corresponded well to decomposition rates measured in situ. Root litter characterized by low lignin-to-nitrogen ratios decomposed more rapidly than low-quality root litter during the first 6Â months. Model runs over different time scales revealed that litter quality substantially influenced SRH on an annual time-scale by determining the rates of root- and leaf litter decomposition. However, litter mass had an overriding influence on SRH over the longer term in 20-year model runs. Synthesis Using simple plant trait data to parameterise the Century model, we were able to accurately simulate changes in SRH in a lowland tropical forest. Our results suggest that this approach could be used to predict changes in tropical soil C dynamics under global change scenarios by including data on changes in plant productivity and C inputs to the soil (for example litterfall and root turnover). |
BibTeX:
@article{Brechet2017,
author = {Bréchet, Laëtitia and Le Dantec, Valérie and Ponton, Stéphane and Goret, Jean Yves and Sayer, Emma and Bonal, Damien and Freycon, Vincent and Roy, Jacques and Epron, Daniel},
title = {Short- and Long-term Influence of Litter Quality and Quantity on Simulated Heterotrophic Soil Respiration in a Lowland Tropical Forest},
journal = {Ecosystems},
year = {2017},
volume = {20},
number = {6},
pages = {1190--1204},
url = {http://link.springer.com/10.1007/s10021-016-0104-x},
doi = {10.1007/s10021-016-0104-x}
}
|
| Brümmer C, Lyshede B, Lempio D, Delorme JP, Rüffer JJ, Fuß R, Moffat AM, Hurkuck M, Ibrom A, Ambus P, Flessa H and Kutsch WL (2017), "Gas chromatography vs. quantum cascade laser-based N2O flux measurements using a novel chamber design", Biogeosciences., mar, 2017. Vol. 14(6), pp. 1365-1381. |
| Abstract: Recent advances in laser spectrometry offer new opportunities to investigate the soil-atmosphere exchange of nitrous oxide. During two field campaigns conducted at a grassland site and a willow field, we tested the performance of a quantum cascade laser (QCL) connected to a newly developed automated chamber system against a conventional gas chromatography (GC) approach using the same chambers plus an automated gas sampling unit with septum capped vials and subsequent laboratory GC analysis. Through its high precision and time resolution, data of the QCL system were used for quantifying the commonly observed nonlinearity in concentration changes during chamber deployment, making the calculation of exchange fluxes more accurate by the application of exponential models. As expected, the curvature values in the concentration increase was higher during long (60min) chamber closure times and under high-flux conditions (FN2O150μg Nm-2h-1) than those values that were found when chambers were closed for only 10min and/or when fluxes were in a typical range of 2 to 50μg Nm-2h-1. Extremely low standard errors of fluxes, i.e., from ∼ 0.2 to 1.7% of the flux value, were observed regardless of linear or exponential flux calculation when using QCL data. Thus, we recommend reducing chamber closure times to a maximum of 10min when a fast-response analyzer is available and this type of chamber system is used to keep soil disturbance low and conditions around the chamber plot as natural as possible. Further, applying linear regression to a 3min data window with rejecting the first 2min after closure and a sampling time of every 5s proved to be sufficient for robust flux determination while ensuring that standard errors of N2O fluxes were still on a relatively low level. Despite low signal-to-noise ratios, GC was still found to be a useful method to determine the mean the soil-atmosphere exchange of N2O on longer timescales during specific campaigns. Intriguingly, the consistency between GC and QCL-based campaign averages was better under low than under high N2O efflux conditions, although single flux values were highly scattered during the low efflux campaign. Furthermore, the QCL technology provides a useful tool to accurately investigate the highly debated topic of diurnal courses of N2O fluxes and its controlling factors. Our new chamber design protects the measurement spot from unintended shading and minimizes disturbance of throughfall, thereby complying with high quality requirements of long-term observation studies and research infrastructures. |
BibTeX:
@article{Brummer2017,
author = {Brümmer, Christian and Lyshede, Bjarne and Lempio, Dirk and Delorme, Jean Pierre and Rüffer, Jeremy J and Fuß, Roland and Moffat, Antje M and Hurkuck, Miriam and Ibrom, Andreas and Ambus, Per and Flessa, Heinz and Kutsch, Werner L},
title = {Gas chromatography vs. quantum cascade laser-based N2O flux measurements using a novel chamber design},
journal = {Biogeosciences},
year = {2017},
volume = {14},
number = {6},
pages = {1365--1381},
url = {https://www.biogeosciences.net/14/1365/2017/},
doi = {10.5194/bg-14-1365-2017}
}
|
| Burrows RM, Laudon H, McKie BG and Sponseller RA (2017), "Seasonal resource limitation of heterotrophic biofilms in boreal streams", Limnology and Oceanography., jan, 2017. Vol. 62(1), pp. 164-176. |
| Abstract: Unraveling the potentially shifting controls over microbial activity among habitats and across seasonal transitions is critical for understanding how freshwater ecosystems influence broader elemental cycles, and how these systems may respond to global changes. We used nutrient-diffusing substrates to investigate seasonal patterns and constraints on microbial activity of biofilms in streams draining distinct landscape features of the boreal biome (forests, mires, and lakes). Microbial respiration (MR) largely mirrored spatial and temporal variation in water temperature. However, limitation by labile carbon (C) was a constraint to microbial activity during ice-covered periods, when MR of control nutrient-diffusing substrates fell below rates predicted from stream temperature alone. Variation in C limitation among the study streams was reflective of putative organic C availability, with C limitation of biofilms weakest in the dissolved organic C (DOC)-rich, mire-outlet stream and greatest in the relatively DOC-poor, forest stream. Incidences of nutrient limitation were only observed during warmer months. Our study illustrates how variation in processes mediated by heterotrophic biofilms and seasonal shifts in resource limitation can emerge in a stream network draining a heterogeneous landscape. In addition, our results show that, for a large portion of the year, heterotrophic processes in boreal streams can be strongly limited by the availability of labile C, despite high DOC concentrations. Metabolic constraints to dissolved organic matter processing at near-freezing temperatures, coupled with hydrological controls over the delivery of more labile organic resources to streams (e.g., soil freezing and flooding), have potentially strong influences on the productivity of boreal streams. |
BibTeX:
@article{Burrows2017,
author = {Burrows, Ryan M and Laudon, Hjalmar and McKie, Brendan G and Sponseller, Ryan A},
title = {Seasonal resource limitation of heterotrophic biofilms in boreal streams},
journal = {Limnology and Oceanography},
year = {2017},
volume = {62},
number = {1},
pages = {164--176},
url = {http://doi.wiley.com/10.1002/lno.10383},
doi = {10.1002/lno.10383}
}
|
| Buschmann M, Deutscher NM, Palm M, Warneke T, Weinzierl C and Notholt J (2017), "The arctic seasonal cycle of total column CO2 and CH4 from ground-based solar and lunar FTIR absorption spectrometry", Atmospheric Measurement Techniques., jul, 2017. Vol. 10(7), pp. 2397-2411. Copernicus GmbH. |
| Abstract: Solar absorption spectroscopy in the near infrared has been performed in Ny-Ålesund (78.9°N, 11.9°E) since 2002; however, due to the high latitude of the site, the sun is below the horizon from October to March (polar night) and no solar absorption measurements are possible. Here we present a novel method of retrieving the total column dry-air mole fractions (DMFs) of CO2 and CH4 using moonlight in winter. Measurements have been taken during the polar nights from 2012 to 2016 and are validated with TCCON (Total Carbon Column Observing Network) measurements by solar and lunar absorption measurements on consecutive days and nights during spring and autumn. The complete seasonal cycle of the DMFs of CO2 and CH4 is presented and a precision of up to 0.5% is achieved. A comparison of solar and lunar measurements on consecutive days during day and night in March 2013 yields non-significant biases of 0. 66 ± 4. 56ppm for xCO2 and -1. 94 ± 20. 63ppb for xCH4. Additionally a model comparison has been performed with data from various reanalysis models. |
BibTeX:
@article{Buschmann2017,
author = {Buschmann, Matthias and Deutscher, Nicholas M. and Palm, Mathias and Warneke, Thorsten and Weinzierl, Christine and Notholt, Justus},
title = {The arctic seasonal cycle of total column CO2 and CH4 from ground-based solar and lunar FTIR absorption spectrometry},
journal = {Atmospheric Measurement Techniques},
publisher = {Copernicus GmbH},
year = {2017},
volume = {10},
number = {7},
pages = {2397--2411},
doi = {10.5194/amt-10-2397-2017}
}
|
| Buysse P, Bodson B, Debacq A, De Ligne A, Heinesch B, Manise T, Moureaux C and Aubinet M (2017), "Carbon budget measurement over 12 years at a crop production site in the silty-loam region in Belgium", Agricultural and Forest Meteorology., nov, 2017. Vol. 246, pp. 241-255. |
| Abstract: Carbon dioxide (CO2) exchanges between crops and the atmosphere are influenced by both climatic and management drivers. In this study, a site at the Lonzée Terrestrial Observatory (candidate ICOS site) in Belgium that had been managed for more than 70 years using conventional farming practices, was monitored over three complete rotation cycles (sugar beet/winter wheat/seed potato/winter wheat) from 2004 to 2016. Continuous eddy-covariance measurements and regular biomass samplings were performed in order to obtain the daily and seasonal Net Ecosystem Exchange (NEE), Gross Primary Productivity (GPP), Total Ecosystem Respiration (TER), Net Primary Productivity (NPP) and Net Biome Production (NBP). Meteorological data and crop management practices were also recorded. Over the 12 crop seasons, total NEE varied both between and within crop types. Crop type influenced net carbon (C) sequestration, with the seed potato crop exhibiting the smallest C fluxes. Despite differences in CO2 assimilation response to weather variables and in cumulated TER/GPP dynamics, the sugar beet, winter wheat and maize crops had similar seasonal NEE values. The NEE inter-annual variability, both between and within crop types, was explained mainly by the length of the active vegetation period, as well as the cumulated photosynthetic photon flux density and average air temperature during this period. The establishment of the C budget over the 12 years of study showed that NEE was a downward (negative) flux (âˆ'4.40 ± 0.05 kg C mâˆ'2), but NBP was an upward (positive) flux (0.99 ± 0.22 kg C mâˆ'2). That is, as soon as C exportation at harvest and C importation (manure, slimes) were included in the budget, the site behaved as a C source. The intercrop periods contributed significantly to the total C budget, and the C fluxes generated during these periods were positively related to crop residue amount and temperature. The largest uncertainties about the crop C budget were those relating to biomass measurements. Carrying out a soil C inventory would help to validate the NBP-based estimate of soil C loss. |
BibTeX:
@article{Buysse2017,
author = {Buysse, Pauline and Bodson, Bernard and Debacq, Alain and De Ligne, Anne and Heinesch, Bernard and Manise, Tanguy and Moureaux, Christine and Aubinet, Marc},
title = {Carbon budget measurement over 12 years at a crop production site in the silty-loam region in Belgium},
journal = {Agricultural and Forest Meteorology},
year = {2017},
volume = {246},
pages = {241--255},
url = {http://linkinghub.elsevier.com/retrieve/pii/S0168192317302204},
doi = {10.1016/j.agrformet.2017.07.004}
}
|
| Bye IJ, North PRJ, Los SO, Kljun N, Rosette JAB, Hopkinson C, Chasmer L and Mahoney C (2017), "Estimating forest canopy parameters from satellite waveform LiDAR by inversion of the FLIGHT three-dimensional radiative transfer model", Remote Sensing of Environment., jan, 2017. Vol. 188, pp. 177-189. |
| Abstract: The Geoscience Laser Altimeter System (GLAS) has the potential to accurately map global vegetation heights and fractional cover metrics using active laser pulse emission/reception. However, large uncertainties in the derivation of data products exist, since multiple physically plausible interpretations of the data are possible. In this study a method is described and evaluated to derive vegetation height and fractional cover from GLAS waveforms by inversion of the FLIGHT radiative transfer model. A lookup-table is constructed giving expected waveforms for a comprehensive set of canopy realisations, and is used to determine the most likely set of biophysical parameters describing the forest structure, consistent with any given GLAS waveform. The parameters retrieved are canopy height, leaf area index (LAI), fractional cover and ground slope. The range of possible parameters consistent with the waveform is used to give a per-retrieval uncertainty estimate for each retrieved parameter. The retrieved estimates were evaluated first using a simulated data set and then validated against airborne laser scanning (ALS) products for three forest sites coincident with GLAS overpasses. Results for height retrieval show mean absolute error (MAE) of 3.71 m for a mixed temperate forest site within Forest of Dean (UK), 3.35 m for the Southern Old Aspen Site, Saskatchewan, Canada, and 5.13 m for a boreal coniferous site in Norunda, Sweden. Fractional cover showed MAE of 0.10 for Forest of Dean and 0.23 for Norunda. Coefficient of determination between ALS and GLAS estimates over the combined dataset gave R2 values of 0.71 for height and 0.48 for fractional cover, with biases of âˆ'3.4 m and 0.02 respectively. Smallest errors were found where overpass dates for ALS data collection closely matched GLAS overpasses. Explicit instrument parameterisation means the method is readily adapted to future planned spaceborne LiDAR instruments such as GEDI. |
BibTeX:
@article{Bye2017,
author = {Bye, I J and North, P R J and Los, S O and Kljun, N and Rosette, J A B and Hopkinson, C and Chasmer, L and Mahoney, C},
title = {Estimating forest canopy parameters from satellite waveform LiDAR by inversion of the FLIGHT three-dimensional radiative transfer model},
journal = {Remote Sensing of Environment},
year = {2017},
volume = {188},
pages = {177--189},
url = {http://linkinghub.elsevier.com/retrieve/pii/S0034425716304278},
doi = {10.1016/j.rse.2016.10.048}
}
|
| Cai Z, Jönsson P, Jin H and Eklundh L (2017), "Performance of smoothing methods for reconstructing NDVI time-series and estimating vegetation phenology from MODIS data", Remote Sensing., dec, 2017. Vol. 9(12), pp. 1271. |
| Abstract: Many time-series smoothing methods can be used for reducing noise and extracting plant phenological parameters from remotely-sensed data, but there is still no conclusive evidence in favor of one method over others. Here we use moderate-resolution imaging spectroradiometer (MODIS) derived normalized difference vegetation index (NDVI) to investigate five smoothing methods: Savitzky-Golay fitting (SG), locally weighted regression scatterplot smoothing (LO), spline smoothing (SP), asymmetric Gaussian function fitting (AG), and double logistic function fitting (DL). We use ground tower measured NDVI (10 sites) and gross primary productivity (GPP, 4 sites) to evaluate the smoothed satellite-derived NDVI time-series, and elevation data to evaluate phenology parameters derived from smoothed NDVI. The results indicate that all smoothing methods can reduce noise and improve signal quality, but that no single method always performs better than others. Overall, the local filtering methods (SG and LO) can generate very accurate results if smoothing parameters are optimally calibrated. If local calibration cannot be performed, cross validation is a way to automatically determine the smoothing parameter. However, this method may in some cases generate poor fits, and when calibration is not possible the function fitting methods (AG and DL) provide the most robust description of the seasonal dynamics. |
BibTeX:
@article{Cai2017,
author = {Cai, Zhanzhang and Jönsson, Per and Jin, Hongxiao and Eklundh, Lars},
title = {Performance of smoothing methods for reconstructing NDVI time-series and estimating vegetation phenology from MODIS data},
journal = {Remote Sensing},
year = {2017},
volume = {9},
number = {12},
pages = {1271},
url = {http://www.mdpi.com/2072-4292/9/12/1271},
doi = {10.3390/rs9121271}
}
|
| Campeau A, Wallin MB, Giesler R, Löfgren S, Mörth CM, Schiff S, Venkiteswaran JJ and Bishop K (2017), "Multiple sources and sinks of dissolved inorganic carbon across Swedish streams, refocusing the lens of stable C isotopes", Scientific Reports., dec, 2017. Vol. 7(1), pp. 9158. |
| Abstract: It is well established that stream dissolved inorganic carbon (DIC) fluxes play a central role in the global C cycle, yet the sources of stream DIC remain to a large extent unresolved. Here, we explore large-scale patterns in δ13C-DIC from streams across Sweden to separate and further quantify the sources and sinks of stream DIC. We found that stream DIC is governed by a variety of sources and sinks including biogenic and geogenic sources, CO2 evasion, as well as in-stream processes. Although soil respiration was the main source of DIC across all streams, a geogenic DIC influence was identified in the northernmost region. All streams were affected by various degrees of atmospheric CO2 evasion, but residual variance in δ13C-DIC also indicated a significant influence of in-stream metabolism and anaerobic processes. Due to those multiple sources and sinks, we emphasize that simply quantifying aquatic DIC fluxes will not be sufficient to characterise their role in the global C cycle. |
BibTeX:
@article{Campeau2017,
author = {Campeau, Audrey and Wallin, Marcus B and Giesler, Reiner and Löfgren, Stefan and Mörth, Carl Magnus and Schiff, Sherry and Venkiteswaran, Jason J and Bishop, Kevin},
title = {Multiple sources and sinks of dissolved inorganic carbon across Swedish streams, refocusing the lens of stable C isotopes},
journal = {Scientific Reports},
year = {2017},
volume = {7},
number = {1},
pages = {9158},
url = {http://www.nature.com/articles/s41598-017-09049-9},
doi = {10.1038/s41598-017-09049-9}
}
|
| Campeau A, Bishop KH, Billett MF, Garnett MH, Laudon H, Leach JA, Nilsson MB, Öquist MG and Wallin MB (2017), "Aquatic export of young dissolved and gaseous carbon from a pristine boreal fen: Implications for peat carbon stock stability", Global Change Biology., dec, 2017. Vol. 23(12), pp. 5523-5536. |
| Abstract: The stability of northern peatland's carbon (C) store under changing climate is of major concern for the global C cycle. The aquatic export of C from boreal peatlands is recognized as both a critical pathway for the remobilization of peat C stocks as well as a major component of the net ecosystem C balance (NECB). Here, we present a full year characterization of radiocarbon content (14C) of dissolved organic carbon (DOC), carbon dioxide (CO2), and methane (CH4) exported from a boreal peatland catchment coupled with 14C characterization of the catchment's peat profile of the same C species. The age of aquatic C in runoff varied little throughout the year and appeared to be sustained by recently fixed C from the atmosphere (60 years), despite stream DOC, CO2, and CH4 primarily being sourced from deep peat horizons (2–4 m) near the mire's outlet. In fact, the 14C content of DOC, CO2, and CH4 across the entire peat profile was considerably enriched with postbomb C compared with the solid peat material. Overall, our results demonstrate little to no mobilization of ancient C stocks from this boreal peatland and a relatively large resilience of the source of aquatic C export to forecasted hydroclimatic changes. |
BibTeX:
@article{Campeau2017a,
author = {Campeau, Audrey and Bishop, Kevin H and Billett, Michael F and Garnett, Mark H and Laudon, Hjalmar and Leach, Jason A and Nilsson, Mats B and Öquist, Mats G and Wallin, Marcus B},
title = {Aquatic export of young dissolved and gaseous carbon from a pristine boreal fen: Implications for peat carbon stock stability},
journal = {Global Change Biology},
year = {2017},
volume = {23},
number = {12},
pages = {5523--5536},
url = {http://doi.wiley.com/10.1111/gcb.13815},
doi = {10.1111/gcb.13815}
}
|
| Chen L, Huang JG, Alam SA, Zhai L, Dawson A, Stadt KJ and Comeau PG (2017), "Drought causes reduced growth of trembling aspen in western Canada", Global Change Biology., jul, 2017. Vol. 23(7), pp. 2887-2902. Blackwell Publishing Ltd. |
| Abstract: Adequate and advance knowledge of the response of forest ecosystems to temperature-induced drought is critical for a comprehensive understanding of the impacts of global climate change on forest ecosystem structure and function. Recent massive decline in aspen-dominated forests and an increased aspen mortality in boreal forests have been associated with global warming, but it is still uncertain whether the decline and mortality are driven by drought. We used a series of ring-width chronologies from 40 trembling aspen (Populus tremuloides Michx.) sites along a latitudinal gradient (from 52° to 58°N) in western Canada, in an attempt to clarify the impacts of drought on aspen growth by using Standardized Precipitation Index (SPI) and Standardized Precipitation Evapotranspiration Index (SPEI). Results indicated that prolonged and large-scale droughts had a strong negative impact on trembling aspen growth. Furthermore, the spatiotemporal variability of drought indices is useful for explaining the spatial heterogeneity in the radial growth of trembling aspen. Due to ongoing global warming and rising temperatures, it is likely that severer droughts with a higher frequency will occur in western Canada. As trembling aspen is sensitive to drought, we suggest that drought indices could be applied to monitor the potential effects of increased drought stress on aspen trees growth, achieve classification of eco-regions and develop effective mitigation strategies to maintain western Canadian boreal forests. |
BibTeX:
@article{Chen2017,
author = {Chen, Lei and Huang, Jian Guo and Alam, Syed Ashraful and Zhai, Lihong and Dawson, Andria and Stadt, Kenneth J. and Comeau, Philip G.},
title = {Drought causes reduced growth of trembling aspen in western Canada},
journal = {Global Change Biology},
publisher = {Blackwell Publishing Ltd},
year = {2017},
volume = {23},
number = {7},
pages = {2887--2902},
doi = {10.1111/gcb.13595}
}
|
| Combe M, de Wit AJW, Vilà-Guerau de Arellano J, van der Molen MK, Magliulo V and Peters W (2017), "Grain Yield Observations Constrain Cropland CO2 Fluxes Over Europe", Journal of Geophysical Research: Biogeosciences., dec, 2017. Vol. 122(12), pp. 3238-3259. |
| Abstract: Carbon exchange over croplands plays an important role in the European carbon cycle over daily to seasonal time scales. A better description of this exchange in terrestrial biosphere models—most of which currently treat crops as unmanaged grasslands—is needed to improve atmospheric CO2 simulations. In the framework we present here, we model gross European cropland CO2 fluxes with a crop growth model constrained by grain yield observations. Our approach follows a two-step procedure. In the first step, we calculate day-to-day crop carbon fluxes and pools with the WOrld FOod STudies (WOFOST) model. A scaling factor of crop growth is optimized regionally by minimizing the final grain carbon pool difference to crop yield observations from the Statistical Office of the European Union. In a second step, we re-run our WOFOST model for the full European 25 × 25 km gridded domain using the optimized scaling factors. We combine our optimized crop CO2 fluxes with a simple soil respiration model to obtain the net cropland CO2 exchange. We assess our model's ability to represent cropland CO2 exchange using 40 years of observations at seven European FluxNet sites and compare it with carbon fluxes produced by a typical terrestrial biosphere model. We conclude that our new model framework provides a more realistic and strongly observation-driven estimate of carbon exchange over European croplands. Its products will be made available to the scientific community through the ICOS Carbon Portal and serve as a new cropland component in the CarbonTracker Europe inverse model. |
BibTeX:
@article{Combe2017,
author = {Combe, M and de Wit, A J W and Vilà-Guerau de Arellano, J and van der Molen, M K and Magliulo, V and Peters, W},
title = {Grain Yield Observations Constrain Cropland CO2 Fluxes Over Europe},
journal = {Journal of Geophysical Research: Biogeosciences},
year = {2017},
volume = {122},
number = {12},
pages = {3238--3259},
url = {http://doi.wiley.com/10.1002/2017JG003937},
doi = {10.1002/2017JG003937}
}
|
| Darenova E, Holub P, Krupkova L and Pavelka M (2017), "Effect of repeated spring drought and summer heavy rain on managed grassland biomass production and CO2 efflux", Journal of Plant Ecology., jun, 2017. Vol. 10(3), pp. 476-485. |
| Abstract: Aims Ecosystem respiration represents an important component of the carbon cycle. The response of respiration to climate change can have a significant effect on carbon sequestration in terrestrial ecosystems in the future when, according to climate scenarios, spring drought and consequent summer heavy rains are expected. Aims of our study were to determine the effect of repeated spring drought on biomass production and CO2 efflux from a mountain grassland in Beskydy Mountains in the Czech Republic and to evaluate factors driving the differences among the study years. Methods CO2 efflux was measured on plots with ambient precipitation conditions (AMB) and on plots where drought conditions (DRY) in the first half of the growing seasons and consequent heavy rain were simulated in 2011–14. Important Findings The spring drought significantly decreased the amount of above-ground biomass sampled just after the simulated drought in all years except for 2014. On the contrary, the spring drought stimulated root production. The drought also resulted in a rapid decrease in CO2 efflux. It was lower by up to 46% for the DRY treatment compared to AMB treatment. After the simulated drought period, differences in CO2 efflux between the treatments gradually decreased. Simulated heavy rains in DRY resulted in fast but temporary increase in CO2 efflux. We can assume that the future spring drought will have a significant effect on carbon balance of grassland ecosystems. The impact will depend on the length of the dry period and the time between the beginning of the growing season and the dry period. |
BibTeX:
@article{Darenova2017,
author = {Darenova, Eva and Holub, Petr and Krupkova, Lenka and Pavelka, Marian},
title = {Effect of repeated spring drought and summer heavy rain on managed grassland biomass production and CO2 efflux},
journal = {Journal of Plant Ecology},
year = {2017},
volume = {10},
number = {3},
pages = {476--485},
url = {https://academic.oup.com/jpe/article-lookup/doi/10.1093/jpe/rtw058},
doi = {10.1093/jpe/rtw058}
}
|
| Delogu E, Le Dantec V, Mordelet P, Ceschia E, Aubinet M, Buysse P and Pattey E (2017), "Improved methodology to quantify the temperature sensitivity of the soil heterotrophic respiration in croplands", Geoderma., jun, 2017. Vol. 296, pp. 18-29. |
| Abstract: Soil heterotrophic respiration (RH) is usually modeled using simple temperature dependence equations where the temperature sensitivity of RH could vary for different soils and climate conditions. The temperature sensitivity is expressed as a function of the base rate of heterotrophic respiration (RH âˆ' 0) and the respiration change rate over a 10 °C temperature shift (Q10). A methodology was developed to better quantify these two parameters, and was validated using seven contrasting year-site soil respiration datasets collected in wheat fields. The data were acquired using soil respiration chambers and eddy flux towers in three mid-latitude European sites and one North American site. The first step consisted in parameterizing and initializing a semi-mechanistic process-based model then validating the prediction performance using 2/3 of the datasets. The coefficient of determinations between the predictions and the observations of daily soil respiration (Rs) was 0.71 and was 0.73 for its heterotrophic component (RH). The second step consisted in using the daily semi-mechanistic model predictions of RH for each growing season and site to calibrate a simple empirical model describing RH response to soil temperature and water content. It was shown with the contrasting years-sites that coherent results were only obtained when a common average Q10 value was determined prior to fit the base rate of heterotrophic respiration coefficient. Using a common Q10 value of 2.2 provided more stable RH âˆ' 0 for each site over time. It reflected the strong relationship between the RH âˆ' 0 and the slow decomposing C in the first 30-cm soil layer. The simple empirical model, which was validated using 1/3 of the data, explained between 42% and 92% of the variability of RH over the different sites. |
BibTeX:
@article{Delogu2017,
author = {Delogu, Emilie and Le Dantec, Valérie and Mordelet, Patrick and Ceschia, Eric and Aubinet, Marc and Buysse, Pauline and Pattey, Elizabeth},
title = {Improved methodology to quantify the temperature sensitivity of the soil heterotrophic respiration in croplands},
journal = {Geoderma},
year = {2017},
volume = {296},
pages = {18--29},
url = {http://linkinghub.elsevier.com/retrieve/pii/S0016706117302677},
doi = {10.1016/j.geoderma.2017.02.017}
}
|
| Delpierre N, Guillemot J, Dufrêne E, Cecchini S and Nicolas M (2017), "Tree phenological ranks repeat from year to year and correlate with growth in temperate deciduous forests", Agricultural and Forest Meteorology., mar, 2017. Vol. 234-235, pp. 1-10. |
| Abstract: The timing of leaf phenophases greatly influences the functioning of trees. Phenological traits are thus considered major components of tree fitness, and are expected to be strongly selected under environmental or biotic pressures. To date, most phenological studies have been conducted at the population scale, with comparatively very few works at the scale of individuals. We take advantage of a unique phenological database, consisting of leaf unfolding (LU) and leaf senescence (LS) observations done at the individual scale for 5 years over 35 populations, representing 1200 dominant and co-dominant trees of three species (Quercus robur, Quercus petraea and Fagus sylvatica), to document the within-population variability of phenological traits in temperate deciduous forest trees. We show that individual phenological ranks mostly repeat from year to year among trees of a given population, though LU ranks tend to repeat more than LS ranks. Using simulated dynamics of soil water content, we suggest that inter-individual differences in the access to soil water may play a role in determining tree phenological ranks. The timing of leaf phenology is further correlated with individual growth in a given tree population. In Beech populations, early-leafers tend to grow more. On the other hand, Oak trees entering senescence later tend to grow more. The growth of Oak trees, being more prone to spring pathogenic attacks than Beech, may benefit less from a spring extension of leaf display. |
BibTeX:
@article{Delpierre2017,
author = {Delpierre, Nicolas and Guillemot, Joannès and Dufrêne, Eric and Cecchini, Sébastien and Nicolas, Manuel},
title = {Tree phenological ranks repeat from year to year and correlate with growth in temperate deciduous forests},
journal = {Agricultural and Forest Meteorology},
year = {2017},
volume = {234-235},
pages = {1--10},
url = {http://linkinghub.elsevier.com/retrieve/pii/S0168192316307274},
doi = {10.1016/j.agrformet.2016.12.008}
}
|
| Demuzere M, Harshan S, Järvi L, Roth M, Grimmond CSB, Masson V, Oleson KW, Velasco E and Wouters H (2017), "Impact of urban canopy models and external parameters on the modelled urban energy balance in a tropical city", Quarterly Journal of the Royal Meteorological Society., apr, 2017. Vol. 143(704), pp. 1581-1596. |
| Abstract: To date, existing urban land surface models (ULSMs) have been mostly evaluated and optimized for mid- and high-latitude cities. For the first time, we provide a comparative evaluation of four ULSMs for a tropical residential neighbourhood in Singapore using directly measured energy balance components. The simulations are performed offline, for an 11 month period, using the bulk scheme TERRA_URB and three models of intermediate complexity (CLM, SURFEX and SUEWS). In addition, information from three different parameter lists are used to quantify the impact (interaction) of (between) external parameter settings and model formulations on the modelled urban energy balance components. Encouragingly, overall results indicate good model performance for most energy balance components and align well with previous findings for midlatitude regions, suggesting the transferability of these models to (sub)tropical regions. Similar to results from midlatitude regions, the outgoing long-wave radiation and latent heat flux remain the most problematic fluxes. In addition, the various combinations of models and different parameter values suggest that error statistics tend to be dominated more by the choice of the latter than the choice of model. Finally, our intercomparison framework enabled the attribution of common deficiencies in the different model approaches found previously in midlatitude regions: the simple representation of water intercepted by impervious surfaces leading to a positive bias in the latent heat flux directly after a precipitation event; and the positive bias in modelled outgoing long-wave radiation that is partly due to neglecting the radiative interactions of water vapour between the surface and the tower sensor. These findings suggest that future developments in urban climate research should continue the integration of more physically based processes in urban canopy models, ensure the consistency between the observed and modelled atmospheric properties and focus on the correct representation of urban morphology, water storage and thermal and radiative characteristics. |
BibTeX:
@article{Demuzere2017,
author = {Demuzere, M and Harshan, S and Järvi, L and Roth, M and Grimmond, C S B and Masson, V and Oleson, K W and Velasco, E and Wouters, H},
title = {Impact of urban canopy models and external parameters on the modelled urban energy balance in a tropical city},
journal = {Quarterly Journal of the Royal Meteorological Society},
year = {2017},
volume = {143},
number = {704},
pages = {1581--1596},
url = {http://doi.wiley.com/10.1002/qj.3028},
doi = {10.1002/qj.3028}
}
|
| Deng J, McCalley CK, Frolking S, Chanton J, Crill P, Varner R, Tyson G, Rich V, Hines M, Saleska SR and Li C (2017), "Adding stable carbon isotopes improves model representation of the role of microbial communities in peatland methane cycling", Journal of Advances in Modeling Earth Systems., jun, 2017. Vol. 9(2), pp. 1412-1430. |
| Abstract: Climate change is expected to have significant and uncertain impacts on methane (CH4) emissions from northern peatlands. Biogeochemical models can extrapolate site-specificCH4 measurements to larger scales and predict responses of CH4 emissions to environmental changes. However, these models include considerable uncertainties and limitations in representing CH4 production, consumption, and transport processes. To improve predictions of CH4 transformations, we incorporated acetate and stable carbon (C) isotopic dynamics associated with CH4 cycling into a biogeochemistry model, DNDC. By including these new features, DNDC explicitly simulates acetate dynamics and the relative contribution of acetotrophic and hydrogenotrophic methanogenesis (AM and HM) to CH4 production, and predicts the C isotopic signature (δ13C) in soil C pools and emitted gases. When tested against biogeochemical and microbial community observations at two sites in a zone of thawing permafrost in a subarctic peatland in Sweden, the new formulation substantially improved agreement with CH4 production pathways and δ13C in emitted CH4 (δ13C-CH4), a measure of the integrated effects of microbial production and consumption, and of physical transport. We also investigated the sensitivity of simulated δ13C-CH4 to C isotopic composition of substrates and, to fractionation factors for CH4 production (αAM and αHM), CH4 oxidation (αMO), and plant-mediated CH4 transport (αTP). The sensitivity analysis indicated that the δ13C-CH4 is highly sensitive to the factors associated with microbial metabolism (αAM, αHM, and αMO). The model framework simulating stable C isotopic dynamics provides a robust basis for better constraining and testing microbial mechanisms in predicting CH4 cycling in peatlands. |
BibTeX:
@article{Deng2017,
author = {Deng, Jia and McCalley, Carmody K and Frolking, Steve and Chanton, Jeff and Crill, Patrick and Varner, Ruth and Tyson, Gene and Rich, Virginia and Hines, Mark and Saleska, Scott R and Li, Changsheng},
title = {Adding stable carbon isotopes improves model representation of the role of microbial communities in peatland methane cycling},
journal = {Journal of Advances in Modeling Earth Systems},
year = {2017},
volume = {9},
number = {2},
pages = {1412--1430},
url = {http://doi.wiley.com/10.1002/2016MS000817},
doi = {10.1002/2016MS000817}
}
|
| de Vries W, Posch M, Simpson D and Reinds GJ (2017), "Modelling long-term impacts of changes in climate, nitrogen deposition and ozone exposure on carbon sequestration of European forest ecosystems", Science of The Total Environment., dec, 2017. Vol. 605-606, pp. 1097-1116. |
BibTeX:
@article{DeVries2017,
author = {de Vries, Wim and Posch, Maximilian and Simpson, David and Reinds, Gert Jan},
title = {Modelling long-term impacts of changes in climate, nitrogen deposition and ozone exposure on carbon sequestration of European forest ecosystems},
journal = {Science of The Total Environment},
year = {2017},
volume = {605-606},
pages = {1097--1116},
url = {https://linkinghub.elsevier.com/retrieve/pii/S004896971731536X},
doi = {10.1016/j.scitotenv.2017.06.132}
}
|
| Digrado A, Bachy A, Mozaffar A, Schoon N, Bussotti F, Amelynck C, Dalcq AC, Fauconnier ML, Aubinet M, Heinesch B, du Jardin P and Delaplace P (2017), "Long-term measurements of chlorophyll a fluorescence using the JIP-test show that combined abiotic stresses influence the photosynthetic performance of the perennial ryegrass (Lolium perenne) in a managed temperate grassland", Physiologia Plantarum., nov, 2017. Vol. 161(3), pp. 355-371. |
| Abstract: Several experiments have highlighted the complexity of stress interactions involved in plant response. The impact in field conditions of combined environmental constraints on the mechanisms involved in plant photosynthetic response, however, remains understudied. In a long-term field study performed in a managed grassland, we investigated the photosynthetic apparatus response of the perennial ryegrass (Lolium perenne L.) to environmental constraints and its ability to recover and acclimatize. Frequent field measurements of chlorophyll a fluorescence (ChlF) were made in order to determine the photosynthetic performance response of a population of L. perenne. Strong midday declines in the maximum quantum yield of primary photochemistry (FVFM) were observed in summer, when a combination of heat and high light intensity increased photosynthetic inhibition. During this period, increase in photosystem I (PSI) activity efficiency was also recorded, suggesting an increase in the photochemical pathway for de-excitation in summer. Strong climatic events (e.g. heat waves) were shown to reduce electron transport between photosystem II (PSII) and PSI. This reduction might have preserved the PSI from photo-oxidation. Periods of low soil moisture and high levels of sun irradiance increased PSII sensitivity to heat stress, suggesting increased susceptibility to combined environmental constraints. Despite the multiple inhibitions of photosynthetic functionality in summer, the L. perenne population showed increased PSII tolerance to environmental stresses in August. This might have been a response to earlier environmental constraints. It could also be linked to the selection and/or emergence of well-adapted individuals. |
BibTeX:
@article{Digrado2017,
author = {Digrado, Anthony and Bachy, Aurélie and Mozaffar, Ahsan and Schoon, Niels and Bussotti, Filippo and Amelynck, Crist and Dalcq, Anne Catherine and Fauconnier, Marie Laure and Aubinet, Marc and Heinesch, Bernard and du Jardin, Patrick and Delaplace, Pierre},
title = {Long-term measurements of chlorophyll a fluorescence using the JIP-test show that combined abiotic stresses influence the photosynthetic performance of the perennial ryegrass (Lolium perenne) in a managed temperate grassland},
journal = {Physiologia Plantarum},
year = {2017},
volume = {161},
number = {3},
pages = {355--371},
url = {http://doi.wiley.com/10.1111/ppl.12594},
doi = {10.1111/ppl.12594}
}
|
| Dinsmore KJ, Drewer J, Levy PE, George C, Lohila A, Aurela M and Skiba UM (2017), "Growing season CH4 and N2O fluxes from a subarctic landscape in northern Finland; From chamber to landscape scale", Biogeosciences., feb, 2017. Vol. 14(4), pp. 799-815. |
| Abstract: Subarctic and boreal emissions of CH4 are important contributors to the atmospheric greenhouse gas (GHG) balance and subsequently the global radiative forcing. Whilst N2O emissions may be lower, the much greater radiative forcing they produce justifies their inclusion in GHG studies. In addition to the quantification of flux magnitude, it is essential that we understand the drivers of emissions to be able to accurately predict climate-driven changes and potential feedback mechanisms. Hence this study aims to increase our understanding of what drives fluxes of CH4 and N2O in a subarctic forest/wetland landscape during peak summer conditions and into the shoulder season, exploring both spatial and temporal variability, and uses satellite-derived spectral data to extrapolate from chamber-scale fluxes to a 2 km × 2 km landscape area. From static chamber measurements made during summer and autumn campaigns in 2012 in the Sodankylä region of northern Finland, we concluded that wetlands represent a significant source of CH4 (3.35 ± 0.44 mg C mg-2 hg-1 during the summer campaign and 0.62 ± 0.09 mg C mg-2 hg-1 during the autumn campaign), whilst the surrounding forests represent a small sink (g-0.06 ± 0.01 mg C mg-2 hg-1 during the summer campaign and g-0.03 ± 0.01 mg C mg-2 hg-1 during the autumn campaign). N2O fluxes were near-zero across both ecosystems. We found a weak negative relationship between CH4 emissions and water table depth in the wetland, with emissions decreasing as the water table approached and flooded the soil surface and a positive relationship between CH4 emissions and the presence of Sphagnum mosses. Temperature was also an important driver of CH4 with emissions increasing to a peak at approximately 12 °C. Little could be determined about the drivers of N2O emissions given the small magnitude of the fluxes. A multiple regression modelling approach was used to describe CH4 emissions based on spectral data from PLEIADES PA1 satellite imagery across a 2 km × 2 km landscape. When applied across the whole image domain we calculated a CH4 source of 2.05 ± 0.61 mg C mg-2 hg-1. This was significantly higher than landscape estimates based on either a simple mean or weighted by forest/wetland proportion (0.99 ± 0.16, 0.93 ± 0.12 mg C mg-2 hg-1, respectively). Hence we conclude that ignoring the detailed spatial variability in CH4 emissions within a landscape leads to a potentially significant underestimation of landscape-scale fluxes. Given the small magnitude of measured N2O fluxes a similar level of detailed upscaling was not needed; we conclude that N2O fluxes do not currently comprise an important component of the landscape-scale GHG budget at this site. |
BibTeX:
@article{Dinsmore2017,
author = {Dinsmore, Kerry J and Drewer, Julia and Levy, Peter E and George, Charles and Lohila, Annalea and Aurela, Mika and Skiba, Ute M},
title = {Growing season CH4 and N2O fluxes from a subarctic landscape in northern Finland; From chamber to landscape scale},
journal = {Biogeosciences},
year = {2017},
volume = {14},
number = {4},
pages = {799--815},
url = {https://www.biogeosciences.net/14/799/2017/},
doi = {10.5194/bg-14-799-2017}
}
|
| Dobler JT, Zaccheo TS, Pernini TG, Blume N, Broquet G, Vogel F, Ramonet M, Braun M, Staufer J, Ciais P and Botos C (2017), "Demonstration of spatial greenhouse gas mapping using laser absorption spectrometers on local scales", Journal of Applied Remote Sensing., mar, 2017. Vol. 11(1), pp. 14002. |
| Abstract: textcopyright 2016 The Authors. A system for measuring the two-dimensional (2-D) spatial distribution of atmospheric CO2 over complex industrial sites and urban areas on the order of 1 to 30 km2 every few minutes with a spatial resolution as high as tens of meters has been developed and demonstrated over the past 3 years. The greenhouse gas (GHG) laser imaging tomography experiment (GreenLITEâ„¢) provides improved measurement capabilities for applications ranging from automated 24/7 monitoring of ground carbon storage/sequestration (GCS) sites to long-duration real-time analyses of GHG sources and sinks in urban environments. GreenLITE combines a set of sensors based on an intensity modulated continuous wave approach with 2-D sparse tomographic reconstruction mechanisms to compute a 2-D map of CO2 concentrations over the area of interest. GreenLITE systems have recently been deployed at a number of test facilities, including a 4000-h demonstration at a GCS site in Illinois and an urban deployment in Paris, France, from November 2015 to the present. This paper describes the GreenLITE concept and the associated measurement capabilities and provides proof of concept results and analyses of observations from both short-term tests as well as longer-term industrial and urban deployments. |
BibTeX:
@article{Dobler2017,
author = {Dobler, Jeremy T and Zaccheo, T Scott and Pernini, Timothy G and Blume, Nathan and Broquet, Gregoire and Vogel, Felix and Ramonet, Michel and Braun, Michael and Staufer, Johannes and Ciais, Philippe and Botos, Chris},
title = {Demonstration of spatial greenhouse gas mapping using laser absorption spectrometers on local scales},
journal = {Journal of Applied Remote Sensing},
year = {2017},
volume = {11},
number = {1},
pages = {14002},
url = {http://remotesensing.spiedigitallibrary.org/article.aspx?doi=10.1117/1.JRS.11.014002},
doi = {10.1117/1.jrs.11.014002}
}
|
| Dumortier P, Aubinet M, Beckers Y, Chopin H, Debacq A, Gourlez de la Motte L, Jérôme E, Wilmus F and Heinesch B (2017), "Methane balance of an intensively grazed pasture and estimation of the enteric methane emissions from cattle", Agricultural and Forest Meteorology., jan, 2017. Vol. 232, pp. 527-535. |
| Abstract: The methane turbulent fluxes of an intensively grazed pasture were measured continuously from June 2012 to December 2013 at the Dorinne Terrestrial Observatory (DTO) in Belgium. During grazing periods, the fluxes were dominated by enteric fermentation and were found to be strongly related to cow stocking density. In 2013, total emission from the pasture was found between 9 and 11 g CH4 mâˆ'2, 97% of which being emitted during grazing periods. Emission per LU (livestock unit) was estimated in a non-invasive way by integrating eddy covariance fluxes over large periods and by assuming a homogeneous average cattle disposition on the pasture. This estimate was compared to the one obtained during confinement periods, where cows were confined in a small part of the pasture. The emission per LU varied between 104 and 134 g CH4 LUâˆ'1 dayâˆ'1 (13 and 17 g CH4 kg DMIâˆ'1), depending on the dataset and the computation method used. Diel course was characterized by two emission peaks, one in the morning and a larger one in the afternoon. For rest periods (no cattle on the pasture), small emissions were observed (median and mean values of 0.5 and 1.5 mg CH4 mâˆ'2 dayâˆ'1, respectively). |
BibTeX:
@article{Dumortier2017,
author = {Dumortier, Pierre and Aubinet, M and Beckers, Y and Chopin, H and Debacq, A and Gourlez de la Motte, L and Jérôme, E and Wilmus, F and Heinesch, B},
title = {Methane balance of an intensively grazed pasture and estimation of the enteric methane emissions from cattle},
journal = {Agricultural and Forest Meteorology},
year = {2017},
volume = {232},
pages = {527--535},
url = {http://linkinghub.elsevier.com/retrieve/pii/S0168192316303914},
doi = {10.1016/j.agrformet.2016.09.010}
}
|
| Dušek J, Hudecová Š and Stellner S (2017), "Extreme precipitation and long-term precipitation changes in a Central European sedge-grass marsh in the context of flood occurrence", Hydrological Sciences Journal., aug, 2017. Vol. 62(11), pp. 1796-1808. |
| Abstract: This study offers a detailed analysis of the extreme precipitation and long-term precipitation changes in a sedge-grass marsh in the “Wet Meadows†area in the Czech Republic (Central Europe) in the context of flood occurrence. Namely, trends in annual maxima of daily precipitation and trends in the occurrence and amount of rainfall are investigated. The analysis is based on daily measurements of precipitation from 1977 to 2015. We found out that extreme precipitation has become significantly more frequent in recent years, and there are also other significant changes in the rainfall distribution. Possible negative effects on the wetland can be linked to a change of carbon exchange between the ecosystem and the atmosphere and a change of biodiversity. Awareness of these changes is necessary for possible positive human intervention when a desirable wetland functioning is threatened. |
BibTeX:
@article{Dusek2017,
author = {Dušek, JiÅ™í and Hudecová, Šárka and Stellner, Stanislav},
title = {Extreme precipitation and long-term precipitation changes in a Central European sedge-grass marsh in the context of flood occurrence},
journal = {Hydrological Sciences Journal},
year = {2017},
volume = {62},
number = {11},
pages = {1796--1808},
url = {https://www.tandfonline.com/doi/full/10.1080/02626667.2017.1353217},
doi = {10.1080/02626667.2017.1353217}
}
|
| Etchanchu J, Rivalland V, Gascoin S, Cros J, Tallec T, Brut A and Boulet G (2017), "Effects of high spatial and temporal resolution Earth observations on simulated hydrometeorological variables in a cropland (southwestern France)", Hydrology and Earth System Sciences. Vol. 21(11), pp. 5693-5708. |
| Abstract: Agricultural landscapes are often constituted by a patchwork of crop fields whose seasonal evolution is dependent on specific crop rotation patterns and phenologies. This temporal and spatial heterogeneity affects surface hydrometeorological processes and must be taken into account in simulations of land surface and distributed hydrological models. The Sentinel-2 mission allows for the monitoring of land cover and vegetation dynamics at unprecedented spatial resolutions and revisit frequencies (20m and 5 days, respectively) that are fully compatible with such heterogeneous agricultural landscapes. Here, we evaluate the impact of Sentinel-2-like remote sensing data on the simulation of surface water and energy fluxes via the Interactions between the Surface Biosphere Atmosphere (ISBA) land surface model included in the EXternalized SURface (SURFEX) modeling platform. The study focuses on the effect of the leaf area index (LAI) spatial and temporal variability on these fluxes.We compare the use of the LAI climatology from ECOCLIMAPII, used by default in SURFEX-ISBA, and time series of LAI derived from the high-resolution Formosat-2 satellite data (8 m). The study area is an agricultural zone in southwestern France covering 576 km2 (24 km×24 km). An innovative plot-scale approach is used, in which each computational unit has a homogeneous vegetation type. Evaluation of the simulations quality is done by comparing model outputs with in situ eddy covariance measurements of latent heat flux (LE). Our results show that the use of LAI derived from high-resolution remote sensing significantly improves simulated evapotranspiration with respect to ECOCLIMAP-II, especially when the surface is covered with summer crops. The comparison with in situ measurements shows an improvement of roughly 0.3 in the correlation coefficient and a decrease of around 30% of the root mean square error (RMSE) in the simulated evapotranspiration. This finding is attributable to a better description of LAI evolution processes with Formosat-2 data, which further modify soil water content and drainage of soil reservoirs. Effects on annual drainage patterns remain small but significant, i.e., an increase roughly equivalent to 4% of annual precipitation levels with simulations using Formosat-2 data in comparison to the reference simulation values. This study illustrates the potential for the Sentinel-2 mission to better represent effects of crop management on water budgeting for large, anthropized river basins. |
BibTeX:
@article{Etchanchu2017,
author = {Etchanchu, Jordi and Rivalland, Vincent and Gascoin, Simon and Cros, Jérôme and Tallec, Tiphaine and Brut, Aurore and Boulet, Gilles},
title = {Effects of high spatial and temporal resolution Earth observations on simulated hydrometeorological variables in a cropland (southwestern France)},
journal = {Hydrology and Earth System Sciences},
year = {2017},
volume = {21},
number = {11},
pages = {5693--5708},
url = {https://www.hydrol-earth-syst-sci.net/21/5693/2017/},
doi = {10.5194/hess-21-5693-2017}
}
|
| Fassbender AJ, Sabine CL and Palevsky HI (2017), "Nonuniform ocean acidification and attenuation of the ocean carbon sink", Geophysical Research Letters., aug, 2017. Vol. 44(16), pp. 8404-8413. Blackwell Publishing Ltd. |
| Abstract: Surface ocean carbon chemistry is changing rapidly. Partial pressures of carbon dioxide gas (pCO2) are rising, pH levels are declining, and the ocean's buffer capacity is eroding. Regional differences in short-term pH trends primarily have been attributed to physical and biological processes; however, heterogeneous seawater carbonate chemistry may also be playing an important role. Here we use Surface Ocean CO2 Atlas Version 4 data to develop 12 month gridded climatologies of carbonate system variables and explore the coherent spatial patterns of ocean acidification and attenuation in the ocean carbon sink caused by rising atmospheric pCO2. High-latitude regions exhibit the highest pH and buffer capacity sensitivities to pCO2 increases, while the equatorial Pacific is uniquely insensitive due to a newly defined aqueous CO2 concentration effect. Importantly, dissimilar regional pH trends do not necessarily equate to dissimilar acidity ([H+]) trends, indicating that [H+] is a more useful metric of acidification. |
BibTeX:
@article{Fassbender2017,
author = {Fassbender, Andrea J. and Sabine, Christopher L. and Palevsky, Hilary I.},
title = {Nonuniform ocean acidification and attenuation of the ocean carbon sink},
journal = {Geophysical Research Letters},
publisher = {Blackwell Publishing Ltd},
year = {2017},
volume = {44},
number = {16},
pages = {8404--8413},
url = {http://doi.wiley.com/10.1002/2017GL074389},
doi = {10.1002/2017GL074389}
}
|
| Fay AR and McKinley GA (2017), "Correlations of surface ocean pCO textlesssubtextgreater2textless/subtextgreater to satellite chlorophyll on monthly to interannual timescales", Global Biogeochemical Cycles., mar, 2017. Vol. 31(3), pp. 436-455. Blackwell Publishing Ltd. |
| Abstract: On the mean, ocean carbon uptake is linked to biological productivity, but how biological variability impacts carbon uptake is poorly quantified. Our ability to diagnose past change, understand present variability, and predict the future state of the global carbon cycle requires improving mechanistic understanding in this area. Here we make use of colocated pCO2 and temperature data, a merged surface ocean color product, and physical fields from an ocean state estimate to assess relationships between surface ocean biology and the carbon cycle on seasonal, monthly anomaly, and interannual timescales over the period 1998–2014. Using a correlation analysis on spatial scales from local to basin-scale biomes, we identify the timescales on which ocean productivity could be directly modifying ocean carbon uptake. On seasonal timescales outside of the equatorial Pacific, biome-scale correlations are negative between chlorophyll and pCO2. Though this relationship is pervasive, the underlying mechanisms vary across timescales and biomes. Consistent with previous findings, biological activity is a significant driver of pCO2 seasonality only in the subpolar biomes. For monthly anomalies acting on top of the mean seasonality, productivity and pCO2 changes are significantly correlated in the subpolar North Pacific and Southern Ocean. Only in the Southern Ocean are correlations consistent with a dominant role for biology in the surface ocean carbon cycle on all timescales. |
BibTeX:
@article{Fay2017,
author = {Fay, Amanda R. and McKinley, Galen A.},
title = {Correlations of surface ocean pCO textlesssubtextgreater2textless/subtextgreater to satellite chlorophyll on monthly to interannual timescales},
journal = {Global Biogeochemical Cycles},
publisher = {Blackwell Publishing Ltd},
year = {2017},
volume = {31},
number = {3},
pages = {436--455},
url = {http://doi.wiley.com/10.1002/2016GB005563},
doi = {10.1002/2016GB005563}
}
|
| Feng EY, Koeve W, Keller DP and Oschlies A (2017), "Model-Based Assessment of the CO textlesssubtextgreater2textless/subtextgreater Sequestration Potential of Coastal Ocean Alkalinization", Earth's Future., dec, 2017. Vol. 5(12), pp. 1252-1266. John Wiley and Sons Inc. |
| Abstract: The potential of coastal ocean alkalinization (COA), a carbon dioxide removal (CDR) climate engineering strategy that chemically increases ocean carbon uptake and storage, is investigated with an Earth system model of intermediate complexity. The CDR potential and possible environmental side effects are estimated for various COA deployment scenarios, assuming olivine as the alkalinity source in ice-free coastal waters (about 8.6% of the global ocean's surface area), with dissolution rates being a function of grain size, ambient seawater temperature, and pH. Our results indicate that for a large-enough olivine deployment of small-enough grain sizes (10 µm), atmospheric CO2 could be reduced by more than 800 GtC by the year 2100. However, COA with coarse olivine grains (1000 µm) has little CO2 sequestration potential on this time scale. Ambitious CDR with fine olivine grains would increase coastal aragonite saturation Ω to levels well beyond those that are currently observed. When imposing upper limits for aragonite saturation levels (Ωlim) in the grid boxes subject to COA (Ωlim = 3.4 and 9 chosen as examples), COA still has the potential to reduce atmospheric CO2 by 265 GtC (Ωlim = 3.4) to 790 GtC (Ωlim = 9) and increase ocean carbon storage by 290 Gt (Ωlim = 3.4) to 913 Gt (Ωlim = 9) by year 2100. |
BibTeX:
@article{Feng2017,
author = {Feng, E. Y. and Koeve, W. and Keller, D. P. and Oschlies, A.},
title = {Model-Based Assessment of the CO textlesssubtextgreater2textless/subtextgreater Sequestration Potential of Coastal Ocean Alkalinization},
journal = {Earth's Future},
publisher = {John Wiley and Sons Inc},
year = {2017},
volume = {5},
number = {12},
pages = {1252--1266},
url = {http://doi.wiley.com/10.1002/2017EF000659},
doi = {10.1002/2017EF000659}
}
|
| Feng S, Trnka M, Hayes M and Zhang Y (2017), "Why do different drought indices show distinct future drought risk outcomes in the U.S. Great Plains?", Journal of Climate., jan, 2017. Vol. 30(1), pp. 265-278. |
| Abstract: Vigorous discussions and disagreements about the future changes in drought intensity in the U.S. Great Plains have been taking place recently within the literature. These discussions have involved widely varying estimates based on drought indices and model-based projections of the future. To investigate and understand the causes for such a disparity between these previous estimates, the authors analyzed the soil moisture at the near-surface soil layer and the entire soil column, as well as the Palmer drought severity index, the Palmer Z index, and the standardized precipitation and evaporation index using the output from the Community Climate System Model, version 4 (CCSM4), and 25 state-of-the-art climate models. These drought indices were computed using potential evapotranspiration estimated by the physically based Penman-Monteith method (PE_pm) and the empirically based Thornthwaite method (PE_th). The results showed that the short-term drought indices are similar to modeled surface soil moisture and show a small but consistent drying trend in the future. The long-term drought indices and the total column soil moisture, however, are consistent in projecting more intense future drought. When normalized, the drought indices with PE_th all show unprecedented future drying, while the drought indices with PE_pm show comparable dryness with the modeled soil moisture. Additionally, the drought indices with PE_pm are closely related to soil moisture during both the twentieth and twenty-first centuries. Overall, the drought indices with PE_pm, as well as the modeled total column soil moisture, suggest a widespread and very significant drying in the Great Plains toward the end of the century. The results suggest that the sharp contrasts about future drought risk in the Great Plains discussed in previous studies are caused by 1) comparing the projected changes in short-term droughts with that of the long-term droughts and/or 2) computing the atmospheric evaporative demand using an empirically based method (e.g., PE_th). The analysis here may be applied for drought projections in other regions across the globe. |
BibTeX:
@article{Feng2017a,
author = {Feng, Song and Trnka, Miroslav and Hayes, Michael and Zhang, Yongjun},
title = {Why do different drought indices show distinct future drought risk outcomes in the U.S. Great Plains?},
journal = {Journal of Climate},
year = {2017},
volume = {30},
number = {1},
pages = {265--278},
url = {http://journals.ametsoc.org/doi/10.1175/JCLI-D-15-0590.1},
doi = {10.1175/JCLI-D-15-0590.1}
}
|
| Fernández-Martínez M, Vicca S, Janssens IA, Ciais P, Obersteiner M, Bartrons M, Sardans J, Verger A, Canadell JG, Chevallier F, Wang X, Bernhofer C, Curtis PS, Gianelle D, Grünwald T, Heinesch B, Ibrom A, Knohl A, Laurila T, Law BE, Limousin JM, Longdoz B, Loustau D, Mammarella I, Matteucci G, Monson RK, Montagnani L, Moors EJ, Munger JW, Papale D, Piao SL and Peñuelas J (2017), "Atmospheric deposition, CO2, and change in the land carbon sink", Scientific Reports., dec, 2017. Vol. 7(1), pp. 9632. |
| Abstract: Concentrations of atmospheric carbon dioxide (CO2) have continued to increase whereas atmospheric deposition of sulphur and nitrogen has declined in Europe and the USA during recent decades. Using time series of flux observations from 23 forests distributed throughout Europe and the USA, and generalised mixed models, we found that forest-level net ecosystem production and gross primary production have increased by 1% annually from 1995 to 2011. Statistical models indicated that increasing atmospheric CO2 was the most important factor driving the increasing strength of carbon sinks in these forests. We also found that the reduction of sulphur deposition in Europe and the USA lead to higher recovery in ecosystem respiration than in gross primary production, thus limiting the increase of carbon sequestration. By contrast, trends in climate and nitrogen deposition did not significantly contribute to changing carbon fluxes during the studied period. Our findings support the hypothesis of a general CO2-fertilization effect on vegetation growth and suggest that, so far unknown, sulphur deposition plays a significant role in the carbon balance of forests in industrialized regions. Our results show the need to include the effects of changing atmospheric composition, beyond CO2, to assess future dynamics of carbon-climate feedbacks not currently considered in earth system/climate modelling. |
BibTeX:
@article{Fernandez-Martinez2017,
author = {Fernández-Martínez, M and Vicca, S and Janssens, I A and Ciais, P and Obersteiner, M and Bartrons, M and Sardans, J and Verger, A and Canadell, J G and Chevallier, F and Wang, X and Bernhofer, C and Curtis, P S and Gianelle, D and Grünwald, T and Heinesch, B and Ibrom, A and Knohl, A and Laurila, T and Law, B E and Limousin, J M and Longdoz, B and Loustau, D and Mammarella, I and Matteucci, G and Monson, R K and Montagnani, L and Moors, E J and Munger, J W and Papale, D and Piao, S L and Peñuelas, J},
title = {Atmospheric deposition, CO2, and change in the land carbon sink},
journal = {Scientific Reports},
year = {2017},
volume = {7},
number = {1},
pages = {9632},
url = {http://www.nature.com/articles/s41598-017-08755-8},
doi = {10.1038/s41598-017-08755-8}
}
|
| Fisher RE, France JL, Lowry D, Lanoisellé M, Brownlow R, Pyle JA, Cain M, Warwick N, Skiba UM, Drewer J, Dinsmore KJ, Leeson SR, Bauguitte SJB, Wellpott A, O'Shea SJ, Allen G, Gallagher MW, Pitt J, Percival CJ, Bower K, George C, Hayman GD, Aalto T, Lohila A, Aurela M, Laurila T, Crill PM, McCalley CK and Nisbet EG (2017), "Measurement of the 13C isotopic signature of methane emissions from northern European wetlands", Global Biogeochemical Cycles., mar, 2017. Vol. 31(3), pp. 605-623. |
| Abstract: Isotopic data provide powerful constraints on regional and global methane emissions and their source profiles. However, inverse modeling of spatially resolved methane flux is currently constrained by a lack of information on the variability of source isotopic signatures. In this study, isotopic signatures of emissions in the Fennoscandian Arctic have been determined in chambers over wetland, in the air 0.3 to 3 m above the wetland surface and by aircraft sampling from 100 m above wetlands up to the stratosphere. Overall, the methane flux to atmosphere has a coherent δ13C isotopic signature of âˆ'71 ± 1‰, measured in situ on the ground in wetlands. This is in close agreement with δ13C isotopic signatures of local and regional methane increments measured by aircraft campaigns flying through air masses containing elevated methane mole fractions. In contrast, results from wetlands in Canadian boreal forest farther south gave isotopic signatures of âˆ'67 ± 1‰. Wetland emissions dominate the local methane source measured over the European Arctic in summer. Chamber measurements demonstrate a highly variable methane flux and isotopic signature, but the results from air sampling within wetland areas show that emissions mix rapidly immediately above the wetland surface and methane emissions reaching the wider atmosphere do indeed have strongly coherent C isotope signatures. The study suggests that for boreal wetlands (60°N) global and regional modeling can use an isotopic signature of âˆ'71‰ to apportion sources more accurately, but there is much need for further measurements over other wetlands regions to verify this. |
BibTeX:
@article{Fisher2017,
author = {Fisher, Rebecca E and France, James L and Lowry, David and Lanoisellé, Mathias and Brownlow, Rebecca and Pyle, John A and Cain, Michelle and Warwick, Nicola and Skiba, Ute M and Drewer, Julia and Dinsmore, Kerry J and Leeson, Sarah R and Bauguitte, Stéphane J B and Wellpott, Axel and O'Shea, Sebastian J and Allen, Grant and Gallagher, Martin W and Pitt, Joseph and Percival, Carl J and Bower, Keith and George, Charles and Hayman, Garry D and Aalto, Tuula and Lohila, Annalea and Aurela, Mika and Laurila, Tuomas and Crill, Patrick M and McCalley, Carmody K and Nisbet, Euan G},
title = {Measurement of the 13C isotopic signature of methane emissions from northern European wetlands},
journal = {Global Biogeochemical Cycles},
year = {2017},
volume = {31},
number = {3},
pages = {605--623},
url = {http://doi.wiley.com/10.1002/2016GB005504},
doi = {10.1002/2016GB005504}
}
|
| Ford D and Barciela R (2017), "Global marine biogeochemical reanalyses assimilating two different sets of merged ocean colour products", Remote Sensing of Environment., dec, 2017. Vol. 203, pp. 40-54. Elsevier Inc.. |
| Abstract: The only observations of marine biogeochemistry with routine global coverage are satellite ocean colour, which provide measurements of ocean bio-optical properties, with coverage still incomplete and limited to the sea surface. Models are therefore required to provide full spatial coverage, and through data assimilation can be combined with observations to create a reanalysis. This can then be used to investigate both observed and non-observed variables, including those relating to the carbon cycle. As part of the Climate Modelling User Group (CMUG) within the European Space Agency's Climate Change Initiative (CCI) project, two global marine biogeochemical reanalyses have been produced by assimilating ocean colour-derived chlorophyll data into a coupled physical-biogeochemical ocean model over the period September 1997 to July 2012. One reanalysis assimilated CCI products, the other assimilated GlobColour products, with a non-assimilative hindcast run for comparison. Each has been validated against independent in situ observations of chlorophyll, nutrients and carbon cycle variables. The assimilation of either source of ocean colour data was found to improve the model's representation of chlorophyll concentration throughout the water column, including the frequency and positioning of deep chlorophyll maxima. The assimilation also resulted in a slight improvement in nutrient concentrations and surface fugacity of carbon dioxide compared with in situ observations, although the overall impact on mean fields was small. This was found to be due in part to cancelling errors within the model, with the assimilation providing information on model biases, which can be used to inform future climate model development. The reanalyses were also able to reproduce expected seasonal cycles, as well as inter-annual variability related to major climate drivers. This study concludes that both CCI and GlobColour products are suitable for assimilation purposes, and that assimilating ocean colour data is of clear benefit. |
BibTeX:
@article{Ford2017,
author = {Ford, David and Barciela, Rosa},
title = {Global marine biogeochemical reanalyses assimilating two different sets of merged ocean colour products},
journal = {Remote Sensing of Environment},
publisher = {Elsevier Inc.},
year = {2017},
volume = {203},
pages = {40--54},
url = {https://ui.adsabs.harvard.edu/abs/2017RSEnv.203...40F/abstract},
doi = {10.1016/j.rse.2017.03.040}
}
|
| Franklin O, Cambui CA, Gruffman L, Palmroth S, Oren R and Näsholm T (2017), "The carbon bonus of organic nitrogen enhances nitrogen use efficiency of plants", Plant Cell and Environment., jan, 2017. Vol. 40(1), pp. 25-35. |
| Abstract: The importance of organic nitrogen (N) for plant nutrition and productivity is increasingly being recognized. Here we show that it is not only the availability in the soil that matters, but also the effects on plant growth. The chemical form of N taken up, whether inorganic (such as nitrate) or organic (such as amino acids), may significantly influence plant shoot and root growth, and nitrogen use efficiency (NUE). We analysed these effects by synthesizing results from multiple laboratory experiments on small seedlings (Arabidopsis, poplar, pine and spruce) based on a tractable plant growth model. A key point is that the carbon cost of assimilating organic N into proteins is lower than that of inorganic N, mainly because of its carbon content. This carbon bonus makes it more beneficial for plants to take up organic than inorganic N, even when its availability to the roots is much lower – up to 70% lower for Arabidopsis seedlings. At equal growth rate, root:shoot ratio was up to three times higher and nitrogen productivity up to 20% higher for organic than inorganic N, which both are factors that may contribute to higher NUE in crop production. |
BibTeX:
@article{Franklin2017,
author = {Franklin, Oskar and Cambui, Camila Aguetoni and Gruffman, Linda and Palmroth, Sari and Oren, Ram and Näsholm, Torgny},
title = {The carbon bonus of organic nitrogen enhances nitrogen use efficiency of plants},
journal = {Plant Cell and Environment},
year = {2017},
volume = {40},
number = {1},
pages = {25--35},
url = {http://doi.wiley.com/10.1111/pce.12772},
doi = {10.1111/pce.12772}
}
|
| Fransson A, Chierici M, Skjelvan I, Olsen A, Assmy P, Peterson AK, Spreen G and Ward B (2017), "Effects of sea‐ice and biogeochemical processes and storms on under‐ice water textlessitextgreaterftextless/itextgreater CO textlesssubtextgreater2textless/subtextgreater during the winter‐spring transition in the high textlessscptextgreaterAtextless/scptextgreater rctic textlessscptextgreaterOtextless/scptextgreater cean: Implications for sea‐air CO textlesssubtextgreater2textless/subtextgreater fluxes", Journal of Geophysical Research: Oceans., jul, 2017. Vol. 122(7), pp. 5566-5587. Blackwell Publishing Ltd. |
| Abstract: We performed measurements of carbon dioxide fugacity (fCO2) in the surface water under Arctic sea ice from January to June 2015 during the Norwegian young sea ICE (N-ICE2015) expedition. Over this period, the ship drifted with four different ice floes and covered the deep Nansen Basin, the slopes north of Svalbard, and the Yermak Plateau. This unique winter-to-spring data set includes the first winter-time under-ice water fCO2 observations in this region. The observed under-ice fCO2 ranged between 315 µatm in winter and 153 µatm in spring, hence was undersaturated relative to the atmospheric fCO2. Although the sea ice partly prevented direct CO2 exchange between ocean and atmosphere, frequently occurring leads and breakup of the ice sheet promoted sea-air CO2 fluxes. The CO2 sink varied between 0.3 and 86 mmol C m−2 d−1, depending strongly on the open-water fractions (OW) and storm events. The maximum sea-air CO2 fluxes occurred during storm events in February and June. In winter, the main drivers of the change in under-ice water fCO2 were dissolution of CaCO3 (ikaite) and vertical mixing. In June, in addition to these processes, primary production and sea-air CO2 fluxes were important. The cumulative loss due to CaCO3 dissolution of 0.7 mol C m−2 in the upper 10 m played a major role in sustaining the undersaturation of fCO2 during the entire study. The relative effects of the total fCO2 change due to CaCO3 dissolution was 38%, primary production 26%, vertical mixing 16%, sea-air CO2 fluxes 16%, and temperature and salinity insignificant. |
BibTeX:
@article{Fransson2017,
author = {Fransson, Agneta and Chierici, Melissa and Skjelvan, Ingunn and Olsen, Are and Assmy, Philipp and Peterson, Algot K. and Spreen, Gunnar and Ward, Brian},
title = {Effects of sea‐ice and biogeochemical processes and storms on under‐ice water textlessitextgreaterftextless/itextgreater CO textlesssubtextgreater2textless/subtextgreater during the winter‐spring transition in the high textlessscptextgreaterAtextless/scptextgreater rctic textlessscptextgreaterOtextless/scptextgreater cean: Implications for sea‐air CO textlesssubtextgreater2textless/subtextgreater fluxes},
journal = {Journal of Geophysical Research: Oceans},
publisher = {Blackwell Publishing Ltd},
year = {2017},
volume = {122},
number = {7},
pages = {5566--5587},
url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/2016JC012478},
doi = {10.1002/2016JC012478}
}
|
| Fu Z, Stoy PC, Luo Y, Chen J, Sun J, Montagnani L, Wohlfahrt G, Rahman AF, Rambal S, Bernhofer C, Wang J, Shirkey G and Niu S (2017), "Climate controls over the net carbon uptake period and amplitude of net ecosystem production in temperate and boreal ecosystems", Agricultural and Forest Meteorology., sep, 2017. Vol. 243, pp. 9-18. |
| Abstract: The seasonal and interannual variability of the terrestrial carbon cycle is regulated by the interactions of climate and ecosystem function. However, the key factors and processes determining the interannual variability of net ecosystem productivity (NEP) in different biomes are far from clear. Here, we quantified yearly anomalies of seasonal and annual NEP, net carbon uptake period (CUP), and the maximum daily NEP (NEPmax) in response to climatic variables in 24 deciduous broadleaf forest (DBF), evergreen forest (EF), and grassland (GRA) ecosystems that include at least eight years of eddy covariance observations. Over the 228 site-years studied, interannual variations in NEP were mostly explained by anomalies of CUP and NEPmax. CUP was determined by spring and autumn net carbon uptake phenology, which were sensitive to annual meteorological variability. Warmer spring temperatures led to an earlier start of net carbon uptake activity and higher spring and annual NEP values in DBF and EF, while warmer autumn temperatures in DBF, higher autumn radiation in EF, and more summer and autumn precipitation in GRA resulted in a later ending date of net carbon uptake and associated higher autumn and annual NEP. Anomalies in NEPmax s were determined by summer precipitation in DBF and GRA, and explained more than 50% of variation in summer NEP anomalies for all the three biomes. Results demonstrate the role of meteorological variability in controlling CUP and NEPmax, which in turn help describe the seasonal and interannual variability of NEP. |
BibTeX:
@article{Fu2017,
author = {Fu, Zheng and Stoy, Paul C and Luo, Yiqi and Chen, Jiquan and Sun, Jian and Montagnani, Leonardo and Wohlfahrt, Georg and Rahman, Abdullah F and Rambal, Serge and Bernhofer, Christian and Wang, Jinsong and Shirkey, Gabriela and Niu, Shuli},
title = {Climate controls over the net carbon uptake period and amplitude of net ecosystem production in temperate and boreal ecosystems},
journal = {Agricultural and Forest Meteorology},
year = {2017},
volume = {243},
pages = {9--18},
url = {http://linkinghub.elsevier.com/retrieve/pii/S0168192317301685},
doi = {10.1016/j.agrformet.2017.05.009}
}
|
| Fu H, Zhu J, Wang C, Wang H and Zhao R (2017), "Underlying topography estimation over forest areas using high-resolution P-band single-baseline polInSAR data", Remote Sensing., apr, 2017. Vol. 9(4), pp. 363. |
| Abstract: This paper discusses the potential and limitations of high-resolution P-band polarimetric synthetic aperture radar (SAR) interferometry (PolInSAR) in underlying topography estimation over forest areas. Time-frequency (TF) analysis in the azimuth direction is utilized to separate the ground scattering contribution from the total PolInSAR signal, without the use of any physical model, because the P-band PolInSAR data have a significant penetration depth and sufficient observation angle interval. To achieve this goal, a one-dimensional polynomial fitting (PF) method is proposed for correcting the residual motion error (RME). The Krycklan catchment test site, which is covered with pine forest, was selected to test the performance of the digital elevation model (DEM) inversion. The results show that the PF method can correct the RMEs for the sub-look interferograms well. When compared to the existing line-fit method, the TF+PF method can provide a more accurate DEM (the accuracy is improved by 26.9%). Moreover, the performance of the DEM inversion is free from the random-volume-over-ground assumption. |
BibTeX:
@article{Fu2017a,
author = {Fu, Haiqiang and Zhu, Jianjun and Wang, Changcheng and Wang, Huiqiang and Zhao, Rong},
title = {Underlying topography estimation over forest areas using high-resolution P-band single-baseline polInSAR data},
journal = {Remote Sensing},
year = {2017},
volume = {9},
number = {4},
pages = {363},
url = {http://www.mdpi.com/2072-4292/9/4/363},
doi = {10.3390/rs9040363}
}
|
| Gałka M, Szal M, Watson EJ, Gallego-Sala A, Amesbury MJ, Charman DJ, Roland TP, Edward Turner T and Swindles GT (2017), "Vegetation Succession, Carbon Accumulation and Hydrological Change in Subarctic Peatlands, Abisko, Northern Sweden", Permafrost and Periglacial Processes., oct, 2017. Vol. 28(4), pp. 589-604. |
| Abstract: High-resolution analyses of plant macrofossils, testate amoebae, pollen, mineral content, bulk density, and carbon and nitrogen were undertaken to examine the late Holocene dynamics of two permafrost peatlands in Abisko, Subarctic Sweden. The peat records were dated using tephrochronology, 14C and 210Pb. Local plant succession and hydrological changes in peatlands were synchronous with climatic shifts, although autogenous plant succession towards ombrotrophic status during peatland development was also apparent. The Marooned peatland experienced a shift ca. 2250Â cal yr BP from rich to poor fen, as indicated by the appearance of Sphagnum fuscum. At Stordalen, a major shift to wetter conditions occurred between 500 and 250Â cal yr BP, probably associated with climate change during the Little Ice Age. During the last few decades, the testate amoeba data suggest a deepening of the water table and an increase in shrub pollen, coinciding with recent climate warming and the associated expansion of shrub communities across the Arctic. Rates of carbon accumulation vary greatly between the sites, illustrating the importance of local vegetation communities, hydrology and permafrost dynamics. Multiproxy data elucidate the palaeoecology of S. lindbergii and show that it indicates wet conditions in peatlands. Copyright textcopyright 2017 John Wiley & Sons, Ltd. |
BibTeX:
@article{Gaka2017,
author = {Gałka, Mariusz and Szal, Marta and Watson, Elizabeth J and Gallego-Sala, Angela and Amesbury, Matthew J and Charman, Dan J and Roland, Thomas P and Edward Turner, T and Swindles, Graeme T},
title = {Vegetation Succession, Carbon Accumulation and Hydrological Change in Subarctic Peatlands, Abisko, Northern Sweden},
journal = {Permafrost and Periglacial Processes},
year = {2017},
volume = {28},
number = {4},
pages = {589--604},
url = {http://doi.wiley.com/10.1002/ppp.1945},
doi = {10.1002/ppp.1945}
}
|
| Gao Y, Markkanen T, Aurela M, Mammarella I, Thum T, Tsuruta A, Yang H and Aalto T (2017), "Response of water use efficiency to summer drought in a boreal Scots pine forest in Finland", Biogeosciences., sep, 2017. Vol. 14(18), pp. 4409-4422. |
| Abstract: The influence of drought on plant functioning has received considerable attention in recent years, however our understanding of the response of carbon and water coupling to drought in terrestrial ecosystems still needs to be improved. A severe soil moisture drought occurred in southern Finland in the late summer of 2006. In this study, we investigated the response of water use efficiency to summer drought in a boreal Scots pine forest (Pinus sylvestris) on the daily time scale mainly using eddy covariance flux data from the Hyytiälä (southern Finland) flux site. In addition, simulation results from the JSBACH land surface model were evaluated against the observed results. Based on observed data, the ecosystem level water use efficiency (EWUE; the ratio of gross primary production, GPP, to evapotranspiration, ET) showed a decrease during the severe soil moisture drought, while the inherent water use efficiency (IWUE; a quantity defined as EWUE multiplied with mean daytime vapour pressure deficit, VPD) increased and the underlying water use efficiency (uWUE, a metric based on IWUE and a simple stomatal model, is the ratio of GPP multiplied with a square root of VPD to ET) was unchanged during the drought. The decrease in EWUE was due to the stronger decline in GPP than in ET. The increase in IWUE was because of the decreased stomatal conductance under increased VPD. The unchanged uWUE indicates that the trade-off between carbon assimilation and transpiration of the boreal Scots pine forest was not disturbed by this drought event at the site. The JSBACH simulation showed declines of both GPP and ET under the severe soil moisture drought, but to a smaller extent compared to the observed GPP and ET. Simulated GPP and ET led to a smaller decrease in EWUE but a larger increase in IWUE because of the severe soil moisture drought in comparison to observations. As in the observations, the simulated uWUE showed no changes in the drought event. The model deficiencies exist mainly due to the lack of the limiting effect of increased VPD on stomatal conductance during the low soil moisture condition. Our study provides a deeper understanding of the coupling of carbon and water cycles in the boreal Scots pine forest ecosystem and suggests possible improvements to land surface models, which play an important role in the prediction of biosphere-atmosphere feedbacks in the climate system. |
BibTeX:
@article{Gao2017,
author = {Gao, Yao and Markkanen, Tiina and Aurela, Mika and Mammarella, Ivan and Thum, Tea and Tsuruta, Aki and Yang, Huiyi and Aalto, Tuula},
title = {Response of water use efficiency to summer drought in a boreal Scots pine forest in Finland},
journal = {Biogeosciences},
year = {2017},
volume = {14},
number = {18},
pages = {4409--4422},
url = {https://www.biogeosciences.net/14/4409/2017/},
doi = {10.5194/bg-14-4409-2017}
}
|
| Garrett LE, Spreitzer GM and Bacevice PA (2017), "Co-constructing a Sense of Community at Work: The Emergence of Community in Coworking Spaces", Organization Studies., jun, 2017. Vol. 38(6), pp. 821-842. SAGE Publications Ltd. |
| Abstract: As more individuals are working remotely, many feel increasingly isolated and socially adrift. To address this challenge, many independent workers are choosing to work in coworking spaces – shared spaces where individuals do their own work but in the presence of others with the express purpose of being part of a community. In this qualitative, single case study, we analyze how members of a coworking space work together to co-construct a sense of community through their day-to-day interactions in the space. We apply a relational constructionist lens to unpack the processes of ‘community work' as an interactive, agentic process. We identify three types of collective actions, or interacts, that contribute to a sense of community: endorsing, encountering, and engaging. These interacts represent different forms of community work that members interactively accomplish to maintain a desired community experience. The rapidly growing coworking movement offers insights, as uncovered in this study, on how to integrate a sense of community into the world of work. |
BibTeX:
@article{Garrett2017,
author = {Garrett, Lyndon E. and Spreitzer, Gretchen M. and Bacevice, Peter A.},
title = {Co-constructing a Sense of Community at Work: The Emergence of Community in Coworking Spaces},
journal = {Organization Studies},
publisher = {SAGE Publications Ltd},
year = {2017},
volume = {38},
number = {6},
pages = {821--842},
doi = {10.1177/0170840616685354}
}
|
| Gerosa G, Marzuoli R, Monteleone B, Chiesa M and Finco A (2017), "Vertical Ozone Gradients above Forests. Comparison of Different Calculation Options with Direct Ozone Measurements above a Mature Forest and Consequences for Ozone Risk Assessment", Forests., sep, 2017. Vol. 8(9), pp. 337. MDPI AG. |
BibTeX:
@article{Gerosa2017,
author = {Gerosa, Giacomo and Marzuoli, Riccardo and Monteleone, Beatrice and Chiesa, Maria and Finco, Angelo},
title = {Vertical Ozone Gradients above Forests. Comparison of Different Calculation Options with Direct Ozone Measurements above a Mature Forest and Consequences for Ozone Risk Assessment},
journal = {Forests},
publisher = {MDPI AG},
year = {2017},
volume = {8},
number = {9},
pages = {337},
url = {http://dx.doi.org/10.3390/f8090337},
doi = {10.3390/f8090337}
}
|
| Gharamti ME, Tjiputra J, Bethke I, Samuelsen A, Skjelvan I, Bentsen M and Bertino L (2017), "Ensemble data assimilation for ocean biogeochemical state and parameter estimation at different sites", Ocean Modelling., apr, 2017. Vol. 112, pp. 65-89. Elsevier Ltd. |
| Abstract: We develop an efficient data assimilation system that aims at quantifying the uncertainties of various biogeochemical states and parameters. We explore the use of four different ensemble estimation techniques for tuning poorly constrained ecosystem parameters using a one-dimensional configuration of the Ocean Biogeochemical General Circulation Model. The schemes are all EnKF-based operating sequentially in time but have different correction equations. The 1D model is used to simulate the biogeochemical cycle at three different stations in mid and high latitudes. We assimilate monthly climatological profiles of nitrate, silicate, phosphate and oxygen in addition to seasonal surface pCO2 data, between 2006 and 2010. We use the data to optimize eleven ecosystem parameters in addition to all state variables of the model, describing the dynamical processes of the water column. Our assimilation results suggest the following: (1) Among all tested schemes, the one-step-ahead smoothing-based ensemble Kalman filter (OSA-EnKF) is robust and the most accurate, providing consistent and reliable state-parameter ensemble realizations. (2) Given the large uncertainties associated with the ecosystem parameters, estimating only the state variables is generally inconclusive and biased. (3) The OSA-EnKF successfully recovers the observed seasonal variability of the ecosystem dynamics at all stations and helps optimizing the parameters, eventually reducing the prediction errors of the nutrients' concentrations. (4) The estimates of the parameters may have some temporally correlated features and they can also vary spatially between different regions depending on the magnitude of the bias in the observed variables and other factors such as the intensity of the bloom period. We further show that the presented assimilation system has the potential to be used in global models. |
BibTeX:
@article{Gharamti2017,
author = {Gharamti, M. E. and Tjiputra, J. and Bethke, I. and Samuelsen, A. and Skjelvan, I. and Bentsen, M. and Bertino, L.},
title = {Ensemble data assimilation for ocean biogeochemical state and parameter estimation at different sites},
journal = {Ocean Modelling},
publisher = {Elsevier Ltd},
year = {2017},
volume = {112},
pages = {65--89},
doi = {10.1016/j.ocemod.2017.02.006}
}
|
| Gim HJ, Park SK, Kang M, Thakuri BM, Kim J and Ho CH (2017), "An improved parameterization of the allocation of assimilated carbon to plant parts in vegetation dynamics for Noah-MP", Journal of Advances in Modeling Earth Systems., aug, 2017. Vol. 9(4), pp. 1776-1794. Blackwell Publishing Ltd. |
| Abstract: In the land surface models predicting vegetation growth and decay, representation of the seasonality of land surface energy and mass fluxes largely depends on how to describe the vegetation dynamics. In this study, we developed a new parameterization scheme to characterize allocation of the assimilated carbon to plant parts, including leaves and fine roots. The amount of carbon allocation in this scheme depends on the climatological net primary production (NPP) of the plants. The newly developed scheme is implemented in the augmented Noah land surface model with multiple parameterization options (Noah-MP) along with other biophysical processes related to variations in photosynthetic capacity. The scheme and the augmented biophysical processes are evaluated against tower measurements of vegetation from four forest sites in various regions—two for the deciduous broadleaf and two for the needleleaf evergreen forest. Results from the augmented Noah-MP showed good agreement with the observations and demonstrated improvements in representing the seasonality of leaf area index (LAI), gross primary production (GPP), ecosystem respiration (ER), and latent heat flux. In particular, significant improvements are found in simulating amplitudes and phase shift timing in the LAI seasonal cycle, and the amount of GPP and ER in the growing season. Furthermore, the augmented Noah-MP performed reasonably well in simulating the spatial distributions of LAI, GPP, and NPP in East Asia, consistent with the satellite observations. |
BibTeX:
@article{Gim2017,
author = {Gim, Hyeon Ju and Park, Seon Ki and Kang, Minseok and Thakuri, Bindu Malla and Kim, Joon and Ho, Chang Hoi},
title = {An improved parameterization of the allocation of assimilated carbon to plant parts in vegetation dynamics for Noah-MP},
journal = {Journal of Advances in Modeling Earth Systems},
publisher = {Blackwell Publishing Ltd},
year = {2017},
volume = {9},
number = {4},
pages = {1776--1794},
doi = {10.1002/2016MS000890}
}
|
| González-Dávila M, Santana Casiano JM and Machín F (2017), "Changes in the partial pressure of carbon dioxide in the Mauritanian–Cap Vert upwelling region between 2005 and 2012", Biogeosciences., aug, 2017. Vol. 14(17), pp. 3859-3871. Copernicus GmbH. |
| Abstract: textlessptextgreaterAbstract. Coastal upwellings along the eastern margins of major ocean basins represent regions of large ecological and economic importance due to the high biological productivity. The role of these regions for the global carbon cycle makes them essential in addressing climate change. The physical forcing of upwelling processes that favor production in these areas are already being affected by global warming, which will modify the intensity of upwelling and, consequently, the carbon dioxide cycle. Here, we present monthly high-resolution surface experimental data for temperature and partial pressure of carbon dioxide in one of the four most important upwelling regions of the planet, the Mauritanian–Cap Vert upwelling region, from 2005 to 2012. This data set provides direct evidence of seasonal and interannual changes in the physical and biochemical processes. Specifically, we show an upwelling intensification and an increase of 0.6 Tg yr−1 in CO2 outgassing due to increased wind speed, despite increased primary productivity. This increase in CO2 outgassing together with the observed decrease in sea surface temperature at the location of the Mauritanian Cap Blanc, 21° N, produced a pH rate decrease of −0.003 ± 0.001 yr−1.textless/ptextgreater |
BibTeX:
@article{Gonzalez-Davila2017,
author = {González-Dávila, Melchor and Santana Casiano, J. Magdalena and Machín, Francisco},
title = {Changes in the partial pressure of carbon dioxide in the Mauritanian–Cap Vert upwelling region between 2005 and 2012},
journal = {Biogeosciences},
publisher = {Copernicus GmbH},
year = {2017},
volume = {14},
number = {17},
pages = {3859--3871},
url = {https://bg.copernicus.org/articles/14/3859/2017/},
doi = {10.5194/bg-14-3859-2017}
}
|
| Gottselig N, Amelung W, Kirchner JW, Bol R, Eugster W, Granger SJ, Hernández-Crespo C, Herrmann F, Keizer JJ, Korkiakoski M, Laudon H, Lehner I, Löfgren S, Lohila A, Macleod CJA, Mölder M, Müller C, Nasta P, Nischwitz V, Paul-Limoges E, Pierret MC, Pilegaard K, Romano N, Sebastià MT, Stähli M, Voltz M, Vereecken H, Siemens J and Klumpp E (2017), "Elemental Composition of Natural Nanoparticles and Fine Colloids in European Forest Stream Waters and Their Role as Phosphorus Carriers", Global Biogeochemical Cycles., oct, 2017. Vol. 31(10), pp. 1592-1607. |
| Abstract: Biogeochemical cycling of elements largely occurs in dissolved state, but many elements may also be bound to natural nanoparticles (NNP, 1–100 nm) and fine colloids (100–450 nm). We examined the hypothesis that the size and composition of stream water NNP and colloids vary systematically across Europe. To test this hypothesis, 96 stream water samples were simultaneously collected in 26 forested headwater catchments along two transects across Europe. Three size fractions (˜1–20 nm, 20–60 nm, and 60 nm) of NNP and fine colloids were identified with Field Flow Fractionation coupled to inductively coupled plasma mass spectrometry and an organic carbon detector. The results showed that NNP and fine colloids constituted between 2 ± 5% (Si) and 53 ± 21% (Fe; mean ± SD) of total element concentrations, indicating a substantial contribution of particles to element transport in these European streams, especially for P and Fe. The particulate contents of Fe, Al, and organic C were correlated to their total element concentrations, but those of particulate Si, Mn, P, and Ca were not. The fine colloidal fractions 60 nm were dominated by clay minerals across all sites. The resulting element patterns of NNP 60 nm changed from North to South Europe from Fe- to Ca-dominated particles, along with associated changes in acidity, forest type, and dominant lithology. |
BibTeX:
@article{Gottselig2017,
author = {Gottselig, N and Amelung, W and Kirchner, J W and Bol, R and Eugster, W and Granger, S J and Hernández-Crespo, C and Herrmann, F and Keizer, J J and Korkiakoski, M and Laudon, H and Lehner, I and Löfgren, S and Lohila, A and Macleod, C J A and Mölder, M and Müller, C and Nasta, P and Nischwitz, V and Paul-Limoges, E and Pierret, M C and Pilegaard, K and Romano, N and Sebastià, M T and Stähli, M and Voltz, M and Vereecken, H and Siemens, J and Klumpp, E},
title = {Elemental Composition of Natural Nanoparticles and Fine Colloids in European Forest Stream Waters and Their Role as Phosphorus Carriers},
journal = {Global Biogeochemical Cycles},
year = {2017},
volume = {31},
number = {10},
pages = {1592--1607},
url = {http://doi.wiley.com/10.1002/2017GB005657},
doi = {10.1002/2017GB005657}
}
|
| Graven H, Allison CE, Etheridge DM, Hammer S, Keeling RF, Levin I, Meijer HAJ, Rubino M, Tans PP, Trudinger CM, Vaughn BH and White JWC (2017), "Compiled records of carbon isotopes in atmospheric CO2 for historical simulations in CMIP6", Geoscientific Model Development., dec, 2017. Vol. 10(12), pp. 4405-4417. |
| Abstract: The isotopic composition of carbon (14°C and 13°C) in atmospheric CO2 and in oceanic and terrestrial carbon reservoirs is influenced by anthropogenic emissions and by natural carbon exchanges, which can respond to and drive changes in climate. Simulations of 14C and 13C in the ocean and terrestrial components of Earth system models (ESMs) present opportunities for model evaluation and for investigation of carbon cycling, including anthropogenic CO2 emissions and uptake. The use of carbon isotopes in novel evaluation of the ESMs' component ocean and terrestrial biosphere models and in new analyses of historical changes may improve predictions of future changes in the carbon cycle and climate system. We compile existing data to produce records of 14C and 13C in atmospheric CO2 for the historical period 1850-2015. The primary motivation for this compilation is to provide the atmospheric boundary condition for historical simulations in the Coupled Model Intercomparison Project 6 (CMIP6) for models simulating carbon isotopes in the ocean or terrestrial biosphere. The data may also be useful for other carbon cycle modelling activities. |
BibTeX:
@article{Graven2017,
author = {Graven, Heather and Allison, Colin E and Etheridge, David M and Hammer, Samuel and Keeling, Ralph F and Levin, Ingeborg and Meijer, Harro A J and Rubino, Mauro and Tans, Pieter P and Trudinger, Cathy M and Vaughn, Bruce H and White, James W C},
title = {Compiled records of carbon isotopes in atmospheric CO2 for historical simulations in CMIP6},
journal = {Geoscientific Model Development},
year = {2017},
volume = {10},
number = {12},
pages = {4405--4417},
url = {https://www.geosci-model-dev.net/10/4405/2017/},
doi = {10.5194/gmd-10-4405-2017}
}
|
| Gregor L, Kok S and Monteiro PMS (2017), "Empirical methods for the estimation of Southern Ocean CO&lt;sub&gt;2&lt;/sub&gt;: support vector and random forest regression", Biogeosciences., dec, 2017. Vol. 14(23), pp. 5551-5569. Copernicus GmbH. |
| Abstract: textlessptextgreaterAbstract. The Southern Ocean accounts for 40 % of oceanic CO2 uptake, but the estimates are bound by large uncertainties due to a paucity in observations. Gap-filling empirical methods have been used to good effect to approximate pCO2 from satellite observable variables in other parts of the ocean, but many of these methods are not in agreement in the Southern Ocean. In this study we propose two additional methods that perform well in the Southern Ocean: support vector regression (SVR) and random forest regression (RFR). The methods are used to estimate ΔpCO2 in the Southern Ocean based on SOCAT v3, achieving similar trends to the SOM-FFN method by Landschützer et al. (2014). Results show that the SOM-FFN and RFR approaches have RMSEs of similar magnitude (14.84 and 16.45 µatm, where 1 atm = 101 325 Pa) where the SVR method has a larger RMSE (24.40 µatm). However, the larger errors for SVR and RFR are, in part, due to an increase in coastal observations from SOCAT v2 to v3, where the SOM-FFN method used v2 data. The success of both SOM-FFN and RFR depends on the ability to adapt to different modes of variability. The SOM-FFN achieves this by having independent regression models for each cluster, while this flexibility is intrinsic to the RFR method. Analyses of the estimates shows that the SVR and RFR's respective sensitivity and robustness to outliers define the outcome significantly. Further analyses on the methods were performed by using a synthetic dataset to assess the following: which method (RFR or SVR) has the best performance? What is the effect of using time, latitude and longitude as proxy variables on ΔpCO2? What is the impact of the sampling bias in the SOCAT v3 dataset on the estimates? We find that while RFR is indeed better than SVR, the ensemble of the two methods outperforms either one, due to complementary strengths and weaknesses of the methods. Results also show that for the RFR and SVR implementations, it is better to include coordinates as proxy variables as RMSE scores are lowered and the phasing of the seasonal cycle is more accurate. Lastly, we show that there is only a weak bias due to undersampling. The synthetic data provide a useful framework to test methods in regions of sparse data coverage and show potential as a useful tool to evaluate methods in future studies.textless/ptextgreater |
BibTeX:
@article{Gregor2017,
author = {Gregor, Luke and Kok, Schalk and Monteiro, Pedro M. S.},
title = {Empirical methods for the estimation of Southern Ocean CO&lt;sub&gt;2&lt;/sub&gt;: support vector and random forest regression},
journal = {Biogeosciences},
publisher = {Copernicus GmbH},
year = {2017},
volume = {14},
number = {23},
pages = {5551--5569},
url = {https://bg.copernicus.org/articles/14/5551/2017/},
doi = {10.5194/bg-14-5551-2017}
}
|
| Guillemot J, Francois C, Hmimina G, Dufrêne E, Martin-StPaul NK, Soudani K, Marie G, Ourcival JM and Delpierre N (2017), "Environmental control of carbon allocation matters for modelling forest growth", New Phytologist., apr, 2017. Vol. 214(1), pp. 180-193. |
| Abstract: We aimed to evaluate the importance of modulations of within-tree carbon (C) allocation by water and low-temperature stress for the prediction of annual forest growth with a process-based model. A new C allocation scheme was implemented in the CASTANEA model that accounts for lagged and direct environmental controls of C allocation. Different approaches (static vs dynamic) to modelling C allocation were then compared in a model–data fusion procedure, using satellite-derived leaf production estimates and biometric measurements at c. 104 sites. The modelling of the environmental control of C allocation significantly improved the ability of CASTANEA to predict the spatial and year-to-year variability of aboveground forest growth along regional gradients. A significant effect of the previous year's water stress on the C allocation to leaves and wood was reported. Our results also are consistent with a prominent role of the environmental modulation of sink demand in the wood growth of the studied species. Data available at large scales can inform forest models about the processes driving annual and seasonal C allocation. Our results call for a greater consideration of C allocation drivers, especially sink–demand fluctuations, for the simulations of current and future forest productivity with process-based models. |
BibTeX:
@article{Guillemot2017,
author = {Guillemot, Joannès and Francois, Christophe and Hmimina, Gabriel and Dufrêne, Eric and Martin-StPaul, Nicolas K and Soudani, Kamel and Marie, Guillaume and Ourcival, Jean Marc and Delpierre, Nicolas},
title = {Environmental control of carbon allocation matters for modelling forest growth},
journal = {New Phytologist},
year = {2017},
volume = {214},
number = {1},
pages = {180--193},
url = {http://doi.wiley.com/10.1111/nph.14320},
doi = {10.1111/nph.14320}
}
|
| Haeni M, Zweifel R, Eugster W, Gessler A, Zielis S, Bernhofer C, Carrara A, Grünwald T, Havránková K, Heinesch B, Herbst M, Ibrom A, Knohl A, Lagergren F, Law BE, Marek M, Matteucci G, McCaughey JH, Minerbi S, Montagnani L, Moors E, Olejnik J, Pavelka M, Pilegaard K, Pita G, Rodrigues A, Sanz Sánchez MJ, Schelhaas MJ, Urbaniak M, Valentini R, Varlagin A, Vesala T, Vincke C, Wu J and Buchmann N (2017), "Winter respiratory C losses provide explanatory power for net ecosystem productivity", Journal of Geophysical Research: Biogeosciences., jan, 2017. Vol. 122(1), pp. 243-260. |
| Abstract: Accurate predictions of net ecosystem productivity (NEPc) of forest ecosystems are essential for climate change decisions and requirements in the context of national forest growth and greenhouse gas inventories. However, drivers and underlying mechanisms determining NEPc (e.g., climate and nutrients) are not entirely understood yet, particularly when considering the influence of past periods. Here we explored the explanatory power of the compensation day (cDOY)—defined as the day of year when winter net carbon losses are compensated by spring assimilation—for NEPc in 26 forests in Europe, North America, and Australia, using different NEPc integration methods. We found cDOY to be a particularly powerful predictor for NEPc of temperate evergreen needleleaf forests (R2 = 0.58) and deciduous broadleaf forests (R2 = 0.68). In general, the latest cDOY correlated with the lowest NEPc. The explanatory power of cDOY depended on the integration method for NEPc, forest type, and whether the site had a distinct winter net respiratory carbon loss or not. The integration methods starting in autumn led to better predictions of NEPc from cDOY then the classical calendar method starting 1 January. Limited explanatory power of cDOY for NEPc was found for warmer sites with no distinct winter respiratory loss period. Our findings highlight the importance of the influence of winter processes and the delayed responses of previous seasons' climatic conditions on current year's NEPc. Such carry-over effects may contain information from climatic conditions, carbon storage levels, and hydraulic traits of several years back in time. |
BibTeX:
@article{Haeni2017,
author = {Haeni, M and Zweifel, R and Eugster, W and Gessler, A and Zielis, S and Bernhofer, C and Carrara, A and Grünwald, T and Havránková, K and Heinesch, B and Herbst, M and Ibrom, A and Knohl, A and Lagergren, F and Law, B E and Marek, M and Matteucci, G and McCaughey, J H and Minerbi, S and Montagnani, L and Moors, E and Olejnik, J and Pavelka, M and Pilegaard, K and Pita, G and Rodrigues, A and Sanz Sánchez, M J and Schelhaas, M J and Urbaniak, M and Valentini, R and Varlagin, A and Vesala, T and Vincke, C and Wu, J and Buchmann, N},
title = {Winter respiratory C losses provide explanatory power for net ecosystem productivity},
journal = {Journal of Geophysical Research: Biogeosciences},
year = {2017},
volume = {122},
number = {1},
pages = {243--260},
url = {http://doi.wiley.com/10.1002/2016JG003455},
doi = {10.1002/2016JG003455}
}
|
| Halmeenmäki E, Heinonsalo J, Putkinen A, Santalahti M, Fritze H and Pihlatie M (2017), "Above- and belowground fluxes of methane from boreal dwarf shrubs and Pinus sylvestris seedlings", Plant and Soil., nov, 2017. Vol. 420(1-2), pp. 361-373. Springer International Publishing. |
| Abstract: Aims: The contribution of boreal forest plants to the methane (CH4) cycle is still uncertain. We studied the above and belowground CH4 fluxes of common boreal plants, and assessed the possible contribution of CH4 producing and oxidizing microbes (methanogens and methanotrophs, respectively) to the fluxes. Methods: We measured the CH4 fluxes and the amounts of methanogens and methanotrophs in the above- and belowground parts of Vaccinium myrtillus, Vaccinium vitis-idaea, Calluna vulgaris and Pinus sylvestris seedlings and in non-planted soil in a microcosm experiment. Results: The shoots of C. vulgaris and P. sylvestris showed on average emissions of CH4, while the shoots of the Vaccinium species indicated small CH4 uptake. All the root-soil-compartments consumed CH4, however, the non-rooted soils showed on average small CH4 emission. We found methanotrophs from all the rooted and non-rooted soils. Methanogens were not detected in the plant or soil materials. Conclusions: The presence of plant roots seem to increase the amount of methanotrophs and thus CH4 uptake in the soil. The CH4 emissions from the shoots of C. vulgaris and P. sylvestris demonstrate that the plants have an important contribution to the CH4 exchange dynamics in the plant-soil systems. |
BibTeX:
@article{Halmeenmaki2017,
author = {Halmeenmäki, Elisa and Heinonsalo, Jussi and Putkinen, Anuliina and Santalahti, Minna and Fritze, Hannu and Pihlatie, Mari},
title = {Above- and belowground fluxes of methane from boreal dwarf shrubs and Pinus sylvestris seedlings},
journal = {Plant and Soil},
publisher = {Springer International Publishing},
year = {2017},
volume = {420},
number = {1-2},
pages = {361--373},
doi = {10.1007/s11104-017-3406-7}
}
|
| Hammer S, Friedrich R, Kromer B, Cherkinsky A, Lehman SJ, Meijer HAJ, Nakamura T, Palonen V, Reimer RW, Smith AM, Southon JR, Szidat S, Turnbull J and Uchida M (2017), "Compatibility of Atmospheric 14CO2 Measurements: Comparing the Heidelberg Low-Level Counting Facility to International Accelerator Mass Spectrometry (AMS) Laboratories", Radiocarbon., jun, 2017. Vol. 59(3), pp. 875-883. |
| Abstract: Combining atmospheric Δ14CO2 data sets from different networks or laboratories requires secure knowledge on their compatibility. In the present study, we compare Δ14CO2 results from the Heidelberg low-level counting (LLC) laboratory to 12 international accelerator mass spectrometry (AMS) laboratories using distributed aliquots of five pure CO2 samples. The averaged result of the LLC laboratory has a measurement bias of -0.3±0.5‰ with respect to the consensus value of the AMS laboratories for the investigated atmospheric Δ14C range of 9.6 to 40.4‰. Thus, the LLC measurements on average are not significantly different from the AMS laboratories, and the most likely measurement bias is smaller than the World Meteorological Organization (WMO) interlaboratory compatibility goal for Δ14CO2 of 0.5‰. The number of intercomparison samples was, however, too small to determine whether the measurement biases of the individual AMS laboratories fulfilled the WMO goal. |
BibTeX:
@article{Hammer2017,
author = {Hammer, Samuel and Friedrich, Ronny and Kromer, Bernd and Cherkinsky, Alexander and Lehman, Scott J and Meijer, Harro A J and Nakamura, Toshio and Palonen, Vesa and Reimer, Ron W and Smith, Andrew M and Southon, John R and Szidat, Sönke and Turnbull, Jocelyn and Uchida, Masao},
title = {Compatibility of Atmospheric 14CO2 Measurements: Comparing the Heidelberg Low-Level Counting Facility to International Accelerator Mass Spectrometry (AMS) Laboratories},
journal = {Radiocarbon},
year = {2017},
volume = {59},
number = {3},
pages = {875--883},
url = {https://www.cambridge.org/core/product/identifier/S003382221600062X/type/journal_article},
doi = {10.1017/RDC.2016.62}
}
|
| Hansen K, Personne E, Skjøth CA, Loubet B, Ibrom A, Jensen R, Sørensen LL and Boegh E (2017), "Investigating sources of measured forest-atmosphere ammonia fluxes using two-layer bi-directional modelling", Agricultural and Forest Meteorology., may, 2017. Vol. 237-238, pp. 80-94. |
BibTeX:
@article{Hansen2017,
author = {Hansen, K and Personne, E and Skjøth, C A and Loubet, B and Ibrom, A and Jensen, R and Sørensen, L L and Boegh, E},
title = {Investigating sources of measured forest-atmosphere ammonia fluxes using two-layer bi-directional modelling},
journal = {Agricultural and Forest Meteorology},
year = {2017},
volume = {237-238},
pages = {80--94},
url = {https://linkinghub.elsevier.com/retrieve/pii/S0168192317300412},
doi = {10.1016/j.agrformet.2017.02.008}
}
|
| He L, Chen JM, Croft H, Gonsamo A, Luo X, Liu J, Zheng T, Liu R and Liu Y (2017), "Nitrogen Availability Dampens the Positive Impacts of CO2 Fertilization on Terrestrial Ecosystem Carbon and Water Cycles", Geophysical Research Letters., nov, 2017. Vol. 44(22), pp. 11,590-11,600. Blackwell Publishing Ltd. |
| Abstract: The magnitude and variability of the terrestrial CO2 sink remain uncertain, partly due to limited global information on ecosystem nitrogen (N) and its cycle. Without N constraint in ecosystem models, the simulated benefits from CO2 fertilization and CO2-induced increases in water use efficiency (WUE) may be overestimated. In this study, satellite observations of a relative measure of chlorophyll content are used as a proxy for leaf photosynthetic N content globally for 2003–2011. Global gross primary productivity (GPP) and evapotranspiration are estimated under elevated CO2 and N-constrained model scenarios. Results suggest that the rate of global GPP increase is overestimated by 85% during 2000–2015 without N limitation. This limitation is found to occur in many tropical and boreal forests, where a negative leaf N trend indicates a reduction in photosynthetic capacity, thereby suppressing the positive vegetation response to enhanced CO2 fertilization. Based on our carbon-water coupled simulations, enhanced CO2 concentration decreased stomatal conductance and hence increased WUE by 10% globally over the 1982 to 2015 time frame. Due to increased anthropogenic N application, GPP in croplands continues to grow and offset the weak negative trend in forests due to N limitation. Our results also show that the improved WUE is unlikely to ease regional droughts in croplands because of increases in evapotranspiration, which are associated with the enhanced GPP. Although the N limitation on GPP increase is large, its associated confidence interval is still wide, suggesting an urgent need for better understanding and quantification of N limitation from satellite observations. |
BibTeX:
@article{He2017,
author = {He, Liming and Chen, Jing M. and Croft, Holly and Gonsamo, Alemu and Luo, Xiangzhong and Liu, Jane and Zheng, Ting and Liu, Ronggao and Liu, Yang},
title = {Nitrogen Availability Dampens the Positive Impacts of CO2 Fertilization on Terrestrial Ecosystem Carbon and Water Cycles},
journal = {Geophysical Research Letters},
publisher = {Blackwell Publishing Ltd},
year = {2017},
volume = {44},
number = {22},
pages = {11,590--11,600},
doi = {10.1002/2017GL075981}
}
|
| Hofmann MEG, Horváth B, Schneider L, Peters W, Schützenmeister K and Pack A (2017), "Atmospheric measurements of Δ17O in CO2 in Göttingen, Germany reveal a seasonal cycle driven by biospheric uptake", Geochimica et Cosmochimica Acta., feb, 2017. Vol. 199, pp. 143-163. |
| Abstract: The triple oxygen isotope composition of tropospheric CO2 might be a promising new tracer for terrestrial gross carbon fluxes. This notion is based on global box modeling of its abundance, and on highly challenging and therefore very sparse measurements of 16O, 17O and 18O in CO2 in the lower atmosphere. Here, we present additional high-precision triple oxygen isotope measurements of ambient air CO2 sampled in Göttingen (NW Germany) over the course of 2 years and of two air samples taken on top of the Brocken Mountain (1140 m, NW Germany). Göttingen differs from other locations where Δ17O was measured by its proximity to both urban sources of CO2, and to extensive uptake of CO2 by vegetation. In our analysis, we specifically try to discern this latter influence on our measurements, and to distinguish it from other known sources of variation in Δ17O. Our triple oxygen isotope data are reported as Δ17O values relative to a CO2-water equilibration line with Δ17O = ln (δ17O + 1) âˆ' 0.5229 × ln (δ18O + 1). We report an average of -0.02 ± 0.05‰ (SD) in the first year and -0.12 ± 0.04‰ (SD) in the second year of our measurements. This year-to-year difference is higher than expected based on other available Δ17O records, but careful scrutiny of our measurement approach did not reveal obvious analytical biases, leaving this aspect of our record unexplained. After removing the year-to-year trend, our time series shows a statistically robust seasonal cycle with maximum values in June/July and an amplitude (peak-to-trough) of 0.13 ± 0.02‰. We compare our observational data to a revised triple oxygen isotope mass balance “box†model of tropospheric CO2 where we reconcile both 18O/16O and 17O/16O fractionation processes. We also compare them to Göttingen-specific output from a three-dimensional transport model simulation of Δ17O in CO2 performed with the Tracer Model 5 (TM5). Both the modeled isofluxes at the surface, and the modeled stratospheric, fossil, and biospheric Δ17O components in the atmosphere at Göttingen confirm that the observed seasonal cycle in Δ17O is driven primarily by the seasonal cycle of gross primary productivity (GPP), and that the seasonal variations in both stratospheric transport and fossil fuel emissions play a minor role at our location. Our results therefore strengthen earlier suggestions that GPP is reflected in Δ17O, and call for more seasonally resolved measurements at continental locations like Göttingen. |
BibTeX:
@article{Hofmann2017,
author = {Hofmann, M E G and Horváth, B and Schneider, L and Peters, W and Schützenmeister, K and Pack, A},
title = {Atmospheric measurements of Δ17O in CO2 in Göttingen, Germany reveal a seasonal cycle driven by biospheric uptake},
journal = {Geochimica et Cosmochimica Acta},
year = {2017},
volume = {199},
pages = {143--163},
url = {http://linkinghub.elsevier.com/retrieve/pii/S0016703716306615},
doi = {10.1016/j.gca.2016.11.019}
}
|
| Horemans JA, Van Gaelen H, Raes D, Zenone T and Ceulemans R (2017), "Can the agricultural AquaCrop model simulate water use and yield of a poplar short-rotation coppice?", GCB Bioenergy., jun, 2017. Vol. 9(6), pp. 1151-1164. |
| Abstract: We calibrated and evaluated the agricultural model AquaCrop for the simulation of water use and yield of a short-rotation coppice (SRC) plantation with poplar (Populus) in East Flanders (Belgium) during the second and the third rotation (first 2 years only). Differences in crop development and growth during the course of the rotations were taken into account during the model calibration. Overall, the AquaCrop model showed good performance for the daily simulation of soil water content (R2 of 0.57–0.85), of green canopy cover (R2  0.87), of evapotranspiration (ET; R2  0.76), and of potential yield. The simulated, total yearly water use of the SRC ranged between 55% and 85% of the water use of a reference grass ecosystem calculated under the same environmental conditions. Crop transpiration was between 67% and 93% of total ET, with lower percentages in the first than in the second year of each rotation. The observed (dry mass) yield ranged from 6.61 to 14.76 Mg haâˆ'1 yrâˆ'1. A yield gap of around 30% was observed between the second and the third rotation, as well as between simulated and observed yield during the third rotation. This could possibly be explained by the expansion of the understory (weed) layer; the relative cover of understory weeds was 22% in the third year of the third rotation. The agricultural AquaCrop model simulated total water use and potential yield of the operational SRC in a reliable way. As the plantation was extensively managed, potential effects of irrigation and/or fertilization on ET and on yield were not considered in this study. |
BibTeX:
@article{Horemans2017,
author = {Horemans, Joanna A and Van Gaelen, Hanne and Raes, Dirk and Zenone, Terenzio and Ceulemans, Reinhart},
title = {Can the agricultural AquaCrop model simulate water use and yield of a poplar short-rotation coppice?},
journal = {GCB Bioenergy},
year = {2017},
volume = {9},
number = {6},
pages = {1151--1164},
url = {http://doi.wiley.com/10.1111/gcbb.12422},
doi = {10.1111/gcbb.12422}
}
|
| Horemans JA, Henrot A, Delire C, Kollas C, Lasch-Born P, Reyer C, Suckow F, Ois LF and Ceulemans R (2017), "Combining multiple statistical methods to evaluate the performance of process-based vegetation models across three forest stands", Central European Forestry Journal., jan, 2017. Vol. 63(4), pp. 153-172. |
| Abstract: Process-based vegetation models are crucial tools to better understand biosphere-atmosphere exchanges and eco-physiological responses to climate change. In this contribution the performance of two global dynamic vegetation models, i.e. CARAIB and ISBACC, and one stand-scale forest model, i.e. 4C, was compared to long-term observed net ecosystem carbon exchange (NEE) time series from eddy covariance monitoring stations at three old-grown European beech (Fagus sylvatica L.) forest stands. Residual analysis, wavelet analysis and singular spectrum analysis were used beside conventional scalar statistical measures to assess model performance with the aim of defining future targets for model improvement. We found that the most important errors for all three models occurred at the edges of the observed NEE distribution and the model errors were correlated with environmental variables on a daily scale. These observations point to possible projection issues under more extreme future climate conditions. Recurrent patterns in the residuals over the course of the year were linked to the approach to simulate phenology and physiological evolution during leaf development and senescence. Substantial model errors occurred on the multi-annual time scale, possibly caused by the lack of inclusion of management actions and disturbances. Other crucial processes defined were the forest structure and the vertical light partitioning through the canopy. Further, model errors were shown not to be transmitted from one time scale to another. We proved that models should be evaluated across multiple sites, preferably using multiple evaluation methods, to identify processes that request reconsideration. |
BibTeX:
@article{Horemans2017a,
author = {Horemans, Joanna A and Henrot, Alexandra and Delire, Christine and Kollas, Chris and Lasch-Born, Petra and Reyer, Christopher and Suckow, Felicitas and Ois, Louis Fran and Ceulemans, Reinhart},
title = {Combining multiple statistical methods to evaluate the performance of process-based vegetation models across three forest stands},
journal = {Central European Forestry Journal},
year = {2017},
volume = {63},
number = {4},
pages = {153--172},
url = {http://www.degruyter.com/view/j/forj.2017.63.issue-4/forj-2017-0025/forj-2017-0025.xml},
doi = {10.1515/forj-2017-0025}
}
|
| Hu Z, Wu G, Zhang L, Li S, Zhu X, Zheng H, Zhang L, Sun X and Yu G (2017), "Modeling and partitioning of regional evapotranspiration using a satellite-driven water-carbon coupling model", Remote Sensing. Vol. 9(1) MDPI AG. |
| Abstract: The modeling and partitioning of regional evapotranspiration (ET) are key issues in global hydrological and ecological research. We incorporated a stomatal conductance model and a light-use efficiency-based gross primary productivity (GPP) model into the Shuttleworth-Wallace model to develop a simplified carbon-water coupling model, SWH, for estimating ET using meteorological and remote sensing data. To enable regional application of the SWH model, we optimized key parameters with measurements from global eddy covariance (EC) tower sites. In addition, we estimated soil water content with the principle of the bucket system. The model prediction of ET agreed well with the estimates obtained with the EC measurements, with an average R2 of 0.77 and a root mean square error of 0.72 mmday-1. The model performance was generally better for woody ecosystems than herbaceous ecosystems. Finally, the spatial patterns of ET and relevant model outputs (i.e., GPP, water-use efficiency and the ratio of soil water evaporation to ET) in China with the model simulations were assessed. |
BibTeX:
@article{Hu2017,
author = {Hu, Zhongmin and Wu, Genan and Zhang, Liangxia and Li, Shenggong and Zhu, Xianjin and Zheng, Han and Zhang, Leiming and Sun, Xiaomin and Yu, Guirui},
title = {Modeling and partitioning of regional evapotranspiration using a satellite-driven water-carbon coupling model},
journal = {Remote Sensing},
publisher = {MDPI AG},
year = {2017},
volume = {9},
number = {1},
doi = {10.3390/rs9010054}
}
|
| Hurdebise Q, Heinesch B, De Ligne A, Vincke C and Aubinet M (2017), "Impact of canopy aerodynamic distance spatial and temporal variability on long term eddy covariance measurements", Agricultural and Forest Meteorology., dec, 2017. Vol. 247, pp. 131-138. |
| Abstract: Understanding if and how the spatial and temporal variability of the surrounding environment affects turbulence is essential for long-term eddy covariance measurements. It requires characterizing the surrounding environment. One way to achieve this is to analyse the canopy aerodynamic distance (Δ), which is the difference between measurement height (zm) and displacement height (d). In this work, an original method to estimate the canopy aerodynamic distance at a fine spatial (30° sectors) and temporal (one year) resolution was proposed. It was based on sensible heat cospectra analysis, calibrated on a measurement height change and validated using canopy height inventories. This method was applied to 20 years of eddy covariance measurements from the Vielsalm Terrestrial Observatory (VTO), a site located in a mixed temperate forest. The method allowed Δ spatio-temporal variability due to changes in canopy or measurement height to be detected. Relationships between Δ and turbulence statistics were then analysed: the momentum correlation coefficient (ruw) was found to be dependent on Δ, confirming that the measurements were made in the roughness sublayer of the atmospheric surface layer. In contrast, no such relationship was found sensible heat, CO2 or water vapour correlation coefficients, suggesting that the Δ variability did not affect significantly these fluxes. There were significant differences, however, between azimuthal directions, suggesting that these scalars were affected by forest heterogeneity in a different way. Various hypotheses were put forward to explain the differences and their relevance was evaluated. This study highlighted the need to consider the spatial and temporal variability of the surrounding environment in order to verify the consistency of long-term eddy covariance datasets. |
BibTeX:
@article{Hurdebise2017,
author = {Hurdebise, Quentin and Heinesch, Bernard and De Ligne, Anne and Vincke, Caroline and Aubinet, Marc},
title = {Impact of canopy aerodynamic distance spatial and temporal variability on long term eddy covariance measurements},
journal = {Agricultural and Forest Meteorology},
year = {2017},
volume = {247},
pages = {131--138},
url = {http://linkinghub.elsevier.com/retrieve/pii/S0168192317302307},
doi = {10.1016/j.agrformet.2017.07.013}
}
|
| Ibánhez JSP, Flores M and Lefèvre N (2017), "Collapse of the tropical and subtropical North Atlantic CO2 sink in boreal spring of 2010", Scientific Reports., jan, 2017. Vol. 7, pp. 41694. |
| Abstract: Following the 2009 Pacific El Niño, a warm event developed in the tropical and subtropical North Atlantic during boreal spring of 2010 promoted a significant increase in the CO2 fugacity of surface waters. This, together with the relaxation of the prevailing wind fields, resulted in the reversal of the atmospheric CO2 absorption capacity of the tropical and subtropical North Atlantic. In the region 0-30°N, 62-10°W, this climatic event led to the reversal of the climatological CO2 sink of -29.3 Tg C to a source of CO2 to the atmosphere of 1.6 Tg C from February to May. The highest impact of this event is verified in the region of the North Equatorial Current, where the climatological CO2 uptake of -22.4 Tg for that period ceased during 2010 (1.2 Tg C). This estimate is higher than current assessments of the multidecadal variability of the sea-air CO2 exchange for the entire North Atlantic (20 Tg year-1), and highlights the potential impact of the increasing occurrence of extreme climate events over the oceanic CO2 sink and atmospheric CO2 composition. |
BibTeX:
@article{Ibanhez2017,
author = {Ibánhez, J Severino P and Flores, Manuel and Lefèvre, Nathalie},
title = {Collapse of the tropical and subtropical North Atlantic CO2 sink in boreal spring of 2010},
journal = {Scientific Reports},
year = {2017},
volume = {7},
pages = {41694},
url = {http://www.nature.com/articles/srep41694},
doi = {10.1038/srep41694}
}
|
| Jammet M, Dengel S, Kettner E, Parmentier FJW, Wik M, Crill P and Friborg T (2017), "Year-round CH4 and CO2 flux dynamics in two contrasting freshwater ecosystems of the subarctic", Biogeosciences., nov, 2017. Vol. 14(22), pp. 5189-5216. |
| Abstract: Lakes and wetlands, common ecosystems of the high northern latitudes, exchange large amounts of the climate-forcing gases methane (CH4) and carbon dioxide (CO2) with the atmosphere. The magnitudes of these fluxes and the processes driving them are still uncertain, particularly for subarctic and Arctic lakes where direct measurements of CH4 and CO2 emissions are often of low temporal resolution and are rarely sustained throughout the entire year. Using the eddy covariance method, we measured surface-atmosphere exchange of CH4 and CO2 during 2.5 years in a thawed fen and a shallow lake of a subarctic peatland complex. Gas exchange at the fen exhibited the expected seasonality of a subarctic wetland with maximum CH4 emissions and CO2 uptake in summer, as well as low but continuous emissions of CH4 and CO2 throughout the snow-covered winter. The seasonality of lake fluxes differed, with maximum CO2 and CH4 flux rates recorded at spring thaw. During the ice-free seasons, we could identify surface CH4 emissions as mostly ebullition events with a seasonal trend in the magnitude of the release, while a net CO2 flux indicated photosynthetic activity. We found correlations between surface CH4 emissions and surface sediment temperature, as well as between diel CO2 uptake and diel solar input. During spring, the breakdown of thermal stratification following ice thaw triggered the degassing of both CH4 and CO2. This spring burst was observed in 2 consecutive years for both gases, with a large inter-annual variability in the magnitude of the CH4 degassing. On the annual scale, spring emissions converted the lake from a small CO2 sink to a CO2 source: 80% of total annual carbon emissions from the lake were emitted as CO2. The annual total carbon exchange per unit area was highest at the fen, which was an annual sink of carbon with respect to the atmosphere. Continuous respiration during the winter partly counteracted the fen summer sink by accounting for, as both CH4 and CO2, 33% of annual carbon exchange. Our study shows (1) the importance of overturn periods (spring or fall) for the annual CH4 and CO2 emissions of northern lakes, (2) the significance of lakes as atmospheric carbon sources in subarctic landscapes while fens can be a strong carbon sink, and (3) the potential for ecosystem-scale eddy covariance measurements to improve the understanding of short-term processes driving lake-atmosphere exchange of CH4 and CO2. |
BibTeX:
@article{Jammet2017,
author = {Jammet, Mathilde and Dengel, Sigrid and Kettner, Ernesto and Parmentier, Frans Jan W and Wik, Martin and Crill, Patrick and Friborg, Thomas},
title = {Year-round CH4 and CO2 flux dynamics in two contrasting freshwater ecosystems of the subarctic},
journal = {Biogeosciences},
year = {2017},
volume = {14},
number = {22},
pages = {5189--5216},
url = {https://www.biogeosciences.net/14/5189/2017/},
doi = {10.5194/bg-14-5189-2017}
}
|
| Järvi L, Grimmond CSB, McFadden JP, Christen A, Strachan IB, Taka M, Warsta L and Heimann M (2017), "Warming effects on the urban hydrology in cold climate regions", Scientific Reports., dec, 2017. Vol. 7(1), pp. 5833. |
| Abstract: While approximately 338 million people in the Northern hemisphere live in regions that are regularly snow covered in winter, there is little hydro-climatologic knowledge in the cities impacted by snow. Using observations and modelling we have evaluated the energy and water exchanges of four cities that are exposed to wintertime snow. We show that the presence of snow critically changes the impact that city design has on the local-scale hydrology and climate. After snow melt, the cities return to being strongly controlled by the proportion of built and vegetated surfaces. However in winter, the presence of snow masks the influence of the built and vegetated fractions. We show how inter-year variability of wintertime temperature can modify this effect of snow. With increasing temperatures, these cities could be pushed towards very different partitioning between runoff and evapotranspiration. We derive the dependency of wintertime runoff on this warming effect in combination with the effect of urban densification. |
BibTeX:
@article{Jarvi2017,
author = {Järvi, L and Grimmond, C S B and McFadden, J P and Christen, A and Strachan, I B and Taka, M and Warsta, L and Heimann, M},
title = {Warming effects on the urban hydrology in cold climate regions},
journal = {Scientific Reports},
year = {2017},
volume = {7},
number = {1},
pages = {5833},
url = {http://www.nature.com/articles/s41598-017-05733-y},
doi = {10.1038/s41598-017-05733-y}
}
|
| Jin H, Jönsson AM, Bolmgren K, Langvall O and Eklundh L (2017), "Disentangling remotely-sensed plant phenology and snow seasonality at northern Europe using MODIS and the plant phenology index", Remote Sensing of Environment., sep, 2017. Vol. 198, pp. 203-212. |
| Abstract: Land surface phenology is frequently derived from remotely sensed data. However, over regions with seasonal snow cover, remotely-sensed land surface phenology may be dominated by snow seasonality, rather than showing true plant phenology. Overlooking snow influences may lead to inaccurate plant phenology estimation, and consequently to misinterpretation of climate-vegetation interactions. To address the problem we apply the recently developed plant phenology index (PPI) to Moderate Resolution Imaging Spectroradiometer (MODIS) data for estimating plant phenology metrics over northern Europe. We compare PPI-derived start and end of the growing season with ground observations by professionals (6 sites) and nonprofessional citizens (378 sites), with phenology metrics derived from gross primary productivity (GPP, 18 sites), and with data on the timing of snow cover. These data are also compared with land surface phenology metrics derived from the normalized difference vegetation index (NDVI) using the same MODIS data. We find that the PPI-retrieved plant phenology agrees with ground observations and GPP-derived phenology, and that the NDVI-derived phenology to a large extent agrees with the end-of-snowmelt for the start-of-season and the start-of-snowing for the end-of-season. PPI is thereby useful for more accurate estimation of plant phenology from remotely sensed data over northern Europe and other regions with seasonal snow cover. |
BibTeX:
@article{Jin2017,
author = {Jin, Hongxiao and Jönsson, Anna Maria and Bolmgren, Kjell and Langvall, Ola and Eklundh, Lars},
title = {Disentangling remotely-sensed plant phenology and snow seasonality at northern Europe using MODIS and the plant phenology index},
journal = {Remote Sensing of Environment},
year = {2017},
volume = {198},
pages = {203--212},
url = {http://linkinghub.elsevier.com/retrieve/pii/S0034425717302742},
doi = {10.1016/j.rse.2017.06.015}
}
|
| Jocher G, Ottosson Löfvenius M, De Simon G, Hörnlund T, Linder S, Lundmark T, Marshall J, Nilsson MB, Näsholm T, Tarvainen L, Öquist M and Peichl M (2017), "Apparent winter CO2 uptake by a boreal forest due to decoupling", Agricultural and Forest Meteorology., jan, 2017. Vol. 232, pp. 23-34. |
| Abstract: Net uptake of carbon dioxide (CO2) was observed during the winter when using the eddy covariance (EC) technique above a ∼90-year-old Scots pine (Pinus sylvestris L.) stand in northern Sweden. This uptake occurred despite photosynthetic dormancy. This discrepancy led us to investigate the potential impact of decoupling of below- and above-canopy air mass flow and accompanying below-canopy horizontal advection on these measurements. We used the correlation of above- and below-canopy standard deviation of vertical wind speed (σw), derived from EC measurements above and below the canopy, as the main mixing criterion. We identified 0.33 m sâˆ'1 and 0.06 m sâˆ'1 as site-specific σw thresholds for above and below canopy, respectively, to reach the fully coupled state. Decoupling was observed in 45% of all cases during the measurement period (5.11.2014–25.2.2015). After filtering out decoupled periods the above-canopy mean winter NEE shifted from âˆ'0.52 μmol mâˆ'2 sâˆ'1 to a more reasonable positive value of 0.31 μmol mâˆ'2 sâˆ'1. None of the above-canopy data filtering criteria we tested (i.e., friction velocity threshold; horizontal wind speed threshold; single-level σw threshold) ensured sufficient mixing. All missed critical periods that were detected only by the two-level filtering approach. Tower-surrounding topography induced a predominant below-canopy wind direction and consequent wind shear between above- and below-canopy air masses. These processes may foster decoupling and below-canopy removal of CO2 rich air. To determine how broadly such a topographical influence might apply, we compared the topography surrounding our tower to that surrounding other forest flux sites worldwide. Medians of maximum elevation differences within 300 m and 1000 m around 110 FLUXNET forest EC towers were 24 m and 66 m, respectively, compared to 24 m and 114 m, respectively, at our site. Consequently, below-canopy flow may influence above-canopy NEE detections at many forested EC sites. Based on our findings we suggest below-canopy measurements as standard procedure at sites evaluating forest CO2 budgets. |
BibTeX:
@article{Jocher2017,
author = {Jocher, Georg and Ottosson Löfvenius, Mikaell and De Simon, Giuseppe and Hörnlund, Thomas and Linder, Sune and Lundmark, Tomas and Marshall, John and Nilsson, Mats B and Näsholm, Torgny and Tarvainen, Lasse and Öquist, Mats and Peichl, Matthias},
title = {Apparent winter CO2 uptake by a boreal forest due to decoupling},
journal = {Agricultural and Forest Meteorology},
year = {2017},
volume = {232},
pages = {23--34},
url = {http://linkinghub.elsevier.com/retrieve/pii/S0168192316303495},
doi = {10.1016/j.agrformet.2016.08.002}
}
|
| Jones EM, Hoppema M, Strass V, Hauck J, Salt L, Ossebaar S, Klaas C, van Heuven SMAC, Wolf-Gladrow D, Stöven T and de Baar HJW (2017), "Mesoscale features create hotspots of carbon uptake in the Antarctic Circumpolar Current", Deep-Sea Research Part II: Topical Studies in Oceanography., apr, 2017. Vol. 138, pp. 39-51. |
| Abstract: The influence of eddy structures on the seasonal depletion of dissolved inorganic carbon (DIC) and carbon dioxide (CO2) disequilibrium was investigated during a trans-Atlantic crossing of the Antarctic Circumpolar Current (ACC) in austral summer 2012. The Georgia Basin, downstream of the island of South Georgia (54-55°S, 36-38°W) is a highly dynamic region due to the mesoscale activity associated with the flow of the Subantarctic Front (SAF) and Polar Front (PF). Satellite sea-surface height and chlorophyll-a anomalies revealed a cyclonic cold core that dominated the northern Georgia Basin that was formed from a large meander of the PF. Warmer waters influenced by the SAF formed a smaller anticyclonic structure to the east of the basin. Both the cold core and warm core eddy structures were hotspots of carbon uptake relative to the rest of the ACC section during austral summer. This was most amplified in the cold core where greatest CO2 undersaturation (âˆ'78 μatm) and substantial surface ocean DIC deficit (5.1 mol mâˆ'2) occurred. In the presence of high wind speeds, the cold core eddy acted as a strong sink for atmospheric CO2 of 25.5 mmol mâˆ'2 dayâˆ'1. Waters of the warm core displayed characteristics of the Polar Frontal Zone (PFZ), with warmer upper ocean waters and enhanced CO2 undersaturation (âˆ'59 μatm) and depletion of DIC (4.9mol mâˆ'2). A proposed mechanism for the enhanced carbon uptake across both eddy structures is based on the Ekman eddy pumping theory: (i) the cold core is seeded with productive (high chlorophyll-a) waters from the Antarctic Zone and sustained biological productivity through upwelled nutrient supply that counteracts DIC inputs from deep waters; (ii) horizontal entrainment of low-DIC surface waters (biological uptake) from the PFZ downwell within the warm core and cause relative DIC-depletion in the upper water column. The observations suggest that the formation and northward propagation of cold core eddies in the region of the PF could project low-DIC waters towards the site of Antarctic Intermediate Water formation and enhance CO2 drawdown into the deep ocean. |
BibTeX:
@article{Jones2017,
author = {Jones, Elizabeth M and Hoppema, Mario and Strass, Volker and Hauck, Judith and Salt, Lesley and Ossebaar, Sharyn and Klaas, Christine and van Heuven, Steven M A C and Wolf-Gladrow, Dieter and Stöven, Tim and de Baar, Hein J W},
title = {Mesoscale features create hotspots of carbon uptake in the Antarctic Circumpolar Current},
journal = {Deep-Sea Research Part II: Topical Studies in Oceanography},
year = {2017},
volume = {138},
pages = {39--51},
url = {http://linkinghub.elsevier.com/retrieve/pii/S0967064515003379},
doi = {10.1016/j.dsr2.2015.10.006}
}
|
| Jonsson M, Burrows RM, Lidman J, Fältström E, Laudon H and Sponseller RA (2017), "Land use influences macroinvertebrate community composition in boreal headwaters through altered stream conditions", Ambio., apr, 2017. Vol. 46(3), pp. 311-323. |
| Abstract: Land use is known to alter the nature of land–water interactions, but the potential effects of widespread forest management on headwaters in boreal regions remain poorly understood. We evaluated the importance of catchment land use, land cover, and local stream variables for macroinvertebrate community and functional trait diversity in 18 boreal headwater streams. Variation in macroinvertebrate metrics was often best explained by in-stream variables, primarily water chemistry (e.g. pH). However, variation in stream variables was, in turn, significantly associated with catchment-scale forestry land use. More specifically, streams running through catchments that were dominated by young (11–50 years) forests had higher pH, greater organic matter standing stock, higher abundance of aquatic moss, and the highest macroinvertebrate diversity, compared to streams running through recently clear-cut and old forests. This indicates that catchment-scale forest management can modify in-stream habitat conditions with effects on stream macroinvertebrate communities and that characteristics of younger forests may promote conditions that benefit headwater biodiversity. |
BibTeX:
@article{Jonsson2017,
author = {Jonsson, Micael and Burrows, Ryan M and Lidman, Johan and Fältström, Emma and Laudon, Hjalmar and Sponseller, Ryan A},
title = {Land use influences macroinvertebrate community composition in boreal headwaters through altered stream conditions},
journal = {Ambio},
year = {2017},
volume = {46},
number = {3},
pages = {311--323},
url = {http://link.springer.com/10.1007/s13280-016-0837-y},
doi = {10.1007/s13280-016-0837-y}
}
|
| Jung M, Reichstein M, Schwalm CR, Huntingford C, Sitch S, Ahlström A, Arneth A, Camps-Valls G, Ciais P, Friedlingstein P, Gans F, Ichii K, Jain AK, Kato E, Papale D, Poulter B, Raduly B, Rödenbeck C, Tramontana G, Viovy N, Wang YP, Weber U, Zaehle S and Zeng N (2017), "Compensatory water effects link yearly global land CO 2 sink changes to temperature", Nature., jan, 2017. Vol. 541(7638), pp. 516-520. |
| Abstract: Large interannual variations in the measured growth rate of atmospheric carbon dioxide (CO 2) originate primarily from fluctuations in carbon uptake by land ecosystems. It remains uncertain, however, to what extent temperature and water availability control the carbon balance of land ecosystems across spatial and temporal scales. Here we use empirical models based on eddy covariance data and process-based models to investigate the effect of changes in temperature and water availability on gross primary productivity (GPP), terrestrial ecosystem respiration (TER) and net ecosystem exchange (NEE) at local and global scales. We find that water availability is the dominant driver of the local interannual variability in GPP and TER. To a lesser extent this is true also for NEE at the local scale, but when integrated globally, temporal NEE variability is mostly driven by temperature fluctuations. We suggest that this apparent paradox can be explained by two compensatory water effects. Temporal water-driven GPP and TER variations compensate locally, dampening water-driven NEE variability. Spatial water availability anomalies also compensate, leaving a dominant temperature signal in the year-to-year fluctuations of the land carbon sink. These findings help to reconcile seemingly contradictory reports regarding the importance of temperature and water in controlling the interannual variability of the terrestrial carbon balance. Our study indicates that spatial climate covariation drives the global carbon cycle response. |
BibTeX:
@article{Jung2017,
author = {Jung, Martin and Reichstein, Markus and Schwalm, Christopher R and Huntingford, Chris and Sitch, Stephen and Ahlström, Anders and Arneth, Almut and Camps-Valls, Gustau and Ciais, Philippe and Friedlingstein, Pierre and Gans, Fabian and Ichii, Kazuhito and Jain, Atul K and Kato, Etsushi and Papale, Dario and Poulter, Ben and Raduly, Botond and Rödenbeck, Christian and Tramontana, Gianluca and Viovy, Nicolas and Wang, Ying Ping and Weber, Ulrich and Zaehle, Sönke and Zeng, Ning},
title = {Compensatory water effects link yearly global land CO 2 sink changes to temperature},
journal = {Nature},
year = {2017},
volume = {541},
number = {7638},
pages = {516--520},
url = {http://www.nature.com/articles/nature20780},
doi = {10.1038/nature20780}
}
|
| Juráň S, Pallozzi E, Guidolotti G, Fares S, Šigut L, Calfapietra C, Alivernini A, Savi F, VečeÅ™ová K, Křůmal K, VečeÅ™a Z and Urban O (2017), "Fluxes of biogenic volatile organic compounds above temperate Norway spruce forest of the Czech Republic", Agricultural and Forest Meteorology., jan, 2017. Vol. 232, pp. 500-513. |
| Abstract: Norway spruce (Picea abies), the most representative forest species in central and northern Europe, has previously been described as a monoterpene emitter. However, past studies have shown variable emission rates. In order to understand emissions at the ecosystem scale, a technique utilizing proton-transfer-reaction-time-of-flight (PTR-TOF) mass spectrometry coupled with eddy covariance was applied to determine fluxes of volatile organic compounds and CO2 above a mountainous Norway spruce forest in the Czech Republic during an intensive field campaign in summer. In addition, an Inverse Lagrangian Transport Model was applied to derive fluxes of various monoterpenes using concentrations measured along a vertical canopy profile by wet effluent diffusion denuder. The Model of Emissions of Gases and Aerosols from Nature (MEGAN) was applied using basal emission factors for sun and shade shoots to predict diurnal fluxes and annual monoterpene emission sums for 5 years. The forest showed itself to be a monoterpene emitter up to 2.03 nmol mâˆ'2 sâˆ'1. Isoprene and 2-methyl-3-buten-2-ol (MBO) reached maximum levels during central hours of the day of 1.6 nmol mâˆ'2 sâˆ'1, whereas daily average maximum fluxes were 1.29 nmol mâˆ'2 sâˆ'1 and 0.77 nmol mâˆ'2 sâˆ'1 for monoterpenes and sum of isoprene and MBO, respectively. The relationship between monoterpene and CO2 fluxes revealed that as much as 47% of variance in MT emission is predictable from the actual gross primary production of a spruce ecosystem. Modelled MT fluxes agreed with the measured fluxes in terms of diurnal pattern, particularly when basal emission factors 2.72 nmol mâˆ'2 sâˆ'1 and 0.55 nmol mâˆ'2 sâˆ'1 for sun and shade shoots, respectively, were used. Nevertheless, strong seasonal variability in MT emission was observed. Our results contribute to better understanding emissions of biogenic volatile organic compounds in central Europe. |
BibTeX:
@article{JuraA2017,
author = {Juráň, Stanislav and Pallozzi, Emanuele and Guidolotti, Gabriele and Fares, Silvano and Šigut, Ladislav and Calfapietra, Carlo and Alivernini, Alessandro and Savi, Flavia and VečeÅ™ová, Kristýna and Křůmal, Kamil and VečeÅ™a, Zbyněk and Urban, Otmar},
title = {Fluxes of biogenic volatile organic compounds above temperate Norway spruce forest of the Czech Republic},
journal = {Agricultural and Forest Meteorology},
year = {2017},
volume = {232},
pages = {500--513},
url = {http://linkinghub.elsevier.com/retrieve/pii/S0168192316303963},
doi = {10.1016/j.agrformet.2016.10.005}
}
|
| Kitidis V, Brown I, Hardman-Mountford N and Lefèvre N (2017), "Surface ocean carbon dioxide during the Atlantic Meridional Transect (1995–2013); evidence of ocean acidification", Progress in Oceanography., nov, 2017. Vol. 158, pp. 65-75. Elsevier Ltd. |
| Abstract: Here we present more than 21,000 observations of carbon dioxide fugacity in air and seawater (fCO2) along the Atlantic Meridional Transect (AMT) programme for the period 1995–2013. Our dataset consists of 11 southbound and 2 northbound cruises in boreal autumn and spring respectively. Our paper is primarily focused on change in the surface-ocean carbonate system during southbound cruises. We used observed fCO2 and total alkalinity (TA), derived from salinity and temperature, to estimate dissolved inorganic carbon (DIC) and pH (total scale). Using this approach, estimated pH was consistent with spectrophotometric measurements carried out on 3 of our cruises. The AMT cruises transect a range of biogeographic provinces where surface Chlorophyll-α spans two orders of magnitude (mesotrophic high latitudes to oligotrophic subtropical gyres). We found that surface Chlorophyll-α was negatively correlated with fCO2, but that the deep chlorophyll maximum was not a controlling variable for fCO2. Our data show clear evidence of ocean acidification across 100° of latitude in the Atlantic Ocean. Over the period 1995–2013 we estimated annual rates of change in: (a) sea surface temperature of 0.01 ± 0.05 °C, (b) seawater fCO2 of 1.44 ± 0.84 μatm, (c) DIC of 0.87 ± 1.02 μmol per kg and (d) pH of −0.0013 ± 0.0009 units. Monte Carlo simulations propagating the respective analytical uncertainties showed that the latter were textless 5% of the observed trends. Seawater fCO2 increased at the same rate as atmospheric CO2. |
BibTeX:
@article{Kitidis2017,
author = {Kitidis, Vassilis and Brown, Ian and Hardman-Mountford, Nicholas and Lefèvre, Nathalie},
title = {Surface ocean carbon dioxide during the Atlantic Meridional Transect (1995–2013); evidence of ocean acidification},
journal = {Progress in Oceanography},
publisher = {Elsevier Ltd},
year = {2017},
volume = {158},
pages = {65--75},
url = {https://ui.adsabs.harvard.edu/abs/2017PrOce.158...65K/abstract},
doi = {10.1016/j.pocean.2016.08.005}
}
|
| Klosterhalfen A, Herbst M, Weihermüller L, Graf A, Schmidt M, Stadler A, Schneider K, Subke JA, Huisman JA and Vereecken H (2017), "Multi-site calibration and validation of a net ecosystem carbon exchange model for croplands", Ecological Modelling., nov, 2017. Vol. 363, pp. 137-156. |
| Abstract: Croplands play an important role in the carbon budget of many regions. However, the estimation of their carbon balance remains difficult due to diversity and complexity of the processes involved. We report the coupling of a one-dimensional soil water, heat, and CO2 flux model (SOILCO2), a pool concept of soil carbon turnover (RothC), and a crop growth module (SUCROS) to predict the net ecosystem exchange (NEE) of carbon. The coupled model, further referred to as AgroC, was extended with routines for managed grassland as well as for root exudation and root decay. In a first step, the coupled model was applied to two winter wheat sites and one upland grassland site in Germany. The model was calibrated based on soil water content, soil temperature, biometric, and soil respiration measurements for each site, and validated in terms of hourly NEE measured with the eddy covariance technique. The overall model performance of AgroC was sufficient with a model efficiency above 0.78 and a correlation coefficient above 0.91 for NEE. In a second step, AgroC was optimized with eddy covariance NEE measurements to examine the effect of different objective functions, constraints, and data-transformations on estimated NEE. It was found that NEE showed a distinct sensitivity to the choice of objective function and the inclusion of soil respiration data in the optimization process. In particular, both positive and negative day- and nighttime fluxes were found to be sensitive to the selected optimization strategy. Additional consideration of soil respiration measurements improved the simulation of small positive fluxes remarkably. Even though the model performance of the selected optimization strategies did not diverge substantially, the resulting cumulative NEE over simulation time period differed substantially. Therefore, it is concluded that data-transformations, definitions of objective functions, and data sources have to be considered cautiously when a terrestrial ecosystem model is used to determine NEE by means of eddy covariance measurements. |
BibTeX:
@article{Klosterhalfen2017,
author = {Klosterhalfen, A and Herbst, M and Weihermüller, L and Graf, A and Schmidt, M and Stadler, A and Schneider, K and Subke, J A and Huisman, J A and Vereecken, H},
title = {Multi-site calibration and validation of a net ecosystem carbon exchange model for croplands},
journal = {Ecological Modelling},
year = {2017},
volume = {363},
pages = {137--156},
url = {http://linkinghub.elsevier.com/retrieve/pii/S0304380017300054},
doi = {10.1016/j.ecolmodel.2017.07.028}
}
|
| Koirala S, Jung M, Reichstein M, de Graaf IEM, Camps-Valls G, Ichii K, Papale D, Ráduly B, Schwalm CR, Tramontana G and Carvalhais N (2017), "Global distribution of groundwater-vegetation spatial covariation", Geophysical Research Letters., may, 2017. Vol. 44(9), pp. 4134-4142. |
| Abstract: Groundwater is an integral component of the water cycle, and it also influences the carbon cycle by supplying moisture to ecosystems. However, the extent and determinants of groundwater-vegetation interactions are poorly understood at the global scale. Using several high-resolution data products, we show that the spatial patterns of ecosystem gross primary productivity and groundwater table depth are correlated during at least one season in more than two thirds of the global vegetated area. Positive relationships, i.e., larger productivity under shallower groundwater table, predominate in moisture-limited dry to mesic conditions with herbaceous and shrub vegetation. Negative relationships, i.e., larger productivity under deeper groundwater, predominate in humid climates with forests, possibly indicating a drawdown of groundwater table due to substantial ecosystem water use. Interestingly, these opposite groundwater-vegetation interactions are primarily associated with differences in vegetation than with climate and surface characteristics. These findings put forth the first evidence, and a need for better representation, of extensive and non-negligible groundwater-vegetation interactions at the global scale. |
BibTeX:
@article{Koirala2017,
author = {Koirala, Sujan and Jung, Martin and Reichstein, Markus and de Graaf, Inge E M and Camps-Valls, Gustau and Ichii, Kazuhito and Papale, Dario and Ráduly, Botond and Schwalm, Christopher R and Tramontana, Gianluca and Carvalhais, Nuno},
title = {Global distribution of groundwater-vegetation spatial covariation},
journal = {Geophysical Research Letters},
year = {2017},
volume = {44},
number = {9},
pages = {4134--4142},
url = {http://doi.wiley.com/10.1002/2017GL072885},
doi = {10.1002/2017GL072885}
}
|
| Kooijmans LMJ, Maseyk K, Seibt U, Sun W, Vesala T, Mammarella I, Kolari P, Aalto J, Franchin A, Vecchi R, Valli G and Chen H (2017), "Canopy uptake dominates nighttime carbonyl sulfide fluxes in a boreal forest", Atmospheric Chemistry and Physics., sep, 2017. Vol. 17(18), pp. 11453-11465. |
| Abstract: Nighttime vegetative uptake of carbonyl sulfide (COS) can exist due to the incomplete closure of stomata and the light independence of the enzyme carbonic anhydrase, which complicates the use of COS as a tracer for gross primary productivity (GPP). In this study we derived nighttime COS fluxes in a boreal forest (the SMEAR II station in Hyytiälä, Finland; 61-510 N, 24-170 E; 181ma.s.l.) from June to November 2015 using two different methods: eddycovariance (EC) measurements (FCOS-EC) and the radontracer method (FCOS-Rn). The total nighttime COS fluxes averaged over the whole measurement period were -6.8±2.2 and -7.9±3.8 pmolm-2 s-1 for FCOS-Rn and FCOS-EC, respectively, which is 33-38% of the average daytime fluxes and 21% of the total daily COS uptake. The correlation of 222Rn (of which the source is the soil) with COS (average R2 D0.58) was lower than with CO2 (0.70), suggesting that the main sink of COS is not located at the ground. These observations are supported by soil chamber measurements that show that soil contributes to only 34-40% of the total nighttime COS uptake. We found a decrease in COS uptake with decreasing nighttime stomatal conductance and increasing vapor-pressure deficit and air temperature, driven by stomatal closure in response to a warm and dry period in August. We also discuss the effect that canopy layer mixing can have on the radon-tracer method and the sensitivity of (FCOS-EC) to atmospheric turbulence. Our results suggest that the nighttime uptake of COS is mainly driven by the tree foliage and is significant in a boreal forest, such that it needs to be taken into account when using COS as a tracer for GPP. |
BibTeX:
@article{Kooijmans2017,
author = {Kooijmans, Linda M J and Maseyk, Kadmiel and Seibt, Ulli and Sun, Wu and Vesala, Timo and Mammarella, Ivan and Kolari, Pasi and Aalto, Juho and Franchin, Alessandro and Vecchi, Roberta and Valli, Gianluigi and Chen, Huilin},
title = {Canopy uptake dominates nighttime carbonyl sulfide fluxes in a boreal forest},
journal = {Atmospheric Chemistry and Physics},
year = {2017},
volume = {17},
number = {18},
pages = {11453--11465},
url = {https://www.atmos-chem-phys.net/17/11453/2017/},
doi = {10.5194/acp-17-11453-2017}
}
|
| Korkiakoski M, Tuovinen JP, Aurela M, Koskinen M, Minkkinen K, Ojanen P, Penttilä T, Rainne J, Laurila T and Lohila A (2017), "Methane exchange at the peatland forest floor - Automatic chamber system exposes the dynamics of small fluxes", Biogeosciences., apr, 2017. Vol. 14(7), pp. 1947-1967. |
| Abstract: We measured methane (CH4) exchange rates with automatic chambers at the forest floor of a nutrient-rich drained peatland in 2011-2013. The fen, located in southern Finland, was drained for forestry in 1969 and the tree stand is now a mixture of Scots pine, Norway spruce, and pubescent birch. Our measurement system consisted of six transparent chambers and stainless steel frames, positioned on a number of different field and moss layer compositions. Gas concentrations were measured with an online cavity ring-down spectroscopy gas analyzer. Fluxes were calculated with both linear and exponential regression. The use of linear regression resulted in systematically smaller CH4 fluxes by 10-45Ä€% as compared to exponential regression. However, the use of exponential regression with small fluxes ( Ä€2.5Ä€μgÄ€CH4Ä€mÄ'2Ä€hÄ'1) typically resulted in anomalously large absolute fluxes and high hour-to-hour deviations. Therefore, we recommend that fluxes are initially calculated with linear regression to determine the threshold for qlow/q fluxes and that higher fluxes are then recalculated using exponential regression. The exponential flux was clearly affected by the length of the fitting period when this period was Ä€190Ä€s, but stabilized with longer periods. Thus, we also recommend the use of a fitting period of several minutes to stabilize the results and decrease the flux detection limit. There were clear seasonal dynamics in the CH4 flux: the forest floor acted as a CH4 sink particularly from early summer until the end of the year, while in late winter the flux was very small and fluctuated around zero. However, the magnitude of fluxes was relatively small throughout the year, ranging mainly from Ä'130 to +100Ä€μgÄ€CH4Ä€mÄ'2Ä€hÄ'1. CH4 emission peaks were observed occasionally, mostly in summer during heavy rainfall events. Diurnal variation, showing a lower CH4 uptake rate during the daytime, was observed in all of the chambers, mainly in the summer and late spring, particularly in dry conditions. It was attributed more to changes in wind speed than air or soil temperature, which suggest that physical rather than biological phenomena are responsible for the observed variation. The annual net CH4 exchange varied from Ä'104Ä€±Ä€30 to Ä'505Ä€±Ä€39Ä€mgÄ€CH4Ä€mÄ'2Ä€yrÄ'1 among the six chambers, with an average of Ä'219Ä€mgÄ€CH4Ä€mÄ'2Ä€yrÄ'1 over the 2-year measurement period. |
BibTeX:
@article{Korkiakoski2017,
author = {Korkiakoski, Mika and Tuovinen, Juha Pekka and Aurela, Mika and Koskinen, Markku and Minkkinen, Kari and Ojanen, Paavo and Penttilä, Timo and Rainne, Juuso and Laurila, Tuomas and Lohila, Annalea},
title = {Methane exchange at the peatland forest floor - Automatic chamber system exposes the dynamics of small fluxes},
journal = {Biogeosciences},
year = {2017},
volume = {14},
number = {7},
pages = {1947--1967},
url = {https://www.biogeosciences.net/14/1947/2017/},
doi = {10.5194/bg-14-1947-2017}
}
|
| Korrensalo A, Alekseychik P, Hájek T, Rinne J, Vesala T, Mehtätalo L, Mammarella I and Tuittila ES (2017), "Species-specific temporal variation in photosynthesis as a moderator of peatland carbon sequestration", Biogeosciences., jan, 2017. Vol. 14(2), pp. 257-269. |
| Abstract: In boreal bogs plant species are low in number, but they differ greatly in their growth forms and photosynthetic properties. We assessed how ecosystem carbon (C) sink dynamics were affected by seasonal variations in the photosynthetic rate and leaf area of different species. Photosynthetic properties (light response parameters), leaf area development and areal cover (abundance) of the species were used to quantify species-specific net and gross photosynthesis rates (PNand PG, respectively), which were summed to express ecosystem-level PNand PG. The ecosystem-level PGwas compared with a gross primary production (GPP) estimate derived from eddy covariance (EC) measurements. Species areal cover, rather than differences in photosynthetic properties, determined the species with the highest PGof both vascular plants and Sphagna. Species-specific contributions to the ecosystem PGvaried over the growing season, which, in turn, determined the seasonal variation in ecosystem PG. The upscaled growing season PGestimate, 230 g C m-2, agreed well with the GPP estimated by the EC (243 g C m-2). Sphagna were superior to vascular plants in ecosystem-level PGthroughout the growing season but had a lower PN. PNresults indicated that areal cover of the species, together with their differences in photosynthetic parameters, shape the ecosystem-level C balance. Species with low areal cover but high photosynthetic efficiency appear to be potentially important for the ecosystem C sink. Results imply that functional diversity, i.e., the presence of plant groups with different seasonal timing and efficiency of photosynthesis, may increase the stability of C sinks of boreal bogs. |
BibTeX:
@article{Korrensalo2017,
author = {Korrensalo, Aino and Alekseychik, Pavel and Hájek, Tomás and Rinne, Janne and Vesala, Timo and Mehtätalo, Lauri and Mammarella, Ivan and Tuittila, Eeva Stiina},
title = {Species-specific temporal variation in photosynthesis as a moderator of peatland carbon sequestration},
journal = {Biogeosciences},
year = {2017},
volume = {14},
number = {2},
pages = {257--269},
url = {http://www.biogeosciences.net/14/257/2017/},
doi = {10.5194/bg-14-257-2017}
}
|
| Köster E, Köster K, Berninger F, Aaltonen H, Zhou X and Pumpanen J (2017), "Carbon dioxide, methane and nitrous oxide fluxes from a fire chronosequence in subarctic boreal forests of Canada", Science of the Total Environment., dec, 2017. Vol. 601-602, pp. 895-905. Elsevier B.V.. |
| Abstract: Forest fires are one of the most important natural disturbances in boreal forests, and their occurrence and severity are expected to increase as a result of climate warming. A combination of factors induced by fire leads to a thawing of the near-surface permafrost layer in subarctic boreal forest. Earlier studies reported that an increase in the active layer thickness results in higher carbon dioxide (CO2) and methane (CH4) emissions. We studied changes in CO2, CH4 and nitrous oxide (N2O) fluxes in this study, and the significance of several environmental factors that influence the greenhouse gas (GHG) fluxes at three forest sites that last had fires in 2012, 1990 and 1969, and we compared these to a control area that had no fire for at least 100 years. The soils in our study acted as sources of CO2 and N2O and sinks for CH4. The elapsed time since the last forest fire was the only factor that significantly influenced all studied GHG fluxes. Soil temperature affected the uptake of CH4, and the N2O fluxes were significantly influenced by nitrogen and carbon content of the soil, and by the active layer depth. Results of our study confirm that the impacts of a forest fire on GHGs last for a rather long period of time in boreal forests, and are influenced by the fire induced changes in the ecosystem. |
BibTeX:
@article{Koster2017,
author = {Köster, Egle and Köster, Kajar and Berninger, Frank and Aaltonen, Heidi and Zhou, Xuan and Pumpanen, Jukka},
title = {Carbon dioxide, methane and nitrous oxide fluxes from a fire chronosequence in subarctic boreal forests of Canada},
journal = {Science of the Total Environment},
publisher = {Elsevier B.V.},
year = {2017},
volume = {601-602},
pages = {895--905},
doi = {10.1016/j.scitotenv.2017.05.246}
}
|
| Kozii N, Laudon H, Ottosson-Löfvenius M and Hasselquist NJ (2017), "Increasing water losses from snow captured in the canopy of boreal forests: A case study using a 30Â year data set", Hydrological Processes., sep, 2017. Vol. 31(20), pp. 3558-3567. |
| Abstract: Water losses from snow intercepted by forest canopy can significantly influence the hydrological cycle in seasonally snow-covered regions, yet how snow interception losses (SIL) are influenced by a changing climate are poorly understood. In this study, we used a unique 30 year record (1986–2015) of snow accumulation and snow water equivalent measurements in a mature mixed coniferous (Picea abies and Pinus sylvestris) forest stand and an adjacent open area to assess how changes in weather conditions influence SIL. Given little change in canopy cover during this study, the 20% increase in SIL was likely the result of changes in winter weather conditions. However, there was no significant change in average wintertime precipitation and temperature during the study period. Instead, mean monthly temperature values increased during the early winter months (i.e., November and December), whereas there was a significant decrease in precipitation in March. We also assessed how daily variation in meteorological variables influenced SIL and found that about 50% of the variation in SIL was correlated to the amount of precipitation that occurred when temperatures were lower than âˆ'3 °C and to the proportion of days with mean daily temperatures higher than +0.4 °C. Taken together, this study highlights the importance of understanding the appropriate time scale and thresholds in which weather conditions influence SIL in order to better predict how projected climate change will influence snow accumulation and hydrology in boreal forests in the future. |
BibTeX:
@article{Kozii2017,
author = {Kozii, Nataliia and Laudon, Hjalmar and Ottosson-Löfvenius, Mikaell and Hasselquist, Niles J},
title = {Increasing water losses from snow captured in the canopy of boreal forests: A case study using a 30Â year data set},
journal = {Hydrological Processes},
year = {2017},
volume = {31},
number = {20},
pages = {3558--3567},
url = {http://doi.wiley.com/10.1002/hyp.11277},
doi = {10.1002/hyp.11277}
}
|
| Krüger JP, Conen F, Leifeld J and Alewell C (2017), "Palsa Uplift Identified by Stable Isotope Depth Profiles and Relation of δ15N to C/N Ratio", Permafrost and Periglacial Processes., apr, 2017. Vol. 28(2), pp. 485-492. |
| Abstract: Palsas develop as permafrost aggradation uplifts peat out of the zone influenced by groundwater. Here we relate δ15N values to C/N ratios along depth profiles through palsas in two peatlands near Abisko, northern Sweden, to identify perturbation of the peat. The perturbation by uplift as well as the potential nutrient input from the adjacent hollows can be detected in soil δ15N values when related to the C/N ratio at the same depth. Nine out of ten profiles show a perturbation at the depth where peat was uplifted by permafrost. Palsa uplift could be detected by the δ15N depth pattern, with the highest δ15N values at the so-called turning point. The δ15N values increase above and decrease below the turning point, when permafrost initiated uplift. Onset of permafrost aggradation calculated from peat accumulation rates was between 80 and 545 years ago, with a mean of 242 (±66) years for Stordalen and 365 (±53) years for Storflaket peatland. The mean ages of permafrost aggradation are within the Little Ice Age. Depth profiles of δ15N, when related to C/N ratio, seem to be a suitable tool to detect perturbation and uplift of palsas. Copyright textcopyright 2016 John Wiley & Sons, Ltd. |
BibTeX:
@article{Kruger2017,
author = {Krüger, Jan Paul and Conen, Franz and Leifeld, Jens and Alewell, Christine},
title = {Palsa Uplift Identified by Stable Isotope Depth Profiles and Relation of δ15N to C/N Ratio},
journal = {Permafrost and Periglacial Processes},
year = {2017},
volume = {28},
number = {2},
pages = {485--492},
url = {http://doi.wiley.com/10.1002/ppp.1936},
doi = {10.1002/ppp.1936}
}
|
| Krupková L, Marková I, Havránková K, Pokorný R, Urban O, Šigut L, Pavelka M, Cienciala E and Marek MV (2017), "Comparison of different approaches of radiation use efficiency of biomass formation estimation in Mountain Norway spruce", Trees - Structure and Function., feb, 2017. Vol. 31(1), pp. 325-337. |
| Abstract: Key message: Radiation use efficiency values estimation based on the biomass increment (one approach) and on NPP from eddy covariance (two approaches) estimation of NPP brings the values of 0.13, 0.40, and 0.47 g (C) MJâˆ'1, respectively. Abstract: The productivity of terrestrial ecosystems is primarily reliant on the absorption of solar radiation energy and its conversion into biomass. Monteith (1977) first introduced the concept of radiation use efficiency (RUE), which expresses the effectiveness of a plant stand to use solar radiation for the formation of new biomass and to maintain existing biomass. The presented paper uses a long-term, decadal, time series of biomass data, which is based on forest inventory data and an allometric relation, and on the application of eddy covariance (EC) estimation of Net Primary Production (NPP). These approaches provide different values of light use efficiency (LUE). LUE is based on direct carbon exchange estimation, LUEi, which denotes instantaneous efficiency based on the relationship between the daily sum of incident global radiation (GRi) and NPP and LUES, calculated as the ratio between the sum of NPP and the sum of GRi per growing season. RUE is based on direct yearly biomass increment expressed in carbon units (carbon = 0.5 × biomass) divided by the sum of GRi per year. The obtained values amount to 0.13, 0.40, and 0.47 g(C) MJâˆ'1 for RUE, LUES, and LUEi, respectively. The higher value of LUEi reflects a direct relation with the efficiency of photosynthetic carbon pumping. In contrast, the RUE value, based on biomass inventories, is the result of woody mass formation that is caused by several mutually related physiological processes and “wastages†of radiation utilization. |
BibTeX:
@article{Krupkova2017,
author = {Krupková, Lenka and Marková, Irena and Havránková, KateÅ™ina and Pokorný, Radek and Urban, Otmar and Šigut, Ladislav and Pavelka, Marian and Cienciala, Emil and Marek, Michal V},
title = {Comparison of different approaches of radiation use efficiency of biomass formation estimation in Mountain Norway spruce},
journal = {Trees - Structure and Function},
year = {2017},
volume = {31},
number = {1},
pages = {325--337},
url = {http://link.springer.com/10.1007/s00468-016-1486-2},
doi = {10.1007/s00468-016-1486-2}
}
|
| Lansø AS, Sørensen LL, Christensen JH, Rutgersson A and Geels C (2017), "The influence of short-term variability in surface water pCO2 on modelled air-sea CO2 exchange", Tellus, Series B: Chemical and Physical Meteorology., jan, 2017. Vol. 69(1), pp. 1302670. |
| Abstract: Coastal seas and estuarine systems are highly variable in both time and space and with their heterogeneity difficult to capture with measurements. Models are useful tools in obtaining a better spatiotemporal coverage or, at least, a better understanding of the impacts such heterogeneity has in driving variability in coastal oceans and estuaries. A modelbased sensitivity study is constructed in this study in order to examine the effects of short-term variability in surface water pCO2 on the annual air-sea CO2 exchange in coastal regions. An atmospheric transport model formed the basis of the modelling framework for the study of the Baltic Sea and the Danish inner waters. Several maps of surface water pCO2 were employed in the modelling framework. While a monthly Baltic Sea climatology (BSC) had already been developed, the current study further extended this with the addition of an improved near-coastal climatology for the Danish inner waters. Furthermore, daily surface fields of pCO2 were obtained from a mixed layer scheme constrained by surface measurements of pCO2 (JENA). Short-term variability in surface water pCO2 was assessed by calculating monthly mean diurnal cycles from continuous measurements of surface water pCO2, observed at stationary sites within the Baltic Sea. No apparent diurnal cycle was evident in winter, but diurnal cycles (with amplitudes up to 27μatm) were found fromApril to October. The present study showed that the temporal resolution of surface water pCO2 played an influential role on the annual air-sea CO2 exchange for the coastal study region. Hence, annual estimates of CO2 exchanges are sensitive to variation on much shorter time scales, and this variability should be included for any model study investigating the exchange of CO2 across the air-sea interface. Furthermore, the choice of surface pCO2 maps also had a crucial influence on the simulated air-sea CO2 exchange. |
BibTeX:
@article{Lansø2017,
author = {Lansø, Anne Sofie and Sørensen, Lise Lotte and Christensen, Jesper H and Rutgersson, Anna and Geels, Camilla},
title = {The influence of short-term variability in surface water pCO2 on modelled air-sea CO2 exchange},
journal = {Tellus, Series B: Chemical and Physical Meteorology},
year = {2017},
volume = {69},
number = {1},
pages = {1302670},
url = {https://www.tandfonline.com/doi/full/10.1080/16000889.2017.1302670},
doi = {10.1080/16000889.2017.1302670}
}
|
| Laruelle GG, Landschützer P, Gruber N, Tison J-L, Delille B and Regnier P (2017), "Global high-resolution monthly &lt;i&gt;p&lt;/i&gt;CO&lt;sub&gt;2&lt;/sub&gt; climatology for the coastal ocean derived from neural network interpolation", Biogeosciences., oct, 2017. Vol. 14(19), pp. 4545-4561. Copernicus GmbH. |
| Abstract: textlessptextgreaterAbstract. In spite of the recent strong increase in the number of measurements of the partial pressure of CO2 in the surface ocean (pCO2), the air–sea CO2 balance of the continental shelf seas remains poorly quantified. This is a consequence of these regions remaining strongly under-sampled in both time and space and of surface pCO2 exhibiting much higher temporal and spatial variability in these regions compared to the open ocean. Here, we use a modified version of a two-step artificial neural network method (SOM-FFN; Landschützer et al., 2013) to interpolate the pCO2 data along the continental margins with a spatial resolution of 0.25° and with monthly resolution from 1998 to 2015. The most important modifications compared to the original SOM-FFN method are (i) the much higher spatial resolution and (ii) the inclusion of sea ice and wind speed as predictors of pCO2. The SOM-FFN is first trained with pCO2 measurements extracted from the SOCATv4 database. Then, the validity of our interpolation, in both space and time, is assessed by comparing the generated pCO2 field with independent data extracted from the LDVEO2015 database. The new coastal pCO2 product confirms a previously suggested general meridional trend of the annual mean pCO2 in all the continental shelves with high values in the tropics and dropping to values beneath those of the atmosphere at higher latitudes. The monthly resolution of our data product permits us to reveal significant differences in the seasonality of pCO2 across the ocean basins. The shelves of the western and northern Pacific, as well as the shelves in the temperate northern Atlantic, display particularly pronounced seasonal variations in pCO2, while the shelves in the southeastern Atlantic and in the southern Pacific reveal a much smaller seasonality. The calculation of temperature normalized pCO2 for several latitudes in different oceanic basins confirms that the seasonality in shelf pCO2 cannot solely be explained by temperature-induced changes in solubility but are also the result of seasonal changes in circulation, mixing and biological productivity. Our results also reveal that the amplitudes of both thermal and nonthermal seasonal variations in pCO2 are significantly larger at high latitudes. Finally, because this product's spatial extent includes parts of the open ocean as well, it can be readily merged with existing global open-ocean products to produce a true global perspective of the spatial and temporal variability of surface ocean pCO2.textless/ptextgreater |
BibTeX:
@article{Laruelle2017,
author = {Laruelle, Goulven G. and Landschützer, Peter and Gruber, Nicolas and Tison, Jean-Louis and Delille, Bruno and Regnier, Pierre},
title = {Global high-resolution monthly &lt;i&gt;p&lt;/i&gt;CO&lt;sub&gt;2&lt;/sub&gt; climatology for the coastal ocean derived from neural network interpolation},
journal = {Biogeosciences},
publisher = {Copernicus GmbH},
year = {2017},
volume = {14},
number = {19},
pages = {4545--4561},
url = {https://bg.copernicus.org/articles/14/4545/2017/},
doi = {10.5194/bg-14-4545-2017}
}
|
| Laudon H, Spence C, Buttle J, Carey SK, McDonnell JJ, McNamara JP, Soulsby C and Tetzlaff D (2017), "Save northern high-latitude catchments", Nature Geoscience., may, 2017. Vol. 10(5), pp. 324-325. |
BibTeX:
@article{Laudon2017,
author = {Laudon, Hjalmar and Spence, Christopher and Buttle, Jim and Carey, Sean K and McDonnell, Jeffrey J and McNamara, James P and Soulsby, Chris and Tetzlaff, Doerthe},
title = {Save northern high-latitude catchments},
journal = {Nature Geoscience},
year = {2017},
volume = {10},
number = {5},
pages = {324--325},
url = {http://www.nature.com/doifinder/10.1038/ngeo2947},
doi = {10.1038/ngeo2947}
}
|
| Laufs S, Cazaunau M, Stella P, Kurtenbach R, Cellier P, Mellouki A, Loubet B and Kleffmann J (2017), "Diurnal fluxes of HONO above a crop rotation", Atmospheric Chemistry and Physics., jun, 2017. Vol. 17(11), pp. 6907-6923. |
| Abstract: Nitrous acid (HONO) fluxes were measured above an agricultural field site near Paris during different seasons. Above bare soil, different crops were measured using the aerodynamic gradient (AG) method. Two LOPAPs (LOng Path Absorption Photometer) were used to determine the HONO gradients between two heights. During daytime mainly positive HONO fluxes were observed, which showed strong correlation with the product of the NO2 concentration and the long wavelength UV light intensity, expressed by the photolysis frequency J(NO2). These results are consistent with HONO formation by photosensitized heterogeneous conversion of NO2 on soil surfaces as observed in recent laboratory studies. An additional influence of the soil temperature on the HONO flux can be explained by the temperature-dependent HONO adsorption on the soil surface. A parameterization of the HONO flux at this location with NO2 concentration, J(NO2), soil temperature and humidity fits reasonably well all flux observations at this location. |
BibTeX:
@article{Laufs2017,
author = {Laufs, Sebastian and Cazaunau, Mathieu and Stella, Patrick and Kurtenbach, Ralf and Cellier, Pierre and Mellouki, Abdelwahid and Loubet, Benjamin and Kleffmann, Jörg},
title = {Diurnal fluxes of HONO above a crop rotation},
journal = {Atmospheric Chemistry and Physics},
year = {2017},
volume = {17},
number = {11},
pages = {6907--6923},
url = {https://www.atmos-chem-phys.net/17/6907/2017/},
doi = {10.5194/acp-17-6907-2017}
}
|
| Leach JA, Lidberg W, Kuglerová L, Peralta-Tapia A, Ågren A and Laudon H (2017), "Evaluating topography-based predictions of shallow lateral groundwater discharge zones for a boreal lake-stream system", Water Resources Research., jul, 2017. Vol. 53(7), pp. 5420-5437. |
| Abstract: Groundwater discharge along streams exerts an important influence on biogeochemistry and thermal regimes of aquatic ecosystems. A common approach for predicting locations of shallow lateral groundwater discharge is to use digital elevation models (DEMs) combined with upslope contributing area algorithms. We evaluated a topography-based prediction of subsurface discharge zones along a 1500 m headwater stream reach using temperature and water isotope tracers. We deployed fiber-optic distributed temperature sensing instrumentation to monitor stream temperature at 0.25 m intervals along the reach. We also collected samples of stream water for the analysis of its water isotope composition at 50 m intervals on five occasions representing distinct streamflow conditions before, during, and after a major rain event. The combined tracer evaluation showed that topography-predicted locations of groundwater discharge were generally accurate; however, predicted magnitude of groundwater inflows estimated from upslope contributing area did not always agree with tracer estimates. At the catchment scale, lateral inflows were an important source of streamflow at base flow and peak flow during a major rain event; however, water from a headwater lake was the dominant water source during the event hydrograph recession. Overall, this study highlights potential utility and limitations of predicting locations and contributions of lateral groundwater discharge zones using topography-based approaches in humid boreal regions. |
BibTeX:
@article{Leach2017,
author = {Leach, J A and Lidberg, W and Kuglerová, L and Peralta-Tapia, A and Ågren, A and Laudon, H},
title = {Evaluating topography-based predictions of shallow lateral groundwater discharge zones for a boreal lake-stream system},
journal = {Water Resources Research},
year = {2017},
volume = {53},
number = {7},
pages = {5420--5437},
url = {http://doi.wiley.com/10.1002/2016WR019804},
doi = {10.1002/2016WR019804}
}
|
| Ledesma JLJ and Futter MN (2017), "Gridded climate data products are an alternative to instrumental measurements as inputs to rainfall–runoff models", Hydrological Processes., aug, 2017. Vol. 31(18), pp. 3283-3293. |
| Abstract: Rainfall–runoff models are widely used to predict flows using observed (instrumental) time series of air temperature and precipitation as inputs. Poor model performance is often associated with difficulties in estimating catchment-scale meteorological variables from point observations. Readily available gridded climate products are an underutilized source of temperature and precipitation time series for rainfall–runoff modelling, which may overcome some of the performance issues associated with poor-quality instrumental data in small headwater monitoring catchments. Here we compare the performance of instrumental measured and E-OBS gridded temperature and precipitation time series as inputs in the rainfall–runoff models “PERSiST†and “HBV†for flow prediction in six small Swedish catchments. For both models and most catchments, the gridded data produced statistically better simulations than did those obtained using instrumental measurements. Despite the high correspondence between instrumental and gridded temperature, both temperature and precipitation were responsible for the difference. We conclude that (a) gridded climate products such as the E-OBS dataset could be more widely used as alternative input to rainfall–runoff models, even when instrumental measurements are available, and (b) the processing applied to gridded climate products appears to provide a more realistic approximation of small catchment-scale temperature and precipitation patterns needed for flow simulations. Further research on this issue is needed and encouraged. |
BibTeX:
@article{Ledesma2017,
author = {Ledesma, José L J and Futter, Martyn N},
title = {Gridded climate data products are an alternative to instrumental measurements as inputs to rainfall–runoff models},
journal = {Hydrological Processes},
year = {2017},
volume = {31},
number = {18},
pages = {3283--3293},
url = {http://doi.wiley.com/10.1002/hyp.11269},
doi = {10.1002/hyp.11269}
}
|
| Lefèvre N, Montes MF, Gaspar FL, Rocha C, Jiang S, De Araújo MC and Severino Pino Ibánhez J (2017), "Net heterotrophy in the Amazon continental shelf changes rapidly to a sink of CO2 in the outer Amazon plume", Frontiers in Marine Science., sep, 2017. Vol. 4(SEP) |
| Abstract: The Amazon continental shelf and adjacent oceanic area were sampled for inorganic and organic carbon parameters in order to improve data coverage and understanding of carbon cycling dynamics within this important region. Seasonal coverage of the Amazon plume on the French Guiana continental shelf further north, was provided by CO2 monitoring using a merchant ship sailing from France to French Guiana (2006-2016). Salinity ranged from 1 to 36 (transects in April 2013, and May 2014). At salinity below 10, strong outgassing was observed with fugacity of CO2 (fCO2) over 2,000μatm. This region displayed net heterotrophy, fueled by organic matter with terrestrial origin, as shown by γ13C and γ15N values of suspended particles. A γ13C cross shelf average of -31% was measured during May 2014, contrasting with oceanic values in excess of -20%. The reactivity of this terrestrial material resulted in the local production of dissolved inorganic and organic carbon as well as fluorescent humic compounds. Further offshore, the dilution of freshwater by ocean waters created a sink for CO2, enhanced by biological activity. The strongest CO2 drawdowns, associated with high chlorophyll a concentrations, were observed on the French Guiana continental shelf in the outer Amazon plume, with fCO2 values below 150 μatm. Here, a CO2 sink was present almost throughout the year, with a seasonal maximum of -9.2 mmol CO2 m-2d-1 observed in June 2015. However, both the CO2 and salinity distributions could vary significantly within a few days, confirming the presence of many eddies in this region. The Amazon continental shelf hence behaved as a transition zone between an inshore source of CO2 to the atmosphere and an offshore sink. Some marine phytoplankton production was detected but occurred mainly close to the French Guiana shelf. A mean net CO2 outgassing of 44 ± 43.6mmol m-2d-1 was estimated for the area. Quantifying the CO2 flux for the entire Amazon shelf area led to a revised annual estimate of the net ocean carbon export of 2.86 1012 mol C from the region. |
BibTeX:
@article{Lefevre2017,
author = {Lefèvre, Nathalie and Montes, Manuel Flores and Gaspar, Felipe L and Rocha, Carlos and Jiang, Shan and De Araújo, Moacyr C and Severino Pino Ibánhez, J},
title = {Net heterotrophy in the Amazon continental shelf changes rapidly to a sink of CO2 in the outer Amazon plume},
journal = {Frontiers in Marine Science},
year = {2017},
volume = {4},
number = {SEP},
url = {http://journal.frontiersin.org/article/10.3389/fmars.2017.00278/full},
doi = {10.3389/fmars.2017.00278}
}
|
| Lefèvre N, da Silva Dias FJ, de Torres AR, Noriega C, Araujo M, de Castro ACL, Rocha C, Jiang S and Ibánhez JSP (2017), "A source of CO2 to the atmosphere throughout the year in the Maranhense continental shelf (2°30'S, Brazil)", Continental Shelf Research., jun, 2017. Vol. 141, pp. 38-50. |
| Abstract: To reduce uncertainty regarding the contribution of continental shelf areas in low latitude regions to the air-sea CO2 exchange, more data are required to understand the carbon turnover in these regions and cover gaps in coverage. For the first time, inorganic carbon and alkalinity were measured along a cross-shelf transect off the coast of Maranhão (North Brazil) in 9 cruises spawning from April 2013 to September 2014. On the last 4 transects, dissolved organic matter and nutrients were also measured. The highest inorganic and organic carbon concentrations are observed close to land. As a result of low productivity and significant remineralization, heterotrophy dominates along the transect throughout the year. Although the temporal variability is significantly reduced at the offshore station with carbon concentrations decreasing seaward, the fugacity of CO2 (fCO2) at this station remains significantly higher, especially during the wet season, than the open ocean values measured routinely by a merchant ship further west. Overall, the continental shelf is a weak source of CO2 to the atmosphere throughout the year with an annual mean flux of 1.81±0.84 mmol mâˆ'2 dâˆ'1. The highest magnitudes of fCO2 are observed during the wet season when the winds are the weakest. As a result, the CO2 flux does not show a clear seasonal pattern. Further offshore, fCO2 is significantly lower than on the continental shelf. However, the oceanic CO2 flux, with an annual mean of 2.32±1.09 mmol mâˆ'2 dâˆ'1, is not statistically different from the CO2 flux at the continental shelf because the wind is stronger in the open ocean. |
BibTeX:
@article{Lefevre2017a,
author = {Lefèvre, Nathalie and da Silva Dias, Francisco Jose and de Torres, Audálio Rebelo and Noriega, Carlos and Araujo, Moacyr and de Castro, Antonio Carlos Leal and Rocha, Carlos and Jiang, Shan and Ibánhez, J Severino P},
title = {A source of CO2 to the atmosphere throughout the year in the Maranhense continental shelf (2°30'S, Brazil)},
journal = {Continental Shelf Research},
year = {2017},
volume = {141},
pages = {38--50},
url = {http://linkinghub.elsevier.com/retrieve/pii/S0278434316305015},
doi = {10.1016/j.csr.2017.05.004}
}
|
| Levin I, Schmithüsen D and Vermeulen A (2017), "Assessment of 222radon progeny loss in long tubing based on static filter measurements in the laboratory and in the field", Atmospheric Measurement Techniques., apr, 2017. Vol. 10(4), pp. 1313-1321. |
| Abstract: Aerosol loss in air intake systems potentially hampers the application of one-filter systems for progeny-based atmospheric 222radon (222Rn) measurements. The artefacts are significant when air has to be collected via long sampling lines, e.g. from elevated heights at tall tower observatories. Here we present results from a study, determining 222Rn progeny loss from ambient air sampled via 8.2mm inner diameter (ID) Decabon tubing in the laboratory and from pre-installed 10mm ID tubing at the Cabauw meteorological tower in the Netherlands. Progeny loss increased steeply with length of the tubing, decreasing sampling efficiency to 66% for 8.2mm ID rolled-up tubing of 200m length at a flow rate of ca. 1m3 h-1. Preliminary theoretical estimation of the loss yielded a sampling efficiency of 64% for the same tubing, when taking into account turbulent inertial deposition of aerosol to the walls as well as loss due to gravitational settling. At Cabauw tower, theoretical estimates of the loss in vertical tubing with 10mm ID and 200m lengths with flow rate of 1.1m3 h1 yielded a total efficiency of 73 %, the same value as observed. 222Rn progeny loss increased strongly at activity concentrations below 1 Bqm-3. Based on our experiments, an empirical correction function for 222Rn progeny measurements when sampling through long Decabon tubing was developed, allowing correction of respective measurements for this particular experimental setting (tubing type and diameter, flow rate, aerosol size distribution) with an estimated uncertainty of 10-20% for activity concentrations between 1 and 2 Bqm-3 and less than 10% for activity concentrations above 2 Bqm-3. |
BibTeX:
@article{Levin2017,
author = {Levin, Ingeborg and Schmithüsen, Dominik and Vermeulen, Alex},
title = {Assessment of 222radon progeny loss in long tubing based on static filter measurements in the laboratory and in the field},
journal = {Atmospheric Measurement Techniques},
year = {2017},
volume = {10},
number = {4},
pages = {1313--1321},
url = {https://www.atmos-meas-tech.net/10/1313/2017/},
doi = {10.5194/amt-10-1313-2017}
}
|
| Li W, Ciais P, Peng S, Yue C, Wang Y, Thurner M, Saatchi SS, Arneth A, Avitabile V, Carvalhais N, Harper AB, Kato E, Koven C, Liu YY, Nabel JEMS, Pan Y, Pongratz J, Poulter B, Pugh TAM, Santoro M, Sitch S, Stocker BD, Viovy N, Wiltshire A, Yousefpour R and Zaehle S (2017), "Land-use and land-cover change carbon emissions between 1901 and 2012 constrained by biomass observations". |
| Abstract: The use of dynamic global vegetation models (DGVMs) to estimate CO2 emissions from land-use and land-cover change (LULCC) offers a new window to account for spatial and temporal details of emissions and for ecosystem processes affected by LULCC. One drawback of LULCC emissions from DGVMs, however, is lack of observation constraint. Here, we propose a new method of using satellite- and inventory-based biomass observations to constrain historical cumulative LULCC emissions (ELUCc) from an ensemble of nine DGVMs based on emerging relationships between simulated vegetation biomass and ELUCc. This method is applicable on the global and regional scale. The original DGVM estimates of ELUCc range from 94 to 273PgC during 1901-2012. After constraining by current biomass observations, we derive a best estimate of 155±50PgC (1σ Gaussian error). The constrained LULCC emissions are higher than prior DGVM values in tropical regions but significantly lower in North America. Our emergent constraint approach independently verifies the median model estimate by biomass observations, giving support to the use of this estimate in carbon budget assessments. The uncertainty in the constrained ELUCc is still relatively large because of the uncertainty in the biomass observations, and thus reduced uncertainty in addition to increased accuracy in biomass observations in the future will help improve the constraint. This constraint method can also be applied to evaluate the impact of land-based mitigation activities. |
BibTeX:
@misc{Li2017,
author = {Li, Wei and Ciais, Philippe and Peng, Shushi and Yue, Chao and Wang, Yilong and Thurner, Martin and Saatchi, Sassan S and Arneth, Almut and Avitabile, Valerio and Carvalhais, Nuno and Harper, Anna B and Kato, Etsushi and Koven, Charles and Liu, Yi Y and Nabel, Julia E M S and Pan, Yude and Pongratz, Julia and Poulter, Benjamin and Pugh, Thomas A M and Santoro, Maurizio and Sitch, Stephen and Stocker, Benjamin D and Viovy, Nicolas and Wiltshire, Andy and Yousefpour, Rasoul and Zaehle, Sönke},
title = {Land-use and land-cover change carbon emissions between 1901 and 2012 constrained by biomass observations},
booktitle = {Biogeosciences},
year = {2017},
volume = {14},
number = {22},
pages = {5053--5067},
doi = {10.5194/bg-14-5053-2017}
}
|
| Liang A, Gong W, Han G and Xiang C (2017), "Comparison of satellite-observed XCO2 from GOSAT, OCO-2, and ground-based TCCON", Remote Sensing., oct, 2017. Vol. 9(10) MDPI AG. |
| Abstract: CO2 is one of the most important greenhouse gases. Its concentration and distribution in the atmosphere have always been important in studying the carbon cycle and the greenhouse effect. This study is the first to validate the XCO2 of satellite observations with total carbon column observing network (TCCON) data and to compare the global XCO2 distribution for the passive satellites Orbiting Carbon Observatory-2 (OCO-2) and Greenhouse Gases Observing Satellite (GOSAT), which are on-orbit greenhouse gas satellites. Results show that since GOSAT was launched in 2009, its mean measurement accuracy was -0.4107 ppm with an error standard deviation of 2.216 ppm since 2009, and has since decreased to -0.62 ppm with an error standard deviation of 2.3 ppm during the past two more years (2014-2016), while the mean measurement accuracy of the OCO-2 was 0.2671 ppm with an error standard deviation of 1.56 ppm from September 2014 to December 2016. GOSAT observations have recently decreased and lagged behind OCO-2 on the ability to monitor the global distribution and monthly detection of XCO2. Furthermore, the XCO2 values gathered by OCO-2 are higher by an average of 1.765 ppm than those by GOSAT. Comparison of the latitude gradient characteristics, seasonal fluctuation amplitude, and annual growth trend of the monthly mean XCO2 distribution also showed differences in values but similar line shapes between OCO-2 and GOSAT. When compared with the NOAA statistics, both satellites' measurements reflect the growth trend of the global XCO2 at a low and smooth level, and reflect the seasonal fluctuation with an absolutely different line shape. |
BibTeX:
@article{Liang2017,
author = {Liang, Ailin and Gong, Wei and Han, Ge and Xiang, Chengzhi},
title = {Comparison of satellite-observed XCO2 from GOSAT, OCO-2, and ground-based TCCON},
journal = {Remote Sensing},
publisher = {MDPI AG},
year = {2017},
volume = {9},
number = {10},
doi = {10.3390/rs9101033}
}
|
| Liang A, Han G, Gong W, Yang J and Xiang C (2017), "Comparison of global XCO2 concentrations from OCO-2 with TCCON data in terms of latitude zones", IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing., jun, 2017. Vol. 10(6), pp. 2491-2498. Institute of Electrical and Electronics Engineers. |
| Abstract: This work evaluated the performance of the orbiting carbon observatory 2 (OCO-2) in terms of global atmospheric CO2 observations for 20 months (September 2014 to April 2016). Three versions of data on CO2 are currently available, namely, version 7, version 7r, and Lite File Product (Lite-FP). For the first time, we evaluated XCO2 measurements from three versions of OCO-2 in terms of utilization efficiency, spatiotemporal coverage, and measurement accuracy compared with data (GGG2014) from the total carbon column observing network (TCCON). In data application, Lite-FP usually displayed the most efficient data volume and relatively stable spatial coverage, i.e., 42% in global scale. In addition, the spatial coverage of XCO2 measurements on land and ocean displayed opposite periodic seasonal fluctuations. However, no data were obtained in some areas where research on carbon ecology is highly significant. In terms of measurement accuracy, we considered the latitude distribution of TCCON sites and performed a site-by-site comparison at different latitude zones between XCO2 from three versions of OCO-2 and TCCON. Results demonstrated that the periodic variation trend of XCO2 from OCO-2 was consistent with that from TCCON. Moreover, the amplitude was similar to that of TCCON except that several sites had significant seasonal variation amplitude. The mean bias of OCO-2 was generally textless 0.8 ppm, with 0.55% deviation. Among the three versions of OCO-2, Lite-FP showed good result in filtering and bias correction in the mid-low latitudes but still needs improvement in the high latitudes of the Northern and the Southern Hemispheres. |
BibTeX:
@article{Liang2017a,
author = {Liang, Ailin and Han, Ge and Gong, Wei and Yang, Jie and Xiang, Chengzhi},
title = {Comparison of global XCO2 concentrations from OCO-2 with TCCON data in terms of latitude zones},
journal = {IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing},
publisher = {Institute of Electrical and Electronics Engineers},
year = {2017},
volume = {10},
number = {6},
pages = {2491--2498},
doi = {10.1109/JSTARS.2017.2650942}
}
|
| Lidberg W, Nilsson M, Lundmark T and Ågren AM (2017), "Evaluating preprocessing methods of digital elevation models for hydrological modelling", Hydrological Processes., dec, 2017. Vol. 31(26), pp. 4660-4668. |
| Abstract: With the introduction of high-resolution digital elevation models, it is possible to use digital terrain analysis to extract small streams. In order to map streams correctly, it is necessary to remove errors and artificial sinks in the digital elevation models. This step is known as preprocessing and will allow water to move across a digital landscape. However, new challenges are introduced with increasing resolution because the effect of anthropogenic artefacts such as road embankments and bridges increases with increased resolution. These are problematic during the preprocessing step because they are elevated above the surrounding landscape and act as artificial dams. The aims of this study were to evaluate the effect of different preprocessing methods such as breaching and filling on digital elevation models with different resolutions (2, 4, 8, and 16Â m) and to evaluate which preprocessing methods most accurately route water across road impoundments at actual culvert locations. A unique dataset with over 30,000 field-mapped road culverts was used to assess the accuracy of stream networks derived from digital elevation models using different preprocessing methods. Our results showed that the accuracy of stream networks increases with increasing resolution. Breaching created the most accurate stream networks on all resolutions, whereas filling was the least accurate. Burning streams from the topographic map across roads from the topographic map increased the accuracy for all methods and resolutions. In addition, the impact in terms of change in area and absolute volume between original and preprocessed digital elevation models was smaller for breaching than for filling. With the appropriate methods, it is possible to extract accurate stream networks from high-resolution digital elevation models with extensive road networks, thus providing forest managers with stream networks that can be used when planning operations in wet areas or areas near streams to prevent rutting, sediment transport, and mercury export. |
BibTeX:
@article{Lidberg2017,
author = {Lidberg, William and Nilsson, Mats and Lundmark, Tomas and Ågren, Anneli M},
title = {Evaluating preprocessing methods of digital elevation models for hydrological modelling},
journal = {Hydrological Processes},
year = {2017},
volume = {31},
number = {26},
pages = {4660--4668},
url = {http://doi.wiley.com/10.1002/hyp.11385},
doi = {10.1002/hyp.11385}
}
|
| Lidman J, Jonsson M, Burrows RM, Bundschuh M and Sponseller RA (2017), "Composition of riparian litter input regulates organic matter decomposition: Implications for headwater stream functioning in a managed forest landscape", Ecology and Evolution., feb, 2017. Vol. 7(4), pp. 1068-1077. |
| Abstract: Although the importance of stream condition for leaf litter decomposition has been extensively studied, little is known about how processing rates change in response to altered riparian vegetation community composition. We investigated patterns of plant litter input and decomposition across 20 boreal headwater streams that varied in proportions of riparian deciduous and coniferous trees. We measured a suite of in-stream physical and chemical characteristics, as well as the amount and type of litter inputs from riparian vegetation, and related these to decomposition rates of native (alder, birch, and spruce) and introduced (lodgepole pine) litter species incubated in coarse- and fine-mesh bags. Total litter inputs ranged more than fivefold among sites and increased with the proportion of deciduous vegetation in the riparian zone. In line with differences in initial litter quality, mean decomposition rate was highest for alder, followed by birch, spruce, and lodgepole pine (12, 55, and 68% lower rates, respectively). Further, these rates were greater in coarse-mesh bags that allow colonization by macroinvertebrates. Variance in decomposition rate among sites for different species was best explained by different sets of environmental conditions, but litter-input composition (i.e., quality) was overall highly important. On average, native litter decomposed faster in sites with higher-quality litter input and (with the exception of spruce) higher concentrations of dissolved nutrients and open canopies. By contrast, lodgepole pine decomposed more rapidly in sites receiving lower-quality litter inputs. Birch litter decomposition rate in coarse-mesh bags was best predicted by the same environmental variables as in fine-mesh bags, with additional positive influences of macroinvertebrate species richness. Hence, to facilitate energy turnover in boreal headwaters, forest management with focus on conifer production should aim at increasing the presence of native deciduous trees along streams, as they promote conditions that favor higher decomposition rates of terrestrial plant litter. |
BibTeX:
@article{Lidman2017,
author = {Lidman, Johan and Jonsson, Micael and Burrows, Ryan M and Bundschuh, Mirco and Sponseller, Ryan A},
title = {Composition of riparian litter input regulates organic matter decomposition: Implications for headwater stream functioning in a managed forest landscape},
journal = {Ecology and Evolution},
year = {2017},
volume = {7},
number = {4},
pages = {1068--1077},
url = {http://doi.wiley.com/10.1002/ece3.2726},
doi = {10.1002/ece3.2726}
}
|
| Lidman F, Boily Å, Laudon H and Köhler SJ (2017), "From soil water to surface water-how the riparian zone controls element transport from a boreal forest to a stream", Biogeosciences., jun, 2017. Vol. 14(12), pp. 3001-3014. |
| Abstract: Boreal headwaters are often lined by strips of highly organic soils, which are the last terrestrial environment to leave an imprint on discharging groundwater before it enters a stream. Because these riparian soils are so different from the Podzol soils that dominate much of the boreal landscape, they are known to have a major impact on the biogeochemistry of important elements such as C, N, P and Fe and the transfer of these elements from terrestrial to aquatic ecosystems. For most elements, however, the role of the riparian zone has remained unclear, although it should be expected that the mobility of many elements is affected by changes in, for example, pH, redox potential and concentration of organic carbon as they are transported through the riparian zone. Therefore, soil water and groundwater was sampled at different depths along a 22μm hillslope transect in the Krycklan catchment in northern Sweden using soil lysimeters and analysed for a large number of major and trace elements (Al, As, B, Ba, Ca, Cd, Cl, Co, Cr, Cs, Cu, Fe, K, La, Li, Mg, Mn, Na, Ni, Pb, Rb, Se, Si, Sr, Th, Ti, U, V, Zn, Zr) and other parameters such as sulfate and total organic carbon (TOC). The results showed that the concentrations of most investigated elements increased substantially (up to 60 times) as the water flowed from the uphill mineral soils and into the riparian zone, largely as a result of higher TOC concentrations. The stream water concentrations of these elements were typically somewhat lower than in the riparian zone, but still considerably higher than in the uphill mineral soils, which suggests that riparian soils have a decisive impact on the water quality of boreal streams. The degree of enrichment in the riparian zone for different elements could be linked to the affinity for organic matter, indicating that the pattern with strongly elevated concentrations in riparian soils is typical for organophilic substances. One likely explanation is that the solubility of many organophilic elements increases as a result of the higher concentrations of TOC in the riparian zone. Elements with low or modest affinity for organic matter (e.g. Na, Cl, K, Mg and Ca) occurred in similar or lower concentrations in the riparian zone. Despite the elevated concentrations of many elements in riparian soil water and groundwater, no increase in the concentrations in biota could be observed (bilberry leaves and spruce shoots). |
BibTeX:
@article{Lidman2017a,
author = {Lidman, Fredrik and Boily, Åsa and Laudon, Hjalmar and Köhler, Stephan J},
title = {From soil water to surface water-how the riparian zone controls element transport from a boreal forest to a stream},
journal = {Biogeosciences},
year = {2017},
volume = {14},
number = {12},
pages = {3001--3014},
url = {https://www.biogeosciences.net/14/3001/2017/},
doi = {10.5194/bg-14-3001-2017}
}
|
| Lim H, Oren R, Linder S, From F, Nordin A, Fahlvik N, Lundmark T and Näsholm T (2017), "Annual climate variation modifies nitrogen induced carbon accumulation of Pinus sylvestris forests", Ecological Applications., sep, 2017. Vol. 27(6), pp. 1838-1851. |
| Abstract: We report results from long-term simulated external nitrogen (N) input experiments in three northern Pinus sylvestris forests, two of moderately high and one of moderately low productivity, assessing effects on annual net primary production (NPP) of woody mass and its interannual variation in response to variability in weather conditions. A sigmoidal response of wood NPP to external N inputs was observed in the both higher and lower productivity stands, reaching a maximum of ∼65% enhancement regardless of the native site productivity, saturating at an external N input of 4-5 g Ntextperiodcenteredm-2textperiodcenteredyr-1. The rate of increase in wood NPP and the N response efficiency (REN, increase in wood NPP per external N input) were maximized at an external N input of ∼3 g Ntextperiodcenteredm-2textperiodcenteredyr-1, regardless of site productivity. The maximum REN was greater in the higher productivity than the lower productivity stand (∼20 vs. ∼14 g C/g N). The N-induced enhancement of wood NPP and its REN were, however, markedly contingent on climatic variables. In both of the higher and lower productivity stands, wood NPP increased with growing season precipitation (P), but only up to ∼400 mm. The sensitivity of the response to P increased with increasing external N inputs. Increasing growing season temperature (T) somewhat increased the N-induced drought effect, whereas decreasing T reduced the drought effect. These responses of wood NPP infused a large temporal variation to REN, making the use of a fixed value unadvisable. Based on these results, we suggest that regional climate conditions and future climate scenarios should be considered when modeling carbon sequestration in response to N deposition in boreal P. sylvestris, and possibly other forests. |
BibTeX:
@article{Lim2017,
author = {Lim, Hyungwoo and Oren, Ram and Linder, Sune and From, Fredrik and Nordin, Annika and Fahlvik, Nils and Lundmark, Tomas and Näsholm, Torgny},
title = {Annual climate variation modifies nitrogen induced carbon accumulation of Pinus sylvestris forests},
journal = {Ecological Applications},
year = {2017},
volume = {27},
number = {6},
pages = {1838--1851},
url = {http://doi.wiley.com/10.1002/eap.1571},
doi = {10.1002/eap.1571}
}
|
| Lin D, Zhu J, Fu H, Xie Q and Zhang B (2017), "A TSVD-based method for forest height inversion from single-baseline polInSAR data", Applied Sciences (Switzerland)., apr, 2017. Vol. 7(5), pp. 435. |
| Abstract: The random volume over ground (RVoG) model associates vegetation vertical structure parameters with multiple complex interferometric coherence observables. In this paper, on the basis of the RVoG model, a truncated singular value decomposition (TSVD)-based method is proposed for forest height inversion from single-baseline polarimetric interferometric synthetic aperture radar (PolInSAR) data. In addition, in order to improve the applicability of TSVD for this issue, a new truncation method is proposed for TSVD. Differing from the traditional three-stage method, the TSVD-based inversion method estimates the pure volume coherence directly from the complex interferometric coherence, and estimates the forest height from the estimated pure volume coherence with a least-squares method. As a result, the TSVD-based method can adjust the contributions of the polarizations in the estimation of the model parameters and avoid the null ground-to-volume ratio assumption. The simulated experiments undertaken in this study confirmed that the TSVD-based method performs better than the three-stage method in forest height inversion. The TSVD-based method was also applied to E-SAR P-band data acquired over the Krycklan Catchment, Sweden, which is covered with mixed pine forest. The results showed that the TSVD-based method improves the root-mean-square error by 48.6% when compared to the three-stage method, which further validates the performance of the TSVD-based method. |
BibTeX:
@article{Lin2017,
author = {Lin, Dongfang and Zhu, Jianjun and Fu, Haiqiang and Xie, Qinghua and Zhang, Bing},
title = {A TSVD-based method for forest height inversion from single-baseline polInSAR data},
journal = {Applied Sciences (Switzerland)},
year = {2017},
volume = {7},
number = {5},
pages = {435},
url = {http://www.mdpi.com/2076-3417/7/5/435},
doi = {10.3390/app7050435}
}
|
| Liu WT and Xie X (2017), "Space Observation of Carbon Dioxide Partial Pressure at Ocean Surface", IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing., dec, 2017. Vol. 10(12), pp. 5472-5484. Institute of Electrical and Electronics Engineers. |
| Abstract: We have developed and validated a statistical model to estimate the partial pressure (or fugacity) of carbon dioxide at the sea surface from space-based observations of sea surface temperature, chlorophyll, and salinity. More than a quarter million in situ measurements coincident with satellite data were compiled. A portion of the data was randomly selected to train and validate the model. We have produced and made accessible nine years (2002-2011) of the partial pressure at 0.5° and daily resolutions over the global oceans. The outputs are found to be sensitive to variability from intraseasonal to interannual time scales and from the equatorial to high-latitude oceans. They can capture known phenomena, such as, annual spring blooms at high latitudes, interannual episodes of El Niño, and westward propagation of tropical instability waves. The feasibility of using a single algorithm to map the partial pressure over global oceans for all seasons is demonstrated. The result is important for characterizing the sources and sinks of atmospheric greenhouse gas and ocean biogeochemistry. We discuss the significance of the Advanced Scanning Microwave Radiometer in the consistent measurement of sea surface temperature, which is the main driver of ocean carbon dioxide change, in cold and warm waters, under clear and cloudy sky. The continuous and consistent coverage of the partial pressure over global ocean using space-based data is discussed. |
BibTeX:
@article{Liu2017,
author = {Liu, W. Timothy and Xie, Xiaosu},
title = {Space Observation of Carbon Dioxide Partial Pressure at Ocean Surface},
journal = {IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing},
publisher = {Institute of Electrical and Electronics Engineers},
year = {2017},
volume = {10},
number = {12},
pages = {5472--5484},
doi = {10.1109/JSTARS.2017.2766138}
}
|
| Liu Y, Gruber N and Brunner D (2017), "Spatiotemporal patterns of the fossil-fuel CO2 signal in central Europe: Results from a high-resolution atmospheric transport model", Atmospheric Chemistry and Physics., nov, 2017. Vol. 17(22), pp. 14145-14169. |
| Abstract: The emission of CO2 from the burning of fossil fuel is a prime determinant of variations in atmospheric CO2. Here, we simulate this fossil-fuel signal together with the natural and background components with a regional high-resolution atmospheric transport model for central and southern Europe considering separately the emissions from different sectors and countries on the basis of emission inventories and hourly emission time functions. The simulated variations in atmospheric CO2 agree very well with observation-based estimates, although the observed variance is slightly underestimated, particularly for the fossil-fuel component. Despite relatively rapid atmospheric mixing, the simulated fossil-fuel signal reveals distinct annual mean structures deep into the troposphere, reflecting the spatially dense aggregation of most emissions. The fossil-fuel signal accounts for more than half of the total (fossil fuel + biospheric + background) temporal variations in atmospheric CO2 in most areas of northern and western central Europe, with the largest variations occurring on diurnal timescales owing to the combination of diurnal variations in emissions and atmospheric mixing and transport out of the surface layer. The covariance of the fossil-fuel emissions and atmospheric transport on diurnal timescales leads to a diurnal fossil-fuel rectifier effect of up to 9 ppm compared to a case with time-constant emissions. The spatial pattern of CO2 from the different sectors largely reflects the distribution and relative magnitude of the corresponding emissions, with power plant emissions leaving the most distinguished mark. An exception is southern and western Europe, where the emissions from the transportation sector dominate the fossil-fuel signal. Most of the fossil-fuel CO2 remains within the country responsible for the emission, although in smaller countries up to 80 % of the fossil-fuel signal can come from abroad. A fossil-fuel emission reduction of 30 % is clearly detectable for a surface-based observing system for atmospheric CO2, while it is beyond the edge of detectability for the current generation of satellites with the exception of a few hotspot sites. Changes in variability in atmospheric CO2 might open an additional door for the monitoring and verification of changes in fossil-fuel emissions, primarily for surface-based systems. |
BibTeX:
@article{Liu2017a,
author = {Liu, Yu and Gruber, Nicolas and Brunner, Dominik},
title = {Spatiotemporal patterns of the fossil-fuel CO2 signal in central Europe: Results from a high-resolution atmospheric transport model},
journal = {Atmospheric Chemistry and Physics},
year = {2017},
volume = {17},
number = {22},
pages = {14145--14169},
url = {https://www.atmos-chem-phys.net/17/14145/2017/},
doi = {10.5194/acp-17-14145-2017}
}
|
| Lognoul M, Theodorakopoulos N, Hiel MP, Regaert D, Broux F, Heinesch B, Bodson B, Vandenbol M and Aubinet M (2017), "Impact of tillage on greenhouse gas emissions by an agricultural crop and dynamics of N2O fluxes: Insights from automated closed chamber measurements", Soil and Tillage Research., apr, 2017. Vol. 167, pp. 80-89. |
| Abstract: Our experiment aimed at studying the impact of long term tillage treatments – reduced tillage (RT) and conventional tillage (CT), on CO2 and N2O emissions by soil and at describing the dynamics of N2O fluxes. Gas measurements were performed from June to October 2015 in a Belgian maize crop, with homemade automated closed chambers, allowing continuous measurement at a high temporal resolution. After 7 years of treatment, CO2 and N2O average emissions were significantly larger in the RT parcel than in the CT parcel. This observation was attributed to the effect of tillage on the distribution of crop residues within the soil profile, leading to higher soil organic C and total N contents and a greater microbial biomass in the upper layer in RT. A single N2O emission peak triggered by a sudden increase of water-filled pore space (WFPS) was observed in the beginning of the measuring campaign. The absence of large emission afterwards was most likely due to a decreasing availability of N as crop grew. N2O background fluxes showed to be significantly correlated to CO2 fluxes but not to WFPS, while the influence of soil temperature remained unclear. Our results question the suitability of reduced tillage as a “climate-smart†practice and suggest that more experiments be conducted on conservation practices and their potent negative effect on environment. |
BibTeX:
@article{Lognoul2017,
author = {Lognoul, Margaux and Theodorakopoulos, Nicolas and Hiel, Marie Pierre and Regaert, Donat and Broux, François and Heinesch, Bernard and Bodson, Bernard and Vandenbol, Micheline and Aubinet, Marc},
title = {Impact of tillage on greenhouse gas emissions by an agricultural crop and dynamics of N2O fluxes: Insights from automated closed chamber measurements},
journal = {Soil and Tillage Research},
year = {2017},
volume = {167},
pages = {80--89},
url = {http://linkinghub.elsevier.com/retrieve/pii/S0167198716302471},
doi = {10.1016/j.still.2016.11.008}
}
|
| Mahecha M, Gans F, Sippel S, Donges J, Kaminski T, Metzger S, Migliavacca M, Papale D, Rammig A and Zscheischler J (2017), "Detecting impacts of extreme events with ecological in situ monitoring networks", Biogeosciences., sep, 2017. Vol. 14(18), pp. 4255-4277. |
| Abstract: Extreme hydrometeorological conditions typically impact ecophysiological processes on land. Satellite-based observations of the terrestrial biosphere provide an important reference for detecting and describing the spatiotemporal development of such events. However, in-depth investigations of ecological processes during extreme events require additional in situ observations. The question is whether the density of existing ecological in situ networks is sufficient for analysing the impact of extreme events, and what are expected event detection rates of ecological in situ networks of a given size. To assess these issues, we build a baseline of extreme reductions in the fraction of absorbed photosynthetically active radiation (FAPAR), identified by a new event detection method tailored to identify extremes of regional relevance. We then investigate the event detection success rates of hypothetical networks of varying sizes. Our results show that large extremes can be reliably detected with relatively small networks, but also reveal a linear decay of detection probabilities towards smaller extreme events in log-log space. For instance, networks with ˜100 randomly placed sites in Europe yield a ≥90% chance of detecting the eight largest (typically very large) extreme events; but only a ≥50% chance of capturing the 39 largest events. These findings are consistent with probability-theoretic considerations, but the slopes of the decay rates deviate due to temporal autocorrelation and the exact implementation of the extreme event detection algorithm. Using the examples of AmeriFlux and NEON, we then investigate to what degree ecological in situ networks can capture extreme events of a given size. Consistent with our theoretical considerations, we find that today's systematically designed networks (i.e. NEON) reliably detect the largest extremes, but that the extreme event detection rates are not higher than would be achieved by randomly designed networks. Spatio-temporal expansions of ecological in situ monitoring networks should carefully consider the size distribution characteristics of extreme events if the aim is also to monitor the impacts of such events in the terrestrial biosphere. |
BibTeX:
@article{Mahecha2017,
author = {Mahecha, Miguel and Gans, Fabian and Sippel, Sebastian and Donges, Jonathan and Kaminski, Thomas and Metzger, Stefan and Migliavacca, Mirco and Papale, Dario and Rammig, Anja and Zscheischler, Jakob},
title = {Detecting impacts of extreme events with ecological in situ monitoring networks},
journal = {Biogeosciences},
year = {2017},
volume = {14},
number = {18},
pages = {4255--4277},
url = {https://www.biogeosciences.net/14/4255/2017/},
doi = {10.5194/bg-14-4255-2017}
}
|
| Manno C, Bednaršek N, Tarling GA, Peck VL, Comeau S, Adhikari D, Bakker DC, Bauerfeind E, Bergan AJ, Berning MI, Buitenhuis E, Burridge AK, Chierici M, Flöter S, Fransson A, Gardner J, Howes EL, Keul N, Kimoto K, Kohnert P, Lawson GL, Lischka S, Maas A, Mekkes L, Oakes RL, Pebody C, Peijnenburg KT, Seifert M, Skinner J, Thibodeau PS, Wall-Palmer D and Ziveri P (2017), "Shelled pteropods in peril: Assessing vulnerability in a high CO2 ocean". jun, 2017. |
| Abstract: The impact of anthropogenic ocean acidification (OA) on marine ecosystems is a vital concern facing marine scientists and managers of ocean resources. Euthecosomatous pteropods (holoplanktonic gastropods) represent an excellent sentinel for indicating exposure to anthropogenic OA because of the sensitivity of their aragonite shells to the OA conditions less favorable for calcification. However, an integration of observations, experiments and modelling efforts is needed to make accurate predictions of how these organisms will respond to future changes to their environment. Our understanding of the underlying organismal biology and life history is far from complete and must be improved if we are to comprehend fully the responses of these organisms to the multitude of stressors in their environment beyond OA. This review considers the present state of research and understanding of euthecosomatous pteropod biology and ecology of these organisms and considers promising new laboratory methods, advances in instrumentation (such as molecular, trace elements, stable isotopes, palaeobiology alongside autonomous sampling platforms, CT scanning and high-quality video recording) and novel field-based approaches (i.e. studies of upwelling and CO2 vent regions) that may allow us to improve our predictive capacity of their vulnerability and/or resilience. In addition to playing a critical ecological and biogeochemical role, pteropods can offer a significant value as an early-indicator of anthropogenic OA. This role as a sentinel species should be developed further to consolidate their potential use within marine environmental management policy making. |
BibTeX:
@misc{Manno2017,
author = {Manno, Clara and Bednaršek, Nina and Tarling, Geraint A. and Peck, Vicky L. and Comeau, Steeve and Adhikari, Deepak and Bakker, Dorothee C.E. and Bauerfeind, Eduard and Bergan, Alexander J. and Berning, Maria I. and Buitenhuis, Erik and Burridge, Alice K. and Chierici, Melissa and Flöter, Sebastian and Fransson, Agneta and Gardner, Jessie and Howes, Ella L. and Keul, Nina and Kimoto, Katsunori and Kohnert, Peter and Lawson, Gareth L. and Lischka, Silke and Maas, Amy and Mekkes, Lisette and Oakes, Rosie L. and Pebody, Corinne and Peijnenburg, Katja T.C.A. and Seifert, Miriam and Skinner, Jennifer and Thibodeau, Patricia S. and Wall-Palmer, Deborah and Ziveri, Patrizia},
title = {Shelled pteropods in peril: Assessing vulnerability in a high CO2 ocean},
booktitle = {Earth-Science Reviews},
publisher = {Elsevier B.V.},
year = {2017},
volume = {169},
pages = {132--145},
doi = {10.1016/j.earscirev.2017.04.005}
}
|
| Marková I, Janouš D and Nezval O (2017), "Temperature conditions at the mountain study site of Bílý KÅ™íž (the Beskids Mts.) during the past 20 years", Beskydy. Vol. 10(1-2), pp. 113-122. |
| Abstract: Global climate change (including temperature changes) had already observable effects on the environment and humanity. Air temperature characteristics have been observed at the mountain study site of Bílý KÅ™íž (the Beskids Mts., Czech Republic) since 1989. This paper presents an analysis of long-term (1997–2016) air temperature conditions at this study. Comparison is made of selected long-term mean air temperature characteristics with mean air temperature characteristics for the period 1997–2016. The results show slightly increasing air temperature, as indicated not only by values for mean annual air temperature but also by changes in number of extreme days (summer, tropical, ice, etc.) and occurrence of hot period. Moreover, the length of the growth season has increase slightly. |
BibTeX:
@article{Markova2017,
author = {Marková, Irena and Janouš, Dalibor and Nezval, OndÅ™ej},
title = {Temperature conditions at the mountain study site of Bílý KÅ™íž (the Beskids Mts.) during the past 20 years},
journal = {Beskydy},
year = {2017},
volume = {10},
number = {1-2},
pages = {113--122},
url = {https://beskydy.mendelu.cz/10/1/0113/},
doi = {10.11118/beskyd201710010113}
}
|
| McKinley GA, Fay AR, Lovenduski NS and Pilcher DJ (2017), "Natural Variability and Anthropogenic Trends in the Ocean Carbon Sink", Annual Review of Marine Science., jan, 2017. Vol. 9(1), pp. 125-150. Annual Reviews Inc.. |
| Abstract: Since preindustrial times, the ocean has removed from the atmosphere 41% of the carbon emitted by human industrial activities. Despite significant uncertainties, the balance of evidence indicates that the globally integrated rate of ocean carbon uptake is increasing in response to increasing atmospheric CO2 concentrations. The El Niño-Southern Oscillation in the equatorial Pacific dominates interannual variability of the globally integrated sink. Modes of climate variability in high latitudes are correlated with variability in regional carbon sinks, but mechanistic understanding is incomplete. Regional sink variability, combined with sparse sampling, means that the growing oceanic sink cannot yet be directly detected from available surface data. Accurate and precise shipboard observations need to be continued and increasingly complemented with autonomous observations. These data, together with a variety of mechanistic and diagnostic models, are needed for better understanding, long-term monitoring, and future projections of this critical climate regulation service. |
BibTeX:
@article{McKinley2017,
author = {McKinley, Galen A. and Fay, Amanda R. and Lovenduski, Nicole S. and Pilcher, Darren J.},
title = {Natural Variability and Anthropogenic Trends in the Ocean Carbon Sink},
journal = {Annual Review of Marine Science},
publisher = {Annual Reviews Inc.},
year = {2017},
volume = {9},
number = {1},
pages = {125--150},
url = {http://www.annualreviews.org/doi/10.1146/annurev-marine-010816-060529},
doi = {10.1146/annurev-marine-010816-060529}
}
|
| Moffat AM and Brümmer C (2017), "Improved parameterization of the commonly used exponential equation for calculating soil-atmosphere exchange fluxes from closed-chamber measurements", Agricultural and Forest Meteorology., jun, 2017. Vol. 240-241, pp. 18-25. |
| Abstract: The concentration change in a closed chamber derived from Fick's law for a steady flux leads to a differential equation which describes an exponential curve of limited growth. Here we introduce and compare an alternative parameterization with those commonly used in the chamber flux community when investigating soil-atmosphere exchange of N2O, CH4, or CO2 using classical gas chromatography systems, infrared gas analyzers, or novel laser absorption spectrometers. This new parameterization has the advantages that the parameters are mathematically less dependent leading to a more stable regression and that all parameters are physically meaningful with one of them being the main quantity of interest, i.e. the initial flux at chamber closure. |
BibTeX:
@article{Moffat2017,
author = {Moffat, Antje M and Brümmer, Christian},
title = {Improved parameterization of the commonly used exponential equation for calculating soil-atmosphere exchange fluxes from closed-chamber measurements},
journal = {Agricultural and Forest Meteorology},
year = {2017},
volume = {240-241},
pages = {18--25},
url = {http://linkinghub.elsevier.com/retrieve/pii/S0168192317300850},
doi = {10.1016/j.agrformet.2017.03.005}
}
|
| Mondav R, McCalley CK, Hodgkins SB, Frolking S, Saleska SR, Rich VI, Chanton JP and Crill PM (2017), "Microbial network, phylogenetic diversity and community membership in the active layer across a permafrost thaw gradient", Environmental Microbiology., aug, 2017. Vol. 19(8), pp. 3201-3218. |
| Abstract: Biogenic production and release of methane (CH4) from thawing permafrost has the potential to be a strong source of radiative forcing. We investigated changes in the active layer microbial community of three sites representative of distinct permafrost thaw stages at a palsa mire in northern Sweden. The palsa site (intact permafrost and low radiative forcing signature) had a phylogenetically clustered community dominated by Acidobacteria and Proteobacteria. The bog (thawing permafrost and low radiative forcing signature) had lower alpha diversity and midrange phylogenetic clustering, characteristic of ecosystem disturbance affecting habitat filtering. Hydrogenotrophic methanogens and Acidobacteria dominated the bog shifting from palsa-like to fen-like at the waterline. The fen (no underlying permafrost, high radiative forcing signature) had the highest alpha, beta and phylogenetic diversity, was dominated by Proteobacteria and Euryarchaeota and was significantly enriched in methanogens. The Mire microbial network was modular with module cores consisting of clusters of Acidobacteria, Euryarchaeota or Xanthomonodales. Loss of underlying permafrost with associated hydrological shifts correlated to changes in microbial composition, alpha, beta and phylogenetic diversity associated with a higher radiative forcing signature. These results support the complex role of microbial interactions in mediating carbon budget changes and climate feedback in response to climate forcing. |
BibTeX:
@article{Mondav2017,
author = {Mondav, Rhiannon and McCalley, Carmody K and Hodgkins, Suzanne B and Frolking, Steve and Saleska, Scott R and Rich, Virginia I and Chanton, Jeff P and Crill, Patrick M},
title = {Microbial network, phylogenetic diversity and community membership in the active layer across a permafrost thaw gradient},
journal = {Environmental Microbiology},
year = {2017},
volume = {19},
number = {8},
pages = {3201--3218},
url = {http://doi.wiley.com/10.1111/1462-2920.13809},
doi = {10.1111/1462-2920.13809}
}
|
| Montzka C, Bogena HR, Zreda M, Monerris A, Morrison R, Muddu S and Vereecken H (2017), "Validation of spaceborne and modelled surface soil moisture products with Cosmic-Ray Neutron Probes", Remote Sensing., jan, 2017. Vol. 9(2), pp. 103. |
| Abstract: The scale difference between point in situ soil moisture measurements and low resolution satellite products limits the quality of any validation efforts in heterogeneous regions. Cosmic Ray Neutron Probes (CRNP) could be an option to fill the scale gap between both systems, as they provide area-average soil moisture within a 150-250 m radius footprint. In this study, we evaluate differences and similarities between CRNP observations, and surface soil moisture products from the Advanced Microwave Scanning Radiometer 2 (AMSR2), the METOP-A/B Advanced Scatterometer (ASCAT), the Soil Moisture Active and Passive (SMAP), the Soil Moisture and Ocean Salinity (SMOS), as well as simulations from the Global Land Data Assimilation System Version 2 (GLDAS2). Six CRNPs located on five continents have been selected as test sites: the Rur catchment in Germany, the COSMOS sites in Arizona and California (USA), and Kenya, one CosmOz site in New SouthWales (Australia), and a site in Karnataka (India). Standard validation scores as well as the Triple Collocation (TC) method identified SMAP to provide a high accuracy soil moisture product with low noise or uncertainties as compared to CRNPs. The potential of CRNPs for satellite soil moisture validation has been proven; however, biomass correction methods should be implemented to improve its application in regions with large vegetation dynamics. |
BibTeX:
@article{Montzka2017,
author = {Montzka, Carsten and Bogena, Heye R and Zreda, Marek and Monerris, Alessandra and Morrison, Ross and Muddu, Sekhar and Vereecken, Harry},
title = {Validation of spaceborne and modelled surface soil moisture products with Cosmic-Ray Neutron Probes},
journal = {Remote Sensing},
year = {2017},
volume = {9},
number = {2},
pages = {103},
url = {http://www.mdpi.com/2072-4292/9/2/103},
doi = {10.3390/rs9020103}
}
|
| Mozaffar A, Schoon N, Digrado A, Bachy A, Delaplace P, du Jardin P, Fauconnier ML, Aubinet M, Heinesch B and Amelynck C (2017), "Methanol emissions from maize: Ontogenetic dependence to varying light conditions and guttation as an additional factor constraining the flux", Atmospheric Environment., mar, 2017. Vol. 152, pp. 405-417. |
| Abstract: Because of its high abundance and long lifetime compared to other volatile organic compounds in the atmosphere, methanol (CH3OH) plays an important role in atmospheric chemistry. Even though agricultural crops are believed to be a large source of methanol, emission inventories from those crop ecosystems are still scarce and little information is available concerning the driving mechanisms for methanol production and emission at different developmental stages of the plants/leaves. This study focuses on methanol emissions from Zea mays L. (maize), which is vastly cultivated throughout the world. Flux measurements have been performed on young plants, almost fully grown leaves and fully grown leaves, enclosed in dynamic flow-through enclosures in a temperature and light-controlled environmental chamber. Strong differences in the response of methanol emissions to variations in PPFD (Photosynthetic Photon Flux Density) were noticed between the young plants, almost fully grown and fully grown leaves. Moreover, young maize plants showed strong emission peaks following light/dark transitions, for which guttation can be put forward as a hypothetical pathway. Young plants' average daily methanol fluxes exceeded by a factor of 17 those of almost fully grown and fully grown leaves when expressed per leaf area. Absolute flux values were found to be smaller than those reported in the literature, but in fair agreement with recent ecosystem scale flux measurements above a maize field of the same variety as used in this study. The flux measurements in the current study were used to evaluate the dynamic biogenic volatile organic compound (BVOC) emission model of Niinemets and Reichstein. The modelled and measured fluxes from almost fully grown leaves were found to agree best when a temperature and light dependent methanol production function was applied. However, this production function turned out not to be suitable for modelling the observed emissions from the young plants, indicating that production must be influenced by (an) other parameter(s). This study clearly shows that methanol emission from maize is complex, especially for young plants. Additional studies at different developmental stages of other crop species will be required in order to develop accurate methanol emission algorithms for agricultural crops. |
BibTeX:
@article{Mozaffar2017,
author = {Mozaffar, A and Schoon, N and Digrado, A and Bachy, A and Delaplace, P and du Jardin, P and Fauconnier, M L and Aubinet, M and Heinesch, B and Amelynck, C},
title = {Methanol emissions from maize: Ontogenetic dependence to varying light conditions and guttation as an additional factor constraining the flux},
journal = {Atmospheric Environment},
year = {2017},
volume = {152},
pages = {405--417},
url = {http://linkinghub.elsevier.com/retrieve/pii/S1352231016310172},
doi = {10.1016/j.atmosenv.2016.12.041}
}
|
| Musavi T, Migliavacca M, Reichstein M, Kattge J, Wirth C, Black TA, Janssens I, Knohl A, Loustau D, Roupsard O, Varlagin A, Rambal S, Cescatti A, Gianelle D, Kondo H, Tamrakar R and Mahecha MD (2017), "Stand age and species richness dampen interannual variation of ecosystem-level photosynthetic capacity", Nature Ecology and Evolution., jan, 2017. Vol. 1(2), pp. 48. |
| Abstract: The total uptake of carbon dioxide by ecosystems via photosynthesis (gross primary productivity, GPP) is the largest flux in the global carbon cycle. A key ecosystem functional property determining GPP is the photosynthetic capacity at light saturation (GPP sat), and its interannual variability (IAV) is propagated to the net land-atmosphere exchange of CO 2. Given the importance of understanding the IAV in CO 2 fluxes for improving the predictability of the global carbon cycle, we have tested a range of alternative hypotheses to identify potential drivers of the magnitude of IAV in GPP sat in forest ecosystems. Our results show that while the IAV in GPP sat within sites is closely related to air temperature and soil water availability fluctuations, the magnitude of IAV in GPP sat is related to stand age and biodiversity (R 2 = 0.55, P 0.0001). We find that the IAV of GPP sat is greatly reduced in older and more diverse forests, and is higher in younger forests with few dominant species. Older and more diverse forests seem to dampen the effect of climate variability on the carbon cycle irrespective of forest type. Preserving old forests and their diversity would therefore be beneficial in reducing the effect of climate variability on Earth's forest ecosystems. |
BibTeX:
@article{Musavi2017,
author = {Musavi, Talie and Migliavacca, Mirco and Reichstein, Markus and Kattge, Jens and Wirth, Christian and Black, T Andrew and Janssens, Ivan and Knohl, Alexander and Loustau, Denis and Roupsard, Olivier and Varlagin, Andrej and Rambal, Serge and Cescatti, Alessandro and Gianelle, Damiano and Kondo, Hiroaki and Tamrakar, Rijan and Mahecha, Miguel D},
title = {Stand age and species richness dampen interannual variation of ecosystem-level photosynthetic capacity},
journal = {Nature Ecology and Evolution},
year = {2017},
volume = {1},
number = {2},
pages = {48},
url = {http://www.nature.com/articles/s41559-016-0048},
doi = {10.1038/s41559-016-0048}
}
|
| Napoly A, Boone A, Samuelsson P, Gollvik S, Martin E, Seferian R, Carrer D, Decharme B and Jarlan L (2017), "The interactions between soil-biosphere-atmosphere (ISBA) land surface model multi-energy balance (MEB) option in SURFEXv8 - Part 2: Introduction of a litter formulation and model evaluation for local-scale forest sites", Geoscientific Model Development., apr, 2017. Vol. 10(4), pp. 1621-1644. |
| Abstract: Land surface models (LSMs) need to balance a complicated trade-off between computational cost and complexity in order to adequately represent the exchanges of energy, water and matter with the atmosphere and the ocean. Some current generation LSMs use a simplified or composite canopy approach that generates recurrent errors in simulated soil temperature and turbulent fluxes. In response to these issues, a new version of the interactions between soil-biosphere-atmosphere (ISBA) land surface model has recently been developed that explicitly solves the transfer of energy and water from the upper canopy and the forest floor, which is characterized as a litter layer. The multi-energy balance (MEB) version of ISBA is first evaluated for three well-instrumented contrasting local-scale sites, and sensitivity tests are performed to explore the behavior of new model parameters. Second, ISBA-MEB is benchmarked against observations from 42 forested sites from the global micro-meteorological network (FLUXNET) for multiple annual cycles. It is shown that ISBA-MEB outperforms the composite version of ISBA in improving the representation of soil temperature, ground, sensible and, to a lesser extent, latent heat fluxes. Both versions of ISBA give comparable results in terms of simulated latent heat flux because of the similar formulations of the water uptake and the stomatal resistance. However, MEB produces a better agreement with the observations of sensible heat flux than the previous version of ISBA for 87.5Ä€% of the simulated years across the 42 forested FLUXNET sites. Most of this improvement arises owing to the improved simulation of the ground conduction flux, which is greatly improved using MEB, especially owing to the forest litter parameterization. It is also shown that certain processes are also modeled more realistically (such as the partitioning of evapotranspiration into transpiration and ground evaporation), even if certain statistical performances are neutral. The analyses demonstrate that the shading effect of the vegetation, the explicit treatment of turbulent transfer for the canopy and ground, and the insulating thermal and hydrological effects of the forest floor litter turn out to be essential for simulating the exchange of energy, water and matter across a large range of forest types and climates. |
BibTeX:
@article{Napoly2017,
author = {Napoly, Adrien and Boone, Aaron and Samuelsson, Patrick and Gollvik, Stefan and Martin, Eric and Seferian, Roland and Carrer, Dominique and Decharme, Bertrand and Jarlan, Lionel},
title = {The interactions between soil-biosphere-atmosphere (ISBA) land surface model multi-energy balance (MEB) option in SURFEXv8 - Part 2: Introduction of a litter formulation and model evaluation for local-scale forest sites},
journal = {Geoscientific Model Development},
year = {2017},
volume = {10},
number = {4},
pages = {1621--1644},
url = {https://www.geosci-model-dev.net/10/1621/2017/},
doi = {10.5194/gmd-10-1621-2017}
}
|
| Nezval O and Pavelka M (2017), "Microclimate changes in a spruce stand and meadow ecosystem during a solar eclipse in the Czech Republic", Weather., mar, 2017. Vol. 72(3), pp. 67-72. |
| Abstract: The objective of this article is to verify the effects of a sudden, short-term change in radiation conditions on microclimatic characteristics within differing ecosystems (forest and meadow) during a partial solar eclipse in spring 2015. During the phenomenon, changes were detected in all measured parameters: global radiation, short-wave radiation, air temperature, relative humidity, and wind speed and direction. It can generally be stated that changes in the meadow and at the free-standing climatological station were more considerable than were those in the enclosed forest stand, where the microclimate was more stable. It can be further stated that even a partial solar eclipse has a substantial effect on microclimatic characteristics in various ecosystem types. |
BibTeX:
@article{Nezval2017,
author = {Nezval, Ondřej and Pavelka, Marian},
title = {Microclimate changes in a spruce stand and meadow ecosystem during a solar eclipse in the Czech Republic},
journal = {Weather},
year = {2017},
volume = {72},
number = {3},
pages = {67--72},
url = {http://doi.wiley.com/10.1002/wea.2802},
doi = {10.1002/wea.2802}
}
|
| Nguyen VX, Guerra Torres CP, Yadav S, Pavelka M and Marek MV (2017), "Wind characteristics of CzeCOS's ecosystem station Bílý KÅ™íž", Beskydy. Vol. 10(1-2), pp. 33-40. |
| Abstract: Eddy-covariance is a direct and accurate method to measure exchanges of greenhouse gases and energy between ecosystems and the atmosphere under good turbulent mixing conditions. Calm conditions can affect the accuracy of the eddy-covariance measurements by potential gas buildup below the measurement height. This study characterizes wind patterns and calm periods at Bílý KÅ™íž Ecosystem Research Station, using four-year (2010-2013) wind data measured on an eddy-covariance tower at the site, located in Beskids Mountains, Czech Republic. The site is covered by young, dense Norway spruce forest on a 12.5° slope facing South. The results show that the prevailing wind direction was from S to SW direction (55 % frequency of occurrence), and to a much lesser extent from N, NE and NW but including the strongest winds above 12 m s -1 , possibly during gale or storm events. Calm condition (u 1 m s -1 ) accounted for 34 % of year time. Summer and Spring were the calmest seasons. Occurrence frequencies of calm conditions for the six-month periods from May to October (plant growing season) were higher than those for the remaining parts of the year (on average 39 % vs 28 % respectively). One should be aware of the calm periods in May-October when processing eddy-covariance data, since it is the time period of most contribution of forest ecosystem as a sink of CO 2 . |
BibTeX:
@article{Nguyen2017,
author = {Nguyen, Vinh Xuan and Guerra Torres, Carlos P and Yadav, Shilpi and Pavelka, Marian and Marek, Michal V},
title = {Wind characteristics of CzeCOS's ecosystem station Bílý KÅ™íž},
journal = {Beskydy},
year = {2017},
volume = {10},
number = {1-2},
pages = {33--40},
url = {https://beskydy.mendelu.cz/10/1/0033/},
doi = {10.11118/beskyd201710010033}
}
|
| Nicolini G, Fratini G, Avilov V, Kurbatova JA, Vasenev I and Valentini R (2017), "Performance of eddy-covariance measurements in fetch-limited applications", Theoretical and Applied Climatology., feb, 2017. Vol. 127(3-4), pp. 829-840. |
| Abstract: When estimating gas fluxes by means of the eddy covariance (EC) technique, measurement representativeness is ensured by the availability of an adequate fetch. In applications over spatially limited fetches, it is possible to constrain the sensed source area by shortening the measurement height, but this comes at the cost of potentially violating some fundamental assumptions of the method or introducing significant measurement errors. In addition, reliability of footprint models when applied to measurements close to the surface is still debatable. In this manuscript, we investigate whether it is possible to use the EC method for determining the surface-atmosphere exchange over spatially limited ecosystems on horizontal scales of about 100 m. The objectives are (1) to determine the adequate positioning of the instruments in the atmospheric boundary layer, (2) to assess the quality of measurement in search of potential biases, (3) establish whether the source area is sufficiently constrained, (4) and evaluate the performances of some popular footprint models in such conditions. Most notably, we carried out an experiment to assess the footprint of two low EC systems and to evaluate the prediction of the selected footprint models against empirical data. Our findings show that (1) depending on the properties of the underlying exchange surface, EC measurements as low as 0.8 m above the canopies' displacement height are still feasible; (2) spectral losses as high as 34 ± 6 % can occur (dominated by instruments displacement), but can still be quantified and largely corrected; and (3) the measurement source area is sufficiently constrained during daytime conditions and two footprint models predict it accurately. We conclude that it is possible to apply EC in fetch-limited applications, at least when surface properties of adjacent land covers do not differ too drastically. |
BibTeX:
@article{Nicolini2017,
author = {Nicolini, G and Fratini, G and Avilov, V and Kurbatova, J A and Vasenev, I and Valentini, R},
title = {Performance of eddy-covariance measurements in fetch-limited applications},
journal = {Theoretical and Applied Climatology},
year = {2017},
volume = {127},
number = {3-4},
pages = {829--840},
url = {http://link.springer.com/10.1007/s00704-015-1673-x},
doi = {10.1007/s00704-015-1673-x}
}
|
| Nijp JJ, Metselaar K, Limpens J, Teutschbein C, Peichl M, Nilsson MB, Berendse F and van der Zee SE (2017), "Including hydrological self-regulating processes in peatland models: Effects on peatmoss drought projections", Science of the Total Environment., feb, 2017. Vol. 580, pp. 1389-1400. Elsevier B.V.. |
| Abstract: The water content of the topsoil is one of the key factors controlling biogeochemical processes, greenhouse gas emissions and biosphere – atmosphere interactions in many ecosystems, particularly in northern peatlands. In these wetland ecosystems, the water content of the photosynthetic active peatmoss layer is crucial for ecosystem functioning and carbon sequestration, and is sensitive to future shifts in rainfall and drought characteristics. Current peatland models differ in the degree in which hydrological feedbacks are included, but how this affects peatmoss drought projections is unknown. The aim of this paper was to systematically test whether the level of hydrological detail in models could bias projections of water content and drought stress for peatmoss in northern peatlands using downscaled projections for rainfall and potential evapotranspiration in the current (1991–2020) and future climate (2061–2090). We considered four model variants that either include or exclude moss (rain)water storage and peat volume change, as these are two central processes in the hydrological self-regulation of peatmoss carpets. Model performance was validated using field data of a peatland in northern Sweden. Including moss water storage as well as peat volume change resulted in a significant improvement of model performance, despite the extra parameters added. The best performance was achieved if both processes were included. Including moss water storage and peat volume change consistently reduced projected peatmoss drought frequency with textgreater 50%, relative to the model excluding both processes. Projected peatmoss drought frequency in the growing season was 17% smaller under future climate than current climate, but was unaffected by including the hydrological self-regulating processes. Our results suggest that ignoring these two fine-scale processes important in hydrological self-regulation of northern peatlands will have large consequences for projected climate change impact on ecosystem processes related to topsoil water content, such as greenhouse gas emissions. |
BibTeX:
@article{Nijp2017,
author = {Nijp, Jelmer J. and Metselaar, Klaas and Limpens, Juul and Teutschbein, Claudia and Peichl, Matthias and Nilsson, Mats B. and Berendse, Frank and van der Zee, Sjoerd E.A.T.M.},
title = {Including hydrological self-regulating processes in peatland models: Effects on peatmoss drought projections},
journal = {Science of the Total Environment},
publisher = {Elsevier B.V.},
year = {2017},
volume = {580},
pages = {1389--1400},
doi = {10.1016/j.scitotenv.2016.12.104}
}
|
| Normand AE, Smith AN, Clark MW, Long JR and Reddy KR (2017), "Chemical Composition of Soil Organic Matter in a Subarctic Peatland: Influence of Shifting Vegetation Communities", Soil Science Society of America Journal. Vol. 81(1), pp. 41-49. |
| Abstract: Climate change in the subarctic region has increased the rate of inundation of peatlands due to increased temperatures, precipitation, and permafrost thaw. Increased inundation may result in vegetation community shifts, as documented in a subarctic mire near Abisko, Sweden. The wet fen communities have established in former sphagnum areas, and sphagnum colonized in degraded palsa hummocks. At Stordalen mire, we studied the influence of vegetation community on chemical composition of peat soil organic matter (SOM). Vegetation and soil samples were obtained along a hydrologic gradient with representative communities: palsa, sphagnum, and fen. Soil organic matter chemical composition indicated shifts in vegetative communities. Total N and N isotope signatures in fen soils showed characteristics of sphagnum and palsa communities at 6-cm depth, and sphagnum soil profile signatures shifted from sphagnum to palsa properties at a 20-cm depth. Soil chemical composition measured by Fourier Transform Infrared (FTIR) spectroscopy and 13C Nuclear Magnetic Resonance (NMR) spectroscopy showed increasing recalcitrant C (alkyl and aromatic) in palsa soil. Sphagnum soil profiles sustained labile organic C (O-Alkyl) until 15 cm then shifted to humified soil, and fen soil profiles showed areas of sphagnum and palsa signatures. Furthermore, the strong relationship between functional group C (O-Alkyl and alkyl) and total N demonstrated that soil N is an effective indicator of peat decomposition. Our results identified change points in soil chemical composition in regards to N content and C functional group which highlights the importance of historic vegetation community on chemical composition of peat soils. textcopyright Soil Science Society of America, 5585 Guilford Rd., Madison WI 53711 USA. All Rights reserved. |
BibTeX:
@article{Normand2017,
author = {Normand, Anna E and Smith, Adam N and Clark, Mark W and Long, Joanna R and Reddy, K Ramesh},
title = {Chemical Composition of Soil Organic Matter in a Subarctic Peatland: Influence of Shifting Vegetation Communities},
journal = {Soil Science Society of America Journal},
year = {2017},
volume = {81},
number = {1},
pages = {41--49},
url = {https://dl.sciencesocieties.org/publications/sssaj/abstracts/81/1/41},
doi = {10.2136/sssaj2016.05.0148}
}
|
| Oney B, Gruber N, Henne S, Leuenberger M and Brunner D (2017), "A CO-based method to determine the regional biospheric signal in atmospheric CO2", Tellus, Series B: Chemical and Physical Meteorology., jan, 2017. Vol. 69(1), pp. 1353388. |
| Abstract: Regional-scale inverse modeling of atmospheric carbon dioxide (CO2) holds promise to determine the net CO2 fluxes between the land biosphere and the atmosphere. This approach requires not only high fidelity of atmospheric transport and mixing, but also an accurate estimation of the contribution of the anthropogenic and background CO2 signals to isolate the biospheric CO2 signal from the atmospheric CO2 variations. Thus, uncertainties in any of these three components directly impact the quality of the biospheric flux inversion. Here, we present and evaluate a carbon monoxide (CO)-based method to reduce these uncertainties solely on the basis of co-located observations. To this end, we use simultaneous observations of CO2 and CO from a background observation site to determine the background mole fractions for both gases, and the regional anthropogenic component of CO together with an estimate of the anthropogenic CO/CO2 mole fraction ratio to determine the anthropogenic CO2 component. We apply this method to two sites of the CarboCount CH observation network on the Swiss Plateau, Beromünster and Lägern-Hochwacht, and use the high-altitude site Jungfraujoch as background for the year 2013. Since such a background site is not always available, we also explore the possibility to use observations from the sites themselves to derive the background. We contrast the method with the standard approach of isolating the biospheric CO2 component by subtracting the anthropogenic and background components simulated by an atmospheric transport model. These tests reveal superior results from the observation-based method with retrieved wintertime biospheric signals being small and having little variance. Both observation- and model-based methods have difficulty to explain observations from late-winter and springtime pollution events in 2013, when anomalously cold temperatures and northeasterly winds tended to bring highly CO-enriched air masses to Switzerland. The uncertainty of anthropogenic CO/CO2 emission ratios is currently the most important factor limiting the method. Further, our results highlight that care needs to be taken when the background component is determined from the site's observations. Nonetheless, we find that future atmospheric carbon monitoring efforts would profit greatly from at least measuring CO alongside CO2. |
BibTeX:
@article{Oney2017,
author = {Oney, Brian and Gruber, Nicolas and Henne, Stephan and Leuenberger, Markus and Brunner, Dominik},
title = {A CO-based method to determine the regional biospheric signal in atmospheric CO2},
journal = {Tellus, Series B: Chemical and Physical Meteorology},
year = {2017},
volume = {69},
number = {1},
pages = {1353388},
url = {https://www.tandfonline.com/doi/full/10.1080/16000889.2017.1353388},
doi = {10.1080/16000889.2017.1353388}
}
|
| Oni SK, Mieres F, Futter MN and Laudon H (2017), "Soil temperature responses to climate change along a gradient of upland–riparian transect in boreal forest", Climatic Change., jul, 2017. Vol. 143(1-2), pp. 27-41. |
| Abstract: There is growing evidence of climate change impacts on northern ecosystems. While most climate change studies base their assessments on air temperature, spatial variation of soil temperature responses have not been fully examined as a metric of climate change. Here we examined spatial variations of soil temperature responses to an ensemble of regional climate model (RCM) projections at multiple depths in upland and riparian zones in the Swedish boreal forest. Modeling showed a stronger influence of air temperature on riparian soil temperature than was simulated for upland soils. The RCM ensemble projected a warming range of 4.7–6.0 °C in riparian and 4.3–5.7 °C in upland soils. However, soils were slightly colder in the riparian zone during winter. While the historical record showed that upland soils are about 0.4 °C warmer than the riparian soils, this may be reversed in the future as model projections showed that on an annual basis, riparian soils might be slightly warmer by 0.2 to 0.4 °C than upland soils. However, upland soils could warm up earlier (April) compared to riparian soils (May). |
BibTeX:
@article{Oni2017,
author = {Oni, S K and Mieres, F and Futter, M N and Laudon, H},
title = {Soil temperature responses to climate change along a gradient of upland–riparian transect in boreal forest},
journal = {Climatic Change},
year = {2017},
volume = {143},
number = {1-2},
pages = {27--41},
url = {http://link.springer.com/10.1007/s10584-017-1977-1},
doi = {10.1007/s10584-017-1977-1}
}
|
| Osterwalder S, Bishop K, Alewell C, Fritsche J, Laudon H, Åkerblom S and Nilsson MB (2017), "Mercury evasion from a boreal peatland shortens the timeline for recovery from legacy pollution", Scientific Reports., dec, 2017. Vol. 7(1), pp. 16022. |
| Abstract: Peatlands are a major source of methylmercury that contaminates downstream aquatic food webs. The large store of mercury (Hg) in peatlands could be a source of Hg for over a century even if deposition is dramatically reduced. However, the reliability of Hg mass balances can be questioned due to missing long-term land-atmosphere flux measurements. We used a novel micrometeorological system for continuous measurement of Hg peatland-atmosphere exchange to derive the first annual Hg budget for a peatland. The evasion of Hg (9.4 μg m-2 yr-1) over the course of a year was seven times greater than stream Hg export, and over two times greater than wet bulk deposition to the boreal peatland. Measurements of dissolved gaseous Hg in the peat pore water also indicate Hg evasion. The net efflux may result from recent declines in atmospheric Hg concentrations that have turned the peatland from a net sink into a source of atmospheric Hg. This net Hg loss suggests that open boreal peatlands and downstream ecosystems can recover more rapidly from past atmospheric Hg deposition than previously assumed. This has important implications for future levels of methylmercury in boreal freshwater fish and the estimation of historical Hg accumulation rates from peat profiles. |
BibTeX:
@article{Osterwalder2017,
author = {Osterwalder, Stefan and Bishop, Kevin and Alewell, Christine and Fritsche, Johannes and Laudon, Hjalmar and Åkerblom, Staffan and Nilsson, Mats B},
title = {Mercury evasion from a boreal peatland shortens the timeline for recovery from legacy pollution},
journal = {Scientific Reports},
year = {2017},
volume = {7},
number = {1},
pages = {16022},
url = {http://www.nature.com/articles/s41598-017-16141-7},
doi = {10.1038/s41598-017-16141-7}
}
|
| Palmqvist K, Franklin O and Näsholm T (2017), "Symbiosis constraints: Strong mycobiont control limits nutrient response in lichens", Ecology and Evolution., sep, 2017. Vol. 7(18), pp. 7420-7433. |
| Abstract: Symbioses such as lichens are potentially threatened by drastic environmental changes. We used the lichen Peltigera aphthosa—a symbiosis between a fungus (mycobiont), a green alga (Coccomyxa sp.), and N2-fixing cyanobacteria (Nostoc sp.)—as a model organism to assess the effects of environmental perturbations in nitrogen (N) or phosphorus (P). Growth, carbon (C) and N stable isotopes, CNP concentrations, and specific markers were analyzed in whole thalli and the partners after 4 months of daily nutrient additions in the field. Thallus N was 40% higher in N-fertilized thalli, amino acid concentrations were twice as high, while fungal chitin but not ergosterol was lower. Nitrogen also resulted in a thicker algal layer and density, and a higher δ13C abundance in all three partners. Photosynthesis was not affected by either N or P. Thallus growth increased with light dose independent of fertilization regime. We conclude that faster algal growth compared to fungal lead to increased competition for light and CO2 among the Coccomyxa cells, and for C between alga and fungus, resulting in neither photosynthesis nor thallus growth responded to N fertilization. This suggests that the symbiotic lifestyle of lichens may prevent them from utilizing nutrient abundance to increase C assimilation and growth. |
BibTeX:
@article{Palmqvist2017,
author = {Palmqvist, Kristin and Franklin, Oskar and Näsholm, Torgny},
title = {Symbiosis constraints: Strong mycobiont control limits nutrient response in lichens},
journal = {Ecology and Evolution},
year = {2017},
volume = {7},
number = {18},
pages = {7420--7433},
url = {http://doi.wiley.com/10.1002/ece3.3257},
doi = {10.1002/ece3.3257}
}
|
| Parard G, Rutgersson A, Parampil SR and Alexandre Charantonis A (2017), "The potential of using remote sensing data to estimate air&ndash;sea CO2 exchange in the Baltic Sea", Earth System Dynamics., dec, 2017. Vol. 8(4), pp. 1093-1106. |
| Abstract: In this article, we present the first climatological map of air&ndash;sea CO2 flux over the Baltic Sea based on remote sensing data: Estimates of pCO2 derived from satellite imaging using self-organizing map classifications along with class-specific linear regressions (SOMLO methodology) and remotely sensed wind estimates. The estimates have a spatial resolution of 4km both in latitude and longitude and a monthly temporal resolution from 1998 to 2011. The CO2 fluxes are estimated using two types of wind products, i.e. reanalysis winds and satellite wind products, the higher-resolution wind product generally leading to higher-amplitude flux estimations. Furthermore, the CO2 fluxes were also estimated using two methods: The method of Wanninkhof et al. (2013) and the method of Rutgersson and Smedman (2009). The seasonal variation in fluxes reflects the seasonal variation in pCO2 unvaryingly over the whole Baltic Sea, with high winter CO2 emissions and high pCO2 uptakes. All basins act as a source for the atmosphere, with a higher degree of emission in the southern regions (mean source of 1.6mmolm-2d-1 for the South Basin and 0.9 for the Central Basin) than in the northern regions (mean source of 0.1mmolm-2d-1) and the coastal areas act as a larger sink (annual uptake of -4.2mmolm-2d-1) than does the open sea (-4mmolm-2d-1). In its entirety, the Baltic Sea acts as a small source of 1.2mmolm-2d-1 on average and this annual uptake has increased from 1998 to 2012. |
BibTeX:
@article{Parard2017,
author = {Parard, Galle and Rutgersson, Anna and Parampil, Sindu Raj and Alexandre Charantonis, Anastase},
title = {The potential of using remote sensing data to estimate air&ndash;sea CO2 exchange in the Baltic Sea},
journal = {Earth System Dynamics},
year = {2017},
volume = {8},
number = {4},
pages = {1093--1106},
url = {http://www.nature.com/articles/s41598-017-16141-7 https://www.earth-syst-dynam.net/8/1093/2017/},
doi = {10.5194/esd-8-1093-2017}
}
|
| Pastorello G, Gunter D, Chu H, Christianson D, Trotta C, Canfora E, Faybishenko B, Cheah YW, Beekwilder N, Chan S, Dengel S, Keenan T, O'brien F, Elbashandy A, Poindexter C, Humphrey M, Papale D and Agarwal D (2017), "Hunting data rogues at scale: Data quality control for observational data in research infrastructures", In Proceedings - 13th IEEE International Conference on eScience, eScience 2017., oct, 2017. , pp. 446-447. IEEE. |
| Abstract: Data quality control is one of the most time consuming activities within Research Infrastructures (RIs), especially when involving observational data and multiple data providers. In this work we report on our ongoing development of data rogues, a scalable approach to manage data quality issues for observational data within RIs. The motivation for this work started with the creation of the FLUXNET2015 dataset, which includes carbon, water, and energy fluxes plus micrometeorological and ancillary data measured in over 200 sites around the world. To create an uniform dataset, including derived data products, extensive work on data quality control was needed. The unpredictable nature of observational data quality issues makes the automation of data quality control inherently difficult. Developed based on this experience, the data rogues methodology allows for increased automation of quality control activities by systematically identifying, cataloging, and documenting implementations of solutions to data issues. We believe this methodology can be extended and applied to others domains and types of data, making the automation of data quality control a more tractable problem. |
BibTeX:
@inproceedings{Pastorello2017,
author = {Pastorello, Gilberto and Gunter, Dan and Chu, Housen and Christianson, Danielle and Trotta, Carlo and Canfora, Eleonora and Faybishenko, Boris and Cheah, You Wei and Beekwilder, Norm and Chan, Stephen and Dengel, Sigrid and Keenan, Trevor and O'brien, Fianna and Elbashandy, Abdelrahman and Poindexter, Cristina and Humphrey, Marty and Papale, Dario and Agarwal, Deb},
title = {Hunting data rogues at scale: Data quality control for observational data in research infrastructures},
booktitle = {Proceedings - 13th IEEE International Conference on eScience, eScience 2017},
publisher = {IEEE},
year = {2017},
pages = {446--447},
url = {http://ieeexplore.ieee.org/document/8109169/},
doi = {10.1109/eScience.2017.64}
}
|
| Patra PK, Crisp D, Kaiser JW, Wunch D, Saeki T, Ichii K, Sekiya T, Wennberg PO, Feist DG, Pollard DF, Griffith DW, Velazco VA, De Maziere M, Sha MK, Roehl C, Chatterjee A and Ishijima K (2017), "The Orbiting Carbon Observatory (OCO-2) tracks 2-3 peta-gram increase in carbon release to the atmosphere during the 2014-2016 El Niño", Scientific Reports., dec, 2017. Vol. 7(1) Nature Publishing Group. |
| Abstract: The powerful El Niño event of 2015-2016 - the third most intense since the 1950s - has exerted a large impact on the Earth's natural climate system. The column-averaged CO2 dry-air mole fraction (XCO2) observations from satellites and ground-based networks are analyzed together with in situ observations for the period of September 2014 to October 2016. From the differences between satellite (OCO-2) observations and simulations using an atmospheric chemistry-transport model, we estimate that, relative to the mean annual fluxes for 2014, the most recent El Niño has contributed to an excess CO2 emission from the Earth's surface (land + ocean) to the atmosphere in the range of 2.4 ± 0.2 PgC (1 Pg = 1015 g) over the period of July 2015 to June 2016. The excess CO2 flux is resulted primarily from reduction in vegetation uptake due to drought, and to a lesser degree from increased biomass burning. It is about the half of the CO2 flux anomaly (range: 4.4-6.7 PgC) estimated for the 1997/1998 El Niño. The annual total sink is estimated to be 3.9 ± 0.2 PgC for the assumed fossil fuel emission of 10.1 PgC. The major uncertainty in attribution arise from error in anthropogenic emission trends, satellite data and atmospheric transport. |
BibTeX:
@article{Patra2017,
author = {Patra, Prabir K. and Crisp, David and Kaiser, Johannes W. and Wunch, Debra and Saeki, Tazu and Ichii, Kazuhito and Sekiya, Takashi and Wennberg, Paul O. and Feist, Dietrich G. and Pollard, David F. and Griffith, David W.T. and Velazco, Voltaire A. and De Maziere, M. and Sha, Mahesh K. and Roehl, Coleen and Chatterjee, Abhishek and Ishijima, Kentaro},
title = {The Orbiting Carbon Observatory (OCO-2) tracks 2-3 peta-gram increase in carbon release to the atmosphere during the 2014-2016 El Niño},
journal = {Scientific Reports},
publisher = {Nature Publishing Group},
year = {2017},
volume = {7},
number = {1},
doi = {10.1038/s41598-017-13459-0}
}
|
| Persson HJ and Fransson JES (2017), "Comparison between TanDEM-X- and ALS-based estimation of aboveground biomass and tree height in boreal forests", Scandinavian Journal of Forest Research., may, 2017. Vol. 32(4), pp. 306-319. |
| Abstract: Interferometric Synthetic Aperture Radar (InSAR) data from TerraSAR-X add-on for Digital Elevation Measurement (TanDEM-X) were used to estimate aboveground biomass (AGB) and tree height with linear regression models. These were compared to models based on airborne laser scanning (ALS) data at two Swedish boreal forest test sites, Krycklan (64°N19°E) and Remningstorp (58°N13°E). The predictions were validated using field data at the stand-level (0.5–26.1 ha) and at the plot-level (10 m radius). Additionally, the ALS metrics percentile 99 (p99) and vegetation ratio, commonly used to estimate AGB and tree height, were estimated in order to investigate the feasibility of replacing ALS data with TanDEM-X InSAR data. Both AGB and tree height could be estimated with about the same accuracy at the stand-level from both TanDEM-X- and ALS-based data. The AGB was estimated with 17.2% and 14.6% root mean square error (RMSE) and the tree height with 7.6% and 4.1% RMSE from TanDEM-X data at the stand-level at the two test sites Krycklan and Remningstorp. The Pearson correlation coefficients between the TanDEM-X height and the ALS height p99 were r =.98 and r =.95 at the two test sites. The TanDEM-X height contains information related to both tree height and forest density, which was validated from several estimation models. |
BibTeX:
@article{Persson2017,
author = {Persson, Henrik J and Fransson, Johan E S},
title = {Comparison between TanDEM-X- and ALS-based estimation of aboveground biomass and tree height in boreal forests},
journal = {Scandinavian Journal of Forest Research},
year = {2017},
volume = {32},
number = {4},
pages = {306--319},
url = {https://www.tandfonline.com/doi/full/10.1080/02827581.2016.1220618},
doi = {10.1080/02827581.2016.1220618}
}
|
| Poltera Y, Martucci G, Collaud Coen M, Hervo M, Emmenegger L, Henne S, Brunner D and Haefele A (2017), "PathfinderTURB: An automatic boundary layer algorithm. Development, validation and application to study the impact on in situ measurements at the Jungfraujoch", Atmospheric Chemistry and Physics., aug, 2017. Vol. 17(16), pp. 10051-10070. Copernicus GmbH. |
| Abstract: We present the development of the PathfinderTURB algorithm for the analysis of ceilometer backscatter data and the real-time detection of the vertical structure of the planetary boundary layer. Two aerosol layer heights are retrieved by PathfinderTURB: the convective boundary layer (CBL) and the continuous aerosol layer (CAL). PathfinderTURB combines the strengths of gradient-and variance-based methods and addresses the layer attribution problem by adopting a geodesic approach. The algorithm has been applied to 1 year of data measured by two ceilometers of type CHM15k, one operated at the Aerological Observatory of Payerne (491 m a.s.l.) on the Swiss plateau and one at the Kleine Scheidegg (2061 m a.s.l.) in the Swiss Alps. The retrieval of the CBL has been validated at Payerne using two reference methods: (1) manual detections of the CBL height performed by human experts using the ceilometer backscatter data; (2) values of CBL heights calculated using the Richardson's method from co-located radio sounding data. We found average biases as small as 27 m (53 m) with respect to reference method 1 (method 2). Based on the excellent agreement between the two reference methods, PathfinderTURB has been applied to the ceilometer data at the mountainous site of the Kleine Scheidegg for the period September 2014 to November 2015. At this site, the CHM15k is operated in a tilted configuration at 71° zenith angle to probe the atmosphere next to the Sphinx Observatory (3580 m a.s.l.) on the Jungfraujoch (JFJ). The analysis of the retrieved layers led to the following results: the CAL reaches the JFJ 41 % of the time in summer and 21 % of the time in winter for a total of 97 days during the two seasons. The season-averaged daily cycles show that the CBL height reaches the JFJ only during short periods (4 % of the time), but on 20 individual days in summer and never during winter. During summer in particular, the CBL and the CAL modify the air sampled in situ at JFJ, resulting in an unequivocal dependence of the measured absorption coefficient on the height of both layers. This highlights the relevance of retrieving the height of CAL and CBL automatically at the JFJ. |
BibTeX:
@article{Poltera2017,
author = {Poltera, Yann and Martucci, Giovanni and Collaud Coen, Martine and Hervo, Maxime and Emmenegger, Lukas and Henne, Stephan and Brunner, Dominik and Haefele, Alexander},
title = {PathfinderTURB: An automatic boundary layer algorithm. Development, validation and application to study the impact on in situ measurements at the Jungfraujoch},
journal = {Atmospheric Chemistry and Physics},
publisher = {Copernicus GmbH},
year = {2017},
volume = {17},
number = {16},
pages = {10051--10070},
doi = {10.5194/acp-17-10051-2017}
}
|
| Post H, Vrugt JA, Fox A, Vereecken H and Hendricks Franssen HJ (2017), "Estimation of Community Land Model parameters for an improved assessment of net carbon fluxes at European sites", Journal of Geophysical Research: Biogeosciences., mar, 2017. Vol. 122(3), pp. 661-689. |
| Abstract: The Community Land Model (CLM) contains many parameters whose values are uncertain and thus require careful estimation for model application at individual sites. Here we used Bayesian inference with the DiffeRential Evolution Adaptive Metropolis (DREAM(zs)) algorithm to estimate eight CLM v.4.5 ecosystem parameters using 1 year records of half-hourly net ecosystem CO2 exchange (NEE) observations of four central European sites with different plant functional types (PFTs). The posterior CLM parameter distributions of each site were estimated per individual season and on a yearly basis. These estimates were then evaluated using NEE data from an independent evaluation period and data from “nearby†FLUXNET sites at ˜600 km distance to the original sites. Latent variables (multipliers) were used to treat explicitly uncertainty in the initial carbon-nitrogen pools. The posterior parameter estimates were superior to their default values in their ability to track and explain the measured NEE data of each site. The seasonal parameter values reduced with more than 50% (averaged over all sites) the bias in the simulated NEE values. The most consistent performance of CLM during the evaluation period was found for the posterior parameter values of the forest PFTs, and contrary to the C3-grass and C3-crop sites, the latent variables of the initial pools further enhanced the quality-of-fit. The carbon sink function of the forest PFTs significantly increased with the posterior parameter estimates. We thus conclude that land surface model predictions of carbon stocks and fluxes require careful consideration of uncertain ecological parameters and initial states. |
BibTeX:
@article{Post2017,
author = {Post, Hanna and Vrugt, Jasper A and Fox, Andrew and Vereecken, Harry and Hendricks Franssen, Harrie Jan},
title = {Estimation of Community Land Model parameters for an improved assessment of net carbon fluxes at European sites},
journal = {Journal of Geophysical Research: Biogeosciences},
year = {2017},
volume = {122},
number = {3},
pages = {661--689},
url = {http://doi.wiley.com/10.1002/2015JG003297},
doi = {10.1002/2015JG003297}
}
|
| Pulliainen J, Aurela M, Laurila T, Aalto T, Takala M, Salminen M, Kulmala M, Barr A, Heimann M, Lindroth A, Laaksonen A, Derksen C, Mäkelä A, Markkanen T, Lemmetyinen J, Susiluoto J, Dengel S, Mammarella I, Tuovinen JP and Vesala T (2017), "Early snowmelt significantly enhances boreal springtime carbon uptake", Proceedings of the National Academy of Sciences of the United States of America., oct, 2017. Vol. 114(42), pp. 11081-11086. |
| Abstract: We determine the annual timing of spring recovery from spaceborne microwave radiometer observations across northern hemisphere boreal evergreen forests for 1979–2014. We find a trend of advanced spring recovery of carbon uptake for this period, with a total average shift of 8.1 d (2.3 d/decade). We use this trend to estimate the corresponding changes in gross primary production (GPP) by applying in situ carbon flux observations. Micrometeoro-logical CO2 measurements at four sites in northern Europe and North America indicate that such an advance in spring recovery would have increased the January–June GPP sum by 29 gtextperiodcenteredCtextperiodcenteredmâˆ'2 [8.4 gtextperiodcenteredCtextperiodcenteredmâˆ'2 (3.7%)/decade]. We find this sensitivity of the measured springtime GPP to the spring recovery to be in accordance with the corresponding sensitivity derived from simulations with a land ecosystem model coupled to a global circulation model. The model-predicted increase in springtime cumulative GPP was 0.035 Pg/decade [15.5 gtextperiodcenteredCtextperiodcenteredmâˆ'2 (6.8%)/decade] for Eurasian forests and 0.017 Pg/decade for forests in North America [9.8 gtextperiodcenteredCtextperiodcenteredmâˆ'2 (4.4%)/decade]. This change in the springtime sum of GPP related to the timing of spring snowmelt is quantified here for boreal evergreen forests. |
BibTeX:
@article{Pulliainen2017,
author = {Pulliainen, Jouni and Aurela, Mika and Laurila, Tuomas and Aalto, Tuula and Takala, Matias and Salminen, Miia and Kulmala, Markku and Barr, Alan and Heimann, Martin and Lindroth, Anders and Laaksonen, Ari and Derksen, Chris and Mäkelä, Annikki and Markkanen, Tiina and Lemmetyinen, Juha and Susiluoto, Jouni and Dengel, Sigrid and Mammarella, Ivan and Tuovinen, Juha Pekka and Vesala, Timo},
title = {Early snowmelt significantly enhances boreal springtime carbon uptake},
journal = {Proceedings of the National Academy of Sciences of the United States of America},
year = {2017},
volume = {114},
number = {42},
pages = {11081--11086},
url = {http://www.pnas.org/lookup/doi/10.1073/pnas.1707889114},
doi = {10.1073/pnas.1707889114}
}
|
| Raivonen M, Smolander S, Backman L, Susiluoto J, Aalto T, Markkanen T, Mäkelä J, Rinne J, Peltola O, Aurela M, Lohila A, Tomasic M, Li X, Larmola T, Juutinen S, Tuittila ES, Heimann M, Sevanto S, Kleinen T, Brovkin V and Vesala T (2017), "HIMMELI v1.0: HelsinkI Model of MEthane buiLd-up and emIssion for peatlands", Geoscientific Model Development., dec, 2017. Vol. 10(12), pp. 4665-4691. |
| Abstract: Wetlands are one of the most significant natural sources of methane (CH4) to the atmosphere. They emit CH4 because decomposition of soil organic matter in waterlogged anoxic conditions produces CH4, in addition to carbon dioxide (CO2). Production of CH4 and how much of it escapes to the atmosphere depend on a multitude of environmental drivers. Models simulating the processes leading to CH4 emissions are thus needed for upscaling observations to estimate present CH4 emissions and for producing scenarios of future atmospheric CH4 concentrations. Aiming at a CH4 model that can be added to models describing peatland carbon cycling, we composed a model called HIMMELI that describes CH4 build-up in and emissions from peatland soils. It is not a full peatland carbon cycle model but it requires the rate of anoxic soil respiration as input. Driven by soil temperature, leaf area index (LAI) of aerenchymatous peatland vegetation, and water table depth (WTD), it simulates the concentrations and transport of CH4, CO2, and oxygen (O2) in a layered one-dimensional peat column. Here, we present the HIMMELI model structure and results of tests on the model sensitivity to the input data and to the description of the peat column (peat depth and layer thickness), and demonstrate that HIMMELI outputs realistic fluxes by comparing modeled and measured fluxes at two peatland sites. As HIMMELI describes only the CH4-related processes, not the full carbon cycle, our analysis revealed mechanisms and dependencies that may remain hidden when testing CH4 models connected to complete peatland carbon models, which is usually the case. Our results indicated that (1) the model is flexible and robust and thus suitable for different environments; (2) the simulated CH4 emissions largely depend on the prescribed rate of anoxic respiration; (3) the sensitivity of the total CH4 emission to other input variables is mainly mediated via the concentrations of dissolved gases, in particular, the O2 concentrations that affect the CH4 production and oxidation rates; (4) with given input respiration, the peat column description does not significantly affect the simulated CH4 emissions in this model version. |
BibTeX:
@article{Raivonen2017,
author = {Raivonen, Maarit and Smolander, Sampo and Backman, Leif and Susiluoto, Jouni and Aalto, Tuula and Markkanen, Tiina and Mäkelä, Jarmo and Rinne, Janne and Peltola, Olli and Aurela, Mika and Lohila, Annalea and Tomasic, Marin and Li, Xuefei and Larmola, Tuula and Juutinen, Sari and Tuittila, Eeva Stiina and Heimann, Martin and Sevanto, Sanna and Kleinen, Thomas and Brovkin, Victor and Vesala, Timo},
title = {HIMMELI v1.0: HelsinkI Model of MEthane buiLd-up and emIssion for peatlands},
journal = {Geoscientific Model Development},
year = {2017},
volume = {10},
number = {12},
pages = {4665--4691},
url = {https://www.geosci-model-dev.net/10/4665/2017/},
doi = {10.5194/gmd-10-4665-2017}
}
|
| Rodrigues A, Vanbeveren SPP, Costa M and Ceulemans R (2017), "Relationship between soil chemical composition and potential fuel quality of biomass from poplar short rotation coppices in Portugal and Belgium", Biomass and Bioenergy., oct, 2017. Vol. 105, pp. 66-72. |
| Abstract: Soil-woody biomass interactions are relevant for the productivity of bioenergy plantations and biomass quality. In this context, the main objective of this study was to evaluate and to quantify possible relationships between chemical variables of the soil and the produced biomass through a multivariate approach. This latter approach allows to overcome the complex issue of multi-collinearity among variables. Soil and woody biomass samples were collected from two poplar short rotation coppices in Santarém (Portugal) and in Lochristi (Belgium). The results from the analyses of those samples were integrated into three databases with soil, woody biomass and site plots as cases, and 23 physical and chemical properties as variables. The databases were subjected to a multivariate sequence of calculations, which included correlation, principal components, factorial and hierarchical clustering analyses. The calculations showed that the site plots and the woody biomass of genotypes in Lochristi were more homogeneous as compared to Santarém; they also confirmed the high interconnection between soil and woody biomass variables. The higher heating value of the woody biomass correlated well with the soil concentrations of P2O5, Mg, Ca, Na and organic C. Linear equations related the higher heating value to the most important soil and woody biomass variables. Finally, the results suggest that the annual monitoring of soil and biomass in SRC systems should be performed to optimize both productivity and woody biomass quality as a fuel. |
BibTeX:
@article{Rodrigues2017,
author = {Rodrigues, Abel and Vanbeveren, Stefan P P and Costa, Mário and Ceulemans, Reinhart},
title = {Relationship between soil chemical composition and potential fuel quality of biomass from poplar short rotation coppices in Portugal and Belgium},
journal = {Biomass and Bioenergy},
year = {2017},
volume = {105},
pages = {66--72},
url = {http://linkinghub.elsevier.com/retrieve/pii/S0961953417302064},
doi = {10.1016/j.biombioe.2017.06.021}
}
|
| Salomón RL, Limousin JM, Ourcival JM, Rodríguez-Calcerrada J and Steppe K (2017), "Stem hydraulic capacitance decreases with drought stress: implications for modelling tree hydraulics in the Mediterranean oak Quercus ilex", Plant Cell and Environment., aug, 2017. Vol. 40(8), pp. 1379-1391. |
| Abstract: Hydraulic modelling is a primary tool to predict plant performance in future drier scenarios. However, as most tree models are validated under non-stress conditions, they may fail when water becomes limiting. To simulate tree hydraulic functioning under moist and dry conditions, the current version of a water flow and storage mechanistic model was further developed by implementing equations that describe variation in xylem hydraulic resistance (RX) and stem hydraulic capacitance (CS) with predawn water potential (ΨPD). The model was applied in a Mediterranean forest experiencing intense summer drought, where six Quercus ilex trees were instrumented to monitor stem diameter variations and sap flow, concurrently with measurements of predawn and midday leaf water potential. Best model performance was observed when CS was allowed to decrease with decreasing ΨPD. Hydraulic capacitance decreased from 62 to 25 kg mâˆ'3 MPaâˆ'1 across the growing season. In parallel, tree transpiration decreased to a greater extent than the capacitive water release and the contribution of stored water to transpiration increased from 2.0 to 5.1%. Our results demonstrate the importance of stored water and seasonality in CS for tree hydraulic functioning, and they suggest that CS should be considered to predict the drought response of trees with models. |
BibTeX:
@article{Salomon2017,
author = {Salomón, Roberto L and Limousin, Jean Marc and Ourcival, Jean Marc and Rodríguez-Calcerrada, Jesús and Steppe, Kathy},
title = {Stem hydraulic capacitance decreases with drought stress: implications for modelling tree hydraulics in the Mediterranean oak Quercus ilex},
journal = {Plant Cell and Environment},
year = {2017},
volume = {40},
number = {8},
pages = {1379--1391},
url = {http://doi.wiley.com/10.1111/pce.12928},
doi = {10.1111/pce.12928}
}
|
| Saunois M, Bousquet P, Poulter B, Peregon A, Ciais P, Canadell JG, Dlugokencky EJ, Etiope G, Bastviken D, Houweling S, Janssens-Maenhout G, Tubiello FN, Castaldi S, Jackson RB, Alexe M, Arora VK, Beerling DJ, Bergamaschi P, Blake DR, Brailsford G, Bruhwiler L, Kim S, Kleinen T, Krummel P, Lamarque J-F, Langenfelds R, Locatelli R, Machida T, Maksyutov S, Melton JR, Morino I, Naik V, O'doherty S, Parmentier F-JW, Patra PK, Peng C, Peng S, Peters GP, Pison I, Prinn R, Ramonet M, Riley WJ, Saito M, Santini M, Schroeder R, Simpson IJ, Spahni R, Takizawa A, Thornton BF, Tian H, Tohjima Y, Viovy N, Voulgarakis A, Weiss R, Wilton DJ, Wiltshire A, Worthy D, Wunch D, Xu X, Yoshida Y, Zhang B, Zhang Z and Zhu Q (2017), "Variability and quasi-decadal changes in the methane budget over the period 2000-2012", Christian Frankenberg. Vol. 17, pp. 11135-11161. |
| Abstract: Following the recent Global Carbon Project (GCP) synthesis of the decadal methane (CH 4) budget over 2000-2012 (Saunois et al., 2016), we analyse here the same dataset with a focus on quasi-decadal and inter-annual variability in CH 4 emissions. The GCP dataset integrates results from top-down studies (exploiting atmospheric observations within an atmospheric inverse-modelling framework) and bottom-up models (including process-based models for estimating land surface emissions and atmospheric chemistry), inventories of anthropogenic emissions, and data-driven approaches. The annual global methane emissions from top-down studies , which by construction match the observed methane growth rate within their uncertainties, all show an increase in total methane emissions over the period 2000-2012, but this increase is not linear over the 13 years. Despite differences between individual studies, the mean emission anomaly of Atmos. Chem. Phys., 17, 11135-11161, 2017 www.atmos-chem-phys.net/17/11135/2017/ M. Saunois et al.: Variability and quasi-decadal changes in the methane budget 11137 the top-down ensemble shows no significant trend in total methane emissions over the period 2000-2006, during the plateau of atmospheric methane mole fractions, and also over the period 2008-2012, during the renewed atmospheric methane increase. However, the top-down ensemble mean produces an emission shift between 2006 and 2008, leading to 22 [16-32] Tg CH 4 yr −1 higher methane emissions over the period 2008-2012 compared to 2002-2006. This emission increase mostly originated from the tropics, with a smaller contribution from mid-latitudes and no significant change from boreal regions. The regional contributions remain uncertain in top-down studies. Tropical South America and South and East Asia seem to contribute the most to the emission increase in the tropics. However, these two regions have only limited atmospheric measurements and remain therefore poorly constrained. The sectorial partitioning of this emission increase between the periods 2002-2006 and 2008-2012 differs from one atmospheric inversion study to another. However, all top-down studies suggest smaller changes in fossil fuel emissions (from oil, gas, and coal industries) compared to the mean of the bottom-up inventories included in this study. This difference is partly driven by a smaller emission change in China from the top-down studies compared to the estimate in the Emission Database for Global Atmospheric Research (EDGARv4.2) inventory, which should be revised to smaller values in a near future. We apply isotopic signatures to the emission changes estimated for individual studies based on five emission sectors and find that for six individual top-down studies (out of eight) the average isotopic signature of the emission changes is not consistent with the observed change in atmospheric 13 CH 4. However, the partitioning in emission change derived from the ensemble mean is consistent with this isotopic constraint. At the global scale, the top-down ensemble mean suggests that the dominant contribution to the resumed atmospheric CH 4 growth after 2006 comes from microbial sources (more from agriculture and waste sectors than from natural wetlands), with an uncertain but smaller contribution from fossil CH 4 emissions. In addition, a decrease in biomass burning emissions (in agreement with the biomass burning emission databases) makes the balance of sources consistent with atmospheric 13 CH 4 observations. In most of the top-down studies included here, OH concentrations are considered constant over the years (seasonal variations but without any inter-annual variability). As a result, the methane loss (in particular through OH oxidation) varies mainly through the change in methane concentrations and not its oxidants. For these reasons, changes in the methane loss could not be properly investigated in this study, although it may play a significant role in the recent atmospheric methane changes as briefly discussed at the end of the paper. |
BibTeX:
@article{Saunois2017,
author = {Saunois, Marielle and Bousquet, Philippe and Poulter, Ben and Peregon, Anna and Ciais, Philippe and Canadell, Josep G and Dlugokencky, Edward J and Etiope, Giuseppe and Bastviken, David and Houweling, Sander and Janssens-Maenhout, Greet and Tubiello, Francesco N and Castaldi, Simona and Jackson, Robert B and Alexe, Mihai and Arora, Vivek K and Beerling, David J and Bergamaschi, Peter and Blake, Donald R and Brailsford, Gordon and Bruhwiler, Lori and Kim, Sook and Kleinen, Thomas and Krummel, Paul and Lamarque, Jean-François and Langenfelds, Ray and Locatelli, Robin and Machida, Toshinobu and Maksyutov, Shamil and Melton, Joe R and Morino, Isamu and Naik, Vaishali and O'doherty, Simon and Parmentier, Frans-Jan W and Patra, Prabir K and Peng, Changhui and Peng, Shushi and Peters, Glen P and Pison, Isabelle and Prinn, Ronald and Ramonet, Michel and Riley, William J and Saito, Makoto and Santini, Monia and Schroeder, Ronny and Simpson, Isobel J and Spahni, Renato and Takizawa, Atsushi and Thornton, Brett F and Tian, Hanqin and Tohjima, Yasunori and Viovy, Nicolas and Voulgarakis, Apostolos and Weiss, Ray and Wilton, David J and Wiltshire, Andy and Worthy, Doug and Wunch, Debra and Xu, Xiyan and Yoshida, Yukio and Zhang, Bowen and Zhang, Zhen and Zhu, Qiuan},
title = {Variability and quasi-decadal changes in the methane budget over the period 2000-2012},
journal = {Christian Frankenberg},
year = {2017},
volume = {17},
pages = {11135--11161},
url = {https://doi.org/10.5194/acp-17-11135-2017},
doi = {10.5194/acp-17-11135-2017}
}
|
| Schlund M, Scipal K and Davidson MWJ (2017), "Forest classification and impact of BIOMASS resolution on forest area and aboveground biomass estimation", International Journal of Applied Earth Observation and Geoinformation., apr, 2017. Vol. 56, pp. 65-76. |
| Abstract: The European Space Agency (ESA) is currently implementing the BIOMASS mission as 7th Earth Explorer satellite. BIOMASS will provide for the first time global forest aboveground biomass estimates based on P-band synthetic aperture radar (SAR) imagery. This paper addresses an often overlooked element of the data processing chain required to ensure reliable and accurate forest biomass estimates: accurate identification of forest areas ahead of the inversion of radar data into forest biomass estimates. The use of the P-band data from BIOMASS itself for the classification into forest and non-forest land cover types is assessed in this paper. For airborne data in tropical, hemi-boreal and boreal forests we demonstrate that classification accuracies from 90 up to 97% can be achieved using radar backscatter and phase information. However, spaceborne data will have a lower resolution and higher noise level compared to airborne data and a higher probability of mixed pixels containing multiple land cover types. Therefore, airborne data was reduced to 50m, 100m and 200m resolution. The analysis revealed that about 50–60% of the area within the resolution level must be covered by forest to classify a pixel with higher probability as forest compared to non-forest. This results in forest omission and commission leading to similar forest area estimation over all resolutions. However, the forest omission resulted in a biased underestimated biomass, which was not equaled by the forest commission. The results underline the necessity of a highly accurate pre-classification of SAR data for an accurate unbiased aboveground biomass estimation. |
BibTeX:
@article{Schlund2017,
author = {Schlund, Michael and Scipal, Klaus and Davidson, Malcolm W J},
title = {Forest classification and impact of BIOMASS resolution on forest area and aboveground biomass estimation},
journal = {International Journal of Applied Earth Observation and Geoinformation},
year = {2017},
volume = {56},
pages = {65--76},
url = {http://linkinghub.elsevier.com/retrieve/pii/S0303243416302008},
doi = {10.1016/j.jag.2016.12.001}
}
|
| Schmithüsen D, Chambers S, Fischer B, Gilge S, Hatakka J, Kazan V, Neubert R, Paatero J, Ramonet M, Schlosser C, Schmid S, Vermeulen A and Levin I (2017), "A European-wide 222radon and 222radon progeny comparison study", Atmospheric Measurement Techniques., apr, 2017. Vol. 10(4), pp. 1299-1312. |
| Abstract: Although atmospheric 222radon (222Rn) activity concentration measurements are currently performed worldwide, they are being made by many different laboratories and with fundamentally different measurement principles, so compatibility issues can limit their utility for regional-To-global applications. Consequently, we conducted a European-wide 222Rn/222Rn progeny comparison study in order to evaluate the different measurement systems in use, determine potential systematic biases between them, and estimate correction factors that could be applied to harmonize data for their use as a tracer in atmospheric applications. Two compact portable Heidelberg radon monitors (HRM) were moved around to run for at least 1 month at each of the nine European measurement stations included in this comparison. Linear regressions between parallel data sets were calculated, yielding correction factors relative to the HRM ranging from 0.68 to 1.45. A calibration bias between ANSTO (Australian Nuclear Science and Technology Organisation) two-filter radon monitors and the HRM of ANSTO/HRMg=1.11± was found. Moreover, for the continental stations using one-filter systems that derive atmospheric 222Rn activity concentrations from measured atmospheric progeny activity concentrations, preliminary 214Po/222Rn disequilibrium values were also estimated. Mean station-specific disequilibrium values between 0.8 at mountain sites (e.g. Schauinsland) and 0.9 at non-mountain sites for sampling heights around 20 to 30m above ground level were determined. The respective corrections for calibration biases and disequilibrium derived in this study need to be applied to obtain a compatible European atmospheric 222Rn data set for use in quantitative applications, such as regional model intercomparison and validation or trace gas flux estimates with the radon tracer method. |
BibTeX:
@article{Schmithusen2017,
author = {Schmithüsen, Dominik and Chambers, Scott and Fischer, Bernd and Gilge, Stefan and Hatakka, Juha and Kazan, Victor and Neubert, Rolf and Paatero, Jussi and Ramonet, Michel and Schlosser, Clemens and Schmid, Sabine and Vermeulen, Alex and Levin, Ingeborg},
title = {A European-wide 222radon and 222radon progeny comparison study},
journal = {Atmospheric Measurement Techniques},
year = {2017},
volume = {10},
number = {4},
pages = {1299--1312},
url = {https://www.atmos-meas-tech.net/10/1299/2017/},
doi = {10.5194/amt-10-1299-2017}
}
|
| Scholze M, Buchwitz M, Dorigo W, Guanter L and Quegan S (2017), "Reviews and syntheses: Systematic Earth observations for use in terrestrial carbon cycle data assimilation systems", Biogeosciences. Vol. 14, pp. 3401-3429. |
| Abstract: The global carbon cycle is an important component of the Earth system and it interacts with the hydrology, energy and nutrient cycles as well as ecosystem dynamics. A better understanding of the global carbon cycle is required for improved projections of climate change including corresponding changes in water and food resources and for the verification of measures to reduce anthropogenic greenhouse gas emissions. An improved understanding of the carbon cycle can be achieved by data assimilation systems, which integrate observations relevant to the carbon cycle into coupled carbon, water, energy and nutrient models. Hence, the ingredients for such systems are a carbon cycle model, an algorithm for the assimilation and systematic and well error-characterised observations relevant to the carbon cycle. Relevant observations for assimilation include various in situ measurements in the atmosphere (e.g. concentrations of CO 2 and other gases) and on land (e.g. fluxes of carbon water and energy, carbon stocks) as well as remote sensing observations (e.g. atmospheric composition, vegetation and surface properties). We briefly review the different existing data assimilation techniques and contrast them to model benchmarking and evaluation efforts (which also rely on observations). A common requirement for all assimilation techniques is a full description of the observational data properties. Uncertainty estimates of the observations are as important as the observations themselves because they similarly determine the outcome of such assimilation systems. Hence, this article reviews the requirements of data assimilation systems on observations and provides a non-exhaustive overview of current observations and their uncertainties for use in terrestrial carbon cycle data assimilation. We report on progress since the review of model-data synthesis in terrestrial carbon observations by Raupach et al. (2005), emphasising the rapid advance in relevant space-based observations. |
BibTeX:
@article{Scholze2017,
author = {Scholze, Marko and Buchwitz, Michael and Dorigo, Wouter and Guanter, Luis and Quegan, Shaun},
title = {Reviews and syntheses: Systematic Earth observations for use in terrestrial carbon cycle data assimilation systems},
journal = {Biogeosciences},
year = {2017},
volume = {14},
pages = {3401--3429},
url = {https://doi.org/10.5194/bg-14-3401-2017},
doi = {10.5194/bg-14-3401-2017}
}
|
| Schrön M, Köhli M, Scheiffele L, Iwema J, Bogena HR, Lv L, Martini E, Baroni G, Rosolem R, Weimar J, Mai J, Cuntz M, Rebmann C, Oswald SE, Dietrich P, Schmidt U and Zacharias S (2017), "Improving calibration and validation of cosmic-ray neutron sensors in the light of spatial sensitivity", Hydrology and Earth System Sciences., oct, 2017. Vol. 21(10), pp. 5009-5030. Copernicus GmbH. |
| Abstract: In the last few years the method of cosmic-ray neutron sensing (CRNS) has gained popularity among hydrologists, physicists, and land-surface modelers. The sensor provides continuous soil moisture data, averaged over several hectares and tens of decimeters in depth. However, the signal still may contain unidentified features of hydrological processes, and many calibration datasets are often required in order to find reliable relations between neutron intensity and water dynamics. Recent insights into environmental neutrons accurately described the spatial sensitivity of the sensor and thus allowed one to quantify the contribution of individual sample locations to the CRNS signal. Consequently, data points of calibration and validation datasets are suggested to be averaged using a more physically based weighting approach. In this work, a revised sensitivity function is used to calculate weighted averages of point data. The function is different from the simple exponential convention by the extraordinary sensitivity to the first few meters around the probe, and by dependencies on air pressure, air humidity, soil moisture, and vegetation. The approach is extensively tested at six distinct monitoring sites: two sites with multiple calibration datasets and four sites with continuous time series datasets. In all cases, the revised averaging method improved the performance of the CRNS products. The revised approach further helped to reveal hidden hydrological processes which otherwise remained unexplained in the data or were lost in the process of overcalibration. The presented weighting approach increases the overall accuracy of CRNS products and will have an impact on all their applications in agriculture, hydrology, and modeling. |
BibTeX:
@article{Schron2017,
author = {Schrön, Martin and Köhli, Markus and Scheiffele, Lena and Iwema, Joost and Bogena, Heye R. and Lv, Ling and Martini, Edoardo and Baroni, Gabriele and Rosolem, Rafael and Weimar, Jannis and Mai, Juliane and Cuntz, Matthias and Rebmann, Corinna and Oswald, Sascha E. and Dietrich, Peter and Schmidt, Ulrich and Zacharias, Steffen},
title = {Improving calibration and validation of cosmic-ray neutron sensors in the light of spatial sensitivity},
journal = {Hydrology and Earth System Sciences},
publisher = {Copernicus GmbH},
year = {2017},
volume = {21},
number = {10},
pages = {5009--5030},
doi = {10.5194/hess-21-5009-2017}
}
|
| Shi H, Li L, Eamus D, Huete A, Cleverly J, Tian X, Yu Q, Wang S, Montagnani L, Magliulo V, Rotenberg E, Pavelka M and Carrara A (2017), "Assessing the ability of MODIS EVI to estimate terrestrial ecosystem gross primary production of multiple land cover types", Ecological Indicators., jan, 2017. Vol. 72, pp. 153-164. |
| Abstract: Terrestrial ecosystem gross primary production (GPP) is the largest component in the global carbon cycle. The enhanced vegetation index (EVI) has been proven to be strongly correlated with annual GPP within several biomes. However, the annual GPP-EVI relationship and associated environmental regulations have not yet been comprehensively investigated across biomes at the global scale. Here we explored relationships between annual integrated EVI (iEVI) and annual GPP observed at 155 flux sites, where GPP was predicted with a log-log model: ln(GPP)=a×ln(iEVI)+b. iEVI was computed from MODIS monthly EVI products following removal of values affected by snow or cold temperature and without calculating growing season duration. Through categorisation of flux sites into 12 land cover types, the ability of iEVI to estimate GPP was considerably improved (R2 from 0.62 to 0.74, RMSE from 454.7 to 368.2 g C mâˆ'2 yrâˆ'1). The biome-specific GPP-iEVI formulae generally showed a consistent performance in comparison to a global benchmarking dataset (R2 = 0.79, RMSE = 387.8 g C mâˆ'2 yrâˆ'1). Specifically, iEVI performed better in cropland regions with high productivity but poorer in forests. The ability of iEVI in estimating GPP was better in deciduous biomes (except deciduous broadleaf forest) than in evergreen due to the large seasonal signal in iEVI in deciduous biomes. Likewise, GPP estimated from iEVI was in a closer agreement to global benchmarks at mid and high-latitudes, where deciduous biomes are more common and cloud cover has a smaller effect on remote sensing retrievals. Across biomes, a significant and negative correlation (R2 = 0.37, p  0.05) was observed between the strength (R2) of GPP-iEVI relationships and mean annual maximum leaf area index (LAImax), and the relationship between the strength and mean annual precipitation followed a similar trend. LAImax also revealed a scaling effect on GPP-iEVI relationships. Our results suggest that iEVI provides a very simple but robust approach to estimate spatial patterns of global annual GPP whereas its effect is comparable to various light-use-efficiency and data-driven models. The impact of vegetation structure on accuracy and sensitivity of EVI in estimating spatial GPP provides valuable clues to improve EVI-based models. |
BibTeX:
@article{Shi2017,
author = {Shi, Hao and Li, Longhui and Eamus, Derek and Huete, Alfredo and Cleverly, James and Tian, Xin and Yu, Qiang and Wang, Shaoqiang and Montagnani, Leonardo and Magliulo, Vincenzo and Rotenberg, Eyal and Pavelka, Marian and Carrara, Arnaud},
title = {Assessing the ability of MODIS EVI to estimate terrestrial ecosystem gross primary production of multiple land cover types},
journal = {Ecological Indicators},
year = {2017},
volume = {72},
pages = {153--164},
url = {http://linkinghub.elsevier.com/retrieve/pii/S1470160X16304836},
doi = {10.1016/j.ecolind.2016.08.022}
}
|
| Shirai T, Ishizawa M, Zhuravlev R, Ganshin A, Belikov D, Saito M, Oda T, Valsala V, Gomez-Pelaez AJ, Langenfelds R and Maksyutov S (2017), "A decadal inversion of CO2 using the Global Eulerian–Lagrangian Coupled Atmospheric model (GELCA): sensitivity to the ground-based observation network", Tellus B: Chemical and Physical Meteorology. Vol. 69(1), pp. 1291158. Taylor & Francis. |
BibTeX:
@article{Shirai2017,
author = {Shirai, T and Ishizawa, M and Zhuravlev, R and Ganshin, A and Belikov, D and Saito, M and Oda, T and Valsala, V and Gomez-Pelaez, A J and Langenfelds, R and Maksyutov, S},
title = {A decadal inversion of CO2 using the Global Eulerian–Lagrangian Coupled Atmospheric model (GELCA): sensitivity to the ground-based observation network},
journal = {Tellus B: Chemical and Physical Meteorology},
publisher = {Taylor & Francis},
year = {2017},
volume = {69},
number = {1},
pages = {1291158},
url = {https://doi.org/10.1080/16000889.2017.1291158},
doi = {10.1080/16000889.2017.1291158}
}
|
| Soja MJ, Askne JIH and Ulander LMH (2017), "Estimation of Boreal Forest Properties from TanDEM-X Data Using Inversion of the Interferometric Water Cloud Model", IEEE Geoscience and Remote Sensing Letters., jul, 2017. Vol. 14(7), pp. 997-1001. |
| Abstract: In this letter, the interferometric water cloud model (IWCM) is fit to 87 VV-polarized TanDEM-X acquisitions made between June 2011 and August 2014 over a boreal forest in Krycklan, northern Sweden, using a new method based on nonlinear least-squares optimization. A high-resolution digital terrain model is used as ground reference during interferometric synthetic-aperture radar (InSAR) processing and 26 stands with areas 1.5-22 ha and unaltered during the study period are studied. The dependence of biomass estimation performance, ground and vegetation backscatter coefficients (σ0gr) and σ0veg), canopy attenuation (α), and zero-biomass coherence (γ0) on selected system and environmental parameters is studied. High correlation between the estimated biomass and reference biomass derived from in situ measurements is observed for all 87 acquisitions (r between 0.81 and 0.93), while the root-mean-square difference is between 18% and 32% for all 43 acquisitions made in snow-free conditions and with heights-of-ambiguity (HOAs) between 36 and 150 m. Significant biomass estimation bias is observed for HOAs above 150 m and for some acquisitions over snow-covered forest. It is also observed that σ0gr and σ0veg are the largest for temperatures below 0 °C and with significant snow cover. For temperatures above 0 °C, σ0gr appears independent of temperature, while σ0veg shows a tendency to increase with temperature. Moreover, γ0 decreases from just below 1 for HOAs around 40 m to around 0.8 for HOAs above 150 m. |
BibTeX:
@article{Soja2017,
author = {Soja, MacIej J and Askne, Jan I H and Ulander, Lars M H},
title = {Estimation of Boreal Forest Properties from TanDEM-X Data Using Inversion of the Interferometric Water Cloud Model},
journal = {IEEE Geoscience and Remote Sensing Letters},
year = {2017},
volume = {14},
number = {7},
pages = {997--1001},
url = {http://ieeexplore.ieee.org/document/7935363/},
doi = {10.1109/LGRS.2017.2691355}
}
|
| Super I, Denier van der Gon HAC, Visschedijk AJH, Moerman MM, Chen H, van der Molen MK and Peters W (2017), "Interpreting continuous in-situ observations of carbon dioxide and carbon monoxide in the urban port area of Rotterdam", Atmospheric Pollution Research., jan, 2017. Vol. 8(1), pp. 174-187. |
| Abstract: Large networks of expensive instruments are often used to independently quantify and monitor urban CO2 emissions with sufficient level of detail. However, many developing regions cannot afford such a monitoring effort. We explore the use of a simple, less costly method to constrain urban emissions using only two measurement sites, one upwind and one downwind of the city of Rotterdam in the Netherlands. This provides an interesting dataset of concentration gradients of multiple combustion tracers over an urban-industrial complex. We find clear emission signals from three source sectors, mainly related to industrial activities in the port and from residential areas. We estimate the anthropogenic CO2 emissions for three footprints from our observations and find them in reasonable agreement with the Dutch National Emission Registration (NER) database after accounting for biogenic fluxes. The large confidence interval for one of the footprints illustrates that the presence of point sources complicates the flux estimates. Additionally, we were able to pinpoint a limitation in the emission database using observed fossil fuel CO:CO2 ratios, although the applicability of this method is limited for the footprint with a large influence from point source emissions. There is also a large variability in the observed ratios per footprint, which indicates that the dominant source type varies over time. Finally, we show that the fossil fuel CO concentration can be used to calculate fossil fuel CO2 if their emission ratio is well-known. |
BibTeX:
@article{Super2017,
author = {Super, I and Denier van der Gon, H A C and Visschedijk, A J H and Moerman, M M and Chen, H and van der Molen, M K and Peters, W},
title = {Interpreting continuous in-situ observations of carbon dioxide and carbon monoxide in the urban port area of Rotterdam},
journal = {Atmospheric Pollution Research},
year = {2017},
volume = {8},
number = {1},
pages = {174--187},
url = {http://linkinghub.elsevier.com/retrieve/pii/S1309104216300228},
doi = {10.1016/j.apr.2016.08.008}
}
|
| Tetzlaff D, Carey SK, McNamara JP, Laudon H and Soulsby C (2017), "The essential value of long-term experimental data for hydrology and water management", Water Resources Research., apr, 2017. Vol. 53(4), pp. 2598-2604. |
| Abstract: Observations and data from long-term experimental watersheds are the foundation of hydrology as a geoscience. They allow us to benchmark process understanding, observe trends and natural cycles, and are prerequisites for testing predictive models. Long-term experimental watersheds also are places where new measurement technologies are developed. These studies offer a crucial evidence base for understanding and managing the provision of clean water supplies, predicting and mitigating the effects of floods, and protecting ecosystem services provided by rivers and wetlands. They also show how to manage land and water in an integrated, sustainable way that reduces environmental and economic costs. |
BibTeX:
@article{Tetzlaff2017,
author = {Tetzlaff, Doerthe and Carey, Sean K and McNamara, James P and Laudon, Hjalmar and Soulsby, Chris},
title = {The essential value of long-term experimental data for hydrology and water management},
journal = {Water Resources Research},
year = {2017},
volume = {53},
number = {4},
pages = {2598--2604},
url = {http://doi.wiley.com/10.1002/2017WR020838},
doi = {10.1002/2017WR020838}
}
|
| Theodorakopoulos N, Lognoul M, Degrune F, Broux F, Regaert D, Muys C, Heinesch B, Bodson B, Aubinet M and Vandenbol M (2017), "Increased expression of bacterial amoA during an N2O emission peak in an agricultural field", Agriculture, Ecosystems and Environment., jan, 2017. Vol. 236, pp. 212-220. |
| Abstract: Levels of N-cycle gene transcripts (nirK, nirS, nosZ, amoA) were measured during an N2O emission peak in an agricultural soil. Automated dynamic closed chambers were used to monitor an N2O emission peak on a maize crop after a natural rainfall. The peak occurred rapidly after the rainfall began. Spatial and temporal variability in N2O emission was observed between chambers. An analysis of N-cycle gene transcript levels revealed an increase in bacterial amoA gene transcripts (but not in archaeal amoA transcripts), correlating strongly with N2O emission. This suggests the involvement of nitrification enzymes, despite a high water-filled pore space (80%). Reverse transcription of bacterial 16S rRNA followed by partial sequencing of the resulting cDNAs revealed few rainfall-induced changes in the potentially active bacterial community, and notably no significant change in the relative abundance of 16S rRNAs from the nitrifier genus Nitrosospira. Expression of the amoA gene appears as a possible proxy for monitoring the N2O emission peak. To our knowledge, this is the first experiment to evaluate the expression of N-cycle genes during an N2O emission peak on an agricultural field. |
BibTeX:
@article{Theodorakopoulos2017,
author = {Theodorakopoulos, Nicolas and Lognoul, Margaux and Degrune, Florine and Broux, François and Regaert, Donat and Muys, Céline and Heinesch, Bernard and Bodson, Bernard and Aubinet, Marc and Vandenbol, Micheline},
title = {Increased expression of bacterial amoA during an N2O emission peak in an agricultural field},
journal = {Agriculture, Ecosystems and Environment},
year = {2017},
volume = {236},
pages = {212--220},
url = {http://linkinghub.elsevier.com/retrieve/pii/S0167880916305849},
doi = {10.1016/j.agee.2016.12.002}
}
|
| Thum T, Zaehle S, Köhler P, Aalto T, Aurela M, Guanter L, Kolari P, Laurila T, Lohila A, Magnani F, Van Der Tol C and Markkanen T (2017), "Modelling sun-induced fluorescence and photosynthesis with a land surface model at local and regional scales in northern Europe", Biogeosciences., apr, 2017. Vol. 14(7), pp. 1969-1984. |
| Abstract: Recent satellite observations of sun-induced chlorophyll fluorescence (SIF) are thought to provide a large-scale proxy for gross primary production (GPP), thus providing a new way to assess the performance of land surface models (LSMs). In this study, we assessed how well SIF is able to predict GPP in the Fenno-Scandinavian region and what potential limitations for its application exist. We implemented a SIF model into the JSBACH LSM and used active leaf-level chlorophyll fluorescence measurements (Chl iF/i) to evaluate the performance of the SIF module at a coniferous forest at Hyytiälä, Finland. We also compared simulated GPP and SIF at four Finnish micrometeorological flux measurement sites to observed GPP as well as to satellite-observed SIF. Finally, we conducted a regional model simulation for the Fenno-Scandinavian region with JSBACH and compared the results to SIF retrievals from the GOME-2 (Global Ozone Monitoring Experiment-2) space-borne spectrometer and to observation-based regional GPP estimates. Both observations and simulations revealed that SIF can be used to estimate GPP at both site and regional scales. At regional scale the model was able to simulate observed SIF averaged over 5 years with ir/i2 of 0.86. The GOME-2-based SIF was a better proxy for GPP than the remotely sensed fAPAR (fraction of absorbed photosynthetic active radiation by vegetation). The observed SIF captured the seasonality of the photosynthesis at site scale and showed feasibility for use in improving of model seasonality at site and regional scale. |
BibTeX:
@article{Thum2017,
author = {Thum, Tea and Zaehle, Sönke and Köhler, Philipp and Aalto, Tuula and Aurela, Mika and Guanter, Luis and Kolari, Pasi and Laurila, Tuomas and Lohila, Annalea and Magnani, Federico and Van Der Tol, Christiaan and Markkanen, Tiina},
title = {Modelling sun-induced fluorescence and photosynthesis with a land surface model at local and regional scales in northern Europe},
journal = {Biogeosciences},
year = {2017},
volume = {14},
number = {7},
pages = {1969--1984},
url = {https://www.biogeosciences.net/14/1969/2017/},
doi = {10.5194/bg-14-1969-2017}
}
|
| Thum T, MacBean N, Peylin P, Bacour C, Santaren D, Longdoz B, Loustau D and Ciais P (2017), "The potential benefit of using forest biomass data in addition to carbon and water flux measurements to constrain ecosystem model parameters: Case studies at two temperate forest sites", Agricultural and Forest Meteorology., mar, 2017. Vol. 234-235, pp. 48-65. |
| Abstract: Biomass as a resource, and as a vulnerable carbon pool, is a key variable to diagnose the impacts of global changes on the terrestrial biosphere, and therefore its proper description in models is crucial. Model-Data Fusion (MDF) or data assimilation methods are useful tools in improving ecosystem models that describe interactions between vegetation and atmosphere. We use a MDF method based on a Bayesian approach, in which data are combined with a process model in order to provide optimized estimates of model parameters and to better quantify model uncertainties, whilst taking into account prior information on the parameters. With this method we are able to use multiple data streams, which allows us to simultaneously constrain modeled variables at site level across different temporal scales. In this study both high frequency eddy covariance flux measurements of net CO2 and evapotranspiration (ET), and low frequency biometric measurements of total aboveground biomass and the annual increment (which includes all compartments), are assimilated with the ORCHIDEE model version “AR5†at a beech (Hesse) and a maritime pine (Le Bray) forest site using four to five years of flux data and nine years of biomass data. When assimilating the observed aboveground annual biomass increment (AGB_inc) together with net CO2 and ET flux, the RMSE of modelled AGB_inc was reduced from the a priori estimates by 37% at Hesse and 69% at Le Bray, without reducing the fit to the net CO2 and ET that can be achieved when assimilating flux data alone. Assimilating biomass increment data also provides insight in the performance of the allocation scheme of the model. Comparison with detailed site-based measurements at Hesse showed that the optimization reduced positive biases in the model, for example in fine root and leaf production. We also investigated how to use stand-scale total aboveground biomass in optimization (AGB_tot). However, this study demonstrated that assimilating AGB_tot measurements in the ORCHIDEE-AR5 model lead to some inconsistencies, particularly for the annual dynamics of the AGB_inc, partly because this version of the model lacked a realistic representation of forest stand processes including management and disturbances. |
BibTeX:
@article{Thum2017a,
author = {Thum, T and MacBean, N and Peylin, P and Bacour, C and Santaren, D and Longdoz, B and Loustau, D and Ciais, P},
title = {The potential benefit of using forest biomass data in addition to carbon and water flux measurements to constrain ecosystem model parameters: Case studies at two temperate forest sites},
journal = {Agricultural and Forest Meteorology},
year = {2017},
volume = {234-235},
pages = {48--65},
url = {http://linkinghub.elsevier.com/retrieve/pii/S0168192316307201},
doi = {10.1016/j.agrformet.2016.12.004}
}
|
| Tiwari T, Lidman F, Laudon H, Lidberg W and Ågren AM (2017), "GIS-based prediction of stream chemistry using landscape composition, wet areas, and hydrological flow pathways", Journal of Geophysical Research: Biogeosciences., jan, 2017. Vol. 122(1), pp. 65-79. |
| Abstract: Landscape morphology exerts strong, scale-dependent controls on stream hydrology and biogeochemistry in heterogeneous catchments. We applied three descriptors of landscape structure at different spatial scales based on new geographic information system tools to predict variability in stream concentrations for a wide range of solutes (Al, Ba, Be, Ca, Fe, K, Mg, Na, S, Si, Sr, Sc, Co, Cr, Ni, Cu, As, Se, Rb, Y, Cd, Sb, Cs, La, Pb, Th, U, DOC, and Cl) using a linear regression analysis. Results showed that less reactive elements, which can be expected to behave more conservatively in the landscape (e.g., Na, K, Ca, Mg, Cl, and Si), generally were best predicted from the broader-scale description of landscape composition (areal coverage of peat, tills, and sorted sediments). These results highlight the importance of mineral weathering as a source of some elements, which was best captured by landscape-scale descriptors of catchment structure. By contrast, more nonconservative elements (e.g., DOC, Al, Cd, Cs, Co, Th, Y, and U), were best predicted by defining wet areas and/or flow path lengths of different patches in the landscape. This change in the predictive models reflect the importance of peat deposits, such as organic-rich riparian zones and mire ecosystems, which are favorable environments for biogeochemical reactions of more nonconservative elements. As such, using this understanding of landscape influences on stream chemistry can provide improved mitigation strategies and management plans that specifically target source areas, so as to minimize mobilization of undesired elements into streams. |
BibTeX:
@article{Tiwari2017,
author = {Tiwari, Tejshree and Lidman, Fredrik and Laudon, Hjalmar and Lidberg, William and Ågren, Anneli M},
title = {GIS-based prediction of stream chemistry using landscape composition, wet areas, and hydrological flow pathways},
journal = {Journal of Geophysical Research: Biogeosciences},
year = {2017},
volume = {122},
number = {1},
pages = {65--79},
url = {http://doi.wiley.com/10.1002/2016JG003399},
doi = {10.1002/2016JG003399}
}
|
| Tsuruta A, Aalto T, Backman L, Hakkarainen J, Van Der Laan-Luijkx IT, Krol MC, Spahni R, Houweling S, Laine M, Dlugokencky E, Gomez-Pelaez AJ, Van Der Schoot M, Langenfelds R, Ellul R, Arduini J, Apadula F, Gerbig C, Feist DG, Kivi R, Yoshida Y and Peters W (2017), "Global methane emission estimates for 2000-2012 from CarbonTracker Europe-CH4 v1.0", Geoscientific Model Development., mar, 2017. Vol. 10(3), pp. 1261-1289. |
| Abstract: We present a global distribution of surface methane (CH4) emission estimates for 2000-2012 derived using the CarbonTracker Europe-CH4 (CTE-CH4) data assimilation system. In CTE-CH4, anthropogenic and biospheric CH4 emissions are simultaneously estimated based on constraints of global atmospheric in situ CH4 observations. The system was configured to either estimate only anthropogenic or biospheric sources per region, or to estimate both categories simultaneously. The latter increased the number of optimizable parameters from 62 to 78. In addition, the differences between two numerical schemes available to perform turbulent vertical mixing in the atmospheric transport model TM5 were examined. Together, the system configurations encompass important axes of uncertainty in inversions and allow us to examine the robustness of the flux estimates. The posterior emission estimates are further evaluated by comparing simulated atmospheric CH4 to surface in situ observations, vertical profiles of CH4 made by aircraft, remotely sensed dry-air total column-averaged mole fraction (XCH4) from the Total Carbon Column Observing Network (TCCON), and XCH4 from the Greenhouse gases Observing Satellite (GOSAT). The evaluation with non-assimilated observations shows that posterior XCH4 is better matched with the retrievals when the vertical mixing scheme with faster interhemispheric exchange is used. Estimated posterior mean total global emissions during 2000-2012 are 516 ± 51 Tg CH4 yr-1, with an increase of 18 Tg CH4 yr-1 from 2000-2006 to 2007-2012. The increase is mainly driven by an increase in emissions from South American temperate, Asian temperate and Asian tropical TransCom regions. In addition, the increase is hardly sensitive to different model configurations ( 2 Tg CH4 yr-1 difference), and much smaller than suggested by EDGAR v4.2 FT2010 inventory (33 Tg CH4 yr-1), which was used for prior anthropogenic emission estimates. The result is in good agreement with other published estimates from inverse modelling studies (16-20 Tg CH4 yr-1). However, this study could not conclusively separate a small trend in biospheric emissions (-5 to +6.9 Tg CH4 yr-1) from the much larger trend in anthropogenic emissions (15-27 Tg CH4 yr-1). Finally, we find that the global and North American CH4 balance could be closed over this time period without the previously suggested need to strongly increase anthropogenic CH4 emissions in the United States. With further developments, especially on the treatment of the atmospheric CH4 sink, we expect the data assimilation system presented here will be able to contribute to the ongoing interpretation of changes in this important greenhouse gas budget. |
BibTeX:
@article{Tsuruta2017,
author = {Tsuruta, Aki and Aalto, Tuula and Backman, Leif and Hakkarainen, Janne and Van Der Laan-Luijkx, Ingrid T and Krol, Maarten C and Spahni, Renato and Houweling, Sander and Laine, Marko and Dlugokencky, Ed and Gomez-Pelaez, Angel J and Van Der Schoot, Marcel and Langenfelds, Ray and Ellul, Raymond and Arduini, Jgor and Apadula, Francesco and Gerbig, Christoph and Feist, DIetrich G and Kivi, Rigel and Yoshida, Yukio and Peters, Wouter},
title = {Global methane emission estimates for 2000-2012 from CarbonTracker Europe-CH4 v1.0},
journal = {Geoscientific Model Development},
year = {2017},
volume = {10},
number = {3},
pages = {1261--1289},
url = {https://www.geosci-model-dev.net/10/1261/2017/},
doi = {10.5194/gmd-10-1261-2017}
}
|
| Vaglio GL, Pirotti F, Callegari M, Chen Q, Cuozzo G, Lingua E, Notarnicola C and Papale D (2017), "Potential of ALOS2 and NDVI to estimate forest above-ground biomass, and comparison with lidar-derived estimates", Remote Sensing., dec, 2017. Vol. 9(1), pp. 18. |
| Abstract: Remote sensing supports carbon estimation, allowing the upscaling of field measurements to large extents. Lidar is considered the premier instrument to estimate above ground biomass, but data are expensive and collected on-demand, with limited spatial and temporal coverage. The previous JERS and ALOS SAR satellites data were extensively employed to model forest biomass, with literature suggesting signal saturation at low-moderate biomass values, and an influence of plot size on estimates accuracy. The ALOS2 continuity mission since May 2014 produces data with improved features with respect to the former ALOS, such as increased spatial resolution and reduced revisit time. We used ALOS2 backscatter data, testing also the integration with additional features (SAR textures and NDVI from Landsat 8 data) together with ground truth, to model and map above ground biomass in two mixed forest sites: Tahoe (California) and Asiago (Alps). While texture was useful to improve the model performance, the best model was obtained using joined SAR and NDVI (R2 equal to 0.66). In this model, only a slight saturation was observed, at higher levels than what usually reported in literature for SAR; the trend requires further investigation but the model confirmed the complementarity of optical and SAR datatypes. For comparison purposes, we also generated a biomass map for Asiago using lidar data, and considered a previous lidar-based study for Tahoe; in these areas, the observed R2 were 0.92 for Tahoe and 0.75 for Asiago, respectively. The quantitative comparison of the carbon stocks obtained with the two methods allows discussion of sensor suitability. The range of local variation captured by lidar is higher than those by SAR and NDVI, with the latter showing overestimation. However, this overestimation is very limited for one of the study areas, suggesting that when the purpose is the overall quantification of the stored carbon, especially in areas with high carbon density, satellite data with lower cost and broad coverage can be as effective as lidar. |
BibTeX:
@article{Vaglio2017,
author = {Vaglio, Gaia Laurin and Pirotti, Francesco and Callegari, Mattia and Chen, Qi and Cuozzo, Giovanni and Lingua, Emanuele and Notarnicola, Claudia and Papale, Dario},
title = {Potential of ALOS2 and NDVI to estimate forest above-ground biomass, and comparison with lidar-derived estimates},
journal = {Remote Sensing},
year = {2017},
volume = {9},
number = {1},
pages = {18},
url = {http://www.mdpi.com/2072-4292/9/1/18},
doi = {10.3390/rs9010018}
}
|
| Vanbeveren SPP, Spinelli R, Eisenbies M, Schweier J, Mola-Yudego B, Magagnotti N, Acuna M, Dimitriou I and Ceulemans R (2017), "Mechanised harvesting of short-rotation coppices", Renewable and Sustainable Energy Reviews., sep, 2017. Vol. 76, pp. 90-104. |
| Abstract: Short-rotation coppice (SRC) is an important source of woody biomass for bioenergy. Despite the research carried out on several aspects of SRC production, many uncertainties create barriers to farmers establishing SRC plantations. One of the key economic sources of uncertainty is harvesting methods and costs; more specifically, the performance of contemporary machine methods is reviewed. We collected data from 25 literature references, describing 166 field trials. Three harvesting systems predominate: 127 used single pass cut-and-chip harvesters, 16 used double pass cut-and-store harvesters, 22 used the cut-and-bale harvester, and one study used a cut-and-billet harvester. Mean effective material capacity (EMC) was 30 Mg fresh weight h-1 (cut-and-chip technique), 19 Mg fresh weight h-1 (cut-and-store technique) and 14 Mg fresh weight h-1 (cut-and-bale technique). However, this comparison does not consider engine power, which varies with harvesting technique; cut-and-chip harvesters are by far the most powerful (200 kW). When limiting harvesters to a maximum engine power of 200 kW, cut-and-chip harvesters achieved the lowest EMC (5 Mg fresh weight h-1), but they also perform a higher degree of material processing (cutting and chipping) than cut-and-store harvesters (only cutting) or than the cut-and-bale harvester (cutting and baling). The trend in commercial machinery is towards increased engine power for cut-and-chip and cut-and-store harvesters. No trends in EMC were documented for the recently developed cut-and-bale harvesting technique, which is presently produced in one version only. Field stocking (5–157 Mg fresh weight ha-1 in the reviewed studies) has a significant effect on harvester EMC. Lower field stocking can constrain the maximum EMC achieved by the machine given that harvesting speed can only be increased to a point. While the reviewed studies did not contain sufficient harvesting cost data for a thorough analysis, harvesting costs ranged between 6 and 99 € Mg-1 fresh weight. |
BibTeX:
@article{Vanbeveren2017,
author = {Vanbeveren, Stefan P P and Spinelli, Raffaele and Eisenbies, Mark and Schweier, Janine and Mola-Yudego, Blas and Magagnotti, Natascia and Acuna, Mauricio and Dimitriou, Ioannis and Ceulemans, Reinhart},
title = {Mechanised harvesting of short-rotation coppices},
journal = {Renewable and Sustainable Energy Reviews},
year = {2017},
volume = {76},
pages = {90--104},
url = {http://linkinghub.elsevier.com/retrieve/pii/S1364032117302782},
doi = {10.1016/j.rser.2017.02.059}
}
|
| Vanbeveren SPP, Magagnotti N and Spinelli R (2017), "Increasing the value recovery from short-rotation coppice harvesting", BioResources., nov, 2017. Vol. 12(1), pp. 696-703. |
| Abstract: Farmers are reluctant to establish short-rotation coppice because too many uncertainties remain about its economic feasibility. Up to now, most progress has been accomplished by increasing plantation yields through genetic improvement and by reducing management costs through mechanization. In contrast, the potential increase of value recovery has received much less attention. We therefore compared whole-tree chipping with integrated harvesting to test whether more profit could be made by producing pulpwood logs and wood chips, rather than wood chips only. The two systems were compared side-by-side with identical machinery on the same field. Chip production cost was higher for integrated harvesting (15 € Mg-1), because the system was less productive (9 Mg h-1), as compared with whole-tree chipping (9 € Mg-1 and 25 Mg h-1). Pulpwood log production only occurred with the integrated harvesting system, at a cost of 8 € Mg-1. Integrated harvesting incurred higher production costs, but also accrued better value recovery. Under current market conditions, the two systems offered similar profits, in the vicinity of 5000 € ha-1. However, integrated harvesting offered higher flexibility, with a potentially better resilience to market fluctuations. |
BibTeX:
@article{Vanbeveren2017a,
author = {Vanbeveren, Stefan P P and Magagnotti, Natascia and Spinelli, Raffaele},
title = {Increasing the value recovery from short-rotation coppice harvesting},
journal = {BioResources},
year = {2017},
volume = {12},
number = {1},
pages = {696--703},
url = {http://ojs.cnr.ncsu.edu/index.php/BioRes/article/view/10724},
doi = {10.15376/biores.12.1.696-703}
}
|
| Vanden Broucke S and Van Lipzig N (2017), "Do convection-permitting models improve the representation of the impact of LUC?", Climate Dynamics., oct, 2017. Vol. 49(7-8), pp. 2749-2763. Springer Verlag. |
| Abstract: In this study we assess the added value of convection permitting scale (CPS) simulations in studies using regional climate models to quantify the bio-geophysical climate impact of land-use change (LUC). To accomplish this, a comprehensive model evaluation methodology is applied to both non-CPS and CPS simulations. The main characteristics of the evaluation methodology are (1) the use of paired eddy-covariance site observations (forest vs open land) and (2) a simultaneous evaluation of all surface energy budget components. Results show that although generally satisfactory, non-CPS simulations fall short of completely reproducing the observed LUC signal because of three key biases. CPS scale simulations succeed at significantly reducing two of these biases, namely, those in daytime shortwave radiation and daytime sensible heat flux. Also, CPS slightly reduces a third bias in nighttime incoming longwave radiation. The daytime improvements can be attributed partially to the switch from parameterized to explicit convection, the associated improvement in the simulation of afternoon convective clouds, and resulting surface energy budget and atmospheric feedbacks. Also responsible for the improvements during daytime is a better representation of surface heterogeneity and thus, surface roughness. Meanwhile, the modest nighttime longwave improvement can be attributed to increased vertical atmospheric resolution. However, the model still fails at reproducing the magnitude of the observed nighttime longwave difference. One possible explanation for this persistent bias is the nighttime radiative effect of biogenic volatile organic compound emissions over the forest site. A correlation between estimated emission rates and the observed nighttime longwave difference, as well as the persistence of the longwave bias provide support for this hypothesis. However, more research is needed to conclusively determine if the effect indeed exists. |
BibTeX:
@article{VandenBroucke2017,
author = {Vanden Broucke, Sam and Van Lipzig, Nicole},
title = {Do convection-permitting models improve the representation of the impact of LUC?},
journal = {Climate Dynamics},
publisher = {Springer Verlag},
year = {2017},
volume = {49},
number = {7-8},
pages = {2749--2763},
doi = {10.1007/s00382-016-3489-5}
}
|
| Van Der Laan-Luijkx IT, Van Der Velde IR, Van Der Veen E, Tsuruta A, Stanislawska K, Babenhauserheide A, Fang Zhang H, Liu Y, He W, Chen H, Masarie KA, Krol MC and Peters W (2017), "The CarbonTracker Data Assimilation Shell (CTDAS) v1.0: Implementation and global carbon balance 2001-2015", Geoscientific Model Development., jul, 2017. Vol. 10(7), pp. 2785-2800. |
| Abstract: Data assimilation systems are used increasingly to constrain the budgets of reactive and long-lived gases measured in the atmosphere. Each trace gas has its own lifetime, dominant sources and sinks, and observational network (from flask sampling and in situ measurements to space-based remote sensing) and therefore comes with its own optimal configuration of the data assimilation. The CarbonTracker Europe data assimilation system for CO2 estimates global carbon sources and sinks, and updates are released annually and used in carbon cycle studies. CarbonTracker Europe simulations are performed using the new modular implementation of the data assimilation system: The CarbonTracker Data Assimilation Shell (CTDAS). Here, we present and document this redesign of the data assimilation code that forms the heart of CarbonTracker, specifically meant to enable easy extension and modification of the data assimilation system. This paper also presents the setup of the latest version of CarbonTracker Europe (CTE2016), including the use of the gridded state vector, and shows the resulting carbon flux estimates. We present the distribution of the carbon sinks over the hemispheres and between the land biosphere and the oceans. We show that with equal fossil fuel emissions, 2015 has a higher atmospheric CO2 growth rate compared to 2014, due to reduced net land carbon uptake in later year. The European carbon sink is especially present in the forests, and the average average net uptake over 2001-2015 was 0:17±0:11 PgCyr-1 with reductions to zero during drought years. Finally, we also demonstrate the versatility of CTDAS by presenting an overview of the wide range of applications for which it has been used so far. |
BibTeX:
@article{VanDerLaan-Luijkx2017,
author = {Van Der Laan-Luijkx, Ingrid T and Van Der Velde, Ivar R and Van Der Veen, Emma and Tsuruta, Aki and Stanislawska, Karolina and Babenhauserheide, Arne and Fang Zhang, Hui and Liu, Yu and He, Wei and Chen, Huilin and Masarie, Kenneth A and Krol, Maarten C and Peters, Wouter},
title = {The CarbonTracker Data Assimilation Shell (CTDAS) v1.0: Implementation and global carbon balance 2001-2015},
journal = {Geoscientific Model Development},
year = {2017},
volume = {10},
number = {7},
pages = {2785--2800},
url = {https://www.geosci-model-dev.net/10/2785/2017/},
doi = {10.5194/gmd-10-2785-2017}
}
|
| van Meeningen Y, Wang M, Karlsson T, Seifert A, Schurgers G, Rinnan R and Holst T (2017), "Isoprenoid emission variation of Norway spruce across a European latitudinal transect", Atmospheric Environment., dec, 2017. Vol. 170, pp. 45-57. |
| Abstract: Norway spruce (Picea abies) is one of the dominant tree species in the European boreal zone with the capacity to grow over large areas within Europe. It is an important emitter of biogenic volatile organic compounds (BVOCs), which can act as precursors of photochemical smog and ozone and contribute to the formation and growth of secondary organic aerosols (SOA) in the atmosphere. Isoprenoid emissions were measured from Norway spruce trees at seven different sites, distributed from Ljubljana in Slovenia to Piikkiö in Finland. Four of the sites were part of a network of genetically identical spruce trees and contained two separate provenances. The remaining three sites were part of other networks which have been used to conduct studies in the European boreal zone. There were minimal differences in the standardized emission rates between sites and across latitudes. The emission profile differed between provenances and sites, but there were not any distinct patterns which could be connected to a change in latitude. By using genetically identical trees and comparing the emission rates between sites and with genetically different trees, it was observed that the emission patterns were mostly influenced by genetics. But in order to confirm this possible stability of the relative emission profile based on genetics, more studies need to be performed. The effects of branch height, season and variation between years on observed emission pattern variations were also investigated. There were indications of potential influences of all three factors. However, due to different experimental setups between measurement campaigns, it is difficult to draw any robust conclusions. |
BibTeX:
@article{VanMeeningen2017,
author = {van Meeningen, Ylva and Wang, Min and Karlsson, Tomas and Seifert, Ana and Schurgers, Guy and Rinnan, Riikka and Holst, Thomas},
title = {Isoprenoid emission variation of Norway spruce across a European latitudinal transect},
journal = {Atmospheric Environment},
year = {2017},
volume = {170},
pages = {45--57},
url = {http://linkinghub.elsevier.com/retrieve/pii/S1352231017306441},
doi = {10.1016/j.atmosenv.2017.09.045}
}
|
| Veloso A, Mermoz S, Bouvet A, Le Toan T, Planells M, Dejoux JF and Ceschia E (2017), "Understanding the temporal behavior of crops using Sentinel-1 and Sentinel-2-like data for agricultural applications", Remote Sensing of Environment., sep, 2017. Vol. 199, pp. 415-426. Elsevier Inc.. |
| Abstract: Crop monitoring information is essential for food security and to improve our understanding of the role of agriculture on climate change, among others. Remotely sensing optical and radar data can help to map crop types and to estimate biophysical parameters, especially with the availability of an unprecedented amount of free Sentinel data within the Copernicus programme. These datasets, whose continuity is guaranteed up to decades, offer a unique opportunity to monitor crops systematically every 5 to 10 days. Before developing operational monitoring methods, it is important to understand the temporal variations of the remote sensing signal of different crop types in a given region. In this study, we analyse the temporal trajectory of remote sensing data for a variety of winter and summer crops that are widely cultivated in the world (wheat, rapeseed, maize, soybean and sunflower). The test region is in southwest France, where Sentinel-1 data have been acquired since 2014. Because Sentinel-2 data were not available for this study, optical satellites similar to Sentinel-2 are used, mainly to derive NDVI, for a comparison between the temporal behaviors with radar data. The SAR backscatter and NDVI temporal profiles of fields with varied management practices and environmental conditions are interpreted physically. Key findings from this analysis, leading to possible applications of Sentinel-1 data, with or without the conjunction of Sentinel-2, are then described. This study points out the interest of SAR data and particularly the VH/VV ratio, which is poorly documented in previous studies. |
BibTeX:
@article{Veloso2017,
author = {Veloso, Amanda and Mermoz, Stéphane and Bouvet, Alexandre and Le Toan, Thuy and Planells, Milena and Dejoux, Jean François and Ceschia, Eric},
title = {Understanding the temporal behavior of crops using Sentinel-1 and Sentinel-2-like data for agricultural applications},
journal = {Remote Sensing of Environment},
publisher = {Elsevier Inc.},
year = {2017},
volume = {199},
pages = {415--426},
doi = {10.1016/j.rse.2017.07.015}
}
|
| Ventrillard I, Xueref-Remy I, Schmidt M, Yver Kwok C, Faïn X and Romanini D (2017), "Comparison of optical-feedback cavity-enhanced absorption spectroscopy and gas chromatography for ground-based and airborne measurements of atmospheric CO concentration", Atmospheric Measurement Techniques., may, 2017. Vol. 10(5), pp. 1803-1812. |
| Abstract: We present the first comparison of carbon monoxide (CO) measurements performed with a portable laser spectrometer that exploits the optical-feedback cavity-enhanced absorption spectroscopy (OF-CEAS) technique, against a high-performance automated gas chromatograph (GC) with a mercuric oxide reduction gas detector (RGD). First, measurements of atmospheric CO mole fraction were continuously collected in a Paris (France) suburb over 1 week. Both instruments showed an excellent agreement within typically 2 ppb (part per billion in volume), fulfilling the World Meteorological Organization (WMO) recommendation for CO inter-laboratory comparison. The compact size and robustness of the OF-CEAS instrument allowed its operation aboard a small aircraft employed for routine tropospheric air analysis over the French Orléans forest area. Direct OF-CEAS real-time CO measurements in tropospheric air were then compared with later analysis of flask samples by the gas chromatograph. Again, a very good agreement was observed. This work establishes that the OF-CEAS laser spectrometer can run unattended at a very high level of sensitivity ( 1 ppb) and stability without any periodic calibration. |
BibTeX:
@article{Ventrillard2017,
author = {Ventrillard, Irene and Xueref-Remy, Irene and Schmidt, Martina and Yver Kwok, Camille and Faïn, Xavier and Romanini, Daniele},
title = {Comparison of optical-feedback cavity-enhanced absorption spectroscopy and gas chromatography for ground-based and airborne measurements of atmospheric CO concentration},
journal = {Atmospheric Measurement Techniques},
year = {2017},
volume = {10},
number = {5},
pages = {1803--1812},
url = {https://www.atmos-meas-tech.net/10/1803/2017/},
doi = {10.5194/amt-10-1803-2017}
}
|
| Verryckt LT, Op De Beeck M, Neirynck J, Gielen B, Roland M and Janssens IA (2017), "No impact of tropospheric ozone on the gross primary productivity of a Belgian pine forest", Biogeosciences., apr, 2017. Vol. 14(7), pp. 1839-1855. |
| Abstract: High stomatal ozone (O3) uptake has been shown to negatively affect crop yields and the growth of tree seedlings. However, little is known about the effect of O3 on the carbon uptake by mature forest trees. This study investigated the effect of high O3 events on gross primary productivity (GPP) for a Scots pine stand near Antwerp, Belgium over the period 1998-2013. Stomatal O3 fluxes were modelled using in situ O3 mixing ratio measurements and a multiplicative stomatal model, which was parameterised and validated for this Scots pine stand. Ozone-induced GPP reduction is most likely to occur during or shortly after days with high stomatal O3 uptake. Therefore, a GPP model within an artificial neural network was parameterised for days with low stomatal O3 uptake rates and used to simulate GPP during periods of high stomatal O3 uptake. Possible negative effects of high stomatal O3 uptake on GPP would then result in an overestimation of GPP by the model during or after high stomatal O3 uptake events. The O3 effects on GPP were linked to AOT40 and POD1. Although the critical levels for both indices were exceeded in every single year, no significant negative effects of O3 on GPP were found, and no correlations between GPP residuals and AOT40 and POD1 were found. Overall, we conclude that no O3 effects were detected on the carbon uptake by this Scots pine stand. |
BibTeX:
@article{Verryckt2017,
author = {Verryckt, Lore T and Op De Beeck, Maarten and Neirynck, Johan and Gielen, Bert and Roland, Marilyn and Janssens, Ivan A},
title = {No impact of tropospheric ozone on the gross primary productivity of a Belgian pine forest},
journal = {Biogeosciences},
year = {2017},
volume = {14},
number = {7},
pages = {1839--1855},
url = {https://www.biogeosciences.net/14/1839/2017/},
doi = {10.5194/bg-14-1839-2017}
}
|
| Vitali V, Büntgen U and Bauhus J (2017), "Silver fir and Douglas fir are more tolerant to extreme droughts than Norway spruce in south-western Germany", Global Change Biology., dec, 2017. Vol. 23(12), pp. 5108-5119. |
| Abstract: Improving our understanding of the potential of forest adaptation is an urgent task in the light of predicted climate change. Long-term alternatives for susceptible yet economically important tree species such as Norway spruce (Picea abies) are required, if the frequency and intensity of summer droughts will continue to increase. Although Silver fir (Abies alba) and Douglas fir (Pseudotsuga menziesii) have both been described as drought-tolerant species, our understanding of their growth responses to drought extremes is still limited. Here, we use a dendroecological approach to assess the resistance, resilience, and recovery of these important central Europe to conifer species the exceptional droughts in 1976 and 2003. A total of 270 trees per species were sampled in 18 managed mixed-species stands along an altitudinal gradient (400–1200 m a.s.l.) at the western slopes of the southern and central Black Forest in southwest Germany. While radial growth in all species responded similarly to the 1976 drought, Norway spruce was least resistant and resilient to the 2003 summer drought. Silver fir showed the overall highest resistance to drought, similarly to Douglas fir, which exhibited the widest growth rings. Silver fir trees from lower elevations were more drought prone than trees at higher elevations. Douglas fir and Norway spruce, however, revealed lower drought resilience at higher altitudes. Although the 1976 and 2003 drought extremes were quite different, Douglas fir maintained consistently the highest radial growth. Although our study did not examine population-level responses, it clearly indicates that Silver fir and Douglas fir are generally more resistant and resilient to previous drought extremes and are therefore suitable alternatives to Norway spruce; Silver fir more so at higher altitudes. Cultivating these species instead of Norway spruce will contribute to maintaining a high level of productivity across many Central European mountain forests under future climate change. |
BibTeX:
@article{Vitali2017,
author = {Vitali, Valentina and Büntgen, Ulf and Bauhus, Jürgen},
title = {Silver fir and Douglas fir are more tolerant to extreme droughts than Norway spruce in south-western Germany},
journal = {Global Change Biology},
year = {2017},
volume = {23},
number = {12},
pages = {5108--5119},
url = {http://doi.wiley.com/10.1111/gcb.13774},
doi = {10.1111/gcb.13774}
}
|
| Vuolo RM, Loubet B, Mascher N, Gueudet JC, Durand B, Laville P, Zurfluh O, Ciuraru R, Stella P and Trebs I (2017), "Nitrogen oxides and ozone fluxes from an oilseed-rape management cycle: The influence of cattle slurry application", Biogeosciences., may, 2017. Vol. 14(8), pp. 2225-2244. Copernicus GmbH. |
| Abstract: This study reports NO, NO2 and O3 mixing ratios and flux measurements using the eddy covariance method during a 7-month period over an oilseed-rape field, spanning an organic and a mineral fertilisation event. Cumulated NO emissions during the whole period were in agreement with previous studies and showed quite low emissions of 0.26 kgNha-1 with an emission factor of 0.27 %, estimated as the ratio between total N emitted in the form of NO and total N input. The NO emissions were higher following organic fertilisation in August due to conditions favouring nitrification (soil water content around 20% and high temperatures), while mineral fertilisation in February did not result in high emissions. The ozone deposition velocity increased significantly after organic fertilisation. The analysis of the chemical and turbulent transport times showed that reactions between NO, NO2 and O3 below the measurement height occurred constantly throughout the 7-month period. Following organic fertilisation, the NO ground fluxes were 30% larger than the NO fluxes at the measurement height (3.2 m), while the NO2 fluxes switched from deposition to emission during certain periods, being negative at the surface and positive at the measurement height. This phenomenon of "apparent NO2 emissions" appears to be significant during strong NO emissions and high O3 ambient mixing ratios, even on a bare soil during August. |
BibTeX:
@article{Vuolo2017,
author = {Vuolo, Raffaella M. and Loubet, Benjamin and Mascher, Nicolas and Gueudet, Jean Christophe and Durand, Brigitte and Laville, Patricia and Zurfluh, Olivier and Ciuraru, Raluca and Stella, Patrick and Trebs, Ivonne},
title = {Nitrogen oxides and ozone fluxes from an oilseed-rape management cycle: The influence of cattle slurry application},
journal = {Biogeosciences},
publisher = {Copernicus GmbH},
year = {2017},
volume = {14},
number = {8},
pages = {2225--2244},
doi = {10.5194/bg-14-2225-2017}
}
|
| Wällstedt T, Björkvald L, Laudon H, Borg H and Mörth CM (2017), "Landscape control on the hydrogeochemistry of As, Co and Pb in a boreal stream network", Geochimica et Cosmochimica Acta., aug, 2017. Vol. 211, pp. 194-213. |
| Abstract: In a boreal stream network, stream water concentrations of As, Co and Pb (filtered, 0.4 μm) of 10 nested streams were studied during two consecutive years in order to evaluate the influence of land cover on the temporal and spatial variability of metal concentrations and speciation. Mean concentrations of Co and Pb showed significant but contrasting relationship to landscape type, while As concentrations were not related to landscape type. Highest concentrations of Pb were found in the wetland dominated streams (30% wetland), which was suggested to be controlled by atmospheric deposition in combination with high DOC release from the wetlands. For Co, the highest concentrations were found in the forest dominated sites (98% forest), which were attributed to the weathering of minerogenic sources. Contrasting response to runoff events could also be related to landscape type; during the spring flood, decreasing concentrations of As, Co and Pb were observed in the wetland dominated catchments due to dilution, while increasing concentrations during spring flood were observed in the mixed catchments (2–30% wetland) and to some degree in the forested catchments, probably due to flushing of the organic-rich riparian sources. Further, metal speciation was calculated using the geochemical equilibrium model Visual MINTEQ. This suggests that dissolved inorganic species of As and Co dominated in headwater streams with low pH while DOC had a major influencing role for Pb. In the larger mixed streams where pH was higher and precipitation of e.g. colloidal Fe and Mn (hydr)oxides was favoured, the major influencing factor was instead adsorption to colloidal Fe for As and Pb, while association to organic matter and colloids of e.g. Mn influenced the concentrations of Co. We thus conclude that landscape type and the magnitude of the runoff events are of great importance for the spatial and temporal variations of As, Co and Pb in this boreal stream network. Projected climate change, with increasing runoff, may therefore influence riverine concentrations and fluxes differently, depending on the prevailing landscape type. |
BibTeX:
@article{Wallstedt2017,
author = {Wällstedt, Teresia and Björkvald, Louise and Laudon, Hjalmar and Borg, Hans and Mörth, Carl Magnus},
title = {Landscape control on the hydrogeochemistry of As, Co and Pb in a boreal stream network},
journal = {Geochimica et Cosmochimica Acta},
year = {2017},
volume = {211},
pages = {194--213},
url = {http://linkinghub.elsevier.com/retrieve/pii/S0016703716304902},
doi = {10.1016/j.gca.2016.08.030}
}
|
| Wang Z, Warneke T, Deutscher NM, Notholt J, Karstens U, Saunois M, Schneider M, Sussmann R, Sembhi H, Griffith DWT, Pollard DF, Kivi R, Petri C, Velazco VA, Ramonet M and Chen H (2017), "Contributions of the troposphere and stratosphere to CH4 model biases", Atmospheric Chemistry and Physics., nov, 2017. Vol. 17(21), pp. 13283-13295. |
| Abstract: Inverse modelling is a useful tool for retrieving CH4 fluxes; however, evaluation of the applied chemical transport model is an important step before using the inverted emissions. For inversions using column data one concern is how well the model represents stratospheric and tropospheric CH4 when assimilating total column measurements. In this study atmospheric CH4 from three inverse models is compared to FTS (Fourier transform spectrometry), satellite and in situ measurements. Using the FTS measurements the model biases are separated into stratospheric and tropospheric contributions. When averaged over all FTS sites the model bias amplitudes (absolute model to FTS differences) are 7.4 ± 5.1, 6.7 ± 4.8, and 8.1 ± 5.5 ppb in the tropospheric partial column (the column from the surface to the tropopause) for the models TM3, TM5-4DVAR, and LMDz-PYVAR, respectively, and 4.3 ± 9.9, 4.7 ± 9.9, and 6.2 ± 11.2 ppb in the stratospheric partial column (the column from the tropopause to the top of the atmosphere). The model biases in the tropospheric partial column show a latitudinal gradient for all models; however there are no clear latitudinal dependencies for the model biases in the stratospheric partial column visible except with the LMDz-PYVAR model. Comparing modelled and FTS-measured tropospheric column-averaged mole fractions reveals a similar latitudinal gradient in the model biases but comparison with in situ measured mole fractions in the troposphere does not show a latitudinal gradient, which is attributed to the different longitudinal coverage of FTS and in situ measurements. Similarly, a latitudinal pattern exists in model biases in vertical CH4 gradients in the troposphere, which indicates that vertical transport of tropospheric CH4 is not represented correctly in the models. |
BibTeX:
@article{Wang2017,
author = {Wang, Zhiting and Warneke, Thorsten and Deutscher, Nicholas M and Notholt, Justus and Karstens, Ute and Saunois, Marielle and Schneider, Matthias and Sussmann, Ralf and Sembhi, Harjinder and Griffith, David W T and Pollard, Dave F and Kivi, Rigel and Petri, Christof and Velazco, Voltaire A and Ramonet, Michel and Chen, Huilin},
title = {Contributions of the troposphere and stratosphere to CH4 model biases},
journal = {Atmospheric Chemistry and Physics},
year = {2017},
volume = {17},
number = {21},
pages = {13283--13295},
url = {https://www.atmos-chem-phys.net/17/13283/2017/},
doi = {10.5194/acp-17-13283-2017}
}
|
| Wang Y, Broquet G, Ciais P, Chevallier F, Vogel F, Kadygrov N, Wu L, Yin Y, Wang R and Tao S (2017), "Estimation of observation errors for large-scale atmospheric inversion of CO 2 emissions from fossil fuel combustion", Tellus B: Chemical and Physical Meteorology., jan, 2017. Vol. 69(1), pp. 1325723. |
BibTeX:
@article{Wang2017a,
author = {Wang, Yilong and Broquet, Grégoire and Ciais, Philippe and Chevallier, Frédéric and Vogel, Felix and Kadygrov, Nikolay and Wu, Lin and Yin, Yi and Wang, Rong and Tao, Shu},
title = {Estimation of observation errors for large-scale atmospheric inversion of CO 2 emissions from fossil fuel combustion},
journal = {Tellus B: Chemical and Physical Meteorology},
year = {2017},
volume = {69},
number = {1},
pages = {1325723},
url = {https://www.tandfonline.com/doi/full/10.1080/16000889.2017.1325723},
doi = {10.1080/16000889.2017.1325723}
}
|
| Williams NL, Juranek LW, Feely RA, Johnson KS, Sarmiento JL, Talley LD, Dickson AG, Gray AR, Wanninkhof R, Russell JL, Riser SC and Takeshita Y (2017), "Calculating surface ocean pCO textlesssubtextgreater2textless/subtextgreater from biogeochemical Argo floats equipped with pH: An uncertainty analysis", Global Biogeochemical Cycles., mar, 2017. Vol. 31(3), pp. 591-604. Blackwell Publishing Ltd. |
| Abstract: More than 74 biogeochemical profiling floats that measure water column pH, oxygen, nitrate, fluorescence, and backscattering at 10 day intervals have been deployed throughout the Southern Ocean. Calculating the surface ocean partial pressure of carbon dioxide (pCO2sw) from float pH has uncertainty contributions from the pH sensor, the alkalinity estimate, and carbonate system equilibrium constants, resulting in a relative standard uncertainty in pCO2sw of 2.7% (or 11 µatm at pCO2sw of 400 µatm). The calculated pCO2sw from several floats spanning a range of oceanographic regimes are compared to existing climatologies. In some locations, such as the subantarctic zone, the float data closely match the climatologies, but in the polar Antarctic zone significantly higher pCO2sw are calculated in the wintertime implying a greater air-sea CO2 efflux estimate. Our results based on four representative floats suggest that despite their uncertainty relative to direct measurements, the float data can be used to improve estimates for air-sea carbon flux, as well as to increase knowledge of spatial, seasonal, and interannual variability in this flux. |
BibTeX:
@article{Williams2017,
author = {Williams, N. L. and Juranek, L. W. and Feely, R. A. and Johnson, K. S. and Sarmiento, J. L. and Talley, L. D. and Dickson, A. G. and Gray, A. R. and Wanninkhof, R. and Russell, J. L. and Riser, S. C. and Takeshita, Y.},
title = {Calculating surface ocean pCO textlesssubtextgreater2textless/subtextgreater from biogeochemical Argo floats equipped with pH: An uncertainty analysis},
journal = {Global Biogeochemical Cycles},
publisher = {Blackwell Publishing Ltd},
year = {2017},
volume = {31},
number = {3},
pages = {591--604},
url = {http://doi.wiley.com/10.1002/2016GB005541},
doi = {10.1002/2016GB005541}
}
|
| Wilson RM, Tfaily MM, Rich VI, Keller JK, Bridgham SD, Zalman CM, Meredith L, Hanson PJ, Hines M, Pfeifer-Meister L, Saleska SR, Crill P, Cooper WT, Chanton JP and Kostka JE (2017), "Hydrogenation of organic matter as a terminal electron sink sustains high CO2:CH4 production ratios during anaerobic decomposition", Organic Geochemistry., oct, 2017. Vol. 112, pp. 22-32. |
| Abstract: Once inorganic electron acceptors are depleted, organic matter in anoxic environments decomposes by hydrolysis, fermentation, and methanogenesis, requiring syntrophic interactions between microorganisms to achieve energetic favorability. In this classic anaerobic food chain, methanogenesis represents the terminal electron accepting (TEA) process, ultimately producing equimolar CO2 and CH4 for each molecule of organic matter degraded. However, CO2:CH4 production in Sphagnum-derived, mineral-poor, cellulosic peat often substantially exceeds this 1:1 ratio, even in the absence of measureable inorganic TEAs. Since the oxidation state of C in both cellulose-derived organic matter and acetate is 0, and CO2 has an oxidation state of +4, if CH4 (oxidation state âˆ'4) is not produced in equal ratio, then some other compound(s) must balance CO2 production by receiving 4 electrons. Here we present evidence for ubiquitous hydrogenation of diverse unsaturated compounds that appear to serve as organic TEAs in peat, thereby providing the necessary electron balance to sustain CO2:CH4 1. While organic electron acceptors have previously been proposed to drive microbial respiration of organic matter through the reversible reduction of quinone moieties, the hydrogenation mechanism that we propose, by contrast, reduces C–C double bonds in organic matter thereby serving as (1) a terminal electron sink, (2) a mechanism for degrading complex unsaturated organic molecules, (3) a potential mechanism to regenerate electron-accepting quinones, and, in some cases, (4) a means to alleviate the toxicity of unsaturated aromatic acids. This mechanism for CO2 generation without concomitant CH4 production has the potential to regulate the global warming potential of peatlands by elevating CO2:CH4 production ratios. |
BibTeX:
@article{Wilson2017,
author = {Wilson, Rachel M and Tfaily, Malak M and Rich, Virginia I and Keller, Jason K and Bridgham, Scott D and Zalman, Cassandra Medvedeff and Meredith, Laura and Hanson, Paul J and Hines, Mark and Pfeifer-Meister, Laurel and Saleska, Scott R and Crill, Patrick and Cooper, William T and Chanton, Jeff P and Kostka, Joel E},
title = {Hydrogenation of organic matter as a terminal electron sink sustains high CO2:CH4 production ratios during anaerobic decomposition},
journal = {Organic Geochemistry},
year = {2017},
volume = {112},
pages = {22--32},
url = {http://linkinghub.elsevier.com/retrieve/pii/S014663801630208X},
doi = {10.1016/j.orggeochem.2017.06.011}
}
|
| Wohlfahrt G and Galvagno M (2017), "Revisiting the choice of the driving temperature for eddy covariance CO2 flux partitioning", Agricultural and Forest Meteorology., may, 2017. Vol. 237-238, pp. 135-142. |
| Abstract: So-called CO2 flux partitioning algorithms are widely used to partition the net ecosystem CO2 exchange into the two component fluxes, gross primary productivity and ecosystem respiration. Common CO2 flux partitioning algorithms conceptualise ecosystem respiration to originate from a single source, requiring the choice of a corresponding driving temperature. Using a conceptual dual-source respiration model, consisting of an above- and a below-ground respiration source each driven by a corresponding temperature, we demonstrate that the typical phase shift between air and soil temperature gives rise to a hysteresis relationship between ecosystem respiration and temperature. The hysteresis proceeds in a clockwise fashion if soil temperature is used to drive ecosystem respiration, while a counter-clockwise response is observed when ecosystem respiration is related to air temperature. As a consequence, nighttime ecosystem respiration is smaller than daytime ecosystem respiration when referenced to soil temperature, while the reverse is true for air temperature. We confirm these qualitative modelling results using measurements of day and night ecosystem respiration made with opaque chambers in a short-statured mountain grassland. Inferring daytime from nighttime ecosystem respiration or vice versa, as attempted by CO2 flux partitioning algorithms, using a single-source respiration model is thus an oversimplification resulting in biased estimates of ecosystem respiration. We discuss the likely magnitude of the bias, options for minimizing it and conclude by emphasizing that the systematic uncertainty of gross primary productivity and ecosystem respiration inferred through CO2 flux partitioning needs to be better quantified and reported. |
BibTeX:
@article{Wohlfahrt2017,
author = {Wohlfahrt, Georg and Galvagno, Marta},
title = {Revisiting the choice of the driving temperature for eddy covariance CO2 flux partitioning},
journal = {Agricultural and Forest Meteorology},
year = {2017},
volume = {237-238},
pages = {135--142},
url = {https://linkinghub.elsevier.com/retrieve/pii/S016819231730045X},
doi = {10.1016/j.agrformet.2017.02.012}
}
|
| Wolf B, Chwala C, Fersch B, Garvelmann J, Junkermann W, Zeeman MJ, Angerer A, Adler B, Beck C, Brosy C, Brugggger P, Emeis S, Dannenmann M, De Roo F, Diaz-Pines E, Haas E, Hagen M, Hajnsek I, Jacobeit J, Jagdhuber T, Kalthoff N, Kiese R, Kunstmann H, Kosak O, Krieg R, Malchow C, Mauder M, Merz R, Notarnicola C, Philipp A, Reif W, Reineke S, Rödiger T, Ruehr N, Schäfer K, Schrön M, Senatore A, Shupe H, Völksch I, Wanninger C, Zacharias S and Schmid HP (2017), "The scalex campaign: Scale-crossing land surface and boundary layer processes in the TERENO-prealpine observatory", Bulletin of the American Meteorological Society., jun, 2017. Vol. 98(6), pp. 1217-1234. |
BibTeX:
@article{Wolf2017,
author = {Wolf, B and Chwala, C and Fersch, B and Garvelmann, J and Junkermann, W and Zeeman, M J and Angerer, A and Adler, B and Beck, C and Brosy, C and Brugggger, P and Emeis, S and Dannenmann, M and De Roo, F and Diaz-Pines, E and Haas, E and Hagen, M and Hajnsek, I and Jacobeit, J and Jagdhuber, T and Kalthoff, N and Kiese, R and Kunstmann, H and Kosak, O and Krieg, R and Malchow, C and Mauder, M and Merz, R and Notarnicola, C and Philipp, A and Reif, W and Reineke, S and Rödiger, T and Ruehr, N and Schäfer, K and Schrön, M and Senatore, A and Shupe, H and Völksch, I and Wanninger, C and Zacharias, S and Schmid, H P},
title = {The scalex campaign: Scale-crossing land surface and boundary layer processes in the TERENO-prealpine observatory},
journal = {Bulletin of the American Meteorological Society},
year = {2017},
volume = {98},
number = {6},
pages = {1217--1234},
url = {http://journals.ametsoc.org/doi/10.1175/BAMS-D-15-00277.1},
doi = {10.1175/BAMS-D-15-00277.1}
}
|
| Wu L, Sproson D, Sahlée E and Rutgersson A (2017), "Surface Wave Impact When Simulating Midlatitude Storm Development", Journal of Atmospheric and Oceanic Technology., jan, 2017. Vol. 34(1), pp. 233-248. |
| Abstract: Surface gravity waves, present at the air–sea interface, can affect the momentum flux and heat fluxes by modifying turbulence in the lower layers of the atmosphere. How to incorporate wave impacts into model parameterizations is still an open issue. In this study, the influence of a dynamic roughness length (considering instantaneous wave-induced stress), horizontal resolution, and the coupling time resolution between waves and the atmosphere on storm simulations are investigated using sensitivity experiments. Based on the simulations of six midlatitude storms using both an atmosphere–wave coupled model and an atmospheric stand-alone model, the impacts are investigated. Adding the wave-induced stress weakens the storm intensity. Applying a roughness length tuned to an average friction velocity is not enough to capture the simulation results from “true†wave-related roughness length. High-horizontal-resolution models intensify the simulation of storms, which is valid for both coupled and uncoupled models. Compared with the atmospheric stand-alone model, the coupled model (considering the influence of dynamic roughness length) is more sensitive to the model horizontal resolution. During reasonable ranges, the coupling time resolution does not have a significant impact on the storm intensity based on the limited experiments used in this study. It is concluded that the dynamic wave influence (instantaneous wave influence) and the model resolution should be taken into account during the development of forecast and climate models. |
BibTeX:
@article{Wu2017,
author = {Wu, Lichuan and Sproson, David and Sahlée, Erik and Rutgersson, Anna},
title = {Surface Wave Impact When Simulating Midlatitude Storm Development},
journal = {Journal of Atmospheric and Oceanic Technology},
year = {2017},
volume = {34},
number = {1},
pages = {233--248},
url = {http://journals.ametsoc.org/doi/10.1175/JTECH-D-16-0070.1},
doi = {10.1175/jtech-d-16-0070.1}
}
|
| Wu L, Rutgersson A and Nilsson E (2017), "Atmospheric boundary layer turbulence closure scheme for wind-following swell conditions", Journal of the Atmospheric Sciences., jul, 2017. Vol. 74(7), pp. 2363-2382. |
| Abstract: Over the ocean, atmospheric boundary layer turbulence can be altered by underlying waves. Under swell conditions, the impact of waves on the atmosphere is more complicated compared to that under wind-wave conditions. Based on large-eddy simulation (LES), the wind-following swell impact on the atmospheric boundary layer is investigated through three terms: swell-induced surface momentum flux, the vertical profile of swell-induced momentum flux, and the swell impact on atmospheric mixing. The swell-induced surface momentum flux displays a decreasing trend with increasing atmospheric convection. The swell-induced momentum flux decays approximately exponentially with height. Compared with atmospheric convection, the decay coefficient is more sensitive to wave age. Atmospheric mixing is enhanced under swell conditions relative to a flat stationary surface. The swell impact on the atmospheric boundary layer is incorporated into a turbulence closure parameterization through the three terms. The modified turbulence closure parameterization is introduced into a single-column atmospheric model to simulate LES cases. Adding only the swell impact on the atmospheric mixing has a limited influence on wind profiles. Adding both the impact of swell on the atmospheric mixing and the profile of swell-induced momentum flux significantly improves the agreement between the 1D atmospheric simulation results and the LES results, to some extent simulating the wave-induced low-level wind jet. It is concluded that the swell impact should be included in atmospheric numerical models. |
BibTeX:
@article{Wu2017a,
author = {Wu, Lichuan and Rutgersson, Anna and Nilsson, Erik},
title = {Atmospheric boundary layer turbulence closure scheme for wind-following swell conditions},
journal = {Journal of the Atmospheric Sciences},
year = {2017},
volume = {74},
number = {7},
pages = {2363--2382},
url = {http://journals.ametsoc.org/doi/10.1175/JAS-D-16-0308.1},
doi = {10.1175/JAS-D-16-0308.1}
}
|
| Wunch D, Wennberg PO, Osterman G, Fisher B, Naylor B, Roehl MC, O'Dell C, Mandrake L, Viatte C, Kiel M, Griffith DW, Deutscher NM, Velazco VA, Notholt J, Warneke T, Petri C, De Maziere M, Sha MK, Sussmann R, Rettinger M, Pollard D, Robinson J, Morino I, Uchino O, Hase F, Blumenstock T, Feist DG, Arnold SG, Strong K, Mendonca J, Kivi R, Heikkinen P, Iraci L, Podolske J, Hillyard P, Kawakami S, Dubey MK, Parker HA, Sepulveda E, García OE, Te Y, Jeseck P, Gunson MR, Crisp D and Eldering A (2017), "Comparisons of the Orbiting Carbon Observatory-2 (OCO-2) XCO2 measurements with TCCON". jun, 2017. |
| Abstract: NASA's Orbiting Carbon Observatory-2 (OCO-2) has been measuring carbon dioxide column-averaged dry-air mole fraction, textlessitextgreaterXtextless/itextgreaterCO2, in the Earth's atmosphere for over 2 years. In this paper, we describe the comparisons between the first major release of the OCO-2 retrieval algorithm (B7r) and textlessitextgreaterXtextless/itextgreaterCO2 from OCO-2's primary ground-based validation network: the Total Carbon Column Observing Network (TCCON). The OCO-2 textlessitextgreaterXtextless/itextgreaterCO2 retrievals, after filtering and bias correction, agree well when aggregated around and coincident with TCCON data in nadir, glint, and target observation modes, with absolute median differences less than 0.4ĝ€ppm and RMS differences less than 1.5ĝ€ppm. After bias correction, residual biases remain. These biases appear to depend on latitude, surface properties, and scattering by aerosols. It is thus crucial to continue measurement comparisons with TCCON to monitor and evaluate the OCO-2 textlessitextgreaterXtextless/itextgreaterCO2 data quality throughout its mission. |
BibTeX:
@misc{Wunch2017,
author = {Wunch, Debra and Wennberg, Paul O. and Osterman, Gregory and Fisher, Brendan and Naylor, Bret and Roehl, M. Coleen and O'Dell, Christopher and Mandrake, Lukas and Viatte, Camille and Kiel, Matthus and Griffith, David W.T. and Deutscher, Nicholas M. and Velazco, Voltaire A. and Notholt, Justus and Warneke, Thorsten and Petri, Christof and De Maziere, Martine and Sha, Mahesh K. and Sussmann, Ralf and Rettinger, Markus and Pollard, David and Robinson, John and Morino, Isamu and Uchino, Osamu and Hase, Frank and Blumenstock, Thomas and Feist, Dietrich G. and Arnold, Sabrina G. and Strong, Kimberly and Mendonca, Joseph and Kivi, Rigel and Heikkinen, Pauli and Iraci, Laura and Podolske, James and Hillyard, Patrick and Kawakami, Shuji and Dubey, Manvendra K. and Parker, Harrison A. and Sepulveda, Eliezer and García, Omaira E. and Te, Yao and Jeseck, Pascal and Gunson, Michael R. and Crisp, David and Eldering, Annmarie},
title = {Comparisons of the Orbiting Carbon Observatory-2 (OCO-2) XCO2 measurements with TCCON},
booktitle = {Atmospheric Measurement Techniques},
publisher = {Copernicus GmbH},
year = {2017},
volume = {10},
number = {6},
pages = {2209--2238},
doi = {10.5194/amt-10-2209-2017}
}
|
| Xie Q, Zhu J, Wang C, Fu H, Lopez-Sanchez JM and Ballester-Berman JD (2017), "A modified dual-baseline PolInSAR method for forest height estimation", Remote Sensing., aug, 2017. Vol. 9(8), pp. 1-17. |
| Abstract: This paper investigates the potentials and limitations of a simple dual-baseline PolInSAR (DBPI) method for forest height inversion. This DBPI method follows the classical three-stage inversion method's idea used in single baseline PolInSAR (SBPI) inversion, but it avoids the assumption of the smallest ground-to-volume amplitude ratio (GVR) by employing an additional baseline to constrain the inversion procedure. In this paper, we present for the first time an assessment of such a method on real PolInSAR data over boreal forest. Additionally, we propose an improvement on the original DBPI method by incorporating the sloped random volume over ground (S-RVoG) model in order to reduce the range terrain slope effect. Therefore, a digital elevation model (DEM) is needed to provide the slope information in the proposed method. Three scenes of P-band airborne PolInSAR data acquired by E-SAR and light detection and ranging (LIDAR) data available in the BioSAR2008 campaign are employed for testing purposes. The performance of the SBPI, DBPI, and modified DBPI methods is compared. The results show that the DBPI method extracts forest heights with an average root mean square error (RMSE) of 4.72 m against LIDAR heights for trees of 18 m height on average. It presents a significant improvement of forest height accuracy over the SBPI method (with a stand-level mean improvement of 42.86%). Concerning the modified DBPI method, it consistently improves the accuracy of forest height inversion over sloped areas. This improvement reaches a stand-level mean of 21.72% improvement (with a mean RMSE of 4.63 m) for slopes greater than 10â—¦. |
BibTeX:
@article{Xie2017,
author = {Xie, Qinghua and Zhu, Jianjun and Wang, Changcheng and Fu, Haiqiang and Lopez-Sanchez, Juan M and Ballester-Berman, J David},
title = {A modified dual-baseline PolInSAR method for forest height estimation},
journal = {Remote Sensing},
year = {2017},
volume = {9},
number = {8},
pages = {1--17},
url = {http://www.mdpi.com/2072-4292/9/8/819},
doi = {10.3390/rs9080819}
}
|
| Yao Y, Liang S, Li X, Zhang Y, Chen J, Jia K, Zhang X, Fisher JB, Wang X, Zhang L, Xu J, Shao C, Posse G, Li Y, Magliulo V, Varlagin A, Moors EJ, Boike J, Macfarlane C, Kato T, Buchmann N, Billesbach DP, Beringer J, Wolf S, Papuga SA, Wohlfahrt G, Montagnani L, Ardö J, Paul-Limoges E, Emmel C, Hörtnagl L, Sachs T, Gruening C, Gioli B, López-Ballesteros A, Steinbrecher R and Gielen B (2017), "Estimation of high-resolution terrestrial evapotranspiration from Landsat data using a simple Taylor skill fusion method", Journal of Hydrology., oct, 2017. Vol. 553, pp. 508-526. |
| Abstract: Estimation of high-resolution terrestrial evapotranspiration (ET) from Landsat data is important in many climatic, hydrologic, and agricultural applications, as it can help bridging the gap between existing coarse-resolution ET products and point-based field measurements. However, there is large uncertainty among existing ET products from Landsat that limit their application. This study presents a simple Taylor skill fusion (STS) method that merges five Landsat-based ET products and directly measured ET from eddy covariance (EC) to improve the global estimation of terrestrial ET. The STS method uses a weighted average of the individual ET products and weights are determined by their Taylor skill scores (S). The validation with site-scale measurements at 206 EC flux towers showed large differences and uncertainties among the five ET products. The merged ET product exhibited the best performance with a decrease in the averaged root-mean-square error (RMSE) by 2–5 W/m2 when compared to the individual products. To evaluate the reliability of the STS method at the regional scale, the weights of the STS method for these five ET products were determined using EC ground-measurements. An example of regional ET mapping demonstrates that the STS-merged ET can effectively integrate the individual Landsat ET products. Our proposed method provides an improved high-resolution ET product for identifying agricultural crop water consumption and providing a diagnostic assessment for global land surface models. |
BibTeX:
@article{Yao2017,
author = {Yao, Yunjun and Liang, Shunlin and Li, Xianglan and Zhang, Yuhu and Chen, Jiquan and Jia, Kun and Zhang, Xiaotong and Fisher, Joshua B and Wang, Xuanyu and Zhang, Lilin and Xu, Jia and Shao, Changliang and Posse, Gabriela and Li, Yingnian and Magliulo, Vincenzo and Varlagin, Andrej and Moors, Eddy J and Boike, Julia and Macfarlane, Craig and Kato, Tomomichi and Buchmann, Nina and Billesbach, D P and Beringer, Jason and Wolf, Sebastian and Papuga, Shirley A and Wohlfahrt, Georg and Montagnani, Leonardo and Ardö, Jonas and Paul-Limoges, Eugénie and Emmel, Carmen and Hörtnagl, Lukas and Sachs, Torsten and Gruening, Carsten and Gioli, Beniamino and López-Ballesteros, Ana and Steinbrecher, Rainer and Gielen, Bert},
title = {Estimation of high-resolution terrestrial evapotranspiration from Landsat data using a simple Taylor skill fusion method},
journal = {Journal of Hydrology},
year = {2017},
volume = {553},
pages = {508--526},
url = {http://linkinghub.elsevier.com/retrieve/pii/S0022169417305395},
doi = {10.1016/j.jhydrol.2017.08.013}
}
|
| Yao Y, Liang S, Li X, Chen J, Liu S, Jia K, Zhang X, Xiao Z, Fisher JB, Mu Q, Pan M, Liu M, Cheng J, Jiang B, Xie X, Grünwald T, Bernhofer C and Roupsard O (2017), "Improving global terrestrial evapotranspiration estimation using support vector machine by integrating three process-based algorithms", Agricultural and Forest Meteorology., aug, 2017. Vol. 242, pp. 55-74. |
| Abstract: Terrestrial evapotranspiration (ET) for each plant functional type (PFT) is a key variable for linking the energy, water and carbon cycles of the atmosphere, hydrosphere and biosphere. Process-based algorithms have been widely used to estimate global terrestrial ET, yet each ET individual algorithm has exhibited large uncertainties. In this study, the support vector machine (SVM) method was introduced to improve global terrestrial ET estimation by integrating three process-based ET algorithms: MOD16, PT-JPL and SEMI-PM. At 200 FLUXNET flux tower sites, we evaluated the performance of the SVM method and others, including the Bayesian model averaging (BMA) method and the general regression neural networks (GRNNs) method together with three process-based ET algorithms. We found that the SVM method was superior to all other methods we evaluated. The validation results showed that compared with the individual algorithms, the SVM method driven by tower-specific (Modern Era Retrospective Analysis for Research and Applications, MERRA) meteorological data reduced the root mean square error (RMSE) by approximately 0.20 (0.15) mm/day for most forest sites and 0.30 (0.20) mm/day for most crop and grass sites and improved the squared correlation coefficient (R2) by approximately 0.10 (0.08) (95% confidence) for most flux tower sites. The water balance of basins and the global terrestrial ET calculation analysis also demonstrated that the regional and global estimates of the SVM-merged ET were reliable. The SVM method provides a powerful tool for improving global ET estimation to characterize the long-term spatiotemporal variations of the global terrestrial water budget. |
BibTeX:
@article{Yao2017a,
author = {Yao, Yunjun and Liang, Shunlin and Li, Xianglan and Chen, Jiquan and Liu, Shaomin and Jia, Kun and Zhang, Xiaotong and Xiao, Zhiqiang and Fisher, Joshua B and Mu, Qiaozhen and Pan, Ming and Liu, Meng and Cheng, Jie and Jiang, Bo and Xie, Xianhong and Grünwald, Thomas and Bernhofer, Christian and Roupsard, Olivier},
title = {Improving global terrestrial evapotranspiration estimation using support vector machine by integrating three process-based algorithms},
journal = {Agricultural and Forest Meteorology},
year = {2017},
volume = {242},
pages = {55--74},
url = {http://linkinghub.elsevier.com/retrieve/pii/S0168192317301466},
doi = {10.1016/j.agrformet.2017.04.011}
}
|
| Yuan Y, Ries L, Petermeier H, Steinbacher M, Gómez-Peláez AJ, Leuenberger MC, Schumacher M, Trickl T, Couret C, Meinhardt F and Menzel A (2017), "Adaptive Baseline Finder, a statistical data selection strategy to identify atmospheric COsub2/sub baseline levels and its application to European elevated mountain stations", Atmospheric Measurement Techniques Discussions., sep, 2017. , pp. 1-27. |
| Abstract: Critical data selection is essential for determining representative baseline levels of atmospheric trace gas measurements even at remote measuring sites. Different data selection techniques have been used around the world which could potentially lead to bias when comparing data from different stations. This paper presents a novel statistical data selection method based on COsub2/sub diurnal pattern occurring typically at high elevated mountain stations. Its capability and applicability was studied for atmospheric measuring records of COsub2/sub from 2010 to 2016 at six Global Atmosphere Watch (GAW) stations in Europe, namely Zugspitze-Schneefernerhaus (Germany), Sonnblick (Austria), Jungfraujoch (Switzerland), Izaña (Spain), Schauinsland (Germany) and Hohenpeissenberg (Germany). Three other frequently applied statistical data selection methods were implemented for comparison. Among all selection routines, the new method named Adaptive Baseline Finder (ABF) resulted in lower selection percentages with lower maxima during winter and higher minima during summer in the selected data. To investigate long-term trend and seasonality, seasonal decomposition technique STL was applied. Compared with the unselected data, mean annual growth rates of all selected data sets were not significantly different except for Schauinsland. However, clear differences were found in the annual amplitudes as well as for the seasonal time structure. Based on correlation analysis, results by ABF selection showed a better representation of the lower free tropospheric conditions. |
BibTeX:
@article{Yuan2017,
author = {Yuan, Ye and Ries, Ludwig and Petermeier, Hannes and Steinbacher, Martin and Gómez-Peláez, Angel J and Leuenberger, Markus C and Schumacher, Marcus and Trickl, Thomas and Couret, Cedric and Meinhardt, Frank and Menzel, Annette},
title = {Adaptive Baseline Finder, a statistical data selection strategy to identify atmospheric COsub2/sub baseline levels and its application to European elevated mountain stations},
journal = {Atmospheric Measurement Techniques Discussions},
year = {2017},
pages = {1--27},
url = {https://www.atmos-meas-tech-discuss.net/amt-2017-316/},
doi = {10.5194/amt-2017-316}
}
|
| Zeng J, Matsunaga T, Saigusa N, Shirai T, Nakaoka S-i and Tan Z-H (2017), "Technical note: Evaluation of three machine learning models for surface ocean CO&lt;sub&gt;2&lt;/sub&gt; mapping", Ocean Science., apr, 2017. Vol. 13(2), pp. 303-313. Copernicus GmbH. |
| Abstract: textlessptextgreaterAbstract. Reconstructing surface ocean CO2 from scarce measurements plays an important role in estimating oceanic CO2 uptake. There are varying degrees of differences among the 14 models included in the Surface Ocean CO2 Mapping (SOCOM) inter-comparison initiative, in which five models used neural networks. This investigation evaluates two neural networks used in SOCOM, self-organizing maps and feedforward neural networks, and introduces a machine learning model called a support vector machine for ocean CO2 mapping. The technique note provides a practical guide to selecting the models.textless/ptextgreater |
BibTeX:
@article{Zeng2017,
author = {Zeng, Jiye and Matsunaga, Tsuneo and Saigusa, Nobuko and Shirai, Tomoko and Nakaoka, Shin-ichiro and Tan, Zheng-Hong},
title = {Technical note: Evaluation of three machine learning models for surface ocean CO&lt;sub&gt;2&lt;/sub&gt; mapping},
journal = {Ocean Science},
publisher = {Copernicus GmbH},
year = {2017},
volume = {13},
number = {2},
pages = {303--313},
url = {https://os.copernicus.org/articles/13/303/2017/},
doi = {10.5194/os-13-303-2017}
}
|
| Zhang Z, Zhang R, Cescatti A, Wohlfahrt G, Buchmann N, Zhu J, Chen G, Moyano F, Pumpanen J, Hirano T, Takagi K and Merbold L (2017), "Effect of climate warming on the annual terrestrial net ecosystem CO2 exchange globally in the boreal and temperate regions", Scientific Reports., dec, 2017. Vol. 7(1), pp. 3108. |
| Abstract: The net ecosystem CO2 exchange is the result of the imbalance between the assimilation process (gross primary production, GPP) and ecosystem respiration (RE). The aim of this study was to investigate temperature sensitivities of these processes and the effect of climate warming on the annual terrestrial net ecosystem CO2 exchange globally in the boreal and temperate regions. A database of 403 site-years of ecosystem flux data at 101 sites in the world was collected and analyzed. Temperature sensitivities of rates of RE and GPP were quantified with Q10, defined as the increase of RE (or GPP) rates with a temperature rise of 10 °C. Results showed that on the annual time scale, the intrinsic temperature sensitivity of GPP (Q10sG) was higher than or equivalent to the intrinsic temperature sensitivity of RE (Q10sR). Q10sG was negatively correlated to the mean annual temperature (MAT), whereas Q10sR was independent of MAT. The analysis of the current temperature sensitivities and net ecosystem production suggested that temperature rise might enhance the CO2 sink of terrestrial ecosystems both in the boreal and temperate regions. In addition, ecosystems in these regions with different plant functional types should sequester more CO2 with climate warming. |
BibTeX:
@article{Zhang2017,
author = {Zhang, Zhiyuan and Zhang, Renduo and Cescatti, Alessandro and Wohlfahrt, Georg and Buchmann, Nina and Zhu, Juan and Chen, Guanhong and Moyano, Fernando and Pumpanen, Jukka and Hirano, Takashi and Takagi, Kentaro and Merbold, Lutz},
title = {Effect of climate warming on the annual terrestrial net ecosystem CO2 exchange globally in the boreal and temperate regions},
journal = {Scientific Reports},
year = {2017},
volume = {7},
number = {1},
pages = {3108},
url = {http://www.nature.com/articles/s41598-017-03386-5},
doi = {10.1038/s41598-017-03386-5}
}
|
| Zhao J, Peichl M and Nilsson MB (2017), "Long-term enhanced winter soil frost alters growing season CO2 fluxes through its impact on vegetation development in a boreal peatland", Global Change Biology., aug, 2017. Vol. 23(8), pp. 3139-3153. |
| Abstract: At high latitudes, winter climate change alters snow cover and, consequently, may cause a sustained change in soil frost dynamics. Altered winter soil conditions could influence the ecosystem exchange of carbon dioxide (CO2) and, in turn, provide feedbacks to ongoing climate change. To investigate the mechanisms that modify the peatland CO2 exchange in response to altered winter soil frost, we conducted a snow exclusion experiment to enhance winter soil frost and to evaluate its short-term (1–3 years) and long-term (11 years) effects on CO2 fluxes during subsequent growing seasons in a boreal peatland. In the first 3 years after initiating the treatment, no significant effects were observed on either gross primary production (GPP) or ecosystem respiration (ER). However, after 11 years, the temperature sensitivity of ER was reduced in the treatment plots relative to the control, resulting in an overall lower ER in the former. Furthermore, early growing season GPP was also lower in the treatment plots than in the controls during periods with photosynthetic photon flux density (PPFD) ≥800 μmol mâˆ'2 sâˆ'1, corresponding to lower sedge leaf biomass in the treatment plots during the same period. During the peak growing season, a higher GPP was observed in the treatment plots under the low light condition (i.e. PPFD 400 μmol mâˆ'2 sâˆ'1) compared to the control. As Sphagnum moss maximizes photosynthesis at low light levels, this GPP difference between the plots may have been due to greater moss photosynthesis, as indicated by greater moss biomass production, in the treatment plots relative to the controls. Our study highlights the different responses to enhanced winter soil frost among plant functional types which regulate CO2 fluxes, suggesting that winter climate change could considerably alter the growing season CO2 exchange in boreal peatlands through its effect on vegetation development. |
BibTeX:
@article{Zhao2017,
author = {Zhao, Junbin and Peichl, Matthias and Nilsson, Mats B},
title = {Long-term enhanced winter soil frost alters growing season CO2 fluxes through its impact on vegetation development in a boreal peatland},
journal = {Global Change Biology},
year = {2017},
volume = {23},
number = {8},
pages = {3139--3153},
url = {http://doi.wiley.com/10.1111/gcb.13621},
doi = {10.1111/gcb.13621}
}
|
| Zribi M, Motte E, Fanise P and Zouaoui W (2017), "Low-Cost GPS Receivers for the Monitoring of Sunflower Cover Dynamics", Journal of Sensors. Vol. 2017 Hindawi Limited. |
| Abstract: The aim of this research is to analyze the potential use of Global Navigation Satellite System (GNSS) signals for the monitoring of in situ vegetation characteristics. An instrument, based on the use of a pair of low-cost receivers and antennas, providing continuous measurements of all the available Global Positioning System (GPS) satellite signals is proposed for the determination of signal attenuation caused by a sunflower cover. Experimental campaigns with this instrument, combined with ground truth measurements of the vegetation, were performed over a nonirrigated sunflower test field for a period of more than two months, corresponding to a significant portion of the vegetation cycle. A method is proposed for the analysis of the signal attenuation data as a function of elevation and azimuth angles. A high correlation is observed between the vegetation's water content and the GPS signals attenuation, and an empirical modeling is tested for the retrieval of signal behavior as a function of vegetation water content (VWC). The VWC was estimated from GNSS signals on a daily basis, over the full length of the study period. |
BibTeX:
@article{Zribi2017,
author = {Zribi, Mehrez and Motte, Erwan and Fanise, Pascal and Zouaoui, Walid},
title = {Low-Cost GPS Receivers for the Monitoring of Sunflower Cover Dynamics},
journal = {Journal of Sensors},
publisher = {Hindawi Limited},
year = {2017},
volume = {2017},
doi = {10.1155/2017/6941739}
}
|
| Zscheischler J, Mahecha MD, Avitabile V, Calle L, Carvalhais N, Ciais P, Gans F, Gruber N, Hartmann J, Herold M, Ichii K, Jung M, Landschützer P, Laruelle GG, Lauerwald R, Papale D, Peylin P, Poulter B, Ray D, Regnier P, Rödenbeck C, Roman-Cuesta RM, Schwalm C, Tramontana G, Tyukavina A, Valentini R, Van Der Werf G, West TO, Wolf JE and Reichstein M (2017), "Reviews and syntheses: An empirical spatiotemporal description of the global surface-atmosphere carbon fluxes: Opportunities and data limitations", Biogeosciences., aug, 2017. Vol. 14(15), pp. 3685-3703. |
| Abstract: Understanding the global carbon (C) cycle is of crucial importance to map current and future climate dynamics relative to global environmental change. A full characterization of C cycling requires detailed information on spatiotemporal patterns of surface-atmosphere fluxes. However, relevant C cycle observations are highly variable in their coverage and reporting standards. Especially problematic is the lack of integration of the carbon dioxide (CO2) exchange of the ocean, inland freshwaters and the land surface with the atmosphere. Here we adopt a data-driven approach to synthesize a wide range of observation-based spatially explicit surface-atmosphere CO2 fluxes from 2001 to 2010, to identify the state of today's observational opportunities and data limitations. The considered fluxes include net exchange of open oceans, continental shelves, estuaries, rivers, and lakes, as well as CO2 fluxes related to net ecosystem productivity, fire emissions, loss of tropical aboveground C, harvested wood and crops, as well as fossil fuel and cement emissions. Spatially explicit CO2 fluxes are obtained through geostatistical and/or remote-sensing-based upscaling, thereby minimizing biophysical or biogeochemical assumptions encoded in process-based models. We estimate a bottom-up net C exchange (NCE) between the surface (land, ocean, and coastal areas) and the atmosphere. Though we provide also global estimates, the primary goal of this study is to identify key uncertainties and observational shortcomings that need to be prioritized in the expansion of in situ observatories. Uncertainties for NCE and its components are derived using resampling. In many regions, our NCE estimates agree well with independent estimates from other sources such as process-based models and atmospheric inversions. This holds for Europe (mean±1 SD: 0.8±0.1PgCyr-1, positive numbers are sources to the atmosphere), Russia (0.1±0.4PgCyr-1), East Asia (1.6±0.3PgCyr-1), South Asia (0.3±0.1PgCyr-1), Australia (0.2±0.3PgCyr-1), and most of the Ocean regions. Our NCE estimates give a likely too large CO2 sink in tropical areas such as the Amazon, Congo, and Indonesia. Overall, and because of the overestimated CO2 uptake in tropical lands, our global bottom-up NCE amounts to a net sink of -5.4±2.0PgCyr-1. By contrast, the accurately measured mean atmospheric growth rate of CO2 over 2001-2010 indicates that the true value of NCE is a net CO2 source of 4.3±0.1PgCyr-1. This mismatch of nearly 10PgCyr-1 highlights observational gaps and limitations of data-driven models in tropical lands, but also in North America. Our uncertainty assessment provides the basis for setting priority regions where to increase carbon observations in the future. High on the priority list are tropical land regions, which suffer from a lack of in situ observations. Second, extensive pCO2 data are missing in the Southern Ocean. Third, we lack observations that could enable seasonal estimates of shelf, estuary, and inland water-atmosphere C exchange. Our consistent derivation of data uncertainties could serve as prior knowledge in multicriteria optimization such as the Carbon Cycle Data Assimilation System (CCDAS) and atmospheric inversions, without over- or under-stating bottom-up data credibility. In the future, NCE estimates of carbon sinks could be aggregated at national scale to compare with the official national inventories of CO2 fluxes in the land use, land use change, and forestry sector, upon which future emission reductions are proposed. |
BibTeX:
@article{Zscheischler2017,
author = {Zscheischler, Jakob and Mahecha, Miguel D and Avitabile, Valerio and Calle, Leonardo and Carvalhais, Nuno and Ciais, Philippe and Gans, Fabian and Gruber, Nicolas and Hartmann, Jens and Herold, Martin and Ichii, Kazuhito and Jung, Martin and Landschützer, Peter and Laruelle, Goulven G and Lauerwald, Ronny and Papale, Dario and Peylin, Philippe and Poulter, Benjamin and Ray, Deepak and Regnier, Pierre and Rödenbeck, Christian and Roman-Cuesta, Rosa M and Schwalm, Christopher and Tramontana, Gianluca and Tyukavina, Alexandra and Valentini, Riccardo and Van Der Werf, Guido and West, Tristram O and Wolf, Julie E and Reichstein, Markus},
title = {Reviews and syntheses: An empirical spatiotemporal description of the global surface-atmosphere carbon fluxes: Opportunities and data limitations},
journal = {Biogeosciences},
year = {2017},
volume = {14},
number = {15},
pages = {3685--3703},
url = {https://www.biogeosciences.net/14/3685/2017/},
doi = {10.5194/bg-14-3685-2017}
}
|
| Ago EE, Agbossou EK, Cohard JM, Galle S and Aubinet M (2016), "Response of CO2 fluxes and productivity to water availability in two contrasting ecosystems in northern Benin (West Africa)", Annals of Forest Science., jun, 2016. Vol. 73(2), pp. 483-500. |
| Abstract: Key message: CO2fluxes were measured during 18 months in a forest and a savannah in northern Benin. Higher values of carbon fluxes were found during the wet season at each site. A strong dependency of carbon fluxes on water relations was found in two contrasting sites. The forest sequestered 640 ± 50 and the savannah 190 ± 40 g C mâˆ'2yearâˆ'1. Context: In West Africa, the main mechanisms or factors governing the dynamics of ecosystems, especially the dynamics of the carbon fluxes and productivity, still remain less known. This study reports the carbon fluxes over two contrasting ecosystems, notably a protected forest (lat 9.79°N, long 1.72°E, alt 414 m) and a cultivated savannah (lat 9.74°N, long 1.60°E, alt 449 m) in northern Benin. The two sites were among those equipped by the AMMA-CATCH observatory and Ouémé 2025 project. Aims: Flux data were analyzed at the daily and seasonal scales in order to understand their controlling variables. We discussed the patterns of CO2 fluxes and the characteristics of the two ecosystems. The study also focused on the different water usage strategies developed by the two ecosystems since the alternation between dry and wet seasons highly influenced the seasonal dynamics. Finally, the annual carbon sequestration was estimated together with its uncertainty. Methods: The carbon fluxes were measured during 18 months (July 2008–December 2009) by an eddy-covariance system over two contrasting sites in northern Benin. Fluxes data were computed following the standard procedure. The responses of CO2 fluxes to the principal climatic and edaphic factors, and the canopy conductance were studied. Results: A clear CO2 fluxes response to main environmental factors was observed, however with difference according to the seasons and vegetation types. The ecosystem respiration showed the highest values during the wet season and a progressive decrease from wet to dry periods. Also, the carbon uptake values were high during the wet period, but low during the dry period. However, the CO2 fluxes for the protected forest were always higher than that for the cultivated savannah within each defined period. This was due to the seasonal changes not only in phenology and physiology but also to the acclimation to environmental conditions, especially to the soil water availability. The water use efficiency was influenced by VPD during the day conditions for two ecosystems. However, the VPD response curve of water usage was relatively constant for the protected forest during the transitional and wet seasons. In contrary, for the cultivated savannah the VPD response decreased about 46 % from transitional dry-wet to wet seasons and remained relatively constant until transitional wet-dry season. The close relationships between the net CO2 assimilation and the canopy conductance were found for the two ecosystems. This suggests a regulation of the stomata by a partial stomatal closure besides the radiation control. Finally, the forest sequestered at the annual scale 640 ± 50 and the savannah 190 ± 40 g C mâˆ'2 yearâˆ'1. Conclusion: We conclude with a strong relation between the carbon fluxes and water in the two investigated ecosystems. Apart from the radiation control, the stomata also play an important role in the regulation of the CO2 assimilation in the two ecosystems. |
BibTeX:
@article{Ago2016,
author = {Ago, Expedit Evariste and Agbossou, Euloge Kossi and Cohard, Jean Martial and Galle, Sylvie and Aubinet, Marc},
title = {Response of CO2 fluxes and productivity to water availability in two contrasting ecosystems in northern Benin (West Africa)},
journal = {Annals of Forest Science},
year = {2016},
volume = {73},
number = {2},
pages = {483--500},
url = {http://link.springer.com/10.1007/s13595-016-0542-9},
doi = {10.1007/s13595-016-0542-9}
}
|
| Agustí-Panareda A, Sebastien M, Chevallier F, Balsamo G, Boussetta S, Dutra E and Beljaars A (2016), "A biogenic CO2 flux adjustment scheme for the mitigation of large-scale biases in global atmospheric CO2 analyses and forecasts", Atmospheric Chemistry and Physics. Vol. 16, pp. 10399-10418. |
| Abstract: Forecasting atmospheric CO 2 daily at the global scale with a good accuracy like it is done for the weather is a challenging task. However, it is also one of the key areas of development to bridge the gaps between weather, air quality and climate models. The challenge stems from the fact that atmospheric CO 2 is largely controlled by the CO 2 fluxes at the surface, which are difficult to constrain with observations. In particular, the biogenic fluxes simulated by land surface models show skill in detecting synoptic and regional-scale disturbances up to sub-seasonal timescales , but they are subject to large seasonal and annual budget errors at global scale, usually requiring a posteriori adjustment. This paper presents a scheme to diagnose and mitigate model errors associated with biogenic fluxes within an atmospheric CO 2 forecasting system. The scheme is an adaptive scaling procedure referred to as a biogenic flux adjustment scheme (BFAS), and it can be applied automatically in real time throughout the forecast. The BFAS method generally improves the continental budget of CO 2 fluxes in the model by combining information from three sources: (1) retrospective fluxes estimated by a global flux inversion system, (2) land-use information, (3) simulated fluxes from the model. The method is shown to produce enhanced skill in the daily CO 2 10-day forecasts without requiring continuous manual intervention. Therefore, it is particularly suitable for near-real-time CO 2 analysis and forecasting systems. |
BibTeX:
@article{Agusti-Panareda2016,
author = {Agustí-Panareda, Anna and Sebastien, Massart and Chevallier, Frédéric and Balsamo, Gianpaolo and Boussetta, Souhail and Dutra, Emanuel and Beljaars, Anton},
title = {A biogenic CO2 flux adjustment scheme for the mitigation of large-scale biases in global atmospheric CO2 analyses and forecasts},
journal = {Atmospheric Chemistry and Physics},
year = {2016},
volume = {16},
pages = {10399--10418},
url = {www.atmos-chem-phys.net/16/10399/2016/},
doi = {10.5194/acp-16-10399-2016}
}
|
| Alden CB, Miller JB, Gatti LV, Gloor MM, Guan K, Michalak AM, van der Laan-Luijkx IT, Touma D, Andrews A, Basso LS, Correia CSC, Domingues LG, Joiner J, Krol MC, Lyapustin AI, Peters W, Shiga YP, Thoning K, van der Velde IR, van Leeuwen TT, Yadav V and Diffenbaugh NS (2016), "Regional atmospheric CO2 inversion reveals seasonal and geographic differences in Amazon net biome exchange", Global change biology., oct, 2016. Vol. 22(10), pp. 3427-3443. |
| Abstract: Understanding tropical rainforest carbon exchange and its response to heat and drought is critical for quantifying the effects of climate change on tropical ecosystems, including global climate-carbon feedbacks. Of particular importance for the global carbon budget is net biome exchange of CO2 with the atmosphere (NBE), which represents nonfire carbon fluxes into and out of biomass and soils. Subannual and sub-Basin Amazon NBE estimates have relied heavily on process-based biosphere models, despite lack of model agreement with plot-scale observations. We present a new analysis of airborne measurements that reveals monthly, regional-scale (˜1-8 × 10(6)  km(2) ) NBE variations. We develop a regional atmospheric CO2 inversion that provides the first analysis of geographic and temporal variability in Amazon biosphere-atmosphere carbon exchange and that is minimally influenced by biosphere model-based first guesses of seasonal and annual mean fluxes. We find little evidence for a clear seasonal cycle in Amazon NBE but do find NBE sensitivity to aberrations from long-term mean climate. In particular, we observe increased NBE (more carbon emitted to the atmosphere) associated with heat and drought in 2010, and correlations between wet season NBE and precipitation (negative correlation) and temperature (positive correlation). In the eastern Amazon, pulses of increased NBE persisted through 2011, suggesting legacy effects of 2010 heat and drought. We also identify regional differences in postdrought NBE that appear related to long-term water availability. We examine satellite proxies and find evidence for higher gross primary productivity (GPP) during a pulse of increased carbon uptake in 2011, and lower GPP during a period of increased NBE in the 2010 dry season drought, but links between GPP and NBE changes are not conclusive. These results provide novel evidence of NBE sensitivity to short-term temperature and moisture extremes in the Amazon, where monthly and sub-Basin estimates have not been previously available. |
BibTeX:
@article{Alden2016,
author = {Alden, Caroline B and Miller, John B and Gatti, Luciana V and Gloor, Manuel M and Guan, Kaiyu and Michalak, Anna M and van der Laan-Luijkx, Ingrid T and Touma, Danielle and Andrews, Arlyn and Basso, Luana S and Correia, Caio S C and Domingues, Lucas G and Joiner, Joanna and Krol, Maarten C and Lyapustin, Alexei I and Peters, Wouter and Shiga, Yoichi P and Thoning, Kirk and van der Velde, Ivar R and van Leeuwen, Thijs T and Yadav, Vineet and Diffenbaugh, Noah S},
title = {Regional atmospheric CO2 inversion reveals seasonal and geographic differences in Amazon net biome exchange},
journal = {Global change biology},
year = {2016},
volume = {22},
number = {10},
pages = {3427--3443},
url = {http://doi.wiley.com/10.1111/gcb.13305},
doi = {10.1111/gcb.13305}
}
|
| Andersson A, Rutgersson A and Sahlée E (2016), "Using eddy covariance to estimate air-sea gas transfer velocity for oxygen", Journal of Marine Systems., jul, 2016. Vol. 159, pp. 67-75. |
| Abstract: Air-sea gas transfer velocity for O2 is calculated using directly measured fluxes with the eddy covariance technique. It is a direct method and is frequently used to determine fluxes of heat, humidity, and CO2, but has not previously been used to estimate transfer velocities for O2, using atmospheric eddy covariance data. The measured O2 fluxes are upward directed, in agreement with the measured air-sea gradient of the O2 concentration, and opposite to the direction of the simultaneously measured CO2 fluxes. The transfer velocities estimated from measurements are compared with prominent wind speed parameterizations of the transfer velocity for CO2 and O2, previously established from various measurement techniques. Our result indicates stronger wind speed dependence for the transfer velocity of O2 compared to CO2 starting at intermediate wind speeds. This stronger wind speed dependence appears to coincide with the onset of whitecap formation in the flux footprint and the strong curvature of a cubic wind-dependent function for the transfer velocity provides the best fit to the data. Additional data using the measured O2 flux and an indirect method (based on the Photosynthetic Quotient) to estimate oxygen concentration in water, support the stronger wind dependence for the transfer velocity of O2 compared to CO2. |
BibTeX:
@article{Andersson2016,
author = {Andersson, Andreas and Rutgersson, Anna and Sahlée, Erik},
title = {Using eddy covariance to estimate air-sea gas transfer velocity for oxygen},
journal = {Journal of Marine Systems},
year = {2016},
volume = {159},
pages = {67--75},
url = {https://linkinghub.elsevier.com/retrieve/pii/S0924796316000440},
doi = {10.1016/j.jmarsys.2016.02.008}
}
|
| Ashton IG, Shutler JD, Land PE, Woolf DK and Quartly GD (2016), "A Sensitivity Analysis of the Impact of Rain on Regional and Global Sea-Air Fluxes of CO2", PLOS ONE., sep, 2016. Vol. 11(9), pp. e0161105. Public Library of Science. |
| Abstract: The global oceans are considered a major sink of atmospheric carbon dioxide (CO2). Rain is known to alter the physical and chemical conditions at the sea surface, and thus influence the transfer of CO2 between the ocean and atmosphere. It can influence gas exchange through enhanced gas transfer velocity, the direct export of carbon from the atmosphere to the ocean, by altering the sea skin temperature, and through surface layer dilution. However, to date, very few studies quantifying these effects on global net sea-air fluxes exist. Here, we include terms for the enhanced gas transfer velocity and the direct export of carbon in calculations of the global net sea-air fluxes, using a 7-year time series of monthly global climate quality satellite remote sensing observations, model and in-situ data. The use of a non-linear relationship between the effects of rain and wind significantly reduces the estimated impact of rain-induced surface turbulence on the rate of sea-air gas transfer, when compared to a linear relationship. Nevertheless, globally, the rain enhanced gas transfer and rain induced direct export increase the estimated annual oceanic integrated net sink of CO2 by up to 6%. Regionally, the variations can be larger, with rain increasing the estimated annual net sink in the Pacific Ocean by up to 15% and altering monthly net flux by textgreater ± 50%. Based on these analyses, the impacts of rain should be included in the uncertainty analysis of studies that estimate net sea-air fluxes of CO2 as the rain can have a considerable impact, dependent upon the region and timescale. |
BibTeX:
@article{Ashton2016,
author = {Ashton, I. G. and Shutler, J. D. and Land, P. E. and Woolf, D. K. and Quartly, G. D.},
editor = {DeCastro, Maite},
title = {A Sensitivity Analysis of the Impact of Rain on Regional and Global Sea-Air Fluxes of CO2},
journal = {PLOS ONE},
publisher = {Public Library of Science},
year = {2016},
volume = {11},
number = {9},
pages = {e0161105},
url = {https://dx.plos.org/10.1371/journal.pone.0161105},
doi = {10.1371/journal.pone.0161105}
}
|
| Aubinet M, Joly L, Loustau D, De Ligne A, Chopin H, Cousin J, Chauvin N, Decarpenterie T and Gross P (2016), "Dimensioning IRGA gas sampling systems: Laboratory and field experiments", Atmospheric Measurement Techniques., mar, 2016. Vol. 9(3), pp. 1361-1367. |
| Abstract: Both laboratory and field experiments were carried out in order to define suitable configuration ranges for the gas sampling systems (GSSs) of infrared gas analyzers (IRGAs) used in eddy covariance measurements./pp classCombining double low line"p"In the laboratory, an original dynamic calibration bench was developed in order to test the frequency attenuation and pressure drop generated by filters. In the field, three IRGAs of the same type equipped with different filters or different rain caps were installed and run and the real frequency response of the complete setup was tested. The main results are as follows. &ndash; Filters may have a strong impact on the pressure drop in the GSS and this impact increases with flow rate. &ndash; Conversely, no impact of the tested filters on cut-off frequency was found, GSSs with and without filters presenting similar cut-off frequencies. &ndash; The main limiting factor of cut-off frequency in the field was found to be the rain cap design. In addition, the impact of this design on pressure drop was also found to be noteworthy. |
BibTeX:
@article{Aubinet2016,
author = {Aubinet, Marc and Joly, Lilian and Loustau, Denis and De Ligne, Anne and Chopin, Henri and Cousin, Julien and Chauvin, Nicolas and Decarpenterie, Thomas and Gross, Patrick},
title = {Dimensioning IRGA gas sampling systems: Laboratory and field experiments},
journal = {Atmospheric Measurement Techniques},
year = {2016},
volume = {9},
number = {3},
pages = {1361--1367},
url = {http://www.atmos-meas-tech.net/9/1361/2016/},
doi = {10.5194/amt-9-1361-2016}
}
|
| Ayalneh Berhanu T, Satar E, Schanda R, Nyfeler P, Moret H, Brunner D, Oney B and Leuenberger M (2016), "Measurements of greenhouse gases at Beromünster tall-tower station in Switzerland", Atmospheric Measurement Techniques., jun, 2016. Vol. 9(6), pp. 2603-2614. |
| Abstract: In order to constrain the regional flux of greenhouse gases, an automated measurement system was built on an old radio tower at Beromünster, Switzerland. The measurement system has been running since November 2012 as part of the Swiss greenhouse gases monitoring network (CarboCount-CH), which is composed of four measurement sites across the country. The Beromünster tall tower has five sampling lines with inlets at 12.5, 44.6, 71.5, 131.6, and 212.5Ä€m above ground level, and it is equipped with a Picarro cavity ring-down spectrometer (CRDS) analyzer (G-2401), which continuously measures CO, CO2, CH4, and H2O. Sensors for detection of wind speed and direction, air temperature, barometric pressure, and humidity have also been installed at each height level. We have observed a non-negligible temperature effect in the calibration measurements, which was found to be dependent on the type of cylinder (steel or aluminum) as well as trace gas species (strongest for CO). From a target gas of known mixing ratio that has been measured once a day, we have calculated a long-term reproducibility of 2.79Ä€ppb, 0.05Ä€ppm, and 0.29Ä€ppb for CO, CO2, and CH4, respectively, over 19 months of measurements. The values obtained for CO2 and CH4 are compliant with the WMO recommendations, while the value calculated for CO is higher than the recommendation. Since the installation of an air-conditioning system recently at the measurement cabin, we have acquired better temperature stability of the measurement system, but no significant improvement was observed in the measurement precision inferred from the target gas measurements. Therefore, it seems that the observed higher variation in CO measurements is associated with the instrumental noise, compatible with the precision provided by the manufacturer. |
BibTeX:
@article{AyalnehBerhanu2016,
author = {Ayalneh Berhanu, Tesfaye and Satar, Ece and Schanda, Rudiger and Nyfeler, Peter and Moret, Hanspeter and Brunner, Dominik and Oney, Brian and Leuenberger, Markus},
title = {Measurements of greenhouse gases at Beromünster tall-tower station in Switzerland},
journal = {Atmospheric Measurement Techniques},
year = {2016},
volume = {9},
number = {6},
pages = {2603--2614},
url = {http://www.atmos-meas-tech.net/9/2603/2016/},
doi = {10.5194/amt-9-2603-2016}
}
|
| Bachy A, Aubinet M, Schoon N, Amelynck C, Bodson B, Moureaux C and Heinesch B (2016), "Are BVOC exchanges in agricultural ecosystems overestimated? Insights from fluxes measured in a maize field over a whole growing season", Atmospheric Chemistry and Physics., apr, 2016. Vol. 16(8), pp. 5343-5356. |
| Abstract: Although maize is the second most important crop worldwide, and the most important C4 crop, no study on biogenic volatile organic compounds (BVOCs) has yet been conducted on this crop at ecosystem scale and over a whole growing season. This has led to large uncertainties in cropland BVOC emission estimations. This paper seeks to fill this gap by presenting, for the first time, BVOC fluxes measured in a maize field at ecosystem scale (using the disjunct eddy covariance by mass scanning technique) over a whole growing season in Belgium. The maize field emitted mainly methanol, although exchanges were bi-directional. The second most exchanged compound was acetic acid, which was taken up mainly in the growing season. Bi-directional exchanges of acetaldehyde, acetone and other oxygenated VOCs also occurred, whereas the terpenes, benzene and toluene exchanges were small, albeit significant. Surprisingly, BVOC exchanges were of the same order of magnitude on bare soil and on well developed vegetation, suggesting that soil is a major BVOC reservoir in agricultural ecosystems. Quantitatively, the maize BVOC emissions observed were lower than those reported in other maize, crops and grasses studies. The standard emission factors (SEFs) estimated in this study (231Ä€±Ä€19Ä€μgÄ€mÄ'2Ä€hÄ'1 for methanol, 8Ä€±Ä€5Ä€μgÄ€mÄ'2Ä€hÄ'1 for isoprene and 4Ä€±Ä€6Ä€μgÄ€mÄ'2Ä€hÄ'1 for monoterpenes) were also much lower than those currently used by models for C4 crops, particularly for terpenes. These results suggest that maize fields are small BVOC exchangers in north-western Europe, with a lower BVOC emission impact than that modelled for growing C4 crops in this part of the world. They also reveal the high variability in BVOC exchanges across world regions for maize and suggest that SEFs should be estimated for each region separately. |
BibTeX:
@article{Bachy2016,
author = {Bachy, Aurlie and Aubinet, Marc and Schoon, Niels and Amelynck, Crist and Bodson, Bernard and Moureaux, Christine and Heinesch, Bernard},
title = {Are BVOC exchanges in agricultural ecosystems overestimated? Insights from fluxes measured in a maize field over a whole growing season},
journal = {Atmospheric Chemistry and Physics},
year = {2016},
volume = {16},
number = {8},
pages = {5343--5356},
url = {http://www.atmos-chem-phys.net/16/5343/2016/},
doi = {10.5194/acp-16-5343-2016}
}
|
| Bakker DCE, Pfeil B, Landa CS, Metzl N, O'Brien KM, Olsen A, Smith K, Cosca C, Harasawa S, Jones SD, Nakaoka SI, Nojiri Y, Schuster U, Steinhoff T, Sweeney C, Takahashi T, Tilbrook B, Wada C, Wanninkhof R, Alin SR, Balestrini CF, Barbero L, Bates NR, Bianchi AA, Bonou F, Boutin J, Bozec Y, Burger EF, Cai WJ, Castle RD, Chen L, Chierici M, Currie K, Evans W, Featherstone C, Feely RA, Fransson A, Goyet C, Greenwood N, Gregor L, Hankin S, Hardman-Mountford NJ, Harlay J, Hauck J, Hoppema M, Humphreys MP, Hunt CW, Huss B, Ibánhez JSP, Johannessen T, Keeling R, Kitidis V, Körtzinger A, Kozyr A, Krasakopoulou E, Kuwata A, Landschützer P, Lauvset SK, Lefèvre N, Lo Monaco C, Manke A, Mathis JT, Merlivat L, Millero FJ, Monteiro PMS, Munro DR, Murata A, Newberger T, Omar AM, Ono T, Paterson K, Pearce D, Pierrot D, Robbins LL, Saito S, Salisbury J, Schlitzer R, Schneider B, Schweitzer R, Sieger R, Skjelvan I, Sullivan KF, Sutherland SC, Sutton AJ, Tadokoro K, Telszewski M, Tuma M, Van Heuven SMAC, Vandemark D, Ward B, Watson AJ and Xu S (2016), "A multi-decade record of high-quality fCO2 data in version 3 of the Surface Ocean CO2 Atlas (SOCAT)", Earth System Science Data., sep, 2016. Vol. 8(2), pp. 383-413. |
| Abstract: The Surface Ocean CO2 Atlas (SOCAT) is a synthesis of quality-controlled fCO2 (fugacity of carbon dioxide) values for the global surface oceans and coastal seas with regular updates. Version 3 of SOCAT has 14.7 million fCO2 values from 3646 data sets covering the years 1957 to 2014. This latest version has an additional 4.6 million fCO2 values relative to version 2 and extends the record from 2011 to 2014. Version 3 also significantly increases the data availability for 2005 to 2013. SOCAT has an average of approximately 1.2 million surface water fCO2 values per year for the years 2006 to 2012. Quality and documentation of the data has improved. A new feature is the data set quality control (QC) flag of E for data from alternative sensors and platforms. The accuracy of surface water fCO2 has been defined for all data set QC flags. Automated range checking has been carried out for all data sets during their upload into SOCAT. The upgrade of the interactive Data Set Viewer (previously known as the Cruise Data Viewer) allows better interrogation of the SOCAT data collection and rapid creation of high-quality figures for scientific presentations. Automated data upload has been launched for version 4 and will enable more frequent SOCAT releases in the future. Highprofile scientific applications of SOCAT include quantification of the ocean sink for atmospheric carbon dioxide and its long-term variation, detection of ocean acidification, as well as evaluation of coupled-climate and ocean-only biogeochemical models. Users of SOCAT data products are urged to acknowledge the contribution of data providers, as stated in the SOCAT Fair Data Use Statement. This ESSD (Earth System Science Data) "living data" publication documents the methods and data sets used for the assembly of this new version of the SOCAT data collection and compares these with those used for earlier versions of the data collection (Pfeil et al., 2013; Sabine et al., 2013; Bakker et al., 2014). Individual data set files, included in the synthesis product, can be downloaded here: doi:10.1594/PANGAEA.849770. The gridded products are available here: doi:10.3334/CDIAC/OTG.SOCAT-V3-GRID. |
BibTeX:
@article{Bakker2016,
author = {Bakker, Dorothee C E and Pfeil, Benjamin and Landa, Camilla S and Metzl, Nicolas and O'Brien, Kevin M and Olsen, Are and Smith, Karl and Cosca, Cathy and Harasawa, Sumiko and Jones, Stephen D and Nakaoka, Shin Ichiro and Nojiri, Yukihiro and Schuster, Ute and Steinhoff, Tobias and Sweeney, Colm and Takahashi, Taro and Tilbrook, Bronte and Wada, Chisato and Wanninkhof, Rik and Alin, Simone R and Balestrini, Carlos F and Barbero, Leticia and Bates, Nicholas R and Bianchi, Alejandro A and Bonou, Frédéric and Boutin, Jacqueline and Bozec, Yann and Burger, Eugene F and Cai, Wei Jun and Castle, Robert D and Chen, Liqi and Chierici, Melissa and Currie, Kim and Evans, Wiley and Featherstone, Charles and Feely, Richard A and Fransson, Agneta and Goyet, Catherine and Greenwood, Naomi and Gregor, Luke and Hankin, Steven and Hardman-Mountford, Nick J and Harlay, Jérôme and Hauck, Judith and Hoppema, Mario and Humphreys, Matthew P and Hunt, Christopher W and Huss, Betty and Ibánhez, J Severino P and Johannessen, Truls and Keeling, Ralph and Kitidis, Vassilis and Körtzinger, Arne and Kozyr, Alex and Krasakopoulou, Evangelia and Kuwata, Akira and Landschützer, Peter and Lauvset, Siv K and Lefèvre, Nathalie and Lo Monaco, Claire and Manke, Ansley and Mathis, Jeremy T and Merlivat, Liliane and Millero, Frank J and Monteiro, Pedro M S and Munro, David R and Murata, Akihiko and Newberger, Timothy and Omar, Abdirahman M and Ono, Tsuneo and Paterson, Kristina and Pearce, David and Pierrot, Denis and Robbins, Lisa L and Saito, Shu and Salisbury, Joe and Schlitzer, Reiner and Schneider, Bernd and Schweitzer, Roland and Sieger, Rainer and Skjelvan, Ingunn and Sullivan, Kevin F and Sutherland, Stewart C and Sutton, Adrienne J and Tadokoro, Kazuaki and Telszewski, Maciej and Tuma, Matthias and Van Heuven, Steven M A C and Vandemark, Doug and Ward, Brian and Watson, Andrew J and Xu, Suqing},
title = {A multi-decade record of high-quality fCO2 data in version 3 of the Surface Ocean CO2 Atlas (SOCAT)},
journal = {Earth System Science Data},
year = {2016},
volume = {8},
number = {2},
pages = {383--413},
url = {http://www.earth-syst-sci-data.net/8/383/2016/},
doi = {10.5194/essd-8-383-2016}
}
|
| Balch WM, Bates NR, Lam PJ, Twining BS, Rosengard SZ, Bowler BC, Drapeau DT, Garley R, Lubelczyk LC, Mitchell C and Rauschenberg S (2016), "Factors regulating the Great Calcite Belt in the Southern Ocean and its biogeochemical significance", Global Biogeochemical Cycles., aug, 2016. Vol. 30(8), pp. 1124-1144. Blackwell Publishing Ltd. |
| Abstract: The Great Calcite Belt (GCB) is a region of elevated surface reflectance in the Southern Ocean (SO) covering ˜16% of the global ocean and is thought to result from elevated, seasonal concentrations of coccolithophores. Here we describe field observations and experiments from two cruises that crossed the GCB in the Atlantic and Indian sectors of the SO. We confirm the presence of coccolithophores, their coccoliths, and associated optical scattering, located primarily in the region of the subtropical, Agulhas, and Subantarctic frontal regions. Coccolithophore-rich regions were typically associated with high-velocity frontal regions with higher seawater partial pressures of CO2 (pCO2) than the atmosphere, sufficient to reverse the direction of gas exchange to a CO2 source. There was no calcium carbonate (CaCO3) enhancement of particulate organic carbon (POC) export, but there were increased POC transfer efficiencies in high-flux particulate inorganic carbon regions. Contemporaneous observations are synthesized with results of trace-metal incubation experiments, 234Th-based flux estimates, and remotely sensed observations to generate a mandala that summarizes our understanding about the factors that regulate the location of the GCB. |
BibTeX:
@article{Balch2016,
author = {Balch, William M. and Bates, Nicholas R. and Lam, Phoebe J. and Twining, Benjamin S. and Rosengard, Sarah Z. and Bowler, Bruce C. and Drapeau, Dave T. and Garley, Rebecca and Lubelczyk, Laura C. and Mitchell, Catherine and Rauschenberg, Sara},
title = {Factors regulating the Great Calcite Belt in the Southern Ocean and its biogeochemical significance},
journal = {Global Biogeochemical Cycles},
publisher = {Blackwell Publishing Ltd},
year = {2016},
volume = {30},
number = {8},
pages = {1124--1144},
url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/2016GB005414},
doi = {10.1002/2016GB005414}
}
|
| Balzarolo M, Vicca S, Nguy-Robertson AL, Bonal D, Elbers JA, Fu YH, Grünwald T, Horemans JA, Papale D, Peñuelas J, Suyker A and Veroustraete F (2016), "Matching the phenology of Net Ecosystem Exchange and vegetation indices estimated with MODIS and FLUXNET in-situ observations", Remote Sensing of Environment., mar, 2016. Vol. 174, pp. 290-300. |
| Abstract: Shifts in ecosystem phenology play an important role in the definition of inter-annual variability of net ecosystem carbon uptake. A good estimate at the global scale of ecosystem phenology, mainly that of photosynthesis or gross primary productivity (GPP), may be provided by vegetation indices derived from MODIS satellite image data.However, the relationship between the start date of a growing (or greening) season (SGS) when derived from different vegetation indices (VI's), and the starting day of carbon uptake is not well elucidated. Additionally, the validation of existing phenology data with in-situ measurements is largely missing. We have investigated the possibility to use different VI's to predict the starting day of the growing season for 28 FLUXNET sites as well as MODIS data. This analysis included main plant functional types (PFT's).Of all VI's taken into account in this paper, the NDVI (Normalized Difference Vegetation Index) shows the highest correlation coefficient for the relationship between the starting day of the growing season as observed with MODIS and in-situ observations. However, MODIS observations elicit a 20-21 days earlier SGS date compared to in-situ observations. The prediction for the NEE start of the growing season diverges when using different VI's, and seems to depend on the amplitude for carbon and VI and on PFT. The optimal VI for estimation of a SGS date was PFT-specific - for example the WRDVI for cropland, but the MODIS NDVI performed best when applied as an estimator for Net Ecosystem Exchange and when considering all PFT's pooled. |
BibTeX:
@article{Balzarolo2016,
author = {Balzarolo, M and Vicca, S and Nguy-Robertson, A L and Bonal, D and Elbers, J A and Fu, Y H and Grünwald, T and Horemans, J A and Papale, D and Peñuelas, J and Suyker, A and Veroustraete, F},
title = {Matching the phenology of Net Ecosystem Exchange and vegetation indices estimated with MODIS and FLUXNET in-situ observations},
journal = {Remote Sensing of Environment},
year = {2016},
volume = {174},
pages = {290--300},
url = {http://linkinghub.elsevier.com/retrieve/pii/S0034425715302388},
doi = {10.1016/j.rse.2015.12.017}
}
|
| Batenburg AM, Popa ME, Vermeulen AT, van den Bulk WCM, Jongejan PAC, Fisher RE, Lowry D, Nisbet EG and Röckmann T (2016), "Observations of molecular hydrogen mixing ratio and stable isotopic composition at the Cabauw tall tower in the Netherlands", Atmospheric Environment., dec, 2016. Vol. 147, pp. 98-108. |
| Abstract: Measurements of the stable isotopic composition (δD(H2) or δD) of atmospheric molecular hydrogen (H2) are a useful addition to mixing ratio (χ(H2)) measurements for understanding the atmospheric H2 cycle. δD datasets published so far consist mostly of observations at background locations. We complement these with observations from the Cabauw tall tower at the CESAR site, situated in a densely populated region of the Netherlands. Our measurements show a large anthropogenic influence on the local H2 cycle, with frequently occurring pollution events that are characterized by χ(H2) values that reach up to ≈1 ppm and low δD values. An isotopic source signature analysis yields an apparent source signature below âˆ'400‰, which is much more D-depleted than the fossil fuel combustion source signature commonly used in H2 budget studies. Two diurnal cycles that were sampled at a suburban site near London also show a more D-depleted source signature (≈âˆ'340‰), though not as extremely depleted as at Cabauw. The source signature of the Northwest European vehicle fleet may have shifted to somewhat lower values due to changes in vehicle technology and driving conditions. Even so, the surprisingly depleted apparent source signature at Cabauw requires additional explanation; microbial H2 production seems the most likely cause. The Cabauw tower site also allowed us to sample vertical profiles. We found no decrease in χ(H2) at lower sampling levels (20 and 60 m) with respect to higher sampling levels (120 and 200 m). There was a significant shift to lower median δD values at the lower levels. This confirms the limited role of soil uptake around Cabauw, and again points to microbial H2 production during an extended growing season, as well as to possible differences in average fossil fuel combustion source signature between the different footprint areas of the sampling levels. So, although knowledge of the background cycle of H2 has improved over the last decade, surprising features come to light when a non-background location is studied, revealing remaining gaps in our understanding. |
BibTeX:
@article{Batenburg2016,
author = {Batenburg, A M and Popa, M E and Vermeulen, A T and van den Bulk, W C M and Jongejan, P A C and Fisher, R E and Lowry, D and Nisbet, E G and Röckmann, T},
title = {Observations of molecular hydrogen mixing ratio and stable isotopic composition at the Cabauw tall tower in the Netherlands},
journal = {Atmospheric Environment},
year = {2016},
volume = {147},
pages = {98--108},
url = {http://linkinghub.elsevier.com/retrieve/pii/S1352231016307762},
doi = {10.1016/j.atmosenv.2016.09.058}
}
|
| Becker M, Andersen N, Erlenkeuser H, Humphreys MP, Tanhua T and Körtzinger A (2016), "An internally consistent dataset of δ13C-DIC in the North Atlantic Ocean - NAC13v1", Earth System Science Data. Vol. 8(2), pp. 559-770. |
| Abstract: The stable carbon isotope composition of dissolved inorganic carbon (δ13C-DIC) can be used to quantify fluxes within the carbon system. For example, knowing the δ13C signature of the inorganic carbon pool can help in describing the amount of anthropogenic carbon in the water column. The measurements can also be used for evaluating modeled carbon fluxes, for making basin-wide estimates of anthropogenic carbon, and for studying seasonal and interannual variability or decadal trends in interior ocean biogeochemistry. For all these purposes, it is not only important to have a sufficient amount of data, but these data must also be internally consistent and of high quality. In this study, we present a δ13C-DIC dataset for the North Atlantic which has undergone secondary quality control. The data originate from oceanographic research cruises between 1981 and 2014. During a primary quality control step based on simple range tests, obviously bad data were flagged. In a second quality control step, biases between measurements from different cruises were quantified through a crossover analysis using nearby data of the respective cruises, and values of biased cruises were adjusted in the data product. The crossover analysis was possible for 24 of the 32 cruises in our dataset, and adjustments were applied to 11 cruises. The internal accuracy of this dataset is 0.017 ‰. |
BibTeX:
@article{Becker2016,
author = {Becker, Meike and Andersen, Nils and Erlenkeuser, Helmut and Humphreys, Matthew P and Tanhua, Toste and Körtzinger, Arne},
title = {An internally consistent dataset of δ13C-DIC in the North Atlantic Ocean - NAC13v1},
journal = {Earth System Science Data},
year = {2016},
volume = {8},
number = {2},
pages = {559--770},
url = {http://www.earth-syst-sci-data.net/8/559/2016/},
doi = {10.5194/essd-8-559-2016}
}
|
| Belviso S, Marco Reiter I, Loubet B, Gros V, Lathière J, Montagne D, Delmotte M, Ramonet M, Kalogridis C, Lebegue B, Bonnaire N, Kazan V, Gauquelin T, Fernandez C and Genty B (2016), "A top-down approach of surface carbonyl sulfide exchange by a Mediterranean oak forest ecosystem in southern France", Atmospheric Chemistry and Physics., dec, 2016. Vol. 16(23), pp. 14909-14923. |
| Abstract: The role that soil, foliage, and atmospheric dynamics have on surface carbonyl sulfide (OCS) exchange in a Mediterranean forest ecosystem in southern France (the Oak Observatory at the Observatoire de Haute Provence, O3HP) was investigated in June of 2012 and 2013 with essentially a top-down approach. Atmospheric data suggest that the site is appropriate for estimating gross primary production (GPP) directly from eddy covariance measurements of OCS fluxes, but it is less adequate for scaling net ecosystem exchange (NEE) to GPP from observations of vertical gradients of OCS relative to CO2 during the daytime. Firstly, OCS and carbon dioxide (CO2) diurnal variations and vertical gradients show no net exchange of OCS at night when the carbon fluxes are dominated by ecosystem respiration. This contrasts with other oak woodland ecosystems of a Mediterranean climate, where nocturnal uptake of OCS by soil and/or vegetation has been observed. Since temperature, water, and organic carbon content of soil at the O3HP should favor the uptake of OCS, the lack of nocturnal net uptake would indicate that its gross consumption in soil is compensated for by emission processes that remain to be characterized. Secondly, the uptake of OCS during the photosynthetic period was characterized in two different ways. We measured ozone (O3) deposition velocities and estimated the partitioning of O3 deposition between stomatal and non-stomatal pathways before the start of a joint survey of OCS and O3 surface concentrations. We observed an increasing trend in the relative importance of the stomatal pathway during the morning hours and synchronous steep drops of mixing ratios of OCS (amplitude in the range of 60-100 ppt) and O3 (amplitude in the range of 15-30 ppb) after sunrise and before the break up of the nocturnal boundary layer. The uptake of OCS by plants was also characterized from vertical profiles. However, the time window for calculation of the ecosystem relative uptake (ERU) of OCS, which is a useful tool for partitioning measured NEE, was limited in June 2012 to a few hours after midday. This was due to the disruption of the vertical distribution of OCS by entrainment of OCS rich tropospheric air in the morning and because the vertical gradient of CO2 reverses when it is still light. Moreover, polluted air masses (up to 700 ppt of OCS) produced dramatic variation in atmospheric OCS / CO2 ratios during the daytime in June 2013, further reducing the time window for ERU calculation. |
BibTeX:
@article{Belviso2016,
author = {Belviso, Sauveur and Marco Reiter, Ilja and Loubet, Benjamin and Gros, Valérie and Lathière, Juliette and Montagne, David and Delmotte, Marc and Ramonet, Michel and Kalogridis, Cerise and Lebegue, Benjamin and Bonnaire, Nicolas and Kazan, Victor and Gauquelin, Thierry and Fernandez, Catherine and Genty, Bernard},
title = {A top-down approach of surface carbonyl sulfide exchange by a Mediterranean oak forest ecosystem in southern France},
journal = {Atmospheric Chemistry and Physics},
year = {2016},
volume = {16},
number = {23},
pages = {14909--14923},
url = {http://www.atmos-chem-phys.net/16/14909/2016/},
doi = {10.5194/acp-16-14909-2016}
}
|
| Bertolini T, Flechard CR, Fattore F, Nicolini G, Stefani P, Materia S, Valentini R, Vaglio Laurin G and Castaldi S (2016), "DRY and BULK atmospheric nitrogen deposition to a West-African humid forest exposed to terrestrial and oceanic sources", Agricultural and Forest Meteorology., mar, 2016. Vol. 218-219, pp. 184-195. |
BibTeX:
@article{Bertolini2016,
author = {Bertolini, Teresa and Flechard, Chris R and Fattore, Ferdinando and Nicolini, Giacomo and Stefani, Paolo and Materia, Stefano and Valentini, Riccardo and Vaglio Laurin, Gaia and Castaldi, Simona},
title = {DRY and BULK atmospheric nitrogen deposition to a West-African humid forest exposed to terrestrial and oceanic sources},
journal = {Agricultural and Forest Meteorology},
year = {2016},
volume = {218-219},
pages = {184--195},
url = {https://linkinghub.elsevier.com/retrieve/pii/S0168192315008175},
doi = {10.1016/j.agrformet.2015.12.026}
}
|
| Bogena HR (2016), "TERENO: German network of terrestrial environmental observatories", Journal of large-scale research facilities JLSRF., feb, 2016. Vol. 2, pp. A52. |
| Abstract: Central elements of the TERENO network are “terrestrial observatories†at the catchment scale which were selected in climate sensitive regions of Germany for the regional analyses of climate change impacts. Within these observatories small scale research facilities and test areas are placed in order to accomplish energy, water, carbon and nutrient process studies across the different compartments of the terrestrial environment. Following a hierarchical scaling approach (point-plot-field) these detailed information and the gained knowledge will be transferred to the regional scale using integrated modelling approaches. Furthermore, existing research stations are enhanced and embedded within the observatories. In addition, mobile measurement platforms enable monitoring of dynamic processes at the local scale up to the determination of spatial pattern at the regional scale are applied within TERENO. |
BibTeX:
@article{Bogena2016,
author = {Bogena, Heye Reemt},
title = {TERENO: German network of terrestrial environmental observatories},
journal = {Journal of large-scale research facilities JLSRF},
year = {2016},
volume = {2},
pages = {A52},
url = {http://jlsrf.org/index.php/lsf/article/view/98},
doi = {10.17815/jlsrf-2-98}
}
|
| Bonou FK, Noriega C, Lefèvre N and Araujo M (2016), "Distribution of CO2 parameters in the Western Tropical Atlantic Ocean", Dynamics of Atmospheres and Oceans., mar, 2016. Vol. 73, pp. 47-60. Elsevier Ltd. |
| Abstract: The variability of sea surface Total Alkalinity (TA) and sea surface Total Inorganic Carbon (CT) is examined using all available data in the western tropical Atlantic (WTA: 20°S-20°N, 60°W-20°W). Lowest TA and CT are observed for the region located between 0°N-15°N/60°W-50°W and are explained by the influence of the Amazon plume during boreal summer. In the southern part of the area, 20°S-10°S/40°W-60°W, the highest values of TA and CT are linked to the CO2-rich waters due to the equatorial upwelling, which are transported by the South Equatorial Current (SEC) flowing from the African coast to the Brazilian shore. An increase of CT of 0.9±0.3μmolkg-1yr-1 has been observed in the SEC region and is consistent with previous published estimates. A revised CT-Sea Surface Salinity (SSS) relationship is proposed for the WTA to take into account the variability of CT at low salinities. This new CT-SSS relationship together with a published TA-SSS relationship allow to calculate pCO2 values that compare well with observed pCO2 (R2=0.90). |
BibTeX:
@article{Bonou2016,
author = {Bonou, Frédéric Kpèdonou and Noriega, Carlos and Lefèvre, Nathalie and Araujo, Moacyr},
title = {Distribution of CO2 parameters in the Western Tropical Atlantic Ocean},
journal = {Dynamics of Atmospheres and Oceans},
publisher = {Elsevier Ltd},
year = {2016},
volume = {73},
pages = {47--60},
doi = {10.1016/j.dynatmoce.2015.12.001}
}
|
| Bourgeois T, Orr JC, Resplandy L, Terhaar J, Ethé C, Gehlen M and Bopp L (2016), "Coastal-ocean uptake of anthropogenic carbon", Biogeosciences., jul, 2016. Vol. 13(14), pp. 4167-4185. Copernicus GmbH. |
| Abstract: textlessptextgreaterAbstract. Anthropogenic changes in atmosphere–ocean and atmosphere–land CO2 fluxes have been quantified extensively, but few studies have addressed the connection between land and ocean. In this transition zone, the coastal ocean, spatial and temporal data coverage is inadequate to assess its global budget. Thus we use a global ocean biogeochemical model to assess the coastal ocean's global inventory of anthropogenic CO2 and its spatial variability. We used an intermediate resolution, eddying version of the NEMO-PISCES model (ORCA05), varying from 20 to 50 km horizontally, i.e. coarse enough to allow multiple century-scale simulations but finer than coarse-resolution models (∼ 200 km) to better resolve coastal bathymetry and complex coastal currents. Here we define the coastal zone as the continental shelf area, excluding the proximal zone. Evaluation of the simulated air–sea fluxes of total CO2 for 45 coastal regions gave a correlation coefficient R of 0.8 when compared to observation-based estimates. Simulated global uptake of anthropogenic carbon results averaged 2.3 Pg C yr−1 during the years 1993–2012, consistent with previous estimates. Yet only 0.1 Pg C yr−1 of that is absorbed by the global coastal ocean. That represents 4.5 % of the anthropogenic carbon uptake of the global ocean, less than the 7.5 % proportion of coastal-to-global-ocean surface areas. Coastal uptake is weakened due to a bottleneck in offshore transport, which is inadequate to reduce the mean anthropogenic carbon concentration of coastal waters to the mean level found in the open-ocean mixed layer.textless/ptextgreater |
BibTeX:
@article{Bourgeois2016,
author = {Bourgeois, Timothée and Orr, James C. and Resplandy, Laure and Terhaar, Jens and Ethé, Christian and Gehlen, Marion and Bopp, Laurent},
title = {Coastal-ocean uptake of anthropogenic carbon},
journal = {Biogeosciences},
publisher = {Copernicus GmbH},
year = {2016},
volume = {13},
number = {14},
pages = {4167--4185},
url = {https://bg.copernicus.org/articles/13/4167/2016/},
doi = {10.5194/bg-13-4167-2016}
}
|
| Bozhinova D, Palstra SWL, van Der Molen MK, Krol MC, Meijer HAJ and Peters W (2016), "Three years of Δ14CO2 observations from maize leaves in the Netherlands and Western Europe", Radiocarbon., sep, 2016. Vol. 58(3), pp. 459-478. |
| Abstract: Atmospheric Δ14CO2measurements are useful to investigate the regional signals of anthropogenic CO2emissions, despite the currently scarce observational network for Δ14CO2. Plant samples are an easily attainable alternative, which have been shown to work well as a qualitative measure of the atmospheric Δ14CO2signals integrated over the time a plant has grown. Here, we present the14C analysis results for 89 individual maize (Zea mays) plant samples from 51 different locations that were gathered in the Netherlands in the years 2010 to 2012, and from western Germany and France in 2012. We describe our sampling strategy and results, and include a comparison to a model simulation of the Δ14CO2that would be accumulated in each plant over a growing season. Our model simulates the Δ14CO2signatures in good agreement with observed plant samples, resulting in a root-mean-square deviation (RMSD) of 3.30‰. This value is comparable to the measurement uncertainty, but still relatively large (20–50%) compared to the total signal. It is also comparable to the spread in Δ14CO2values found across multiple plants from a single site, and to the spread found when averaging across larger regions. We nevertheless find that both measurements and model capture the large-scale (100 km) regional Δ14CO2gradients, with significant observation-model correlations in all three countries in which we collected samples. The modeled plant results suggest that the largest gradients found in the Netherlands and Germany are associated with emissions from energy production and road traffic, while in France, the14CO2enrichment from nuclear sources dominates in many samples. Overall, the required model-based interpretation of plant samples adds additional uncertainty to the already relatively large measurement uncertainty in Δ14CO2, and we suggest that future fossil fuel monitoring efforts should prioritize other strategies such as direct atmospheric sampling of CO2and Δ14CO2. |
BibTeX:
@article{Bozhinova2016,
author = {Bozhinova, D and Palstra, S W L and van Der Molen, M K and Krol, M C and Meijer, H A J and Peters, W},
title = {Three years of Δ14CO2 observations from maize leaves in the Netherlands and Western Europe},
journal = {Radiocarbon},
year = {2016},
volume = {58},
number = {3},
pages = {459--478},
url = {https://www.cambridge.org/core/product/identifier/S0033822216000205/type/journal_article},
doi = {10.1017/RDC.2016.20}
}
|
| Brilli F, Gioli B, Fares S, Terenzio Z, Zona D, Gielen B, Loreto F, Janssens IA and Ceulemans R (2016), "Rapid leaf development drives the seasonal pattern of volatile organic compound (VOC) fluxes in a 'coppiced' bioenergy poplar plantation", Plant Cell and Environment., mar, 2016. Vol. 39(3), pp. 539-555. |
| Abstract: Leaves of fast-growing, woody bioenergy crops often emit volatile organic compounds (VOC). Some reactive VOC (especially isoprene) play a key role in climate forcing and may negatively affect local air quality. We monitored the seasonal exchange of VOC using the eddy covariance technique in a 'coppiced' poplar plantation. The complex interactions of VOC fluxes with climatic and physiological variables were also explored by using an artificial neural network (Self Organizing Map). Isoprene and methanol were the most abundant VOC emitted by the plantation. Rapid development of the canopy (and thus of the leaf area index, LAI) was associated with high methanol emissions and high rates of gross primary production (GPP) since the beginning of the growing season, while the onset of isoprene emission was delayed. The highest emissions of isoprene, and of isoprene photo-oxidation products (Methyl Vinyl Ketone and Methacrolein, iox), occurred on the hottest and sunniest days, when GPP and evapotranspiration were highest, and formaldehyde was significantly deposited. Canopy senescence enhanced the exchange of oxygenated VOC. The accuracy of methanol and isoprene emission simulations with the Model of Emissions of Gases and Aerosols from Nature increased by applying a function to modify their basal emission factors, accounting for seasonality of GPP or LAI. • Some reactive volatile organic compounds (VOC) (especially isoprene) emitted in the atmosphere from leaves of widespread fast-growing woody bioenergy crops play a key role in climate forcing and local air quality. • Eddy covariance VOC emission and deposition fluxes were monitored in a 'coppiced' poplar plantation during an entire growing season, and their complex interactions with climatic and physiological variables also including canopy structural traits were explored by using the Self-organizing Map. • Rapid development of a canopy (and thus of leaf area index, LAI) was associated with high methanol emissions and high rates of gross primary production (GPP) since the beginning of the growing season, while the onset of isoprene emission was delayed. • The highest emissions of isoprene, and of isoprene photooxidation products (methyl vinyl ketone and methacrolein, iox) occurred on the hottest and sunniest days, when also GPP and evapotranspiration were highest and formaldehyde was significantly deposited. • The accuracy of methanol and isoprene emission simulations with the MEGAN model increased by applying a function to modify their basal emission factors, accounting for seasonality of GPP or LAI. |
BibTeX:
@article{Brilli2016,
author = {Brilli, Federico and Gioli, Beniamino and Fares, Silvano and Terenzio, Zenone and Zona, Donatella and Gielen, Bert and Loreto, Francesco and Janssens, Ivan A and Ceulemans, Reinhart},
title = {Rapid leaf development drives the seasonal pattern of volatile organic compound (VOC) fluxes in a 'coppiced' bioenergy poplar plantation},
journal = {Plant Cell and Environment},
year = {2016},
volume = {39},
number = {3},
pages = {539--555},
url = {http://doi.wiley.com/10.1111/pce.12638},
doi = {10.1111/pce.12638}
}
|
| Campioli M, Malhi Y, Vicca S, Luyssaert S, Papale D, Peñuelas J, Reichstein M, Migliavacca M, Arain MA and Janssens IA (2016), "Evaluating the convergence between eddy-covariance and biometric methods for assessing carbon budgets of forests", Nature Communications., dec, 2016. Vol. 7, pp. 13717. |
| Abstract: The eddy-covariance (EC) micro-meteorological technique and the ecology-based biometric methods (BM) are the primary methodologies to quantify CO 2 exchange between terrestrial ecosystems and the atmosphere (net ecosystem production, NEP) and its two components, ecosystem respiration and gross primary production. Here we show that EC and BM provide different estimates of NEP, but comparable ecosystem respiration and gross primary production for forest ecosystems globally. Discrepancies between methods are not related to environmental or stand variables, but are consistently more pronounced for boreal forests where carbon fluxes are smaller. BM estimates are prone to underestimation of net primary production and overestimation of leaf respiration. EC biases are not apparent across sites, suggesting the effectiveness of standard post-processing procedures. Our results increase confidence in EC, show in which conditions EC and BM estimates can be integrated, and which methodological aspects can improve the convergence between EC and BM. |
BibTeX:
@article{Campioli2016,
author = {Campioli, M and Malhi, Y and Vicca, S and Luyssaert, S and Papale, D and Peñuelas, J and Reichstein, M and Migliavacca, M and Arain, M A and Janssens, I A},
title = {Evaluating the convergence between eddy-covariance and biometric methods for assessing carbon budgets of forests},
journal = {Nature Communications},
year = {2016},
volume = {7},
pages = {13717},
url = {http://www.nature.com/doifinder/10.1038/ncomms13717},
doi = {10.1038/ncomms13717}
}
|
| Chambers SD, Williams AG, Conen F, Griffiths AD, Reimann S, Steinbacher M, Krummel PB, Steele LP, van der Schoot MV, Galbally IE, Molloy SB and Barnes JE (2016), "Towards a universal “Baseline†characterisation of air masses for high- and low-altitude observing stations using radon-222", Aerosol and Air Quality Research. Vol. 16(3), pp. 885-899. |
| Abstract: We demonstrate the ability of atmospheric radon concentrations to reliably and unambiguously identify local and remote terrestrial influences on an air mass, and thereby the potential for alteration of trace gas composition by anthropogenic and biogenic processes. Based on high accuracy (lower limit of detection 10-40 mBq m-3), high temporal resolution (hourly) measurements of atmospheric radon concentration we describe, apply and evaluate a simple two-step method for identifying and characterising constituent mole fractions in baseline air. The technique involves selecting a radon-based threshold concentration to identify the “cleanest†(least terrestrially influenced) air masses, and then performing an outlier removal step based on the distribution of constituent mole fractions in the identified clean air masses. The efficacy of this baseline selection technique is tested at three contrasting WMO GAW stations: Cape Grim (a coastal low-altitude site), Mauna Loa (a remote high-altitude island site), and Jungfraujoch (a continental high-altitude site). At Cape Grim and Mauna Loa the two-step method is at least as effective as more complicated methods employed to characterise baseline conditions, some involving up to nine steps. While it is demonstrated that Jungfraujoch air masses rarely meet the baseline criteria of the more remote sites, a selection method based on a variable monthly radon threshold is shown to produce credible “near baseline†characteristics. The seasonal peak-to-peak amplitude of recent monthly baseline CO2 mole fraction deviations from the long-term trend at Cape Grim, Mauna Loa and Jungfraujoch are estimated to be 1.1, 6.0 and 8.1 ppm, respectively. |
BibTeX:
@article{Chambers2016,
author = {Chambers, Scott D and Williams, Alastair G and Conen, Franz and Griffiths, Alan D and Reimann, Stefan and Steinbacher, Martin and Krummel, Paul B and Steele, L Paul and van der Schoot, Marcel V and Galbally, Ian E and Molloy, Suzie B and Barnes, John E},
title = {Towards a universal “Baseline†characterisation of air masses for high- and low-altitude observing stations using radon-222},
journal = {Aerosol and Air Quality Research},
year = {2016},
volume = {16},
number = {3},
pages = {885--899},
url = {http://www.aaqr.org/doi/10.4209/aaqr.2015.06.0391},
doi = {10.4209/aaqr.2015.06.0391}
}
|
| Chen Y, Ryder J, Bastrikov V, McGrath MJ, Naudts K, Otto J, Ottlé C, Peylin P, Polcher J, Valade A, Black A, Elbers JA, Moors E, Foken T, Van Gorsel E, Haverd V, Heinesch B, Tiedemann F, Knohl A, Launiainen S, Loustau D, Ogeé J, Vessala T and Luyssaert S (2016), "Evaluating the performance of land surface model ORCHIDEE-CAN v1.0 on water and energy flux estimation with a single-and multi-layer energy budget scheme", Geoscientific Model Development., sep, 2016. Vol. 9(9), pp. 2951-2972. |
| Abstract: Canopy structure is one of the most important vegetation characteristics for land-atmosphere interactions, as it determines the energy and scalar exchanges between the land surface and the overlying air mass. In this study we evaluated the performance of a newly developed multi-layer energy budget in the ORCHIDEE-CAN v1.0 land surface model (Organising Carbon and Hydrology In Dynamic Ecosystems-CANopy), which simulates canopy structure and can be coupled to an atmospheric model using an implicit coupling procedure. We aim to provide a set of acceptable parameter values for a range of forest types. Top-canopy and sub-canopy flux observations from eight sites were collected in order to conduct this evaluation. The sites crossed climate zones from temperate to boreal and the vegetation types included deciduous, evergreen broad-leaved and evergreen needle-leaved forest with a maximum leaf area index (LAI; all-sided) ranging from 3.5 to 7.0. The parametrization approach proposed in this study was based on three selected physical processes-namely the diffusion, advection, and turbulent mixing within the canopy. Short-term sub-canopy observations and long-term surface fluxes were used to calibrate the parameters in the sub-canopy radiation, turbulence, and resistance modules with an automatic tuning process. The multi-layer model was found to capture the dynamics of sub-canopy turbulence, temperature, and energy fluxes. The performance of the new multi-layer model was further compared against the existing single-layer model. Although the multi-layer model simulation results showed few or no improvements to both the nighttime energy balance and energy partitioning during winter compared with a single-layer model simulation, the increased model complexity does provide a more detailed description of the canopy micrometeorology of various forest types. The multi-layer model links to potential future environmental and ecological studies such as the assessment of in-canopy species vulnerability to climate change, the climate effects of disturbance intensities and frequencies, and the consequences of biogenic volatile organic compound (BVOC) emissions from the terrestrial ecosystem. |
BibTeX:
@article{Chen2016,
author = {Chen, Yiying and Ryder, James and Bastrikov, Vladislav and McGrath, Matthew J and Naudts, Kim and Otto, Juliane and Ottlé, Catherine and Peylin, Philippe and Polcher, Jan and Valade, Aude and Black, Andrew and Elbers, Jan A and Moors, Eddy and Foken, Thomas and Van Gorsel, Eva and Haverd, Vanessa and Heinesch, Bernard and Tiedemann, Frank and Knohl, Alexander and Launiainen, Samuli and Loustau, Denis and Ogeé, Jérôme and Vessala, Timo and Luyssaert, Sebastiaan},
title = {Evaluating the performance of land surface model ORCHIDEE-CAN v1.0 on water and energy flux estimation with a single-and multi-layer energy budget scheme},
journal = {Geoscientific Model Development},
year = {2016},
volume = {9},
number = {9},
pages = {2951--2972},
url = {http://www.geosci-model-dev.net/9/2951/2016/},
doi = {10.5194/gmd-9-2951-2016}
}
|
| Chiesi M, Chirici G, Marchetti M, Hasenauer H, Moreno A, Knohl A, Matteucci G, Pilegaard K, Granier A, Longdoz B and Maselli F (2016), "Testing the applicability of BIOME-BGC to simulate beech gross primary production in Europe using a new continental weather dataset", Annals of Forest Science., sep, 2016. Vol. 73(3), pp. 713-727. |
| Abstract: Key message: A daily 1-km Pan-European weather dataset can drive the BIOME-BGC model for the estimation of current and future beech gross primary production (GPP). Annual beech GPP is affected primarily by spring temperature and more irregularly by summer water stress. Context: The spread of beech forests in Europe enhances the importance of modelling and monitoring their growth in view of ongoing climate changes. Aims: The current paper assesses the capability of a biogeochemical model to simulate beech gross primary production (GPP) using a Pan-European 1-km weather dataset. Methods: The model BIOME-BGC is applied in four European forest ecosystems having different climatic conditions where the eddy covariance technique is used to measure water and carbon fluxes. The experiment is in three main steps. First, the accuracy of BIOME-BGC GPP simulations is assessed through comparison with flux observations. Second, the influence of two major meteorological drivers (spring minimum temperature and growing season dryness) on observed and simulated inter-annual GPP variations is analysed. Lastly, the impacts of two climate change scenarios on beech GPP are evaluated through statistical analyses of the ground data and model simulations. Results: The weather dataset can drive BIOME-BGC to simulate most of the beech GPP evolution in all four test areas. Both observed and simulated inter-annual GPP variations are mainly dependent on minimum temperature around the beginning of the growing season, while spring/summer dryness exerts a secondary role. BIOME-BGC can also reasonably predict the impacts of the examined climate change scenarios. Conclusion: The proposed modelling approach is capable of approximately reproducing spatial and temporal beech GPP variations and impacts of expected climate changes in the examined European sites. |
BibTeX:
@article{Chiesi2016,
author = {Chiesi, Marta and Chirici, Gherardo and Marchetti, Marco and Hasenauer, Hubert and Moreno, Adam and Knohl, Alexander and Matteucci, Giorgio and Pilegaard, Kim and Granier, André and Longdoz, Bernard and Maselli, Fabio},
title = {Testing the applicability of BIOME-BGC to simulate beech gross primary production in Europe using a new continental weather dataset},
journal = {Annals of Forest Science},
year = {2016},
volume = {73},
number = {3},
pages = {713--727},
url = {http://link.springer.com/10.1007/s13595-016-0560-7},
doi = {10.1007/s13595-016-0560-7}
}
|
| Chirici G, Chiesi M, Corona P, Salvati R, Papale D, Fibbi L, Sirca C, Spano D, Duce P, Marras S, Matteucci G, Cescatti A and Maselli F (2016), "Estimating daily forest carbon fluxes using a combination of ground and remotely sensed data", Journal of Geophysical Research: Biogeosciences., feb, 2016. Vol. 121(2), pp. 266-279. |
| Abstract: Several studies have demonstrated that Monteith's approach can efficiently predict forest gross primary production (GPP), while the modeling of net ecosystem production (NEP) is more critical, requiring the additional simulation of forest respirations. The NEP of different forest ecosystems in Italy was currently simulated by the use of a remote sensing driven parametric model (modified C-Fix) and a biogeochemical model (BIOME-BGC). The outputs of the two models, which simulate forests in quasi-equilibrium conditions, are combined to estimate the carbon fluxes of actual conditions using information regarding the existing woody biomass. The estimates derived from the methodology have been tested against daily reference GPP and NEP data collected through the eddy correlation technique at five study sites in Italy. The first test concerned the theoretical validity of the simulation approach at both annual and daily time scales and was performed using optimal model drivers (i.e., collected or calibrated over the site measurements). Next, the test was repeated to assess the operational applicability of the methodology, which was driven by spatially extended data sets (i.e., data derived from existing wall-to-wall digital maps). A good estimation accuracy was generally obtained for GPP and NEP when using optimal model drivers. The use of spatially extended data sets worsens the accuracy to a varying degree, which is properly characterized. The model drivers with the most influence on the flux modeling strategy are, in increasing order of importance, forest type, soil features, meteorology, and forest woody biomass (growing stock volume). |
BibTeX:
@article{Chirici2016,
author = {Chirici, Gherardo and Chiesi, Marta and Corona, Piermaria and Salvati, Riccardo and Papale, Dario and Fibbi, Luca and Sirca, Costantino and Spano, Donatella and Duce, Pierpaolo and Marras, Serena and Matteucci, Giorgio and Cescatti, Alessandro and Maselli, Fabio},
title = {Estimating daily forest carbon fluxes using a combination of ground and remotely sensed data},
journal = {Journal of Geophysical Research: Biogeosciences},
year = {2016},
volume = {121},
number = {2},
pages = {266--279},
url = {http://doi.wiley.com/10.1002/2015JG003019},
doi = {10.1002/2015JG003019}
}
|
| Chiti T, Certini G, Forte C, Papale D and Valentini R (2016), "Radiocarbon-Based Assessment of Heterotrophic Soil Respiration in Two Mediterranean Forests", Ecosystems., jan, 2016. Vol. 19(1), pp. 62-72. Springer New York LLC. |
| Abstract: The amount of soil organic carbon (SOC) released into the atmosphere as carbon dioxide (CO2), which is referred to as heterotrophic respiration (Rh), is technically difficult to measure despite its necessity to the understanding of how to protect and increase soil carbon stocks. Within this context, the aim of this study is to determine Rh in two Mediterranean forests dominated by pine and oak using radiocarbon measurements of the bulk SOC from different soil layers. The annual Rh was 3.22 Mg C ha−1 y−1 under pine and 3.13 Mg C ha−1 y−1 under oak, corresponding to 38 and 31% of the annual soil respiration, respectively. The accuracy of the Rh values was evaluated by determining the net primary production (NPP), as the sum of the Rh and the net ecosystem production measured by eddy covariance, then comparing it with the NPP obtained through independent biometric measurements. No significant differences were observed, which suggested the suitability of our methodology to infer Rh. Assuming the C inputs to soil to consist exclusively of the aboveground and belowground litter and the C output exclusively of the Rh, both soils were C sinks, which is consistent with a previous modeling study that was performed in the same stands. In conclusion, radiocarbon analysis of bulk SOC provided a reliable estimate of the average annual amount of soil carbon released to the atmosphere; hence, its application is convenient for calculating Rh because it utilizes only a single soil sampling and no time-consuming monitoring activities. |
BibTeX:
@article{Chiti2016,
author = {Chiti, Tommaso and Certini, Giacomo and Forte, Claudia and Papale, Dario and Valentini, Riccardo},
title = {Radiocarbon-Based Assessment of Heterotrophic Soil Respiration in Two Mediterranean Forests},
journal = {Ecosystems},
publisher = {Springer New York LLC},
year = {2016},
volume = {19},
number = {1},
pages = {62--72},
doi = {10.1007/s10021-015-9915-4}
}
|
| Ciavatta S, Kay S, Saux-Picart S, Butenschön M and Allen JI (2016), "Decadal reanalysis of biogeochemical indicators and fluxes in the North West European shelf-sea ecosystem", Journal of Geophysical Research: Oceans., mar, 2016. Vol. 121(3), pp. 1824-1845. Blackwell Publishing Ltd. |
| Abstract: This paper presents the first decadal reanalysis simulation of the biogeochemistry of the North West European shelf, along with a full evaluation of its skill, confidence, and value. An error-characterized satellite product for chlorophyll was assimilated into a physical-biogeochemical model of the North East Atlantic, applying a localized Ensemble Kalman filter. The results showed that the reanalysis improved the model simulation of assimilated chlorophyll in 60% of the study region. Model validation metrics showed that the reanalysis had skill in matching a large data set of in situ observations for 10 ecosystem variables. Spearman rank correlations were significant and higher than 0.7 for physical-chemical variables (temperature, salinity, and oxygen), ?0.6 for chlorophyll and nutrients (phosphate, nitrate, and silicate), and significant, though lower in value, for partial pressure of dissolved carbon dioxide (?0.4). The reanalysis captured the magnitude of pH and ammonia observations, but not their variability. The value of the reanalysis for assessing environmental status and variability has been exemplified in two case studies. The first shows that between 325,000 and 365,000 km2 of shelf bottom waters were vulnerable to oxygen deficiency potentially threatening bottom fishes and benthos. The second application confirmed that the shelf is a net sink of atmospheric carbon dioxide, but the total amount of uptake varies between 36 and 46 Tg C yr-1 at a 90% confidence level. These results indicate that the reanalysis output data set can inform the management of the North West European shelf ecosystem, in relation to eutrophication, fishery, and variability of the carbon cycle. |
BibTeX:
@article{Ciavatta2016,
author = {Ciavatta, S. and Kay, S. and Saux-Picart, S. and Butenschön, M. and Allen, J. I.},
title = {Decadal reanalysis of biogeochemical indicators and fluxes in the North West European shelf-sea ecosystem},
journal = {Journal of Geophysical Research: Oceans},
publisher = {Blackwell Publishing Ltd},
year = {2016},
volume = {121},
number = {3},
pages = {1824--1845},
doi = {10.1002/2015JC011496}
}
|
| Collalti A, Marconi S, Ibrom A, Trotta C, Anav A, D'andrea E, Matteucci G, Montagnani L, Gielen B, Mammarella I, Grünwald T, Knohl A, Berninger F, Zhao Y, Valentini R and Santini M (2016), "Validation of 3D-CMCC Forest Ecosystem Model (v.5.1) against eddy covariance data for 10 European forest sites", Geoscientific Model Development., feb, 2016. Vol. 9(2), pp. 479-504. |
| Abstract: This study evaluates the performances of the new version (v.5.1) of 3D-CMCC Forest Ecosystem Model (FEM) in simulating gross primary productivity (GPP), against eddy covariance GPP data for 10 FLUXNET forest sites across Europe. A new carbon allocation module, coupled with new both phenological and autotrophic respiration schemes, was implemented in this new daily version. Model ability in reproducing timing and magnitude of daily and monthly GPP fluctuations is validated at intra-annual and inter-annual scale, including extreme anomalous seasons. With the purpose to test the 3D-CMCC FEM applicability over Europe without a site-related calibration, the model has been deliberately parametrized with a single set of species-specific parametrizations for each forest ecosystem. The model consistently reproduces both in timing and in magnitude daily and monthly GPP variability across all sites, with the exception of the two Mediterranean sites. We find that 3D-CMCC FEM tends to better simulate the timing of inter-annual anomalies than their magnitude within measurements' uncertainty. In six of eight sites where data are available, the model well reproduces the 2003 summer drought event. Finally, for three sites we evaluate whether a more accurate representation of forest structural characteristics (i.e. cohorts, forest layers) and species composition can improve model results. In two of the three sites results reveal that model slightly increases its performances although, statistically speaking, not in a relevant way. |
BibTeX:
@article{Collalti2016,
author = {Collalti, A and Marconi, S and Ibrom, A and Trotta, C and Anav, A and D'andrea, E and Matteucci, G and Montagnani, L and Gielen, B and Mammarella, I and Grünwald, T and Knohl, A and Berninger, F and Zhao, Y and Valentini, R and Santini, M},
title = {Validation of 3D-CMCC Forest Ecosystem Model (v.5.1) against eddy covariance data for 10 European forest sites},
journal = {Geoscientific Model Development},
year = {2016},
volume = {9},
number = {2},
pages = {479--504},
url = {https://www.geosci-model-dev.net/9/479/2016/},
doi = {10.5194/gmd-9-479-2016}
}
|
| Combe M, de Arellano JVG, Ouwersloot HG and Peters W (2016), "Plant water-stress parameterization determines the strength of land-atmosphere coupling", Agricultural and Forest Meteorology., feb, 2016. Vol. 217, pp. 61-73. |
| Abstract: Land-surface models used in studies of the atmosphere and vegetation during droughts usually include an underlying parameterization that describes the response of plants to water stress. Here, we show that different formulations of this parameterization can lead to significant differences in the coupling strength (i.e. the magnitude of the carbon and water exchange) between the land surface and the atmospheric boundary layer (ABL). We use a numerical model that couples the daytime surface fluxes typical for low vegetation to the dynamics of a convective ABL, to systematically investigate a range of plant water-stress responses. We find that under dry soil conditions, changing from a sensitive to an insensitive vegetation response to water stress has the same impact on the land-atmosphere (L-A) coupling as a strong increase in soil moisture content. The insensitive vegetation allows stomata to remain open for transpiration (+150Wm-2 compared to the sensitive one), which cools the atmosphere (-3.5K) and limits the ABL growth (-500m). During the progressive development of a dry spell, the insensitive response will first dampen atmospheric heating because the vegetation continues to transpire a maximum of 4.6mmday-1 while soil moisture is available. In contrast, the more sensitive vegetation response reduces its transpiration by more than 1mmday-1 to prevent soil moisture depletion. But when soil moisture comes close to wilting point, the insensitive vegetation will suddenly close its stomata causing a switch to a L-A coupling regime dominated by sensible heat exchange. We find that in both cases, progressive soil moisture depletion contributes to further atmospheric warming up to 6K, reduced photosynthesis up to 89%, and CO2 enrichment up to 30ppm, but the full impact is strongly delayed for the insensitive vegetation. Then, when we analyze the impact of a deviation of the modeled large-scale boundary conditions (e.g. subsidence, cloud cover, free-troposphere lapse rates, etc.) from their true state during a drought, we find that the two coupled systems (with a sensitive or insensitive vegetation) respond much differently to the generated atmospheric warming, this due to the difference in the basic surface coupling regime (coupled vs. uncoupled). This is of importance for the simulation of heat waves and meteorological droughts, as well as carbon-climate projections, as we show the predictive skill of coupled models is tied to the underlying vegetation response to water stress. |
BibTeX:
@article{Combe2016,
author = {Combe, Marie and de Arellano, Jordi Vilà Guerau and Ouwersloot, Huug G and Peters, Wouter},
title = {Plant water-stress parameterization determines the strength of land-atmosphere coupling},
journal = {Agricultural and Forest Meteorology},
year = {2016},
volume = {217},
pages = {61--73},
url = {http://linkinghub.elsevier.com/retrieve/pii/S0168192315007571},
doi = {10.1016/j.agrformet.2015.11.006}
}
|
| Couldrey MP, Oliver KIC, Yool A, Halloran PR and Achterberg EP (2016), "On which timescales do gas transfer velocities control North Atlantic CO 2 flux variability?", Global Biogeochemical Cycles., may, 2016. Vol. 30(5), pp. 787-802. |
BibTeX:
@article{Couldrey2016,
author = {Couldrey, Matthew P. and Oliver, Kevin I. C. and Yool, Andrew and Halloran, Paul R. and Achterberg, Eric P.},
title = {On which timescales do gas transfer velocities control North Atlantic CO 2 flux variability?},
journal = {Global Biogeochemical Cycles},
year = {2016},
volume = {30},
number = {5},
pages = {787--802},
url = {http://doi.wiley.com/10.1002/2015GB005267},
doi = {10.1002/2015GB005267}
}
|
| Cowan NJ, Levy PE, Famulari D, Anderson M, Drewer J, Carozzi M, Reay DS and Skiba UM (2016), "The influence of tillage on Nsub2/subO fluxes from an intensively managed grazed grassland in Scotland", Biogeosciences Discussions., jan, 2016. , pp. 1-22. |
| Abstract: Intensively managed grass production in high rainfall temperate climate zones is a globally important source of Nsub2/subO. Many of these grasslands are occasionally tilled and can lead to increased Nsub2/subO emissions. This was investigated by comparing Nsub2/subO fluxes from two adjacent intensively managed grazed grasslands in Scotland, one of which was tilled. A combination of eddy covariance, high resolution dynamic chamber and static chamber methods greatly improved the temporal and spatial coverage of Nsub2/subO fluxes before and after the tillage event and is recommended to be followed in future studies. brbr Total cumulative fluxes calculated for the tilled and un-tilled fields over the 175 day measurement period were 2.45 ± 0.27 and 2.08 ± 0.23 kg Nsub2/subO-N hasup&minus;1/sup, respectively. Nsub2/subO emissions from the tilled field increased significantly for several days immediately after ploughing and remained elevated for approximately two months after the tillage event contributing to an estimated increase in Nsub2/subO fluxes of 1.08 ± 0.14 kg Nsub2/subO-N hasup&minus;1/sup. Cumulative fluxes calculated over a 28 day period in August after the application of 70 kg-N hasup&minus;1/sup as ammonium nitrate to both fields were estimated at 0.42 ± 0.15 and 0.75 ± 0.14 kg Nsub2/subO N hasup&minus;1/sup for the tilled and un-tilled fields, respectively. The tillage event appears to have substantially increased Nsub2/subO fluxes from the tilled grassland field over a two month period; however, this increase may have been fractionally offset by a decrease in emissions after the August fertilisation event. |
BibTeX:
@article{Cowan2016,
author = {Cowan, N J and Levy, P E and Famulari, D and Anderson, M and Drewer, J and Carozzi, M and Reay, D S and Skiba, U M},
title = {The influence of tillage on Nsub2/subO fluxes from an intensively managed grazed grassland in Scotland},
journal = {Biogeosciences Discussions},
year = {2016},
pages = {1--22},
url = {http://www.biogeosciences-discuss.net/bg-2015-643/},
doi = {10.5194/bg-2015-643}
}
|
| Creamer RE, Stone D, Berry P and Kuiper I (2016), "Measuring respiration profiles of soil microbial communities across Europe using MicroRespâ„¢ method", Applied Soil Ecology., jan, 2016. Vol. 97, pp. 36-43. |
| Abstract: A European "transect" was established to assess soil microbial activity, using the MicroRespâ„¢ method, as part of a larger project looking at soil biodiversity and function across Europe. 81 sites were sampled across five biogeographical zones described and mapped in the EEA report (. EEA, 2012) and included the following classes; Boreal, Atlantic, Continental, Mediterranean and Alpine, three land-use types (Arable, Grass and Forest) incorporating a wide range of soil pH, soil organic carbon (org C) and texture. Seven carbon substrates were used to determine multiple substrate induced respiration (MSIR), incorporating; acids, bases, sugars and amino acids. Substrates included: D-(+)-galactose, l-malic acid, gamma amino butyric acid, n-acetyl glucosamine, D-(+)-glucose, alpha ketogluterate, citric acid and water. MicroRespâ„¢ results showed discrimination of land-use type over a large spatial scale and response to soil pH and soil organic carbon. Substrates behaved differently depending upon combinations of land-use and soil properties specifically the greater utilisation of carboxylic acid based substrates in arable sites. |
BibTeX:
@article{Creamer2016,
author = {Creamer, R E and Stone, D and Berry, P and Kuiper, I},
title = {Measuring respiration profiles of soil microbial communities across Europe using MicroRespâ„¢ method},
journal = {Applied Soil Ecology},
year = {2016},
volume = {97},
pages = {36--43},
url = {https://linkinghub.elsevier.com/retrieve/pii/S0929139315300573},
doi = {10.1016/j.apsoil.2015.08.004}
}
|
| Dong F, Li Y, Wang B, Huang W, Shi Y and Dong W (2016), "Global air-sea CO2 flux in 22 CMIP5 models: Multiyear mean and interannual variability", Journal of Climate., apr, 2016. Vol. 29(7), pp. 2407-2431. American Meteorological Society. |
| Abstract: To assess the capability of the latest Earth system models (ESMs) in representing historical global air-sea CO2 flux, 22 models from phase 5 of the Coupled Model Intercomparision Project (CMIP5) are analyzed, with a focus on the spatial distribution of multiyear mean and interannual variability. Results show that the global distribution of air-sea CO2 flux is reasonable in most of the models and that the main differences between models and observationally based results exist in regions with strong vertical movement. The annual mean flux in the 18-member multimodel ensemble (MME; four models were excluded because of their poor performances) mean during 1996-2004 is 1.95 Pg C yr-1 (1 Pg = 1015 g; positive values mean into the ocean), and all but one model describe the rapid increasing trend of air-sea CO2 flux observed during 1960-2000. The first mode of the global air-sea CO2 flux variability during 1870-2000 in six of the models represents the El Niño-Southern Oscillation (ENSO) mode. The remaining 12 models fail to represent this important character for the following reasons: In five models, the tropical Pacific does not play a dominant role in the interannual variability of global air-sea CO2 flux because of stronger interannual variability in the Southern Ocean; two models poorly represent the interannual fluctuation of dissolved inorganic carbon (DIC) in the surface ocean of the tropical Pacific; and four models have shorter periods of the air-sea CO2 flux, which are out of the period range of ENSO events. |
BibTeX:
@article{Dong2016,
author = {Dong, Fang and Li, Yangchun and Wang, Bin and Huang, Wenyu and Shi, Yanyan and Dong, Wenhao},
title = {Global air-sea CO2 flux in 22 CMIP5 models: Multiyear mean and interannual variability},
journal = {Journal of Climate},
publisher = {American Meteorological Society},
year = {2016},
volume = {29},
number = {7},
pages = {2407--2431},
url = {http://dx.doi.org/10.1175/JCLI-D-14-00788.s1.},
doi = {10.1175/JCLI-D-14-00788.1}
}
|
| Dupuy E, Morino I, Deutscher NM, Yoshida Y, Uchino O, Connor BJ, De Mazière M, Griffith DW, Hase F, Heikkinen P, Hillyard PW, Iraci LT, Kawakami S, Kivi R, Matsunaga T, Notholt J, Petri C, Podolske JR, Pollard DF, Rettinger M, Roehl CM, Sherlock V, Sussmann R, Toon GC, Velazco VA, Warneke T, Wennberg PO, Wunch D and Yokota T (2016), "Comparison of XH2O retrieved from GOSAT short-wavelength infrared spectra with observations from the TCCON network", Remote Sensing. Vol. 8(5) MDPI AG. |
| Abstract: Understanding the atmospheric distribution of water (H2O) is crucial for global warming studies and climate change mitigation. In this context, reliable satellite data are extremely valuable for their global and continuous coverage, once their quality has been assessed. Short-wavelength infrared spectra are acquired by the Thermal And Near-infrared Sensor for carbon Observation-Fourier Transform Spectrometer (TANSO-FTS) aboard the Greenhouse gases Observing Satellite (GOSAT). From these, column-averaged dry-air mole fractions of carbon dioxide, methane and water vapor (XH2O) have been retrieved at the National Institute for Environmental Studies (NIES, Japan) and are available as a Level 2 research product. We compare the NIES XH2O data, Version 02.21, with retrievals from the ground-based Total Carbon Column Observing Network (TCCON, Version GGG2014). The datasets are in good overall agreement, with GOSAT data showing a slight global low bias of -3.1%±24.0%, good consistency over different locations (station bias of -1.53%±10.35%) and reasonable correlation with TCCON (R = 0.89). We identified two potential sources of discrepancy between the NIES and TCCON retrievals over land. While the TCCON XH2O amounts can reach 6000-7000ppm when the atmospheric water content is high, the correlated NIES values do not exceed 5500 ppm. This could be due to a dry bias of TANSO-FTS in situations of high humidity and aerosol content. We also determined that the GOSAT-TCCON differences directly depend on the altitude difference between the TANSO-FTS footprint and the TCCON site. Further analysis will account for these biases, but the NIES V02.21 XH2O product, after public release, can already be useful for water cycle studies. |
BibTeX:
@article{Dupuy2016,
author = {Dupuy, Eric and Morino, Isamu and Deutscher, Nicholas M. and Yoshida, Yukio and Uchino, Osamu and Connor, Brian J. and De Mazière, Martine and Griffith, David W.T. and Hase, Frank and Heikkinen, Pauli and Hillyard, Patrick W. and Iraci, Laura T. and Kawakami, Shuji and Kivi, Rigel and Matsunaga, Tsuneo and Notholt, Justus and Petri, Christof and Podolske, James R. and Pollard, David F. and Rettinger, Markus and Roehl, Coleen M. and Sherlock, Vanessa and Sussmann, Ralf and Toon, Geoffrey C. and Velazco, Voltaire A. and Warneke, Thorsten and Wennberg, Paul O. and Wunch, Debra and Yokota, Tatsuya},
title = {Comparison of XH2O retrieved from GOSAT short-wavelength infrared spectra with observations from the TCCON network},
journal = {Remote Sensing},
publisher = {MDPI AG},
year = {2016},
volume = {8},
number = {5},
doi = {10.3390/rs8050414}
}
|
| Eyring V, Righi M, Lauer A, Evaldsson M, Wenzel S, Jones C, Anav A, Andrews O, Cionni I, Davin EL, Deser C, Ehbrecht C, Friedlingstein P, Gleckler P, Gottschaldt K-D, Hagemann S, Juckes M, Kindermann S, Krasting J, Kunert D, Levine R, Loew A, Mäkelä J, Martin G, Mason E, Phillips AS, Read S, Rio C, Roehrig R, Senftleben D, Sterl A, van Ulft LH, Walton J, Wang S and Williams KD (2016), "ESMValTool (v1.0) – a community diagnostic and performance metrics tool for routine evaluation of Earth system models in CMIP", Geoscientific Model Development., may, 2016. Vol. 9(5), pp. 1747-1802. Copernicus GmbH. |
| Abstract: textlessptextgreaterAbstract. A community diagnostics and performance metrics tool for the evaluation of Earth system models (ESMs) has been developed that allows for routine comparison of single or multiple models, either against predecessor versions or against observations. The priority of the effort so far has been to target specific scientific themes focusing on selected essential climate variables (ECVs), a range of known systematic biases common to ESMs, such as coupled tropical climate variability, monsoons, Southern Ocean processes, continental dry biases, and soil hydrology–climate interactions, as well as atmospheric CO2 budgets, tropospheric and stratospheric ozone, and tropospheric aerosols. The tool is being developed in such a way that additional analyses can easily be added. A set of standard namelists for each scientific topic reproduces specific sets of diagnostics or performance metrics that have demonstrated their importance in ESM evaluation in the peer-reviewed literature. The Earth System Model Evaluation Tool (ESMValTool) is a community effort open to both users and developers encouraging open exchange of diagnostic source code and evaluation results from the Coupled Model Intercomparison Project (CMIP) ensemble. This will facilitate and improve ESM evaluation beyond the state-of-the-art and aims at supporting such activities within CMIP and at individual modelling centres. Ultimately, we envisage running the ESMValTool alongside the Earth System Grid Federation (ESGF) as part of a more routine evaluation of CMIP model simulations while utilizing observations available in standard formats (obs4MIPs) or provided by the user.textless/ptextgreater |
BibTeX:
@article{Eyring2016,
author = {Eyring, Veronika and Righi, Mattia and Lauer, Axel and Evaldsson, Martin and Wenzel, Sabrina and Jones, Colin and Anav, Alessandro and Andrews, Oliver and Cionni, Irene and Davin, Edouard L. and Deser, Clara and Ehbrecht, Carsten and Friedlingstein, Pierre and Gleckler, Peter and Gottschaldt, Klaus-Dirk and Hagemann, Stefan and Juckes, Martin and Kindermann, Stephan and Krasting, John and Kunert, Dominik and Levine, Richard and Loew, Alexander and Mäkelä, Jarmo and Martin, Gill and Mason, Erik and Phillips, Adam S. and Read, Simon and Rio, Catherine and Roehrig, Romain and Senftleben, Daniel and Sterl, Andreas and van Ulft, Lambertus H. and Walton, Jeremy and Wang, Shiyu and Williams, Keith D.},
title = {ESMValTool (v1.0) – a community diagnostic and performance metrics tool for routine evaluation of Earth system models in CMIP},
journal = {Geoscientific Model Development},
publisher = {Copernicus GmbH},
year = {2016},
volume = {9},
number = {5},
pages = {1747--1802},
url = {https://gmd.copernicus.org/articles/9/1747/2016/},
doi = {10.5194/gmd-9-1747-2016}
}
|
| Faußer AC, Dušek J, Čížková H and Kazda M (2016), "Diurnal dynamics of oxygen and carbon dioxide concentrations in shoots and rhizomes of a perennial in a constructed wetland indicate down-regulation of below ground oxygen consumption", AoB PLANTS. Vol. 8 Oxford University Press. |
| Abstract: Wetland plants actively provide oxygen for aerobic processes in submerged tissues and the rhizosphere. The novel concomitant assessment of diurnal dynamics of oxygen and carbon dioxide concentrations under field conditions tests the whole-system interactions in plant-internal gas exchange and regulation. Oxygen concentrations ([O2]) were monitored in-situ in central culm and rhizome pith cavities of common reed (Phragmites australis) using optical oxygen sensors. The corresponding carbon dioxide concentrations ([CO2]) were assessed via gas samples from the culms. Highly dynamic diurnal courses of [O2] were recorded, which started at 6.5-13 % in the morning, increased rapidly up to 22 % during midday and declined exponentially during the night. Internal [CO2] were high in the morning (1.55-17.5 %) and decreased (0.04-0.94 %) during the rapid increase of [O2] in the culms. The observed negative correlations between [O2] and [CO2] particularly describe the below ground relationship between plant-mediated oxygen supply and oxygen use by respiration and biogeochemical processes in the rhizosphere. Furthermore, the nocturnal declining slopes of [O2] in culms and rhizomes indicated a down-regulation of the demand for oxygen in the complete below ground plant-associated system. These findings emphasize the need for measurements of plant-internal gas exchange processes under field conditions because it considers the complex interactions in the oxic-anoxic interface. |
BibTeX:
@article{Faußer2016,
author = {Faußer, Anna C. and Dušek, Jiří and Čížková, Hana and Kazda, Marian},
title = {Diurnal dynamics of oxygen and carbon dioxide concentrations in shoots and rhizomes of a perennial in a constructed wetland indicate down-regulation of below ground oxygen consumption},
journal = {AoB PLANTS},
publisher = {Oxford University Press},
year = {2016},
volume = {8},
doi = {10.1093/aobpla/plw025}
}
|
| Feng L, Palmer PI, Parker RJ, Deutscher NM, Feist DG, Kivi R, Morino I and Sussmann R (2016), "Estimates of European uptake of CO2 inferred from GOSAT XCO2 retrievals: Sensitivity to measurement bias inside and outside Europe", Atmospheric Chemistry and Physics., feb, 2016. Vol. 16(3), pp. 1289-1302. Copernicus GmbH. |
| Abstract: Estimates of the natural CO2 flux over Europe inferred from in situ measurements of atmospheric CO2 mole fraction have been used previously to check top-down flux estimates inferred from space-borne dry-air CO2 column (XCO2) retrievals. Several recent studies have shown that CO2 fluxes inferred from XCO2 data from the Japanese Greenhouse gases Observing SATellite (GOSAT) and the Scanning Imaging Absorption Spectrometer for Atmospheric CHartographY (SCIAMACHY) have larger seasonal amplitudes and a more negative annual net CO2 balance than those inferred from the in situ data. The cause of this elevated European uptake of CO2 is still unclear, but some recent studies have suggested that this is a genuine scientific phenomenon. Here, we put forward an alternative hypothesis and show that realistic levels of bias in GOSAT data can result in an erroneous estimate of elevated uptake over Europe. We use a global flux inversion system to examine the relationship between measurement biases and estimates of CO2 uptake from Europe. We establish a reference in situ inversion that uses an Ensemble Kalman Filter (EnKF) to assimilate conventional surface mole fraction observations and XCO2 retrievals from the surface-based Total Carbon Column Observing Network (TCCON). We use the same EnKF system to assimilate two independent versions of GOSAT XCO2 data. We find that the GOSAT-inferred European terrestrial biosphere uptake peaks during the summer, similar to the reference inversion, but the net annual flux is 1.40 ± 0.19 GtC a-1 compared to a value of 0.58 ± 0.14 GtC a-1 for our control inversion that uses only in situ data. To reconcile these two estimates, we perform a series of numerical experiments that assimilate observations with added biases or assimilate synthetic observations for which part or all of the GOSAT XCO2 data are replaced with model data. We find that for our global flux inversions, a large portion (60-90 %) of the elevated European uptake inferred from GOSAT data in 2010 is due to retrievals outside the immediate European region, while the remainder can largely be explained by a sub-ppm retrieval bias over Europe. We use a data assimilation approach to estimate monthly GOSAT XCO2 biases from the joint assimilation of in situ observations and GOSAT XCO2 retrievals. The inferred biases represent an estimate of systematic differences between GOSAT XCO2 retrievals and the inversion system at regional or sub-regional scales. We find that a monthly varying bias of up to 0.5 ppm can explain an overestimate of the annual sink of up to 0.20 GtC a-1. Our results highlight the sensitivity of CO2 flux estimates to regional observation biases, which have not been fully characterized by the current observation network. Without further dedicated measurements we cannot prove or disprove that European ecosystems are taking up a larger-than-expected amount of CO2. More robust inversion systems are also needed to infer consistent fluxes from multiple observation types. |
BibTeX:
@article{Feng2016,
author = {Feng, L. and Palmer, P. I. and Parker, R. J. and Deutscher, N. M. and Feist, D. G. and Kivi, R. and Morino, I. and Sussmann, R.},
title = {Estimates of European uptake of CO2 inferred from GOSAT XCO2 retrievals: Sensitivity to measurement bias inside and outside Europe},
journal = {Atmospheric Chemistry and Physics},
publisher = {Copernicus GmbH},
year = {2016},
volume = {16},
number = {3},
pages = {1289--1302},
doi = {10.5194/acp-16-1289-2016}
}
|
| Fiedler B, Grundle DS, Schütte F, Karstensen J, Löscher CR, Hauss H, Wagner H, Loginova A, Kiko R, Silva P, Tanhua T and Körtzinger A (2016), "Oxygen utilization and downward carbon flux in an oxygen-depleted eddy in the eastern tropical North Atlantic", Biogeosciences., oct, 2016. Vol. 13(19), pp. 5633-5647. |
| Abstract: The occurrence of mesoscale eddies that develop suboxic environments at shallow depth (about 40-100m) has recently been reported for the eastern tropical North Atlantic (ETNA). Their hydrographic structure suggests that the water mass inside the eddy is well isolated from ambient waters supporting the development of severe near-surface oxygen deficits. So far, hydrographic and biogeochemical characterization of these eddies was limited to a few autonomous surveys, with the use of moorings, underwater gliders and profiling floats. In this study we present results from the first dedicated biogeochemical survey of one of these eddies conducted in March 2014 near the Cape Verde Ocean Observatory (CVOO). During the survey the eddy core showed oxygen concentrations as low as 5μmolg kg-1 with a pH of around 7.6 at approximately 100m depth. Correspondingly, the aragonite saturation level dropped to 1 at the same depth, thereby creating unfavorable conditions for calcifying organisms. To our knowledge, such enhanced acidity within near-surface waters has never been reported before for the open Atlantic Ocean. Vertical distributions of particulate organic matter and dissolved organic matter (POM and DOM), generally showed elevated concentrations in the surface mixed layer (0-70m), with DOM also accumulating beneath the oxygen minimum. With the use of reference data from the upwelling region where these eddies are formed, the oxygen utilization rate was calculated by determining oxygen consumption through the remineralization of organic matter. Inside the core, we found these rates were almost 1 order of magnitude higher (apparent oxygen utilization rate (aOUR); 0.26μmolg kg-1day-1) than typical values for the open North Atlantic. Computed downward fluxes for particulate organic carbon (POC), were around 0.19 to 0.23 g C m-2day-1 at 100 m depth, clearly exceeding fluxes typical for an oligotrophic open-ocean setting. The observations support the view that the oxygen-depleted eddies can be viewed as isolated, westwards propagating upwelling systems of their own, thereby represent re-occurring alien biogeochemical environments in the ETNA. |
BibTeX:
@article{Fiedler2016,
author = {Fiedler, Björn and Grundle, Damian S and Schütte, Florian and Karstensen, Johannes and Löscher, Carolin R and Hauss, Helena and Wagner, Hannes and Loginova, Alexandra and Kiko, Rainer and Silva, Péricles and Tanhua, Toste and Körtzinger, Arne},
title = {Oxygen utilization and downward carbon flux in an oxygen-depleted eddy in the eastern tropical North Atlantic},
journal = {Biogeosciences},
year = {2016},
volume = {13},
number = {19},
pages = {5633--5647},
url = {http://www.biogeosciences.net/13/5633/2016/},
doi = {10.5194/bg-13-5633-2016}
}
|
| Forkel M, Carvalhais N, Rödenbeck C, Keeling R, Heimann M, Thonicke K, Zaehle S and Reichstein M (2016), "Enhanced seasonal CO2 exchange caused by amplified plant productivity in northern ecosystems", Science., feb, 2016. Vol. 351(6274), pp. 696-699. American Association for the Advancement of Science. |
| Abstract: Atmospheric monitoring of high northern latitudes (above 40°N) has shown an enhanced seasonal cycle of carbon dioxide (CO2) since the 1960s, but the underlying mechanisms are not yet fully understood. The much stronger increase in high latitudes relative to low ones suggests that northern ecosystems are experiencing large changes in vegetation and carbon cycle dynamics. We found that the latitudinal gradient of the increasing CO2 amplitude is mainly driven by positive trends in photosynthetic carbon uptake caused by recent climate change and mediated by changing vegetation cover in northern ecosystems. Our results underscore the importance of climate-vegetation-carbon cycle feedbacks at high latitudes; moreover, they indicate that in recent decades, photosynthetic carbon uptake has reacted much more strongly to warming than have carbon release processes. |
BibTeX:
@article{Forkel2016,
author = {Forkel, Matthias and Carvalhais, Nuno and Rödenbeck, Christian and Keeling, Ralph and Heimann, Martin and Thonicke, Kirsten and Zaehle, Sönke and Reichstein, Markus},
title = {Enhanced seasonal CO2 exchange caused by amplified plant productivity in northern ecosystems},
journal = {Science},
publisher = {American Association for the Advancement of Science},
year = {2016},
volume = {351},
number = {6274},
pages = {696--699},
url = {http://science.sciencemag.org/},
doi = {10.1126/science.aac4971}
}
|
| Francisco R, Stone D, Creamer RE, Sousa JP and Morais PV (2016), "European scale analysis of phospholipid fatty acid composition of soils to establish operating ranges", Applied Soil Ecology., jan, 2016. Vol. 97, pp. 49-60. |
| Abstract: Recent preoccupations regarding possible negative effects of pollution, inappropriate land management, climate change, desertification, erosion, compaction or over-exploitation on soils has led to initiatives for the survey of soils. One of them, EcoFINDERS, launched a pan-European survey in order to define normal operating ranges for soil biodiversity and quality, through the use of several methodologies. The objective of the current work was the characterization of European soils under different land uses and from representative bio-geographical locations, using a PLFA method developed in the context of the mentioned survey, in order to recognize and define operation ranges for soil PLFA. PLFA analysis demonstrated to be a valuable tool in the evaluation, comparison and distinction of several land uses and biogeographical (BG) zones. The analysis of the PLFA diversity with PCA and PERMANOVA/SIMPER demonstrated a good separation of soil samples relatively to each defined land use and BG zone. Soils of the same BG zone and land use group showed an average biomarker constitution with consistent differences of PLFA/biomarker compositions relatively to other groups, especially concerning land uses. Total PLFA biomass was consistently higher in non-arable environments, i.e., forest or grass soils. Arable soils contained a total PLFA biomass that was in average 2.5-2.9 times lower than grassland or forest soil. Arable and grassland soils contained significantly low relative quantities of the saprophytic Fungi biomarker 18:2ω6,9c (which decreased more than 18:1ω9c), and low Total Fungi biomarkers/Bacteria biomarkers ratio (TF/B). The opposite occurred in forestry soil samples, and the Boreal BG zone stood out, showing the highest total fungal composition, with a most important contribution of the 18:2ω6,9c saprophytic Fungi biomarker. Grasslands (all BG zones) showed to be the richest (3.5-3.8%) in Arbuscular Mycorrhizae Fungi biomarker, 16:1ω5c. High proportions of Gram-positive, relatively to Gram-negative biomarkers occurred essentially in arable soils, in this study, but also in Alpine grasslands, which main Gram-positive biomarkers were a15:0, and i15:0. Total biomass, PLFA Biomarker groups, and different balances between individual PLFA enabled the discrimination of samples originating from both different BG zones and land uses. |
BibTeX:
@article{Francisco2016,
author = {Francisco, Romeu and Stone, Dorothy and Creamer, Rachel E and Sousa, José Paulo and Morais, Paula Vasconcelos},
title = {European scale analysis of phospholipid fatty acid composition of soils to establish operating ranges},
journal = {Applied Soil Ecology},
year = {2016},
volume = {97},
pages = {49--60},
url = {https://linkinghub.elsevier.com/retrieve/pii/S0929139315300809},
doi = {10.1016/j.apsoil.2015.09.001}
}
|
| Gao Y, Markkanen T, Thum T, Aurela M, Lohila A, Mammarella I, Kämäraïnen M, Hagemann S and Aalto T (2016), "Assessing various drought indicators in representing summer drought in boreal forests in Finland", Hydrology and Earth System Sciences., jan, 2016. Vol. 20(1), pp. 175-191. Copernicus GmbH. |
| Abstract: Droughts can have an impact on forest functioning and production, and even lead to tree mortality. However, drought is an elusive phenomenon that is difficult to quantify and define universally. In this study, we assessed the performance of a set of indicators that have been used to describe drought conditions in the summer months (June, July, August) over a 30-year period (1981-2010) in Finland. Those indicators include the Standardized Precipitation Index (SPI), the Standardized Precipitation-Evapotranspiration Index (SPEI), the Soil Moisture Index (SMI), and the Soil Moisture Anomaly (SMA). Herein, regional soil moisture was produced by the land surface model JSBACH of the Max Planck Institute for Meteorology Earth System Model (MPI-ESM). Results show that the buffering effect of soil moisture and the associated soil moisture memory can impact on the onset and duration of drought as indicated by the SMI and SMA, while the SPI and SPEI are directly controlled by meteorological conditions. In particular, we investigated whether the SMI, SMA and SPEI are able to indicate the Extreme Drought affecting Forest health (EDF), which we defined according to the extreme drought that caused severe forest damages in Finland in 2006. The EDF thresholds for the aforementioned indicators are suggested, based on the reported statistics of forest damages in Finland in 2006. SMI was found to be the best indicator in capturing the spatial extent of forest damage induced by the extreme drought in 2006. In addition, through the application of the EDF thresholds over the summer months of the 30-year study period, the SPEI and SMA tended to show more frequent EDF events and a higher fraction of influenced area than SMI. This is because the SPEI and SMA are standardized indicators that show the degree of anomalies from statistical means over the aggregation period of climate conditions and soil moisture, respectively. However, in boreal forests in Finland, the high initial soil moisture or existence of peat often prevent the EDFs indicated by the SPEI and SMA to produce very low soil moisture that could be indicated as EDFs by the SMI. Therefore, we consider SMI is more appropriate for indicating EDFs in boreal forests. The selected EDF thresholds for those indicators could be calibrated when there are more forest health observation data available. Furthermore, in the context of future climate scenarios, assessments of EDF risks in northern areas should, in addition to climate data, rely on a land surface model capable of reliable prediction of soil moisture. |
BibTeX:
@article{Gao2016,
author = {Gao, Y. and Markkanen, T. and Thum, T. and Aurela, M. and Lohila, A. and Mammarella, I. and Kämäraïnen, M. and Hagemann, S. and Aalto, T.},
title = {Assessing various drought indicators in representing summer drought in boreal forests in Finland},
journal = {Hydrology and Earth System Sciences},
publisher = {Copernicus GmbH},
year = {2016},
volume = {20},
number = {1},
pages = {175--191},
doi = {10.5194/hess-20-175-2016}
}
|
| Gebauer R, Vanbeveren SPP, VolaÅ™ík D, Plichta R and Ceulemans R (2016), "Petiole and leaf traits of poplar in relation to parentage and biomass yield", Forest Ecology and Management., feb, 2016. Vol. 362, pp. 1-9. |
| Abstract: Poplars grown under a short-rotation coppice (SRC) regime for biomass production offer a promising alternative source of renewable energy to fossil fuels. We examined the potential of leaf and petiole traits of 12 different poplar genotypes as early selection criteria for breeding and selection programmes. Petiole traits included theoretical hydraulic conductivity of the petiole, petiole xylem area and the number of vessels in each petiole. The different genotypes clustered largely according to their breeding programmes and to their parentage. Leaf and petiole traits showed strong correlations, which enabled the prediction of difficult-to-measure petiole traits as xylem area, total vessel lumen area and number of vessels based on the more common and easily measurable leaf dry mass. We found significant correlations between above-ground woody biomass and nine leaf and petiole traits. We developed three predictive correlative models based on the easy-to-measure petiole and leaf traits (petiole cross-section area, petiole thickness and leaf dry mass). These simple models can be used as early selection criteria for biomass yield in poplar breeding programmes. The usefulness of the easy-to-measure petiole thickness for biomass prediction should be further tested on other poplar genotypes. |
BibTeX:
@article{Gebauer2016,
author = {Gebauer, Roman and Vanbeveren, Stefan P P and VolaÅ™ík, Daniel and Plichta, Roman and Ceulemans, Reinhart},
title = {Petiole and leaf traits of poplar in relation to parentage and biomass yield},
journal = {Forest Ecology and Management},
year = {2016},
volume = {362},
pages = {1--9},
url = {http://linkinghub.elsevier.com/retrieve/pii/S0378112715006593},
doi = {10.1016/j.foreco.2015.11.036}
}
|
| Gerbig C, Rödenbeck C, Karstens U and Heimann M (2016), "Atmospheric CO 2 inversions at the mesoscale using data driven Panagiotis Kountouris", Atmos. Chem. Phys. Discuss. |
| Abstract: 1 2 Optimized biogenic carbon fluxes for Europe were estimated from high resolution regional scale 3 inversions, utilizing atmospheric CO 2 measurements at 16 stations for the year 2007. Additional 4 sensitivity tests with different data-driven error structures were performed. As the atmospheric 5 network is rather sparse and consequently contains large spatial gaps, we use a priori biospheric 6 fluxes to further constrain the inversions. The biospheric fluxes were simulated by the 7 Vegetation Photosynthesis and Respiration Model (VPRM) at a resolution of 0.1º and optimized 8 against Eddy covariance data. Overall we estimate an a priori uncertainty of 0.54 GtC y-1 related 9 to the poor spatial representation between the biospheric model and the ecosystem sites. The sink 10 estimated from the atmospheric inversions for the area of Europe (as represented in the model 11 domain) ranges between 0.23 and 0.38 GtC y-1 (0.30 and 0.49 GtC y-1 up-scaled to geographical 12 Europe). This is within the range of posterior flux uncertainty estimates of previous studies using 13 ground based observations. |
BibTeX:
@article{Gerbig2016,
author = {Gerbig, Christoph and Rödenbeck, Christian and Karstens, Ute and Heimann, Martin},
title = {Atmospheric CO 2 inversions at the mesoscale using data driven Panagiotis Kountouris},
journal = {Atmos. Chem. Phys. Discuss},
year = {2016},
doi = {10.5194/acp-2016-578}
}
|
| Glazunov A, Rannik Ü, Stepanenko V, Lykosov V, Auvinen M, Vesala T and Mammarella I (2016), "Large-eddy simulation and stochastic modeling of Lagrangian particles for footprint determination in the stable boundary layer", Geoscientific Model Development., aug, 2016. Vol. 9(9), pp. 2925-2949. Copernicus GmbH. |
| Abstract: Large-eddy simulation (LES) and Lagrangian stochastic modeling of passive particle dispersion were applied to the scalar flux footprint determination in the stable atmospheric boundary layer. The sensitivity of the LES results to the spatial resolution and to the parameterizations of small-scale turbulence was investigated. It was shown that the resolved and partially resolved ("subfilter-scale") eddies are mainly responsible for particle dispersion in LES, implying that substantial improvement may be achieved by using recovering of small-scale velocity fluctuations. In LES with the explicit filtering, this recovering consists of the application of the known inverse filter operator. The footprint functions obtained in LES were compared with the functions calculated with the use of first-order single-particle Lagrangian stochastic models (LSMs) and zeroth-order Lagrangian stochastic models-the random displacement models (RDMs). According to the presented LES, the source area and footprints in the stable boundary layer can be substantially more extended than those predicted by the modern LSMs. |
BibTeX:
@article{Glazunov2016,
author = {Glazunov, Andrey and Rannik, Üllar and Stepanenko, Victor and Lykosov, Vasily and Auvinen, Mikko and Vesala, Timo and Mammarella, Ivan},
title = {Large-eddy simulation and stochastic modeling of Lagrangian particles for footprint determination in the stable boundary layer},
journal = {Geoscientific Model Development},
publisher = {Copernicus GmbH},
year = {2016},
volume = {9},
number = {9},
pages = {2925--2949},
doi = {10.5194/gmd-9-2925-2016}
}
|
| Görres CM, Kammann C and Ceulemans R (2016), "Automation of soil flux chamber measurements: Potentials and pitfalls", Biogeosciences., mar, 2016. Vol. 13(6), pp. 1949-1966. |
| Abstract: Recent technological advances have enabled the wider application of automated chambers for soil greenhouse gas (GHG) flux measurements, several of them commercially available. However, few studies addressed the challenges associated with operating these systems. In this contribution we compared two commercial soil GHG chamber systems - the LI-8100A Automated Soil CO2 Flux System and the greenhouse gas monitoring system AGPS. From April until August 2014, the two systems monitored in parallel soil respiration (SR) fluxes at a recently harvested poplar (Populus) plantation, which provided a bare field situation directly after the harvest as well as a closed canopy later on. For the bare field situation (15 April-30 June 2014), the cumulated average SR obtained from the unfiltered data sets of the LI-8100A and the AGPS were 520 and 433 g CO2 m-2 respectively. For the closed canopy phase (1 July-31 August 2014), which was characterized by a higher soil moisture content, the cumulated average SR estimates were not significantly different with 507 and 501 g CO2 m-2 for the AGPS and the LI-8100A respectively. Flux quality control and filtering did not significantly alter the results obtained by the LI-8100A, whereas the AGPS SR estimates were reduced by at least 20 %. The main reasons for the observed differences in the performance of the two systems were (i) a lower data coverage provided by the AGPS due to technical problems; (ii) incomplete headspace mixing in the AGPS chambers; (iii) lateral soil CO2 diffusion below the collars during AGPS chamber measurements; and (iv) a possible overestimation of nighttime SR fluxes by the LI-8100A. Additionally, increased root growth was observed within the LI-8100A collars but not within the AGPS collars, which might have also contributed to the observed differences. In contrast to the LI-8100A, the AGPS had the gas sample inlets installed inside the collars and not the chambers. This unique design feature enabled for the first time the detection of disturbed chamber measurements during nights with a stratified atmosphere, resulting in unbiased nighttime SR estimates. Thus besides providing high temporal frequency flux data, automated chamber systems offer another possibility to greatly improve our understanding of SR fluxes. |
BibTeX:
@article{Gorres2016,
author = {Görres, Carolyn Monika and Kammann, Claudia and Ceulemans, Reinhart},
title = {Automation of soil flux chamber measurements: Potentials and pitfalls},
journal = {Biogeosciences},
year = {2016},
volume = {13},
number = {6},
pages = {1949--1966},
url = {http://www.biogeosciences.net/13/1949/2016/},
doi = {10.5194/bg-13-1949-2016}
}
|
| Gourlez de la Motte L, Jérôme E, Mamadou O, Beckers Y, Bodson B, Heinesch B and Aubinet M (2016), "Carbon balance of an intensively grazed permanent grassland in southern Belgium", Agricultural and Forest Meteorology., nov, 2016. Vol. 228-229, pp. 370-383. |
| Abstract: Grasslands are an important component of the global carbon balance, but their carbon storage potential is still highly uncertain. In particular, the impact of weather variability and management practices on grassland carbon budgets need to be assessed. This study investigated the carbon balance of an intensively managed permanent grassland and its uncertainties by drawing together 5 years of eddy covariance measurements and other organic carbon exchanges estimates. The results showed that, despite the high stocking rate and the old age of the pasture, the site acted as a relatively stable carbon sink from year to year, with a 5-year average net biome productivity of âˆ'161 [âˆ'134 âˆ'180] g C mâˆ'2 yrâˆ'1. Lateral organic carbon fluxes were found to increase the carbon sink because of high carbon imports (organic fertilization, feed complements) and low carbon exports in form of meat compared to dairy pastures. The cattle stocking density was adapted to grass production, which itself depends on weather conditions and photosynthesizing area, in order to maintain a steady meat production. This resulted in a coupling between grazing management and weather conditions. As a consequence, both weather and grazing impacts on net ecosystem exchange were difficult to distinguish. Indeed, no correlation was found between weather variables anomalies and net ecosystem exchange anomalies. This coupling could also partly explain the low C budget inter-annual variability. The findings in this study are in agreement with those reported by other studies that have shown that well-managed grasslands could act as carbon sinks. |
BibTeX:
@article{GourlezdelaMotte2016,
author = {Gourlez de la Motte, Louis and Jérôme, Elisabeth and Mamadou, Ossénatou and Beckers, Yves and Bodson, Bernard and Heinesch, Bernard and Aubinet, Marc},
title = {Carbon balance of an intensively grazed permanent grassland in southern Belgium},
journal = {Agricultural and Forest Meteorology},
year = {2016},
volume = {228-229},
pages = {370--383},
url = {http://linkinghub.elsevier.com/retrieve/pii/S0168192316303069},
doi = {10.1016/j.agrformet.2016.06.009}
}
|
| Griffiths RI, Thomson BC, Plassart P, Gweon HS, Stone D, Creamer RE, Lemanceau P and Bailey MJ (2016), "Mapping and validating predictions of soil bacterial biodiversity using European and national scale datasets", Applied Soil Ecology., jan, 2016. Vol. 97, pp. 61-68. |
| Abstract: Recent research has highlighted strong correlations between soil edaphic parameters and bacterial biodiversity. Here we seek to explore these relationships across the European Union member states with respect to mapping bacterial biodiversity at the continental scale. As part of the EU FP7 EcoFINDERs project, bacterial communities from 76 soil samples taken across Europe were assessed from eleven countries encompassing Arctic to Southern Mediterranean climes, representing a diverse range of soil types and land uses (grassland, forest and arable land). We found predictable relationships between community biodiversity (ordination site scores) and land use factors as well as soil properties such as pH. Based on the modelled relationship between soil pH and bacterial biodiversity found for the surveyed soils, we were able to predict biodiversity in ∼1000 soils for which soil pH data had been collected as part of national scale monitoring. We then performed interpolative mapping utilising existing EU wide soil pH data to present the first map of bacterial biodiversity across the EU member states. The predictive accuracy of the map was assessed again using the national scale data, but this time contrasting the EU wide spatial predictions with point data on bacterial communities. Generally the maps were useful at predicting broad extremes of biodiversity reflective of low or high pH soils, though predictive accuracy was limited for Britain particularly for organic/acidic soil communities. Spatial accuracy could however be increased by utilising published maps of soil pH calculated using geostatistical approaches at both global and national scales. These findings will contribute to wider efforts to predict and understand the spatial distribution of soil biodiversity at global scales. Further work should focus on enhancing the predictive power of such maps, by harmonising global datasets on soil conditioning parameters, soil properties and biodiversity; and the continued efforts to advance the geostatistical modelling of specific components of soil biodiversity at local to global scales. |
BibTeX:
@article{Griffiths2016,
author = {Griffiths, Robert I and Thomson, Bruce C and Plassart, Pierre and Gweon, Hyun S and Stone, Dorothy and Creamer, Rachael E and Lemanceau, Philippe and Bailey, Mark J},
title = {Mapping and validating predictions of soil bacterial biodiversity using European and national scale datasets},
journal = {Applied Soil Ecology},
year = {2016},
volume = {97},
pages = {61--68},
url = {https://linkinghub.elsevier.com/retrieve/pii/S0929139315300330},
doi = {10.1016/j.apsoil.2015.06.018}
}
|
| Gundale MJ, Nilsson MC, Pluchon N and Wardle DA (2016), "The effect of biochar management on soil and plant community properties in a boreal forest", GCB Bioenergy., jul, 2016. Vol. 8(4), pp. 777-789. |
| Abstract: Biochar management has been proposed as a possible tool to mitigate anthropogenic CO2 emissions, and thus far its impacts in forested environments remain poorly understood. We conducted a large-scale, replicated field experiment using 0.05-ha plots in the boreal region in northern Sweden to evaluate how soil and vegetation properties and processes responded to biochar application and the disturbance associated with burying biochar in the soil. We employed a randomized block design, where biochar and soil mixing treatments were established in factorial combination (i.e., control, soil mixing only, biochar only, and biochar and soil mixing; n = 6 plots of each). After two growing seasons, we found that biochar application enhanced net soil N mineralization rates and soil NH4+ concentrations regardless of the soil mixing treatment, but had no impact on the availability of NO3-, the majority of soil microbial community parameters, or soil respiration. Meanwhile, soil mixing enhanced soil NO3- concentrations, but had negative impacts on net N mineralization rates and several soil microbial community variables. Many of the effects of soil mixing on soil nutrient and microbial community properties were less extreme when biochar was also added. Biochar addition had almost no effects on vegetation properties (except for a small reduction in species richness of the ground layer vegetation), while soil mixing caused significant reductions in graminoid and total ground layer vegetation cover, and enhanced seedling survival rates of P. sylvestris, and seed germination rates for four tree species. Our results suggest that biochar application can serve as an effective tool to store soil C in boreal forests while enhancing NH4+ availability. They also suggest that biochar may serve as a useful complement to site preparation techniques that are frequently used in the boreal region, by enhancing soil fertility and reducing nutrient losses when soils are scarified during site preparation. |
BibTeX:
@article{Gundale2016,
author = {Gundale, Michael J and Nilsson, Marie Charlotte and Pluchon, Nathalie and Wardle, David A},
title = {The effect of biochar management on soil and plant community properties in a boreal forest},
journal = {GCB Bioenergy},
year = {2016},
volume = {8},
number = {4},
pages = {777--789},
url = {http://doi.wiley.com/10.1111/gcbb.12274},
doi = {10.1111/gcbb.12274}
}
|
| Hasper TB, Wallin G, Lamba S, Hall M, Jaramillo F, Laudon H, Linder S, Medhurst JL, Räntfors M, Sigurdsson BD and Uddling J (2016), "Water use by Swedish boreal forests in a changing climate", Functional Ecology., may, 2016. Vol. 30(5), pp. 690-699. |
| Abstract: The rising levels of atmospheric carbon dioxide concentration ([CO2]) and temperature have the potential to substantially affect the terrestrial water and energy balance by altering the stomatal conductance and transpiration of trees. Many models assume decreases in stomatal conductance and plant water use under rising [CO2], which has been used as a plausible explanation for the positive global trend in river run-off over the past century. Plant water use is, however, also affected by changes in temperature, precipitation and land use, and there is yet no consensus about the contribution of different drivers to temporal trends of evapotranspiration (ET) and river run-off. In this study, we assessed water-use responses to climate change by using both long-term monitoring and experimental data in Swedish boreal forests. Historical trends and patterns in ET of large-scale boreal landscapes were determined using climate and run-off data from the past 50 years, while explicit tree water-use responses to elevated [CO2] and/or air temperature were examined in a whole-tree chamber experiment using mature Norway spruce (Picea abies (L.) Karst.) trees. The results demonstrated that ET estimated from water budgets at the catchment scale increased by 18% over the past 50 years while run-off did not significantly change. The increase in ET was related to increasing precipitation and a steady increase in forest standing biomass over time. The whole-tree chamber experiment showed that Norway spruce trees did not save water under elevated [CO2] and that experimentally elevated air temperature did not increase transpiration as decreased stomatal conductance cancelled the effect of higher vapour pressure deficit in warmed air. Our findings have important implications for projections of future water use of European boreal coniferous forests, indicating that changes in precipitation and standing biomass are more important than the effects of elevated [CO2] or temperature on transpiration rates. |
BibTeX:
@article{Hasper2016,
author = {Hasper, Thomas B and Wallin, Göran and Lamba, Shubhangi and Hall, Marianne and Jaramillo, Fernando and Laudon, Hjalmar and Linder, Sune and Medhurst, Jane L and Räntfors, Mats and Sigurdsson, Bjarni D and Uddling, Johan},
editor = {Tjoelker, Mark},
title = {Water use by Swedish boreal forests in a changing climate},
journal = {Functional Ecology},
year = {2016},
volume = {30},
number = {5},
pages = {690--699},
url = {http://doi.wiley.com/10.1111/1365-2435.12546},
doi = {10.1111/1365-2435.12546}
}
|
| Haughton N, Abramowitz G, Pitman AJ, Or D, Best MJ, Johnson HR, Balsamo G, Boone A, Cuntz M, Decharme B, Dirmeyer PA, Dong J, Ek M, Guo Z, Haverd V, van den Hurk BJJ, Nearing GS, Pak B, Santanello JA, Stevens LE and Vuichard N (2016), "The plumbing of land surface models: Is poor performance a result of methodology or data quality?", Journal of Hydrometeorology., jun, 2016. Vol. 17(6), pp. 1705-1723. |
| Abstract: The Protocol for the Analysis of Land Surface Models (PALS) Land Surface Model Benchmarking Evaluation Project (PLUMBER) illustrated the value of prescribing a priori performance targets in model intercomparisons. It showed that the performance of turbulent energy flux predictions from different land surface models, at a broad range of flux tower sites using common evaluation metrics, was on average worse than relatively simple empirical models. For sensible heat fluxes, all land surface models were outperformed by a linear regression against downward shortwave radiation. For latent heat flux, all land surface models were outperformed by a regression against downward shortwave radiation, surface air temperature, and relative humidity. These results are explored here in greater detail and possible causes are investigated. It is examined whether particular metrics or sites unduly influence the collated results, whether results change according to time-scale aggregation, and whether a lack of energy conservation in flux tower data gives the empirical models an unfair advantage in the intercomparison. It is demonstrated that energy conservation in the observational data is not responsible for these results. It is also shown that the partitioning between sensible and latent heat fluxes in LSMs, rather than the calculation of available energy, is the cause of the original findings. Finally, evidence is presented that suggests that the nature of this partitioning problem is likely shared among all contributing LSMs. While a single candidate explanation for why land surface models perform poorly relative to empirical benchmarks in PLUMBER could not be found, multiple possible explanations are excluded and guidance is provided on where future research should focus. |
BibTeX:
@article{Haughton2016,
author = {Haughton, Ned and Abramowitz, Gab and Pitman, Andy J and Or, Dani and Best, Martin J and Johnson, Helen R and Balsamo, Gianpaolo and Boone, Aaron and Cuntz, Matthias and Decharme, Bertrand and Dirmeyer, Paul A and Dong, Jairui and Ek, Michael and Guo, Zichang and Haverd, Vanessa and van den Hurk, Bart J J and Nearing, Grey S and Pak, Bernard and Santanello, Joe A and Stevens, Lauren E and Vuichard, Nicolas},
title = {The plumbing of land surface models: Is poor performance a result of methodology or data quality?},
journal = {Journal of Hydrometeorology},
year = {2016},
volume = {17},
number = {6},
pages = {1705--1723},
url = {http://journals.ametsoc.org/doi/10.1175/JHM-D-15-0171.1},
doi = {10.1175/JHM-D-15-0171.1}
}
|
| Hazan L, Tarniewicz J, Ramonet M, Laurent O and Abbaris A (2016), "Automatic processing of atmospheric CO2 and CH4 mole fractions at the ICOS Atmosphere Thematic Centre", Atmospheric Measurement Techniques., sep, 2016. Vol. 9(9), pp. 4719-4736. |
| Abstract: The Integrated Carbon Observation System Atmosphere Thematic Centre (ICOS ATC) automatically processes atmospheric greenhouse gases mole fractions of data coming from sites of the ICOS network. Daily transferred raw data files are automatically processed and archived. Data are stored in the ICOS atmospheric database, the backbone of the system, which has been developed with an emphasis on the traceability of the data processing. Many data products, updated daily, explore the data through different angles to support the quality control of the dataset performed by the principal operators in charge of the instruments. The automatic processing includes calibration and water vapor corrections as described in the paper. The mole fractions calculated in near-real time (NRT) are automatically revaluated as soon as a new instrument calibration is processed or when the station supervisors perform quality control. By analyzing data from 11 sites, we determined that the average calibration corrections are equal to 1:7±0:3μmol mol-1 for CO2 and 2:8±3 nmol mol-1 for CH4. These biases are important to correct to avoid artificial gradients between stations that could lead to error in flux estimates when using atmospheric inversion techniques. We also calculated that the average drift between two successive calibrations separated by 15 days amounts to ±0.05 μmol mol-1 and 0.7 nmol mol-1 for CO2 and CH4, respectively. Outliers are generally due to errors in the instrument configuration and can be readily detected thanks to the data products provided by the ATC. Several developments are still ongoing to improve the processing, including automated spike detection and calculation of time-varying uncertainties. |
BibTeX:
@article{Hazan2016,
author = {Hazan, Lynn and Tarniewicz, Jérôme and Ramonet, Michel and Laurent, Olivier and Abbaris, Amara},
title = {Automatic processing of atmospheric CO2 and CH4 mole fractions at the ICOS Atmosphere Thematic Centre},
journal = {Atmospheric Measurement Techniques},
year = {2016},
volume = {9},
number = {9},
pages = {4719--4736},
url = {http://www.atmos-meas-tech.net/9/4719/2016/},
doi = {10.5194/amt-9-4719-2016}
}
|
| Hellström M, Vermeulen A, Mirzov O, Sabbatini S, Vitale D, Papale D, Tarniewicz J, Hazan L, Rivier L, Jones SD, Pfeil B and Johannessen T (2016), "Near Real Time Data Processing In ICOS RI", In Zenodo. |
| Abstract: — This paper describes the implementation of (near) real-time (NRT) data processing in the recently launched European environmental research infrastructure ICOS. NRT applications include handling of raw sensor data (including safe storage and quality control), processing and evaluation of greenhouse gas mixing ratios and exchange fluxes, and the provision of data to the RI's user communities. |
BibTeX:
@inproceedings{Hellstrom2016,
author = {Hellström, Margareta and Vermeulen, Alex and Mirzov, Oleg and Sabbatini, Simone and Vitale, Domenico and Papale, Dario and Tarniewicz, Jérôme and Hazan, Lynn and Rivier, Leonard and Jones, Steve D and Pfeil, Benjamin and Johannessen, Truls},
title = {Near Real Time Data Processing In ICOS RI},
booktitle = {Zenodo},
year = {2016},
doi = {10.5281/zenodo.204817}
}
|
| Hendriksen NB, Creamer RE, Stone D and Winding A (2016), "Soil exo-enzyme activities across Europe-The influence of climate, land-use and soil properties", Applied Soil Ecology., jan, 2016. Vol. 97, pp. 44-48. |
| Abstract: The assessment and monitoring requirements of soil quality have been debated for many years at European and Global scales. To monitor the activity and diversity of microbial communities a number of methods have been applied including the activity of extracellular soil enzymes. Here is the activity of eight hydrolytic extracellular enzymes on 79 sites across Europe measured, the sites are from five different climatic zones with three different land-uses, and they vary in physicochemical characteristics. The results show that the activity of the enzymes primarily depends on soil organic matter and to a lesser extent on pH, while the activities were not related to climate or land-use. Sites were selected to represent a broad spectrum of key soil properties across three different land-uses and five different climatic biogeographical zones across Europe, so the overall conclusion is based on the analysis of soils representing soil characteristics across Europe. |
BibTeX:
@article{Hendriksen2016,
author = {Hendriksen, N B and Creamer, R E and Stone, D and Winding, A},
title = {Soil exo-enzyme activities across Europe-The influence of climate, land-use and soil properties},
journal = {Applied Soil Ecology},
year = {2016},
volume = {97},
pages = {44--48},
url = {https://linkinghub.elsevier.com/retrieve/pii/S0929139315300652},
doi = {10.1016/j.apsoil.2015.08.012}
}
|
| Henne S, Brunner D, Oney B, Leuenberger M, Eugster W, Bamberger I, Meinhardt F, Steinbacher M and Emmenegger L (2016), "Validation of the Swiss methane emission inventory by atmospheric observations and inverse modelling", Atmospheric Chemistry and Physics., mar, 2016. Vol. 16(6), pp. 3683-3710. |
| Abstract: Atmospheric inverse modelling has the potential to provide observation-based estimates of greenhouse gas emissions at the country scale, thereby allowing for an independent validation of national emission inventories. Here, we present a regional-scale inverse modelling study to quantify the emissions of methane (CH4) from Switzerland, making use of the newly established CarboCount-CH measurement network and a high-resolution Lagrangian transport model. In our reference inversion, prior emissions were taken from the "bottom-up" Swiss Greenhouse Gas Inventory (SGHGI) as published by the Swiss Federal Office for the Environment in 2014 for the year 2012. Overall we estimate national CH4 emissions to be 196±18 Ggyr-1 for the year 2013 (1σ uncertainty). This result is in close agreement with the recently revised SGHGI estimate of 206-33 Ggyr-1 as reported in 2015 for the year 2012. Results from sensitivity inversions using alternative prior emissions, uncertainty covariance settings, large-scale background mole fractions, two different inverse algorithms (Bayesian and extended Kalman filter), and two different transport models confirm the robustness and independent character of our estimate. According to the latest SGHGI estimate the main CH4 source categories in Switzerland are agriculture (78 %), waste handling (15 %) and natural gas distribution and combustion (6 %). The spatial distribution and seasonal variability of our posterior emissions suggest an overestimation of agricultural CH4 emissions by 10 to 20% in the most recent SGHGI, which is likely due to an overestimation of emissions from manure handling. Urban areas do not appear as emission hotspots in our posterior results, suggesting that leakages from natural gas distribution are only a minor source of CH4 in Switzerland. This is consistent with rather low emissions of 8.4 Ggyr-1 reported by the SGHGI but inconsistent with the much higher value of 32 Ggyr-1 implied by the EDGARv4.2 inventory for this sector. Increased CH4 emissions (up to 30% compared to the prior) were deduced for the northeastern parts of Switzerland. This feature was common to most sensitivity inversions, which is a strong indicator that it is a real feature and not an artefact of the transport model and the inversion system. However, it was not possible to assign an unambiguous source process to the region. The observations of the CarboCount-CH network provided invaluable and independent information for the validation of the national bottom-up inventory. Similar systems need to be sustained to provide independent monitoring of future climate agreements. |
BibTeX:
@article{Henne2016,
author = {Henne, Stephan and Brunner, Dominik and Oney, Brian and Leuenberger, Markus and Eugster, Werner and Bamberger, Ines and Meinhardt, Frank and Steinbacher, Martin and Emmenegger, Lukas},
title = {Validation of the Swiss methane emission inventory by atmospheric observations and inverse modelling},
journal = {Atmospheric Chemistry and Physics},
year = {2016},
volume = {16},
number = {6},
pages = {3683--3710},
url = {http://www.atmos-chem-phys.net/16/3683/2016/},
doi = {10.5194/acp-16-3683-2016}
}
|
| Hervo M, Poltera Y and Haefele A (2016), "An empirical method to correct for temperature-dependent variations in the overlap function of CHM15k ceilometers", Atmospheric Measurement Techniques., jul, 2016. Vol. 9(7), pp. 2947-2959. Copernicus GmbH. |
| Abstract: Imperfections in a lidar's overlap function lead to artefacts in the background, range and overlap-corrected lidar signals. These artefacts can erroneously be interpreted as an aerosol gradient or, in extreme cases, as a cloud base leading to false cloud detection. A correct specification of the overlap function is hence crucial in the use of automatic elastic lidars (ceilometers) for the detection of the planetary boundary layer or of low cloud. In this study, an algorithm is presented to correct such artefacts. It is based on the assumption of a homogeneous boundary layer and a correct specification of the overlap function down to a minimum range, which must be situated within the boundary layer. The strength of the algorithm lies in a sophisticated quality-check scheme which allows the reliable identification of favourable atmospheric conditions. The algorithm was applied to 2 years of data from a CHM15k ceilometer from the company Lufft. Backscatter signals corrected for background, range and overlap were compared using the overlap function provided by the manufacturer and the one corrected with the presented algorithm. Differences between corrected and uncorrected signals reached up to 45% in the first 300 m above ground. The amplitude of the correction turned out to be temperature dependent and was larger for higher temperatures. A linear model of the correction as a function of the instrument's internal temperature was derived from the experimental data. Case studies and a statistical analysis of the strongest gradient derived from corrected signals reveal that the temperature model is capable of a high-quality correction of overlap artefacts, in particular those due to diurnal variations. The presented correction method has the potential to significantly improve the detection of the boundary layer with gradient-based methods because it removes false candidates and hence simplifies the attribution of the detected gradients to the planetary boundary layer. A particularly significant benefit can be expected for the detection of shallow stable layers typical of night-time situations. The algorithm is completely automatic and does not require any on-site intervention but requires the definition of an adequate instrument-specific configuration. It is therefore suited for use in large ceilometer networks. |
BibTeX:
@article{Hervo2016,
author = {Hervo, Maxime and Poltera, Yann and Haefele, Alexander},
title = {An empirical method to correct for temperature-dependent variations in the overlap function of CHM15k ceilometers},
journal = {Atmospheric Measurement Techniques},
publisher = {Copernicus GmbH},
year = {2016},
volume = {9},
number = {7},
pages = {2947--2959},
doi = {10.5194/amt-9-2947-2016}
}
|
| Hingerl L, Kunstmann H, Wagner S, Mauder M, Bliefernicht J and Rigon R (2016), "Spatio-temporal variability of water and energy fluxes – a case study for a mesoscale catchment in pre-alpine environment", Hydrological Processes., oct, 2016. Vol. 30(21), pp. 3804-3823. |
| Abstract: Water and energy fluxes at and between the land surface, the subsurface and the atmosphere are inextricably linked over all spatio-temporal scales. Our research focuses on the joint analysis of both water and energy fluxes in a pre-alpine catchment (55 km2) in southern Germany, which is part of the Terrestrial Environmental Observatories (TERENO). We use a novel three-dimensional, physically based and distributed modelling approach to reproduce both observed streamflow as an integral measure for water fluxes and heat flux and soil temperature measurements at an observation location over a period of 2 years. While heat fluxes are often used for comparison of the simulations of one-dimensional land surface models, they are rarely used for additional validation of physically based and distributed hydrological modelling approaches. The spatio-temporal variability of the water and energy balance components and their partitioning for dominant land use types of the study region are investigated. The model shows good performance for simulating daily streamflow (Nash–Sutcliffe efficiency 0.75). Albeit only streamflow measurements are used for calibration, the simulations of hourly heat fluxes and soil temperatures at the observation site also show a good performance, particularly during summer. A limitation of the model is the simulation of temperature-driven heat fluxes during winter, when the soil is covered by snow. An analysis of the simulated spatial fields reveals heat flux patterns that reflect the distribution of the land use and soil types of the catchment. The water and energy partitioning is characterized by a strong seasonal cycle and shows clear differences between the selected land use types. Copyright textcopyright 2016 The Authors Hydrological Processes Published by John Wiley & Sons Ltd. |
BibTeX:
@article{Hingerl2016,
author = {Hingerl, Luitpold and Kunstmann, Harald and Wagner, Sven and Mauder, Matthias and Bliefernicht, Jan and Rigon, Riccardo},
title = {Spatio-temporal variability of water and energy fluxes – a case study for a mesoscale catchment in pre-alpine environment},
journal = {Hydrological Processes},
year = {2016},
volume = {30},
number = {21},
pages = {3804--3823},
url = {http://doi.wiley.com/10.1002/hyp.10893},
doi = {10.1002/hyp.10893}
}
|
| Hurkuck M, Brümmer C and Kutsch WL (2016), "Near-neutral carbon dioxide balance at a seminatural, temperate bog ecosystem", Journal of Geophysical Research: Biogeosciences., feb, 2016. Vol. 121(2), pp. 370-384. |
| Abstract: The majority of peatlands in the temperate zone is subjected to drainage and agricultural land use and have been found to be anthropogenic emission hot spots for greenhouse gases. At the same time, many peatlands receive increased atmospheric nitrogen (N) deposition by intensive agricultural practices. Here we provide eddy covariance measurements determining net ecosystem carbon dioxide (CO2) exchange at a protected but moderately drained ombrotrophic bog in Northwestern Germany over three consecutive years. The region is dominated by intensive agricultural land use with total (wet and dry) atmospheric N deposition being about 25 kg N ha-1 yr-1. The investigated peat bog was a small net CO2 sink during all three years ranging from -9 to -73 g C m-2 yr-1. We found temperature- and light-dependent ecosystem respiration (Reco) and gross primary production, respectively, but only weak correlations to water table depths despite large interannual and seasonal variability. Significant short-term effects of atmospheric N deposition on CO2 flux components could not be observed, as the primary controlling factors for N deposition and C sequestration, i.e., fertilization of adjacent fields as well as temperature and light availability, respectively, exceeded potential interactions between the two. |
BibTeX:
@article{Hurkuck2016,
author = {Hurkuck, Miriam and Brümmer, Christian and Kutsch, Werner L},
title = {Near-neutral carbon dioxide balance at a seminatural, temperate bog ecosystem},
journal = {Journal of Geophysical Research: Biogeosciences},
year = {2016},
volume = {121},
number = {2},
pages = {370--384},
url = {http://doi.wiley.com/10.1002/2015JG003195},
doi = {10.1002/2015JG003195}
}
|
| Ibánhez JSP, Araujo M and Lefèvre N (2016), "The overlooked tropical oceanic CO textlesssubtextgreater2textless/subtextgreater sink", Geophysical Research Letters., apr, 2016. Vol. 43(8), pp. 3804-3812. Blackwell Publishing Ltd. |
| Abstract: The intense rainfall in the tropical Atlantic spatially overlaps with the spread of the Amazon plume. Based on remote-sensed sea surface salinity and rainfall, we removed the contribution of rainfall to the apparent Amazon plume area, thus refining the quantification of its extension (0.84 ± 0.06 × 106 km2 to 0.89 ± 0.06 × 106 km2). Despite the previous overestimation of the Amazon plume area due to the influence of rainfall (textgreater16%), our calculated annual CO2 flux based on rainfall-corrected sea surface CO2 fugacity confirms that the Amazon River plume is an atmospheric CO2 sink of global importance (-7.61 ± 1.01 to -7.85 ± 1.02 Tg C yr-1). Yet we show that current sea-air CO2 flux assessments for the tropical Atlantic could be overestimated in about 10% by neglecting the CO2 sink associated to the Amazon plume. Thus, including the Amazon plume, the sea-air CO2 exchange for the tropical Atlantic is estimated to be 81.1 ± 1.1 to 81.5 ± 1.1 Tg C yr-1. |
BibTeX:
@article{Ibanhez2016,
author = {Ibánhez, J. Severino P. and Araujo, Moacyr and Lefèvre, Nathalie},
title = {The overlooked tropical oceanic CO textlesssubtextgreater2textless/subtextgreater sink},
journal = {Geophysical Research Letters},
publisher = {Blackwell Publishing Ltd},
year = {2016},
volume = {43},
number = {8},
pages = {3804--3812},
url = {http://doi.wiley.com/10.1002/2016GL068020},
doi = {10.1002/2016GL068020}
}
|
| Inoue M, Morino I, Uchino O, Nakatsuru T, Yoshida Y, Yokota T, Wunch D, Wennberg PO, Roehl CM, Griffith DW, Velazco VA, Deutscher NM, Warneke T, Notholt J, Robinson J, Sherlock V, Hase F, Blumenstock T, Rettinger M, Sussmann R, Kyrö E, Kivi R, Shiomi K, Kawakami S, De Mazière M, Arnold SG, Feist DG, Barrow EA, Barney J, Dubey M, Schneider M, Iraci LT, Podolske JR, Hillyard PW, Machida T, Sawa Y, Tsuboi K, Matsueda H, Sweeney C, Tans PP, Andrews AE, Biraud SC, Fukuyama Y, Pittman JV, Kort EA and Tanaka T (2016), "Bias corrections of GOSAT SWIR XCO2 and XCH4 with TCCON data and their evaluation using aircraft measurement data", Atmospheric Measurement Techniques., aug, 2016. Vol. 9(8), pp. 3491-3512. Copernicus GmbH. |
| Abstract: We describe a method for removing systematic biases of column-averaged dry air mole fractions of CO2 (XCO2) and CH4 (XCH4) derived from short-wavelength infrared (SWIR) spectra of the Greenhouse gases Observing SATellite (GOSAT). We conduct correlation analyses between the GOSAT biases and simultaneously retrieved auxiliary parameters. We use these correlations to bias correct the GOSAT data, removing these spurious correlations. Data from the Total Carbon Column Observing Network (TCCON) were used as reference values for this regression analysis. To evaluate the effectiveness of this correction method, the tnzuncorrected/corrected GOSAT data were compared to independent XCO2 and XCH4 data derived from aircraft measurements taken for the Comprehensive Observation Network for TRace gases by AIrLiner (CONTRAIL) project, the National Oceanic and Atmospheric Administration (NOAA), the US Department of Energy (DOE), the National Institute for Environmental Studies (NIES), the Japan Meteorological Agency (JMA), the HIAPER Pole-to-Pole observations (HIPPO) program, and the GOSAT validation aircraft observation campaign over Japan. These comparisons demonstrate that the empirically derived bias correction improves the agreement between GOSAT XCO2/XCH4 and the aircraft data. Finally, we present spatial distributions and temporal variations of the derived GOSAT biases. |
BibTeX:
@article{Inoue2016,
author = {Inoue, Makoto and Morino, Isamu and Uchino, Osamu and Nakatsuru, Takahiro and Yoshida, Yukio and Yokota, Tatsuya and Wunch, Debra and Wennberg, Paul O. and Roehl, Coleen M. and Griffith, David W.T. and Velazco, Voltaire A. and Deutscher, Nicholas M. and Warneke, Thorsten and Notholt, Justus and Robinson, John and Sherlock, Vanessa and Hase, Frank and Blumenstock, Thomas and Rettinger, Markus and Sussmann, Ralf and Kyrö, Esko and Kivi, Rigel and Shiomi, Kei and Kawakami, Shuji and De Mazière, Martine and Arnold, Sabrina G. and Feist, Dietrich G. and Barrow, Erica A. and Barney, James and Dubey, Manvendra and Schneider, Matthias and Iraci, Laura T. and Podolske, James R. and Hillyard, Patrick W. and Machida, Toshinobu and Sawa, Yousuke and Tsuboi, Kazuhiro and Matsueda, Hidekazu and Sweeney, Colm and Tans, Pieter P. and Andrews, Arlyn E. and Biraud, Sebastien C. and Fukuyama, Yukio and Pittman, Jasna V. and Kort, Eric A. and Tanaka, Tomoaki},
title = {Bias corrections of GOSAT SWIR XCO2 and XCH4 with TCCON data and their evaluation using aircraft measurement data},
journal = {Atmospheric Measurement Techniques},
publisher = {Copernicus GmbH},
year = {2016},
volume = {9},
number = {8},
pages = {3491--3512},
doi = {10.5194/amt-9-3491-2016}
}
|
| Inoue M, Morino I, Uchino O, Nakatsuru T, Yoshida Y, Yokota T, Wunch D, Wennberg PO, Roehl CM, Griffith DWT, Velazco VA, Deutscher NM, Warneke T, Notholt J, Robinson J, Sherlock V, Hase F, Blumenstock T, Rettinger M, Sussmann R, Kyrö E, Kivi R, Shiomi K, Kawakami S, De Mazière M, Arnold SG, Feist DG, Barrow EA, Barney J, Dubey M, Schneider M, Iraci L, Podolske JR, Hillyard P, Machida T, Sawa Y, Tsuboi K, Matsueda H, Sweeney C, Tans PP, Andrews AE, Biraud SC, Fukuyama Y, Pittman JV, Kort EA and Tanaka T (2016), "Bias corrections of GOSAT SWIR XCOsub2/sub and XCHsub4/sub with TCCON data and their evaluation using aircraft measurement data", Atmospheric Measurement Techniques Discussions., jan, 2016. , pp. 1-49. |
| Abstract: We describe a method for removing systematic biases of column-averaged dry air mole fractions of COsub2/sub (XCOsub2/sub) and CHsub4/sub (XCHsub4/sub) derived from short-wavelength infrared (SWIR) spectra of the Greenhouse gases Observing SATellite (GOSAT). We conduct correlation analyses between the GOSAT biases and simultaneously-retrieved auxiliary parameters. We use these correlations to bias correct the GOSAT data, removing these spurious correlations. Data from Total Carbon Column Observing Network (TCCON) were used as reference values for this regression analysis. To evaluate the effectiveness of this correction method, the uncorrected/corrected GOSAT data were compared to independent XCOsub2/sub and XCHsub4/sub data derived from aircraft measurements taken for the Comprehensive Observation Network for TRace gases by AIrLiner (CONTRAIL) project, the National Oceanic and Atmospheric Administration (NOAA), the U.S. Department of Energy (DOE), the National Institute for Environmental Studies (NIES), the Japan Meteorological Agency (JMA), the HIAPER Pole- to-Pole observations (HIPPO) program, and the GOSAT validation aircraft observation campaign over Japan. These comparisons demonstrate that the empirically-derived bias correction improves the agreement between GOSAT XCOsub2/sub/XCHsub4/sub and the aircraft data. Finally, we present latitudinal distributions and temporal variations of the derived GOSAT biases. |
BibTeX:
@article{Inoue2016a,
author = {Inoue, M and Morino, I and Uchino, O and Nakatsuru, T and Yoshida, Y and Yokota, T and Wunch, D and Wennberg, P O and Roehl, C M and Griffith, D W T and Velazco, V A and Deutscher, N M and Warneke, T and Notholt, J and Robinson, J and Sherlock, V and Hase, F and Blumenstock, T and Rettinger, M and Sussmann, R and Kyrö, E and Kivi, R and Shiomi, K and Kawakami, S and De Mazière, M and Arnold, S G and Feist, D G and Barrow, E A and Barney, J and Dubey, M and Schneider, M and Iraci, L and Podolske, J R and Hillyard, P and Machida, T and Sawa, Y and Tsuboi, K and Matsueda, H and Sweeney, C and Tans, P P and Andrews, A E and Biraud, S C and Fukuyama, Y and Pittman, J V and Kort, E A and Tanaka, T},
title = {Bias corrections of GOSAT SWIR XCOsub2/sub and XCHsub4/sub with TCCON data and their evaluation using aircraft measurement data},
journal = {Atmospheric Measurement Techniques Discussions},
year = {2016},
pages = {1--49},
url = {http://www.atmos-meas-tech-discuss.net/amt-2015-366/},
doi = {10.5194/amt-2015-366}
}
|
| Ishizawa M, Mabuchi K, Shirai T, Inoue M, Morino I, Uchino O, Yoshida Y, Belikov D and Maksyutov S (2016), "Inter-annual variability of summertime CO
2 exchange in Northern Eurasia inferred from GOSAT XCO 2", Environmental Research Letters., sep, 2016. Vol. 11(10), pp. 105001. IOP Publishing. |
| Abstract: Northern Eurasia is one of the largest terrestrial carbon reservoirs on the Earth's surface. However, since the coverage of surface CO2 observations is still limited, the response to the climate variability remains uncertain. We estimated monthly CO2 fluxes for three sub-regions in Northern Eurasia (north of ∼60°N), Northeastern Europe, Western Siberia and Eastern Siberia, using CO2 retrievals from the Japanese Greenhouse Gases Observing SATellite (GOSAT). The variations of estimated CO2 fluxes were examined in terms of the regional climate variability, for the three consecutive growing seasons of 2009–2011. The CO2 fluxes estimated using GOSAT data are highly correlated with the surface temperature anomalies in July and August (r textgreater 0.8) while no correlation is found in the CO2 fluxes estimated only using surface observations. The estimated fluxes from GOSAT data exhibit high negative correlations with one-month lagged positive precipitation anomalies in late summer (r textgreater −0.7) through surface temperature and the Normalized Difference Vegetation Index (NDVI). The results indicate that GOSAT data reflects the changes in terrestrial biospheric processes responding to climate anomalies. In 2010, a large part of Eurasia experienced an extremely hot and dry summer, while cold and wet weather conditions were recorded in Western Siberia. The CO2 fluxes estimated from GOSAT data showed a reduction of net CO2 uptake in Northeastern Europe and Eastern Siberia, but the enhancement of net CO2 uptake in Western Siberia. These opposite sub-regional flux anomalies can be explained by the different climate anomalies on a sub-regional scale in Northern Eurasia. Thus, this study demonstrates that space-based observations by GOSAT compensate for the lack of ground-based observational coverage so as to better capture the inter-annually varying atmosphere-terrestrial biosphere CO2 exchange on a regional scale. |
BibTeX:
@article{Ishizawa2016,
author = {Ishizawa, M and Mabuchi, K and Shirai, T and Inoue, M and Morino, I and Uchino, O and Yoshida, Y and Belikov, D and Maksyutov, S},
title = {Inter-annual variability of summertime CO
|
| Ito RG, Garcia CAE and Tavano VM (2016), "Net sea-air CO2 fluxes and modelled pCO2 in the southwestern subtropical Atlantic continental shelf during spring 2010 and summer 2011", Continental Shelf Research., may, 2016. Vol. 119, pp. 68-84. Elsevier Ltd. |
| Abstract: Sea-air CO2 fluxes over continental shelves vary substantially in time on both seasonal and sub-seasonal scales, driven primarily by variations in surface pCO2 due to several oceanic mechanisms. Furthermore, coastal zones have not been appropriately considered in global estimates of sea-air CO2 fluxes, despite their importance to ecology and to productivity. In this work, we aimed to improve our understanding of the role played by shelf waters in controlling sea-air CO2 fluxes by investigating the southwestern Atlantic Ocean (21-35°S) region, where physical, chemical and biological measurements were made on board the Brazilian R. V. Cruzeiro do Sul during late spring 2010 and early summer 2011. Features such as discharge from the La Plata River, intrusions of tropical waters on the outer shelf due to meandering and flow instabilities of the Brazil Current, and coastal upwelling in the Santa Marta Grande Cape and São Tomé Cape were detected by both in situ measurements and ocean colour and thermal satellite imagery. Overall, shelf waters in the study area were a source of CO2 to the atmosphere, with an average of 1.2 mmol CO2 m-2 day-1 for the late spring and 11.2 mmol CO2 m-2 day-1 for the early summer cruises. The spatial variability in ocean pCO2 was associated with surface ocean properties (temperature, salinity and chlorophyll-a concentration) in both the slope and shelf waters. Empirical algorithms for predicting temperature-normalized surface ocean pCO2 as a function of surface ocean properties were shown to perform well in both shelf and slope waters, except (a) within cyclonic eddies produced by baroclinic instability of the Brazil Current as detected by satellite SST imagery and (b) in coastal upwelling regions. In these regions, surface ocean pCO2 values were higher as a result of upwelled CO2-enriched subsurface waters. Finally, a pCO2 algorithm based on both sea surface temperature and surface chlorophyll-a was developed that enabled the spatial variability of surface ocean pCO2 to be mapped from satellite data in the southern region. |
BibTeX:
@article{Ito2016,
author = {Ito, Rosane Gonçalves and Garcia, Carlos Alberto Eiras and Tavano, Virginia Maria},
title = {Net sea-air CO2 fluxes and modelled pCO2 in the southwestern subtropical Atlantic continental shelf during spring 2010 and summer 2011},
journal = {Continental Shelf Research},
publisher = {Elsevier Ltd},
year = {2016},
volume = {119},
pages = {68--84},
doi = {10.1016/j.csr.2016.03.013}
}
|
| Jiang F, Chen JM, Zhou L, Ju W, Zhang H, Machida T, Ciais P, Peters W, Wang H, Chen B, Liu L, Zhang C, Matsueda H and Sawa Y (2016), "A comprehensive estimate of recent carbon sinks in China using both top-down and bottom-up approaches", Scientific Reports., apr, 2016. Vol. 6(1), pp. 22130. |
| Abstract: Atmospheric inversions use measurements of atmospheric CO2 gradients to constrain regional surface fluxes. Current inversions indicate a net terrestrial CO2 sink in China between 0.16 and 0.35 PgC/yr. The uncertainty of these estimates is as large as the mean because the atmospheric network historically contained only one high altitude station in China. Here, we revisit the calculation of the terrestrial CO2 flux in China, excluding emissions from fossil fuel burning and cement production, by using two inversions with three new CO2 monitoring stations in China as well as aircraft observations over Asia. We estimate a net terrestrial CO2 uptake of 0.39-0.51 PgC/yr with a mean of 0.45 PgC/yr in 2006-2009. After considering the lateral transport of carbon in air and water and international trade, the annual mean carbon sink is adjusted to 0.35 PgC/yr. To evaluate this top-down estimate, we constructed an independent bottom-up estimate based on ecosystem data, and giving a net land sink of 0.33 PgC/yr. This demonstrates closure between the top-down and bottom-up estimates. Both top-down and bottom-up estimates give a higher carbon sink than previous estimates made for the 1980s and 1990s, suggesting a trend towards increased uptake by land ecosystems in China. |
BibTeX:
@article{Jiang2016,
author = {Jiang, Fei and Chen, Jing M and Zhou, Lingxi and Ju, Weimin and Zhang, Huifang and Machida, Toshinobu and Ciais, Philippe and Peters, Wouter and Wang, Hengmao and Chen, Baozhang and Liu, Lixin and Zhang, Chunhua and Matsueda, Hidekazu and Sawa, Yousuke},
title = {A comprehensive estimate of recent carbon sinks in China using both top-down and bottom-up approaches},
journal = {Scientific Reports},
year = {2016},
volume = {6},
number = {1},
pages = {22130},
url = {http://www.nature.com/articles/srep22130},
doi = {10.1038/srep22130}
}
|
| Jones CD, Arora V, Friedlingstein P, Bopp L, Brovkin V, Dunne J, Graven H, Hoffman F, Ilyina T, John JG, Jung M, Kawamiya M, Koven C, Pongratz J, Raddatz T, Randerson J and Zaehle S (2016), "The C4MIP experimental protocol for CMIP6", Geoscientific Model Development Discussions., mar, 2016. , pp. 1-52. Copernicus GmbH. |
| Abstract: Coordinated experimental design and implementation has become a cornerstone of global climate modelling. So-called Model Intercomparison Projects (MIPs) enable systematic and robust analysis of results across many models to identify common signals and understand model similarities and differences without being hindered by ad-hoc differences in model set-up or experimental boundary conditions. The activity known as the Coupled Model Intercomparison Project (CMIP) has thus grown significantly in scope and as it enters its 6th phase, CMIP6, the design and documentation of individual simulations has been devolved to individual climate science communities. textlessbrtextgreatertextlessbrtextgreater The Coupled Climate-Carbon Cycle Model Intercomparison Project (C4MIP) takes responsibility for design, documentation and analysis of carbon cycle feedbacks and interactions in climate simulations. These feedbacks are potentially large and play a leading order contribution in determining the atmospheric composition in response to human emissions of COtextlesssubtextgreater2textless/subtextgreater and in the setting of emissions targets to stabilise climate or avoid dangerous climate change. For over a decade C4MIP has coordinated coupled climate-carbon cycle simulations and in this paper we describe the C4MIP simulations that will be formally part of CMIP6. While the climate-carbon cycle community has formed this experimental design the simulations also fit into the wider CMIP activity and conform to some common standards such as documentation and diagnostic requests and are designed to complement the CMIP core experiments known as the DECK. textlessbrtextgreatertextlessbrtextgreater C4MIP has 3 key strands of scientific motivation and the requested simulations are designed to satisfy their needs: (1) pre-industrial and historical simulations (formally part of the common set of CMIP6 experiments) to enable model evaluation; (2) idealised coupled and partially-coupled simulations with 1 % per year increases in COtextlesssubtextgreater2textless/subtextgreater to enable diagnosis of feedback strength and its components; (3) future scenario simulations to project how the Earth System will respond over the 21st century and beyond to anthropogenic activity. textlessbrtextgreatertextlessbrtextgreater This paper documents in detail these simulations, explains their rationale and planned analysis, and describes how to set-up and run the simulations. Particular attention is paid to boundary conditions and input data required, and also the output diagnostics requested. It is important that modelling groups participating in C4MIP adhere as closely as possible to this experimental design. |
BibTeX:
@article{Jones2016,
author = {Jones, Chris D. and Arora, Vivek and Friedlingstein, Pierre and Bopp, Laurent and Brovkin, Victor and Dunne, John and Graven, Heather and Hoffman, Forrest and Ilyina, Tatiana and John, Jasmin G. and Jung, Martin and Kawamiya, Michio and Koven, Charlie and Pongratz, Julia and Raddatz, Thomas and Randerson, Jim and Zaehle, Sönke},
title = {The C4MIP experimental protocol for CMIP6},
journal = {Geoscientific Model Development Discussions},
publisher = {Copernicus GmbH},
year = {2016},
pages = {1--52},
doi = {10.5194/gmd-2016-36}
}
|
| Kanakidou M, Myriokefalitakis S, Daskalakis N, Fanourgakis G, Nenes A, Baker AR, Tsigaridis K and Mihalopoulos N (2016), "Past, Present, and Future Atmospheric Nitrogen Deposition", Journal of the Atmospheric Sciences., may, 2016. Vol. 73(5), pp. 2039-2047. |
| Abstract: pReactive nitrogen emissions into the atmosphere are increasing as a result of human activities, affecting nitrogen deposition to the surface and impacting the productivity of terrestrial and marine ecosystems. An atmospheric chemistry–transport model [Tracer Model 4 of the Environmental Chemical Processes Laboratory (TM4-ECPL)] is here used to calculate the global distribution of total nitrogen deposition, accounting for the first time for both its inorganic and organic fractions in gaseous and particulate phases and past and projected changes due to anthropogenic activities. The anthropogenic and biomass-burning Atmospheric Chemistry and Climate Model Intercomparison Project (ACCMIP) historical and RCP6.0 and RCP8.5 emissions scenarios are used. Accounting for organic nitrogen (ON) primary emissions, the present-day global nitrogen atmospheric source is about 60% anthropogenic, while total N deposition increases by about 20% relative to simulations without ON primary emissions. About 20%–25% of total deposited N is ON. About 10% of the emitted nitrogen oxides are deposited as ON instead of inorganic nitrogen (IN), as is considered in most global models. Almost a threefold increase over land (twofold over the ocean) has been calculated for soluble N deposition due to human activities from 1850 to present. The investigated projections indicate significant changes in the regional distribution of N deposition and chemical composition, with reduced compounds gaining importance relative to oxidized ones, but very small changes in the global total flux. Sensitivity simulations quantify uncertainties due to the investigated model parameterizations of IN partitioning onto aerosols and of N chemically fixed on organics to be within 10% for the total soluble N deposition and between 25% and 35% for the dissolved ON deposition. Larger uncertainties are associated with N emissions./p |
BibTeX:
@article{Kanakidou2016,
author = {Kanakidou, M and Myriokefalitakis, S and Daskalakis, N and Fanourgakis, G and Nenes, A and Baker, A R and Tsigaridis, K and Mihalopoulos, N},
title = {Past, Present, and Future Atmospheric Nitrogen Deposition},
journal = {Journal of the Atmospheric Sciences},
year = {2016},
volume = {73},
number = {5},
pages = {2039--2047},
url = {http://journals.ametsoc.org/doi/10.1175/JAS-D-15-0278.1},
doi = {10.1175/JAS-D-15-0278.1}
}
|
| Karsisto P, Fortelius C, Demuzere M, Grimmond CS, Oleson KW, Kouznetsov R, Masson V and Järvi L (2016), "Seasonal surface urban energy balance and wintertime stability simulated using three land-surface models in the high-latitude city Helsinki", Quarterly Journal of the Royal Meteorological Society., jan, 2016. Vol. 142(694), pp. 401-417. John Wiley and Sons Ltd. |
| Abstract: The performance of three urban land-surface models, run in off-line mode, with their default external parameters, is evaluated for two distinctly different sites in Helsinki: Torni and Kumpula. The former is a dense city-centre site with 22% vegetation, while the latter is a suburban site with over 50% vegetation. At both locations the models are compared against sensible and latent heat fluxes measured using the eddy covariance technique, along with snow depth observations. The cold climate experienced by the city causes strong seasonal variations that include snow cover and stable atmospheric conditions. Most of the time the three models are able to account for the differences between the study areas as well as the seasonal and diurnal variability of the energy balance components. However, the performances are not systematic across the modelled components, seasons and surface types. The net all-wave radiation is well simulated, with the greatest uncertainties related to snow-melt timing, when the fraction of snow cover has a key role, particularly in determining the surface albedo. For the turbulent fluxes, more variation between the models is seen which can partly be explained by the different methods in their calculation and partly by surface parameter values. For the sensible heat flux, simulation of wintertime values was the main problem, which also leads to issues in predicting near-surface stabilities particularly at the dense city-centre site. All models have the most difficulties in simulating latent heat flux. This study particularly emphasizes that improvements are needed in the parametrization of anthropogenic heat flux and thermal parameters in winter, snow cover in spring, and evapotranspiration, in order to improve the surface energy balance modelling in cold-climate cities. |
BibTeX:
@article{Karsisto2016,
author = {Karsisto, P. and Fortelius, C. and Demuzere, M. and Grimmond, C. S.B. and Oleson, K. W. and Kouznetsov, R. and Masson, V. and Järvi, L.},
title = {Seasonal surface urban energy balance and wintertime stability simulated using three land-surface models in the high-latitude city Helsinki},
journal = {Quarterly Journal of the Royal Meteorological Society},
publisher = {John Wiley and Sons Ltd},
year = {2016},
volume = {142},
number = {694},
pages = {401--417},
doi = {10.1002/qj.2659}
}
|
| Kasurinen V, Alfredsen K, Ojala A, Pumpanen J, Weyhenmeyer GA, Futter MN, Laudon H and Berninger F (2016), "Modeling nonlinear responses of DOC transport in boreal catchments in Sweden", Water Resources Research., jul, 2016. Vol. 52(7), pp. 4970-4989. Blackwell Publishing Ltd. |
| Abstract: Stream water dissolved organic carbon (DOC) concentrations display high spatial and temporal variation in boreal catchments. Understanding and predicting these patterns is a challenge with great implications for water quality projections and carbon balance estimates. Although several biogeochemical models have been used to estimate stream water DOC dynamics, model biases common during both rain and snow melt-driven events. The parsimonious DOC-model, K-DOC, with 10 calibrated parameters, uses a nonlinear discharge and catchment water storage relationship including soil temperature dependencies of DOC release and consumption. K-DOC was used to estimate the stream water DOC concentrations over 5 years for eighteen nested boreal catchments having total area of 68 km2 (varying from 0.04 to 67.9 km2). The model successfully simulated DOC concentrations during base flow conditions, as well as, hydrological events in catchments dominated by organic and mineral soils reaching NSEs from 0.46 to 0.76. Our semimechanistic model was parsimonious enough to have all parameters estimated using statistical methods. We did not find any clear differences between forest and mire-dominated catchments that could be explained by soil type or tree species composition. However, parameters controlling slow release and consumption of DOC from soil water behaved differently for small headwater catchments (less than 2 km2) than for those that integrate larger areas of different ecosystem types (10–68 km2). Our results emphasize that it is important to account for nonlinear dependencies of both, soil temperature, and catchment water storage, when simulating DOC dynamics of boreal catchments. |
BibTeX:
@article{Kasurinen2016,
author = {Kasurinen, Ville and Alfredsen, Knut and Ojala, Anne and Pumpanen, Jukka and Weyhenmeyer, Gesa A. and Futter, Martyn N. and Laudon, Hjalmar and Berninger, Frank},
title = {Modeling nonlinear responses of DOC transport in boreal catchments in Sweden},
journal = {Water Resources Research},
publisher = {Blackwell Publishing Ltd},
year = {2016},
volume = {52},
number = {7},
pages = {4970--4989},
doi = {10.1002/2015WR018343}
}
|
| Kessler A and Tjiputra J (2016), "The Southern Ocean as a constraint to reduce uncertainty in future ocean carbon sinks", Earth System Dynamics., apr, 2016. Vol. 7(2), pp. 295-312. Copernicus GmbH. |
| Abstract: textlessptextgreaterAbstract. Earth system model (ESM) simulations exhibit large biases compares to observation-based estimates of the present ocean CO2 sink. The inter-model spread in projections increases nearly 2-fold by the end of the 21st century and therefore contributes significantly to the uncertainty of future climate projections. In this study, the Southern Ocean (SO) is shown to be one of the hot-spot regions for future uptake of anthropogenic CO2, characterized by both the solubility pump and biologically mediated carbon drawdown in the spring and summer. We show, by analyzing a suite of fully interactive ESMs simulations from the Coupled Model Intercomparison Project phase 5 (CMIP5) over the 21st century under the high-CO2 Representative Concentration Pathway (RCP) 8.5 scenario, that the SO is the only region where the atmospheric CO2 uptake rate continues to increase toward the end of the 21st century. Furthermore, our study discovers a strong inter-model link between the contemporary CO2 uptake in the Southern Ocean and the projected global cumulated uptake over the 21st century. This strong correlation suggests that models with low (high) carbon uptake rate in the contemporary SO tend to simulate low (high) uptake rate in the future. Nevertheless, our analysis also shows that none of the models fully capture the observed biophysical mechanisms governing the CO2 fluxes in the SO. The inter-model spread for the contemporary CO2 uptake in the Southern Ocean is attributed to the variations in the simulated seasonal cycle of surface pCO2. Two groups of model behavior have been identified. The first one simulates anomalously strong SO carbon uptake, generally due to both too strong a net primary production and too low a surface pCO2 in December–January. The second group simulates an opposite CO2 flux seasonal phase, which is driven mainly by the bias in the sea surface temperature variability. We show that these biases are persistent throughout the 21st century, which highlights the urgent need for a sustained and comprehensive biogeochemical monitoring system in the Southern Ocean to better constrain key processes represented in current model systems.textless/ptextgreater |
BibTeX:
@article{Kessler2016,
author = {Kessler, A. and Tjiputra, J.},
title = {The Southern Ocean as a constraint to reduce uncertainty in future ocean carbon sinks},
journal = {Earth System Dynamics},
publisher = {Copernicus GmbH},
year = {2016},
volume = {7},
number = {2},
pages = {295--312},
url = {https://esd.copernicus.org/articles/7/295/2016/},
doi = {10.5194/esd-7-295-2016}
}
|
| Kieloaho AJ, Pihlatie M, Dominguez Carrasco M, Kanerva S, Parshintsev J, Riekkola ML, Pumpanen J and Heinonsalo J (2016), "Stimulation of soil organic nitrogen pool: The effect of plant and soil organic matter degrading enzymes", Soil Biology and Biochemistry., may, 2016. Vol. 96, pp. 97-106. Elsevier Ltd. |
| Abstract: The majority of nitrogen (N) in boreal forest soils is bound to soil organic matter (SOM) in forms not readily available to plants. Northern boreal forest ecosystems are often N limited, despite atmospheric N deposition, and the utilization of organic N from SOM is of crucial importance to the site productivity. The effect of microbial produced oxidative SOM degrading enzymes (laccase and manganese peroxidases) and proteases on soil N forms and availability was studied in a pot experiment with or without a Scots pine (Pinus sylvestris L.) seedling. The combination of SOM degrading enzymes and proteases decreased the total soil N content and increased the N losses significantly in the absence of the Scots pine seedlings. The total soil N content also decreased in the presence of the Scots pine seedlings, irrespective of the enzyme treatment. Most of the other N parameters studied were not sensitive to enzyme additions, and differed only between planted and non-planted treatments. Our results show that the alkylamine content of boreal forest soil are at the same levels as nitrate. We showed that SOM decomposition, stimulated by oxidative enzyme additions, is a key step in soil organic N utilization, while proteases alone do not increase N use from SOM. Plants stimulate N losses from SOM highlighting the importance of rhizosphere processes in soil C and N cycling. |
BibTeX:
@article{Kieloaho2016,
author = {Kieloaho, Antti Jussi and Pihlatie, Mari and Dominguez Carrasco, Maria and Kanerva, Sanna and Parshintsev, Jevgeni and Riekkola, Marja Liisa and Pumpanen, Jukka and Heinonsalo, Jussi},
title = {Stimulation of soil organic nitrogen pool: The effect of plant and soil organic matter degrading enzymes},
journal = {Soil Biology and Biochemistry},
publisher = {Elsevier Ltd},
year = {2016},
volume = {96},
pages = {97--106},
doi = {10.1016/j.soilbio.2016.01.013}
}
|
| Kiendler-Scharr A, Mensah AA, Friese E, Topping D, Nemitz E, Prevot ASH, Äijälä M, Allan J, Canonaco F, Canagaratna M, Carbone S, Crippa M, Dall Osto M, Day DA, De Carlo P, Di Marco CF, Elbern H, Eriksson A, Freney E, Hao L, Herrmann H, Hildebrandt L, Hillamo R, Jimenez JL, Laaksonen A, McFiggans G, Mohr C, O'Dowd C, Otjes R, Ovadnevaite J, Pandis SN, Poulain L, Schlag P, Sellegri K, Swietlicki E, Tiitta P, Vermeulen A, Wahner A, Worsnop D and Wu HC (2016), "Ubiquity of organic nitrates from nighttime chemistry in the European submicron aerosol", Geophysical Research Letters., jul, 2016. Vol. 43(14), pp. 7735-7744. |
| Abstract: In the atmosphere nighttime removal of volatile organic compounds is initiated to a large extent by reaction with the nitrate radical (NO3) forming organic nitrates which partition between gas and particulate phase. Here we show based on particle phase measurements performed at a suburban site in the Netherlands that organic nitrates contribute substantially to particulate nitrate and organic mass. Comparisons with a chemistry transport model indicate that most of the measured particulate organic nitrates are formed by NO3 oxidation. Using aerosol composition data from three intensive observation periods at numerous measurement sites across Europe, we conclude that organic nitrates are a considerable fraction of fine particulate matter (PM1) at the continental scale. Organic nitrates represent 34% to 44% of measured submicron aerosol nitrate and are found at all urban and rural sites, implying a substantial potential of PM reduction by NOx emission control. |
BibTeX:
@article{Kiendler-Scharr2016,
author = {Kiendler-Scharr, A and Mensah, A A and Friese, E and Topping, D and Nemitz, E and Prevot, A S H and Äijälä, M and Allan, J and Canonaco, F and Canagaratna, M and Carbone, S and Crippa, M and Dall Osto, M and Day, D A and De Carlo, P and Di Marco, C F and Elbern, H and Eriksson, A and Freney, E and Hao, L and Herrmann, H and Hildebrandt, L and Hillamo, R and Jimenez, J L and Laaksonen, A and McFiggans, G and Mohr, C and O'Dowd, C and Otjes, R and Ovadnevaite, J and Pandis, S N and Poulain, L and Schlag, P and Sellegri, K and Swietlicki, E and Tiitta, P and Vermeulen, A and Wahner, A and Worsnop, D and Wu, H C},
title = {Ubiquity of organic nitrates from nighttime chemistry in the European submicron aerosol},
journal = {Geophysical Research Letters},
year = {2016},
volume = {43},
number = {14},
pages = {7735--7744},
url = {http://onlinelibrary.wiley.com/doi/10.1002/2016GL069239/abstract http://doi.wiley.com/10.1002/2016GL069239},
doi = {10.1002/2016GL069239}
}
|
| Koffi EN, Bergamaschi P, Karstens U, Krol M, Segers A, Schmidt M, Levin I, Vermeulen AT, Fisher RE, Kazan V, Klein Baltink H, Lowry D, Manca G, Meijer HAJ, Moncrieff J, Pal S, Ramonet M, Scheeren HA and Williams AG (2016), "Evaluation of the boundary layer dynamics of the TM5 model over Europe", Geoscientific Model Development., sep, 2016. Vol. 9(9), pp. 3137-3160. Copernicus Publications. |
| Abstract: We evaluate the capability of the global atmospheric transport model TM5 to simulate the boundary layer dynamics and associated variability of trace gases close to the surface, using radon (222Rn). Focusing on the European scale, we compare the boundary layer height (BLH) in the TM5 model with observations from the National Oceanic and Atmospheric Admnistration (NOAA) Integrated Global Radiosonde Archive (IGRA) and also with ceilometer and lidar (light detection and ranging) BLH retrievals at two stations. Furthermore, we compare TM5 simulations of 222Rn activity concentrations, using a novel, process-based 222Rn flux map over Europe (Karstens et al., 2015), with harmonised 222Rn measurements at 10 stations. The TM5 model reproduces relatively well the daytime BLH (within 10-20% for most of the stations), except for coastal sites, for which differences are usually larger due to model representation errors. During night, however, TM5 overestimates the shallow nocturnal BLHs, especially for the very low observed BLHs (100m) during summer. The 222Rn activity concentration simulations based on the new 222Rn flux map show significant improvements especially regarding the average seasonal variability, compared to simulations using constant 222Rn fluxes. Nevertheless, the (relative) differences between simulated and observed daytime minimum 222Rn activity concentrations are larger for several stations (on the order of 50%) than the (relative) differences between simulated and observed BLH at noon. Although the nocturnal BLH is often higher in the model than observed, simulated 222Rn nighttime maxima are actually larger at several continental stations. This counterintuitive behaviour points to potential deficiencies of TM5 to correctly simulate the vertical gradients within the nocturnal boundary layer, limitations of the 222Rn flux map, or issues related to the definition of the nocturnal BLH. At several stations the simulated decrease of 222Rn activity concentrations in the morning is faster than observed. In addition, simulated vertical 222Rn activity concentration gradients at Cabauw decrease faster than observations during the morning transition period, and are in general lower than observed gradients during daytime. Although these effects may be partially due to the slow response time of the radon detectors, they clearly point to too fast vertical mixing in the TM5 boundary layer during daytime. Furthermore, the capability of the TM5 model to simulate the diurnal BLH cycle is limited by the current coarse temporal resolution (3h/6h) of the TM5 input meteorology. |
BibTeX:
@article{Koffi2016,
author = {Koffi, E N and Bergamaschi, P and Karstens, U and Krol, M and Segers, A and Schmidt, M and Levin, I and Vermeulen, A T and Fisher, R E and Kazan, V and Klein Baltink, H and Lowry, D and Manca, G and Meijer, H A J and Moncrieff, J and Pal, S and Ramonet, M and Scheeren, H A and Williams, A G},
title = {Evaluation of the boundary layer dynamics of the TM5 model over Europe},
journal = {Geoscientific Model Development},
publisher = {Copernicus Publications},
year = {2016},
volume = {9},
number = {9},
pages = {3137--3160},
url = {http://www.geosci-model-dev-discuss.net/gmd-2016-48/ http://www.geosci-model-dev-discuss.net/gmd-2016-48/gmd-2016-48.pdf http://www.geosci-model-dev.net/9/3137/2016/},
doi = {10.5194/gmd-9-3137-2016}
}
|
| Kooijmans LMJ, Uitslag NAM, Zahniser MS, Nelson DD, Montzka SA and Chen H (2016), "Continuous and high-precision atmospheric concentration measurements of COS, CO2, CO and H2O using a quantum cascade laser spectrometer (QCLS)", Atmospheric Measurement Techniques., nov, 2016. Vol. 9(11), pp. 5293-5314. |
| Abstract: Carbonyl sulfide (COS) has been suggested as a useful tracer for gross primary production as it is taken up by plants in a similar way as CO2. To explore and verify the application of this novel tracer, it is highly desired to develop the ability to perform continuous and high-precision in situ atmospheric measurements of COS and CO2. In this study we have tested a quantum cascade laser spectrometer (QCLS) for its suitability to obtain accurate and high-precision measurements of COS and CO2. The instrument is capable of simultaneously measuring COS, CO2, CO and H2O after including a weak CO absorption line in the extended wavelength range. An optimal background and calibration strategy was developed based on laboratory tests to ensure accurate field measurements. We have derived water vapor correction factors based on a set of laboratory experiments and found that for COS the interference associated with a water absorption line can dominate over the effect of dilution. This interference can be solved mathematically by fitting the COS spectral line separately from the H2O spectral line. Furthermore, we improved the temperature stability of the QCLS by isolating it in an enclosed box and actively cooling its electronics with the same thermoelectric chiller used to cool the laser. The QCLS was deployed at the Lutjewad atmospheric monitoring station (60m; 6°21'E, 53°24'N; 1ma.s.l.) in the Netherlands from July 2014 to April 2015. The QCLS measurements of independent working standards while deployed in the field showed a mean difference with the assigned cylinder value within 3.3ppt COS, 0.05ppm for CO2 and 1.7ppb for CO over a period of 35 days. The different contributions to uncertainty in measurements of COS, CO2 and CO were summarized and the overall uncertainty was determined to be 7.5ppt for COS, 0.23ppm for CO2 and 3.3ppb for CO for 1-minute data. A comparison of in situ QCLS measurements with those from concurrently filled flasks that were subsequently measured by the QCLS showed a difference of -9.7±4.6ppt for COS. Comparison of the QCLS with a cavity ring-down spectrometer showed a difference of 0.12±0.77ppm for CO2 and -0.9±3.8ppb for CO. |
BibTeX:
@article{Kooijmans2016,
author = {Kooijmans, Linda M J and Uitslag, Nelly A M and Zahniser, Mark S and Nelson, David D and Montzka, Stephen A and Chen, Huilin},
title = {Continuous and high-precision atmospheric concentration measurements of COS, CO2, CO and H2O using a quantum cascade laser spectrometer (QCLS)},
journal = {Atmospheric Measurement Techniques},
year = {2016},
volume = {9},
number = {11},
pages = {5293--5314},
url = {http://www.atmos-meas-tech.net/9/5293/2016/},
doi = {10.5194/amt-9-5293-2016}
}
|
| Korrensalo A, Hájek T, Vesala T, Mehtätalo L and Tuittila ES (2016), "Variation in photosynthetic properties among bog plants", Botany., aug, 2016. Vol. 94(12), pp. 1127-1139. Canadian Science Publishing. |
| Abstract: Plant functional types (PFTs) are used to make generalizations in modeling how plants impact ecosystem functioning. In boreal bogs the number of plant species is small, but several PFTs are represented, namely sedges, deciduous and evergreen dwarf-shrubs, as well as hummock, lawn, and hollow Sphagna. Despite the use of PFTs in modeling, the value of PFTs to describe the photosynthetic properties of bog plants has not been systematically studied. We aim to quantify the photosynthetic properties of typical bog plant species and assess how well PFT divisions reflect differences among species. We measured photosynthetic light response and physiological state of photosystem II of 19 species, monthly, over a growing season. Differences were assessed using principal component analysis and mixed models. Photosynthetic properties separated Sphagna into traditional PFTs, of which hollow species had the highest gross photosynthesis. Sphagnum photosynthesis had large seasonal variation, as monthly differences exceeded those among PFTs or species. The photosynthetic properties of vascular plants differed widely among species but did not follow traditional PFTs. Vascular plant seasonal changes were of less importance than interspecific differences. The results justify using PFTs to describe the ability of bog Sphagna to bind carbon, but do not justify the same approach for vascular plants. |
BibTeX:
@article{Korrensalo2016,
author = {Korrensalo, Aino and Hájek, Tomáš and Vesala, Timo and Mehtätalo, Lauri and Tuittila, Eeva Stiina},
title = {Variation in photosynthetic properties among bog plants},
journal = {Botany},
publisher = {Canadian Science Publishing},
year = {2016},
volume = {94},
number = {12},
pages = {1127--1139},
doi = {10.1139/cjb-2016-0117}
}
|
| Kuglerová L, Dynesius M, Laudon H and Jansson R (2016), "Relationships Between Plant Assemblages and Water Flow Across a Boreal Forest Landscape: A Comparison of Liverworts, Mosses, and Vascular Plants", Ecosystems., jan, 2016. Vol. 19(1), pp. 170-184. |
| Abstract: The distribution of water across landscapes affects the diversity and composition of ecological communities, as demonstrated by studies on variation in vascular plant communities along river networks and in relation to groundwater. However, non-vascular plants have been neglected in this regard. Bryophytes are dominant components of boreal flora, performing many ecosystem functions and affecting ecosystem processes, but how their diversity and species composition vary across catchments is poorly known. We asked how terrestrial assemblages of mosses and liverworts respond to variation in (i) catchment size, going from upland-forest to riparian settings along increasingly large streams and (ii) groundwater discharge conditions. We compared the patterns found for liverworts and mosses to vascular plants in the same set of study plots. Species richness of vascular plants and mosses increased with catchment size, whereas liverworts peaked along streams of intermediate size. All three taxonomic groups responded to groundwater discharge in riparian zones by maintaining high species richness further from the stream channel. Groundwater discharge thus provided riparian-like habitat further away from the streams and also in upland-forest sites compared to the non-discharge counterparts. In addition, soil chemistry (C:N ratio, pH) and light availability were important predictors of vascular plant species richness. Mosses and liverworts responded to the availability of specific substrates (stones and topographic hollows), but were also affected by soil C:N. Overall, assemblages of mosses and vascular plants exhibited many similarities in how they responded to hydrological gradients, whereas the patterns of liverworts differed from the other two groups. |
BibTeX:
@article{Kuglerova2016,
author = {Kuglerová, Lenka and Dynesius, Mats and Laudon, Hjalmar and Jansson, Roland},
title = {Relationships Between Plant Assemblages and Water Flow Across a Boreal Forest Landscape: A Comparison of Liverworts, Mosses, and Vascular Plants},
journal = {Ecosystems},
year = {2016},
volume = {19},
number = {1},
pages = {170--184},
url = {http://link.springer.com/10.1007/s10021-015-9927-0},
doi = {10.1007/s10021-015-9927-0}
}
|
| Landschützer P, Gruber N and Bakker DC (2016), "Decadal variations and trends of the global ocean carbon sink", Global Biogeochemical Cycles., oct, 2016. Vol. 30(10), pp. 1396-1417. Blackwell Publishing Ltd. |
| Abstract: We investigate the variations of the ocean CO2 sink during the past three decades using global surface ocean maps of the partial pressure of CO2 reconstructed from observations contained in the Surface Ocean CO2 Atlas Version 2. To create these maps, we used the neural network-based data interpolation method of Landschützer et al. (2014) but extended the work in time from 1998 to 2011 to the period from 1982 through 2011. Our results suggest strong decadal variations in the global ocean carbon sink around a long-term increase that corresponds roughly to that expected from the rise in atmospheric CO2. The sink is estimated to have weakened during the 1990s toward a minimum uptake of only −0.8 ± 0.5 Pg C yr−1 in 2000 and thereafter to have strengthened considerably to rates of more than −2.0 ± 0.5 Pg C yr−1. These decadal variations originate mostly from the extratropical oceans, while the tropical regions contribute primarily to interannual variations. Changes in sea surface temperature affecting the solubility of CO2 explain part of these variations, particularly at subtropical latitudes. But most of the higher-latitude changes are attributed to modifications in the surface concentration of dissolved inorganic carbon and alkalinity, induced by decadal variations in atmospheric forcing, with patterns that are reminiscent of those of the Northern and Southern Annular Modes. These decadal variations lead to a substantially smaller cumulative anthropogenic CO2 uptake of the ocean over the 1982 through 2011 period (reduction of 7.5 ± 5.5 Pg C) relative to that derived by the Global Carbon Budget. |
BibTeX:
@article{Landschutzer2016,
author = {Landschützer, Peter and Gruber, Nicolas and Bakker, Dorothee C.E.},
title = {Decadal variations and trends of the global ocean carbon sink},
journal = {Global Biogeochemical Cycles},
publisher = {Blackwell Publishing Ltd},
year = {2016},
volume = {30},
number = {10},
pages = {1396--1417},
url = {https://agupubs.onlinelibrary.wiley.com/doi/full/10.1002/2015GB005359 https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1002/2015GB005359 https://agupubs.onlinelibrary.wiley.com/doi/10.1002/2015GB005359},
doi = {10.1002/2015GB005359}
}
|
| Lappalainen HK, Kerminen VM, Petäjä T, Kurten T, Baklanov A, Shvidenko A, Bäck J, Vihma T, Alekseychik P, Andreae MO, Arnold SR, Arshinov M, Asmi E, Belan B, Bobylev L, Chalov S, Cheng Y, Chubarova N, De Leeuw G, Ding A, Dobrolyubov S, Dubtsov S, Dyukarev E, Elansky N, Eleftheriadis K, Esau I, Filatov N, Flint M, Fu C, Glezer O, Gliko A, Heimann M, Holtslag AA, Hõrrak U, Janhunen J, Juhola S, Järvi L, Järvinen H, Kanukhina A, Konstantinov P, Kotlyakov V, Kieloaho AJ, Komarov AS, Kujansuu J, Kukkonen I, Duplissy EM, Laaksonen A, Laurila T, Lihavainen H, Lisitzin A, Mahura A, Makshtas A, Mareev E, Mazon S, Matishov D, Melnikov V, Mikhailov E, Moisseev D, Nigmatulin R, Noe SM, Ojala A, Pihlatie M, Popovicheva O, Pumpanen J, Regerand T, Repina I, Shcherbinin A, Shevchenko V, Sipilä M, Skorokhod A, Spracklen DV, Su H, Subetto DA, Sun J, Terzhevik AY, Timofeyev Y, Troitskaya Y, Tynkkynen VP, Kharuk VI, Zaytseva N, Zhang J, Viisanen Y, Vesala T, Hari P, Christen Hansson H, Matvienko GG, Kasimov NS, Guo H, Bondur V, Zilitinkevich S and Kulmala M (2016), "Pan-Eurasian Experiment (PEEX): Towards a holistic understanding of the feedbacks and interactions in the land-Atmosphere-ocean-society continuum in the northern Eurasian region", Atmospheric Chemistry and Physics., nov, 2016. Vol. 16(22), pp. 14421-14461. Copernicus GmbH. |
| Abstract: The northern Eurasian regions and Arctic Ocean will very likely undergo substantial changes during the next decades. The Arctic-boreal natural environments play a crucial role in the global climate via albedo change, carbon sources and sinks as well as atmospheric aerosol production from biogenic volatile organic compounds. Furthermore, it is expected that global trade activities, demographic movement, and use of natural resources will be increasing in the Arctic regions. There is a need for a novel research approach, which not only identifies and tackles the relevant multi-disciplinary research questions, but also is able to make a holistic system analysis of the expected feedbacks. In this paper, we introduce the research agenda of the Pan-Eurasian Experiment (PEEX), a multi-scale, multi-disciplinary and international program started in 2012 (textlessa hrefCombining double low line"https://www.atm.helsinki.fi/peex/" targetCombining double low line"blank"textgreaterhttps://www.atm.helsinki.fi/peex/textless/atextgreater). PEEX sets a research approach by which large-scale research topics are investigated from a system perspective and which aims to fill the key gaps in our understanding of the feedbacks and interactions between the land-Atmosphere-Aquatic-society continuum in the northern Eurasian region. We introduce here the state of the art for the key topics in the PEEX research agenda and present the future prospects of the research, which we see relevant in this context. |
BibTeX:
@article{Lappalainen2016,
author = {Lappalainen, Hanna K. and Kerminen, Veli Matti and Petäjä, Tuukka and Kurten, Theo and Baklanov, Aleksander and Shvidenko, Anatoly and Bäck, Jaana and Vihma, Timo and Alekseychik, Pavel and Andreae, Meinrat O. and Arnold, Stephen R. and Arshinov, Mikhail and Asmi, Eija and Belan, Boris and Bobylev, Leonid and Chalov, Sergey and Cheng, Yafang and Chubarova, Natalia and De Leeuw, Gerrit and Ding, Aijun and Dobrolyubov, Sergey and Dubtsov, Sergei and Dyukarev, Egor and Elansky, Nikolai and Eleftheriadis, Kostas and Esau, Igor and Filatov, Nikolay and Flint, Mikhail and Fu, Congbin and Glezer, Olga and Gliko, Aleksander and Heimann, Martin and Holtslag, Albert A.M. and Hõrrak, Urmas and Janhunen, Juha and Juhola, Sirkku and Järvi, Leena and Järvinen, Heikki and Kanukhina, Anna and Konstantinov, Pavel and Kotlyakov, Vladimir and Kieloaho, Antti Jussi and Komarov, Alexander S. and Kujansuu, Joni and Kukkonen, Ilmo and Duplissy, Ella Maria and Laaksonen, Ari and Laurila, Tuomas and Lihavainen, Heikki and Lisitzin, Alexander and Mahura, Alexsander and Makshtas, Alexander and Mareev, Evgeny and Mazon, Stephany and Matishov, Dmitry and Melnikov, Vladimir and Mikhailov, Eugene and Moisseev, Dmitri and Nigmatulin, Robert and Noe, Steffen M. and Ojala, Anne and Pihlatie, Mari and Popovicheva, Olga and Pumpanen, Jukka and Regerand, Tatjana and Repina, Irina and Shcherbinin, Aleksei and Shevchenko, Vladimir and Sipilä, Mikko and Skorokhod, Andrey and Spracklen, Dominick V. and Su, Hang and Subetto, Dmitry A. and Sun, Junying and Terzhevik, Arkady Y. and Timofeyev, Yuri and Troitskaya, Yuliya and Tynkkynen, Veli Pekka and Kharuk, Viacheslav I. and Zaytseva, Nina and Zhang, Jiahua and Viisanen, Yrjö and Vesala, Timo and Hari, Pertti and Christen Hansson, Hans and Matvienko, Gennady G. and Kasimov, Nikolai S. and Guo, Huadong and Bondur, Valery and Zilitinkevich, Sergej and Kulmala, Markku},
title = {Pan-Eurasian Experiment (PEEX): Towards a holistic understanding of the feedbacks and interactions in the land-Atmosphere-ocean-society continuum in the northern Eurasian region},
journal = {Atmospheric Chemistry and Physics},
publisher = {Copernicus GmbH},
year = {2016},
volume = {16},
number = {22},
pages = {14421--14461},
doi = {10.5194/acp-16-14421-2016}
}
|
| Launiainen S, Katul GG, Kolari P, Lindroth A, Lohila A, Aurela M, Varlagin A, Grelle A and Vesala T (2016), "Do the energy fluxes and surface conductance of boreal coniferous forests in Europe scale with leaf area?", Global Change Biology., dec, 2016. Vol. 22(12), pp. 4096-4113. Blackwell Publishing Ltd. |
| Abstract: Earth observing systems are now routinely used to infer leaf area index (LAI) given its significance in spatial aggregation of land surface fluxes. Whether LAI is an appropriate scaling parameter for daytime growing season energy budget, surface conductance (Gs), water- and light-use efficiency and surface–atmosphere coupling of European boreal coniferous forests was explored using eddy-covariance (EC) energy and CO2 fluxes. The observed scaling relations were then explained using a biophysical multilayer soil–vegetation–atmosphere transfer model as well as by a bulk Gs representation. The LAI variations significantly alter radiation regime, within-canopy microclimate, sink/source distributions of CO2, H2O and heat, and forest floor fluxes. The contribution of forest floor to ecosystem-scale energy exchange is shown to decrease asymptotically with increased LAI, as expected. Compared with other energy budget components, dry-canopy evapotranspiration (ET) was reasonably ‘conservative' over the studied LAI range 0.5–7.0 m2 m−2. Both ET and Gs experienced a minimum in the LAI range 1–2 m2 m−2 caused by opposing nonproportional response of stomatally controlled transpiration and ‘free' forest floor evaporation to changes in canopy density. The young forests had strongest coupling with the atmosphere while stomatal control of energy partitioning was strongest in relatively sparse (LAI ˜2 m2 m−2) pine stands growing on mineral soils. The data analysis and model results suggest that LAI may be an effective scaling parameter for net radiation and its partitioning but only in sparse stands (LAI textless3 m2 m−2). This finding emphasizes the significance of stand-replacing disturbances on the controls of surface energy exchange. In denser forests, any LAI dependency varies with physiological traits such as light-saturated water-use efficiency. The results suggest that incorporating species traits and site conditions are necessary when LAI is used in upscaling energy exchanges of boreal coniferous forests. |
BibTeX:
@article{Launiainen2016,
author = {Launiainen, Samuli and Katul, Gabriel G. and Kolari, Pasi and Lindroth, Anders and Lohila, Annalea and Aurela, Mika and Varlagin, Andrej and Grelle, Achim and Vesala, Timo},
title = {Do the energy fluxes and surface conductance of boreal coniferous forests in Europe scale with leaf area?},
journal = {Global Change Biology},
publisher = {Blackwell Publishing Ltd},
year = {2016},
volume = {22},
number = {12},
pages = {4096--4113},
doi = {10.1111/gcb.13497}
}
|
| Leach JA, Larsson A, Wallin MB, Nilsson MB and Laudon H (2016), "Twelve year interannual and seasonal variability of stream carbon export from a boreal peatland catchment", Journal of Geophysical Research: Biogeosciences., jul, 2016. Vol. 121(7), pp. 1851-1866. Blackwell Publishing Ltd. |
| Abstract: Understanding stream carbon export dynamics is needed to accurately predict how the carbon balance of peatland catchments will respond to climatic and environmental change. We used a 12 year record (2003–2014) of continuous streamflow and manual spot measurements of total organic carbon (TOC), dissolved inorganic carbon (DIC), methane (CH4), and organic carbon quality (carbon-specific ultraviolet absorbance at 254 nm per dissolved organic carbon) to assess interannual and seasonal variability in stream carbon export for a peatland catchment (70% mire and 30% forest cover) in northern Sweden. Mean annual total carbon export for the 12 year period was 12.2 gCm−2 yr−1, but individual years ranged between 6 and 18 gCm−2 yr−1. TOC, which was primarily composed of dissolved organic carbon (textgreater99%), was the dominant form of carbon being exported, comprising 63% to 79% of total annual exports, and DIC contributed between 19% and 33%. CH4 made up less than 5% of total export. When compared to previously published annual net ecosystem exchange (NEE) for the studied peatland system, stream carbon export typically accounted for 12 to 50% of NEE for most years. However, in 2006 stream carbon export accounted for 63 to 90% (estimated uncertainty range) of NEE due to a dry summer which suppressed NEE, followed by a wet autumn that resulted in considerable stream export. Runoff exerted a primary control on stream carbon export from this catchment; however, our findings suggest that seasonal variations in biologic and hydrologic processes responsible for production and transport of carbon within the peatland were secondary influences on stream carbon export. Consideration of these seasonal dynamics is needed when predicting stream carbon export response to environmental change. |
BibTeX:
@article{Leach2016,
author = {Leach, J. A. and Larsson, A. and Wallin, M. B. and Nilsson, M. B. and Laudon, H.},
title = {Twelve year interannual and seasonal variability of stream carbon export from a boreal peatland catchment},
journal = {Journal of Geophysical Research: Biogeosciences},
publisher = {Blackwell Publishing Ltd},
year = {2016},
volume = {121},
number = {7},
pages = {1851--1866},
doi = {10.1002/2016JG003357}
}
|
| Legout A, van der Heijden G, Jaffrain J, Boudot J-P and Ranger J (2016), "Tree species effects on solution chemistry and major element fluxes: A case study in the Morvan (Breuil, France)", Forest Ecology and Management., oct, 2016. Vol. 378, pp. 244-258. |
BibTeX:
@article{Legout2016,
author = {Legout, Arnaud and van der Heijden, Gregory and Jaffrain, Jérôme and Boudot, Jean-Pierre and Ranger, Jacques},
title = {Tree species effects on solution chemistry and major element fluxes: A case study in the Morvan (Breuil, France)},
journal = {Forest Ecology and Management},
year = {2016},
volume = {378},
pages = {244--258},
url = {https://linkinghub.elsevier.com/retrieve/pii/S0378112716303498},
doi = {10.1016/j.foreco.2016.07.003}
}
|
| Le Quéré C, Andrew RM, Canadell JG, Sitch S, Ivar Korsbakken J, Peters GP, Manning AC, Boden TA, Tans PP, Houghton RA, Keeling RF, Alin S, Andrews OD, Anthoni P, Barbero L, Bopp L, Chevallier F, Chini LP, Ciais P, Currie K, Delire C, Doney SC, Friedlingstein P, Gkritzalis T, Harris I, Hauck J, Haverd V, Hoppema M, Klein Goldewijk K, Jain AK, Kato E, Körtzinger A, Landschützer P, Lefèvre N, Lenton A, Lienert S, Lombardozzi D, Melton JR, Metzl N, Millero F, Monteiro PMS, Munro DR, Nabel JEMS, Nakaoka SI, O'Brien K, Olsen A, Omar AM, Ono T, Pierrot D, Poulter B, Rödenbeck C, Salisbury J, Schuster U, Schwinger J, Séférian R, Skjelvan I, Stocker BD, Sutton AJ, Takahashi T, Tian H, Tilbrook B, Van Der Laan-Luijkx IT, Van Der Werf GR, Viovy N, Walker AP, Wiltshire AJ and Zaehle S (2016), "Global Carbon Budget 2016", Earth System Science Data., nov, 2016. Vol. 8(2), pp. 605-649. |
| Abstract: Accurate assessment of anthropogenic carbon dioxide (CO2) emissions and their redistribution among the atmosphere, ocean, and terrestrial biosphere-the "global carbon budget"-is important to better understand the global carbon cycle, support the development of climate policies, and project future climate change. Here we describe data sets and methodology to quantify all major components of the global carbon budget, including their uncertainties, based on the combination of a range of data, algorithms, statistics, and model estimates and their interpretation by a broad scientific community. We discuss changes compared to previous estimates and consistency within and among components, alongside methodology and data limitations. CO2 emissions from fossil fuels and industry (EFF) are based on energy statistics and cement production data, respectively, while emissions from land-use change (ELUC), mainly deforestation, are based on combined evidence from land-cover change data, fire activity associated with deforestation, and models. The global atmospheric CO2 concentration is measured directly and its rate of growth (GATM) is computed from the annual changes in concentration. The mean ocean CO2 sink (SOCEAN) is based on observations from the 1990s, while the annual anomalies and trends are estimated with ocean models. The variability in SOCEAN is evaluated with data products based on surveys of ocean CO2 measurements. The global residual terrestrial CO2 sink (SLAND) is estimated by the difference of the other terms of the global carbon budget and compared to results of independent dynamic global vegetation models. We compare the mean land and ocean fluxes and their variability to estimates from three atmospheric inverse methods for three broad latitude bands. All uncertainties are reported as ± reflecting the current capacity to characterise the annual estimates of each component of the global carbon budget. For the last decade available (2006-2015), EFF was 9.3±0.5 GtC yr-1, ELUC 1.0±0.5 GtC yr-1, GATM 4.5±0.1 GtC yr-1, SOCEAN 2.6±0.5 GtC yr-1, and SLAND 3.1±0.9 GtC yr-1. For year 2015 alone, the growth in EFF was approximately zero and emissions remained at 9.9±0.5 GtC yr-1, showing a slowdown in growth of these emissions compared to the average growth of 1.8%yr-1 that took place during 2006-2015. Also, for 2015, ELUC was 1.3±0.5 GtC yr-1, GATM was 6.3±0.2 GtC yr-1, SOCEAN was 3.0±0.5 GtC yr-1, and SLAND was 1.9±0.9 GtC yr-1. GATM was higher in 2015 compared to the past decade (2006-2015), reflecting a smaller SLAND for that year. The global atmospheric CO2 concentration reached 399.4±0.1 ppm averaged over 2015. For 2016, preliminary data indicate the continuation of low growth in EFF with C0.2% (range of-1.0 to C1.8 %) based on national emissions projections for China and USA, and projections of gross domestic product corrected for recent changes in the carbon intensity of the economy for the rest of the world. In spite of the low growth of EFF in 2016, the growth rate in atmospheric CO2 concentration is expected to be relatively high because of the persistence of the smaller residual terrestrial sink (SLAND) in response to El Ninbackslash˜o conditions of 2015-2016. From this projection of EFF and assumed constant ELUC for 2016, cumulative emissions of CO2 will reach 565±55 GtC (2075±205 GtCO2) for 1870-2016, about 75% from EFF and 25% from ELUC. This living data update documents changes in the methods and data sets used in this new carbon budget compared with previous publications of this data set (Le Quéré et al., 2015b, a, 2014, 2013). All observations presented here can be downloaded from the Carbon Dioxide Information Analysis Center. |
BibTeX:
@article{LeQuere2016,
author = {Le Quéré, Corinne and Andrew, Robbie M and Canadell, Josep G and Sitch, Stephen and Ivar Korsbakken, Jan and Peters, Glen P and Manning, Andrew C and Boden, Thomas A and Tans, Pieter P and Houghton, Richard A and Keeling, Ralph F and Alin, Simone and Andrews, Oliver D and Anthoni, Peter and Barbero, Leticia and Bopp, Laurent and Chevallier, Frédéric and Chini, Louise P and Ciais, Philippe and Currie, Kim and Delire, Christine and Doney, Scott C and Friedlingstein, Pierre and Gkritzalis, Thanos and Harris, Ian and Hauck, Judith and Haverd, Vanessa and Hoppema, Mario and Klein Goldewijk, Kees and Jain, Atul K and Kato, Etsushi and Körtzinger, Arne and Landschützer, Peter and Lefèvre, Nathalie and Lenton, Andrew and Lienert, Sebastian and Lombardozzi, Danica and Melton, Joe R and Metzl, Nicolas and Millero, Frank and Monteiro, Pedro M S and Munro, David R and Nabel, Julia E M S and Nakaoka, Shin Ichiro and O'Brien, Kevin and Olsen, Are and Omar, Abdirahman M and Ono, Tsuneo and Pierrot, Denis and Poulter, Benjamin and Rödenbeck, Christian and Salisbury, Joe and Schuster, Ute and Schwinger, Jörg and Séférian, Roland and Skjelvan, Ingunn and Stocker, Benjamin D and Sutton, Adrienne J and Takahashi, Taro and Tian, Hanqin and Tilbrook, Bronte and Van Der Laan-Luijkx, Ingrid T and Van Der Werf, Guido R and Viovy, Nicolas and Walker, Anthony P and Wiltshire, Andrew J and Zaehle, Sönke},
title = {Global Carbon Budget 2016},
journal = {Earth System Science Data},
year = {2016},
volume = {8},
number = {2},
pages = {605--649},
url = {http://www.earth-syst-sci-data.net/8/605/2016/},
doi = {10.5194/essd-8-605-2016}
}
|
| Li T, Raivonen M, Alekseychik P, Aurela M, Lohila A, Zheng X, Zhang Q, Wang G, Mammarella I, Rinne J, Yu L, Xie B, Vesala T and Zhang W (2016), "Importance of vegetation classes in modeling CH4 emissions from boreal and subarctic wetlands in Finland", Science of the Total Environment., dec, 2016. Vol. 572, pp. 1111-1122. Elsevier B.V.. |
| Abstract: Boreal/arctic wetlands are dominated by diverse plant species, which vary in their contribution to CH4 production, oxidation and transport processes. Earlier studies have often lumped the processes all together, which may induce large uncertainties into the results. We present a novel model, which includes three vegetation classes and can be used to simulate CH4 emissions from boreal and arctic treeless wetlands. The model is based on an earlier biogeophysical model, CH4MODwetland. We grouped the vegetation as graminoids, shrubs and Sphagnum and recalibrated the vegetation parameters according to their different CH4 production, oxidation and transport capacities. Then, we used eddy-covariance-based CH4 flux observations from a boreal (Siikaneva) and a subarctic fen (Lompolojänkkä) in Finland to validate the model. The results showed that the recalibrated model could generally simulate the seasonal patterns of the Finnish wetlands with different plant communities. The comparison between the simulated and measured daily CH4 fluxes resulted in a correlation coefficient (R2) of 0.82 with a slope of 1.0 and an intercept of − 0.1 mg m− 2 h− 1 for the Siikaneva site (n = 2249, p textless 0.001) and an R2 of 0.82 with a slope of 1.0 and an intercept of 0.0 mg m− 2 h− 1 for the Lompolojänkkä site (n = 1826, p textless 0.001). Compared with the original model, the recalibrated model in this study significantly improved the model efficiency (EF), from − 5.5 to 0.8 at the Siikaneva site and from − 0.4 to 0.8 at the Lompolojänkkä site. The simulated annual CH4 emissions ranged from 7 to 24 g m− 2 yr− 1, which was consistent with the observations (7–22 g m− 2 yr− 1). However, there are some discrepancies between the simulated and observed daily CH4 fluxes for the Siikaneva site (RMSE = 50.0%) and the Lompolojänkkä site (RMSE = 47.9%). Model sensitivity analysis showed that increasing the proportion of the graminoids would significantly increase the CH4 emission levels. Our study demonstrated that the parameterization of the different vegetation processes was important in estimating long-term wetland CH4 emissions. |
BibTeX:
@article{Li2016,
author = {Li, Tingting and Raivonen, Maarit and Alekseychik, Pavel and Aurela, Mika and Lohila, Annalea and Zheng, Xunhua and Zhang, Qing and Wang, Guocheng and Mammarella, Ivan and Rinne, Janne and Yu, Lijun and Xie, Baohua and Vesala, Timo and Zhang, Wen},
title = {Importance of vegetation classes in modeling CH4 emissions from boreal and subarctic wetlands in Finland},
journal = {Science of the Total Environment},
publisher = {Elsevier B.V.},
year = {2016},
volume = {572},
pages = {1111--1122},
doi = {10.1016/j.scitotenv.2016.08.020}
}
|
| Li H, Ilyina T, Müller WA and Sienz F (2016), "Decadal predictions of the North Atlantic CO2 uptake", Nature Communications., mar, 2016. Vol. 7(1), pp. 1-7. Nature Publishing Group. |
| Abstract: As a major CO2 sink, the North Atlantic, especially its subpolar gyre region, is essential for the global carbon cycle. Decadal fluctuations of CO2 uptake in the North Atlantic subpolar gyre region are associated with the evolution of the North Atlantic Oscillation, the Atlantic meridional overturning circulation, ocean mixing and sea surface temperature anomalies. While variations in the physical state of the ocean can be predicted several years in advance by initialization of Earth system models, predictability of CO2 uptake has remained unexplored. Here we investigate the predictability of CO2 uptake variations by initialization of the MPI-ESM decadal prediction system. We find large multi-year variability in oceanic CO2 uptake and demonstrate that its potential predictive skill in the western subpolar gyre region is up to 4-7 years. The predictive skill is mainly maintained in winter and is attributed to the improved physical state of the ocean. |
BibTeX:
@article{Li2016a,
author = {Li, Hongmei and Ilyina, Tatiana and Müller, Wolfgang A. and Sienz, Frank},
title = {Decadal predictions of the North Atlantic CO2 uptake},
journal = {Nature Communications},
publisher = {Nature Publishing Group},
year = {2016},
volume = {7},
number = {1},
pages = {1--7},
url = {www.nature.com/naturecommunications},
doi = {10.1038/ncomms11076}
}
|
| Li W, Ciais P, Wang Y, Peng S, Broquet G, Ballantyne AP, Canadell JG, Cooper L, Friedlingstein P, Le Quéré C, Myneni RB, Peters GP, Piao S and Pongratz J (2016), "Reducing uncertainties in decadal variability of the global carbon budget with multiple datasets", Proceedings of the National Academy of Sciences of the United States of America., nov, 2016. Vol. 113(46), pp. 13104-13108. National Academy of Sciences. |
| Abstract: Conventional calculations of the global carbon budget infer the land sink as a residual between emissions, atmospheric accumulation, and the ocean sink. Thus, the land sink accumulates the errors from the other flux terms and bears the largest uncertainty. Here, we present a Bayesian fusion approach that combines multiple observations in different carbon reservoirs to optimize the land (B) and ocean (O) carbon sinks, land use change emissions (L), and indirectly fossil fuel emissions (F) from 1980 to 2014. Compared with the conventional approach, Bayesian optimization decreases the uncertainties in B by 41% and in O by 46%. The L uncertainty decreases by 47%, whereas F uncertainty is marginally improved through the knowledge of natural fluxes. Both ocean and net land uptake (B + L) rates have positive trends of 29 ± 8 and 37 ± 17 Tg Ctextperiodcenteredy-2 since 1980, respectively. Our Bayesian fusion of multiple observations reduces uncertainties, thereby allowing us to isolate important variability in global carbon cycle processes. |
BibTeX:
@article{Li2016b,
author = {Li, Wei and Ciais, Philippe and Wang, Yilong and Peng, Shushi and Broquet, Grégoire and Ballantyne, Ashley P. and Canadell, Josep G. and Cooper, Leila and Friedlingstein, Pierre and Le Quéré, Corinne and Myneni, Ranga B. and Peters, Glen P. and Piao, Shilong and Pongratz, Julia},
title = {Reducing uncertainties in decadal variability of the global carbon budget with multiple datasets},
journal = {Proceedings of the National Academy of Sciences of the United States of America},
publisher = {National Academy of Sciences},
year = {2016},
volume = {113},
number = {46},
pages = {13104--13108},
url = {www.pnas.org/cgi/doi/10.1073/pnas.1603956113},
doi = {10.1073/pnas.1603956113}
}
|
| Logue JB, Stedmon CA, Kellerman AM, Nielsen NJ, Andersson AF, Laudon H, Lindström ES and Kritzberg ES (2016), "Experimental insights into the importance of aquatic bacterial community composition to the degradation of dissolved organic matter", ISME Journal., mar, 2016. Vol. 10(3), pp. 533-545. |
| Abstract: Bacteria play a central role in the cycling of carbon, yet our understanding of the relationship between the taxonomic composition and the degradation of dissolved organic matter (DOM) is still poor. In this experimental study, we were able to demonstrate a direct link between community composition and ecosystem functioning in that differently structured aquatic bacterial communities differed in their degradation of terrestrially derived DOM. Although the same amount of carbon was processed, both the temporal pattern of degradation and the compounds degraded differed among communities. We, moreover, uncovered that low-molecular-weight carbon was available to all communities for utilisation, whereas the ability to degrade carbon of greater molecular weight was a trait less widely distributed. Finally, whereas the degradation of either low- or high-molecular-weight carbon was not restricted to a single phylogenetic clade, our results illustrate that bacterial taxa of similar phylogenetic classification differed substantially in their association with the degradation of DOM compounds. Applying techniques that capture the diversity and complexity of both bacterial communities and DOM, our study provides new insight into how the structure of bacterial communities may affect processes of biogeochemical significance. |
BibTeX:
@article{Logue2016,
author = {Logue, Jürg B and Stedmon, Colin A and Kellerman, Anne M and Nielsen, Nikoline J and Andersson, Anders F and Laudon, Hjalmar and Lindström, Eva S and Kritzberg, Emma S},
title = {Experimental insights into the importance of aquatic bacterial community composition to the degradation of dissolved organic matter},
journal = {ISME Journal},
year = {2016},
volume = {10},
number = {3},
pages = {533--545},
url = {http://www.nature.com/articles/ismej2015131},
doi = {10.1038/ismej.2015.131}
}
|
| Lohila A, Aalto T, Aurela M, Hatakka J, Tuovinen JP, Kilkki J, Penttilä T, Vuorenmaa J, Hänninen P, Sutinen R, Viisanen Y and Laurila T (2016), "Large contribution of boreal upland forest soils to a catchment-scale CH4 balance in a wet year", Geophysical Research Letters., mar, 2016. Vol. 43(6), pp. 2946-2953. Blackwell Publishing Ltd. |
| Abstract: Upland forest soils affect the atmospheric methane (CH4) balance, not only through the soil sink but also due to episodic high emissions in wet conditions. We measured methane fluxes and found that during a wet fall the forest soil turned from a CH4 sink into a large source for several months, while the CH4 emissions from a nearby wetland did not increase. When upscaled to the whole catchment area the contribution of forests amounted to 60% of the annual CH4 emission from the wetlands, while in a normal year the forest soil consumes 10% of the wetland emission. The period of high upland soil emission was also captured by the nearby atmospheric concentration measurement station. Since the land cover within the catchment is representative of larger regions, our findings imply that upland forests in the boreal zone constitute an important part in the global CH4 cycle not previously accounted for. |
BibTeX:
@article{Lohila2016,
author = {Lohila, Annalea and Aalto, Tuula and Aurela, Mika and Hatakka, Juha and Tuovinen, Juha Pekka and Kilkki, Juho and Penttilä, Timo and Vuorenmaa, Jussi and Hänninen, Pekka and Sutinen, Raimo and Viisanen, Yrjö and Laurila, Tuomas},
title = {Large contribution of boreal upland forest soils to a catchment-scale CH4 balance in a wet year},
journal = {Geophysical Research Letters},
publisher = {Blackwell Publishing Ltd},
year = {2016},
volume = {43},
number = {6},
pages = {2946--2953},
doi = {10.1002/2016GL067718}
}
|
| Machacova K, Bäck J, Vanhatalo A, Halmeenmäki E, Kolari P, Mammarella I, Pumpanen J, Acosta M, Urban O and Pihlatie M (2016), "Pinus sylvestris as a missing source of nitrous oxide and methane in boreal forest", Scientific Reports., mar, 2016. Vol. 6 Nature Publishing Group. |
| Abstract: Boreal forests comprise 73% of the world's coniferous forests. Based on forest floor measurements, they have been considered a significant natural sink of methane (CH4) and a natural source of nitrous oxide (N2O), both of which are important greenhouse gases. However, the role of trees, especially conifers, in ecosystem N2O and CH4 exchange is only poorly understood. We show for the first time that mature Scots pine (Pinus sylvestris L.) trees consistently emit N2O and CH4 from both stems and shoots. The shoot fluxes of N2O and CH4 exceeded the stem flux rates by 16 and 41 times, respectively. Moreover, higher stem N2O and CH4 fluxes were observed from wet than from dry areas of the forest. The N2O release from boreal pine forests may thus be underestimated and the uptake of CH4 may be overestimated when ecosystem flux calculations are based solely on forest floor measurements. The contribution of pine trees to the N2O and CH4 exchange of the boreal pine forest seems to increase considerably under high soil water content, thus highlighting the urgent need to include tree-emissions in greenhouse gas emission inventories. |
BibTeX:
@article{Machacova2016,
author = {Machacova, Katerina and Bäck, Jaana and Vanhatalo, Anni and Halmeenmäki, Elisa and Kolari, Pasi and Mammarella, Ivan and Pumpanen, Jukka and Acosta, Manuel and Urban, Otmar and Pihlatie, Mari},
title = {Pinus sylvestris as a missing source of nitrous oxide and methane in boreal forest},
journal = {Scientific Reports},
publisher = {Nature Publishing Group},
year = {2016},
volume = {6},
doi = {10.1038/srep23410}
}
|
| Mamadou O, Gourlez de la Motte L, De Ligne A, Heinesch B and Aubinet M (2016), "Sensitivity of the annual net ecosystem exchange to the cospectral model used for high frequency loss corrections at a grazed grassland site", Agricultural and Forest Meteorology., nov, 2016. Vol. 228-229, pp. 360-369. |
| Abstract: Given the increasing use of the eddy covariance technique to estimate CO2 fluxes, more attention needs to be paid to the measurement method used. Among other procedures, the way high frequency loss corrections are established and, more particularly, the choice of the cospectrum shape that is used to implement the correction appears particularly important in this regard. In this study, we compared three approaches to high frequency loss correction for CO2 fluxes measured by a closed path eddy covariance system and evaluated their impact on the carbon balance at the Dorinne Terrestrial Observatory (DTO), an intensively grazed grassland site in Belgium. In the first approach, the computation of correction factors was based on the local cospectra, whereas the other two were based on Kansas cospectra models. The correction approaches were validated by comparing the nighttime eddy covariance CO2 fluxes corrected with each approach and chamber-based total ecosystem respiration estimates. We found that the local cospectra differed from the Kansas cospectra shape, although the site could not be considered as difficult (i.e., fairly flat, homogeneous, low vegetation, sufficient measurement height). The Kansas cospectra have more spectral power at high frequencies than the local cospectra under (un) stable conditions. This difference greatly affected the correction factor, especially for night fluxes. Night fluxes measured by eddy covariance were found to be in good accord with total chamber based ecosystem respiration estimates when corrected with local cospectra and to be overestimated when corrected with Kansas cospectra. As the difference between correction factors was larger in stable than unstable conditions, it acts as a selective systematic error and has an important impact on annual carbon fluxes. On the basis of a 4-year average, at DTO the errors reach 71–150 g C mâˆ'2 yâˆ'1 for net ecosystem exchange (NEE), 280–562 g C mâˆ'2 yâˆ'1 for total ecosystem respiration (TER) and 209–412 g C mâˆ'2 yâˆ'1 for gross primary productivity (GPP), depending on the approach used. We finally encourage site PIs to check the cospectrum shape at their sites and, if necessary, compute frequency correction factors on the basis of local cospectra rather than on Kansas cospectra. |
BibTeX:
@article{Mamadou2016,
author = {Mamadou, Ossénatou and Gourlez de la Motte, Louis and De Ligne, Anne and Heinesch, Bernard and Aubinet, Marc},
title = {Sensitivity of the annual net ecosystem exchange to the cospectral model used for high frequency loss corrections at a grazed grassland site},
journal = {Agricultural and Forest Meteorology},
year = {2016},
volume = {228-229},
pages = {360--369},
url = {http://linkinghub.elsevier.com/retrieve/pii/S0168192316303057},
doi = {10.1016/j.agrformet.2016.06.008}
}
|
| Mammarella I, Peltola O, Nordbo A and Järvi L (2016), "Quantifying the uncertainty of eddy covariance fluxes due to the use of different software packages and combinations of processing steps in two contrasting ecosystems", Atmospheric Measurement Techniques. Vol. 9(10), pp. 4915-4933. |
| Abstract: We have carried out an inter-comparison between EddyUH and EddyPro, two public software packages for post-field processing of eddy covariance data. Datasets including carbon dioxide, methane and water vapour fluxes measured over 2 months at a wetland in southern Finland and carbon dioxide and water vapour fluxes measured over 3 months at an urban site in Helsinki were processed and analysed. The purpose was to estimate the flux uncertainty due to the use of different software packages and to evaluate the most critical processing steps, determining the largest deviations in the calculated fluxes. Turbulent fluxes calculated with a reference combination of processing steps were in good agreement, the systematic difference between the two software packages being up to 2.0 and 6.7% for half-hour and cumulative sum values, respectively. The raw data preparation and processing steps were consistent between the software packages, and most of the deviations in the estimated fluxes were due to the flux corrections. Among the different calculation procedures analysed, the spectral correction had the biggest impact for closed-path latent heat fluxes, reaching a nocturnal median value of 15% at the wetland site. We found up to a 43% median value of deviation (with respect to the run with all corrections included) if the closed-path carbon dioxide flux is calculated without the dilution correction, while the methane fluxes were up to 10% lower without both dilution and spectroscopic corrections. TheWebb-Pearman-Leuning (WPL) and spectroscopic corrections were the most critical steps for open-path systems. However, we found also large spectral correction factors for the open-path methane fluxes, due to the sensor separation effect. |
BibTeX:
@article{Mammarella2016,
author = {Mammarella, Ivan and Peltola, Olli and Nordbo, Annika and Järvi, Leena},
title = {Quantifying the uncertainty of eddy covariance fluxes due to the use of different software packages and combinations of processing steps in two contrasting ecosystems},
journal = {Atmospheric Measurement Techniques},
year = {2016},
volume = {9},
number = {10},
pages = {4915--4933},
doi = {10.5194/amt-9-4915-2016}
}
|
| Mammarella I, Peltola O, Nordbo A, Järvi L and Rannik Ü (2016), "EddyUH: an advanced software package for eddy covariance flux calculation for a wide range of instrumentation and ecosystems", Atmospheric Measurement Techniques Discussions., jan, 2016. , pp. 1-33. |
| Abstract: We have carried out an inter-comparison between EddyUH and EddyPro®, two public software packages for post-field processing of eddy covariance data. Datasets including carbon dioxide, methane and water vapour fluxes measured over two months at a wetland in Southern Finland and carbon dioxide and water vapour fluxes measured over three months at an urban site in Helsinki, were processed and analysed. The purpose was to estimate the flux uncertainty due to the use of different software packages and to evaluate the most critical processing steps, determining the largest deviations in the calculated fluxes. Turbulent fluxes calculated with a reference combination of processing steps were in good agreement, the systematic difference between the two software packages being up to 2% and 6.7% for half-hour and cumulative sum values, respectively. The raw data preparation and processing steps were consistent between the software packages, and most of the deviations in the estimated fluxes were due to the flux corrections. Among the different calculation procedures analysed, the spectral correction had biggest impact for closed-path latent heat fluxes, reaching nocturnal median value of 15% at the wetland site. We found up to 43% median value of deviation (with respect to the run with all corrections included) if closed path carbon dioxide flux is calculated without the dilution correction, while the methane fluxes were up to 10% lower without both dilution and spectroscopic corrections. The density (and spectroscopic) correction was the most critical step for open-path systems. However, we found also large spectral correction factors for the open-path methane fluxes, due to the sensor separation effect. |
BibTeX:
@article{Mammarella2016a,
author = {Mammarella, I and Peltola, O and Nordbo, A and Järvi, L and Rannik, Ü},
title = {EddyUH: an advanced software package for eddy covariance flux calculation for a wide range of instrumentation and ecosystems},
journal = {Atmospheric Measurement Techniques Discussions},
year = {2016},
pages = {1--33},
url = {http://www.atmos-meas-tech-discuss.net/amt-2015-323/},
doi = {10.5194/amt-2015-323}
}
|
| Massart S, Agusti-Panareda A, Heymann J, Buchwitz M, Chevallier F, Reuter M, Hilker M, Burrows JP, Deutscher NM, Feist DG, Hase F, Sussmann R, Desmet F, Dubey MK, Griffith DW, Kivi R, Petri C, Schneider M and Velazco VA (2016), "Ability of the 4-D-Var analysis of the GOSAT BESD XCO2 retrievals to characterize atmospheric CO2 at large and synoptic scales", Atmospheric Chemistry and Physics., feb, 2016. Vol. 16(3), pp. 1653-1671. Copernicus GmbH. |
| Abstract: This study presents results from the European Centre for Medium-RangeWeather Forecasts (ECMWF) carbon dioxide (CO2) analysis system where the atmospheric CO2 is controlled through the assimilation of columnaveraged dry-air mole fractions of CO2(XCO2) from the Greenhouse gases Observing Satellite (GOSAT). The analysis is compared to a free-run simulation (without assimilation of XCO2), and they are both evaluated against XCO2 data from the Total Carbon Column Observing Network (TCCON). We show that the assimilation of the GOSAT XCO2 product from the Bremen Optimal Estimation Differential Optical Absorption Spectroscopy (BESD) algorithm during the year 2013 provides XCO2 fields with an improved mean absolute error of 0.6 parts per million (ppm) and an improved station-to-station bias deviation of 0.7 ppm compared to the free run (1.1 and 1.4 ppm, respectively) and an improved estimated precision of 1 ppm compared to the GOSAT BESD data (3.3 ppm). We also show that the analysis has skill for synoptic situations in the vicinity of frontal systems, where the GOSAT retrievals are sparse due to cloud contamination. We finally computed the 10-day forecast from each analysis at 00:00 UTC, and we demonstrate that the CO2 forecast shows synoptic skill for the largest-scale weather patterns (of the order of 1000 km) even up to day 5 compared to its own analysis. |
BibTeX:
@article{Massart2016,
author = {Massart, Sébastien and Agusti-Panareda, Anna and Heymann, Jens and Buchwitz, Michael and Chevallier, Frédéric and Reuter, Maximilian and Hilker, Michael and Burrows, John P. and Deutscher, Nicholas M. and Feist, Dietrich G. and Hase, Frank and Sussmann, Ralf and Desmet, Filip and Dubey, Manvendra K. and Griffith, David W.T. and Kivi, Rigel and Petri, Christof and Schneider, Matthias and Velazco, Voltaire A.},
title = {Ability of the 4-D-Var analysis of the GOSAT BESD XCO2 retrievals to characterize atmospheric CO2 at large and synoptic scales},
journal = {Atmospheric Chemistry and Physics},
publisher = {Copernicus GmbH},
year = {2016},
volume = {16},
number = {3},
pages = {1653--1671},
doi = {10.5194/acp-16-1653-2016}
}
|
| Mathijssen PJ, Väliranta M, Korrensalo A, Alekseychik P, Vesala T, Rinne J and Tuittila ES (2016), "Reconstruction of Holocene carbon dynamics in a large boreal peatland complex, southern Finland", Quaternary Science Reviews. Vol. 142, pp. 1-15. Elsevier Ltd. |
| Abstract: Holocene peatland development and associated carbon (C) dynamics were reconstructed for a southern boreal Finnish peatland complex with fen and bog areas. In order to assess the role of local factors and long-term allogenic climate forcing in peatland development patterns, we studied a total of 18 peat cores and reconstructed vertical peat growth and lateral peat area expansion rates, the C accumulation rate (CAR), past vegetation composition and past methane (CH4) fluxes. We combined fossil plant data with measured contemporary CH4 flux – vegetation relationship data to reconstruct CH4 fluxes over time. When these reconstructions were added to the CAR estimations, a more complete picture of Holocene-scale C dynamics was achieved. Basal peat ages showed that expansion of the peat area was rapid between 11,000 and 8000 cal. BP, but decreased during the dry mid-Holocene and is probably currently limited by basal topography. A similar pattern was observed for peat growth and CAR in the fen core, whereas in the bog core CAR increased after ombrotrophication, i.e. after 4400 cal. BP. The effect of fire on vegetation and CAR was more conspicuous at the bog site than at the fen site. The CH4 flux reconstructions showed that during the Holocene CH4 emissions at the fen site decreased from 19 ± 15 to 16 ± 8 g CH4 m−2 yr−1 and at the bog site from 20 ± 15 to 14 ± 8 g CH4 m−2 yr−1. Our results suggest that a combination of changing climate, fire events and local conditions have modified the autogenic peatland development and C dynamics. |
BibTeX:
@article{Mathijssen2016,
author = {Mathijssen, Paul J.H. and Väliranta, Minna and Korrensalo, Aino and Alekseychik, Pavel and Vesala, Timo and Rinne, Janne and Tuittila, Eeva Stiina},
title = {Reconstruction of Holocene carbon dynamics in a large boreal peatland complex, southern Finland},
journal = {Quaternary Science Reviews},
publisher = {Elsevier Ltd},
year = {2016},
volume = {142},
pages = {1--15},
doi = {10.1016/j.quascirev.2016.04.013}
}
|
| McKinley GA, Pilcher DJ, Fay AR, Lindsay K, Long MC and Lovenduski NS (2016), "Timescales for detection of trends in the ocean carbon sink", Nature., feb, 2016. Vol. 530(7591), pp. 469-472. Nature Publishing Group. |
| Abstract: The ocean has absorbed 41 per cent of all anthropogenic carbon emitted as a result of fossil fuel burning and cement manufacture. The magnitude and the large-scale distribution of the ocean carbon sink is well quantified for recent decades. In contrast, temporal changes in the oceanic carbon sink remain poorly understood. It has proved difficult to distinguish between air-to-sea carbon flux trends that are due to anthropogenic climate change and those due to internal climate variability. Here we use a modelling approach that allows for this separation, revealing how the ocean carbon sink may be expected to change throughout this century in different oceanic regions. Our findings suggest that, owing to large internal climate variability, it is unlikely that changes in the rate of anthropogenic carbon uptake can be directly observed in most oceanic regions at present, but that this may become possible between 2020 and 2050 in some regions. |
BibTeX:
@article{McKinley2016,
author = {McKinley, Galen A. and Pilcher, Darren J. and Fay, Amanda R. and Lindsay, Keith and Long, Matthew C. and Lovenduski, Nicole S.},
title = {Timescales for detection of trends in the ocean carbon sink},
journal = {Nature},
publisher = {Nature Publishing Group},
year = {2016},
volume = {530},
number = {7591},
pages = {469--472},
url = {https://www.nature.com/articles/nature16958},
doi = {10.1038/nature16958}
}
|
| Medinets S, Gasche R, Skiba U, Schindlbacher A, Kiese R and Butterbach-Bahl K (2016), "Cold season soil NO fluxes from a temperate forest: drivers and contribution to annual budgets", Environmental Research Letters., nov, 2016. Vol. 11(11), pp. 114012. |
BibTeX:
@article{Medinets2016,
author = {Medinets, S and Gasche, R and Skiba, U and Schindlbacher, A and Kiese, R and Butterbach-Bahl, K},
title = {Cold season soil NO fluxes from a temperate forest: drivers and contribution to annual budgets},
journal = {Environmental Research Letters},
year = {2016},
volume = {11},
number = {11},
pages = {114012},
url = {https://iopscience.iop.org/article/10.1088/1748-9326/11/11/114012},
doi = {10.1088/1748-9326/11/11/114012}
}
|
| Metzger C, Nilsson MB, Peichl M and Jansson PE (2016), "Parameter interactions and sensitivity analysis for modelling carbon heat and water fluxes in a natural peatland, using CoupModel v5". dec, 2016. |
| Abstract: In contrast to previous peatland carbon dioxide (CO2/model sensitivity analyses, which usually focussed on only one or a few processes, this study investigates interactions between various biotic and abiotic processes and their parameters by comparing CoupModel v5 results with multiple observation variables. Many interactions were found not only within but also between various process categories simulating plant growth, decomposition, radiation interception, soil temperature, aerodynamic resistance, transpiration, soil hydrology and snow. Each measurement variable was sensitive to up to 10 (out of 54) parameters, from up to 7 different process categories. The constrained parameter ranges varied, depending on the variable and performance index chosen as criteria, and on other calibrated parameters (equifinalities). Therefore, transferring parameter ranges between models needs to be done with caution, especially if such ranges were achieved by only considering a few processes. The identified interactions and constrained parameters will be of great interest to use for comparisons with model results and data from similar ecosystems. All of the available measurement variables (net ecosystem exchange, leaf area index, sensible and latent heat fluxes, net radiation, soil temperatures, water table depth and snow depth) improved the model constraint. If hydraulic properties or water content were measured, further parameters could be constrained, resolving several equifinalities and reducing model uncertainty. The presented results highlight the importance of considering biotic and abiotic processes together and can help modellers and experimentalists to design and calibrate models as well as to direct experimental set-ups in peatland ecosystems towards modelling needs. |
BibTeX:
@misc{Metzger2016,
author = {Metzger, Christine and Nilsson, Mats B. and Peichl, Matthias and Jansson, Per Erik},
title = {Parameter interactions and sensitivity analysis for modelling carbon heat and water fluxes in a natural peatland, using CoupModel v5},
booktitle = {Geoscientific Model Development},
publisher = {Copernicus GmbH},
year = {2016},
volume = {9},
number = {12},
pages = {4313--4338},
doi = {10.5194/gmd-9-4313-2016}
}
|
| Molina-Herrera S, Haas E, Klatt S, Kraus D, Augustin J, Magliulo V, Tallec T, Ceschia E, Ammann C, Loubet B, Skiba U, Jones S, Brümmer C, Butterbach-Bahl K and Kiese R (2016), "A modeling study on mitigation of N2O emissions and NO3 leaching at different agricultural sites across Europe using LandscapeDNDC", Science of the Total Environment., may, 2016. Vol. 553, pp. 128-140. |
| Abstract: The identification of site-specific agricultural management practices in order to maximize yield while minimizing environmental nitrogen losses remains in the center of environmental pollution research. Here, we used the biogeochemical model LandscapeDNDC to explore different agricultural practices with regard to their potential to reduce soil N2O emissions and NO3 leaching while maintaining yields. In a first step, the model was tested against observations of N2O emissions, NO3 leaching, soil micrometeorology as well as crop growth for eight European cropland and grassland sites. Across sites, LandscapeDNDC predicts very well mean N2O emissions (r2 = 0.99) and simulates the magnitude and general temporal dynamics of soil inorganic nitrogen pools. For the assessment of site-specific mitigation potentials of environmental nitrogen losses a Monte Carlo optimization technique considering different agricultural management options (i.e., timing of planting, harvest and fertilization, amount of applied fertilizer as well as residue management) was used. The identified optimized field management practices reduce N2O emissions and NO3 leaching from croplands on average by 21% and 31%, respectively. Likewise, average reductions of 55% for N2O emissions and 16% for NO3 leaching are estimated for grasslands. For mitigating environmental loss - while maintaining yield levels - it was most important to reduce fertilizer application rates by in average 10%. Our analyses indicate that yield scaled N2O emissions and NO3 leaching indicate possible improvements of nitrogen use efficiencies in European farming systems. Moreover, the applied optimization approach can be used also in a prognostic way to predict optimal timings and fertilization options (rates and splitting) upon accurate weather forecasts combined with the knowledge of modeled soil nutrient availability and plant nitrogen demand. |
BibTeX:
@article{Molina-Herrera2016,
author = {Molina-Herrera, Saúl and Haas, Edwin and Klatt, Steffen and Kraus, David and Augustin, Jürgen and Magliulo, Vincenzo and Tallec, Tiphaine and Ceschia, Eric and Ammann, Christof and Loubet, Benjamin and Skiba, Ute and Jones, Stephanie and Brümmer, Christian and Butterbach-Bahl, Klaus and Kiese, Ralf},
title = {A modeling study on mitigation of N2O emissions and NO3 leaching at different agricultural sites across Europe using LandscapeDNDC},
journal = {Science of the Total Environment},
year = {2016},
volume = {553},
pages = {128--140},
url = {http://linkinghub.elsevier.com/retrieve/pii/S0048969715312560},
doi = {10.1016/j.scitotenv.2015.12.099}
}
|
| Moussa H, Benallal MA, Goyet C and Lefèvre N (2016), "Satellite-derived CO2 fugacity in surface seawater of the tropical Atlantic Ocean using a feedforward neural network", International Journal of Remote Sensing., feb, 2016. Vol. 37(3), pp. 580-598. Taylor and Francis Ltd.. |
| Abstract: A feedforward neural network is used to quantify the fugacity of CO (Formula presented.) in surface seawater (f(CO(Formula presented.))) of the tropical Atlantic Ocean, exclusively from satellite data: sea-surface temperature, sea-surface salinity, and chlorophyll-a (chl-a), at a 4 km (Formula presented.) 4 km spatial resolution, for the period of spring (March and April). The model was constructed using 7188 in situ data provided by the ‘Surface Ocean CO (Formula presented.) ATlas' (SOCAT) products, and the ‘EC-funded project CARBOOCEAN IP program' products, available for the years 2001, 2002, 2004, 2006, 2007, and 2009. The model was tested using remote sensing data of the Moderate Resolution Imaging Spectroradiometer Aqua. This approach was validated over the area extending from 8°N-61°W to 23°N-20°W. A comparison with multiple linear regression model was established. The neural network has provided better results (root mean square error (RMSE) of 8.7 atm (0.881 Pa)) than linear regression (RMSE of 9.6 atm (0.973 Pa)) for f (CO (Formula presented.)) interpolation using remote sensing data. Since the required input data are available, this approach could be applied to the whole tropical Atlantic Ocean and for the remaining seasons (summer, fall, and winter). |
BibTeX:
@article{Moussa2016,
author = {Moussa, H. and Benallal, M. A. and Goyet, C. and Lefèvre, N.},
title = {Satellite-derived CO2 fugacity in surface seawater of the tropical Atlantic Ocean using a feedforward neural network},
journal = {International Journal of Remote Sensing},
publisher = {Taylor and Francis Ltd.},
year = {2016},
volume = {37},
number = {3},
pages = {580--598},
url = {https://www.tandfonline.com/doi/abs/10.1080/01431161.2015.1131872},
doi = {10.1080/01431161.2015.1131872}
}
|
| Müller D, Warneke T, Rixen T, Müller M, Mujahid A, Bange HW and Notholt J (2016), "Fate of terrestrial organic carbon and associated CO2 and CO emissions from two Southeast Asian estuaries", Biogeosciences., feb, 2016. Vol. 13(3), pp. 691-705. |
| Abstract: Southeast Asian rivers convey large amounts of organic carbon, but little is known about the fate of this terrestrial material in estuaries. Although Southeast Asia is, by area, considered a hotspot of estuarine carbon dioxide (CO2) emissions, studies in this region are very scarce. We measured dissolved and particulate organic carbon, as well as CO2 partial pressures and carbon monoxide (CO) concentrations in two tropical estuaries in Sarawak, Malaysia, whose coastal area is covered by carbon-rich peatlands. We surveyed the estuaries of the rivers Lupar and Saribas during the wet and dry season, respectively. Carbon-to-nitrogen ratios suggest that dissolved organic matter (DOM) is largely of terrestrial origin. We found evidence that a large fraction of this carbon is respired. The median pCO2 in the estuaries ranged between 640 and 5065 μatm with little seasonal variation. CO2 fluxes were determined with a floating chamber and estimated to amount to 14-268 mol m-2 yr-1, which is high compared to other studies from tropical and subtropical sites. Estimates derived from a merely wind-driven turbulent diffusivity model were considerably lower, indicating that these models might be inappropriate in estuaries, where tidal currents and river discharge make an important contribution to the turbulence driving water-air gas exchange. Although an observed diurnal variability of CO concentrations suggested that CO was photochemically produced, the overall concentrations and fluxes were relatively moderate (0.4-1.3 nmol L-1 and 0.7-1.8 mmol m-2 yr-1) if compared to published data for oceanic or upwelling systems. We attributed this to the large amounts of suspended matter (4-5004 mg L-1), limiting the light penetration depth and thereby inhibiting CO photoproduction. We concluded that estuaries in this region function as an efficient filter for terrestrial organic carbon and release large amounts of CO2 to the atmosphere. The Lupar and Saribas rivers deliver 0.3 ± 0.2 Tg C yr-1 to the South China Sea as organic carbon and their mid-estuaries release approximately 0.4 ± 0.2 Tg C yr-1 into the atmosphere as CO2. |
BibTeX:
@article{Muller2016,
author = {Müller, D and Warneke, T and Rixen, T and Müller, M and Mujahid, A and Bange, H W and Notholt, J},
title = {Fate of terrestrial organic carbon and associated CO2 and CO emissions from two Southeast Asian estuaries},
journal = {Biogeosciences},
year = {2016},
volume = {13},
number = {3},
pages = {691--705},
url = {http://www.biogeosciences.net/13/691/2016/},
doi = {10.5194/bg-13-691-2016}
}
|
| Müller D, Bange HW, Warneke T, Rixen T, Müller M, Mujahid A and Notholt J (2016), "Nitrous oxide and methane in two tropical estuaries in a peat-dominated region of North-western Borneo", Biogeosciences Discussions., jan, 2016. , pp. 1-28. |
| Abstract: Estuaries are sources of nitrous oxide (Nsub2/subO) and methane (CHsub4/sub) to the atmosphere. However, our present knowledge of Nsub2/subO and CHsub4/sub emissions from estuaries in the tropics is very limited because data is scarce. In this study, we present first measurements of dissolved Nsub2/subO and CHsub4/sub from two estuaries in a peat-dominated region of north-western Borneo. Two campaigns (during the dry seaso n in June 2013 and during the wet season in March 2014) were conducted in the estuaries of the rivers Lupar and Saribas. Median Nsub2/subO concentrations ranged between 7.2 and 12.3 nmol L-1and were higher in the marine end-member (13.0 ± 7.0 nmol Lsup-1/sup). CHsub4/sub concentrations were low in the coastal ocean (3.6 ± 0.2 nmol Lsup-1/sup) and higher in the estuaries (medians between 12.2 and 64.0 nmol Lsup-1/sup). The respiration of abundant organic matter and presumably anthropogenic input caused a slight eutrophication, which did not lead to hypoxia or enhanced Nsub2/subO concentrations, however. Generally, Nsub2/subO concentrations were not related to dissolved inorganic nitrogen concentrations. Thus, the use of an emission factor for the calculation of Nsub2/subO emissions from the inorganic nitrogen load leads to an overestimation of the flux from the Lupar and Saribas estuaries. Nsub2/subO was negatively correlated with salinity during the dry season, which suggests a riverine source. In contrast, Nsub2/subO concentrations during the wet season were not correlated with salinity but locally enhanced within the estuaries, implying that there were additional estuarine sources during the wet (i.e. monsoon) season. Estuarine CHsub4/sub distributions were not driven by freshwater input but rather by tidal variations. Both Nsub2/subO and CHsub4/sub concentrations were more variable during the wet season. We infer that the wet season dominates the variability of the Nsub2/subO and CHsub4/sub concentrations and subsequent emissions from tropical estuaries. Thus, we speculate that any changes the Southeast Asian monsoon system will lead to changes in the Nsub2/subO and CHsub4/sub emissions from these systems. We also suggest that the ongoing cultivation of peat soil in Borneo is likely to increase Nsub2/subO emissions from these estuaries, while the effect on CHsub4/sub remains uncertain. |
BibTeX:
@article{Muller2016a,
author = {Müller, D and Bange, H W and Warneke, T and Rixen, T and Müller, M and Mujahid, A and Notholt, J},
title = {Nitrous oxide and methane in two tropical estuaries in a peat-dominated region of North-western Borneo},
journal = {Biogeosciences Discussions},
year = {2016},
pages = {1--28},
url = {http://www.biogeosciences-discuss.net/bg-2016-4/},
doi = {10.5194/bg-2016-4}
}
|
| Musavi T, Migliavacca M, van de Weg MJ, Kattge J, Wohlfahrt G, van Bodegom PM, Reichstein M, Bahn M, Carrara A, Domingues TF, Gavazzi M, Gianelle D, Gimeno C, Granier A, Gruening C, Havránková K, Herbst M, Hrynkiw C, Kalhori A, Kaminski T, Klumpp K, Kolari P, Longdoz B, Minerbi S, Montagnani L, Moors E, Oechel WC, Reich PB, Rohatyn S, Rossi A, Rotenberg E, Varlagin A, Wilkinson M, Wirth C and Mahecha MD (2016), "Potential and limitations of inferring ecosystem photosynthetic capacity from leaf functional traits", Ecology and Evolution. Vol. 6(20), pp. 7352-7366. |
| Abstract: The aim of this study was to systematically analyze the potential and limitations of using plant functional trait observations from global databases versus in situ data to improve our understanding of vegetation impacts on ecosystem functional properties (EFPs). Using ecosystem photosynthetic capacity as an example, we first provide an objective approach to derive robust EFP estimates from gross primary productivity (GPP) obtained from eddy covariance flux measurements. Second, we investigate the impact of synchronizing EFPs and plant functional traits in time and space to evaluate their relationships, and the extent to which we can benefit from global plant trait databases to explain the variability of ecosystem photosynthetic capacity. Finally, we identify a set of plant functional traits controlling ecosystem photosynthetic capacity at selected sites. Suitable estimates of the ecosystem photosynthetic capacity can be derived from light response curve of GPP responding to radiation (photosynthetically active radiation or absorbed photosynthetically active radiation). Although the effect of climate is minimized in these calculations, the estimates indicate substantial interannual variation of the photosynthetic capacity, even after removing site-years with confounding factors like disturbance such as fire events. The relationships between foliar nitrogen concentration and ecosystem photosynthetic capacity are tighter when both of the measurements are synchronized in space and time. When using multiple plant traits simultaneously as predictors for ecosystem photosynthetic capacity variation, the combination of leaf carbon to nitrogen ratio with leaf phosphorus content explains the variance of ecosystem photosynthetic capacity best (adjusted R2Â =Â 0.55). Overall, this study provides an objective approach to identify links between leaf level traits and canopy level processes and highlights the relevance of the dynamic nature of ecosystems. Synchronizing measurements of eddy covariance fluxes and plant traits in time and space is shown to be highly relevant to better understand the importance of intra- and interspecific trait variation on ecosystem functioning. |
BibTeX:
@article{Musavi2016,
author = {Musavi, Talie and Migliavacca, Mirco and van de Weg, Martine Janet and Kattge, Jens and Wohlfahrt, Georg and van Bodegom, Peter M and Reichstein, Markus and Bahn, Michael and Carrara, Arnaud and Domingues, Tomas F and Gavazzi, Michael and Gianelle, Damiano and Gimeno, Cristina and Granier, André and Gruening, Carsten and Havránková, KateÅ™ina and Herbst, Mathias and Hrynkiw, Charmaine and Kalhori, Aram and Kaminski, Thomas and Klumpp, Katja and Kolari, Pasi and Longdoz, Bernard and Minerbi, Stefano and Montagnani, Leonardo and Moors, Eddy and Oechel, Walter C and Reich, Peter B and Rohatyn, Shani and Rossi, Alessandra and Rotenberg, Eyal and Varlagin, Andrej and Wilkinson, Matthew and Wirth, Christian and Mahecha, Miguel D},
title = {Potential and limitations of inferring ecosystem photosynthetic capacity from leaf functional traits},
journal = {Ecology and Evolution},
year = {2016},
volume = {6},
number = {20},
pages = {7352--7366},
doi = {10.1002/ece3.2479}
}
|
| Nair RKF, Perks MP, Weatherall A, Baggs EM and Mencuccini M (2016), "Does canopy nitrogen uptake enhance carbon sequestration by trees?", Global Change Biology., feb, 2016. Vol. 22(2), pp. 875-888. |
BibTeX:
@article{Nair2016,
author = {Nair, Richard K F and Perks, Micheal P and Weatherall, Andrew and Baggs, Elizabeth M and Mencuccini, Maurizio},
title = {Does canopy nitrogen uptake enhance carbon sequestration by trees?},
journal = {Global Change Biology},
year = {2016},
volume = {22},
number = {2},
pages = {875--888},
url = {http://doi.wiley.com/10.1111/gcb.13096},
doi = {10.1111/gcb.13096}
}
|
| Necki JM, Gałkowski M, Chmura Ł, Gerbig C, Zimnoch M, Zieba D, Bartyzel J, Wołkowicz W and Różaʼnski K (2016), "Regional representativeness of CH4 and N2O mixing ratio measurements at high-altitude mountain station Kasprowy Wierch, southern Poland", Aerosol and Air Quality Research. Vol. 16(3), pp. 568-580. |
| Abstract: Records of trace gas composition of the atmosphere originating from mountain stations are difficult to interpret in terms of continental gas balances due to complex topography and local wind patterns. Kasprowy Wierch station, located in the High Tatra Mountains, Poland, provides datasets to European GHG databases and can be used for regional and continental balances of trace gases in Earth's atmosphere. Although it suffers from strong influence of local valley winds, the concentration record obtained at Kasprowy Wierch contains also a discernible fraction of methane (up to 100 ppb) emitted mainly by large regional source of this gas (Silesian Coal Basin) located ca. 150 km north-west of Kasprowy Wierch. Comparison of GOSAT satellite CH4 record in the pixel including High Tatras at the level of 850 hPa with the data obtained at Kasprowy Wierch mountain station revealed surprisingly good correlation, even for relatively short time intervals. |
BibTeX:
@article{Necki2016,
author = {Necki, Jarosław M and Gałkowski, Michał and Chmura, Łukasz and Gerbig, Christoph and Zimnoch, Mirosław and Zieba, Damian and Bartyzel, Jakub and Wołkowicz, Wojciech and Różaʼnski, Kazimierz},
title = {Regional representativeness of CH4 and N2O mixing ratio measurements at high-altitude mountain station Kasprowy Wierch, southern Poland},
journal = {Aerosol and Air Quality Research},
year = {2016},
volume = {16},
number = {3},
pages = {568--580},
url = {http://aaqr.org/Doi.php?id=9_AAQR-15-05-SIMtS-0357&v=16&i=3&m=3&y=2016},
doi = {10.4209/aaqr.2015.05.0357}
}
|
| Obersteiner F, Bönisch H and Engel A (2016), "An automated gas chromatography time-of-flight mass spectrometry instrument for the quantitative analysis of halocarbons in air", Atmospheric Measurement Techniques., jan, 2016. Vol. 9(1), pp. 179-194. |
| Abstract: We present the characterization and application of a new gas chromatography time-of-flight mass spectrometry instrument (GC-TOFMS) for the quantitative analysis of halocarbons in air samples. The setup comprises three fundamental enhancements compared to our earlier work (Hoker et al., 2015): (1) full automation, (2) a mass resolving power R = m/Δm of the TOFMS (Tofwerk AG, Switzerland) increased up to 4000 and (3) a fully accessible data format of the mass spectrometric data. Automation in combination with the accessible data allowed an in-depth characterization of the instrument. Mass accuracy was found to be approximately 5 ppm in mean after automatic recalibration of the mass axis in each measurement. A TOFMS configuration giving R = 3500 was chosen to provide an R-to-sensitivity ratio suitable for our purpose. Calculated detection limits are as low as a few femtograms by means of the accurate mass information. The precision for substance quantification was 0.15 % at the best for an individual measurement and in general mainly determined by the signal-to-noise ratio of the chromatographic peak. Detector non-linearity was found to be insignificant up to a mixing ratio of roughly 150 ppt at 0.5 L sampled volume. At higher concentrations, non-linearities of a few percent were observed (precision level: 0.2 %) but could be attributed to a potential source within the detection system. A straightforward correction for those non-linearities was applied in data processing, again by exploiting the accurate mass information. Based on the overall characterization results, the GC-TOFMS instrument was found to be very well suited for the task of quantitative halocarbon trace gas observation and a big step forward compared to scanning, quadrupole MS with low mass resolving power and a TOFMS technique reported to be non-linear and restricted by a small dynamical range. |
BibTeX:
@article{Obersteiner2016,
author = {Obersteiner, F and Bönisch, H and Engel, A},
title = {An automated gas chromatography time-of-flight mass spectrometry instrument for the quantitative analysis of halocarbons in air},
journal = {Atmospheric Measurement Techniques},
year = {2016},
volume = {9},
number = {1},
pages = {179--194},
url = {http://www.atmos-meas-tech.net/9/179/2016/},
doi = {10.5194/amt-9-179-2016}
}
|
| Osterwalder S, Fritsche J, Alewell C, Schmutz M, Nilsson MB, Jocher G, Sommar J, Rinne J and Bishop K (2016), "A dual-inlet, single detector relaxed eddy accumulation system for long-term measurement of mercury flux", Atmospheric Measurement Techniques., feb, 2016. Vol. 9(2), pp. 509-524. Copernicus GmbH. |
| Abstract: The fate of anthropogenic emissions of mercury (Hg) to the atmosphere is influenced by the exchange of elemental Hg with the earth surface. This exchange holds the key to a better understanding of Hg cycling from local to global scales, which has been difficult to quantify. To advance research about land-atmosphere Hg interactions, we developed a dual-inlet, single detector relaxed eddy accumulation (REA) system. REA is an established technique for measuring turbulent fluxes of trace gases and aerosol particles in the atmospheric surface layer. Accurate determination of gaseous elemental mercury (GEM) fluxes has proven difficult due to technical challenges presented by extremely small concentration differences (typicallytextless0.5ng m-3) between updrafts and downdrafts. We present an advanced REA design that uses two inlets and two pairs of gold cartridges for continuous monitoring of GEM fluxes. This setup reduces the major uncertainty created by the sequential sampling in many previous designs. Additionally, the instrument is equipped with a GEM reference gas generator that monitors drift and recovery rates. These innovations facilitate continuous, utonomous measurement of GEM flux. To demonstrate the system performance, we present results from field campaigns in two contrasting environments: an urban setting with a heterogeneous fetch and a boreal peatland during snowmelt. The observed average emission rates were 15 and 3ng m-2 respectively. We believe that this dual-inlet, single detector approach is a significant improvement of the REA system for ultra-trace gases and can help to advance our understanding of long-term land atmosphere GEM exchange. |
BibTeX:
@article{Osterwalder2016,
author = {Osterwalder, S. and Fritsche, J. and Alewell, C. and Schmutz, M. and Nilsson, M. B. and Jocher, G. and Sommar, J. and Rinne, J. and Bishop, K.},
title = {A dual-inlet, single detector relaxed eddy accumulation system for long-term measurement of mercury flux},
journal = {Atmospheric Measurement Techniques},
publisher = {Copernicus GmbH},
year = {2016},
volume = {9},
number = {2},
pages = {509--524},
doi = {10.5194/amt-9-509-2016}
}
|
| Parard G, Charantonis AA and Rutgersson A (2016), "Using satellite data to estimate partial pressure of CO textlesssubtextgreater2textless/subtextgreater in the Baltic Sea", Journal of Geophysical Research: Biogeosciences., mar, 2016. Vol. 121(3), pp. 1002-1015. Blackwell Publishing Ltd. |
| Abstract: In this study we focused on estimating the pressure partial of CO2 (pCO2) in the entire Baltic Sea which can be considered a coastal area in its entirety. We used the self-organizing multiple linear output (SOMLO) method to estimate the ocean surface pCO2 in the Baltic Sea from the remotely sensed sea surface temperature, chlorophyll a, colored dissolved organic matter, net primary production, and mixed-layer depth. Uncertainties in the estimates include sparsity of in situ data used to train the algorithms, in particular, for some sectors and seasons. For this application we divided the Baltic Sea in four basins. When comparing the results obtained with this division to those obtained in previous studies, we notice a decrease in the root-mean-square error (textless40 μatm) between the reconstruction of the pCO2 and their corresponding in situ measurements, as well as an increase of the correlation coefficient (textgreater 0.96) between them. The outputs of this research have a horizontal resolution of 4 km and cover the 1998-2011 period. For the first time, a climatological mean distribution of surface water pCO2 over the Baltic Sea was calculated based on the SOMLO method with a mean pCO2 of 368.3 ± 100 μatm, and a range of 234-514 μatm. The seasonal variability is similar throughout the Baltic Sea, being high in winter and low in summer. |
BibTeX:
@article{Parard2016,
author = {Parard, Gaëlle and Charantonis, Anastase Alexandre and Rutgersson, Anna},
title = {Using satellite data to estimate partial pressure of CO textlesssubtextgreater2textless/subtextgreater in the Baltic Sea},
journal = {Journal of Geophysical Research: Biogeosciences},
publisher = {Blackwell Publishing Ltd},
year = {2016},
volume = {121},
number = {3},
pages = {1002--1015},
url = {http://doi.wiley.com/10.1002/2015JG003064},
doi = {10.1002/2015JG003064}
}
|
| Petäjä T, O'Connor EJ, Moisseev D, Sinclair VA, Manninen AJ, Väänänen R, Von Lerber A, Thornton JA, Nicoll K, Petersen W, Chandrasekar V, Smith JN, Winkler PM, KrüGer O, Hakola H, Timonen H, Brus D, Laurila T, Asmi E, Riekkola ML, Mona L, Massoli P, Engelmann R, Komppula M, Wang J, Kuang C, BäCk J, Virtanen A, Levula J, Ritsche M and Hickmon N (2016), "A field campaign to elucidate the impact of biogenic aerosols on clouds and climate", Bulletin of the American Meteorological Society., oct, 2016. Vol. 97(10), pp. 1909-1928. American Meteorological Society. |
| Abstract: Observations obtained during an 8-month deployment of AMF2 in a boreal environment in Hyytiälä, Finland, and comprehensive in situ data from the SMEAR II station enable the characterization of biogenic aerosol, clouds, and precipitation and their interactions. |
BibTeX:
@article{Petaja2016,
author = {Petäjä, Tuukka and O'Connor, Ewan J. and Moisseev, Dmitri and Sinclair, Victoria A. and Manninen, Antti J. and Väänänen, Riikka and Von Lerber, Annakaisa and Thornton, Joel A. and Nicoll, Keri and Petersen, Walt and Chandrasekar, V. and Smith, James N. and Winkler, Paul M. and KrüGer, Olaf and Hakola, Hannele and Timonen, Hilkka and Brus, David and Laurila, Tuomas and Asmi, Eija and Riekkola, Marja Liisa and Mona, Lucia and Massoli, Paola and Engelmann, Ronny and Komppula, Mika and Wang, Jian and Kuang, Chongai and BäCk, Jaana and Virtanen, Annele and Levula, Janne and Ritsche, Michael and Hickmon, Nicki},
title = {A field campaign to elucidate the impact of biogenic aerosols on clouds and climate},
journal = {Bulletin of the American Meteorological Society},
publisher = {American Meteorological Society},
year = {2016},
volume = {97},
number = {10},
pages = {1909--1928},
doi = {10.1175/BAMS-D-14-00199.1}
}
|
| Pihlatie M, Rannik, Haapanala S, Peltola O, Shurpali N, Martikainen PJ, Lind S, Hyvönen N, Virkajärvi P, Zahniser M and Mammarella I (2016), "Seasonal and diurnal variation in CO fluxes from an agricultural bioenergy crop", Biogeosciences Discussions., jan, 2016. Vol. 2016, pp. 1-27. |
| Abstract: Carbon monoxide (CO) is an important reactive trace gas in the atmosphere, while its sources and sinks in the biosphere are only poorly understood. Emissions of CO have been reported from a wide range of soil-plant systems. However, soils are generally considered as a sink of CO due to microbial oxidation processes. We measured CO fluxes by micrometeorological eddy covariance method from a bioenergy crop (reed canary grass) in Eastern Finland over April to November 2011. Continuous flux measurements allowed us to assess the seasonal and diurnal variability, and to compare the CO fluxes to simultaneously measured CO2, N2O and heat fluxes as well as relevant meteorological, soil and plant variables in order to investigate factors driving the CO exchange. The reed canary grass crop was a net source of CO from mid-April to mid-June, and a net sink throughout the rest of the measurement period from July to November 2011. CO fluxes had a distinct diurnal pattern with a net CO uptake in the night and an emission during the daytime with a maximum emission at noon. This pattern was most pronounced during the spring and early summer, during which the most significant relationships were found between daytime CO fluxes and global radiation, net radiation, sensible heat flux, soil heat flux, relative humidity and net ecosystem exchange. The strong positive correlation between CO fluxes and radiation suggests towards abiotic CO production processes, whereas, the relationship of CO fluxes with net ecosystem exchange indicates towards biotic CO formation during crop growth. The study shows a clear need for detailed process-studies accompanied with continuous flux measurements of CO exchange to improve the understanding of the processes associated with CO exchange. |
BibTeX:
@article{Pihlatie2016,
author = {Pihlatie, M and Rannik and Haapanala, S and Peltola, O and Shurpali, N and Martikainen, P J and Lind, S and Hyvönen, N and Virkajärvi, P and Zahniser, M and Mammarella, I},
title = {Seasonal and diurnal variation in CO fluxes from an agricultural bioenergy crop},
journal = {Biogeosciences Discussions},
year = {2016},
volume = {2016},
pages = {1--27},
url = {http://www.biogeosciences-discuss.net/bg-2015-622/},
doi = {10.5194/bg-2015-622}
}
|
| Qu W, Bogena HR, Huisman JA, Schmidt M, Kunkel R, Weuthen A, Schiedung H, Schilling B, Sorg J and Vereecken H (2016), "The integrated water balance and soil data set of the Rollesbroich hydrological observatory", Earth System Science Data., oct, 2016. Vol. 8(2), pp. 517-529. |
| Abstract: The Rollesbroich headwater catchment located in western Germany is a densely instrumented hydrological observatory and part of the TERENO (Terrestrial Environmental Observatories) initiative. The measurements acquired in this observatory present a comprehensive data set that contains key hydrological fluxes in addition to important hydrological states and properties. Meteorological data (i.e., precipitation, air temperature, air humidity, radiation components, and wind speed) are continuously recorded and actual evapotranspiration is measured using the eddy covariance technique. Runoff is measured at the catchment outlet with a gauging station. In addition, spatiotemporal variations in soil water content and temperature are measured at high resolution with a wireless sensor network (SoilNet). Soil physical properties were determined using standard laboratory procedures from samples taken at a large number of locations in the catchment. This comprehensive data set can be used to validate remote sensing retrievals and hydrological models, to improve the understanding of spatial temporal dynamics of soil water content, to optimize data assimilation and inverse techniques for hydrological models, and to develop upscaling and downscaling procedures of soil water content information. The complete data set is freely available online (http://www.tereno.net, doi.org/10.5880/TERENO.2016.001, doi:10.5880/TERENO.2016.001,doi.org/10.5880/TERENO.2016.004,doi:10.5880/TERENO.2016.004,doi.org/10.5880/TERENO.2016.003,doi:10.5880/TERENO.2016.003) and additionally referenced by three persistent identifiers securing the long-term data and metadata availability. |
BibTeX:
@article{Qu2016,
author = {Qu, Wei and Bogena, Heye R and Huisman, Johan A and Schmidt, Marius and Kunkel, Ralf and Weuthen, Ansgar and Schiedung, Henning and Schilling, Bernd and Sorg, Jürgen and Vereecken, Harry},
title = {The integrated water balance and soil data set of the Rollesbroich hydrological observatory},
journal = {Earth System Science Data},
year = {2016},
volume = {8},
number = {2},
pages = {517--529},
url = {http://www.earth-syst-sci-data.net/8/517/2016/},
doi = {10.5194/essd-8-517-2016}
}
|
| Rannik Ü, Zhou L, Zhou P, Gierens R, Mammarella I, Sogachev A and Boy M (2016), "Aerosol dynamics within and above forest in relation to turbulent transport and dry deposition", Atmospheric Chemistry and Physics., mar, 2016. Vol. 16(5), pp. 3145-3160. Copernicus GmbH. |
| Abstract: A 1-D atmospheric boundary layer (ABL) model coupled with a detailed atmospheric chemistry and aerosol dynamical model, the model SOSAA, was used to predict the ABL and detailed aerosol population (characterized by the number size distribution) time evolution. The model was applied over a period of 10 days in May 2013 to a pine forest site in southern Finland. The period was characterized by frequent new particle formation events and simultaneous intensive aerosol transformation. The aim of the study was to analyze and quantify the role of aerosol and ABL dynamics in the vertical transport of aerosols. It was of particular interest to what extent the fluxes above the canopy deviate from the particle dry deposition on the canopy foliage due to the above-mentioned processes. The model simulations revealed that the particle concentration change due to aerosol dynamics frequently exceeded the effect of particle deposition by even an order of magnitude or more. The impact was, however, strongly dependent on particle size and time. In spite of the fact that the timescale of turbulent transfer inside the canopy is much smaller than the timescales of aerosol dynamics and dry deposition, leading us to assume well-mixed properties of air, the fluxes at the canopy top frequently deviated from deposition inside the forest. This was due to transformation of aerosol concentration throughout the ABL and resulting complicated pattern of vertical transport. Therefore we argue that the comparison of timescales of aerosol dynamics and deposition defined for the processes below the flux measurement level do not unambiguously describe the importance of aerosol dynamics for vertical transport above the canopy.We conclude that under dynamical conditions reported in the current study the micrometeorological particle flux measurements can significantly deviate from the dry deposition into the canopy. The deviation can be systematic for certain size ranges so that the time-averaged particle fluxes can be also biased with respect to deposition sink. |
BibTeX:
@article{Rannik2016,
author = {Rannik, Üllar and Zhou, Luxi and Zhou, Putian and Gierens, Rosa and Mammarella, Ivan and Sogachev, Andrey and Boy, Michael},
title = {Aerosol dynamics within and above forest in relation to turbulent transport and dry deposition},
journal = {Atmospheric Chemistry and Physics},
publisher = {Copernicus GmbH},
year = {2016},
volume = {16},
number = {5},
pages = {3145--3160},
doi = {10.5194/acp-16-3145-2016}
}
|
| Rannik Ü, Peltola O and Mammarella I (2016), "Random uncertainties of flux measurements by the eddy covariance technique", Atmospheric Measurement Techniques Discussions., feb, 2016. , pp. 1-31. |
| Abstract: Large variability is inherent to turbulent flux observations. We review different methods used to estimate the flux random errors. Flux errors are calculated using measured turbulent and simulated artificial records. We recommend two flux errors with clear physical meaning: the flux error of the co-variance, defining the error of the measured flux as one standard deviation of the random uncertainty of turbulent flux observed over an averaging period of typically 30 min to 1 hour duration; and the error of the flux due to the instrumental noise. We suggest that the numerical approximation by Finkelstein and Sims (2001) is a robust and accurate method for calculation of the first error estimate. The method appeared insensitive to the integration period and the value 200 s sufficient to obtain the estimate without significant bias for variety of sites and wide range of observation conditions. The error proposed by Wienhold et al. (1995) is a good approximation to the total flux random uncertainty provided that independent cross-covariance values far from the maximum are used in estimation as suggested in this study. For the error due to instrumental noise the method by Lenschow et al. (2000) is useful in evaluation of the respective uncertainty. The method was found to be reliable for signal-to-noise ratio, defined by the ratio of the standard deviation of the signal to that of the noise in this study, less than three. Finally, the random uncertainty of the error estimates was determined to be in the order of 10 to 30 % for the total flux error depending on the conditions and method of estimation. |
BibTeX:
@article{Rannik2016a,
author = {Rannik, Üllar and Peltola, Olli and Mammarella, Ivan},
title = {Random uncertainties of flux measurements by the eddy covariance technique},
journal = {Atmospheric Measurement Techniques Discussions},
year = {2016},
pages = {1--31},
url = {http://www.atmos-meas-tech-discuss.net/amt-2016-31/},
doi = {10.5194/amt-2016-31}
}
|
| Rantala P, Järvi L, Taipale R, Laurila TK, Patokoski J, Kajos MK, Kurppa M, Haapanala S, Siivola E, Petäjä T, Ruuskanen TM and Rinne J (2016), "Anthropogenic and biogenic influence on VOC fluxes at an urban background site in Helsinki, Finland", Atmospheric Chemistry and Physics., jul, 2016. Vol. 16(12), pp. 7981-8007. Copernicus GmbH. |
| Abstract: We measured volatile organic compounds (VOCs), carbon dioxide (CO2) and carbon monoxide (CO) at an urban background site near the city centre of Helsinki, Finland, northern Europe. The VOC and CO2 measurements were obtained between January 2013 and September 2014 whereas for CO a shorter measurement campaign in April-May 2014 was conducted. Both anthropogenic and biogenic sources were identified for VOCs in the study. Strong correlations between VOC fluxes and CO fluxes and traffic rates indicated anthropogenic source of many VOCs. The VOC with the highest emission rate to the atmosphere was methanol, which originated mostly from traffic and other anthropogenic sources. The traffic was also a major source for aromatic compounds in all seasons whereas isoprene was mostly emitted from biogenic sources during summer. Some amount of traffic-related isoprene emissions were detected during other seasons but this might have also been an instrumental contamination from cycloalkane products. Generally, the observed VOC fluxes were found to be small in comparison with previous urban VOC flux studies. However, the differences were probably caused by lower anthropogenic activities as the CO2 fluxes were also relatively small at the site. |
BibTeX:
@article{Rantala2016,
author = {Rantala, Pekka and Järvi, Leena and Taipale, Risto and Laurila, Terhi K. and Patokoski, Johanna and Kajos, Maija K. and Kurppa, Mona and Haapanala, Sami and Siivola, Erkki and Petäjä, Tuukka and Ruuskanen, Taina M. and Rinne, Janne},
title = {Anthropogenic and biogenic influence on VOC fluxes at an urban background site in Helsinki, Finland},
journal = {Atmospheric Chemistry and Physics},
publisher = {Copernicus GmbH},
year = {2016},
volume = {16},
number = {12},
pages = {7981--8007},
doi = {10.5194/acp-16-7981-2016}
}
|
| Rérolle V, Ruiz-Pino D, Rafizadeh M, Loucaides S, Papadimitriou S, Mowlem M and Chen J (2016), "Measuring pH in the Arctic Ocean: Colorimetric method or SeaFET?", Methods in Oceanography., dec, 2016. Vol. 17, pp. 32-49. Elsevier. |
| Abstract: The suitability of the colorimetric method in a custom-made instrumental set-up and the commercial potentiometric SeaFET®electrode sensor to measure pH in surface oceanic water in the Arctic was investigated during the Chinese Arctic Research Expedition (CHINARE) in summer 2014. The instruments were set up in parallel on the on-board underway seawater supply for 65 days, enabling comparison in various conditions in the Arctic Ocean from the Chukchi Sea to the ice-covered high latitudes (81°N) and the open-water North-western Pacific Ocean. Overall, the instruments yielded pH datasets of similar high quality (method uncertainty ≤0.010). Detailed comparison with the parallel colorimetric pH measurements indicated that the measurements with the SeaFET external electrode in the low salinity ice-covered area were problematical and that the internal reference electrode failed after almost 2 months of cruise. Reasons for discrepancies between the data from the two instruments and recommendations for the use of either instrument for pH measurements in the Arctic are discussed. Finally, the investigation yielded a reliable high-resolution pH dataset in surface waters along a transect from the Pacific to the Arctic Ocean. Large pH variations were observed in the ice-free Arctic surface waters, with pH ranging between 7.98 and 8.49. The highest pH values were observed at the ice edge, whereas a relatively invariable pH (8.02±0.02) was measured in under-ice seawater in the ice-covered Arctic Ocean. The high resolution surface seawater pH dataset obtained here could be used as reference to detect the on-going acidification rate in the Pacific Arctic. |
BibTeX:
@article{Rerolle2016,
author = {Rérolle, Victoire and Ruiz-Pino, Diana and Rafizadeh, Mehrad and Loucaides, Socratis and Papadimitriou, Stathys and Mowlem, Matthew and Chen, Jianfang},
title = {Measuring pH in the Arctic Ocean: Colorimetric method or SeaFET?},
journal = {Methods in Oceanography},
publisher = {Elsevier},
year = {2016},
volume = {17},
pages = {32--49},
doi = {10.1016/j.mio.2016.05.006}
}
|
| Riikonen A, Järvi L and Nikinmaa E (2016), "Environmental and crown related factors affecting street tree transpiration in Helsinki, Finland", Urban Ecosystems., dec, 2016. Vol. 19(4), pp. 1693-1715. Springer New York LLC. |
| Abstract: We investigated the drivers of street tree transpiration in boreal conditions, in order to better understand tree water use in the context of urban tree planning and stormwater management. Two streets built in Helsinki in 2002, hemiboreal zone that had been planted either with Tilia × vulgaris or Alnus glutinosa f. pyramidalis were used as the study sites. Tree water use was measured from sap flow over the 2008–2011 period by the heat dissipation method. Penman-Monteith based evapotranspiration models of increasing complexity were tested against the tree water use measurements to assess the role of environmental and tree related factors in tree transpiration. Alnus and Tilia respectively used 1.1 and 0.8 l of water per m2 of leaf area per day under ample water conditions, but the annual variation was high. The Penman-Monteith evapotranspiration estimate and soil water status changes explained over 80 % of the variation in tree transpiration when the model was parameterized annually. The addition of tree crown surface area in the model improved its accuracy and diminished variation between years and sites. Using single parameterization over all four years instead of annually varying one did not produce reliable estimates of tree transpiration. Tree transpiration, scaled to different canopy cover percentages, implied that the columnar Alnus trees could transpire as much as all annual rainfall at or less than 50 % canopy cover. |
BibTeX:
@article{Riikonen2016,
author = {Riikonen, Anu and Järvi, Leena and Nikinmaa, Eero},
title = {Environmental and crown related factors affecting street tree transpiration in Helsinki, Finland},
journal = {Urban Ecosystems},
publisher = {Springer New York LLC},
year = {2016},
volume = {19},
number = {4},
pages = {1693--1715},
doi = {10.1007/s11252-016-0561-1}
}
|
| RÓzANSKI K, Chmura L, Gałkowski M, NÈtextcopyrightCKI J, Zimnoch M, Bartyzel J and O'doherty S (2016), "Monitoring of Greenhouse Gases in the Atmosphere-A Polish Perspective", Papers on Global Change IGBP., jan, 2016. Vol. 23(1), pp. 111-126. |
| Abstract: An overview of systematic observations of the trace-gas composition of the atmosphere over southern Poland is presented, against the background of data available for other greenhouse gas (GHG) monitoring stations in Europe. The results of GHG monitoring for three major greenhouse gases (CO2, CH4, N2O) are discussed. Measurements were performed at two locations of contrasting characteristics, i.e. (i) the high-Altitude mountain station of Kasprowy Wierch in the High Tatras, representing atmospheric conditions relatively free of local influences, and (ii) an urban station located in the Krakow agglomeration. The GHG data available for the Kasprowy Wierch station were compared with relevant data available for two marine reference stations (Mace Head, Ireland and Terceira Island, Azores), and two continental stations (Hohenpeissenberg, Germany and Pallas-Sammaltunturi, Finland). The growth rates for the CO2 mole fraction recorded at these five stations reveal only small temporal changes that almost coincide, leading to a quasi-linear increase of the CO2 mixing ratio over the European continent over the past 20 years. While N2O observations also reveal a steady increase over this time period, the mole fraction accounted for by CH4 is increasing again, after a period of stagnation in the years 2001-2007. The impact of continental sources of CH4 and N2O is seen clearly in the Kasprowy Wierch records. The mean departure between the CH4 mixing ratios recorded at Kasprowy Wierch and at the marine reference stations in the period 1994-2014 is of 27.3 ppb, and stems from continental emissions of this gas originating mainly from anthropogenic activities (leaking natural-gas distribution networks, landfills and livestock). For N2O, a departure of 1 ppb was observed for the period 2009-2014. Comparison of quasi-continuous measurements of CO2, CH4 and N2O mixing ratios made in the urban atmosphere of Krakow and at the regional reference site Kasprowy Wierch (located approximately 100 km away), allows for a deeper insight into the mechanisms controlling daily variations in atmospheric mixing ratios of these gases at the two sites. The development of a nocturnal inversion layer in the atmosphere above the city leads to local enhancements of CO2, CH4 and N2O mole fractions in the Krakow atmosphere during the night hours, with these exceeding the baseline level significantly. |
BibTeX:
@article{ROzANSKI2016,
author = {RÓzANSKI, Kazimierz and Chmura, Lukasz and Gałkowski, Michał and NÈtextcopyrightCKI, Jarosław and Zimnoch, Mirosław and Bartyzel, Jakub and O'doherty, Simon},
title = {Monitoring of Greenhouse Gases in the Atmosphere-A Polish Perspective},
journal = {Papers on Global Change IGBP},
year = {2016},
volume = {23},
number = {1},
pages = {111--126},
url = {http://www.degruyter.com/view/j/igbp.2016.23.issue-1/igbp-2016-0009/igbp-2016-0009.xml},
doi = {10.1515/igbp-2016-0009}
}
|
| Rutgers M, Wouterse M, Drost SM, Breure AM, Mulder C, Stone D, Creamer RE, Winding A and Bloem J (2016), "Monitoring soil bacteria with community-level physiological profiles using Biologâ„¢ ECO-plates in the Netherlands and Europe", Applied Soil Ecology., jan, 2016. Vol. 97, pp. 23-35. |
| Abstract: Soil samples were analyzed with community-level physiological profiles (CLPP) using Biologâ„¢ ECO-plates in the Netherlands Soil Monitoring Network (NSMN; 704 samples) and in a European-wide transect (73 samples). The selection of sites was based on a representative sample of major soil texture types, land uses and climate zones. This method for determination of CLPP was specifically designed to be applied in large and long-term monitoring activities. It encompassed a solution for the inoculum-density dependence of colour formation patterns in ECO-plates, through stepwise dilution to extinction of the bacterial inoculum. The CLPP in Dutch and European soil samples appeared to be reproducible and sensitive to land use and/or soil texture. Although the method is selective, CLPP based parameters correlated well with other microbial parameters and soil characteristics. Consistent patterns in CLPP and soil habitat characteristics are emerging, as brought about by environmental disturbances, land management and soil texture. The applicability of CLPP analysis in monitoring systems is discussed. |
BibTeX:
@article{Rutgers2016,
author = {Rutgers, Michiel and Wouterse, Marja and Drost, Sytske M and Breure, Anton M and Mulder, Christian and Stone, Dorothy and Creamer, Rachel E and Winding, Anne and Bloem, Jaap},
title = {Monitoring soil bacteria with community-level physiological profiles using Biologâ„¢ ECO-plates in the Netherlands and Europe},
journal = {Applied Soil Ecology},
year = {2016},
volume = {97},
pages = {23--35},
url = {https://linkinghub.elsevier.com/retrieve/pii/S0929139315300238},
doi = {10.1016/j.apsoil.2015.06.007}
}
|
| Sabbatini S, Arriga N, Bertolini T, Castaldi S, Chiti T, Consalvo C, Njakou Djomo S, Gioli B, Matteucci G and Papale D (2016), "Greenhouse gas balance of cropland conversion to bioenergy poplar short-rotation coppice", Biogeosciences., jan, 2016. Vol. 13(1), pp. 95-113. |
| Abstract: The production of bioenergy in Europe is one of the strategies conceived to reduce greenhouse gas (GHG) emissions. The suitability of the land use change from a cropland (REF site) to a short-rotation coppice plantation of hybrid poplar (SRC site) was investigated by comparing the GHG budgets of these two systems over 24 months in Viterbo, Italy. This period corresponded to a single rotation of the SRC site. The REF site was a crop rotation between grassland and winter wheat, i.e. the same management of the SRC site before the conversion to short-rotation coppice. Eddy covariance measurements were carried out to quantify the net ecosystem exchange of CO2 (FCO2/, whereas chambers were used to measure N2O and CH4 emissions from soil. The measurements began 2 years after the conversion of arable land to SRC so that an older poplar plantation was used to estimate the soil organic carbon (SOC) loss due to SRC establishment and to estimate SOC recovery over time. Emissions from tractors and from production and transport of agricultural inputs (FMAN/were modelled. A GHG emission offset, due to the substitution of natural gas with SRC biomass, was credited to the GHG budget of the SRC site. Emissions generated by the use of biomass (FEXP/were also considered. Suitability was finally assessed by comparing the GHG budgets of the two sites. CO2 uptake was 3512±224 g CO2 m-2 at the SRC site in 2 years, and 1838±107 g CO2 m-2 at the REF site. FEXP was equal to 1858±240 g CO2 m-2 at the REF site, thus basically compensating for FCO2 , while it was 1118±521 g CO2 m-2 at the SRC site. The SRC site could offset 379.7±175.1 g CO2eqm-2 from fossil fuel displacement. Soil CH4 and N2O fluxes were negligible. FMAN made up 2 and 4% in the GHG budgets of SRC and REF sites respectively, while the SOC loss was 455±524 g CO2 m-2 in 2 years. Overall, the REF site was close to neutrality from a GHG perspective (156±264 g CO2eqm-2/, while the SRC site was a net sink of 2202±792 g CO2eqm-2. In conclusion the experiment led to a positive evaluation from a GHG viewpoint of the conversion of cropland to bioenergy SRC. |
BibTeX:
@article{Sabbatini2016,
author = {Sabbatini, S and Arriga, N and Bertolini, T and Castaldi, S and Chiti, T and Consalvo, C and Njakou Djomo, S and Gioli, B and Matteucci, G and Papale, D},
title = {Greenhouse gas balance of cropland conversion to bioenergy poplar short-rotation coppice},
journal = {Biogeosciences},
year = {2016},
volume = {13},
number = {1},
pages = {95--113},
url = {https://www.biogeosciences.net/13/95/2016/},
doi = {10.5194/bg-13-95-2016}
}
|
| Santalahti M, Sun H, Jumpponen A, Pennanen T and Heinonsalo J (2016), "Vertical and seasonal dynamics of fungal communities in boreal Scots pine forest soil", FEMS Microbiology Ecology., nov, 2016. Vol. 92(11), pp. fiw170. Oxford University Press (OUP). |
| Abstract: Fungal communities are important for carbon (C) transformations in boreal forests that are one of the largest C pools in terrestrial ecosystems, warranting thus further investigation of fungal community dynamics in time and space. We investigated fungal diversity and community composition seasonally and across defined soil horizons in boreal Scots pine forest in Finland using 454-pyrosequencing. We collected a total of 120 samples from five vertical soil horizons monthly from March to October; in March, under snow. Boreal forest soil generally harbored diverse fungal communities across soil horizons. The communities shifted drastically and rapidly over time. In late winter, saprotrophs dominated the community and were replaced by ectomycorrhizal fungi during the growing season. Our studies are among the first to dissect the spatial and temporal dynamics in boreal forest ecosystems and highlights the ecological importance of vertically distinct communities and their rapid seasonal dynamics. As climate change is predicted to result in warmer and longer snow-free winter seasons, as well as increase the rooting depth of trees in boreal forest, the seasonal and vertical distribution of fungal communities may change. These changes are likely to affect the organic matter decomposition by the soil-inhabiting fungi and thus alter organic C pools. |
BibTeX:
@article{Santalahti2016,
author = {Santalahti, Minna and Sun, Hui and Jumpponen, Ari and Pennanen, Taina and Heinonsalo, Jussi},
title = {Vertical and seasonal dynamics of fungal communities in boreal Scots pine forest soil},
journal = {FEMS Microbiology Ecology},
publisher = {Oxford University Press (OUP)},
year = {2016},
volume = {92},
number = {11},
pages = {fiw170},
doi = {10.1093/femsec/fiw170}
}
|
| Satar E, Berhanu TA, Brunner D, Henne S and Leuenberger M (2016), "Continuous CO2/CH4/CO measurements (2012-2014) at Beromunster tall tower station in Switzerland", Biogeosciences., may, 2016. Vol. 13(9), pp. 2623-2635. |
| Abstract: The understanding of the continental carbon budget is essential to predict future climate change. In order to quantify CO2 and CH4 fluxes at the regional scale, a measurement system was installed at the former radio tower in Beromünster as part of the Swiss greenhouse gas monitoring network (CarboCount CH). We have been measuring the mixing ratios of CO2, CH4 and CO on this tower with sample inlets at 12.5, 44.6, 71.5, 131.6 and 212.5m above ground level using a cavity ring down spectroscopy (CRDS) analyzer. The first 2-year (December 2012-December 2014) continuous atmospheric record was analyzed for seasonal and diurnal variations and inter-species correlations. In addition, storage fluxes were calculated from the hourly profiles along the tower. The atmospheric growth rates from 2013 to 2014 determined from this 2-year data set were 1.78 ppm yr-1, 9.66 ppb yr-1 and-1.27 ppb yr-1 for CO2, CH4 and CO, respectively. After detrending, clear seasonal cycles were detected for CO2 and CO, whereas CH4 showed a stable baseline suggesting a net balance between sources and sinks over the course of the year. CO and CO2 were strongly correlated (r2 0.75) in winter (DJF), but almost uncorrelated in summer. In winter, anthropogenic emissions dominate the biospheric CO2 fluxes and the variations in mixing ratios are large due to reduced vertical mixing. The diurnal variations of all species showed distinct cycles in spring and summer, with the lowest sampling level showing the most pronounced diurnal amplitudes. The storage flux estimates exhibited reasonable diurnal shapes for CO2, but underestimated the strength of the surface sinks during daytime. This seems plausible, keeping in mind that we were only able to calculate the storage fluxes along the profile of the tower but not the flux into or out of this profile, since no Eddy covariance flux measurements were taken at the top of the tower. |
BibTeX:
@article{Satar2016,
author = {Satar, Ece and Berhanu, Tesfaye A and Brunner, Dominik and Henne, Stephan and Leuenberger, Markus},
title = {Continuous CO2/CH4/CO measurements (2012-2014) at Beromunster tall tower station in Switzerland},
journal = {Biogeosciences},
year = {2016},
volume = {13},
number = {9},
pages = {2623--2635},
url = {http://www.biogeosciences.net/13/2623/2016/},
doi = {10.5194/bg-13-2623-2016}
}
|
| Schaefer H, Fletcher SE, Veidt C, Lassey KR, Brailsford GW, Bromley TM, Dlugokencky EJ, Michel SE, Miller JB, Levin I, Lowe DC, Martin RJ, Vaughn BH and White JWC (2016), "A 21st-century shift from fossil-fuel to biogenic methane emissions indicated by 13CH4", Science., apr, 2016. Vol. 352(6281), pp. 80-84. |
| Abstract: Between 1999 and 2006, a plateau interrupted the otherwise continuous increase of atmospheric methane concentration [CH4] since preindustrial times. Causes could be sink variability or a temporary reduction in industrial or climate-sensitive sources. We reconstructed the global history of [CH4] and its stable carbon isotopes from ice cores, archived air, and a global network of monitoring stations. A box-model analysis suggests that diminishing thermogenic emissions, probably from the fossil-fuel industry, and/or variations in the hydroxyl CH4 sink caused the [CH4] plateau. Thermogenic emissions did not resume to cause the renewed [CH4] rise after 2006, which contradicts emission inventories. Post-2006 source increases are predominantly biogenic, outside the Arctic, and arguably more consistent with agriculture than wetlands. If so, mitigating CH4 emissions must be balanced with the need for food production. |
BibTeX:
@article{Schaefer2016,
author = {Schaefer, Hinrich and Fletcher, Sara E.Mikaloff and Veidt, Cordelia and Lassey, Keith R and Brailsford, Gordon W and Bromley, Tony M and Dlugokencky, Edward J and Michel, Sylvia E and Miller, John B and Levin, Ingeborg and Lowe, Dave C and Martin, Ross J and Vaughn, Bruce H and White, James W C},
title = {A 21st-century shift from fossil-fuel to biogenic methane emissions indicated by 13CH4},
journal = {Science},
year = {2016},
volume = {352},
number = {6281},
pages = {80--84},
url = {http://www.sciencemag.org/cgi/doi/10.1126/science.aad2705},
doi = {10.1126/science.aad2705}
}
|
| Schibig MF, Mahieu E, Henne S, Lejeune B and Leuenberger MC (2016), "Intercomparison of in situ NDIR and column FTIR measurements of CO2 at Jungfraujoch", Atmospheric Chemistry and Physics., aug, 2016. Vol. 16(15), pp. 9935-9949. |
| Abstract: We compare two CO2 time series measured at the High Alpine Research Station Jungfraujoch, Switzerland (3580ma.s.l.), in the period from 2005 to 2013 with an in situ surface measurement system using a nondispersive infrared analyzer (NDIR) and a ground-based remote sensing system using solar absorption Fourier transform infrared (FTIR) spectrometry. Although the two data sets show an absolute shift of about 13 ppm, the slopes of the annual CO2 increase are in good agreement within their uncertainties. They are 2.04±0.07 and 1.97±0.05 ppm yr-1 for the FTIR and the NDIR systems, respectively. The seasonality of the FTIR and the NDIR systems is 4.46±1.11 and 10.10±0.73 ppm, respectively. The difference is caused by a dampening of the CO2 signal with increasing altitude due to mixing processes. Whereas the minima of both data series occur in the middle of August, the maxima of the two data sets differ by about 10 weeks; the maximum of the FTIR measurements is in the middle of January, and the maximum of the NDIR measurements is found at the end of March. Sensitivity analyses revealed that the air masses measured by the NDIR system at the surface of Jungfraujoch are mainly influenced by central Europe, whereas the air masses measured by the FTIR system in the column above Jungfraujoch are influenced by regions as far west as the Caribbean and the USA. The correlation between the hourly averaged CO2 values of the NDIR system and the individual FTIR CO2 measurements is 0.820, which is very encouraging given the largely different sampling volumes. Further correlation analyses showed, that the correlation is mainly driven by the annual CO2 increase and to a lesser degree by the seasonality. Both systems are suitable to monitor the long-term CO2 increase, because this signal is represented in the whole atmosphere due to mixing. |
BibTeX:
@article{Schibig2016,
author = {Schibig, Michael F and Mahieu, Emmanuel and Henne, Stephan and Lejeune, Bernard and Leuenberger, Markus C},
title = {Intercomparison of in situ NDIR and column FTIR measurements of CO2 at Jungfraujoch},
journal = {Atmospheric Chemistry and Physics},
year = {2016},
volume = {16},
number = {15},
pages = {9935--9949},
url = {http://www.atmos-chem-phys.net/16/9935/2016/},
doi = {10.5194/acp-16-9935-2016}
}
|
| Senapati N, Jansson PE, Smith P and Chabbi A (2016), "Modelling heat, water and carbon fluxes in mown grassland under multi-objective and multi-criteria constraints", Environmental Modelling and Software., jun, 2016. Vol. 80, pp. 201-224. Elsevier Ltd. |
| Abstract: A Monte Carlo-based calibration and uncertainty assessment was performed for heat, water and carbon (C) fluxes, simulated by a soil-plant-atmosphere system model (CoupModel), in mown grassland. Impact of different multi-objective and multi-criteria constraints was investigated on model performance and parameter behaviour. Good agreements between hourly modelled and measurement data were obtained for latent and sensible heat fluxes (R2 = 0.61, ME = 0.48 MJ m-2 day-1), soil water contents (R2 = 0.68, ME = 0.34%) and carbon-dioxide flux (R2 = 0.60, ME = -0.18 g C m-2 day-1). Multi-objective and multi-criteria constraints were efficient in parameter conditioning, reducing simulation uncertainty and identifying critical parameters. Enforcing multi-constraints separately on heat, water and C processes resulted in the highest model improvement for that specific process, including some improvement too for other processes. Imposing multi-constraints on all groups of variables, associated with heat, water and C fluxes together, resulted in general effective parameters conditioning and model improvement. |
BibTeX:
@article{Senapati2016,
author = {Senapati, Nimai and Jansson, Per Erik and Smith, Pete and Chabbi, Abad},
title = {Modelling heat, water and carbon fluxes in mown grassland under multi-objective and multi-criteria constraints},
journal = {Environmental Modelling and Software},
publisher = {Elsevier Ltd},
year = {2016},
volume = {80},
pages = {201--224},
doi = {10.1016/j.envsoft.2016.02.025}
}
|
| Serrano-Ortiz P, Sánchez-Cañete EP, Olmo FJ, Metzger S, Pérez-Priego O, Carrara A, Alados-Arboledas L and Kowalski AS (2016), "Surface-Parallel Sensor Orientation for Assessing Energy Balance Components on Mountain Slopes", Boundary-Layer Meteorology., mar, 2016. Vol. 158(3), pp. 489-499. |
| Abstract: The consistency of eddy-covariance measurements is often evaluated in terms of the degree of energy balance closure. Even over sloping terrain, instrumentation for measuring energy balance components is commonly installed horizontally, i.e. perpendicular to the geo-potential gradient. Subsequently, turbulent fluxes of sensible and latent heat are rotated perpendicular to the mean streamlines using tilt-correction algorithms. However, net radiation (Formula presented.) and soil heat fluxes (G) are treated differently, and typically only (Formula presented.) is corrected to account for slope. With an applied case study, we show and argue several advantages of installing sensors surface-parallel to measure surface-normal (Formula presented.) and G. For a 17 % south-west-facing slope, our results show that horizontal installation results in hysteresis in the energy balance closure and errors of up to 25 %. Finally, we propose an approximation to estimate the surface-normal (Formula presented.) , when only vertical (Formula presented.) measurements are available. |
BibTeX:
@article{Serrano-Ortiz2016,
author = {Serrano-Ortiz, P and Sánchez-Cañete, E P and Olmo, F J and Metzger, S and Pérez-Priego, O and Carrara, A and Alados-Arboledas, L and Kowalski, A S},
title = {Surface-Parallel Sensor Orientation for Assessing Energy Balance Components on Mountain Slopes},
journal = {Boundary-Layer Meteorology},
year = {2016},
volume = {158},
number = {3},
pages = {489--499},
url = {http://link.springer.com/10.1007/s10546-015-0099-4},
doi = {10.1007/s10546-015-0099-4}
}
|
| Shurpali NJ, Rannik Ü, Jokinen S, Lind S, Biasi C, Mammarella I, Peltola O, Pihlatie M, Hyvönen N, Räty M, Haapanala S, Zahniser M, Virkajärvi P, Vesala T and Martikainen PJ (2016), "Neglecting diurnal variations leads to uncertainties in terrestrial nitrous oxide emissions", Scientific Reports., may, 2016. Vol. 6 Nature Publishing Group. |
| Abstract: Nitrous oxide (N 2 O) is an important greenhouse gas produced in soil and aquatic ecosystems. Its warming potential is 296 times higher than that of CO 2. Most N 2 O emission measurements made so far are limited in temporal and spatial resolution causing uncertainties in the global N 2 O budget. Recent advances in laser spectroscopic techniques provide an excellent tool for area-integrated, direct and continuous field measurements of N 2 O fluxes using the eddy covariance method. By employing this technique on an agricultural site with four laser-based analysers, we show here that N 2 O exchange exhibits contrasting diurnal behaviour depending upon soil nitrogen availability. When soil N was high due to fertilizer application, N 2 O emissions were higher during daytime than during the night. However, when soil N became limited, emissions were higher during the night than during the day. These reverse diurnal patterns supported by isotopic analyses may indicate a dominant role of plants on microbial processes associated with N 2 O exchange. This study highlights the potential of new technologies in improving estimates of global N 2 O sources. |
BibTeX:
@article{Shurpali2016,
author = {Shurpali, Narasinha J. and Rannik, Üllar and Jokinen, Simo and Lind, Saara and Biasi, Christina and Mammarella, Ivan and Peltola, Olli and Pihlatie, Mari and Hyvönen, Niina and Räty, Mari and Haapanala, Sami and Zahniser, Mark and Virkajärvi, Perttu and Vesala, Timo and Martikainen, Pertti J.},
title = {Neglecting diurnal variations leads to uncertainties in terrestrial nitrous oxide emissions},
journal = {Scientific Reports},
publisher = {Nature Publishing Group},
year = {2016},
volume = {6},
doi = {10.1038/srep25739}
}
|
| Shutler JD, Land PE, Piolle JF, Woolf DK, Goddijn-Murphy L, Paul F, Girard-Ardhuin F, Chapron B and Donlon CJ (2016), "FluxEngine: A flexible processing system for calculating atmosphere-ocean carbon dioxide gas fluxes and climatologies", Journal of Atmospheric and Oceanic Technology., apr, 2016. Vol. 33(4), pp. 741-756. American Meteorological Society. |
| Abstract: The air-sea flux of greenhouse gases [e.g., carbon dioxide (CO2)] is a critical part of the climate system and a major factor in the biogeochemical development of the oceans. More accurate and higher-resolution calculations of these gas fluxes are required if researchers are to fully understand and predict future climate. Satellite Earth observation is able to provide large spatial-scale datasets that can be used to study gas fluxes. However, the large storage requirements needed to host such data can restrict its use by the scientific community. Fortunately, the development of cloud computing can provide a solution. This paper describes an open-source air-sea CO2 flux processing toolbox called the "FluxEngine," designed for use on a cloud-computing infrastructure. The toolbox allows users to easily generate global and regional air-sea CO2 flux data from model, in situ, and Earth observation data, and its air-sea gas flux calculation is user configurable. Its current installation on the Nephalae Cloud allows users to easily exploit more than 8 TB of climate-quality Earth observation data for the derivation of gas fluxes. The resultant netCDF data output files contain textgreater 20 data layers containing the various stages of the flux calculation along with process indicator layers to aid interpretation of the data. This paper describes the toolbox design, which verifies the air-sea CO2 flux calculations; demonstrates the use of the tools for studying global and shelf sea air-sea fluxes; and describes future developments. |
BibTeX:
@article{Shutler2016,
author = {Shutler, Jamie D. and Land, Peter E. and Piolle, Jean Francois and Woolf, David K. and Goddijn-Murphy, Lonneke and Paul, Frederic and Girard-Ardhuin, Fanny and Chapron, Bertrand and Donlon, Craig J.},
title = {FluxEngine: A flexible processing system for calculating atmosphere-ocean carbon dioxide gas fluxes and climatologies},
journal = {Journal of Atmospheric and Oceanic Technology},
publisher = {American Meteorological Society},
year = {2016},
volume = {33},
number = {4},
pages = {741--756},
url = {http://globwave.ifremer.fr/},
doi = {10.1175/JTECH-D-14-00204.1}
}
|
| Simmonds PG, Rigby M, Manning AJ, Lunt MF, O'Doherty S, McCulloch A, Fraser PJ, Henne S, Vollmer MK, Mühle J, Weiss RF, Salameh PK, Young D, Reimann S, Wenger A, Arnold T, Harth CM, Krummel PB, Steele LP, Dunse BL, Miller BR, Lunder CR, Hermansen O, Schmidbauer N, Saito T, Yokouchi Y, Park S, Li S, Yao B, Zhou LX, Arduini J, Maione M, Wang RHJ, Ivy D and Prinn RG (2016), "Global and regional emissions estimates of 1,1-difluoroethane (HFC-152a, CH3CHF2) from in situ and air archive observations", Atmospheric Chemistry and Physics., jan, 2016. Vol. 16(1), pp. 365-382. |
| Abstract: High frequency, in situ observations from 11 globally distributed sites for the period 1994-2014 and archived air measurements dating from 1978 onward have been used to determine the global growth rate of 1,1-difluoroethane (HFC-152a, CH3CHF2). These observations have been combined with a range of atmospheric transport models to derive global emission estimates in a top-down approach. HFC-152a is a greenhouse gas with a short atmospheric lifetime of about 1.5 years. Since it does not contain chlorine or bromine, HFC-152a makes no direct contribution to the destruction of stratospheric ozone and is therefore used as a substitute for the ozone depleting chlorofluorocarbons (CFCs) and hydrochlorofluorocarbons (HCFCs). The concentration of HFC-152a has grown substantially since the first direct measurements in 1994, reaching a maximum annual global growth rate of 0.84 ± 0.05 ppt yr1 in 2006, implying a substantial increase in emissions up to 2006. However, since 2007, the annual rate of growth has slowed to 0.38 ± 0.04 ppt yr1 in 2010 with a further decline to an annual average rate of growth in 2013-2014 of -0.06 ± 0.05 ppt yr1. The annual average Northern Hemisphere (NH) mole fraction in 1994 was 1.2 ppt rising to an annual average mole fraction of 10.1 ppt in 2014. Average annual mole fractions in the Southern Hemisphere (SH) in 1998 and 2014 were 0.84 and 4.5 ppt, respectively. We estimate global emissions of HFC-152a have risen from 7.3 ± 5.6 Gg yr1 in 1994 to a maximum of 54.4 ± 17.1 Gg yr1 in 2011, declining to 52.5 ± 20.1 Gg yr1 in 2014 or 7.2 ± 2.8 Tg-CO2 eq yr1. Analysis of mole fraction enhancements above regional background atmospheric levels suggests substantial emissions from North America, Asia, and Europe. Global HFC emissions (so called "bottom up" emissions) reported by the United Nations Framework Convention on Climate Change (UNFCCC) are based on cumulative national emission data reported to the UNFCCC, which in turn are based on national consumption data. There appears to be a significant underestimate ( 20 Gg) of "bottom-up" reported emissions of HFC-152a, possibly arising from largely underestimated USA emissions and undeclared Asian emissions. |
BibTeX:
@article{Simmonds2016,
author = {Simmonds, P G and Rigby, M and Manning, A J and Lunt, M F and O'Doherty, S and McCulloch, A and Fraser, P J and Henne, S and Vollmer, M K and Mühle, J and Weiss, R F and Salameh, P K and Young, D and Reimann, S and Wenger, A and Arnold, T and Harth, C M and Krummel, P B and Steele, L P and Dunse, B L and Miller, B R and Lunder, C R and Hermansen, O and Schmidbauer, N and Saito, T and Yokouchi, Y and Park, S and Li, S and Yao, B and Zhou, L X and Arduini, J and Maione, M and Wang, R H J and Ivy, D and Prinn, R G},
title = {Global and regional emissions estimates of 1,1-difluoroethane (HFC-152a, CH3CHF2) from in situ and air archive observations},
journal = {Atmospheric Chemistry and Physics},
year = {2016},
volume = {16},
number = {1},
pages = {365--382},
url = {http://www.atmos-chem-phys.net/16/365/2016/},
doi = {10.5194/acp-16-365-2016}
}
|
| Soubie R, Heinesch B, Granier A, Aubinet M and Vincke C (2016), "Evapotranspiration assessment of a mixed temperate forest by four methods: Eddy covariance, soil water budget, analytical and model", Agricultural and Forest Meteorology., nov, 2016. Vol. 228-229, pp. 191-204. |
| Abstract: In forest ecosystems, assessment of evapotranspiration fluxes (ET) and distinction of its components, i.e. tree transpiration (T), rainfall interception (I), and soil plus understory evapotranspiration (ETu), are a major issue. At the Vielsalm Terrestrial Observatory in Belgium (VTO, Integrated Carbon Observation System network, ICOS), covered by a mixed forest of broadleaved (mainly Fagus sylvatica L.) and coniferous species (mainly Pseudotsuga menziesii [Mirb.] Franco), the water vapor fluxes have been continuously measured by eddy covariance since 1996, without distinction of its components. Widely validated for CO2 fluxes, water vapor fluxes measured by eddy covariance still lack validation, particularly in mixed and/or heterogeneous stands. During 2010–2011, three other methods to assess ET were implemented, in order to inter-validate them and to disentangle species specific ET into its components. These methods were: (i) the analytical method which relies on measurement of each elementary flux, i.e. tree transpiration, interception loss and evapotranspiration of soil plus understory (ETA); (ii) the soil water budget method (ETS) and (iii) modeling of stand ET (ETM). Our results showed that during dry foliage conditions, stand T + ETu estimated by the analytical method or model were in very good agreement with eddy covariance ET measurements. Interception loss measured was 14% and 30% of rainfall (P) for beech and Douglas-fir respectively, leading to 19% for the whole stand. Beech interception being quite low, ETA for the stand is probably slightly underestimated. Over 2010 and 2011, the mean seasonal value of ET was 1.9 mm dâˆ'1, considering all the methods. The four methods gave close estimates, with maximum deviations from the mean being of 12%, and uncertainties, while remaining acceptable (maximum 26% with analytical method) overlap between methods. Regardless of methods, flux measurements during rainy conditions were more complex to characterize. A slight underestimation of ET by the eddy covariance method was observed at different time step, in comparison to the others implemented methods. On an annual scale, the forest water balance model estimates (BILJOUtextcopyright; ETM) were similar in beech (68% of potential evapotranspiration, PET) and Douglas-fir sub-stands (72% of PET), despite their differences in phenology and water use patterns. Low differences were also observed between species in the water flux partitioning, with modeled ET composed of ca. 58%, 33% and 9% of T, I and ETu respectively on the annual timescale (2010–2011). |
BibTeX:
@article{Soubie2016,
author = {Soubie, R and Heinesch, B and Granier, A and Aubinet, M and Vincke, C},
title = {Evapotranspiration assessment of a mixed temperate forest by four methods: Eddy covariance, soil water budget, analytical and model},
journal = {Agricultural and Forest Meteorology},
year = {2016},
volume = {228-229},
pages = {191--204},
url = {http://linkinghub.elsevier.com/retrieve/pii/S0168192316303276},
doi = {10.1016/j.agrformet.2016.07.001}
}
|
| Spank U, Köstner B, Moderow U, Grünwald T and Bernhofer C (2016), "Surface conductance of five different crops based on 10 years of eddy-covariance measurements", Meteorologische Zeitschrift., jun, 2016. Vol. 25(3), pp. 251-256. |
| Abstract: The Penman-Monteith (PM) equation is a state-of-the-art modelling approach to simulate evapotranspiration (ET) at site and local scale. However, its practical application is often restricted by the availability and quality of required parameters. One of these parameters is the canopy conductance. Long term measurements of evapotranspiration by the eddy-covariance method provide an improved data basis to determine this parameter by inverse modelling. Because this approach may also include evaporation from the soil, not only the 'actual' canopy conductance but the whole surface conductance (gc) is addressed. Two full cycles of crop rotation with five different crop types (winter barley, winter rape seed, winter wheat, silage maize, and spring barley) have been continuously monitored for 10 years. These data form the basis for this study. As estimates of gc are obtained on basis of measurements, we investigated the impact of measurements uncertainties on obtained values of gc. Here, two different foci were inspected more in detail. Firstly, the effect of the energy balance closure gap (EBCG) on obtained values of gc was analysed. Secondly, the common hydrological practice to use vegetation height (hc) to determine the period of highest plant activity (i.e., times with maximum gc concerning CO2-exchange and transpiration) was critically reviewed. The results showed that hc and gc do only agree at the beginning of the growing season but increasingly differ during the rest of the growing season. Thus, the utilisation of hc as a proxy to assess maximum gc (gc, max) can lead to inaccurate estimates of gc, max which in turn can cause serious shortcomings in simulated ET. The light use efficiency (LUE) is superior to hc as a proxy to determine periods with maximum gc. Based on this proxy, crop specific estimates of gc, max could be determined for the first (and the second) cycle of crop rotation: winter barley, 19.2mms-1 (16.0mms-1); winter rape seed, 12.3mms-1 (13.1mms-1); winter wheat, 16.5mms-1 (11.2mms-1); silage maize, 7.4mms-1 (8.5mms-1); and spring barley, 7.0mms-1 (6.2mms-1). |
BibTeX:
@article{Spank2016,
author = {Spank, Uwe and Köstner, Barbara and Moderow, Uta and Grünwald, Thomas and Bernhofer, Christian},
title = {Surface conductance of five different crops based on 10 years of eddy-covariance measurements},
journal = {Meteorologische Zeitschrift},
year = {2016},
volume = {25},
number = {3},
pages = {251--256},
url = {http://www.schweizerbart.de/papers/metz/detail/25/85526/Surface_Conductance_of_Five_Different_Crops_Based_?af=crossref},
doi = {10.1127/metz/2016/0732}
}
|
| Sperlich P, Uitslag NAM, Richter JM, Rothe M, Geilmann H, van der Veen C, Röckmann T, Blunier T and Brand WA (2016), "Development and evaluation of a suite of isotope reference gases for methane in air", Atmospheric Measurement Techniques Discussions., jan, 2016. , pp. 1-24. |
| Abstract: Measurements made by multiple analytical facilities can only be comparable if they are related to a unifying and traceable reference. However, reference materials that fulfil these fundamental requirements are unavailable for the analysis of isotope ratios in atmospheric methane, which led to misinterpretations of combined data sets in the past. We developed a method to produce a suite of standard gases that can be used to unify methane isotope ratio measurements of laboratories in the atmospheric monitoring community. We calibrated a suite of pure methane gases of different methanogenic origin against international referencing materials that define the VSMOW and VPDB isotope scales. The isotope ratios of our pure methane gases range between âˆ'320 and +40 ‰ for δsup2/supH-CHsub4/sub and between âˆ'70 and âˆ'40 ‰ for δsup13/supC-CHsub4/sub, enveloping the isotope ratios of tropospheric methane (about âˆ'90 ‰ and âˆ'47 ‰ for δsup2/supH-CHsub4/sub and δsup13/supC-CHsub4/sub, respectively). We estimate combined uncertainties for our δsup2/supH and δsup13/supC calibrations of 1.5 ‰ and 0.2 ‰, respectively. Aliquots of the calibrated pure methane gases have been diluted with methane-free air to atmospheric methane levels and filled into 5-L glass flasks. These synthetic gas mixtures comprise atmospheric oxygen/nitrogen ratios as well as appropriate argon, krypton and nitrous oxide mole fractions to prevent gas-specific measurement artefacts. The resulting synthetic atmospheric reference gases will be available to the atmospheric monitoring community. This will provide unifying isotope scale anchors for isotope ratio measurements of atmospheric methane so that data sets can be merged into a consistent global data frame. |
BibTeX:
@article{Sperlich2016,
author = {Sperlich, P and Uitslag, N A M and Richter, J M and Rothe, M and Geilmann, H and van der Veen, C and Röckmann, T and Blunier, T and Brand, W A},
title = {Development and evaluation of a suite of isotope reference gases for methane in air},
journal = {Atmospheric Measurement Techniques Discussions},
year = {2016},
pages = {1--24},
url = {http://www.atmos-meas-tech-discuss.net/amt-2016-15/},
doi = {10.5194/amt-2016-15}
}
|
| Stepanenko V, Mammarella I, Ojala A, Miettinen H, Lykosov V and Vesala T (2016), "LAKE 2.0: A model for temperature, methane, carbon dioxide and oxygen dynamics in lakes", Geoscientific Model Development., may, 2016. Vol. 9(5), pp. 1977-2006. Copernicus GmbH. |
| Abstract: A one-dimensional (1-D) model for an enclosed basin (lake) is presented, which reproduces temperature, horizontal velocities, oxygen, carbon dioxide and methane in the basin. All prognostic variables are treated in a unified manner via a generic 1-D transport equation for horizontally averaged property. A water body interacts with underlying sediments. These sediments are represented by a set of vertical columns with heat, moisture and CH4 transport inside. The model is validated vs. a comprehensive observational data set gathered at Kuivajärvi Lake (southern Finland), demonstrating a fair agreement. The value of a key calibration constant, regulating the magnitude of methane production in sediments, corresponded well to that obtained from another two lakes. We demonstrated via surface seiche parameterization that the near-bottom turbulence induced by surface seiches is likely to significantly affect CH4 accumulation there. Furthermore, our results suggest that a gas transfer through thermocline under intense internal seiche motions is a bottleneck in quantifying greenhouse gas dynamics in dimictic lakes, which calls for further research. |
BibTeX:
@article{Stepanenko2016,
author = {Stepanenko, Victor and Mammarella, Ivan and Ojala, Anne and Miettinen, Heli and Lykosov, Vasily and Vesala, Timo},
title = {LAKE 2.0: A model for temperature, methane, carbon dioxide and oxygen dynamics in lakes},
journal = {Geoscientific Model Development},
publisher = {Copernicus GmbH},
year = {2016},
volume = {9},
number = {5},
pages = {1977--2006},
doi = {10.5194/gmd-9-1977-2016}
}
|
| Stone D, Blomkvist P, Hendriksen NB, Bonkowski M, Jørgensen HB, Carvalho F, Dunbar MB, Gardi C, Geisen S, Griffiths R, Hug AS, Jensen J, Laudon H, Mendes S, Morais PV, Orgiazzi A, Plassart P, Römbke J, Rutgers M, Schmelz RM, Sousa JP, Steenbergen E, Suhadolc M, Winding A, Zupan M, Lemanceau P and Creamer RE (2016), "A method of establishing a transect for biodiversity and ecosystem function monitoring across Europe", Applied Soil Ecology., jan, 2016. Vol. 97, pp. 3-11. |
| Abstract: The establishment of the range of soil biodiversity found within European soils is needed to guide EU policy development regarding the protection of soil. Such a base-line should be collated from a wide-ranging sampling campaign to ensure that soil biodiversity from the majority of soil types, land-use or management systems, and European climatic (bio-geographical zones) were included. This paper reports the design and testing of a method to achieve the large scale sampling associated with the establishment of such a baseline, carried out within the remit of the EcoFINDERS project, and outlines points to consider when such a task is undertaken. Applying a GIS spatial selection process, a sampling campaign was undertaken by 13 EcoFINDERS partners across 11 countries providing data on the range of indicators of biodiversity and ecosystem functions including; micro and meso fauna biodiversity, extracellular enzyme activity, PLFA and community level physiological profiling (MicroRespâ„¢ and Biologâ„¢). Physical, chemical and bio-geographical parameters of the 81 sites sampled were used to determine whether the model predicted a wide enough range of sites to allow assessment of the biodiversity indicators tested.Discrimination between the major bio-geographical zones of Atlantic and Continental was possible for all land-use types. Boreal and Alpine zones only allowed discrimination in the most common land-use type for that area e.g. forestry and grassland sites, respectively, while the Mediterranean zone did not have enough sites sampled to draw conclusions across all land-use types. The method used allowed the inclusion of a range of land-uses in both the model prediction stage and the final sites sampled. The establishment of the range of soil biodiversity across Europe is possible, though a larger targeted campaign is recommended. The techniques applied within the EcoFINDERS sampling would be applicable to a larger campaign. |
BibTeX:
@article{Stone2016,
author = {Stone, D and Blomkvist, P and Hendriksen, N Bohse and Bonkowski, M and Jørgensen, H Bracht and Carvalho, F and Dunbar, M B and Gardi, C and Geisen, S and Griffiths, R and Hug, A S and Jensen, J and Laudon, H and Mendes, S and Morais, P V and Orgiazzi, A and Plassart, P and Römbke, J and Rutgers, M and Schmelz, R M and Sousa, J P and Steenbergen, E and Suhadolc, M and Winding, A and Zupan, M and Lemanceau, P and Creamer, R E},
title = {A method of establishing a transect for biodiversity and ecosystem function monitoring across Europe},
journal = {Applied Soil Ecology},
year = {2016},
volume = {97},
pages = {3--11},
url = {https://linkinghub.elsevier.com/retrieve/pii/S0929139315300342},
doi = {10.1016/j.apsoil.2015.06.017}
}
|
| Sun H, Santalahti M, Pumpanen J, Köster K, Berninger F, Raffaello T, Asiegbu FO and Heinonsalo J (2016), "Bacterial community structure and function shift across a northern boreal forest fire chronosequence", Scientific Reports., aug, 2016. Vol. 6 Nature Publishing Group. |
| Abstract: Soil microbial responses to fire are likely to change over the course of forest recovery. Investigations on long-term changes in bacterial dynamics following fire are rare. We characterized the soil bacterial communities across three different times post fire in a 2 to 152-year fire chronosequence by Illumina MiSeq sequencing, coupled with a functional gene array (GeoChip). The results showed that the bacterial diversity did not differ between the recently and older burned areas, suggesting a concomitant recovery in the bacterial diversity after fire. The differences in bacterial communities over time were mainly driven by the rare operational taxonomic units (OTUs textless 0.1%). Proteobacteria (39%), Acidobacteria (34%) and Actinobacteria (17%) were the most abundant phyla across all sites. Genes involved in C and N cycling pathways were present in all sites showing high redundancy in the gene profiles. However, hierarchical cluster analysis using gene signal intensity revealed that the sites with different fire histories formed separate clusters, suggesting potential differences in maintaining essential biogeochemical soil processes. Soil temperature, pH and water contents were the most important factors in shaping the bacterial community structures and function. This study provides functional insight on the impact of fire disturbance on soil bacterial community. |
BibTeX:
@article{Sun2016,
author = {Sun, Hui and Santalahti, Minna and Pumpanen, Jukka and Köster, Kajar and Berninger, Frank and Raffaello, Tommaso and Asiegbu, Fred O. and Heinonsalo, Jussi},
title = {Bacterial community structure and function shift across a northern boreal forest fire chronosequence},
journal = {Scientific Reports},
publisher = {Nature Publishing Group},
year = {2016},
volume = {6},
doi = {10.1038/srep32411}
}
|
| Thompson RL, Patra PK, Chevallier F, Maksyutov S, Law RM, Ziehn T, Van Der Laan-Luijkx IT, Peters W, Ganshin A, Zhuravlev R, Maki T, Nakamura T, Shirai T, Ishizawa M, Saeki T, Machida T, Poulter B, Canadell JG and Ciais P (2016), "Top-down assessment of the Asian carbon budget since the mid 1990s", Nature Communications., feb, 2016. Vol. 7, pp. 10724. |
| Abstract: Increasing atmospheric carbon dioxide (CO2) is the principal driver of anthropogenic climate change. Asia is an important region for the global carbon budget, with 4 of the world's 10 largest national emitters of CO2. Using an ensemble of seven atmospheric inverse systems, we estimated land biosphere fluxes (natural, land-use change and fires) based on atmospheric observations of CO2 concentration. The Asian land biosphere was a net sink of -0.46 (-0.70-0.24) PgC per year (median and range) for 1996-2012 and was mostly located in East Asia, while in South and Southeast Asia the land biosphere was close to carbon neutral. In East Asia, the annual CO2 sink increased between 1996-2001 and 2008-2012 by 0.56 (0.30-0.81) PgC, accounting for ∼35% of the increase in the global land biosphere sink. Uncertainty in the fossil fuel emissions contributes significantly (32%) to the uncertainty in land biosphere sink change. |
BibTeX:
@article{Thompson2016,
author = {Thompson, R L and Patra, P K and Chevallier, F and Maksyutov, S and Law, R M and Ziehn, T and Van Der Laan-Luijkx, I T and Peters, W and Ganshin, A and Zhuravlev, R and Maki, T and Nakamura, T and Shirai, T and Ishizawa, M and Saeki, T and Machida, T and Poulter, B and Canadell, J G and Ciais, P},
title = {Top-down assessment of the Asian carbon budget since the mid 1990s},
journal = {Nature Communications},
year = {2016},
volume = {7},
pages = {10724},
url = {http://www.nature.com/doifinder/10.1038/ncomms10724},
doi = {10.1038/ncomms10724}
}
|
| Tian H, Lu C, Ciais P, Michalak AM, Canadell JG, Saikawa E, Huntzinger DN, Gurney KR, Sitch S, Zhang B, Yang J, Bousquet P, Bruhwiler L, Chen G, Dlugokencky E, Friedlingstein P, Melillo J, Pan S, Poulter B, Prinn R, Saunois M, Schwalm CR and Wofsy SC (2016), "The terrestrial biosphere as a net source of greenhouse gases to the atmosphere", Nature., mar, 2016. Vol. 531(7593), pp. 225-228. |
BibTeX:
@article{Tian2016,
author = {Tian, Hanqin and Lu, Chaoqun and Ciais, Philippe and Michalak, Anna M. and Canadell, Josep G. and Saikawa, Eri and Huntzinger, Deborah N. and Gurney, Kevin R. and Sitch, Stephen and Zhang, Bowen and Yang, Jia and Bousquet, Philippe and Bruhwiler, Lori and Chen, Guangsheng and Dlugokencky, Edward and Friedlingstein, Pierre and Melillo, Jerry and Pan, Shufen and Poulter, Benjamin and Prinn, Ronald and Saunois, Marielle and Schwalm, Christopher R. and Wofsy, Steven C.},
title = {The terrestrial biosphere as a net source of greenhouse gases to the atmosphere},
journal = {Nature},
year = {2016},
volume = {531},
number = {7593},
pages = {225--228},
url = {http://www.nature.com/articles/nature16946},
doi = {10.1038/nature16946}
}
|
| Tramontana G, Jung M, Schwalm CR, Ichii K, Camps-Valls G, Ráduly B, Reichstein M, Arain MA, Cescatti A, Kiely G, Merbold L, Serrano-Ortiz P, Sickert S, Wolf S and Papale D (2016), "Predicting carbon dioxide and energy fluxes across global FLUXNET sites with regression algorithms", Biogeosciences., jul, 2016. Vol. 13(14), pp. 4291-4313. |
| Abstract: Spatio-temporal fields of land-atmosphere fluxes derived from data-driven models can complement simulations by process-based land surface models. While a number of strategies for empirical models with eddy-covariance flux data have been applied, a systematic intercomparison of these methods has been missing so far. In this study, we performed a cross-validation experiment for predicting carbon dioxide, latent heat, sensible heat and net radiation fluxes across different ecosystem types with 11 machine learning (ML) methods from four different classes (kernel methods, neural networks, tree methods, and regression splines). We applied two complementary setups: (1) 8-day average fluxes based on remotely sensed data and (2) daily mean fluxes based on meteorological data and a mean seasonal cycle of remotely sensed variables. The patterns of predictions from different ML and experimental setups were highly consistent. There were systematic differences in performance among the fluxes, with the following ascending order: net ecosystem exchange (R2 0.5), ecosystem respiration (R2 0.6), gross primary production (R2 0.7), latent heat (R2 0.7), sensible heat (R2 0.7), and net radiation (R2 0.8). The ML methods predicted the across-site variability and the mean seasonal cycle of the observed fluxes very well (R2 0.7), while the 8-day deviations from the mean seasonal cycle were not well predicted (R2 0.5). Fluxes were better predicted at forested and temperate climate sites than at sites in extreme climates or less represented by training data (e.g., the tropics). The evaluated large ensemble of ML-based models will be the basis of new global flux products. |
BibTeX:
@article{Tramontana2016,
author = {Tramontana, Gianluca and Jung, Martin and Schwalm, Christopher R and Ichii, Kazuhito and Camps-Valls, Gustau and Ráduly, Botond and Reichstein, Markus and Arain, M Altaf and Cescatti, Alessandro and Kiely, Gerard and Merbold, Lutz and Serrano-Ortiz, Penelope and Sickert, Sven and Wolf, Sebastian and Papale, Dario},
title = {Predicting carbon dioxide and energy fluxes across global FLUXNET sites with regression algorithms},
journal = {Biogeosciences},
year = {2016},
volume = {13},
number = {14},
pages = {4291--4313},
url = {http://www.biogeosciences.net/13/4291/2016/},
doi = {10.5194/bg-13-4291-2016}
}
|
| Vanbeveren SPP, Gebauer R, Plichta R, VolaÅ™ík D and Ceulemans R (2016), "Nutrients and energy in proleptic branches and leaves of poplar under a short-rotation coppice", Biomass and Bioenergy., feb, 2016. Vol. 85, pp. 271-277. |
| Abstract: Renewable energy is often generated from biomass, produced in short-rotation coppice (SRC) cultures. These cultures are frequently established on former agricultural land with ample availability of plant nutrients as nitrogen, phosphorous, potassium, calcium and magnesium. Nevertheless, little is known about the annual recycling of these nutrients through the leaves, as well as about the amounts that are removed at harvest. We therefore quantified soil nutrient concentrations, as well as nutrient concentrations and the gross calorific value of the proleptic branches and of the leaves of 12 poplar (Populus) genotypes in the second rotation of an operational SRC (with two-year rotations). For the produced leaf biomass, we also quantified the standing energy stock and the nutrient stock of each genotype. After four years the P, K, Ca and Mg soil concentrations had not significantly changed, while the N concentration at 30-60 cm of soil depth had significantly increased. On average, the standing aboveground woody biomass of the 12 genotypes in 2013 was 13.75 Mg ha-1 and the total leaf biomass was 3.54 Mg ha-1. This resulted in an average standing energy stock in the leaves of 64.8 GJ ha-1. Nutrient concentrations were lower in the proleptic branches as compared to the leaves, but the proleptic branches and leaf nutrient concentrations significantly varied among the genotypes. |
BibTeX:
@article{Vanbeveren2016,
author = {Vanbeveren, S P P and Gebauer, R and Plichta, R and VolaÅ™ík, D and Ceulemans, R},
title = {Nutrients and energy in proleptic branches and leaves of poplar under a short-rotation coppice},
journal = {Biomass and Bioenergy},
year = {2016},
volume = {85},
pages = {271--277},
url = {http://linkinghub.elsevier.com/retrieve/pii/S0961953415301884},
doi = {10.1016/j.biombioe.2015.12.016}
}
|
| van der Laan S, Manohar SN, Vermeulen AT, Bosveld FC, Meijer HAJ, Manning AC, van der Molen MK and van der Laan-Luijkx IT (2016), "Inferring sup222/supRadon soil fluxes from ambient sup222/supRadon activity and eddy covariance measurements of COsub2/sub", Atmospheric Measurement Techniques Discussions., may, 2016. Vol. 2016, pp. 1-18. Copernicus Publications. |
| Abstract: We present a new methodology, which we call Single Pair of Observations Technique with Eddy Covariance (SPOT- EC), to estimate regional scale surface fluxes of sup222/supRadon (sup222/supRn) from tower-based observations of sup222/supRn activity, COsub2/sub mole fractions and direct COsub2/sub flux measurements from eddy covariance. For specific events, the regional (sup222/supRn) surface flux is calculated from short term changes in ambient (sup222/supRn) activity scaled with the ratio of the mean COsub2/sub surface flux for the specific event versus the change in its observed mole fraction. The resulting sup222/supRn surface emissions are integrated in time (between the moment of observation and the last prior background levels) and space (i.e. over the footprint of the observations). The measurement uncertainty obtained is about ±&thinsp;15&thinsp;% for diurnal events and about ±&thinsp;10&thinsp;% for longer term (e.g. seasonal or annual) means. The method does not provide continuous observations, but reliable daily averages can be obtained. We applied our method to in-situ observations from two sites in the Netherlands: Cabauw station (CBW) and Lutjewad station (LUT). For LUT, which is an intensive agricultural site, we estimated a mean sup222/supRn surface flux of (0.29&thinsp;±&thinsp;0.02) atoms&thinsp;cmsup&minus;2/sup&thinsp;ssup&minus;1/sup with values &thinsp;0.5&thinsp;atoms&thinsp;cmsup&minus;2/sup&thinsp;ssup&minus;1/sup to the south and southeast. For CBW we estimated a mean sup222/supRn surface flux of (0.63&thinsp;±&thinsp;0.04) atoms&thinsp;cmsup&minus;2/sup&thinsp;ssup&minus;1/sup. Highest values were observed to the southwest, where the soil type is mainly peat or river-clay respectively. For both stations a good agreement was found between our results and those from measurements with accumulation chambers and two recently published sup222/supRn soil flux maps for Europe. At both sites, large spatial and temporal variability of sup222/supRn surface fluxes were observed which would be impractical to measure with an accumulation chamber. SPOT-EC therefore offers an important new tool for estimating region scale sup222/supRn surface fluxes and for gaining new insights in the driving mechanisms behind sup222/supRn surface emissions. Practical applications furthermore include calibration of process-based sup222/supRn soil flux models, validation of atmospheric transport models and performing regional scale inversions of e.g. greenhouse gases via the SPOT sup222/supRn-tracer method. |
BibTeX:
@article{VanderLaan2016,
author = {van der Laan, S and Manohar, S N and Vermeulen, A T and Bosveld, F C and Meijer, H A J and Manning, A C and van der Molen, M K and van der Laan-Luijkx, I T},
title = {Inferring sup222/supRadon soil fluxes from ambient sup222/supRadon activity and eddy covariance measurements of COsub2/sub},
journal = {Atmospheric Measurement Techniques Discussions},
publisher = {Copernicus Publications},
year = {2016},
volume = {2016},
pages = {1--18},
doi = {10.5194/amt-2016-93}
}
|
| Van Der Molen MK, De Jeu RAM, Wagner W, Van Der Velde IR, Kolari P, Kurbatova J, Varlagin A, Maximov TC, Kononov AV, Ohta T, Kotani A, Krol MC and Peters W (2016), "The effect of assimilating satellite-derived soil moisture data in SiBCASA on simulated carbon fluxes in Boreal Eurasia", Hydrology and Earth System Sciences., feb, 2016. Vol. 20(2), pp. 605-624. |
| Abstract: Boreal Eurasia is a region where the interaction between droughts and the carbon cycle may have significant impacts on the global carbon cycle. Yet the region is extremely data sparse with respect to meteorology, soil moisture, and carbon fluxes as compared to e.g. Europe. To better constrain our vegetation model SiBCASA, we increase data usage by assimilating two streams of satellite-derived soil moisture. We study whether the assimilation improved SiBCASA's soil moisture and its effect on the simulated carbon fluxes. By comparing to unique in situ soil moisture observations, we show that the passive microwave soil moisture product did not improve the soil moisture simulated by SiBCASA, but the active data seem promising in some aspects. The match between SiBCASA and ASCAT soil moisture is best in the summer months over low vegetation. Nevertheless, ASCAT failed to detect the major droughts occurring between 2007 and 2013. The performance of ASCAT soil moisture seems to be particularly sensitive to ponding, rather than to biomass. The effect on the simulated carbo n fluxes is large, 5-10% on annual GPP and TER, tens of percent on local NEE, and 2% on area-integrated NEE, which is the same order of magnitude as the inter-annual variations. Consequently, this study shows that assimilation of satellite-derived soil moisture has potentially large impacts, while at the same time further research is needed to understand under which conditions the satellite-derived soil moisture improves the simulated soil moisture. |
BibTeX:
@article{VanDerMolen2016,
author = {Van Der Molen, M K and De Jeu, R A M and Wagner, W and Van Der Velde, I R and Kolari, P and Kurbatova, J and Varlagin, A and Maximov, T C and Kononov, A V and Ohta, T and Kotani, A and Krol, M C and Peters, W},
title = {The effect of assimilating satellite-derived soil moisture data in SiBCASA on simulated carbon fluxes in Boreal Eurasia},
journal = {Hydrology and Earth System Sciences},
year = {2016},
volume = {20},
number = {2},
pages = {605--624},
url = {https://www.hydrol-earth-syst-sci.net/20/605/2016/},
doi = {10.5194/hess-20-605-2016}
}
|
| Vardag SN, Hammer S and Levin I (2016), "Evaluation of 4 years of continuous δ13C(CO2) data using a moving Keeling plot method", Biogeosciences., jul, 2016. Vol. 13(14), pp. 4237-4251. Copernicus GmbH. |
| Abstract: Different carbon dioxide (CO2) emitters can be distinguished by their carbon isotope ratios. Therefore measurements of atmospheric δ13C(CO2) and CO2 concentration contain information on the CO2 source mix in the catchment area of an atmospheric measurement site. This information may be illustratively presented as the mean isotopic source signature. Recently an increasing number of continuous measurements of δ13C(CO2) and CO2 have become available, opening the door to the quantification of CO2 shares from different sources at high temporal resolution. Here, we present a method to compute the CO2 source signature (δS) continuously and evaluate our result using model data from the Stochastic Time-Inverted Lagrangian Transport model. Only when we restrict the analysis to situations which fulfill the basic assumptions of the Keeling plot method does our approach provide correct results with minimal biases in δS. On average, this bias is 0.2%with an interquartile range of about 1.2 % for hourly model data. As a consequence of applying the required strict filter criteria, 85% of the data points - mainly daytime values - need to be discarded. Applying the method to a 4-year dataset of CO2 and δ13C(CO2) measured in Heidelberg, Germany, yields a distinct seasonal cycle of δS. Disentangling this seasonal source signature into shares of source components is, however, only possible if the isotopic end members of these sources - i.e., the biosphere, δbio, and the fuel mix, δF - are known. From the mean source signature record in 2012, δbio could be reliably estimated only for summer to (-25.0±1.0) % and δF only for winter to (-32.5±2.5) %. As the isotopic end members δbio and δF were shown to change over the season, no year-round estimation of the fossil fuel or biosphere share is possible from the measured mean source signature record without additional information from emission inventories or other tracer measurements. |
BibTeX:
@article{Vardag2016,
author = {Vardag, Sanam Noreen and Hammer, Samuel and Levin, Ingeborg},
title = {Evaluation of 4 years of continuous δ13C(CO2) data using a moving Keeling plot method},
journal = {Biogeosciences},
publisher = {Copernicus GmbH},
year = {2016},
volume = {13},
number = {14},
pages = {4237--4251},
doi = {10.5194/bg-13-4237-2016}
}
|
| Vicca S, Balzarolo M, Filella I, Granier A, Herbst M, Knohl A, Longdoz B, Mund M, Nagy Z, Pintér K, Rambal S, Verbesselt J, Verger A, Zeileis A, Zhang C and Peñuelas J (2016), "Remotely-sensed detection of effects of extreme droughts on gross primary production", Scientific Reports., sep, 2016. Vol. 6(1), pp. 28269. |
| Abstract: Severe droughts strongly impact photosynthesis (GPP), and satellite imagery has yet to demonstrate its ability to detect drought effects. Especially changes in vegetation functioning when vegetation state remains unaltered (no browning or defoliation) pose a challenge to satellite-derived indicators. We evaluated the performance of different satellite indicators to detect strong drought effects on GPP in a beech forest in France (Hesse), where vegetation state remained largely unaffected while GPP decreased substantially. We compared the results with three additional sites: a Mediterranean holm oak forest (Puéchabon), a temperate beech forest (Hainich), and a semi-arid grassland (Bugacpuszta). In Hesse, a three-year reduction in GPP following drought was detected only by the Enhanced Vegetation Index (EVI). The Photochemical Reflectance Index (PRI) also detected this drought effect, but only after normalization for absorbed light. In Puéchabon normalized PRI outperformed the other indicators, while the short-term drought effect in Hainich was not detected by any tested indicator. In contrast, most indicators, but not PRI, captured the drought effects in Bugacpuszta. Hence, PRI improved detection of drought effects on GPP in forests and we propose that PRI normalized for absorbed light is considered in future algorithms to estimate GPP from space. |
BibTeX:
@article{Vicca2016,
author = {Vicca, Sara and Balzarolo, Manuela and Filella, Iolanda and Granier, André and Herbst, Mathias and Knohl, Alexander and Longdoz, Bernard and Mund, Martina and Nagy, Zoltan and Pintér, Krisztina and Rambal, Serge and Verbesselt, Jan and Verger, Aleixandre and Zeileis, Achim and Zhang, Chao and Peñuelas, Josep},
title = {Remotely-sensed detection of effects of extreme droughts on gross primary production},
journal = {Scientific Reports},
year = {2016},
volume = {6},
number = {1},
pages = {28269},
url = {http://www.nature.com/articles/srep28269},
doi = {10.1038/srep28269}
}
|
| Walter S, Kock A, Steinhoff T, Fiedler B, Fietzek P, Kaiser J, Krol M, Popa ME, Chen Q, Tanhua T and Röckmann T (2016), "Isotopic evidence for biogenic molecular hydrogen production in the Atlantic Ocean", Biogeosciences., jan, 2016. Vol. 13(1), pp. 323-340. |
| Abstract: Oceans are a net source of molecular hydrogen (H2) to the atmosphere. The production of marine H2 is assumed to be mainly biological by N2 fixation, but photochemical pathways are also discussed. We present measurements of mole fraction and isotopic composition of dissolved and atmospheric H2 from the southern and northern Atlantic between 2008 and 2010. In total almost 400 samples were taken during 5 cruises along a transect between Punta Arenas (Chile) and Bremerhaven (Germany), as well as at the coast of Mauritania. The isotopic source signatures of dissolved H2 extracted from surface water are highly deuterium-depleted and correlate negatively with temperature, showing δD values of (629 ± 54) for water temperatures at (27 ± 3) and (-249±88) below (19±1) C. The results for warmer water masses are consistent with the biological production of H2. This is the first time that marine H2 excess has been directly attributed to biological production by isotope measurements. However, the isotope values obtained in the colder water masses indicate that beside possible biological production, a significant different source should be considered. The atmospheric measurements show distinct differences between both hemispheres as well as between seasons. Results from the global chemistry transport model TM5 reproduce the measured H2 mole fractions and isotopic composition well. The climatological global oceanic emissions from the GEMS database are in line with our data and previously published flux calculations. The good agreement between measurements and model results demonstrates that both the magnitude and the isotopic signature of the main components of the marine H2 cycle are in general adequately represented in current atmospheric models despite a proposed source different from biological production or a substantial underestimation of nitrogen fixation by several authors. |
BibTeX:
@article{Walter2016,
author = {Walter, S and Kock, A and Steinhoff, T and Fiedler, B and Fietzek, P and Kaiser, J and Krol, M and Popa, M E and Chen, Q and Tanhua, T and Röckmann, T},
title = {Isotopic evidence for biogenic molecular hydrogen production in the Atlantic Ocean},
journal = {Biogeosciences},
year = {2016},
volume = {13},
number = {1},
pages = {323--340},
url = {http://www.biogeosciences.net/13/323/2016/},
doi = {10.5194/bg-13-323-2016}
}
|
| Wolf S, Keenan TF, Fisher JB, Baldocchi DD, Desai AR, Richardson AD, Scott RL, Law BE, Litvak ME, Brunsell NA, Peters W and Van Der Laan-Luijkx IT (2016), "Warm spring reduced carbon cycle impact of the 2012 US summer drought", Proceedings of the National Academy of Sciences of the United States of America., may, 2016. Vol. 113(21), pp. 5880-5885. |
| Abstract: The global terrestrial carbon sink offsets one-third of the world's fossil fuel emissions, but the strength of this sink is highly sensitive to large-scale extreme events. In 2012, the contiguous United States experienced exceptionally warm temperatures and the most severe drought since the Dust Bowl era of the 1930s, resulting in substantial economic damage. It is crucial to understand the dynamics of such events because warmer temperatures and a higher prevalence of drought are projected in a changing climate. Here, we combine an extensive network of direct ecosystem flux measurements with satellite remote sensing and atmospheric inverse modeling to quantify the impact of the warmer spring and summer drought on biosphereatmosphere carbon and water exchange in 2012. We consistently find that earlier vegetation activity increased spring carbon uptake and compensated for the reduced uptake during the summer drought, which mitigated the impact on net annual carbon uptake. The early phenological development in the Eastern Temperate Forests played a major role for the continental-scale carbon balance in 2012. The warm spring also depleted soil water resources earlier, and thus exacerbated water limitations during summer. Our results show that the detrimental effects of severe summer drought on ecosystem carbon storage can be mitigated by warming-induced increases in spring carbon uptake. However, the results also suggest that the positive carbon cycle effect of warm spring enhances water limitations and can increase summer heating through biosphere-atmosphere feedbacks. |
BibTeX:
@article{Wolf2016,
author = {Wolf, Sebastian and Keenan, Trevor F and Fisher, Joshua B and Baldocchi, Dennis D and Desai, Ankur R and Richardson, Andrew D and Scott, Russell L and Law, Beverly E and Litvak, Marcy E and Brunsell, Nathaniel A and Peters, Wouter and Van Der Laan-Luijkx, Ingrid T},
title = {Warm spring reduced carbon cycle impact of the 2012 US summer drought},
journal = {Proceedings of the National Academy of Sciences of the United States of America},
year = {2016},
volume = {113},
number = {21},
pages = {5880--5885},
url = {http://www.pnas.org/lookup/doi/10.1073/pnas.1519620113},
doi = {10.1073/pnas.1519620113}
}
|
| Wrobel I and Piskozub J (2016), "Effect of gas-transfer velocity parameterization choice on air–sea CO&lt;sub&gt;2&lt;/sub&gt; fluxes in the North Atlantic Ocean and the European Arctic", Ocean Science., sep, 2016. Vol. 12(5), pp. 1091-1103. Copernicus GmbH. |
| Abstract: textlessptextgreaterAbstract. The oceanic sink of carbon dioxide (CO2) is an important part of the global carbon budget. Understanding uncertainties in the calculation of this net flux into the ocean is crucial for climate research. One of the sources of the uncertainty within this calculation is the parameterization chosen for the CO2 gas-transfer velocity. We used a recently developed software toolbox, called the FluxEngine (Shutler et al., 2016), to estimate the monthly air–sea CO2 fluxes for the extratropical North Atlantic Ocean, including the European Arctic, and for the global ocean using several published quadratic and cubic wind speed parameterizations of the gas-transfer velocity. The aim of the study is to constrain the uncertainty caused by the choice of parameterization in the North Atlantic Ocean. This region is a large oceanic sink of CO2, and it is also a region characterized by strong winds, especially in winter but with good in situ data coverage. We show that the uncertainty in the parameterization is smaller in the North Atlantic Ocean and the Arctic than in the global ocean. It is as little as 5 % in the North Atlantic and 4 % in the European Arctic, in comparison to 9 % for the global ocean when restricted to parameterizations with quadratic wind dependence. This uncertainty becomes 46, 44, and 65 %, respectively, when all parameterizations are considered. We suggest that this smaller uncertainty (5 and 4 %) is caused by a combination of higher than global average wind speeds in the North Atlantic (textgreater 7 ms−1) and lack of any seasonal changes in the direction of the flux direction within most of the region. We also compare the impact of using two different in situ pCO2 data sets (Takahashi et al. (2009) and Surface Ocean CO2 Atlas (SOCAT) v1.5 and v2.0, for the flux calculation. The annual fluxes using the two data sets differ by 8 % in the North Atlantic and 19 % in the European Arctic. The seasonal fluxes in the Arctic computed from the two data sets disagree with each other possibly due to insufficient spatial and temporal data coverage, especially in winter.textless/ptextgreater |
BibTeX:
@article{Wrobel2016,
author = {Wrobel, Iwona and Piskozub, Jacek},
title = {Effect of gas-transfer velocity parameterization choice on air–sea CO&lt;sub&gt;2&lt;/sub&gt; fluxes in the North Atlantic Ocean and the European Arctic},
journal = {Ocean Science},
publisher = {Copernicus GmbH},
year = {2016},
volume = {12},
number = {5},
pages = {1091--1103},
url = {https://os.copernicus.org/articles/12/1091/2016/},
doi = {10.5194/os-12-1091-2016}
}
|
| Wu X, Vuichard N, Ciais P, Viovy N, De Noblet-Ducoudré N, Wang X, Magliulo V, Wattenbach M, Vitale L, Di Tommasi P, Moors EJ, Jans W, Elbers J, Ceschia E, Tallec T, Bernhofer C, Grünwald T, Moureaux C, Manise T, Ligne A, Cellier P, Loubet B, Larmanou E and Ripoche D (2016), "ORCHIDEE-CROP (v0), a new process-based agro-land surface model: Model description and evaluation over Europe", Geoscientific Model Development., mar, 2016. Vol. 9(2), pp. 857-873. |
| Abstract: The response of crops to changing climate and atmospheric CO2 concentration ([CO2]) could have large effects on food production, and impact carbon, water, and energy fluxes, causing feedbacks to the climate. To simulate the response of temperate crops to changing climate and [CO2], which accounts for the specific phenology of crops mediated by management practice, we describe here the development of a process-oriented terrestrial biogeochemical model named ORCHIDEE-CROP (v0), which integrates a generic crop phenology and harvest module, and a very simple parameterization of nitrogen fertilization, into the land surface model (LSM) ORCHIDEEv196, in order to simulate biophysical and biochemical interactions in croplands, as well as plant productivity and harvested yield. The model is applicable for a range of temperate crops, but is tested here using maize and winter wheat, with the phenological parameterizations of two European varieties originating from the STICS agronomical model. We evaluate the ORCHIDEE-CROP (v0) model against eddy covariance and biometric measurements at seven winter wheat and maize sites in Europe. The specific ecosystem variables used in the evaluation are CO2 fluxes (net ecosystem exchange, NEE), latent heat, and sensible heat fluxes. Additional measurements of leaf area index (LAI) and aboveground biomass and yield are used as well. Evaluation results revealed that ORCHIDEE-CROP (v0) reproduced the observed timing of crop development stages and the amplitude of the LAI changes. This is in contrast to ORCHIDEEv196 where, by default, crops have the same phenology as grass. A halving of the root mean square error for LAI from 2.38 ± 0.77 to 1.08 ± 0.34 m2 m-2 was obtained when ORCHIDEEv196 and ORCHIDEE-CROP (v0) were compared across the seven study sites. Improved crop phenology and carbon allocation led to a good match between modeled and observed aboveground biomass (with a normalized root mean squared error (NRMSE) of 11.0-54.2 %), crop yield, daily carbon and energy fluxes (with a NRMSE of ∼9.0-20.1 and ∼9.4-22.3 % for NEE), and sensible and latent heat fluxes. The simulated yields for winter wheat and maize from ORCHIDEE-CROP (v0) showed a good match with the simulated results from STICS for three sites with available crop yield observations, where the average NRMSE was ∼8.8 %. The model data misfit for energy fluxes were within the uncertainties of the measurements, which themselves showed an incomplete energy balance closure within the range 80.6-86.3 %. The remaining discrepancies between the modeled and observed LAI and other variables at specific sites were partly attributable to unrealistic representations of management events by the model. ORCHIDEE-CROP (v0) has the ability to capture the spatial gradients of carbon and energy-related variables, such as gross primary productivity, NEE, and sensible and latent heat fluxes across the sites in Europe, which is an important requirement for future spatially explicit simulations. Further improvement of the model, with an explicit parameterization of nutritional dynamics and management, is expected to improve its predictive ability to simulate croplands in an Earth system model. |
BibTeX:
@article{Wu2016,
author = {Wu, X and Vuichard, N and Ciais, P and Viovy, N and De Noblet-Ducoudré, N and Wang, X and Magliulo, V and Wattenbach, M and Vitale, L and Di Tommasi, P and Moors, E J and Jans, W and Elbers, J and Ceschia, E and Tallec, T and Bernhofer, C and Grünwald, T and Moureaux, C and Manise, T and Ligne, A and Cellier, P and Loubet, B and Larmanou, E and Ripoche, D},
title = {ORCHIDEE-CROP (v0), a new process-based agro-land surface model: Model description and evaluation over Europe},
journal = {Geoscientific Model Development},
year = {2016},
volume = {9},
number = {2},
pages = {857--873},
url = {http://www.geosci-model-dev.net/9/857/2016/},
doi = {10.5194/gmd-9-857-2016}
}
|
| Yasunaka S, Murata A, Watanabe E, Chierici M, Fransson A, van Heuven S, Hoppema M, Ishii M, Johannessen T, Kosugi N, Lauvset SK, Mathis JT, Nishino S, Omar AM, Olsen A, Sasano D, Takahashi T and Wanninkhof R (2016), "Mapping of the air–sea CO2 flux in the Arctic Ocean and its adjacent seas: Basin-wide distribution and seasonal to interannual variability", Polar Science., sep, 2016. Vol. 10(3), pp. 323-334. Elsevier B.V.. |
| Abstract: We produced 204 monthly maps of the air–sea CO2 flux in the Arctic north of 60°N, including the Arctic Ocean and its adjacent seas, from January 1997 to December 2013 by using a self-organizing map technique. The partial pressure of CO2 (pCO2) in surface water data were obtained by shipboard underway measurements or calculated from alkalinity and total inorganic carbon of surface water samples. Subsequently, we investigated the basin-wide distribution and seasonal to interannual variability of the CO2 fluxes. The 17-year annual mean CO2 flux shows that all areas of the Arctic Ocean and its adjacent seas were net CO2 sinks. The estimated annual CO2 uptake by the Arctic Ocean was 180 TgC yr−1. The CO2 influx was strongest in winter in the Greenland/Norwegian Seas (textgreater15 mmol m−2 day−1) and the Barents Sea (textgreater12 mmol m−2 day−1) because of strong winds, and strongest in summer in the Chukchi Sea (∼10 mmol m−2 day−1) because of the sea-ice retreat. In recent years, the CO2 uptake has increased in the Greenland/Norwegian Sea and decreased in the southern Barents Sea, owing to increased and decreased air–sea pCO2 differences, respectively. |
BibTeX:
@article{Yasunaka2016,
author = {Yasunaka, Sayaka and Murata, Akihiko and Watanabe, Eiji and Chierici, Melissa and Fransson, Agneta and van Heuven, Steven and Hoppema, Mario and Ishii, Masao and Johannessen, Truls and Kosugi, Naohiro and Lauvset, Siv K. and Mathis, Jeremy T. and Nishino, Shigeto and Omar, Abdirahman M. and Olsen, Are and Sasano, Daisuke and Takahashi, Taro and Wanninkhof, Rik},
title = {Mapping of the air–sea CO2 flux in the Arctic Ocean and its adjacent seas: Basin-wide distribution and seasonal to interannual variability},
journal = {Polar Science},
publisher = {Elsevier B.V.},
year = {2016},
volume = {10},
number = {3},
pages = {323--334},
doi = {10.1016/j.polar.2016.03.006}
}
|
| Zellweger C, Emmenegger L, Firdaus M, Hatakka J, Heimann M, Kozlova E, Gerard Spain T, Steinbacher M, Van Der Schoot MV and Buchmann B (2016), "Assessment of recent advances in measurement techniques for atmospheric carbon dioxide and methane observations", Atmospheric Measurement Techniques., sep, 2016. Vol. 9(9), pp. 4737-4757. |
| Abstract: Until recently, atmospheric carbon dioxide (CO2) and methane (CH4) measurements were made almost exclusively using nondispersive infrared (NDIR) absorption and gas chromatography with flame ionisation detection (GC/FID) techniques, respectively. Recently, commercially available instruments based on spectroscopic techniques such as cavity ring-down spectroscopy (CRDS), off-axis integrated cavity output spectroscopy (OA-ICOS) and Fourier transform infrared (FTIR) spectroscopy have become more widely available and affordable. This resulted in a widespread use of these techniques at many measurement stations. This paper is focused on the comparison between a CRDS "travelling instrument" that has been used during performance audits within the Global Atmosphere Watch (GAW) programme of the World Meteorological Organization (WMO) with instruments incorporating other, more traditional techniques for measuring CO2 and CH4 (NDIR and GC/FID). We demonstrate that CRDS instruments and likely other spectroscopic techniques are suitable for WMO/GAW stations and allow a smooth continuation of historic CO2 and CH4 time series. Moreover, the analysis of the audit results indicates that the spectroscopic techniques have a number of advantages over the traditional methods which will lead to the improved accuracy of atmospheric CO2 and CH4 measurements. |
BibTeX:
@article{Zellweger2016,
author = {Zellweger, Christoph and Emmenegger, Lukas and Firdaus, Mohd and Hatakka, Juha and Heimann, Martin and Kozlova, Elena and Gerard Spain, T and Steinbacher, Martin and Van Der Schoot, Marcel V and Buchmann, Brigitte},
title = {Assessment of recent advances in measurement techniques for atmospheric carbon dioxide and methane observations},
journal = {Atmospheric Measurement Techniques},
year = {2016},
volume = {9},
number = {9},
pages = {4737--4757},
url = {http://www.atmos-meas-tech.net/9/4737/2016/},
doi = {10.5194/amt-9-4737-2016}
}
|
| Zenone T, Zona D, Gelfand I, Gielen B, Camino-Serrano M and Ceulemans R (2016), "CO2 uptake is offset by CH4 and N2O emissions in a poplar short-rotation coppice", GCB Bioenergy., may, 2016. Vol. 8(3), pp. 524-538. |
| Abstract: The need for renewable energy sources will lead to a considerable expansion in the planting of dedicated fast-growing biomass crops across Europe. These are commonly cultivated as short-rotation coppice (SRC), and currently poplar (Populus spp.) is the most widely planted. In this study, we report the greenhouse gas (GHG) fluxes of carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O) measured using eddy covariance technique in an SRC plantation for bioenergy production. Measurements were made during the period 2010-2013, that is, during the first two rotations of the SRC. The overall GHG balance of the 4 years of the study was an emission of 1.90 (±1.37) Mg CO2eq ha-1; this indicated that soil trace gas emissions offset the CO2 uptake by the plantation. CH4 and N2O contributed almost equally to offset the CO2 uptake of -5.28 (±0.67) Mg CO2eq ha-1 with an overall emission of 3.56 (±0.35) Mg CO2eq ha-1 of N2O and of 3.53 (±0.85) Mg CO2eq ha-1 of CH4. N2O emissions mostly occurred during one single peak a few months after the site was converted to SRC; this peak comprised 44% of the total N2O loss during the two rotations. Accurately capturing emission events proved to be critical for deriving correct estimates of the GHG balance. The nitrogen (N) content of the soil and the water table depth were the two drivers that best explained the variability in N2O and CH4, respectively. This study underlines the importance of the 'non-CO2 GHGs' on the overall balance. Further long-term investigations of soil trace gas emissions should monitor the N content and the mineralization rate of the soil, as well as the microbial community, as drivers of the trace gas emissions. |
BibTeX:
@article{Zenone2016,
author = {Zenone, Terenzio and Zona, Donatella and Gelfand, Ilya and Gielen, Bert and Camino-Serrano, Marta and Ceulemans, Reinhart},
title = {CO2 uptake is offset by CH4 and N2O emissions in a poplar short-rotation coppice},
journal = {GCB Bioenergy},
year = {2016},
volume = {8},
number = {3},
pages = {524--538},
url = {http://doi.wiley.com/10.1111/gcbb.12269},
doi = {10.1111/gcbb.12269}
}
|
| Zenone T, Hendriks C, Brilli F, Fransen E, Gioli B, Portillo-Estrada M, Schaap M and Ceulemans R (2016), "Interaction between isoprene and ozone fluxes in a poplar plantation and its impact on air quality at the European level", Scientific Reports., dec, 2016. Vol. 6(1), pp. 32676. |
| Abstract: The emission of isoprene and other biogenic volatile organic compounds from vegetation plays an important role in tropospheric ozone (O3) formation. The potentially large expansion of isoprene emitting species (e.g., poplars) for bioenergy production might, therefore, impact tropospheric O3 formation. Using the eddy covariance technique we have simultaneously measured fluxes isoprene, O3 and of CO2 from a poplar (Populus) plantation grown for bioenergy production. We used the chemistry transport model LOTOS-EUROS to scale-up the isoprene emissions associated with the existing poplar plantations in Europe, and we assessed the impact of isoprene fluxes on ground level O3 concentrations. Our findings suggest that isoprene emissions from existing poplar-for-bioenergy plantations do not significantly affect the ground level of O3 concentration. Indeed the overall land in Europe covered with poplar plantations has not significantly changed over the last two decades despite policy incentives to produce bioenergy crops. The current surface area of isoprene emitting poplars-for-bioenergy remains too limited to significantly enhance O3 concentrations and thus to be considered a potential threat for air quality and human health. |
BibTeX:
@article{Zenone2016a,
author = {Zenone, Terenzio and Hendriks, Carlijn and Brilli, Federico and Fransen, Erik and Gioli, Beniamio and Portillo-Estrada, Miguel and Schaap, Martijn and Ceulemans, Reinhart},
title = {Interaction between isoprene and ozone fluxes in a poplar plantation and its impact on air quality at the European level},
journal = {Scientific Reports},
year = {2016},
volume = {6},
number = {1},
pages = {32676},
url = {http://www.nature.com/articles/srep32676},
doi = {10.1038/srep32676}
}
|
| Zhao J, Peichl M and Nilsson MB (2016), "Enhanced winter soil frost reduces methane emission during the subsequent growing season in a boreal peatland", Global Change Biology., feb, 2016. Vol. 22(2), pp. 750-762. Blackwell Publishing Ltd. |
| Abstract: Winter climate change may result in reduced snow cover and could, consequently, alter the soil frost regime and biogeochemical processes underlying the exchange of methane (CH4) in boreal peatlands. In this study, we investigated the short-term (1-3 years) vs. long-term (11 years) effects of intensified winter soil frost (induced by experimental snow exclusion) on CH4 exchange during the following growing season in a boreal peatland. In the first 3 years (2004-2006), lower CH4 emissions in the treatment plots relative to the control coincided with delayed soil temperature increase in the treatment plots at the beginning of the growing season (May). After 11 treatment years (in 2014), CH4 emissions were lower in the treatment plots relative to the control over the entire growing season, resulting in a reduction in total growing season CH4 emission by 27%. From May to July 2014, reduced sedge leaf area coincided with lower CH4 emissions in the treatment plots compared to the control. From July to August, lower dissolved organic carbon concentrations in the pore water of the treatment plots explained 72% of the differences in CH4 emission between control and treatment. In addition, greater Sphagnum moss growth in the treatment plots resulted in a larger distance between the moss surface and the water table (i.e., increasing the oxic layer) which may have enhanced the CH4 oxidation potential in the treatment plots relative to the control in 2014. The differences in vegetation might also explain the lower temperature sensitivity of CH4 emission observed in the treatment plots relative to the control. Overall, this study suggests that greater soil frost, associated with future winter climate change, might substantially reduce the growing season CH4 emission in boreal peatlands through altering vegetation dynamics and subsequently causing vegetation-mediated effects on CH4 exchange. |
BibTeX:
@article{Zhao2016,
author = {Zhao, Junbin and Peichl, Matthias and Nilsson, Mats B.},
title = {Enhanced winter soil frost reduces methane emission during the subsequent growing season in a boreal peatland},
journal = {Global Change Biology},
publisher = {Blackwell Publishing Ltd},
year = {2016},
volume = {22},
number = {2},
pages = {750--762},
doi = {10.1111/gcb.13119}
}
|
| Zhao J, Peichl M, Öquist M and Nilsson MB (2016), "Gross primary production controls the subsequent winter CO2 exchange in a boreal peatland". dec, 2016. |
| Abstract: In high-latitude regions, carbon dioxide (CO2) emissions during the winter represent an important component of the annual ecosystem carbon budget; however, the mechanisms that control the winter CO2 emissions are currently not well understood. It has been suggested that substrate availability from soil labile carbon pools is a main driver of winter CO2 emissions. In ecosystems that are dominated by annual herbaceous plants, much of the biomass produced during the summer is likely to contribute to the soil labile carbon pool through litter fall and root senescence in the autumn. Thus, the summer carbon uptake in the ecosystem may have a significant influence on the subsequent winter CO2 emissions. To test this hypothesis, we conducted a plot-scale shading experiment in a boreal peatland to reduce the gross primary production (GPP) during the growing season. At the growing season peak, vascular plant biomass in the shaded plots was half that in the control plots. During the subsequent winter, the mean CO2 emission rates were 21% lower in the shaded plots than in the control plots. In addition, long-term (2001–2012) eddy covariance data from the same site showed a strong correlation between the GPP (particularly the late summer and autumn GPP) and the subsequent winter net ecosystem CO2 exchange (NEE). In contrast, abiotic factors during the winter could not explain the interannual variation in the cumulative winter NEE. Our study demonstrates the presence of a cross-seasonal link between the growing season biotic processes and winter CO2 emissions, which has important implications for predicting winter CO2 emission dynamics in response to future climate change. |
BibTeX:
@misc{Zhao2016a,
author = {Zhao, Junbin and Peichl, Matthias and Öquist, Mats and Nilsson, Mats B.},
title = {Gross primary production controls the subsequent winter CO2 exchange in a boreal peatland},
booktitle = {Global Change Biology},
publisher = {Blackwell Publishing Ltd},
year = {2016},
volume = {22},
number = {12},
pages = {4028--4037},
doi = {10.1111/gcb.13308}
}
|
| Zhou M, Dils B, Wang P, Detmers R, Yoshida Y, O'Dell CW, Feist DG, Velazco VA, Schneider M and De Mazière M (2016), "Validation of TANSO-FTS/GOSAT XCO2 and XCH4 glint mode retrievals using TCCON data from near-ocean sites", Atmospheric Measurement Techniques., apr, 2016. Vol. 9(3), pp. 1415-1430. Copernicus GmbH. |
| Abstract: The thermal And near infrared sensor for carbon observations Fourier transform spectrometer (TANSO-FTS) on board the Greenhouse Gases Observing Satellite (GOSAT) applies the normal nadir mode above the land ("land data") and sun glint mode over the ocean ("ocean data") to provide global distributions of column-averaged dry-air mole fractions of CO2 and CH4, or XCO2 and XCH4. Several algorithms have been developed to obtain highly accurate greenhouse gas concentrations from TANSO-FTS/GOSAT spectra. So far, all the retrieval algorithms have been validated with the measurements from ground-based Fourier transform spectrometers from the Total Carbon Column Observing Network (TCCON), but limited to the land data. In this paper, the ocean data of the SRPR, SRFP (the proxy and full-physics versions 2.3.5 of SRON/KIT's RemoTeC algorithm), NIES (National Institute for Environmental Studies operational algorithm version 02.21) and ACOS (NASA's Atmospheric CO2 Observations from Space version 3.5) are compared with FTIR measurements from five TCCON sites and nearby GOSAT land data. For XCO2, both land and ocean data of NIES, SRFP and ACOS show good agreement with TCCON measurements. Averaged over all TCCON sites, the relative biases of ocean data and land data are -0.33 and -0.13 % for NIES, 0.03 and 0.04 % for SRFP, 0.06 and -0.03 % for ACOS, respectively. The relative scatter ranges between 0.31 and 0.49 %. For XCH4, the relative bias of ocean data is even less than that of the land data for the NIES (0.02 vs. -0.35 %), SRFP (0.04 vs. 0.20 %) and SRPR (-0.02 vs. 0.06 %) algorithms. Compared to the results for XCO2, the XCH4 retrievals show larger relative scatter (0.65-0.81 %). |
BibTeX:
@article{Zhou2016,
author = {Zhou, Minqiang and Dils, Bart and Wang, Pucai and Detmers, Rob and Yoshida, Yukio and O'Dell, Christopher W. and Feist, Dietrich G. and Velazco, Voltaire Almario and Schneider, Matthias and De Mazière, Martine},
title = {Validation of TANSO-FTS/GOSAT XCO2 and XCH4 glint mode retrievals using TCCON data from near-ocean sites},
journal = {Atmospheric Measurement Techniques},
publisher = {Copernicus GmbH},
year = {2016},
volume = {9},
number = {3},
pages = {1415--1430},
doi = {10.5194/amt-9-1415-2016}
}
|
| Ziembliʼnska K, Urbaniak M, Chojnicki BH, Black TA, Niu S and Olejnik J (2016), "Net ecosystem productivity and its environmental controls in a mature Scots pine stand in north-western Poland", Agricultural and Forest Meteorology. Vol. 228-229, pp. 60-72. |
| Abstract: Although there have been many studies of the net ecosystem productivity (NEP) of different types of forests around the world, the CO2 dynamics in afforested pine stands of Central Europe are poorly understood. To fill this gap, continuous eddy-covariance (EC) measurements of net ecosystem exchange (NEE) were made from January 2008 to December 2013 in a 62-year-old temperate afforested Scots pine stand near Tuczno. The site is located in north-western Poland, where forests account for almost 30% of the land area and are dominated by Scots pine. Weather conditions during this 5-year period were mostly warm and wet. In all 5 years, air temperature (Ta) was higher than the 30-year (1983–2013) mean and by 3.3 °C during winter 2008, while precipitation (P) was noticeably higher only in summer months. The high productivity of the forest, which sequestered 118 Mg of CO2 per ha over the 5-year period, is likely because it was planted on fertile meadowland. Annual net ecosystem productivity (NEP = âˆ'NEE) ranged from 494 g C mâˆ'2 in 2012 to 765 g C mâˆ'2 in 2009, with an average of 645 g C mâˆ'2. The interannual variation in NEP was attributed more to the interannual variation in gross ecosystem photosynthesis (GEP) than to ecosystem respiration (R). Moreover, both annual NEP and GEP significantly decreased over the 5 years. This was the result of increasingly drier springs and wetter summers as time progressed during the 5-year period, as compared to the 30-year averages, which resulted in a gradual reduction in the growing season NEP and consequently the annual values. Seasonal values of NEP were highly correlated with Ta, photosynthetic photon flux density and vapor pressure deficit. The sensitivity of NEP to Ta was largely due to the much higher sensitivity of GEP to Ta compared to that of R. Although the interannual variability in NEP for separate seasons could not be explained using seasonal values of individual meteorological variables, a hygrothermal index, defined as P/10Ta, explained a large proportion of the interannual variability in NEP in spring and summer. |
BibTeX:
@article{Ziemblinska2016,
author = {Ziembliʼnska, K and Urbaniak, M and Chojnicki, B H and Black, T A and Niu, S and Olejnik, J},
title = {Net ecosystem productivity and its environmental controls in a mature Scots pine stand in north-western Poland},
journal = {Agricultural and Forest Meteorology},
year = {2016},
volume = {228-229},
pages = {60--72},
doi = {10.1016/j.agrformet.2016.05.022}
}
|
| Zweifel R, Haeni M, Buchmann N and Eugster W (2016), "Are trees able to grow in periods of stem shrinkage?", New Phytologist., aug, 2016. Vol. 211(3), pp. 839-849. |
| Abstract: Separating continuously measured stem radius (SR) fluctuations into growth-induced irreversible stem expansion (GRO) and tree water deficit-induced reversible stem shrinkage (TWD) requires a conceptualization of potential growth processes that may occur during periods of shrinking and expanding SR below a precedent maximum. Here, we investigated two physiological concepts: the linear growth (LG) concept, assuming linear growth, versus the zero growth (ZG) concept, assuming no growth during periods of stem shrinkage. We evaluated the physiological mechanisms underlying these two concepts and assessed their respective plausibilities using SR data obtained from 15 deciduous and evergreen trees. The application of the LG concept produced steady growth rates, whereas growth rates varied strongly under the ZG concept, more in accordance with mechanistic expectations. Further, growth increased for a maximum of 120 min after periods of stem shrinkage, indicating limited growth activity during those periods. However, this extra growth was found to be a small fraction of total growth only. Furthermore, TWD under the ZG concept was better explained by a hydraulic plant model than TWD under the LG concept. We conclude that periods of stem shrinkage allow for very little growth in the four tree species investigated. However, further studies should focus on obtaining independent growth data to ultimately validate these findings. |
BibTeX:
@article{Zweifel2016,
author = {Zweifel, Roman and Haeni, Matthias and Buchmann, Nina and Eugster, Werner},
title = {Are trees able to grow in periods of stem shrinkage?},
journal = {New Phytologist},
year = {2016},
volume = {211},
number = {3},
pages = {839--849},
url = {http://doi.wiley.com/10.1111/nph.13995},
doi = {10.1111/nph.13995}
}
|
| Zweifel R (2016), "Radial stem variations - a source of tree physiological information not fully exploited yet", Plant, Cell and Environment., feb, 2016. Vol. 39(2), pp. 231-232. |
BibTeX:
@article{Zweifel2016a,
author = {Zweifel, Roman},
title = {Radial stem variations - a source of tree physiological information not fully exploited yet},
journal = {Plant, Cell and Environment},
year = {2016},
volume = {39},
number = {2},
pages = {231--232},
url = {http://doi.wiley.com/10.1111/pce.12613},
doi = {10.1111/pce.12613}
}
|
| Aalto T, Hatakka J, Kouznetsov R and Stanislawska K (2015), "Background and anthropogenic influences on atmospheric co 2 concentrations measured at Pallas: comparison of two models for tracing air mass history" |
| Abstract: Aalto T., Hatakka J., Kouznetsov R. & Stanislawska K. 2015: Background and anthropogenic influences on atmospheric CO 2 concentrations measured at Pallas: Comparison of two models for tracing air mass history. Boreal Env. Res. 20: 213-226. The FLEXTRA and SILAM models were utilized in estimating the influence regions (IR) for the measured CO 2 concentration ([CO 2 ]) at Pallas together with tracers for anthro-pogenic emissions. The models produced similar synoptic features and associated background [CO 2 ] with marine IR and elevated [CO 2 ] with continental IR, but there were also differences which affected the interpretation of measurements. The background, i.e. marine boundary layer (MBL) signal, was compared to the NOAA MBL reference. Both models performed well, with monthly mean deviations from the reference usually inside 1 ppm. The FLEXTRA MBL signal had some seasonality in the difference, however, only very few cases were associated with anthropogenic emissions. We used [CO] and fossil fuel [CO 2 ] simulations by the TM5 (CarbonTracker CT2011_oi) model as emission tracers. The model and [CO] captured well the timing of high [CO 2 ] in measurements. The anthropo-genic influence was more pronounced in winter than in summer, and it had a large inter-annual variation. |
BibTeX:
@techreport{Aalto2015,
author = {Aalto, Tuula and Hatakka, Juha and Kouznetsov, Rostislav and Stanislawska, Karolina},
title = {Background and anthropogenic influences on atmospheric co 2 concentrations measured at Pallas: comparison of two models for tracing air mass history},
year = {2015},
url = {http://www.esrl.}
}
|
| Ago EE, Serça D, Agbossou EK, Galle S and Aubinet M (2015), "Carbon dioxide fluxes from a degraded woodland in West Africa and their responses to main environmental factors", Carbon Balance and Management., dec, 2015. Vol. 10(1), pp. 22. |
| Abstract: Background: In West Africa, natural ecosystems such as woodlands are the main source for energy, building poles and livestock fodder. They probably behave like net carbon sinks, but there are only few studies focusing on their carbon exchange with the atmosphere. Here, we have analyzed CO2 fluxes measured for 17 months by an eddy-covariance system over a degraded woodland in northern Benin. Specially, temporal evolution of the fluxes and their relationships with the main environmental factors were investigated between the seasons. Results: This study shows a clear response of CO2 absorption to photosynthetic photon flux density (Qp), but it varies according to the seasons. After a significant and long dry period, the ecosystem respiration (R) has increased immediately to the first significant rains. No clear dependency of ecosystem respiration on temperature has been observed. The degraded woodlands are probably the "carbon neutral" at the annual scale. The net ecosystem exchange (NEE) was negative during wet season and positive during dry season, and its annual accumulation was equal to +29 ± 16 g C m-2. The ecosystem appears to be more efficient in the morning and during the wet season than in the afternoon and during the dry season. Conclusions: This study shows diurnal and seasonal contrasted variations in the CO2 fluxes in relation to the alternation between dry and wet seasons. The Nangatchori site is close to the equilibrium state according to its carbon exchanges with the atmosphere. The length of the observation period was too short to justify the hypothesis about the "carbon neutrality" of the degraded woodlands at the annual scale in West Africa. Besides, the annual net ecosystem exchange depends on the intensity of disturbances due to the site management system. Further research works are needed to define a woodland management policy that might keep these ecosystems as carbon sinks. |
BibTeX:
@article{Ago2015,
author = {Ago, Expedit Evariste and Serça, Dominique and Agbossou, Euloge Kossi and Galle, Sylvie and Aubinet, Marc},
title = {Carbon dioxide fluxes from a degraded woodland in West Africa and their responses to main environmental factors},
journal = {Carbon Balance and Management},
year = {2015},
volume = {10},
number = {1},
pages = {22},
url = {http://www.cbmjournal.com/content/10/1/22},
doi = {10.1186/s13021-015-0033-6}
}
|
| Ågren AM, Lidberg W and Ring E (2015), "Mapping temporal dynamics in a forest stream network-implications for riparian forest management", Forests., aug, 2015. Vol. 6(9), pp. 2982-3001. |
| Abstract: This study focuses on avoiding negative effects on surface waters using new techniques for identifying wet areas near surface waters. This would aid planning and designing of forest buffer zones and off-road forestry traffic. The temporal variability in the geographical distribution of the stream network renders this type of planning difficult. A field study was performed in the 68 km2 Krycklan Catchment to illustrate the variability of a boreal stream network. The perennial stream length was 140 km while the stream length during high-flow conditions was 630 km. Comparing the field-measured stream network to the network presented on current maps showed that 58% of the perennial and 76% of the fully expanded network was missing on current maps. Similarly, cartographic depth-to-water maps showed that associated wet soils constituted 5% of the productive forest land during baseflow and 25% during high flow. Using a new technique, maps can be generated that indicate full stream networks, as well as seasonally active streams and associated wet soils, thus, forestry planning can be performed more efficiently and impacts on surface waters can be reduced. |
BibTeX:
@article{Agren2015,
author = {Ågren, Anneli M and Lidberg, William and Ring, Eva},
title = {Mapping temporal dynamics in a forest stream network-implications for riparian forest management},
journal = {Forests},
year = {2015},
volume = {6},
number = {9},
pages = {2982--3001},
url = {http://www.mdpi.com/1999-4907/6/9/2982},
doi = {10.3390/f6092982}
}
|
| Åkerblom S, Meili M and Bishop K (2015), "Organic matter in rain: An overlooked influence on mercury deposition", Environmental Science and Technology Letters., apr, 2015. Vol. 2(4), pp. 128-132. |
| Abstract: The importance of Hg emissions for deposition will be scrutinized in the future as new legislation to control emissions of Hg to the atmosphere comes into effect. We show that mercury (Hg) concentrations in rainfall are closely linked to organic matter (OM) with consistent Hg/TOC ratios over large spatial scales decreasing from that in an open field (OF, 1.5 μg g-1) to that in throughfall (TF, 0.9 μg g-1). The leaf area index was positively correlated with both TF [Hg] and total organic carbon ([TOC]), but not the Hg/TOC ratio. This study shows that the progression in the Hg/TOC ratio through catchments starts in precipitation with Hg/TOCbulk dep Hg/TOCsoil water Hg/TOCstreamwater. These findings raise an intriguing question about the extent to which it is not just atmospheric [Hg] but also OM that influences [Hg] in precipitation. This question should be resolved to improve the ability to discern the importance of changing global Hg emissions for deposition of Hg at specific sites. |
BibTeX:
@article{Akerblom2015,
author = {Åkerblom, Staffan and Meili, Markus and Bishop, Kevin},
title = {Organic matter in rain: An overlooked influence on mercury deposition},
journal = {Environmental Science and Technology Letters},
year = {2015},
volume = {2},
number = {4},
pages = {128--132},
url = {http://pubs.acs.org/doi/10.1021/acs.estlett.5b00009},
doi = {10.1021/acs.estlett.5b00009}
}
|
| Alberti G, Vicca S, Inglima I, Belelli-Marchesini L, Genesio L, Miglietta F, Marjanovic H, Martinez C, Matteucci G, D'Andrea E, Peressotti A, Petrella F, Rodeghiero M and Cotrufo MF (2015), "Soil C:N stoichiometry controls carbon sink partitioning between above-ground tree biomass and soil organic matter in high fertility forests", iForest - Biogeosciences and Forestry., apr, 2015. Vol. 8(2), pp. 195-206. |
BibTeX:
@article{Alberti2015,
author = {Alberti, G and Vicca, S and Inglima, I and Belelli-Marchesini, L and Genesio, L and Miglietta, F and Marjanovic, H and Martinez, C and Matteucci, G and D'Andrea, E and Peressotti, A and Petrella, F and Rodeghiero, M and Cotrufo, M F},
title = {Soil C:N stoichiometry controls carbon sink partitioning between above-ground tree biomass and soil organic matter in high fertility forests},
journal = {iForest - Biogeosciences and Forestry},
year = {2015},
volume = {8},
number = {2},
pages = {195--206},
url = {https://iforest.sisef.org/?doi=ifor1196-008},
doi = {10.3832/ifor1196-008}
}
|
| Alexe M, Bergamaschi P, Segers A, Detmers R, Butz A, Hasekamp O, Guerlet S, Parker R, Boesch H, Frankenberg C, Scheepmaker RA, Dlugokencky E, Sweeney C, Wofsy SC and Kort EA (2015), "Inverse modelling of CH4 emissions for 2010-2011 using different satellite retrieval products from GOSAT and SCIAMACHY", Atmospheric Chemistry and Physics., jan, 2015. Vol. 15(1), pp. 113-133. |
| Abstract: At the beginning of 2009 new space-borne observations of dry-air column-averaged mole fractions of atmospheric methane (XCH4) became available from the Thermal And Near infrared Sensor for carbon Observations-Fourier Transform Spectrometer (TANSO-FTS) instrument on board the Greenhouse Gases Observing SATellite (GOSAT). Until April 2012 concurrent methane (CH4) retrievals were provided by the SCanning Imaging Absorption spectroMeter for Atmospheric CartograpHY (SCIAMACHY) instrument on board the ENVironmental SATellite (ENVISAT). The GOSAT and SCIAMACHY XCH4 retrievals can be compared during the period of overlap. We estimate monthly average CH4 emissions between January 2010 and December 2011, using the TM5-4DVAR inverse modelling system. In addition to satellite data, high-accuracy measurements from the Cooperative Air Sampling Network of the National Oceanic and Atmospheric Administration Earth System Research Laboratory (NOAA ESRL) are used, providing strong constraints on the remote surface atmosphere. We discuss five inversion scenarios that make use of different GOSAT and SCIAMACHY XCH4 retrieval products, including two sets of GOSAT proxy retrievals processed independently by the Netherlands Institute for Space Research (SRON)/Karlsruhe Institute of Technology (KIT), and the University of Leicester (UL), and the RemoTeC "Full-Physics" (FP) XCH4 retrievals available from SRON/KIT. The GOSAT-based inversions show significant reductions in the root mean square (rms) difference between retrieved and modelled XCH4, and require much smaller bias corrections compared to the inversion using SCIAMACHY retrievals, reflecting the higher precision and relative accuracy of the GOSAT XCH4. Despite the large differences between the GOSAT and SCIAMACHY retrievals, 2-year average emission maps show overall good agreement among all satellitebased inversions, with consistent flux adjustment patterns, particularly across equatorial Africa and North America. Over North America, the satellite inversions result in a significant redistribution of CH4 emissions from North-East to South-Central United States. This result is consistent with recent independent studies suggesting a systematic underestimation of CH4 emissions from North American fossil fuel sources in bottom-up inventories, likely related to natural gas production facilities. Furthermore, all four satellite inversions yield lower CH4 fluxes across the Congo basin compared to the NOAA-only scenario, but higher emissions across tropical East Africa. The GOSAT and SCIAMACHY inversions show similar performance when validated against independent shipboard and aircraft observations, and XCH4 retrievals available from the Total Carbon Column Observing Network (TCCON). |
BibTeX:
@article{Alexe2015,
author = {Alexe, M and Bergamaschi, P and Segers, A and Detmers, R and Butz, A and Hasekamp, O and Guerlet, S and Parker, R and Boesch, H and Frankenberg, C and Scheepmaker, R A and Dlugokencky, E and Sweeney, C and Wofsy, S C and Kort, E A},
title = {Inverse modelling of CH4 emissions for 2010-2011 using different satellite retrieval products from GOSAT and SCIAMACHY},
journal = {Atmospheric Chemistry and Physics},
year = {2015},
volume = {15},
number = {1},
pages = {113--133},
url = {http://www.atmos-chem-phys.net/15/113/2015/},
doi = {10.5194/acp-15-113-2015}
}
|
| Ali G, Tetzlaff D, Mcdonnell JJ, Soulsby C, Carey S, Laudon H, Mcguire K, Buttle J, Seibert J and Shanley J (2015), "Comparison of threshold hydrologic response across northern catchments", Hydrological Processes., jul, 2015. Vol. 29(16), pp. 3575-3591. |
| Abstract: Nine mid-latitude to high-latitude headwater catchments - part of the Northern Watershed Ecosystem Response to Climate Change (North-Watch) programme - were used to analyze threshold response to rainfall and snowmelt-driven events and link the different responses to the catchment characteristics of the nine sites. The North-Watch data include daily time-series of various lengths of multiple variables such as air temperature, precipitation and discharge. Rainfall and meltwater inputs were differentiated using a degree-day snowmelt approach. Distinct hydrological events were identified, and precipitation-runoff response curves were visually assessed. Results showed that eight of nine catchments showed runoff initiation thresholds and effective precipitation input thresholds. For rainfall-triggered events, catchment hydroclimatic and physical characteristics (e.g. mean annual air temperature, median flow path distance to the stream, median sub-catchment area) were strong predictors of threshold strength. For snowmelt-driven events, however, thresholds and the factors controlling precipitation-runoff response were difficult to identify. The variability in catchments responses to snowmelt was not fully explained by runoff initiation thresholds and input magnitude thresholds. The quantification of input intensity thresholds (e.g. snow melting and permafrost thawing rates) is likely required for an adequate characterization of nonlinear spring runoff generation in such northern environments. |
BibTeX:
@article{Ali2015,
author = {Ali, Genevieve and Tetzlaff, Doerthe and Mcdonnell, Jeffrey J and Soulsby, Chris and Carey, Sean and Laudon, Hjalmar and Mcguire, Kevin and Buttle, Jim and Seibert, Jan and Shanley, Jamie},
title = {Comparison of threshold hydrologic response across northern catchments},
journal = {Hydrological Processes},
year = {2015},
volume = {29},
number = {16},
pages = {3575--3591},
url = {http://doi.wiley.com/10.1002/hyp.10527},
doi = {10.1002/hyp.10527}
}
|
| Allin SJ, Laube JC, Witrant E, Kaiser J, McKenna E, Dennis P, Mulvaney R, Capron E, Martinerie P, Röckmann T, Blunier T, Schwander J, Fraser PJ, Langenfelds RL and Sturges WT (2015), "Chlorine isotope composition in chlorofluorocarbons CFC-11, CFC-12 and CFC-113 in firn, stratospheric and tropospheric air", Atmospheric Chemistry and Physics., jun, 2015. Vol. 15(12), pp. 6867-6877. |
| Abstract: The stratospheric degradation of chlorofluorocarbons (CFCs) releases chlorine, which is a major contributor to the destruction of stratospheric ozone (O3). A recent study reported strong chlorine isotope fractionation during the breakdown of the most abundant CFC (CFC-12, CCl2F2, Laube et al., 2010a), similar to effects seen in nitrous oxide (N2O). Using air archives to obtain a long-term record of chlorine isotope ratios in CFCs could help to identify and quantify their sources and sinks. We analyse the three most abundant CFCs and show that CFC-11 (CCl2F) and CFC-113 (CClF2CCl2F) exhibit significant stratospheric chlorine isotope fractionation, in common with CFC-12. The apparent isotope fractionation (app) for mid- and high-latitude stratospheric samples are respectively -2.4 (0.5) and -2.3 (0.4) ‰ for CFC-11, -12.2 (1.6) and -6.8 (0.8) ‰ for CFC-12 and -3.5 (1.5) and -3.3 (1.2) ‰ for CFC-113, where the number in parentheses is the numerical value of the standard uncertainty expressed in per mil. Assuming a constant isotope composition of emissions, we calculate the expected trends in the tropospheric isotope signature of these gases based on their stratospheric 37Cl enrichment and stratosphere-troposphere exchange. We compare these projections to the long-term δ (37Cl) trends of all three CFCs, measured on background tropospheric samples from the Cape Grim air archive (Tasmania, 1978-2010) and tropospheric firn air samples from Greenland (North Greenland Eemian Ice Drilling (NEEM) site) and Antarctica (Fletcher Promontory site). From 1970 to the present day, projected trends agree with tropospheric measurements, suggesting that within analytical uncertainties, a constant average emission isotope delta (δ) is a compatible scenario. The measurement uncertainty is too high to determine whether the average emission isotope δ has been affected by changes in CFC manufacturing processes or not. Our study increases the suite of trace gases amenable to direct isotope ratio measurements in small air volumes (approximately 200 mL), using a single-detector gas chromatography-mass spectrometry (GC-MS) system. |
BibTeX:
@article{Allin2015,
author = {Allin, S J and Laube, J C and Witrant, E and Kaiser, J and McKenna, E and Dennis, P and Mulvaney, R and Capron, E and Martinerie, P and Röckmann, T and Blunier, T and Schwander, J and Fraser, P J and Langenfelds, R L and Sturges, W T},
title = {Chlorine isotope composition in chlorofluorocarbons CFC-11, CFC-12 and CFC-113 in firn, stratospheric and tropospheric air},
journal = {Atmospheric Chemistry and Physics},
year = {2015},
volume = {15},
number = {12},
pages = {6867--6877},
url = {http://www.atmos-chem-phys.net/15/6867/2015/},
doi = {10.5194/acp-15-6867-2015}
}
|
| Alory G, Delcroix T, Téchiné P, Diverrès D, Varillon D, Cravatte S, Gouriou Y, Grelet J, Jacquin S, Kestenare E, Maes C, Morrow R, Perrier J, Reverdin G and Roubaud F (2015), "The French contribution to the voluntary observing ships network of sea surface salinity", Deep Sea Research Part I: Oceanographic Research Papers., nov, 2015. Vol. 105, pp. 1-18. Elsevier BV. |
| Abstract: Abstract Sea Surface Salinity (SSS) is an essential climate variable that requires long term in situ observation. The French SSS Observation Service (SSS-OS) manages a network of Voluntary Observing Ships equipped with thermosalinographs (TSG). The network is global though more concentrated in the tropical Pacific and North Atlantic oceanic basins. The acquisition system is autonomous with real time transmission and is regularly serviced at harbor calls. There are distinct real time and delayed time processing chains. Real time processing includes automatic alerts to detect potential instrument problems, in case raw data are outside of climatic limits, and graphical monitoring tools. Delayed time processing relies on a dedicated software for attribution of data quality flags by visual inspection, and correction of TSG time series by comparison with daily water samples and collocated Argo data. A method for optimizing the automatic attribution of quality flags in real time, based on testing different thresholds for data deviation from climatology and retroactively comparing the resulting flags to delayed time flags, is presented. The SSS-OS real time data feed the Coriolis operational oceanography database, while the research-quality delayed time data can be extracted for selected time and geographical ranges through a graphical web interface. Delayed time data have been also combined with other SSS data sources to produce gridded files for the Pacific and Atlantic oceans. A short review of the research activities conducted with such data is given. It includes observation-based process-oriented and climate studies from regional to global scale as well as studies where in situ SSS is used for calibration/validation of models, coral proxies or satellite data. |
BibTeX:
@article{Alory2015,
author = {Alory, G. and Delcroix, T. and Téchiné, P. and Diverrès, D. and Varillon, D. and Cravatte, S. and Gouriou, Y. and Grelet, J. and Jacquin, S. and Kestenare, E. and Maes, C. and Morrow, R. and Perrier, J. and Reverdin, G. and Roubaud, F.},
title = {The French contribution to the voluntary observing ships network of sea surface salinity},
journal = {Deep Sea Research Part I: Oceanographic Research Papers},
publisher = {Elsevier BV},
year = {2015},
volume = {105},
pages = {1--18},
doi = {10.1016/j.dsr.2015.08.005}
}
|
| Anav A, Friedlingstein P, Beer C, Ciais P, Harper A, Jones C, Murray-Tortarolo G, Papale D, Parazoo NC, Peylin P, Piao S, Sitch S, Viovy N, Wiltshire A and Zhao M (2015), "Spatiotemporal patterns of terrestrial gross primary production: A review", Reviews of Geophysics., sep, 2015. Vol. 53(3), pp. 785-818. |
| Abstract: Great advances have been made in the last decade in quantifying and understanding the spatiotemporal patterns of terrestrial gross primary production (GPP) with ground, atmospheric, and space observations. However, although global GPP estimates exist, each data set relies upon assumptions and none of the available data are based only on measurements. Consequently, there is no consensus on the global total GPP and large uncertainties exist in its benchmarking. The objective of this review is to assess how the different available data sets predict the spatiotemporal patterns of GPP, identify the differences among data sets, and highlight the main advantages/disadvantages of each data set. We compare GPP estimates for the historical period (1990-2009) from two observation-based data sets (Model Tree Ensemble and Moderate Resolution Imaging Spectroradiometer) to coupled carbon-climate models and terrestrial carbon cycle models from the Fifth Climate Model Intercomparison Project and TRENDY projects and to a new hybrid data set (CARBONES). Results show a large range in the mean global GPP estimates. The different data sets broadly agree on GPP seasonal cycle in terms of phasing, while there is still discrepancy on the amplitude. For interannual variability (IAV) and trends, there is a clear separation between the observation-based data that show little IAV and trend, while the process-based models have large GPP variability and significant trends. These results suggest that there is an urgent need to improve observation-based data sets and develop carbon cycle modeling with processes that are currently treated either very simplistically to correctly estimate present GPP and better quantify the future uptake of carbon dioxide by the world's vegetation. Key Points At global scale, direct measurements of GPP do not exist Large uncertainties exist on terrestrial global GPP benchmarking Models show large variability in mean global GPP estimates |
BibTeX:
@article{Anav2015,
author = {Anav, Alessandro and Friedlingstein, Pierre and Beer, Christian and Ciais, Philippe and Harper, Anna and Jones, Chris and Murray-Tortarolo, Guillermo and Papale, Dario and Parazoo, Nicholas C and Peylin, Philippe and Piao, Shilong and Sitch, Stephen and Viovy, Nicolas and Wiltshire, Andy and Zhao, Maosheng},
title = {Spatiotemporal patterns of terrestrial gross primary production: A review},
journal = {Reviews of Geophysics},
year = {2015},
volume = {53},
number = {3},
pages = {785--818},
url = {http://doi.wiley.com/10.1002/2015RG000483},
doi = {10.1002/2015RG000483}
}
|
| Arévalo-Martínez DL, Kock A, Löscher CR, Schmitz RA, Stramma L and Bange HW (2015), "Influence of mesoscale eddies on the distribution of nitrous oxide in the eastern tropical South Pacific", Biogeosciences Discussions., jun, 2015. Vol. 12(12), pp. 9243-9273. |
| Abstract: Recent observations in the eastern tropical South Pacific (ETSP) demonstrated the key role of meso- and submesoscale processes (e.g. eddies) in shaping its hydrographic and biogeochemical properties. Off Peru, elevated primary production from coastal upwelling in combination with sluggish ventilation of subsurface waters fuels a prominent oxygen minimum zone (OMZ). Given that nitrous oxide (N2O) production/consumption processes on the water column are sensitive to oxygen (O2) concentrations, the ETSP is a region of particular interest to investigate its source-sink dynamics. To date, no detailed surveys linking mesoscale processes and N2O distributions as well as their relevance to nitrogen (N) cycling are available. In this study, we present the first measurements of N2O across three mesoscale eddies (two mode water or anticyclonic and one cyclonic) which were identified, tracked and sampled during two surveys carried out in the ETSP in November-December 2012. A "two peak" structure was observed for N2O, wherein the two maxima coincide with the upper and lower boundaries of the OMZ, indicating active nitrification and partial denitrification. This was further supported by the abundances of the key gene for nitrification amoA and the gene marker for N2O production during denitrification, nirS. Conversely, we found strong N2O depletion in the core of the OMZ (O2 5 μmol L-1) to be consistent with nitrite (NO2-) accumulation and low levels of nitrate (NO3-), thus suggesting active denitrification. N2O depletion within the OMZ's core was substantially higher in the center of mode water eddies, supporting the view that eddy activity enhances N-loss processes off Peru, in particular near the shelf break where nutrient-rich, productive waters from upwelling are trapped before being transported offshore. Analysis of eddies during their propagation towards the open ocean showed that, in general, "aging" of mesoscale eddies tends to decrease N2O concentrations through the water column in response to reduced supply of material to fuel N-loss, although hydrographic variability might also significantly impact the pace of the production/consumption pathways for N2O. Our results demonstrate the relevance of mode water eddies for N2O distribution, thereby improving our understanding of the N-cycling processes, which are of crucial importance in times of climate change and ocean deoxygenation. |
BibTeX:
@article{Arevalo-Martinez2015,
author = {Arévalo-Martínez, D L and Kock, A and Löscher, C R and Schmitz, R A and Stramma, L and Bange, H W},
title = {Influence of mesoscale eddies on the distribution of nitrous oxide in the eastern tropical South Pacific},
journal = {Biogeosciences Discussions},
year = {2015},
volume = {12},
number = {12},
pages = {9243--9273},
url = {http://www.biogeosciences-discuss.net/12/9243/2015/},
doi = {10.5194/bgd-12-9243-2015}
}
|
| Arévalo-Martínez DL, Kock A, Löscher CR, Schmitz RA and Bange HW (2015), "Massive nitrous oxide emissions from the tropical South Pacific Ocean", Nature Geoscience., jun, 2015. Vol. 8(7), pp. 530-533. |
| Abstract: Nitrous oxide is a potent greenhouse gas and a key compound in stratospheric ozone depletion. In the ocean, nitrous oxide is produced at intermediate depths through nitrification and denitrification, in particular at low oxygen concentrations. Although a third of natural emissions of nitrous oxide to the atmosphere originate from the ocean, considerable uncertainties in the distribution and magnitude of the emissions still exist. Here we present high-resolution surface measurements and vertical profiles of nitrous oxide that include the highest reported nitrous oxide concentrations in marine surface waters, suggesting that there is a hotspot of nitrous oxide emissions in high-productivity upwelling ecosystems along the Peruvian coast. We estimate that off Peru, the extremely high nitrous oxide supersaturations we observed drive a massive efflux of 0.2-0.9 Tg of nitrogen emitted as nitrous oxide per year, equivalent to 5-22% of previous estimates of global marine nitrous oxide emissions. Nutrient and gene abundance data suggest that coupled nitrification-denitrification in the upper oxygen minimum zone and transport of resulting nitrous oxide to the surface by upwelling lead to the high nitrous oxide concentrations. Our estimate of nitrous oxide emissions from the Peruvian coast surpasses values from similar, highly productive areas. |
BibTeX:
@article{Arevalo-Martinez2015a,
author = {Arévalo-Martínez, D L and Kock, A and Löscher, C R and Schmitz, R A and Bange, H W},
title = {Massive nitrous oxide emissions from the tropical South Pacific Ocean},
journal = {Nature Geoscience},
year = {2015},
volume = {8},
number = {7},
pages = {530--533},
url = {http://www.nature.com/doifinder/10.1038/ngeo2469},
doi = {10.1038/ngeo2469}
}
|
| Arruda R, Calil PHR, Bianchi AA, Doney SC, Gruber N, Lima I and Turi G (2015), "Air-sea CO&lt;sub&gt;2&lt;/sub&gt; fluxes and the controls on ocean surface &lt;i&gt;p&lt;/i&gt;CO&lt;sub&gt;2&lt;/sub&gt; seasonal variability in the coastal and open-ocean southwestern Atlantic Ocean: a modeling study", Biogeosciences., oct, 2015. Vol. 12(19), pp. 5793-5809. Copernicus GmbH. |
| Abstract: textlessptextgreaterAbstract. We use an eddy-resolving, regional ocean biogeochemical model to investigate the main variables and processes responsible for the climatological spatio-temporal variability of pCO2 and the air-sea CO2 fluxes in the southwestern Atlantic Ocean. Overall, the region acts as a sink of atmospheric CO2 south of 30° S, and is close to equilibrium with the atmospheric CO2 to the north. On the shelves, the ocean acts as a weak source of CO2, except for the mid/outer shelves of Patagonia, which act as sinks. In contrast, the inner shelves and the low latitude open ocean of the southwestern Atlantic represent source regions. Observed nearshore-to-offshore and meridional pCO2 gradients are well represented by our simulation. A sensitivity analysis shows the importance of the counteracting effects of temperature and dissolved inorganic carbon (DIC) in controlling the seasonal variability of pCO2. Biological production and solubility are the main processes regulating pCO2, with biological production being particularly important on the shelves. The role of mixing/stratification in modulating DIC, and therefore surface pCO2, is shown in a vertical profile at the location of the Ocean Observatories Initiative (OOI) site in the Argentine Basin (42° S, 42° W).textless/ptextgreater |
BibTeX:
@article{Arruda2015,
author = {Arruda, R. and Calil, P. H. R. and Bianchi, A. A. and Doney, S. C. and Gruber, N. and Lima, I. and Turi, G.},
title = {Air-sea CO&lt;sub&gt;2&lt;/sub&gt; fluxes and the controls on ocean surface &lt;i&gt;p&lt;/i&gt;CO&lt;sub&gt;2&lt;/sub&gt; seasonal variability in the coastal and open-ocean southwestern Atlantic Ocean: a modeling study},
journal = {Biogeosciences},
publisher = {Copernicus GmbH},
year = {2015},
volume = {12},
number = {19},
pages = {5793--5809},
url = {https://bg.copernicus.org/articles/12/5793/2015/},
doi = {10.5194/bg-12-5793-2015}
}
|
| Baatz R, Bogena HR, Hendricks Franssen HJ, Huisman JA, Montzka C and Vereecken H (2015), "An empirical vegetation correction for soil water content quantification using cosmic ray probes", Water Resources Research., apr, 2015. Vol. 51(4), pp. 2030-2046. |
| Abstract: Cosmic ray probes are an emerging technology to continuously monitor soil water content at a scale significant to land surface processes. However, the application of this method is hampered by its susceptibility to the presence of aboveground biomass. Here we present a simple empirical framework to account for moderation of fast neutrons by aboveground biomass in the calibration. The method extends the N0-calibration function and was developed using an extensive data set from a network of 10 cosmic ray probes located in the Rur catchment, Germany. The results suggest a 0.9% reduction in fast neutron intensity per 1 kg of dry aboveground biomass per m2 or per 2 kg of biomass water equivalent per m2. We successfully tested the novel vegetation correction using temporary cosmic ray probe measurements along a strong gradient in biomass due to deforestation, and using the COSMIC, and the hmf method as independent soil water content retrieval algorithms. The extended N0-calibration function was able to explain 95% of the overall variability in fast neutron intensity. |
BibTeX:
@article{Baatz2015,
author = {Baatz, R and Bogena, H R and Hendricks Franssen, H J and Huisman, J A and Montzka, C and Vereecken, H},
title = {An empirical vegetation correction for soil water content quantification using cosmic ray probes},
journal = {Water Resources Research},
year = {2015},
volume = {51},
number = {4},
pages = {2030--2046},
url = {http://doi.wiley.com/10.1002/2014WR016443},
doi = {10.1002/2014WR016443}
}
|
| Babenhauserheide A, Basu S, Houweling S, Peters W and Butz A (2015), "Comparing the CarbonTracker and M5-4DVar data assimilation systems for CO2 surface flux inversions", Atmospheric Chemistry and Physics., sep, 2015. Vol. 15(17), pp. 9747-9763. |
| Abstract: Data assimilation systems allow for estimating surface fluxes of greenhouse gases from atmospheric concentration measurements. Good knowledge about fluxes is essential to understand how climate change affects ecosystems and to characterize feedback mechanisms. Based on the assimilation of more than 1 year of atmospheric in situ concentration measurements, we compare the performance of two established data assimilation models, CarbonTracker and TM5-4DVar (Transport Model 5 - Four-Dimensional Variational model), for CO2 flux estimation. CarbonTracker uses an ensemble Kalman filter method to optimize fluxes on ecoregions. TM5-4DVar employs a 4-D variational method and optimizes fluxes on a 6° x 4° longitude-latitude grid. Harmonizing the input data allows for analyzing the strengths and weaknesses of the two approaches by direct comparison of the modeled concentrations and the estimated fluxes. We further assess the sensitivity of the two approaches to the density of observations and operational parameters such as the length of the assimilation time window. Our results show that both models provide optimized CO2 concentration fields of similar quality. In Antarctica CarbonTracker underestimates the wintertime CO2 concentrations, since its 5-week assimilation window does not allow for adjusting the distant surface fluxes in response to the detected concentration mismatch. Flux estimates by CarbonTracker and TM5-4DVar are consistent and robust for regions with good observation coverage, regions with low observation coverage reveal significant differences. In South America, the fluxes estimated by TM5-4DVar suffer from limited representativeness of the few observations. For the North American continent, mimicking the historical increase of the measurement network density shows improving agreement between CarbonTracker and TM5-4DVar flux estimates for increasing observation density. |
BibTeX:
@article{Babenhauserheide2015,
author = {Babenhauserheide, A and Basu, S and Houweling, S and Peters, W and Butz, A},
title = {Comparing the CarbonTracker and M5-4DVar data assimilation systems for CO2 surface flux inversions},
journal = {Atmospheric Chemistry and Physics},
year = {2015},
volume = {15},
number = {17},
pages = {9747--9763},
url = {http://www.atmos-chem-phys.net/15/9747/2015/},
doi = {10.5194/acp-15-9747-2015}
}
|
| Ballantyne AP, Andres R, Houghton R, Stocker BD, Wanninkhof R, Anderegg W, Cooper LA, DeGrandpre M, Tans PP, Miller JB, Alden C and White JWC (2015), "Audit of the global carbon budget: estimate errors and their impact on uptake uncertainty", Biogeosciences., apr, 2015. Vol. 12(8), pp. 2565-2584. Copernicus GmbH. |
| Abstract: textlessptextgreaterAbstract. Over the last 5 decades monitoring systems have been developed to detect changes in the accumulation of carbon (C) in the atmosphere and ocean; however, our ability to detect changes in the behavior of the global C cycle is still hindered by measurement and estimate errors. Here we present a rigorous and flexible framework for assessing the temporal and spatial components of estimate errors and their impact on uncertainty in net C uptake by the biosphere. We present a novel approach for incorporating temporally correlated random error into the error structure of emission estimates. Based on this approach, we conclude that the 2σ uncertainties of the atmospheric growth rate have decreased from 1.2 Pg C yr−1 in the 1960s to 0.3 Pg C yr−1 in the 2000s due to an expansion of the atmospheric observation network. The 2σ uncertainties in fossil fuel emissions have increased from 0.3 Pg C yr−1 in the 1960s to almost 1.0 Pg C yr−1 during the 2000s due to differences in national reporting errors and differences in energy inventories. Lastly, while land use emissions have remained fairly constant, their errors still remain high and thus their global C uptake uncertainty is not trivial. Currently, the absolute errors in fossil fuel emissions rival the total emissions from land use, highlighting the extent to which fossil fuels dominate the global C budget. Because errors in the atmospheric growth rate have decreased faster than errors in total emissions have increased, a ˜20% reduction in the overall uncertainty of net C global uptake has occurred. Given all the major sources of error in the global C budget that we could identify, we are 93% confident that terrestrial C uptake has increased and 97% confident that ocean C uptake has increased over the last 5 decades. Thus, it is clear that arguably one of the most vital ecosystem services currently provided by the biosphere is the continued removal of approximately half of atmospheric CO2 emissions from the atmosphere, although there are certain environmental costs associated with this service, such as the acidification of ocean waters.textless/ptextgreater |
BibTeX:
@article{Ballantyne2015,
author = {Ballantyne, A. P. and Andres, R. and Houghton, R. and Stocker, B. D. and Wanninkhof, R. and Anderegg, W. and Cooper, L. A. and DeGrandpre, M. and Tans, P. P. and Miller, J. B. and Alden, C. and White, J. W. C.},
title = {Audit of the global carbon budget: estimate errors and their impact on uptake uncertainty},
journal = {Biogeosciences},
publisher = {Copernicus GmbH},
year = {2015},
volume = {12},
number = {8},
pages = {2565--2584},
url = {https://bg.copernicus.org/articles/12/2565/2015/},
doi = {10.5194/bg-12-2565-2015}
}
|
| Balzarolo M, Vescovo L, Hammerle A, Gianelle D, Papale D, Tomelleri E and Wohlfahrt G (2015), "On the relationship between ecosystem-scale hyperspectral reflectance and CO2 exchange in European mountain grasslands", Biogeosciences., may, 2015. Vol. 12(10), pp. 3089-3108. |
| Abstract: In this paper we explore the skill of hyperspectral reflectance measurements and vegetation indices (VIs) derived from these in estimating carbon dioxide (CO2) fluxes of grasslands. Hyperspectral reflectance data, CO2 fluxes and biophysical parameters were measured at three grassland sites located in European mountain regions using standardized protocols. The relationships between CO2 fluxes, ecophysiological variables, traditional VIs and VIs derived using all two-band combinations of wavelengths available from the whole hyperspectral data space were analysed. We found that VIs derived from hyperspectral data generally explained a large fraction of the variability in the investigated dependent variables but differed in their ability to estimate midday and daily average CO2 fluxes and various derived ecophysiological parameters. Relationships between VIs and CO2 fluxes and ecophysiological parameters were site-specific, likely due to differences in soils, vegetation parameters and environmental conditions. Chlorophyll and water-content-related VIs explained the largest fraction of variability in most of the dependent variables. Band selection based on a combination of a genetic algorithm with random forests (GA-rF) confirmed that it is difficult to select a universal band region suitable across the investigated ecosystems. Our findings have major implications for upscaling terrestrial CO2 fluxes to larger regions and for remote- and proximal-sensing sampling and analysis strategies and call for more cross-site synthesis studies linking ground-based spectral reflectance with ecosystem-scale CO2 fluxes. |
BibTeX:
@article{Balzarolo2015,
author = {Balzarolo, M and Vescovo, L and Hammerle, A and Gianelle, D and Papale, D and Tomelleri, E and Wohlfahrt, G},
title = {On the relationship between ecosystem-scale hyperspectral reflectance and CO2 exchange in European mountain grasslands},
journal = {Biogeosciences},
year = {2015},
volume = {12},
number = {10},
pages = {3089--3108},
url = {http://www.biogeosciences.net/12/3089/2015/},
doi = {10.5194/bg-12-3089-2015}
}
|
| Barton L, Wolf B, Rowlings D, Scheer C, Kiese R, Grace P, Stefanova K and Butterbach-Bahl K (2015), "Sampling frequency affects estimates of annual nitrous oxide fluxes", Scientific Reports., nov, 2015. Vol. 5, pp. 15912. |
| Abstract: Quantifying nitrous oxide (N2O) fluxes, a potent greenhouse gas, from soils is necessary to improve our knowledge of terrestrial N2O losses. Developing universal sampling frequencies for calculating annual N2O fluxes is difficult, as fluxes are renowned for their high temporal variability. We demonstrate daily sampling was largely required to achieve annual N2O fluxes within 10% of the "best" estimate for 28 annual datasets collected from three continents - Australia, Europe and Asia. Decreasing the regularity of measurements either under- or overestimated annual N2O fluxes, with a maximum overestimation of 935%. Measurement frequency was lowered using a sampling strategy based on environmental factors known to affect temporal variability, but still required sampling more than once a week. Consequently, uncertainty in current global terrestrial N2O budgets associated with the upscaling of field-based datasets can be decreased significantly using adequate sampling frequencies. |
BibTeX:
@article{Barton2015,
author = {Barton, L and Wolf, B and Rowlings, D and Scheer, C and Kiese, R and Grace, P and Stefanova, K and Butterbach-Bahl, K},
title = {Sampling frequency affects estimates of annual nitrous oxide fluxes},
journal = {Scientific Reports},
year = {2015},
volume = {5},
pages = {15912},
url = {http://www.nature.com/articles/srep15912},
doi = {10.1038/srep15912}
}
|
| Bergamaschi P, Corazza M, Karstens U, Athanassiadou M, Thompson RL, Pison I, Manning AJ, Bousquet P, Segers A, Vermeulen AT, Janssens-Maenhout G, Schmidt M, Ramonet M, Meinhardt F, Aalto T, Haszpra L, Moncrieff J, Popa ME, Lowry D, Steinbacher M, Jordan A, O'Doherty S, Piacentino S and Dlugokencky E (2015), "Top-down estimates of European CH4 and N2O emissions based on four different inverse models", Atmospheric Chemistry and Physics., jan, 2015. Vol. 15(2), pp. 715-736. |
| Abstract: European CH4 and N2O emissions are estimated for 2006 and 2007 using four inverse modelling systems, based on different global and regional Eulerian and Lagrangian transport models. This ensemble approach is designed to provide more realistic estimates of the overall uncertainties in the derived emissions, which is particularly important for verifying bottom-up emission inventories. We use continuous observations from 10 European stations (including 5 tall towers) for CH4 and 9 continuous stations for N2O, complemented by additional European and global discrete air sampling sites. The available observations mainly constrain CH4 and N2O emissions from north-western and eastern Europe. The inversions are strongly driven by the observations and the derived total emissions of larger countries show little dependence on the emission inventories used a priori. Three inverse models yield 26-56% higher total CH4 emissions from north-western and eastern Europe compared to bottom-up emissions reported to the UNFCCC, while one model is close to the UNFCCC values. In contrast, the inverse modelling estimates of European N2O emissions are in general close to the UNFCCC values, with the overall range from all models being much smaller than the UNFCCC uncertainty range for most countries. Our analysis suggests that the reported uncertainties for CH4 emissions might be underestimated, while those for N2O emissions are likely overestimated. |
BibTeX:
@article{Bergamaschi2015,
author = {Bergamaschi, P and Corazza, M and Karstens, U and Athanassiadou, M and Thompson, R L and Pison, I and Manning, A J and Bousquet, P and Segers, A and Vermeulen, A T and Janssens-Maenhout, G and Schmidt, M and Ramonet, M and Meinhardt, F and Aalto, T and Haszpra, L and Moncrieff, J and Popa, M E and Lowry, D and Steinbacher, M and Jordan, A and O'Doherty, S and Piacentino, S and Dlugokencky, E},
title = {Top-down estimates of European CH4 and N2O emissions based on four different inverse models},
journal = {Atmospheric Chemistry and Physics},
year = {2015},
volume = {15},
number = {2},
pages = {715--736},
url = {http://www.atmos-chem-phys.net/15/715/2015/},
doi = {10.5194/acp-15-715-2015}
}
|
| Berggren M, Bergström AK and Karlsson J (2015), "Intraspecific autochthonous and allochthonous resource use by zooplankton in a humic lake during the transitions between winter, summer and fall", PLoS ONE., mar, 2015. Vol. 10(3), pp. e0120575. |
| Abstract: Seasonal patterns in assimilation of externally produced, allochthonous, organic matter into aquatic food webs are poorly understood, especially in brown-water lakes. We studied the allochthony (share biomass of terrestrial origin) in cladoceran, calanoid and cyclopoid micro-crustacean zooplankton from late winter to fall during two years in a small humic lake (Sweden). The use of allochthonous resources was important for sustaining a small population of calanoids in the water column during late winter. However, in summer the calanoids shifted to 100% herbivory, increasing their biomass several-fold by making efficient use of the pelagic primary production. In contrast, the cyclopoids and cladocerans remained at high levels of allochthony throughout the seasons, both groups showing the mean allochthony of 0.56 (range in mean 0.17-0.79 and 0.34-0.75, for the respective group, depending on model parameters). Our study shows that terrestrial organic matter can be an important resource for cyclopoids and cladocerans on an annual basis, forming a significant link between terrestrial organic matter and the higher trophic levels of the food web, but it can also be important for sustaining otherwise herbivorous calanoids during periods of low primary production in late winter. |
BibTeX:
@article{Berggren2015,
author = {Berggren, Martin and Bergström, Ann Kristin and Karlsson, Jan},
editor = {Iwata, Tomoya},
title = {Intraspecific autochthonous and allochthonous resource use by zooplankton in a humic lake during the transitions between winter, summer and fall},
journal = {PLoS ONE},
year = {2015},
volume = {10},
number = {3},
pages = {e0120575},
url = {http://dx.plos.org/10.1371/journal.pone.0120575},
doi = {10.1371/journal.pone.0120575}
}
|
| Berhongaray G, Verlinden MS, Broeckx LS and Ceulemans R (2015), "Changes in belowground biomass after coppice in two Populus genotypes", Forest Ecology and Management., feb, 2015. Vol. 337, pp. 1-10. |
| Abstract: Despite the potential of high-density, short-rotation woody biomass plantations to sequester carbon (C) in the soil, few studies have examined their belowground components. We were particularly interested in the biomass allocation patterns after the change from a single-stem (pre-coppice) to a multi-shoot (post-coppice) system, as well as in the fine root (Fr; θ2mm) mortality after coppice for their implications in the belowground C cycle. The root system of selected trees from two poplar (Populus spp.) genotypes - Skado and Koster - were excavated for the determination of coarse (Cr, θ5mm) and medium-sized (Mr, θ2-5mm) roots. After two 2-year rotations, the Cr biomass (dry mass, DM) was higher in the P. trichocarpa × P. maximowiczii genotype Skado (187.0gDM m-2) than in the P. deltoides × P. nigra genotype Koster (155.4gDM m-2). Both genotypes showed a relatively shallow, but extensive root system. Allometric equations were fitted between DM of Cr and Mr, and basal area. The root:shoot ratio decreased exponentially with basal area, showing the same trend for single-stem and multi-shoot trees. The soil coring technique was used to determine Fr mass at different dates and at different soil depths. The highest Fr biomass was detected in the upper 15cm of the soil; no genotypic differences in Fr mass were detected at any soil depth. After coppice Fr mortality was significantly increased and weed root biomass significantly reduced. The coppice of the aboveground stems and shoots resulted in a high input of C into the soil and a large amount of C was stored in belowground tree biomass. |
BibTeX:
@article{Berhongaray2015,
author = {Berhongaray, G and Verlinden, M S and Broeckx, L S and Ceulemans, R},
title = {Changes in belowground biomass after coppice in two Populus genotypes},
journal = {Forest Ecology and Management},
year = {2015},
volume = {337},
pages = {1--10},
url = {http://linkinghub.elsevier.com/retrieve/pii/S0378112714006173},
doi = {10.1016/j.foreco.2014.10.035}
}
|
| Berhongaray G and Ceulemans R (2015), "Neglected carbon pools and fluxes in the soil balance of short-rotation woody biomass crops", Biomass and Bioenergy., feb, 2015. Vol. 73, pp. 62-66. |
| Abstract: The cultivation of dedicated bioenergy crops is being stimulated because of their potential to replace fossil fuels and to maintain or to sequester carbon (C) in the soil, and thus help to mitigate the rising atmospheric CO2 levels. There are, however, still a lot of inaccuracies with regard to the dynamics of C in the soil, and thus with the potential to sequester soil C in these bioenergy crops. Using experimental data observed at the intensively monitored short-rotation woody crops (SRWC) plantation of the POPFULL project, we demonstrate that frequently neglected C pools and fluxes can be of crucial importance for the soil C balance. We highlight three specific cases. First, C inputs into the soil due to weed roots may equal or exceed those due to poplar fine roots, especially during the establishment phase of the plantation. Secondly, harvesting influences the dynamics of above- and belowground C inputs, as well as the soil environment. Large amounts of C are stored in the belowground woody biomass, which represents a long-term C pool. Thirdly, spatial differences related to the planting design are an important source of error in the upscaling of soil variables. We call upon researchers to consider and measure these neglected C pools and fluxes. |
BibTeX:
@article{Berhongaray2015a,
author = {Berhongaray, G and Ceulemans, R},
title = {Neglected carbon pools and fluxes in the soil balance of short-rotation woody biomass crops},
journal = {Biomass and Bioenergy},
year = {2015},
volume = {73},
pages = {62--66},
url = {http://linkinghub.elsevier.com/retrieve/pii/S0961953414005339},
doi = {10.1016/j.biombioe.2014.12.002}
}
|
| Biavati G, Feist DG, Gerbig C and Kretschmer R (2015), "Error estimation for localized signal properties: Application to atmospheric mixing height retrievals", Atmospheric Measurement Techniques., oct, 2015. Vol. 8(10), pp. 4215-4230. Copernicus GmbH. |
| Abstract: The mixing height is a key parameter for many applications that relate surface-atmosphere exchange fluxes to atmospheric mixing ratios, e.g., in atmospheric transport modeling of pollutants. The mixing height can be estimated with various methods: profile measurements from radiosondes as well as remote sensing (e.g., optical backscatter measurements). For quantitative applications, it is important to estimate not only the mixing height itself but also the uncertainty associated with this estimate. However, classical error propagation typically fails on mixing height estimates that use thresholds in vertical profiles of some measured or measurement-derived quantity. Therefore, we propose a method to estimate the uncertainty of an estimation of the mixing height. The uncertainty we calculate is related not to the physics of the boundary layer (e.g., entrainment zone thickness) but to the quality of the analyzed signals. The method relies on the concept of statistical confidence and on the knowledge of the measurement errors. It can also be applied to problems outside atmospheric mixing height retrievals where properties have to be assigned to a specific position, e.g., the location of a local extreme. |
BibTeX:
@article{Biavati2015,
author = {Biavati, G. and Feist, D. G. and Gerbig, C. and Kretschmer, R.},
title = {Error estimation for localized signal properties: Application to atmospheric mixing height retrievals},
journal = {Atmospheric Measurement Techniques},
publisher = {Copernicus GmbH},
year = {2015},
volume = {8},
number = {10},
pages = {4215--4230},
doi = {10.5194/amt-8-4215-2015}
}
|
| Bidleman T, Agosta K, Andersson A, Brorström-Lundén E, Haglund P, Hansson K, Laudon H, Newton S, Nygren O, Ripszam M, Tysklind M and Wiberg K (2015), "Atmospheric pathways of chlorinated pesticides and natural bromoanisoles in the northern Baltic Sea and its catchment", Ambio., jun, 2015. Vol. 44(S3), pp. 472-483. |
| Abstract: Long-range atmospheric transport is a major pathway for delivering persistent organic pollutants to the oceans. Atmospheric deposition and volatilization of chlorinated pesticides and algae-produced bromoanisoles (BAs) were estimated for Bothnian Bay, northern Baltic Sea, based on air and water concentrations measured in 2011–2012. Pesticide fluxes were estimated using monthly air and water temperatures and assuming 4 months ice cover when no exchange occurs. Fluxes were predicted to increase by about 50 % under a 2069–2099 prediction scenario of higher temperatures and no ice. Total atmospheric loadings to Bothnian Bay and its catchment were derived from air–sea gas exchange and “bulk†(precipitation + dry particle) deposition, resulting in net gains of 53 and 46 kg yearsupâˆ'1/sup for endosulfans and hexachlorocyclohexanes, respectively, and net loss of 10 kg yearsupâˆ'1/sup for chlordanes. Volatilization of BAs releases bromine to the atmosphere and may limit their residence time in Bothnian Bay. This initial study provides baseline information for future investigations of climate change on biogeochemical cycles in the northern Baltic Sea and its catchment. |
BibTeX:
@article{Bidleman2015,
author = {Bidleman, Terry and Agosta, Kathleen and Andersson, Agneta and Brorström-Lundén, Eva and Haglund, Peter and Hansson, Katarina and Laudon, Hjalmar and Newton, Seth and Nygren, Olle and Ripszam, Matyas and Tysklind, Mats and Wiberg, Karin},
title = {Atmospheric pathways of chlorinated pesticides and natural bromoanisoles in the northern Baltic Sea and its catchment},
journal = {Ambio},
year = {2015},
volume = {44},
number = {S3},
pages = {472--483},
url = {http://link.springer.com/10.1007/s13280-015-0666-4},
doi = {10.1007/s13280-015-0666-4}
}
|
| Bishop K and Seibert J (2015), "A primer for hydrology: The beguiling simplicity of Water's journey from rain to stream at 30", Hydrological Processes., jul, 2015. Vol. 29(16), pp. 3443-3446. |
| Abstract: Water's journey from rain to stream by Harald Grip and Allan Rodhe (1985, in Swedish: Vattnets väg från regn till bäck) was one of the first textbooks to present groundwater contributions as a major feature of runoff generation, with implications for water quality and management. Three decades later, we have the privilege of presenting a special issue of Hydrological Processes, 'Runoff Generation in a Nordic Light: 30Years with Water's Journey from Rain to Stream' that seeks to introduce the book to a larger audience and continue the journey of ideas that the authors set in motion with their book. |
BibTeX:
@article{Bishop2015,
author = {Bishop, Kevin and Seibert, Jan},
title = {A primer for hydrology: The beguiling simplicity of Water's journey from rain to stream at 30},
journal = {Hydrological Processes},
year = {2015},
volume = {29},
number = {16},
pages = {3443--3446},
url = {http://doi.wiley.com/10.1002/hyp.10516},
doi = {10.1002/hyp.10516}
}
|
| Bogena HR, Bol R, Borchard N, Brüggemann N, Diekkrüger B, Drüe C, Groh J, Gottselig N, Huisman JA, Lücke A, Missong A, Neuwirth B, Pütz T, Schmidt M, Stockinger M, Tappe W, Weihermüller L, Wiekenkamp I and Vereecken H (2015), "A terrestrial observatory approach to the integrated investigation of the effects of deforestation on water, energy, and matter fluxes", Science China Earth Sciences., jan, 2015. Vol. 58(1), pp. 61-75. |
| Abstract: Integrated observation platforms have been set up to investigate consequences of global change within a terrestrial network of observatories (TERENO) in Germany. The aim of TERENO is to foster the understanding of water, energy, and matter fluxes in terrestrial systems, as well as their biological and physical drivers. Part of the Lower Rhine Valley-Eifel observatory of TERENO is located within the Eifel National Park. Recently, the National Park forest management started to promote the natural regeneration of near-natural beech forest by removing a significant proportion of the spruce forest that was established for timber production after World War II. Within this context, the effects of such a disturbance on forest ecosystem functioning are currently investigated in a deforestation experiment in the Wüstebach catchment, which is one of the key experimental research sites within the Lower Rhine Valley-Eifel observatory. Here, we present the integrated observation system of the Wüstebach test site to exemplarily demonstrate the terrestrial observatory concept of TERENO that allows for a detailed monitoring of changes in hydrological and biogeochemical states and fluxes triggered by environmental disturbances. We present the observation platforms and the soil sampling campaign, as well as preliminary results including an analysis of data consistency. We specifically highlight the capability of integrated datasets to enable improved process understanding of the post-deforestation changes in ecosystem functioning. |
BibTeX:
@article{Bogena2015,
author = {Bogena, H R and Bol, R and Borchard, N and Brüggemann, N and Diekkrüger, B and Drüe, C and Groh, J and Gottselig, N and Huisman, J A and Lücke, A and Missong, A and Neuwirth, B and Pütz, T and Schmidt, M and Stockinger, M and Tappe, W and Weihermüller, L and Wiekenkamp, I and Vereecken, H},
title = {A terrestrial observatory approach to the integrated investigation of the effects of deforestation on water, energy, and matter fluxes},
journal = {Science China Earth Sciences},
year = {2015},
volume = {58},
number = {1},
pages = {61--75},
url = {http://link.springer.com/10.1007/s11430-014-4911-7},
doi = {10.1007/s11430-014-4911-7}
}
|
| Bonne JL, Steen-Larsen HC, Risi C, Werner M, Sodemann H, Lacour JL, Fettweis X, Cesana G, Delmotte M, Cattani O, Vallelonga P, Kjær HA, Clerbaux C, Sveinbjörnsdóttir ÁE and Masson-Delmotte V (2015), "The summer 2012 Greenland heat wave: In situ and remote sensing observations of water vapor isotopic composition during an atmospheric river event", Journal of Geophysical Research. Vol. 120(7), pp. 2970-2989. Wiley-Blackwell. |
| Abstract: During 7-12 July 2012, extreme moist and warm conditions occurred over Greenland, leading to widespread surface melt. To investigate the physical processes during the atmospheric moisture transport of this event, we study the water vapor isotopic composition using surface in situ observations in Bermuda Island, South Greenland coast (Ivittuut), and northwest Greenland ice sheet (NEEM), as well as remote sensing observations (Infrared Atmospheric Sounding Interferometer (IASI) instrument on board MetOp-A), depicting propagation of similar surface and midtropospheric humidity and δD signals. Simulations using Lagrangian moisture source diagnostic and water tagging in a regional model showed that Greenland was affected by an atmospheric river transporting moisture from the western subtropical North Atlantic Ocean, which is coherent with observations of snow pit impurities deposited at NEEM. At Ivittuut, surface air temperature, humidity, and δD increases are observed. At NEEM, similar temperature increase is associated with a large and long-lasting ˜100‰δD enrichment and ˜15‰ deuterium excess decrease, thereby reaching Ivittuut level. We assess the simulation of this event in two isotope-enabled atmospheric general circulation models (LMDz-iso and ECHAM5-wiso). LMDz-iso correctly captures the timing of propagation for this event identified in IASI data but depict too gradual variations when compared to surface data. Both models reproduce the surface meteorological and isotopic values during the event but underestimate the background deuterium excess at NEEM. Cloud liquid water content parametrization in LMDz-iso poorly impacts the vapor isotopic composition. Our data demonstrate that during this atmospheric river event the deuterium excess signal is conserved from the moisture source to northwest Greenland. |
BibTeX:
@article{Bonne2015,
author = {Bonne, Jean Louis and Steen-Larsen, Hans Christian and Risi, Camille and Werner, Martin and Sodemann, Harald and Lacour, Jean Lionel and Fettweis, Xavier and Cesana, Grégory and Delmotte, Marc and Cattani, Olivier and Vallelonga, Paul and Kjær, Helle Astrid and Clerbaux, Cathy and Sveinbjörnsdóttir, Árny Erla and Masson-Delmotte, Valérie},
title = {The summer 2012 Greenland heat wave: In situ and remote sensing observations of water vapor isotopic composition during an atmospheric river event},
journal = {Journal of Geophysical Research},
publisher = {Wiley-Blackwell},
year = {2015},
volume = {120},
number = {7},
pages = {2970--2989},
doi = {10.1002/2014JD022602}
}
|
| Bosco S, Volpi I, o Di Nasso NN, Triana F, Roncucci N, Tozzini C, Villani R, Laville P, Neri S, Mattei F, Virgili G, Nuvoli S, Fabbrini L and Bonari E (2015), "LIFE+IPNOA mobile prototype for the monitoring of soil N2O emissions from arable crops: First-year results on durum wheat", Italian Journal of Agronomy., sep, 2015. Vol. 10(3), pp. 124-131. |
| Abstract: Agricultural activities are co-responsible for the emission of the most important greenhouse gases: carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O). Development of methodologies to improve monitoring techniques for N2O are still needful. The LIFE+IPNOA project aims to improve the emissions monitoring of nitrous oxide from agricultural soils and to identify the agricultural practices that can limit N2O production. In order to achieve this objective, both a mobile and a stationary instrument were developed and validated. Several experimental field trials were set up in two different sites investigating the most representative crops of Tuscany (Central Italy), namely durum wheat, maize, sunflower, tomato and faba bean. The field trials were realized in order to test the effect on N2O emissions of key factors: tillage intensity, nitrogen fertiliser rate and irrigation. The field trial on durum wheat was set up in 2013 to test the effect of tillage intensity (minimum and conventional tillage) and nitrogen fertilisation rate (0, 110, 170 kg N ha-1) on soil N2O flux. Monitoring was carried out using the IPNOA mobile prototype. Preliminary results on N2O emissions for the durum wheat growing season showed that mean daily N2O fluxes ranged from –0.13 to 6.43 mg m-2 day-1 and cumulative N2O-N emissions over the period ranged from 827 to 2340 g N2O-N ha-1. Tillage did not affect N2O flux while increasing nitrogen fertilisation rate resulted to significantly increase N2O emissions. The IPNOA mobile prototype performed well during this first year of monitoring, allowing to catch both very low fluxes and peaks on N2O emissions after nitrogen supply, showing a good suitability to the field conditions. |
BibTeX:
@article{Bosco2015,
author = {Bosco, Simona and Volpi, Iride and o Di Nasso, Nicoletta Nassi and Triana, Federico and Roncucci, Neri and Tozzini, Cristiano and Villani, Ricardo and Laville, Patricia and Neri, Simone and Mattei, Federica and Virgili, Giorgio and Nuvoli, Stefania and Fabbrini, Luigi and Bonari, Enrico},
title = {LIFE+IPNOA mobile prototype for the monitoring of soil N2O emissions from arable crops: First-year results on durum wheat},
journal = {Italian Journal of Agronomy},
year = {2015},
volume = {10},
number = {3},
pages = {124--131},
url = {http://www.agronomy.it/index.php/agro/article/view/669},
doi = {10.4081/ija.2015.669}
}
|
| Brix H, Menemenlis D, Hill C, Dutkiewicz S, Jahn O, Wang D, Bowman K and Zhang H (2015), "Using Green's Functions to initialize and adjust a global, eddying ocean biogeochemistry general circulation model", Ocean Modelling. Vol. 95, pp. 1-14. |
| Abstract: The NASA Carbon Monitoring System (CMS) Flux Project aims to attribute changes in the atmospheric accumulation of carbon dioxide to spatially resolved fluxes by utilizing the full suite of NASA data, models, and assimilation capabilities. For the oceanic part of this project, we introduce ECCO2-Darwin, a new ocean biogeochemistry general circulation model based on combining the following pre-existing components: (i) a full-depth, eddying, global-ocean configuration of the Massachusetts Institute of Technology general circulation model (MITgcm), (ii) an adjoint-method-based estimate of ocean circulation from the Estimating the Circulation and Climate of the Ocean, Phase II (ECCO2) project, (iii) the MIT ecosystem model "Darwin", and (iv) a marine carbon chemistry model. Air-sea gas exchange coefficients and initial conditions of dissolved inorganic carbon, alkalinity, and oxygen are adjusted using a Green's Functions approach in order to optimize modeled air-sea CO 2 fluxes. Data constraints include observations of carbon dioxide partial pressure (pCO 2) for 2009-2010, global air-sea CO 2 flux estimates, and the seasonal cycle of the Takahashi et al. (2009) Atlas. The model sensitivity experiments (or Green's Functions) include simulations that start from different initial conditions as well as experiments that perturb air-sea gas exchange parameters and the ratio of particulate inorganic to organic carbon. The Green's Functions approach yields a linear combination of these sensitivity experiments that minimizes model-data differences. The resulting initial conditions and gas exchange coefficients are then used to integrate the ECCO2-Darwin model forward. Despite the small number (six) of control parameters, the adjusted simulation is significantly closer to the data constraints (37% cost function reduction, i.e., reduction in the model-data difference, relative to the baseline simulation) and to independent observations (e.g., alkalinity). The adjusted air-sea gas exchange parameter differs by only 3% from the baseline value and has little impact (−0.1%) on the cost function. The particulate inorganic to organic carbon ratio was increased more than threefold and reduced the cost function by 22% relative to the baseline integration, indicating a significant influence of biology on air-sea gas exchange. The largest contribution to cost reduction (35%) comes from the adjustment of initial conditions. In addition to reducing biases relative to observations, the adjusted simulation exhibits smaller model drift than the baseline. We estimate drift by integrating the model with repeated 2009 atmospheric forcing for seven years and find a volume-weighted drift reduction of, for example, 12.5% for nitrate and 30% for oxygen in the top 300 m. Although there remain several regions with large model-data discrepancies, for example, overly strong carbon uptake in the Southern Ocean, the adjusted simulation is a first step towards a more accurate representation of the ocean carbon cycle at high spatial and temporal resolution. |
BibTeX:
@article{Brix2015,
author = {Brix, H and Menemenlis, D and Hill, C and Dutkiewicz, S and Jahn, O and Wang, D and Bowman, K and Zhang, H},
title = {Using Green's Functions to initialize and adjust a global, eddying ocean biogeochemistry general circulation model},
journal = {Ocean Modelling},
year = {2015},
volume = {95},
pages = {1--14},
url = {http://dx.doi.org/10.1016/j.ocemod.2015.07.008},
doi = {10.1016/j.ocemod.2015.07.008}
}
|
| Brown PJ, Jullion L, Landschützer P, Bakker DCE, Naveira Garabato AC, Meredith MP, Torres-Valdés S, Watson AJ, Hoppema M, Loose B, Jones EM, Telszewski M, Jones SD and Wanninkhof R (2015), "Carbon dynamics of the Weddell Gyre, Southern Ocean", Global Biogeochemical Cycles., mar, 2015. Vol. 29(3), pp. 288-306. |
| Abstract: The accumulation of carbon within the Weddell Gyre and its exchanges across the gyre boundaries are investigated with three recent full-depth oceanographic sections enclosing this climatically important region. The combination of carbon measurements with ocean circulation transport estimates from a box inverse analysis reveals that deepwater transports associated with Warm Deep Water (WDW) and Weddell Sea Deep Water dominate the gyre's carbon budget, while a dual-cell vertical overturning circulation leads to both upwelling and the delivery of large quantities of carbon to the deep ocean. Historical sea surface pCO2 observations, interpolated using a neural network technique, confirm the net summertime sink of 0.044 to 0.058 ± 0.010 Pg C yr-1 derived from the inversion. However, a wintertime outgassing signal similar in size results in a statistically insignificant annual air-to-sea CO2 flux of 0.002 ± 0.007 Pg C yr-1 (mean 1998-2011) to 0.012 ± 0.024 Pg C yr-1 (mean 2008-2010) to be diagnosed for the Weddell Gyre. A surface layer carbon balance, independently derived from in situ biogeochemical measurements, reveals that freshwater inputs and biological drawdown decrease surface ocean inorganic carbon levels more than they are increased by WDW entrainment, resulting in an estimated annual carbon sink of 0.033 ± 0.021 Pg C yr-1. Although relatively less efficient for carbon uptake than the global oceans, the summertime Weddell Gyre suppresses the winter outgassing signal, while its biological pump and deepwater formation act as key conduits for transporting natural and anthropogenic carbon to the deep ocean where they can reside for long time scales. |
BibTeX:
@article{Brown2015,
author = {Brown, Peter J and Jullion, Loïc and Landschützer, Peter and Bakker, Dorothee C E and Naveira Garabato, Alberto C and Meredith, Michael P and Torres-Valdés, Sinhue and Watson, Andrew J and Hoppema, Mario and Loose, Brice and Jones, Elizabeth M and Telszewski, Maciej and Jones, Steve D and Wanninkhof, Rik},
title = {Carbon dynamics of the Weddell Gyre, Southern Ocean},
journal = {Global Biogeochemical Cycles},
year = {2015},
volume = {29},
number = {3},
pages = {288--306},
url = {http://doi.wiley.com/10.1002/2014GB005006},
doi = {10.1002/2014GB005006}
}
|
| Brutsaert W (2015), "A generalized complementary principle with physical constraints for land-surface evaporation", Water Resources Research., oct, 2015. Vol. 51(10), pp. 8087-8093. Blackwell Publishing Ltd. |
| Abstract: The idea of complementary evaporative fluxes, first advanced by Bouchet (1963), is reformulated as a general polynomial, satisfying boundary conditions based on strictly physical considerations. Experimental evidence supports the validity of the imposed constraints. Earlier complementary relationships are shown to be special cases which satisfy only one of the necessary conditions. The new formulation provides a more rigorous base for the complementary principle. |
BibTeX:
@article{Brutsaert2015,
author = {Brutsaert, Wilfried},
title = {A generalized complementary principle with physical constraints for land-surface evaporation},
journal = {Water Resources Research},
publisher = {Blackwell Publishing Ltd},
year = {2015},
volume = {51},
number = {10},
pages = {8087--8093},
doi = {10.1002/2015WR017720}
}
|
| Burrows RM, Hotchkiss ER, Jonsson M, Laudon H, Mckie BG and Sponseller RA (2015), "Nitrogen limitation of heterotrophic biofilms in boreal streams", Freshwater Biology., jul, 2015. Vol. 60(7), pp. 1237-1251. |
| Abstract: Summary: Nutrient limitation of the biofilm is fundamental to stream ecosystem processes, as microbial activity shapes the biological availability and biogeochemical cycling of carbon and nutrients. We used nutrient-diffusing substrata (NDS) to investigate heterotrophic nutrient limitation of microbial respiration (MR) across 20 streams draining boreal landscapes in northern Sweden. We also explored variation in microbial biomass and community structure of biofilms that developed on NDS using phospholipid fatty acid (PLFA) biomarkers. Limitation was determined as a significant response of MR and biomass production on cellulose surfaces to enrichment with nitrogen (N), phosphorus (P) or N + P, relative to controls. Microbial respiration was N-limited, with an average 3.3-fold increase on N-amended NDS. Nitrogen limitation decreased, and control rates of MR increased, with greater background concentrations of inorganic N across the sites. In contrast to MR, microbial biomass was primarily N-limited but was greatest for the N + P NDS. Accordingly, differences in respiratory versus biomass responses to nutrient addition resulted in significantly greater biomass-specific MR on N-amended NDS compared to all other treatments. In addition, PLFA biomarkers indicated distinct microbial communities on N and N + P NDS compared to controls and/or P NDS. Greater MR and biomass, and the development of distinct microbial communities, when supplied with inorganic N suggest that factors which alter aquatic N loading during autumn may have important implications for ecosystem processes and the biogeochemistry of boreal streams and rivers. Our findings add to a growing body of evidence that the productivity of Fennoscandian boreal landscapes is constrained by N availability. |
BibTeX:
@article{Burrows2015,
author = {Burrows, Ryan M and Hotchkiss, Erin R and Jonsson, Micael and Laudon, Hjalmar and Mckie, Brendan G and Sponseller, Ryan A},
title = {Nitrogen limitation of heterotrophic biofilms in boreal streams},
journal = {Freshwater Biology},
year = {2015},
volume = {60},
number = {7},
pages = {1237--1251},
url = {http://doi.wiley.com/10.1111/fwb.12549},
doi = {10.1111/fwb.12549}
}
|
| Bužková R, Acosta M, Dařenová E, Pokorný R and Pavelka M (2015), "Environmental factors influencing the relationship between stem CO2 efflux and sap flow", Trees - Structure and Function. Vol. 29(2), pp. 333-343. Springer Verlag. |
| Abstract: Key message: Beside temperature, soil moisture was found as the most important environmental factor influencing the relationship between stem CO2 efflux and sap flow. Stem CO2 efflux is an important component of the forest carbon balance. Even after several studies on this issue, there is still uncertainty about the influence of the sap flux on stem CO2 efflux. This study analyses stem CO2 efflux and sap flow measured on Norway spruce [Picea abies (L.) Karst] trees and environmental factors influencing this relationship during the growing seasons of 2010 and 2011. Stem CO2 efflux measurements were performed using an automatic dynamic closed gasometrical system, whilst sap flow measurements were carried out by applying a sap flow method heat pulse velocity. Stem CO2 efflux was positively correlated with stem temperature; sap flow was positively correlated with incident global radiation. During optimal soil moisture conditions, stem CO2 efflux and sap flow were positively correlated while during dry conditions, stem CO2 efflux and sap flow were not positively correlated. Almost all significant correlations between stem CO2 efflux and sap flow were not controlled by any investigated environmental factor. |
BibTeX:
@article{Buzkova2015,
author = {Bužková, Romana and Acosta, Manuel and Dařenová, Eva and Pokorný, Radek and Pavelka, Marian},
title = {Environmental factors influencing the relationship between stem CO2 efflux and sap flow},
journal = {Trees - Structure and Function},
publisher = {Springer Verlag},
year = {2015},
volume = {29},
number = {2},
pages = {333--343},
doi = {10.1007/s00468-014-1113-z}
}
|
| Campioli M, Vicca S, Luyssaert S, Bilcke J, Ceschia E, Chapin FS, Ciais P, Fernández-Martínez M, Malhi Y, Obersteiner M, Olefeldt D, Papale D, Piao SL, Peñuelas J, Sullivan PF, Wang X, Zenone T and Janssens IA (2015), "Biomass production efficiency controlled by management in temperate and boreal ecosystems", Nature Geoscience., nov, 2015. Vol. 8(11), pp. 843-846. |
| Abstract: Plants acquire carbon through photosynthesis to sustain biomass production, autotrophic respiration and production of non-structural compounds for multiple purposes. The fraction of photosynthetic production used for biomass production, the biomass production efficiency, is a key determinant of the conversion of solar energy to biomass. In forest ecosystems, biomass production efficiency was suggested to be related to site fertility. Here we present a database of biomass production efficiency from 131 sites compiled from individual studies using harvest, biometric, eddy covariance, or process-based model estimates of production. The database is global, but dominated by data from Europe and North America. We show that instead of site fertility, ecosystem management is the key factor that controls biomass production efficiency in terrestrial ecosystems. In addition, in natural forests, grasslands, tundra, boreal peatlands and marshes, biomass production efficiency is independent of vegetation, environmental and climatic drivers. This similarity of biomass production efficiency across natural ecosystem types suggests that the ratio of biomass production to gross primary productivity is constant across natural ecosystems. We suggest that plant adaptation results in similar growth efficiency in high- and low-fertility natural systems, but that nutrient influxes under managed conditions favour a shift to carbon investment from the belowground flux of non-structural compounds to aboveground biomass. |
BibTeX:
@article{Campioli2015,
author = {Campioli, M and Vicca, S and Luyssaert, S and Bilcke, J and Ceschia, E and Chapin, F S and Ciais, P and Fernández-Martínez, M and Malhi, Y and Obersteiner, M and Olefeldt, D and Papale, D and Piao, S L and Peñuelas, J and Sullivan, P F and Wang, X and Zenone, T and Janssens, I A},
title = {Biomass production efficiency controlled by management in temperate and boreal ecosystems},
journal = {Nature Geoscience},
year = {2015},
volume = {8},
number = {11},
pages = {843--846},
url = {http://www.nature.com/articles/ngeo2553},
doi = {10.1038/ngeo2553}
}
|
| Chen Z, Yu G, Zhu X, Wang Q, Niu S and Hu Z (2015), "Covariation between gross primary production and ecosystem respiration across space and the underlying mechanisms: A global synthesis", Agricultural and Forest Meteorology., apr, 2015. Vol. 203, pp. 180-190. Elsevier. |
| Abstract: Gross primary production (GPP) and ecosystem respiration (RE) are two important processes in the terrestrial carbon cycle. Understanding the relationships between GPP and RE across space, as well as the underlying mechanisms, is helpful for understanding the terrestrial carbon cycle and predicting the global carbon budget. In this study, we investigated the correlation between the spatial variations in GPP and RE by compiling carbon flux data from 264 sites across the Asian, European, North American, South American, African, and Oceanian regions. The results indicated that GPP and RE covaried across space regionally and globally (Ptextless. 0.001). The spatial variations in GPP explained 66-98% of the variations in RE in the six regions (approximately explained 60-76% when considered the effects of self-correlation caused by current flux partitioning algorithm), and it explained 90% of RE variations at the global scale (about 70% when considered the effects of self-correlation). RE/GPP values were not significantly different among the six regions or between the two hemispheres. RE/GPP values consistently averaged at 0.87 ± 0.04 along the spatial variations in climate and vegetation index. This covariation between GPP and RE across space is largely attributed to the parallel responses of GPP and RE to the common climatic and vegetation factors, but the underlying mechanism lies in productivity as the primary and direct substrate supplier for respiration which fundamentally constrains RE. These results suggest that the variation in photosynthate availability is the dominant driver for respiration across space and that this process must be fully considered in the cross-site RE comparisons. |
BibTeX:
@article{Chen2015,
author = {Chen, Zhi and Yu, Guirui and Zhu, Xianjin and Wang, Qiufeng and Niu, Shuli and Hu, Zhongmin},
title = {Covariation between gross primary production and ecosystem respiration across space and the underlying mechanisms: A global synthesis},
journal = {Agricultural and Forest Meteorology},
publisher = {Elsevier},
year = {2015},
volume = {203},
pages = {180--190},
doi = {10.1016/j.agrformet.2015.01.012}
}
|
| Combe M, Vilà-Guerau De Arellano J, Ouwersloot HG, Jacobs CMJ and Peters W (2015), "Two perspectives on the coupled carbon, water and energy exchange in the planetary boundary layer", Biogeosciences., jan, 2015. Vol. 12(1), pp. 103-123. |
| Abstract: Understanding the interactions between the land surface and the atmosphere is key to modelling boundary-layer meteorology and cloud formation, as well as carbon cycling and crop yield. In this study we explore these interactions in the exchange of water, heat and CO2 in a cropland-atmosphere system at the diurnal and local scale. To that end, we couple an atmospheric mixed-layer model (MXL) to two land-surface schemes developed from two different perspectives: while one land-surface scheme (A-gs) simulates vegetation from an atmospheric point of view, the other (GECROS) simulates vegetation from a carbon-storage point of view. We calculate surface fluxes of heat, moisture and carbon, as well as the resulting atmospheric state and boundary-layer dynamics, over a maize field in the Netherlands, on a day for which we have a rich set of observations available. Particular emphasis is placed on understanding the role of upper-atmosphere conditions like subsidence in comparison to the role of surface forcings like soil moisture. We show that the atmospheric-oriented model (MXL-A-gs) outperforms the carbon storage-oriented model (MXL-GECROS) on this diurnal scale. We find this performance is partly due to the difference of scales at which the models were made to run. Most importantly, this performance strongly depends on the sensitivity of the modelled stomatal conductance to water stress, which is implemented differently in each model. This sensitivity also influences the magnitude of the surface fluxes of CO2, water and heat (surface control) and subsequently impacts the boundary-layer growth and entrainment fluxes (upper atmosphere control), which alter the atmospheric state. These findings suggest that observed CO2 mole fractions in the boundary layer can reflect strong influences of both the surface and upper-atmosphere conditions, and the interpretation of CO2 mole fraction variations depends on the assumed land-surface coupling. We illustrate this with a sensitivity analysis where high subsidence and soil moisture depletion, typical for periods of drought, have competing and opposite effects on the boundary-layer height h. The resulting net decrease in h induces a change of 12 ppm in the late-afternoon CO2 mole fraction. Also, the effect of such high subsidence and soil moisture depletion on the surface Bowen ratio are of the same magnitude. Thus, correctly including such two-way land-surface interactions on the diurnal scale can potentially improve our understanding and interpretation of observed variations in atmospheric CO2, as well as improve crop yield forecasts by better describing the water loss and carbon gain. |
BibTeX:
@article{Combe2015,
author = {Combe, M and Vilà-Guerau De Arellano, J and Ouwersloot, H G and Jacobs, C M J and Peters, W},
title = {Two perspectives on the coupled carbon, water and energy exchange in the planetary boundary layer},
journal = {Biogeosciences},
year = {2015},
volume = {12},
number = {1},
pages = {103--123},
url = {http://www.biogeosciences.net/12/103/2015/},
doi = {10.5194/bg-12-103-2015}
}
|
| Creed IF, McKnight DM, Pellerin BA, Green MB, Bergamaschi BA, Aiken GR, Burns DA, Findlay SEG, Shanley JB, Striegl RG, Aulenbach BT, Clow DW, Laudon H, McGlynn BL, McGuire KJ, Smith RA and Stackpoole SM (2015), "The river as a chemostat: Fresh perspectives on dissolved organic matter flowing down the river continuum", Canadian Journal of Fisheries and Aquatic Sciences., aug, 2015. Vol. 72(8), pp. 1272-1285. |
| Abstract: A better understanding is needed of how hydrological and biogeochemical processes control dissolved organic carbon (DOC) concentrations and dissolved organic matter (DOM) composition from headwaters downstream to large rivers. We examined a large DOM dataset from the National Water Information System of the US Geological Survey, which represents approximately 100 000 measurements of DOC concentration and DOM composition at many sites along rivers across the United States. Application of quantile regression revealed a tendency towards downstream spatial and temporal homogenization of DOC concentrations and a shift from dominance of aromatic DOM in headwaters to more aliphatic DOM downstream. The DOC concentration–discharge (C-Q) relationships at each site revealed a downstream tendency towards a slope of zero. We propose that despite complexities in river networks that have driven many revisions to the River Continuum Concept, rivers show a tendency towards chemostasis (C-Q slope of zero) because of a downstream shift from a dominance of hydrologic drivers that connect terrestrialDOMsources to streams in the headwaters towards a dominance of instream and near-stream biogeochemical processes that result in preferential losses of aromatic DOM and preferential gains of aliphatic DOM. |
BibTeX:
@article{Creed2015,
author = {Creed, Irena F and McKnight, Diane M and Pellerin, Brian A and Green, Mark B and Bergamaschi, Brian A and Aiken, George R and Burns, Douglas A and Findlay, Stuart E G and Shanley, Jamie B and Striegl, Rob G and Aulenbach, Brent T and Clow, David W and Laudon, Hjalmar and McGlynn, Brian L and McGuire, Kevin J and Smith, Richard A and Stackpoole, Sarah M},
editor = {Smith, Ralph},
title = {The river as a chemostat: Fresh perspectives on dissolved organic matter flowing down the river continuum},
journal = {Canadian Journal of Fisheries and Aquatic Sciences},
year = {2015},
volume = {72},
number = {8},
pages = {1272--1285},
url = {http://www.nrcresearchpress.com/doi/10.1139/cjfas-2014-0400},
doi = {10.1139/cjfas-2014-0400}
}
|
| Danehpash S (2015), "Evaluation of Standards and Techniques for Retrieval of Geospatial Raster Data A study for the ICOS Carbon Portal", In Student thesis series INES; (2015). |
| Abstract: Evaluation of Standards and Techniques for Retrieval of Geospatial Raster Data - A study for ICOS Carbon Portal
Geospatial raster data represent the world as a surface with its geographic information which varies continuously. These data can be grid-based data like Digital Terrain Elevation Data (DTED) and geographic image data like multispectral images. The Integrated Carbon Observation System (ICOS) European project is launched to measure greenhouse gases emission. The outputs of these measurements are the data in both geospatial vector (raw data) and raster formats (elaborated data). By using these measurements, scientists create flux maps over Europe. The flux maps are important for many groups such as researchers, stakeholders and public users. In this regard, ICOS Carbon Portal (ICOS CP) looks for a sufficient way to make the ICOS elaborated data available for all of these groups in an online environment. Among others, ICOS CP desires to design a geoportal to let users download the modelled geospatial raster data in different formats and geographic extents. Open GeoSpatial Consortium (OGC) Web Coverage Service (WCS) defines a geospatial web service to render geospatial raster data such as flux maps in any desired subset in space and time. This study presents two techniques to design a geoportal compatible with WCS. This geoportal should be able to retrieve the ICOS data in both NetCDF and GeoTIFF formats as well as allow retrieval of subsets in time and space. In the first technique, a geospatial raster database (Rasdaman) is used to store the data. Rasdaman OGC component (Petascope) as the server tool connects the database to the client side through WCS protocol. In the Second technique, an advanced file-based system (NetCDF) is applied to maintain the data. THREDDS as the WCS server ships the data to the client side through WCS protocol. These two techniques returned good result to download the data in desired formats and subsets. |
BibTeX:
@techreport{Danehpash2015,
author = {Danehpash, Shirin},
title = {Evaluation of Standards and Techniques for Retrieval of Geospatial Raster Data A study for the ICOS Carbon Portal},
booktitle = {Student thesis series INES; (2015)},
year = {2015},
url = {http://lup.lub.lu.se/student-papers/record/8166797}
}
|
| De Groote T, Zona D, Broeckx LS, Verlinden MS, Luyssaert S, Bellassen V, Vuichard N, Ceulemans R, Gobin A and Janssens IA (2015), "ORCHIDEE-SRC v1.0: An extension of the land surface model ORCHIDEE for simulating short rotation coppice poplar plantations", Geoscientific Model Development., may, 2015. Vol. 8(5), pp. 1461-1471. |
| Abstract: Modelling biomass production and the environmental impact of short rotation coppice (SRC) plantations is necessary for planning their deployment, as they are becoming increasingly important for global energy production. This paper describes the modification of the widely used land surface model ORCHIDEE for stand-scale simulations of SRC plantations. The model uses weather data, soil texture and species-specific parameters to predict the aboveground (harvestable) biomass production, as well as carbon and energy fluxes of an SRC plantation. Modifications to the model were made to the management, growth, and allocation modules of ORCHIDEE. The modifications presented in this paper were evaluated using data from two Belgian poplar-based SRC sites, for which multiple measurements and meteorological data were available. Biomass yield data were collected from 23 other sites across Europe and compared to 22 simulations across a comparable geographic range. The simulations show that the model predicts very well aboveground (harvestable) biomass production (within measured ranges), ecosystem photosynthesis (Rsup2/sup =0.78, NRMSE =0.064, PCC =0.89) and ecosystem respiration (Rsup2/sup =0.95, NRMSE =0.078 PCC =0.91). Also soil temperature and soil moisture are simulated adequately, but due to the simplicity of the soil moisture simulation, there are some discrepancies, which also influence the simulation of the latent heat flux. Overall, the extended model, ORCHIDEE-SRC, proved to be a tool suitable for predicting biomass production of SRC plantations. |
BibTeX:
@article{DeGroote2015,
author = {De Groote, T and Zona, D and Broeckx, L S and Verlinden, M S and Luyssaert, S and Bellassen, V and Vuichard, N and Ceulemans, R and Gobin, A and Janssens, I A},
title = {ORCHIDEE-SRC v1.0: An extension of the land surface model ORCHIDEE for simulating short rotation coppice poplar plantations},
journal = {Geoscientific Model Development},
year = {2015},
volume = {8},
number = {5},
pages = {1461--1471},
url = {http://www.geosci-model-dev.net/8/1461/2015/},
doi = {10.5194/gmd-8-1461-2015}
}
|
| de la Paz M, Huertas IE, Flecha S, Ríos AF and Pérez FF (2015), "Nitrous oxide and methane in Atlantic and Mediterranean waters in the Strait of Gibraltar: Air-sea fluxes and inter-basin exchange", Progress in Oceanography., nov, 2015. Vol. 138, pp. 18-31. |
| Abstract: The global ocean plays an important role in the overall budget of nitrous oxide (N2O) and methane (CH4), as both gases are produced within the ocean and released to the atmosphere. However, for large parts of the open and coastal oceans there is little or no spatial data coverage for N2O and CH4. Hence, a better assessment of marine emissions estimates is necessary. As a contribution to remedying the scarcity of data on marine regions, N2O and CH4 concentrations have been determined in the Strait of Gibraltar at the ocean Fixed Time series (GIFT). During six cruises performed between July 2011 and November 2014 samples were collected at the surface and various depths in the water column, and subsequently measured using gas chromatography. From this we were able to quantify the temporal variability of the gas air-sea exchange in the area and examine the vertical distribution of N2O and CH4 in Atlantic and Mediterranean waters. Results show that surface Atlantic waters are nearly in equilibrium with the atmosphere whereas deeper Mediterranean waters are oversaturated in N2O, and a gradient that gradually increases with depth was detected in the water column. Temperature was found to be the main factor responsible for the seasonal variability of N2O in the surface layer. Furthermore, although CH4 levels did not reveal any feature clearly associated with the circulation of water masses, vertical distributions showed that higher concentrations are generally observed in the Atlantic layer, and that the deeper Mediterranean waters are considerably undersaturated (by up to 50%). Even though surface waters act as a source of atmospheric N2O during certain periods, on an annual basis the net N2O flux in the Strait of Gibraltar is only 0.35±0.27μmolm-2d-1, meaning that these waters are almost in a neutral status with respect to the atmosphere. Seasonally, the region behaves as a slight sink for atmospheric CH4 in winter and as a source in spring and fall. Approximating the circulation pattern in the Strait to a bi-layer scheme, N2O exchange between basins was also calculated, and a net export from the Mediterranean Sea to the Atlantic Ocean equivalent to 39μmolm-2d-1 was found. |
BibTeX:
@article{DelaPaz2015,
author = {de la Paz, M and Huertas, I E and Flecha, S and Ríos, A F and Pérez, F F},
title = {Nitrous oxide and methane in Atlantic and Mediterranean waters in the Strait of Gibraltar: Air-sea fluxes and inter-basin exchange},
journal = {Progress in Oceanography},
year = {2015},
volume = {138},
pages = {18--31},
url = {http://linkinghub.elsevier.com/retrieve/pii/S0079661115001998},
doi = {10.1016/j.pocean.2015.09.009}
}
|
| Dvorská A, Sedlák P, Schwarz J, Fusek M, Hanuš V, Vodička P and Trusina J (2015), "Atmospheric station KÅ™ešín u Pacova, Czech Republic – a Central European research infrastructure for studying greenhouse gases, aerosols and air quality", Advances in Science and Research., may, 2015. Vol. 12(1), pp. 79-83. |
| Abstract: pstrongAbstract./strong Long-lasting research infrastructures covering the research areas of atmospheric chemistry, meteorology and climatology are of highest importance. The Atmospheric Station (AS) KÅ™ešín u Pacova, central Czech Republic, is focused on monitoring of the occurence and long-range transport of greenhouse gases, atmospheric aerosols, selected gaseous atmospheric pollutants and basic meteorological characteristics. The AS and its 250 m tall tower was built according to the recommendations of the Integrated Carbon Observation System (ICOS) and cooperates with numerous national and international projects and monitoring programmes. First measurements conducted at ground started in 2012, vertical profile measurements were added in 2013. A seasonal variability with slightly higher autumn and winter concentrations of elemental and organic carbon was revealed. The suitability of the doubly left-censored Weibull distribution for modelling and interpretation of elemental carbon concentrations, which are often lower than instrumental quantification limits, was verified. Initial data analysis also suggests that in summer, the tower top at 250 m is frequently above the nocturnal surface inversions, thus being decoupled from local influences./p |
BibTeX:
@article{Dvorska2015,
author = {Dvorská, A and Sedlák, P and Schwarz, J and Fusek, M and Hanuš, V and Vodička, P and Trusina, J},
title = {Atmospheric station KÅ™ešín u Pacova, Czech Republic – a Central European research infrastructure for studying greenhouse gases, aerosols and air quality},
journal = {Advances in Science and Research},
year = {2015},
volume = {12},
number = {1},
pages = {79--83},
url = {http://www.adv-sci-res.net/12/79/2015/},
doi = {10.5194/asr-12-79-2015}
}
|
| Eder F, Schmidt M, Damian T, Träumner K and Mauder M (2015), "Mesoscale eddies affect near-surface turbulent exchange: Evidence from lidar and tower measurements", Journal of Applied Meteorology and Climatology., jan, 2015. Vol. 54(1), pp. 189-206. |
| Abstract: The eddy-covariance technique tends to underestimate turbulent heat fluxes, which results in nonclosure of the surface energy balance. This study shows experimental evidence that mesoscale turbulent organized structures, which are inherently not captured by the standard eddy-covariance technique, can affect nearsurface turbulent exchange. By using a combined setup of three Doppler wind lidars above a croplanddominated area in Germany, low-frequency turbulent structures were detected in the surface layer down to a few meters above ground. In addition, data from two micrometeorological stations in the study area were analyzed with respect to energy balance closure. In accordance with several previous studies, the data confirm a strong friction velocity dependence of the energy balance residual. At both stations, the energy balance residual was found to be positively correlated with the vertical moisture gradient in the lower atmospheric boundary layer, but at only one station was it correlated with the temperature gradient. This result indicates that mesoscale transport probably contributes more to the latent heat flux than to the sensible heat flux, but this conclusion depends largely on the measurement site. Moreover, flow distortion due to tower mountings and measurement devices affects the energy balance closure considerably for certain wind directions. |
BibTeX:
@article{Eder2015,
author = {Eder, Fabian and Schmidt, Marius and Damian, Thomas and Träumner, Katja and Mauder, Matthias},
title = {Mesoscale eddies affect near-surface turbulent exchange: Evidence from lidar and tower measurements},
journal = {Journal of Applied Meteorology and Climatology},
year = {2015},
volume = {54},
number = {1},
pages = {189--206},
url = {http://journals.ametsoc.org/doi/10.1175/JAMC-D-14-0140.1},
doi = {10.1175/JAMC-D-14-0140.1}
}
|
| Eklöf K, Kraus A, Futter M, Schelker J, Meili M, Boyer EW and Bishop K (2015), "Parsimonious Model for Simulating Total Mercury and Methylmercury in Boreal Streams Based on Riparian Flow Paths and Seasonality", Environmental Science and Technology., jul, 2015. Vol. 49(13), pp. 7851-7859. |
| Abstract: The complexity of mercury (Hg) biogeochemistry has made it difficult to model surface water concentrations of both total Hg (THg) and especially methylmercury (MeHg), the species of Hg having the highest potential for bioaccumulation. To simulate THg and MeHg variation in low-order streams, we have adapted a conceptual modeling framework where a continuum of lateral flows through riparian soils determines streamflow concentrations. The model was applied to seven forest catchments located in two boreal regions in Sweden spanning a range of climatic, soil, and forest management conditions. Discharge, and simulated riparian soil water concentrations profiles, represented by two calibrated parameters, were able to explain much of the variability of THg and MeHg concentrations in the streams issuing from the catchments (Nash Sutcliffe (NS) up to 0.54 for THg and 0.58 for MeHg). Model performance for all catchments was improved (NS up to 0.76 for THg and 0.85 for MeHg) by adding two to four parameters to represent seasonality in riparian soil water THg and MeHg concentrations profiles. These results are consistent with the hypothesis that riparian flow-pathways and seasonality in riparian soil concentrations are the major controls on temporal variation of THg and MeHg concentrations in low-order streams. (Graph Presented). |
BibTeX:
@article{Eklof2015,
author = {Eklöf, Karin and Kraus, Andrea and Futter, Martyn and Schelker, Jakob and Meili, Markus and Boyer, Elizabeth W and Bishop, Kevin},
title = {Parsimonious Model for Simulating Total Mercury and Methylmercury in Boreal Streams Based on Riparian Flow Paths and Seasonality},
journal = {Environmental Science and Technology},
year = {2015},
volume = {49},
number = {13},
pages = {7851--7859},
url = {http://pubs.acs.org/doi/10.1021/acs.est.5b00852},
doi = {10.1021/acs.est.5b00852}
}
|
| El Kasmioui O, Verbruggen A and Ceulemans R (2015), "The 2013 reforms of the Flemish renewable electricity support: Missed opportunities", Renewable Energy., nov, 2015. Vol. 83, pp. 905-917. |
| Abstract: The Flemish renewable electricity support system has struggled to address a number of problematic issues in the past. These included excessive profit margins and general malfunctioning of the green certificate market, as well as a lack of qualification of various existing renewable energy technologies. The Flemish government responded to these issues by introducing major reforms in 2013, including "banding" to differentiate the support for various technologies. However, reliable methods for differentiating renewable electricity technologies and calculating support levels have not been sufficiently developed. The main objective of the 2013 reforms was to reduce support costs, but application of German feed-in tariffs on 18 reference technologies has shown that most projects in Flanders continue to receive high levels of support. The 2013 reforms did not succeed in addressing malfunctioning of the green certificate market. On the contrary, the confidence of investors in renewable electricity plants has decreased as the terms of support can be altered retroactively by adjusting remuneration levels and through political interventions. Future adaptations are likely to be made which will further decrease the overall stability and effectiveness of the system. |
BibTeX:
@article{ElKasmioui2015,
author = {El Kasmioui, O and Verbruggen, A and Ceulemans, R},
title = {The 2013 reforms of the Flemish renewable electricity support: Missed opportunities},
journal = {Renewable Energy},
year = {2015},
volume = {83},
pages = {905--917},
url = {http://linkinghub.elsevier.com/retrieve/pii/S0960148115004024},
doi = {10.1016/j.renene.2015.05.023}
}
|
| Erhagen B, Ilstedt U and Nilsson MB (2015), "Temperature sensitivity of heterotrophic soil CO2 production increases with increasing carbon substrate uptake rate", Soil Biology and Biochemistry., jan, 2015. Vol. 80, pp. 45-52. |
| Abstract: Temperature profoundly affects saprotrophic respiration rates, and carbon quality theory predicts that the rates' temperature sensitivity should increase as the quality of the carbon source declines. However, reported relationships between saprotrophic respiration responses to temperature and carbon quality vary widely. Some of this variability may arise from confounding effects related to both substrate quality and substrate availability. The importance of these variables, as well as substrate diffusion and uptake rates, for the temperature sensitivity of saprotrophic respiration has been validated theoretically, but not empirically demonstrated. Thus, we tested effects of varying substrate uptake rates on the temperature sensitivity of organic carbon degradation.For this purpose we created a model system using the organic layer (O-horizon), of a boreal forest soil, specifically to test effects of varying monomer uptake and release rates. The addition of both monomers and polymers generally increased the temperature sensitivity of saprotrophic respiration. In response to added monomers, there was a linear increase in the temperature sensitivity of both substrate-induced respiration and the specific growth rate with increasing rate of substrate uptake as indicated by the CO2 production at 14 °C. Both of these responses diverge from those predicted by the carbon quality theory, but they provide the first empirical evidence consistent with model predictions demonstrating increased temperature sensitivity with increased uptake rate of carbon monomers over the cell membrane. These results may explain why organic material of higher carbon quality induces higher temperature responses than lower carbon quality compounds, without contradicting carbon quality theory. |
BibTeX:
@article{Erhagen2015,
author = {Erhagen, Björn and Ilstedt, Ulrik and Nilsson, Mats B},
title = {Temperature sensitivity of heterotrophic soil CO2 production increases with increasing carbon substrate uptake rate},
journal = {Soil Biology and Biochemistry},
year = {2015},
volume = {80},
pages = {45--52},
url = {https://linkinghub.elsevier.com/retrieve/pii/S0038071714003290},
doi = {10.1016/j.soilbio.2014.09.021}
}
|
| Eugster W and Merbold L (2015), "Eddy covariance for quantifying trace gas fluxes from soils", Soil., feb, 2015. Vol. 1(1), pp. 187-205. |
| Abstract: Soils are highly complex physical and biological systems, and hence measuring soil gas exchange fluxes with high accuracy and adequate spatial representativity remains a challenge. A technique which has become increasingly popular is the eddy covariance (EC) method. This method takes advantage of the fact that surface fluxes are mixed into the near-surface atmosphere via turbulence. As a consequence, measurements with an EC system can be done at some distance above the surface, providing accurate and spatially integrated flux density estimates. In this paper we provide a basic overview targeting scientists who are not familiar with the EC method. This review gives examples of successful deployments from a wide variety of ecosystems. The primary focus is on the three major greenhouse gases: carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O). Several limitations to the application of EC systems exist, requiring a careful experimental design, which we discuss in detail. Thereby we group these experiments into two main classes: (1) manipulative experiments, and (2) survey-type experiments. Recommendations and examples of successful studies using various approaches are given, including the combination of EC flux measurements with online measurements of stable isotopes. We conclude that EC should not be considered a substitute to traditional (e.g., chamber based) flux measurements but instead an addition to them. The greatest strength of EC measurements in soil science are (1) their uninterrupted continuous measurement of gas concentrations and fluxes that can also capture short-term bursts of fluxes that easily could be missed by other methods and (2) the spatial integration covering the ecosystem scale (several square meters to hectares), thereby integrating over small-scale heterogeneity in the soil. |
BibTeX:
@article{Eugster2015,
author = {Eugster, W and Merbold, L},
title = {Eddy covariance for quantifying trace gas fluxes from soils},
journal = {Soil},
year = {2015},
volume = {1},
number = {1},
pages = {187--205},
url = {http://www.soil-journal.net/1/187/2015/},
doi = {10.5194/soil-1-187-2015}
}
|
| Eyer S, Tuzson B, Popa ME, van der Veen C, Röckmann T, Rothe M, Brand WA, Fisher R, Lowry D, Nisbet EG, Brennwald MS, Harris E, Zellweger C, Emmenegger L, Fischer H and Mohn J (2015), " Real-time analysis of δ 13 C- and δD-CH 4 in ambient air with laser spectroscopy: method development and first intercomparison results ", Atmospheric Measurement Techniques Discussions., aug, 2015. Vol. 8(8), pp. 8925-8970. |
| Abstract: Abstract. In situ and simultaneous measurement of the three most abundant isotopologues of methane using mid-infrared laser absorption spectroscopy is demonstrated. A field-deployable, autonomous platform is realized by coupling a compact quantum cascade laser absorption spectrometer (QCLAS) to a preconcentration unit, called TRace gas EXtractor (TREX). This unit enhances CH4 mole fractions by a factor of up to 500 above ambient levels and quantitatively separates interfering trace gases such as N2O and CO2. The analytical precision of the QCLAS isotope measurement on the preconcentrated (750 ppm, parts-per-million, μmole/mole) methane is 0.1 and 0.5 ‰ for δ13C- and δD-CH4 at 10 min averaging time. Based on replicate measurements of compressed air during a two-week intercomparison campaign, the repeatability of the TREX-QCLAS was determined to be 0.19 and 1.9 ‰ for δ13C and δD-CH4, respectively. In this intercomparison campaign the new in situ technique is compared to isotope-ratio mass-spectrometry (IRMS) based on glass flask and bag sampling and real time CH4 isotope analysis by two commercially available laser spectrometers. Both laser-based analyzers were limited to methane mole fraction and δ13C-CH4 analysis, and only one of them, a cavity ring down spectrometer, was capable to deliver meaningful data for the isotopic composition. After correcting for scale offsets, the average difference between TREX–QCLAS data and bag/flask sampling–IRMS values are within the extended WMO compatibility goals of 0.2 and 5 ‰ for δ13C- and δD-CH4, respectively. Thus, the intercomparison also reveals the need for reference air samples with accurately determined isotopic composition of CH4 to further improve the interlaboratory compatibility. |
BibTeX:
@article{Eyer2015,
author = {Eyer, S and Tuzson, B and Popa, M E and van der Veen, C and Röckmann, T and Rothe, M and Brand, W A and Fisher, R and Lowry, D and Nisbet, E G and Brennwald, M S and Harris, E and Zellweger, C and Emmenegger, L and Fischer, H and Mohn, J},
title = { Real-time analysis of δ 13 C- and δD-CH 4 in ambient air with laser spectroscopy: method development and first intercomparison results },
journal = {Atmospheric Measurement Techniques Discussions},
year = {2015},
volume = {8},
number = {8},
pages = {8925--8970},
url = {http://www.atmos-meas-tech-discuss.net/8/8925/2015/},
doi = {10.5194/amtd-8-8925-2015}
}
|
| Fang Z, Bogena H, Kollet S, Koch J and Vereecken H (2015), "Spatio-temporal validation of long-term 3D hydrological simulations of a forested catchment using empirical orthogonal functions and wavelet coherence analysis", Journal of Hydrology., oct, 2015. Vol. 529, pp. 1754-1767. |
| Abstract: Soil moisture plays a key role in the water and energy balance in soil, vegetation and atmosphere systems. According to Wood et al. (2011) there is a grand need to increase global-scale hyper-resolution water-energy-biogeochemistry land surface modelling capabilities. These modelling capabilities should also recognize epistemic uncertainties, as well as the nonlinearity and hysteresis in its dynamics. Unfortunately, it is not clear how to parameterize hydrological processes as a function of scale, and how to test deterministic models with regard to epistemic uncertainties. In this study, high resolution long-term simulations were conducted in the highly instrumented TERENO hydrological observatory of the Wüstebach catchment. Soil hydraulic parameters were derived using inverse modelling with the Hydrus-1D model using the global optimization scheme SCE-UA and soil moisture data from a wireless soil moisture sensor network. The estimated parameters were then used for 3D simulations of water transport using the integrated parallel simulation platform ParFlow-CLM. The simulated soil moisture dynamics, as well as evapotranspiration (ET) and runoff, were compared with long-term field observations to illustrate how well the model was able to reproduce the water budget dynamics. We investigated different anisotropies of hydraulic conductivity to analyze how fast lateral flow processes above the underlying bedrock affect the simulation results. For a detail investigation of the model results we applied the empirical orthogonal function (EOF) and wavelet coherence methods. The EOF analysis of temporal-spatial patterns of simulated and observed soil moisture revealed that introduction of heterogeneity in the soil porosity effectively improves estimates of soil moisture patterns. Our wavelet coherence analysis indicates that wet and dry seasons have significant effect on temporal correlation between observed and simulated soil moisture and ET. Our study demonstrates the usefulness of the EOF and wavelet coherence methods for a more in-depth validation of spatially highly resolved hydrological 3D models. |
BibTeX:
@article{Fang2015,
author = {Fang, Zhufeng and Bogena, Heye and Kollet, Stefan and Koch, Julian and Vereecken, Harry},
title = {Spatio-temporal validation of long-term 3D hydrological simulations of a forested catchment using empirical orthogonal functions and wavelet coherence analysis},
journal = {Journal of Hydrology},
year = {2015},
volume = {529},
pages = {1754--1767},
url = {http://linkinghub.elsevier.com/retrieve/pii/S0022169415005703},
doi = {10.1016/j.jhydrol.2015.08.011}
}
|
| Fichot R, Brignolas F, Cochard H and Ceulemans R (2015), "Vulnerability to drought-induced cavitation in poplars: Synthesis and future opportunities", Plant, Cell and Environment., jul, 2015. Vol. 38(7), pp. 1233-1251. |
| Abstract: Vulnerability to drought-induced cavitation is a key trait of plant water relations. Here, we summarize the available literature on vulnerability to drought-induced cavitation in poplars (Populus spp.), a genus of agronomic, ecological and scientific importance. Vulnerability curves and vulnerability parameters (including the water potential inducing 50% loss in hydraulic conductivity, Pinf50/inf) were collected from 37 studies published between 1991 and 2014, covering a range of 10 species and 12 interspecific hybrid crosses. Results of our meta-analysis confirm that poplars are among the most vulnerable woody species to drought-induced cavitation (mean Pinf50/inf=-1.44 and -1.55MPa across pure species and hybrids, respectively). Yet, significant variation occurs among species (Pinf50/inf range: 1.43MPa) and among hybrid crosses (Pinf50/inf range: 1.12MPa), within species and hybrid crosses (max. Pinf50/inf range reported: 0.8MPa) as well as in response to environmental factors including nitrogen fertilization, irradiance, temperature and drought (max. Pinf50/inf range reported: 0.75MPa). Potential implications and gaps in knowledge are discussed in the context of poplar cultivation, species adaptation and climate modifications. We suggest that poplars represent a valuable model for studies on drought-induced cavitation, especially to elucidate the genetic and molecular basis of cavitation resistance in Angiosperms. Over the last 25 years our knowledge with regard to the anatomical, physiological and ecological aspects of vulnerability to cavitation has grown considerably. It is now clear that vulnerability to drought-induced cavitation is a key trait of plant water-relations. As poplars (Populus spp.) are among the fastest growing temperate hardwood trees and high water consumers, they are particularly sensitive to water limitations and to drought induced cavitation. The Populus genus has therefore been studied quite intensively. In our review contribution we review and synthesize all the data published in the literature since 1991 on drought induced cavitation in poplar. We discuss and analyse the literature data in terms of (i) genetic variations among and within pure species or hybrids, and (ii) acclimation in response to environmental factors (drought, nutrients, light...). We also link the observations from this comprehensive review with other anatomical and ecophysiological traits. Practical implications, actual gaps in knowledge and future research opportunities offered by poplar as a model tree are also presented. |
BibTeX:
@article{Fichot2015,
author = {Fichot, Régis and Brignolas, Franck and Cochard, Hervé and Ceulemans, Reinhart},
title = {Vulnerability to drought-induced cavitation in poplars: Synthesis and future opportunities},
journal = {Plant, Cell and Environment},
year = {2015},
volume = {38},
number = {7},
pages = {1233--1251},
url = {http://doi.wiley.com/10.1111/pce.12491},
doi = {10.1111/pce.12491}
}
|
| Filipovic M, Laudon H, McLachlan MS and Berger U (2015), "Mass Balance of Perfluorinated Alkyl Acids in a Pristine Boreal Catchment", Environmental Science and Technology., oct, 2015. Vol. 49(20), pp. 12127-12135. |
| Abstract: Mass balances of ten individual perfluorinated alkyl acids (PFAAs) in two nested pristine catchments in Northern Sweden with different sizes and hydrological functions were assembled for 2011-2012. Concentrations of PFAAs in rain and snowmelt, as well as in streamwater at the outlet of the two watersheds were measured and used to calculate PFAA atmospheric inputs to and riverine outputs from the catchments. The results generally showed a great excess of PFAA inputs for both catchments over the whole study year. However, during the spring flood period, the inputs and outputs were within a factor of 2 for several PFAAs and the streamwater showed PFAA patterns resembling the patterns in rain (as opposed to snowmelt), suggesting that snowmelt water infiltrating the ground had displaced water from the previous summer. Comparison of PFAA mass balances between the two catchments further suggested that atmospheric inputs of short-chain (replacement) perfluoroalkyl carboxylic acids had increased in the years before sampling, while inputs of the legacy perfluorooctane sulfonic acid had decreased. Overall, the mass balances indicate that a considerable portion of the PFAAs deposited from the atmosphere are stored in soil and may be released to surface and marine water environments in the future. |
BibTeX:
@article{Filipovic2015,
author = {Filipovic, Marko and Laudon, Hjalmar and McLachlan, Michael S and Berger, Urs},
title = {Mass Balance of Perfluorinated Alkyl Acids in a Pristine Boreal Catchment},
journal = {Environmental Science and Technology},
year = {2015},
volume = {49},
number = {20},
pages = {12127--12135},
url = {http://pubs.acs.org/doi/10.1021/acs.est.5b03403},
doi = {10.1021/acs.est.5b03403}
}
|
| Ganesan AL, Manning AJ, Grant A, Young D, Oram DE, Sturges WT, Moncrieff JB and O'Doherty S (2015), "Quantifying methane and nitrous oxide emissions from the UK and Ireland using a national-scale monitoring network", Atmospheric Chemistry and Physics., jun, 2015. Vol. 15(11), pp. 6393-6406. |
| Abstract: The UK is one of several countries around the world that has enacted legislation to reduce its greenhouse gas emissions. In this study, we present top-down emissions of methane (CH4) and nitrous oxide (N2O) for the UK and Ireland over the period August 2012 to August 2014. These emissions were inferred using measurements from a network of four sites around the two countries. We used a hierarchical Bayesian inverse framework to infer fluxes as well as a set of covariance parameters that describe uncertainties in the system. We inferred average UK total emissions of 2.09 (1.65-2.67) Tg yr-1 CH4 and 0.101 (0.068-0.150) Tg yr-1 N2O and found our derived UK estimates to be generally lower than the a priori emissions, which consisted primarily of anthropogenic sources and with a smaller contribution from natural sources. We used sectoral distributions from the UK National Atmospheric Emissions Inventory (NAEI) to determine whether these discrepancies can be attributed to specific source sectors. Because of the distinct distributions of the two dominant CH4 emissions sectors in the UK, agriculture and waste, we found that the inventory may be overestimated in agricultural CH4 emissions. We found that annual mean N2O emissions were consistent with both the prior and the anthropogenic inventory but we derived a significant seasonal cycle in emissions. This seasonality is likely due to seasonality in fertilizer application and in environmental drivers such as temperature and rainfall, which are not reflected in the annual resolution inventory. Through the hierarchical Bayesian inverse framework, we quantified uncertainty covariance parameters and emphasized their importance for high-resolution emissions estimation. We inferred average model errors of approximately 20 and 0.4 ppb and correlation timescales of 1.0 (0.72-1.43) and 2.6 (1.9-3.9) days for CH4 and N2O, respectively. These errors are a combination of transport model errors as well as errors due to unresolved emissions processes in the inventory. We found the largest CH4 errors at the Tacolneston station in eastern England, which may be due to sporadic emissions from landfills and offshore gas in the North Sea. |
BibTeX:
@article{Ganesan2015,
author = {Ganesan, A L and Manning, A J and Grant, A and Young, D and Oram, D E and Sturges, W T and Moncrieff, J B and O'Doherty, S},
title = {Quantifying methane and nitrous oxide emissions from the UK and Ireland using a national-scale monitoring network},
journal = {Atmospheric Chemistry and Physics},
year = {2015},
volume = {15},
number = {11},
pages = {6393--6406},
url = {http://www.atmos-chem-phys.net/15/6393/2015/},
doi = {10.5194/acp-15-6393-2015}
}
|
| Gebauer R, Čermák J, Plichta R, Špinlerová Z, Urban J, VolaÅ™ík D and Ceulemans R (2015), "Within-canopy variation in needle morphology and anatomy of vascular tissues in a sparse Scots pine forest", Trees - Structure and Function., oct, 2015. Vol. 29(5), pp. 1447-1457. |
| Abstract: Key message: Azimuthal sides of the canopy affected neither needle morphology nor vascular anatomy. However, a significance was found to be associated with canopy height. The needle morphological and anatomical parameters of vascular tissues were scaled up to the forest stand level. Abstract: In conifers the needle is the key organ for photosynthesis and transpiration, and these two processes are influenced by the morphological and anatomical structure of the needle. Although many factors are involved in needle development, long-term irradiance gradients through the canopy as well as across the forest are among the main drivers. The present study had two principal objectives: (1) to obtain a better knowledge of the morphological and anatomical parameters of sun, transient and shade needles taken from different azimuthal orientations of a sparse Scots pine (Pinus sylvestris L.) stand; and (2) to scale up these needle data to the forest stand level. One-year-old needles were collected from mature Scots pine trees from branches on the south- and the north-facing azimuthal sides of the canopy at three different canopy heights. Needle structural parameters were measured on cross sections at the needle base. Azimuthal sides of the canopy had no effect on the needle morphology and anatomy since the irradiation was similar on both canopy sides due to the low leaf area index (1.31) of the sparse Scots pine forest. However, sampling height (i.e. sun versus shade needles) had a significant effect on the studied parameters, the largest differences being needle stele area, xylem area, phloem area and number of tracheids. Tracheid frequency, leaf-specific hydraulic conductivity and needle density were the only parameters which were not influenced by canopy height. Our measurements revealed that in a given hectare of pine forest stand, water was transported through approximately 40 × 109 tracheids situated in 380 × 106 needles, whose xylem area was 4.34 m2. This type of data could be helpful for modelling and could provide a better understanding of the forest stand environment, of tree hydraulic systems or of eddy covariance flux measurements of this stand, an established ecosystem site within the European ICOS network. |
BibTeX:
@article{Gebauer2015,
author = {Gebauer, Roman and Čermák, Jan and Plichta, Roman and Špinlerová, Zuzana and Urban, Josef and VolaÅ™ík, Daniel and Ceulemans, Reinhart},
title = {Within-canopy variation in needle morphology and anatomy of vascular tissues in a sparse Scots pine forest},
journal = {Trees - Structure and Function},
year = {2015},
volume = {29},
number = {5},
pages = {1447--1457},
url = {http://link.springer.com/10.1007/s00468-015-1224-1},
doi = {10.1007/s00468-015-1224-1}
}
|
| Gebler S, Hendricks Franssen HJ, Pütz T, Post H, Schmidt M and Vereecken H (2015), "Actual evapotranspiration and precipitation measured by lysimeters: A comparison with eddy covariance and tipping bucket", Hydrology and Earth System Sciences., may, 2015. Vol. 19(5), pp. 2145-2161. |
| Abstract: This study compares actual evapotranspiration (ETa) measurements by a set of six weighable lysimeters, ETa estimates obtained with the eddy covariance (EC) method, and evapotranspiration calculated with the full-form Penman-Monteith equation (ETPM) for the Rollesbroich site in the Eifel (western Germany). The comparison of ETa measured by EC (including correction of the energy balance deficit) and by lysimeters is rarely reported in the literature and allows more insight into the performance of both methods. An evaluation of ETa for the two methods for the year 2012 shows a good agreement with a total difference of 3.8% (19 mm) between the ETa estimates. The highest agreement and smallest relative differences ( 8%) on a monthly basis between both methods are found in summer. ETa was close to ETPM, indicating that ET was energy limited and not limited by water availability. ETa differences between lysimeter and EC were mainly related to differences in grass height caused by harvest and the EC footprint. The lysimeter data were also used to estimate precipitation amounts in combination with a filter algorithm for the high-precision lysimeters recently introduced by Peters et al. (2014). The estimated precipitation amounts from the lysimeter data differ significantly from precipitation amounts recorded with a standard rain gauge at the Rollesbroich test site. For the complete year 2012 the lysimeter records show a 16 % higher precipitation amount than the tipping bucket. After a correction of the tipping bucket measurements by the method of Richter (1995) this amount was reduced to 3%. With the help of an on-site camera the precipitation measurements of the lysimeters were analyzed in more detail. It was found that the lysimeters record more precipitation than the tipping bucket, in part related to the detection of rime and dew, which contribute 17% to the yearly difference between both methods. In addition, fog and drizzle explain an additional 5.5% of the total difference. Larger differences are also recorded for snow and sleet situations. During snowfall, the tipping bucket device underestimated precipitation severely, and these situations contributed also 7.9% to the total difference. However, 36% of the total yearly difference was associated with snow cover without apparent snowfall, and under these conditions snow bridges and snow drift seem to explain the strong overestimation of precipitation by the lysimeter. The remaining precipitation difference (about 33%) could not be explained and did not show a clear relation to wind speed. The variation of the individual lysimeters devices compared to the lysimeter mean are small, showing variations up to 3% for precipitation and 8% for evapotranspiration. |
BibTeX:
@article{Gebler2015,
author = {Gebler, S and Hendricks Franssen, H J and Pütz, T and Post, H and Schmidt, M and Vereecken, H},
title = {Actual evapotranspiration and precipitation measured by lysimeters: A comparison with eddy covariance and tipping bucket},
journal = {Hydrology and Earth System Sciences},
year = {2015},
volume = {19},
number = {5},
pages = {2145--2161},
url = {http://www.hydrol-earth-syst-sci.net/19/2145/2015/},
doi = {10.5194/hess-19-2145-2015}
}
|
| Goddijn-Murphy LM, Woolf DK, Land PE, Shutler JD and Donlon C (2015), "The OceanFlux Greenhouse Gases methodology for deriving a sea surface climatology of CO&lt;sub&gt;2&lt;/sub&gt; fugacity in support of air–sea gas flux studies", Ocean Science., jul, 2015. Vol. 11(4), pp. 519-541. Copernicus GmbH. |
| Abstract: textlessptextgreaterAbstract. Climatologies, or long-term averages, of essential climate variables are useful for evaluating models and providing a baseline for studying anomalies. The Surface Ocean CO2 Atlas (SOCAT) has made millions of global underway sea surface measurements of CO2 publicly available, all in a uniform format and presented as fugacity, fCO2. As fCO2 is highly sensitive to temperature, the measurements are only valid for the instantaneous sea surface temperature (SST) that is measured concurrently with the in-water CO2 measurement. To create a climatology of fCO2 data suitable for calculating air–sea CO2 fluxes, it is therefore desirable to calculate fCO2 valid for a more consistent and averaged SST. This paper presents the OceanFlux Greenhouse Gases methodology for creating such a climatology. We recomputed SOCAT's fCO2 values for their respective measurement month and year using monthly composite SST data on a 1° × 1° grid from satellite Earth observation and then extrapolated the resulting fCO2 values to reference year 2010. The data were then spatially interpolated onto a 1° × 1° grid of the global oceans to produce 12 monthly fCO2 distributions for 2010, including the prediction errors of fCO2 produced by the spatial interpolation technique. The partial pressure of CO2 (pCO2) is also provided for those who prefer to use pCO2. The CO2 concentration difference between ocean and atmosphere is the thermodynamic driving force of the air–sea CO2 flux, and hence the presented fCO2 distributions can be used in air–sea gas flux calculations together with climatologies of other climate variables.textless/ptextgreater |
BibTeX:
@article{Goddijn-Murphy2015,
author = {Goddijn-Murphy, L. M. and Woolf, D. K. and Land, P. E. and Shutler, J. D. and Donlon, C.},
title = {The OceanFlux Greenhouse Gases methodology for deriving a sea surface climatology of CO&lt;sub&gt;2&lt;/sub&gt; fugacity in support of air–sea gas flux studies},
journal = {Ocean Science},
publisher = {Copernicus GmbH},
year = {2015},
volume = {11},
number = {4},
pages = {519--541},
url = {https://os.copernicus.org/articles/11/519/2015/},
doi = {10.5194/os-11-519-2015}
}
|
| Goffin S, Wylock C, Haut B, Maier M, Longdoz B and Aubinet M (2015), "Modeling soil CO2 production and transport to investigate the intra-day variability of surface efflux and soil CO2 concentration measurements in a Scots Pine Forest (Pinus Sylvestris, L.)", Plant and Soil., may, 2015. Vol. 390(1-2), pp. 195-211. |
| Abstract: Aimed: The main aim of this study is to improve the mechanistic understanding of soil CO2 efflux (Fs), especially its temporal variation at short-time scales, by investigating, through modeling, which underlying process among CO2 production and its transport up to the atmosphere is responsible for observed intra-day variation of Fs and soil CO2 concentration [CO2].
Methods: In this study, a measurement campaign of Fs and vertical soil [CO2] profiles was conducted in a Scots Pine Forest soil in Hartheim (Germany) and used to develop a model testing several hypotheses. A reference model taking into account a purely diffusive CO2 transport and a temperature-dependent CO2 production is compared to models with a more complex description of either CO2 production or CO2 transport. For transport, the introduction of advection and the dispersion is investigated. For the production, the emergent hypothesis of the phloem pressure concentration wave (PPCW) influence is tested. Results: We show that intra-day variation of Fs and [CO2] is better represented when the more complex CO2 production expression is taken into account compared to the more detailed description of CO2 transport. Conclusion: We conclude that focus should be placed on the potential factors affecting the CO2 production, rather than on the transport process description |
BibTeX:
@article{Goffin2015,
author = {Goffin, Stéphanie and Wylock, Christophe and Haut, Benoit and Maier, Martin and Longdoz, Bernard and Aubinet, Marc},
title = {Modeling soil CO2 production and transport to investigate the intra-day variability of surface efflux and soil CO2 concentration measurements in a Scots Pine Forest (Pinus Sylvestris, L.)},
journal = {Plant and Soil},
year = {2015},
volume = {390},
number = {1-2},
pages = {195--211},
url = {http://link.springer.com/10.1007/s11104-015-2381-0},
doi = {10.1007/s11104-015-2381-0}
}
|
| Gouttevin I, Lehning M, Jonas T, Gustafsson D and Mölder M (2015), "A two-layer canopy model with thermal inertia for an improved snowpack energy balance below needleleaf forest (model SNOWPACK, version 3.2.1, revision 741)", Geoscientific Model Development., aug, 2015. Vol. 8(8), pp. 2379-2398. |
| Abstract: A new, two-layer canopy module with thermal inertia as part of the detailed snow model SNOWPACK (version 3.2.1) is presented and evaluated. As a by-product of these new developments, an exhaustive description of the canopy module of the SNOWPACK model is provided, thereby filling a gap in the existing literature. In its current form, the two-layer canopy module is suited for evergreen needleleaf forest, with or without snow cover. It is designed to reproduce the difference in thermal response between leafy and woody canopy elements, and their impact on the underlying snowpack or ground surface energy balance. Given the number of processes resolved, the SNOWPACK model with its enhanced canopy module constitutes a sophisticated physics-based modeling chain of the continuum going from atmosphere to soil through the canopy and snow. Comparisons of modeled sub-canopy thermal radiation to stand-scale observations at an Alpine site (Alptal, Switzerland) demonstrate improvements induced by the new canopy module. Both thermal heat mass and the two-layer canopy formulation contribute to reduce the daily amplitude of the modeled canopy temperature signal, in agreement with observations. Particularly striking is the attenuation of the nighttime drop in canopy temperature, which was a key model bias. We specifically show that a single-layered canopy model is unable to produce this limited temperature drop correctly. The impact of the new parameterizations on the modeled dynamics of the sub-canopy snowpack is analyzed. The new canopy module yields consistent results but the frequent occurrence of mixed-precipitation events at Alptal prevents a conclusive assessment of model performance against snow data. The new model is also successfully tested without specific tuning against measured tree temperature and biomass heat-storage fluxes at the boreal site of Norunda (Sweden). This provides an independent assessment of its physical consistency and stresses the robustness and transferability of the chosen parameterizations. The SNOWPACK code including the new canopy module, is available under Gnu General Public License (GPL) license and upon creation of an account at https://models.slf.ch/. |
BibTeX:
@article{Gouttevin2015,
author = {Gouttevin, I and Lehning, M and Jonas, T and Gustafsson, D and Mölder, M},
title = {A two-layer canopy model with thermal inertia for an improved snowpack energy balance below needleleaf forest (model SNOWPACK, version 3.2.1, revision 741)},
journal = {Geoscientific Model Development},
year = {2015},
volume = {8},
number = {8},
pages = {2379--2398},
url = {https://www.geosci-model-dev.net/8/2379/2015/},
doi = {10.5194/gmd-8-2379-2015}
}
|
| Graziosi F, Arduini J, Furlani F, Giostra U, Kuijpers LJM, Montzka SA, Miller BR, O'Doherty SJ, Stohl A, Bonasoni P and Maione M (2015), "European emissions of HCFC-22 based on eleven years of high frequency atmospheric measurements and a Bayesian inversion method", Atmospheric Environment., jul, 2015. Vol. 112, pp. 196-207. |
| Abstract: HCFC-22 (CHClFinf2/inf), a stratospheric ozone depleting substance and a powerful greenhouse gas, is the third most abundant anthropogenic halocarbon in the atmosphere. Primarily used in refrigeration and air conditioning systems, its global production and consumption have increased during the last 60 years, with the global increases in the last decade mainly attributable to developing countries. In 2007, an adjustment to the Montreal Protocol for Substances that Deplete the Ozone Layer called for an accelerated phase out of HCFCs, implying a 75% reduction (base year 1989) of HCFC production and consumption by 2010 in developed countries against the previous 65% reduction. In Europe HCFC-22 is continuously monitored at the two sites Mace Head (Ireland) and Monte Cimone (Italy). Combining atmospheric observations with a Bayesian inversion technique, we estimated fluxes of HCFC-22 from Europe and from eight macro-areas within it, over an 11-year period from January 2002 to December 2012, during which the accelerated restrictions on HCFCs production and consumption have entered into force. According to our study, the maximum emissions over the entire domain was in 2003 (38.2±4.7Ggyrsup-1/sup), and the minimum in 2012 (12.1±2.0Ggyrsup-1/sup); emissions continuously decreased between these years, except for secondary maxima in the 2008 and 2010. Despite such a decrease in regional emissions, background values of HCFC-22 measured at the two European stations over 2002-2012 are still increasing as a consequence of global emissions, in part from developing countries, with an average trend of ca 7.0pptyrsup-1/sup. However, the observations at the two European stations show also that since 2008 a decrease in the global growth rate has occurred. In general, our European emission estimates are in good agreement with those reported by previous studies that used different techniques. Since the currently dominant emission source of HCFC-22 is from banks, we assess the banks' size and their contribution to the total European emissions up to 2030, and we project a fast decrease approaching negligible emissions in the last five years of the considered period. Finally, inversions conducted over three month periods showed evidence for a seasonal cycle in emissions in regions in the Mediterranean basin but not outside it. Emissions derived from regions in the Mediterranean basin were ca. 25% higher in warmer months than in colder months. |
BibTeX:
@article{Graziosi2015,
author = {Graziosi, F and Arduini, J and Furlani, F and Giostra, U and Kuijpers, L J M and Montzka, S A and Miller, B R and O'Doherty, S J and Stohl, A and Bonasoni, P and Maione, M},
title = {European emissions of HCFC-22 based on eleven years of high frequency atmospheric measurements and a Bayesian inversion method},
journal = {Atmospheric Environment},
year = {2015},
volume = {112},
pages = {196--207},
url = {http://linkinghub.elsevier.com/retrieve/pii/S1352231015300431},
doi = {10.1016/j.atmosenv.2015.04.042}
}
|
| Hahmann AN, Vincent CL, Peña A, Lange J and Hasager CB (2015), "Wind climate estimation using WRF model output: Method and model sensitivities over the sea", International Journal of Climatology., oct, 2015. Vol. 35(12), pp. 3422-3439. |
| Abstract: High-quality tall mast and wind lidar measurements over the North and Baltic Seas are used to validate the wind climatology produced from winds simulated by the Weather, Research and Forecasting (WRF) model in analysis mode. Biases in annual mean wind speed between model and observations at heights around 100m are smaller than 3.2% at offshore sites, except for those that are affected by the wake of a wind farm or the coastline. These biases are smaller than those obtained by using winds directly from the reanalysis. We study the sensitivity of the WRF-simulated wind climatology to various model setup parameters. The results of the year-long sensitivity simulations show that the long-term mean wind speed simulated by the WRF model offshore in the region studied is quite insensitive to the global reanalysis, the number of vertical levels, and the horizontal resolution of the sea surface temperature used as lower boundary conditions. Also, the strength and form (grid vs spectral) of the nudging is quite irrelevant for the mean wind speed at 100m. Large sensitivity is found to the choice of boundary layer parametrization, and to the length of the period that is discarded as spin-up to produce a wind climatology. It is found that the spin-up period for the boundary layer winds is likely larger than 12 h over land and could affect the wind climatology for points offshore for quite a distance downstream from the coast. |
BibTeX:
@article{Hahmann2015,
author = {Hahmann, Andrea N and Vincent, Claire L and Peña, Alfredo and Lange, Julia and Hasager, Charlotte B},
title = {Wind climate estimation using WRF model output: Method and model sensitivities over the sea},
journal = {International Journal of Climatology},
year = {2015},
volume = {35},
number = {12},
pages = {3422--3439},
url = {http://doi.wiley.com/10.1002/joc.4217},
doi = {10.1002/joc.4217}
}
|
| Hari P, Petäjä T, Bäck J, Kerminen V-M, Lappalainen HK, Vihma T, Laurila T, Viisanen Y, Vesala T and Kulmala M (2015), "Conceptual design of a measurement network of the global change", Atmospheric Chemistry and Physics Discussions., aug, 2015. Vol. 15(15), pp. 21063-21093. |
| Abstract: Abstract. The global environment is changing rapidly due to anthropogenic emissions and actions. Such activities modify aerosol and greenhouse gas concentrations in the atmosphere, leading to regional and global climate change and affecting e.g. food and fresh-water security, sustainable use of natural resources and even demography. Here we present a conceptual design of a global, hierarchical observation network that can provide tools and increased understanding to tackle the inter-connected environmental and societal challenges that we will face in the coming decades. The philosophy behind the conceptual design relies on physical conservation laws of mass, energy and momentum, as well as on concentration gradients that act as driving forces for the atmosphere-biosphere exchange. The network is composed of standard, flux/advanced and flagship stations, each of which having specific and identified tasks. Each ecosystem type on the globe has its own characteristic features that have to be taken into consideration. The hierarchical network as a whole is able to tackle problems related to large spatial scales, heterogeneity of ecosystems and their complexity. The most comprehensive observations are envisioned to occur in flag ship stations, with which the process-level understanding can be expanded to continental and global scales together with advanced data analysis, earth system modelling and satellite remote sensing. The denser network of the flux and standard stations allow application and up-scaling of the results obtained from flag ship stations to the global level. |
BibTeX:
@article{Hari2015,
author = {Hari, P and Petäjä, T and Bäck, J and Kerminen, V.-M. and Lappalainen, H K and Vihma, T and Laurila, T and Viisanen, Y and Vesala, T and Kulmala, M},
title = {Conceptual design of a measurement network of the global change},
journal = {Atmospheric Chemistry and Physics Discussions},
year = {2015},
volume = {15},
number = {15},
pages = {21063--21093},
url = {http://www.atmos-chem-phys-discuss.net/15/21063/2015/},
doi = {10.5194/acpd-15-21063-2015}
}
|
| Hartman SE, Jiang Z-P, Turk D, Lampitt RS, Frigstad H, Ostle C and Schuster U (2015), "Biogeochemical variations at the Porcupine Abyssal Plain sustained Observatory in the northeast Atlantic Ocean, from weekly to inter-annual timescales", Biogeosciences., feb, 2015. Vol. 12(3), pp. 845-853. Copernicus GmbH. |
| Abstract: textlessptextgreaterAbstract. We present high-resolution autonomous measurements of carbon dioxide partial pressure p(CO2) taken in situ at the Porcupine Abyssal Plain sustained Observatory (PAP-SO) in the northeast Atlantic (49° N, 16.5° W; water depth of 4850 m) for the period 2010–2012. Measurements of p(CO2) made at 30 m depth on a sensor frame are compared with other autonomous biogeochemical measurements at that depth (including chlorophyll a fluorescence and nitrate concentration data) to analyse weekly to seasonal controls on p(CO2) flux in the inter-gyre region of the North Atlantic. Comparisons are also made with in situ regional time series data from a ship of opportunity and mixed layer depth (MLD) measurements from profiling Argo floats. There is a persistent under-saturation of CO2 in surface waters throughout the year which gives rise to a perennial CO2 sink. Comparison with an earlier data set collected at the site (2003–2005) confirms seasonal and inter-annual changes in surface seawater chemistry. There is year-to-year variability in the timing of deep winter mixing and the intensity of the spring bloom. The 2010–2012 period shows an overall increase in p(CO2) values when compared to the 2003–2005 period as would be expected from increases due to anthropogenic CO2 emissions. The surface temperature, wind speed and MLD measurements are similar for both periods of time. Future work should incorporate daily CO2 flux measurements made using CO2 sensors at 1 m depth and the in situ wind speed data now available from the UK Met Office Buoy.textless/ptextgreater |
BibTeX:
@article{Hartman2015,
author = {Hartman, S. E. and Jiang, Z.-P. and Turk, D. and Lampitt, R. S. and Frigstad, H. and Ostle, C. and Schuster, U.},
title = {Biogeochemical variations at the Porcupine Abyssal Plain sustained Observatory in the northeast Atlantic Ocean, from weekly to inter-annual timescales},
journal = {Biogeosciences},
publisher = {Copernicus GmbH},
year = {2015},
volume = {12},
number = {3},
pages = {845--853},
url = {https://bg.copernicus.org/articles/12/845/2015/},
doi = {10.5194/bg-12-845-2015}
}
|
| Haszpra L, Barcza Z, Haszpra T, Pátkai ZS and Davis KJ (2015), "How well do tall-tower measurements characterize the CO2 mole fraction distribution in the planetary boundary layer?", Atmospheric Measurement Techniques., apr, 2015. Vol. 8(4), pp. 1657-1671. |
| Abstract: Planetary boundary layer (PBL) COinf2/inf mole fraction data are needed by transport models and carbon budget models as both input and reference for validation. The height of in situ COinf2/inf mole fraction measurements is usually different from that of the model levels where the data are needed; data from short towers, in particular, are difficult to utilize in atmospheric models that do not simulate the surface layer well. Tall-tower COinf2/inf mole fraction measurements observed at heights ranging from 10 to 115 m above ground level at a rural site in Hungary and regular airborne vertical mole fraction profile measurements (136 vertical profiles) above the tower allowed us to estimate how well a tower of a given height could estimate the COinf2/inf mole fraction above the tower in the PBL. The statistical evaluation of the height-dependent bias between the real PBL COinf2/inf mole fraction profile (measured by the aircraft) and the measurement at a given elevation above the ground was performed separately for the summer and winter half years to take into account the different dynamics of the lower troposphere and the different surface COinf2/inf flux in the different seasons. The paper presents (1) how accurately the vertical distribution of COinf2/inf in the PBL can be estimated from the measurements on the top of a tower of height iH/i; (2) how tall of a tower would be needed for the satisfaction of different requirements on the accuracy of the estimation of the COinf2/inf vertical distribution; (3) how accurate of a COinf2/inf vertical distribution estimation can be expected from the existing towers; and (4) how much improvement can be achieved in the accuracy of the estimation of COinf2/inf vertical distribution by applying the virtual tall-tower concept. |
BibTeX:
@article{Haszpra2015,
author = {Haszpra, L and Barcza, Z and Haszpra, T and Pátkai, Z S and Davis, K J},
title = {How well do tall-tower measurements characterize the CO2 mole fraction distribution in the planetary boundary layer?},
journal = {Atmospheric Measurement Techniques},
year = {2015},
volume = {8},
number = {4},
pages = {1657--1671},
url = {http://www.atmos-meas-tech.net/8/1657/2015/},
doi = {10.5194/amt-8-1657-2015}
}
|
| Hausmann P, Sussmann R and Smale D (2015), "Contribution of oil and natural gas production to renewed increase of atmospheric methane (2007-2014): Top-down estimate from ethane and methane column observations", Atmospheric Chemistry and Physics Discussions., dec, 2015. Vol. 15(24), pp. 35991-36028. |
| Abstract: Harmonized time series of column-averaged mole fractions of atmospheric methane and ethane over the period 1999-2014 are derived from solar Fourier transform infrared (FTIR) measurements at the Zugspitze summit (47° N, 2964 m a.s.l.) and at Lauder (45° S, 370 m a.s.l.). Long-term trend analysis reveals a consistent renewed methane increase since 2007 of 6.2 [5.6, 6.9] ppb yr-1 at the Zugspitze and 6.0 [5.3, 6.7] ppb yr-1 at Lauder (95 % confidence intervals). Several recent studies provide pieces of evidence that the renewed methane increase is most likely driven by two main factors: (i) increased methane emissions from tropical wetlands, followed by (ii) increased thermogenic methane emissions due to growing oil and natural gas production. Here, we quantify the magnitude of the second class of sources, using long-term measurements of atmospheric ethane as tracer for thermogenic methane emissions. In 2007, after years of weak decline, the Zugspitze ethane time series shows the sudden onset of a significant positive trend (2.3 [1.8, 2.8] × 10-2 ppb yr-1 for 2007-2014), while a negative trend persists at Lauder after 2007 (-0.4 [-0.6, -0.1] × 10-2 ppb yr-1). Zugspitze methane and ethane time series are significantly correlated for the period 2007-2014 and can be assigned to thermogenic methane emissions with an ethane-to-methane ratio of 10-21 %. We present optimized emission scenarios for 2007-2014 derived from an atmospheric two-box model. From our trend observations we infer a total ethane emission increase over the period 2007-2014 from oil and natural gas sources of 1-11 Tg yr-1 along with an overall methane emission increase of 24-45 Tg yr-1. Based on these results, the oil and natural gas emission contribution C to the renewed methane increase is deduced using three different emission scenarios with dedicated ranges of methane-to-ethane ratios (MER). Reference scenario 1 assumes an oil and gas emission combination with MER Combining double low line 3.3-7.6, which results in a minimum contribution C 28 % (given as lower bound of 99 % confidence interval). For the limiting cases of pure oil-related emissions with MER Combining double low line 1.7-3.3 (scenario 2) and pure natural gas sources with MER Combining double low line 7.6-12.1 (scenario 3) the results are C 13 % and C 53 %, respectively. Our results suggest that long-term observations of column-averaged ethane provide a valuable constraint on the source attribution of methane emission changes and provide basic knowledge for developing effective climate change mitigation strategies. |
BibTeX:
@article{Hausmann2015,
author = {Hausmann, P and Sussmann, R and Smale, D},
title = {Contribution of oil and natural gas production to renewed increase of atmospheric methane (2007-2014): Top-down estimate from ethane and methane column observations},
journal = {Atmospheric Chemistry and Physics Discussions},
year = {2015},
volume = {15},
number = {24},
pages = {35991--36028},
url = {http://www.atmos-chem-phys-discuss.net/15/35991/2015/},
doi = {10.5194/acpd-15-35991-2015}
}
|
| Heinonsalo J, Sun H, Santalahti M, Bäcklund K, Hari P and Pumpanen J (2015), "Evidences on the ability of mycorrhizal genus Piloderma to use organic nitrogen and deliver it to Scots pine", PLoS ONE., jul, 2015. Vol. 10(7) Public Library of Science. |
| Abstract: Ectomycorrhizal (ECM) symbiosis has been proposed to link plant photosynthesis and soil organic matter (SOM) decomposition through the production of fungal enzymes which promote SOM degradation and nitrogen (N) uptake. However, laboratory and field evidence for the existence of these processes are rare. Piloderma sp., a common ECM genus in boreal forest soil, was chosen as model mycorrhiza for this study. The abundance of Piloderma sp. was studied in root tips and soil over one growing season and in winter. Protease production was measured from ectomycorrhiza and soil solution in the field and pure fungal cultures. We also tested the effect of Piloderma olivaceum on host plant organic N nutrition in the laboratory. The results showed that Piloderma sp. was highly abundant in the field and produced extracellular proteases, which correlated positively with the gross primary production, temperature and soil respiration. In the laboratory, Piloderma olivaceum could improve the ability of Pinus sylvestris L. to utilize N from extragenous proteins. We suggest that ECM fungi, although potentially retaining N in their hyphae, are important in forest C and N cycling due to their ability to access proteinaeous N. As Piloderma sp. abundance appeared to be seasonally highly variable, recycling of fungal-bound N after hyphal death may therefore be of primary importance for the N cycling in boreal ecosystems. |
BibTeX:
@article{Heinonsalo2015,
author = {Heinonsalo, Jussi and Sun, Hui and Santalahti, Minna and Bäcklund, Kirsi and Hari, Pertti and Pumpanen, Jukka},
title = {Evidences on the ability of mycorrhizal genus Piloderma to use organic nitrogen and deliver it to Scots pine},
journal = {PLoS ONE},
publisher = {Public Library of Science},
year = {2015},
volume = {10},
number = {7},
doi = {10.1371/journal.pone.0131561}
}
|
| Heiskanen JJ, Mammarella I, Ojala A, Stepanenko V, Erkkilä KM, Miettinen H, Sandström H, Eugster W, Leppäranta M, Järvinen H, Vesala T and Nordbo A (2015), "Effects of water clarity on lake stratification and lake-atmosphere heat exchange", Journal of Geophysical Research., aug, 2015. Vol. 120(15), pp. 7412-7428. |
| Abstract: Recent progress of including lake subroutines in numerical weather prediction (NWP) models has led to more accurate forecasts. In lake models, one essential parameter is water clarity, parameterized via the light extinction coefficient, Kd, for which a global constant value is usually used. We used direct eddy covariance fluxes and basic meteorological measurements coupled with lake water temperature and clarity measurements from a boreal lake to estimate the performance of two lake models, LAKE and FLake. These models represent two 1-D modeling frameworks broadly used in NWP. The results show that the lake models are very sensitive to changes in Kd when it is lower than 0.5m-1. The progress of thermal stratification depended strongly on Kd. In dark-water simulations the mixed layer was shallower, longwave and turbulent heat losses higher, and therefore the average water column temperatures lower than in clear-water simulations. Thus, changes in water clarity can also affect the onset of ice cover. The more complex LAKE modeled the seasonal thermocline deepening, whereas it remained virtually constant during summer in the FLake model. Bothmodels overestimated the surface water temperatures by about 1°C and latent heat flux by 30%, but the variations in heat storage and sensible heat flux were adequately simulated. Our results suggest that, at least for humic lakes, a lake-specific, but not time-depending, constant value for Kd can be used and that a global mapping of Kd would be most beneficial in regions with relatively clear lakes, e.g., in lakes at high altitudes. |
BibTeX:
@article{Heiskanen2015,
author = {Heiskanen, Jouni J and Mammarella, Ivan and Ojala, Anne and Stepanenko, Victor and Erkkilä, Kukka Maaria and Miettinen, Heli and Sandström, Heidi and Eugster, Werner and Leppäranta, Matti and Järvinen, Heikki and Vesala, Timo and Nordbo, Annika},
title = {Effects of water clarity on lake stratification and lake-atmosphere heat exchange},
journal = {Journal of Geophysical Research},
year = {2015},
volume = {120},
number = {15},
pages = {7412--7428},
url = {http://doi.wiley.com/10.1002/2014JD022938},
doi = {10.1002/2014JD022938}
}
|
| Hellsten A, Luukkonen SM, Steinfeld G, Kanani-Sühring F, Markkanen T, Järvi L, Lento J, Vesala T and Raasch S (2015), "Footprint Evaluation for Flux and Concentration Measurements for an Urban-Like Canopy with Coupled Lagrangian Stochastic and Large-Eddy Simulation Models", Boundary-Layer Meteorology., nov, 2015. Vol. 157(2), pp. 191-217. |
| Abstract: A footprint algorithm, based on a Lagrangian stochastic (LS) model embedded into a parallelized large-eddy simulation (LES) model, is used for the evaluation of flux and concentration footprints of passive scalars in flow in and above an urban-like canopy layer of a neutrally stratified 440 m deep boundary layer. The urban-like canopy layer is realized by an aligned array of cuboids whose height H is 40 m. The canopy flow involves strong small-scale inhomogeneities although it is homogeneous at the large scale. The source height is 1m (0.025H) above the ground in the street canyons, roughly mimicking traffic emissions. Footprints are evaluated for four heights from 0.25H to 2.5H, and for up to eight different horizontal sensor positions per measurement height, comprising sensor positions inside as well as outside of the street canyon that extend perpendicular to the mean wind direction. The LES-LS footprints are compared with footprints estimated by a conventional model (Kormann and Meixner, in Boundary-Layer Meteorol 99:207–224, 2001). It becomes evident that the local heterogeneity of the flow has a considerable impact on flux and concentration footprints. As expected, footprints for measurements within and right above the canopy layer show complex and completely different footprint shapes compared to the ellipsoidal shape obtained from conventional footprint models that assume horizontal homogeneity of the turbulent flow as well as the sources of passive scalars. Our results show the importance of street-canyon flow and turbulence for the vertical mixing of scalar concentration. |
BibTeX:
@article{Hellsten2015,
author = {Hellsten, Antti and Luukkonen, Sofia M and Steinfeld, Gerald and Kanani-Sühring, Farah and Markkanen, Tiina and Järvi, Leena and Lento, Juha and Vesala, Timo and Raasch, Siegfried},
title = {Footprint Evaluation for Flux and Concentration Measurements for an Urban-Like Canopy with Coupled Lagrangian Stochastic and Large-Eddy Simulation Models},
journal = {Boundary-Layer Meteorology},
year = {2015},
volume = {157},
number = {2},
pages = {191--217},
url = {http://link.springer.com/10.1007/s10546-015-0062-4},
doi = {10.1007/s10546-015-0062-4}
}
|
| Henriksson N, Tarvainen L, Lim H, Tor-Ngern P, Palmroth S, Oren R, Marshall J and Näsholm T (2015), "Stem compression reversibly reduces phloem transport in Pinus sylvestris trees", Tree Physiology., oct, 2015. Vol. 35(10), pp. 1075-1085. |
| Abstract: Manipulating tree belowground carbon (C) transport enables investigation of the ecological and physiological roles of tree roots and their associated mycorrhizal fungi, as well as a range of other soil organisms and processes. Girdling remains the most reliable method for manipulating this flux and it has been used in numerous studies. However, girdling is destructive and irreversible. Belowground C transport is mediated by phloem tissue, pressurized through the high osmotic potential resulting from its high content of soluble sugars. We speculated that phloem transport may be reversibly blocked through the application of an external pressure on tree stems. Thus, we here introduce a technique based on compression of the phloem, which interrupts belowground flow of assimilates, but allows trees to recover when the external pressure is removed. Metal clamps were wrapped around the stems and tightened to achieve a pressure theoretically sufficient to collapse the phloem tissue, thereby aiming to block transport. The compression's performance was tested in two field experiments: a 13C canopy labelling study conducted on small Scots pine (Pinus sylvestris L.) trees [2-3 m tall, 3-7 cm diameter at breast height (DBH)] and a larger study involving mature pines (∼15 m tall, 15-25 cm DBH) where stem respiration, phloem and root carbohydrate contents, and soil CO2 efflux were measured. The compression's effectiveness was demonstrated by the successful blockage of 13C transport. Stem compression doubled stem respiration above treatment, reduced soil CO2 efflux by 34% and reduced phloem sucrose content by 50% compared with control trees. Stem respiration and soil CO2 efflux returned to normal within 3 weeks after pressure release, and 13C labelling revealed recovery of phloem function the following year. Thus, we show that belowground phloem C transport can be reduced by compression, and we also demonstrate that trees recover after treatment, resuming C transport in the phloem. |
BibTeX:
@article{Henriksson2015,
author = {Henriksson, Nils and Tarvainen, Lasse and Lim, Hyungwoo and Tor-Ngern, Pantana and Palmroth, Sari and Oren, Ram and Marshall, John and Näsholm, Torgny},
editor = {Tissue, David},
title = {Stem compression reversibly reduces phloem transport in Pinus sylvestris trees},
journal = {Tree Physiology},
year = {2015},
volume = {35},
number = {10},
pages = {1075--1085},
url = {https://academic.oup.com/treephys/article-lookup/doi/10.1093/treephys/tpv078},
doi = {10.1093/treephys/tpv078}
}
|
| Herbst M, Mund M, Tamrakar R and Knohl A (2015), "Differences in carbon uptake and water use between a managed and an unmanaged beech forest in central Germany", Forest Ecology and Management., nov, 2015. Vol. 355, pp. 101-108. |
| Abstract: Net atmospheric carbon dioxide exchange, total evapotranspiration and net primary production of two neighbouring beech (Fagus sylvatica L. .) forests in central Germany differing in site management were measured using the eddy covariance technique and biometric methods. The unmanaged site was an old-growth forest with admixtures of ash (Fraxinus excelsior L.) and sycamore (Acer pseudoplatanus L.) trees whereas the managed site was a regularly thinned, even-aged (about 130. years old), pure beech stand. Average carbon fluxes measured over seven years did not differ significantly between the two forests. Evapotranspiration was slightly higher (and consequently water use efficiency lower) at the unmanaged site. The maximum rates as well as the interannual variability of both net ecosystem exchange and net primary production were considerably larger at the managed, even-aged stand. The lowest annual carbon sequestration rates were observed in years with high fruit production in beech combined with cold and dry spells during leaf development which affected the carbon balance of the managed forest more than that of the unmanaged forest. In contrast, an extraordinarily dry period in late summer 2003 caused a stronger reduction in net carbon uptake in the old-growth forest which can probably be attributed to the contribution of ash to the ecosystem fluxes. Ash has a different phenology which made it more susceptible to the late summer drought. The relative importance of tree and structural (age, size) diversity, leaf area index and regenerative growth as well as the temporal frame and extent of single weather extremes for the forest-atmosphere exchange is discussed and it is concluded that site management and forest structure needs to be included in soil-vegetation-atmosphere-transfer models as it can often override effects of land use or plant functional type. |
BibTeX:
@article{Herbst2015,
author = {Herbst, Mathias and Mund, Martina and Tamrakar, Rijan and Knohl, Alexander},
title = {Differences in carbon uptake and water use between a managed and an unmanaged beech forest in central Germany},
journal = {Forest Ecology and Management},
year = {2015},
volume = {355},
pages = {101--108},
url = {http://linkinghub.elsevier.com/retrieve/pii/S0378112715003126},
doi = {10.1016/j.foreco.2015.05.034}
}
|
| Hoker J, Obersteiner F, Bönisch H and Engel A (2015), "Comparison of GC/time-of-flight MS with GC/quadrupole MS for halocarbon trace gas analysis", Atmospheric Measurement Techniques., may, 2015. Vol. 8(5), pp. 2195-2206. |
| Abstract: We present the application of time-of-flight mass spectrometry (TOF MS) for the analysis of halocarbons in the atmosphere after cryogenic sample preconcentration and gas chromatographic separation. For the described field of application, the quadrupole mass spectrometer (QP MS) is a state-of-the-art detector. This work aims at comparing two commercially available instruments, a QP MS and a TOF MS, with respect to mass resolution, mass accuracy, stability of the mass axis and instrument sensitivity, detector sensitivity, measurement precision and detector linearity. Both mass spectrometers are operated on the same gas chromatographic system by splitting the column effluent to both detectors. The QP MS had to be operated in optimised single ion monitoring (SIM) mode to achieve a sensitivity which could compete with the TOF MS. The TOF MS provided full mass range information in any acquired mass spectrum without losing sensitivity. Whilst the QP MS showed the performance already achieved in earlier tests, the sensitivity of the TOF MS was on average higher than that of the QP MS in the "operational" SIM mode by a factor of up to 3, reaching detection limits of less than 0.2 pg. Measurement precision determined for the whole analytical system was up to 0.2% depending on substance and sampled volume. The TOF MS instrument used for this study displayed significant non-linearities of up to 10% for two-thirds of all analysed substances. |
BibTeX:
@article{Hoker2015,
author = {Hoker, J and Obersteiner, F and Bönisch, H and Engel, A},
title = {Comparison of GC/time-of-flight MS with GC/quadrupole MS for halocarbon trace gas analysis},
journal = {Atmospheric Measurement Techniques},
year = {2015},
volume = {8},
number = {5},
pages = {2195--2206},
url = {http://www.atmos-meas-tech.net/8/2195/2015/},
doi = {10.5194/amt-8-2195-2015}
}
|
| Holding JM, Duarte CM, Sanz-Martín M, Mesa E, Arrieta JM, Chierici M, Hendriks IE, García-Corral LS, Regaudie-De-Gioux A, Delgado A, Reigstad M, Wassmann P and Agustí S (2015), "Temperature dependence of CO2-enhanced primary production in the European Arctic Ocean", Nature Climate Change., dec, 2015. Vol. 5(12), pp. 1079-1082. Nature Publishing Group. |
| Abstract: The Arctic Ocean is warming at two to three times the global rate and is perceived to be a bellwether for ocean acidification. Increased CO2 concentrations are expected to have a fertilization effect on marine autotrophs, and higher temperatures should lead to increased rates of planktonic primary production. Yet, simultaneous assessment of warming and increased CO2 on primary production in the Arctic has not been conducted. Here we test the expectation that CO2-enhanced gross primary production (GPP) may be temperature dependent, using data from several oceanographic cruises and experiments from both spring and summer in the European sector of the Arctic Ocean. Results confirm that CO2 enhances GPP (by a factor of up to ten) over a range of 145-2,099μatm; however, the greatest effects are observed only at lower temperatures and are constrained by nutrient and light availability to the spring period. The temperature dependence of CO2-enhanced primary production has significant implications for metabolic balance in a warmer, CO2-enriched Arctic Ocean in the future. In particular, it indicates that a twofold increase in primary production during the spring is likely in the Arctic. |
BibTeX:
@article{Holding2015,
author = {Holding, J. M. and Duarte, C. M. and Sanz-Martín, M. and Mesa, E. and Arrieta, J. M. and Chierici, M. and Hendriks, I. E. and García-Corral, L. S. and Regaudie-De-Gioux, A. and Delgado, A. and Reigstad, M. and Wassmann, P. and Agustí, S.},
title = {Temperature dependence of CO2-enhanced primary production in the European Arctic Ocean},
journal = {Nature Climate Change},
publisher = {Nature Publishing Group},
year = {2015},
volume = {5},
number = {12},
pages = {1079--1082},
url = {https://www.nature.com/articles/nclimate2768},
doi = {10.1038/nclimate2768}
}
|
| Hu G, Jia L and Menenti M (2015), "Comparison of MOD16 and LSA-SAF MSG evapotranspiration products over Europe for 2011", Remote Sensing of Environment., jan, 2015. Vol. 156, pp. 510-526. |
| Abstract: Terrestrial actual evapotranspiration (ETa) is an important component of the terrestrial water cycle. Currently there are two operational ETa products using moderate spatial resolution remote sensing data at continental and global scales, i.e. MOD16 and LSA-SAF MSG ETa. These two products are based on different parameterizations and forcing data, with the spatial and temporal resolutions of 1-km/8-day and 5-km/daily for MOD16 and LSA-SAF MSG ETa respectively. We compared the MOD16 ETa and LSA-SAF MSG ETa products and evaluated them against in-situ measurements at 15 ground sites with biome types ranging from croplands, grasslands, shrublands, savannas, to forests over Europe for 2011. The intercomparison results at local scale demonstrate that LSA-SAF MSG ETa is closer to eddy covariance (EC) measurements than MOD16 ETa product, with larger correlation coefficient Rest-obs, smaller root mean square error RMSEest-obs and bias of LSA-SAF MSG vs. EC at most of the 15 flux sites. Spatial distributions of the RMOD16-MSG and RMSEMOD16-MSG between MOD16 and LSA-SAF MSG ETa for 2011 show that both ETa data products are consistent over most of Europe, except for some semi-arid regions where the water availability is the main limiting factor of land surface evapotranspiration. LSA-SAF MSG ETa is shown to have a more adequate response to the forest fire. Our study contributes to assess the quality and uncertainty of each product, which can be beneficial for improving ETa algorithm and product quality. copy; 2014 Elsevier Inc. |
BibTeX:
@article{Hu2015,
author = {Hu, Guangcheng and Jia, Li and Menenti, Massimo},
title = {Comparison of MOD16 and LSA-SAF MSG evapotranspiration products over Europe for 2011},
journal = {Remote Sensing of Environment},
year = {2015},
volume = {156},
pages = {510--526},
url = {http://linkinghub.elsevier.com/retrieve/pii/S0034425714004271},
doi = {10.1016/j.rse.2014.10.017}
}
|
| Hytteborn JK, Temnerud J, Alexander RB, Boyer EW, Futter MN, Fröberg M, Dahné J and Bishop KH (2015), "Patterns and predictability in the intra-annual organic carbon variability across the boreal and hemiboreal landscape", Science of the Total Environment., jul, 2015. Vol. 520, pp. 260-269. |
| Abstract: Factors affecting total organic carbon (TOC) concentrations in 215 watercourses across Sweden were investigated using parameter parsimonious regression approaches to explain spatial and temporal variabilities of the TOC water quality responses. We systematically quantified the effects of discharge, seasonality, and long-term trend as factors controlling intra-annual (among year) and inter-annual (within year) variabilities of TOC by evaluating the spatial variability in model coefficients and catchment characteristics (e.g. land cover, retention time, soil type).Catchment area (0.18-47,000km2) and land cover types (forests, agriculture and alpine terrain) are typical for the boreal and hemiboreal zones across Fennoscandia. Watercourses had at least 6years of monthly water quality observations between 1990 and 2010. Statistically significant models (p0.05) describing variation of TOC in streamflow were identified in 209 of 215 watercourses with a mean Nash-Sutcliffe efficiency index of 0.44. Increasing long-term trends were observed in 149 (70%) of the watercourses, and intra-annual variation in TOC far exceeded inter-annual variation. The average influences of the discharge and seasonality terms on intra-annual variations in daily TOC concentration were 1.4 and 1.3mgl-1 (13 and 12% of the mean annual TOC), respectively. The average increase in TOC was 0.17mgl-1year-1 (1.6% year-1).Multivariate regression with over 90 different catchment characteristics explained 21% of the spatial variation in the linear trend coefficient, less than 20% of the variation in the discharge coefficient and 73% of the spatial variation in mean TOC. Specific discharge, water residence time, the variance of daily precipitation, and lake area, explained 45% of the spatial variation in the amplitude of the TOC seasonality.Because the main drivers of temporal variability in TOC are seasonality and discharge, first-order estimates of the influences of climatic variability and change on TOC concentration should be predictable if the studied catchments continue to respond similarly. |
BibTeX:
@article{Hytteborn2015,
author = {Hytteborn, Julia K and Temnerud, Johan and Alexander, Richard B and Boyer, Elizabeth W and Futter, Martyn N and Fröberg, Mats and Dahné, Joel and Bishop, Kevin H},
title = {Patterns and predictability in the intra-annual organic carbon variability across the boreal and hemiboreal landscape},
journal = {Science of the Total Environment},
year = {2015},
volume = {520},
pages = {260--269},
url = {https://linkinghub.elsevier.com/retrieve/pii/S0048969715003071},
doi = {10.1016/j.scitotenv.2015.03.041}
}
|
| Ibánhez JSP, Diverrès D, Araujo M and Lefèvre N (2015), "Seasonal and interannual variability of sea-air CO textlesssubtextgreater2textless/subtextgreater fluxes in the tropical Atlantic affected by the Amazon River plume", Global Biogeochemical Cycles., oct, 2015. Vol. 29(10), pp. 1640-1655. Blackwell Publishing Ltd. |
| Abstract: CO2 fugacities obtained from a merchant ship sailing from France to French Guyana were used to explore the seasonal and interannual variability of the sea-air CO2 exchange in the western tropical North Atlantic (TNA; 5-14-N, 41-52-W). Two distinct oceanic water masses were identified in the area associated to the main surface currents, i.e., the North Brazil Current (NBC) and the North Equatorial Current (NEC). The NBC was characterized by permanent CO2 oversaturation throughout the studied period, contrasting with the seasonal pattern identified in the NEC. The NBC retroflection was the main contributor to the North Equatorial Counter Current (NECC), thus spreading into the central TNA, the Amazon River plume, and the CO2-rich waters probably originated from the equatorial upwelling. Strong CO2 undersaturation was associated to the Amazon River plume. Total inorganic carbon drawdown due to biological activity was estimated to be 154 μmol kg-1 within the river plume. As a consequence, the studied area acted as a net sink of atmospheric CO2 (from -72.2 ± 10.2 mmol m-2 month-1 in February to 14.3 ± 4.5 mmol m-2 month-1 in May). This contrasted with the net CO2 efflux estimated by the main global sea-air CO2 flux climatologies. Interannual sea surface temperature changes in the TNA caused by large-scale climatic events could determine the direction and intensity of the sea-air CO2 fluxes in the NEC. Positive temperature anomalies observed in the TNA led to an almost permanent CO2 outgassing in the NEC in 2010. |
BibTeX:
@article{Ibanhez2015,
author = {Ibánhez, J. Severino P. and Diverrès, Denis and Araujo, Moacyr and Lefèvre, Nathalie},
title = {Seasonal and interannual variability of sea-air CO textlesssubtextgreater2textless/subtextgreater fluxes in the tropical Atlantic affected by the Amazon River plume},
journal = {Global Biogeochemical Cycles},
publisher = {Blackwell Publishing Ltd},
year = {2015},
volume = {29},
number = {10},
pages = {1640--1655},
url = {http://doi.wiley.com/10.1002/2015GB005110},
doi = {10.1002/2015GB005110}
}
|
| Jantze EJ, Laudon H, Dahlke HE and Lyon SW (2015), "Spatial Variability of Dissolved Organic and Inorganic Carbon in Subarctic Headwater Streams", Arctic, Antarctic, and Alpine Research., aug, 2015. Vol. 47(3), pp. 529-546. |
| Abstract: The subarctic landscape is composed of a complex mosaic of vegetation, geology and topography, which control both the hydrology and biogeochemistry of streams across space and time. We present a synoptic sampling campaign that aimed to estimate dissolved C export variability under low-flow conditions from a subarctic landscape. The results included measurements of stream discharge and concentrations of both dissolved organic carbon (DOC), dissolved inorganic carbon (DIC), and carbon dioxide (CO2) for 32 subcatchments of the Abiskojokka catchment in northern Sweden. For these subarctic headwater streams, we found that DOC, DIC and CO2 concentrations showed significant variability (p 0.05) relative to catchment size, discharge, specific discharge, lithology, electrical conductivity, weathering products, and the estimated travel time of water through the subcatchment. Our results indicate that neither vegetation cover nor lithology alone could explain the concentrations and mass flux rates of DOC and DIC. Instead, we found that mass flux rates of DOC, DIC, and CO2 depended mainly on specific discharge and water travel time. Furthermore, our results demonstrate the importance of studying lateral carbon transport in combination with hydrological flow paths at small scales to establish a knowledge foundation applicable for expected carbon cycle and hydroclimatic shifts due to climate change. |
BibTeX:
@article{Jantze2015,
author = {Jantze, E J and Laudon, H and Dahlke, H E and Lyon, S W},
title = {Spatial Variability of Dissolved Organic and Inorganic Carbon in Subarctic Headwater Streams},
journal = {Arctic, Antarctic, and Alpine Research},
year = {2015},
volume = {47},
number = {3},
pages = {529--546},
url = {https://www.tandfonline.com/doi/full/10.1657/AAAR0014-044},
doi = {10.1657/AAAR0014-044}
}
|
| Johansson S, Carlqvist K, Kataria R, Ulvcrona T, Bergsten U, Arshadi M, Galbe M and Lidén G (2015), "Implications of differences in macromolecular composition of stem fractions for processing of Scots pine", Wood Science and Technology., sep, 2015. Vol. 49(5), pp. 1037-1054. |
| Abstract: Use of wood feedstocks for sugar-based biorefineries requires suitable treatments of the various tree fractions to optimize yields. In the current study, stem wood fractions (sapwood, heartwood and knotwood) were sampled at different heights from well-documented Scots pine trees taken from two contrasting stands. The fractions were assessed in terms of chemical composition, response to SO2-catalysed steam pretreatment and enzymatic digestibility. There were significant differences in total extractive contents between the fractions, where the heartwood fractions had an extractive content 1–3 wt% higher than sapwood (corresponding to a relative increase of 20–60 %) for samples at the same height. In contrast, the differences in macromolecular carbohydrate contents between the fractions were smaller and mainly insignificant. One exception was the xylan content, which was higher in heartwood than in sapwood at the same tree height (a relative difference of 10–15 %). Steam pretreatment resulted in a clearly higher degree of hydrolysis for sapwood than for heartwood at the same conditions. However, at optimal pretreatment temperatures a higher total sugar yield was in fact obtained for heartwood, showing the importance of tuning the process conditions for the respective wood fractions. |
BibTeX:
@article{Johansson2015,
author = {Johansson, Sara and Carlqvist, Karin and Kataria, Rashmi and Ulvcrona, Thomas and Bergsten, Urban and Arshadi, Mehrdad and Galbe, Mats and Lidén, Gunnar},
title = {Implications of differences in macromolecular composition of stem fractions for processing of Scots pine},
journal = {Wood Science and Technology},
year = {2015},
volume = {49},
number = {5},
pages = {1037--1054},
url = {http://link.springer.com/10.1007/s00226-015-0739-3},
doi = {10.1007/s00226-015-0739-3}
}
|
| Jones SD, Le Quéré C, Rödenbeck C, Manning AC and Olsen A (2015), "A statistical gap-filling method to interpolate global monthly surface ocean carbon dioxide data", Journal of Advances in Modeling Earth Systems., dec, 2015. Vol. 7(4), pp. 1554-1575. Blackwell Publishing Ltd. |
| Abstract: We have developed a statistical gap-filling method adapted to the specific coverage and properties of observed fugacity of surface ocean CO2 (fCO2). We have used this method to interpolate the Surface Ocean CO2 Atlas (SOCAT) v2 database on a 2.5°×2.5° global grid (south of 70°N) for 1985-2011 at monthly resolution. The method combines a spatial interpolation based on a "radius of influence" to determine nearby similar fCO2 values with temporal harmonic and cubic spline curve-fitting, and also fits long-term trends and seasonal cycles. Interannual variability is established using deviations of observations from the fitted trends and seasonal cycles. An uncertainty is computed for all interpolated values based on the spatial and temporal range of the interpolation. Tests of the method using model data show that it performs as well as or better than previous regional interpolation methods, but in addition it provides a near-global and interannual coverage. |
BibTeX:
@article{Jones2015,
author = {Jones, Steve D. and Le Quéré, Corinne and Rödenbeck, Christian and Manning, Andrew C. and Olsen, Are},
title = {A statistical gap-filling method to interpolate global monthly surface ocean carbon dioxide data},
journal = {Journal of Advances in Modeling Earth Systems},
publisher = {Blackwell Publishing Ltd},
year = {2015},
volume = {7},
number = {4},
pages = {1554--1575},
url = {http://doi.wiley.com/10.1002/2014MS000416},
doi = {10.1002/2014MS000416}
}
|
| Kadygrov N, Broquet G, Chevallier F, Rivier L, Gerbig C and Ciais P (2015), "On the potential of the ICOS atmospheric CO2 measurement network for estimating the biogenic CO2 budget of Europe", Atmospheric Chemistry and Physics., nov, 2015. Vol. 15(22), pp. 12765-12787. |
| Abstract: We present a performance assessment of the European Integrated Carbon Observing System (ICOS) atmospheric network for constraining European biogenic CO2 fluxes (hereafter net ecosystem exchange, NEE). The performance of the network is assessed in terms of uncertainty in the fluxes, using a state-of-the-art mesoscale variational atmospheric inversion system assimilating hourly averages of atmospheric data to solve for NEE at 6 h and 0.5° resolution. The performance of the ICOS atmospheric network is also assessed in terms of uncertainty reduction compared to typical uncertainties in the flux estimates from ecosystem models, which are used as prior information by the inversion. The uncertainty in inverted fluxes is computed for two typical periods representative of northern summer and winter conditions in July and in December 2007, respectively. These computations are based on a observing system simulation experiment (OSSE) framework. We analyzed the uncertainty in a 2-week-mean NEE as a function of the spatial scale with a focus on the model native grid scale (0.5°), the country scale and the European scale (including western Russia and Turkey). Several network configurations, going from 23 to 66 sites, and different configurations of the prior uncertainties and atmospheric model transport errors are tested in order to assess and compare the improvements that can be expected in the future from the extension of the network, from improved prior information or transport models. Assimilating data from 23 sites (a network comparable to present-day capability) with errors estimated from the present prior information and transport models, the uncertainty reduction on a 2-week-mean NEE should range between 20 and 50 % for 0.5° resolution grid cells in the best sampled area encompassing eastern France and western Germany. At the European scale, the prior uncertainty in a 2-week-mean NEE is reduced by 50 % (66 %), down to ∼ 43 Tg C monthg-1 (26 Tg C monthg-1) in July (December). Using a larger network of 66 stations, the prior uncertainty of NEE is reduced by the inversion by 64 % (down to ∼ 33 Tg C monthg-1) in July and by 79 % (down to ∼ 15 Tg C monthg-1) in December. When the results are integrated over the well-observed western European domain, the uncertainty reduction shows no seasonal variability. The effect of decreasing the correlation length of the prior uncertainty, or of reducing the transport model errors compared to their present configuration (when conducting real-data inversion cases) can be larger than that of the extension of the measurement network in areas where the 23 station observation network is the densest. We show that with a configuration of the ICOS atmospheric network containing 66 sites that can be expected on the long-term, the uncertainties in a 2-week-mean NEE will be reduced by up to 50-80 % for countries like Finland, Germany, France and Spain, which could significantly improvement (and at least a high complementarity to) our knowledge of NEE derived from biomass and soil carbon inventories at multi-annual scales. |
BibTeX:
@article{Kadygrov2015,
author = {Kadygrov, N and Broquet, G and Chevallier, F and Rivier, L and Gerbig, C and Ciais, P},
title = {On the potential of the ICOS atmospheric CO2 measurement network for estimating the biogenic CO2 budget of Europe},
journal = {Atmospheric Chemistry and Physics},
year = {2015},
volume = {15},
number = {22},
pages = {12765--12787},
url = {http://www.atmos-chem-phys.net/15/12765/2015/},
doi = {10.5194/acp-15-12765-2015}
}
|
| Karstens U, Schwingshackl C, Schmithüsen D and Levin I (2015), "A process-based 222radon flux map for Europe and its comparison to long-term observations", Atmospheric Chemistry and Physics., nov, 2015. Vol. 15(22), pp. 12845-12865. |
| Abstract: Detailed 222radon (222Rn) flux maps are an essential pre-requisite for the use of radon in atmospheric transport studies. Here we present a high-resolution 222Rn flux map for Europe, based on a parameterization of 222Rn production and transport in the soil. The 222Rn exhalation rate is parameterized based on soil properties, uranium content, and modelled soil moisture from two different land-surface reanalysis data sets. Spatial variations in exhalation rates are primarily determined by the uranium content of the soil, but also influenced by soil texture and local water-table depth. Temporal variations are related to soil moisture variations as the molecular diffusion in the unsaturated soil zone depends on available air-filled pore space. The implemented diffusion parameterization was tested against campaign-based 222Rn soil profile measurements. Monthly 222Rn exhalation rates from European soils were calculated with a nominal spatial resolution of 0.083° × 0.083° and compared to long-term direct measurements of 222Rn exhalation rates in different areas of Europe. The two realizations of the 222Rn flux map, based on the different soil moisture data sets, both realistically reproduce the observed seasonality in the fluxes but yield considerable differences for absolute flux values. The mean 222Rn flux from soils in Europe is estimated to be 10 mBq mg-2 sg-1 (ERA-Interim/Land soil moisture) or 15 mBq mg-2 sg-1 (GLDAS (Global Land Data Assimilation System) Noah soil moisture) for the period 2006-2010. The corresponding seasonal variations with low fluxes in winter and high fluxes in summer range in the two realizations from ca. 7 to ca. 14 mBq mg-2 sg-1 and from ca. 11 to ca. 20 mBq mg-2 sg-1, respectively. These systematic differences highlight the importance of realistic soil moisture data for a reliable estimation of 222Rn exhalation rates. Comparison with observations suggests that the flux estimates based on the GLDAS Noah soil moisture model on average better represent observed fluxes. |
BibTeX:
@article{Karstens2015,
author = {Karstens, U and Schwingshackl, C and Schmithüsen, D and Levin, I},
title = {A process-based 222radon flux map for Europe and its comparison to long-term observations},
journal = {Atmospheric Chemistry and Physics},
year = {2015},
volume = {15},
number = {22},
pages = {12845--12865},
url = {http://www.atmos-chem-phys.net/15/12845/2015/},
doi = {10.5194/acp-15-12845-2015}
}
|
| Karstensen J, Fiedler B, Schütte F, Brandt P, Körtzinger A, Fischer G, Zantopp R, Hahn J, Visbeck M and Wallace D (2015), "Open ocean dead zones in the tropical North Atlantic Ocean", Biogeosciences., apr, 2015. Vol. 12(8), pp. 2597-2605. |
| Abstract: Here we present first observations, from instrumentation installed on moorings and a float, of unexpectedly low ( 2 μmol kgsup-1/sup) oxygen environments in the open waters of the tropical North Atlantic, a region where oxygen concentration does normally not fall much below 40 μmol kgsup-1/sup. The low-oxygen zones are created at shallow depth, just below the mixed layer, in the euphotic zone of cyclonic eddies and anticyclonic-modewater eddies. Both types of eddies are prone to high surface productivity. Net respiration rates for the eddies are found to be 3 to 5 times higher when compared with surrounding waters. Oxygen is lowest in the centre of the eddies, in a depth range where the swirl velocity, defining the transition between eddy and surroundings, has its maximum. It is assumed that the strong velocity at the outer rim of the eddies hampers the transport of properties across the eddies boundary and as such isolates their cores. This is supported by a remarkably stable hydrographic structure of the eddies core over periods of several months. The eddies propagate westward, at about 4 to 5 km daysup-1/sup, from their generation region off the West African coast into the open ocean. High productivity and accompanying respiration, paired with sluggish exchange across the eddy boundary, create the "dead zone" inside the eddies, so far only reported for coastal areas or lakes. We observe a direct impact of the open ocean dead zones on the marine ecosystem as such that the diurnal vertical migration of zooplankton is suppressed inside the eddies. |
BibTeX:
@article{Karstensen2015,
author = {Karstensen, J and Fiedler, B and Schütte, F and Brandt, P and Körtzinger, A and Fischer, G and Zantopp, R and Hahn, J and Visbeck, M and Wallace, D},
title = {Open ocean dead zones in the tropical North Atlantic Ocean},
journal = {Biogeosciences},
year = {2015},
volume = {12},
number = {8},
pages = {2597--2605},
url = {http://www.biogeosciences.net/12/2597/2015/},
doi = {10.5194/bg-12-2597-2015}
}
|
| Kilkki J, tuula Aalto, Hatakka J, harri Portin and tuomas Laurila (2015), "atmospheric co 2 observations at Finnish urban and rural sites" |
| Abstract: Kilkki J., aalto t., hatakka J., Portin h. & laurila t. 2015: atmospheric co 2 observations at Finnish urban and rural sites. Boreal Env. Res. 20: 227-242. Four new ground-based atmospheric monitoring stations in Finland were examined for local and large-scale signals in carbon dioxide mole fraction, and the results were compared with the corresponding values obtained from WMO/GAW site Pallas, northern Finland and NOAA/ESRL marine boundary layer reference time series. The measurements were filtered with knowledge of local weather and air composition. Periods of a presumably well-mixed boundary layer and relatively pollutant-free air were close to the Pallas time series in mole fraction, particularly in the winter. Wintertime mole fractions were 5-10 ppm higher than the signal in the marine boundary layer at all stations. The seasonal amplitude was 18-24 ppm, and diurnal amplitude was 0-3 ppm in winter and 3-20 ppm in the summer months. All stations, with the possible exception of the urban site in Helsinki, showed potential for observing a large-scale carbon dioxide signal. |
BibTeX:
@techreport{Kilkki2015,
author = {Kilkki, Juho and tuula Aalto and Hatakka, Juha and harri Portin and tuomas Laurila},
title = {atmospheric co 2 observations at Finnish urban and rural sites},
year = {2015},
url = {http://www.esrl.}
}
|
| Köchy M, Don A, Van Der Molen MK and Freibauer A (2015), "Global distribution of soil organic carbon – Part 2: Certainty of changes related to land use and climate", SOIL. Vol. 1(1), pp. 367-380. Copernicus GmbH. |
| Abstract: Global biosphere models vary greatly in their projections of future changes of global soil organic carbon (SOC) stocks and aggregated global SOC masses in response to climate change. We estimated the certainty (likelihood) and quantity of increases and decreases on a half-degree grid. We assessed the effect of changes in controlling factors, including net primary productivity (NPP), litter quality, soil acidity, water saturation, depth of permafrost, land use, temperature, and aridity associated with probabilities (Bayesian network) on an embedded, temporally discrete, three-pool decomposition model. In principle, controlling factors were discretized into classes, where each class was associated with a probability and linked to an output variable. This creates a network of links that are ultimately linked to a set of equations for carbon (C) input and output to and from soil C pools. The probability-weighted results show that, globally, climate effects on NPP had the strongest impact on SOC stocks and the certainty of change after 75 years. Actual land use had the greatest effect locally because the assumed certainty of land use change per unit area was small. The probability-weighted contribution of climate to decomposition was greatest in the humid tropics because of greater absolute effects on decomposition fractions at higher temperatures. In contrast, climate effects on decomposition fractions were small in cold regions. Differences in decomposition rates between contemporary and future climate were greatest in arid subtropical regions because of projected strong increases in precipitation. Warming in boreal and arctic regions increased NPP, balancing or outweighing potential losses from thawing of permafrost. Across contrasting NPP scenarios, tropical mountain forests were identified as hotspots of future highly certain C losses. Global soil C mass will increase by 1 % with a certainty of 75 % if NPP increases due to carbon dioxide fertilization. At a certainty level of 75 %, soil C mass will not change if CO2-induced increase of NPP is limited by nutrients. |
BibTeX:
@article{Kochy2015,
author = {Köchy, M. and Don, A. and Van Der Molen, M. K. and Freibauer, A.},
title = {Global distribution of soil organic carbon – Part 2: Certainty of changes related to land use and climate},
journal = {SOIL},
publisher = {Copernicus GmbH},
year = {2015},
volume = {1},
number = {1},
pages = {367--380},
doi = {10.5194/soil-1-367-2015}
}
|
| Kothawala DN, Ji X, Laudon H, Ågren AM, Futter MN, Köhler SJ and Tranvik LJ (2015), "The relative influence of land cover, hydrology, and in-stream processing on the composition of dissolved organic matter in boreal streams", Journal of Geophysical Research G: Biogeosciences., aug, 2015. Vol. 120(8), pp. 1491-1505. |
| Abstract: Low-order boreal streams are particularly sensitive interfaces where dissolved organic matter (DOM) is transported from soils to inland waters. Disentangling the relative influence of key environmental factors suspected to influence stream water DOM composition is highly relevant to predicting the reactivity and fate of terrestrial DOM entering inland waters. Here we examined changes to DOM composition using absorbance and fluorescence, from 17 boreal streams ranging from first to fourth orders, over 14 months, including the rarely studied winter season, and two snowmelt periods (n = 836). We also analyzed soil pore water samples from three forest soil lysimeters to a depth of 70 cm (n = 60). Of five identified fluorescing parallel factor analysis components, two (C4 and C5) expressed a clear mire wetland or forest signature, providing distinct molecular markers of dominant land cover. In fact, land cover alone explained 49% of the variability in DOM composition. In contrast, seasonal fluctuations in hydrology only contributed to minor shifts (8%) in the composition of stream water DOM, while in-stream transformations to DOM composition were undetectable. These findings suggest that low-order boreal streams act as a passive pipe, since in-stream processing of DOM is restricted by short water residence times (6 h to 2 days). In addition, we demonstrated the sensitivity of optical approaches to distinguish between key terrestrial sources of DOM in the boreal landscape. By distinguishing the proportional leverage of key environmental controls on headwater stream DOM composition, we are better equipped to predict where and when key DOM transformations occur in the aquatic conduit. Key Points Land cover has a dominating influence on the composition of stream DOM Hydrological controls on stream DOM composition are minor There was no evidence of in-stream transformations to DOM composition |
BibTeX:
@article{Kothawala2015,
author = {Kothawala, Dolly N and Ji, Xing and Laudon, Hjalmar and Ågren, Anneli M and Futter, Martyn N and Köhler, Stephan J and Tranvik, Lars J},
title = {The relative influence of land cover, hydrology, and in-stream processing on the composition of dissolved organic matter in boreal streams},
journal = {Journal of Geophysical Research G: Biogeosciences},
year = {2015},
volume = {120},
number = {8},
pages = {1491--1505},
url = {http://doi.wiley.com/10.1002/2015JG002946},
doi = {10.1002/2015JG002946}
}
|
| Kugler F, Lee SK, Hajnsek I and Papathanassiou KP (2015), "Forest Height Estimation by Means of Pol-InSAR Data Inversion: The Role of the Vertical Wavenumber", IEEE Transactions on Geoscience and Remote Sensing., oct, 2015. Vol. 53(10), pp. 5294-5311. |
| Abstract: This paper examines the multifaceted effect of the effective spatial baseline, as expressed through the vertical (interferometric) wavenumber, on the inversion of forest height from polarimetric interferometric synthetic aperture radar (Pol-InSAR) data. First, the role of the vertical wavenumber in relating forest height to the interferometric (volume) coherence is introduced. Through the review of the forest height inversion from Pol-InSAR data, the effect of the vertical wavenumber on the inversion performance is evaluated. The selection of optimum with respect to forest height inversion performance, vertical wavenumbers is discussed. The impact of the acquisition geometry and terrain slopes on the vertical wavenumber and their consideration in the inversion methodology is addressed. The individual effects discussed are demonstrated by means of airborne repeat pass Pol-InSAR acquisitions in L- and P-band acquired over different forest conditions, including a boreal, a temperate, and a tropical forest test site. The achieved forest height inversion performance is validated against reference height data derived from airborne LIDAR acquisitions. |
BibTeX:
@article{Kugler2015,
author = {Kugler, Florian and Lee, Seung Kuk and Hajnsek, Irena and Papathanassiou, Konstantinos P},
title = {Forest Height Estimation by Means of Pol-InSAR Data Inversion: The Role of the Vertical Wavenumber},
journal = {IEEE Transactions on Geoscience and Remote Sensing},
year = {2015},
volume = {53},
number = {10},
pages = {5294--5311},
url = {http://ieeexplore.ieee.org/document/7101230/},
doi = {10.1109/TGRS.2015.2420996}
}
|
| Kuglerova L, Jansson R, Sponseller RA, Laudon H and Malm-Renöfält B (2015), "Local and regional processes determine plant species richness in a river-network metacommunity", Ecology., feb, 2015. Vol. 96(2), pp. 381-391. |
| Abstract: River systems form dendritic ecological networks that influence the spatial structure of riverine communities. Few empirical studies have evaluated how regional, dispersal-related processes and local habitat factors interact to govern network patterns of species composition. We explore such interactions in a boreal watershed and show that riparian plant species richness increases strongly with drainage size, i.e., with downstream position in the network. Assemblage composition was nested, with new species successively added downstream. These spatial patterns in species composition were related to a combination of local and regional processes. Breadth in local habitat conditions increased downstream in the network, resulting in higher habitat heterogeneity and reduced niche overlap among species, which together with similar trends in disturbance, allows more species to coexist. Riparian edaphic conditions were also increasingly favorable to more species within the regional pool along larger streams, with greater nitrogen availability (manifested as lower C:N) and more rapid mineralization of C and N (as indicated by ratios of stable isotopes) observed with downstream position in the network. The number of species with the capacity for water dispersal increased with stream size, providing a mechanistic link between plant traits and the downstream accumulation of species as more propagules arrive from upstream sites. Similarity in species composition between sites was related to both geographical and environmental distance. Our results provide the first empirical evidence that position in the river network drives spatial patterns in riparian plant diversity and composition by the joint influence of local (disturbance, habitat conditions, and habitat breadth) and regional (dispersal) forces. |
BibTeX:
@article{Kuglerova2015,
author = {Kuglerova, Lenka and Jansson, Roland and Sponseller, Ryan A and Laudon, Hjalmar and Malm-Renöfält, Birgitta},
title = {Local and regional processes determine plant species richness in a river-network metacommunity},
journal = {Ecology},
year = {2015},
volume = {96},
number = {2},
pages = {381--391},
url = {http://doi.wiley.com/10.1890/14-0552.1},
doi = {10.1890/14-0552.1}
}
|
| Kurppa M, Nordbo A, Haapanala S and Järvi L (2015), "Effect of seasonal variability and land use on particle number and COtextlessinftextgreater2textless/inftextgreater exchange in Helsinki, Finland", Urban Climate., sep, 2015. Vol. 13, pp. 94-109. Elsevier. |
| Abstract: Turbulent fluxes of particle number and COtextlessinftextgreater2textless/inftextgreater were analysed in Helsinki between July 2011 and June 2013. The fluxes were measured using the eddy covariance method in a dense city centre and suburban location next to a large road allowing the study of the mutual connections of the two fluxes and their dependencies between different high intensity road traffic areas.In the city centre, the median particle (Ftextlessinftextgreaterptextless/inftextgreater) and COtextlessinftextgreater2textless/inftextgreater fluxes (Ftextlessinftextgreaterctextless/inftextgreater) were 0.18×10textlesssuptextgreater9textless/suptextgreatermtextlesssuptextgreater-2textless/suptextgreaterstextlesssuptextgreater-1textless/suptextgreater and 9.8μmolmtextlesssuptextgreater-2textless/suptextgreaterstextlesssuptextgreater-1textless/suptextgreater, and at the suburban site 0.17×10textlesssuptextgreater9textless/suptextgreatermtextlesssuptextgreater-2textless/suptextgreaterstextlesssuptextgreater-1textless/suptextgreater and 5.7μmolmtextlesssuptextgreater-2textless/suptextgreaterstextlesssuptextgreater-1textless/suptextgreater, respectively. Ftextlessinftextgreaterctextless/inftextgreater was larger in the city centre than at the suburban site whereas particles were emitted with a similar strength from a single large road as from the city centre. Ftextlessinftextgreaterptextless/inftextgreater had the largest net fluxes in winter and the smallest in summer, whereas seasonal variability in Ftextlessinftextgreaterctextless/inftextgreater was minor. Partly this can be explained by increasing particle emissions in colder temperatures. Also the different vertical transfer efficiency of the two scalars affects the different behaviour. This study demonstrates how the behaviour of two seemingly similar urban pollutants vary already at a kilometre scale and with different meteorological conditions. |
BibTeX:
@article{Kurppa2015,
author = {Kurppa, Mona and Nordbo, Annika and Haapanala, Sami and Järvi, Leena},
title = {Effect of seasonal variability and land use on particle number and COtextlessinftextgreater2textless/inftextgreater exchange in Helsinki, Finland},
journal = {Urban Climate},
publisher = {Elsevier},
year = {2015},
volume = {13},
pages = {94--109},
doi = {10.1016/j.uclim.2015.07.006}
}
|
| Kutsch WL and Kolari P (2015), "Data quality and the role of nutrients in forest carbon-use efficiency", Nature Climate Change., nov, 2015. Vol. 5(11), pp. 959-960. |
BibTeX:
@article{Kutsch2015,
author = {Kutsch, Werner L and Kolari, Pasi},
title = {Data quality and the role of nutrients in forest carbon-use efficiency},
journal = {Nature Climate Change},
year = {2015},
volume = {5},
number = {11},
pages = {959--960},
url = {http://www.nature.com/articles/nclimate2793},
doi = {10.1038/nclimate2793}
}
|
| Lam N, Nathanson M, Lundgren N, Rehnström R and Lyon SW (2015), "A Cost-Effective Laser Scanning Method for Mapping Stream Channel Geometry and Roughness", Journal of the American Water Resources Association., oct, 2015. Vol. 51(5), pp. 1211-1220. |
| Abstract: This brief pilot study implements a camera-based laser scanning system that potentially offers a viable, cost-effective alternative to traditional terrestrial laser scanning (TLS) and LiDAR equipment. We adapted a low-cost laser ranging system (SICK LSM111) to acquire area scans of the channel and bed for a temporarily diverted stream. The 5 m × 2 m study area was scanned at a 4 mm point spacing which resulted in a point cloud density of 5,600 points/m2. A local maxima search algorithm was applied to the point cloud and a grain size distribution of the stream bed was extracted. The 84th and 90th percentiles of this distribution, which are commonly used to characterize channel roughness, were 90 mm and 109 mm, respectively. Our example shows the system can resolve both large-scale geometry (e.g., bed slope and channel width) and small-scale roughness elements (e.g., grain sizes between about 30 and 255 mm) in an exposed stream channel thereby providing a resolution adequate for the estimation of ecohydraulic roughness parameters such as Manning's n. While more work is necessary to refine our specific field-deployable system's design, these initial results are promising in particular for those working on a limited or fixed budget. This opens up a realm of laser scanning applications and monitoring strategies for water resources that may not have been possible previously due to cost limitations associated with traditional TLS systems. |
BibTeX:
@article{Lam2015,
author = {Lam, Norris and Nathanson, Marcus and Lundgren, Niclas and Rehnström, Robin and Lyon, Steve W},
title = {A Cost-Effective Laser Scanning Method for Mapping Stream Channel Geometry and Roughness},
journal = {Journal of the American Water Resources Association},
year = {2015},
volume = {51},
number = {5},
pages = {1211--1220},
url = {http://doi.wiley.com/10.1111/1752-1688.12299},
doi = {10.1111/1752-1688.12299}
}
|
| Landschützer P, Gruber N, Haumann FA, Rödenbeck C, Bakker DCE, Van Heuven S, Hoppema M, Metzl N, Sweeney C, Takahashi T, Tilbrook B and Wanninkhof R (2015), "The reinvigoration of the Southern Ocean carbon sink", Science., sep, 2015. Vol. 349(6253), pp. 1221-1224. |
| Abstract: Several studies have suggested that the carbon sink in the Southern Ocean-the ocean's strongest region for the uptake of anthropogenic CO2-has weakened in recent decades. We demonstrated, on the basis of multidecadal analyses of surface ocean CO2 observations, that this weakening trend stopped around 2002, and by 2012 the Southern Ocean had regained its expected strength based on the growth of atmospheric CO2. All three Southern Ocean sectors have contributed to this reinvigoration of the carbon sink, yet differences in the processes between sectors exist, related to a tendency toward a zonally more asymmetric atmospheric circulation. The large decadal variations in the Southern Ocean carbon sink suggest a rather dynamic ocean carbon cycle that varies more in time than previously recognized. |
BibTeX:
@article{Landschutzer2015,
author = {Landschützer, Peter and Gruber, Nicolas and Haumann, F Alexander and Rödenbeck, Christian and Bakker, Dorothee C E and Van Heuven, Steven and Hoppema, Mario and Metzl, Nicolas and Sweeney, Colm and Takahashi, Taro and Tilbrook, Bronte and Wanninkhof, Rik},
title = {The reinvigoration of the Southern Ocean carbon sink},
journal = {Science},
year = {2015},
volume = {349},
number = {6253},
pages = {1221--1224},
url = {http://www.sciencemag.org/lookup/doi/10.1126/science.aab2620},
doi = {10.1126/science.aab2620}
}
|
| Langer M, Westermann S, Walter Anthony K, Wischnewski K and Boike J (2015), "Frozen ponds: Production and storage of methane during the Arctic winter in a lowland tundra landscape in northern Siberia, Lena River delta", Biogeosciences., feb, 2015. Vol. 12(4), pp. 977-990. |
| Abstract: Lakes and ponds play a key role in the carbon cycle of permafrost ecosystems, where they are considered to be hotspots of carbon dioxide CO2 and methane CH4 emission. The strength of these emissions is, however, controlled by a variety of physical and biogeochemical processes whose responses to a warming climate are complex and only poorly understood. Small waterbodies have been attracting an increasing amount of attention since recent studies demonstrated that ponds can make a significant contribution to the CO2 and CH4emissions of tundra ecosystems. Waterbodies also have a marked effect on the thermal state of the surrounding permafrost; during the freezing period they prolong the period of time during which thawed soil material is available for microbial decomposition. This study presents net CH4 production rates during the freezing period from ponds within a typical lowland tundra landscape in northern Siberia. Rate estimations were based on CH4 concentrations measured in surface lake ice from a variety of waterbody types. Vertical profiles along ice blocks showed an exponential increase in CH4 concentration with depth. These CH4 profiles were reproduced by a 1-D mass balance model and the net CH4 production rates were then inferred through inverse modeling. Results revealed marked differences in early winter net CH4 production among various ponds. Ponds situated within intact polygonal ground structures yielded low net production rates, of the order of 10-11 to 10-10 mol m-2 s-1 (0.01 to 0.14 mgCH4 m-2 day-1). In contrast, ponds exhibiting clear signs of erosion yielded net CH4 production rates of the order of 10-7 mol m-2 s-1 (140 mg CH4 m-2 day-1). Our results therefore indicate that once a particular threshold in thermal erosion has been crossed, ponds can develop into major CH4 sources. This implies that any future warming of the climate may result in nonlinear CH4 emission behavior in tundra ecosystems. |
BibTeX:
@article{Langer2015,
author = {Langer, M and Westermann, S and Walter Anthony, K and Wischnewski, K and Boike, J},
title = {Frozen ponds: Production and storage of methane during the Arctic winter in a lowland tundra landscape in northern Siberia, Lena River delta},
journal = {Biogeosciences},
year = {2015},
volume = {12},
number = {4},
pages = {977--990},
url = {http://www.biogeosciences.net/12/977/2015/},
doi = {10.5194/bg-12-977-2015}
}
|
| Langford B, Acton W, Ammann C, Valach A and Nemitz E (2015), "Eddy-covariance data with low signal-to-noise ratio: Time-lag determination, uncertainties and limit of detection", Atmospheric Measurement Techniques. Vol. 8(10), pp. 4197-4213. |
| Abstract: All eddy-covariance flux measurements are associated with random uncertainties which are a combination of sampling error due to natural variability in turbulence and sensor noise. The former is the principal error for systems where the signal-to-noise ratio of the analyser is high, as is usually the case when measuring fluxes of heat, CO2 or H2O. Where signal is limited, which is often the case for measurements of other trace gases and aerosols, instrument uncertainties dominate. Here, we are applying a consistent approach based on auto- and cross-covariance functions to quantify the total random flux error and the random error due to instrument noise separately. As with previous approaches, the random error quantification assumes that the time lag between wind and concentration measurement is known. However, if combined with commonly used automated methods that identify the individual time lag by looking for the maximum in the cross-covariance function of the two entities, analyser noise additionally leads to a systematic bias in the fluxes. Combining data sets from several analysers and using simulations, we show that the method of time-lag determination becomes increasingly important as the magnitude of the instrument error approaches that of the sampling error. The flux bias can be particularly significant for disjunct data, whereas using a prescribed time lag eliminates these effects (provided the time lag does not fluctuate unduly over time). We also demonstrate that when sampling at higher elevations, where low frequency turbulence dominates and covariance peaks are broader, both the probability and magnitude of bias are magnified. We show that the statistical significance of noisy flux data can be increased (limit of detection can be decreased) by appropriate averaging of individual fluxes, but only if systematic biases are avoided by using a prescribed time lag. Finally, we make recommendations for the analysis and reporting of data with low signal-to-noise and their associated errors. |
BibTeX:
@article{Langford2015,
author = {Langford, B and Acton, W and Ammann, C and Valach, A and Nemitz, E},
title = {Eddy-covariance data with low signal-to-noise ratio: Time-lag determination, uncertainties and limit of detection},
journal = {Atmospheric Measurement Techniques},
year = {2015},
volume = {8},
number = {10},
pages = {4197--4213},
doi = {10.5194/amt-8-4197-2015}
}
|
| Lauvset SK, Gruber N, Landschützer P, Olsen A and Tjiputra J (2015), "Trends and drivers in global surface ocean pH over the past 3 decades", Biogeosciences., mar, 2015. Vol. 12(5), pp. 1285-1298. Copernicus GmbH. |
| Abstract: textlessptextgreaterAbstract. We report global long-term trends in surface ocean pH using a new pH data set computed by combining fCO2 observations from the Surface Ocean CO2 Atlas (SOCAT) version 2 with surface alkalinity estimates based on temperature and salinity. Trends were determined over the periods 1981–2011 and 1991–2011 for a set of 17 biomes using a weighted linear least squares method. We observe significant decreases in surface ocean pH in ˜70% of all biomes and a mean rate of decrease of 0.0018 ± 0.0004 yr−1 for 1991–2011. We are not able to calculate a global trend for 1981–2011 because too few biomes have enough data for this. In half the biomes, the rate of change is commensurate with the trends expected based on the assumption that the surface ocean pH change is only driven by the surface ocean CO2 chemistry remaining in a transient equilibrium with the increase in atmospheric CO2. In the remaining biomes, deviations from such equilibrium may reflect that the trend of surface ocean fCO2 is not equal to that of the atmosphere, most notably in the equatorial Pacific Ocean, or may reflect changes in the oceanic buffer (Revelle) factor. We conclude that well-planned and long-term sustained observational networks are key to reliably document the ongoing and future changes in ocean carbon chemistry due to anthropogenic forcing.textless/ptextgreater |
BibTeX:
@article{Lauvset2015,
author = {Lauvset, S. K. and Gruber, N. and Landschützer, P. and Olsen, A. and Tjiputra, J.},
title = {Trends and drivers in global surface ocean pH over the past 3 decades},
journal = {Biogeosciences},
publisher = {Copernicus GmbH},
year = {2015},
volume = {12},
number = {5},
pages = {1285--1298},
url = {https://bg.copernicus.org/articles/12/1285/2015/},
doi = {10.5194/bg-12-1285-2015}
}
|
| Lebegue B, Schmidt M, Ramonet M, Wastine B, Yver Kwok C, Laurent O, Belviso S, Guemri A, Philippon C, Smith J, Conil S, Jost HJ and Crosson ER (2015), " Comparison of nitrous oxide (N 2 O) analyzers for high-precision measurements of atmospheric mole fractions ", Atmospheric Measurement Techniques Discussions., oct, 2015. Vol. 8(10), pp. 10937-10982. |
| Abstract: Abstract. Over the last few decades, in-situ measurements of atmospheric N2O mole fractions have been performed using gas chromatographs (GCs) equipped with electron capture detectors (ECDs). When trying to meet the World Meteorological Organization's (WMO) quality goal, this technique becomes very challenging as the detectors are highly non-linear and the GCs at remote stations require a considerable amount of maintenance by qualified technicians to maintain good short-term and long-term repeatability. With more robust optical spectrometers being now available for N2O measurements, we aim to identify a robust and stable analyzer that can be integrated into atmospheric monitoring networks, such as the Integrated Carbon Observation System (ICOS). In this study, we tested seven analyzers that were developed and commercialized from five different companies and compared the results with established techniques. Each instrument was characterized during a time period of approximately eight weeks. The test protocols included the characterization of the short-term and long-term repeatability, drift, temperature dependence, linearity and sensitivity to water vapor. During the test period, ambient air measurements were compared under field conditions at the Gif-sur-Yvette station. All of the analyzers showed a standard deviation better than 0.1 ppb for the 10 min averages. Some analyzers would benefit from improvements in temperature stability to reduce the instrument drift, which could then help in reducing the frequency of calibrations. For most instruments, the water vapor correction algorithms applied by companies are not sufficient for high-precision atmospheric measurements, which results in the need to dry the ambient air prior to analysis. |
BibTeX:
@article{Lebegue2015,
author = {Lebegue, B and Schmidt, M and Ramonet, M and Wastine, B and Yver Kwok, C and Laurent, O and Belviso, S and Guemri, A and Philippon, C and Smith, J and Conil, S and Jost, H J and Crosson, E R},
title = { Comparison of nitrous oxide (N 2 O) analyzers for high-precision measurements of atmospheric mole fractions },
journal = {Atmospheric Measurement Techniques Discussions},
year = {2015},
volume = {8},
number = {10},
pages = {10937--10982},
url = {http://www.atmos-meas-tech-discuss.net/8/10937/2015/},
doi = {10.5194/amtd-8-10937-2015}
}
|
| Ledesma JLJ, Grabs T, Bishop KH, Schiff SL and Köhler SJ (2015), "Potential for long-term transfer of dissolved organic carbon from riparian zones to streams in boreal catchments", Global Change Biology., aug, 2015. Vol. 21(8), pp. 2963-2979. |
| Abstract: Boreal regions store most of the global terrestrial carbon, which can be transferred as dissolved organic carbon (DOC) to inland waters with implications for both aquatic ecology and carbon budgets. Headwater riparian zones (RZ) are important sources of DOC, and often just a narrow 'dominant source layer' (DSL) within the riparian profile is responsible for most of the DOC export. Two important questions arise: how long boreal RZ could sustain lateral DOC fluxes as the sole source of exported carbon and how its hydromorphological variability influences this role. We estimate theoretical turnover times by comparing carbon pools and lateral exports in the DSL of 13 riparian profiles distributed over a 69 kmsup2/sup catchment in northern Sweden. The thickness of the DSL was 36 ± 18 (average ± SD) cm. Thus, only about one-third of the 1-m-deep riparian profile contributed 90% of the lateral DOC flux. The 13 RZ exported 8.7 ± 6.5 g C msup-2/sup yearsup-1/sup, covering the whole range of boreal stream DOC exports. The variation could be explained by local hydromorphological characteristics including RZ width (Rsup2/sup = 0.90). The estimated theoretical turnover times were hundreds to a few thousands of years, that is there is a potential long-lasting supply of DOC. Estimates of net ecosystem production in the RZ suggest that lateral fluxes, including both organic and inorganic C, could be maintained without drawing down the riparian pools. This was supported by measurements of stream DOsup14/supC that indicated modern carbon as the predominant fraction exported, including streams disturbed by ditching. The transfer of DOC into boreal inland waters from new and old carbon sources has a major influence on surface water quality and global carbon balances. This study highlights the importance of local variations in RZ hydromorphology and DSL extent for future DOC fluxes under a changing climate. |
BibTeX:
@article{Ledesma2015,
author = {Ledesma, José L J and Grabs, Thomas and Bishop, Kevin H and Schiff, Sherry L and Köhler, Stephan J},
title = {Potential for long-term transfer of dissolved organic carbon from riparian zones to streams in boreal catchments},
journal = {Global Change Biology},
year = {2015},
volume = {21},
number = {8},
pages = {2963--2979},
url = {http://doi.wiley.com/10.1111/gcb.12872},
doi = {10.1111/gcb.12872}
}
|
| Legge OJ, Bakker DCE, Johnson MT, Meredith MP, Venables HJ, Brown PJ and Lee GA (2015), "The seasonal cycle of ocean-atmosphere CO textlesssubtextgreater2textless/subtextgreater flux in Ryder Bay, west Antarctic Peninsula", Geophysical Research Letters., apr, 2015. Vol. 42(8), pp. 2934-2942. Blackwell Publishing Ltd. |
| Abstract: Approximately 15 million km2 of the Southern Ocean is seasonally ice covered, yet the processes affecting carbon cycling and gas exchange in this climatically important region remain inadequately understood. Here, 3 years of dissolved inorganic carbon (DIC) measurements and carbon dioxide (CO2) fluxes from Ryder Bay on the west Antarctic Peninsula (WAP) are presented. During spring and summer, primary production in the surface ocean promotes atmospheric CO2 uptake. In winter, higher DIC, caused by net heterotrophy and vertical mixing with Circumpolar Deep Water, results in outgassing of CO2 from the ocean. Ryder Bay is found to be a net sink of atmospheric CO2 of 0.59-0.94 mol Cm-2 yr-1 (average of 3 years). Seasonal sea ice cover increases the net annual CO2 uptake, but its effect on gas exchange remains poorly constrained. A reduction in sea ice on the WAP shelf may reduce the strength of the oceanic CO2 sink in this region. |
BibTeX:
@article{Legge2015,
author = {Legge, Oliver J. and Bakker, Dorothee C. E. and Johnson, Martin T. and Meredith, Michael P. and Venables, Hugh J. and Brown, Peter J. and Lee, Gareth A.},
title = {The seasonal cycle of ocean-atmosphere CO textlesssubtextgreater2textless/subtextgreater flux in Ryder Bay, west Antarctic Peninsula},
journal = {Geophysical Research Letters},
publisher = {Blackwell Publishing Ltd},
year = {2015},
volume = {42},
number = {8},
pages = {2934--2942},
url = {http://doi.wiley.com/10.1002/2015GL063796},
doi = {10.1002/2015GL063796}
}
|
| Leith FI, Dinsmore KJ, Wallin MB, Billett MF, Heal KV, Laudon H, Öquist MG and Bishop K (2015), "Carbon dioxide transport across the hillslope-riparian-stream continuum in a boreal headwater catchment", Biogeosciences., mar, 2015. Vol. 12(6), pp. 1881-1902. |
| Abstract: Headwater streams export COinf2/inf as lateral downstream export and vertical evasion from the stream surface. COinf2/inf in boreal headwater streams generally originates from adjacent terrestrial areas, so determining the sources and rate of COinf2/inf transport along the hillslope-riparian-stream continuum could improve estimates of COinf2/inf export via the aquatic pathway, especially by quantifying evasion at higher temporal resolutions. Continuous measurements of dissolved COinf2/inf concentrations and water table were made along the hillslope-riparian-stream continuum in the Västrabäcken sub-catchment of the Krycklan catchment, Sweden. Daily water and COinf2/inf export from the hillslope and riparian zone were estimated over one hydrological year (October 2012-September 2013) using a flow-concentration model and compared with measured lateral downstream COinf2/inf export. Total water export over the hydrological year from the hillslope was 230 mm yrsup-1/sup compared with 270 mm yrsup-1/sup from the riparian zone. This corresponds well (proportional to the relative upslope contributing area) to the annual catchment runoff of 265 mm yrsup-1/sup. Total COinf2/inf export from the riparian zone to the stream was 3.0 g COinf2/inf-C msup-2/sup yrsup-1/sup. A hotspot for riparian COinf2/inf export was observed at 30-50 cm depth (accounting for 71 % of total riparian export). Seasonal variability was high with export peaks during the spring flood and autumn storm events. Downstream lateral COinf2/inf export (determined from stream water dissolved COinf2/inf concentrations and discharge) was 1.2 g COinf2/inf-C msup-2/sup yrsup-1/sup. Subtracting downstream lateral export from riparian export (3.0 g COinf2/inf-C msup-2/sup yrsup-1/sup) gives 1.8 g COinf2/inf-C msup-2/sup yrsup-1/sup which can be attributed to evasion losses (accounting for 60 % of export via the aquatic pathway). The results highlight the importance of terrestrial COinf2/inf export, especially from the riparian zone, for determining catchment aquatic COinf2/inf losses and the importance of the COinf2/inf evasion component to carbon export via the aquatic conduit. |
BibTeX:
@article{Leith2015,
author = {Leith, F I and Dinsmore, K J and Wallin, M B and Billett, M F and Heal, K V and Laudon, H and Öquist, M G and Bishop, K},
title = {Carbon dioxide transport across the hillslope-riparian-stream continuum in a boreal headwater catchment},
journal = {Biogeosciences},
year = {2015},
volume = {12},
number = {6},
pages = {1881--1902},
url = {https://www.biogeosciences.net/12/1881/2015/},
doi = {10.5194/bg-12-1881-2015}
}
|
| Le Quéré C, Moriarty R, Andrew RM, Canadell JG, Sitch S, Korsbakken JI, Friedlingstein P, Peters GP, Andres RJ, Boden TA, Houghton RA, House JI, Keeling RF, Tans P, Arneth A, Bakker DCE, Barbero L, Bopp L, Chang J, Chevallier F, Chini LP, Ciais P, Fader M, Feely RA, Gkritzalis T, Harris I, Hauck J, Ilyina T, Jain AK, Kato E, Kitidis V, Klein Goldewijk K, Koven C, Landschützer P, Lauvset SK, Lefèvre N, Lenton A, Lima ID, Metzl N, Millero F, Munro DR, Murata A, S. Nabel JEM, Nakaoka S, Nojiri Y, O'Brien K, Olsen A, Ono T, Pérez FF, Pfeil B, Pierrot D, Poulter B, Rehder G, Rödenbeck C, Saito S, Schuster U, Schwinger J, Séférian R, Steinhoff T, Stocker BD, Sutton AJ, Takahashi T, Tilbrook B, Van Der Laan-Luijkx IT, Van Der Werf GR, Van Heuven S, Vandemark D, Viovy N, Wiltshire A, Zaehle S and Zeng N (2015), "Global Carbon Budget 2015", Earth System Science Data., dec, 2015. Vol. 7(2), pp. 349-396. |
| Abstract: Accurate assessment of anthropogenic carbon dioxide (CO2) emissions and their redistribution among the atmosphere, ocean, and terrestrial biosphere is important to better understand the global carbon cycle, support the development of climate policies, and project future climate change. Here we describe data sets and a methodology to quantify all major components of the global carbon budget, including their uncertainties, based on the combination of a range of data, algorithms, statistics, and model estimates and their interpretation by a broad scientific community. We discuss changes compared to previous estimates as well as consistency within and among components, alongside methodology and data limitations. CO2 emissions from fossil fuels and industry (iE/iFF) are based on energy statistics and cement production data, while emissions from land-use change (iE/iLUC), mainly deforestation, are based on combined evidence from land-cover-change data, fire activity associated with deforestation, and models. The global atmospheric CO2 concentration is measured directly and its rate of growth (iG/iATM) is computed from the annual changes in concentration. The mean ocean CO2 sink (iS/iOCEAN) is based on observations from the 1990s, while the annual anomalies and trends are estimated with ocean models. The variability in iS/iOCEAN is evaluated with data products based on surveys of ocean CO2 measurements. The global residual terrestrial CO2 sink (iS/iLAND) is estimated by the difference of the other terms of the global carbon budget and compared to results of independent dynamic global vegetation models forced by observed climate, CO2, and land-cover change (some including nitrogen-carbon interactions). We compare the mean land and ocean fluxes and their variability to estimates from three atmospheric inverse methods for three broad latitude bands. All uncertainties are reported as ±1&sigma;, reflecting the current capacity to characterise the annual estimates of each component of the global carbon budget. For the last decade available (2005-2014), iE/iFF was 9.0 ± 0.5 GtC yrg'1, iE/iLUC was 0.9 ± 0.5 GtC yrg'1, iG/iATM was 4.4 ± 0.1 GtC yrg'1, iS/iOCEAN was 2.6 ± 0.5 GtC yrg'1, and iS/iLAND was 3.0 ± 0.8 GtC yrg'1. For the year 2014 alone, iE/iFF grew to 9.8 ± 0.5 GtC yrg'1, 0.6 % above 2013, continuing the growth trend in these emissions, albeit at a slower rate compared to the average growth of 2.2 % yrg'1 that took place during 2005-2014. Also, for 2014, iE/iLUC was 1.1 ± 0.5 GtC yrg'1, iG/iATM was 3.9 ± 0.2 GtC yrg'1, iS/iOCEAN was 2.9 ± 0.5 GtC yrg'1, and iS/iLAND was 4.1 ± 0.9 GtC yrg'1. iG/iATM was lower in 2014 compared to the past decade (2005-2014), reflecting a larger iS/iLAND for that year. The global atmospheric CO2 concentration reached 397.15 ± 0.10 ppm averaged over 2014. For 2015, preliminary data indicate that the growth in iE/iFF will be near or slightly below zero, with a projection of g'0.6 [range of g'1.6 to +0.5] %, based on national emissions projections for China and the USA, and projections of gross domestic product corrected for recent changes in the carbon intensity of the global economy for the rest of the world. From this projection of iE/iFF and assumed constant iE/iLUC for 2015, cumulative emissions of CO2 will reach about 555 ± 55 GtC (2035 ± 205 GtCO2) for 1870-2015, about 75 % from iE/iFF and 25 % from iE/iLUC. This living data update documents changes in the methods and data sets used in this new carbon budget compared with previous publications of this data set (Le Quéré et al., 2015, 2014, 2013). All observations presented here can be downloaded from the Carbon Dioxide Information Analysis Center (a hrefCombining double low line"http://dx.doi.org/10.3334/CDIAC/GCP-2015"doi:10.3334/CDIAC/GCP-2015/a). |
BibTeX:
@article{LeQuere2015,
author = {Le Quéré, C and Moriarty, R and Andrew, R M and Canadell, J G and Sitch, S and Korsbakken, J I and Friedlingstein, P and Peters, G P and Andres, R J and Boden, T A and Houghton, R A and House, J I and Keeling, R F and Tans, P and Arneth, A and Bakker, D C E and Barbero, L and Bopp, L and Chang, J and Chevallier, F and Chini, L P and Ciais, P and Fader, M and Feely, R A and Gkritzalis, T and Harris, I and Hauck, J and Ilyina, T and Jain, A K and Kato, E and Kitidis, V and Klein Goldewijk, K and Koven, C and Landschützer, P and Lauvset, S K and Lefèvre, N and Lenton, A and Lima, I D and Metzl, N and Millero, F and Munro, D R and Murata, A and S. Nabel, J E M and Nakaoka, S and Nojiri, Y and O'Brien, K and Olsen, A and Ono, T and Pérez, F F and Pfeil, B and Pierrot, D and Poulter, B and Rehder, G and Rödenbeck, C and Saito, S and Schuster, U and Schwinger, J and Séférian, R and Steinhoff, T and Stocker, B D and Sutton, A J and Takahashi, T and Tilbrook, B and Van Der Laan-Luijkx, I T and Van Der Werf, G R and Van Heuven, S and Vandemark, D and Viovy, N and Wiltshire, A and Zaehle, S and Zeng, N},
title = {Global Carbon Budget 2015},
journal = {Earth System Science Data},
year = {2015},
volume = {7},
number = {2},
pages = {349--396},
url = {http://www.earth-syst-sci-data.net/7/349/2015/},
doi = {10.5194/essd-7-349-2015}
}
|
| Le Quéré C, Moriarty R, Andrew RM, Peters GP, Ciais P, Friedlingstein P, Jones SD, Sitch S, Tans P, Arneth A, Boden TA, Bopp L, Bozec Y, Séférian R, Segschneider J, Steinhoff T, Stocker BD, Sutton AJ, Takahashi T, Tilbrook B, Van Der Werf GR, Viovy N, Wang Y-P, Wanninkhof R, Wiltshire A and Zeng N (2015), "Global carbon budget 2014", Earth Syst. Sci. Data. Vol. 7, pp. 20. |
| Abstract: Accurate assessment of anthropogenic carbon dioxide (CO 2) emissions and their redistribution among the atmosphere, ocean, and terrestrial biosphere is important to better understand the global carbon cycle, support the development of climate policies, and project future climate change. Here we describe data sets and a methodology to quantify all major components of the global carbon budget, including their uncertainties , based on the combination of a range of data, algorithms, statistics, and model estimates and their interpretation by a broad scientific community. We discuss changes compared to previous estimates, consistency within and among components, alongside methodology and data limitations. CO 2 emissions from fossil Earth Syst. Sci. Data, 7, 47-85, 2015 www.earth-syst-sci-data.net/7/47/2015/ C. Le Quéré et al.: Global carbon budget 2014 49 fuel combustion and cement production (E FF) are based on energy statistics and cement production data, respectively , while emissions from land-use change (E LUC), mainly deforestation, are based on combined evidence from land-cover-change data, fire activity associated with deforestation, and models. The global atmospheric CO 2 concentration is measured directly and its rate of growth (G ATM) is computed from the annual changes in concentration. The mean ocean CO 2 sink (S OCEAN) is based on observations from the 1990s, while the annual anomalies and trends are estimated with ocean models. The variability in S OCEAN is evaluated with data products based on surveys of ocean CO 2 measurements. The global residual terrestrial CO 2 sink (S LAND) is estimated by the difference of the other terms of the global carbon budget and compared to results of independent dynamic global vegetation models forced by observed climate, CO 2 , and land-cover-change (some including nitrogen-carbon interactions). We compare the mean land and ocean fluxes and their variability to estimates from three atmospheric inverse methods for three broad latitude bands. All uncertainties are reported as ±1σ , reflecting the current capacity to characterise the annual estimates of each component of the global carbon budget. For the last decade available (2004-2013), E FF was 8.9 ± 0.4 GtC yr −1 , E LUC 0.9 ± 0.5 GtC yr −1 , G ATM 4.3 ± 0.1 GtC yr −1 , S OCEAN 2.6 ± 0.5 GtC yr −1 , and S LAND 2.9 ± 0.8 GtC yr −1. For year 2013 alone, E FF grew to 9.9 ± 0.5 GtC yr −1 , 2.3 % above 2012, continuing the growth trend in these emissions , E LUC was 0.9 ± 0.5 GtC yr −1 , G ATM was 5.4 ± 0.2 GtC yr −1 , S OCEAN was 2.9 ± 0.5 GtC yr −1 , and S LAND was 2.5 ± 0.9 GtC yr −1. G ATM was high in 2013, reflecting a steady increase in E FF and smaller and opposite changes between S OCEAN and S LAND compared to the past decade (2004-2013). The global atmospheric CO 2 concentration reached 395.31 ± 0.10 ppm averaged over 2013. We estimate that E FF will increase by 2.5 % (1.3-3.5 %) to 10.1 ± 0.6 GtC in 2014 (37.0 ± 2.2 GtCO 2 yr −1), 65 % above emissions in 1990, based on projections of world gross domestic product and recent changes in the carbon intensity of the global economy. From this projection of E FF and assumed constant E LUC for 2014, cumulative emissions of CO 2 will reach about 545 ± 55 GtC (2000 ± 200 GtCO 2) for 1870-2014, about 75 % from E FF and 25 % from E LUC . |
BibTeX:
@article{LeQuere2015a,
author = {Le Quéré, C and Moriarty, R and Andrew, R M and Peters, G P and Ciais, P and Friedlingstein, P and Jones, S D and Sitch, S and Tans, P and Arneth, A and Boden, T A and Bopp, L and Bozec, Y and Séférian, R and Segschneider, J and Steinhoff, T and Stocker, B D and Sutton, A J and Takahashi, T and Tilbrook, B and Van Der Werf, G R and Viovy, N and Wang, Y.-P and Wanninkhof, R and Wiltshire, A and Zeng, N},
title = {Global carbon budget 2014},
journal = {Earth Syst. Sci. Data},
year = {2015},
volume = {7},
pages = {20},
url = {www.earth-syst-sci-data.net/7/47/2015/},
doi = {10.5194/essd-7-47-2015}
}
|
| Li T, Zhang W, Zhang Q, Lu Y, Wang G, Niu Z, Raivonen M and Vesala T (2015), "Impacts of climate and reclamation on temporal variations in CH4 emissions from different wetlands in China: From 1950 to 2010", Biogeosciences., dec, 2015. Vol. 12(23), pp. 6853-6868. Copernicus GmbH. |
| Abstract: Natural wetlands are among the most important sources of atmospheric methane and thus important for better understanding the long-term temporal variations in the atmospheric methane concentration. During the last 60 years, wetlands have experienced extensive conversion and impacts from climate warming which might result in complicated temporal and spatial variations in the changes of the wetland methane emissions. In this paper, we present a modeling framework, integrating CH4MODwetland, TOPMODEL, and TEM models, to analyze the temporal and spatial variations in CH4 emissions from natural wetlands (including inland marshes/swamps, coastal wetlands, lakes, and rivers) in China. Our analysis revealed a total increase of 25.5 %, averaging 0.52 g mg'2 per decade, in the national CH4 fluxes from 1950 to 2010, which was mainly induced by climate warming. Larger CH4 flux increases occurred in northeastern, northern, and northwestern China, where there have been higher temperature rises. However, decreases in precipitation due to climate warming offset the increment of CH4 fluxes in these regions. The CH4 fluxes from the wetland on the Qinghai-Tibet Plateau exhibited the lowest CH4 increase (0.17 g mg'2 per decade). Although climate warming has accelerated CH4 fluxes, the total amount of national CH4 emissions decreased by approximately 2.35 Tg (1.91-2.81 Tg), i.e., from 4.50 Tg in the early 1950s to 2.15 Tg in the late 2000s, due to the wetland loss totalling 17.0 million ha. Of this reduction, 0.26 Tg (0.24-0.28 Tg) was derived from lakes and rivers, 0.16 Tg (0.13-0.20 Tg) from coastal wetlands, and 1.92 Tg (1.54-2.33 Tg) from inland wetlands. Spatially, northeastern China contributed the most to the total reduction, with a loss of 1.68 Tg. The wetland CH4 emissions reduced by more than half in most regions in China except for the Qinghai-Tibet Plateau, where the CH4 decrease was only 23.3 %. |
BibTeX:
@article{Li2015,
author = {Li, T. and Zhang, W. and Zhang, Q. and Lu, Y. and Wang, G. and Niu, Z. and Raivonen, M. and Vesala, T.},
title = {Impacts of climate and reclamation on temporal variations in CH4 emissions from different wetlands in China: From 1950 to 2010},
journal = {Biogeosciences},
publisher = {Copernicus GmbH},
year = {2015},
volume = {12},
number = {23},
pages = {6853--6868},
doi = {10.5194/bg-12-6853-2015}
}
|
| Lin X, Indira NK, Ramonet M, Delmotte M, Ciais P, Bhatt BC, Reddy MV, Angchuk D, Balakrishnan S, Jorphail S, Dorjai T, Mahey TT, Patnaik S, Begum M, Brenninkmeijer C, Durairaj S, Kirubagaran R, Schmidt M, Swathi PS, Vinithkumar NV, Yver Kwok C and Gaur VK (2015), "Long-lived atmospheric trace gases measurements in flask samples from three stations in India", Atmospheric Chemistry and Physics., sep, 2015. Vol. 15(17), pp. 9819-9849. |
| Abstract: With the rapid growth in population and economic development, emissions of greenhouse gases (GHGs) from the Indian subcontinent have sharply increased during recent decades. However, evaluation of regional fluxes of GHGs and characterization of their spatial and temporal variations by atmospheric inversions remain uncertain due to a sparse regional atmospheric observation network. As a result of an Indo-French collaboration, three new atmospheric stations were established in India at Hanle (HLE), Pondicherry (PON) and Port Blair (PBL), with the objective of monitoring the atmospheric concentrations of GHGs and other trace gases. Here we present the results of the measurements of CO2, CH4, N2O, SF6, CO, and H2 from regular flask sampling at these three stations over the period 2007-2011. For each species, annual means, seasonal cycles and gradients between stations were calculated and related to variations in natural GHG fluxes, anthropogenic emissions, and monsoon circulations. Covariances between species at the synoptic scale were analyzed to investigate the likely source(s) of emissions. The flask measurements of various trace gases at the three stations have the potential to constrain the inversions of fluxes over southern and northeastern India. However, this network of ground stations needs further extension to other parts of India to better constrain the GHG budgets at regional and continental scales. |
BibTeX:
@article{Lin2015,
author = {Lin, X and Indira, N K and Ramonet, M and Delmotte, M and Ciais, P and Bhatt, B C and Reddy, M V and Angchuk, D and Balakrishnan, S and Jorphail, S and Dorjai, T and Mahey, T T and Patnaik, S and Begum, M and Brenninkmeijer, C and Durairaj, S and Kirubagaran, R and Schmidt, M and Swathi, P S and Vinithkumar, N V and Yver Kwok, C and Gaur, V K},
title = {Long-lived atmospheric trace gases measurements in flask samples from three stations in India},
journal = {Atmospheric Chemistry and Physics},
year = {2015},
volume = {15},
number = {17},
pages = {9819--9849},
url = {http://www.atmos-chem-phys.net/15/9819/2015/},
doi = {10.5194/acp-15-9819-2015}
}
|
| Lindfors L, Hölttä T, Lintunen A, Porcar-Castell A, Nikinmaa E and Juurola E (2015), "Dynamics of leaf gas exchange, chlorophyll fluorescence and stem diameter changes during freezing and thawing of Scots pine seedlings", Tree Physiology., jun, 2015. Vol. 35(12), pp. 1314-1324. Oxford University Press. |
| Abstract: Boreal trees experience repeated freeze-thaw cycles annually. While freezing has been extensively studied in trees, the dynamic responses occurring during the freezing and thawing remain poorly understood. At freezing and thawing, rapid changes take place in the water relations of living cells in needles and in stem. While freezing is mostly limited to extracellular spaces, living cells dehydrate, shrink and their osmotic concentration increases. We studied how the freezing-thawing dynamics reflected on leaf gas exchange, chlorophyll fluorescence and xylem and living bark diameter changes of Scots pine (Pinus sylvestris L.) saplings in controlled experiments. Photosynthetic rate quickly declined following ice nucleation and extracellular freezing in xylem and needles, almost parallel to a rapid shrinking of xylem diameter, while that of living bark followed with a slightly longer delay. While xylem and living bark diameters responded well to decreasing temperature and water potential of ice, the relationship was less consistent in the case of increasing temperature. Xylem showed strong temporal swelling at thawing suggesting water movement from bark. After thawing xylem diameter recovered to a pre-freezing level but living bark remained shrunk. We found that freezing affected photosynthesis at multiple levels. The distinct dynamics of photosynthetic rate and stomatal conductance reveals that the decreased photosynthetic rate reflects impaired dark reactions rather than stomatal closure. Freezing also inhibited the capacity of the light reactions to dissipate excess energy as heat, via non-photochemical quenching, whereas photochemical quenching of excitation energy decreased gradually with temperature in agreement with the gas exchange data. |
BibTeX:
@article{Lindfors2015,
author = {Lindfors, Lauri and Hölttä, Teemu and Lintunen, Anna and Porcar-Castell, Albert and Nikinmaa, Eero and Juurola, Eija},
title = {Dynamics of leaf gas exchange, chlorophyll fluorescence and stem diameter changes during freezing and thawing of Scots pine seedlings},
journal = {Tree Physiology},
publisher = {Oxford University Press},
year = {2015},
volume = {35},
number = {12},
pages = {1314--1324},
doi = {10.1093/treephys/tpv095}
}
|
| Lindqvist H, O'Dell CW, Basu S, Boesch H, Chevallier F, Deutscher N, Feng L, Fisher B, Hase F, Inoue M, Kivi R, Morino I, Palmer PI, Parker R, Schneider M, Sussmann R and Yoshida Y (2015), "Does GOSAT capture the true seasonal cycle of carbon dioxide?", Atmospheric Chemistry and Physics., nov, 2015. Vol. 15(22), pp. 13023-13040. |
| Abstract: The seasonal cycle accounts for a dominant mode of total column CO2 (XCO2) annual variability and is connected to CO2 uptake and release; it thus represents an important quantity to test the accuracy of the measurements from space. We quantitatively evaluate the XCO2 seasonal cycle of the Greenhouse Gases Observing Satellite (GOSAT) observations from the Atmospheric CO2 Observations from Space (ACOS) retrieval system and compare average regional seasonal cycle features to those directly measured by the Total Carbon Column Observing Network (TCCON). We analyse the mean seasonal cycle amplitude, dates of maximum and minimum XCO2, as well as the regional growth rates in XCO2 through the fitted trend over several years. We find that GOSAT/ACOS captures the seasonal cycle amplitude within 1.0 ppm accuracy compared to TCCON, except in Europe, where the difference exceeds 1.0 ppm at two sites, and the amplitude captured by GOSAT/ACOS is generally shallower compared to TCCON. This bias over Europe is not as large for the other GOSAT retrieval algorithms (NIES v02.21, RemoTeC v2.35, UoL v5.1, and NIES PPDF-S v.02.11), although they have significant biases at other sites. We find that the ACOS bias correction partially explains the shallow amplitude over Europe. The impact of the co-location method and aerosol changes in the ACOS algorithm were also tested and found to be few tenths of a ppm and mostly non-systematic. We find generally good agreement in the date of minimum XCO2 between ACOS and TCCON, but ACOS generally infers a date of maximum XCO2 2-3 weeks later than TCCON. We further analyse the latitudinal dependence of the seasonal cycle amplitude throughout the Northern Hemisphere and compare the dependence to that predicted by current optimized models that assimilate in situ measurements of CO2. In the zonal averages, models are consistent with the GOSAT amplitude to within 1.4 ppm, depending on the model and latitude. We also show that the seasonal cycle of XCO2 depends on longitude especially at the mid-latitudes: the amplitude of GOSAT XCO2 doubles from western USA to East Asia at 45-50° N, which is only partially shown by the models. In general, we find that model-to-model differences can be larger than GOSAT-to-model differences. These results suggest that GOSAT/ACOS retrievals of the XCO2 seasonal cycle may be sufficiently accurate to evaluate land surface models in regions with significant discrepancies between the models. |
BibTeX:
@article{Lindqvist2015,
author = {Lindqvist, H and O'Dell, C W and Basu, S and Boesch, H and Chevallier, F and Deutscher, N and Feng, L and Fisher, B and Hase, F and Inoue, M and Kivi, R and Morino, I and Palmer, P I and Parker, R and Schneider, M and Sussmann, R and Yoshida, Y},
title = {Does GOSAT capture the true seasonal cycle of carbon dioxide?},
journal = {Atmospheric Chemistry and Physics},
year = {2015},
volume = {15},
number = {22},
pages = {13023--13040},
url = {http://www.atmos-chem-phys.net/15/13023/2015/},
doi = {10.5194/acp-15-13023-2015}
}
|
| Locatelli R, Bousquet P, Hourdin F, Saunois M, Cozic A, Couvreux F, Grandpeix JY, Lefebvre MP, Rio C, Bergamaschi P, Chambers SD, Karstens U, Kazan V, Van Der Laan S, Meijer HAJ, Moncrieff J, Ramonet M, Scheeren HA, Schlosser C, Schmidt M, Vermeulen A and Williams AG (2015), "Atmospheric transport and chemistry of trace gases in LMDz5B: Evaluation and implications for inverse modelling", Geoscientific Model Development., feb, 2015. Vol. 8(2), pp. 129-150. |
| Abstract: Representation of atmospheric transport is a major source of error in the estimation of greenhouse gas sources and sinks by inverse modelling. Here we assess the impact on trace gas mole fractions of the new physical parameterizations recently implemented in the atmospheric global climate model LMDz to improve vertical diffusion, mesoscale mixing by thermal plumes in the planetary boundary layer (PBL), and deep convection in the troposphere. At the same time, the horizontal and vertical resolution of the model used in the inverse system has been increased. The aim of this paper is to evaluate the impact of these developments on the representation of trace gas transport and chemistry, and to anticipate the implications for inversions of greenhouse gas emissions using such an updated model. Comparison of a one-dimensional version of LMDz with large eddy simulations shows that the thermal scheme simulates shallow convective tracer transport in the PBL over land very efficiently, and much better than previous versions of the model. This result is confirmed in three-dimensional simulations, by a much improved reproduction of the radon-222 diurnal cycle. However, the enhanced dynamics of tracer concentrations induces a stronger sensitivity of the new LMDz configuration to external meteorological forcings. At larger scales, the inter-hemispheric exchange is slightly slower when using the new version of the model, bringing them closer to observations. The increase in the vertical resolution (from 19 to 39 layers) significantly improves the representation of stratosphere/troposphere exchange. Furthermore, changes in atmospheric thermodynamic variables, such as temperature, due to changes in the PBL mixing modify chemical reaction rates, which perturb chemical equilibriums of reactive trace gases. brbr One implication of LMDz model developments for future inversions of greenhouse gas emissions is the ability of the updated system to assimilate a larger amount of high-frequency data sampled at high-variability stations. Others implications are discussed at the end of the paper. |
BibTeX:
@article{Locatelli2015,
author = {Locatelli, R and Bousquet, P and Hourdin, F and Saunois, M and Cozic, A and Couvreux, F and Grandpeix, J Y and Lefebvre, M P and Rio, C and Bergamaschi, P and Chambers, S D and Karstens, U and Kazan, V and Van Der Laan, S and Meijer, H A J and Moncrieff, J and Ramonet, M and Scheeren, H A and Schlosser, C and Schmidt, M and Vermeulen, A and Williams, A G},
title = {Atmospheric transport and chemistry of trace gases in LMDz5B: Evaluation and implications for inverse modelling},
journal = {Geoscientific Model Development},
year = {2015},
volume = {8},
number = {2},
pages = {129--150},
url = {http://www.geosci-model-dev.net/8/129/2015/},
doi = {10.5194/gmd-8-129-2015}
}
|
| Lohila A, Tuovinen J-P, Hatakka J, Aurela M and Vuorenmaa J (2015), "Carbon dioxide and energy fluxes over a northern boreal lake" |
| Abstract: Lohila A., Tuovinen J.-P., Hatakka J., Aurela M., Vuorenmaa J., Haakana M. & Laurila T. 2015: Carbon dioxide and energy fluxes over a northern boreal lake. Boreal Env. Res. 20: 474-488. We present a data set covering three months of carbon dioxide (CO 2) and energy fluxes measured by the eddy covariance method over a northern boreal lake that collects waters from a surrounding catchment dominated by upland forest and wetlands. The data period comprises more than half of the open-water period of 2013. The 30-min averages of CO 2 fluxes ranged from-0.02 to 0.05 mg m-2 s-1. The monthly CO 2 balances varied from 20 to 30 g m-2 (emission) between July and September, and decreased in October. A small daytime uptake of CO 2 , probably caused by the aquatic plants growing near the measurement mast, was observed from July to September. In September, we observed a temporary enhancement of CO 2 efflux, which was attributed to both high wind speed and rapid cooling of the water and subsequent water column overturn. This peak was accompanied by a period of high sensible heat flux (SHF) from the water to the atmosphere, which is known to enhance the mixing of the water. The seasonal CO 2 flux during the open-water period from the shallow part of the lake was estimated to be 120 g m-2 yr-1 , which corresponds to a loss of approximately 25 g m-2 yr-1 from the terrestrial part of the catchment, assuming that the observed lake CO 2 emissions result from the decomposition of the imported carbon. At midday, the net energy received by the lake was used mostly to heat the water, and only a minor part of it was converted to SHF and latent heat flux (LHF), with more energy used for the latter. While the SHF showed a clear diurnal cycle with a peak early in the morning and no flux in the afternoon, the diurnal pattern of LHF was more even, with evaporation occurring throughout the day until the freezing of the lake. Our data from this northern lake highlight the importance of thermal water mixing in the air-lake CO 2 flux dynamics and imply that this flux constitutes a significant part of the annual catchment-scale carbon budget. |
BibTeX:
@techreport{Lohila2015,
author = {Lohila, Annalea and Tuovinen, Juha-Pekka and Hatakka, Juha and Aurela, Mika and Vuorenmaa, Jussi},
title = {Carbon dioxide and energy fluxes over a northern boreal lake},
year = {2015}
}
|
| Lopez M, Schmidt M, Ramonet M, Bonne JL, Colomb A, Kazan V, Laj P and Pichon JM (2015), "Three years of semicontinuous greenhouse gas measurements at the Puy de Dôme station (central France)", Atmospheric Measurement Techniques., sep, 2015. Vol. 8(9), pp. 3941-3958. |
| Abstract: Three years of greenhouse gas measurements, obtained using a gas chromatograph (GC) system located at the Puy de Dôme station at 1465 m a.s.l. in central France, are presented. The GC system was installed in 2010 at Puy de Dôme and was designed for automatic and accurate semicontinuous measurements of atmospheric carbon dioxide, methane, nitrous oxide and sulfur hexafluoride mole fractions. We present in detail the instrumental setup and the calibration strategy, which together allow the GC to reach repeatabilities of 0.1 μmol mol1, 1.2 nmol mol1, 0.3 nmol mol1 and 0.06 pmol mol1 for CO2, CH4, N2O and SF6, respectively. The analysis of the 3-year atmospheric time series revealed how the planetary boundary layer height drives the mole fractions observed at a mountain site such as Puy de Dôme where air masses alternate between the planetary boundary layer and the free troposphere. Accurate long-lived greenhouse gas measurements collocated with 222Rn measurements as an atmospheric tracer allowed us to determine the CO2, CH4 and N2O emissions in the catchment area of the station. The derived CO2 surface flux revealed a clear seasonal cycle, with net uptake by plant assimilation in the spring and net emission caused by the biosphere and burning of fossil fuel during the remainder of the year. We calculated a mean annual CO2 flux of 1310 ± 680 t CO2 km2. The derived CH4 and N2O emissions in the station catchment area were 7.0 ± 4.0 t CH4 km2 yr1 and 1.8 ± 1.0 t N2O km2 yr1, respectively. Our derived annual CH4 flux is in agreement with the national French inventory, whereas our derived N2O flux is 5 times larger than the same inventory. |
BibTeX:
@article{Lopez2015,
author = {Lopez, M and Schmidt, M and Ramonet, M and Bonne, J L and Colomb, A and Kazan, V and Laj, P and Pichon, J M},
title = {Three years of semicontinuous greenhouse gas measurements at the Puy de Dôme station (central France)},
journal = {Atmospheric Measurement Techniques},
year = {2015},
volume = {8},
number = {9},
pages = {3941--3958},
url = {http://www.atmos-meas-tech.net/8/3941/2015/},
doi = {10.5194/amt-8-3941-2015}
}
|
| Lunt MF, Rigby M, Ganesan AL, Manning AJ, Prinn RG, O'Doherty S, Mühle J, Harth CM, Salameh PK, Arnold T, Weiss RF, Saito T, Yokouchi Y, Krummel PB, Steele LP, Fraser PJ, Li S, Park S, Reimann S, Vollmer MK, Lunder C, Hermansen O, Schmidbauer N, Maione M, Arduini J, Young D and Simmonds PG (2015), "Reconciling reported and unreported HFC emissions with atmospheric observations", Proceedings of the National Academy of Sciences of the United States of America., may, 2015. Vol. 112(19), pp. 5927-5931. |
| Abstract: We infer global and regional emissions of five of the most abundant hydrofluorocarbons (HFCs) using atmospheric measurements from the Advanced Global Atmospheric Gases Experiment and the National Institute for Environmental Studies, Japan, networks. We find that the total COinf2/inf-equivalent emissions of the five HFCs from countries that are required to provide detailed, annual reports to the United Nations Framework Convention on Climate Change (UNFCCC) increased from 198 (175-221) Tg-COinf2/inf-eqtextperiodcenteredysup-1/sup in 2007 to 275 (246-304) Tg-COinf2/inf-eqtextperiodcenteredysup-1/sup in 2012. These global warming potential-weighted aggregated emissions agree well with those reported to the UNFCCC throughout this period and indicate that the gap between reported emissions and global HFC emissions derived from atmospheric trends is almost entirely due to emissions from nonreporting countries. However, our measurement-based estimates of individual HFC species suggest that emissions, from reporting countries, of the most abundant HFC, HFC-134a, were only 79% (63-95%) of the UNFCCC inventory total, while other HFC emissions were significantly greater than the reported values. These results suggest that there are inaccuracies in the reporting methods for individual HFCs, which appear to cancel when aggregated together. |
BibTeX:
@article{Lunt2015,
author = {Lunt, Mark F and Rigby, Matthew and Ganesan, Anita L and Manning, Alistair J and Prinn, Ronald G and O'Doherty, Simon and Mühle, Jens and Harth, Christina M and Salameh, Peter K and Arnold, Tim and Weiss, Ray F and Saito, Takuya and Yokouchi, Yoko and Krummel, Paul B and Steele, L Paul and Fraser, Paul J and Li, Shanlan and Park, Sunyoung and Reimann, Stefan and Vollmer, Martin K and Lunder, Chris and Hermansen, Ove and Schmidbauer, Norbert and Maione, Michela and Arduini, Jgor and Young, Dickon and Simmonds, Peter G},
title = {Reconciling reported and unreported HFC emissions with atmospheric observations},
journal = {Proceedings of the National Academy of Sciences of the United States of America},
year = {2015},
volume = {112},
number = {19},
pages = {5927--5931},
url = {http://www.pnas.org/lookup/doi/10.1073/pnas.1420247112},
doi = {10.1073/pnas.1420247112}
}
|
| Lyon SW, Nathanson M, Lam N, Dahlke HE, Rutzinger M, Kean JW and Laudon H (2015), "Can low-resolution airborne laser scanning data be used to model stream rating curves?", Water (Switzerland)., mar, 2015. Vol. 7(4), pp. 1324-1339. |
| Abstract: This pilot study explores the potential of using low-resolution (0.2 points/msup2/sup) airborne laser scanning (ALS)-derived elevation data to model stream rating curves. Rating curves, which allow the functional translation of stream water depth into discharge, making them integral to water resource monitoring efforts, were modeled using a physics-based approach that captures basic geometric measurements to establish flow resistance due to implicit channel roughness. We tested synthetically thinned high-resolution (more than 2 points/msup2/sup) ALS data as a proxy for low-resolution data at a point density equivalent to that obtained within most national-scale ALS strategies. Our results show that the errors incurred due to the effect of low-resolution versus high-resolution ALS data were less than those due to flow measurement and empirical rating curve fitting uncertainties. As such, although there likely are scale and technical limitations to consider, it is theoretically possible to generate rating curves in a river network from ALS data of the resolution anticipated within national-scale ALS schemes (at least for rivers with relatively simple geometries). This is promising, since generating rating curves from ALS scans would greatly enhance our ability to monitor streamflow by simplifying the overall effort required. |
BibTeX:
@article{Lyon2015,
author = {Lyon, Steve W and Nathanson, Marcus and Lam, Norris and Dahlke, Helen E and Rutzinger, Martin and Kean, Jason W and Laudon, Hjalmar},
title = {Can low-resolution airborne laser scanning data be used to model stream rating curves?},
journal = {Water (Switzerland)},
year = {2015},
volume = {7},
number = {4},
pages = {1324--1339},
url = {http://www.mdpi.com/2073-4441/7/4/1324},
doi = {10.3390/w7041324}
}
|
| Ma M, Wang D, Du H, Sun T, Zhao Z and Wei S (2015), "Atmospheric mercury deposition and its contribution of the regional atmospheric transport to mercury pollution at a national forest nature reserve, southwest China", Environmental Science and Pollution Research., dec, 2015. Vol. 22(24), pp. 20007-20018. |
| Abstract: Atmospheric mercury deposition by wet and dry processes contributes to the transformation of mercury from atmosphere to terrestrial and aquatic systems. Factors influencing the amount of mercury deposited to subtropical forests were identified in this study. Throughfall and open field precipitation samples were collected in 2012 and 2013 using precipitation collectors from forest sites located across Mt. Jinyun in southwest China. Samples were collected approximately every 2 weeks and analyzed for total (THg) and methyl mercury (MeHg). Forest canopy was the primary factor on THg and MeHg deposition. Simultaneously, continuous measurements of atmospheric gaseous elemental mercury (GEM) were carried out from March 2012 to February 2013 at the summit of Mt. Jinyun. Atmospheric GEM concentrations averaged 3.8 ± 1.5 ng mâˆ'3, which was elevated compared with global background values. Sources identification indicated that both regional industrial emissions and long-range transport of Hg from central, northeast, and southwest China were corresponded to the elevated GEM levels. Precipitation deposition fluxes of THg and MeHg in Mt. Jinyun were slightly higher than those reported in Europe and North America, whereas total fluxes of MeHg and THg under forest canopy on Mt. Jiuyun were 3 and 2.9 times of the fluxes of THg in wet deposition in the open. Highly elevated litterfall deposition fluxes suggest that even in remote forest areas of China, deposition of atmospheric Hg0 via uptake by vegetation leaf may be a major pathway for the deposition of atmospheric Hg. The result illustrates that areas with greater atmospheric pollution can be expected to have greater fluxes of Hg to soils via throughfall and litterfall. |
BibTeX:
@article{Ma2015,
author = {Ma, Ming and Wang, Dingyong and Du, Hongxia and Sun, Tao and Zhao, Zheng and Wei, Shiqing},
title = {Atmospheric mercury deposition and its contribution of the regional atmospheric transport to mercury pollution at a national forest nature reserve, southwest China},
journal = {Environmental Science and Pollution Research},
year = {2015},
volume = {22},
number = {24},
pages = {20007--20018},
url = {http://link.springer.com/10.1007/s11356-015-5152-9},
doi = {10.1007/s11356-015-5152-9}
}
|
| Maaroufi NI, Nordin A, Hasselquist NJ, Bach LH, Palmqvist K and Gundale MJ (2015), "Anthropogenic nitrogen deposition enhances carbon sequestration in boreal soils", Global Change Biology., aug, 2015. Vol. 21(8), pp. 3169-3180. |
| Abstract: It is proposed that carbon (C) sequestration in response to reactive nitrogen (Ninfr/inf) deposition in boreal forests accounts for a large portion of the terrestrial sink for anthropogenic COinf2/inf emissions. While studies have helped clarify the magnitude by which Ninfr/inf deposition enhances C sequestration by forest vegetation, there remains a paucity of long-term experimental studies evaluating how soil C pools respond. We conducted a long-term experiment, maintained since 1996, consisting of three N addition levels (0, 12.5, and 50kgNhasup-1/supyrsup-1/sup) in the boreal zone of northern Sweden to understand how atmospheric Ninfr/inf deposition affects soil C accumulation, soil microbial communities, and soil respiration. We hypothesized that soil C sequestration will increase, and soil microbial biomass and soil respiration will decrease, with disproportionately large changes expected compared to low levels of N addition. Our data showed that the low N addition treatment caused a non-significant increase in the organic horizon C pool of 15% and a significant increase of 30% in response to the high N treatment relative to the control. The relationship between C sequestration and N addition in the organic horizon was linear, with a slope of 10kgCkgsup-1/supN. We also found a concomitant decrease in total microbial and fungal biomasses and a 11% reduction in soil respiration in response to the high N treatment. Our data complement previous data from the same study system describing aboveground C sequestration, indicating a total ecosystem sequestration rate of 26kgCkgsup-1/supN. These estimates are far lower than suggested by some previous modeling studies, and thus will help improve and validate current modeling efforts aimed at separating the effect of multiple global change factors on the C balance of the boreal region. |
BibTeX:
@article{Maaroufi2015,
author = {Maaroufi, Nadia I and Nordin, Annika and Hasselquist, Niles J and Bach, Lisbet H and Palmqvist, Kristin and Gundale, Michael J},
title = {Anthropogenic nitrogen deposition enhances carbon sequestration in boreal soils},
journal = {Global Change Biology},
year = {2015},
volume = {21},
number = {8},
pages = {3169--3180},
url = {http://doi.wiley.com/10.1111/gcb.12904},
doi = {10.1111/gcb.12904}
}
|
| Mammarella I, Nordbo A, Rannik Ü, Haapanala S, Levula J, Laakso H, Ojala A, Peltola O, Heiskanen J, Pumpanen J and Vesala T (2015), "Carbon dioxide and energy fluxes over a small boreal lake in Southern Finland", Journal of Geophysical Research G: Biogeosciences., jul, 2015. Vol. 120(7), pp. 1296-1314. |
| Abstract: Dynamics of carbon dioxide and energy exchange over a small boreal lake were investigated. Flux measurements have been carried out by the eddy covariance technique during two open-water periods (June-October) at Lake Kuivajärvi in Finland. Sensible heat (H) flux peaked in the early morning, and upward sensible heat flux at night results in unstable stratification over the lake. Minimum H was measured in the late afternoon, often resulting in adiabatic conditions or slightly stable stratification over the lake. The latent heat flux (LE) showed a different pattern, peaking in the afternoon and having a minimum at night. High correlation (rsup2/sup0.75) between H and water-air temperature difference multiplied by wind speed (U) was found, while LE strongly correlated with the water vapor pressure deficit multiplied by U (rsup2/sup0.78). Monthly average values of energy balance closure ranged between 70 and 99%. The lake acted as net source of carbon dioxide, and the measured flux (FinfCO2/inf) averaged over the two open-water periods (0.7μmolmsup-2/supssup-1/sup) was up to 3 times higher than those reported in other studies. Furthermore, it was found that during period of high wind speed (3mssup-1/sup) shear-induced water turbulence controls the water-air gas transfer efficiency. However, under calm nighttime conditions, FinfCO2/inf was poorly correlated with the difference between the water and the equilibrium COinf2/inf concentrations multiplied by U. Nighttime cooling of surface water enhances the gas transfer efficiency through buoyancy-driven turbulent mixing, and simple wind speed-based transfer velocity models strongly underestimate FinfCO2/inf. Key Points Dynamics of COinf2/inf and energy exchange over a boreal lake are studied The lake acted as net source of carbon dioxide Nighttime cooling of surface water enhances the gas transfer efficiency |
BibTeX:
@article{Mammarella2015,
author = {Mammarella, Ivan and Nordbo, Annika and Rannik, Üllar and Haapanala, Sami and Levula, Janne and Laakso, Heikki and Ojala, Anne and Peltola, Olli and Heiskanen, Jouni and Pumpanen, Jukka and Vesala, Timo},
title = {Carbon dioxide and energy fluxes over a small boreal lake in Southern Finland},
journal = {Journal of Geophysical Research G: Biogeosciences},
year = {2015},
volume = {120},
number = {7},
pages = {1296--1314},
url = {http://doi.wiley.com/10.1002/2014JG002873},
doi = {10.1002/2014JG002873}
}
|
| Marrec P, Cariou T, Macé E, Morin P, Salt LA, Vernet M, Taylor B, Paxman K and Bozec Y (2015), "Dynamics of air–sea CO&lt;sub&gt;2&lt;/sub&gt; fluxes in the northwestern European shelf based on voluntary observing ship and satellite observations", Biogeosciences., sep, 2015. Vol. 12(18), pp. 5371-5391. Copernicus GmbH. |
| Abstract: textlessptextgreaterAbstract. From January 2011 to December 2013, we constructed a comprehensive pCO2 data set based on voluntary observing ship (VOS) measurements in the western English Channel (WEC). We subsequently estimated surface pCO2 and air–sea CO2 fluxes in northwestern European continental shelf waters using multiple linear regressions (MLRs) from remotely sensed sea surface temperature (SST), chlorophyll a concentration (Chl a), wind speed (WND), photosynthetically active radiation (PAR) and modeled mixed layer depth (MLD). We developed specific MLRs for the seasonally stratified northern WEC (nWEC) and the permanently well-mixed southern WEC (sWEC) and calculated surface pCO2 with uncertainties of 17 and 16 μatm, respectively. We extrapolated the relationships obtained for the WEC based on the 2011–2013 data set (1) temporally over a decade and (2) spatially in the adjacent Celtic and Irish seas (CS and IS), two regions which exhibit hydrographical and biogeochemical characteristics similar to those of WEC waters. We validated these extrapolations with pCO2 data from the SOCAT and LDEO databases and obtained good agreement between modeled and observed data. On an annual scale, seasonally stratified systems acted as a sink of CO2 from the atmosphere of −0.6 ± 0.3, −0.9 ± 0.3 and −0.5 ± 0.3 mol C m−2 yr−1 in the northern Celtic Sea, southern Celtic sea and nWEC, respectively, whereas permanently well-mixed systems acted as source of CO2 to the atmosphere of 0.2 ± 0.2 and 0.3 ± 0.2 mol C m−2 yr−1 in the sWEC and IS, respectively. Air–sea CO2 fluxes showed important inter-annual variability resulting in significant differences in the intensity and/or direction of annual fluxes. We scaled the mean annual fluxes over these provinces for the last decade and obtained the first annual average uptake of −1.11 ± 0.32 Tg C yr−1 for this part of the northwestern European continental shelf. Our study showed that combining VOS data with satellite observations can be a powerful tool to estimate and extrapolate air–sea CO2 fluxes in sparsely sampled area.textless/ptextgreater |
BibTeX:
@article{Marrec2015,
author = {Marrec, P. and Cariou, T. and Macé, E. and Morin, P. and Salt, L. A. and Vernet, M. and Taylor, B. and Paxman, K. and Bozec, Y.},
title = {Dynamics of air–sea CO&lt;sub&gt;2&lt;/sub&gt; fluxes in the northwestern European shelf based on voluntary observing ship and satellite observations},
journal = {Biogeosciences},
publisher = {Copernicus GmbH},
year = {2015},
volume = {12},
number = {18},
pages = {5371--5391},
url = {https://bg.copernicus.org/articles/12/5371/2015/},
doi = {10.5194/bg-12-5371-2015}
}
|
| Matteucci M, Gruening C, Goded Ballarin I, Seufert G and Cescatti A (2015), "Components, drivers and temporal dynamics of ecosystem respiration in a Mediterranean pine forest", Soil Biology and Biochemistry., sep, 2015. Vol. 88, pp. 224-235. Elsevier Ltd. |
| Abstract: To investigate the climate impacts on the different components of ecosystem respiration, we combined soil efflux data from a tree-girdling experiment with eddy covariance COtextlessinftextgreater2textless/inftextgreater fluxes in a Mediterranean maritime pine (Pinus pinaster) forest in Central Italy. 73 trees were stem girdled to stop the flux of photosynthates from the canopy to the roots, and weekly soil respiration surveys were carried out for one year. Heterotrophic respiration (RtextlessinftextgreaterHtextless/inftextgreater) was estimated from the soil COtextlessinftextgreater2textless/inftextgreater flux measured in girdled plots, and rhizosphere respiration (RtextlessinftextgreaterAbtextless/inftextgreater) was calculated as the difference between respiration from controls (RtextlessinftextgreaterStextless/inftextgreater) and girdled plots (RtextlessinftextgreaterHtextless/inftextgreater).Results show that the RtextlessinftextgreaterStextless/inftextgreater dynamics were clearly driven by RtextlessinftextgreaterHtextless/inftextgreater (average RtextlessinftextgreaterHtextless/inftextgreater/RtextlessinftextgreaterStextless/inftextgreater ratio 0.74). RtextlessinftextgreaterHtextless/inftextgreater predictably responded to environmental variables, being predominantly controlled by soil water availability during the hot and dry growing season (May-October) and by soil temperature during the wetter and colder months (November-March). High RtextlessinftextgreaterStextless/inftextgreater and RtextlessinftextgreaterHtextless/inftextgreater peaks were recorded after rain pulses greater than 10 mm on dry soil, indicating that large soil carbon emissions were driven by the rapid microbial oxidation of labile carbon compounds. We also observed a time-lag of one week between water pulses and RtextlessinftextgreaterAbtextless/inftextgreater peaks, which might be due to the delay in the translocation of recently assimilated photosynthates from the canopy to the root system. At the ecosystem scale, total autotrophic respiration (RtextlessinftextgreaterAttextless/inftextgreater, i.e. the sum of carbon respired by the rhizosphere and aboveground biomass) amounted to 60% of ecosystem respiration. RtextlessinftextgreaterAttextless/inftextgreater was predominantly controlled by photosynthesis, and showed high temperature sensitivity (Qtextlessinftextgreater10textless/inftextgreater) only during the wet periods. Despite the fact that the study coincided with an anomalous dry year and results might therefore not represent a general pattern, these data highlight the complex climatic control of the respiratory processes responsible for ecosystem COtextlessinftextgreater2textless/inftextgreater emissions. |
BibTeX:
@article{Matteucci2015,
author = {Matteucci, Marco and Gruening, Carsten and Goded Ballarin, Ignacio and Seufert, Guenther and Cescatti, Alessandro},
title = {Components, drivers and temporal dynamics of ecosystem respiration in a Mediterranean pine forest},
journal = {Soil Biology and Biochemistry},
publisher = {Elsevier Ltd},
year = {2015},
volume = {88},
pages = {224--235},
doi = {10.1016/j.soilbio.2015.05.017}
}
|
| Monteiro PM, Gregor L, Lévy M, Maenner S, Sabine CL and Swart S (2015), "Intraseasonal variability linked to sampling alias in air-sea CO2 fluxes in the Southern Ocean", Geophysical Research Letters., oct, 2015. Vol. 42(20), pp. 8507-8514. Blackwell Publishing Ltd. |
| Abstract: The Southern Ocean (SO) contributes most of the uncertainty in contemporary estimates of the mean annual flux of carbon dioxide CO2 between the ocean and the atmosphere. Attempts to reduce this uncertainty have aimed at resolving the seasonal cycle of the fugacity of CO2 (fCO2). We use hourly CO2 flux and driver observations collected by the combined deployment of ocean gliders to show that resolving the seasonal cycle is not sufficient to reduce the uncertainty of the flux of CO2 to below the threshold required to reveal climatic trends in CO2 fluxes. This was done by iteratively subsampling the hourly CO2 data set at various time intervals. We show that because of storm-linked intraseasonal variability in the spring-late summer, sampling intervals longer than 2 days alias the seasonal mean flux estimate above the required threshold. Moreover, the regional nature and long-term trends in storm characteristics may be an important influence in the future role of the SO in the carbon-climate system. Key Points fCO2 and air-sea flux of CO2 strongly modulated by intraseasonal variability in the SO Uncertainty of the mean seasonal or annual air-sea flux is sensitive to sampling resolution A sampling resolution textless2 days is necessary in 30-40% of the SO to reduce the uncertainty to textless10% |
BibTeX:
@article{Monteiro2015,
author = {Monteiro, Pedro M.S. and Gregor, Luke and Lévy, Marina and Maenner, Stacy and Sabine, Christopher L. and Swart, Sebastiaan},
title = {Intraseasonal variability linked to sampling alias in air-sea CO2 fluxes in the Southern Ocean},
journal = {Geophysical Research Letters},
publisher = {Blackwell Publishing Ltd},
year = {2015},
volume = {42},
number = {20},
pages = {8507--8514},
doi = {10.1002/2015GL066009}
}
|
| Nauta AL, Heijmans MMPD, Blok D, Limpens J, Elberling B, Gallagher A, Li B, Petrov RE, Maximov TC, Van Huissteden J and Berendse F (2015), "Permafrost collapse after shrub removal shifts tundra ecosystem to a methane source", Nature Climate Change., nov, 2015. Vol. 5(1), pp. 67-70. |
| Abstract: Arctic tundra ecosystems are warming almost twice as fast as the global average. Permafrost thaw and the resulting release of greenhouse gases from decomposing soil organic carbon have the potential to accelerate climate warming. In recent decades, Arctic tundra ecosystems have changed rapidly, including expansion of woody vegetation, in response to changing climate conditions. How such vegetation changes contribute to stabilization or destabilization of the permafrost is unknown. Here we present six years of field observations in a shrub removal experiment at a Siberian tundra site. Removing the shrub part of the vegetation initiated thawing of ice-rich permafrost, resulting in collapse of the originally elevated shrub patches into waterlogged depressions within five years. This thaw pond development shifted the plots from a methane sink into a methane source. The results of our field experiment demonstrate the importance of the vegetation cover for protection of the massive carbon reservoirs stored in the permafrost and illustrate the strong vulnerability of these tundra ecosystems to perturbations. If permafrost thawing can more frequently trigger such local permafrost collapse, methane-emitting wet depressions could become more abundant in the lowland tundra landscape, at the cost of permafrost-stabilizing low shrub vegetation. |
BibTeX:
@article{Nauta2015,
author = {Nauta, Ake L and Heijmans, Monique M P D and Blok, Daan and Limpens, Juul and Elberling, Bo and Gallagher, Angela and Li, Bingxi and Petrov, Roman E and Maximov, Trofim C and Van Huissteden, Jacobus and Berendse, Frank},
title = {Permafrost collapse after shrub removal shifts tundra ecosystem to a methane source},
journal = {Nature Climate Change},
year = {2015},
volume = {5},
number = {1},
pages = {67--70},
url = {http://www.nature.com/doifinder/10.1038/nclimate2446},
doi = {10.1038/nclimate2446}
}
|
| Nijp JJ, Limpens J, Metselaar K, Peichl M, Nilsson MB, van der Zee SE and Berendse F (2015), "Rain events decrease boreal peatland net CO2 uptake through reduced light availability", Global Change Biology., jun, 2015. Vol. 21(6), pp. 2309-2320. Blackwell Publishing Ltd. |
| Abstract: Boreal peatlands store large amounts of carbon, reflecting their important role in the global carbon cycle. The short-term exchange and the long-term storage of atmospheric carbon dioxide (CO2) in these ecosystems are closely associated with the permanently wet surface conditions and are susceptible to drought. Especially, the single most important peat forming plant genus, Sphagnum, depends heavily on surface wetness for its primary production. Changes in rainfall patterns are expected to affect surface wetness, but how this transient rewetting affects net ecosystem exchange of CO2 (NEE) remains unknown. This study explores how the timing and characteristics of rain events during photosynthetic active periods, that is daytime, affect peatland NEE and whether rain event associated changes in environmental conditions modify this response (e.g. water table, radiation, vapour pressure deficit, temperature). We analysed an 11-year time series of half-hourly eddy covariance and meteorological measurements from Degerö Stormyr, a boreal peatland in northern Sweden. Our results show that daytime rain events systematically decreased the sink strength of peatlands for atmospheric CO2. The decrease was best explained by rain associated reduction in light, rather than by rain characteristics or drought length. An average daytime growing season rain event reduced net ecosystem CO2 uptake by 0.23-0.54 gC m-2. On an annual basis, this reduction of net CO2 uptake corresponds to 24% of the annual net CO2 uptake (NEE) of the study site, equivalent to a 4.4% reduction of gross primary production (GPP) during the growing season. We conclude that reduced light availability associated with rain events is more important in explaining the NEE response to rain events than rain characteristics and changes in water availability. This suggests that peatland CO2 uptake is highly sensitive to changes in cloud cover formation and to altered rainfall regimes, a process hitherto largely ignored. |
BibTeX:
@article{Nijp2015,
author = {Nijp, Jelmer J. and Limpens, Juul and Metselaar, Klaas and Peichl, Matthias and Nilsson, Mats B. and van der Zee, Sjoerd E.A.T.M. and Berendse, Frank},
title = {Rain events decrease boreal peatland net CO2 uptake through reduced light availability},
journal = {Global Change Biology},
publisher = {Blackwell Publishing Ltd},
year = {2015},
volume = {21},
number = {6},
pages = {2309--2320},
doi = {10.1111/gcb.12864}
}
|
| Nordbo A, Karsisto P, Matikainen L, Wood CR and Järvi L (2015), "Urban surface cover determined with airborne lidar at 2m resolution - Implications for surface energy balance modelling", Urban Climate., sep, 2015. Vol. 13, pp. 52-72. Elsevier. |
| Abstract: Urban surface cover largely determines surface-atmosphere interaction via turbulent fluxes, and its description is vital for several applications. Land-cover classification using lidar has been done for small urban areas (textless10kmtextlesssuptextgreater2textless/suptextgreater) whereas surface-cover maps in atmospheric modelling often have resolutions textgreater10m. We classified land cover of the urban/suburban area (54kmtextlesssuptextgreater2textless/suptextgreater) of Helsinki into six classes based on airborne lidar data, and an algorithm for machine-learning classification trees. Individual lidar returns were classified (accuracy 91%) and further converted to 2-m-resolution grid (95% accuracy). Useful lidar data included: return height and intensity, returns-per-pulse and height difference between first and last returns.The sensitivity of urban surface-energy-balance model, SUEWS, to simulate turbulent sensible and latent heat fluxes was examined. Model results were compared with eddy-covariance flux measurements in central Helsinki. An aggregation of the surface-cover map from 2 to 100 m reduced the fraction of vegetation by two thirds resulting in 16% increase in simulated sensible heat and 56% reduction in latent heat flux. Street trees became indistinguishable already at 10 m resolution causing 19% reduction in modelled latent heat flux. We thus recommend having surface-cover data with 2 m resolution over cities with street trees, or other patchy vegetation. |
BibTeX:
@article{Nordbo2015,
author = {Nordbo, Annika and Karsisto, Petteri and Matikainen, Leena and Wood, Curtis R. and Järvi, Leena},
title = {Urban surface cover determined with airborne lidar at 2m resolution - Implications for surface energy balance modelling},
journal = {Urban Climate},
publisher = {Elsevier},
year = {2015},
volume = {13},
pages = {52--72},
doi = {10.1016/j.uclim.2015.05.004}
}
|
| Ostler A, Sussmann R, Patra PK, Wennberg PO, Deutscher NM, Griffith DWT, Blumenstock T, Hase F, Kivi R, Warneke T, Wang Z, De Mazière M, Robinson J and Ohyama H (2015), "The imprint of stratospheric transport on column-averaged methane", Atmospheric Chemistry and Physics Discussions., jul, 2015. Vol. 15(14), pp. 20395-20447. |
| Abstract: pstrongAbstract./strong Model simulations of column-averaged methane mixing ratios (XCHsub4/sub) are extensively used for inverse estimates of methane (CHsub4/sub) emissions from atmospheric measurements. Our study shows that virtually all chemical transport models (CTM) used for this purpose are affected by stratospheric model-transport errors. We quantify the impact of such model transport errors on the simulation of stratospheric CHsub4/sub concentrations via an a posteriori correction method. This approach compares measurements of the mean age of air with modeled age and expresses the difference in terms of a correction to modeled stratospheric CHsub4/sub mixing ratios. We find age differences up to ˜ 3 years yield to a bias in simulated CHsub4/sub of up to 250 parts per billion (ppb). Comparisons between model simulations and ground-based XCHsub4/sub observations from the Total Carbon Column Network (TCCON) reveal that stratospheric model-transport errors cause biases in XCHsub4/sub of ˜ 20 ppb in the midlatitudes and ˜ 27 ppb in the arctic region. Improved overall as well as seasonal model-observation agreement in XCHsub4/sub suggests that the proposed, age-of-air-based stratospheric correction is reasonable. brbr The latitudinal model bias in XCHsub4/sub is supposed to reduce the accuracy of inverse estimates using satellite-derived XCHsub4/sub data. Therefore, we provide an estimate of the impact of stratospheric model-transport errors in terms of CHsub4/sub flux errors. Using a one-box approximation, we show that average model errors in stratospheric transport correspond to an overestimation of CHsub4/sub emissions by ˜ 40 % (˜ 7 Tg yrsup&minus;1/sup) for the arctic, ˜ 5 % (˜ 7 Tg yrsup&minus;1/sup) for the northern, and ˜ 60 % (˜ 7 Tg yrsup&minus;1/sup) for the southern hemispheric mid-latitude region. We conclude that an improved modeling of stratospheric transport is highly desirable for the joint use with atmospheric XCHsub4/sub observations in atmospheric inversions./p |
BibTeX:
@article{Ostler2015,
author = {Ostler, A and Sussmann, R and Patra, P K and Wennberg, P O and Deutscher, N M and Griffith, D W T and Blumenstock, T and Hase, F and Kivi, R and Warneke, T and Wang, Z and De Mazière, M and Robinson, J and Ohyama, H},
title = {The imprint of stratospheric transport on column-averaged methane},
journal = {Atmospheric Chemistry and Physics Discussions},
year = {2015},
volume = {15},
number = {14},
pages = {20395--20447},
url = {http://www.atmos-chem-phys-discuss.net/15/20395/2015/},
doi = {10.5194/acpd-15-20395-2015}
}
|
| Pal S, Lopez M, Schmidt M, Ramonet M, Gibert F, Xueref-Remy I and Ciais P (2015), "Investigation of the atmospheric boundary layer depth variability and its impact on the 222Rn concentration at a rural site in France", Journal of Geophysical Research., jan, 2015. Vol. 120(2), pp. 623-643. |
| Abstract: Continuous monitoring of the atmospheric boundary layer (ABL) depth (zi) is important for investigations of trace gases with near-surface sources. The aim of this study is to examine the temporal variability of zi on both diurnal and seasonal time scales over a full year (2011) and relate these changes to the atmospheric 222Rn concentrations (CRn) measured near the top of a 200m tower at a rural site (Trainou) in France. Continuous zi estimates were made using a combination of lidar and hourly four-height carbon dioxide (CO2) profile measurements. Over the diurnal cycle, the 180m CRn reached a maximum in the late morning as the growing ABL passed through the inlet height (180 m) transporting upward high CRn air from the nocturnal boundary layer. During late afternoon, a minimum in the CRn occurred mainly due to ABL-mixing. We argue that ABL dilution occurs in two stages: first, during the rapid morning growth into the residual layer, and second, during afternoon with the free atmosphere when zi has reached its quasi-stationary height (around 750m in winter or 1700m in summer). An anticorrelation (R2 of -0.49) was found while performing a linear regression analysis between the daily zi growth rates and the corresponding changes in the CRn illustrating the ABL-dilution effect. We also analyzed the numerical proportions of the time within a season when zi remained lower than the inlet height and found a clear seasonal variability for the nighttime measurements with higher number of cases with shallow zi (200 m) in winter (67.3%) than in summer (33.9%) and spring (54.5%). Thus, this pilot study helps delineate the impact of zi on CRn at the site mainly for different regimes of ABL, in particular, during the times when the zi is above the measurement height. It is suggested that when the zi is well below the inlet height, measurements are most possibly indicative of the residual layer 222Rn, an important issue that should be considered in the mass budget approach. |
BibTeX:
@article{Pal2015,
author = {Pal, S and Lopez, M and Schmidt, M and Ramonet, M and Gibert, F and Xueref-Remy, I and Ciais, P},
title = {Investigation of the atmospheric boundary layer depth variability and its impact on the 222Rn concentration at a rural site in France},
journal = {Journal of Geophysical Research},
year = {2015},
volume = {120},
number = {2},
pages = {623--643},
url = {http://doi.wiley.com/10.1002/2014JD022322},
doi = {10.1002/2014JD022322}
}
|
| Papale D, Black TA, Carvalhais N, Cescatti A, Chen J, Jung M, Kiely G, Lasslop G, Mahecha MD, Margolis H, Merbold L, Montagnani L, Moors E, Olesen JE, Reichstein M, Tramontana G, Van Gorsel E, Wohlfahrt G and Ráduly B (2015), "Effect of spatial sampling from European flux towers for estimating carbon and water fluxes with artificial neural networks", Journal of Geophysical Research: Biogeosciences., oct, 2015. Vol. 120(10), pp. 1941-1957. Blackwell Publishing Ltd. |
| Abstract: Empirical modeling approaches are frequently used to upscale local eddy covariance observations of carbon, water, and energy fluxes to regional and global scales. The predictive capacity of such models largely depends on the data used for parameterization and identification of input-output relationships, while prediction for conditions outside the training domain is generally uncertain. In this work, artificial neural networks (ANNs) were used for the prediction of gross primary production (GPP) and latent heat flux (LE) on local and European scales with the aim to assess the portion of uncertainties in extrapolation due to sample selection. ANNs were found to be a useful tool for GPP and LE prediction, in particular for extrapolation in time (mean absolute error MAE for GPP between 0.53 and 1.56 gC m-2 d-1). Extrapolation in space in similar climatic and vegetation conditions also gave good results (GPP MAE 0.7-1.41 gC m-2 d-1), while extrapolation in areas with different seasonal cycles and controlling factors (e.g., the tropical regions) showed noticeably higher errors (GPP MAE 0.8-2.09 gC m-2 d-1). The distribution and the number of sites used for ANN training had a remarkable effect on prediction uncertainty in both, regional GPP and LE budgets and their interannual variability. Results obtained show that for ANN upscaling for continents with relatively small networks of sites, the error due to the sampling can be large and needs to be considered and quantified. The analysis of the spatial variability of the uncertainty helped to identify the meteorological drivers driving the uncertainty. Key Points Uncertainty due to spatial sampling is evaluated using ANNs and FLUXNET data GPP and LE budgets and IAV are analyzed with different site networks The uncertainty in upscaling due to spatial sampling is highly heterogeneous |
BibTeX:
@article{Papale2015,
author = {Papale, Dario and Black, T. Andrew and Carvalhais, Nuno and Cescatti, Alessandro and Chen, Jiquan and Jung, Martin and Kiely, Gerard and Lasslop, Gitta and Mahecha, Miguel D. and Margolis, Hank and Merbold, Lutz and Montagnani, Leonardo and Moors, Eddy and Olesen, Jørgen E. and Reichstein, Markus and Tramontana, Gianluca and Van Gorsel, Eva and Wohlfahrt, Georg and Ráduly, Botond},
title = {Effect of spatial sampling from European flux towers for estimating carbon and water fluxes with artificial neural networks},
journal = {Journal of Geophysical Research: Biogeosciences},
publisher = {Blackwell Publishing Ltd},
year = {2015},
volume = {120},
number = {10},
pages = {1941--1957},
doi = {10.1002/2015JG002997}
}
|
| Parard G, Charantonis AA and Rutgerson A (2015), "Remote sensing the sea surface CO2 of the Baltic Sea using the SOMLO methodology", Biogeosciences., jun, 2015. Vol. 12(11), pp. 3369-3384. |
| Abstract: Studies of coastal seas in Europe have noted the high variability of the CO2 system. This high variability, generated by the complex mechanisms driving the CO2 fluxes, complicates the accurate estimation of these mechanisms. This is particularly pronounced in the Baltic Sea, where the mechanisms driving the fluxes have not been characterized in as much detail as in the open oceans. In addition, the joint availability of in situ measurements of CO2 and of sea-surface satellite data is limited in the area. In this paper, we used the SOMLO (self-organizing multiple linear output; Sasse et al., 2013) methodology, which combines two existing methods (i.e. self-organizing maps and multiple linear regression) to estimate the ocean surface partial pressure of CO2 (pCO2) in the Baltic Sea from the remotely sensed sea surface temperature, chlorophyll, coloured dissolved organic matter, net primary production, and mixed-layer depth. The outputs of this research have a horizontal resolution of 4 km and cover the 1998-2011 period. These outputs give a monthly map of the Baltic Sea at a very fine spatial resolution. The reconstructed pCO2 values over the validation data set have a correlation of 0.93 with the in situ measurements and a root mean square error of 36 atm. Removing any of the satellite parameters degraded this reconstructed CO2 flux, so we chose to supply any missing data using statistical imputation. The pCO2 maps produced using this method also provide a confidence level of the reconstruction at each grid point. The results obtained are encouraging given the sparsity of available data, and we expect to be able to produce even more accurate reconstructions in coming years, given the predicted acquisition of new data. |
BibTeX:
@article{Parard2015,
author = {Parard, G and Charantonis, A A and Rutgerson, A},
title = {Remote sensing the sea surface CO2 of the Baltic Sea using the SOMLO methodology},
journal = {Biogeosciences},
year = {2015},
volume = {12},
number = {11},
pages = {3369--3384},
url = {https://www.biogeosciences.net/12/3369/2015/},
doi = {10.5194/bg-12-3369-2015}
}
|
| Parker RJ, Boesch H, Byckling K, Webb AJ, Palmer PI, Feng L, Bergamaschi P, Chevallier F, Notholt J, Deutscher N, Warneke T, Hase F, Sussmann R, Kawakami S, Kivi R, Griffith DWT and Velazco V (2015), "Assessing 5 years of GOSAT Proxy XCH4 data and associated uncertainties", Atmospheric Measurement Techniques., nov, 2015. Vol. 8(11), pp. 4785-4801. |
| Abstract: We present 5 years of GOSAT XCH4 retrieved using the "proxy" approach. The Proxy XCH4 data are validated against ground-based TCCON observations and are found to be of high quality with a small bias of 4.8 ppb (&sim; 0.27 %) and a single-sounding precision of 13.4 ppb (&sim; 0.74 %). The station-to-station bias (ameasure of the relative accuracy) is found to be 4.2 ppb. For the first time the XCH4/XCO2 ratio component of the Proxy retrieval is validated (bias of 0.014 ppb ppm&minus;1 (&sim; 0.30 %), single-sounding precision of 0.033 ppb ppm&minus;1 (&sim; 0.72 %)). The uncertainty relating to the model XCO2 component of the Proxy XCH4 is assessed through the use of an ensemble of XCO2 models. While each individual XCO2 model is found to agree well with the TCCON validation data (ir/i Combining double low line 0.94-0.97), it is not possible to select one model as the best from our comparisons. The median XCO2 value of the ensemble has a smaller scatter against TCCON (a standard deviation of 0.92 ppm) than any of the individual models whilst maintaining a small bias (0.15 ppm). This model median XCO2 is used to calculate the Proxy XCH4 with the maximum deviation of the ensemble from the median used as an estimate of the uncertainty. We compare this uncertainty to the a posteriori retrieval error (which is assumed to reduce with sqrt(iN/i)) and find typically that the model XCO2 uncertainty becomes significant during summer months when the a posteriori error is at its lowest due to the increase in signal related to increased summertime reflected sunlight. We assess the significance of these model and retrieval uncertainties on flux inversion by comparing the GOSAT XCH4 against modelled XCH4 from TM5-4DVAR constrained by NOAA surface observations (MACC reanalysis scenario S1-NOAA). We find that for the majority of regions the differences are much larger than the estimated uncertainties. Our findings show that useful information will be provided to the inversions for the majority of regions in addition to that already provided by the assimilated surface measurements. |
BibTeX:
@article{Parker2015,
author = {Parker, R J and Boesch, H and Byckling, K and Webb, A J and Palmer, P I and Feng, L and Bergamaschi, P and Chevallier, F and Notholt, J and Deutscher, N and Warneke, T and Hase, F and Sussmann, R and Kawakami, S and Kivi, R and Griffith, D W T and Velazco, V},
title = {Assessing 5 years of GOSAT Proxy XCH4 data and associated uncertainties},
journal = {Atmospheric Measurement Techniques},
year = {2015},
volume = {8},
number = {11},
pages = {4785--4801},
url = {http://www.atmos-meas-tech.net/8/4785/2015/},
doi = {10.5194/amt-8-4785-2015}
}
|
| Patricia Laville, Simone Neri, David Continanza, Luca Ferrante Vero, Simona Bosco and Giorgio Virgili (2015), "Cross-Validation of a Mobile N2O Flux Prototype (IPNOA) Using Micrometeorological and Chamber Methods", Journal of Energy and Power Engineering., apr, 2015. Vol. 9(4) |
BibTeX:
@article{PatriciaLaville2015,
author = {Patricia Laville and Simone Neri and David Continanza and Luca Ferrante Vero and Simona Bosco and Giorgio Virgili},
title = {Cross-Validation of a Mobile N2O Flux Prototype (IPNOA) Using Micrometeorological and Chamber Methods},
journal = {Journal of Energy and Power Engineering},
year = {2015},
volume = {9},
number = {4},
url = {http://www.davidpublisher.org/index.php/Home/Article/index?id=7863.html},
doi = {10.17265/1934-8975/2015.04.007}
}
|
| Peltola O, Hensen A, Belelli Marchesini L, Helfter C, Bosveld FC, van den Bulk WCM, Haapanala S, van Huissteden J, Laurila T, Lindroth A, Nemitz E, Röckmann T, Vermeulen AT and Mammarella I (2015), "Studying the spatial variability of methane flux with five eddy covariance towers of varying height", Agricultural and Forest Meteorology., dec, 2015. Vol. 214-215, pp. 456-472. Elsevier B.V.. |
| Abstract: In this study, the spatial representativeness of eddy covariance (EC) methane (CH4) measurements was examined by comparing parallel CH4 fluxes from three short (6 m) towers separated by a few kilometres and from two higher levels (20 m and 60 m) at one location. The measurement campaign was held on an intensively managed grassland on peat soil in the Netherlands. The land use and land cover types are to a large degree homogeneous in the area. The CH4 fluxes exhibited significant variability between the sites on 30-min scale. The spatial coefficient of variation (CVspa) between the three short towers was 56% and it was of similar magnitude as the temporal variability, unlike for the other fluxes (friction velocity, sensible heat flux) for which the temporal variability was considerably larger than the spatial variability. The CVspa decreased with temporal averaging, although less than what could be expected for a purely random process (1/N), and it was 14% for 26-day means of CH4 flux. This reflects the underlying heterogeneity of CH4 flux in the studied landscape at spatial scales ranging from 1ha (flux footprint) to 10 km2 (area bounded by the short towers). This heterogeneity should be taken into account when interpreting and comparing EC measurements. On an annual scale, the flux spatial variability contributed up to 50% of the uncertainty in CH4 emissions. It was further tested whether EC flux measurements at higher levels could be used to acquire a more accurate estimate of the spatially integrated CH4 emissions. Contrarily to what was expected, flux intensity was found to both increase and decrease depending on measurement height. Using footprint modelling, 56% of the variation between 6m and 60 m CH4 fluxes was attributed to emissions from local anthropogenic hotspots (farms). Furthermore, morning hours proved to be demanding for the tall tower EC where fluxes at 60m were up to four-fold those at lower heights. These differences were connected with the onset of convective mixing during the morning period. |
BibTeX:
@article{Peltola2015,
author = {Peltola, O and Hensen, A and Belelli Marchesini, L and Helfter, C and Bosveld, F C and van den Bulk, W C M and Haapanala, S and van Huissteden, J and Laurila, T and Lindroth, A and Nemitz, E and Röckmann, T and Vermeulen, A T and Mammarella, I},
title = {Studying the spatial variability of methane flux with five eddy covariance towers of varying height},
journal = {Agricultural and Forest Meteorology},
publisher = {Elsevier B.V.},
year = {2015},
volume = {214-215},
pages = {456--472},
doi = {10.1016/j.agrformet.2015.09.007}
}
|
| Peralta-Tapia A, Sponseller RA, Ågren A, Tetzlaff D, Soulsby C and Laudon H (2015), "Scale-dependent groundwater contributions influence patterns of winter baseflow stream chemistry in boreal catchments", Journal of Geophysical Research: Biogeosciences., may, 2015. Vol. 120(5), pp. 847-858. |
| Abstract: Understanding how the sources of surface water change along river networks is an important challenge, with implications for soil-stream interactions, and our ability to predict hydrological and biogeochemical responses to environmental change. Network-scale patterns of stream water reflect distinct hydrological processes among headwater units, as well as variable contributions from deeper groundwater stores, which may vary nonlinearly with drainage basin size. Here we explore the spatial variability of groundwater inputs to streams, and the corresponding implications for surface water chemistry, during winter baseflow in a boreal river network. The relative contribution of recent and older groundwater was determined using stable isotopes of water (δ18O) at 78 locations ranging from small headwaters (0.12 km2) to fourth-order streams (68 km2) in combination with 79 precipitation and 10 deep groundwater samples. Results from a two end-member mixing model indicate that deeper groundwater inputs increased nonlinearly with drainage area, ranging from ∼20% in smaller headwater subcatchments to 70-80% for catchments with a 10.6 km2 area or larger. Increases in the groundwater contribution were positively correlated to network-scale patterns in surface stream pH and base cation concentrations and negatively correlated to dissolved organic carbon. These trends in chemical variables are consistent with the production of weathering products and the mineralization of organic matter along groundwater flow paths. Together, the use of stable isotopes and biogeochemical markers illustrate how variation in hydrologic routing and groundwater contributions shape network-scale patterns in stream chemistry as well as patchiness in the relative sensitivity of streams to environmental change and perturbation. |
BibTeX:
@article{Peralta-Tapia2015,
author = {Peralta-Tapia, Andrés and Sponseller, Ryan A and Ågren, Anneli and Tetzlaff, Doerthe and Soulsby, Chris and Laudon, Hjalmar},
title = {Scale-dependent groundwater contributions influence patterns of winter baseflow stream chemistry in boreal catchments},
journal = {Journal of Geophysical Research: Biogeosciences},
year = {2015},
volume = {120},
number = {5},
pages = {847--858},
url = {http://doi.wiley.com/10.1002/2014JG002878},
doi = {10.1002/2014JG002878}
}
|
| Peralta-Tapia A, Sponseller RA, Tetzlaff D, Soulsby C and Laudon H (2015), "Connecting precipitation inputs and soil flow pathways to stream water in contrasting boreal catchments", Hydrological Processes., jul, 2015. Vol. 29(16), pp. 3546-3555. |
| Abstract: Stable isotopes of water are one of the most widely used tools to track the pathways of precipitation inputs to streams. In the past, soils have often been treated as black-boxes through which precipitation is routed to streams without much consideration of how, when, and where water is transported along soil and groundwater flow paths. Here, we use time series of stable isotopes (sup18/supO) in precipitation, soil/groundwater, and stream water to evaluate how landscape structure and heterogeneity influence seasonal hydrological patterns characteristic of boreal headwater catchments. To do this, we collected water throughout a full year at three adjacent catchments draining forest, mire, and mire/lake ecosystems within the Krycklan Experimental Catchment of northern Sweden. Isotope time series from forest and mire groundwater piezometers showed spatial and temporal heterogeneity in the dominant hydrologic flow pathways connecting precipitation to stream flow at different sites. The isotopic signature of stream water suggested strong connections to the dominant landscape elements within each catchment. These connections translated into greater temporal variability in the isotopic response of streams draining lake and wetland patches, and a much more attenuated pattern in the forest-dominated catchment. Overall, seasonal changes in the isotopic composition of streams and groundwater illustrate how differences in landscape structure result in variable hydrological patterns in the boreal landscape. |
BibTeX:
@article{Peralta-Tapia2015a,
author = {Peralta-Tapia, A and Sponseller, R A and Tetzlaff, D and Soulsby, C and Laudon, H},
title = {Connecting precipitation inputs and soil flow pathways to stream water in contrasting boreal catchments},
journal = {Hydrological Processes},
year = {2015},
volume = {29},
number = {16},
pages = {3546--3555},
url = {http://doi.wiley.com/10.1002/hyp.10300},
doi = {10.1002/hyp.10300}
}
|
| Pérez-Priego O, López-Ballesteros A, Sánchez-Cañete EP, Serrano-Ortiz P, Kutzbach L, Domingo F, Eugster W and Kowalski AS (2015), "Analysing uncertainties in the calculation of fluxes using whole-plant chambers: random and systematic errors", Plant and Soil., aug, 2015. Vol. 393(1-2), pp. 229-244. Kluwer Academic Publishers. |
| Abstract: Aims: Gas exchange measurements on individual plants depend largely on chamber systems, and uncertainties and corrections in current flux calculation procedures require further assessment. Methods: We present a practical study with novel methods for analyses of flux uncertainties in an original chamber design excluding soil fluxes and allowing simultaneous measurements of whole-plant photosynthesis and transpiration. Results: Results indicate that random errors caused by IRGA noise and the lack of criteria to optimize the time window (TW) of chamber enclosure lead to significant flux uncertainties (12 %). Although enclosure should be rapid to minimize plant disturbances, longer TWs (3 min) increase confidence in flux estimates. Indeterminate stabilization periods in existing calculation protocols cause significant systematic errors. Stabilization times were identified via the change-point detection method, and flux uncertainties were reduced. Photosynthesis was overestimated by up to 28 % when not correcting the evolving CO2 molar fraction for water vapour dilution. Leakage can compromise flux estimates, but was negligible (ca. 2 %) here due to the large chamber-headspace and relatively small values of both collar contact length and closure time. Conclusions: A bootstrapping, resampling-based flux calculation method is presented and recommended to better assess random errors and improve flux precision. We present practical recommendations for the use of whole-plant chambers. |
BibTeX:
@article{Perez-Priego2015,
author = {Pérez-Priego, Oscar and López-Ballesteros, Ana and Sánchez-Cañete, Enrique P. and Serrano-Ortiz, Penélope and Kutzbach, Lars and Domingo, Francisco and Eugster, Werner and Kowalski, Andrew S.},
title = {Analysing uncertainties in the calculation of fluxes using whole-plant chambers: random and systematic errors},
journal = {Plant and Soil},
publisher = {Kluwer Academic Publishers},
year = {2015},
volume = {393},
number = {1-2},
pages = {229--244},
doi = {10.1007/s11104-015-2481-x}
}
|
| Personne E, Tardy F, Génermont S, Decuq C, Gueudet JC, Mascher N, Durand B, Masson S, Lauransot M, Fléchard C, Burkhardt J and Loubet B (2015), "Investigating sources and sinks for ammonia exchanges between the atmosphere and a wheat canopy following slurry application with trailing hose", Agricultural and Forest Meteorology., jul, 2015. Vol. 207, pp. 11-23. |
| Abstract: Ammonia exchanges between the atmosphere and terrestrial ecosystems are composed of several pathways including exchange with the soil, the litter, the plant surfaces (cuticle) and through the stomata. In this study, the fate of nitrogen in the different pools (soil and plant) was analyzed with the aim of determining the sources and sink of atmospheric ammonia after slurry application on a wheat canopy. To do this, we measured ammonia exchanges between a winter wheat canopy and the atmosphere following cattle slurry application with a trailing hose. From 12 March to 8 April in Grignon near Paris, France, the ammonia fluxes ranged from an emission peak of 54,300 NH3 ngm-2s-1 on the day of slurry application (with a median during the first 24h of 5990 NH3 ngm-2s-1) to a deposition flux of -600 NH3 ngm-2s-1 (with a median during the last period of -16 NH3 ngm-2s-1). The ammonia compensation points were evaluated for apoplasm, foliar bulk, root bulk and litter bulk tissue, as well as for soil surface. Ammonia emission potentials defined by the ratios between the concentration in [NH4+] and [H+] for each N ecosystem pool were in the same order of magnitude for the plant decomposed in apoplastic liquid, green leaf bulk tissue and cuticle, respectively, averaging at 73, 160 and 120; in green leaf bulk tissues, the emission potential decreased gradually from 230 to 78 during the period after slurry application, while in the dead leaf bulk tissues considered as litter, the emission potential reached a maximum of 50,200 after application stabilized at around 20000. The dynamic of the emission potential for roots was similar to the ammonium concentration in the first two centimeters of the soil, with a maximum of 820 reached two days after application and a minimum of 44 reached three weeks later. The surfatm-NH3 model interpreted the emission and deposition fluxes by testing soil surface resistance. We conclude that emission of the first day application was driven by climatic conditions and ammonia concentration at the soil surface, with no surface resistance and with only soil surface emission potential. On the next three days, the ammonia emission originated from the soil surface with the growth of a dry surface layer inducing surface resistance and regulated by slurry infiltration. The following days need a more detailed description of soil surface processes and the integration of vegetation exchanges (stomatal and cuticle pathways), particularly in the last period, in order to explain the ammonia deposition. |
BibTeX:
@article{Personne2015,
author = {Personne, Erwan and Tardy, Florence and Génermont, Sophie and Decuq, Céline and Gueudet, Jean Christophe and Mascher, Nicolas and Durand, Brigitte and Masson, Sylvie and Lauransot, Michel and Fléchard, Christophe and Burkhardt, Jürgen and Loubet, Benjamin},
title = {Investigating sources and sinks for ammonia exchanges between the atmosphere and a wheat canopy following slurry application with trailing hose},
journal = {Agricultural and Forest Meteorology},
year = {2015},
volume = {207},
pages = {11--23},
url = {http://linkinghub.elsevier.com/retrieve/pii/S0168192315000805},
doi = {10.1016/j.agrformet.2015.03.002}
}
|
| Petrescu AMR, Lohila A, Tuovinen JP, Baldocchi DD, Desai AR, Roulet NT, Vesala T, Dolman AJ, Oechel WC, Marcolla B, Friborg T, Rinne J, Matthes JH, Merbold L, Meijide A, Kiely G, Sottocornola M, Sachs T, Zona D, Varlagin A, Lai DYF, Veenendaal E, Parmentier FJW, Skiba U, Lund M, Hensen A, Van Huissteden J, Flanagan LB, Shurpali NJ, Grünwald T, Humphreys ER, Jackowicz-Korczyʼnski M, Aurela MA, Laurila T, Grüning C, Corradi CAR, Schrier-Uijl AP, Christensen TR, Tamstorf MP, Mastepanov M, Martikainen PJ, Verma SB, Bernhofer C and Cescatti A (2015), "The uncertain climate footprint of wetlands under human pressure", Proceedings of the National Academy of Sciences of the United States of America., apr, 2015. Vol. 112(15), pp. 4594-4599. |
| Abstract: Significant climate risks are associated with a positive carbon-temperature feedback in northern latitude carbon-rich ecosystems, making an accurate analysis of human impacts on the net greenhouse gas balance of wetlands a priority. Here, we provide a coherent assessment of the climate footprint of a network of wetland sites based on simultaneous and quasi-continuous ecosystem observations of COinf2/inf and CHinf4/inf fluxes. Experimental areas are located both in natural and in managed wetlands and cover a wide range of climatic regions, ecosystem types, and management practices. Based on direct observations we predict that sustained CHinf4/inf emissions in natural ecosystems are in the long term (i.e., several centuries) typically offset by COinf2/inf uptake, although with large spatiotemporal variability. Using a space-for-time analogy across ecological and climatic gradients, we represent the chronosequence from natural to managed conditions to quantify the "cost" of CHinf4/inf emissions for the benefit of net carbon sequestration. With a sustained pulse-response radiative forcing model, we found a significant increase in atmospheric forcing due to land management, in particular for wetland converted to cropland. Our results quantify the role of human activities on the climate footprint of northern wetlands and call for development of active mitigation strategies for managed wetlands and new guidelines of the Intergovernmental Panel on Climate Change (IPCC) accounting for both sustained CHinf4/inf emissions and cumulative COinf2/inf exchange. |
BibTeX:
@article{Petrescu2015,
author = {Petrescu, Ana Maria Roxana and Lohila, Annalea and Tuovinen, Juha Pekka and Baldocchi, Dennis D and Desai, Ankur R and Roulet, Nigel T and Vesala, Timo and Dolman, Albertus Johannes and Oechel, Walter C and Marcolla, Barbara and Friborg, Thomas and Rinne, Janne and Matthes, Jaclyn Hatala and Merbold, Lutz and Meijide, Ana and Kiely, Gerard and Sottocornola, Matteo and Sachs, Torsten and Zona, Donatella and Varlagin, Andrej and Lai, Derrick Y F and Veenendaal, Elmar and Parmentier, Frans Jan W and Skiba, Ute and Lund, Magnus and Hensen, Arjan and Van Huissteden, Jacobus and Flanagan, Lawrence B and Shurpali, Narasinha J and Grünwald, Thomas and Humphreys, Elyn R and Jackowicz-Korczyʼnski, Marcin and Aurela, Mika A and Laurila, Tuomas and Grüning, Carsten and Corradi, Chiara A R and Schrier-Uijl, Arina P and Christensen, Torben R and Tamstorf, Mikkel P and Mastepanov, Mikhail and Martikainen, Pertti J and Verma, Shashi B and Bernhofer, Christian and Cescatti, Alessandro},
title = {The uncertain climate footprint of wetlands under human pressure},
journal = {Proceedings of the National Academy of Sciences of the United States of America},
year = {2015},
volume = {112},
number = {15},
pages = {4594--4599},
url = {http://www.pnas.org/lookup/doi/10.1073/pnas.1416267112},
doi = {10.1073/pnas.1416267112}
}
|
| Post H, Hendricks Franssen HJ, Graf A, Schmidt M and Vereecken H (2015), "Uncertainty analysis of eddy covariance CO2 flux measurements for different EC tower distances using an extended two-tower approach", Biogeosciences., feb, 2015. Vol. 12(4), pp. 1205-1221. |
| Abstract: The use of eddy covariance (EC) CO2 flux measurements in data assimilation and other applications requires an estimate of the random uncertainty. In previous studies, the (classical) two-tower approach has yielded robust uncertainty estimates, but care must be taken to meet the often competing requirements of statistical independence (non-overlapping footprints) and ecosystem homogeneity when choosing an appropriate tower distance. The role of the tower distance was investigated with help of a roving station separated between 8 m and 34 km from a permanent EC grassland station. Random uncertainty was estimated for five separation distances with the classical two-tower approach and an extended approach which removed systematic differences of CO2 fluxes measured at two EC towers. This analysis was made for a data set where (i) only similar weather conditions at the two sites were included, and (ii) an unfiltered one. The extended approach, applied to weather-filtered data for separation distances of 95 and 173 m gave uncertainty estimates in best correspondence with an independent reference method. The introduced correction for systematic flux differences considerably reduced the overestimation of the two-tower based uncertainty of net CO2 flux measurements and decreased the sensitivity of results to tower distance. We therefore conclude that corrections for systematic flux differences (e.g., caused by different environmental conditions at both EC towers) can help to apply the two-tower approach to more site pairs with less ideal conditions. |
BibTeX:
@article{Post2015,
author = {Post, H and Hendricks Franssen, H J and Graf, A and Schmidt, M and Vereecken, H},
title = {Uncertainty analysis of eddy covariance CO2 flux measurements for different EC tower distances using an extended two-tower approach},
journal = {Biogeosciences},
year = {2015},
volume = {12},
number = {4},
pages = {1205--1221},
url = {http://www.biogeosciences.net/12/1205/2015/},
doi = {10.5194/bg-12-1205-2015}
}
|
| Potier E, Ogée J, Jouanguy J, Lamaud E, Stella P, Personne E, Durand B, Mascher N and Loubet B (2015), "Multilayer modelling of ozone fluxes on winter wheat reveals large deposition on wet senescing leaves", Agricultural and Forest Meteorology., oct, 2015. Vol. 211-212, pp. 58-71. Elsevier. |
| Abstract: Understanding how ozone is deposited on vegetation canopies is needed to perform tropospheric greenhouse gas budgets and evaluate the associated damage on vegetation. In this study, we propose a new multilayer scheme of ozone deposition on vegetation canopies that predicts stomatal, cuticular and soil deposition pathways separately. This mechanistic ozone deposition scheme is based on the multi-layer, multi-leaf mass and energy transfer model MuSICA. This model was chosen because it explicitly simulates the processes of rain interception, through fall and evaporation at different depths within the vegetation canopy, so that ozone deposition on wet leaf cuticles can be explicitly modelled with ozone dissolution, diffusion and chemical reaction inside the water films. The model was evaluated against a 3-year dataset of ozone, COtextlessinftextgreater2textless/inftextgreater and evapotranspiration flux measurements over a winter wheat field near Paris, France (ICOS Fr-GRI). Only periods with fully developed canopies (including senescence) were considered to minimise the contribution of soil deposition to the total ozone flux. Before senescence, the model could reproduce the measured ozone deposition rates as well as the COtextlessinftextgreater2textless/inftextgreater and water vapour fluxes. During senescence, large ozone deposition rates were observed under wet canopy conditions that could only be explained by first-order reaction rates in the water film of around 10textlesssuptextgreater5textless/suptextgreaterstextlesssuptextgreater-1textless/suptextgreater. Such reaction rates are not compatible with the chemical composition of rainwater. We therefore hypothesise that, during senescence, the cell content leaks out of the leaves when they become wet, exposing anti-oxidants to ozone. These results provide for the first time a mechanistic explanation of the commonly observed increase in ozone deposition rates during rain or dew formation. |
BibTeX:
@article{Potier2015,
author = {Potier, E. and Ogée, J. and Jouanguy, J. and Lamaud, E. and Stella, P. and Personne, E. and Durand, B. and Mascher, N. and Loubet, B.},
title = {Multilayer modelling of ozone fluxes on winter wheat reveals large deposition on wet senescing leaves},
journal = {Agricultural and Forest Meteorology},
publisher = {Elsevier},
year = {2015},
volume = {211-212},
pages = {58--71},
doi = {10.1016/j.agrformet.2015.05.006}
}
|
| Raivonen M, Mäkiranta P, Lohila A, Juutinen S, Vesala T and Tuittila ES (2015), "A simple CO2 exchange model simulates the seasonal leaf area development of peatland sedges", Ecological Modelling., oct, 2015. Vol. 314, pp. 32-43. Elsevier. |
| Abstract: Sedges (Cyperaceae) are dominant plants in many northern wetlands and contribute to the carbon cycling in several ways. In order to more accurately estimate the carbon balance of a wetland it is essential to be able to simulate the temporal changes of the leaf area of the sedges. Our aim was to test the ability of a simple carbon dioxide (CO2) exchange model to predict the seasonal development of sedge leaf area index (LAI). The model simulates the development of sedge LAI that depends on carbon gain/loss in net photosynthesis, utilization of stored carbon in spring, and LAI decline due to senescence in late summer. The net photosynthesis model is driven by LAI, air temperature, water table depth and photosynthetically active radiation. We parameterized and validated the model with two years of observational LAI data from two boreal pristine peatland sites and included data points from both pristine and manipulated (drainage and warming) treatment plots. Model parameter values other than the timing of the start of senescence, LAI decline rate in senescence and size of carbon storage were independent of observational data. The model successfully simulated the seasonal course of LAI development and is thus an easy and adjustable tool for producing estimates of sedge LAI for other peatland sites. It can be adjusted to different sites although it cannot predict the exact LAI level of a site that is controlled by site characteristics. Its ability to simulate the interannual variation in this two-year dataset was inadequate so there is a need to test the model against longer time series of measured LAIs in order to validate models' capability to predict the interannual variability of LAI. |
BibTeX:
@article{Raivonen2015,
author = {Raivonen, Maarit and Mäkiranta, Päivi and Lohila, Annalea and Juutinen, Sari and Vesala, Timo and Tuittila, Eeva Stiina},
title = {A simple CO2 exchange model simulates the seasonal leaf area development of peatland sedges},
journal = {Ecological Modelling},
publisher = {Elsevier},
year = {2015},
volume = {314},
pages = {32--43},
doi = {10.1016/j.ecolmodel.2015.07.008}
}
|
| Rantakari M, Heiskanen J, Mammarella I, Tulonen T, Linnaluoma J, Kankaala P and Ojala A (2015), "Different Apparent Gas Exchange Coefficients for CO2 and CH4: Comparing a Brown-Water and a Clear-Water Lake in the Boreal Zone during the Whole Growing Season", Environmental Science and Technology., oct, 2015. Vol. 49(19), pp. 11388-11394. |
| Abstract: The air-water exchange of carbon dioxide (CO2) and methane (CH4) is a central process during attempts to establish carbon budgets for lakes and landscapes containing lakes. Lake-atmosphere diffusive gas exchange is dependent on the concentration gradient between air and surface water and also on the gas transfer velocity, often described with the gas transfer coefficient k. We used the floating-chamber method in connection with surface water gas concentration measurements to estimate the gas transfer velocity of CO2 (kCO2) and CH4 (kCH4) weekly throughout the entire growing season in two contrasting boreal lakes, a humic oligotrophic lake and a clear-water productive lake, in order to investigate the earlier observed differences between kCO2 and kCH4. We found that the seasonally averaged gas transfer velocity of CH4 was the same for both lakes. When the lakes were sources of CO2, the gas transfer velocity of CO2 was also similar between the two study lakes. The gas transfer velocity of CH4 was constantly higher than that of CO2 in both lakes, a result also found in other studies but for reasons not yet fully understood. We found no differences between the lakes, demonstrating that the difference between kCO2 and kCH4 is not dependent on season or the characteristics of the lake. |
BibTeX:
@article{Rantakari2015,
author = {Rantakari, Miitta and Heiskanen, Jouni and Mammarella, Ivan and Tulonen, Tiina and Linnaluoma, Jessica and Kankaala, Paula and Ojala, Anne},
title = {Different Apparent Gas Exchange Coefficients for CO2 and CH4: Comparing a Brown-Water and a Clear-Water Lake in the Boreal Zone during the Whole Growing Season},
journal = {Environmental Science and Technology},
year = {2015},
volume = {49},
number = {19},
pages = {11388--11394},
url = {http://pubs.acs.org/doi/10.1021/acs.est.5b01261},
doi = {10.1021/acs.est.5b01261}
}
|
| Rhoderick GC, Hall BD, Harth CM, Kim JS, Lee J, Montzka SA, Mühle J, Reimann S, Vollmer MK and Weiss RF (2015), "Comparison of halocarbon measurements in an atmospheric dry whole air sampleInter-comparison of halocarbons in an atmospheric dry whole air sample", Elementa., nov, 2015. Vol. 3, pp. 75. |
| Abstract: The growing awareness of climate change/global warming, and continuing concerns regarding stratospheric ozone depletion, will require continued measurements and standards for many compounds, in particular halocarbons that are linked to these issues. In order to track atmospheric mole fractions and assess the impact of policy on emission rates, it is necessary to demonstrate measurement equivalence at the highest levels of accuracy for assigned values of standards. Precise measurements of these species aid in determining small changes in their atmospheric abundance. A common source of standards/scales and/or well-documented agreement of different scales used to calibrate the measurement instrumentation are key to understanding many sets of data reported by researchers. This report describes the results of a comparison study among National Metrology Institutes and atmospheric research laboratories for the chlorofluorocarbons (CFCs) dichlorodifluoromethane (CFC-12), trichlorofluoromethane (CFC-11), and 1,1,2-trichlorotrifluoroethane (CFC-113); the hydrochlorofluorocarbons (HCFCs) chlorodifluoromethane (HCFC-22) and 1-chloro-1,1-difluoroethane (HCFC-142b); and the hydrofluorocarbon (HFC) 1,1,1,2-tetrafluoroethane (HFC-134a), all in a dried whole air sample. The objective of this study is to compare calibration standards/scales and the measurement capabilities of the participants for these halocarbons at trace atmospheric levels. The results of this study show agreement among four independent calibration scales to better than 2.5% in almost all cases, with many of the reported agreements being better than 1.0%. |
BibTeX:
@article{Rhoderick2015,
author = {Rhoderick, George C and Hall, Bradley D and Harth, Christina M and Kim, Jin Seog and Lee, Jeongsoon and Montzka, Stephen A and Mühle, Jens and Reimann, Stefan and Vollmer, Martin K and Weiss, Ray F},
title = {Comparison of halocarbon measurements in an atmospheric dry whole air sampleInter-comparison of halocarbons in an atmospheric dry whole air sample},
journal = {Elementa},
year = {2015},
volume = {3},
pages = {75},
url = {http://elementascience.org/article/info:doi/10.12952/journal.elementa.000075},
doi = {10.12952/journal.elementa.000075}
}
|
| Richter F, Döring C, Jansen M, Panferov O, Spank U and Bernhofer C (2015), "How to predict hydrological effects of local land use change: How the vegetation parameterisation for short rotation coppices influences model results", Hydrology and Earth System Sciences., aug, 2015. Vol. 19(8), pp. 3457-3474. |
| Abstract: Among the different bioenergy sources, short rotation coppices (SRC) with poplar and willow trees are one of the promising options in Europe. SRC provide not only woody biomass but also additional ecosystem services. However, a known shortcoming is the potentially lower groundwater recharge caused by the potentially higher evapotranspiration demand compared to annual crops. The complex feedbacks between vegetation cover and water cycle can be only correctly assessed by application of well-parameterised and calibrated numerical models. In the present study, the hydrological model system WaSim (Wasserhaushalts-Simulations-Model) is implemented for assessment of the water balance. The focus is the analysis of simulation uncertainties caused by the use of guidelines or transferred parameter sets from scientific literature compared to "actual" parameterisations derived from local measurements of leaf area index (LAI), stomatal resistance (Rsc) and date of leaf unfolding (LU). The analysis showed that uncertainties in parameterisation of vegetation lead to implausible model results. LAI, Rsc and LU are the most sensitive plant physiological parameters concerning the effects of enhanced SRC cultivation on water budget or groundwater recharge. Particularly sensitive is the beginning of the growing season, i.e. LU. When this estimation is wrong, the accuracy of LAI and Rsc description plays a minor role. Our analyses illustrate that the use of locally measured vegetation parameters, like maximal LAI, and meteorological variables, like air temperature, to estimate LU give better results than literature data or data from remote network stations. However, the direct implementation of locally measured data is not always advisable or possible. Regarding Rsc, the adjustment of local measurements gives the best model evaluation. For local and accurate studies, measurements of model sensitive parameters like LAI, Rsc and LU are valuable information. The derivation of these model parameters based on local measurements shows the best model fit. Additionally, the adjusted seasonal course of LAI and Rsc is less sensitive to different estimates for LU. Different parameterisations, as they are all eligible either from local measurements or scientific literature, can result in modelled ground water recharge to be present or completely absent in certain years under poplar SRC. |
BibTeX:
@article{Richter2015,
author = {Richter, F and Döring, C and Jansen, M and Panferov, O and Spank, U and Bernhofer, C},
title = {How to predict hydrological effects of local land use change: How the vegetation parameterisation for short rotation coppices influences model results},
journal = {Hydrology and Earth System Sciences},
year = {2015},
volume = {19},
number = {8},
pages = {3457--3474},
url = {http://www.hydrol-earth-syst-sci.net/19/3457/2015/},
doi = {10.5194/hess-19-3457-2015}
}
|
| Rödenbeck C, Bakker DC, Gruber N, Iida Y, Jacobson AR, Jones S, Landschützer P, Metzl N, Nakaoka S, Olsen A, Park GH, Peylin P, Rodgers KB, Sasse TP, Schuster U, Shutler JD, Valsala V, Wanninkhof R and Zeng J (2015), "Data-based estimates of the ocean carbon sink variability - First results of the Surface Ocean pCO2 Mapping intercomparison (SOCOM)", Biogeosciences., dec, 2015. Vol. 12(23), pp. 7251-7278. Copernicus GmbH. |
| Abstract: Using measurements of the surface-ocean CO2 partial pressure (pCO2) and 14 different pCO2 mapping methods recently collated by the Surface Ocean pCO2 Mapping intercomparison (SOCOM) initiative, variations in regional and global sea-air CO2 fluxes are investigated. Though the available mapping methods use widely different approaches, we find relatively consistent estimates of regional pCO2 seasonality, in line with previous estimates. In terms of interannual variability (IAV), all mapping methods estimate the largest variations to occur in the eastern equatorial Pacific. Despite considerable spread in the detailed variations, mapping methods that fit the data more closely also tend to agree more closely with each other in regional averages. Encouragingly, this includes mapping methods belonging to complementary types - taking variability either directly from the pCO2 data or indirectly from driver data via regression. From a weighted ensemble average, we find an IAV amplitude of the global sea-air CO2 flux of 0.31 PgC yr1 (standard deviation over 1992-2009), which is larger than simulated by biogeochemical process models. From a decadal perspective, the global ocean CO2 uptake is estimated to have gradually increased since about 2000, with little decadal change prior to that. The weighted mean net global ocean CO2 sink estimated by the SOCOM ensemble is -1.75 PgC yr1 (1992-2009), consistent within uncertainties with estimates from ocean-interior carbon data or atmospheric oxygen trends. |
BibTeX:
@article{Rodenbeck2015,
author = {Rödenbeck, C. and Bakker, D. C.E. and Gruber, N. and Iida, Y. and Jacobson, A. R. and Jones, S. and Landschützer, P. and Metzl, N. and Nakaoka, S. and Olsen, A. and Park, G. H. and Peylin, P. and Rodgers, K. B. and Sasse, T. P. and Schuster, U. and Shutler, J. D. and Valsala, V. and Wanninkhof, R. and Zeng, J.},
title = {Data-based estimates of the ocean carbon sink variability - First results of the Surface Ocean pCO2 Mapping intercomparison (SOCOM)},
journal = {Biogeosciences},
publisher = {Copernicus GmbH},
year = {2015},
volume = {12},
number = {23},
pages = {7251--7278},
doi = {10.5194/bg-12-7251-2015}
}
|
| Roland M, Vicca S, Bahn M, Ladreiter-Knauss T, Schmitt M and Janssens IA (2015), "Importance of nondiffusive transport for soil CO2 efflux in a temperate mountain grassland", Journal of Geophysical Research: Biogeosciences., aug, 2015. Vol. 120(3), pp. 502-512. Blackwell Publishing Ltd. |
| Abstract: Soil respiration and its biotic and abiotic drivers have been an important research topic in recent years. While the bulk of these efforts has focused on the emission of CO2 from soils, the production and subsequent transport of CO2 from soil to atmosphere received far less attention. However, to understand processes underlying emissions of CO2 from terrestrial ecosystems, both processes need to be fully evaluated. In this study, we tested to what extent the transport of CO2 in a grassland site in the Austrian Alps could be modeled based on the common assumption that diffusion is the main transport mechanism for trace gases in soils. Therefore, we compared the CO2 efflux calculated from the soil CO2 concentration gradient with the CO2 efflux from chamber measurements. We used four commonly used diffusion-driven models for the flux-gradient approach. Models generally underestimated the soil chamber effluxes and their amplitudes, indicating that processes other than diffusion were responsible for the transport of CO2. We further observed that transport rates correlated well with irradiation and, below a soil moisture content of 33%, with wind speed. This suggests that mechanisms such as bulk soil air transport, due to pressure pumping or thermal expansion of soil air due to local surface heating, considerably influence soil CO2 transport at this site. Our results suggest that nondiffusive transport may be an important mechanism influencing diel and day-to-day dynamics of soil CO2 emissions, leading to a significant mismatch (10-87% depending on the model used) between the two approaches at short time scales. |
BibTeX:
@article{Roland2015,
author = {Roland, Marilyn and Vicca, Sara and Bahn, Michael and Ladreiter-Knauss, Thomas and Schmitt, Michael and Janssens, Ivan A.},
title = {Importance of nondiffusive transport for soil CO2 efflux in a temperate mountain grassland},
journal = {Journal of Geophysical Research: Biogeosciences},
publisher = {Blackwell Publishing Ltd},
year = {2015},
volume = {120},
number = {3},
pages = {502--512},
doi = {10.1002/2014JG002788}
}
|
| Santoro M, Eriksson LEB and Fransson JES (2015), "Reviewing ALOS PALSAR backscatter observations for stem volume retrieval in Swedish forest", Remote Sensing., apr, 2015. Vol. 7(4), pp. 4290-4317. |
| Abstract: Between 2006 and 2011, the Advanced Land Observing Satellite (ALOS) Phased Array L-type Synthetic Aperture Radar (PALSAR) instrument acquired multi-temporal datasets under several environmental conditions and multiple configurations of look angle and polarization. The extensive archive of SAR backscatter observations over the forest test sites of Krycklan (boreal) and Remningstorp (hemi-boreal), Sweden, was used to assess the retrieval of stem volume at stand level. The retrieval was based on the inversion of a simple Water Cloud Model with gaps; single estimates of stem volume are then combined to obtain the final multi-temporal estimate. The model matched the relationship between the SAR backscatter and the stem volume under all configurations. The retrieval relative Root Mean Square Error (RMSE) differed depending upon environmental conditions, polarization and look angle. Stem volume was best retrieved in Krycklan using only HV-polarized data acquired under unfrozen conditions with a look angle of 34.3° (relative RMSE: 44.0%). In Remningstorp, the smallest error was obtained using only HH-polarized data acquired under predominantly frozen conditions with a look angle of 34.3° (relative RMSE: 35.1%). The relative RMSE was below 30% for stands 20 ha, suggesting high accuracy of ALOS PALSAR estimates of stem volumes aggregated at moderate resolution. |
BibTeX:
@article{Santoro2015,
author = {Santoro, Maurizio and Eriksson, Leif E B and Fransson, Johan E S},
title = {Reviewing ALOS PALSAR backscatter observations for stem volume retrieval in Swedish forest},
journal = {Remote Sensing},
year = {2015},
volume = {7},
number = {4},
pages = {4290--4317},
url = {http://www.mdpi.com/2072-4292/7/4/4290},
doi = {10.3390/rs70404290}
}
|
| Schelker J, Sponseller R, Ring E, Högbom L, Löfgren S and Laudon H (2015), "Nitrogen export from a boreal stream network following forest harvesting: seasonal nitrate removal and conservative export of organic forms", Biogeosciences Discussions., aug, 2015. Vol. 12(15), pp. 12061-12089. |
| Abstract: Abstract. Boreal streams are under pressure from large scale disturbance by forestry. Recent scenarios predict an increase in forest production in Scandinavia to meet market demands and to mitigate higher anthropogenic CO2 emissions. Increased fertilization and shorter forest rotations are anticipated which will likely enhance the pressure on boreal streams in the near future. Among the major environmental impacts of forest harvesting is the increased mobilization of inorganic nitrogen (N), primarily as nitrate (NO3-) into surface waters. But whereas NO3- inputs to first-order streams have been previously described, their downstream fate and impact is not well understood. We evaluated the downstream fate of N inputs in a boreal landscape that has been altered by forest harvests over a 10 year period to estimate the effects of multiple clear-cuts on aquatic N export in a boreal stream network. Small streams showed substantial leaching of NO3- in response to harvests with concentrations increasing by ˜ 15 fold. NO3- concentrations at two sampling stations further downstream in the network were strongly seasonal and increased significantly in response to harvesting at the medium size, but not at the larger stream. Nitrate removal efficiency, Er, calculated as the percentage of "forestry derived" NO3- that was retained within the landscape using a mass balance model was highest during the snow melt season followed by the growing season, but declined continuously throughout the dormant season. In contrast, export of organic N from the landscape indicated little removal and was essentially conservative. Overall, net removal of NO3- between 2008 and 2011 accounted for ˜ 70 % of the total NO3- mass exported from harvested patches distributed across the landscape. These results highlight the capacity and limitation of N-limited terrestrial and aquatic ecosystems to buffer inorganic N mobilization that arises from multiple clear-cuts within meso-scale boreal watersheds. |
BibTeX:
@article{Schelker2015,
author = {Schelker, J and Sponseller, R and Ring, E and Högbom, L and Löfgren, S and Laudon, H},
title = {Nitrogen export from a boreal stream network following forest harvesting: seasonal nitrate removal and conservative export of organic forms},
journal = {Biogeosciences Discussions},
year = {2015},
volume = {12},
number = {15},
pages = {12061--12089},
url = {http://www.biogeosciences-discuss.net/12/12061/2015/},
doi = {10.5194/bgd-12-12061-2015}
}
|
| Schibig MF, Steinbacher M, Buchmann B, Van Der Laan-Luijkx IT, Van Der Laan S, Ranjan S and Leuenberger MC (2015), "Comparison of continuous in situ CO2 observations at Jungfraujoch using two different measurement techniques", Atmospheric Measurement Techniques., jan, 2015. Vol. 8(1), pp. 57-68. |
| Abstract: Since 2004, atmospheric carbon dioxide (CO2) is being measured at the High Altitude Research Station Jungfraujoch by the division of Climate and Environmental Physics at the University of Bern (KUP) using a nondispersive infrared gas analyzer (NDIR) in combination with a paramagnetic O2 analyzer. In January 2010, CO2 measurements based on cavity ring-down spectroscopy (CRDS) as part of the Swiss National Air Pollution Monitoring Network were added by the Swiss Federal Laboratories for Materials Science and Technology (Empa). To ensure a smooth transition-a prerequisite when merging two data sets, e.g., for trend determinations-the two measurement systems run in parallel for several years. Such a long-term intercomparison also allows the identification of potential offsets between the two data sets and the collection of information about the compatibility of the two systems on different time scales. A good agreement of the seasonality, short-term variations and, to a lesser extent mainly due to the short common period, trend calculations is observed. However, the comparison reveals some issues related to the stability of the calibration gases of the KUP system and their assigned CO2 mole fraction. It is possible to adapt an improved calibration strategy based on standard gas determinations, which leads to better agreement between the two data sets. By excluding periods with technical problems and bad calibration gas cylinders, the average hourly difference (CRDS-NDIR) of the two systems is g'0.03 ppm ± 0.25 ppm. Although the difference of the two data sets is in line with the compatibility goal of ±0.1 ppm of the World Meteorological Organization (WMO), the standard deviation is still too high. A significant part of this uncertainty originates from the necessity to switch the KUP system frequently (every 12 min) for 6 min from ambient air to a working gas in order to correct short-term variations of the O2 measurement system. Allowing additional time for signal stabilization after switching the sample, an effective data coverage of only one-sixth for the KUP system is achieved while the Empa system has a nearly complete data coverage. Additionally, different internal volumes and flow rates may affect observed differences. |
BibTeX:
@article{Schibig2015,
author = {Schibig, M F and Steinbacher, M and Buchmann, B and Van Der Laan-Luijkx, I T and Van Der Laan, S and Ranjan, S and Leuenberger, M C},
title = {Comparison of continuous in situ CO2 observations at Jungfraujoch using two different measurement techniques},
journal = {Atmospheric Measurement Techniques},
year = {2015},
volume = {8},
number = {1},
pages = {57--68},
url = {http://www.atmos-meas-tech.net/8/57/2015/},
doi = {10.5194/amt-8-57-2015}
}
|
| Schneider B, Buecker S, Kaitala S, Maunula P and Wasmund N (2015), "Characteristics of the spring/summer production in the Mecklenburg Bight (Baltic Sea) as revealed by long-term pCO2 data", Oceanologia., oct, 2015. Vol. 57(4), pp. 375-385. |
| Abstract: Summary Automated CO2 partial pressure, pCO2, measurements were performed on a cargo ship that commutes between the Gulf of Finland and the Mecklenburg Bight in the southwest of the Baltic Sea. The data from 2004 to 2014 along a sub-transect in the Mecklenburg Bight are used to analyze the timing and intensity of the net community production (NCP). The start of the spring bloom, identified by the first continuous drop of the pCO2 below the atmospheric level, spanned from mid-February to mid-March. Converting the pCO2 decrease during spring to changes in the total CO2 concentration and taking into account air-sea gas exchange, the spring NCP was determined. The NCP increased by about 80% during 2004-2014, the mean amounted to 40 μmol L-1. In two years a distinct second pCO2 minimum in mid-summer succeeded the minimum in spring. This was attributed to production fuelled by nitrogen fixation since the nitrate concentrations were virtually zero and since the atmospheric deposition could not satisfy the NCP nitrogen demand. Furthermore, investigations of the plankton composition revealed a cyanobacteria biomass peak in the year with the highest mid-summer NCP. Based on the calculation of the mid-summer NCP in the two particular years and on the C/N ratio of particulate organic matter, the corresponding nitrogen fixation activity was calculated. These values and the analysis of the relationship between the integrated NCP and temperature indicated that the nitrogen fixation activity in the Mecklenburg Bight was by a factor 3-4 lower than in the central Baltic Sea. |
BibTeX:
@article{Schneider2015,
author = {Schneider, B and Buecker, S and Kaitala, S and Maunula, P and Wasmund, N},
title = {Characteristics of the spring/summer production in the Mecklenburg Bight (Baltic Sea) as revealed by long-term pCO2 data},
journal = {Oceanologia},
year = {2015},
volume = {57},
number = {4},
pages = {375--385},
url = {http://linkinghub.elsevier.com/retrieve/pii/S0078323415000901},
doi = {10.1016/j.oceano.2015.07.001}
}
|
| Schoenenberger F, Vollmer MK, Rigby M, Hill M, Fraser PJ, Krummel PB, Langenfelds RL, Rhee TS, Peter T and Reimann S (2015), "First observations, trends, and emissions of HCFC-31 (CH2ClF) in the global atmosphere", Geophysical Research Letters., sep, 2015. Vol. 42(18), pp. 7817-7824. |
| Abstract: We report the first multiyear atmospheric record of HCFC-31 (CH2ClF), based on flask samples and in situ analyses of air from both hemispheres. Although HCFC-31 has never been produced in large amounts, observed mole fractions in the Northern Hemisphere increased from 2000 onward, reaching 170 ppq (parts per quadrillion, 10-15) in 2011-2012 before decreasing rapidly. By combining our observations with a two-dimensional atmospheric chemistry-transport model, we infer an increase in global emissions from 240- t- yr-1 in 2000 to 840- t- yr-1 in 2011-2012, followed by a relatively fast decline to 570- t- yr-1 in 2014. Emissions of HCFC-31 originate most probably from intermediate product release during the manufacturing process of HFC-32 (CH2F2). The rapid decline in recent years could be due to changes in production methods rather than declines in diffusive sources such as landfills or HCFC-31 contaminations in merchandised HFC-32. Key Point First observations of HCFC-31 in the atmosphere |
BibTeX:
@article{Schoenenberger2015,
author = {Schoenenberger, Fabian and Vollmer, Martin K and Rigby, Matt and Hill, Matthias and Fraser, Paul J and Krummel, Paul B and Langenfelds, Ray L and Rhee, Tae Siek and Peter, Thomas and Reimann, Stefan},
title = {First observations, trends, and emissions of HCFC-31 (CH2ClF) in the global atmosphere},
journal = {Geophysical Research Letters},
year = {2015},
volume = {42},
number = {18},
pages = {7817--7824},
url = {http://doi.wiley.com/10.1002/2015GL064709},
doi = {10.1002/2015GL064709}
}
|
| Schurgers G, Lagergren F, Mölder M and Lindroth A (2015), "The importance of micrometeorological variations for photosynthesis and transpiration in a boreal coniferous forest", Biogeosciences., jan, 2015. Vol. 12(1), pp. 237-256. |
| Abstract: Plant canopies affect the canopy micrometeorology, and thereby alter canopy exchange processes. For the simulation of these exchange processes on a regional or global scale, large-scale vegetation models often assume homogeneous environmental conditions within the canopy. In this study, we address the importance of vertical variations in light, temperature, CO2 concentration and humidity within the canopy for fluxes of photosynthesis and transpiration of a boreal coniferous forest in central Sweden. A leaf-level photosynthesis-stomatal conductance model was used for aggregating these processes to canopy level while applying the within-canopy distributions of these driving variables. The simulation model showed good agreement with eddy covariance-derived gross primary production (GPP) estimates on daily and annual timescales, and showed a reasonable agreement between transpiration and observed H2O fluxes, where discrepancies are largely attributable to a lack of forest floor evaporation in the model. Simulations in which vertical heterogeneity was artificially suppressed revealed that the vertical distribution of light is the driver of vertical heterogeneity. Despite large differences between above-canopy and within-canopy humidity, and despite large gradients in CO2 concentration during early morning hours after nights with stable conditions, neither humidity nor CO2 played an important role for vertical heterogeneity of photosynthesis and transpiration. |
BibTeX:
@article{Schurgers2015,
author = {Schurgers, G and Lagergren, F and Mölder, M and Lindroth, A},
title = {The importance of micrometeorological variations for photosynthesis and transpiration in a boreal coniferous forest},
journal = {Biogeosciences},
year = {2015},
volume = {12},
number = {1},
pages = {237--256},
url = {http://www.biogeosciences.net/12/237/2015/},
doi = {10.5194/bg-12-237-2015}
}
|
| Siegenthaler A, Welch B, Pangala SR, Peacock M and Gauci V (2015), "Technical Note: Semi-rigid chambers for methane gas flux measurements on tree-stems", Biogeosciences Discussions., sep, 2015. Vol. 12(18), pp. 16019-16048. |
| Abstract: Abstract. There is increasing interest in the measurement of methane (CH4) emissions from tree stems in a wide range of ecosystems so as to determine how they contribute to the total ecosystem flux. To date, tree CH4 fluxes are commonly measured using rigid closed chambers (static or dynamic), which often pose challenges as these are bulky and limit measurement of CH4 fluxes to only a very narrow range of tree stem sizes and shapes. To overcome these challenges we aimed to design, describe and test new semi-rigid stem-flux chambers (or sleeves). We compared semi-rigid chamber's gas permeability to CH4 against the traditional rigid chamber approach, in the laboratory and in the field, with continuous flow or syringe injections. We found that the semi-rigid chambers performed well, and had numerous benefits including reduced gas permeability and optimal stem gas exchange surface to total chamber volume ratio (Sc/Vtot) allowing better headspace mixing, especially when connected in a dynamic mode to a continuous flow gas analyser. Semi-rigid sleeves can easily be constructed and transported in multiple sizes, are extremely light, cheap to build and fast to deploy. This makes them ideal for use in remote ecosystems where access logistics are complicated. |
BibTeX:
@article{Siegenthaler2015,
author = {Siegenthaler, A and Welch, B and Pangala, S R and Peacock, M and Gauci, V},
title = {Technical Note: Semi-rigid chambers for methane gas flux measurements on tree-stems},
journal = {Biogeosciences Discussions},
year = {2015},
volume = {12},
number = {18},
pages = {16019--16048},
url = {http://www.biogeosciences-discuss.net/12/16019/2015/},
doi = {10.5194/bgd-12-16019-2015}
}
|
| Song J, Fan W, Li S and Zhou M (2015), "Impact of Surface Waves on the Steady Near-Surface Wind Profiles over the Ocean", Boundary-Layer Meteorology., apr, 2015. Vol. 155(1), pp. 111-127. |
| Abstract: The impacts of surface waves on the steady near-surface wind profiles in the marine atmospheric boundary layer (ABL) are studied based on the Ekman theory, modified by introducing a wave-induced component on the total stress. An analytic solution is presented for the wave-modified Ekman model for an eddy viscosity coefficient varying linearly with height. The solution can be determined by the two-dimensional wavenumber spectrum of ocean waves, the wave-growth or decay rate, the geostrophic wind velocity, the Coriolis parameter and the densities of air and water. Wind profiles are calculated as examples for two cases: one with a monochromatic wave and the other with a fully-developed wind-generated sea. The effects of the surface waves on the wind profiles in the marine ABL are illustrated, and solutions proposed are compared with those of the model where the wave-induced stress is neglected. The solutions are also compared with observations from a tower on Östergarnsholm Island in the Baltic Sea. Illustrative examples and the comparisons between observations and the theoretical predictions demonstrate that the surface waves have a considerable impact, not only on the near-surface mean wind profile, but also on the turbulence structure of the marine ABL, as they change qualitatively the structure of the ABL. |
BibTeX:
@article{Song2015,
author = {Song, Jinbao and Fan, Wei and Li, Shuang and Zhou, Ming},
title = {Impact of Surface Waves on the Steady Near-Surface Wind Profiles over the Ocean},
journal = {Boundary-Layer Meteorology},
year = {2015},
volume = {155},
number = {1},
pages = {111--127},
url = {http://link.springer.com/10.1007/s10546-014-9983-6},
doi = {10.1007/s10546-014-9983-6}
}
|
| Štroch M, Materová Z, Vrábl D, Karlický V, Šigut L, Nezval J and Špunda V (2015), "Protective effect of UV-A radiation during acclimation of the photosynthetic apparatus to UV-B treatment", Plant Physiology and Biochemistry. Vol. 96, pp. 90-96. Elsevier Masson SAS. |
| Abstract: We examined the acclimation response of the photosynthetic apparatus of barley (Hordeum vulgare L.) to a combination of UV-A and UV-B radiation (UVAB) and to UV-B radiation alone. Our aim was to evaluate whether UV-A radiation prevents UV-B-induced damage to the photosynthetic apparatus and whether UV-A pre-acclimation is required to mitigate the negative influence of UV-B radiation. Barley plants were grown from seeds under low photosynthetically active radiation (50μmolmtextlesssuptextgreater-2textless/suptextgreaterstextlesssuptextgreater-1textless/suptextgreater) either in the absence or presence of UV-A radiation (UVA- and UVA+plants, respectively). After 8 days of development, plants were exposed simultaneously to UV-A and UV-B radiation for the next 6 days. Additionally, UVA- plants were exposed to UV-B radiation alone. The UVA+plants had a higher COtextlessinftextgreater2textless/inftextgreater assimilation rate near the light-saturation region (AtextlessinftextgreaterNtextless/inftextgreater) and a higher content of both total chlorophylls (Chls) and total carotenoids than the UVA- plants. Chls content, AtextlessinftextgreaterNtextless/inftextgreater, the potential quantum yield of photosystem II (PSII) photochemistry (FtextlessinftextgreaterVtextless/inftextgreater/FtextlessinftextgreaterMtextless/inftextgreater), the capacity of light-induced thermal energy dissipation and the efficiency of excitation energy transfer within PSII remained the same or even increased in both UVA+ and UVA- plants after UVAB treatment. On the contrary, exposure of UVA- plants to UV-B radiation itself led to a reduction in all these characteristics. We revealed that the presence of UV-A radiation during UVAB treatment not only mitigated but completely eliminated the negative effect of UV-B radiation on the functioning of the photosynthetic apparatus and that UV-A pre-acclimation was not crucial for development of this UV-A-induced resistance against UV-B irradiation. |
BibTeX:
@article{Stroch2015,
author = {Štroch, Michal and Materová, Zuzana and Vrábl, Daniel and Karlický, Václav and Šigut, Ladislav and Nezval, Jakub and Špunda, Vladimír},
title = {Protective effect of UV-A radiation during acclimation of the photosynthetic apparatus to UV-B treatment},
journal = {Plant Physiology and Biochemistry},
publisher = {Elsevier Masson SAS},
year = {2015},
volume = {96},
pages = {90--96},
doi = {10.1016/j.plaphy.2015.07.017}
}
|
| Sun H, Santalahti M, Pumpanen J, Köster K, Berninger F, Raffaello T, Jumpponen A, Asiegbu FO and Heinonsalo J (2015), "Fungal community shifts in structure and function across a boreal forest fire chronosequence", Applied and Environmental Microbiology. Vol. 81(22), pp. 7869-7880. American Society for Microbiology. |
| Abstract: Forest fires are a common natural disturbance in forested ecosystems and have a large impact on the microbial communities in forest soils. The response of soil fungal communities to forest fire is poorly documented. Here, we investigated fungal community structure and function across a 152-year boreal forest fire chronosequence using high-throughput sequencing of the internal transcribed spacer 2 (ITS2) region and a functional gene array (GeoChip). Our results demonstrate that the boreal forest soil fungal community was most diverse soon after a fire disturbance and declined over time. The differences in the fungal communities were explained by changes in the abundance of basidiomycetes and ascomycetes. Ectomycorrhizal (ECM) fungi contributed to the increase in basidiomycete abundance over time, with the operational taxonomic units (OTUs) representing the genera Cortinarius and Piloderma dominating in abundance. Hierarchical cluster analysis by using gene signal intensity revealed that the sites with different fire histories formed separate clusters, suggesting differences in the potential to maintain essential biogeochemical soil processes. The site with the greatest biological diversity had also the most diverse genes. The genes involved in organic matter degradation in the mature forest, in which ECM fungi were the most abundant, were as common in the youngest site, in which saprotrophic fungi had a relatively higher abundance. This study provides insight into the impact of fire disturbance on soil fungal community dynamics. |
BibTeX:
@article{Sun2015,
author = {Sun, Hui and Santalahti, Minna and Pumpanen, Jukka and Köster, Kajar and Berninger, Frank and Raffaello, Tommaso and Jumpponen, Ari and Asiegbu, Fred O. and Heinonsalo, Jussi},
title = {Fungal community shifts in structure and function across a boreal forest fire chronosequence},
journal = {Applied and Environmental Microbiology},
publisher = {American Society for Microbiology},
year = {2015},
volume = {81},
number = {22},
pages = {7869--7880},
doi = {10.1128/AEM.02063-15}
}
|
| Sundqvist E, Mölder M, Crill P, Kljun N and Lindroth A (2015), "Methane exchange in a boreal forest estimated by gradient method", Tellus, Series B: Chemical and Physical Meteorology., jul, 2015. Vol. 67(1) |
| Abstract: Forests are generally considered to be net sinks of atmospheric methane (CHinf4/inf) because of oxidation by methanotrophic bacteria in well-aerated forests soils. However, emissions from wet forest soils, and sometimes canopy fluxes, are often neglected when quantifying the CHinf4/inf budget of a forest. We used a modified Bowen ratio method and combined eddy covariance and gradient methods to estimate net CHinf4/inf exchange at a boreal forest site in central Sweden. Results indicate that the site is a net source of CHinf4/inf. This is in contrast to soil, branch and leaf chamber measurements of uptake of CHinf4/inf. Wetter soils within the footprint of the canopy are thought to be responsible for the discrepancy. We found no evidence for canopy emissions per se. However, the diel pattern of the CHinf4/inf exchange with minimum emissions at daytime correlated well with gross primary production, which supports an uptake in the canopy. More distant source areas could also contribute to the diel pattern; their contribution might be greater at night during stable boundary layer conditions. |
BibTeX:
@article{Sundqvist2015,
author = {Sundqvist, Elin and Mölder, Meelis and Crill, Patrick and Kljun, Natascha and Lindroth, Anders},
title = {Methane exchange in a boreal forest estimated by gradient method},
journal = {Tellus, Series B: Chemical and Physical Meteorology},
year = {2015},
volume = {67},
number = {1},
url = {http://www.tellusb.net/index.php/tellusb/article/view/26688},
doi = {10.3402/tellusb.v67.26688}
}
|
| Sundqvist E, Persson A, Kljun N, Vestin P, Chasmer L, Hopkinson C and Lindroth A (2015), "Upscaling of methane exchange in a boreal forest using soil chamber measurements and high-resolution LiDAR elevation data", Agricultural and Forest Meteorology., dec, 2015. Vol. 214-215, pp. 393-401. |
| Abstract: Forest soils are generally considered to be net sinks of methane (CH4), but CH4 fluxes vary spatially depending on soil conditions. Measuring CH4 exchange with chambers, which are commonly used for this purpose, might not result in representative fluxes at site scale. Appropriate methods for upscaling CH4 fluxes from point measurements to site scale are therefore needed. At the boreal forest research site, Norunda, chamber measurements of soils and vegetation indicate that the site is a net sink of CH4, while tower gradient measurements indicate that the site is a net source of CH4. We investigated the discrepancy between chamber and tower gradient measurements by upscaling soil CH4 exchange to a 100ha area based on an empirical model derived from chamber measurements of CH4 exchange and measurements of soil moisture, soil temperature and water table depth. A digital elevation model (DEM) derived from high-resolution airborne Light Detection and Ranging (LiDAR) data was used to generate gridded water table depth and soil moisture data of the study area as input data for the upscaling. Despite the simplistic approach, modeled fluxes were significantly correlated to four out of five chambers with R0.68. The upscaling resulted in a net soil sink of CH4 of -10μmolm-2h-1, averaged over the entire study area and time period (June-September, 2010). Our findings suggest that additional contributions from CH4 soil sources outside the upscaling study area and possibly CH4 emissions from vegetation could explain the net emissions measured by tower gradient measurements. |
BibTeX:
@article{Sundqvist2015a,
author = {Sundqvist, E and Persson, A and Kljun, N and Vestin, P and Chasmer, L and Hopkinson, C and Lindroth, A},
title = {Upscaling of methane exchange in a boreal forest using soil chamber measurements and high-resolution LiDAR elevation data},
journal = {Agricultural and Forest Meteorology},
year = {2015},
volume = {214-215},
pages = {393--401},
url = {http://linkinghub.elsevier.com/retrieve/pii/S016819231500708X},
doi = {10.1016/j.agrformet.2015.09.003}
}
|
| Temnerud J, von Brömssen C, Fölster J, Buffam I, Andersson J-O, Nyberg L and Bishop K (2015), "Map-based prediction of organic carbon in headwaters streams improved by downstream observations from the river outlet", Biogeosciences Discussions., jun, 2015. Vol. 12(12), pp. 9005-9041. |
| Abstract: Abstract. In spite of the great abundance and ecological importance of headwater streams, managers are usually limited by a lack of information about water chemistry in these headwaters. In this study we test whether river outlet chemistry can be used as an additional source of information to improve the prediction of the chemistry of upstream headwaters (size 2 km2), relative to models based on map information alone. Between 2000 and 2008, we conducted 17 synoptic surveys of streams within 9 mesoscale catchments (size 32–235 km2). Over 900 water samples were collected from catchments ranging in size from 0.03 to 235 km2. First we used partial least square regression (PLS) to model headwater stream total organic carbon (TOC) median and interquartile values for a given catchment, based on a large number of candidate variables including catchment characteristics from GIS, and measured chemistry at the catchment outlet. The best candidate variables from the PLS models were then used in hierarchical linear mixed models (MM) to model TOC in individual headwater streams. Three predictor variables were consistently selected for the MM calibration sets: (1) proportion of forested wetlands in the sub-catchment (positively correlated with headwater stream TOC), (2) proportion of lake surface cover in the sub-catchment (negatively correlated with headwater stream TOC), and (3) whole-catchment river outlet TOC (positively correlated with headwater stream TOC). Including river outlet TOC as a predictor in the models gave 5–15% lower prediction errors than using map information alone. Thus, data on water chemistry measured at river outlets offers information which can complement GIS-based modelling of headwater stream chemistry. |
BibTeX:
@article{Temnerud2015,
author = {Temnerud, J and von Brömssen, C and Fölster, J and Buffam, I and Andersson, J.-O. and Nyberg, L and Bishop, K},
title = {Map-based prediction of organic carbon in headwaters streams improved by downstream observations from the river outlet},
journal = {Biogeosciences Discussions},
year = {2015},
volume = {12},
number = {12},
pages = {9005--9041},
url = {http://www.biogeosciences-discuss.net/12/9005/2015/},
doi = {10.5194/bgd-12-9005-2015}
}
|
| Tetzlaff D, Buttle J, Carey SK, Mcguire K, Laudon H and Soulsby C (2015), "Tracer-based assessment of flow paths, storage and runoff generation in northern catchments: A review", Hydrological Processes., jul, 2015. Vol. 29(16), pp. 3475-3490. |
| Abstract: We examine how tracer studies have enhanced our understanding of flow paths, residence times and sources of stream flow in northern catchments. We define northern catchments as non-glacial sites in the temperate conifer/boreal/permafrost zone, focussing our review mainly on sites in North America and Europe. Improved empirical and theoretical understanding of hydrological functioning has advanced the analytical tools available for tracer-based hydrograph separations, derivation of transit time distributions and tracer-aided rainfall-runoff models that are better able to link hydrological response to storage changes. However, the lack of comprehensive tracer data sets still hinders development of a generalized understanding of how northern catchments will respond to change. This paucity of empirical data leads to many outstanding research needs, particularly in rapidly changing areas that are already responding to climatic warming and economic development. To continually improve our understanding of hydrological processes in these regions our knowledge needs to be advanced using a range of techniques and approaches. Recent technological developments for improved monitoring, distributed hydrological sensor systems, more economic analysis of large sample numbers in conjunction with novel, tracer-aided modelling approaches and the use of remote sensing have the potential to help the understanding of the northern hydrological systems as well as inform policy at a time of rapid environmental change. |
BibTeX:
@article{Tetzlaff2015,
author = {Tetzlaff, Doerthe and Buttle, Jim and Carey, Sean K and Mcguire, Kevin and Laudon, Hjalmar and Soulsby, Chris},
title = {Tracer-based assessment of flow paths, storage and runoff generation in northern catchments: A review},
journal = {Hydrological Processes},
year = {2015},
volume = {29},
number = {16},
pages = {3475--3490},
url = {http://doi.wiley.com/10.1002/hyp.10412},
doi = {10.1002/hyp.10412}
}
|
| Tetzlaff D, Buttle J, Carey SK, van Huijgevoort MHJ, Laudon H, Mcnamara JP, Mitchell CPJ, Spence C, Gabor RS and Soulsby C (2015), "A preliminary assessment of water partitioning and ecohydrological coupling in northern headwaters using stable isotopes and conceptual runoff models", Hydrological Processes., dec, 2015. Vol. 29(25), pp. 5153-5173. |
| Abstract: We combined a conceptual rainfall-runoff model and input-output relationships of stable isotopes to understand ecohydrological influences on hydrological partitioning in snow-influenced northern catchments. Six sites in Sweden (Krycklan), Canada (Wolf Creek; Baker Creek; Dorset), Scotland (Girnock) and the USA (Dry Creek) span moisture and energy gradients found at high latitudes. A meta-analysis was carried out using the Hydrologiska Byråns Vattenbalansavdelning (HBV) model to estimate the main storage changes characterizing annual water balances. Annual snowpack storage importance was ranked as Wolf CreekKrycklanDorsetBaker CreekDry CreekGirnock. The subsequent rate and longevity of melt were reflected in calibrated parameters that determine partitioning of waters between more rapid and slower flowpaths and associated variations in soil and groundwater storage. Variability of stream water isotopic composition depends on the following: (i) rate and duration of spring snowmelt. (ii) significance of summer/autumn rainfall; and (iii) relative importance of near-surface and deeper flowpaths in routing water to the stream. Flowpath partitioning also regulates influences of summer evaporation on drainage waters. Deviations of isotope data from the Global Meteoric Water Line showed subtle effects of internal catchment processes on isotopic fractionation most likely through evaporation. Such effects are highly variable among sites and with seasonal differences at some sites. After accounting for climate, evaporative fractionation is strongest at sites where lakes and near-surface runoff processes in wet riparian soils can mobilize isotopically enriched water during summer and autumn. Given close soil-vegetation coupling, this may result in spatial variability in soil water isotope pools available for plant uptake. We argue that stable isotope studies are crucial in addressing the many open questions on hydrological functioning of northern environments. |
BibTeX:
@article{Tetzlaff2015a,
author = {Tetzlaff, Doerthe and Buttle, James and Carey, Sean K and van Huijgevoort, Marjolein H J and Laudon, Hjalmar and Mcnamara, James P and Mitchell, Carl P J and Spence, Chris and Gabor, Rachel S and Soulsby, Chris},
title = {A preliminary assessment of water partitioning and ecohydrological coupling in northern headwaters using stable isotopes and conceptual runoff models},
journal = {Hydrological Processes},
year = {2015},
volume = {29},
number = {25},
pages = {5153--5173},
url = {http://doi.wiley.com/10.1002/hyp.10515},
doi = {10.1002/hyp.10515}
}
|
| Thornton BF, Wik M and Crill PM (2015), "Climate-forced changes in available energy and methane bubbling from subarctic lakes", Geophysical Research Letters., mar, 2015. Vol. 42(6), pp. 1936-1942. |
| Abstract: Strong correlations between seasonal energy input and methane (CHinf4/inf) bubbling (ebullition) in northern lakes suggest that energy proxies might provide a constraint on the magnitude of future CHinf4/inf emissions. Ebullition is a major pathway for transporting anaerobically produced CHinf4/inf from lake sediments to the atmosphere and represents a large unquantified CHinf4/inf source. In high-latitude, postglacial lakes during the ice-free season, solar shortwave energy input can constrain CHinf4/inf productivity via control of sediment temperature. Utilizing long-term climatic predictors, we calculate CHinf4/inf ebullition from three subarctic lakes in northern Sweden over the period of 1916-2079. Using observed energy trends, the seasonal average lake CHinf4/inf ebullition is predicted to increase by 80% between the 1916-1926 decade and the 2040-2079 period. Present-day seasonal average methane ebullition is estimated to have already increased 24% since the 1916-1926 decade. Key Points Expanded data set reinforces strong energy-CHinf4/inf ebullition link in subarctic lakes Twenty eight years of shortwave energy measurements used to estimate past CHinf4/inf ebullition Study lake CHinf4/inf ebullition increases 80% between years 1916-1926 and 2040-2079 |
BibTeX:
@article{Thornton2015,
author = {Thornton, Brett F and Wik, Martin and Crill, Patrick M},
title = {Climate-forced changes in available energy and methane bubbling from subarctic lakes},
journal = {Geophysical Research Letters},
year = {2015},
volume = {42},
number = {6},
pages = {1936--1942},
url = {http://doi.wiley.com/10.1002/2015GL063189},
doi = {10.1002/2015GL063189}
}
|
| Tortell PD, Bittig HC, Körtzinger A, Jones EM and Hoppema M (2015), "Biological and physical controls on N2, O2, and CO2 distributions in contrasting Southern Ocean surface waters", Global Biogeochemical Cycles., jul, 2015. Vol. 29(7), pp. 994-1013. |
| Abstract: We present measurements of pCO2, O2 concentration, biological oxygen saturation (ΔO2/Ar), and N2 saturation (ΔN2) in Southern Ocean surface waters during austral summer, 2010-2011. Phytoplankton biomass varied strongly across distinct hydrographic zones, with high chlorophyll a (Chl a) concentrations in regions of frontal mixing and sea ice melt. pCO2 and ΔO2/Ar exhibited large spatial gradients (range 90 to 450μatm and -10 to 60%, respectively) and covaried strongly with Chl a. However, the ratio of biological O2 accumulation to dissolved inorganic carbon (DIC) drawdown was significantly lower than expected from photosynthetic stoichiometry, reflecting the differential time scales of O2 and CO2 air-sea equilibration. We measured significant oceanic CO2 uptake, with a mean air-sea flux (∼-10mmolm-2d-1) that significantly exceeded regional climatological values. N2 was mostly supersaturated in surface waters (mean ΔN2 of +2.5%), while physical processes resulted in both supersaturation and undersaturation of mixed layer O2 (mean ΔO2phys=2.1%). Box model calculations were able to reproduce much of the spatial variability of ΔN2 and ΔO2phys along the cruise track, demonstrating significant effects of air-sea exchange processes (e.g., atmospheric pressure changes and bubble injection) and mixed layer entrainment on surface gas disequilibria. Net community production (NCP) derived from entrainment-corrected surface ΔO2/Ar data, ranged from ∼-40 to 300mmolO2m-2d-1 and showed good coherence with independent NCP estimates based on seasonal mixed layer DIC deficits. Elevated NCP was observed in hydrographic frontal zones and stratified regions of sea ice melt, reflecting physical controls on surface water light fields and nutrient availability. Key Points Biological and physical controls on Southern Ocean gases are quantified Sea-air CO2 fluxes significantly exceed regional climatological values Net community production estimates are corrected for physical processes |
BibTeX:
@article{Tortell2015,
author = {Tortell, Philippe D and Bittig, Henry C and Körtzinger, Arne and Jones, Elizabeth M and Hoppema, Mario},
title = {Biological and physical controls on N2, O2, and CO2 distributions in contrasting Southern Ocean surface waters},
journal = {Global Biogeochemical Cycles},
year = {2015},
volume = {29},
number = {7},
pages = {994--1013},
url = {http://doi.wiley.com/10.1002/2014GB004975},
doi = {10.1002/2014GB004975}
}
|
| Tramontana G, Ichii K, Camps-Valls G, Tomelleri E and Papale D (2015), "Uncertainty analysis of gross primary production upscaling using Random Forests, remote sensing and eddy covariance data", Remote Sensing of Environment., oct, 2015. Vol. 168, pp. 360-373. |
| Abstract: The accurate quantification of carbon fluxes at continental spatial scale is important for future policy decisions in the context of global climate change. However, many elements contribute to the uncertainty of such estimate. In this study, the uncertainties of eight days gross primary production (GPP) predicted by Random Forest (RF) machine learning models were analysed at the site, ecosystem and European spatial scales. At the site level, the uncertainties caused by the missing of key drivers were evaluated. The most accurate predictions of eight days GPP were obtained when all available drivers were used (Pearson's correlation coefficient, ρ˜0.84; Root Mean Square Error (RMSE)˜1.8g C msup-2/sup dsup-1/sup). However, when predictions were based on only remotely sensed data the accuracy was close to the optimum (ρ˜0.8; RMSE˜1.9g C msup-2/sup dsup-1/sup) and to a commonly used light use efficiency model (MOD17) with parameters optimised for the applied study sites (the MOD17+, ρ˜0.79; RMSE˜2.04g C msup-2/sup dsup-1/sup). Remotely sensed data were key drivers for the accurate prediction of GPP in ecosystems with high variability of green biomass over the phenological cycle (e.g., deciduous broad-leaved forests) or highly affected by the human management (e.g. croplands). In contrast, in the ecosystems with low variability of greenness (e.g., evergreen broad-leaved forests), the predictions were poor when meteorological information were not used. At a European spatial scale, when modelled grids of meteorological, land cover and fPAR data were used as inputs, the propagation of their uncertainty, not accounted in the models training, had significant effects on the uncertainty of the mean annual GPP. At this scale, the effects of meteorological uncertainty were higher than the misclassification error. These findings suggested that a strategy based on satellite-measured data could be a favourable improvement for the spatial upscaling of GPP, because avoiding the propagation of the uncertainties of the modelled grids. |
BibTeX:
@article{Tramontana2015,
author = {Tramontana, Gianluca and Ichii, Kazuito and Camps-Valls, Gustau and Tomelleri, Enrico and Papale, Dario},
title = {Uncertainty analysis of gross primary production upscaling using Random Forests, remote sensing and eddy covariance data},
journal = {Remote Sensing of Environment},
year = {2015},
volume = {168},
pages = {360--373},
url = {http://linkinghub.elsevier.com/retrieve/pii/S0034425715300699},
doi = {10.1016/j.rse.2015.07.015}
}
|
| Tupek B, Minkkinen K, Pumpanen J, Vesala T and Nikinmaa E (2015), "CH4 and N2O dynamics in the boreal forest-mire ecotone", Biogeosciences., jan, 2015. Vol. 12(2), pp. 281-297. Copernicus GmbH. |
| Abstract: In spite of advances in greenhouse gas research, the spatiotemporal CH4 and N2O dynamics of boreal landscapes remain challenging, e.g., we need clarification of whether forest-mire transitions are occasional hotspots of landscape CH4 and N2O emissions during exceptionally high and low ground water level events. In our study, we tested the differences and drivers of CH4 and N2O dynamics of forest/mire types in field conditions along the soil moisture gradient of the forest-mire ecotone. Soils changed from Podzols to Histosols and ground water rose downslope from a depth of 10 m in upland sites to 0.1 m in mires. Yearly meteorological conditions changed from being exceptionally wet to typical and exceptionally dry for the local climate. The median fluxes measured with a static chamber technique varied from -51 to 586 μg m-2 h-1 for CH4 and from 0 to 6 μg m-2 h-1 for N2O between forest and mire types throughout the entire wet-dry period. In spite of the highly dynamic soil water fluctuations in carbon rich soils in forest-mire transitions, there were no large peak emissions in CH4 and N2O fluxes and the flux rates changed minimally between years. Methane uptake was significantly lower in poorly drained transitions than in the well-drained uplands. Water-saturated mires showed large CH4 emissions, which were reduced entirely during the exceptional summer drought period. Near-zero N2O fluxes did not differ significantly between the forest and mire types probably due to their low nitrification potential. When upscaling boreal landscapes, pristine forest-mire transitions should be regarded as CH4 sinks and minor N2O sources instead of CH4 and N2O emission hotspots. |
BibTeX:
@article{Tupek2015,
author = {Tupek, B. and Minkkinen, K. and Pumpanen, J. and Vesala, T. and Nikinmaa, E.},
title = {CH4 and N2O dynamics in the boreal forest-mire ecotone},
journal = {Biogeosciences},
publisher = {Copernicus GmbH},
year = {2015},
volume = {12},
number = {2},
pages = {281--297},
doi = {10.5194/bg-12-281-2015}
}
|
| Turner AJ, Jacob DJ, Wecht KJ, Maasakkers JD, Lundgren E, Andrews AE, Biraud SC, Boesch H, Bowman KW, Deutscher NM, Dubey MK, Griffith DWT, Hase F, Kuze A, Notholt J, Ohyama H, Parker R, Payne VH, Sussmann R, Sweeney C, Velazco VA, Warneke T, Wennberg PO and Wunch D (2015), "Estimating global and North American methane emissions with high spatial resolution using GOSAT satellite data", Atmospheric Chemistry and Physics., jun, 2015. Vol. 15(12), pp. 7049-7069. |
| Abstract: We use 2009-2011 space-borne methane observations from the Greenhouse Gases Observing SATellite (GOSAT) to estimate global and North American methane emissions with 4° x 5° and up to 50 km x 50 km spatial resolution, respectively. GEOS-Chem and GOSAT data are first evaluated with atmospheric methane observations from surface and tower networks (NOAA/ESRL, TCCON) and aircraft (NOAA/ESRL, HIPPO), using the GEOS-Chem chemical transport model as a platform to facilitate comparison of GOSAT with in situ data. This identifies a high-latitude bias between the GOSAT data and GEOS-Chem that we correct via quadratic regression. Our global adjoint-based inversion yields a total methane source of 539 Tga-1 with some important regional corrections to the EDGARv4.2 inventory used as a prior. Results serve as dynamic boundary conditions for an analytical inversion of North American methane emissions using radial basis functions to achieve high resolution of large sources and provide error characterization. We infer a US anthropogenic methane source of 40.2-42.7 Tga-1, as compared to 24.9-27.0 Tga-1 in the EDGAR and EPA bottom-up inventories, and 30.0-44.5 Tga-1 in recent inverse studies. Our estimate is supported by independent surface and aircraft data and by previous inverse studies for California. We find that the emissions are highest in the southern-central US, the Central Valley of California, and Florida wetlands; large isolated point sources such as the US Four Corners also contribute. Using prior information on source locations, we attribute 29-44% of US anthropogenic methane emissions to livestock, 22-31% to oil/gas, 20% to landfills/wastewater, and 11-15% to coal. Wetlands contribute an additional 9.0-10.1 Tga-1. |
BibTeX:
@article{Turner2015,
author = {Turner, A J and Jacob, D J and Wecht, K J and Maasakkers, J D and Lundgren, E and Andrews, A E and Biraud, S C and Boesch, H and Bowman, K W and Deutscher, N M and Dubey, M K and Griffith, D W T and Hase, F and Kuze, A and Notholt, J and Ohyama, H and Parker, R and Payne, V H and Sussmann, R and Sweeney, C and Velazco, V A and Warneke, T and Wennberg, P O and Wunch, D},
title = {Estimating global and North American methane emissions with high spatial resolution using GOSAT satellite data},
journal = {Atmospheric Chemistry and Physics},
year = {2015},
volume = {15},
number = {12},
pages = {7049--7069},
url = {http://www.atmos-chem-phys.net/15/7049/2015/},
doi = {10.5194/acp-15-7049-2015}
}
|
| Van Asperen H, Warneke T, Sabbatini S, Nicolini G, Papale D and Notholt J (2015), "The role of photo- And thermal degradation for CO2 and CO fluxes in an arid ecosystem", Biogeosciences., jul, 2015. Vol. 12(13), pp. 4161-4174. |
| Abstract: Recent studies have suggested the potential importance of abiotic degradation in arid ecosystems. In this study, the role of photo- And thermal degradation in ecosystem CO2 and CO exchange is assessed. A field experiment was performed in Italy using an FTIR-spectrometer (Fourier Transform Infrared) coupled to a flux gradient system and to flux chambers. In a laboratory experiment, field samples were exposed to different temperatures and radiation intensities. No photodegradation-induced CO2 and CO fluxes of in literature suggested magnitudes were found in the field nor in the laboratory study. In the laboratory, we measured CO2 and CO fluxes that were derived from thermal degradation. In the field experiment, CO uptake and emission have been measured and are proposed to be a result of biological uptake and abiotic thermal degradation-production. We suggest that previous studies, addressing direct photodegradation, have overestimated the role of photodegradation and observed fluxes might be due to thermal degradation, which is an indirect effect of radiation. The potential importance of abiotic decomposition in the form of thermal degradation, especially for arid regions, should be considered in future studies. 1 Introduction CO2 is the main carbon species being exchanged between biosphere and atmosphere and the most important anthropogenic greenhouse gas. CO is a less abundant nongreenhouse gas but considered important in the climate debate due to its oxidation process with atmospheric OH (Stocker et al., 2013). Yearly, terrestrial ecosystems exchange approximately 120 Pg of carbon with the atmosphere (Stocker et al., 2013). Arid ecosystems account for approximately 40% of land area and 20%of the soil carbon pool but are still an unknown factor in climate models (Lal, 2004). In recent studies, the possible importance of abiotic degradation for arid regions, such as photo- And thermal degradation, has been recognized (Austin and Vivanco, 2006; King et al., 2012; Rutledge et al., 2010). |
BibTeX:
@article{VanAsperen2015,
author = {Van Asperen, H and Warneke, T and Sabbatini, S and Nicolini, G and Papale, D and Notholt, J},
title = {The role of photo- And thermal degradation for CO2 and CO fluxes in an arid ecosystem},
journal = {Biogeosciences},
year = {2015},
volume = {12},
number = {13},
pages = {4161--4174},
url = {http://www.biogeosciences.net/12/4161/2015/},
doi = {10.5194/bg-12-4161-2015}
}
|
| Vanbeveren SPP, Schweier J, Berhongaray G and Ceulemans R (2015), "Operational short rotation woody crop plantations: Manual or mechanised harvesting?", Biomass and Bioenergy., jan, 2015. Vol. 72, pp. 8-18. |
| Abstract: Harvesting is the most expensive, but the least investigated process in the cultivation of short rotation woody crops (SRWC). To get a better idea of the harvesting process (in terms of its performance, productivity, cost, soil compaction, cutting height and quality as well as biomass losses), we closely monitored the second harvest of a SRWC culture in Flanders (Belgium). We compared our results to the harvests of other, small European parcels. The trees at our site were harvested with both a manual and a mechanised (Stemster harvester) cut-and-store system, while the cut-and-chip system was analysed from an extensive literature survey. The production cost (to the edge of the field) at our site reached 426 (manual) and 94 (mechanised) €t-1, while the average values found in the literature are respectively 104 and 78€t-1, versus 17€t-1 for the cut-and-chip harvesting system. The productivity at our site reached 14 (manual) and 22 (mechanised) oven-dry tonnes per scheduled machine hour, while the average values found in the literature are respectively 15 and 23th-1. Based on the good performance (hah-1) and productivity (th-1) of the cut-and-chip system as well as its lower costs, this harvesting system is recommended for operational SRWC. |
BibTeX:
@article{Vanbeveren2015,
author = {Vanbeveren, S P P and Schweier, J and Berhongaray, G and Ceulemans, R},
title = {Operational short rotation woody crop plantations: Manual or mechanised harvesting?},
journal = {Biomass and Bioenergy},
year = {2015},
volume = {72},
pages = {8--18},
url = {http://linkinghub.elsevier.com/retrieve/pii/S096195341400525X},
doi = {10.1016/j.biombioe.2014.11.019}
}
|
| Van Der Laan-Luijkx IT, Van Der Velde IR, Krol MC, Gatti LV, Domingues LG, Correia CSC, Miller JB, Gloor M, Van Leeuwen TT, Kaiser JW, Wiedinmyer C, Basu S, Clerbaux C and Peters W (2015), "Response of the Amazon carbon balance to the 2010 drought derived with CarbonTracker South America", Global Biogeochemical Cycles., jul, 2015. Vol. 29(7), pp. 1092-1108. |
| Abstract: Two major droughts in the past decade had large impacts on carbon exchange in the Amazon. Recent analysis of vertical profile measurements of atmospheric COinf2/inf and CO by Gatti et al. (2014) suggests that the 2010 drought turned the normally close-to-neutral annual Amazon carbon balance into a substantial source of nearly 0.5 PgC/yr, revealing a strong drought response. In this study, we revisit this hypothesis and interpret not only the same COinf2/inf/CO vertical profile measurements but also additional constraints on carbon exchange such as satellite observations of CO, burned area, and fire hot spots. The results from our CarbonTracker South America data assimilation system suggest that carbon uptake by vegetation was indeed reduced in 2010 but that the magnitude of the decrease strongly depends on the estimated 2010 and 2011 biomass burning emissions. We have used fire products based on burned area (Global Fire Emissions Database version 4), satellite-observed CO columns (Infrared Atmospheric Sounding Interferometer), fire radiative power (Global Fire Assimilation System version 1), and fire hot spots (Fire Inventory from NCAR version 1), and found an increase in biomass burning emissions in 2010 compared to 2011 of 0.16 to 0.24 PgC/yr. We derived a decrease of biospheric uptake ranging from 0.08 to 0.26 PgC/yr, with the range determined from a set of alternative inversions using different biomass burning estimates. Our numerical analysis of the 2010 Amazon drought results in a total reduction of carbon uptake of 0.24 to 0.50 PgC/yr and turns the balance from carbon sink to source. Our findings support the suggestion that the hydrological cycle will be an important driver of future changes in Amazonian carbon exchange. Key Points Amazon carbon budget estimated by CarbonTracker South America Biospheric uptake decreases by 0.08-0.26 PgC/yr in response to 2010 drought Amazon biomass burning emissions more than doubled during 2010 drought |
BibTeX:
@article{VanDerLaan-Luijkx2015,
author = {Van Der Laan-Luijkx, I T and Van Der Velde, I R and Krol, M C and Gatti, L V and Domingues, L G and Correia, C S C and Miller, J B and Gloor, M and Van Leeuwen, T T and Kaiser, J W and Wiedinmyer, C and Basu, S and Clerbaux, C and Peters, W},
title = {Response of the Amazon carbon balance to the 2010 drought derived with CarbonTracker South America},
journal = {Global Biogeochemical Cycles},
year = {2015},
volume = {29},
number = {7},
pages = {1092--1108},
url = {http://doi.wiley.com/10.1002/2014GB005082},
doi = {10.1002/2014GB005082}
}
|
| Vardag SN, Hammer S, Sabasch M, Griffith DWT and Levin I (2015), "First continuous measurements of δ18O-CO2 in air with a Fourier transform infrared spectrometer", Atmospheric Measurement Techniques., feb, 2015. Vol. 8(2), pp. 579-592. |
| Abstract: The continuous in situ measurement of δ18O in atmospheric CO2 opens a new door to differentiating between CO2 source and sink components with high temporal resolution. Continuous 13C-CO2 measurement systems have already been commercially available for some time, but until now, only few instruments have been able to provide a continuous measurement of the oxygen isotope ratio in CO2. Besides precise 13C/12C observations, the Fourier transform infrared (FTIR) spectrometer is also able to measure the 18O/16O ratio in CO2, but the precision and accuracy of the measurements have not yet been evaluated. Here we present a first analysis of δ18O-CO2 (and δ13C-CO2) measurements with the FTIR analyser in Heidelberg. We used Allan deviation to determine the repeatability of δ18O-CO2 measurements and found that it decreases from 0.25‰ for 10 min averages to about 0.1‰ after 2 h and remains at that value up to 24 h. We evaluated the measurement precision over a 10-month period (intermediate measurement precision) using daily working gas measurements and found that our spectrometer measured δ18O-CO2 to better than 0.3‰ at a temporal resolution of less than 10 min. The compatibility of our FTIR-spectrometric measurements to isotope-ratio mass-spectrometric (IRMS) measurements was determined by comparing FTIR measurements of cylinder gases and ambient air with IRMS measurements of flask samples, filled with gases of the same cylinders or collected from the same ambient air intake. Two-sample t tests revealed that, at the 0.01 significance level, the FTIR and the IRMS measurements do not differ significantly from each other and are thus compatible. We describe two weekly episodes of ambient air measurements, one in winter and one in summer, and discuss what potential insights and new challenges combined highly resolved CO2, δ13C-CO2 and δ18O-CO2 records may provide in terms of better understanding regional scale continental carbon exchange processes. |
BibTeX:
@article{Vardag2015,
author = {Vardag, S N and Hammer, S and Sabasch, M and Griffith, D W T and Levin, I},
title = {First continuous measurements of δ18O-CO2 in air with a Fourier transform infrared spectrometer},
journal = {Atmospheric Measurement Techniques},
year = {2015},
volume = {8},
number = {2},
pages = {579--592},
url = {http://www.atmos-meas-tech.net/8/579/2015/},
doi = {10.5194/amt-8-579-2015}
}
|
| Vardag SN, Gerbig C, Janssens-Maenhout G and Levin I (2015), "Estimation of continuous anthropogenic CO2: Model-based evaluation of CO2, CO, δ13C(CO2) and Δ14C(CO2) tracer methods", Atmospheric Chemistry and Physics., nov, 2015. Vol. 15(22), pp. 12705-12729. |
| Abstract: We investigate different methods for estimating anthropogenic CO2 using modeled continuous atmospheric concentrations of CO2 alone, as well as CO2 in combination with the surrogate tracers CO, δ13C(CO2) and Δ14C(CO2). These methods are applied at three hypothetical stations representing rural, urban and polluted conditions. We find that, independent of the tracer used, an observation-based estimate of continuous anthropogenic CO2 is not yet feasible at rural measurement sites due to the low signal-to-noise ratio of anthropogenic CO2 estimates at such settings. The tracers δ13C(CO2) and CO provide an accurate possibility to determine anthropogenic CO2 continuously, only if all CO2 sources in the catchment area are well characterized or calibrated with respect to their isotopic signature and CO to anthropogenic CO2 ratio. We test different calibration strategies for the mean isotopic signature and CO to CO2 ratio using precise Δ14C(CO2) measurements on monthly integrated as well as on grab samples. For δ13C(CO2), a calibration with annually averaged 14C(CO2) grab samples is most promising, since integrated sampling introduces large biases into anthropogenic CO2 estimates. For CO, these biases are smaller. The precision of continuous anthropogenic CO2 determination using δ13C(CO2) depends on measurement precision of δ13C(CO2) and CO2, while the CO method is mainly limited by the variation in natural CO sources and sinks. At present, continuous anthropogenic CO2 could be determined using the tracers δ13C(CO2) and/or CO with a precision of about 30 %, a mean bias of about 10 % and without significant diurnal discrepancies. Hypothetical future measurements of continuous Δ14C(CO2) with a precision of 5 ‰ are promising for anthropogenic CO2 determination (precision ca. 10-20 %) but are not yet available. The investigated tracer-based approaches open the door to improving, validating and reducing biases of highly resolved emission inventories using atmospheric observation and regional modeling. |
BibTeX:
@article{Vardag2015a,
author = {Vardag, S N and Gerbig, C and Janssens-Maenhout, G and Levin, I},
title = {Estimation of continuous anthropogenic CO2: Model-based evaluation of CO2, CO, δ13C(CO2) and Δ14C(CO2) tracer methods},
journal = {Atmospheric Chemistry and Physics},
year = {2015},
volume = {15},
number = {22},
pages = {12705--12729},
url = {http://www.atmos-chem-phys.net/15/12705/2015/},
doi = {10.5194/acp-15-12705-2015}
}
|
| Vargas A, Arnold D, Adame JA, Grossi C, Hernández-Ceballos MA and Bolivar JP (2015), "Analysis of the vertical radon structure at the spanish "El arenosillo" tower station", Journal of Environmental Radioactivity., jan, 2015. Vol. 139, pp. 1-17. |
| Abstract: This paper presents an analysis of one year of hourly radon and meteorological measurements at 10m and 100m a.g.l. at El Arenosillo tall-tower station, in the south-west of the Iberian Peninsula. Whole-year and seasonal composites of the diurnal radon cycle show the expected behaviour, with larger concentrations at 10m than at 100m during the night, due to poor vertical mixing, and similar concentrations at both heights during the daylight hours. Wind speed and wind direction analyses by sector show the prevailing contributions for each season. Sectors with air which has spent a longer period over the ocean and high wind speeds will lead to low concentrations at both levels, whereas inland sectors show a clear increase of the concentrations with similar overall averages for the two levels. The Sierra Morena, Guadalquivir and Bethics System sectors (continental pathways) are the sectors that show higher concentrations for mild to large wind speeds. The daily evolution of radon concentration differences at both heights has been grouped into four clusters by using a K-means algorithm method. The four clusters have been selected so that they sufficiently describe different characteristics in terms of stability. The temporal evolution of the mixing height (MH) and of the bulk diffusivity parameter (Kb) during the nocturnal period has been calculated by using the temporal variation of 222Rn concentration at 10m and the concentration gradient with height, respectively. |
BibTeX:
@article{Vargas2015,
author = {Vargas, A and Arnold, D and Adame, J A and Grossi, C and Hernández-Ceballos, M A and Bolivar, J P},
title = {Analysis of the vertical radon structure at the spanish "El arenosillo" tower station},
journal = {Journal of Environmental Radioactivity},
year = {2015},
volume = {139},
pages = {1--17},
url = {http://linkinghub.elsevier.com/retrieve/pii/S0265931X14002847},
doi = {10.1016/j.jenvrad.2014.09.018}
}
|
| Verlinden MS, Fichot R, Broeckx LS, Vanholme B, Boerjan W and Ceulemans R (2015), "Carbon isotope compositions (δ13C) of leaf, wood and holocellulose differ among genotypes of poplar and between previous land uses in a short-rotation biomass plantation", Plant, Cell and Environment., jan, 2015. Vol. 38(1), pp. 144-156. |
| Abstract: The efficiency of water use to produce biomass is a key trait in designing sustainable bioenergy-devoted systems. We characterized variations in the carbon isotope composition (δ13C) of leaves, current year wood and holocellulose (as proxies for water use efficiency, WUE) among six poplar genotypes in a short-rotation plantation. Values of δ13Cwood and δ13Cholocellulose were tightly and positively correlated, but the offset varied significantly among genotypes (0.79-1.01‰). Leaf phenology was strongly correlated with δ13C, and genotypes with a longer growing season showed a higher WUE. In contrast, traits related to growth and carbon uptake were poorly linked to δ13C. Trees growing on former pasture with higher N-availability displayed higher δ13C as compared with trees growing on former cropland. The positive relationships between δ13Cleaf and leaf N suggested that spatial variations in WUE over the plantation were mainly driven by an N-related effect on photosynthetic capacities. The very coherent genotype ranking obtained with δ13C in the different tree compartments has some practical outreach. Because WUE remains largely uncoupled from growth in poplar plantations, there is potential to identify genotypes with satisfactory growth and higher WUE. |
BibTeX:
@article{Verlinden2015,
author = {Verlinden, M S and Fichot, R and Broeckx, L S and Vanholme, B and Boerjan, W and Ceulemans, R},
title = {Carbon isotope compositions (δ13C) of leaf, wood and holocellulose differ among genotypes of poplar and between previous land uses in a short-rotation biomass plantation},
journal = {Plant, Cell and Environment},
year = {2015},
volume = {38},
number = {1},
pages = {144--156},
url = {http://doi.wiley.com/10.1111/pce.12383},
doi = {10.1111/pce.12383}
}
|
| Verlinden MS, Broeckx LS and Ceulemans R (2015), "First vs. second rotation of a poplar short rotation coppice: Above-ground biomass productivity and shoot dynamics", Biomass and Bioenergy., feb, 2015. Vol. 73, pp. 174-185. |
| Abstract: Within the global search for renewable energy sources, woody biomass from short rotation coppice (SRC) cultures is a valuable option. So far there is a shortage of large-scale field yield data to support stakeholders. We investigated an operational-scale SRC plantation (POPFULL) with 12 poplar genotypes in Flanders during its first two biennial rotations. By inventorying shoot numbers and diameters, combined with allometric relationships, productivity related data were derived after each growing season. We observed significant variation in biomass yield and productivity-related characteristics among the 12 poplar genotypes, of which two recently selected. Genotype Hees (Populus deltoides × Populus nigra) and Skado (Populus trichocarpa × Populus maximowiczii, selected in 2005) reached the highest productivity among genotypes, i.e. 16Mgha-1y-1 of dry matter (DM) yield in the second rotation, which was more than double than the poorest performing genotype Brandaris (a pure P. nigra). However, with many small shoots genotype Hees had a different growth strategy than Skado that resprouted with few, thicker and higher shoots. Biomass production increased from a plantation average of 4.04Mgha-1y-1 of DM in the first (establishment) rotation to 12.24Mgha-1y-1 in the second rotation. Mean height growth raised from 2.08my-1 during the first rotation to 2.99my-1 during the second rotation. The influence of the first coppicing on tree mortality was negligible. Monitoring of subsequent rotations over the plantations' lifetime - which counts for SRC bioenergy cultures in general - is essential to evaluate productivity in the long term. |
BibTeX:
@article{Verlinden2015a,
author = {Verlinden, M S and Broeckx, L S and Ceulemans, R},
title = {First vs. second rotation of a poplar short rotation coppice: Above-ground biomass productivity and shoot dynamics},
journal = {Biomass and Bioenergy},
year = {2015},
volume = {73},
pages = {174--185},
url = {http://linkinghub.elsevier.com/retrieve/pii/S0961953414005431},
doi = {10.1016/j.biombioe.2014.12.012}
}
|
| Vinciková H, Hanuš J and Pechar L (2015), "Spectral reflectance is a reliable water-quality estimator for small, highly turbid wetlands", Wetlands Ecology and Management., oct, 2015. Vol. 23(5), pp. 933-946. Kluwer Academic Publishers. |
| Abstract: Spectral reflectance from water surfaces was measured in small (0.01–5 km2), turbid, eutrophic fishponds and mesotrophic quarry lakes in the Třeboň basin (South Bohemia, Czech Republic). A spectral scanner for direct field measurements from water surfaces and a hyperspectral airborne scanner were both used. The quarry lakes and fishponds differed in their spectral signature, which reflected the extent of their eutrophication. Their chlorophyll-a (chl-a) concentrations ranged from 2 to 455 µg/l−1. Various algorithms were tested to best fit the relationships between reflectance patterns and the water-quality parameters used—concentration of chl-a and the total amount of suspended solids. The reflectance ratios at 714 and 650 nm gave the best estimates for chl-a concentrations, and simple reflectance at near infrared wavelengths, especially at 806 nm, gave the best predictive values for total suspended solid evaluation (r2 = 0.89). Field surface reflectance and airborne sensing measurements were well correlated; however, airborne reflectance data showed higher variability (r2 = 0.93 and 0.86, respectively). The results support the validity of reflectance measurements, both field and airborne, as a rapid tool for evaluating water quality in many turbid and greatly disturbed, small water bodies. |
BibTeX:
@article{Vincikova2015,
author = {Vinciková, Hana and Hanuš, Jan and Pechar, Libor},
title = {Spectral reflectance is a reliable water-quality estimator for small, highly turbid wetlands},
journal = {Wetlands Ecology and Management},
publisher = {Kluwer Academic Publishers},
year = {2015},
volume = {23},
number = {5},
pages = {933--946},
doi = {10.1007/s11273-015-9431-5}
}
|
| Vollmer MK, Rigby M, Laube JC, Henne S, Rhee TS, Gooch LJ, Wenger A, Young D, Steele LP, Langenfelds RL, Brenninkmeijer CAM, Wang JL, Ou-Yang CF, Wyss SA, Hill M, Oram DE, Krummel PB, Schoenenberger F, Zellweger C, Fraser PJ, Sturges WT, O'Doherty S and Reimann S (2015), "Abrupt reversal in emissions and atmospheric abundance of HCFC-133a (CF3CH2Cl)", Geophysical Research Letters., oct, 2015. Vol. 42(20), pp. 8702-8710. |
| Abstract: Hydrochlorofluorocarbon HCFC-133a (CF3CH2Cl) is an anthropogenic compound whose consumption for emissive use is restricted under the Montreal Protocol. A recent study showed rapidly increasing atmospheric abundances and emissions. We report that, following this rise, the atmospheric abundance and emissions have declined sharply in the past three years. We find a Northern Hemisphere HCFC-133a increase from 0.13 ppt (dry-air mole fraction in parts per trillion) in 2000 to 0.50 ppt in 2012-mid-2013 followed by an abrupt drop to ∼0.44 ppt by early 2015. Global emissions derived from these observations peaked at 3.1 kt in 2011, followed by a rapid decline of ∼0.5 kt yr-2 to reach 1.5 kt yr-1 in 2014. Sporadic HCFC-133a pollution events are detected in Europe from our high-resolution HCFC-133a records at three European stations, and in Asia from samples collected in Taiwan. European emissions are estimated to be 0.1 kt yr-1 although emission hot spots were identified in France. Key Points Atmospheric abundances of HCFC-133a and emissions have suddenly reversed in the last three years The sources of HCFC-133a to the atmosphere are likely from the production of HFC-134a In Europe, the emissions of HCFC-133a are less than 0.1 kt/yr while globally about 1.5 kt/yr |
BibTeX:
@article{Vollmer2015,
author = {Vollmer, Martin K and Rigby, Matt and Laube, Johannes C and Henne, Stephan and Rhee, Tae Siek and Gooch, Lauren J and Wenger, Angelina and Young, Dickon and Steele, L Paul and Langenfelds, Ray L and Brenninkmeijer, Carl A M and Wang, Jia Lin and Ou-Yang, Chang Feng and Wyss, Simon A and Hill, Matthias and Oram, David E and Krummel, Paul B and Schoenenberger, Fabian and Zellweger, Christoph and Fraser, Paul J and Sturges, William T and O'Doherty, Simon and Reimann, Stefan},
title = {Abrupt reversal in emissions and atmospheric abundance of HCFC-133a (CF3CH2Cl)},
journal = {Geophysical Research Letters},
year = {2015},
volume = {42},
number = {20},
pages = {8702--8710},
url = {http://doi.wiley.com/10.1002/2015GL065846},
doi = {10.1002/2015GL065846}
}
|
| Vollmer MK, Rhee TS, Rigby M, Hofstetter D, Hill M, Schoenenberger F and Reimann S (2015), "Modern inhalation anesthetics: Potent greenhouse gases in the global atmosphere", Geophysical Research Letters., mar, 2015. Vol. 42(5), pp. 1606-1611. |
| Abstract: Modern halogenated inhalation anesthetics undergo little metabolization during clinical application and evaporate almost completely to the atmosphere. Based on their first measurements in a range of environments, from urban areas to the pristine Antarctic environment, we detect a rapid accumulation and ubiquitous presence of isoflurane, desflurane, and sevoflurane in the global atmosphere. Over the past decade, their abundances in the atmosphere have increased to global mean mole fractions in 2014 of 0.097ppt, 0.30ppt, and 0.13ppt (parts per trillion, 10sup-12/sup, in dry air), respectively. Emissions of these long-lived greenhouse gases inferred from the observations suggest a global combined release to the atmosphere of 3.1 ± 0.6 million t COinf2/inf equivalent in 2014 of which ≈80% stems from desflurane. We also report on halothane, a previously widely used anesthetic. Its global mean mole fraction has declined to 9.2ppq (parts per quadrillion, 10sup-15/sup) by 2014. However, the inferred present usage is still 280 ±120t yrsup-1/sup. |
BibTeX:
@article{Vollmer2015a,
author = {Vollmer, Martin K and Rhee, Tae Siek and Rigby, Matt and Hofstetter, Doris and Hill, Matthias and Schoenenberger, Fabian and Reimann, Stefan},
title = {Modern inhalation anesthetics: Potent greenhouse gases in the global atmosphere},
journal = {Geophysical Research Letters},
year = {2015},
volume = {42},
number = {5},
pages = {1606--1611},
url = {http://doi.wiley.com/10.1002/2014GL062785},
doi = {10.1002/2014GL062785}
}
|
| Vollmer MK, Reimann S, Hill M and Brunner D (2015), "First observations of the fourth generation synthetic halocarbons HFC-1234yf, HFC-1234ze(E), and HCFC-1233zd(E) in the atmosphere", Environmental Science and Technology., mar, 2015. Vol. 49(5), pp. 2703-2708. |
| Abstract: Halogenated alkenes are a class of anthropogenic substances, which replace ozone-depleting substances and long-lived greenhouse gases in the foam-blowing, refrigeration, and solvent sectors. We report the first multiyear atmospheric measurements of the hydrofluorocarbons HFC-1234yf (2,3,3,3-tetrafluoroprop-1-ene, CF3CF=CH2), and HFC-1234ze(E) (E-1,3,3,3-tetrafluoroprop-1-ene trans-CF3CH=CHF), and the hydrochlorofluorocarbon HCFC-1233zd(E) (E-1-chloro-3,3,3-trifluoroprop-1-ene trans-CF3CH=CHCl) from the high altitude observatory at Jungfraujoch and from urban Dubendorf (Switzerland). When observations started in 2011 HFC-1234yf was undetectable at Jungfraujoch (mole fractions 0.003 ppt, parts-per-trillion, 10-12) but since then the percentage of measurements with detectable mole fractions has steadily increased to 4.5% in 2014. By contrast, in 2014 HFC-1234ze(E) was detectable in half of our samples at Jungfraujoch and in all samples at Dubendorf demonstrating the wide use of this compound within the air mass footprints of the stations. Our back trajectory analysis for the Jungfraujoch observations suggests high emission strength of HFC-1234ze(E) in the Belgium/Netherlands region. HCFC-1233zd(E) is present at very low mole fractions (typically 0.03 ppt) at both stations, and features pronounced seasonality and a general absence of pollution events during our 2013-2014 measurements. This is indicative of the presence of significant emissions from source locations outside the footprints of the two stations. Based on a simple one-box model calculation we estimate globally increasing HCFC-1233zd(E) emissions from 0.2 Gg yr-1 in 2013 to 0.5 Gg yr-1 for 2014. |
BibTeX:
@article{Vollmer2015b,
author = {Vollmer, Martin K and Reimann, Stefan and Hill, Matthias and Brunner, Dominik},
title = {First observations of the fourth generation synthetic halocarbons HFC-1234yf, HFC-1234ze(E), and HCFC-1233zd(E) in the atmosphere},
journal = {Environmental Science and Technology},
year = {2015},
volume = {49},
number = {5},
pages = {2703--2708},
url = {http://pubs.acs.org/doi/abs/10.1021/es505123x},
doi = {10.1021/es505123x}
}
|
| Vuichard N and Papale D (2015), "Filling the gaps in meteorological continuous data measured at FLUXNET sites with ERA-Interim reanalysis", Earth System Science Data., jul, 2015. Vol. 7(2), pp. 157-171. |
| Abstract: Exchanges of carbon, water and energy between the land surface and the atmosphere are monitored by eddy covariance technique at the ecosystem level. Currently, the FLUXNET database contains more than 500 registered sites, and up to 250 of them share data (free fair-use data set). Many modelling groups use the FLUXNET data set for evaluating ecosystem models' performance, but this requires uninterrupted time series for the meteorological variables used as input. Because original in situ data often contain gaps, from very short (few hours) up to relatively long (some months) ones, we develop a new and robust method for filling the gaps in meteorological data measured at site level. Our approach has the benefit of making use of continuous data available globally (ERA-Interim) and a high temporal resolution spanning from 1989 to today. These data are, however, not measured at site level, and for this reason a method to downscale and correct the ERA-Interim data is needed. We apply this method to the level 4 data (L4) from the La Thuile collection, freely available after registration under a fair-use policy. The performance of the developed method varies across sites and is also function of the meteorological variable. On average over all sites, applying the bias correction method to the ERA-Interim data reduced the mismatch with the in situ data by 10 to 36 %, depending on the meteorological variable considered. In comparison to the internal variability of the in situ data, the root mean square error (RMSE) between the in situ data and the unbiased ERA-I (ERA-Interim) data remains relatively large (on average over all sites, from 27 to 76 % of the standard deviation of in situ data, depending on the meteorological variable considered). The performance of the method remains poor for the wind speed field, in particular regarding its capacity to conserve a standard deviation similar to the one measured at FLUXNET stations. The ERA-Interim reanalysis data de-biased at FLUXNET sites can be downloaded from the PANGAEA data centre (http://doi.pangaea.de/10.1594/PANGAEA.838234). |
BibTeX:
@article{Vuichard2015,
author = {Vuichard, N and Papale, D},
title = {Filling the gaps in meteorological continuous data measured at FLUXNET sites with ERA-Interim reanalysis},
journal = {Earth System Science Data},
year = {2015},
volume = {7},
number = {2},
pages = {157--171},
url = {http://www.earth-syst-sci-data.net/7/157/2015/},
doi = {10.5194/essd-7-157-2015}
}
|
| Wingate L, Ogeé J, Cremonese E, Filippa G, Mizunuma T, Migliavacca M, Moisy C, Wilkinson M, Moureaux C, Wohlfahrt G, Hammerle A, Hörtnagl L, Gimeno C, Porcar-Castell A, Galvagno M, Nakaji T, Morison J, Kolle O, Knohl A, Kutsch W, Kolari P, Nikinmaa E, Ibrom A, Gielen B, Eugster W, Balzarolo M, Papale D, Klumpp K, Köstner B, Grünwald T, Joffre R, Ourcival JM, Hellstrom M, Lindroth A, George C, Longdoz B, Genty B, Levula J, Heinesch B, Sprintsin M, Yakir D, Manise T, Guyon D, Ahrends H, Plaza-Aguilar A, Guan JH and Grace J (2015), "Interpreting canopy development and physiology using a European phenology camera network at flux sites", Biogeosciences., oct, 2015. Vol. 12(20), pp. 5995-6015. |
| Abstract: Plant phenological development is orchestrated through subtle changes in photoperiod, temperature, soil moisture and nutrient availability. Presently, the exact timing of plant development stages and their response to climate and management practices are crudely represented in land surface models. As visual observations of phenology are laborious, there is a need to supplement long-term observations with automated techniques such as those provided by digital repeat photography at high temporal and spatial resolution. We present the first synthesis from a growing observational network of digital cameras installed on towers across Europe above deciduous and evergreen forests, grasslands and croplands, where vegetation and atmosphere CO2 fluxes are measured continuously. Using colour indices from digital images and using piecewise regression analysis of time series, we explored whether key changes in canopy phenology could be detected automatically across different land use types in the network. The piecewise regression approach could capture the start and end of the growing season, in addition to identifying striking changes in colour signals caused by flowering and management practices such as mowing. Exploring the dates of green-up and senescence of deciduous forests extracted by the piecewise regression approach against dates estimated from visual observations, we found that these phenological events could be detected adequately (RMSE 8 and 11 days for leaf out and leaf fall, respectively). We also investigated whether the seasonal patterns of red, green and blue colour fractions derived from digital images could be modelled mechanistically using the PROSAIL model parameterised with information of seasonal changes in canopy leaf area and leaf chlorophyll and carotenoid concentrations. From a model sensitivity analysis we found that variations in colour fractions, and in particular the late spring 'green hump' observed repeatedly in deciduous broadleaf canopies across the network, are essentially dominated by changes in the respective pigment concentrations. Using the model we were able to explain why this spring maximum in green signal is often observed out of phase with the maximum period of canopy photosynthesis in ecosystems across Europe. Coupling such quasi-continuous digital records of canopy colours with co-located CO2 flux measurements will improve our understanding of how changes in growing season length are likely to shape the capacity of European ecosystems to sequester CO2 in the future. |
BibTeX:
@article{Wingate2015,
author = {Wingate, L and Ogeé, J and Cremonese, E and Filippa, G and Mizunuma, T and Migliavacca, M and Moisy, C and Wilkinson, M and Moureaux, C and Wohlfahrt, G and Hammerle, A and Hörtnagl, L and Gimeno, C and Porcar-Castell, A and Galvagno, M and Nakaji, T and Morison, J and Kolle, O and Knohl, A and Kutsch, W and Kolari, P and Nikinmaa, E and Ibrom, A and Gielen, B and Eugster, W and Balzarolo, M and Papale, D and Klumpp, K and Köstner, B and Grünwald, T and Joffre, R and Ourcival, J M and Hellstrom, M and Lindroth, A and George, C and Longdoz, B and Genty, B and Levula, J and Heinesch, B and Sprintsin, M and Yakir, D and Manise, T and Guyon, D and Ahrends, H and Plaza-Aguilar, A and Guan, J H and Grace, J},
title = {Interpreting canopy development and physiology using a European phenology camera network at flux sites},
journal = {Biogeosciences},
year = {2015},
volume = {12},
number = {20},
pages = {5995--6015},
url = {http://www.biogeosciences.net/12/5995/2015/},
doi = {10.5194/bg-12-5995-2015}
}
|
| Wohlfahrt G, Amelynck C, Ammann C, Arneth A, Bamberger I, Goldstein AH, Gu L, Guenther A, Hansel A, Heinesch B, Holst T, Hörtnagl L, Karl T, Laffineur Q, Neftel A, Mckinney K, Munger JW, Pallardy SG, Schade GW, Seco R and Schoon N (2015), "An ecosystem-scale perspective of the net land methanol flux: Synthesis of micrometeorological flux measurements", Atmospheric Chemistry and Physics., jul, 2015. Vol. 15(13), pp. 7413-7427. |
| Abstract: Methanol is the second most abundant volatile organic compound in the troposphere and plays a significant role in atmospheric chemistry. While there is consensus about the dominant role of living plants as the major source and the reaction with OH as the major sink of methanol, global methanol budgets diverge considerably in terms of source/sink estimates, reflecting uncertainties in the approaches used to model and the empirical data used to separately constrain these terms. Here we compiled micrometeorological methanol flux data from eight different study sites and reviewed the corresponding literature in order to provide a first cross-site synthesis of the terrestrial ecosystem-scale methanol exchange and present an independent data-driven view of the land-atmosphere methanol exchange. Our study shows that the controls of plant growth on production, and thus the methanol emission magnitude, as well as stomatal conductance on the hourly methanol emission variability, established at the leaf level, hold across sites at the ecosystem level. Unequivocal evidence for bi-directional methanol exchange at the ecosystem scale is presented. Deposition, which at some sites even exceeds methanol emissions, represents an emerging feature of ecosystem-scale measurements and is likely related to environmental factors favouring the formation of surface wetness. Methanol may adsorb to or dissolve in this surface water and eventually be chemically or biologically removed from it. Management activities in agriculture and forestry are shown to increase local methanol emission by orders of magnitude; however, they are neglected at present in global budgets. While contemporary net land methanol budgets are overall consistent with the grand mean of the micrometeorological methanol flux measurements, we caution that the present approach of simulating methanol emission and deposition separately is prone to opposing systematic errors and does not allow for full advantage to be taken of the rich information content of micrometeorological flux measurements. |
BibTeX:
@article{Wohlfahrt2015,
author = {Wohlfahrt, G and Amelynck, C and Ammann, C and Arneth, A and Bamberger, I and Goldstein, A H and Gu, L and Guenther, A and Hansel, A and Heinesch, B and Holst, T and Hörtnagl, L and Karl, T and Laffineur, Q and Neftel, A and Mckinney, K and Munger, J W and Pallardy, S G and Schade, G W and Seco, R and Schoon, N},
title = {An ecosystem-scale perspective of the net land methanol flux: Synthesis of micrometeorological flux measurements},
journal = {Atmospheric Chemistry and Physics},
year = {2015},
volume = {15},
number = {13},
pages = {7413--7427},
url = {http://www.atmos-chem-phys.net/15/7413/2015/},
doi = {10.5194/acp-15-7413-2015}
}
|
| Yver Kwok C, Laurent O, Guemri A, Philippon C, Wastine B, Rella CW, Vuillemin C, Truong F, Delmotte M, Kazan V, Darding M, Lebègue B, Kaiser C, Xueref-Rémy I and Ramonet M (2015), "Comprehensive laboratory and field testing of cavity ring-down spectroscopy analyzers measuring H2O, CO2, CH4 and CO", Atmospheric Measurement Techniques., sep, 2015. Vol. 8(9), pp. 3867-3892. |
| Abstract: To develop an accurate measurement network of greenhouse gases, instruments in the field need to be stable and precise and thus require infrequent calibrations and a low consumption of consumables. For about 10 years, cavity ring-down spectroscopy (CRDS) analyzers have been available that meet these stringent requirements for precision and stability. Here, we present the results of tests of CRDS instruments in the laboratory (47 instruments) and in the field (15 instruments). The precision and stability of the measurements are studied. We demonstrate that, thanks to rigorous testing, newer models generally perform better than older models, especially in terms of reproducibility between instruments. In the field, we see the importance of individual diagnostics during the installation phase, and we show the value of calibration and target gases that assess the quality of the data. Finally, we formulate recommendations for use of these analyzers in the field. |
BibTeX:
@article{YverKwok2015,
author = {Yver Kwok, C and Laurent, O and Guemri, A and Philippon, C and Wastine, B and Rella, C W and Vuillemin, C and Truong, F and Delmotte, M and Kazan, V and Darding, M and Lebègue, B and Kaiser, C and Xueref-Rémy, I and Ramonet, M},
title = {Comprehensive laboratory and field testing of cavity ring-down spectroscopy analyzers measuring H2O, CO2, CH4 and CO},
journal = {Atmospheric Measurement Techniques},
year = {2015},
volume = {8},
number = {9},
pages = {3867--3892},
url = {http://www.atmos-meas-tech.net/8/3867/2015/},
doi = {10.5194/amt-8-3867-2015}
}
|
| Zazzeri G, Lowry D, Fisher RE, France JL, Lanoisellé M and Nisbet EG (2015), "Plume mapping and isotopic characterisation of anthropogenic methane sources", Atmospheric Environment., jun, 2015. Vol. 110, pp. 151-162. |
| Abstract: Methane stable isotope analysis, coupled with mole fraction measurement, has been used to link isotopic signature to methane emissions from landfill sites, coal mines and gas leaks in the United Kingdom. A mobile Picarro G2301 CRDS (Cavity Ring-Down Spectroscopy) analyser was installed on a vehicle, together with an anemometer and GPS receiver, to measure atmospheric methane mole fractions and their relative location while driving at speeds up to 80 kph. In targeted areas, when the methane plume was intercepted, air samples were collected in Tedlar bags, for δsup13/supC-CHinf4/inf isotopic analysis by CF-GC-IRMS (Continuous Flow Gas Chromatography-Isotope Ratio Mass Spectrometry). This method provides high precision isotopic values, determining δsup13/supC-CHinf4/inf to ±0.05 per mil. The bulk signature of the methane plume into the atmosphere from the whole source area was obtained by Keeling plot analysis, and a δsup13/supC-CHinf4/inf signature, with the relative uncertainty, allocated to each methane source investigated. Both landfill and natural gas emissions in SE England have tightly constrained isotopic signatures. The averaged δsup13/supC-CHinf4/inf for landfill sites is-58±3‰. The δsup13/supC-CHinf4/inf signature for gas leaks is also fairly constant around-36±2‰, a value characteristic of homogenised North Sea supply. In contrast, signatures for coal mines in N. England and Wales fall in a range of-51.2±0.3‰ to-30.9±1.4‰, but can be tightly constrained by region. The study demonstrates that CRDS-based mobile methane measurement coupled with off-line high precision isotopic analysis of plume samples is an efficient way of characterising methane sources. It shows that isotopic measurements allow type identification, and possible location of previously unknown methane sources. In modelling studies this measurement provides an independent constraint to determine the contributions of different sources to the regional methane budget and in the verification of inventory source distribution. |
BibTeX:
@article{Zazzeri2015,
author = {Zazzeri, G and Lowry, D and Fisher, R E and France, J L and Lanoisellé, M and Nisbet, E G},
title = {Plume mapping and isotopic characterisation of anthropogenic methane sources},
journal = {Atmospheric Environment},
year = {2015},
volume = {110},
pages = {151--162},
url = {http://linkinghub.elsevier.com/retrieve/pii/S1352231015002538},
doi = {10.1016/j.atmosenv.2015.03.029}
}
|
| Zeng J, Nojiri Y, Nakaoka S-i, Nakajima H and Shirai T (2015), "Surface ocean CO textlesssubtextgreater2textless/subtextgreater in 1990-2011 modelled using a feed-forward neural network", Geoscience Data Journal., jul, 2015. Vol. 2(1), pp. 47-51. John Wiley and Sons Ltd. |
| Abstract: This dataset includes the monthly distributions of CO2 fugacity in the world surface oceans reconstructed using a feed-forward neural network model and the CO2 measurements of the Surface Ocean CO2 Atlas version 2.0. It has a spatial resolution of 1 × 1° and spans a period of 22 years, from January 1990 to December 2011. The dataset also includes necessary parameters for the reconstruction and an estimate of the CO2 fluxes between the ocean and the atmosphere. The aim of this work is to provide a dataset for estimating the oceans' contribution to the global carbon budget. |
BibTeX:
@article{Zeng2015,
author = {Zeng, Jiye and Nojiri, Yukihiro and Nakaoka, Shin-ichiro and Nakajima, Hideaki and Shirai, Tomoko},
title = {Surface ocean CO textlesssubtextgreater2textless/subtextgreater in 1990-2011 modelled using a feed-forward neural network},
journal = {Geoscience Data Journal},
publisher = {John Wiley and Sons Ltd},
year = {2015},
volume = {2},
number = {1},
pages = {47--51},
url = {http://doi.wiley.com/10.1002/gdj3.26},
doi = {10.1002/gdj3.26}
}
|
| Zenone T, Fischer M, Arriga N, Broeckx LS, Verlinden MS, Vanbeveren S, Zona D and Ceulemans R (2015), "Biophysical drivers of the carbon dioxide, water vapor, and energy exchanges of a short-rotation poplar coppice", Agricultural and Forest Meteorology., sep, 2015. Vol. 209-210, pp. 22-35. |
| Abstract: We used the eddy-covariance technique to measure the temporal dynamics and the relationships between leaf area index (LAI) and exchanges of carbon dioxide (COinf2/inf), latent heat (LE) and sensible heat (H) in a multi-genotype short-rotation poplar coppice (SRC) located in East-Flanders (Belgium). The study was carried out over four years (2010-2013) corresponding to the first two rotations of the plantation. The net carbon (C) balance during the first two-year rotation was 75.2 (±4.4) gCmsup-2/sup in the establishment year 2010 and -95.6 (±5.9) gCmsup-2/sup in 2011. After the harvest (second two-year rotation) the coppice was a net source of carbon, 151.0 (±10.5) gCmsup-2/sup in 2012, but a sink of -274.6 (±18.8) gCmsup-2/sup in 2013. Overall, at the end of the second rotation this SRC, was a net COinf2/inf sink with a cumulative uptake of -144.0 (±22.8) gCmsup-2/sup. The temporal dynamics and the magnitude of the ratio between gross primary production (GPP) and ecosystem respiration (Rinfeco/inf) were similar to a deciduous forest. The evolution of LAI showed values ranging from 0.96 (±0.4) to 2.0 (±1.2) and from 5.1 (±1.5) to 4.5 (±0.84) during the first and the second rotation, respectively. The GPP (measured close to light saturation) was significantly related to LAI (rsup2/sup of 0.76, p0.001). The cumulative evapotranspiration (ET) measured during the first rotation was 241.7mm and 349.9mm for 2010 and 2011, respectively, and 464.6mm and 372.1mm for 2012 and 2013. The average value of surface conductance (Ginfs/inf) was 0.35molmsup-2/supssup-1/sup and 0.24molmsup-2/supssup-1/sup for the foliated and unfoliated periods, respectively. The mean decoupling factors (Ω) were 0.35 and 0.23 for the foliated and unfoliated periods, respectively, indicating that ET was primarily controlled by vapor pressure deficit (VPD) and Ginfs/inf (a well-coupled system). The mean Priestley-Taylor coefficient (α) was 0.77 and 0.53 for the foliated and the unfoliated periods, respectively. Such low values indicate that ET was significantly lower than the equilibrium evaporation and thus also lower than the ET of a hypothetical reference crop. During the whole experiment only two short episodes of drought were identified when in May-June 2011 and June 2013 the evaporative fraction dropped below 0.4. The analysis of Ginfs/inf showed a rather low stomatal control (anisohydric stomatal response) that put the poplar SRC at greater risk during severe drought conditions. All the three mentioned parameters related to ET and GPP (Ginfs/inf, Ω and α) were significantly and positively correlated to LAI (rsup2/sup from 0.14 to 0.2, p0.0001), suggesting that LAI was the main biophysical driver controlling the carbon and water balances in this bioenergy production system. |
BibTeX:
@article{Zenone2015,
author = {Zenone, Terenzio and Fischer, Milan and Arriga, Nicola and Broeckx, Laura S and Verlinden, Melanie S and Vanbeveren, Stefan and Zona, Donatella and Ceulemans, Reinhart},
title = {Biophysical drivers of the carbon dioxide, water vapor, and energy exchanges of a short-rotation poplar coppice},
journal = {Agricultural and Forest Meteorology},
year = {2015},
volume = {209-210},
pages = {22--35},
url = {http://linkinghub.elsevier.com/retrieve/pii/S0168192315001136},
doi = {10.1016/j.agrformet.2015.04.009}
}
|
| Zhang LX, Zhou DC, Fan JW and Hu ZM (2015), "Comparison of four light use efficiency models for estimating terrestrial gross primary production", Ecological Modelling., mar, 2015. Vol. 300, pp. 30-39. Elsevier. |
| Abstract: Light use efficiency (LUE) models that with different structures (i.e., methods to address environmental stresses on LUE) have been widely used to estimate terrestrial gross primary production (GPP) because of their theoretical soundness and practical conveniences. However, a systematic validation of those models with field observations across diverse ecosystems is still lacking and whether the model can be further improved by structural optimization remains unclear. Using GPP estimates at global 51 eddy covariance flux towers that cover a wide climate range and diverse vegetation types, we evaluated the performances of the four major LUE models (i.e., Carnegie-Ames-Stanford approach (CASA), Global Production Efficiency Model (GLO-PEM), Vegetation Photosynthesis Model (VPM), and Eddy Covariance-Light Use Efficiency (EC-LUE)) and examined the possible further improvement of the better-performed model(s) via model structural optimization. Our results showed that the GLO-PEM, VPM, and EC-LUE exhibited the similar capabilities in simulating GPP (explained around 68% of the total variations) and overall performed better than CASA (58%). Nevertheless, the EC-LUE and VPM were the optimal ones because they required less model inputs than the GLO-PEM. For the two optimal models, we found that the minimum method is better than the multiplication approach to integrate multiple environmental stresses on LUE. Moreover, we found that the VPM can be further improved by incorporating the constraint of water vapor deficit (VPDs). We suggested that a modified VPM by using minimum method and adding VPDs may be the best model in estimating large-scale GPP if high-quality remote sensing data available, otherwise, the modified models with the water stress reflected by VPDs only is optimal. |
BibTeX:
@article{Zhang2015,
author = {Zhang, Liang Xia and Zhou, De Cheng and Fan, Jiang Wen and Hu, Zhong Min},
title = {Comparison of four light use efficiency models for estimating terrestrial gross primary production},
journal = {Ecological Modelling},
publisher = {Elsevier},
year = {2015},
volume = {300},
pages = {30--39},
doi = {10.1016/j.ecolmodel.2015.01.001}
}
|
| Zhao Z, Martin P, Grosso P, Los W, De Laat C, Jeffrey K, Hardisty A, Vermeulen A, Castelli D, Legre Y and Kutsch W (2015), "Reference model guided system design and implementation for interoperable environmental research infrastructures", In Proceedings - 11th IEEE International Conference on eScience, eScience 2015., aug, 2015. , pp. 551-556. IEEE. |
| Abstract: Environmental research infrastructures (RIs) support their respective research communities by integrating large-scale sensor/observation networks with data curation services, analytical tools and common operational policies. These RIs are developed as pillars of intra-and interdisciplinary research, however comprehension of the complex, pathologically interconnected aspects of the Earth's ecosystem increasingly requires that researchers conduct their experiments across infrastructure boundaries. Consequently, almost all data-related activities within these infrastructures, from data capture to data usage, needs to be designed to be broadly interoperable in order to enable real interdisciplinary innovation. The Data for Science theme in the EU Horizon 2020 project ENVRIPLUS intends to address this interoperability challenge as it relates to the design, implementation and operation of environmental science RIs, the theme focuses on key issues of data identification and citation, curation, cataloguing, processing, optimization, and provenance, supported by a generic cross-infrastructure reference model. |
BibTeX:
@inproceedings{Zhao2015,
author = {Zhao, Zhiming and Martin, Paul and Grosso, Paola and Los, Wouter and De Laat, Cees and Jeffrey, Keith and Hardisty, Alex and Vermeulen, Alex and Castelli, Donatella and Legre, Yannick and Kutsch, Werner},
title = {Reference model guided system design and implementation for interoperable environmental research infrastructures},
booktitle = {Proceedings - 11th IEEE International Conference on eScience, eScience 2015},
publisher = {IEEE},
year = {2015},
pages = {551--556},
url = {http://ieeexplore.ieee.org/document/7304340/},
doi = {10.1109/eScience.2015.41}
}
|
| Ago EE, Agbossou EK, Galle S, Cohard JM, Heinesch B and Aubinet M (2014), "Long term observations of carbon dioxide exchange over cultivated savanna under a Sudanian climate in Benin (West Africa)", Agricultural and Forest Meteorology., oct, 2014. Vol. 197, pp. 13-25. |
| Abstract: Turbulent CO2 exchanges between a cultivated Sudanian savanna and the atmosphere were measured during 29 months (August 2007-December 2009) by an eddy-covariance system in North-Western Benin, West Africa. The site (Lat 9.74°N, Long 1.60°E, Alt: 449m) is the one of three sites fitted out by the international AMMA-CATCH program. The flux station footprint area is mainly composed of herbs and crops with some sparse trees and shrubs. Fluxes data were completed by an inventory of dominating species around the tower and the meteorological measurements. Flux response to climatic and edaphic factors was studied. Water was found the main controlling factor of ecosystem dynamics: much larger uptake was found in wet than dry season. During wet season, a very clear answer of net CO2 fluxes to photosynthetic photon fluxes density (PPFD) was observed. A low limitation in response to saturation deficit and soil water variability was however observed. The total ecosystem respiration (TER) was found highly dependent on soil moisture below 0.1m3m-3, but saturates above this threshold. The average annual carbon sequestration was 232±27gCm-2 with its inter-annual variability mainly controlled by TER. Finally, the ecosystem appeared more efficient during morning and wet season than during afternoon and dry period. textcopyright 2014 Elsevier B.V. |
BibTeX:
@article{Ago2014,
author = {Ago, Expedit Evariste and Agbossou, Euloge Kossi and Galle, Sylvie and Cohard, Jean Martial and Heinesch, Bernard and Aubinet, Marc},
title = {Long term observations of carbon dioxide exchange over cultivated savanna under a Sudanian climate in Benin (West Africa)},
journal = {Agricultural and Forest Meteorology},
year = {2014},
volume = {197},
pages = {13--25},
url = {http://linkinghub.elsevier.com/retrieve/pii/S0168192314001476},
doi = {10.1016/j.agrformet.2014.06.005}
}
|
| Agustí-Panareda A, Massart S, Chevallier F, Boussetta S, Balsamo G, Beljaars A, Ciais P, Deutscher NM, Engelen R, Jones L, Kivi R, Paris J-D, Peuch V-H, Sherlock V, Vermeulen AT, Wennberg PO and Wunch D (2014), " Forecasting global atmospheric CO 2 ", Atmospheric Chemistry and Physics Discussions., may, 2014. Vol. 14(9), pp. 13909-13962. |
| Abstract: Abstract. A new global atmospheric carbon dioxide (CO2) real-time forecast is now available as part of the pre-operational Monitoring of Atmospheric Composition and Climate – Interim Implementation (MACC-II) service using the infrastructure of the European Centre for Medium-Range Weather Forecasts (ECMWF) Integrated Forecasting System (IFS). One of the strengths of the CO2 forecasting system is that the land surface, including vegetation CO2 fluxes, is modelled online within the IFS. Other CO2 fluxes are prescribed from inventories and from off-line statistical and physical models. The CO2 forecast also benefits from the transport modelling from a state-of-the-art numerical weather prediction (NWP) system initialized daily with a wealth of meteorological observations. This paper describes the capability of the forecast in modelling the variability of CO2 on different temporal and spatial scales compared to observations. The modulation of the amplitude of the CO2 diurnal cycle by near-surface winds and boundary layer height is generally well represented in the forecast. The CO2 forecast also has high skill in simulating day-to-day synoptic variability. In the atmospheric boundary layer, this skill is significantly enhanced by modelling the day-to-day variability of the CO2 fluxes from vegetation compared to using equivalent monthly mean fluxes with a diurnal cycle. However, biases in the modelled CO2 fluxes also lead to accumulating errors in the CO2 forecast. These biases vary with season with an underestimation of the amplitude of the seasonal cycle both for the CO2 fluxes compared to total optimized fluxes and the atmospheric CO2 compared to observations. The largest biases in the atmospheric CO2 forecast are found in spring, corresponding to the onset of the growing season in the Northern Hemisphere. In the future, the forecast will be re-initialized regularly with atmospheric CO2 analyses based on the assimilation of CO2 satellite retrievals, as they become available in near-real time. In this way, the accumulation of errors in the atmospheric CO2 forecast will be reduced. Improvements in the CO2 forecast are also expected with the continuous developments in the operational IFS. |
BibTeX:
@article{Agusti-Panareda2014,
author = {Agustí-Panareda, A and Massart, S and Chevallier, F and Boussetta, S and Balsamo, G and Beljaars, A and Ciais, P and Deutscher, N M and Engelen, R and Jones, L and Kivi, R and Paris, J.-D. and Peuch, V.-H. and Sherlock, V and Vermeulen, A T and Wennberg, P O and Wunch, D},
title = { Forecasting global atmospheric CO 2 },
journal = {Atmospheric Chemistry and Physics Discussions},
year = {2014},
volume = {14},
number = {9},
pages = {13909--13962},
url = {http://www.atmos-chem-phys-discuss.net/14/13909/2014/},
doi = {10.5194/acpd-14-13909-2014}
}
|
| Arnold T, Ivy DJ, Harth CM, Vollmer MK, Mühle J, Salameh PK, Paul Steele L, Krummel PB, Wang RHJ, Young D, Lunder CR, Hermansen O, Rhee TS, Kim J, Reimann S, O'Doherty S, Fraser PJ, Simmonds PG, Prinn RG and Weiss RF (2014), "HFC-43-10mee atmospheric abundances and global emission estimates", Geophysical Research Letters., mar, 2014. Vol. 41(6), pp. 2228-2235. |
| Abstract: We report in situ atmospheric measurements of hydrofluorocarbon HFC-43-10mee (C5H2F10; 1,1,1,2,2,3,4,5,5,5- decafluoropentane) from seven observatories at various latitudes, together with measurements of archived air samples and recent Antarctic flask air samples. The global mean tropospheric abundance was 0.21 ± 0.05 ppt (parts per trillion, dry air mole fraction) in 2012, rising from 0.04 ± 0.03 ppt in 2000. We combine the measurements with a model and an inverse method to estimate rising global emissions - from 0.43 ± 0.34 Gg yr-1 in 2000 to 1.13 ± 0.31 Gg yr-1 in 2012 (∼1.9 Tg CO2-eq yr-1 based on a 100 year global warming potential of 1660). HFC-43-10mee - a cleaning solvent used in the electronics industry - is currently a minor contributor to global radiative forcing relative to total HFCs; however, our calculated emissions highlight a significant difference from the available reported figures and projected estimates. textcopyright 2014. American Geophysical Union. All Rights Reserved. |
BibTeX:
@article{Arnold2014,
author = {Arnold, Tim and Ivy, Diane J and Harth, Christina M and Vollmer, Martin K and Mühle, Jens and Salameh, Peter K and Paul Steele, L and Krummel, Paul B and Wang, Ray H J and Young, Dickon and Lunder, Chris R and Hermansen, Ove and Rhee, Tae Siek and Kim, Jooil and Reimann, Stefan and O'Doherty, Simon and Fraser, Paul J and Simmonds, Peter G and Prinn, Ronald G and Weiss, Ray F},
title = {HFC-43-10mee atmospheric abundances and global emission estimates},
journal = {Geophysical Research Letters},
year = {2014},
volume = {41},
number = {6},
pages = {2228--2235},
url = {http://doi.wiley.com/10.1002/2013GL059143},
doi = {10.1002/2013GL059143}
}
|
| Baatz R, Bogena HR, Hendricks Franssen HJ, Huisman JA, Qu W, Montzka C and Vereecken H (2014), "Calibration of a catchment scale cosmic-ray probe network: A comparison of three parameterization methods", Journal of Hydrology., aug, 2014. Vol. 516, pp. 231-244. |
| Abstract: The objective of this work was to assess the accuracy of soil water content determination from neutron flux measured by cosmic-ray probes under humid climate conditions. Ten cosmic-ray probes were set up in the Rur catchment located in western Germany, and calibrated by gravimetric soil sampling campaigns. Aboveground biomass was estimated at the sites to investigate the role of vegetation cover on the neutron flux and the calibration procedure. Three parameterization methods were used to generate site-specific neutron flux - soil water content calibration curves: (i) the N0-method, (ii) the hydrogen molar fraction method (hmf-method), and (iii) the COSMIC-method. At five locations, calibration measurements were repeated to evaluate site-specific calibration parameters obtained in two different sampling campaigns. At two locations, soil water content determined by cosmic-ray probes was evaluated with horizontally and vertically weighted soil water content measurements of two distributed in situ soil water content sensor networks. All three methods were successfully calibrated to determine field scale soil water content continuously at the ten sites. The hmf-method and the COSMIC-method had more similar calibration curves than the N0-method. The three methods performed similarly well in the validation and errors were within the uncertainty of neutron flux measurements despite observed differences in the calibration curves and variable model complexity. In addition, we found that the obtained calibration parameters NCOSMIC, N0 and NS showed a strong correlation with aboveground biomass. |
BibTeX:
@article{Baatz2014,
author = {Baatz, R and Bogena, H R and Hendricks Franssen, H J and Huisman, J A and Qu, W and Montzka, C and Vereecken, H},
title = {Calibration of a catchment scale cosmic-ray probe network: A comparison of three parameterization methods},
journal = {Journal of Hydrology},
year = {2014},
volume = {516},
pages = {231--244},
url = {http://linkinghub.elsevier.com/retrieve/pii/S0022169414001346},
doi = {10.1016/j.jhydrol.2014.02.026}
}
|
| Babst F, Bouriaud O, Papale D, Gielen B, Janssens IA, Nikinmaa E, Ibrom A, Wu J, Bernhofer C, Köstner B, Grünwald T, Seufert G, Ciais P and Frank D (2014), "Above-ground woody carbon sequestration measured from tree rings is coherent with net ecosystem productivity at five eddy-covariance sites", New Phytologist., mar, 2014. Vol. 201(4), pp. 1289-1303. |
| Abstract: Attempts to combine biometric and eddy-covariance (EC) quantifications of carbon allocation to different storage pools in forests have been inconsistent and variably successful in the past. We assessed above-ground biomass changes at five long-term EC forest stations based on tree-ring width and wood density measurements, together with multiple allometric models. Measurements were validated with site-specific biomass estimates and compared with the sum of monthly CO2 fluxes between 1997 and 2009. Biometric measurements and seasonal net ecosystem productivity (NEP) proved largely compatible and suggested that carbon sequestered between January and July is mainly used for volume increase, whereas that taken up between August and September supports a combination of cell wall thickening and storage. The inter-annual variability in above-ground woody carbon uptake was significantly linked with wood production at the sites, ranging between 110 and 370 g C m-2 yr-1, thereby accounting for 10-25% of gross primary productivity (GPP), 15-32% of terrestrial ecosystem respiration (TER) and 25-80% of NEP. The observed seasonal partitioning of carbon used to support different wood formation processes refines our knowledge on the dynamics and magnitude of carbon allocation in forests across the major European climatic zones. It may thus contribute, for example, to improved vegetation model parameterization and provides an enhanced framework to link tree-ring parameters with EC measurements. textcopyright 2013 New Phytologist Trust. |
BibTeX:
@article{Babst2014,
author = {Babst, Flurin and Bouriaud, Olivier and Papale, Dario and Gielen, Bert and Janssens, Ivan A and Nikinmaa, Eero and Ibrom, Andreas and Wu, Jian and Bernhofer, Christian and Köstner, Barbara and Grünwald, Thomas and Seufert, Günther and Ciais, Philippe and Frank, David},
title = {Above-ground woody carbon sequestration measured from tree rings is coherent with net ecosystem productivity at five eddy-covariance sites},
journal = {New Phytologist},
year = {2014},
volume = {201},
number = {4},
pages = {1289--1303},
url = {http://doi.wiley.com/10.1111/nph.12589},
doi = {10.1111/nph.12589}
}
|
| Bakker DCE, Pfeil B, Smith K, Hankin S, Olsen A, Alin SR, Cosca C, Harasawa S, Kozyr A, Nojiri Y, O'Brien KM, Schuster U, Telszewski M, Tilbrook B, Wada C, Akl J, Barbero L, Bates NR, Boutin J, Bozec Y, Cai WJ, Castle RD, Chavez FP, Chen L, Chierici M, Currie K, De Baar HJW, Evans W, Feely RA, Fransson A, Gao Z, Hales B, Hardman-Mountford NJ, Hoppema M, Huang WJ, Hunt CW, Huss B, Ichikawa T, Johannessen T, Jones EM, Jones SD, Jutterström S, Kitidis V, Körtzinger A, Landschützer P, Lauvset SK, Lefèvre N, Manke AB, Mathis JT, Merlivat L, Metzl N, Murata A, Newberger T, Omar AM, Ono T, Park GH, Paterson K, Pierrot D, Ríos AF, Sabine CL, Saito S, Salisbury J, S. Sarma VVS, Schlitzer R, Sieger R, Skjelvan I, Steinhoff T, Sullivan KF, Sun H, Sutton AJ, Suzuki T, Sweeney C, Takahashi T, Tjiputra J, Tsurushima N, C. Van Heuven SMA, Vandemark D, Vlahos P, Wallace DWR, Wanninkhof R and Watson AJ (2014), "An update to the surface ocean CO2 atlas (SOCAT version 2)", Earth System Science Data., mar, 2014. Vol. 6(1), pp. 69-90. |
| Abstract: The Surface Ocean CO2 Atlas (SOCAT), an activity of the international marine carbon research community, provides access to synthesis and gridded fCO2 (fugacity of carbon dioxide) products for the surface oceans. Version 2 of SOCAT is an update of the previous release (version 1) with more data (increased from 6.3 million to 10.1 million surface water fCO 2 values) and extended data coverage (from 1968-2007 to 1968-2011). The quality control criteria, while identical in both versions, have been applied more strictly in version 2 than in version 1. The SOCAT website (http://www.socat.info/) has links to quality control comments, metadata, individual data set files, and synthesis and gridded data products. Interactive online tools allow visitors to explore the richness of the data. Applications of SOCAT include process studies, quantification of the ocean carbon sink and its spatial, seasonal, year-to-year and longerterm variation, as well as initialisation or validation of ocean carbon models and coupled climate-carbon models. textcopyright Author(s) 2014. CC Attribution 3.0 License. |
BibTeX:
@article{Bakker2014,
author = {Bakker, D C E and Pfeil, B and Smith, K and Hankin, S and Olsen, A and Alin, S R and Cosca, C and Harasawa, S and Kozyr, A and Nojiri, Y and O'Brien, K M and Schuster, U and Telszewski, M and Tilbrook, B and Wada, C and Akl, J and Barbero, L and Bates, N R and Boutin, J and Bozec, Y and Cai, W J and Castle, R D and Chavez, F P and Chen, L and Chierici, M and Currie, K and De Baar, H J W and Evans, W and Feely, R A and Fransson, A and Gao, Z and Hales, B and Hardman-Mountford, N J and Hoppema, M and Huang, W J and Hunt, C W and Huss, B and Ichikawa, T and Johannessen, T and Jones, E M and Jones, S D and Jutterström, S and Kitidis, V and Körtzinger, A and Landschützer, P and Lauvset, S K and Lefèvre, N and Manke, A B and Mathis, J T and Merlivat, L and Metzl, N and Murata, A and Newberger, T and Omar, A M and Ono, T and Park, G H and Paterson, K and Pierrot, D and Ríos, A F and Sabine, C L and Saito, S and Salisbury, J and S. Sarma, V V S and Schlitzer, R and Sieger, R and Skjelvan, I and Steinhoff, T and Sullivan, K F and Sun, H and Sutton, A J and Suzuki, T and Sweeney, C and Takahashi, T and Tjiputra, J and Tsurushima, N and C. Van Heuven, S M A and Vandemark, D and Vlahos, P and Wallace, D W R and Wanninkhof, R and Watson, A J},
title = {An update to the surface ocean CO2 atlas (SOCAT version 2)},
journal = {Earth System Science Data},
year = {2014},
volume = {6},
number = {1},
pages = {69--90},
url = {http://www.earth-syst-sci-data.net/6/69/2014/},
doi = {10.5194/essd-6-69-2014}
}
|
| Balzarolo M, Boussetta S, Balsamo G, Beljaars A, Maignan F, Calvet JC, Lafont S, Barbu A, Poulter B, Chevallier F, Szczypta C and Papale D (2014), "Evaluating the potential of large-scale simulations to predict carbon fluxes of terrestrial ecosystems over a European eddy covariance network", Biogeosciences., may, 2014. Vol. 11(10), pp. 2661-2678. |
| Abstract: This paper reports a comparison between large-scale simulations of three different land surface models (LSMs), ORCHIDEE, ISBA-A-gs and CTESSEL, forced with the same meteorological data, and compared with the carbon fluxes measured at 32 eddy covariance (EC) flux tower sites in Europe. The results show that the three simulations have the best performance for forest sites and the poorest performance for cropland and grassland sites. In addition, the three simulations have difficulties capturing the seasonality of Mediterranean and sub-tropical biomes, characterized by dry summers. This reduced simulation performance is also reflected in deficiencies in diagnosed light-use efficiency (LUE) and vapour pressure deficit (VPD) dependencies compared to observations. Shortcomings in the forcing data may also play a role. These results indicate that more research is needed on the LUE and VPD functions for Mediterranean and sub-tropical biomes. Finally, this study highlights the importance of correctly representing phenology (i.e. leaf area evolution) and management (i.e. rotation-irrigation for cropland, and grazing-harvesting for grassland) to simulate the carbon dynamics of European ecosystems and the importance of ecosystem-level observations in model development and validation. copyright textcopyright Author(s) 2014. |
BibTeX:
@article{Balzarolo2014,
author = {Balzarolo, M and Boussetta, S and Balsamo, G and Beljaars, A and Maignan, F and Calvet, J C and Lafont, S and Barbu, A and Poulter, B and Chevallier, F and Szczypta, C and Papale, D},
title = {Evaluating the potential of large-scale simulations to predict carbon fluxes of terrestrial ecosystems over a European eddy covariance network},
journal = {Biogeosciences},
year = {2014},
volume = {11},
number = {10},
pages = {2661--2678},
url = {http://www.biogeosciences.net/11/2661/2014/},
doi = {10.5194/bg-11-2661-2014}
}
|
| Bonne JL, Masson-Delmotte V, Cattani O, Delmotte M, Risi C, Sodemann H and Steen-Larsen HC (2014), "The isotopic composition of water vapour and precipitation in Ivittuut, southern Greenland", Atmospheric Chemistry and Physics., may, 2014. Vol. 14(9), pp. 4419-4439. European Geosciences Union. |
| Abstract: Since September 2011, a wavelength-scanned cavity ring-down spectroscopy analyser has been remotely operated in Ivittuut, southern Greenland, providing the first record of surface water vapour isotopic composition based on continuous measurements in South Greenland and the first record including the winter season in Greenland. The comparison of vapour data with measurements of precipitation isotopic composition suggest an equilibrium between surface vapour and precipitation. textlessbrtextgreatertextlessbrtextgreater δ18O and deuterium excess are generally anti-correlated and show important seasonal variations, with respective amplitudes of ∼10 and ∼20&permil;, as well as large synoptic variations. The data depict small summer diurnal variations. At the seasonal scale, δ18O has a minimum in November-December and a maximum in June-July, while deuterium excess has a minimum in May-June and a maximum in November. The approach of low-pressure systems towards South Greenland leads to δ18O increase (typically +5&permil;) and deuterium excess decrease (typically -15&permil;). Seasonal and synoptic variations coincide with shifts in the moisture sources, estimated using a quantitative moisture source diagnostic based on a Lagrangian back-trajectory model. The atmospheric general circulation model LMDZiso correctly captures the seasonal and synoptic variability of δ18O, but does not capture the observed magnitude of deuterium excess variability. Covariations of water vapour isotopic composition with local and moisture source meteorological parameters have been evaluated. δ18O is strongly correlated with the logarithm of local surface humidity, consistent with Rayleigh distillation processes, and with local surface air temperature, associated with a slope of ∼0.4% °C-1. Deuterium excess correlates with local surface relative humidity as well as surface relative humidity from the dominant moisture source area located in the North Atlantic, south of Greenland and Iceland. textcopyright Author(s) 2014. |
BibTeX:
@article{Bonne2014,
author = {Bonne, J. L. and Masson-Delmotte, V. and Cattani, O. and Delmotte, M. and Risi, C. and Sodemann, H. and Steen-Larsen, H. C.},
title = {The isotopic composition of water vapour and precipitation in Ivittuut, southern Greenland},
journal = {Atmospheric Chemistry and Physics},
publisher = {European Geosciences Union},
year = {2014},
volume = {14},
number = {9},
pages = {4419--4439},
doi = {10.5194/acp-14-4419-2014}
}
|
| Bozhinova D, Van Der Molen MK, Van Der Velde IR, Krol MC, Van Der Laan S, Meijer HAJ and Peters W (2014), "Simulating the integrated summertime δ14CO2 signature from anthropogenic emissions over Western Europe", Atmospheric Chemistry and Physics., jul, 2014. Vol. 14(14), pp. 7273-7290. |
| Abstract: Radiocarbon dioxide (14CO2, reported in δ14CO2) can be used to determine the fossil fuel CO2 addition to the atmosphere, since fossil fuel CO2 no longer contains any 14C. After the release of CO2 at the source, atmospheric transport causes dilution of strong local signals into the background and detectable gradients of δ14CO2 only remain in areas with high fossil fuel emissions. This fossil fuel signal can moreover be partially masked by the enriching effect that anthropogenic emissions of 14CO2 from the nuclear industry have on the atmospheric δ14CO2 signature. In this paper, we investigate the regional gradients in 14CO2 over the European continent and quantify the effect of the emissions from nuclear industry. We simulate the emissions and transport of fossil fuel CO2 and nuclear 14CO2 for Western Europe using the Weather Research and Forecast model (WRF-Chem) for a period covering 6 summer months in 2008. We evaluate the expected CO2 gradients and the resulting δ14CO2 in simulated integrated air samples over this period, as well as in simulated plant samples. We find that the average gradients of fossil fuel CO2 in the lower 1200 m of the atmosphere are close to 15 ppm at a 12 km × 12 km horizontal resolution. The nuclear influence on δ14CO2 signatures varies considerably over the domain and for large areas in France and the UK it can range from 20 to more than 500% of the influence of fossil fuel emissions. Our simulations suggest that the resulting gradients in δ14CO2 are well captured in plant samples, but due to their time-varying uptake of CO 2, their signature can be different with over 3&permil; from the atmospheric samples in some regions. We conclude that the framework presented will be well-suited for the interpretation of actual air and plant 14CO2 samples. textcopyright Author(s) 2014. CC Attribution 3.0 License. |
BibTeX:
@article{Bozhinova2014,
author = {Bozhinova, D and Van Der Molen, M K and Van Der Velde, I R and Krol, M C and Van Der Laan, S and Meijer, H A J and Peters, W},
title = {Simulating the integrated summertime δ14CO2 signature from anthropogenic emissions over Western Europe},
journal = {Atmospheric Chemistry and Physics},
year = {2014},
volume = {14},
number = {14},
pages = {7273--7290},
url = {http://www.atmos-chem-phys.net/14/7273/2014/},
doi = {10.5194/acp-14-7273-2014}
}
|
| Brilli F, Gioli B, Zona D, Pallozzi E, Zenone T, Fratini G, Calfapietra C, Loreto F, Janssens IA and Ceulemans R (2014), "Simultaneous leaf- and ecosystem-level fluxes of volatile organic compounds from a poplar-based SRC plantation", Agricultural and Forest Meteorology., apr, 2014. Vol. 187, pp. 22-35. |
| Abstract: Emission of carbon from ecosystems in the form of volatile organic compounds (VOC) represents a minor component flux in the global carbon cycle that has a large impact on ground-level ozone, particle and aerosol formation and thus on air chemistry and quality. This study reports exchanges of CO2 and VOC between a poplar-based short rotation coppice (SRC) plantation and the atmosphere, measured simultaneously at two spatial scale, one at stand level and another at leaf level. The first technique combined Proton Transfer Reaction "Time-of-Flight" mass spectrometry (PTR-TOF-MS) with the eddy covariance method, to measure fluxes of a multitude of VOC. Abundant fluxes of isoprene, methanol and, to a lesser extent, fluxes of other oxygenated VOC such as formaldehyde, isoprene oxidation products (methyl vinyl ketone and methacrolein), methyl ethyl ketone, acetaldehyde, acetone and acetic acid, were measured. Under optimal environmental conditions, isoprene flux was mostly controlled by temperature and light. Differently, methanol flux underwent a combined enzymatic and stomatal control, together involving environmental drivers such as vapour pressure deficit (VPD), temperature and light intensity. Moreover fair weather condition favoured ozone deposition to the poplar plantation.The second technique involved trapping the VOCs emitted from leaves followed by gas chromatography-mass spectrometry (GC-MS) analysis. These leaf-level measurements showed that emission of isoprene in adult leaves and of monoterpenes in juvenile leaves are widespread across poplar genotypes. Detection of isoprene oxidation products (iox) emission with leaf-level measurements confirmed that a fraction of isoprene may be already oxidized within leaves, possibly when isoprene copes with foliar reactive oxygen species (ROS) formed during warm and sunny days. textcopyright 2013 Elsevier B.V. |
BibTeX:
@article{Brilli2014,
author = {Brilli, Federico and Gioli, Beniamino and Zona, Donatella and Pallozzi, Emanuele and Zenone, Terenzio and Fratini, Gerardo and Calfapietra, Carlo and Loreto, Francesco and Janssens, Ivan A and Ceulemans, Reinhart},
title = {Simultaneous leaf- and ecosystem-level fluxes of volatile organic compounds from a poplar-based SRC plantation},
journal = {Agricultural and Forest Meteorology},
year = {2014},
volume = {187},
pages = {22--35},
url = {http://linkinghub.elsevier.com/retrieve/pii/S0168192313002967},
doi = {10.1016/j.agrformet.2013.11.006}
}
|
| Brilli F, Gioli B, Ciccioli P, Zona D, Loreto F, Janssens IA and Ceulemans R (2014), "Proton Transfer Reaction Time-of-Flight Mass Spectrometric (PTR-TOF-MS) determination of volatile organic compounds (VOCs) emitted from a biomass fire developed under stable nocturnal conditions", Atmospheric Environment., nov, 2014. Vol. 97, pp. 54-67. |
| Abstract: Combustion of solid and liquid fuels is the largest source of potentially toxic volatile organic compounds (VOCs), which can strongly affect health and the physical and chemical properties of the atmosphere. Among combustion processes, biomass burning is one of the largest at global scale. We used a Proton Transfer Reaction "Time-of-Flight" Mass Spectrometer (PTR-TOF-MS), which couples high sensitivity with high mass resolution, for real-time detection of multiple VOCs emitted by burned hay and straw in a barn located near our measuring station. We detected 132 different organic ions directly attributable to VOCs emitted from the fire. Methanol, acetaldehyde, acetone, methyl vinyl ether (MVE), acetic acid and glycolaldehyde dominated the VOC mixture composition. The time-course of the 25 most abundant VOCs, representing ˜85% of the whole mixture of VOCs, was associated with that of carbon monoxide (CO), carbon dioxide (CO2) and methane (CH4) emissions. The strong linear relationship between the concentrations of pyrogenic VOC and of a reference species (i.e. CO) allowed us to compile a list of emission ratios (ERs) and emission factors (EFs), but values of ER (and EF) were overestimated due to the limited mixing of the gases under the stable (non-turbulent) nocturnal conditions. In addition to the 25 most abundant VOCs, chemical formula and concentrations of the residual, less abundant VOCs in the emitted mixture were also estimated by PTR-TOF-MS. Furthermore, the evolution of the complex combustion process was described on the basis of the diverse types of pyrogenic gases recorded. |
BibTeX:
@article{Brilli2014a,
author = {Brilli, Federico and Gioli, Beniamino and Ciccioli, Paolo and Zona, Donatella and Loreto, Francesco and Janssens, Ivan A and Ceulemans, Reinhart},
title = {Proton Transfer Reaction Time-of-Flight Mass Spectrometric (PTR-TOF-MS) determination of volatile organic compounds (VOCs) emitted from a biomass fire developed under stable nocturnal conditions},
journal = {Atmospheric Environment},
year = {2014},
volume = {97},
pages = {54--67},
url = {http://linkinghub.elsevier.com/retrieve/pii/S1352231014006013},
doi = {10.1016/j.atmosenv.2014.08.007}
}
|
| Broeckx LS, Verlinden MS, Berhongaray G, Zona D, Fichot R and Ceulemans R (2014), "The effect of a dry spring on seasonal carbon allocation and vegetation dynamics in a poplar bioenergy plantation", GCB Bioenergy., sep, 2014. Vol. 6(5), pp. 473-487. |
| Abstract: In this study the seasonal variation in carbon, water and energy fluxes as well as in net primary productivity (NPP) of different tree components is presented for a 2-year-old poplar (Populus spp.) plantation. A thorough ecophysiological study was performed at ecosystem scale, at tree and at leaf level, in this high-density bioenergy plantation. Seasonal variation in NPP and fluxes was analysed in relation to meteorological parameters at the field site. The growing season length in terms of carbon uptake was controlled by leaf area development until the maximum leaf area index (LAImax) was reached. Afterwards, a shift to belowground carbon allocation was observed. A dry period in spring caused a reduced leaf area production as well as a decrease in net ecosystem exchange and gross primary production (GPP) due to stomatal closure. Water use efficiency and fine root growth increased in response to limiting soil water availability in the root zone. When soil water availability was not limiting, GPP was controlled by a decrease in solar radiation and air temperature. The results of this study indicate that the productivity of recently established bioenergy plantations with fast-growing trees is very sensitive to drought. The interaction between soil water availability and factors controlling ecosystem GPP is crucial in assessing the CO2 mitigation potential under future climate conditions. textcopyright 2013 The Authors. GCB Bioenergy published by John Wiley & Sons Ltd. |
BibTeX:
@article{Broeckx2014,
author = {Broeckx, Laura S and Verlinden, Melanie S and Berhongaray, Gonzalo and Zona, Donatella and Fichot, Régis and Ceulemans, Reinhart},
title = {The effect of a dry spring on seasonal carbon allocation and vegetation dynamics in a poplar bioenergy plantation},
journal = {GCB Bioenergy},
year = {2014},
volume = {6},
number = {5},
pages = {473--487},
url = {http://doi.wiley.com/10.1111/gcbb.12087},
doi = {10.1111/gcbb.12087}
}
|
| Broeckx LS, Fichot R, Verlinden MS and Ceulemans R (2014), "Seasonal variations in photosynthesis, intrinsic water-use efficiency and stable isotope composition of poplar leaves in a short-rotation plantation", Tree Physiology., jul, 2014. Vol. 34(7), pp. 701-715. |
| Abstract: Photosynthetic carbon assimilation and transpirational water loss play an important role in the yield and the carbon sequestration potential of bioenergy-devoted cultures of fast-growing trees. For six poplar (Populus) genotypes in a short-rotation plantation, we observed significant seasonal and genotypic variation in photosynthetic parameters, intrinsic water-use efficiency (WUEi) and leaf stable isotope composition (δ13C and δ18O). The poplars maintained high photosynthetic rates (between 17.8 and 26.9μmolm-2s-1 depending on genotypes) until late in the season, in line with their fast-growth habit. Seasonal fluctuations were mainly explained by variations in soil water availability and by stomatal limitation upon photosynthesis. Stomatal rather than biochemical limitation was confirmed by the constant intrinsic photosynthetic capacity (Vcmax) during the growing season, closely related to leaf nitrogen (N) content. Intrinsic water-use efficiency scaled negatively with carbon isotope discrimination (Δ13C bl) and positively with the ratio between mesophyll diffusion conductance (gm) and stomatal conductance. The WUE i-Δ13Cbl relationship was partly influenced by gm. There was a trade-off between WUEi and photosynthetic N-use efficiency, but only when soil water availability was limiting. Our results suggest that seasonal fluctuations in relation to soil water availability should be accounted for in future modelling studies assessing the carbon sequestration potential and the water-use efficiency of woody energy crops. textcopyright 2014 The Author. Published by Oxford University Press. |
BibTeX:
@article{Broeckx2014a,
author = {Broeckx, L S and Fichot, R and Verlinden, M S and Ceulemans, R},
title = {Seasonal variations in photosynthesis, intrinsic water-use efficiency and stable isotope composition of poplar leaves in a short-rotation plantation},
journal = {Tree Physiology},
year = {2014},
volume = {34},
number = {7},
pages = {701--715},
url = {https://academic.oup.com/treephys/article-lookup/doi/10.1093/treephys/tpu057},
doi = {10.1093/treephys/tpu057}
}
|
| Budishchev A, Mi Y, Van Huissteden J, Belelli-Marchesini L, Schaepman-Strub G, Parmentier FJW, Fratini G, Gallagher A, Maximov TC and Dolman AJ (2014), "Evaluation of a plot-scale methane emission model using eddy covariance observations and footprint modelling", Biogeosciences., sep, 2014. Vol. 11(17), pp. 4651-4664. |
| Abstract: Most plot-scale methane emission models - of which many have been developed in the recent past - are validated using data collected with the closed-chamber technique. This method, however, suffers from a low spatial representativeness and a poor temporal resolution. Also, during a chamber-flux measurement the air within a chamber is separated from the ambient atmosphere, which negates the influence of wind on emissions. Additionally, some methane models are validated by upscaling fluxes based on the area-weighted averages of modelled fluxes, and by comparing those to the eddy covariance (EC) flux. This technique is rather inaccurate, as the area of upscaling might be different from the EC tower footprint, therefore introducing significant mismatch. In this study, we present an approach to validate plot-scale methane models with EC observations using the footprint-weighted average method. Our results show that the fluxes obtained by the footprint-weighted average method are of the same magnitude as the EC flux. More importantly, the temporal dynamics of the EC flux on a daily timescale are also captured (r2 = 0.7). In contrast, using the area-weighted average method yielded a low (r2 = 0.14) correlation with the EC measurements. This shows that the footprint-weighted average method is preferable when validating methane emission models with EC fluxes for areas with a heterogeneous and irregular vegetation pattern. textcopyright Author(s) 2014. CC Attribution 3.0 License. |
BibTeX:
@article{Budishchev2014,
author = {Budishchev, A and Mi, Y and Van Huissteden, J and Belelli-Marchesini, L and Schaepman-Strub, G and Parmentier, F J W and Fratini, G and Gallagher, A and Maximov, T C and Dolman, A J},
title = {Evaluation of a plot-scale methane emission model using eddy covariance observations and footprint modelling},
journal = {Biogeosciences},
year = {2014},
volume = {11},
number = {17},
pages = {4651--4664},
url = {http://www.biogeosciences.net/11/4651/2014/},
doi = {10.5194/bg-11-4651-2014}
}
|
| Camino-Serrano M, Gielen B, Luyssaert S, Ciais P, Vicca S, Guenet B, Vos BD, Cools N, Ahrens B, Altaf Arain M, Borken W, Clarke N, Clarkson B, Cummins T, Don A, Pannatier EG, Laudon H, Moore T, Nieminen TM, Nilsson MB, Peichl M, Schwendenmann L, Siemens J and Janssens I (2014), "Linking variability in soil solution dissolved organic carbon to climate, soil type, and vegetation type", Global Biogeochemical Cycles., may, 2014. Vol. 28(5), pp. 497-509. |
| Abstract: Lateral transport of carbon plays an important role in linking the carbon cycles of terrestrial and aquatic ecosystems. There is, however, a lack of information on the factors controlling one of the main C sources of this lateral flux, i.e., the concentration of dissolved organic carbon (DOC) in soil solution across large spatial scales and under different soil, vegetation, and climate conditions. We compiled a database on DOC in soil solution down to 80-cm and analyzed it with the aim, first, to quantify the differences in DOC concentrations among terrestrial ecosystems, climate zones, soil, and vegetation types at global scale and second, to identify potential determinants of the site-to-site variability of DOC concentration in soil solution across European broadleaved and coniferous forests. We found that DOC concentrations were 75% lower in mineral than in organic soil, and temperate sites showed higher DOC concentrations than boreal and tropical sites. The majority of the variation (R2-=-0.67-0.99) in DOC concentrations in mineral European forest soils correlates with NH4+, C/N, Al, and Fe as the most important predictors. Overall, our results show that the magnitude (23% lower in broadleaved than in coniferous forests) and the controlling factors of DOC in soil solution differ between forest types, with site productivity being more important in broadleaved forests and water balance in coniferous stands. Key Points Soil DOC concentration is higher under coniferous forests than under broadleaves N, Fe and Al are important factors for DOC concentration variability in forests textcopyright2014. American Geophysical Union. All Rights Reserved. |
BibTeX:
@article{Camino-Serrano2014,
author = {Camino-Serrano, Marta and Gielen, Bert and Luyssaert, Sebastiaan and Ciais, Philippe and Vicca, Sara and Guenet, Bertrand and Vos, Bruno De and Cools, Nathalie and Ahrens, Bernhard and Altaf Arain, M and Borken, Werner and Clarke, Nicholas and Clarkson, Beverley and Cummins, Thomas and Don, Axel and Pannatier, Elisabeth Graf and Laudon, Hjalmar and Moore, Tim and Nieminen, Tiina M and Nilsson, Mats B and Peichl, Matthias and Schwendenmann, Luitgard and Siemens, Jan and Janssens, Ivan},
title = {Linking variability in soil solution dissolved organic carbon to climate, soil type, and vegetation type},
journal = {Global Biogeochemical Cycles},
year = {2014},
volume = {28},
number = {5},
pages = {497--509},
url = {http://doi.wiley.com/10.1002/2013GB004726},
doi = {10.1002/2013GB004726}
}
|
| Churakova (Sidorova) OV, Eugster W, Zielis S, Cherubini P, Etzold S, Saurer M, Siegwolf R and Buchmann N (2014), "Increasing relevance of spring temperatures for Norway spruce trees in Davos, Switzerland, after the 1950s", Trees - Structure and Function., feb, 2014. Vol. 28(1), pp. 183-191. |
| Abstract: Key message: Relevance of spring temperatures for tree-ring growth steadily increased since 1950s. Closely linked tree-ring growth and net CO 2 exchange driven by spring temperatures. We investigated long-term (over 100 years) tree-ring width (TRW) variabilities as well as short-term (10 years) variations in net ecosystem productivity (NEP) in response to climate to assess the driving factors for stem growth of Norway spruce in a subalpine forest at Davos in Switzerland. A tree-ring width index (TRWi) chronology for the period from 1750 to 2006 was constructed and linked with climate data from 1876 to 2006, and with NEP available for the period from 1997 to 2006. Based on TRWi, we found that only two out of the 257 years exhibited extreme negative TRWi, compared to 29 years with extreme positive anomalies, observed mainly in recent decades. Annual temperature, annual precipitation, as well as autumn and winter temperature signals were well preserved in the TRWi chronology over the last 130 years. Spring temperatures became increasingly relevant for TRWi, explaining less than 1 % of the variation in TRWi for the period from 1876 to 2006, but 8 % for the period from 1950 to 2006 (p = 0.032), and even 47 % for 1997-2006 (p = 0.028). We also observed a strong positive relationship between annual TRWi and annual NEP (r = 0.661; p = 0.037), both strongly related to spring temperatures (r = 0.687 and r = 0.678 for TRWi and NEP, respectively; p = 0.028; p = 0.032). Moreover, we found strong links between monthly NEP of March and annual TRWi (r = 0.912; p = 0.0001), both related to March temperatures (r = 0.767, p = 0.010 and r = 0.724, p = 0.018, respectively). Thus, under future climate warming, we expect stem growth of these subalpine trees and also ecosystem carbon (C) sequestration to increase, as long as water does not become a limiting factor. textcopyright 2013 Springer-Verlag Berlin Heidelberg. |
BibTeX:
@article{ChurakovaSidorova2014,
author = {Churakova (Sidorova), Olga V and Eugster, Werner and Zielis, Sebastian and Cherubini, Paolo and Etzold, Sophia and Saurer, Matthias and Siegwolf, Rolf and Buchmann, Nina},
title = {Increasing relevance of spring temperatures for Norway spruce trees in Davos, Switzerland, after the 1950s},
journal = {Trees - Structure and Function},
year = {2014},
volume = {28},
number = {1},
pages = {183--191},
url = {http://link.springer.com/10.1007/s00468-013-0941-6},
doi = {10.1007/s00468-013-0941-6}
}
|
| Cowan NJ, Famulari D, Levy PE, Anderson M, Reay DS and Skiba UM (2014), "Investigating uptake of N2O in agricultural soils using a high-precision dynamic chamber method", Atmospheric Measurement Techniques., dec, 2014. Vol. 7(12), pp. 4455-4462. |
| Abstract: Uptake (or negative flux) of nitrous oxide (N2O) in agricultural soils is a controversial issue which has proved difficult to investigate in the past due to constraints such as instrumental precision and methodological uncertainties. Using a recently developed high-precision quantum cascade laser gas analyser combined with a closed dynamic chamber, a well-defined detection limit of 4 μg N2O-N m-2 h-1 could be achieved for individual soil flux measurements. 1220 measurements of N2O flux were made from a variety of UK soils using this method, of which 115 indicated uptake by the soil (i.e. a negative flux in the micrometeorological sign convention). Only four of these apparently negative fluxes were greater than the detection limit of the method, which suggests that the vast majority of reported negative fluxes from such measurements are actually due to instrument noise. As such, we suggest that the bulk of negative N2O fluxes reported for agricultural fields are most likely due to limits in detection of a particular flux measurement methodology and not a result of microbiological activity consuming atmospheric N2O. |
BibTeX:
@article{Cowan2014,
author = {Cowan, N J and Famulari, D and Levy, P E and Anderson, M and Reay, D S and Skiba, U M},
title = {Investigating uptake of N2O in agricultural soils using a high-precision dynamic chamber method},
journal = {Atmospheric Measurement Techniques},
year = {2014},
volume = {7},
number = {12},
pages = {4455--4462},
url = {http://www.atmos-meas-tech.net/7/4455/2014/},
doi = {10.5194/amt-7-4455-2014}
}
|
| Deng J, Li C, Frolking S, Zhang Y, Bäckstrand K and Crill P (2014), "Assessing effects of permafrost thaw on C fluxes based on multiyear modeling across a permafrost thaw gradient at Stordalen, Sweden", Biogeosciences., sep, 2014. Vol. 11(17), pp. 4753-4770. |
| Abstract: Northern peatlands in permafrost regions contain a large amount of organic carbon (C) in the soil. Climate warming and associated permafrost degradation are expected to have significant impacts on the C balance of these ecosystems, but the magnitude is uncertain. We incorporated a permafrost model, Northern Ecosystem Soil Temperature (NEST), into a biogeochemical model, DeNitrification-DeComposition (DNDC), to model C dynamics in high-latitude peatland ecosystems. The enhanced model was applied to assess effects of permafrost thaw on C fluxes of a subarctic peatland at Stordalen, Sweden. DNDC simulated soil freeze-thaw dynamics, net ecosystem exchange of CO2 (NEE), and CH4 fluxes across three typical land cover types, which represent a gradient in the process of ongoing permafrost thaw at Stordalen. Model results were compared with multiyear field measurements, and the validation indicates that DNDC was able to simulate observed differences in seasonal soil thaw, NEE, and CH4 fluxes across the three land cover types. Consistent with the results from field studies, the modeled C fluxes across the permafrost thaw gradient demonstrate that permafrost thaw and the associated changes in soil hydrology and vegetation not only increase net uptake of C from the atmosphere but also increase the annual to decadal radiative forcing impacts on climate due to increased CH4 emissions. This study indicates the potential of utilizing biogeochemical models, such as DNDC, to predict the soil thermal regime in permafrost areas and to investigate impacts of permafrost thaw on ecosystem C fluxes after incorporating a permafrost component into the model framework. |
BibTeX:
@article{Deng2014,
author = {Deng, J and Li, C and Frolking, S and Zhang, Y and Bäckstrand, K and Crill, P},
title = {Assessing effects of permafrost thaw on C fluxes based on multiyear modeling across a permafrost thaw gradient at Stordalen, Sweden},
journal = {Biogeosciences},
year = {2014},
volume = {11},
number = {17},
pages = {4753--4770},
url = {https://www.biogeosciences.net/11/4753/2014/},
doi = {10.5194/bg-11-4753-2014}
}
|
| Deng F, Jones DBA, Henze DK, Bousserez N, Bowman KW, Fisher JB, Nassar R, O'Dell C, Wunch D, Wennberg PO, Kort EA, Wofsy SC, Blumenstock T, Deutscher NM, Griffith DWT, Hase F, Heikkinen P, Sherlock V, Strong K, Sussmann R and Warneke T (2014), "Inferring regional sources and sinks of atmospheric CO2 from GOSAT XCO2 data", Atmospheric Chemistry and Physics., apr, 2014. Vol. 14(7), pp. 3703-3727. |
| Abstract: We have examined the utility of retrieved column-averaged, dry-air mole fractions of CO2 (XCO2) from the Greenhouse Gases Observing Satellite (GOSAT) for quantifying monthly, regional flux estimates of CO2, using the GEOS-Chem four-dimensional variational (4D-Var) data assimilation system. We focused on assessing the potential impact of biases in the GOSAT CO2 data on the regional flux estimates. Using different screening and bias correction approaches, we selected three different subsets of the GOSAT XCO2 data for the 4D-Var inversion analyses, and found that the inferred global fluxes were consistent across the three XCO2 inversions. However, the GOSAT observational coverage was a challenge for the regional flux estimates. In the northern extratropics, the inversions were more sensitive to North American fluxes than to European and Asian fluxes due to the lack of observations over Eurasia in winter and over eastern and southern Asia in summer. The regional flux estimates were also sensitive to the treatment of the residual bias in the GOSAT XCO2 data. The largest differences obtained were for temperate North America and temperate South America, for which the largest spread between the inversions was 1.02 and 0.96 Pg C, respectively. In the case of temperate North America, one inversion suggested a strong source, whereas the second and third XCO2 inversions produced a weak and strong sink, respectively. Despite the discrepancies in the regional flux estimates between the three XCO2 inversions, the a posteriori CO 2 distributions were in good agreement (with a mean difference between the three inversions of typically less than 0.5 ppm) with independent data from the Total Carbon Column Observing Network (TCCON), the surface flask network, and from the HIAPER Pole-to-Pole Observations (HIPPO) aircraft campaign. The discrepancy in the regional flux estimates from the different inversions, despite the agreement of the global flux estimates suggests the need for additional work to determine the minimum spatial scales at which we can reliably quantify the fluxes using GOSAT XCO2. The fact that the a posteriori CO2 from the different inversions were in good agreement with the independent data although the regional flux estimates differed significantly, suggests that innovative ways of exploiting existing data sets, and possibly additional observations, are needed to better evaluate the inferred regional flux estimates. textcopyright 2014 Author(s). |
BibTeX:
@article{Deng2014a,
author = {Deng, F and Jones, D B A and Henze, D K and Bousserez, N and Bowman, K W and Fisher, J B and Nassar, R and O'Dell, C and Wunch, D and Wennberg, P O and Kort, E A and Wofsy, S C and Blumenstock, T and Deutscher, N M and Griffith, D W T and Hase, F and Heikkinen, P and Sherlock, V and Strong, K and Sussmann, R and Warneke, T},
title = {Inferring regional sources and sinks of atmospheric CO2 from GOSAT XCO2 data},
journal = {Atmospheric Chemistry and Physics},
year = {2014},
volume = {14},
number = {7},
pages = {3703--3727},
url = {http://www.atmos-chem-phys.net/14/3703/2014/},
doi = {10.5194/acp-14-3703-2014}
}
|
| de Vries W, Du E and Butterbach-Bahl K (2014), "Short and long-term impacts of nitrogen deposition on carbon sequestration by forest ecosystems", Current Opinion in Environmental Sustainability., nov, 2014. Vol. 9-10, pp. 90-104. |
BibTeX:
@article{DeVries2014,
author = {de Vries, Wim and Du, Enzai and Butterbach-Bahl, Klaus},
title = {Short and long-term impacts of nitrogen deposition on carbon sequestration by forest ecosystems},
journal = {Current Opinion in Environmental Sustainability},
year = {2014},
volume = {9-10},
pages = {90--104},
url = {https://linkinghub.elsevier.com/retrieve/pii/S1877343514000566},
doi = {10.1016/j.cosust.2014.09.001}
}
|
| Dils B, Buchwitz M, Reuter M, Schneising O, Boesch H, Parker R, Guerlet S, Aben I, Blumenstock T, Burrows JP, Butz A, Deutscher NM, Frankenberg C, Hase F, Hasekamp OP, Heymann J, De Mazière M, Notholt J, Sussmann R, Warneke T, Griffith D, Sherlock V and Wunch D (2014), "The greenhouse gas climate change initiative (GHG-CCI): Comparative validation of GHG-CCI SCIAMACHY/ENVISAT and TANSO-FTS/GOSAT CO2 and CH4 retrieval algorithm products with measurements from the TCCON", Atmospheric Measurement Techniques., jun, 2014. Vol. 7(6), pp. 1723-1744. |
| Abstract: Column-averaged dry-air mole fractions of carbon dioxide and methane have been retrieved from spectra acquired by the TANSO-FTS (Thermal And Near-infrared Sensor for carbon Observations-Fourier Transform Spectrometer) and SCIAMACHY (Scanning Imaging Absorption Spectrometer for Atmospheric Cartography) instruments on board GOSAT (Greenhouse gases Observing SATellite) and ENVISAT (ENVIronmental SATellite), respectively, using a range of European retrieval algorithms. These retrievals have been compared with data from ground-based high-resolution Fourier transform spectrometers (FTSs) from the Total Carbon Column Observing Network (TCCON). The participating algorithms are the weighting function modified differential optical absorption spectroscopy (DOAS) algorithm (WFMD, University of Bremen), the Bremen optimal estimation DOAS algorithm (BESD, University of Bremen), the iterative maximum a posteriori DOAS (IMAP, Jet Propulsion Laboratory (JPL) and Netherlands Institute for Space Research algorithm (SRON)), the proxy and full-physics versions of SRON's RemoTeC algorithm (SRPR and SRFP, respectively) and the proxy and full-physics versions of the University of Leicester's adaptation of the OCO (Orbiting Carbon Observatory) algorithm (OCPR and OCFP, respectively). The goal of this algorithm inter-comparison was to identify strengths and weaknesses of the various so-called round- robin data sets generated with the various algorithms so as to determine which of the competing algorithms would proceed to the next round of the European Space Agency's (ESA) Greenhouse Gas Climate Change Initiative (GHG-CCI) project, which is the generation of the so-called Climate Research Data Package (CRDP), which is the first version of the Essential Climate Variable (ECV) "greenhouse gases" (GHGs). For XCO2, all algorithms reach the precision requirements for inverse modelling ( 8 ppm), with only WFMD having a lower precision (4.7 ppm) than the other algorithm products (2.4-2.5 ppm). When looking at the seasonal relative accuracy (SRA, variability of the bias in space and time), none of the algorithms have reached the demanding 0.5 ppm threshold. For XCH4, the precision for both SCIAMACHY products (50.2 ppb for IMAP and 76.4 ppb for WFMD) fails to meet the 34 ppb threshold for inverse modelling, but note that this work focusses on the period after the 2005 SCIAMACHY detector degradation. The GOSAT XCH4 precision ranges between 18.1 and 14.0 ppb. Looking at the SRA, all GOSAT algorithm products reach the 10 ppm threshold (values ranging between 5.4 and 6.2 ppb). For SCIAMACHY, IMAP and WFMD have a SRA of 17.2 and 10.5 ppb, respectively. textcopyright 2014 Author(s). CC Attribution 3.0 License. |
BibTeX:
@article{Dils2014,
author = {Dils, B and Buchwitz, M and Reuter, M and Schneising, O and Boesch, H and Parker, R and Guerlet, S and Aben, I and Blumenstock, T and Burrows, J P and Butz, A and Deutscher, N M and Frankenberg, C and Hase, F and Hasekamp, O P and Heymann, J and De Mazière, M and Notholt, J and Sussmann, R and Warneke, T and Griffith, D and Sherlock, V and Wunch, D},
title = {The greenhouse gas climate change initiative (GHG-CCI): Comparative validation of GHG-CCI SCIAMACHY/ENVISAT and TANSO-FTS/GOSAT CO2 and CH4 retrieval algorithm products with measurements from the TCCON},
journal = {Atmospheric Measurement Techniques},
year = {2014},
volume = {7},
number = {6},
pages = {1723--1744},
url = {http://www.atmos-meas-tech.net/7/1723/2014/},
doi = {10.5194/amt-7-1723-2014}
}
|
| Drolet G, Wade T, Nichol CJ, MacLellan C, Levula J, Porcar-Castell A, Nikinmaa E and Vesala T (2014), "A temperature-controlled spectrometer system for continuous and unattended measurements of canopy spectral radiance and reflectance", International Journal of Remote Sensing. Vol. 35(5), pp. 1769-1785. Taylor and Francis Ltd.. |
| Abstract: This paper describes the development of a fully automated system for collecting high-resolution spectral data over a forested footprint. The system comprises a pair of off-the-shelf spectrometers in a custom-built thermal enclosure with a fixed off-nadir downward (target)-pointing fibre and upward-pointing fibre for irradiance measurement. Both instruments sample simultaneously via custom-written and user-controlled software during all weathers and sky conditions. The system is mounted on a 25 m eddy covariance scaffolding tower, approximately 7 m from a Scots pine forest canopy. The system was installed at the University of Helsinki's SMEAR-II Field Station in Hyytiälä in March 2010 and has been operating continuously through a joint programme between the Universities of Edinburgh and Helsinki. The system was designed to capture diurnal and seasonal variation in vegetation light-use efficiency and fluorescence through the capture and analysis of well-defined narrow spectral features, but its implementation would permit the extraction of further optical signals linked to vegetation biophysical variables, and provide a continuous data stream with which to validate satellite data products including vegetation indices such as the photochemical reflectance index (PRI) as well as spectral indicators of solar induced fluorescence. textcopyright 2014 Taylor & Francis. |
BibTeX:
@article{Drolet2014,
author = {Drolet, Guillaume and Wade, Tom and Nichol, Caroline J. and MacLellan, Chris and Levula, Janne and Porcar-Castell, Albert and Nikinmaa, Eero and Vesala, Timo},
title = {A temperature-controlled spectrometer system for continuous and unattended measurements of canopy spectral radiance and reflectance},
journal = {International Journal of Remote Sensing},
publisher = {Taylor and Francis Ltd.},
year = {2014},
volume = {35},
number = {5},
pages = {1769--1785},
doi = {10.1080/01431161.2014.882035}
}
|
| Ershadi A, Mccabe MF, Evans JP, Chaney NW and Wood EF (2014), "Multi-site evaluation of terrestrial evaporation models using FLUXNET data", Agricultural and Forest Meteorology. Vol. 187, pp. 46-61. |
| Abstract: We evaluated the performance of four commonly applied land surface evaporation models using a high-quality dataset of selected FLUXNET towers. The models that were examined include an energy balance approach (Surface Energy Balance System; SEBS), a combination-type technique (single-source Penman-Monteith; PM), a complementary method (advection-aridity; AA) and a radiation based approach (modified Priestley-Taylor; PT-JPL). Twenty FLUXNET towers were selected based upon satisfying stringent forcing data requirements and representing a wide range of biomes. These towers encompassed a number of grassland, cropland, shrubland, evergreen needleleaf forest and deciduous broadleaf forest sites. Based on the mean value of the Nash-Sutcliffe efficiency (NSE) and the root mean squared difference (RMSD), the order of overall performance of the models from best to worst were: ensemble mean of models (0.61, 64), PT-JPL (0.59, 66), SEBS (0.42, 84), PM (0.26, 105) and AA (0.18, 105) [statistics stated as (NSE, RMSD in W m −2)]. Although PT-JPL uses a relatively simple and largely empirical formulation of the evaporative process, the technique showed improved performance compared to PM, possibly due to its partitioning of total evaporation (canopy transpiration, soil evaporation, wet canopy evaporation) and lower uncertainties in the required forcing data. The SEBS model showed low performance over tall and heterogeneous canopies, which was likely a consequence of the effects of the roughness sub-layer parameterization employed in this scheme. However, SEBS performed well overall. Relative to PT-JPL and SEBS, the PM and AA showed low performance over the majority of sites, due to their sensitivity to the parameterization of resistances. Importantly, it should be noted that no single model was consistently best across all biomes. Indeed, this outcome highlights the need for further evaluation of each model's structure and parameterizations to identify sensitivities and their appropriate application to different surface types and conditions. It is expected that the results of this study can be used to inform decisions regarding model choice for water resources and agricultural management, as well as providing insight into model selection for global flux monitoring efforts. |
BibTeX:
@article{Ershadi2014,
author = {Ershadi, A and Mccabe, M F and Evans, J P and Chaney, N W and Wood, E F},
title = {Multi-site evaluation of terrestrial evaporation models using FLUXNET data},
journal = {Agricultural and Forest Meteorology},
year = {2014},
volume = {187},
pages = {46--61},
url = {http://dx.doi.org/10.1016/j.agrformet.2013.11.008},
doi = {10.1016/j.agrformet.2013.11.008}
}
|
| Etminan M, Highwood EJ, Laube JC, McPheat R, Marston G, Shine KP and Smith KM (2014), "Infrared absorption spectra, radiative efficiencies, and global warming potentials of newly-detected halogenated compounds: CFC-113a, CFC-112 and HCFC-133a", Atmosphere., jul, 2014. Vol. 5(3), pp. 473-483. |
| Abstract: CFC-113a (CF3CCl3), CFC-112 (CFCl2CFCl2) and HCFC-133a (CF3CH2Cl) are three newly detected molecules in the atmosphere that are almost certainly emitted as a result of human activity. It is important to characterise the possible contribution of these gases to radiative forcing of climate change and also to provide information on the CO2-equivalence of their emissions. We report new laboratory measurements of absorption cross-sections of these three compounds at a resolution of 0.01 cm-1 for two temperatures 250 K and 295 K in the spectral range of 600-1730 cm-1. These spectra are then used to calculate the radiative efficiencies and global warming potentials (GWP). The radiative efficiencies are found to be between 0.15 and 0.3 W.m-2.ppbv-1. The GWP for a 100 year time horizon, relative to carbon dioxide, ranges from 340 for the relatively short-lived HCFC-133a to 3840 for the longer-lived CFC-112. At current (2012) concentrations, these gases make a trivial contribution to total radiative forcing; however, the concentrations of CFC-113a and HCFC-133a are continuing to increase. The 2012 CO2-equivalent emissions, using the GWP (100), are estimated to be about 4% of the current global CO2-equivalent emissions of HFC-134a. textcopyright 2014 by the authors. |
BibTeX:
@article{Etminan2014,
author = {Etminan, Maryam and Highwood, Eleanor J and Laube, Johannes C and McPheat, Robert and Marston, George and Shine, Keith P and Smith, Kevin M},
title = {Infrared absorption spectra, radiative efficiencies, and global warming potentials of newly-detected halogenated compounds: CFC-113a, CFC-112 and HCFC-133a},
journal = {Atmosphere},
year = {2014},
volume = {5},
number = {3},
pages = {473--483},
url = {http://www.mdpi.com/2073-4433/5/3/473/},
doi = {10.3390/atmos5030473}
}
|
| Etzold S, Waldner P, Thimonier A, Schmitt M and Dobbertin M (2014), "Tree growth in Swiss forests between 1995 and 2010 in relation to climate and stand conditions: Recent disturbances matter", Forest Ecology and Management., jan, 2014. Vol. 311, pp. 41-55. |
BibTeX:
@article{Etzold2014,
author = {Etzold, Sophia and Waldner, Peter and Thimonier, Anne and Schmitt, Maria and Dobbertin, Matthias},
title = {Tree growth in Swiss forests between 1995 and 2010 in relation to climate and stand conditions: Recent disturbances matter},
journal = {Forest Ecology and Management},
year = {2014},
volume = {311},
pages = {41--55},
url = {https://linkinghub.elsevier.com/retrieve/pii/S0378112713003393},
doi = {10.1016/j.foreco.2013.05.040}
}
|
| Eyer S, Stadie NP, Borgschulte A, Emmenegger L and Mohn J (2014), "Methane preconcentration by adsorption: A methodology for materials and conditions selection", Adsorption., aug, 2014. Vol. 20(5-6), pp. 657-666. |
| Abstract: Methane (CH 4) adsorption has been widely studied, mainly in the context of natural gas purification. A much less prominent, but highly relevant application is the preconcentration of CH 4 from ambient air. In this study, we compare six different commercial adsorbent materials with respect to their effectiveness for methane preconcentration: a macroporous polymeric resin (HayeSep D), multi-walled carbon nanotubes, two microporous metal-organic frameworks (HKUST-1 and ZIF-8), and two zeolites (5A and 13X). The most relevant properties, such as isosteric enthalpy of adsorption, specific surface area and the selectivity for CH 4 adsorption over N 2 were characterized by analyzing adsorption/desorption isotherms. Using these parameters, we discuss the tested adsorbents with respect to the most important properties and identify the most promising candidates. Furthermore we identify the experimental conditions that are expected to give the best results with respect to practical applications. textcopyright 2014 The Author(s). |
BibTeX:
@article{Eyer2014,
author = {Eyer, Simon and Stadie, Nicholas P and Borgschulte, Andreas and Emmenegger, Lukas and Mohn, Joachim},
title = {Methane preconcentration by adsorption: A methodology for materials and conditions selection},
journal = {Adsorption},
year = {2014},
volume = {20},
number = {5-6},
pages = {657--666},
url = {http://link.springer.com/10.1007/s10450-014-9609-9},
doi = {10.1007/s10450-014-9609-9}
}
|
| Fady B, Benard A, Pichot C, Peiffer M, Leban JM and Dreyer E (2014), "The open data debate: A need for accessible and shared data in forest science", Annals of Forest Science., jul, 2014. Vol. 71(5), pp. 523-525. |
BibTeX:
@article{Fady2014,
author = {Fady, Bruno and Benard, Alain and Pichot, Christian and Peiffer, Marianne and Leban, Jean Michel and Dreyer, Erwin},
title = {The open data debate: A need for accessible and shared data in forest science},
journal = {Annals of Forest Science},
year = {2014},
volume = {71},
number = {5},
pages = {523--525},
url = {http://link.springer.com/10.1007/s13595-014-0375-3},
doi = {10.1007/s13595-014-0375-3}
}
|
| Fernández-Martínez M, Vicca S, Janssens IA, Sardans J, Luyssaert S, Campioli M, Chapin FS, Ciais P, Malhi Y, Obersteiner M, Papale D, Piao SL, Reichstein M, Rodà F and Peñuelas J (2014), "Nutrient availability as the key regulator of global forest carbon balance", Nature Climate Change., jun, 2014. Vol. 4(6), pp. 471-476. |
| Abstract: Forests strongly affect climate through the exchange of large amounts of atmospheric CO 2 (ref.). The main drivers of spatial variability in net ecosystem production (NEP) on a global scale are, however, poorly known. As increasing nutrient availability increases the production of biomass per unit of photosynthesis and reduces heterotrophic respiration in forests, we expected nutrients to determine carbon sequestration in forests. Our synthesis study of 92 forests in different climate zones revealed that nutrient availability indeed plays a crucial role in determining NEP and ecosystem carbon-use efficiency (CUEe; that is, the ratio of NEP to gross primary production (GPP)). Forests with high GPP exhibited high NEP only in nutrient-rich forests (CUEe = 33 ± 4%; mean ± s.e.m.). In nutrient-poor forests, a much larger proportion of GPP was released through ecosystem respiration, resulting in lower CUEe (6 ± 4%). Our finding that nutrient availability exerts a stronger control on NEP than on carbon input (GPP) conflicts with assumptions of nearly all global coupled carbon cycle-climate models, which assume that carbon inputs through photosynthesis drive biomass production and carbon sequestration. An improved global understanding of nutrient availability would therefore greatly improve carbon cycle modelling and should become a critical focus for future research. textcopyright 2014 Macmillan Publishers Limited. |
BibTeX:
@article{Fernandez-Martinez2014,
author = {Fernández-Martínez, M and Vicca, S and Janssens, I A and Sardans, J and Luyssaert, S and Campioli, M and Chapin, F S and Ciais, P and Malhi, Y and Obersteiner, M and Papale, D and Piao, S L and Reichstein, M and Rodà, F and Peñuelas, J},
title = {Nutrient availability as the key regulator of global forest carbon balance},
journal = {Nature Climate Change},
year = {2014},
volume = {4},
number = {6},
pages = {471--476},
url = {http://www.nature.com/articles/nclimate2177},
doi = {10.1038/nclimate2177}
}
|
| Fietzek P, Fiedler B, Steinhoff T and Körtzinger A (2014), "In situ quality assessment of a novel underwater pCO 2 sensor based on membrane equilibration and NDIR spectrometry", Journal of Atmospheric and Oceanic Technology., jan, 2014. Vol. 31(1), pp. 181-196. American Meteorological Society. |
| Abstract: This paper presents a detailed quality assessment of a novel underwater sensor for the measurement of CO 2 partial pressure (pCO 2 ) based on surface water field deployments carried out between 2008 and 2011. The commercially available sensor, which is based on membrane equilibration and nondispersive IR (NDIR) spectrometry is small and can be integrated into mobile platforms. It is calibrated in water against a proven flow-through pCO 2 instrument within a custom-built calibration setup. The aspect of highest concern with respect to achievable data quality of the sensor is the compensation for signal drift inevitably connected to absorption measurements. Three means are used to correct for drift effects: (i) a filter correlation or dualbeam setup, (ii) regular zero gas measurements realized automatically within the sensor, and (iii) a zero-based transformation of two sensor calibrations flanking the time of sensor deployment. Three sensors were tested against an underway pCO 2 system during two major research cruises, providing an in situ temperature range from 7.4° to 30.1°C and pCO 2 values between 289 and 445μatm. The average difference between sensor and reference pCO 2 was found to be -0.6±3.0μatm with an RMSE of 3.7μatm. textcopyright 2014 American Meteorological Society. |
BibTeX:
@article{Fietzek2014,
author = {Fietzek, Peer and Fiedler, Björn and Steinhoff, Tobias and Körtzinger, Arne},
title = {In situ quality assessment of a novel underwater pCO 2 sensor based on membrane equilibration and NDIR spectrometry},
journal = {Journal of Atmospheric and Oceanic Technology},
publisher = {American Meteorological Society},
year = {2014},
volume = {31},
number = {1},
pages = {181--196},
url = {http://journals.ametsoc.org/jtech/article-pdf/31/1/181/3359831/jtech-d-13-00083_1.pdf},
doi = {10.1175/JTECH-D-13-00083.1}
}
|
| Fraser PJ, Dunse BL, Manning AJ, Walsh S, Wang RHJ, Krummel PB, Steele LP, Porter LW, Allison C, O'Doherty S, Simmonds PG, Mühle J, Weiss RF and Prinn RG (2014), "Australian carbon tetrachloride emissions in a global context", Environmental Chemistry. Vol. 11(1), pp. 77-88. |
| Abstract: Global (1978-2012) and Australian (1996-2011) carbon tetrachloride emissions are estimated from atmospheric observations of CCl4 using data from the Advanced Global Atmospheric Gases Experiment (AGAGE) global network, in particular from Cape Grim, Tasmania. Global and Australian emissions are in decline in response to Montreal Protocol restrictions on CCl4 production and consumption for dispersive uses in the developed and developing world. However, atmospheric data-derived emissions are significantly larger than 'bottom-up' estimates from direct and indirect CCl4 production, CCl4 transportation and use. Australian CCl4 emissions are not a result of these sources, and the identification of the origin of Australian emissions may provide a clue to the origin of some of these 'missing' global sources. Journal compilation textcopyright CSIRO 2014. |
BibTeX:
@article{Fraser2014,
author = {Fraser, Paul J and Dunse, Bronwyn L and Manning, Alistair J and Walsh, Sean and Wang, R Hsiang J and Krummel, Paul B and Steele, L Paul and Porter, Laurie W and Allison, Colin and O'Doherty, Simon and Simmonds, Peter G and Mühle, Jens and Weiss, Ray F and Prinn, Ronald G},
title = {Australian carbon tetrachloride emissions in a global context},
journal = {Environmental Chemistry},
year = {2014},
volume = {11},
number = {1},
pages = {77--88},
url = {http://www.publish.csiro.au/?paper=EN13171},
doi = {10.1071/EN13171}
}
|
| Fraser A, Palmer PI, Feng L, Bösch H, Parker R, Dlugokencky EJ, Krummel PB and Langenfelds RL (2014), " Estimating regional fluxes of CO 2 and CH 4 using space-borne observations of XCH 4 : XCO 2 ", Atmospheric Chemistry and Physics Discussions., jun, 2014. Vol. 14(11), pp. 15867-15894. |
| Abstract: Abstract. We use the GEOS-Chem global 3-D atmospheric chemistry transport model to interpret XCH4:XCO2 column ratios retrieved using a proxy method from the Japanese Greenhouse gases Observing SATellite (GOSAT). The advantage of these data over CO2 and CH4 columns retrieved independently using a full physics optimal estimation algorithm is that they suffer less from scattering-related regional bias. We show the model is able to reproduce observed global and regional spatial (mean bias =0.7%) and temporal variations (global r2=0.92) of this ratio with model bias 2.5%. We also show these variations are driven by emissions of CO2 and CH4 that are typically six months out of phase which may reduce the sensitivity of the ratio to changes in either gas. To simultaneously estimate fluxes of CO2 and CH4 we use a formal Bayesian inverse model infrastructure. We use two approaches to independently resolve flux estimates of these two gases using GOSAT observations of XCH4:XCO2: (1) the a priori error covariance between CO2 and CH4 describing common source from biomass burning; and (2) also fitting independent surface atmospheric measurements of CH4 and CO2 mole fraction that provide additional constraints, improving the effectiveness of the observed GOSAT ratio to constrain fluxes. We demonstrate the impact of these two approaches using Observing System Simulation Experiments. A posteriori flux estimates inferred using only the GOSAT ratios and taking advantage of the error covariance due to biomass burning are not consistent with the true fluxes in our experiments, as the inversion system cannot judge which species' fluxes to adjust. This can result in a posteriori fluxes that are further from the truth than the a priori fluxes. We find that adding the surface data to the inversion dramatically improves the ability of the GOSAT ratios to infer both CH4 and CO2 fluxes. We show that using real GOSAT XCH4:XCO2 ratios together with the surface data during 2010 outcompetes inversions using the individual XCH4 or the full-physics XCO2 data products. Regional fluxes that show the greatest improvements have model minus observation differences with a large seasonal cycle such as Tropical South America for which we report a small but significant annual source of CO2 compared to a small annual sink inferred from the XCO2 data. Based on our analysis we argue that using the ratios we may be reaching the limitations on the precision of these data. |
BibTeX:
@article{Fraser2014a,
author = {Fraser, A and Palmer, P I and Feng, L and Bösch, H and Parker, R and Dlugokencky, E J and Krummel, P B and Langenfelds, R L},
title = { Estimating regional fluxes of CO 2 and CH 4 using space-borne observations of XCH 4 : XCO 2 },
journal = {Atmospheric Chemistry and Physics Discussions},
year = {2014},
volume = {14},
number = {11},
pages = {15867--15894},
url = {http://www.atmos-chem-phys-discuss.net/14/15867/2014/},
doi = {10.5194/acpd-14-15867-2014}
}
|
| Fratini G, McDermitt DK and Papale D (2014), "Eddy-covariance flux errors due to biases in gas concentration measurements: Origins, quantification and correction", Biogeosciences., feb, 2014. Vol. 11(4), pp. 1037-1051. |
| Abstract: Errors in gas concentration measurements by infrared gas analysers can occur during eddy-covariance campaigns, associated with actual or apparent instrumental drifts or biases due to thermal expansion, dirt contamination, aging of components or errors in field operations. If occurring on long timescales (hours to days), these errors are normally ignored during flux computation, under the assumption that errors in mean gas concentrations do not affect the estimation of turbulent fluctuations and, hence, of covariances. By analysing instrument theory of operation, and using numerical simulations and field data, we show that this is not the case for instruments with curvilinear calibrations; we further show that if not appropriately accounted for, concentration biases can lead to roughly proportional systematic flux errors, where the fractional errors in fluxes are about 30-40% the fractional errors in concentrations. We quantify these errors and characterize their dependency on main determinants. We then propose a correction procedure that largely-potentially completely-eliminates these errors. The correction, to be applied during flux computation, is based on knowledge of instrument calibration curves and on field or laboratory calibration data. Finally, we demonstrate the occurrence of such errors and validate the correction procedure by means of a field experiment, and accordingly provide recommendations for in situ operations. textcopyright 2014 Author(s). |
BibTeX:
@article{Fratini2014,
author = {Fratini, G and McDermitt, D K and Papale, D},
title = {Eddy-covariance flux errors due to biases in gas concentration measurements: Origins, quantification and correction},
journal = {Biogeosciences},
year = {2014},
volume = {11},
number = {4},
pages = {1037--1051},
url = {http://www.biogeosciences.net/11/1037/2014/},
doi = {10.5194/bg-11-1037-2014}
}
|
| Galli A, Guerlet S, Butz A, Aben I, Suto H, Kuze A, Deutscher NM, Notholt J, Wunch D, Wennberg PO, Griffith DWT, Hasekamp O and Landgraf J (2014), "The impact of spectral resolution on satellite retrieval accuracy of CO2 and CH4", Atmospheric Measurement Techniques., apr, 2014. Vol. 7(4), pp. 1105-1119. |
| Abstract: The Fourier-transform spectrometer on board the Japanese GOSAT (Greenhouse gases Observing SATellite) satellite offers an excellent opportunity to study the impact of instrument resolution on retrieval accuracy of CO2 and CH4. This is relevant to further improve retrieval accuracy and to optimize the cost-benefit ratio of future satellite missions for the remote sensing of greenhouse gases. To address this question, we degrade GOSAT measurements with a spectral resolution of ≈ 0.24 cm-1 step by step to a resolution of 1.5 cm-1. We examine the results by comparing relative differences at various resolutions, by referring the results to reference values from the Total Carbon Column Observing Network (TCCON), and by calculating and inverting synthetic spectra for which the true CO2 and CH4 columns are known. The main impacts of degrading the spectral resolution are reproduced for all approaches based on GOSAT measurements; pure forward model errors identified with simulated measurements are much smaller. For GOSAT spectra, the most notable effect on CO2 retrieval accuracy is the increase of the standard deviation of retrieval errors from 0.7 to 1.0% when the spectral resolution is reduced by a factor of six. The retrieval biases against atmospheric water abundance and air mass become stronger with decreasing resolution. The error scatter increase for CH4 columns is less pronounced. The selective degradation of single spectral windows demonstrates that the retrieval accuracy of CO2 and CH4 is dominated by the spectral range where the absorption lines of the target molecule are located. For both GOSAT and synthetic measurements, retrieval accuracy decreases with lower spectral resolution for a given signal-to-noise ratio, suggesting increasing interference errors. textcopyright Author(s) 2014. |
BibTeX:
@article{Galli2014,
author = {Galli, A and Guerlet, S and Butz, A and Aben, I and Suto, H and Kuze, A and Deutscher, N M and Notholt, J and Wunch, D and Wennberg, P O and Griffith, D W T and Hasekamp, O and Landgraf, J},
title = {The impact of spectral resolution on satellite retrieval accuracy of CO2 and CH4},
journal = {Atmospheric Measurement Techniques},
year = {2014},
volume = {7},
number = {4},
pages = {1105--1119},
url = {http://www.atmos-meas-tech.net/7/1105/2014/},
doi = {10.5194/amt-7-1105-2014}
}
|
| Goffin S, Aubinet M, Maier M, Plain C, Schack-Kirchner H and Longdoz B (2014), "Characterization of the soil CO2 production and its carbon isotope composition in forest soil layers using the flux-gradient approach", Agricultural and Forest Meteorology., may, 2014. Vol. 188, pp. 45-57. |
| Abstract: The Flux-Gradient Approach (FGA) allows the vertical distribution of gas turnover and production in the soil to be calculated. This approach has been used successfully for greenhouse gases, such as CO2, CH4 and N2O but not yet for the stable isotope composition of soil CO2 (δ13CO2), although this subject has become increasingly important. In this study, an innovative experimental set-up, based on the MEmbrane Tube Technique (METT) and adapted to C stable isotope recording, was used to carry out in situ measurements in a Scots pine forest soil in Hartheim, Germany. Continuous measurements of soil CO2 and δ13CO2 efflux and of soil air CO2 and δ13CO2 concentration were combined with the FGA to investigate the vertical distribution and temporal variability in CO2 production (P) and its isotopic signature (δ13P). The FGA gave consistent values for P and δ13P in each soil horizon, except for the Ol horizon where diffusive transport seemed to be affected by atmospheric turbulence. The results showed that P was subjected to a significant vertical stratification, whereas no significant δ13P vertical variation was found. The surface soil water content (SWC) was reported to be critical to the accurate partitioning of P between the topsoil layers. In addition, significant temporal P and δ13P variations were found in the most productive horizon, the first being best explained by the soil temperature, the second depending on the moisture conditions. No visible δ13P climatic dependence was visible in the measured surface flux isotopic composition (δ13Fs). Finally, in the litter layer (Ol), a significant correlation was found between P and friction velocity. This was attributed to the predominance of non-diffusive transport in the litter layer. textcopyright 2014 Elsevier B.V. |
BibTeX:
@article{Goffin2014,
author = {Goffin, Stéphanie and Aubinet, Marc and Maier, Martin and Plain, Caroline and Schack-Kirchner, Helmer and Longdoz, Bernard},
title = {Characterization of the soil CO2 production and its carbon isotope composition in forest soil layers using the flux-gradient approach},
journal = {Agricultural and Forest Meteorology},
year = {2014},
volume = {188},
pages = {45--57},
url = {http://linkinghub.elsevier.com/retrieve/pii/S0168192313002955},
doi = {10.1016/j.agrformet.2013.11.005}
}
|
| Graf A, Bogena HR, Drüe C, Hardelauf H, Pütz T, Heinemann G and Vereecken H (2014), "Spatiotemporal relations between water budget components and soil water content in a forested tributary catchment", Water Resources Research., jun, 2014. Vol. 50(6), pp. 4837-4857. |
| Abstract: We examined 3 years of measured daily values of all major water budget components (precipitation P, potential evapotranspiration PET, actual evapotranspiration ET, and runoff R) and volumetric soil water content θ of a small, forested catchment located in the west of Germany. The spatial distribution of θ was determined from a wireless sensor network of 109 points with 3 measurement depths each; ET was calculated from eddy-covariance tower measurements. The water budget was dominantly energy limited, with ET amounting to approximately 90% of PET, and a runoff ratio R/P of 56%. P, ET, and R closed the long-term water budget with a residual of 2% of precipitation. On the daily time scale, the residual of the water budget was larger than on the annual time scale, and explained to a moderate extent by θ (R2 = 0.40). Wavelet analysis revealed subweekly time scales, presumably dominated by unaccounted fast-turnover storage terms such as interception, as a major source of uncertainty in water balance closure. At weekly resolution, soil water content explained more than half (R2 = 0.62) of the residual. By means of combined empirical orthogonal function and cluster analysis, two slightly different spatial patterns of θ could be identified that were associated with mean θ values below and above 0.35 cm3/cm 3, respectively. The timing of these patterns as well as the varying coherence between PET, ET, and soil water content responded to changes in water availability, including a moderate response to the European drought in spring 2011. textcopyright 2014. American Geophysical Union. All Rights Reserved. |
BibTeX:
@article{Graf2014,
author = {Graf, Alexander and Bogena, Heye R and Drüe, Clemens and Hardelauf, Horst and Pütz, Thomas and Heinemann, Günther and Vereecken, Harry},
title = {Spatiotemporal relations between water budget components and soil water content in a forested tributary catchment},
journal = {Water Resources Research},
year = {2014},
volume = {50},
number = {6},
pages = {4837--4857},
url = {http://doi.wiley.com/10.1002/2013WR014516},
doi = {10.1002/2013WR014516}
}
|
| Griffiths AD, Conen F, Weingartner E, Zimmermann L, Chambers SD, Williams AG and Steinbacher M (2014), "Surface-to-mountaintop transport characterised by radon observations at the Jungfraujoch", Atmospheric Chemistry and Physics., dec, 2014. Vol. 14(23), pp. 12763-12779. |
| Abstract: Atmospheric composition measurements at Jungfraujoch are affected intermittently by boundary-layer air which is brought to the station by processes including thermally driven (anabatic) mountain winds. Using observations of radon-222, and a new objective analysis method, we quantify the land-surface influence at Jungfraujoch hour by hour and detect the presence of anabatic winds on a daily basis. During 2010-2011, anabatic winds occurred on 40% of days, but only from April to September. Anabatic wind days were associated with warmer air temperatures over a large fraction of Europe and with a shift in air-mass properties, even when comparing days with a similar mean radon concentration. Excluding days with anabatic winds, however, did not lead to a better definition of the unperturbed aerosol background than a definition based on radon alone. This implies that a radon threshold reliably excludes local influences from both anabatic and non-anabatic vertical-transport processes. |
BibTeX:
@article{Griffiths2014,
author = {Griffiths, A D and Conen, F and Weingartner, E and Zimmermann, L and Chambers, S D and Williams, A G and Steinbacher, M},
title = {Surface-to-mountaintop transport characterised by radon observations at the Jungfraujoch},
journal = {Atmospheric Chemistry and Physics},
year = {2014},
volume = {14},
number = {23},
pages = {12763--12779},
url = {http://www.atmos-chem-phys.net/14/12763/2014/},
doi = {10.5194/acp-14-12763-2014}
}
|
| GROTE R, MORFOPOULOS C, NIINEMETS ÜLO, SUN Z, KEENAN TF, PACIFICO F and BUTLER TIM (2014), "A fully integrated isoprenoid emissions model coupling emissions to photosynthetic characteristics", Plant, Cell & Environment., aug, 2014. Vol. 37(8), pp. 1965-1980. |
BibTeX:
@article{GROTE2014,
author = {GROTE, RÜDIGER and MORFOPOULOS, CATHERINE and NIINEMETS, Ü L O and SUN, ZHIHONG and KEENAN, TREVOR F and PACIFICO, FEDERICA and BUTLER, T I M},
title = {A fully integrated isoprenoid emissions model coupling emissions to photosynthetic characteristics},
journal = {Plant, Cell & Environment},
year = {2014},
volume = {37},
number = {8},
pages = {1965--1980},
url = {http://doi.wiley.com/10.1111/pce.12326},
doi = {10.1111/pce.12326}
}
|
| Gundale MJ, From F, Bach LH and Nordin A (2014), "Anthropogenic nitrogen deposition in boreal forests has a minor impact on the global carbon cycle", Global Change Biology., jan, 2014. Vol. 20(1), pp. 276-286. |
BibTeX:
@article{Gundale2014,
author = {Gundale, Michael J and From, Fredrik and Bach, Lisbet H and Nordin, Annika},
title = {Anthropogenic nitrogen deposition in boreal forests has a minor impact on the global carbon cycle},
journal = {Global Change Biology},
year = {2014},
volume = {20},
number = {1},
pages = {276--286},
url = {http://doi.wiley.com/10.1111/gcb.12422},
doi = {10.1111/gcb.12422}
}
|
| Hall BD, Engel A, Mühle J, Elkins JW, Artuso F, Atlas E, Aydin M, Blake D, Brunke EG, Chiavarini S, Fraser PJ, Happell J, Krummel PB, Levin I, Loewenstein M, Maione M, Montzka SA, O'Doherty S, Reimann S, Rhoderick G, Saltzman ES, Scheel HE, Steele LP, Vollmer MK, Weiss RF, Worthy D and Yokouchi Y (2014), "Results from the International Halocarbons in Air Comparison Experiment (IHALACE)", Atmospheric Measurement Techniques., feb, 2014. Vol. 7(2), pp. 469-490. |
| Abstract: The International Halocarbons in Air Comparison Experiment (IHALACE) was conducted to document relationships between calibration scales among various laboratories that measure atmospheric greenhouse and ozone depleting gases. This study included trace gases such as chlorofluorocarbons (CFCs), hydrochlorofluorocarbons (HCFCs), and hydrofluorocarbons (HFCs), as well as nitrous oxide, methane, sulfur hexafluoride, very short-lived halocompounds, and carbonyl sulfide. Many of these gases are present in the unpolluted atmosphere at pmol mol-1 (parts per trillion) or nmol mol-1 (parts per billion) levels. Six stainless steel cylinders containing natural and modified natural air samples were circulated among 19 laboratories. Results from this experiment reveal relatively good agreement (within a few percent) among commonly used calibration scales. Scale relationships for some gases, such as CFC-12 and CCl4, were found to be consistent with those derived from estimates of global mean mole fractions, while others, such as halon-1211 and CH3Br, revealed discrepancies. The transfer of calibration scales among laboratories was problematic in many cases, meaning that measurements tied to a particular scale may not, in fact, be compatible. Large scale transfer errors were observed for CH3CCl3 (10-100 %) and CCl4 (2-30 %), while much smaller scale transfer errors ( 1 %) were observed for halon-1211, HCFC-22, and HCFC-142b. These results reveal substantial improvements in calibration over previous comparisons. However, there is room for improvement in communication and coordination of calibration activities with respect to the measurement of halogenated and related trace gases. |
BibTeX:
@article{Hall2014,
author = {Hall, B D and Engel, A and Mühle, J and Elkins, J W and Artuso, F and Atlas, E and Aydin, M and Blake, D and Brunke, E G and Chiavarini, S and Fraser, P J and Happell, J and Krummel, P B and Levin, I and Loewenstein, M and Maione, M and Montzka, S A and O'Doherty, S and Reimann, S and Rhoderick, G and Saltzman, E S and Scheel, H E and Steele, L P and Vollmer, M K and Weiss, R F and Worthy, D and Yokouchi, Y},
title = {Results from the International Halocarbons in Air Comparison Experiment (IHALACE)},
journal = {Atmospheric Measurement Techniques},
year = {2014},
volume = {7},
number = {2},
pages = {469--490},
url = {http://www.atmos-meas-tech.net/7/469/2014/},
doi = {10.5194/amt-7-469-2014}
}
|
| Heiskanen JJ, Mammarella I, Haapanala S, Pumpanen J, Vesala T, Macintyre S and Ojala A (2014), "Effects of cooling and internal wave motions on gas transfer coefficients in a boreal lake", Tellus, Series B: Chemical and Physical Meteorology., may, 2014. Vol. 66(1) |
| Abstract: Lakes and other inland waters contribute significantly to regional and global carbon budgets. Emissions from lakes are often computed as the product of a gas transfer coefficient, k600, and the difference in concentration across the diffusive boundary layer at the air-water interface. Eddy covariance (EC) techniques are increasingly being used in lacustrine gas flux studies and tend to report higher values for derived k600 than other approaches. Using results from an EC study of a small, boreal lake, we modelled k600 using a boundarylayer approach that included wind shear and cooling. During stratification, fluxes estimated by EC occasionally were higher than those obtained by our models. The high fluxes co-occurred with winds strong enough to induce deflections of the thermocline. We attribute the higher measured fluxes to upwelling-induced spatial variability in surface concentrations of CO2 within the EC footprint. We modelled the increased gas concentrations due to the upwelling and corrected our k600 values using these higher CO2 concentrations. This approach led to greater congruence between measured and modelled k values during the stratified period. k600 has a well-resolved and ˜cubic relationship with wind speed when the water column is unstratified and the dissolved gases well mixed. During stratification and using the corrected k600, the same pattern is evident at higher winds, but k600 has a median value of ˜7 cm h-1 when winds are less than 6 m s-1, similar to observations in recent oceanographic studies. Our models for k600 provide estimates of gas evasion at least 200% higher than earlier wind-based models. Our improved k600 estimates emphasize the need for integrating within lake physics into models of greenhouse gas evasion. textcopyright 2014 J. J. Heiskanen et al. |
BibTeX:
@article{Heiskanen2014,
author = {Heiskanen, Jouni J and Mammarella, Ivan and Haapanala, Sami and Pumpanen, Jukka and Vesala, Timo and Macintyre, Sally and Ojala, Anne},
title = {Effects of cooling and internal wave motions on gas transfer coefficients in a boreal lake},
journal = {Tellus, Series B: Chemical and Physical Meteorology},
year = {2014},
volume = {66},
number = {1},
url = {http://www.tellusb.net/index.php/tellusb/article/view/22827},
doi = {10.3402/tellusb.v66.22827}
}
|
| Hirsikko A, O'Connor EJ, Komppula M, Korhonen K, Pfüller A, Giannakaki E, Wood CR, Bauer-Pfundstein M, Poikonen A, Karppinen T, Lonka H, Kurri M, Heinonen J, Moisseev D, Asmi E, Aaltonen V, Nordbo A, Rodriguez E, Lihavainen H, Laaksonen A, Lehtinen KEJ, Laurila T, Petäjä T, Kulmala M and Viisanen Y (2014), "Observing wind, aerosol particles, cloud and precipitation: Finland's new ground-based remote-sensing network", Atmospheric Measurement Techniques., may, 2014. Vol. 7(5), pp. 1351-1375. |
| Abstract: The Finnish Meteorological Institute, in collaboration with the University of Helsinki, has established a new ground-based remote-sensing network in Finland. The network consists of five topographically, ecologically and climatically different sites distributed from southern to northern Finland. The main goal of the network is to monitor air pollution and boundary layer properties in near real time, with a Doppler lidar and ceilometer at each site. In addition to these operational tasks, two sites are members of the Aerosols, Clouds and Trace gases Research InfraStructure Network (ACTRIS); a K/a band cloud radar at Sodankylä will provide cloud retrievals within CloudNet, and a multi-wavelength Raman lidar, PollyXT (POrtabLe Lidar sYstem eXTended), in Kuopio provides optical and microphysical aerosol properties through EARLINET (the European Aerosol Research Lidar Network). Three C-band weather radars are located in the Helsinki metropolitan area and are deployed for operational and research applications. We performed two inter-comparison campaigns to investigate the Doppler lidar performance, compare the backscatter signal and wind profiles, and to optimize the lidar sensitivity through adjusting the telescope focus length and data-integration time to ensure sufficient signal-to-noise ratio (SNR) in low-aerosol-content environments. In terms of statistical characterization, the wind-profile comparison showed good agreement between different lidars. Initially, there was a discrepancy in the SNR and attenuated backscatter coefficient profiles which arose from an incorrectly reported telescope focus setting from one instrument, together with the need to calibrate. After diagnosing the true telescope focus length, calculating a new attenuated backscatter coefficient profile with the new telescope function and taking into account calibration, the resulting attenuated backscatter profiles all showed good agreement with each other. It was thought that harsh Finnish winters could pose problems, but, due to the built-in heating systems, low ambient temperatures had no, or only a minor, impact on the lidar operation-including scanning-head motion. However, accumulation of snow and ice on the lens has been observed, which can lead to the formation of a water/ice layer thus attenuating the signal inconsistently. Thus, care must be taken to ensure continuous snow removal. textcopyright 2014 Author(s). |
BibTeX:
@article{Hirsikko2014,
author = {Hirsikko, A and O'Connor, E J and Komppula, M and Korhonen, K and Pfüller, A and Giannakaki, E and Wood, C R and Bauer-Pfundstein, M and Poikonen, A and Karppinen, T and Lonka, H and Kurri, M and Heinonen, J and Moisseev, D and Asmi, E and Aaltonen, V and Nordbo, A and Rodriguez, E and Lihavainen, H and Laaksonen, A and Lehtinen, K E J and Laurila, T and Petäjä, T and Kulmala, M and Viisanen, Y},
title = {Observing wind, aerosol particles, cloud and precipitation: Finland's new ground-based remote-sensing network},
journal = {Atmospheric Measurement Techniques},
year = {2014},
volume = {7},
number = {5},
pages = {1351--1375},
url = {http://www.atmos-meas-tech.net/7/1351/2014/},
doi = {10.5194/amt-7-1351-2014}
}
|
| Hommeltenberg J, Schmid HP, Drösler M and Werle P (2014), "Can a bog drained for forestry be a stronger carbon sink than a natural bog forest?", Biogeosciences., jul, 2014. Vol. 11(13), pp. 3477-3493. |
| Abstract: This study compares the CO2 exchange of a natural bog forest, and of a bog drained for forestry in the pre-Alpine region of southern Germany. The sites are separated by only 10 km, they share the same soil formation history and are exposed to the same climate and weather conditions. In contrast, they differ in land use history: at the Schechenfilz site a natural bog-pine forest (Pinus mugossp. rotundata) grows on an undisturbed, about 5 m thick peat layer; at Mooseurach a planted spruce forest (Picea abies) grows on drained and degraded peat (3.4 m). The net ecosystem exchange of CO2 (NEE) at both sites has been investigated for 2 years (July 2010-June 2012), using the eddy covariance technique. Our results indicate that the drained, forested bog at Mooseurach is a much stronger carbon dioxide sink (ÄÌ‚'130 ± 31 and ÄÌ‚'300 ± 66 g C mÄÌ‚'2 aÄÌ‚'1 in the first and second year, respectively) than the natural bog forest at Schechenfilz (ÄÌ‚'53 ± 28 and ÄÌ‚'73 ± 38 g C mÄÌ‚'2 aÄÌ‚'1). The strong net CO2 uptake can be explained by the high gross primary productivity of the 44-year old spruces that over-compensates the two-times stronger ecosystem respiration at the drained site. The larger productivity of the spruces can be clearly attributed to the larger plant area index (PAI) of the spruce site. However, even though current flux measurements indicate strong CO2 uptake of the drained spruce forest, the site is a strong net CO2 source when the whole life-cycle since forest planting is considered. It is important to access this result in terms of the long-term biome balance. To do so, we used historical data to estimate the difference between carbon fixation by the spruces and the carbon loss from the peat due to drainage since forest planting. This rough estimate indicates a strong carbon release of +134 t C haÄÌ‚'1 within the last 44 years. Thus, the spruces would need to grow for another 100 years at about the current rate, to compensate the potential peat loss of the former years. In contrast, the natural bog-pine ecosystem has likely been a small but stable carbon sink for decades, which our results suggest is very robust regarding short-term changes of environmental factors. textcopyright Author(s) 2014. CC Attribution 3.0 License. |
BibTeX:
@article{Hommeltenberg2014,
author = {Hommeltenberg, J and Schmid, H P and Drösler, M and Werle, P},
title = {Can a bog drained for forestry be a stronger carbon sink than a natural bog forest?},
journal = {Biogeosciences},
year = {2014},
volume = {11},
number = {13},
pages = {3477--3493},
url = {http://www.biogeosciences.net/11/3477/2014/},
doi = {10.5194/bg-11-3477-2014}
}
|
| Hünerbein A, Deneke H, Macke A, Ebell K and Görsdorf U (2014), "Combining the perspective of satellite- and ground-based observations to analyze cloud frontal systems", Journal of Applied Meteorology and Climatology. Vol. 53(11), pp. 2538-2552. American Meteorological Society. |
| Abstract: A method is presented to analyze the cloud life cycle of frontal systems passing over European supersites. It combines information on the vertical profiles of cloud properties derived from ground-based observations with cloud products obtained from satellite-based observations, including their spatial variability. The Euler and Lagrange perspectives are adopted to consider the history of a cloud system that passes the supersites. The forward model known as RTTOV (Radiative Transfer for the Television and Infrared Observation Satellite Operational Vertical Sounder) and the ground-based "CloudNET" products are used to simulate synthetic satellite observations at the supersites, which are subsequently compared with the actual observations of the Meteosat Spinning Enhanced Visible and Infrared Imager (SEVIRI) instrument. Different metrics are considered to quantify and interpret the consistency of the synthetic and the observed satellite data: brightness temperatures at the thermal IR channels, the split-window channels, and trispectral combinations, as well as the outgoing longwave radiation. In this way, the uncertainties of the individual datasets are investigated. This knowledge provides the motivation to combine the disjunct cloud products from satellite with those from ground instruments to characterize the development of the passing cloud frontal systems. In addition, back trajectories started at different stages of the cloud system were used to analyze its history prior to the supersite overpass. The trajectories are used to study, for example, the life time of the cloud frontal system, changes of the cloud phase, and the evolution of cloud physics such as optical thickness, effective particle size, and water path. As a test bed, a case study with a cold front passing Lindenberg, Germany, is presented. |
BibTeX:
@article{Hunerbein2014,
author = {Hünerbein, Anja and Deneke, Hartwig and Macke, Andreas and Ebell, Kerstin and Görsdorf, Ulrich},
title = {Combining the perspective of satellite- and ground-based observations to analyze cloud frontal systems},
journal = {Journal of Applied Meteorology and Climatology},
publisher = {American Meteorological Society},
year = {2014},
volume = {53},
number = {11},
pages = {2538--2552},
doi = {10.1175/JAMC-D-13-0274.1}
}
|
| Järvi L, Grimmond CS, Taka M, Nordbo A, Setälä H and Strachan IB (2014), "Development of the Surface Urban Energy and Water Balance Scheme (SUEWS) for cold climate cities", Geoscientific Model Development., aug, 2014. Vol. 7(4), pp. 1691-1711. |
| Abstract: The Surface Urban Energy and Water Balance Scheme (SUEWS) is developed to include snow. The processes addressed include accumulation of snow on the different urban surface types: snow albedo and density aging, snow melting and re-freezing of meltwater. Individual model parameters are assessed and independently evaluated using long-term observations in the two cold climate cities of Helsinki and Montreal. Eddy covariance sensible and latent heat fluxes and snow depth observations are available for two sites in Montreal and one in Helsinki. Surface runoff from two catchments (24 and 45 ha) in Helsinki and snow properties (albedo and density) from two sites in Montreal are also analysed. As multiple observation sites with different land-cover characteristics are available in both cities, model development is conducted independent of evaluation. The developed model simulates snowmelt related runoff well (within 19% and 3% for the two catchments in Helsinki when there is snow on the ground), with the springtime peak estimated correctly. However, the observed runoff peaks tend to be smoother than the simulated ones, likely due to the water holding capacity of the catchments and the missing time lag between the catchment and the observation point in the model. For all three sites the model simulates the timing of the snow accumulation and melt events well, but underestimates the total snow depth by 18-20% in Helsinki and 29-33% in Montreal. The model is able to reproduce the diurnal pattern of net radiation and turbulent fluxes of sensible and latent heat during cold snow, melting snow and snow-free periods. The largest model uncertainties are related to the timing of the melting period and the parameterization of the snowmelt. The results show that the enhanced model can simulate correctly the exchange of energy and water in cold climate cities at sites with varying surface cover. textcopyright Author(s) 2014. |
BibTeX:
@article{Jarvi2014,
author = {Järvi, L. and Grimmond, C. S.B. and Taka, M. and Nordbo, A. and Setälä, H. and Strachan, I. B.},
title = {Development of the Surface Urban Energy and Water Balance Scheme (SUEWS) for cold climate cities},
journal = {Geoscientific Model Development},
year = {2014},
volume = {7},
number = {4},
pages = {1691--1711},
doi = {10.5194/gmd-7-1691-2014}
}
|
| Järvi L, Nordbo A, Rannik Ü, Haapanala S, Mammarella I and Pihlatie M (2014), "Urban nitrous-oxide fluxes measured using the eddy-covariance technique in Helsinki, Finland"
[BibTeX] |
BibTeX:
@techreport{Jarvi2014a,
author = {Järvi, Leena and Nordbo, Annika and Rannik, Üllar and Haapanala, Sami and Mammarella, Ivan and Pihlatie, Mari},
title = {Urban nitrous-oxide fluxes measured using the eddy-covariance technique in Helsinki, Finland},
year = {2014}
}
|
| JérÔme E, Beckers Y, Bodson B, Heinesch B, Moureaux C and Aubinet M (2014), "Impact of grazing on carbon dioxide exchanges in an intensively managed Belgian grassland", Agriculture, Ecosystems and Environment., sep, 2014. Vol. 194, pp. 7-16. |
| Abstract: Given that the soil carbon (C) sequestration potential by grasslands can be used to partly mitigate the total greenhouse gas emissions of livestock production systems, a better understanding of the effects of management practices, and especially grazing, on grassland carbon dioxide (CO2) exchanges has become a major concern. This study aimed at quantifying grazing impact on CO2 fluxes measured by eddy covariance by using innovative data analyses and experiments. For that, we distinguished direct and indirect grazing impact. Indirect impact results from biomass consumption, excretion deposits and soil compaction by cattle that modify CO2 exchanges. Direct impact results from livestock CO2 emissions through respiration that add to total ecosystem respiration. For the indirect impact, the variation during periods with fixed stocking rate of gross primary productivity at light saturation (GPPmax) and normalized dark respiration (Rd,10) was analyzed. On average, GPPmax decreased during grazing periods and increased during non-grazing periods which could be explained by aboveground biomass reduction and re-growth, respectively. In addition, GPPmax variations were negatively correlated to grazing intensity (defined as the product of the stocking rate and the grazing duration). On the contrary, no significant evolution of Rd,10 was found during both grazing and non-grazing periods, probably due to a combination of opposing effects of grazing on the total ecosystem respiration components. The direct impact was emphasized through four specific designed confinement experiments. Each experiment extended over three successive days. On the first and third day, there was no cattle on the plot, while, on the second day, cattle were confined in the main wind direction area of the eddy covariance set-up to increase the stocking rate (≈26livestockunitsha-1). The average livestock CO2 emissions during confinement, FCO2,livestock, were deduced from the differences between half-hourly measurements taken at 24h interval with or without cattle and under similar environmental conditions. They were estimated to be 2.59±0.58kgClivestockunit-1d-1 on average. This result was corroborated by independent estimates based on the C ingested by cattle during confinement. Using an annual average stocking of 2livestockunitsha-1, we found that livestock CO2 emissions represent only 8% of this grassland annual total ecosystem respiration. To our knowledge, this study is the first to quantify both direct and indirect livestock contribution to CO2 fluxes exchanged at the ecosystem scale using the eddy covariance technique. textcopyright 2014 Elsevier B.V. |
BibTeX:
@article{JerOme2014,
author = {JérÔme, Elisabeth and Beckers, Yves and Bodson, Bernard and Heinesch, Bernard and Moureaux, Christine and Aubinet, Marc},
title = {Impact of grazing on carbon dioxide exchanges in an intensively managed Belgian grassland},
journal = {Agriculture, Ecosystems and Environment},
year = {2014},
volume = {194},
pages = {7--16},
url = {http://linkinghub.elsevier.com/retrieve/pii/S0167880914002382},
doi = {10.1016/j.agee.2014.04.021}
}
|
| eija Juurola, J Korhonen JF and markku Kulmala (2014), "Janne levula 8) , laura riuttanen 1) , ella-maria Kyrö 1) , ivaylo Dzhedzhev 5) , eero nikinmaa 2) , timo vesala 1)" |
| Abstract: Knowledge transfer of climate-ecosystem-interactions between science and society-introducing the climate Whirl concept. Boreal Env. Res. 19 (suppl. B): 406-411. Making scientific principles behind the forest-atmosphere interactions more understandable for the general public would help them to follow and evaluate the political or personal decisions related to climate and climate change. Climate Whirl is a concept developed by a trans-disciplinary group of researchers in the area of science, art, education and software design. It aims at introducing a holistic view on climate and ecosystem research, using not only the traditional scientific communication channels, but also artistic manifestations in the form of workshops, exhibitions, seminars and interactive websites. Our aim is to increase public awareness of the interactions between climate and forests, as well as of the role of boreal forests in climate change. An already existing website Carbon Tree is a starting point that provides tools utilised in the further development of the concept. We present the first activities of the concept: Carbon Tree website, Interactive Carbon Tree installation , Hyytiälä Art Residency and interdisciplinary workshops. |
BibTeX:
@techreport{Juurola2014,
author = {eija Juurola and J Korhonen, Janne F and markku Kulmala},
title = {Janne levula 8) , laura riuttanen 1) , ella-maria Kyrö 1) , ivaylo Dzhedzhev 5) , eero nikinmaa 2) , timo vesala 1)},
year = {2014}
}
|
| Kasurinen V, Alfredsen K, Kolari P, Mammarella I, Alekseychik P, Rinne J, Vesala T, Bernier P, Boike J, Langer M, Belelli Marchesini L, van Huissteden K, Dolman H, Sachs T, Ohta T, Varlagin A, Rocha A, Arain A, Oechel W, Lund M, Grelle A, Lindroth A, Black A, Aurela M, Laurila T, Lohila A and Berninger F (2014), "Latent heat exchange in the boreal and arctic biomes", Global Change Biology., nov, 2014. Vol. 20(11), pp. 3439-3456. |
| Abstract: In this study latent heat flux (λE) measurements made at 65 boreal and arctic eddy-covariance (EC) sites were analyses by using the Penman-Monteith equation. Sites were stratified into nine different ecosystem types: harvested and burnt forest areas, pine forests, spruce or fir forests, Douglas-fir forests, broadleaf deciduous forests, larch forests, wetlands, tundra and natural grasslands. The Penman-Monteith equation was calibrated with variable surface resistances against half-hourly eddy-covariance data and clear differences between ecosystem types were observed. Based on the modeled behavior of surface and aerodynamic resistances, surface resistance tightly control λE in most mature forests, while it had less importance in ecosystems having shorter vegetation like young or recently harvested forests, grasslands, wetlands and tundra. The parameters of the Penman-Monteith equation were clearly different for winter and summer conditions, indicating that phenological effects on surface resistance are important. We also compared the simulated λE of different ecosystem types under meteorological conditions at one site. Values of λE varied between 15% and 38% of the net radiation in the simulations with mean ecosystem parameters. In general, the simulations suggest that λE is higher from forested ecosystems than from grasslands, wetlands or tundra-type ecosystems. Forests showed usually a tighter stomatal control of λE as indicated by a pronounced sensitivity of surface resistance to atmospheric vapor pressure deficit. Nevertheless, the surface resistance of forests was lower than for open vegetation types including wetlands. Tundra and wetlands had higher surface resistances, which were less sensitive to vapor pressure deficits. The results indicate that the variation in surface resistance within and between different vegetation types might play a significant role in energy exchange between terrestrial ecosystems and atmosphere. These results suggest the need to take into account vegetation type and phenology in energy exchange modeling. |
BibTeX:
@article{Kasurinen2014,
author = {Kasurinen, Ville and Alfredsen, Knut and Kolari, Pasi and Mammarella, Ivan and Alekseychik, Pavel and Rinne, Janne and Vesala, Timo and Bernier, Pierre and Boike, Julia and Langer, Moritz and Belelli Marchesini, Luca and van Huissteden, Ko and Dolman, Han and Sachs, Torsten and Ohta, Takeshi and Varlagin, Andrej and Rocha, Adrian and Arain, Altaf and Oechel, Walter and Lund, Magnus and Grelle, Achim and Lindroth, Anders and Black, Andy and Aurela, Mika and Laurila, Tuomas and Lohila, Annalea and Berninger, Frank},
title = {Latent heat exchange in the boreal and arctic biomes},
journal = {Global Change Biology},
year = {2014},
volume = {20},
number = {11},
pages = {3439--3456},
url = {http://doi.wiley.com/10.1111/gcb.12640},
doi = {10.1111/gcb.12640}
}
|
| Kolari P, Chan T, Porcar-Castell A, Bäck J, Nikinmaa E and Juurola E (2014), "Field and controlled environment measurements show strong seasonal acclimation in photosynthesis and respiration potential in boreal Scots pine", Frontiers in Plant Science., dec, 2014. Vol. 5(DEC) Frontiers Research Foundation. |
| Abstract: Understanding the seasonality of photosynthesis in boreal evergreen trees and its control by the environment requires separation of the instantaneous and slow responses, as well as the dynamics of light reactions, carbon reactions, and respiration. We determined the seasonality of photosynthetic light response and respiration parameters of Scots pine (Pinus sylvestris L.) in the field in southern Finland and in controlled laboratory conditions. CO2 exchange and chlorophyll fluorescence were measured in the field using a continuously operated automated chamber setup and fluorescence monitoring systems. We also carried out monthly measurements of photosynthetic light, CO2 and temperature responses in standard conditions with a portable IRGA and fluorometer instrument. The field and response measurements indicated strong seasonal variability in the state of the photosynthetic machinery with a deep downregulation during winter. Despite the downregulation, the photosynthetic machinery retained a significant capacity during winter, which was not visible in the field measurements. Light-saturated photosynthesis (Psat) and the initial slope of the photosynthetic light response (α) obtained in standard conditions were up to 20% of their respective summertime values. Respiration also showed seasonal acclimation with peak values of respiration in standard temperature in spring and decline in autumn. Spring recovery of all photosynthetic parameters could be predicted with temperature history. On the other hand, the operating quantum yield of photosystem II and the initial slope of photosynthetic light response stayed almost at the summertime level until late autumn while at the same time Psat decreased following the prevailing temperature. Comparison of photosynthetic parameters with the environmental drivers suggests that light and minimum temperature are also decisive factors in the seasonal acclimation of photosynthesis in boreal evergreen trees. |
BibTeX:
@article{Kolari2014,
author = {Kolari, Pasi and Chan, Tommy and Porcar-Castell, Albert and Bäck, Jaana and Nikinmaa, Eero and Juurola, Eija},
title = {Field and controlled environment measurements show strong seasonal acclimation in photosynthesis and respiration potential in boreal Scots pine},
journal = {Frontiers in Plant Science},
publisher = {Frontiers Research Foundation},
year = {2014},
volume = {5},
number = {DEC},
doi = {10.3389/fpls.2014.00717}
}
|
| Kretschmer R, Gerbig C, Karstens U, Biavati G, Vermeulen A, Vogel F, Hammer S and Totsche KU (2014), "Impact of optimized mixing heights on simulated regional atmospheric transport of CO2", Atmospheric Chemistry and Physics., jul, 2014. Vol. 14(14), pp. 7149-7172. |
| Abstract: The mixing height (MH) is a crucial parameter in commonly used transport models that proportionally affects air concentrations of trace gases with sources/sinks near the ground and on diurnal scales. Past synthetic data experiments indicated the possibility to improve tracer transport by minimizing errors of simulated MHs. In this paper we evaluate a method to constrain the Lagrangian particle dispersion model STILT (Stochastic Time-Inverted Lagrangian Transport) with MH diagnosed from radiosonde profiles using a bulk Richardson method. The same method was used to obtain hourly MHs for the period September/October 2009 from the Weather Research and Forecasting (WRF) model, which covers the European continent at 10 km horizontal resolution. Kriging with external drift (KED) was applied to estimate optimized MHs from observed and modelled MHs, which were used as input for STILT to assess the impact on CO 2 transport. Special care has been taken to account for uncertainty in MH retrieval in this estimation process. MHs and CO2 concentrations were compared to vertical profiles from aircraft in situ data. We put an emphasis on testing the consistency of estimated MHs to observed vertical mixing of CO2. Modelled CO2 was also compared with continuous measurements made at Cabauw and Heidelberg stations. WRF MHs were significantly biased by ∼10&ndash;20% during day and ∼40-60% during night. Optimized MHs reduced this bias to ∼5% with additional slight improvements in random errors. The KED MHs were generally more consistent with observed CO2 mixing. The use of optimized MHs had in general a favourable impact on CO2 transport, with bias reductions of 5-45% (day) and 60-90% (night). This indicates that a large part of the found CO 2 model-data mismatch was indeed due to MH errors. Other causes for CO2 mismatch are discussed. Applicability of our method is discussed in the context of CO2 inversions at regional scales. textcopyright 2014 Author(s). |
BibTeX:
@article{Kretschmer2014,
author = {Kretschmer, R and Gerbig, C and Karstens, U and Biavati, G and Vermeulen, A and Vogel, F and Hammer, S and Totsche, K U},
title = {Impact of optimized mixing heights on simulated regional atmospheric transport of CO2},
journal = {Atmospheric Chemistry and Physics},
year = {2014},
volume = {14},
number = {14},
pages = {7149--7172},
url = {http://www.atmos-chem-phys.net/14/7149/2014/},
doi = {10.5194/acp-14-7149-2014}
}
|
| Kulmala L, Aaltonen H, Berninger F, Kieloaho AJ, Levula J, Bäck J, Hari P, Kolari P, Korhonen JFJ, Kulmala M, Nikinmaa E, Pihlatie M, Vesala T and Pumpanen J (2014), "Changes in biogeochemistry and carbon fluxes in a boreal forest after the clear-cutting and partial burning of slash", Agricultural and Forest Meteorology., may, 2014. Vol. 188, pp. 33-44. |
| Abstract: We quantified the changes in the soil properties and fluxes of soil CO2, CH4 and volatile organic compound (VOC) fluxes following a clear-cut (CC) and prescribed burning of slash (BCC) over a three year time period in a mature spruce forest. Clear-cutting increased soil moisture, soil temperature, pH as well as NH4-N and NO3-N concentrations in the soil. PH and soil temperature in the BCC site were even higher than in the CC site.Probably due to decreased tree root respiration, the soil CO2 efflux decreased only slightly in the first growing season following the clear-cut. During the following two years, the CO2 efflux at the CC site was significantly higher than in the mature control forest due to increased decomposition, which was stimulated by higher soil moisture and temperature. The temperature dependencies of the CO2 efflux did not differ between these sites. The clear-cut and burning of slash, however, decreased the CO2 efflux and its temperature response in BCC for two years but in the third year, the differences between control and BCC were no longer significant.Soil was a sink for CH4 in all treatments. After the clear-cutting and burning of slash, the net CH4 uptake was immediately decreased, but one year later the uptake was comparable to that of the mature control forest. The CC treatment decreased the soil CH4 uptake, however, it did not significantly differ from that of the control.The soil VOC emissions measured at the BCC site were 100-fold compared to those measured before clear-cutting, but the emissions decreased rapidly during the three months following the burning.Although the CO2 effluxes from the BCC site were lower for more than 2.5 years compared to the CC site, the total amount of carbon released from prescribed burning was higher due to the immediate carbon losses. Moreover, the clear-cut and burning of slash temporarily decreased the ability of the forest to bind atmospheric CH4 and increased the VOC emissions significantly. textcopyright 2014 Elsevier B.V. |
BibTeX:
@article{Kulmala2014,
author = {Kulmala, Liisa and Aaltonen, Hermanni and Berninger, Frank and Kieloaho, Antti Jussi and Levula, Janne and Bäck, Jaana and Hari, Pertti and Kolari, Pasi and Korhonen, Janne F J and Kulmala, Markku and Nikinmaa, Eero and Pihlatie, Mari and Vesala, Timo and Pumpanen, Jukka},
title = {Changes in biogeochemistry and carbon fluxes in a boreal forest after the clear-cutting and partial burning of slash},
journal = {Agricultural and Forest Meteorology},
year = {2014},
volume = {188},
pages = {33--44},
url = {http://linkinghub.elsevier.com/retrieve/pii/S0168192313003146},
doi = {10.1016/j.agrformet.2013.12.003}
}
|
| Landschützer P, Gruber N, Bakker DC and Schuster U (2014), "Recent variability of the global ocean carbon sink", Global Biogeochemical Cycles., sep, 2014. Vol. 28(9), pp. 927-949. Blackwell Publishing Ltd. |
| Abstract: We present a new observation-based estimate of the global oceanic carbon dioxide (COtextlessinftextgreater2textless/inftextgreater) sink and its temporal variation on a monthly basis from 1998 through 2011 and at a spatial resolution of 1×1. This sink estimate rests upon a neural network-based mapping of global surface ocean observations of the partial pressure of COtextlessinftextgreater2textless/inftextgreater (pCOtextlessinftextgreater2textless/inftextgreater) from the Surface Ocean COtextlessinftextgreater2textless/inftextgreater Atlas database. The resulting pCOtextlessinftextgreater2textless/inftextgreater has small biases when evaluated against independent observations in the different ocean basins, but larger randomly distributed differences exist particularly in high latitudes. The seasonal climatology of our neural network-based product agrees overall well with the Takahashi et al. (2009) climatology, although our product produces a stronger seasonal cycle at high latitudes. From our global pCOtextlessinftextgreater2textless/inftextgreater product, we compute a mean net global ocean (excluding the Arctic Ocean and coastal regions) COtextlessinftextgreater2textless/inftextgreater uptake flux of -1.42 ± 0.53 Pg C yrtextlesssuptextgreater-1textless/suptextgreater, which is in good agreement with ocean inversion-based estimates. Our data indicate a moderate level of interannual variability in the ocean carbon sink (±0.12 Pg C yrtextlesssuptextgreater-1textless/suptextgreater, 1σ) from 1998 through 2011, mostly originating from the equatorial Pacific Ocean, and associated with the El Niño-Southern Oscillation. Accounting for steady state riverine and Arctic Ocean carbon fluxes our estimate further implies a mean anthropogenic COtextlessinftextgreater2textless/inftextgreater uptake of -1.99 ± 0.59 Pg C yrtextlesssuptextgreater-1textless/suptextgreater over the analysis period. From this estimate plus the most recent estimates for fossil fuel emissions and atmospheric COtextlessinftextgreater2textless/inftextgreater accumulation, we infer a mean global land sink of -2.82 ± 0.85 Pg C yrtextlesssuptextgreater-1textless/suptextgreater over the 1998 through 2011 period with strong interannual variation. |
BibTeX:
@article{Landschutzer2014,
author = {Landschützer, P. and Gruber, N. and Bakker, D. C.E. and Schuster, U.},
title = {Recent variability of the global ocean carbon sink},
journal = {Global Biogeochemical Cycles},
publisher = {Blackwell Publishing Ltd},
year = {2014},
volume = {28},
number = {9},
pages = {927--949},
url = {https://agupubs.onlinelibrary.wiley.com/doi/full/10.1002/2014GB004853 https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1002/2014GB004853 https://agupubs.onlinelibrary.wiley.com/doi/10.1002/2014GB004853},
doi = {10.1002/2014GB004853}
}
|
| Laruelle GG, Lauerwald R, Pfeil B and Regnier P (2014), "Regionalized global budget of the CO2 exchange at the air-water interface in continental shelf seas", Global Biogeochemical Cycles. Vol. 28(11), pp. 1199-1214. Blackwell Publishing Ltd. |
| Abstract: Over the past decade, estimates of the atmospheric CO2 uptake by continental shelf seas were constrained within the 0.18-0.45 Pg C yr-1 range. However, most of those estimates are based on extrapolations from limited data sets of local flux measurements (n textless 100). Here we propose to derive the CO2 air-sea exchange of the shelf seas by extracting 3 textperiodcentered 106 direct surface ocean CO2 measurements from the global database SOCAT (Surface Ocean CO2 Atlas), atmospheric CO2 values from GlobalVIEW and calculating gas transfer rates using readily available global temperature, salinity, and wind speed fields. We then aggregate our results using a global segmentation of the shelf in 45 units and 152 subunits to establish a consistent regionalized CO2 exchange budget at the global scale.Within each unit, the data density determines the spatial and temporal resolutions at which the air-sea CO2 fluxes are calculated and range from a 0.5° resolution in the best surveyed regions to a whole unit resolution in areas where data coverage is limited. Our approach also accounts, for the first time, for the partial sea ice cover of polar shelves. Our new regionalized global CO2 sink estimate of 0.19 ± 0.05 Pg C yr-1 falls in the low end of previous estimates. Reported to an ice-free surface area of 22 textperiodcentered 106 km2, this value yields a flux density of 0.7 mol C m-2 yr-1, ∼40% more intense than that of the open ocean. Our results also highlight the significant contribution of Arctic shelves to this global CO2 uptake (0.07 Pg C yr-1). |
BibTeX:
@article{Laruelle2014,
author = {Laruelle, Goulven G. and Lauerwald, Ronny and Pfeil, Benjamin and Regnier, Pierre},
title = {Regionalized global budget of the CO2 exchange at the air-water interface in continental shelf seas},
journal = {Global Biogeochemical Cycles},
publisher = {Blackwell Publishing Ltd},
year = {2014},
volume = {28},
number = {11},
pages = {1199--1214},
doi = {10.1002/2014GB004832}
}
|
| Laube JC, Newland MJ, Hogan C, Brenninkmeijer CAM, Fraser PJ, Martinerie P, Oram DE, Reeves CE, Röckmann T, Schwander J, Witrant E and Sturges WT (2014), "Newly detected ozone-depleting substances in the atmosphere", Nature Geoscience., mar, 2014. Vol. 7(4), pp. 266-269. |
| Abstract: Ozone-depleting substances emitted through human activities cause large-scale damage to the stratospheric ozone layer, and influence global climate. Consequently, the production of many of these substances has been phased out; prominent examples are the chlorofluorocarbons (CFCs), and their intermediate replacements, the hydrochlorofluorocarbons (HCFCs). So far, seven types of CFC and six types of HCFC have been shown to contribute to stratospheric ozone destruction. Here, we report the detection and quantification of a further three CFCs and one HCFC. We analysed the composition of unpolluted air samples collected in Tasmania between 1978 and 2012, and extracted from deep firn snow in Greenland in 2008, using gas chromatography with mass spectrometric detection. Using the firn data, we show that all four compounds started to emerge in the atmosphere in the 1960s. Two of the compounds continue to accumulate in the atmosphere. We estimate that, before 2012, emissions of all four compounds combined amounted to more than 74,000 tonnes. This is small compared with peak emissions of other CFCs in the 1980s of more than one million tonnes each year. However, the reported emissions are clearly contrary to the intentions behind the Montreal Protocol, and raise questions about the sources of these gases. textcopyright 2014 Macmillan Publishers Limited. All rights reserved. |
BibTeX:
@article{Laube2014,
author = {Laube, Johannes C and Newland, Mike J and Hogan, Christopher and Brenninkmeijer, Carl A M and Fraser, Paul J and Martinerie, Patricia and Oram, David E and Reeves, Claire E and Röckmann, Thomas and Schwander, Jakob and Witrant, Emmanuel and Sturges, William T},
title = {Newly detected ozone-depleting substances in the atmosphere},
journal = {Nature Geoscience},
year = {2014},
volume = {7},
number = {4},
pages = {266--269},
url = {http://www.nature.com/doifinder/10.1038/ngeo2109},
doi = {10.1038/ngeo2109}
}
|
| LEGOUT A, HANSSON K, VAN DER HEIJDEN G, LACLAU J-P, AUGUSTO L and RANGER J (2014), "Fertilité chimique des sols forestiers : concepts de base", Revue Forestière Française., apr, 2014. (4), pp. Fr.], ISSN 0035. |
BibTeX:
@article{LEGOUT2014,
author = {LEGOUT, Arnaud and HANSSON, Karna and VAN DER HEIJDEN, Grégory and LACLAU, Jean-Paul and AUGUSTO, Laurent and RANGER, Jacques},
title = {Fertilité chimique des sols forestiers : concepts de base},
journal = {Revue Forestière Française},
year = {2014},
number = {4},
pages = {Fr.], ISSN 0035},
url = {http://hdl.handle.net/2042/56556},
doi = {10.4267/2042/56556}
}
|
| Le Quéré C, Peters GP, Andres RJ, Andrew RM, Boden TA, Ciais P, Friedlingstein P, Houghton RA, Marland G, Moriarty R, Sitch S, Tans P, Arneth A, Arvanitis A, Bakker DCE, Bopp L, Canadell JG, Chini LP, Doney SC, Harper A, Harris I, House JI, Jain AK, Jones SD, Kato E, Keeling RF, Klein Goldewijk K, Körtzinger A, Koven C, Lefèvre N, Maignan F, Omar A, Ono T, Park GH, Pfeil B, Poulter B, Raupach MR, Regnier P, Rödenbeck C, Saito S, Schwinger J, Segschneider J, Stocker BD, Takahashi T, Tilbrook B, Van Heuven S, Viovy N, Wanninkhof R, Wiltshire A and Zaehle S (2014), "Global carbon budget 2013", Earth System Science Data., jun, 2014. Vol. 6(1), pp. 235-263. |
| Abstract: Accurate assessment of anthropogenic carbon dioxide (CO2) emissions and their redistribution among the atmosphere, ocean, and terrestrial biosphere is important to better understand the global carbon cycle, support the development of climate policies, and project future climate change. Here we describe data sets and a methodology to quantify all major components of the global carbon budget, including their uncertainties, based on the combination of a range of data, algorithms, statistics and model estimates and their interpretation by a broad scientific community. We discuss changes compared to previous estimates, consistency within and among components, alongside methodology and data limitations. CO2 emissions from fossil-fuel combustion and cement production (EFF) are based on energy statistics, while emissions from land-use change (ELUC), mainly deforestation, are based on combined evidence from land-cover change data, fire activity associated with deforestation, and models. The global atmospheric CO2 concentration is measured directly and its rate of growth (G ATM) is computed from the annual changes in concentration. The mean ocean CO2 sink (SOCEAN) is based on observations from the 1990s, while the annual anomalies and trends are estimated with ocean models. The variability in SOCEAN is evaluated for the first time in this budget with data products based on surveys of ocean CO2 measurements. The global residual terrestrial CO2 sink (SLAND) is estimated by the difference of the other terms of the global carbon budget and compared to results of independent dynamic global vegetation models forced by observed climate, CO2 and land cover change (some including nitrogen-carbon interactions). All uncertainties are reported as ±1σ , reflecting the current capacity to characterise the annual estimates of each component of the global carbon budget. For the last decade available (2003-2012), EFF was 8.6±0.4 GtC yr-1, ELUC 0.9±0.5 GtC yr-1, GATM 4.3±0.1 GtC yr-1, SOCEAN 2.5±0.5 GtC yr -1, and SLAND 2.8±0.8 GtC yr-1. For year 2012 alone, EFF grew to 9.7±0.5 GtC yr-1, 2.2% above 2011, reflecting a continued growing trend in these emissions, G ATM was 5.1±0.2 GtC yr-1, SOCEAN was 2.9±0.5 GtC yr-1, and assuming an ELUC of 1.0±0.5 GtC yr-1 (based on the 2001-2010 average), S LAND was 2.7±0.9 GtC yr-1. GATM was high in 2012 compared to the 2003-2012 average, almost entirely reflecting the high EFF. The global atmospheric CO2 concentration reached 392.52±0.10 ppm averaged over 2012. We estimate that EFF will increase by 2.1% (1.1- 3.1 %) to 9.9±0.5 GtC in 2013, 61% above emissions in 1990, based on projections of world gross domestic product and recent changes in the carbon intensity of the economy.With this projection, cumulative emissions ofCO2 will reach about 535±55 GtC for 1870-2013, about 70% from EFF (390±20 GtC) and 30% from ELUC (145±50 GtC). This paper also documents any changes in the methods and data sets used in this new carbon budget from previous budgets (Le Quéré et al., 2013). All observations presented here can be downloaded from the Carbon Dioxide Information Analysis Center (doi:10.3334/CDIAC/GCP-2013-V2.3). textcopyright 2014 Author(s) CC Attribution 3.0 License. |
BibTeX:
@article{LeQuere2014,
author = {Le Quéré, C and Peters, G P and Andres, R J and Andrew, R M and Boden, T A and Ciais, P and Friedlingstein, P and Houghton, R A and Marland, G and Moriarty, R and Sitch, S and Tans, P and Arneth, A and Arvanitis, A and Bakker, D C E and Bopp, L and Canadell, J G and Chini, L P and Doney, S C and Harper, A and Harris, I and House, J I and Jain, A K and Jones, S D and Kato, E and Keeling, R F and Klein Goldewijk, K and Körtzinger, A and Koven, C and Lefèvre, N and Maignan, F and Omar, A and Ono, T and Park, G H and Pfeil, B and Poulter, B and Raupach, M R and Regnier, P and Rödenbeck, C and Saito, S and Schwinger, J and Segschneider, J and Stocker, B D and Takahashi, T and Tilbrook, B and Van Heuven, S and Viovy, N and Wanninkhof, R and Wiltshire, A and Zaehle, S},
title = {Global carbon budget 2013},
journal = {Earth System Science Data},
year = {2014},
volume = {6},
number = {1},
pages = {235--263},
url = {http://www.earth-syst-sci-data.net/6/235/2014/},
doi = {10.5194/essd-6-235-2014}
}
|
| Lintunen A, Lindfors L, Kolari P, Juurola E, Nikinmaa E and Hölttä T (2014), "Bursts of CO2 released during freezing offer a new perspective on avoidance of winter embolism in trees", Annals of Botany., dec, 2014. Vol. 114(8), pp. 1711-1718. Oxford University Press. |
| Abstract: Background and Aims Woody plants can suffer from winter embolism as gas bubbles are formed in the water-conducting conduits when freezing occurs: gases are not soluble in ice, and the bubbles may expand and fill the conduits with air during thawing. A major assumption usually made in studies of winter embolism formation is that all of the gas dissolved in the xylem sap is trapped within the conduits and forms bubbles during freezing. The current study tested whether this assumption is actually valid, or whether efflux of gases from the stem during freezing reduces the occurrence of embolism. Methods CO2 efflux measurements were conducted during freezing experiments for saplings of three Scots pine (Pinus sylvestris) and three Norway spruce (Picea abies) trees under laboratory conditions, and the magnitudes of the freezing-related bursts of CO2 released from the stems were analysed using a previously published mechanistic model of CO2 production, storage, diffusion and efflux from a tree stem. The freezing-related bursts of CO2 released from a mature Scots pine tree growing in field conditions were also measured and analysed. Key Results Substantial freezing-related bursts of CO2 released from the stem were found to occur during both the laboratory experiments and under field conditions. In the laboratory, the fraction of CO2 released from the stem ranged between 27 and 96 % of the total CO2 content within the stem. Conclusions All gases dissolved in the xylem sap are not trapped within the ice in the stem during freezing, as has previously been assumed, thus adding a new dimension to the understanding of winter embolism formation. The conduit water volume not only determines the volume of bubbles formed during freezing, but also the efficiency of gas efflux out of the conduit during the freezing process. |
BibTeX:
@article{Lintunen2014,
author = {Lintunen, A. and Lindfors, L. and Kolari, P. and Juurola, E. and Nikinmaa, E. and Hölttä, T.},
title = {Bursts of CO2 released during freezing offer a new perspective on avoidance of winter embolism in trees},
journal = {Annals of Botany},
publisher = {Oxford University Press},
year = {2014},
volume = {114},
number = {8},
pages = {1711--1718},
doi = {10.1093/aob/mcu190}
}
|
| Luyssaert S, Jammet M, Stoy PC, Estel S, Pongratz J, Ceschia E, Churkina G, Don A, Erb K, Ferlicoq M, Gielen B, Grünwald T, Houghton RA, Klumpp K, Knohl A, Kolb T, Kuemmerle T, Laurila T, Lohila A, Loustau D, McGrath MJ, Meyfroidt P, Moors EJ, Naudts K, Novick K, Otto J, Pilegaard K, Pio CA, Rambal S, Rebmann C, Ryder J, Suyker AE, Varlagin A, Wattenbach M and Dolman AJ (2014), "Land management and land-cover change have impacts of similar magnitude on surface temperature", Nature Climate Change., may, 2014. Vol. 4(5), pp. 389-393. |
| Abstract: Anthropogenic changes to land cover (LCC) remain common, but continuing land scarcity promotes the widespread intensification of land management changes (LMC) to better satisfy societal demand for food, fibre, fuel and shelter. The biophysical effects of LCC on surface climate are largely understood, particularly for the boreal and tropical zones, but fewer studies have investigated the biophysical consequences of LMC; that is, anthropogenic modification without a change in land cover type. Harmonized analysis of ground measurements and remote sensing observations of both LCC and LMC revealed that, in the temperate zone, potential surface cooling from increased albedo is typically offset by warming from decreased sensible heat fluxes, with the net effect being a warming of the surface. Temperature changes from LMC and LCC were of the same magnitude, and averaged 2 K at the vegetation surface and were estimated at 1.7 K in the planetary boundary layer. Given the spatial extent of land management (42-58% of the land surface) this calls for increasing the efforts to integrate land management in Earth System Science to better take into account the human impact on the climate. textcopyright 2014 Macmillan Publishers Limited. All rights reserved. |
BibTeX:
@article{Luyssaert2014,
author = {Luyssaert, Sebastiaan and Jammet, Mathilde and Stoy, Paul C and Estel, Stephan and Pongratz, Julia and Ceschia, Eric and Churkina, Galina and Don, Axel and Erb, Karlheinz and Ferlicoq, Morgan and Gielen, Bert and Grünwald, Thomas and Houghton, Richard A and Klumpp, Katja and Knohl, Alexander and Kolb, Thomas and Kuemmerle, Tobias and Laurila, Tuomas and Lohila, Annalea and Loustau, Denis and McGrath, Matthew J and Meyfroidt, Patrick and Moors, Eddy J and Naudts, Kim and Novick, Kim and Otto, Juliane and Pilegaard, Kim and Pio, Casimiro A and Rambal, Serge and Rebmann, Corinna and Ryder, James and Suyker, Andrew E and Varlagin, Andrej and Wattenbach, Martin and Dolman, A Johannes},
title = {Land management and land-cover change have impacts of similar magnitude on surface temperature},
journal = {Nature Climate Change},
year = {2014},
volume = {4},
number = {5},
pages = {389--393},
url = {http://www.nature.com/articles/nclimate2196},
doi = {10.1038/nclimate2196}
}
|
| Masarie KA, Peters W, Jacobson AR and Tans PP (2014), "ObsPack: A framework for the preparation, delivery, and attribution of atmospheric greenhouse gas measurements", Earth System Science Data., dec, 2014. Vol. 6(2), pp. 375-384. |
| Abstract: Observation Package (ObsPack) is a framework designed to bring together atmospheric greenhouse gas observations from a variety of sampling platforms, prepare them with specific applications in mind, and package and distribute them in a self-consistent and well-documented product. Data products created using the ObsPack framework (called "ObsPack products") are intended to support carbon cycle modeling studies and represent a next generation of value-added greenhouse gas observation products modeled after the cooperative GLOBALVIEW products introduced in 1996. Depending on intended use, ObsPack products may include data in their original form reformatted using the ObsPack framework or may contain derived data consisting of averages, subsets, or smoothed representations of original data. All products include extensive ancillary information (metadata) intended to help ensure the data are used appropriately, their calibration and quality assurance history are clearly described, and that individuals responsible for the measurements (data providers or principal investigators (PIs)) are properly acknowledged for their work. ObsPack products are made freely available using a distribution strategy designed to improve communication between data providers and product users. The strategy includes a data usage policy that requires users to directly communicate with data providers and an automated e-mail notification system triggered when a product is accessed. ObsPack products will be assigned a unique digital object identifier (DOI) to ensure each product can be unambiguously identified in scientific literature. Here we describe the ObsPack framework and its potential role in supporting the evolving needs of both data providers and product users. |
BibTeX:
@article{Masarie2014,
author = {Masarie, K A and Peters, W and Jacobson, A R and Tans, P P},
title = {ObsPack: A framework for the preparation, delivery, and attribution of atmospheric greenhouse gas measurements},
journal = {Earth System Science Data},
year = {2014},
volume = {6},
number = {2},
pages = {375--384},
url = {http://www.earth-syst-sci-data.net/6/375/2014/},
doi = {10.5194/essd-6-375-2014}
}
|
| Maselli F, Papale D, Chiesi M, Matteucci G, Angeli L, Raschi A and Seufert G (2014), "Operational monitoring of daily evapotranspiration by the combination of MODIS NDVI and ground meteorological data: Application and evaluation in Central Italy", Remote Sensing of Environment., sep, 2014. Vol. 152, pp. 279-290. |
| Abstract: Time-varying crop coefficients (Kc) can be obtained from remotely sensed data and combined with daily potential evapotranspiration estimates for the operational prediction of actual evapotranspiration (ETA). This approach, however, presents relevant limitations when applied in mixed, water stressed ecosystems. The current paper addresses these issues by introducing two innovations. First, fractional vegetation cover (FVC) is derived from NDVI and utilized to split evaporating and transpiring surfaces, whose behavior is simulated under fully watered conditions by the use of generalized Kc. Next, the short term effect of water shortage is taken into account by means of downregulating factors which are based on meteorological observations (potential evapotranspiration and rainfall) and act differently for vegetated and not vegetated surfaces. The new method is tested against latent heat of evaporation (LE) measurements taken by the eddy covariance technique in six sites of Central Italy representative of various forest and herbaceous ecosystems. In this experiment the method is driven by 1-km meteorological data obtained from a pan-European archive and by 250m MODIS NDVI imagery. Satisfactory accuracies are obtained in all experimental situations, which encourages the application of the method for the operational monitoring of ETA on regional scale. textcopyright 2014 Elsevier Inc. |
BibTeX:
@article{Maselli2014,
author = {Maselli, Fabio and Papale, Dario and Chiesi, Marta and Matteucci, Giorgio and Angeli, Luca and Raschi, Antonio and Seufert, Guenther},
title = {Operational monitoring of daily evapotranspiration by the combination of MODIS NDVI and ground meteorological data: Application and evaluation in Central Italy},
journal = {Remote Sensing of Environment},
year = {2014},
volume = {152},
pages = {279--290},
url = {http://linkinghub.elsevier.com/retrieve/pii/S0034425714002417},
doi = {10.1016/j.rse.2014.06.021}
}
|
| McCalley CK, Woodcroft BJ, Hodgkins SB, Wehr RA, Kim EH, Mondav R, Crill PM, Chanton JP, Rich VI, Tyson GW and Saleska SR (2014), "Methane dynamics regulated by microbial community response to permafrost thaw", Nature., oct, 2014. Vol. 514(7253), pp. 478-481. |
| Abstract: Permafrost contains about50% of the global soil carbon1. It is thought that the thawing of permafrost can lead to a loss of soil carbon in the form of methane and carbon dioxide emissions2,3. The magnitude of the resulting positive climate feedback of such greenhouse gas emissions is still unknown3 and may to a large extent depend on the poorly understood role of microbial community composition in regulating the metabolic processes that drive such ecosystem-scale greenhouse gas fluxes. Here we show that changes in vegetation and increasing methane emissionswith permafrost thaware associated with a switch from hydrogenotrophic to partly acetoclasticmethanogenesis, resulting inalargeshift in theδ13Csignature (10-15%) of emitted methane. We used a natural landscape gradient of permafrost thawinnorthern Sweden4,5 as a model to investigate the role of microbial communities in regulatingmethane cycling, and to test whether a knowledge of community dynamics could improvepredictions of carbonemissions under loss of permafrost. Abundance of the meth anogen Candidatus 'Meth anoflorens stordalenmirensis'6 is a key predictor of the shifts in methane isotopes, which in turn predicts the proportions of carbon emitted as methane and as carbon dioxide, an important factor for simulating the climate feedback associated with permafrost thaw in global models3,7. By showing that the abundance of key microbial lineages can be used to predict atmospherically relevant patterns in methane isotopes and the proportion of carbonmetabolized to methane during permafrost thaw, we establish a basis for scaling changing microbial communities to ecosystem isotope dynamics. Our findings indicate that microbial ecology may be important in ecosystem-scale responses to global change. |
BibTeX:
@article{McCalley2014,
author = {McCalley, Carmody K and Woodcroft, Ben J and Hodgkins, Suzanne B and Wehr, Richard A and Kim, Eun Hae and Mondav, Rhiannon and Crill, Patrick M and Chanton, Jeffrey P and Rich, Virginia I and Tyson, Gene W and Saleska, Scott R},
title = {Methane dynamics regulated by microbial community response to permafrost thaw},
journal = {Nature},
year = {2014},
volume = {514},
number = {7253},
pages = {478--481},
url = {http://www.nature.com/articles/nature13798},
doi = {10.1038/nature13798}
}
|
| Mizunuma T, Mencuccini M, Wingate L, Ogée J, Nichol C and Grace J (2014), "Sensitivity of colour indices for discriminating leaf colours from digital photographs", Methods in Ecology and Evolution., oct, 2014. Vol. 5(10), pp. 1078-1085. British Ecological Society. |
| Abstract: Digital images of tree canopies have been analysed to understand how forest phenology responds to climate change. Researchers have used different colour indices to carry out quantitative analyses, but uncertainties over the performance of the various indices are hampering progress in their use. To compare the various indices under controlled conditions, we carried out experiments using a low-cost off-the-shelf digital camera with a set of standard colour charts as model leaves for different stages: emerging leaves, yellowish green; newly expanded leaves, green; fully mature leaves, dark green; senescent leaves, yellow. Two models of cameras, a compact digital camera and a surveillance 'live image' camera were used, and photographs were taken by two cameras for each model under clear or overcast sky conditions with two colour balance settings. The indices were also compared with those derived from spectral reflectance. Colour indices based on hue distinguished leaf colour samples with only a small influence of camera models, balance setting and sky conditions, while indices based on green were strongly influenced by camera models and were relatively insensitive to leaf colours. The strength of the green channel relative to the total of digital numbers took similar values for the mature and senescent replica leaves, highlighting its poor ability to identify the change of colour in autumn. Spectral-based hue was also sensitive to the gradation of leaf colours and showed a good correlation with the digital representation of hue regardless of camera models and balance setting. Remarkably, the primitive digital number of red, Ntextlessinftextgreaterredtextless/inftextgreater, also discriminated leaf colours well, with a small influence of the factors investigated here, showing a good correlation with the reflectance of the red band, except from images taken by the surveillance cameras with auto balance. Hue was a robust index across the image set, while the green-based indices often used to quantify canopy phenology in previous studies performed poorly. Hue was well correlated with spectral reflectance indices and worked better than all other indices to discriminate leaf colours. We recommend using hue as a colour index for tracking different stages of leaf development. |
BibTeX:
@article{Mizunuma2014,
author = {Mizunuma, Toshie and Mencuccini, Maurizio and Wingate, Lisa and Ogée, Jérôme and Nichol, Caroline and Grace, John},
title = {Sensitivity of colour indices for discriminating leaf colours from digital photographs},
journal = {Methods in Ecology and Evolution},
publisher = {British Ecological Society},
year = {2014},
volume = {5},
number = {10},
pages = {1078--1085},
doi = {10.1111/2041-210X.12260}
}
|
| Nisbet EG, Dlugokencky EJ and Bousquet P (2014), "Methane on the rise - Again", Science., jan, 2014. Vol. 343(6170), pp. 493-495. |
| Abstract: Atmospheric concentrations of the greenhouse gas methane are rising, but the reasons remain incompletely understood. |
BibTeX:
@article{Nisbet2014,
author = {Nisbet, Euan G and Dlugokencky, Edward J and Bousquet, Philippe},
title = {Methane on the rise - Again},
journal = {Science},
year = {2014},
volume = {343},
number = {6170},
pages = {493--495},
url = {http://www.sciencemag.org/cgi/doi/10.1126/science.1247828},
doi = {10.1126/science.1247828}
}
|
| Nordbo A, Kekäläinen P, Siivola E, Mammarella I, Timonen J and Vesala T (2014), "Sorption-caused attenuation and delay of water vapor signals in eddy-covariance sampling tubes and filters", Journal of Atmospheric and Oceanic Technology. Vol. 31(12), pp. 2629-2649. American Meteorological Society. |
| Abstract: Adsorption and desorption (together called sorption) processes in sampling tubes and filters of eddycovariance stations cause attenuation and delay of water vapor signals, leading to an underestimation of water vapor fluxes by tens of percent. The aim of this work was (i) to quantify the effects on sorption in filters and tubes of humidity, flow rate, and dirtiness and (ii) to test a recently introduced sorption model that facilitates correction of fluxes. Laboratory measurements on the transport of water vapor pulses through tubes and filters were carried out, and eddy-covariance field measurements were also used. In the laboratory measurements, the effects of sorption processes were evident, and filters caused a similar attenuation and delay of the signal as tubes. Filters could have a larger impact than a long tube, whereas the flow rate had a much smaller impact on the flux loss than the sorption processes (Reynolds numbers 2120-3360). The sorption model represented well the water vapor pulses in a wide range of conditions. As for the field measurements, the transfer function (TF) derived from the sorption model represented well the observations. Fitting parameters were found to depend strongly on the relative humidity and correlate with the signal delay. Having a more complex shape, TF of the sorption model represented much better the measured TFs than, for example, a Lorentzian or adjusted Gaussian TF, leading on average to a 4% unit difference in the flux corrections. Use of this more complex TF is recommended and its implementation is assisted by the codes provided in appendix B. |
BibTeX:
@article{Nordbo2014,
author = {Nordbo, Annika and Kekäläinen, Pekka and Siivola, Erkki and Mammarella, Ivan and Timonen, Jussi and Vesala, Timo},
title = {Sorption-caused attenuation and delay of water vapor signals in eddy-covariance sampling tubes and filters},
journal = {Journal of Atmospheric and Oceanic Technology},
publisher = {American Meteorological Society},
year = {2014},
volume = {31},
number = {12},
pages = {2629--2649},
doi = {10.1175/JTECH-D-14-00056.1}
}
|
| O'Doherty S, Rigby M, Mühle J, Ivy DJ, Miller BR, Young D, Simmonds PG, Reimann S, Vollmer MK, Krummel PB, Fraser PJ, Steele LP, Dunse B, Salameh PK, Harth CM, Arnold T, Weiss RF, Kim J, Park S, Li S, Lunder C, Hermansen O, Schmidbauer N, Zhou LX, Yao B, Wang RHJ, Manning AJ and Prinn RG (2014), "Global emissions of HFC-143a (CH3CF3) and HFC-32 (CH2F2) from in situ and air archive atmospheric observations", Atmospheric Chemistry and Physics., sep, 2014. Vol. 14(17), pp. 9249-9258. |
| Abstract: High-frequency, in situ observations from the Advanced Global Atmospheric Gases Experiment (AGAGE), for the period 2003 to 2012, combined with archive flask measurements dating back to 1977, have been used to capture the rapid growth of HFC-143a (CH3CF3) and HFC- 32 (CH2F2) mole fractions and emissions into the atmosphere. Here we report the first in situ global measurements of these two gases. HFC-143a and HFC-32 are the third and sixth most abundant hydrofluorocarbons (HFCs) respectively and they currently make an appreciable contribution to the HFCs in terms of atmospheric radiative forcing (1.7±0.04 and 0.7±0.02mWm-2 in 2012 respectively). In 2012 the global average mole fraction of HFC- 143a was 13.4±0.3 ppt (1o) in the lower troposphere and its growth rate was 1.4±0.04 ppt yr-1; HFC-32 had a global mean mole fraction of 6.2±0.2 ppt and a growth rate of 1.1±0.04 ppt yr-1 in 2012. The extensive observations presented in this work have been combined with an atmospheric transport model to simulate global atmospheric abundances and derive global emission estimates. It is estimated that 23±3 Gg yr-1 of HFC-143a and 21±11 Gg yr-1 of HFC- 32 were emitted globally in 2012, and the emission rates are estimated to be increasing by 7±5%yr-1 for HFC-143a and 14±11%yr-1 for HFC-32. |
BibTeX:
@article{ODoherty2014,
author = {O'Doherty, S and Rigby, M and Mühle, J and Ivy, D J and Miller, B R and Young, D and Simmonds, P G and Reimann, S and Vollmer, M K and Krummel, P B and Fraser, P J and Steele, L P and Dunse, B and Salameh, P K and Harth, C M and Arnold, T and Weiss, R F and Kim, J and Park, S and Li, S and Lunder, C and Hermansen, O and Schmidbauer, N and Zhou, L X and Yao, B and Wang, R H J and Manning, A J and Prinn, R G},
title = {Global emissions of HFC-143a (CH3CF3) and HFC-32 (CH2F2) from in situ and air archive atmospheric observations},
journal = {Atmospheric Chemistry and Physics},
year = {2014},
volume = {14},
number = {17},
pages = {9249--9258},
url = {http://www.atmos-chem-phys.net/14/9249/2014/},
doi = {10.5194/acp-14-9249-2014}
}
|
| Olascoaga B, eija Juurola, Pinho P, Lukeš P, liisa Halonen, eero Nikinmaa, Bäck J and Porcar-Castell A (2014), "Seasonal variation in the reflectance of photosynthetically active radiation from epicuticular waxes of Scots pine (Pinus sylvestris) needles" |
| Abstract: 2014: Seasonal variation in the reflectance of photosynthetically active radiation from epicuticular waxes of Scots pine (Pinus sylvestris) needles. Boreal Env. Res. 19 (suppl. B): 132-141. Epicuticular waxes influence leaf reflectance, but the spatiotemporal dynamics in their reflectance properties have not been properly characterized, and its consequences remain unknown. In this study, we analysed the seasonal changes in wax reflectance of Scots pine needles. It tended to decrease with needle age and towards lower positions within the canopy. In addition, we also identified a clear seasonal pattern of variation superimposed on the of above-mentioned wax weathering effect. We conclude that spatiotemporal dynamics in wax optical properties need to be considered in studies that implicitly assume constant light absorption, particularly when different leaf age classes, canopy positions or seasons are compared, and especially in species with substantial amount of waxes. We suggest that the observed dynamics in wax reflectance could represent a new photoprotective mechanism operating at the seasonal scale as they modulate the absorption of the photo-synthetically active radiation (PAR) over time. |
BibTeX:
@techreport{Olascoaga2014,
author = {Olascoaga, Beñat and eija Juurola and Pinho, Paulo and Lukeš, Petr and liisa Halonen and eero Nikinmaa and Bäck, Jaana and Porcar-Castell, Albert},
title = {Seasonal variation in the reflectance of photosynthetically active radiation from epicuticular waxes of Scots pine (Pinus sylvestris) needles},
year = {2014}
}
|
| Öquist MG, Bishop K, Grelle A, Klemedtsson L, Köhler SJ, Laudon H, Lindroth A, Ottosson Löfvenius M, Wallin MB and Nilsson MB (2014), "The Full Annual Carbon Balance of Boreal Forests Is Highly Sensitive to Precipitation", Environmental Science and Technology Letters., jul, 2014. Vol. 1(7), pp. 315-319. |
| Abstract: The boreal forest carbon balance is predicted to be particularly sensitive to climate change. Carbon balance estimates of these biomes stem mainly from eddy-covariance measurements of net ecosystem exchange (NEE). However, a full net ecosystem carbon balance (NECB) must include the lateral carbon export (LCE) through discharge. We show that annual LCE at a boreal forest site ranged from 4 to 28%, averaging 11% (standard deviation of 8%), of annual NEE over 13 years. Annual LCE and NEE are strongly anticorrelated; years with weak NEE coincide with high LCE. The decreased NEE in response to increased precipitation is caused by a reduction in the amount of incoming radiation caused by clouds. If our finding is also valid for other sites, it implies that increased precipitation at high latitudes may shift forest NECB in large areas of the boreal biome. Our results call for future analysis of this dual effect of precipitation on NEE and LCE. |
BibTeX:
@article{Oquist2014,
author = {Öquist, M G and Bishop, K and Grelle, A and Klemedtsson, L and Köhler, S J and Laudon, H and Lindroth, A and Ottosson Löfvenius, M and Wallin, M B and Nilsson, M B},
title = {The Full Annual Carbon Balance of Boreal Forests Is Highly Sensitive to Precipitation},
journal = {Environmental Science and Technology Letters},
year = {2014},
volume = {1},
number = {7},
pages = {315--319},
url = {http://pubs.acs.org/doi/10.1021/ez500169j},
doi = {10.1021/ez500169j}
}
|
| O'Shea SJ, Allen G, Fleming ZL, Bauguitte SJB, Percival CJ, Gallagher MW, Lee J, Helfter C and Nemitz E (2014), "Area fluxes of carbon dioxide, methane, and carbon monoxide derived from airborne measurements around Greater London: A case study during summer 2012", Journal of Geophysical Research., apr, 2014. Vol. 119(8), pp. 4940-4952. |
| Abstract: Airborne measurements of thermodynamic properties and carbon dioxide (CO2), methane (CH4), and carbon monoxide (CO) mole fractions were recorded on board the FAAMBAe-146 UK research aircraft and used to characterize the inflow and outflow from Greater London on 30 July 2012. All three trace gases were observed to be significantly enhanced downwind of Greater London with spatially resolved plumes of comparable extent and position. A mass budget calculation using a box model approach (and uncertainty propagation) was used to determine net regional fluxes of 21 ± 3 µmol CO2 m-2 s-1, 0.13±0.02µmol CH4 m-2 s-1, and 0.12 ± 0.02 µmol CO m-2 s-1 for Greater London. These fluxes are comparable with simultaneous surface observations and previous studies in urban environments. A comparison was made with the 2010 UK National Atmospheric Emissions Inventory (NAEI), and fluxes from this study are found to be factors 2.3 for CO2 and 2.2 for CO larger than those estimated by the spatially disaggregated NAEI (2011) for Greater London. Fluxes of CH4 were found to be a factor 3.4 larger than the UK NAEI (2009). The efficacy of this mass balance approach, in general, is also discussed in terms of key assumptions and uncertainties, and we offer advice for future studies on how uncertainties could be reduced. |
BibTeX:
@article{OShea2014,
author = {O'Shea, Sebastian J and Allen, Grant and Fleming, Zoë L and Bauguitte, Stephane J B and Percival, Carl J and Gallagher, Martin W and Lee, James and Helfter, Carole and Nemitz, Eiko},
title = {Area fluxes of carbon dioxide, methane, and carbon monoxide derived from airborne measurements around Greater London: A case study during summer 2012},
journal = {Journal of Geophysical Research},
year = {2014},
volume = {119},
number = {8},
pages = {4940--4952},
url = {http://doi.wiley.com/10.1002/2013JD021269},
doi = {10.1002/2013JD021269}
}
|
| Ostler A, Sussmann R, Rettinger M, Deutscher NM, Dohe S, Hase F, Jones N and Palm M (2014), "Multistation intercomparison of column-averaged methane from NDACC and TCCON: Impact of dynamical variability", Atmospheric Measurement Techniques., dec, 2014. Vol. 7(12), pp. 4081-4101. |
| Abstract: Dry-air column-averaged mole fractions of methane (XCH4) retrieved from ground-based solar Fourier transform infrared (FTIR) measurements provide valuable information for satellite validation, evaluation of chemical-transport models, and source-sink-inversions. In this context, Sussmann et al. (2013) have shown that midinfrared (MIR) soundings from the Network for the Detection of Atmospheric Composition Change (NDACC) can be combined with near-infrared (NIR) soundings from the Total Carbon Column Observing Network (TCCON) without the need to apply an overall intercalibration factor. However, in spite of efforts to reduce a priori impact, some residual seasonal biases were identified, and the reasons behind remained unclear. In extension to this previous work, which was based on multiannual quasi-coincident MIR and NIR measurements from the stations Garmisch (47.48° N, 11.06° E, 743 m a.s.l.) and Wollongong (34.41° S, 150.88° E, 30 m a.s.l.), we now investigate upgraded retrievals with longer temporal coverage and include three additional stations (Ny-Ålesund, 78.92° N, 11.93° E, 20 m a.s.l.; Karlsruhe, 49.08° N, 8.43° E, 110 m a.s.l.; Izanã, 28.31° N, 16.45° W, 2.370 m a.s.l.). Our intercomparison results (except for Ny-Ålesund) confirm that there is no overall bias between MIR and NIR XCH4 retrievals, and all MIR and NIR time series reveal a quasi-periodic seasonal bias for all stations, except for Izanã. brbr We find that dynamical variability causes MIR-NIR differences of up to ∼ 30 ppb (parts per billion) for Ny-Ålesund, ∼ 20 ppb for Wollongong, ∼ 18 ppb for Garmisch, and ∼ 12 ppb for Karlsruhe. The mechanisms behind this variability are elaborated via two case studies, one dealing with stratospheric subsidence induced by the polar vortex at Ny-Ålesund and the other with a deep stratospheric intrusion event at Garmisch. Smoothing effects caused by the dynamical variability during these events are different for MIR and NIR retrievals depending on the altitude of the perturbation area. MIR retrievals appear to be more realistic in the case of stratospheric subsidence, while NIR retrievals are more accurate in the case of stratosphere-troposphere exchange (STE) in the upper troposphere/lower stratosphere (UTLS) region. About 35% of the FTIR measurement days at Garmisch are impacted by STE, and about 23% of the measurement days at Ny-Ålesund are influenced by polar vortex subsidence. The exclusion of data affected by these dynamical situations resulted in improved agreement of MIR and NIR seasonal cycles for Ny-Ålesund and Garmisch. We found that dynamical variability is a key factor in constraining the accuracy of MIR and NIR seasonal cycles. To mitigate this impact it is necessary to use more realistic a priori profiles that take these dynamical events into account (e.g., via improved models), and/or to improve the FTIR retrievals to achieve a more uniform sensitivity at all altitudes (possibly including profile retrievals for the TCCON data). |
BibTeX:
@article{Ostler2014,
author = {Ostler, A and Sussmann, R and Rettinger, M and Deutscher, N M and Dohe, S and Hase, F and Jones, N and Palm, M},
title = {Multistation intercomparison of column-averaged methane from NDACC and TCCON: Impact of dynamical variability},
journal = {Atmospheric Measurement Techniques},
year = {2014},
volume = {7},
number = {12},
pages = {4081--4101},
url = {http://www.atmos-meas-tech.net/7/4081/2014/},
doi = {10.5194/amt-7-4081-2014}
}
|
| Otto J, Berveiller D, Bréon FM, Delpierre N, Geppert G, Granier A, Jans W, Knohl A, Kuusk A, Longdoz B, Moors E, Mund M, Pinty B, Schelhaas MJ and Luyssaert S (2014), "Forest summer albedo is sensitive to species and thinning: How should we account for this in Earth system models?", Biogeosciences., apr, 2014. Vol. 11(8), pp. 2411-2427. |
| Abstract: Although forest management is one of the instruments proposed to mitigate climate change, the relationship between forest management and canopy albedo has been ignored so far by climate models. Here we develop an approach that could be implemented in Earth system models. A stand-level forest gap model is combined with a canopy radiation transfer model and satellite-derived model parameters to quantify the effects of forest thinning on summertime canopy albedo. This approach reveals which parameter has the largest affect on summer canopy albedo: we examined the effects of three forest species (pine, beech, oak) and four thinning strategies with a constant forest floor albedo (light to intense thinning regimes) and five different solar zenith angles at five different sites (40° N 9° E-60° N 9° E). During stand establishment, summertime canopy albedo is driven by tree species. In the later stages of stand development, the effect of tree species on summertime canopy albedo decreases in favour of an increasing influence of forest thinning. These trends continue until the end of the rotation, where thinning explains up to 50% of the variance in near-infrared albedo and up to 70% of the variance in visible canopy albedo. brbr The absolute summertime canopy albedo of all species ranges from 0.03 to 0.06 (visible) and 0.20 to 0.28 (near-infrared); thus the albedo needs to be parameterised at species level. In addition, Earth system models need to account for forest management in such a way that structural changes in the canopy are described by changes in leaf area index and crown volume (maximum change of 0.02 visible and 0.05 near-infrared albedo) and that the expression of albedo depends on the solar zenith angle (maximum change of 0.02 visible and 0.05 near-infrared albedo). Earth system models taking into account these parameters would not only be able to examine the spatial effects of forest management but also the total effects of forest management on climate. textcopyright 2014 Author(s). |
BibTeX:
@article{Otto2014,
author = {Otto, J and Berveiller, D and Bréon, F M and Delpierre, N and Geppert, G and Granier, A and Jans, W and Knohl, A and Kuusk, A and Longdoz, B and Moors, E and Mund, M and Pinty, B and Schelhaas, M J and Luyssaert, S},
title = {Forest summer albedo is sensitive to species and thinning: How should we account for this in Earth system models?},
journal = {Biogeosciences},
year = {2014},
volume = {11},
number = {8},
pages = {2411--2427},
url = {http://www.biogeosciences.net/11/2411/2014/},
doi = {10.5194/bg-11-2411-2014}
}
|
| Palatella L, Rana G and Vitale D (2014), "Towards a Flux-Partitioning Procedure Based on the Direct Use of High-Frequency Eddy-Covariance Data", Boundary-Layer Meteorology., oct, 2014. Vol. 153(2), pp. 327-337. Kluwer Academic Publishers. |
| Abstract: Scanlon and Sahu (Water Resour Res 44(10):W10418, 2008) proposed an interesting method to estimate assimilation, respiration, evaporation and transpiration directly using high-frequency eddy-covariance measurements. In this note we critically revise this method and, in particular, using the Descartes' rule of sign, we show that one branch of solutions can be directly neglected reducing the analytical complexity of the procedure. We also discuss the stability of the results of the method with respect to the input parameters, especially to the water-use efficiency. |
BibTeX:
@article{Palatella2014,
author = {Palatella, Luigi and Rana, Gianfranco and Vitale, Domenico},
title = {Towards a Flux-Partitioning Procedure Based on the Direct Use of High-Frequency Eddy-Covariance Data},
journal = {Boundary-Layer Meteorology},
publisher = {Kluwer Academic Publishers},
year = {2014},
volume = {153},
number = {2},
pages = {327--337},
doi = {10.1007/s10546-014-9947-x}
}
|
| Pastorello G, Agarwal D, Papale D, Samak T, Trotta C, Ribeca A, Poindexter C, Faybishenko B, Gunter D, Hollowgrass R and Canfora E (2014), "Observational data patterns for time series data quality assessment", In Proceedings - 2014 IEEE 10th International Conference on eScience, eScience 2014., oct, 2014. Vol. 1, pp. 271-278. IEEE. |
| Abstract: Observational data are fundamental for scientific research in almost any domain. Recent advances in sensor and data management technologies are enabling unprecedented amounts of observational data to be collected and analyzed. However, an essential part of using observational data is not currently as scalable as data collection and analysis methods: data quality assurance and control. While specialized tools for very narrow domains do exist, general methods are harder to create. This paper explores the identification of data issues that lead to the creation of data tests and tools to perform data quality control activities. Developing this identification step in a systematic manner allows for better and more general quality control tools. As our case study, we use carbon, water, and energy fluxes as well as micro-meteorological data collected at field sites that are part of FLUXNET, a network of over 400 ecosystem-level monitoring stations. In an effort toward the release of a new global data set of fluxes, we are doing data quality control for these data. The experience from this work led to the creation of a catalog of issues identified in the data. This paper presents this catalog and its generalization into a set of patterns of data quality issues that can be detected in observational data. |
BibTeX:
@inproceedings{Pastorello2014,
author = {Pastorello, Gilberto and Agarwal, Deb and Papale, Dario and Samak, Taghrid and Trotta, Carlo and Ribeca, Alessio and Poindexter, Cristina and Faybishenko, Boris and Gunter, Dan and Hollowgrass, Rachel and Canfora, Eleonora},
title = {Observational data patterns for time series data quality assessment},
booktitle = {Proceedings - 2014 IEEE 10th International Conference on eScience, eScience 2014},
publisher = {IEEE},
year = {2014},
volume = {1},
pages = {271--278},
url = {http://ieeexplore.ieee.org/document/6972274/},
doi = {10.1109/eScience.2014.45}
}
|
| Peichl M, Sonnentag O and Nilsson MB (2014), "Bringing Color into the Picture: Using Digital Repeat Photography to Investigate Phenology Controls of the Carbon Dioxide Exchange in a Boreal Mire", Ecosystems. Vol. 18(1), pp. 115-131. Springer New York LLC. |
| Abstract: Mire vegetation phenology is closely linked to the ecosystem carbon cycle but rarely monitored and quantified with high temporal resolution. In this study, we use digital repeat photography to explore phenology as a control of the carbon dioxide (CO2) exchange measured by eddy covariance (EC) in a minerogenic boreal mire in northern Sweden over 2 years (2011–2012). Strong correlations and seasonal hysteresis effects were observed between the green chromatic coordinate (gcc) derived from the digital image archive and leaf area index, day length, and growing degree-day sum (GDDS). Differences in GDDS between the 2 years were the main control on the between-year variations in the spring patterns of gcc. Periods with lower water table level coincided with an increase of the red chromatic coordinate. The onset and magnitudes of EC-derived photosynthetic CO2 uptake (that is, gross ecosystem production, GEP) and net ecosystem CO2 exchange (NEE) during the spring green-up of vascular plants were more closely related to those of gcc than to those of air temperature and photosynthetically active radiation. In contrast, abiotic variables controlled GEP during the summer period when vascular plant canopy cover was fully developed. Stepwise regression analysis suggested that gcc contributed substantially in explaining variations in GEP during spring and autumn. Over both growing seasons, gcc was well correlated with GEP (r2 = 0.68), NEE (r2 = 0.58), and ecosystem respiration (r2 = 0.50). Overall, we show that digital repeat photography provides an inexpensive and effective method for the continuous quantification of the phenological patterns of the vascular plant community in mire ecosystems. Our results suggest that vegetation phenology is an important control of the mire CO2 exchange and should be considered in both experimental and modeling studies to better account for the separate effects of phenology and abiotic drivers on mire carbon dynamics. |
BibTeX:
@article{Peichl2014,
author = {Peichl, Matthias and Sonnentag, Oliver and Nilsson, Mats B.},
title = {Bringing Color into the Picture: Using Digital Repeat Photography to Investigate Phenology Controls of the Carbon Dioxide Exchange in a Boreal Mire},
journal = {Ecosystems},
publisher = {Springer New York LLC},
year = {2014},
volume = {18},
number = {1},
pages = {115--131},
doi = {10.1007/s10021-014-9815-z}
}
|
| Peltola O, Hensen A, Helfter C, Belelli Marchesini L, Bosveld FC, Van Den Bulk WCM, Elbers JA, Haapanala S, Holst J, Laurila T, Lindroth A, Nemitz E, Röckmann T, Vermeulen AT and Mammarella I (2014), "Evaluating the performance of commonly used gas analysers for methane eddy covariance flux measurements: the InGOS inter-comparison field experiment", Biogeosciences., jun, 2014. Vol. 11(12), pp. 3163-3186. |
| Abstract: The performance of eight fast-response methane (CH4) gas analysers suitable for eddy covariance flux measurements were tested at a grassland site near the Cabauw tall tower (Netherlands) during June 2012. The instruments were positioned close to each other in order to minimise the effect of varying turbulent conditions. The moderate CH4 fluxes observed at the location, of the order of 25 nmol mg-2 sg-1, provided a suitable signal for testing the instruments' performance. Generally, all analysers tested were able to quantify the concentration fluctuations at the frequency range relevant for turbulent exchange and were able to deliver high-quality data. The tested cavity ringdown spectrometer (CRDS) instruments from Picarro, models G2311-f and G1301-f, were superior to other CH4 analysers with respect to instrumental noise. As an open-path instrument susceptible to the effects of rain, the LI-COR LI-7700 achieved lower data coverage and also required larger density corrections; however, the system is especially useful for remote sites that are restricted in power availability. In this study the open-path LI-7700 results were compromised due to a data acquisition problem in our data-logging setup. Some of the older closed-path analysers tested do not measure H2O concentrations alongside CH4 (i.e. FMA1 and DLT-100 by Los Gatos Research) and this complicates data processing since the required corrections for dilution and spectroscopic interactions have to be based on external information. To overcome this issue, we used H2O mole fractions measured by other gas analysers, adjusted them with different methods and then applied them to correct the CH4 fluxes. Following this procedure we estimated a bias of the order of 0.1 g (CH4) mg-2 (8% of the measured mean flux) in the processed and corrected CH4 fluxes on a monthly scale due to missing H2O concentration measurements. Finally, cumulative CH4 fluxes over 14 days from three closed-path gas analysers, G2311-f (Picarro Inc.), FGGA (Los Gatos Research) and FMA2 (Los Gatos Research), which were measuring H2O concentrations in addition to CH4, agreed within 3% (355-367 mg (CH4) mg-2) and were not clearly different from each other, whereas the other instruments derived total fluxes which showed small but distinct differences (±10%, 330-399 mg (CH4) mg-2). textcopyright Author(s) 2014. |
BibTeX:
@article{Peltola2014,
author = {Peltola, O and Hensen, A and Helfter, C and Belelli Marchesini, L and Bosveld, F C and Van Den Bulk, W C M and Elbers, J A and Haapanala, S and Holst, J and Laurila, T and Lindroth, A and Nemitz, E and Röckmann, T and Vermeulen, A T and Mammarella, I},
title = {Evaluating the performance of commonly used gas analysers for methane eddy covariance flux measurements: the InGOS inter-comparison field experiment},
journal = {Biogeosciences},
year = {2014},
volume = {11},
number = {12},
pages = {3163--3186},
url = {http://www.biogeosciences.net/11/3163/2014/},
doi = {10.5194/bg-11-3163-2014}
}
|
| Pumpanen J, Lindén A, Miettinen H, Kolari P, Ilvesniemi H, Mammarella I, Hari P, Nikinmaa E, Heinonsalo J, Bäck J, Ojala A, Berninger F and Vesala T (2014), "Precipitation and net ecosystem exchange are the most important drivers of DOC flux in upland boreal catchments", Journal of Geophysical Research: Biogeosciences., sep, 2014. Vol. 119(9), pp. 1861-1878. |
| Abstract: According to recent studies, dissolved organic carbon (DOC) concentrations in rivers throughout the boreal zone are increasing. However, the mechanistic explanation of this phenomenon is not yet well known. We studied how the short and long-term changes in precipitation, soil temperature, soil water content, and net ecosystem exchange (NEE) are reflected to DOC concentrations and runoff DOC fluxes in two small forested upland catchments in Southern Finland. We used continuous eddy covariance measurements above the forest and runoff flow measurements from the catchment areas conducted over a 15 year long time period to study the correlation between NEE, gross photosynthetic production, total ecosystem respiration, litter production, and runoff DOC. In addition, we looked for the most important environmental variables in explaining the interannual changes in runoff DOC by using multiple linear regression. Finally, we studied the temporal connection between runoff DOC concentrations, precipitation, soil water content, and NEE by using wavelet coherence analysis technique. Our results indicate that the DOC concentrations have increased over the last 15 years. The DOC flux was to a large extent determined by the amount of precipitation, but the previous year's NEE and litter production had also a small but significant effect on runoff DOC fluxes. |
BibTeX:
@article{Pumpanen2014,
author = {Pumpanen, Jukka and Lindén, Aki and Miettinen, Heli and Kolari, Pasi and Ilvesniemi, Hannu and Mammarella, Ivan and Hari, Pertti and Nikinmaa, Eero and Heinonsalo, Jussi and Bäck, Jaana and Ojala, Anne and Berninger, Frank and Vesala, Timo},
title = {Precipitation and net ecosystem exchange are the most important drivers of DOC flux in upland boreal catchments},
journal = {Journal of Geophysical Research: Biogeosciences},
year = {2014},
volume = {119},
number = {9},
pages = {1861--1878},
url = {http://doi.wiley.com/10.1002/2014JG002705},
doi = {10.1002/2014JG002705}
}
|
| Rannik Ü, Haapanala S, Shurpali NJ, Mammarella I, Lind S, Hyvönen N, Peltola O, Zahniser M, Martikainen PJ and Vesala T (2014), "Intercomparison of fast response commercial gas analysers for nitrous oxide flux measurements under field conditions", Biogeosciences Discussions., aug, 2014. Vol. 11(8), pp. 11747-11783. |
| Abstract: Abstract. Four gas analysers capable of measuring nitrous oxide (N2O) concentration at a response time necessary for eddy covariance flux measurements were operated from spring till winter 2011 over a field cultivated with reed canary grass (RCG, Phalaris arundinaceae, L.), a perennial bioenergy crop in Eastern Finland. The instruments were TGA100A (Campbell Scientific Inc.), CW-TILDAS-CS (Aerodyne Research Inc.), N2O/CO-23d (Los Gatos Research Inc.) and QC-TILDAS-76-CS (Aerodyne Research Inc.). The period with high emission, lasting for about two weeks after fertilization in late May, was characterised by an up to two orders of magnitude higher emission, whereas during the rest of the campaign the N2O fluxes were small, from 0.1 to 1 nmol mâˆ'2 sâˆ'1. Two instruments, CW-TILDAS-CS and N2O/CO-23d, determined the N2O exchange with minor systematic difference throughout the campaign, when operated simultaneously. TGA100A produced cumulatively highest N2O estimates (with 29% higher value during the period when all instruments were operational). QC-TILDAS-76-CS obtained 36% lower fluxes than CW-TILDAS-CS during the first period, including the emission episode, whereas the correspondence with other instruments during the rest of the campaign was good. The reason for these episodic higher and lower estimates by the two instruments is not currently known, suggesting further need for detailed evaluation of instrument performance under field conditions with emphasis on stability, calibration and, in particular, simultaneous accurate determination of water vapour concentration due to its large impact on small N2O fluxes through spectroscopic and dilution corrections. The instrument CW-TILDAS-CS was characterised by the lowest noise level (std around 0.12 ppb at 10 Hz sampling rate), as compared to N2O/CO-23d and QC-TILDAS-76-CS (around 0.50 ppb) and TGA100A (around 2 ppb). Both instruments based on Continuous-Wave Quantum Cascade Lasers, CW-TILDAS-CS and N2O/CO-23d, were able to determine the same sample of low N2O fluxes with high mutual coefficient of determination at 30 min averaging level and with minor systematic difference over the observation period of several months. |
BibTeX:
@article{Rannik2014,
author = {Rannik, Ü and Haapanala, S and Shurpali, N J and Mammarella, I and Lind, S and Hyvönen, N and Peltola, O and Zahniser, M and Martikainen, P J and Vesala, T},
title = {Intercomparison of fast response commercial gas analysers for nitrous oxide flux measurements under field conditions},
journal = {Biogeosciences Discussions},
year = {2014},
volume = {11},
number = {8},
pages = {11747--11783},
url = {http://www.biogeosciences-discuss.net/11/11747/2014/},
doi = {10.5194/bgd-11-11747-2014}
}
|
| Reuter M, Buchwitz M, Hilker M, Heymann J, Schneising O, Pillai D, Bovensmann H, Burrows JP, Bösch H, Parker R, Butz A, Hasekamp O, O'Dell CW, Yoshida Y, Gerbig C, Nehrkorn T, Deutscher NM, Warneke T, Notholt J, Hase F, Kivi R, Sussmann R, Machida T, Matsueda H and Sawa Y (2014), "Satellite-inferred European carbon sink larger than expected", Atmospheric Chemistry and Physics., dec, 2014. Vol. 14(24), pp. 13739-13753. |
| Abstract: Current knowledge about the European terrestrial biospheric carbon sink, from the Atlantic to the Urals, relies upon bottom-up inventory and surface flux inverse model estimates (e.g. 0.27±0.16 GtC a&minus;1 for 2000-2005 (Schulze et al., 2009), 0.17±0.44 GtC a&minus;1 for 2001-2007 (Peters et al., 2010), 0.45±0.40 GtC a&minus;1 for 2010 (Chevallier et al., 2014), 0.40±0.42 GtC a&minus;1 for 2001-2004 (Peylin et al., 2013)). Inverse models assimilate in situ CO2 atmospheric concentrations measured by surface-based air sampling networks. The intrinsic sparseness of these networks is one reason for the relatively large flux uncertainties (Peters et al., 2010; Bruhwiler et al., 2011). Satellite-based CO2 measurements have the potential to reduce these uncertainties (Miller et al., 2007; Chevallier et al., 2007). Global inversion experiments using independent models and independent GOSAT satellite data products consistently derived a considerably larger European sink (1.0-1.3 GtC a&minus;1 for 09/2009-08/2010 (Basu et al., 2013), 1.2-1.8 GtC a&minus;1 in 2010 (Chevallier et al., 2014)). However, these results have been considered unrealistic due to potential retrieval biases and/or transport errors (Chevallier et al., 2014) or have not been discussed at all (Basu et al., 2013; Takagi et al., 2014). Our analysis comprises a regional inversion approach using STILT (Gerbig et al., 2003; Lin et al., 2003) short-range (days) particle dispersion modelling, rendering it insensitive to large-scale retrieval biases and less sensitive to long-range transport errors. We show that the satellite-derived European terrestrial carbon sink is indeed much larger (1.02±0.30 GtC a&minus;1 in 2010) than previously expected. This is qualitatively consistent among an ensemble of five different inversion set-ups and five independent satellite retrievals (BESD (Reuter et al., 2011) 2003-2010, ACOS (Og€™Dell et al., 2012) 2010, UoL-FP (Cogan et al., 2012) 2010, RemoTeC (Butz et al., 2011) 2010, and NIES (Yoshida et al., 2013) 2010) using data from two different instruments (SCIAMACHY (Bovensmann et al., 1999) and GOSAT (Kuze et al., 2009)). The difference to in situ based inversions (Peylin et al., 2013), whilst large with respect to the mean reported European carbon sink (0.4 GtC a&minus;1 for 2001-2004), is similar in magnitude to the reported uncertainty (0.42 GtC a&minus;1). The highest gain in information is obtained during the growing season when satellite observation conditions are advantageous, a priori uncertainties are largest, and the surface sink maximises; during the dormant season, the results are dominated by the a priori. Our results provide evidence that the current understanding of the European carbon sink has to be revisited. |
BibTeX:
@article{Reuter2014,
author = {Reuter, M and Buchwitz, M and Hilker, M and Heymann, J and Schneising, O and Pillai, D and Bovensmann, H and Burrows, J P and Bösch, H and Parker, R and Butz, A and Hasekamp, O and O'Dell, C W and Yoshida, Y and Gerbig, C and Nehrkorn, T and Deutscher, N M and Warneke, T and Notholt, J and Hase, F and Kivi, R and Sussmann, R and Machida, T and Matsueda, H and Sawa, Y},
title = {Satellite-inferred European carbon sink larger than expected},
journal = {Atmospheric Chemistry and Physics},
year = {2014},
volume = {14},
number = {24},
pages = {13739--13753},
url = {http://www.atmos-chem-phys.net/14/13739/2014/},
doi = {10.5194/acp-14-13739-2014}
}
|
| Rey A, Belelli-Marchesini L, Etiope G, Papale D, Canfora E, Valentini R and Pegoraro E (2014), "Partitioning the net ecosystem carbon balance of a semiarid steppe into biological and geological components", Biogeochemistry., apr, 2014. Vol. 118(1-3), pp. 83-101. |
| Abstract: Recent studies have highlighted the need to consider geological carbon sources when estimating the net ecosystem carbon balance (NECB) of terrestrial ecosystems located in areas potentially affected by geofluid circulation. We propose a new methodology using physical parameters of the atmospheric boundary layer to quantify the CO2 coming from deep ground origin in a steppe ecosystem located in the SE of Spain. Then, we compared published NECB estimates at the site with seasonal patterns of soil CO2 efflux and biological activity measured by satellite images over a 2-year period (2007/2008). The alpha grass ecosystem was a net carbon source (93.8 and 145.1 g C m-2 year-1, in 2007 and 2008, respectively), particularly as a result of large amounts of carbon released over the dry period that were not related to biological activity. While the highest ecosystem CO2 emission rates were measured over the dry period (reaching up to 15 μmol m-2 s-1), soil CO2 efflux rates (ca. 0.5 μmol m-2 s-1) and plant productivity were minimal during this period. After using a linear relationship between NECB and wind speed for different stability conditions and wind sectors, we estimated the geological flux F GEO (217.9 and 244.0 g C m-2 in 2007 and 2008, respectively) and subtracted it from the NECB to obtain the biological flux F BIO (-124.0 and -98.9 g C m-2 in 2007 and 2008, respectively). We then partitioned F BIO into gross primary productivity and ecosystem respiration and proved that, after removing F GEO, ecosystem respiration and soil CO2 efflux followed similar seasonal patterns. The annual contribution of the geological component to NECB was 49.6 and 46.7 % for the year 2007 and 2008, respectively. Therefore, it is clear that geological carbon sources should be quantified in those ecosystems located in areas with potential natural emission of geological gases to the surface. textcopyright 2013 Springer Science+Business Media Dordrecht. |
BibTeX:
@article{Rey2014,
author = {Rey, A and Belelli-Marchesini, L and Etiope, G and Papale, D and Canfora, E and Valentini, R and Pegoraro, E},
title = {Partitioning the net ecosystem carbon balance of a semiarid steppe into biological and geological components},
journal = {Biogeochemistry},
year = {2014},
volume = {118},
number = {1-3},
pages = {83--101},
url = {http://link.springer.com/10.1007/s10533-013-9907-4},
doi = {10.1007/s10533-013-9907-4}
}
|
| Rödenbeck C, Bakker DC, Metzl N, Olsen A, Sabine C, Cassar N, Reum F, Keeling RF and Heimann M (2014), "Interannual sea-air CO2 flux variability from an observation-driven ocean mixed-layer scheme", Biogeosciences., sep, 2014. Vol. 11(17), pp. 4599-4613. Copernicus GmbH. |
| Abstract: Interannual anomalies in the sea-air carbon dioxide (CO2) exchange have been estimated from surface-ocean CO2 partial pressure measurements. Available data are sufficient to constrain these anomalies in large parts of the tropical and North Pacific and in the North Atlantic, in some areas covering the period from the mid 1980s to 2011. Global interannual variability is estimated as about 0.31 Pg C yr-1 (temporal standard deviation 1993-2008). The tropical Pacific accounts for a large fraction of this global variability, closely tied to El Niño-Southern Oscillation (ENSO). Anomalies occur more than 6 months later in the east than in the west. The estimated amplitude and ENSO response are roughly consistent with independent information from atmospheric oxygen data. This both supports the variability estimated from surface-ocean carbon data and demonstrates the potential of the atmospheric oxygen signal to constrain ocean biogeochemical processes. The ocean variability estimated from surface-ocean carbon data can be used to improve land CO2 flux estimates from atmospheric inversions. textcopyright Author(s) 2014. |
BibTeX:
@article{Rodenbeck2014,
author = {Rödenbeck, C. and Bakker, D. C.E. and Metzl, N. and Olsen, A. and Sabine, C. and Cassar, N. and Reum, F. and Keeling, R. F. and Heimann, M.},
title = {Interannual sea-air CO2 flux variability from an observation-driven ocean mixed-layer scheme},
journal = {Biogeosciences},
publisher = {Copernicus GmbH},
year = {2014},
volume = {11},
number = {17},
pages = {4599--4613},
url = {www.biogeosciences-discuss.net/11/3167/2014/},
doi = {10.5194/bg-11-4599-2014}
}
|
| RÓŻAŃSKI K, NECKI J, CHMURA Ł, ŚLIWKA I, ZIMNOCH M, BIELEWSKI J, GAŁKOWSKI M, BARTYZEL J and ROSIEK J (2014), "Anthropogenic changes of CO2, CH4, N2O, CFCl3, CF2Cl2, CCl2FCClF2, CHCl3, CH3CCl3, CCl4, SF6 and SF5CF3 mixing ratios in the atmosphere over southern Poland", Geological Quarterly., apr, 2014. |
BibTeX:
@article{ROZANSKI2014,
author = {RÓŻAŃSKI, Kazimierz and NECKI, Jarosław and CHMURA, Łukasz and ŚLIWKA, Ireneusz and ZIMNOCH, Mirosław and BIELEWSKI, Jarosław and GAŁKOWSKI, Michał and BARTYZEL, Jakub and ROSIEK, Janusz},
title = {Anthropogenic changes of CO2, CH4, N2O, CFCl3, CF2Cl2, CCl2FCClF2, CHCl3, CH3CCl3, CCl4, SF6 and SF5CF3 mixing ratios in the atmosphere over southern Poland},
journal = {Geological Quarterly},
year = {2014},
url = {https://gq.pgi.gov.pl/article/view/10077/pdf_1153},
doi = {10.7306/gq.1163}
}
|
| Saad KM, Wunch D, Toon GC, Bernath P, Boone C, Connor B, Deutscher NM, Griffith DWT, Kivi R, Notholt J, Roehl C, Schneider M, Sherlock V and Wennberg PO (2014), "Derivation of tropospheric methane from TCCON CH4and HF total column observations", Atmospheric Measurement Techniques., sep, 2014. Vol. 7(9), pp. 2907-2918. |
| Abstract: The Total Carbon Column Observing Network (TCCON) is a global ground-based network of Fourier transform spectrometers that produce precise measurements of column-averaged dry-air mole fractions of atmospheric methane (CH4). Temporal variability in the total column of CH4due to stratospheric dynamics obscures fluctuations and trends driven by tropospheric transport and local surface fluxes that are critical for understanding CH4sources and sinks. We reduce the contribution of stratospheric variability from the total column average by subtracting an estimate of the stratospheric CH4derived from simultaneous measurements of hydrogen fluoride (HF). HF provides a proxy for stratospheric CH4because it is strongly correlated to CH4in the stratosphere, has an accurately known tropospheric abundance (of zero), and is measured at most TCCON stations. The stratospheric partial column of CH4is calculated as a function of the zonal and annual trends in the relationship between CH4and HF in the stratosphere, which we determine from ACE-FTS satellite data. We also explicitly take into account the CH4column averaging kernel to estimate the contribution of stratospheric CH4to the total column. The resulting tropospheric CH4columns are consistent with in situ aircraft measurements and augment existing observations in the troposphere. |
BibTeX:
@article{Saad2014,
author = {Saad, K M and Wunch, D and Toon, G C and Bernath, P and Boone, C and Connor, B and Deutscher, N M and Griffith, D W T and Kivi, R and Notholt, J and Roehl, C and Schneider, M and Sherlock, V and Wennberg, P O},
title = {Derivation of tropospheric methane from TCCON CH4and HF total column observations},
journal = {Atmospheric Measurement Techniques},
year = {2014},
volume = {7},
number = {9},
pages = {2907--2918},
url = {http://www.atmos-meas-tech.net/7/2907/2014/},
doi = {10.5194/amt-7-2907-2014}
}
|
| Saikawa E, Prinn RG, Dlugokencky E, Ishijima K, Dutton GS, Hall BD, Langenfelds R, Tohjima Y, Machida T, Manizza M, Rigby M, O'Doherty S, Patra PK, Harth CM, Weiss RF, Krummel PB, Van Der Schoot M, Fraser PJ, Steele LP, Aoki S, Nakazawa T and Elkins JW (2014), "Global and regional emissions estimates for N2O", Atmospheric Chemistry and Physics., may, 2014. Vol. 14(9), pp. 4617-4641. |
| Abstract: We present a comprehensive estimate of nitrous oxide (N2O) emissions using observations and models from 1995 to 2008. High-frequency records of tropospheric N2O are available from measurements at Cape Grim, Tasmania; Cape Matatula, American Samoa; Ragged Point, Barbados; Mace Head, Ireland; and at Trinidad Head, California using the Advanced Global Atmospheric Gases Experiment (AGAGE) instrumentation and calibrations. The Global Monitoring Division of the National Oceanic and Atmospheric Administration/Earth System Research Laboratory (NOAA/ESRL) has also collected discrete air samples in flasks and in situ measurements from remote sites across the globe and analyzed them for a suite of species including N2O. In addition to these major networks, we include in situ and aircraft measurements from the National Institute of Environmental Studies (NIES) and flask measurements from the Tohoku University and Commonwealth Scientific and Industrial Research Organization (CSIRO) networks. All measurements show increasing atmospheric mole fractions of N2O, with a varying growth rate of 0.1-0.7% per year, resulting in a 7.4% increase in the background atmospheric mole fraction between 1979 and 2011. Using existing emission inventories as well as bottom-up process modeling results, we first create globally gridded a priori N2O emissions over the 37 years since 1975. We then use the three-dimensional chemical transport model, Model for Ozone and Related Chemical Tracers version 4 (MOZART v4), and a Bayesian inverse method to estimate global as well as regional annual emissions for five source sectors from 13 regions in the world. This is the first time that all of these measurements from multiple networks have been combined to determine emissions. Our inversion indicates that global and regional N2O emissions have an increasing trend between 1995 and 2008. Despite large uncertainties, a significant increase is seen from the Asian agricultural sector in recent years, most likely due to an increase in the use of nitrogenous fertilizers, as has been suggested by previous studies. Copyright textcopyright 2014 by ASME. |
BibTeX:
@article{Saikawa2014,
author = {Saikawa, E and Prinn, R G and Dlugokencky, E and Ishijima, K and Dutton, G S and Hall, B D and Langenfelds, R and Tohjima, Y and Machida, T and Manizza, M and Rigby, M and O'Doherty, S and Patra, P K and Harth, C M and Weiss, R F and Krummel, P B and Van Der Schoot, M and Fraser, P J and Steele, L P and Aoki, S and Nakazawa, T and Elkins, J W},
title = {Global and regional emissions estimates for N2O},
journal = {Atmospheric Chemistry and Physics},
year = {2014},
volume = {14},
number = {9},
pages = {4617--4641},
url = {http://www.atmos-chem-phys.net/14/4617/2014/},
doi = {10.5194/acp-14-4617-2014}
}
|
| Schneider B, Gülzow W, Sadkowiak B and Rehder G (2014), "Detecting sinks and sources of CO2 and CH4 by ferrybox-based measurements in the Baltic Sea: Three case studies", Journal of Marine Systems., dec, 2014. Vol. 140(PA), pp. 13-25. |
| Abstract: A fully automated measurement system for recording of the surface water CO2 partial pressure, pCO2, was deployed on VOS (voluntary observation ship) "Finnpartner/Finnmaid" in 2003. Since 2009, an amendment of the system also allows for the continuous detection of the surface water partial pressure of methane, pCH4. The ship commutes regularly at 2-3day intervals between the Gulf of Finland (Helsinki) and the Mecklenburg Bight (Lübeck) in the southwest of the Baltic Sea.The pCO2 data in the central Gotland Sea showed a pronounced seasonality that was mainly controlled by the biological production and decomposition of organic matter in combination with stratification/mixing of the water column. CO2 consumption in spring/summer caused pCO2 that were by up to 300μatm below the atmospheric level. In contrast, the pCO2 exceeded the atmospheric values during autumn/winter when deep mixing transports CO2-enriched water to the surface. To identify the central Baltic Sea as a sink or source for atmospheric CO2, an air-sea CO2 gas exchange balance was established for three selected years (2005, 2008 and 2009). During each year the surface water acted as a net sink for atmospheric CO2 with uptake rates ranging between 0.60 and 0.89molm-2yr-1. The rates correspond approximately to the enhanced carbon burial in sediments during the last century and suggest a link between eutrophication and CO2 uptake.The data of the surface methane concentration are used to focus on situations were extraordinarily high methane concentrations were observed. Temporary methane peaks were observed south of the Island of Gotland, which could clearly be attributed to frequent upwelling events.Between spring 2012 and 2013, Finnmaid went at a few occasions to St. Petersburg in the east of the Gulf of Finland. Methane concentration of up to 130nmolL-1 where found close to the River Neva mouth but decreased rapidly to the west. The plume of methane-enriched waters was observed farthest to the west during the winter period. This was attributed to air-sea gas exchange that was most effective during summer but inhibited during winter because of the ice coverage. |
BibTeX:
@article{Schneider2014,
author = {Schneider, Bernd and Gülzow, Wanda and Sadkowiak, Bernd and Rehder, Gregor},
title = {Detecting sinks and sources of CO2 and CH4 by ferrybox-based measurements in the Baltic Sea: Three case studies},
journal = {Journal of Marine Systems},
year = {2014},
volume = {140},
number = {PA},
pages = {13--25},
url = {http://linkinghub.elsevier.com/retrieve/pii/S0924796314000748},
doi = {10.1016/j.jmarsys.2014.03.014}
}
|
| Séférian R, Ribes A and Bopp L (2014), "Detecting the anthropogenic influences on recent changes in ocean carbon uptake", Geophysical Research Letters., aug, 2014. Vol. 41(16), pp. 5968-5977. Blackwell Publishing Ltd. |
| Abstract: Anthropogenic greenhouse gas emissions have modified the rate at which oceans have absorbed atmospheric COtextlessinftextgreater2textless/inftextgreater over the last centuries through rising atmospheric COtextlessinftextgreater2textless/inftextgreater and modifications in climate. However, there are still missing pieces in our understanding of the recent evolution of air-sea COtextlessinftextgreater2textless/inftextgreater exchanges related to the magnitude of their response to anthropogenic forcings versus that controlled by the internal variability. Here, to detect and attribute anthropogenic influences on oceanic COtextlessinftextgreater2textless/inftextgreater uptake between 1960 and 2005, we compare an ensemble of Coupled Model Intercomparison Project Phase 5 (CMIP5) climate model simulations forced by individual drivers to ocean-only model reconstructions. We demonstrate that the evolution of the global oceanic carbon sink over the last decades can be understood without invoking climate change, attributing rising atmospheric COtextlessinftextgreater2textless/inftextgreater as prominent driver of the oceanic sink. Nonetheless, at regional scale, the influence of climate change on air-sea COtextlessinftextgreater2textless/inftextgreater exchanges seems to emerge from the internal variability within the low-latitude oceans. |
BibTeX:
@article{Seferian2014,
author = {Séférian, Roland and Ribes, Aurélien and Bopp, Laurent},
title = {Detecting the anthropogenic influences on recent changes in ocean carbon uptake},
journal = {Geophysical Research Letters},
publisher = {Blackwell Publishing Ltd},
year = {2014},
volume = {41},
number = {16},
pages = {5968--5977},
url = {http://doi.wiley.com/10.1002/2014GL061223},
doi = {10.1002/2014GL061223}
}
|
| Senapati N, Chabbi A, Gastal F, Smith P, Mascher N, Loubet B, Cellier P and Naisse C (2014), "Net carbon storage measured in a mowed and grazed temperate sown grassland shows potential for carbon sequestration under grazed system", Carbon Management. Vol. 5(2), pp. 131-144. Future Science. |
| Abstract: Background: Managed temperate grassland has the potential to sequester carbon if management practices are improved. In this study, CO2 flux was measured by the eddy covariance technique in two identical temperate sown grasslands under different managements, viz. mowing and grazing, to estimate and compare net carbon storage under both the management systems. Results: In both mowing and grazing systems, the averaged annual gross plant productivity, ecosystem respiration and net ecosystem exchange were -1720 and -1741, 1244 and 1510, and -476 and -231 g C m-2 year-1, respectively. Although the management practices did not significantly influence gross plant productivity (p textgreater 0.05), grazing system increased Reco significantly by 21% (p textless 0.05) but reduced net ecosystem exchange by 52% (p textless 0.05) compared to mowing system. However, averaged annual net carbon storage were 23 and 141 g C m-2 year-1 under mowing and grazing, respectively. Conclusion: The results indicate that temperate sown grassland has the potential to sequester carbon under grazing. |
BibTeX:
@article{Senapati2014,
author = {Senapati, Nimai and Chabbi, Abad and Gastal, François and Smith, Pete and Mascher, Nicolas and Loubet, Benjamin and Cellier, Pierre and Naisse, Christophe},
title = {Net carbon storage measured in a mowed and grazed temperate sown grassland shows potential for carbon sequestration under grazed system},
journal = {Carbon Management},
publisher = {Future Science},
year = {2014},
volume = {5},
number = {2},
pages = {131--144},
doi = {10.1080/17583004.2014.912863}
}
|
| Sepúlveda E, Schneider M, Hase F, Barthlott S, Dubravica D, García OE, Gomez-Pelaez A, González Y, Guerra JC, Gisi M, Kohlhepp R, Dohe S, Blumenstock T, Strong K, Weaver D, Palm M, Sadeghi A, Deutscher NM, Warneke T, Notholt J, Jones N, Griffith DWT, Smale D, Brailsford GW, Robinson J, Meinhardt F, Steinbacher M, Aalto T and Worthy D (2014), "Tropospheric CH4 signals as observed by NDACC FTIR at globally distributed sites and comparison to GAW surface in situ measurements", Atmospheric Measurement Techniques., jul, 2014. Vol. 7(7), pp. 2337-2360. |
| Abstract: We present lower/middle tropospheric column-averaged CH4 mole fraction time series measured by nine globally distributed ground-based FTIR (Fourier transform infrared) remote sensing experiments of the Network for the Detection of Atmospheric Composition Change (NDACC). We show that these data are well representative of the tropospheric regional-scale CH4 signal, largely independent of the local surface small-scale signals, and only weakly dependent on upper tropospheric/lower stratospheric (UTLS) CH4 variations. In order to achieve the weak dependency on the UTLS, we use an a posteriori correction method. We estimate a typical precision for daily mean values of about 0.5% and a systematic error of about 2.5%. The theoretical assessments are complemented by an extensive empirical study. For this purpose, we use surface in situ CH4 measurements made within the Global Atmosphere Watch (GAW) network and compare them to the remote sensing data. We briefly discuss different filter methods for removing the local small-scale signals from the surface in situ data sets in order to obtain the in situ regional-scale signals. We find good agreement between the filtered in situ and the remote sensing data. The agreement is consistent for a variety of timescales that are interesting for CH4 source/sink research: day-to-day, monthly, and inter-annual. The comparison study confirms our theoretical estimations and proves that the NDACC FTIR measurements can provide valuable data for investigating the cycle of CH4. textcopyright Author(s) 2014. |
BibTeX:
@article{Sepulveda2014,
author = {Sepúlveda, E and Schneider, M and Hase, F and Barthlott, S and Dubravica, D and García, O E and Gomez-Pelaez, A and González, Y and Guerra, J C and Gisi, M and Kohlhepp, R and Dohe, S and Blumenstock, T and Strong, K and Weaver, D and Palm, M and Sadeghi, A and Deutscher, N M and Warneke, T and Notholt, J and Jones, N and Griffith, D W T and Smale, D and Brailsford, G W and Robinson, J and Meinhardt, F and Steinbacher, M and Aalto, T and Worthy, D},
title = {Tropospheric CH4 signals as observed by NDACC FTIR at globally distributed sites and comparison to GAW surface in situ measurements},
journal = {Atmospheric Measurement Techniques},
year = {2014},
volume = {7},
number = {7},
pages = {2337--2360},
url = {http://www.atmos-meas-tech.net/7/2337/2014/},
doi = {10.5194/amt-7-2337-2014}
}
|
| Smallman TL, Williams M and Moncrieff JB (2014), "Can seasonal and interannual variation in landscape CO2 fluxes be detected by atmospheric observations of CO2 concentrations made at a tall tower?", Biogeosciences., feb, 2014. Vol. 11(3), pp. 735-747. |
| Abstract: The coupled numerical weather model WRF-SPA (Weather Research and Forecasting model and Soil-Plant-Atmosphere model) has been used to investigate a 3 yr time series of observed atmospheric CO2 concentrations from a tall tower in Scotland, UK. Ecosystem-specific tracers of net CO2 uptake and net CO2 release were used to investigate the contributions to the tower signal of key land covers within its footprint, and how contributions varied at seasonal and interannual timescales. In addition, WRF-SPA simulated atmospheric CO2 concentrations were compared with two coarse global inversion models, CarbonTrackerEurope and the National Oceanic and Atmospheric Administration's CarbonTracker (CTE-CT). WRF-SPA realistically modelled both seasonal (except post harvest) and daily cycles seen in observed atmospheric CO2 at the tall tower (iR/i2 Combining double low line 0.67, rmse Combining double low line 3.5 ppm, bias Combining double low line 0.58 ppm). Atmospheric CO2 concentrations from the tall tower were well simulated by CTE-CT, but the inverse model showed a poorer representation of diurnal variation and simulated a larger bias from observations (up to 1.9 ppm) at seasonal timescales, compared to the forward modelling of WRF-SPA. However, we have highlighted a consistent post-harvest increase in the seasonal bias between WRF-SPA and observations. Ecosystem-specific tracers of CO2 exchange indicate that the increased bias is potentially due to the representation of agricultural processes within SPA and/or biases in land cover maps. The ecosystem-specific tracers also indicate that the majority of seasonal variation in CO2 uptake for Scotland's dominant ecosystems (forests, cropland and managed grassland) is detectable in observations within the footprint of the tall tower; however, the amount of variation explained varies between years. The between years variation in detectability of Scotland's ecosystems is potentially due to seasonal and interannual variation in the simulated prevailing wind direction. This result highlights the importance of accurately representing atmospheric transport used within atmospheric inversion models used to estimate terrestrial source/sink distribution and magnitude. textcopyright Author(s) 2014. |
BibTeX:
@article{Smallman2014,
author = {Smallman, T L and Williams, M and Moncrieff, J B},
title = {Can seasonal and interannual variation in landscape CO2 fluxes be detected by atmospheric observations of CO2 concentrations made at a tall tower?},
journal = {Biogeosciences},
year = {2014},
volume = {11},
number = {3},
pages = {735--747},
url = {http://www.biogeosciences.net/11/735/2014/},
doi = {10.5194/bg-11-735-2014}
}
|
| Stepanenko V, Jöhnk KD, Machulskaya E, Perroud M, Subin Z, Nordbo A, Mammarella I and Mironov D (2014), "Simulation of surface energy fluxes and stratification of a small boreal lake by a set of one-dimensional models", Tellus, Series A: Dynamic Meteorology and Oceanography. Vol. 66(1) Co-Action Publishing. |
| Abstract: Five one-dimensional (1D) lake models were run for the open water season in 2006 for Lake Valkea-Kotinen (Finland) using on-lake measured meteorological forcing. The model results were validated using measurements of water temperature and of eddy covariance (EC) fluxes. The surface temperature is satisfactorily simulated by all models showing slight overestimation (by 0.1-1.1°C). Both sensible and latent heat fluxes are positively biased in respect to EC data, consistent with earlier studies. However, correlation coefficients between EC-fluxes and those simulated are relatively high ranging from 0.55 to 0.74. The skill to simulate vertical temperature profiles by different models is assessed as well. It is found that the lake models underestimate the EC-derived surface drag coefficient, however providing realistic temperature profiles. It is argued that the real momentum flux from the atmosphere is larger than simulated, however it is split up between the wave development and the acceleration of lake currents. Adopting the simple parameterisation for momentum flux partitioning in one of the models showed that this mechanism can be significant. Finally, the effect of including the lake bathymetry data in k-σ models was the drastic overheating of water below the thermocline. This is likely to be caused by omitting the heat flux at the lake margins. Thus, the parameterisation of heat flux at the lake's margins should be included in the models; otherwise it is recommended to neglect bathymetry effects for such small water bodies as the Lake Valkea-Kotinen. textcopyright 2014 V. Stepanenko et al. |
BibTeX:
@article{Stepanenko2014,
author = {Stepanenko, Victor and Jöhnk, Klaus D. and Machulskaya, Ekaterina and Perroud, Marjorie and Subin, Zack and Nordbo, Annika and Mammarella, Ivan and Mironov, Dmitri},
title = {Simulation of surface energy fluxes and stratification of a small boreal lake by a set of one-dimensional models},
journal = {Tellus, Series A: Dynamic Meteorology and Oceanography},
publisher = {Co-Action Publishing},
year = {2014},
volume = {66},
number = {1},
doi = {10.3402/tellusa.v66.21389}
}
|
| Sundqvist E, Vestin P, Crill P, Persson T and Lindroth A (2014), "Short-term effects of thinning, clear-cutting and stump harvesting on methane exchange in a boreal forest", Biogeosciences., nov, 2014. Vol. 11(21), pp. 6095-6105. |
| Abstract: Abstract. Forest management practices can alter soil conditions, affecting the consumption and production processes that control soil methane (CH4) exchange. We studied the short-term effects of thinning, clear-cutting and stump harvesting on the CH4 exchange between soil and atmosphere at a boreal forest site in central Sweden, using an undisturbed plot as the control. Chambers in combination with a high-precision laser gas analyser were used for continuous measurements. Both the undisturbed plot and the thinned plot were net sinks of CH4, whereas the clear-cut plot and the stump harvested plot were net CH4 sources. The CH4 uptake at the thinned plot was reduced in comparison to the undisturbed plot. The shift from sink to source at the clear-cut and stump harvested plots was probably due to a rise in the water table and an increase in soil moisture, leading to lower gas diffusivity and more reduced conditions, which favour CH4 production by archea. Reduced evapotranspiration after harvesting leads to wetter soils, decreased CH4 consumption and increased CH4 production, and should be accounted for in the CH4 budget of managed forests. |
BibTeX:
@article{Sundqvist2014,
author = {Sundqvist, E. and Vestin, P. and Crill, P. and Persson, T. and Lindroth, A.},
title = {Short-term effects of thinning, clear-cutting and stump harvesting on methane exchange in a boreal forest},
journal = {Biogeosciences},
year = {2014},
volume = {11},
number = {21},
pages = {6095--6105},
url = {https://bg.copernicus.org/articles/11/6095/2014/},
doi = {10.5194/bg-11-6095-2014}
}
|
| Takahashi T, Sutherland SC, Chipman DW, Goddard JG and Ho C (2014), "Climatological distributions of pH, pCO2, total CO2, alkalinity, and CaCO3 saturation in the global surface ocean, and temporal changes at selected locations", Marine Chemistry., aug, 2014. Vol. 164, pp. 95-125. Elsevier. |
| Abstract: Climatological mean monthly distributions of pH in the total H+ scale, total CO2 concentration (TCO2), and the degree of CaCO3 saturation for the global surface ocean waters (excluding coastal areas) are calculated using a data set for pCO2, alkalinity and nutrient concentrations in surface waters (depths textless50m), which is built upon the GLODAP, CARINA and LDEO databases. The mutual consistency among these measured parameters is demonstrated using the inorganic carbon chemistry model with the dissociation constants for carbonic acid by Lueker et al. (2000) and for boric acid by Dickson (1990). Linear potential alkalinity-salinity relationships are established for 24 regions of the global ocean. The mean monthly distributions of pH and carbon chemistry parameters for the reference year 2005 are computed using the climatological mean monthly pCO2 data adjusted to a reference year 2005 and the alkalinity estimated from the potential alkalinity-salinity relationships. The equatorial zone (4°N-4°S) of the Pacific is excluded from the analysis because of the large interannual changes associated with ENSO events. The pH thus calculated ranges from 7.9 to 8.2. Lower values are located in the upwelling regions in the tropical Pacific and in the Arabian and Bering Seas; higher values are found in the subpolar and polar waters during the spring-summer months of intense photosynthetic production. The vast areas of subtropical oceans have seasonally varying pH values ranging from 8.05 during warmer months to 8.15 during colder months. The warm tropical and subtropical waters are supersaturated by a factor of as much as 4.2 with respect to aragonite and 6.3 for calcite, whereas the cold subpolar and polar waters are supersaturated by 1.2 for aragonite and 2.0 for calcite because of the lower pH values resulting from greater TCO2 concentrations. In the western Arctic Ocean, aragonite undersaturation is observed. The time-series data from the Bermuda (BATS), Hawaii (HOT), Canary (ESTOC) and the Drake Passage show that pH has been declining at a mean rate of about -0.02 pH per decade, and that pCO2 has been increasing at about 19 μatm per decade tracking the atmospheric pCO2 increase rate. This suggests that the ocean acidification is caused primarily by the uptake of atmospheric CO2. The relative importance of the four environmental drivers (temperature, salinity, alkalinity and total CO2 concentration) controlling the seasonal variability of carbonate chemistry at these sites is quantitatively assessed. The ocean carbon chemistry is governed sensitively by the TA/TCO2 ratio, and the rate of change in TA is equally important for the future ocean environment as is the TCO2 in ocean waters increases in the future. textcopyright 2014 Elsevier B.V. |
BibTeX:
@article{Takahashi2014,
author = {Takahashi, Taro and Sutherland, S. C. and Chipman, D. W. and Goddard, J. G. and Ho, Cheng},
title = {Climatological distributions of pH, pCO2, total CO2, alkalinity, and CaCO3 saturation in the global surface ocean, and temporal changes at selected locations},
journal = {Marine Chemistry},
publisher = {Elsevier},
year = {2014},
volume = {164},
pages = {95--125},
doi = {10.1016/j.marchem.2014.06.004}
}
|
| Tang X, Li H, Desai AR, Nagy Z, Luo J, Kolb TE, Olioso A, Xu X, Yao L, Kutsch W, Pilegaard K, Köstner B and Ammann C (2014), "How is water-use efficiency of terrestrial ecosystems distributed and changing on Earth?", Scientific Reports., may, 2014. Vol. 4(1), pp. 7483. |
| Abstract: A better understanding of ecosystem water-use efficiency (WUE) will help us improve ecosystem management for mitigation as well as adaption to global hydrological change. Here, long-term flux tower observations of productivity and evapotranspiration allow us to detect a consistent latitudinal trend in WUE, rising from the subtropics to the northern high-latitudes. The trend peaks at approximately 51°N, and then declines toward higher latitudes. These ground-based observations are consistent with global-scale estimates of WUE. Global analysis of WU Ereveals existence of strong regional variations that correspond to global climate patterns. The latitudinal trends of global WUEfor Earth's major plant functional types reveal two peaks in the Northern Hemisphere not detected by ground-based measurements. One peak is located at 20° ˜ 30°N and the other extends a little farther north than 51°N. Finally, long-term spatiotemporal trend analysis using satellite-based remote sensing data reveals that land-cover and land-use change in recent years has led to a decline in global WUE. Our study provides a new framework for global research on the interactions between carbon and water cycles as well as responses to natural and human impacts. |
BibTeX:
@article{Tang2014,
author = {Tang, Xuguang and Li, Hengpeng and Desai, Ankur R and Nagy, Zoltan and Luo, Juhua and Kolb, Thomas E and Olioso, Albert and Xu, Xibao and Yao, Li and Kutsch, Werner and Pilegaard, Kim and Köstner, Barbara and Ammann, Christof},
title = {How is water-use efficiency of terrestrial ecosystems distributed and changing on Earth?},
journal = {Scientific Reports},
year = {2014},
volume = {4},
number = {1},
pages = {7483},
url = {http://www.nature.com/articles/srep07483},
doi = {10.1038/srep07483}
}
|
| Tang J, Luyssaert S, Richardson AD, Kutsch W and Janssens IA (2014), "Steeper declines in forest photosynthesis than respiration explain age-driven decreases in forest growth", Proceedings of the National Academy of Sciences of the United States of America., jun, 2014. Vol. 111(24), pp. 8856-8860. |
| Abstract: The traditional view of forest dynamics originated by Kira and Shidei [Kira T, Shidei T (1967) Jap J Ecol 17:70-87] and Odum [Odum EP (1969) Science 164(3877):262-270] suggests a decline in net primary productivity (NPP) in aging forests due to stabilized gross primary productivity (GPP) and continuously increased autotrophic respiration (Ra). The validity of these trends in GPP and Ra is, however, very difficult to test because of the lack of long-term ecosystem-scale field observations of both GPP and Ra. Ryan and colleagues [Ryan MG, Binkley D, Fownes JH (1997) Ad Ecol Res 27:213-262] have proposed an alternative hypothesis drawn from site-specific results that aboveground respiration and below-ground allocation decreased in aging forests. Here, we analyzed data from a recently assembled global database of carbon fluxes and show that the classical view of the mechanisms underlying the age-driven decline in forest NPP is incorrect and thus support Ryan's alternative hypothesis. Our results substantiate the age-driven decline in NPP, but in contrast to the traditional view, both GPP and Ra decline in aging boreal and temperate forests. We find that the decline in NPP in aging forests is primarily driven by GPP, which decreases more rapidly with increasing age than Ra does, but the ratio of NPP/GPP remains approximately constant within a biome. Our analytical models describing forest succession suggest that dynamic forest ecosystem models that follow the traditional paradigm need to be revisited. |
BibTeX:
@article{Tang2014a,
author = {Tang, Jianwu and Luyssaert, Sebastiaan and Richardson, Andrew D and Kutsch, Werner and Janssens, Ivan A},
title = {Steeper declines in forest photosynthesis than respiration explain age-driven decreases in forest growth},
journal = {Proceedings of the National Academy of Sciences of the United States of America},
year = {2014},
volume = {111},
number = {24},
pages = {8856--8860},
url = {http://www.pnas.org/cgi/doi/10.1073/pnas.1320761111},
doi = {10.1073/pnas.1320761111}
}
|
| Thompson RL, Patra PK, Ishijima K, Saikawa E, Corazza M, Karstens U, Wilson C, Bergamaschi P, Dlugokencky E, Sweeney C, Prinn RG, Weiss RF, O&apos, Doherty S, Fraser PJ, Steele LP, Krummel PB, Saunois M, Chipperfield M and Bousquet P (2014), " TransCom N 2 O model inter-comparison – Part 1: Assessing the influence of transport and surface fluxes on tropospheric N 2 O variability ", In Atmospheric Chemistry and Physics Discussions., jan, 2014. Vol. 14(2), pp. 2307-2362. |
| Abstract: Abstract. We present a comparison of chemistry-transport models (TransCom-N2O) to examine the importance of atmospheric transport and surface fluxes on the variability of N2O mixing ratios in the troposphere. Six different models and two model variants participated in the inter-comparison and simulations were made for the period 2006 to 2009. In addition to N2O, simulations of CFC-12 and SF6 were made by a subset of four of the models to provide information on the models proficiency in stratosphere-troposphere exchange (STE) and meridional transport, respectively. The same prior emissions were used by all models to restrict differences among models to transport and chemistry alone. Four different N2O flux scenarios totalling between 14 and 17 Tg N yrâˆ'1 (for 2005) globally were also compared. The modelled N2O mixing ratios were assessed against observations from in-situ stations, discrete air sampling networks, and aircraft. All models adequately captured the large-scale patterns of N2O and the vertical gradient from the troposphere to the stratosphere and most models also adequately captured the N2O tropospheric growth rate. However, all models underestimated the inter-hemispheric N2O gradient by at least 0.33 ppb (equivalent to 1.5 Tg N), which, even after accounting for an overestimate of emissions in the Southern Ocean of circa 1.0 Tg N, points to a likely underestimate of the Northern Hemisphere source by up to 0.5 Tg N and/or an overestimate of STE in the Northern Hemisphere. Comparison with aircraft data reveal that the models overestimate the amplitude of the N2O seasonal cycle at Hawaii (21° N, 158° W) below circa 6000 m, suggesting an overestimate of the importance of stratosphere to troposphere transport in the lower troposphere at this latitude. In the Northern Hemisphere, most of the models that provided CFC-12 simulations captured the phase of the CFC-12, seasonal cycle, indicating a reasonable representation of the timing of STE. However, for N2O all models simulated a too early minimum by 2 to 3 months owing to errors in the seasonal cycle in the prior soil emissions, which is still not adequately represented by terrestrial biosphere models. In the Southern Hemisphere, most models failed to capture the N2O and CFC-12 seasonality at Cape Grim, Tasmania, and all failed at the South Pole, whereas for SF6, all models could capture the seasonality at all sites, suggesting that there are large errors in modeled vertical transport in high southern latitudes. |
BibTeX:
@book{Thompson2014,
author = {Thompson, R L and Patra, P K and Ishijima, K and Saikawa, E and Corazza, M and Karstens, U and Wilson, C and Bergamaschi, P and Dlugokencky, E and Sweeney, C and Prinn, R G and Weiss, R F and O&apos;Doherty, S and Fraser, P J and Steele, L P and Krummel, P B and Saunois, M and Chipperfield, M and Bousquet, P},
title = { TransCom N 2 O model inter-comparison – Part 1: Assessing the influence of transport and surface fluxes on tropospheric N 2 O variability },
booktitle = {Atmospheric Chemistry and Physics Discussions},
year = {2014},
volume = {14},
number = {2},
pages = {2307--2362},
url = {http://www.atmos-chem-phys-discuss.net/14/2307/2014/},
doi = {10.5194/acpd-14-2307-2014}
}
|
| Thompson RL, Ishijima K, Saikawa E, Corazza M, Karstens U, Patra PK, Bergamaschi P, Chevallier F, Dlugokencky E, Prinn RG, Weiss RF, O'Doherty S, Fraser PJ, Steele LP, Krummel PB, Vermeulen A, Tohjima Y, Jordan A, Haszpra L, Steinbacher M, Van Der Laan S, Aalto T, Meinhardt F, Popa ME, Moncrieff J and Bousquet P (2014), "TransCom N2O model inter-comparison, Part II: Atmospheric inversion estimates of N2O emissions", Atmospheric Chemistry and Physics Discussions., feb, 2014. Vol. 14(4), pp. 5271-5321. |
| Abstract: This study examines N2O emission estimates from 5 different atmospheric inversion frameworks. The 5 frameworks differ in the choice of atmospheric transport model, meteorological data, prior uncertainties and inversion method but use the same prior emissions and observation dataset. The mean emissions for 2006 to 2008 are compared in terms of the spatial distribution and seasonality. Overall, there is a good agreement among the inversions for the mean global total emission, which ranges from 16.1 to 18.7 Tg N yr-1 and is consistent with previous estimates. Ocean emissions represent between 31% and 38% of the global total compared to widely varying previous estimates of 24% to 38%. Emissions from the northern mid to high latitudes are likely to be more important, with a consistent shift in emissions from the tropics and subtropics to the mid to high latitudes in the Northern Hemisphere; the emission ratio for 0-30 °N to 30-90 °N ranges from 1.5 to 1.9 compared with 2.9 to 3.0 in previous estimates. The largest discrepancies across inversions are seen for the regions of South and East Asia and for tropical and South America owing to the poor observational constraint for these areas and to considerable differences in the modelled transport, especially inter-hemispheric exchange rates and tropical convection. Estimates of the seasonal cycle in N2O emissions are also sensitive to errors in modelled stratosphere-to-troposphere transport in the tropics and southern extra-tropics. Overall, the results show a convergence in the global and regional emissions compared to previous independent studies. textcopyright Author(s) 2014. |
BibTeX:
@article{Thompson2014a,
author = {Thompson, R L and Ishijima, K and Saikawa, E and Corazza, M and Karstens, U and Patra, P K and Bergamaschi, P and Chevallier, F and Dlugokencky, E and Prinn, R G and Weiss, R F and O'Doherty, S and Fraser, P J and Steele, L P and Krummel, P B and Vermeulen, A and Tohjima, Y and Jordan, A and Haszpra, L and Steinbacher, M and Van Der Laan, S and Aalto, T and Meinhardt, F and Popa, M E and Moncrieff, J and Bousquet, P},
title = {TransCom N2O model inter-comparison, Part II: Atmospheric inversion estimates of N2O emissions},
journal = {Atmospheric Chemistry and Physics Discussions},
year = {2014},
volume = {14},
number = {4},
pages = {5271--5321},
url = {http://www.atmos-chem-phys-discuss.net/14/5271/2014/},
doi = {10.5194/acpd-14-5271-2014}
}
|
| Thompson RL, Chevallier F, Crotwell AM, Dutton G, Langenfelds RL, Prinn RG, Weiss RF, Tohjima Y, Nakazawa T, Krummel PB, Steele LP, Fraser P, O'Doherty S, Ishijima K and Aoki S (2014), "Nitrous oxide emissions 1999 to 2009 from a global atmospheric inversion", Atmospheric Chemistry and Physics., feb, 2014. Vol. 14(4), pp. 1801-1817. |
| Abstract: N2O surface fluxes were estimated for 1999 to 2009 using a time-dependent Bayesian inversion technique. Observations were drawn from 5 different networks, incorporating 59 surface sites and a number of ship-based measurement series. To avoid biases in the inverted fluxes, the data were adjusted to a common scale and scale offsets were included in the optimization problem. The fluxes were calculated at the same resolution as the transport model (3.75 longitude × 2.5 latitude) and at monthly time resolution. Over the 11-year period, the global total N2O source varied from 17.5 to 20.1 Tg a-1 N. Tropical and subtropical land regions were found to consistently have the highest N2O emissions, in particular in South Asia (20 ± 3% of global total), South America (13 ± 4%) and Africa (19 ± 3%), while emissions from temperate regions were smaller: Europe (6 ± 1%) and North America (7 ± 2%). A significant multi-annual trend in N2O emissions (0.045 Tg a-2 N) from South Asia was found and confirms inventory estimates of this trend. Considerable interannual variability in the global N2O source was observed (0.8 Tg a-1 N, 1 standard deviation, SD) and was largely driven by variability in tropical and subtropical soil fluxes, in particular in South America (0.3 Tg a-1 N, 1 SD) and Africa (0.3 Tg a-1 N, 1 SD). Notable variability was also found for N2O fluxes in the tropical and southern oceans (0.15 and 0.2 Tg a-1 N, 1 SD, respectively). Interannual variability in the N2O source shows some correlation with the El Niño-Southern Oscillation (ENSO), where El Niño conditions are associated with lower N2O fluxes from soils and from the ocean and vice versa for La Niña conditions. textcopyright 2014 Author(s). |
BibTeX:
@article{Thompson2014b,
author = {Thompson, R L and Chevallier, F and Crotwell, A M and Dutton, G and Langenfelds, R L and Prinn, R G and Weiss, R F and Tohjima, Y and Nakazawa, T and Krummel, P B and Steele, L P and Fraser, P and O'Doherty, S and Ishijima, K and Aoki, S},
title = {Nitrous oxide emissions 1999 to 2009 from a global atmospheric inversion},
journal = {Atmospheric Chemistry and Physics},
year = {2014},
volume = {14},
number = {4},
pages = {1801--1817},
url = {http://www.atmos-chem-phys.net/14/1801/2014/},
doi = {10.5194/acp-14-1801-2014}
}
|
| Tjiputra JF, Olsen A, Bopp L, Lenton A, Pfeil B, Roy T, Segschneider J, Totterdell I and Heinze C (2014), "Long-term surface pCO2 trends from observations and models", Tellus, Series B: Chemical and Physical Meteorology., jan, 2014. Vol. 66(1), pp. 23083. Co-Action Publishing. |
| Abstract: We estimate regional long-term surface ocean pCO2 growth rates using all available underway and bottled biogeochemistry data collected over the past four decades. These observed regional trends are compared with those simulated by five state-of-the-art Earth system models over the historical period. Oceanic pCO2 growth rates faster than the atmospheric growth rates indicate decreasing atmospheric CO2 uptake, while ocean pCO2 growth rates slower than the atmospheric growth rates indicate increasing atmospheric CO2 uptake. Aside from the western subpolar North Pacific and the subtropical North Atlantic, our analysis indicates that the current observation-based basin-scale trends may be underestimated, indicating that more observations are needed to determine the trends in these regions. Encouragingly, good agreement between the simulated and observed pCO2 trends is found when the simulated fields are subsampled with the observational coverage. In agreement with observations, we see that the simulated pCO2 trends are primarily associated with the increase in surface dissolved inorganic carbon (DIC) associated with atmospheric carbon uptake, and in part by warming of the sea surface. Under the RCP8.5 future scenario, DIC continues to be the dominant driver of pCO2 trends, with little change in the relative contribution of SST. However, the changes in the hydrological cycle play an increasingly important role. For the contemporary (1970-2011) period, the simulated regional pCO2 trends are lower than the atmospheric growth rate over 90% of the ocean. However, by year 2100 more than 40% of the surface ocean area has a higher oceanic pCO2 trend than the atmosphere, implying a reduction in the atmospheric CO2 uptake rate. The fastest pCO2 growth rates are projected for the subpolar North Atlantic, while the high-latitude Southern Ocean and eastern equatorial Pacific have the weakest growth rates, remaining below the atmospheric pCO2 growth rate. Our work also highlights the importance and need for a sustained long-term observing strategy to continue monitoring the change in the ocean anthropogenic CO2 sink and to better understand the potential carbon cycle feedbacks to climate that could arise from it. textcopyright 2014 J. F. Tjiputra et al. |
BibTeX:
@article{Tjiputra2014,
author = {Tjiputra, Jerry F. and Olsen, Are and Bopp, Laurent and Lenton, Andrew and Pfeil, Benjamin and Roy, Tilla and Segschneider, Joachim and Totterdell, Ian and Heinze, Christoph},
title = {Long-term surface pCO2 trends from observations and models},
journal = {Tellus, Series B: Chemical and Physical Meteorology},
publisher = {Co-Action Publishing},
year = {2014},
volume = {66},
number = {1},
pages = {23083},
url = {https://www.tandfonline.com/doi/full/10.3402/tellusb.v66.23083},
doi = {10.3402/tellusb.v66.23083}
}
|
| Turi G, Lachkar Z and Gruber N (2014), "Spatiotemporal variability and drivers of &lt;i&gt;p&lt;/i&gt;CO&lt;sub&gt;2&lt;/sub&gt; and air–sea CO&lt;sub&gt;2&lt;/sub&gt; fluxes in the California Current System: an eddy-resolving modeling study", Biogeosciences., feb, 2014. Vol. 11(3), pp. 671-690. |
| Abstract: textlessptextgreaterAbstract. We quantify the CO2 source/sink nature of the California Current System (CalCS) and determine the drivers and processes behind the mean and spatiotemporal variability of the partial pressure of CO2 (pCO2) in the surface ocean. To this end, we analyze eddy-resolving, climatological simulations of a coupled physical–biogeochemical oceanic model on the basis of the Regional Oceanic Modeling System (ROMS). In the annual mean, the entire CalCS within 800 km of the coast and from ∼33° N to 46° N is essentially neutral with regard to atmospheric CO2: the model simulates an integrated uptake flux of −0.9 ± 3.6 Tg C yr−1, corresponding to an average flux density of −0.05 ± 0.20 mol C m−2 yr−1. This near zero flux is a consequence of an almost complete regional compensation between (i) strong outgassing in the nearshore region (first 100 km) that brings waters with high concentrations of dissolved inorganic carbon (DIC) to the surface and (ii) and a weaker, but more widespread uptake flux in the offshore region due to an intense biological reduction of this DIC, driven by the nutrients that are upwelled together with the DIC. The air–sea CO2 fluxes vary substantially in time, both on seasonal and sub-seasonal timescales, largely driven by variations in surface ocean pCO2. Most of the variability in pCO2 is associated with the seasonal cycle, with the exception of the nearshore region, where sub-seasonal variations driven by mesoscale processes dominate. In the regions offshore of 100 km, changes in surface temperature are the main driver, while in the nearshore region, changes in surface temperature, as well as anomalies in DIC and alkalinity (Alk) owing to changes in circulation, biological productivity and air–sea CO2 fluxes dominate. The prevalence of eddy-driven variability in the nearshore 100 km leads to a complex spatiotemporal mosaic of surface ocean pCO2 and air–sea CO2 fluxes that require a substantial observational effort to determine the source/sink nature of this region reliably.textless/ptextgreater |
BibTeX:
@article{Turi2014,
author = {Turi, G. and Lachkar, Z. and Gruber, N.},
title = {Spatiotemporal variability and drivers of &lt;i&gt;p&lt;/i&gt;CO&lt;sub&gt;2&lt;/sub&gt; and air–sea CO&lt;sub&gt;2&lt;/sub&gt; fluxes in the California Current System: an eddy-resolving modeling study},
journal = {Biogeosciences},
year = {2014},
volume = {11},
number = {3},
pages = {671--690},
url = {https://bg.copernicus.org/articles/11/671/2014/},
doi = {10.5194/bg-11-671-2014}
}
|
| Ulfsbo A, Cassar N, Korhonen M, Van Heuven S, Hoppema M, Kattner G and Anderson LG (2014), "Late summer net community production in the central Arctic Ocean using multiple approaches", Global Biogeochemical Cycles., oct, 2014. Vol. 28(10), pp. 1129-1148. Blackwell Publishing Ltd. |
| Abstract: Large-scale patterns of net community production (NCP) were estimated during the late summer cruise ARK-XXVI/3 (TransArc, August/September 2011) to the central Arctic Ocean. Several approaches were used based on the following: (i) continuous measurements of surface water oxygen to argon ratios (O2/Ar), (ii) underway measurements of surface partial pressure of carbon dioxide (pCO2), (iii) discrete samples of dissolved inorganic carbon, and (iv) dissolved inorganic nitrogen and phosphate. The NCP estimates agreed well within the uncertainties associated with each approach. The highest late summer NCP (up to 6 mol C m-2) was observed in the marginal sea ice zone region. Low values (textless1 mol C m-2) were found in the sea ice-covered deep basins with a strong spatial variability. Lowest values were found in the Amundsen Basin and moderate values in the Nansen and Makarov Basins with slightly higher estimates over the Mendeleev Ridge. Our findings support a coupling of NCP to sea ice coverage and nutrient supply and thus stress a potential change in spatial and temporal distribution of NCP in a future Arctic Ocean. To follow the evolution of NCP in space and time, it is suggested to apply one or several of these approaches in shipboard investigations with a time interval of 3 to 5 years. Key Points Late summer NCP in the central Arctic Ocean by multiple approachesHigh NCP in the marginal sea ice zone and low NCP in the central basinsBasin-specific variability coupled to sea ice cover and nutrient supply |
BibTeX:
@article{Ulfsbo2014,
author = {Ulfsbo, Adam and Cassar, Nicolas and Korhonen, Meri and Van Heuven, Steven and Hoppema, Mario and Kattner, Gerhard and Anderson, Leif G.},
title = {Late summer net community production in the central Arctic Ocean using multiple approaches},
journal = {Global Biogeochemical Cycles},
publisher = {Blackwell Publishing Ltd},
year = {2014},
volume = {28},
number = {10},
pages = {1129--1148},
url = {https://agupubs.onlinelibrary.wiley.com/doi/full/10.1002/2014GB004833 https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1002/2014GB004833 https://agupubs.onlinelibrary.wiley.com/doi/10.1002/2014GB004833},
doi = {10.1002/2014GB004833}
}
|
| Valentini R, Arneth A, Bombelli A, Castaldi S, Cazzolla Gatti R, Chevallier F, Ciais P, Grieco E, Hartmann J, Henry M, Houghton RA, Jung M, Kutsch WL, Malhi Y, Mayorga E, Merbold L, Murray-Tortarolo G, Papale D, Peylin P, Poulter B, Raymond PA, Santini M, Sitch S, Vaglio Laurin G, Van Der Werf GR, Williams CA and Scholes RJ (2014), "A full greenhouse gases budget of africa: Synthesis, uncertainties, and vulnerabilities", Biogeosciences., jan, 2014. Vol. 11(2), pp. 381-407. |
| Abstract: This paper, developed under the framework of the RECCAP initiative, aims at providing improved estimates of the carbon and GHG (CO2, CH4 and N2O) balance of continental Africa. The various components and processes of the African carbon and GHG budget are considered, existing data reviewed, and new data from different methodologies (inventories, ecosystem flux measurements, models, and atmospheric inversions) presented. Uncertainties are quantified and current gaps and weaknesses in knowledge and monitoring systems described in order to guide future requirements. The majority of results agree that Africa is a small sink of carbon on an annual scale, with an average value of -0.61 ± 0.58 Pg C yr-1. Nevertheless, the emissions of CH4 and N2O may turn Africa into a net source of radiative forcing in CO2 equivalent terms. At sub-regional level, there is significant spatial variability in both sources and sinks, due to the diversity of biomes represented and differences in the degree of anthropic impacts. Southern Africa is the main source region; while central Africa, with its evergreen tropical forests, is the main sink. Emissions from land-use change in Africa are significant (around 0.32 ± 0.05 Pg C yr-1), even higher than the fossil fuel emissions: this is a unique feature among all the continents. There could be significant carbon losses from forest land even without deforestation, resulting from the impact of selective logging. Fires play a significant role in the African carbon cycle, with 1.03 ± 0.22 Pg C yr-1 of carbon emissions, and 90% originating in savannas and dry woodlands. A large portion of the wild fire emissions are compensated by CO2 uptake during the growing season, but an uncertain fraction of the emission from wood harvested for domestic use is not. Most of these fluxes have large interannual variability, on the order of ±0.5 Pg C yr-1 in standard deviation, accounting for around 25% of the year-to-year variation in the global carbon budget. brbr Despite the high uncertainty, the estimates provided in this paper show the important role that Africa plays in the global carbon cycle, both in terms of absolute contribution, and as a key source of interannual variability. textcopyright Author(s) 2014. CC Attribution 3.0 License. |
BibTeX:
@article{Valentini2014,
author = {Valentini, R and Arneth, A and Bombelli, A and Castaldi, S and Cazzolla Gatti, R and Chevallier, F and Ciais, P and Grieco, E and Hartmann, J and Henry, M and Houghton, R A and Jung, M and Kutsch, W L and Malhi, Y and Mayorga, E and Merbold, L and Murray-Tortarolo, G and Papale, D and Peylin, P and Poulter, B and Raymond, P A and Santini, M and Sitch, S and Vaglio Laurin, G and Van Der Werf, G R and Williams, C A and Scholes, R J},
title = {A full greenhouse gases budget of africa: Synthesis, uncertainties, and vulnerabilities},
journal = {Biogeosciences},
year = {2014},
volume = {11},
number = {2},
pages = {381--407},
url = {http://www.biogeosciences.net/11/381/2014/},
doi = {10.5194/bg-11-381-2014}
}
|
| Van Der Velde IR, Miller JB, Schaefer K, Van Der Werf GR, Krol MC and Peters W (2014), "Terrestrial cycling of 13CO2 by photosynthesis, respiration, and biomass burning in SiBCASA", Biogeosciences., dec, 2014. Vol. 11(23), pp. 6553-6571. |
| Abstract: We present an enhanced version of the SiBCASA terrestrial biosphere model that is extended with (a) biomass burning emissions from the SiBCASA carbon pools using remotely sensed burned area from the Global Fire Emissions Database (GFED), (b) an isotopic discrimination scheme that calculates 13C signatures of photosynthesis and autotrophic respiration, and (c) a separate set of 13C pools to carry isotope ratios into heterotrophic respiration. We quantify in this study the terrestrial exchange of CO2 and 13CO2 as a function of environmental changes in humidity and biomass burning. The implementation of biomass burning yields similar fluxes as CASA-GFED both in magnitude and spatial patterns. The implementation of isotope exchange gives a global mean discrimination value of 15.2&permil;, ranges between 4 and 20&permil; depending on the photosynthetic pathway in the plant, and compares favorably (annually and seasonally) with other published values. Similarly, the isotopic disequilibrium is similar to other studies that include a small effect of biomass burning as it shortens the turnover of carbon. In comparison to measurements, a newly modified starch/sugar storage pool propagates the isotopic discrimination anomalies to respiration much better. In addition, the amplitude of the drought response by SiBCASA is lower than suggested by the measured isotope ratios. We show that a slight increase in the stomatal closure for large vapor pressure deficit would amplify the respired isotope ratio variability. Our study highlights the importance of isotope ratio observations of 13C to assess and improve biochemical models like SiBCASA, especially with regard to the allocation and turnover of carbon and the responses to drought. |
BibTeX:
@article{VanDerVelde2014,
author = {Van Der Velde, I R and Miller, J B and Schaefer, K and Van Der Werf, G R and Krol, M C and Peters, W},
title = {Terrestrial cycling of 13CO2 by photosynthesis, respiration, and biomass burning in SiBCASA},
journal = {Biogeosciences},
year = {2014},
volume = {11},
number = {23},
pages = {6553--6571},
url = {http://www.biogeosciences.net/11/6553/2014/},
doi = {10.5194/bg-11-6553-2014}
}
|
| Vardag SN, Hammer S, O'Doherty S, Spain TG, Wastine B, Jordan A and Levin I (2014), "Comparisons of continuous atmospheric CH4, CO2 and N2O measurements - Results from a travelling instrument campaign at Mace Head", Atmospheric Chemistry and Physics., aug, 2014. Vol. 14(16), pp. 8403-8418. |
| Abstract: A 2-month measurement campaign with a Fourier transform infrared analyser as a travelling comparison instrument (TCI) was performed at the Advanced Global Atmospheric Gases Experiment (AGAGE) andWorld Meteorological Organization (WMO) Global AtmosphereWatch (GAW) station at Mace Head, Ireland. The aim was to evaluate the compatibility of atmospheric methane (CH4), carbon dioxide (CO2) and nitrous oxide (N2O) measurements of the routine station instrumentation, consisting of a gas chromatograph (GC) for CH4 and N2O as well as a cavity ring-down spectroscopy (CRDS) system for CH4 and CO2. The advantage of a TCI approach for quality control is that the comparison covers the entire ambient air measurement system, including the sample intake system and the data evaluation process. For initial quality and performance control, the TCI was run in parallel with the Heidelberg GC before and after the measurement campaign at Mace Head. Median differences between the Heidelberg GC and the TCI were well within the WMO inter-laboratory compatibility target for all three greenhouse gases. At Mace Head, the median difference between the station GC and the TCI were -0.04 nmol mol-1 for CH4 and -0.37 nmol mol-1 for N2O (GC-TCI). For N2O, a similar difference (-0.40 nmol mol-1) was found when measuring surveillance or working gas cylinders with both instruments. This suggests that the difference observed in ambient air originates from a calibration offset that could partly be due to a difference between theWMON2O X2006a reference scale used for the TCI and the Scripps Institution of Oceanography (SIO-1998) scale used at Mace Head and in the whole AGAGE network. Median differences between the CRDS G1301 and the TCI at Mace Head were 0.12 nmol mol-1 for CH4 and 0.14 μmol mol-1 for CO2 (CRDS G1301 - TCI). The difference between both instruments for CO2 could not be explained, as direct measurements of calibration gases show no such difference. The CH4 differences between the TCI, the GC and the CRDS G1301 at Mace Head are much smaller than the WMO inter-laboratory compatibility target, while this is not the case for CO2 and N2O. |
BibTeX:
@article{Vardag2014,
author = {Vardag, S N and Hammer, S and O'Doherty, S and Spain, T G and Wastine, B and Jordan, A and Levin, I},
title = {Comparisons of continuous atmospheric CH4, CO2 and N2O measurements - Results from a travelling instrument campaign at Mace Head},
journal = {Atmospheric Chemistry and Physics},
year = {2014},
volume = {14},
number = {16},
pages = {8403--8418},
url = {http://www.atmos-chem-phys.net/14/8403/2014/},
doi = {10.5194/acp-14-8403-2014}
}
|
| Wang G, Dai M, Shen SSP, Bai Y and Xu Y (2014), " Quantifying uncertainty sources in the gridded data of sea surface CO 2 partial pressure ", Journal of Geophysical Research: Oceans., aug, 2014. Vol. 119(8), pp. 5181-5189. American Geophysical Union (AGU). |
| Abstract: DOM的吸光系数可以用来评估盐度,如果CDOM吸光和盐度是保守的而且卫星的吸光算法够准。长江口区:建立一个盐度和吸光的反转模型,有效性用一个独立的数据库检验:73.6%的盐度误差在±1,87.5%的盐度误差在±1.5.影响保守性的因素,主要关注浮游植物产生的自身CDOM。另外多处的卫星吸光算法和现场实测的数据作为比较。发现用卫星数据回推的盐度是可靠的,可以帮助生地化循环的研究。 |
BibTeX:
@article{Wang2014,
author = {Wang, Guizhi and Dai, Minhan and Shen, Samuel S. P. and Bai, Yan and Xu, Yi},
title = { Quantifying uncertainty sources in the gridded data of sea surface CO 2 partial pressure },
journal = {Journal of Geophysical Research: Oceans},
publisher = {American Geophysical Union (AGU)},
year = {2014},
volume = {119},
number = {8},
pages = {5181--5189},
url = {https://agupubs.onlinelibrary.wiley.com/doi/full/10.1002/2013JC009577 https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1002/2013JC009577 https://agupubs.onlinelibrary.wiley.com/doi/10.1002/2013JC009577},
doi = {10.1002/2013jc009577}
}
|
| Wang Z, Deutscher NM, Warneke T, Notholt J, Dils B, Griffith DWT, Schmidt M, Ramonet M and Gerbig C (2014), "Retrieval of tropospheric column-averaged CH4 mole fraction by solar absorption FTIR-spectrometry using N2O as a proxy", Atmospheric Measurement Techniques., oct, 2014. Vol. 7(10), pp. 3295-3305. |
| Abstract: Tropospheric column-averaged CH4 mole fractions were derived from ground-based column absorption measurements. The method uses stratospheric N2O columns to correct for the stratospheric contribution to the CH4 total column. The method was applied to four Total Carbon Column Observing Network (TCCON) sites covering locations from the Northern Arctic to the tropics. It performs well for all sites. The derived tropospheric CH4 concentrations were compared with profiles measured by aircraft at three sites. The results indicate an inter-site consistency within 6 ppb (∼0.3%). With aircraft profiles up to 3 km, the seasonal behavior of the derived tropospheric CH4 concentration was also checked, revealing a difference of around 20 ppb. The mean relative uncertainty of the four sites, as estimated from the daily standard deviations, is 0.23%. |
BibTeX:
@article{Wang2014a,
author = {Wang, Z and Deutscher, N M and Warneke, T and Notholt, J and Dils, B and Griffith, D W T and Schmidt, M and Ramonet, M and Gerbig, C},
title = {Retrieval of tropospheric column-averaged CH4 mole fraction by solar absorption FTIR-spectrometry using N2O as a proxy},
journal = {Atmospheric Measurement Techniques},
year = {2014},
volume = {7},
number = {10},
pages = {3295--3305},
url = {http://www.atmos-meas-tech.net/7/3295/2014/},
doi = {10.5194/amt-7-3295-2014}
}
|
| Weaver C, Kiemle C, Kawa SR, Aalto T, Necki J, Steinbacher M, Arduini J, Apadula F, Berkhout H and Hatakka J (2014), "Retrieval of methane source strengths in Europe using a simple modeling approach to assess the potential of spaceborne lidar observations", Atmospheric Chemistry and Physics., mar, 2014. Vol. 14(5), pp. 2625-2637. |
| Abstract: We investigate the sensitivity of future spaceborne lidar measurements to changes in surface methane emissions. We use surface methane observations from nine European ground stations and a Lagrangian transport model to infer surface methane emissions for 2010. Our inversion shows the strongest emissions from the Netherlands, the coal mines in Upper Silesia, Poland, and wetlands in southern Finland. The simulated methane surface concentrations capture at least half of the daily variability in the observations, suggesting that the transport model is correctly simulating the regional transport pathways over Europe. With this tool we can test whether proposed methane lidar instruments will be sensitive to changes in surface emissions. We show that future lidar instruments should be able to detect a 50% reduction in methane emissions from the Netherlands and Germany, at least during summer. textcopyright 2014 Author(s). |
BibTeX:
@article{Weaver2014,
author = {Weaver, C and Kiemle, C and Kawa, S R and Aalto, T and Necki, J and Steinbacher, M and Arduini, J and Apadula, F and Berkhout, H and Hatakka, J},
title = {Retrieval of methane source strengths in Europe using a simple modeling approach to assess the potential of spaceborne lidar observations},
journal = {Atmospheric Chemistry and Physics},
year = {2014},
volume = {14},
number = {5},
pages = {2625--2637},
url = {http://www.atmos-chem-phys.net/14/2625/2014/},
doi = {10.5194/acp-14-2625-2014}
}
|
| Wecht KJ, Jacob DJ, Sulprizio MP, Santoni GW, Wofsy SC, Parker R, Bösch H and Worden J (2014), "Spatially resolving methane emissions in California: Constraints from the CalNex aircraft campaign and from present (GOSAT, TES) and future (TROPOMI, geostationary) satellite observations", Atmospheric Chemistry and Physics., aug, 2014. Vol. 14(15), pp. 8173-8184. |
| Abstract: We apply a continental-scale inverse modeling system for North America based on the GEOS-Chem model to optimize California methane emissions at 1/2° × 2/3° horizontal resolution using atmospheric observations from the CalNex aircraft campaign (May-June 2010) and from satellites. Inversion of the CalNex data yields a best estimate for total California methane emissions of 2.86 ± 0.21 Tg asup-1/sup, compared with 1.92 Tg a sup-1/sup in the EDGAR v4.2 emission inventory used as a priori and 1.51 Tg asup-1/sup in the California Air Resources Board (CARB) inventory used for state regulations of greenhouse gas emissions. These results are consistent with a previous Lagrangian inversion of the CalNex data. Our inversion provides 12 independent pieces of information to constrain the geographical distribution of emissions within California. Attribution to individual source types indicates dominant contributions to emissions from landfills/wastewater (1.1 Tg a sup-1/sup), livestock (0.87 Tg asup-1/sup), and gas/oil (0.64 Tg a sup-1/sup). EDGAR v4.2 underestimates emissions from livestock, while CARB underestimates emissions from landfills/wastewater and gas/oil. Current satellite observations from GOSAT can constrain methane emissions in the Los Angeles Basin but are too sparse to constrain emissions quantitatively elsewhere in California (they can still be qualitatively useful to diagnose inventory biases). Los Angeles Basin emissions derived from CalNex and GOSAT inversions are 0.42 ± 0.08 and 0.31 ± 0.08 Tg asup-1/sup that the future TROPOMI satellite instrument (2015 launch) will be able to constrain California methane emissions at a detail comparable to the CalNex aircraft campaign. Geostationary satellite observations offer even greater potential for constraining methane emissions in the future. textcopyright Author(s) 2014. |
BibTeX:
@article{Wecht2014,
author = {Wecht, K J and Jacob, D J and Sulprizio, M P and Santoni, G W and Wofsy, S C and Parker, R and Bösch, H and Worden, J},
title = {Spatially resolving methane emissions in California: Constraints from the CalNex aircraft campaign and from present (GOSAT, TES) and future (TROPOMI, geostationary) satellite observations},
journal = {Atmospheric Chemistry and Physics},
year = {2014},
volume = {14},
number = {15},
pages = {8173--8184},
url = {http://www.atmos-chem-phys.net/14/8173/2014/},
doi = {10.5194/acp-14-8173-2014}
}
|
| Wei S, Yi C, Hendrey G, Eaton T, Rustic G, Wang S, Liu H, Krakauer NY, Wang W, Desai AR, Montagnani L, Tha Paw U K, Falk M, Black A, Bernhofer C, Grünwald T, Laurila T, Cescatti A, Moors E, Bracho R and Valentini R (2014), "Data-based perfect-deficit approach to understanding climate extremes and forest carbon assimilation capacity", Environmental Research Letters., may, 2014. Vol. 9(6), pp. 65002. |
| Abstract: Several lines of evidence suggest that the warming climate plays a vital role in driving certain types of extreme weather. The impact of warming and of extreme weather on forest carbon assimilation capacity is poorly known. Filling this knowledge gap is critical towards understanding the amount of carbon that forests can hold. Here, we used a perfect-deficit approach to identify forest canopy photosynthetic capacity (CPC) deficits and analyze how they correlate to climate extremes, based on observational data measured by the eddy covariance method at 27 forest sites over 146 site-years. We found that droughts severely affect the carbon assimilation capacities of evergreen broadleaf forest (EBF) and deciduous broadleaf forest. The carbon assimilation capacities of Mediterranean forests were highly sensitive to climate extremes, while marine forest climates tended to be insensitive to climate extremes. Our estimates suggest an average global reduction of forest CPC due to unfavorable climate extremes of 6.3 Pg C (∼5.2% of global gross primary production) per growing season over 2001-2010, with EBFs contributing 52% of the total reduction. textcopyright 2014 IOP Publishing Ltd. |
BibTeX:
@article{Wei2014,
author = {Wei, Suhua and Yi, Chuixiang and Hendrey, George and Eaton, Timothy and Rustic, Gerald and Wang, Shaoqiang and Liu, Heping and Krakauer, Nir Y and Wang, Weiguo and Desai, Ankur R and Montagnani, Leonardo and Tha Paw U, Kyaw and Falk, Matthias and Black, Andrew and Bernhofer, Christian and Grünwald, Thomas and Laurila, Tuomas and Cescatti, Alessandro and Moors, Eddy and Bracho, Rosvel and Valentini, Riccardo},
title = {Data-based perfect-deficit approach to understanding climate extremes and forest carbon assimilation capacity},
journal = {Environmental Research Letters},
year = {2014},
volume = {9},
number = {6},
pages = {65002},
url = {http://stacks.iop.org/1748-9326/9/i=6/a=065002?key=crossref.b296a40b3b5135f3084266af15e0ebfd},
doi = {10.1088/1748-9326/9/6/065002}
}
|
| Yuan W, Cai W, Liu S, Dong W, Chen J, Arain MA, Blanken PD, Cescatti A, Wohlfahrt G, Georgiadis T, Genesio L, Gianelle D, Grelle A, Kiely G, Knohl A, Liu D, Marek MV, Merbold L, Montagnani L, Panferov O, Peltoniemi M, Rambal S, Raschi A, Varlagin A and Xia J (2014), "Vegetation-specific model parameters are not required for estimating gross primary production", Ecological Modelling., nov, 2014. Vol. 292, pp. 1-10. |
| Abstract: Models of gross primary production (GPP) based on remote sensing measurements are currently parameterized with vegetation-specific parameter sets and therefore require accurate information on the distribution of vegetation to drive them. Can this parameterization scheme be replaced with a vegetation-invariant set of parameters that can maintain or increase model applicability by reducing errors introduced from the uncertainty of land cover classification? Based on the measurements of ecosystem carbon fluxes from 168 globally distributed sites in a range of vegetation types, we examined the predictive capacity of seven light use efficiency (LUE) models. Two model experiments were conducted: (i) a constant set of parameters for various vegetation types and (ii) vegetation-specific parameters. The results showed no significant differences in model performance in simulating GPP while using both set of parameters. These results indicate that a universal of set of parameters, which is independent of vegetation cover type and characteristics can be adopted in prevalent LUE models. Availability of this well tested and universal set of parameters would help to improve the accuracy and applicability of LUE models in various biomes and geographic regions. textcopyright 2014 Elsevier B.V. |
BibTeX:
@article{Yuan2014,
author = {Yuan, Wenping and Cai, Wenwen and Liu, Shuguang and Dong, Wenjie and Chen, Jiquan and Arain, M Altaf and Blanken, Peter D and Cescatti, Alessandro and Wohlfahrt, Georg and Georgiadis, Teodoro and Genesio, Lorenzo and Gianelle, Damiano and Grelle, Achim and Kiely, Gerard and Knohl, Alexander and Liu, Dan and Marek, Michal V and Merbold, Lutz and Montagnani, Leonardo and Panferov, Oleg and Peltoniemi, Mikko and Rambal, Serge and Raschi, Antonio and Varlagin, Andrej and Xia, Jiangzhou},
title = {Vegetation-specific model parameters are not required for estimating gross primary production},
journal = {Ecological Modelling},
year = {2014},
volume = {292},
pages = {1--10},
url = {http://linkinghub.elsevier.com/retrieve/pii/S0304380014003962},
doi = {10.1016/j.ecolmodel.2014.08.017}
}
|
| Zeng J, Nojiri Y, Landschützer P, Telszewski M and Nakaoka S (2014), "A global surface ocean fCO2 climatology based on a feed-forward neural network", Journal of Atmospheric and Oceanic Technology., aug, 2014. Vol. 31(8), pp. 1838-1849. American Meteorological Society. |
| Abstract: A feed-forward neural network is used to create a monthly climatology of the sea surface fugacity of CO2 (fCO2) on a 1° × 1° spatial resolution. Using 127 880 data points from 1990 to 2011 in the track-gridded database of the Surface Ocean CO2 Atlas version 2.0 (Bakker et al.), the model yields a global mean fCO2 increase rate of 1.50 μatm yr-1. The rate was used to normalize multiple years' fCO2 observations to the reference year of 2000. A total of 73 265 data points from the normalized data were used to model the global fCO2 climatology. The model simulates monthly fCO2 distributions that agree well with observations and yields an anthropogenic CO2 update of -1.9 to -2.3 PgCyr-1. The range reflects the uncertainty related to using different wind products for the flux calculation. This estimate is in good agreement with the recently derived best estimate by Wanninkhof et al. The model product benefits from a finer spatial resolution compared to the product of Lamont-Doherty Earth Observatory (Takahashi et al.), which is currently the most frequently used product. It therefore has the potential to improve estimates of the global ocean CO2 uptake. The method's benefits include but are not limited to the following: (i) a fixed structure is not required to model fCO2 as a nonlinear function of biogeochemical variables, (ii) only one neural network configuration is sufficient to model global fCO2 in all seasons, and (iii) the model can be extended to produce global fCO2 maps at a higher resolution in time and space as long as the required data for input variables are available. textcopyright 2014 American Meteorological Society. |
BibTeX:
@article{Zeng2014,
author = {Zeng, J. and Nojiri, Y. and Landschützer, P. and Telszewski, M. and Nakaoka, S.},
title = {A global surface ocean fCO2 climatology based on a feed-forward neural network},
journal = {Journal of Atmospheric and Oceanic Technology},
publisher = {American Meteorological Society},
year = {2014},
volume = {31},
number = {8},
pages = {1838--1849},
url = {http://journals.ametsoc.org/jtech/article-pdf/31/8/1838/3369010/jtech-d-13-00137_1.pdf},
doi = {10.1175/JTECH-D-13-00137.1}
}
|
| Zhang HF, Chen BZ, van der Laan-Luijkx IT, Machida T, Matsueda H, Sawa Y, Fukuyama Y, Langenfelds R, Van Der Schoot M, Xu G, Yan JW, Cheng ML, Zhou LX, Tans PP and Peters W (2014), "Estimating Asian terrestrial carbon fluxes from CONTRAIL aircraft and surface CO2 observations for the period 2006-2010", Atmospheric Chemistry and Physics., jun, 2014. Vol. 14(11), pp. 5807-5824. |
| Abstract: Current estimates of the terrestrial carbon fluxes in Asia show large uncertainties particularly in the boreal and mid-latitudes and in China. In this paper, we present an updated carbon flux estimate for Asia ("Asia" refers to lands as far west as the Urals and is divided into boreal Eurasia, temperate Eurasia and tropical Asia based on TransCom regions) by introducing aircraft CO2 measurements from the CONTRAIL (Comprehensive Observation Network for Trace gases by Airline) program into an inversion modeling system based on the CarbonTracker framework. We estimated the averaged annual total Asian terrestrial land CO2 sink was about -1.56 Pg Cyr-1 over the period 2006-2010, which offsets about one-third of the fossil fuel emission from Asia (+4.15 Pg C yr-1). The uncertainty of the terrestrial uptake estimate was derived from a set of sensitivity tests and ranged from -1.07 to -1.80 Pg Cyr-1, comparable to the formal Gaussian error of ±1.18 Pg Cyr-1 (1-sigma). The largest sink was found in forests, predominantly in coniferous forests (-0.64 ± 0.70 Pg C yr-1) and mixed forests (-0.14 ± 0.27 Pg C yr -1); and the second and third large carbon sinks were found in grass/shrub lands and croplands, accounting for -0.44 ± 0.48 Pg Cyr -1 and -0.20 ± 0.48 Pg Cyr-1, respectively. The carbon fluxes per ecosystem type have large a priori Gaussian uncertainties, and the reduction of uncertainty based on assimilation of sparse observations over Asia is modest (8.7-25.5%) for most individual ecosystems. The ecosystem flux adjustments follow the detailed a priori spatial patterns by design, which further increases the reliance on the a priori biosphere exchange model. The peak-to-peak amplitude of inter-annual variability (IAV) was 0.57 Pg Cyr -1 ranging from -1.71 Pg Cyr-1 to -2.28 Pg Cyr -1. The IAV analysis reveals that the Asian CO2 sink was sensitive to climate variations, with the lowest uptake in 2010 concurrent with a summer flood and autumn drought and the largest CO2 sink in 2009 owing to favorable temperature and plentiful precipitation conditions. We also found the inclusion of the CONTRAIL data in the inversion modeling system reduced the uncertainty by 11% over the whole Asian region, with a large reduction in the southeast of boreal Eurasia, southeast of temperate Eurasia and most tropical Asian areas. textcopyright Author(s) 2014. |
BibTeX:
@article{Zhang2014,
author = {Zhang, H F and Chen, B Z and van der Laan-Luijkx, I T and Machida, T and Matsueda, H and Sawa, Y and Fukuyama, Y and Langenfelds, R and Van Der Schoot, M and Xu, G and Yan, J W and Cheng, M L and Zhou, L X and Tans, P P and Peters, W},
title = {Estimating Asian terrestrial carbon fluxes from CONTRAIL aircraft and surface CO2 observations for the period 2006-2010},
journal = {Atmospheric Chemistry and Physics},
year = {2014},
volume = {14},
number = {11},
pages = {5807--5824},
url = {http://www.atmos-chem-phys.net/14/5807/2014/},
doi = {10.5194/acp-14-5807-2014}
}
|
| Zhang HF, Chen BZ, Van Der Laan-Luijkx IT, Chen J, Xu G, Yan JW, Zhou LX, Fukuyama Y, Tans PP and Peters W (2014), "Net terrestrial CO2 exchange over China during 2001–2010 estimated with an ensemble data assimilation system for atmospheric CO2", Journal of Geophysical Research., mar, 2014. Vol. 119(6), pp. 3500-3515. |
| Abstract: In this paper we present an estimate of net ecosystem CO2 exchange over China for the years 2001–2010 using the CarbonTracker Data Assimilation System for CO2 (CTDAS). Additional Chinese and Asian CO2 observations are used in CTDAS to improve our estimate. We found that the combined terrestrial ecosystems in China absorbed about -0.33 Pg C yr-1 during 2001–2010. The uncertainty on Chinese terrestrial carbon exchange estimates as derived from a set of sensitivity experiments suggests a range of -0.29 to -0.64 Pg C yr-1. This total Chinese terrestrial CO2 sink is attributed to the three major biomes (forests, croplands, and grass/shrublands) with estimated CO2 fluxes of -0.12 Pg C yr-1 (range from -0.09 to -0.19 Pg C yr-1), -0.12 Pg C yr-1 (range from -0.09 to -0.26 Pg C yr-1), and -0.09 Pg C yr-1 (range from -0.09 to -0.17 Pg C yr-1), respectively. The peak-to-peak amplitude of interannual variability of the Chinese terrestrial ecosystem carbon flux is 0.21 Pg C yr-1 (˜64% of mean annual average), with the smallest CO2 sink (-0.19 Pg C yr-1) in 2003 and the largest CO2 sink (0.40 Pg C yr-1) in 2007. We stress that our estimate of terrestrial ecosystem CO2 uptake based on inverse modeling strongly depends on a limited number of atmospheric CO2 observations used. More observations in China specifically and in Asia in general are needed to improve the accuracy of terrestrial carbon budgeting for this region. |
BibTeX:
@article{Zhang2014a,
author = {Zhang, H F and Chen, B Z and Van Der Laan-Luijkx, I T and Chen, J and Xu, G and Yan, J W and Zhou, L X and Fukuyama, Y and Tans, P P and Peters, W},
title = {Net terrestrial CO2 exchange over China during 2001–2010 estimated with an ensemble data assimilation system for atmospheric CO2},
journal = {Journal of Geophysical Research},
year = {2014},
volume = {119},
number = {6},
pages = {3500--3515},
url = {http://doi.wiley.com/10.1002/2013JD021297},
doi = {10.1002/2013JD021297}
}
|
| Zielis S, Etzold S, Zweifel R, Eugster W, Haeni M and Buchmann N (2014), "NEP of a Swiss subalpine forest is significantly driven not only by current but also by previous year's weather", Biogeosciences., mar, 2014. Vol. 11(6), pp. 1627-1635. |
| Abstract: Understanding the response of forest net ecosystem productivity (NEP) to environmental drivers under climate change is highly relevant for predictions of annual forest carbon (C) flux budgets. Modeling annual forest NEP with soil-vegetation-atmosphere transfer models (SVATs), however, remains challenging due to unknown delayed responses to weather of the previous year. In this study, we addressed the influence of previous year's weather on the interannual variability of NEP for a subalpine spruce forest in Switzerland. Analysis of long-term (1997-2011) eddy covariance measurements showed that the Norway spruce forest Davos Seehornwald was a consistent sink for atmospheric CO2, sequestering 210 ± 88 g C m-2 yr-1 on average. Previous year's weather strongly affected interannual variability of NEP, increasing the explained variance in linear models to 53% compared to 20% without accounting for previous year's weather. Thus, our results highlight the need to consider previous year's weather in modeling annual C budgets of forests. Furthermore, soil temperature in the current year's spring played a major role controlling annual NEP, mainly by influencing gross primary productivity early in the year, with spring NEP accounting for 56% of annual NEP. Consequently, we expect an increase in net CO2 uptake with future climate warming, as long as no other resources become limiting. |
BibTeX:
@article{Zielis2014,
author = {Zielis, S and Etzold, S and Zweifel, R and Eugster, W and Haeni, M and Buchmann, N},
title = {NEP of a Swiss subalpine forest is significantly driven not only by current but also by previous year's weather},
journal = {Biogeosciences},
year = {2014},
volume = {11},
number = {6},
pages = {1627--1635},
url = {http://www.biogeosciences.net/11/1627/2014/},
doi = {10.5194/bg-11-1627-2014}
}
|
| Zona D, Gioli B, Fares S, De Groote T, Pilegaard K, Ibrom A and Ceulemans R (2014), "Environmental controls on ozone fluxes in a poplar plantation in Western Europe", Environmental Pollution., jan, 2014. Vol. 184, pp. 201-210. |
| Abstract: Tropospheric O3 is a strong oxidant that may affect vegetation and human health. Here we report on the O3 fluxes from a poplar plantation in Belgium during one year. Surprisingly, the winter and autumn O3 fluxes were of similar magnitude to ones observed during most of the peak vegetation development. Largest O3 uptakes were recorded at the beginning of the growing season in correspondence to a minimum stomatal uptake. Wind speed was the most important control and explained 44% of the variability in the nighttime O3 fluxes, suggesting that turbulent mixing and the mechanical destruction of O3 played a substantial role in the O3 fluxes. The stomatal O3 uptake accounted for a seasonal average of 59% of the total O3 uptake. Multiple regression and partial correlation analyses showed that net ecosystem exchange was not affected by the stomatal O3 uptake. textcopyright 2013 The Authors. Published by Elsevier Ltd. All rights reserved. |
BibTeX:
@article{Zona2014,
author = {Zona, D and Gioli, B and Fares, S and De Groote, T and Pilegaard, K and Ibrom, A and Ceulemans, R},
title = {Environmental controls on ozone fluxes in a poplar plantation in Western Europe},
journal = {Environmental Pollution},
year = {2014},
volume = {184},
pages = {201--210},
url = {http://linkinghub.elsevier.com/retrieve/pii/S0269749113004570},
doi = {10.1016/j.envpol.2013.08.032}
}
|
| Alekseychik P, Mammarella I, Launiainen S, Rannik Ü and Vesala T (2013), "Evolution of the nocturnal decoupled layer in a pine forest canopy", Agricultural and Forest Meteorology., jun, 2013. Vol. 174-175, pp. 15-27. |
| Abstract: Estimates of the biosphere-atmosphere exchange rates measured using the eddy-covariance (EC) technique are often found to deviate from their expected values. The mismatch is caused by a variety of poorly known and quantified processes, such as storage, subcanopy advection, drainage flows and other non-turbulent air motions, which become particularly important at nighttime. In many forest sites, clear and calm nights favor the generation of the phenomenon commonly known as decoupling, when the above- and sub-canopy air layers relation can be significantly weakened. The data obtained above and within a Scots pine forest at the SMEAR II-station in Hyytiälä, southern Finland, were used to study the decoupling conditions. Certain features of the site (sloping terrain, tall pine trees, sharp separation of the canopy and trunk spaces, insignificant undergrowth) facilitate and augment the development of decoupling conditions. As a result, the EC measurement data contain a multitude of severe CO2 flux loss cases biasing the carbon balance estimates. The results concerning decoupling cases are presented and the mechanisms of generation and alteration of the decoupling conditions are discussed. Different regimes of decoupling were detected based on the vertical profile of the mean wind direction. Decoupling was defined as the periods when the wind directional shear in the canopy or trunk space exceeded predefined thresholds. In at least 18.6% of all nighttime periods, decoupling conditions were identifiable by high wind directional shear in the canopy sublayer.A close relation between the stability estimated by the Richardson number and the decoupled layer thickness was observed. Decoupling interface tended to move to a higher level as stability increased. Drainage flow was detected near the ground in the cases of maximum decoupled layer thickness. Finally, the difference was drawn between the drainage flow and the decoupled layer based on observational evidence. textcopyright 2013 Elsevier B.V. |
BibTeX:
@article{Alekseychik2013,
author = {Alekseychik, P and Mammarella, I and Launiainen, S and Rannik, Ü and Vesala, T},
title = {Evolution of the nocturnal decoupled layer in a pine forest canopy},
journal = {Agricultural and Forest Meteorology},
year = {2013},
volume = {174-175},
pages = {15--27},
url = {http://linkinghub.elsevier.com/retrieve/pii/S0168192313000257},
doi = {10.1016/j.agrformet.2013.01.011}
}
|
| Arévalo-Martínez DL, Beyer M, Krumbholz M, Piller I, Kock A, Steinhoff T, Körtzinger A and Bange HW (2013), "A new method for continuous measurements of oceanic and atmospheric N 2O, CO and CO2: Performance of off-axis integrated cavity output spectroscopy (OA-ICOS) coupled to non-dispersive infrared detection (NDIR)", Ocean Science., dec, 2013. Vol. 9(6), pp. 1071-1087. |
| Abstract: A new system for continuous, highly resolved oceanic and atmospheric measurements of N2O, CO and CO2 is described. The system is based upon off-axis integrated cavity output spectroscopy (OA-ICOS) and a non-dispersive infrared analyzer (NDIR), both coupled to a Weiss-type equilibrator. Performance of the combined setup was evaluated by testing its precision, accuracy, long-term stability, linearity and response time. Furthermore, the setup was tested during two oceanographic campaigns in the equatorial Atlantic Ocean in order to explore its potential for autonomous deployment onboard voluntary observing ships (VOS). Improved equilibrator response times for N2O (2.5 min) and CO (45 min) were achieved in comparison to response times from similar chamber designs used by previous studies. High stability of the OA-ICOS analyzer was demonstrated by low optimal integration times of 2 and 4 min for N2O and CO respectively, as well as detection limits of 40 ppt and precision better than 0.3 ppb Hz -1/2. Results from a direct comparison of the method presented here and well-established discrete methods for oceanic N2O and CO 2 measurements showed very good consistency. The favorable agreement between underway atmospheric N2O, CO and CO2 measurements and monthly means at Ascension Island (7.96°S 14.4°W) further suggests a reliable operation of the underway setup in the field. The potential of the system as an improved platform for measurements of trace gases was explored by using continuous N2O and CO2 data to characterize the development of the seasonal equatorial upwelling in the Atlantic Ocean during two R/V Maria S. Merian cruises. A similar record of high-resolution CO measurements was simultaneously obtained, offering, for the first time, the possibility of a comprehensive view of the distribution and emissions of these climate-relevant gases in the area studied. The relatively simple underway N2O/CO/CO2 setup is suitable for long-term deployment onboard research and commercial vessels although potential sources of drift, such as cavity temperature, and further technical improvements towards automation, still need to be addressed. textcopyright Author(s) 2013. CC Attribution 3.0 License. |
BibTeX:
@article{Arevalo-Martinez2013,
author = {Arévalo-Martínez, D L and Beyer, M and Krumbholz, M and Piller, I and Kock, A and Steinhoff, T and Körtzinger, A and Bange, H W},
title = {A new method for continuous measurements of oceanic and atmospheric N 2O, CO and CO2: Performance of off-axis integrated cavity output spectroscopy (OA-ICOS) coupled to non-dispersive infrared detection (NDIR)},
journal = {Ocean Science},
year = {2013},
volume = {9},
number = {6},
pages = {1071--1087},
url = {http://www.ocean-sci.net/9/1071/2013/},
doi = {10.5194/os-9-1071-2013}
}
|
| Arias-Navarro C, Díaz-Pinés E, Kiese R, Rosenstock TS, Rufino MC, Stern D, Neufeldt H, Verchot LV and Butterbach-Bahl K (2013), "Gas pooling: A sampling technique to overcome spatial heterogeneity of soil carbon dioxide and nitrous oxide fluxes", Soil Biology and Biochemistry., dec, 2013. Vol. 67, pp. 20-23. |
| Abstract: Small-scale spatial variability in soil carbon dioxide (CO2) and nitrous oxide (N2O) fluxes poses serious challenges to the experimental design, and number of gas samples needed to provide a reliable estimate of flux usually exceeds analytical capacities. We pooled gas samples -analogously to soil pooling - toovercome this challenge. Our sample pooling technique collects a composite gas sample from several chambers instead of the conventional practise of analyzing samples from chambers individually, thusreducing numbers of gas samples. The method was verified to be reasonably accurate in forest, grassland and agricultural fields over a four week measurement campaign. Pooling technique results differed by2-8% for CO2 and by 3-4% for N2O when compared to individual chamber means. That shows pooling of gas samples across individual static chambers is an acceptable approach to integrate spatial heterogeneity. textcopyright 2013 Elsevier Ltd. |
BibTeX:
@article{Arias-Navarro2013,
author = {Arias-Navarro, Cristina and Díaz-Pinés, Eugenio and Kiese, Ralf and Rosenstock, Todd S and Rufino, Mariana C and Stern, David and Neufeldt, Henry and Verchot, Louis V and Butterbach-Bahl, Klaus},
title = {Gas pooling: A sampling technique to overcome spatial heterogeneity of soil carbon dioxide and nitrous oxide fluxes},
journal = {Soil Biology and Biochemistry},
year = {2013},
volume = {67},
pages = {20--23},
url = {http://linkinghub.elsevier.com/retrieve/pii/S0038071713002769},
doi = {10.1016/j.soilbio.2013.08.011}
}
|
| Barr AG, Richardson AD, Hollinger DY, Papale D, Arain MA, Black TA, Bohrer G, Dragoni D, Fischer ML, Gu L, Law BE, Margolis HA, Mccaughey JH, Munger JW, Oechel W and Schaeffer K (2013), "Use of change-point detection for friction-velocity threshold evaluation in eddy-covariance studies", Agricultural and Forest Meteorology., apr, 2013. Vol. 171-172, pp. 31-45. |
| Abstract: The eddy-covariance method often underestimates fluxes under stable, low-wind conditions at night when turbulence is not well developed. The most common approach to resolve the problem of nighttime flux underestimation is to identify and remove the deficit periods using friction-velocity (u*) threshold filters (u*Th). This study modifies an accepted method for u*Th evaluation by incorporating change-point-detection techniques. The original and modified methods are evaluated at 38 sites as part of the North American Carbon Program (NACP) site-level synthesis. At most sites, the modified method produced u*Th estimates that were higher and less variable than the original method. It also provided an objective method to identify sites that lacked a u*Th response. The modified u*Th estimates were robust and comparable among years. Inter-annual u*Th differences were small, so that a single u*Th value was warranted at most sites. No variation in the u*Th was observed by time of day (dusk versus mid or late night), however, a few sites showed significant u*Th variation with time of year. Among-site variation in the u*Th was strongly related to canopy height and the mean annual nighttime u*. The modified u*Th estimates excluded a high fraction of nighttime data - 61% on average. However, the negative impact of the high exclusion rate on annual net ecosystem production (NEP) was small compared to the larger impact of underestimating the u*Th. Compared to the original method, the higher u*Th estimates from the modified method caused a mean 8% reduction in annual NEP across all site-years, and a mean 7% increase in total ecosystem respiration (Re). The modified method also reduced the u*Th-related uncertainties in annual NEP and Re by more than 50%. These results support the use of u*Th filters as a pragmatic solution to a complex problem. textcopyright 2012 A.G. Barr. |
BibTeX:
@article{Barr2013,
author = {Barr, A G and Richardson, A D and Hollinger, D Y and Papale, D and Arain, M A and Black, T A and Bohrer, G and Dragoni, D and Fischer, M L and Gu, L and Law, B E and Margolis, H A and Mccaughey, J H and Munger, J W and Oechel, W and Schaeffer, K},
title = {Use of change-point detection for friction-velocity threshold evaluation in eddy-covariance studies},
journal = {Agricultural and Forest Meteorology},
year = {2013},
volume = {171-172},
pages = {31--45},
url = {http://linkinghub.elsevier.com/retrieve/pii/S0168192312003607},
doi = {10.1016/j.agrformet.2012.11.023}
}
|
| Berchet A, Pison I, Chevallier F, Bousquet P, Conil S, Geever M, Laurila T, LavriÄ J, Lopez M, Moncrieff J, Necki J, Ramonet M, Schmidt M, Steinbacher M and Tarniewicz J (2013), "Towards better error statistics for atmospheric inversions of methane surface fluxes", Atmospheric Chemistry and Physics., jul, 2013. Vol. 13(14), pp. 7115-7132A. |
| Abstract: We adapt general statistical methods to estimate the optimal error covariance matrices in a regional inversion system inferring methane surface emissions from atmospheric concentrations. Using a minimal set of physical hypotheses on the patterns of errors, we compute a guess of the error statistics that is optimal in regard to objective statistical criteria for the specific inversion system. With this very general approach applied to a real-data case, we recover sources of errors in the observations and in the prior state of the system that are consistent with expert knowledge while inferred from objective criteria and with affordable computation costs. By not assuming any specific error patterns, our results depict the variability and the inter-dependency of errors induced by complex factors such as the misrepresentation of the observations in the transport model or the inability of the model to reproduce well the situations of steep gradients of concentrations. Situations with probable significant biases (e.g., during the night when vertical mixing is ill-represented by the transport model) can also be diagnosed by our methods in order to point at necessary improvement in a model. By additionally analysing the sensitivity of the inversion to each observation, guidelines to enhance data selection in regional inversions are also proposed. We applied our method to a recent significant accidental methane release from an offshore platform in the North Sea and found methane fluxes of the same magnitude than what was officially declared. |
BibTeX:
@article{Berchet2013,
author = {Berchet, A and Pison, I and Chevallier, F and Bousquet, P and Conil, S and Geever, M and Laurila, T and LavriÄ, J and Lopez, M and Moncrieff, J and Necki, J and Ramonet, M and Schmidt, M and Steinbacher, M and Tarniewicz, J},
title = {Towards better error statistics for atmospheric inversions of methane surface fluxes},
journal = {Atmospheric Chemistry and Physics},
year = {2013},
volume = {13},
number = {14},
pages = {7115--7132A},
url = {http://www.atmos-chem-phys.net/13/7115/2013/},
doi = {10.5194/acp-13-7115-2013}
}
|
| Berhongaray G, Janssens IA, King JS and Ceulemans R (2013), "Fine root biomass and turnover of two fast-growing poplar genotypes in a short-rotation coppice culture", Plant and Soil., dec, 2013. Vol. 373(1-2), pp. 269-283. |
| Abstract: Background and aims: The quantification of root dynamics remains a major challenge in ecological research because root sampling is laborious and prone to error due to unavoidable disturbance of the delicate soil-root interface. The objective of the present study was to quantify the distribution of the biomass and turnover of roots of poplars (Populus) and associated understory vegetation during the second growing season of a high-density short rotation coppice culture. Methods: Roots were manually picked from soil samples collected with a soil core from narrow (75 cm apart) and wide rows (150 cm apart) of the double-row planting system from two genetically contrasting poplar genotypes. Several methods of estimating root production and turnover were compared. Results: Poplar fine root biomass was higher in the narrow rows than in the wide rows. In spite of genetic differences in above-ground biomass, annual fine root productivity was similar for both genotypes (ca. 44 g DM m-2 year-1). Weed root biomass was equally distributed over the ground surface, and root productivity was more than two times higher compared to poplar fine roots (ca. 109 g DM m-2 year-1). Conclusions: Early in SRC plantation development, weeds result in significant root competition to the crop tree poplars, but may confer certain ecosystem services such as carbon input to soil and retention of available soil N until the trees fully occupy the site. textcopyright 2013 The Author(s). |
BibTeX:
@article{Berhongaray2013,
author = {Berhongaray, Gonzalo and Janssens, I A and King, J S and Ceulemans, R},
title = {Fine root biomass and turnover of two fast-growing poplar genotypes in a short-rotation coppice culture},
journal = {Plant and Soil},
year = {2013},
volume = {373},
number = {1-2},
pages = {269--283},
url = {http://link.springer.com/10.1007/s11104-013-1778-x},
doi = {10.1007/s11104-013-1778-x}
}
|
| Berhongaray G, King JS, Janssens IA and Ceulemans R (2013), "An optimized fine root sampling methodology balancing accuracy and time investment", Plant and Soil., may, 2013. Vol. 366(1-2), pp. 351-361. |
| Abstract: Aims: Tree roots are spatially highly heterogeneous and it thus requires large numbers of samples to detect statistically significant changes in root biomass. The objectives of this study were to understand and quantify the sources of error in the assessment of fine root biomass (2 mm) during the second year of a high-density Populus plantation. Methods: Soil cores were collected in winter (n = 35) and in summer (n = 20), and fine roots were picked by hand for varying lengths of time: 1, 2, 5, 20, 40, and 60 min. The root biomass data were used to identify the best combination of the time spent for root picking and the number of samples collected, that minimizes the overall uncertainty (i. e. the combination of the spatial error due to the incomplete sampling and the temporal error due to the incomplete core processing). Results: On average, 25 min was enough time to pick 90 % of the fine root biomass in winter, while in summer only 10 min were needed. In winter fewer samples were needed, but more time for picking was necessary as compared to summer when root biomass was higher. Conclusions: Fine root sampling can be optimized by minimizing the uncertainty of the biomass estimates and simultaneously decreasing root sampling time investment. textcopyright 2012 Springer Science+Business Media B.V. |
BibTeX:
@article{Berhongaray2013a,
author = {Berhongaray, G and King, J S and Janssens, I A and Ceulemans, R},
title = {An optimized fine root sampling methodology balancing accuracy and time investment},
journal = {Plant and Soil},
year = {2013},
volume = {366},
number = {1-2},
pages = {351--361},
url = {http://link.springer.com/10.1007/s11104-012-1438-6},
doi = {10.1007/s11104-012-1438-6}
}
|
| Berhongaray G, El Kasmioui O and Ceulemans R (2013), "Comparative analysis of harvesting machines onan operational high-density short rotation woody crop (SRWC) culture: One-process versus two-process harvest operation", Biomass and Bioenergy., nov, 2013. Vol. 58, pp. 333-342. |
| Abstract: Short rotation woody crops (SRWCs) are being studied and cultivated because of their potential for bioenergy production. The harvest operation represents the highest input cost for these short rotation woody crops. We evaluated three different harvesting machines representing two harvesting systems at one operational large-scale SRWC plantation. On average, 8tonha-1 of biomass was harvested. The cut-and-chip harvesters were faster than the whole stem harvester; and the self-propelled harvester was faster than the tractor-pulled. Harvesting costs differed among the harvesting machines used and ranged from 388€ha-1 to 541€ha-1. The realized stem cutting heights were 15.46cm and 16.00cm for the tractor-pulled stem harvester and the self-propelled cut-and-chip harvester respectively, although a cutting height of 10cm was requested in advance. From the potential harvestable biomass, only 77.4% was harvested by the self-propelled cut-and-chip harvester, while 94.5% was harvested by the tractor-pulled stem harvester. An increase of the machinery use efficiency (i.e. harvest losses, cost) is necessary to reduce costs and increase the competitiveness of biomass with other energy sources.textcopyright 2013 The Authors. |
BibTeX:
@article{Berhongaray2013b,
author = {Berhongaray, G and El Kasmioui, O and Ceulemans, R},
title = {Comparative analysis of harvesting machines onan operational high-density short rotation woody crop (SRWC) culture: One-process versus two-process harvest operation},
journal = {Biomass and Bioenergy},
year = {2013},
volume = {58},
pages = {333--342},
url = {http://linkinghub.elsevier.com/retrieve/pii/S0961953413003206},
doi = {10.1016/j.biombioe.2013.07.003}
}
|
| Bhullar GS, Iravani M, Edwards PJ and Olde Venterink H (2013), "Methane transport and emissions from soil as affected by water table and vascular plants", BMC Ecology. Vol. 13(1), pp. 32. |
| Abstract: Background: The important greenhouse gas (GHG) methane is produced naturally in anaerobic wetland soils. By affecting the production, oxidation and transport of methane to the atmosphere, plants have a major influence upon the quantities emitted by wetlands. Different species and functional plant groups have been shown to affect these processes differently, but our knowledge about how these effects are influenced by abiotic factors such as water regime and temperature remains limited. Here we present a mesocosm experiment comparing eight plant species for their effects on internal transport and overall emissions of methane under contrasting hydrological conditions. To quantify how much methane was transported internally through plants (the chimney effect), we blocked diffusion from the soil surface with an agar seal. Results: We found that graminoids caused higher methane emissions than forbs, although the emissions from mesocosms with different species were either lower than or comparable to those from control mesocosms with no plant (i.e. bare soil). Species with a relatively greater root volume and a larger biomass exhibited a larger chimney effect, though overall methane emissions were negatively related to plant biomass. Emissions were also reduced by lowering the water table. Conclusions: We conclude that plant species (and functional groups) vary in the degree to which they transport methane to the atmosphere. However, a plant with a high capacity to transport methane does not necessarily emit more methane, as it may also cause more rhizosphere oxidation of methane. A shift in plant species composition from graminoids to forbs and/or from low to high productive species may lead to reduction of methane emissions. textcopyright 2013 Bhullar et al.; licensee BioMed Central Ltd. |
BibTeX:
@article{Bhullar2013,
author = {Bhullar, Gurbir S and Iravani, Majid and Edwards, Peter J and Olde Venterink, Harry},
title = {Methane transport and emissions from soil as affected by water table and vascular plants},
journal = {BMC Ecology},
year = {2013},
volume = {13},
number = {1},
pages = {32},
url = {http://bmcecol.biomedcentral.com/articles/10.1186/1472-6785-13-32},
doi = {10.1186/1472-6785-13-32}
}
|
| Boesch H, Deutscher NM, Warneke T, Byckling K, Cogan AJ, Griffith DWT, Notholt J, Parker RJ and Wang Z (2013), "HDO/H2O ratio retrievals from GOSAT", Atmospheric Measurement Techniques., mar, 2013. Vol. 6(3), pp. 599-612. |
| Abstract: We report a new shortwave infrared (SWIR) retrieval of the column-averaged HDO/H2O ratio from the Japanese Greenhouse Gases Observing Satellite (GOSAT). From synthetic simulation studies, we have estimated that the inferred δD values will typically have random errors between 20 ‰ (desert surface and 30° solar zenith angle) and 120 ‰ (conifer surface and 60° solar zenith angle). We find that the retrieval will have a small but significant sensitivity to the presence of cirrus clouds, the HDO a priori profile shape and atmospheric temperature, which has the potential of introducing some regional-scale biases in the retrieval. From comparisons to ground-based column observations from the Total Carbon Column Observing Network (TCCON), we find differences between δD from GOSAT and TCCON of around -30 ‰ for northern hemispheric sites which increase up to -70 ‰ for Australian sites. The bias for the Australian sites significantly reduces when decreasing the spatial co-location criteria, which shows that spatial averaging contributes to the observed differences over Australia. The GOSAT retrievals allow mapping the global distribution of δD and its variations with season, and we find in our global GOSAT retrievals the expected strong latitudinal gradients with significant enhancements over the tropics. The comparisons to the ground-based TCCON network and the results of the global retrieval are very encouraging, and they show that δD retrieved from GOSAT should be a useful product that can be used to complement datasets from thermal-infrared sounder and ground-based networks and to extend the δD dataset from SWIR retrievals established from the recently ended SCIAMACHY mission. textcopyright Author(s) 2013. |
BibTeX:
@article{Boesch2013,
author = {Boesch, H and Deutscher, N M and Warneke, T and Byckling, K and Cogan, A J and Griffith, D W T and Notholt, J and Parker, R J and Wang, Z},
title = {HDO/H2O ratio retrievals from GOSAT},
journal = {Atmospheric Measurement Techniques},
year = {2013},
volume = {6},
number = {3},
pages = {599--612},
url = {http://www.atmos-meas-tech.net/6/599/2013/},
doi = {10.5194/amt-6-599-2013}
}
|
| Boussetta S, Balsamo G, Beljaars A, Panareda AA, Calvet JC, Jacobs C, Van Den Hurk B, Viterbo P, Lafont S, Dutra E, Jarlan L, Balzarolo M, Papale D and Van Der Werf G (2013), "Natural land carbon dioxide exchanges in the ECMWF integrated forecasting system: Implementation and offline validation", Journal of Geophysical Research Atmospheres., jun, 2013. Vol. 118(12), pp. 5923-5946. |
| Abstract: The European Centre for Medium-Range Weather Forecasts land surface model has been extended to include a carbon dioxide module. This relates photosynthesis to radiation, atmospheric carbon dioxide (COinf2/inf) concentration, soil moisture, and temperature. Furthermore, it has the option of deriving a canopy resistance from photosynthesis and providing it as a stomatal control to the transpiration formulation. Ecosystem respiration is based on empirical relations dependent on temperature, soil moisture, snow depth, and land use. The COinf2/inf model is designed for the numerical weather prediction (NWP) environment where it benefits from good quality meteorological input (i.e., radiation, temperature, and soil moisture). This paper describes the COinf2/inf model formulation and the way it is optimized making use of off-line simulations for a full year of tower observations at 34 sites. The model is then evaluated against the same observations for a different year. A correlation coefficient of 0.65 is obtained between model simulations and observations based on 10 day averaged COinf2/inf fluxes. For sensible and latent heat fluxes there is a correlation coefficient of 0.80. To study the impact on atmospheric COinf2/inf, coupled integrations are performed for the 2003 to 2008 period. The global atmospheric growth is well reproduced. The simulated interannual variability is shown to reproduce the observationally based estimates with a correlation coefficient of 0.70. The main conclusions are (i) the simple carbon dioxide model is highly suitable for the numerical weather prediction environment where environmental factors are controlled by data assimilation, (ii) the use of a carbon dioxide model for stomatal control has a positive impact on evapotranspiration, and (iii) even using a climatological leaf area index, the interannual variability of the global atmospheric COinf2/inf budget is well reproduced due to the interannual variability in the meteorological forcing (i.e., radiation, precipitation, temperature, humidity, and soil moisture) despite the simplified or missing processes. This highlights the importance of meteorological forcing but also cautions the use of such a simple model for process attribution. Key Points Land surface carbon fluxes modeling within a global NWP system Improved surface energy fluxes Better interannual variability of atmospheric CO2 growth textcopyright 2013. American Geophysical Union. All Rights Reserved. |
BibTeX:
@article{Boussetta2013,
author = {Boussetta, Souhail and Balsamo, Gianpaolo and Beljaars, Anton and Panareda, Anna Agusti and Calvet, Jean Christophe and Jacobs, Cor and Van Den Hurk, Bart and Viterbo, Pedro and Lafont, Sebastien and Dutra, Emanuel and Jarlan, Lionel and Balzarolo, Manuela and Papale, Dario and Van Der Werf, Guido},
title = {Natural land carbon dioxide exchanges in the ECMWF integrated forecasting system: Implementation and offline validation},
journal = {Journal of Geophysical Research Atmospheres},
year = {2013},
volume = {118},
number = {12},
pages = {5923--5946},
url = {http://doi.wiley.com/10.1002/jgrd.50488},
doi = {10.1002/jgrd.50488}
}
|
| Bozhinova D, Combe M, Palstra SWL, Meijer HAJ, Krol MC and Peters W (2013), "The importance of crop growth modeling to interpret the Δ14CO2 signature of annual plants", Global Biogeochemical Cycles., sep, 2013. Vol. 27(3), pp. 792-803. |
| Abstract: The 14C/C abundance in CO2(Δ 14CO2) promises to provide useful constraints on regional fossil fuel emissions and atmospheric transport through the large gradients introduced by anthropogenic activity. The currently sparse atmospheric Δ14CO2 monitoring network can potentially be augmented by using plant biomass as an integrated sample of the atmospheric Δ14CO2. But the interpretation of such an integrated sample requires knowledge about the daytoday CO2 uptake of the sampled plants. We investigate here the required detail in daily plant growth variations needed to accurately interpret regional fossil fuel emissions from annual plant samples. We use a crop growth model driven by daily meteorology to reproduce daily fixation of Δ14CO2 in maize and wheat plants in the Netherlands in 2008. When comparing the integrated Δ14CO2 simulated with this detailed model to the values obtained when using simpler proxies for daily plant growth (such as radiation and temperature), we find differences that can exceed the reported measurement precision of Δ14CO2(∼2‰). Furthermore, we show that even in the absence of any spatial differences in fossil fuel emissions, differences in regional weather can induce plant growth variations that result in spatial gradients of up to 3.5‰ in plant samples. These gradients are even larger when interpreting separate plant organs (leaves, stems, roots, or fruits), as they each develop during different time periods. Not accounting for these growthinduced differences in Δ14CO2 in plant samples would introduce a substantial bias (1.5-2 ppm) when estimating the fraction of atmospheric CO 2 variations resulting from nearby fossil fuel emissions. We advise to use crop models to simulate the 14C content of plant samplesPlant phenology results in different 14C signal in the plant organsWeather variations induce spatial gradients in crop growth and thus 14C content textcopyright2013. American Geophysical Union. All Rights Reserved. |
BibTeX:
@article{Bozhinova2013,
author = {Bozhinova, D and Combe, M and Palstra, S W L and Meijer, H A J and Krol, M C and Peters, W},
title = {The importance of crop growth modeling to interpret the Δ14CO2 signature of annual plants},
journal = {Global Biogeochemical Cycles},
year = {2013},
volume = {27},
number = {3},
pages = {792--803},
url = {http://doi.wiley.com/10.1002/gbc.20065},
doi = {10.1002/gbc.20065}
}
|
| Broquet G, Chevallier F, BrÉon FM, Kadygrov N, Alemanno M, Apadula F, Hammer S, Haszpra L, Meinhardt F, Morguí JA, Necki J, Piacentino S, Ramonet M, Schmidt M, Thompson RL, Vermeulen AT, Yver C and Ciais P (2013), "Regional inversion of CO2 ecosystem fluxes from atmospheric measurements: Reliability of the uncertainty estimates", Atmospheric Chemistry and Physics., sep, 2013. Vol. 13(17), pp. 9039-9056. |
| Abstract: The Bayesian framework of CO2 flux inversions permits estimates of the retrieved flux uncertainties. Here, the reliability of these theoretical estimates is studied through a comparison against the misfits between the inverted fluxes and independent measurements of the CO2 Net Ecosystem Exchange (NEE) made by the eddy covariance technique at local (few hectares) scale. Regional inversions at 0.5 resolution are applied for the western European domain where ∼ 50 eddy covariance sites are operated. These inversions are conducted for the period 2002-2007. They use a mesoscale atmospheric transport model, a prior estimate of the NEE from a terrestrial ecosystem model and rely on the variational assimilation of in situ continuous measurements of CO2 atmospheric mole fractions. Averaged over monthly periods and over the whole domain, the misfits are in good agreement with the theoretical uncertainties for prior and inverted NEE, and pass the chi-square test for the variance at the 30% and 5% significance levels respectively, despite the scale mismatch and the independence between the prior (respectively inverted) NEE and the flux measurements. The theoretical uncertainty reduction for the monthly NEE at the measurement sites is 53% while the inversion decreases the standard deviation of the misfits by 38%. These results build confidence in the NEE estimates at the European/monthly scales and in their theoretical uncertainty from the regional inverse modelling system. However, the uncertainties at the monthly (respectively annual) scale remain larger than the amplitude of the inter-annual variability of monthly (respectively annual) fluxes, so that this study does not engender confidence in the inter-annual variations. The uncertainties at the monthly scale are significantly smaller than the seasonal variations. The seasonal cycle of the inverted fluxes is thus reliable. In particular, the CO2 sink period over the European continent likely ends later than represented by the prior ecosystem model. textcopyright Author(s) 2013. CC Attribution 3.0 License. |
BibTeX:
@article{Broquet2013,
author = {Broquet, G and Chevallier, F and BrÉon, F M and Kadygrov, N and Alemanno, M and Apadula, F and Hammer, S and Haszpra, L and Meinhardt, F and Morguí, J A and Necki, J and Piacentino, S and Ramonet, M and Schmidt, M and Thompson, R L and Vermeulen, A T and Yver, C and Ciais, P},
title = {Regional inversion of CO2 ecosystem fluxes from atmospheric measurements: Reliability of the uncertainty estimates},
journal = {Atmospheric Chemistry and Physics},
year = {2013},
volume = {13},
number = {17},
pages = {9039--9056},
url = {http://www.atmos-chem-phys.net/13/9039/2013/},
doi = {10.5194/acp-13-9039-2013}
}
|
| Buysse P, Schnepf-Kiss AC, Carnol M, Malchair S, Roisin C and Aubinet M (2013), "Fifty years of crop residue management have a limited impact on soil heterotrophic respiration", Agricultural and Forest Meteorology., oct, 2013. Vol. 180, pp. 102-111. |
| Abstract: The impacts of crop residue management on soil microbial biomass, labile carbon and heterotrophic respiration (HR) were assessed at a long-term experimental site in the Hesbaye region in Belgium. Three treatments, residue export (RE), farmyard manure addition (FYM) and residue restitution after harvest (RR), have been applied continuously since 1959. The soil is a Eutric Cambisol with, in 2010, significantly different total soil organic carbon contents of 4.4, 5.1 and 5.9kgCm-2 under the RE, RR and FYM treatments, respectively. Manual field HR measurements were carried out during the 2010 and 2012 crop seasons using a dynamic closed chamber system. Microbial biomass, labile C content and metabolic diversity of soil bacteria were assessed in spring 2012.Fifty-one years after the beginning of the treatments, residue management had a limited impact on HR. Based on daily averaged values, the treatment had a significant impact (α= 10%) in 2012 but not in 2010. Based on the individual measurement dates, the treatment impact was less obvious in 2012; with the observation of a significant impact (α= 10%) on HR in only 7% and 36.8% of the measurement dates in 2010 and 2012, respectively. Labile C and microbial biomass were significantly lower in the RE treatment than in FYM and RR. Residue management had no significant effect on cold-water extracted carbon and metabolic diversity of heterotrophic soil bacteria. The limited impact of residue management on HR could be explained by (i) the relatively low amounts of recent above-ground crop inputs, (ii) the large proportion of below-ground residues and other non-exportable above-ground residues reducing the potential differences between treatments and (iii) the relatively large spatial variability of HR.In conclusion, carbon losses due to heterotrophic respiration did not differ between RE, FYM and RR treatments in the studied soil. This contrasts with the different soil organic carbon contents observed in these three treatments after 50 years of experiment. Further investigations regarding the reduction of spatial variability and the potential roles played by organic matter protection within aggregates and biochemical composition of inputs are needed. textcopyright 2013 Elsevier B.V. |
BibTeX:
@article{Buysse2013,
author = {Buysse, Pauline and Schnepf-Kiss, Anne Caroline and Carnol, Monique and Malchair, Sandrine and Roisin, Christian and Aubinet, Marc},
title = {Fifty years of crop residue management have a limited impact on soil heterotrophic respiration},
journal = {Agricultural and Forest Meteorology},
year = {2013},
volume = {180},
pages = {102--111},
url = {http://linkinghub.elsevier.com/retrieve/pii/S0168192313001214},
doi = {10.1016/j.agrformet.2013.05.004}
}
|
| Buysse P, Roisin C and Aubinet M (2013), "Fifty years of contrasted residue management of an agricultural crop: Impacts on the soil carbon budget and on soil heterotrophic respiration", Agriculture, Ecosystems and Environment., mar, 2013. Vol. 167, pp. 52-59. |
| Abstract: Crop management exerts a strong influence on the soil carbon (C) balance. This study investigated a long-term experiment initiated in 1959 at a site in the Hesbaye region of Belgium and focused on three contrasted treatments: residue export (RE), farmyard manure (FYM) addition and residue restitution (RR) after harvest. The objectives were to quantify the components of the C budget of croplands from a 50-year perspective and to identify the impact of the treatments on this budget and soil C sequestration, given the relatively low levels of residue application. The soil C budget was calculated for each treatment on the basis of total soil organic C (SOC) content measurements and C input data collected since the experiment had begun and drawn from the literature. To evaluate the robustness of this approach, the budget-based output estimates were compared with annual heterotrophic respiration (HR) averages extrapolated from seasonal field HR measurements carried out at the same experimental site in 2010. The soil C budget-based output estimates accorded well with field-based HR measurements and with most HR estimates in the literature, suggesting that, despite the many uncertainties affecting the soil C budget, these results were robust. The three treatments investigated in this study had different impacts on SOC stocks, mainly during the first 20 years of the experiment. RE and FYM caused significant SOC decreases (on average, -7±5gCm-2year-1 over the 50 years) and increases (10±5gCm-2year-1), respectively, whereas RR had no significant impact on the SOC stocks. The study also showed (i) the very large part (about two-thirds of the total input) that represented the below-ground input, weeds and other left-over residues in the C budget, (ii) the important role probably played by residue quality in C sequestration and (iii) the large proportion of C lost annually from the soil (which represents 93-98, 100 and 102-107% of the amounts of fresh residue brought to the soil each year in the FYM, RR and RE treatments, respectively). textcopyright 2013 Elsevier B.V. |
BibTeX:
@article{Buysse2013a,
author = {Buysse, Pauline and Roisin, Christian and Aubinet, Marc},
title = {Fifty years of contrasted residue management of an agricultural crop: Impacts on the soil carbon budget and on soil heterotrophic respiration},
journal = {Agriculture, Ecosystems and Environment},
year = {2013},
volume = {167},
pages = {52--59},
url = {http://linkinghub.elsevier.com/retrieve/pii/S0167880913000182},
doi = {10.1016/j.agee.2013.01.006}
}
|
| Buysse P, Goffin S, Carnol M, Malchair S, Debacq A, Longdoz B and Aubinet M (2013), "Short-term temperature impact on soil heterotrophic respiration in limed agricultural soil samples", Biogeochemistry., mar, 2013. Vol. 112(1-3), pp. 441-455. |
| Abstract: This study sought to investigate the hourly and daily timescale responses of soil CO2 fluxes to temperature in a limed agricultural soil. Observations from different incubation experiments were compared with the results of a model combining biotic (heterotrophic respiration) and abiotic (carbonate weathering) components. Several samples were pre-incubated for 8-9 days at three temperatures (5, 15 and 25 °C) and then submitted to short-term temperature (STT) cycles (where the temperature was increased from 5 to 35 °C in 10 °C stages, with each stage being 3 h long). During the temperature cycles (hourly timescale), the soil CO2 fluxes increased significantly with temperature under all pre-incubation temperature (PIT) treatments. A hysteresis effect and negative fluxes during cooling phases were also systematically observed. At a given hourly timescale temperature, there was a negative relationship of the CO2 fluxes with the PIT. Using the combined model allowed the experimental results to be clearly described, including the negative fluxes and the hysteresis effect, showing the potentially large contribution of abiotic fluxes to total fluxes in limed soils, after STT changes. The fairly good agreement between the measured and simulated flux results also suggested that the biotic flux temperature sensitivity was probably unaffected by timescale (hourly or daily) or PIT. The negative relationship of the CO2 fluxes with the PIT probably derived from very labile soil carbon depletion, as shown in the simulations. This was not, however, confirmed by soil carbon measurements, which leaves open the possibility of adaptation within the microbial community. textcopyright 2012 Springer Science+Business Media B.V. |
BibTeX:
@article{Buysse2013b,
author = {Buysse, Pauline and Goffin, Stéphanie and Carnol, Monique and Malchair, Sandrine and Debacq, Alain and Longdoz, Bernard and Aubinet, Marc},
title = {Short-term temperature impact on soil heterotrophic respiration in limed agricultural soil samples},
journal = {Biogeochemistry},
year = {2013},
volume = {112},
number = {1-3},
pages = {441--455},
url = {http://link.springer.com/10.1007/s10533-012-9739-7},
doi = {10.1007/s10533-012-9739-7}
}
|
| Cameron DR, Van Oijen M, Werner C, Butterbach-Bahl K, Grote R, Haas E, Heuvelink GBM, Kiese R, Kros J, Kuhnert M, Leip A, Reinds GJ, Reuter HI, Schelhaas MJ, De Vries W and Yeluripati J (2013), "Environmental change impacts on the C- and N-cycle of European forests: a model comparison study", Biogeosciences., mar, 2013. Vol. 10(3), pp. 1751-1773. |
| Abstract: pAbstract. Forests are important components of the greenhouse gas balance of Europe. There is considerable uncertainty about how predicted changes to climate and nitrogen deposition will perturb the carbon and nitrogen cycles of European forests and thereby alter forest growth, carbon sequestration and N2O emission. The present study aimed to quantify the carbon and nitrogen balance, including the exchange of greenhouse gases, of European forests over the period 2010–2030, with a particular emphasis on the spatial variability of change. The analysis was carried out for two tree species: European beech and Scots pine. For this purpose, four different dynamic models were used: BASFOR, DailyDayCent, INTEGRATOR and Landscape-DNDC. These models span a range from semi-empirical to complex mechanistic. Comparison of these models allowed assessment of the extent to which model predictions depended on differences in model inputs and structure. We found a European average carbon sink of 0.160 ± 0.020 kgC mâˆ'2 yrâˆ'1 (pine) and 0.138 ± 0.062 kgC mâˆ'2 yrâˆ'1 (beech) and N2O source of 0.285 ± 0.125 kgN haâˆ'1 yrâˆ'1 (pine) and 0.575 ± 0.105 kgN haâˆ'1 yrâˆ'1 (beech). The European average greenhouse gas potential of the carbon sink was 18 (pine) and 8 (beech) times that of the N2O source. Carbon sequestration was larger in the trees than in the soil. Carbon sequestration and forest growth were largest in central Europe and lowest in northern Sweden and Finland, N. Poland and S. Spain. No single driver was found to dominate change across Europe. Forests were found to be most sensitive to change in environmental drivers where the drivers were limiting growth, where changes were particularly large or where changes acted in concert. The models disagreed as to which environmental changes were most significant for the geographical variation in forest growth and as to which tree species showed the largest rate of carbon sequestration. Pine and beech forests were found to have differing sensitivities to environmental change, in particular the response to changes in nitrogen and precipitation, with beech forest more vulnerable to drought. There was considerable uncertainty about the geographical location of N2O emissions. Two of the models BASFOR and LandscapeDNDC had largest emissions in central Europe where nitrogen deposition and soil nitrogen were largest, whereas the two other models identified different regions with large N2O emission. N2O emissions were found to be larger from beech than pine forests and were found to be particularly sensitive to forest growth./p |
BibTeX:
@article{Cameron2013,
author = {Cameron, D R and Van Oijen, M and Werner, C and Butterbach-Bahl, K and Grote, R and Haas, E and Heuvelink, G B M and Kiese, R and Kros, J and Kuhnert, M and Leip, A and Reinds, G J and Reuter, H I and Schelhaas, M J and De Vries, W and Yeluripati, J},
title = {Environmental change impacts on the C- and N-cycle of European forests: a model comparison study},
journal = {Biogeosciences},
year = {2013},
volume = {10},
number = {3},
pages = {1751--1773},
url = {https://www.biogeosciences.net/10/1751/2013/},
doi = {10.5194/bg-10-1751-2013}
}
|
| Danielewska A, Clarke N, Olejnik J, Hansen K, de Vries W, Lundin L, Tuovinen JP, Fischer R, Urbaniak M and Paoletti E (2013), "A meta-database comparison from various European research and monitoring networks dedicated to forest sites", IForest., jan, 2013. Vol. 6(JANUARY 2013), pp. 1-9. |
| Abstract: Of a wide variety of international forest research and monitoring networks, several networks are dedicated to the effects of climate change on forests, while the effects of anthropogenic pollutants on forests have been a major area for both monitoring and research for decades. The large amounts of data already obtained within existing monitoring programmes and large-scale international projects can be used to increase understanding of the state and potential of forest mitigation and adaptation to climate change in a polluted environment, and a major challenge now is to evaluate and integrate the presently available databases. We present a meta-database with the main goal to highlight available data and integrate the information about research and monitoring of selected European Research and Monitoring Networks (ERMNs). Depending on the selected ERMNs, the list of variables and the measurement units differ widely in the databases. As a result, activities related to the identification, evaluation and integration of the presently available databases are important for the scientific community. Furthermore, and equally important, the recognition of current knowledge gaps and future needed research is made easier. This analysis suggests that: ground-level ozone is under-investigated, although it is one of the pollutants of greatest concern to forests; in addition to CO2, long-term other greenhouse gasses (GHG) flux measurements should be carried out; there is still a need of improving links between monitoring of atmospheric changes and impacts on forests; research-oriented manipulative experiments in the forests are missing. textcopyright iForest - Biogeosciences and Forestry. |
BibTeX:
@article{Danielewska2013,
author = {Danielewska, Alina and Clarke, Nicholas and Olejnik, Janusz and Hansen, Karin and de Vries, Wim and Lundin, Lars and Tuovinen, Juha Pekka and Fischer, Richard and Urbaniak, Marek and Paoletti, Elena},
title = {A meta-database comparison from various European research and monitoring networks dedicated to forest sites},
journal = {IForest},
year = {2013},
volume = {6},
number = {JANUARY 2013},
pages = {1--9},
url = {http://www.sisef.it/iforest/?doi=10.3832/ifor0751-006},
doi = {10.3832/ifor0751-006}
}
|
| Danielewska A, Paoletti E, Clarke N, Olejnik J, Urbaniak M, Baran M, Siedlecki P, Hansen K, Lundin L, de Vries W, Mikkelsen TN, Dillen S and Fischer R (2013), "Towards integration of research and monitoring at forest ecosystems in Europe", Forest Systems., nov, 2013. Vol. 22(3), pp. 535-545. |
| Abstract: Aim of study: The main aim of the work was to summarize availability, quality and comparability of on-going European Research and Monitoring Networks (ERMN), based on the results of a COST FP0903 Action questionnaire carried out in September 2010 and May 2012. Area of study: The COST Action FP0903 involves 29 European countries and 4 non-COST institutions from USA, Morocco and Tunisia. In this study, the total of 22 replies to the questionnaire from 18 countries were included. Materials and methods: Based on the feedback from the Action FP0903 countries, the most popular European Networks were identified. Thereafter, the access to the network database, available quality assurance/quality control procedures and publication were described. Finally, the so-called "Supersites" concept, defined as a "highly instrumented research infrastructure, for both research and monitoring of soil-plant-atmosphere interactions" was discussed. Main results: The result of the survey indicate that the vast majority of the Action FP0903 countries participate in the International Cooperative Programme on Assessment and Monitoring of Air Pollution Effects on Forest (ICP Forest). The multi-disciplinary International Cooperative Programme on Integrated Monitoring of Air Pollution Effects on Ecosystems (ICPIM) is the second most widespread forest programme. Research highlights: To fully understand biochemical cycles in forest ecosystems, long-term monitoring is needed. Hence, a network of "Supersites", is proposed. The application of the above infrastructure can be an effective way to attain a better integration of research and monitoring networks at forest sites in Europe. |
BibTeX:
@article{Danielewska2013a,
author = {Danielewska, A and Paoletti, E and Clarke, N and Olejnik, J and Urbaniak, M and Baran, M and Siedlecki, P and Hansen, K and Lundin, L and de Vries, W and Mikkelsen, T Nørgaard and Dillen, S and Fischer, R},
title = {Towards integration of research and monitoring at forest ecosystems in Europe},
journal = {Forest Systems},
year = {2013},
volume = {22},
number = {3},
pages = {535--545},
url = {http://revistas.inia.es/index.php/fs/article/view/3675},
doi = {10.5424/fs/2013223-03675}
}
|
| Deng F, Chen JM, Pan Y, Peters W, Birdsey R, McCullough K and Xiao J (2013), "The use of forest stand age information in an atmospheric CO2 inversion applied to North America", Biogeosciences., aug, 2013. Vol. 10(8), pp. 5335-5348. |
| Abstract: Atmospheric inversions have become an important tool in quantifying carbon dioxide (CO2) sinks and sources at a variety of spatiotemporal scales, but associated large uncertainties restrain the inversion research community from reaching agreement on many important subjects. We enhanced an atmospheric inversion of the CO2 flux for North America by introducing spatially explicit information on forest stand age for US and Canada as an additional constraint, since forest carbon dynamics are closely related to time since disturbance. To use stand age information in the inversion, we converted stand age into an age factor, and included the covariances between subcontinental regions in the inversion based on the similarity of the age factors. Our inversion results show that, considering age factors, regions with recently disturbed or old forests are often nudged towards carbon sources, while regions with middle-aged productive forests are shifted towards sinks. This conforms to stand age effects observed in flux networks. At the subcontinental level, our inverted carbon fluxes agree well with continuous estimates of net ecosystem carbon exchange (NEE) upscaled from eddy covariance flux data based on MODIS data. Inverted fluxes with the age constraint exhibit stronger correlation to these upscaled NEE estimates than those inverted without the age constraint. While the carbon flux at the continental and subcontinental scales is predominantly determined by atmospheric CO2 observations, the age constraint is shown to have potential to improve the inversion of the carbon flux distribution among subcontinental regions, especially for regions lacking atmospheric CO2 observations. textcopyright 2013 Author(s). |
BibTeX:
@article{Deng2013,
author = {Deng, F and Chen, J M and Pan, Y and Peters, W and Birdsey, R and McCullough, K and Xiao, J},
title = {The use of forest stand age information in an atmospheric CO2 inversion applied to North America},
journal = {Biogeosciences},
year = {2013},
volume = {10},
number = {8},
pages = {5335--5348},
url = {http://www.biogeosciences.net/10/5335/2013/},
doi = {10.5194/bg-10-5335-2013}
}
|
| Dengel S, Zona D, Sachs T, Aurela M, Jammet M, Parmentier FJW, Oechel W and Vesala T (2013), "Testing the applicability of neural networks as a gap-filling method using CH4 flux data from high latitude wetlands", Biogeosciences., dec, 2013. Vol. 10(12), pp. 8185-8200. |
| Abstract: Since the advancement in CH4 gas analyser technology and its applicability to eddy covariance flux measurements, monitoring of CH4 emissions is becoming more widespread. In order to accurately determine the greenhouse gas balance, high quality gap-free data is required. Currently there is still no consensus on CH4 gap-filling methods, and methods applied are still study-dependent and often carried out on low resolution, daily data. In the current study, we applied artificial neural networks to six distinctively different CH4 time series from high latitudes, explain the method and test its functionality. We discuss the applicability of neural networks in CH4 flux studies, the advantages and disadvantages of this method, and what information we were able to extract from such models. Three different approaches were tested by including drivers such as air and soil temperature, barometric air pressure, solar radiation, wind direction (indicator of source location) and in addition the lagged effect of water table depth and precipitation. In keeping with the principle of parsimony, we included up to five of these variables traditionally measured at CH4 flux measurement sites. Fuzzy sets were included representing the seasonal change and time of day. High Pearson correlation coefficients (r)of up to 0.97 achieved in the final analysis are indicative for the high performance of neural networks and their applicability as a gap-filling method for CH4 flux data time series. This novel approach which we show to be appropriate for CH 4 fluxes is a step towards standardising CH4 gap-filling protocols. textcopyright Author(s) 2013. CC Attribution 3.0 License. |
BibTeX:
@article{Dengel2013,
author = {Dengel, S and Zona, D and Sachs, T and Aurela, M and Jammet, M and Parmentier, F J W and Oechel, W and Vesala, T},
title = {Testing the applicability of neural networks as a gap-filling method using CH4 flux data from high latitude wetlands},
journal = {Biogeosciences},
year = {2013},
volume = {10},
number = {12},
pages = {8185--8200},
url = {http://www.biogeosciences.net/10/8185/2013/},
doi = {10.5194/bg-10-8185-2013}
}
|
| El Kasmioui O and Ceulemans R (2013), "Financial Analysis of the Cultivation of Short Rotation Woody Crops for Bioenergy in Belgium: Barriers and Opportunities", Bioenergy Research., mar, 2013. Vol. 6(1), pp. 336-350. |
| Abstract: This paper analyses the financial performance of a poplar short rotation woody crop (SRWC) plantation in Belgium, from a farmer's and an investor's viewpoint, based on simulations from the newly developed model POPFINUA. The establishment, production and harvest costs were investigated to calculate the net present value (NPV) and the equivalent annual value (EAV) of the SRWC cultivation when the biomass chips were sold at a price of 40 € Mg-1 with a moisture content (m. c.) of 50 %. The calculated NPVs were 229 and -485 € ha-1, and the EAVs equalled 16. 3 and -34. 6 € ha-1 year-1 for the farmer's and investor's scenario, respectively. The break-even price at which the produced biomass could be sold at the farm gate excluding transport, handling, storage and profit margins of the involved companies was calculated using the levellised costs (LC) method and equalled 78. 4 and 83. 5 € oven-dried ton (odt)-1 for the farmer's and investor's viewpoint, respectively. Three harvesting strategies, applied on a SRWC plantation of 18. 1 ha in Flanders (Belgium), were studied and compared. It became clear that preference should be given to more economic, small-scale harvesters instead of large-scale self-propelled harvesters, given the relatively limited surface available for SRWCs in Belgium. Furthermore, the inclusion of transportation over a distance of 50 km by truck increased the LC by 15. 1 € odt-1. Moreover, subsidies such as establishment grants and/or yearly incentives proved indispensable to make this long-term investment profitable. This is particularly true for the scenario where an investor decides to cultivate SRWCs for energy purposes. textcopyright 2012 Springer Science+Business Media New York. |
BibTeX:
@article{ElKasmioui2013,
author = {El Kasmioui, Ouafik and Ceulemans, Reinhart},
title = {Financial Analysis of the Cultivation of Short Rotation Woody Crops for Bioenergy in Belgium: Barriers and Opportunities},
journal = {Bioenergy Research},
year = {2013},
volume = {6},
number = {1},
pages = {336--350},
url = {http://link.springer.com/10.1007/s12155-012-9262-7},
doi = {10.1007/s12155-012-9262-7}
}
|
| Fiedler B, Fietzek P, Vieira N, Silva P, Bittig HC and Körtzinger A (2013), "In situ CO2 and O2 measurements on a profiling float", Journal of Atmospheric and Oceanic Technology., jan, 2013. Vol. 30(1), pp. 112-126. |
| Abstract: In recent years, profiling floats, which form the basis of the successful international Argo observatory, are also being considered as platforms for marine biogeochemical research. This study showcases the utility of floats as a novel tool for combined gas measurements of CO2 partial pressure (pCO2) and O2. These float prototypes were equipped with a small-sized and submersible pCO2 sensor and an optode O2 sensor for highresolution measurements in the surface ocean layer. Four consecutive deployments were carried out during November 2010 and June 2011 near the Cape Verde Ocean Observatory (CVOO) in the eastern tropical North Atlantic. The profiling float performed upcasts every 31 h while measuring pCO2, O2, salinity, temperature, and hydrostatic pressure in the upper 200 m of the water column. To maintain accuracy, regular pCO2 sensor zeroings at depth and surface, as well as optode measurements in air, were performed for each profile. Through the application of data processing procedures (e.g., time-lag correction), accuracies of floatborne pCO2 measurements were greatly improved (10-15 μatm for the water column and 5 matm for surface measurements). O2 measurements yielded an accuracy of 2 μmol kg-1. First results of this pilot study show the possibility of using profiling floats as a platform for detailed and unattended observations of the marine carbon and oxygen cycle dynamics. textcopyright 2013 American Meteorological Society. |
BibTeX:
@article{Fiedler2013,
author = {Fiedler, Björn and Fietzek, Peer and Vieira, Nuno and Silva, Péricles and Bittig, Henry C and Körtzinger, Arne},
title = {In situ CO2 and O2 measurements on a profiling float},
journal = {Journal of Atmospheric and Oceanic Technology},
year = {2013},
volume = {30},
number = {1},
pages = {112--126},
url = {http://journals.ametsoc.org/doi/abs/10.1175/JTECH-D-12-00043.1},
doi = {10.1175/JTECH-D-12-00043.1}
}
|
| Flechard CR, Massad R-S, Loubet B, Personne E, Simpson D, Bash JO, Cooter EJ, Nemitz E and Sutton MA (2013), "Advances in understanding, models and parameterizations of biosphere-atmosphere ammonia exchange", Biogeosciences., jul, 2013. Vol. 10(7), pp. 5183-5225. |
| Abstract: pAbstract. Atmospheric ammonia (NH3) dominates global emissions of total reactive nitrogen (Nr), while emissions from agricultural production systems contribute about two-thirds of global NH3 emissions; the remaining third emanates from oceans, natural vegetation, humans, wild animals and biomass burning. On land, NH3 emitted from the various sources eventually returns to the biosphere by dry deposition to sink areas, predominantly semi-natural vegetation, and by wet and dry deposition as ammonium (NH4&plus;) to all surfaces. However, the land/atmosphere exchange of gaseous NH3 is in fact bi-directional over unfertilized as well as fertilized ecosystems, with periods and areas of emission and deposition alternating in time (diurnal, seasonal) and space (patchwork landscapes). The exchange is controlled by a range of environmental factors, including meteorology, surface layer turbulence, thermodynamics, air and surface heterogeneous-phase chemistry, canopy geometry, plant development stage, leaf age, organic matter decomposition, soil microbial turnover, and, in agricultural systems, by fertilizer application rate, fertilizer type, soil type, crop type, and agricultural management practices. We review the range of processes controlling NH3 emission and uptake in the different parts of the soil-canopy-atmosphere continuum, with NH3 emission potentials defined at the substrate and leaf levels by different [NH4+] / [H+] ratios (Γ). Surface/atmosphere exchange models for NH3 are necessary to compute the temporal and spatial patterns of emissions and deposition at the soil, plant, field, landscape, regional and global scales, in order to assess the multiple environmental impacts of airborne and deposited NH3 and NH4+. Models of soil/vegetation/atmosphere NH3 exchange are reviewed from the substrate and leaf scales to the global scale. They range from simple steady-state, "big leaf" canopy resistance models, to dynamic, multi-layer, multi-process, multi-chemical species schemes. Their level of complexity depends on their purpose, the spatial scale at which they are applied, the current level of parameterization, and the availability of the input data they require. State-of-the-art solutions for determining the emission/sink Γ potentials through the soil/canopy system include coupled, interactive chemical transport models (CTM) and soil/ecosystem modelling at the regional scale. However, it remains a matter for debate to what extent realistic options for future regional and global models should be based on process-based mechanistic versus empirical and regression-type models. Further discussion is needed on the extent and timescale by which new approaches can be used, such as integration with ecosystem models and satellite observations./p |
BibTeX:
@article{Flechard2013,
author = {Flechard, C R and Massad, R.-S. and Loubet, B and Personne, E and Simpson, D and Bash, J O and Cooter, E J and Nemitz, E and Sutton, M A},
title = {Advances in understanding, models and parameterizations of biosphere-atmosphere ammonia exchange},
journal = {Biogeosciences},
year = {2013},
volume = {10},
number = {7},
pages = {5183--5225},
url = {https://www.biogeosciences.net/10/5183/2013/},
doi = {10.5194/bg-10-5183-2013}
}
|
| Fleischer K, Rebel KT, Van Der Molen MK, Erisman JW, Wassen MJ, Van Loon EE, Montagnani L, Gough CM, Herbst M, Janssens IA, Gianelle D and Dolman AJ (2013), "The contribution of nitrogen deposition to the photosynthetic capacity of forests", Global Biogeochemical Cycles., mar, 2013. Vol. 27(1), pp. 187-199. |
| Abstract: Global terrestrial carbon (C) sequestration has increased over the last few decades. The drivers of carbon sequestration, the geographical spread and magnitude of this sink are however hotly debated. Photosynthesis determines the total C uptake of terrestrial ecosystems and is a major flux of the global C balance. We contribute to the discussion on enhanced C sequestration by analyzing the influence of nitrogen (N) deposition on photosynthetic capacity (Amax) of forest canopies. Eddy covariance measurements of net exchange of carbon provide estimates of gross primary production, from which Amax is derived with a novel approach. Canopy Amax is combined with modeled N deposition, environmental variables and stand characteristics to study the relative effects on Amax for a unique global data set of 80 forest FLUXNET sites. Canopy Amax relates positively to N deposition for evergreen needleleaf forests below an observed critical load of ∼ 8 kg N ha-1 yr-1, with a slope of 2.0 ± 0.4 (S.E.) μmol CO2 m-2 s-1 per 1 kg N ha-1 yr-1. Above this threshold canopy A max levels off, exhibiting a saturating response in line with the N saturation hypothesis. Climate effects on canopy Amax cannot be separated from the effect of N deposition due to considerable covariation. For deciduous broadleaf forests and forests in the temperate (-continental) climate zones, the analysis shows the N deposition effect to be either small or absent. Leaf area index and foliar N concentration are positively but weakly related to Amax. We conclude that flux tower measurements of C fluxes provide valuable data to study physiological processes at the canopy scale. Future efforts need to be directed toward standardizing measures N cycling and pools within C monitoring networks to gain a better understanding of C and N interactions, and to disentangle the role of climate and N deposition in forest ecosystems. textcopyright2013. American Geophysical Union. All Rights Reserved. |
BibTeX:
@article{Fleischer2013,
author = {Fleischer, K and Rebel, K T and Van Der Molen, M K and Erisman, J W and Wassen, M J and Van Loon, E E and Montagnani, L and Gough, C M and Herbst, M and Janssens, I A and Gianelle, D and Dolman, A J},
title = {The contribution of nitrogen deposition to the photosynthetic capacity of forests},
journal = {Global Biogeochemical Cycles},
year = {2013},
volume = {27},
number = {1},
pages = {187--199},
url = {http://doi.wiley.com/10.1002/gbc.20026},
doi = {10.1002/gbc.20026}
}
|
| Fraser A, Palmer PI, Feng L, Boesch H, Cogan A, Parker R, Dlugokencky EJ, Fraser PJ, Krummel PB, Langenfelds RL, O'Doherty S, Prinn RG, Steele LP, Van Der Schoot M and Weiss RF (2013), "Estimating regional methane surface fluxes: The relative importance of surface and GOSAT mole fraction measurements", Atmospheric Chemistry and Physics., jun, 2013. Vol. 13(11), pp. 5697-5713. |
| Abstract: We use an ensemble Kalman filter (EnKF), together with the GEOS-Chem chemistry transport model, to estimate regional monthly methane (CH4) fluxes for the period June 2009-December 2010 using proxy dry-air columnaveraged mole fractions of methane (XCH4) from GOSAT (Greenhouse gases Observing SATellite) and/or NOAA ESRL (Earth System Research Laboratory) and CSIRO GASLAB (Global Atmospheric Sampling Laboratory) CH4 surface mole fraction measurements. Global posterior estimates using GOSAT and/or surface measurements are between 510-516 Tg yr-1, which is less than, though within the uncertainty of, the prior global flux of 529±25 Tg yr-1. We find larger differences between regional prior and posterior fluxes, with the largest changes in monthly emissions (75 Tg yr-1) occurring in Temperate Eurasia. In non-boreal regions the error reductions for inversions using the GOSAT data are at least three times larger (up to 45 %) than if only surface data are assimilated, a reflection of the greater spatial coverage of GOSAT, with the two exceptions of latitudes 60° associated with a data filter and over Europe where the surface network adequately describes fluxes on our model spatial and temporal grid. We use CarbonTracker and GEOSChem XCO2 model output to investigate model error on quantifying proxy GOSAT XCH4 (involving model XCO2) and inferring methane flux estimates from surface mole fraction data and show similar resulting fluxes, with differences reflecting initial differences in the proxy value. Using a series of observing system simulation experiments (OSSEs) we characterize the posterior flux error introduced by nonuniform atmospheric sampling by GOSAT. We show that clear-sky measurements can theoretically reproduce fluxes within 10% of true values, with the exception of tropical regions where, due to a large seasonal cycle in the number of measurements because of clouds and aerosols, fluxes are within 15% of true fluxes. We evaluate our posterior methane fluxes by incorporating them into GEOS-Chem and sampling the model at the location and time of surface CH4 measurements from the AGAGE (Advanced Global Atmospheric Gases Experiment) network and column XCH4 measurements from TCCON (Total Carbon Column Observing Network). The posterior fluxes modestly improve the model agreement with AGAGE and TCCON data relative to prior fluxes, with the correlation coefficients (r2) increasing by a mean of 0.04 (range: -0.17 to 0.23) and the biases decreasing by a mean of 0.4 ppb (range: -8.9 to 8.4 ppb). |
BibTeX:
@article{Fraser2013,
author = {Fraser, A and Palmer, P I and Feng, L and Boesch, H and Cogan, A and Parker, R and Dlugokencky, E J and Fraser, P J and Krummel, P B and Langenfelds, R L and O'Doherty, S and Prinn, R G and Steele, L P and Van Der Schoot, M and Weiss, R F},
title = {Estimating regional methane surface fluxes: The relative importance of surface and GOSAT mole fraction measurements},
journal = {Atmospheric Chemistry and Physics},
year = {2013},
volume = {13},
number = {11},
pages = {5697--5713},
url = {http://www.atmos-chem-phys.net/13/5697/2013/},
doi = {10.5194/acp-13-5697-2013}
}
|
| Gielen B, De Vos B, Campioli M, Neirynck J, Papale D, Verstraeten A, Ceulemans R and Janssens IA (2013), "Biometric and eddy covariance-based assessment of decadal carbon sequestration of a temperate Scots pine forest", Agricultural and Forest Meteorology., jun, 2013. Vol. 174-175, pp. 135-143. |
| Abstract: In recent years, the status of forests as sources or sinks of carbon has received much attention. Nonetheless, evidence-based long-term estimates of the magnitude of the carbon sequestration in forests are still scarce. In this study we present two independent estimates of net carbon sequestration in a temperate Scots pine dominated forest ecosystem over a 9-year period (2002-2010). First, the net ecosystem carbon balance (NECB) was estimated from net ecosystem CO2 exchange as measured by the eddy covariance technique (NECBEC). To this end, the eddy covariance estimates were combined with non-CO2 carbon fluxes such as DOC leaching and VOC emissions. The second approach to determine the carbon sequestration was based on the changes in the ecosystem carbon stocks over time (NECBSC). For this NECBSC estimate, two assessments of the ecosystem carbon stocks (2002 and 2010) were compared. Results showed that the eddy covariance approach estimated a net uptake of 2.4±1.25tCha-1yr-1, while the stock based approach suggested a carbon sink of 1.8±1.20tCha-1yr-1. No significant change was observed in the mineral soil carbon, while the carbon stock of the litter layer slightly decreased. Phytomass was thus the main carbon sink (2.1tCha-1yr-1) in the pine forest, predominantly in the stems (1.3tCha-1yr-1). The fact that stem wood is the main carbon sink within the ecosystem implies that the future harvesting has the potential to fully offset the CO2 uptake by this Scots pine forest. textcopyright 2013 Elsevier B.V. |
BibTeX:
@article{Gielen2013,
author = {Gielen, B and De Vos, B and Campioli, M and Neirynck, J and Papale, D and Verstraeten, A and Ceulemans, R and Janssens, I A},
title = {Biometric and eddy covariance-based assessment of decadal carbon sequestration of a temperate Scots pine forest},
journal = {Agricultural and Forest Meteorology},
year = {2013},
volume = {174-175},
pages = {135--143},
url = {http://linkinghub.elsevier.com/retrieve/pii/S0168192313000361},
doi = {10.1016/j.agrformet.2013.02.008}
}
|
| Grossi C, Curcoll R, Morguí JA, Àgueda A, Ealo M, Occhipinti P, Nofuentes M, Sánchez-García L, Batet O, Vargas A, Vermeulen AT and Rodó X (2013), "H15-92: Application of atmospheric transport models at the new atmospheric EBRE delta station (Climadat Network) in Eastern Spain", In Proceedings of the 15th International Conference on Harmonisation within Atmospheric Dispersion Modelling for Regulatory Purposes, HARMO 2013. , pp. 705-709. |
| Abstract: The Ebre Delta atmospheric station (DEC3) was installed in Eastern Spain, within the framework of the ClimaDat project of the Institut Català de Ciències del Clima (IC3). This station offers continuous measurements of greenhouse gases and tracers concentrations (CO2, CH4, CO, N2O and SF6), along with atmospheric concentrations of the natural radioactive gas222Rn. Meteorological parameters, such as humidity, temperature, wind speed and wind direction are also measured at DEC3 site. This qualitative analysis aims to use the FLEXPART and the HYSPLIT models, with meteorological input of ECMWF and with spatial resolution of 0.2 degrees, to perform back trajectories at DEC3 station and qualitatively analyze how different air masses coming from the Northern Western Europe or from the Mediterranean Sea influence observed gases concentrations. |
BibTeX:
@inproceedings{Grossi2013,
author = {Grossi, C and Curcoll, R and Morguí, J A and Àgueda, A and Ealo, M and Occhipinti, P and Nofuentes, M and Sánchez-García, L and Batet, O and Vargas, A and Vermeulen, A T and Rodó, X},
title = {H15-92: Application of atmospheric transport models at the new atmospheric EBRE delta station (Climadat Network) in Eastern Spain},
booktitle = {Proceedings of the 15th International Conference on Harmonisation within Atmospheric Dispersion Modelling for Regulatory Purposes, HARMO 2013},
year = {2013},
pages = {705--709}
}
|
| Guerlet S, Butz A, Schepers D, Basu S, Hasekamp OP, Kuze A, Yokota T, Blavier JF, Deutscher NM, Griffith DWT, Hase F, Kyro E, Morino I, Sherlock V, Sussmann R, Galli A and Aben I (2013), "Impact of aerosol and thin cirrus on retrieving and validating XCO 2 from GOSAT shortwave infrared measurements", Journal of Geophysical Research Atmospheres., may, 2013. Vol. 118(10), pp. 4887-4905. |
| Abstract: Inadequate treatment of aerosol scattering can be a significant source of error when retrieving column-averaged dry-air mole fractions of CO2 (XCO2) from space-based measurements of backscattered solar shortwave radiation. We have developed a retrieval algorithm, RemoTeC, that retrieves three aerosol parameters (amount, size, and height) simultaneously with XCO 2. Here we evaluate the ability of RemoTeC to account for light path modifications by clouds, subvisual cirrus, and aerosols when retrieving XCO 2 from Greenhouse Gases Observing Satellite (GOSAT) Thermal and Near-infrared Sensor for carbon Observation (TANSO)-Fourier Transform Spectrometer (FTS) measurements. We first evaluate a cloud filter based on measurements from the Cloud and Aerosol Imager and a cirrus filter that uses radiances measured by TANSO-FTS in the 2 micron spectral region, with strong water absorption. For the cloud-screened scenes, we then evaluate errors due to aerosols. We find that RemoTeC is well capable of accounting for scattering by aerosols for values of aerosol optical thickness at 750 nm up to 0.25. While no significant correlation of errors is found with albedo, correlations are found with retrieved aerosol parameters. To further improve the XCO2 accuracy, we propose and evaluate a bias correction scheme. Measurements from 12 ground-based stations of the Total Carbon Column Observing Network (TCCON) are used as a reference in this study. We show that spatial colocation criteria may be relaxed using additional constraints based on modeled XCO2 gradients, to increase the size and diversity of validation data and provide a more robust evaluation of GOSAT retrievals. Global-scale validation of satellite data remains challenging and would be improved by increasing TCCON coverage. Key Points Errors due to clouds and aerosols are evaluated in full physics XCO2 retrievalsA bias correction is tested to improve regional accuracy of RemoTeC retrievalsTwo co-location methods are evaluated for validation of satellite retrievals textcopyright2013. American Geophysical Union. All Rights Reserved. |
BibTeX:
@article{Guerlet2013,
author = {Guerlet, S and Butz, A and Schepers, D and Basu, S and Hasekamp, O P and Kuze, A and Yokota, T and Blavier, J F and Deutscher, N M and Griffith, D W T and Hase, F and Kyro, E and Morino, I and Sherlock, V and Sussmann, R and Galli, A and Aben, I},
title = {Impact of aerosol and thin cirrus on retrieving and validating XCO 2 from GOSAT shortwave infrared measurements},
journal = {Journal of Geophysical Research Atmospheres},
year = {2013},
volume = {118},
number = {10},
pages = {4887--4905},
url = {http://doi.wiley.com/10.1002/jgrd.50332},
doi = {10.1002/jgrd.50332}
}
|
| Gülzow W, Rehder G, Deimling JSV, Seifert T and Tóth Z (2013), "One year of continuous measurements constraining methane emissions from the Baltic Sea to the atmosphere using a ship of opportunity", Biogeosciences., jan, 2013. Vol. 10(1), pp. 81-99. |
| Abstract: Methane and carbon dioxide were measured with an autonomous and continuous running system on a ferry line crossing the Baltic Sea on a 2-3 day interval from the Mecklenburg Bight to the Gulf of Finland in 2010. Surface methane saturations show great seasonal differences in shallow regions like the Mecklenburg Bight (103-507%) compared to deeper regions like the Gotland Basin (96-161%). The influence of controlling parameters like temperature, wind, mixing depth and processes like upwelling, mixing of the water column and sedimentary methane emissions on methane oversaturation and emission to the atmosphere are investigated. Upwelling was found to influence methane surface concentrations in the area of Gotland significantly during the summer period. In February 2010, an event of elevated methane concentrations in the surface water and water column of the Arkona Basin was observed, which could be linked to a wind-derived water level change as a potential triggering mechanism. The Baltic Sea is a source of methane to the atmosphere throughout the year, with highest fluxes occurring during the winter season. Stratification was found to promote the formation of a methane reservoir in deeper regions like Gulf of Finland or Bornholm Basin, which leads to long lasting elevated methane concentrations and enhanced methane fluxes, when mixed to the surface during mixed layer deepening in autumn and winter. Methane concentrations and fluxes from shallow regions like the Mecklenburg Bight are predominantly controlled by sedimentary production and consumption of methane, wind events and the change in temperature-dependent solubility of methane in the surface water. Methane fluxes vary significantly in shallow regions (e.g. Mecklenburg Bight) and regions with a temporal stratification (e.g. Bornholm Basin, Gulf of Finland). On the contrary, areas with a permanent stratification like the Gotland Basin show only small seasonal fluctuations in methane fluxes. textcopyright Author(s) 2013. CC Attribution 3.0 License. |
BibTeX:
@article{Gulzow2013,
author = {Gülzow, W and Rehder, G and Deimling, J Schneider V and Seifert, T and Tóth, Z},
title = {One year of continuous measurements constraining methane emissions from the Baltic Sea to the atmosphere using a ship of opportunity},
journal = {Biogeosciences},
year = {2013},
volume = {10},
number = {1},
pages = {81--99},
url = {http://www.biogeosciences.net/10/81/2013/},
doi = {10.5194/bg-10-81-2013}
}
|
| Hammer S, Konrad G, Vermeulen AT, Laurent O, Delmotte M, Jordan A, Hazan L, Conil S and Levin I (2013), "Feasibility study of using a "travelling" CO2 and CH4 instrument to validate continuous in situ measurement stations", Atmospheric Measurement Techniques., may, 2013. Vol. 6(5), pp. 1201-1216. |
| Abstract: In the course of the ICOS (Integrated Carbon Observation System) Demonstration Experiment a feasibility study on the usefulness of a travelling comparison instrument (TCI) was conducted in order to evaluate continuous atmospheric CO2 and CH4 measurements at two European stations. The aim of the TCI is to independently measure ambient air in parallel to the standard station instrumentation, thus providing a comprehensive comparison that includes the sample intake system, the instrument itself as well as its calibration and data evaluation. Observed differences between the TCI and a gas chromatographic system, which acted as a reference for the TCI, were -0.02 ± 0.08 μmol mol-1 for CO2 and -0.3 ± 2.3 nmol mol-1 for CH4. Over a period of two weeks each, the continuous CO2 and CH4 measurements at two ICOS field stations, Cabauw (CBW), the Netherlands and Houdelaincourt (Observatoire Pérenne de l'Environnement, OPE), France, were compared to co-located TCI measurements. At Cabauw mean differences of 0.21 ± 0.06 μmol mol-1 for CO2 and 0.41 ± 0.50 nmol mol -1 for CH4 were found. For OPE the mean differences were 0.13 ± 0.07 μmol mol-1 for CO2 and 0.44 ± 0.36 nmol mol-1 for CH4. Offsets arising from differences in the working standard calibrations or leakages/contaminations in the drying systems are too small to explain the observed differences. Hence the most likely causes of these observed differences are leakages or contaminations in the intake lines and/or their flushing pumps. For the Cabauw instrument an additional error contribution originates from insufficient flushing of standard gases. Although the TCI is an extensive quality control approach it cannot replace other quality control systems. Thus, a comprehensive quality management strategy for atmospheric monitoring networks is proposed as well. textcopyright Author(s) 2013. |
BibTeX:
@article{Hammer2013,
author = {Hammer, S and Konrad, G and Vermeulen, A T and Laurent, O and Delmotte, M and Jordan, A and Hazan, L and Conil, S and Levin, I},
title = {Feasibility study of using a "travelling" CO2 and CH4 instrument to validate continuous in situ measurement stations},
journal = {Atmospheric Measurement Techniques},
year = {2013},
volume = {6},
number = {5},
pages = {1201--1216},
url = {http://www.atmos-meas-tech.net/6/1201/2013/},
doi = {10.5194/amt-6-1201-2013}
}
|
| Hammer S, Griffith DWT, Konrad G, Vardag S, Caldow C and Levin I (2013), "Assessment of a multi-species in situ FTIR for precise atmospheric greenhouse gas observations", Atmospheric Measurement Techniques., may, 2013. Vol. 6(5), pp. 1153-1170. |
| Abstract: We thoroughly evaluate the performance of a multi-species, in situ Fourier transform infrared (FTIR) analyser with respect to high-accuracy needs for greenhouse gas monitoring networks. The in situ FTIR analyser is shown to measure CO2, CO, CH4 and N2O mole fractions continuously, all with better reproducibility than the inter-laboratory compatibility (ILC) goals, requested by the World Meteorological Organization (WMO) for the Global Atmosphere Watch (GAW) programme. Simultaneously determined δ13CO2 reaches reproducibility as good as 0.03 ‰. Second-order dependencies between the measured components and the thermodynamic properties of the sample, (temperature, pressure and flow rate) and the cross sensitivities among the sample constituents are investigated and quantified. We describe an improved sample delivery and control system that minimises the pressure and flow rate variations, making post-processing corrections for those quantities non-essential. Temperature disequilibrium effects resulting from the evacuation of the sample cell are quantified and improved by the usage of a faster temperature sensor. The instrument has proven to be linear for all measured components in the ambient concentration range. The temporal stability of the instrument is characterised on different time scales. Instrument drifts on a weekly time scale are only observed for CH4 (0.04 nmol mol-1 day-1) and δ13CO 2 (0.02 ‰ day-1). Based on 10 months of continuously collected quality control measures, the long-term reproducibility of the instrument is estimated to ±0.016 μmol mol-1 CO 2, ±0.03 ‰ δ13CO2, ±0.14 nmol mol-1 CH4, ±0.1 nmol mol -1 CO and ±0.04 nmol mol-1 N2O. We propose a calibration and quality control scheme with weekly calibrations of the instrument that is sufficient to reach WMO-GAW inter-laboratory compatibility goals. textcopyright Author(s) 2013. |
BibTeX:
@article{Hammer2013a,
author = {Hammer, S and Griffith, D W T and Konrad, G and Vardag, S and Caldow, C and Levin, I},
title = {Assessment of a multi-species in situ FTIR for precise atmospheric greenhouse gas observations},
journal = {Atmospheric Measurement Techniques},
year = {2013},
volume = {6},
number = {5},
pages = {1153--1170},
url = {http://www.atmos-meas-tech.net/6/1153/2013/},
doi = {10.5194/amt-6-1153-2013}
}
|
| Hansen K, Sørensen LL, Hertel O, Geels C, Skjøth CA, Jensen B and Boegh E (2013), "Ammonia emissions from deciduous forest after leaf fall", Biogeosciences., jul, 2013. Vol. 10(7), pp. 4577-4589. |
| Abstract: pAbstract. The understanding of biochemical feedback mechanisms in the climate system is lacking knowledge in relation to bi-directional ammonia (NH3) exchange between natural ecosystems and the atmosphere. We therefore study the atmospheric NH3 fluxes during a 25-day period during autumn 2010 (21 October to 15 November) for the Danish beech forest Lille Bøgeskov to address the hypothesis that NH3 emissions occur from deciduous forests in relation to leaf fall. This is accomplished by using observations of vegetation status, NH3 fluxes and model calculations. Vegetation status was observed using plant area index (PAI) and leaf area index (LAI). NH3 fluxes were measured using the relaxed eddy accumulation (REA) method. The REA-based NH3 concentrations were compared to NH3 denuder measurements. Model calculations of the atmospheric NH3 concentration were obtained with the Danish Ammonia MOdelling System (DAMOS). The relative contribution from the forest components to the atmospheric NH3 flux was assessed using a simple two-layer bi-directional canopy compensation point model. A total of 57.7% of the fluxes measured showed emission and 19.5% showed deposition. A clear tendency of the flux going from deposition of âˆ'0.25 ± 0.30 μg NH3-N mâˆ'2 sâˆ'1 to emission of up to 0.67 ± 0.28 μg NH3-N mâˆ'2 sâˆ'1 throughout the measurement period was found. In the leaf fall period (23 October to 8 November), an increase in the atmospheric NH3 concentrations was related to the increasing forest NH3 flux. Following leaf fall, the magnitude and temporal structure of the measured NH3 emission fluxes could be adequately reproduced with the bi-directional resistance model; it suggested the forest ground layer (soil and litter) to be the main contributing component to the NH3 emissions. The modelled concentration from DAMOS fits well the measured concentrations before leaf fall, but during and after leaf fall, the modelled concentrations are too low. The results indicate that the missing contribution to atmospheric NH3 concentration from vegetative surfaces related to leaf fall are of a relatively large magnitude. We therefore conclude that emissions from deciduous forests are important to include in model calculations of atmospheric NH3 for forest ecosystems. Finally, diurnal variations in the measured NH3 concentrations were related to meteorological conditions, forest phenology and the spatial distribution of local anthropogenic NH3 sources. This suggests that an accurate description of ammonia fluxes over forest ecosystems requires a dynamic description of atmospheric and vegetation processes./p |
BibTeX:
@article{Hansen2013,
author = {Hansen, K and Sørensen, L L and Hertel, O and Geels, C and Skjøth, C A and Jensen, B and Boegh, E},
title = {Ammonia emissions from deciduous forest after leaf fall},
journal = {Biogeosciences},
year = {2013},
volume = {10},
number = {7},
pages = {4577--4589},
url = {https://www.biogeosciences.net/10/4577/2013/},
doi = {10.5194/bg-10-4577-2013}
}
|
| Hase F, Drouin BJ, Roehl CM, Toon GC, Wennberg PO, Wunch D, Blumenstock T, Desmet F, Feist DG, Heikkinen P, De Mazière M, Rettinger M, Robinson J, Schneider M, Sherlock V, Sussmann R, Té Y, Warneke T and Weinzierl C (2013), "Calibration of sealed HCl cells used for TCCON instrumental line shape monitoring", Atmospheric Measurement Techniques., dec, 2013. Vol. 6(12), pp. 3527-3537. |
| Abstract: The TCCON (Total Carbon Column Observing Network) FTIR (Fourier transform infrared) network provides highly accurate observations of greenhouse gas column-averaged dry-air mole fractions. As an important component of TCCON quality assurance, sealed cells filled with approximately 5 mbar of HCl are used for instrumental line shape (ILS) monitoring at all TCCON sites. Here, we introduce a calibration procedure for the HCl cells which employs a refillable, pressure-monitored reference cell filled with C2H2. Using this method, we identify variations of HCl purity between the TCCON cells as a non-negligible disturbance. The new calibration procedure introduced here assigns effective pressure values to each individual cell to account for additional broadening of the HCl lines. This approach will improve the consistency of the network by significantly reducing possible station-to-station biases due to inconsistent ILS results from different HCl cells. We demonstrate that the proposed method is accurate enough to turn the ILS uncertainty into an error source of secondary importance from the viewpoint of network consistency. textcopyright Author(s) 2013. |
BibTeX:
@article{Hase2013,
author = {Hase, F and Drouin, B J and Roehl, C M and Toon, G C and Wennberg, P O and Wunch, D and Blumenstock, T and Desmet, F and Feist, D G and Heikkinen, P and De Mazière, M and Rettinger, M and Robinson, J and Schneider, M and Sherlock, V and Sussmann, R and Té, Y and Warneke, T and Weinzierl, C},
title = {Calibration of sealed HCl cells used for TCCON instrumental line shape monitoring},
journal = {Atmospheric Measurement Techniques},
year = {2013},
volume = {6},
number = {12},
pages = {3527--3537},
url = {http://www.atmos-meas-tech.net/6/3527/2013/},
doi = {10.5194/amt-6-3527-2013}
}
|
| Hensen A, Skiba U and Famulari D (2013), "Low cost and state of the art methods to measure nitrous oxide emissions", Environmental Research Letters., jun, 2013. Vol. 8(2), pp. 25022. |
| Abstract: This letter provides an overview of the available measurement techniques for nitrous oxide (N2O) flux measurement. It is presented to aid the choice of the most appropriate methods for different situations. Nitrous oxide is a very potent greenhouse gas; the effect of 1 kg of N2O is estimated to be equivalent to 300 kg of CO2. Emissions of N 2O from the soil have a larger uncertainty compared to other greenhouse gases. Important reasons for this are low atmospheric concentration levels and enormous spatial and temporal variability. Traditionally such small increases are measured by chambers and analyzed by gas chromatography. Spatial and temporal resolution is poor, but costs are low. To detect emissions at the field scale and high temporal resolution, differences at tens of ppt levels need to be resolved. Reliable instruments are now available to measure N 2O by a range of micrometeorological methods, but at high financial cost. Although chambers are effective in identifying processes and treatment effects and mitigation, the future lies with the more versatile high frequency and high sensitivity sensors. textcopyright 2013 IOP Publishing Ltd. |
BibTeX:
@article{Hensen2013,
author = {Hensen, Arjan and Skiba, Ute and Famulari, Daniela},
title = {Low cost and state of the art methods to measure nitrous oxide emissions},
journal = {Environmental Research Letters},
year = {2013},
volume = {8},
number = {2},
pages = {25022},
url = {http://stacks.iop.org/1748-9326/8/i=2/a=025022?key=crossref.06fe71ce5ce997875305d33a5e049fcd},
doi = {10.1088/1748-9326/8/2/025022}
}
|
| Hmimina G, Dufrêne E, Pontailler JY, Delpierre N, Aubinet M, Caquet B, de Grandcourt A, Burban B, Flechard C, Granier A, Gross P, Heinesch B, Longdoz B, Moureaux C, Ourcival JM, Rambal S, Saint André L and Soudani K (2013), "Evaluation of the potential of MODIS satellite data to predict vegetation phenology in different biomes: An investigation using ground-based NDVI measurements", Remote Sensing of Environment., may, 2013. Vol. 132, pp. 145-158. |
| Abstract: Vegetation phenology is the study of the timing of seasonal events that are considered to be the result of adaptive responses to climate variations on short and long time scales. In the field of remote sensing of vegetation phenology, phenological metrics are derived from time series of optical data. For that purpose, considerable effort has been specifically focused on developing noise reduction and cloud-contaminated data removal techniques to improve the quality of remotely-sensed time series. Comparative studies between time series composed of satellite data acquired under clear and cloudy conditions and from radiometric data obtained with high accuracy from ground-based measurements constitute a direct and effective way to assess the operational use and limitations of remote sensing for predicting the main plant phenological events. In the present paper, we sought to explicitly evaluate the potential use of MODerate resolution Imaging Spectroradiometer (MODIS) remote sensing data for monitoring the seasonal dynamics of different types of vegetation cover that are representative of the major terrestrial biomes, including temperate deciduous forests, evergreen forests, African savannah, and crops. After cloud screening and filtering, we compared the temporal patterns and phenological metrics derived from in situ NDVI time series and from MODIS daily and 16-composite products. We also evaluated the effects of residual noise and the influence of data gaps in MODIS NDVI time series on the identification of the most relevant metrics for vegetation phenology monitoring. The results show that the inflexion points of a model fitted to a MODIS NDVI time series allow accurate estimates of the onset of greenness in the spring and the onset of yellowing in the autumn in deciduous forests (RMSE ≤ one week). Phenological metrics identical to those provided with the MODIS Global Vegetation Phenology product (MDC12Q2) are less robust to data gaps, and they can be subject to large biases of approximately two weeks or more during the autumn phenological transitions. In the evergreen forests, in situ NDVI time series describe the phenology with high fidelity despite small temporal changes in the canopy foliage. However, MODIS is unable to provide consistent phenological patterns. In crops and savannah, MODIS NDVI time series reproduce the general temporal patterns of phenology, but significant discrepancies appear between MODIS and ground-based NDVI time series during very localized periods of time depending on the weather conditions and spatial heterogeneity within the MODIS pixel. In the rainforest, the temporal pattern exhibited by a MODIS 16-day composite NDVI time series is more likely due to a pattern of noise in the NDVI data structure according to both rainy and dry seasons rather than to phenological changes. More investigations are needed, but in all cases, this result leads us to conclude that MODIS time series in tropical rainforests should be interpreted with great caution. textcopyright 2013 Elsevier Inc. |
BibTeX:
@article{Hmimina2013,
author = {Hmimina, G and Dufrêne, E and Pontailler, J Y and Delpierre, N and Aubinet, M and Caquet, B and de Grandcourt, A and Burban, B and Flechard, C and Granier, A and Gross, P and Heinesch, B and Longdoz, B and Moureaux, C and Ourcival, J M and Rambal, S and Saint André, L and Soudani, K},
title = {Evaluation of the potential of MODIS satellite data to predict vegetation phenology in different biomes: An investigation using ground-based NDVI measurements},
journal = {Remote Sensing of Environment},
year = {2013},
volume = {132},
pages = {145--158},
url = {http://linkinghub.elsevier.com/retrieve/pii/S0034425713000229},
doi = {10.1016/j.rse.2013.01.010}
}
|
| Huotari J, Haapanala S, Pumpanen J, Vesala T and Ojala A (2013), "Efficient gas exchange between a boreal river and the atmosphere", Geophysical Research Letters., nov, 2013. Vol. 40(21), pp. 5683-5686. |
| Abstract: The largest uncertainties in accurately resolving the role of rivers and streams in carbon cycling stem from difficulties in determining gas exchange between water and the atmosphere. So far, estimates for river-atmosphere gas exchange have lacked direct ecosystem-scale flux measurements not disturbing gas exchange across the air-water interface. We conducted the first direct riverine gas exchange measurements with eddy covariance in tandem with continuous surface water CO2 measurements in a large boreal river for 30 days. Our measured gas transfer velocity was, on average, 20.8 cm h-1, which is clearly higher than the model estimates based on river channel morphology and water velocity, whereas our floating chambers gave comparable values at 17.3 cm h-1. These results demonstrate that present estimates for riverine CO2 emissions are very likely too low. This result is also relevant to any other gases emitted, as their diffusive exchange rates are similarly proportional to gas transfer velocity. textcopyright2013. American Geophysical Union. All Rights Reserved. |
BibTeX:
@article{Huotari2013,
author = {Huotari, Jussi and Haapanala, Sami and Pumpanen, Jukka and Vesala, Timo and Ojala, Anne},
title = {Efficient gas exchange between a boreal river and the atmosphere},
journal = {Geophysical Research Letters},
year = {2013},
volume = {40},
number = {21},
pages = {5683--5686},
url = {http://doi.wiley.com/10.1002/2013GL057705},
doi = {10.1002/2013GL057705}
}
|
| Jiang F, Wang HW, Chen JM, Zhou LX, Ju WM, Ding AJ, Liu LX and Peters W (2013), "Nested atmospheric inversion for the terrestrial carbon sources and sinks in China", Biogeosciences., aug, 2013. Vol. 10(8), pp. 5311-5324. |
| Abstract: In this study, we establish a nested atmospheric inversion system with a focus on China using the Bayesian method. The global surface is separated into 43 regions based on the 22 TransCom large regions, with 13 small regions in China. Monthly CO2 concentrations from 130 GlobalView sites and 3 additional China sites are used in this system. The core component of this system is an atmospheric transport matrix, which is created using the TM5 model with a horizontal resolution of 3 × 2 . The net carbon fluxes over the 43 global land and ocean regions are inverted for the period from 2002 to 2008. The inverted global terrestrial carbon sinks mainly occur in boreal Asia, South and Southeast Asia, eastern America and southern South America. Most China areas appear to be carbon sinks, with strongest carbon sinks located in Northeast China. From 2002 to 2008, the global terrestrial carbon sink has an increasing trend, with the lowest carbon sink in 2002. The inter-annual variation (IAV) of the land sinks shows remarkable correlation with the El Niño Southern Oscillation (ENSO). The terrestrial carbon sinks in China also show an increasing trend. However, the IAV in China is not the same as that of the globe. There is relatively stronger land sink in 2002, lowest sink in 2006, and strongest sink in 2007 in China. This IAV could be reasonably explained with the IAVs of temperature and precipitation in China. The mean global and China terrestrial carbon sinks over the period 2002-2008 are -3.20 ± 0.63 and -0.28 ± 0.18 PgC yr-1, respectively. Considering the carbon emissions in the form of reactive biogenic volatile organic compounds (BVOCs) and from the import of wood and food, we further estimate that China's land sink is about -0.31 PgC yr-1. textcopyright 2013 Author(s). |
BibTeX:
@article{Jiang2013,
author = {Jiang, F and Wang, H W and Chen, J M and Zhou, L X and Ju, W M and Ding, A J and Liu, L X and Peters, W},
title = {Nested atmospheric inversion for the terrestrial carbon sources and sinks in China},
journal = {Biogeosciences},
year = {2013},
volume = {10},
number = {8},
pages = {5311--5324},
url = {http://www.biogeosciences.net/10/5311/2013/},
doi = {10.5194/bg-10-5311-2013}
}
|
| Juszczak R and Augustin J (2013), "Exchange of the greenhouse gases methane and nitrous oxide between the atmosphere and a temperate peatland in Central Europe", Wetlands., oct, 2013. Vol. 33(5), pp. 895-907. |
| Abstract: Fluxes of methane (CH4), nitrous oxide (N2O), and respired CO2 were measured with an automated chamber system (SIGMA) over the autumn of 2009 and growing season of 2010 in an undisturbed peatland with a floating carpet of mosses in western Poland. The main goal of our investigation was to deliver estimations of CH4 and N2O emission rates for this unique peatland type in Central Europe. CO2 and CH4 fluxes were also measured using a non-steady-state-flow- through manual chamber systems equipped with infrared gas analyzers and used to validate and adjust results obtained with the SIGMA system. The average methane fluxes for the 2009-2010 (excluding winter) period was 95.4 (±32.4) mg CH4-C m-2 d-1 resulting in a cumulative CH 4 emission of 23.4 (±2.4) g CH4-C m-2 day growing season and 29.2 (±3.2) g CH4-C m-2 year-1 for the whole of 2010. The average seasonal N2O fluxes were 13.6 (± 28.2) μg N2O-N m-2 d -1. N2O fluxes were highly variable in time and sign (both uptake and emissions of N2O were observed during the accumulation periods). Maximum estimates of the annual emission rates of N2O were 0.004 g N2O-N m-2 year-1. Methane fluxes correlated significantly with the air and peat temperatures, but they were not dependent on water table depth. The N2O fluxes did not demonstrate a clear response to any environmental variables. Both CH4 and N 2O emission rates were in the range of fluxes recorded in pristine peatlands in other climatic zones. textcopyright 2013 The Author(s). |
BibTeX:
@article{Juszczak2013,
author = {Juszczak, Radosław and Augustin, Jürgen},
title = {Exchange of the greenhouse gases methane and nitrous oxide between the atmosphere and a temperate peatland in Central Europe},
journal = {Wetlands},
year = {2013},
volume = {33},
number = {5},
pages = {895--907},
url = {http://link.springer.com/10.1007/s13157-013-0448-3},
doi = {10.1007/s13157-013-0448-3}
}
|
| Juszczak R (2013), "Biases in methane chamber measurements in peatlands", International Agrophysics., jan, 2013. Vol. 27(2), pp. 159-168. |
| Abstract: The paper presents results of CH4 emission measurements at peatland with the application of the dynamic chamber technique. The measurements were conducted in two types of chambers differing in shape, height, volume and technology used to assure their tightness. The study tested how the following factors: 1) forced chamber headspace mixing or its absence, 2) mistakes of the person conducting measurements, 3) improper application of linear technique for calculating CH4 fluxes, and 4) simulated air sampling typical for static chambers, influence the significance of errors and the underestimation rate of CH4 fluxes measured in situ. It was indicated that chamber headspace mixing allows estimating methane fluxes with a smaller error than in the case of measurements conducted without mixing, and CH4 fluxes in such conditions can be 47 to 58% higher (depending on the chamber type) than in a chamber without fans. Using dynamic chambers and a fast analyzer to measure methane fluxes allows shortening the methane measurement process to a few minutes. On the other hand, using static chambers for methane flux measurements may lead to 70% underestimation of the calculated flux. textcopyright 2013 Institute of Agrophysics, Polish Academy of Sciences. |
BibTeX:
@article{Juszczak2013a,
author = {Juszczak, R},
title = {Biases in methane chamber measurements in peatlands},
journal = {International Agrophysics},
year = {2013},
volume = {27},
number = {2},
pages = {159--168},
url = {http://www.degruyter.com/view/j/intag.2013.27.issue-2/v10247-012-0081-z/v10247-012-0081-z.xml},
doi = {10.2478/v10247-012-0081-z}
}
|
| King JS, Ceulemans R, Albaugh JM, Dillen SY, Domec J-C, Fichot R, Fischer M, Leggett Z, Sucre E, Trnka M and Zenone T (2013), "The Challenge of Lignocellulosic Bioenergy in a Water-Limited World", BioScience., feb, 2013. Vol. 63(2), pp. 102-117. |
| Abstract: It is hoped that lignocellulosic sources will provide energy security, offset carbon dioxide enrichment of the atmosphere, and stimulate the development of new economic sectors. However, little is known about the productivity and sustainability of plant cell-wall energy industries. In this study, we used 16 global circulation models to project the global distribution of relative water availability in the coming decades and summarized the available data on the water-use efficiency of tree- and grass-based bioenergy systems. The data on bioenergy water use were extremely limited. Productivity was strongly correlated with water-use efficiency, with C4 grasses having a distinct advantage in this regard. Our analysis of agro climatic drivers of bioenergy productivity suggests that relative water availability will be one of the most important climatic changes to consider in the design of bioenergy systems. textcopyright 2013 by American Institute of Biological Sciences. All rights reserved. |
BibTeX:
@article{King2013,
author = {King, John S and Ceulemans, Reinhart and Albaugh, Janine M and Dillen, Sophie Y and Domec, Jean-Christophe and Fichot, Regis and Fischer, Milan and Leggett, Zakiya and Sucre, Eric and Trnka, Mirek and Zenone, Terenzio},
title = {The Challenge of Lignocellulosic Bioenergy in a Water-Limited World},
journal = {BioScience},
year = {2013},
volume = {63},
number = {2},
pages = {102--117},
url = {https://academic.oup.com/bioscience/article-lookup/doi/10.1525/bio.2013.63.2.6},
doi = {10.1525/bio.2013.63.2.6}
}
|
| Kirschke S, Bousquet P, Ciais P, Saunois M, Canadell JG, Dlugokencky EJ, Bergamaschi P, Bergmann D, Blake DR, Bruhwiler L, Cameron-Smith P, Castaldi S, Chevallier F, Feng L, Fraser A, Heimann M, Hodson EL, Houweling S, Josse B, Fraser PJ, Krummel PB, Lamarque JF, Langenfelds RL, Le Quéré C, Naik V, O'doherty S, Palmer PI, Pison I, Plummer D, Poulter B, Prinn RG, Rigby M, Ringeval B, Santini M, Schmidt M, Shindell DT, Simpson IJ, Spahni R, Steele LP, Strode SA, Sudo K, Szopa S, Van Der Werf GR, Voulgarakis A, Van Weele M, Weiss RF, Williams JE and Zeng G (2013), "Three decades of global methane sources and sinks", Nature Geoscience., sep, 2013. Vol. 6(10), pp. 813-823. |
| Abstract: Methane is an important greenhouse gas, responsible for about 20% of the warming induced by long-lived greenhouse gases since pre-industrial times. By reacting with hydroxyl radicals, methane reduces the oxidizing capacity of the atmosphere and generates ozone in the troposphere. Although most sources and sinks of methane have been identified, their relative contributions to atmospheric methane levels are highly uncertain. As such, the factors responsible for the observed stabilization of atmospheric methane levels in the early 2000s, and the renewed rise after 2006, remain unclear. Here, we construct decadal budgets for methane sources and sinks between 1980 and 2010, using a combination of atmospheric measurements and results from chemical transport models, ecosystem models, climate chemistry models and inventories of anthropogenic emissions. The resultant budgets suggest that data-driven approaches and ecosystem models overestimate total natural emissions. We build three contrasting emission scenarios-which differ in fossil fuel and microbial emissions-to explain the decadal variability in atmospheric methane levels detected, here and in previous studies, since 1985. Although uncertainties in emission trends do not allow definitive conclusions to be drawn, we show that the observed stabilization of methane levels between 1999 and 2006 can potentially be explained by decreasing-to-stable fossil fuel emissions, combined with stable-to-increasing microbial emissions. We show that a rise in natural wetland emissions and fossil fuel emissions probably accounts for the renewed increase in global methane levels after 2006, although the relative contribution of these two sources remains uncertain. textcopyright 2013 Macmillan Publishers Limited. |
BibTeX:
@article{Kirschke2013,
author = {Kirschke, Stefanie and Bousquet, Philippe and Ciais, Philippe and Saunois, Marielle and Canadell, Josep G and Dlugokencky, Edward J and Bergamaschi, Peter and Bergmann, Daniel and Blake, Donald R and Bruhwiler, Lori and Cameron-Smith, Philip and Castaldi, Simona and Chevallier, Frédéric and Feng, Liang and Fraser, Annemarie and Heimann, Martin and Hodson, Elke L and Houweling, Sander and Josse, Béatrice and Fraser, Paul J and Krummel, Paul B and Lamarque, Jean François and Langenfelds, Ray L and Le Quéré, Corinne and Naik, Vaishali and O'doherty, Simon and Palmer, Paul I and Pison, Isabelle and Plummer, David and Poulter, Benjamin and Prinn, Ronald G and Rigby, Matt and Ringeval, Bruno and Santini, Monia and Schmidt, Martina and Shindell, Drew T and Simpson, Isobel J and Spahni, Renato and Steele, L Paul and Strode, Sarah A and Sudo, Kengo and Szopa, Sophie and Van Der Werf, Guido R and Voulgarakis, Apostolos and Van Weele, Michiel and Weiss, Ray F and Williams, Jason E and Zeng, Guang},
title = {Three decades of global methane sources and sinks},
journal = {Nature Geoscience},
year = {2013},
volume = {6},
number = {10},
pages = {813--823},
url = {http://www.nature.com/doifinder/10.1038/ngeo1955},
doi = {10.1038/ngeo1955}
}
|
| Korhonen JFJ, Pihlatie M, Pumpanen J, Aaltonen H, Hari P, Levula J, Kieloaho AJ, Nikinmaa E, Vesala T and Ilvesniemi H (2013), "Nitrogen balance of a boreal Scots pine forest", Biogeosciences., feb, 2013. Vol. 10(2), pp. 1083-1095. |
| Abstract: The productivity of boreal forests is considered to be limited by low nitrogen (N) availability. Increased atmospheric N deposition has altered the functioning and N cycling of these N-sensitive ecosystems by increasing the availability of reactive nitrogen. The most important components of N pools and fluxes were measured in a boreal Scots pine stand in Hyytiälä, Southern Finland. The measurements at the site allowed direct estimations of nutrient pools in the soil and biomass, inputs from the atmosphere and outputs as drainage flow and gaseous losses from two micro-catchments. N was accumulating in the system, mainly in woody biomass, at a rate of 7 kg N ha -1 yr-1. Nitrogen input as atmospheric deposition was 7.4 kg N ha-1 yr-1. Dry deposition and organic N in wet deposition contributed over half of the inputs in deposition. Total outputs were 0.4 kg N ha-1 yr-1, the most important outputs being N2O emission to the atmosphere and organic N flux in drainage flow. Nitrogen uptake and retranslocation were equally important sources of N for plant growth. Most of the assimilated N originated from decomposition of organic matter, and the fraction of N that could originate directly from deposition was about 30%. In conclusion, atmospheric N deposition fertilizes the site considerably, but there are no signs of N saturation. Further research is needed to estimate soil N2 fluxes (emission and fixation), which may amount up to several kg N ha-1 yr-1. textcopyright 2013 Author(s). |
BibTeX:
@article{Korhonen2013,
author = {Korhonen, J F J and Pihlatie, M and Pumpanen, J and Aaltonen, H and Hari, P and Levula, J and Kieloaho, A J and Nikinmaa, E and Vesala, T and Ilvesniemi, H},
title = {Nitrogen balance of a boreal Scots pine forest},
journal = {Biogeosciences},
year = {2013},
volume = {10},
number = {2},
pages = {1083--1095},
url = {http://www.biogeosciences.net/10/1083/2013/},
doi = {10.5194/bg-10-1083-2013}
}
|
| Kowalska N, Chojnicki BH, Rinne J, Haapanala S, Siedlecki P, Urbaniak M, Juszczak R and Olejnik J (2013), "Measurements of methane emission from a temperate wetland by the eddy covariance method", International Agrophysics., jan, 2013. Vol. 27(3), pp. 283-290. |
| Abstract: Methane emission from a wetland was measured with the eddy covariance system. The location of the system allowed observation of methane efflux from areas that were covered by different vegetation types. The data presented in this paper were collected in the period between the13th of June and the 31st of August 2012. During the warmest months of the summer, there was no strong correlation between methane emissions and either the water table depth or peat temperature. The presence of reed and cattail contributed to a pronounced diurnal pattern of the flux and lower methane emission, while areas covered by sedges emitted higher amounts more with no clear diurnal pattern. textcopyright 2013 Institute of Agrophysics, Polish Academy of Sciences. |
BibTeX:
@article{Kowalska2013,
author = {Kowalska, N and Chojnicki, B H and Rinne, J and Haapanala, S and Siedlecki, P and Urbaniak, M and Juszczak, R and Olejnik, J},
title = {Measurements of methane emission from a temperate wetland by the eddy covariance method},
journal = {International Agrophysics},
year = {2013},
volume = {27},
number = {3},
pages = {283--290},
url = {http://www.degruyter.com/view/j/intag.2013.27.issue-3/v10247-012-0096-5/v10247-012-0096-5.xml},
doi = {10.2478/v10247-012-0096-5}
}
|
| Krol M, Peters W, Hooghiemstra P, George M, Clerbaux C, Hurtmans D, McInerney D, Sedano F, Bergamaschi P, El Hajj M, Kaiser JW, Fisher D, Yershov V and Muller JP (2013), "How much CO was emitted by the 2010 fires around Moscow?", Atmospheric Chemistry and Physics., may, 2013. Vol. 13(9), pp. 4737-4747. |
| Abstract: The fires around Moscow in July and August 2010 emitted a large amount of pollutants to the atmosphere. Here we estimate the carbon monoxide (CO) source strength of the Moscow fires in July and August by using the TM5-4DVAR system in combination with CO column observations of the Infrared Atmospheric Sounding Interferometer (IASI). It is shown that the IASI observations provide a strong constraint on the total emissions needed in the model. Irrespective of the prior emissions used, the optimised CO fire emission estimates from mid-July to mid-August 2010 amount to approximately 24TgCO. This estimate depends only weakly ( 15%) on the assumed diurnal variations and injection height of the emissions. However, the estimated emissions might depend on unaccounted model uncertainties such as vertical transport. Our emission estimate of 22-27 TgCO during roughly one month of intense burning is less than suggested by another recent study, but substantially larger than predicted by the bottom-up inventories. This latter discrepancy suggests that bottom-up emission estimates for extreme peat burning events require improvements. textcopyright Author(s) 2013. |
BibTeX:
@article{Krol2013,
author = {Krol, M and Peters, W and Hooghiemstra, P and George, M and Clerbaux, C and Hurtmans, D and McInerney, D and Sedano, F and Bergamaschi, P and El Hajj, M and Kaiser, J W and Fisher, D and Yershov, V and Muller, J P},
title = {How much CO was emitted by the 2010 fires around Moscow?},
journal = {Atmospheric Chemistry and Physics},
year = {2013},
volume = {13},
number = {9},
pages = {4737--4747},
url = {http://www.atmos-chem-phys.net/13/4737/2013/},
doi = {10.5194/acp-13-4737-2013}
}
|
| Laffineur Q, Aubinet M, Schoon N, Amelynck C, Müller JF, Dewulf J, Steppe K and Heinesch B (2013), "Impact of diffuse light on isoprene and monoterpene emissions from amixed temperate forest", Atmospheric Environment., aug, 2013. Vol. 74, pp. 385-392. |
| Abstract: This study investigated the impact of diffuse light on canopy scale emission of isoprene and monoterpenes measured continuously above a mixed temperate forest, using the disjunct eddy-covariance by mass scanning technique with a proton transfer reaction-mass spectrometer (PTR-MS) instrument. To assess this impact, the relationship between emissions/radiation and emissions/gross primary production (GPP) under clear sky and cloudy conditions were analysed.Under cloudy conditions (high proportion of diffuse radiation), the isoprene and monoterpene fluxes were enhanced compared to clear sky conditions (low proportion of diffuse radiation) at equivalent temperature and above-canopy total radiation. The whole-canopy enzymatic activity of the metabolic isoprene production pathway, however, was suggested to be lower under cloudy conditions than under clear sky conditions at equivalent temperature. The mechanisms behind these observations are probably linked to the better penetration of diffuse radiation in the canopy. Shade leaves/needles receive more radiation in cloudy conditions than in clear sky conditions, thereby inducing the observed effects. •Isoprene/monoterpene emissions were measured continuously at the canopy scale.•Isoprene/monoterpene emissions were studied under clear sky and cloudy conditions.•The relationship between emissions/radiation and emissions/GPP were analysed.•Under cloudy conditions, emissions were higher than under clear sky conditions.•The enzymatic activity (canopy) was suggested to be lower under cloudy conditions. textcopyright 2013 Elsevier Ltd. |
BibTeX:
@article{Laffineur2013,
author = {Laffineur, Q and Aubinet, M and Schoon, N and Amelynck, C and Müller, J F and Dewulf, J and Steppe, K and Heinesch, B},
title = {Impact of diffuse light on isoprene and monoterpene emissions from amixed temperate forest},
journal = {Atmospheric Environment},
year = {2013},
volume = {74},
pages = {385--392},
url = {http://linkinghub.elsevier.com/retrieve/pii/S1352231013002707},
doi = {10.1016/j.atmosenv.2013.04.025}
}
|
| Lenton A, Tilbrook B, Law RM, Bakker D, Doney SC, Gruber N, Ishii M, Hoppema M, Lovenduski NS, Matear RJ, McNeil BI, Metzl N, Fletcher SE, Monteiro PMS, Rödenbeck C, Sweeney C and Takahashi T (2013), "Sea-air CO2 fluxes in the Southern Ocean for the period 1990-2009", Biogeosciences., jun, 2013. Vol. 10(6), pp. 4037-4054. |
| Abstract: The Southern Ocean (44-75° S) plays a critical role in the global carbon cycle, yet remains one of the most poorly sampled ocean regions. Different approaches have been used to estimate sea-air CO2 fluxes in this region: synthesis of surface ocean observations, ocean biogeochemical models, and atmospheric and ocean inversions. As part of the RECCAP (REgional Carbon Cycle Assessment and Processes) project, we combine these different approaches to quantify and assess the magnitude and variability in Southern Ocean sea-air CO2 fluxes between 1990-2009. Using all models and inversions (26), the integrated median annual sea-air CO2 flux of -0.42±0.07 PgC yr-1 for the 44-75° S region, is consistent with the -0.27±0.13 PgC yr-1 calculated using surface observations. The circumpolar region south of 58° S has a small net annual flux (model and inversion median: -0.04±0.07 PgC yr-1 and observations: +0.04±0.02 PgC yr-1), with most of the net annual flux located in the 44 to 58° S circumpolar band (model and inversion median: -0.36±0.09 PgC yr-1 and observations: -0.35±0.09 PgC yr-1). Seasonally, in the 44-58° S region, the median of 5 ocean biogeochemical models captures the observed sea-air CO2 flux seasonal cycle, while the median of 11 atmospheric inversions shows little seasonal change in the net flux. South of 58° S, neither atmospheric inversions nor ocean biogeochemical models reproduce the phase and amplitude of the observed seasonal sea-air CO2 flux, particularly in the AustralWinter. Importantly, no individual atmospheric inversion or ocean biogeochemical model is capable of reproducing both the observed annual mean uptake and the observed seasonal cycle. This raises concerns about projecting future changes in Southern Ocean CO2 fluxes. The median interannual variability from atmospheric inversions and ocean biogeochemical models is substantial in the Southern Ocean; up to 25% of the annual mean flux, with 25% of this interannual variability attributed to the region south of 58° S. Resolving long-term trends is difficult due to the large interannual variability and short time frame (1990-2009) of this study; this is particularly evident from the large spread in trends from inversions and ocean biogeochemical models. Nevertheless, in the period 1990-2009 ocean biogeochemical models do show increasing oceanic uptake consistent with the expected increase of -0.05 PgC yr-1 decade-1. In contrast, atmospheric inversions suggest little change in the strength of the CO 2 sink broadly consistent with the results of Le Quéré et al. (2007). textcopyright Author(s) 2013. CC Attribution 3.0 License. |
BibTeX:
@article{Lenton2013,
author = {Lenton, A and Tilbrook, B and Law, R M and Bakker, D and Doney, S C and Gruber, N and Ishii, M and Hoppema, M and Lovenduski, N S and Matear, R J and McNeil, B I and Metzl, N and Fletcher, S E.Mikaloff and Monteiro, P M S and Rödenbeck, C and Sweeney, C and Takahashi, T},
title = {Sea-air CO2 fluxes in the Southern Ocean for the period 1990-2009},
journal = {Biogeosciences},
year = {2013},
volume = {10},
number = {6},
pages = {4037--4054},
url = {http://www.biogeosciences.net/10/4037/2013/},
doi = {10.5194/bg-10-4037-2013}
}
|
| Le Quéré C, Andres RJ, Boden T, Conway T, Houghton RA, House JI, Marland G, Peters GP, Van Der Werf GR, Ahlström A, Andrew RM, Bopp L, Canadell JG, Ciais P, Doney SC, Enright C, Friedlingstein P, Huntingford C, Jain AK, Jourdain C, Kato E, Keeling RF, Klein Goldewijk K, Levis S, Levy P, Lomas M, Poulter B, Raupach MR, Schwinger J, Sitch S, Stocker BD, Viovy N, Zaehle S and Zeng N (2013), "The global carbon budget 1959-2011", Earth System Science Data., may, 2013. Vol. 5(1), pp. 165-185. |
| Abstract: Accurate assessments of anthropogenic carbon dioxide (CO2) emissions and their redistribution among the atmosphere, ocean, and terrestrial biosphere is important to better understand the global carbon cycle, support the climate policy process, and project future climate change. Present-day analysis requires the combination of a range of data, algorithms, statistics and model estimates and their interpretation by a broad scientific community. Here we describe datasets and a methodology developed by the global carbon cycle science community to quantify all major components of the global carbon budget, including their uncertainties. We discuss changes compared to previous estimates, consistency within and among components, and methodology and data limitations. CO2 emissions from fossil fuel combustion and cement production (EFF) are based on energy statistics, while emissions from Land-Use Change (ELUC), including deforestation, are based on combined evidence from land cover change data, fire activity in regions undergoing deforestation, and models. The global atmospheric CO2 concentration is measured directly and its rate of growth (GATM) is computed from the concentration. The mean ocean CO2 sink (SOCEAN) is based on observations from the 1990s, while the annual anomalies and trends are estimated with ocean models. Finally, the global residual terrestrial CO2 sink (SLAND) is estimated by the difference of the other terms. For the last decade available (2002-2011), EFF was 8.3 ± 0.4 PgC yr-1, ELUC 1.0 ± 0.5 PgC yr-1, GATM 4.3 ± 0.1PgC yr-1, SOCEAN 2.5 ± 0.5 PgC yr-1, and SLAND 2.6 ± 0.8 PgC yr-1. For year 2011 alone, EFF was 9.5 ± 0.5 PgC yr -1, 3.0 percent above 2010, reflecting a continued trend in these emissions; ELUC was 0.9 ± 0.5 PgC yr-1, approximately constant throughout the decade; GATM was 3.6 ± 0.2 PgC yr-1, SOCEAN was 2.7 ± 0.5 PgC yr-1, and SLAND was 4.1 ± 0.9 PgC yr-1. GATM was low in 2011 compared to the 2002-2011 average because of a high uptake by the land probably in response to natural climate variability associated to La Niña conditions in the Pacific Ocean. The global atmospheric CO2 concentration reached 391.31 ± 0.13 ppm at the end of year 2011. We estimate that EFF will have increased by 2.6% (1.9-3.5%) in 2012 based on projections of gross world product and recent changes in the carbon intensity of the economy. All uncertainties are reported as ±1 sigma (68% confidence assuming Gaussian error distributions that the real value lies within the given interval), reflecting the current capacity to characterise the annual estimates of each component of the global carbon budget. This paper is intended to provide a baseline to keep track of annual carbon budgets in the future. textcopyright 2013 Author(s). |
BibTeX:
@article{LeQuere2013,
author = {Le Quéré, C and Andres, R J and Boden, T and Conway, T and Houghton, R A and House, J I and Marland, G and Peters, G P and Van Der Werf, G R and Ahlström, A and Andrew, R M and Bopp, L and Canadell, J G and Ciais, P and Doney, S C and Enright, C and Friedlingstein, P and Huntingford, C and Jain, A K and Jourdain, C and Kato, E and Keeling, R F and Klein Goldewijk, K and Levis, S and Levy, P and Lomas, M and Poulter, B and Raupach, M R and Schwinger, J and Sitch, S and Stocker, B D and Viovy, N and Zaehle, S and Zeng, N},
title = {The global carbon budget 1959-2011},
journal = {Earth System Science Data},
year = {2013},
volume = {5},
number = {1},
pages = {165--185},
url = {http://www.earth-syst-sci-data.net/5/165/2013/},
doi = {10.5194/essd-5-165-2013}
}
|
| Levin I, Kromer B and Hammer S (2013), "Atmospheric δ14CO2 trend in Western European background air from 2000 to 2012", Tellus, Series B: Chemical and Physical Meteorology. Vol. 65(1) |
| Abstract: Long-term measurements of atmospheric δ14CO2 from two monitoring stations, one in the European Alps (Jungfraujoch, Switzerland) and the other in the Black Forest (Schauinsland, Germany), are presented. Both records show a steady decrease, changing from about 60/∞ per year at the beginning of the century to only 30/∞ per year on average in the last 4 yr. A significant seasonal variation of δ14CO2 is observed at both sites with maxima during late summer and minima in late winter/early spring. While the δ14C maxima are similar at Jungfraujoch and Schauinsland, the minima at Schauinsland are lower by up to 100/∞, due to a larger influence from 14C-free fossil fuel CO2 emissions in the footprint of the Schauinsland station in winter. Summer mean δ14C values at Schauinsland are considered best suited as input for studies of biospheric carbon cycling in midnorthern latitudes or for dating of organic material of the last half century. textcopyright 2013 I. Levin et al. |
BibTeX:
@article{Levin2013,
author = {Levin, Ingeborg and Kromer, Bernd and Hammer, Samuel},
title = {Atmospheric δ14CO2 trend in Western European background air from 2000 to 2012},
journal = {Tellus, Series B: Chemical and Physical Meteorology},
year = {2013},
volume = {65},
number = {1},
doi = {10.3402/tellusb.v65i0.20092}
}
|
| Loubet B, Cellier P, Fléchard C, Zurfluh O, Irvine M, Lamaud E, Stella P, Roche R, Durand B, Flura D, Masson S, Laville P, Garrigou D, Personne E, Chelle M and Castell JF (2013), "Investigating discrepancies in heat, CO2 fluxes and O3 deposition velocity over maize as measured by the eddy-covariance and the aerodynamic gradient methods", Agricultural and Forest Meteorology., feb, 2013. Vol. 169, pp. 35-50. |
| Abstract: The eddy covariance (EC) method is widely considered as the reference method for heat and trace gas exchange flux measurements. However, for some species of interest, the aerodynamic gradient method (AG) is still a valuable method. Furthermore, some useful datasets are based on the AG method. In this study we compare the EC and the AG methods for latent (LE) and sensible (H) heat, carbon dioxide (Fc) fluxes and ozone deposition velocity (Vd O3) over a maize field near Paris. The AG method gave roughly 15% smaller Fc and LE, similar H, and 40% larger Vd O3 than the EC method. The differences between the two methods are discussed. In particular, the effects of the displacement height and heights of measurements on the AG fluxes are explored and the similarity among heat, CO2, H2O and O3 is tested. Furthermore, the vertical divergence of the flux above the canopy is estimated with the AG method. textcopyright 2012 Elsevier B.V.. |
BibTeX:
@article{Loubet2013,
author = {Loubet, Benjamin and Cellier, Pierre and Fléchard, Christophe and Zurfluh, Olivier and Irvine, Mark and Lamaud, Eric and Stella, Patrick and Roche, Romain and Durand, Brigitte and Flura, Dominique and Masson, Sylvie and Laville, Patricia and Garrigou, Didier and Personne, Erwan and Chelle, Michael and Castell, Jean François},
title = {Investigating discrepancies in heat, CO2 fluxes and O3 deposition velocity over maize as measured by the eddy-covariance and the aerodynamic gradient methods},
journal = {Agricultural and Forest Meteorology},
year = {2013},
volume = {169},
pages = {35--50},
url = {http://linkinghub.elsevier.com/retrieve/pii/S0168192312002845},
doi = {10.1016/j.agrformet.2012.09.010}
}
|
| Luo GJ, Kiese R, Wolf B and Butterbach-Bahl K (2013), "Effects of soil temperature and moisture on methane uptake and nitrous oxide emissions across three different ecosystem types", Biogeosciences., may, 2013. Vol. 10(5), pp. 3205-3219. |
| Abstract: In this paper, we investigate similarities of effects of soil environmental drivers on year-round daily soil fluxes of nitrous oxide and methane for three distinct semi-natural or natural ecosystems: temperate spruce forest, Germany; tropical rain forest, Queensland, Australia; and ungrazed semi-arid steppe, Inner Mongolia, China. Annual cumulative fluxes of nitrous oxide and methane varied markedly among ecosystems, with nitrous oxide fluxes being highest for the tropical forest site (tropical forest: 0.96 kgNha-1 yr -1; temperate forest: 0.67 kgNha-1 yr-1; steppe: 0.22 kgNha-1 yr-1), while rates of soil methane uptake were approximately equal for the temperate forest (-3.45 kgC ha -1 yr-1) and the steppe (-3.39 kgC ha-1 yr -1), but lower for the tropical forest site (-2.38 kgC ha -1 yr-1). In order to allow for cross-site comparison of effects of changes in soil moisture and soil temperature on fluxes of methane and nitrous oxide, we used a normalization approach. Data analysis with normalized data revealed that, across sites, optimum rates of methane uptake are found at environmental conditions representing approximately average site environmental conditions. This might have rather important implications for understanding effects of climate change on soil methane uptake potential, since any shift in environmental conditions is likely to result in a reduction of soil methane uptake ability. For nitrous oxide, our analysis revealed expected patterns: highest nitrous oxide emissions under moist and warm conditions and large nitrous oxide fluxes if soils are exposed to freeze-thawing effects at sufficiently high soil moisture contents. However, the explanatory power of relationships of soil moisture or soil temperature to nitrous oxide fluxes remained rather poor (R2 ≤0.36). When combined effects of changes in soil moisture and soil temperature were considered, the explanatory power of our empirical relationships with regard to temporal variations in nitrous oxide fluxes were at maximum about 50 %. This indicates that other controlling factors such as N and C availability or microbial community dynamics might exert a significant control on the temporal dynamic of nitrous oxide fluxes. Though underlying microbial processes such as nitrification and denitrification are sensitive to changes in the environmental regulating factors, important regulating factors like moisture and temperature seem to have both synergistic and antagonistic effects on the status of other regulating factors. Thus we cannot expect a simple relationship between them and the pattern in the rate of emissions, associated with denitrification or nitrification in the soils. In conclusion, we hypothesize that our approach of data generalization may prove beneficial for the development of environmental response models, which can be used across sites, and which are needed to help achieve a better understanding of climate change feedbacks on biospheric sinks or sources of nitrous oxide and methane. textcopyright Author(s) 2013. |
BibTeX:
@article{Luo2013,
author = {Luo, G J and Kiese, R and Wolf, B and Butterbach-Bahl, K},
title = {Effects of soil temperature and moisture on methane uptake and nitrous oxide emissions across three different ecosystem types},
journal = {Biogeosciences},
year = {2013},
volume = {10},
number = {5},
pages = {3205--3219},
url = {http://www.biogeosciences.net/10/3205/2013/},
doi = {10.5194/bg-10-3205-2013}
}
|
| Maksyutov S, Takagi H, Valsala VK, Saito M, Oda T, Saeki T, Belikov DA, Saito R, Ito A, Yoshida Y, Morino I, Uchino O, Andres RJ and Yokota T (2013), "Regional CO2 flux estimates for 2009-2010 based on GOSAT and ground-based CO2 observations", Atmospheric Chemistry and Physics., sep, 2013. Vol. 13(18), pp. 9351-9373. |
| Abstract: We present the application of a global carbon cycle modeling system to the estimation of monthly regional CO2 fluxes from the column-averaged mole fractions of CO2 (XCO2) retrieved from spectral observations made by the Greenhouse gases Observing SATellite (GOSAT). The regional flux estimates are to be publicly disseminated as the GOSAT Level 4 data product. The forward modeling components of the system include an atmospheric tracer transport model, an anthropogenic emissions inventory, a terrestrial biosphere exchange model, and an oceanic flux model. The atmospheric tracer transport was simulated using isentropic coordinates in the stratosphere and was tuned to reproduce the age of air. We used a fossil fuel emission inventory based on large point source data and observations of nighttime lights. The terrestrial biospheric model was optimized by fitting model parameters to observed atmospheric CO2 seasonal cycle, net primary production data, and a biomass distribution map. The oceanic surface pCO2 distribution was estimated with a 4-D variational data assimilation system based on reanalyzed ocean currents. Monthly CO2 fluxes of 64 sub-continental regions, between June 2009 and May 2010, were estimated from GOSAT FTS SWIR Level 2 XCO2 retrievals (ver. 02.00) gridded to 5° × 5° cells and averaged on a monthly basis and monthly-mean GLOBALVIEW-CO2 data. Our result indicated that adding the GOSAT XCO2 retrievals to the GLOBALVIEW data in the flux estimation brings changes to fluxes of tropics and other remote regions where the surface-based data are sparse. The uncertainties of these remote fluxes were reduced by as much as 60% through such addition. Optimized fluxes estimated for many of these regions, were brought closer to the prior fluxes by the addition of the GOSAT retrievals. In most of the regions and seasons considered here, the estimated fluxes fell within the range of natural flux variabilities estimated with the component models. textcopyright Author(s) 2013. CC Attribution 3.0 License. |
BibTeX:
@article{Maksyutov2013,
author = {Maksyutov, S and Takagi, H and Valsala, V K and Saito, M and Oda, T and Saeki, T and Belikov, D A and Saito, R and Ito, A and Yoshida, Y and Morino, I and Uchino, O and Andres, R J and Yokota, T},
title = {Regional CO2 flux estimates for 2009-2010 based on GOSAT and ground-based CO2 observations},
journal = {Atmospheric Chemistry and Physics},
year = {2013},
volume = {13},
number = {18},
pages = {9351--9373},
url = {http://www.atmos-chem-phys.net/13/9351/2013/},
doi = {10.5194/acp-13-9351-2013}
}
|
| Manohar SN, Meijer HAJ and Herber MA (2013), "Radon flux maps for the Netherlands and Europe using terrestrial gamma radiation derived from soil radionuclides", Atmospheric Environment., dec, 2013. Vol. 81, pp. 399-412. |
| Abstract: Naturally occurring radioactive noble gas, radon (222Rn) is a valuable tracer to study atmospheric processes and to validate global chemical transport models. However, the use of radon as a proxy in atmospheric and climate research is limited by the uncertainties in the magnitude and distribution of the radon flux density over the Earth's surface. Terrestrial gamma radiation is a useful proxy for generating radon flux maps. A previously reported radon flux map of Europe used terrestrial gamma radiation extracted from automated radiation monitoring networks. This approach failed to account for the influence of local artificial radiation sources around the detector, leading to under/over estimation of the reported radon flux values at different locations. We present an alternative approach based on soil radionuclides which enables us to generate accurate radon flux maps with good confidence. Firstly, we present a detailed comparison between the terrestrial gamma radiation obtained from the National Radiation Monitoring network of the Netherlands and the terrestrial gamma radiation calculated from soil radionuclides. Extending further, we generated radon flux maps of the Netherlands and Europe using our proposed approach. The modelled flux values for the Netherlands agree reasonably well with the two observed direct radon flux measurements (within 2σ level). On the European scale, we find that the observed radon flux values are higher than our modelled values and we introduce a correction factor to account for this difference. Our approach discussed in this paper enables us to develop reliable and accurate radon flux maps in countries with little or no information on radon flux values. textcopyright 2013 Elsevier Ltd. |
BibTeX:
@article{Manohar2013,
author = {Manohar, S N and Meijer, H A J and Herber, M A},
title = {Radon flux maps for the Netherlands and Europe using terrestrial gamma radiation derived from soil radionuclides},
journal = {Atmospheric Environment},
year = {2013},
volume = {81},
pages = {399--412},
url = {http://linkinghub.elsevier.com/retrieve/pii/S1352231013006936},
doi = {10.1016/j.atmosenv.2013.09.005}
}
|
| Manrique-Suñén A, Nordbo A, Balsamo G, Beljaars A and Mammarella I (2013), "Representing land surface heterogeneity: Offline analysis of the tiling method", Journal of Hydrometeorology. Vol. 14(3), pp. 850-867. |
| Abstract: The tiling method is used in many land surface models to represent the surface heterogeneity. Each grid box is divided into fractions of different types of land use with independent solutions of the surface energy budget. An area-weighted average of the energy fluxes is computed to couple with the atmosphere, assuming the air above the surface is well blended at a given height. In the framework of validation of the tiling method, the ECMWF land surface scheme has been tested in offline mode driven by meteorological forcing provided by the ECMWF Interim Re-Analysis (ERA-Interim). Two contrasting surfaces in the boreal region of southern Finland are considered: a Scots pine forest (Hyytiealea) and a small nearby lake (Valkea-Kotinen). The field observations are used to evaluate the land surface model simulations for both energy fluxes and reservoirs. The model is able to characterize the main difference between the two sites, which appears in the energy partitioning, explained by the lake's large thermal inertia. In fact, while a large portion of the incoming solar radiation in the forest is released as sensible heat, the lake stores a substantial amount of energy in the water during late spring and summer and releases it in autumn. The different behavior of the fluxes both on annual and diurnal time scales confirms the benefit of a tiling mechanism in the presence of large contrast. However, it is also shown that the assumption of similar conditions at the blending height introduces errors. textcopyright 2013 American Meteorological Society. |
BibTeX:
@article{Manrique-Sunen2013,
author = {Manrique-Suñén, Andrea and Nordbo, Annika and Balsamo, Gianpaolo and Beljaars, Anton and Mammarella, Ivan},
title = {Representing land surface heterogeneity: Offline analysis of the tiling method},
journal = {Journal of Hydrometeorology},
year = {2013},
volume = {14},
number = {3},
pages = {850--867},
doi = {10.1175/JHM-D-12-0108.1}
}
|
| Maselli F, Argenti G, Chiesi M, Angeli L and Papale D (2013), "Simulation of grassland productivity by the combination of ground and satellite data", Agriculture, Ecosystems and Environment., jan, 2013. Vol. 165, pp. 163-172. |
| Abstract: This paper presents the assessment of a NDVI-based parametric model (C-Fix) and a bio-geochemical model (BIOME-BGC) for the simulation of semi-natural grassland primary productivity in Italy. The two models are first calibrated using the gross primary productivity (GPP) data of an eddy covariance flux tower placed over a Mediterranean-temperate hilly area in Central Italy. Next, they are applied to estimate the net primary productivity (NPP) of three independent areas representative of different eco-climatic zones. The first area shows a typical Alpine climate, while the other two are characterized by more or less pronounced Mediterranean features. The accuracy of the NPP estimates is assessed through comparison with destructive dry matter measurements taken in the three areas. The results obtained support the capability of the two models to predict spatial NPP differences across the various grassland sites. The greatest estimation errors are found in the mountain area, mostly due to inaccuracies in the meteorological input data. These errors affect particularly the outputs of the bio-geochemical model and are mitigated by the use of C-Fix, which exploits the remotely sensed information related to the seasonal evolution of green biomass. textcopyright 2012 Elsevier B.V. |
BibTeX:
@article{Maselli2013,
author = {Maselli, F and Argenti, G and Chiesi, M and Angeli, L and Papale, D},
title = {Simulation of grassland productivity by the combination of ground and satellite data},
journal = {Agriculture, Ecosystems and Environment},
year = {2013},
volume = {165},
pages = {163--172},
url = {http://linkinghub.elsevier.com/retrieve/pii/S016788091200429X},
doi = {10.1016/j.agee.2012.11.006}
}
|
| Mauder M, Cuntz M, Drüe C, Graf A, Rebmann C, Schmid HP, Schmidt M and Steinbrecher R (2013), "A strategy for quality and uncertainty assessment of long-term eddy-covariance measurements", Agricultural and Forest Meteorology., feb, 2013. Vol. 169, pp. 122-135. |
| Abstract: Eddy-covariance measurements are performed at several hundred sites all over the world on a long-term basis. The gathered data are used to characterise ecosystem exchanges of trace gases, water and energy and to validate or constrain process-based models. There is an increasing demand on standardised and comprehensive quality flagging and uncertainty quantification of these fluxes. In this paper, we review established quality assessment procedures and present a comprehensive newly composed strategy emphasising tests on high-frequency raw data, expanding existing tests on statistics, fluxes and corrections, plus quantification of errors. Moreover, representativity of fluxes is checked by footprint analysis. This strategy is applied within the recently launched TERENO network of ecosystem observatories, and its robustness is demonstrated for data acquired with different measurement set-ups. Four test data sets from TERENO and one data set from CarboEurope-IP were subjected to this quality assessment. The presented strategy is compared with established quality assessment schemes, and it is demonstrated that unrealistic fluxes are now efficiently excluded while retaining the largest possible amount of high quality data. Additionally, the algorithms applied provide comprehensive, reproducible, qualitative and quantitative uncertainty estimates for users of eddy-covariance flux data. textcopyright 2012 Elsevier B.V. |
BibTeX:
@article{Mauder2013,
author = {Mauder, Matthias and Cuntz, Matthias and Drüe, Clemens and Graf, Alexander and Rebmann, Corinna and Schmid, Hans Peter and Schmidt, Marius and Steinbrecher, Rainer},
title = {A strategy for quality and uncertainty assessment of long-term eddy-covariance measurements},
journal = {Agricultural and Forest Meteorology},
year = {2013},
volume = {169},
pages = {122--135},
url = {http://linkinghub.elsevier.com/retrieve/pii/S0168192312002808},
doi = {10.1016/j.agrformet.2012.09.006}
}
|
| Melaas EK, Richardson AD, Friedl MA, Dragoni D, Gough CM, Herbst M, Montagnani L and Moors E (2013), "Using FLUXNET data to improve models of springtime vegetation activity onset in forest ecosystems", Agricultural and Forest Meteorology., apr, 2013. Vol. 171-172, pp. 46-56. |
| Abstract: Vegetation phenology is sensitive to climate change and variability, and is a first order control on the carbon budget of forest ecosystems. Robust representation of phenology is therefore needed to support model-based projections of how climate change will affect ecosystem function. A variety of models have been developed to predict species or site-specific phenology of trees. However, extension of these models to other sites or species has proven difficult. Using meteorological and eddy covariance data for 29 forest sites (encompassing 173 site-years), we evaluated the accuracy with which 11 different models were able to simulate, as a function of air temperature and photoperiod, spatial and temporal variability in the onset of spring photosynthetic activity. In parallel, we also evaluated the accuracy with which dynamics in remotely sensed vegetation indices from MODIS captured the timing of spring onset. To do this, we used a subset of sites in the FLUXNET La Thuile database located in evergreen needleleaf and deciduous broadleaf forests with distinct active and dormant seasons and where temperature is the primary driver of seasonality. As part of this analysis we evaluated predictions from refined versions of the 11 original models that include parameterizations for geographic variation in both thermal and photoperiod constraints on phenology. Results from cross-validation analysis show that the refined models predict the onset of spring photosynthetic activity with significantly higher accuracy than the original models. Estimates for the timing of spring onset from MODIS were highly correlated with the onset of photosynthesis derived from flux measurements, but were biased late for needleleaf sites. Our results demonstrate that simple phenology models can be used to predict the timing of spring photosynthetic onset both across sites and across years at individual sites. By extension, these models provide an improved basis for predicting how the phenology and carbon budgets of temperature-limited forest ecosystems may change in the coming decades. textcopyright 2012 Elsevier B.V. |
BibTeX:
@article{Melaas2013,
author = {Melaas, Eli K and Richardson, Andrew D and Friedl, Mark A and Dragoni, Danilo and Gough, Christopher M and Herbst, Mathias and Montagnani, Leonardo and Moors, Eddy},
title = {Using FLUXNET data to improve models of springtime vegetation activity onset in forest ecosystems},
journal = {Agricultural and Forest Meteorology},
year = {2013},
volume = {171-172},
pages = {46--56},
url = {http://linkinghub.elsevier.com/retrieve/pii/S0168192312003553},
doi = {10.1016/j.agrformet.2012.11.018}
}
|
| Mencuccini M, Hölttä T, Sevanto S and Nikinmaa E (2013), "Concurrent measurements of change in the bark and xylem diameters of trees reveal a phloem-generated turgor signal", New Phytologist., jun, 2013. Vol. 198(4), pp. 1143-1154. |
| Abstract: Currently, phloem transport in plants under field conditions is not well understood. This is largely the result of the lack of techniques suitable for the measurement of the physiological properties of phloem. We present a model that interprets the changes in xylem diameter and live bark thickness and separates the components responsible for such changes. We test the predictions from this model on data from three mature Scots pine trees in Finland. The model separates the live bark thickness variations caused by bark water capacitance from a residual signal interpreted to indicate the turgor changes in the bark. The predictions from the model are consistent with processes related to phloem transport. At the diurnal scale, this signal is related to patterns of photosynthetic activity and phloem loading. At the seasonal scale, bark turgor showed rapid changes during two droughts and after two rainfall events, consistent with physiological predictions. Daily cumulative totals of this turgor term were related to daily cumulative totals of canopy photosynthesis. Finally, the model parameter representing radial hydraulic conductance between phloem and xylem showed a temperature dependence consistent with the temperature-driven changes in water viscosity. We propose that this model has potential for the continuous field monitoring of tree phloem function. textcopyright 2013 The Authors. New Phytologist textcopyright 2013 New Phytologist Trust. |
BibTeX:
@article{Mencuccini2013,
author = {Mencuccini, Maurizio and Hölttä, Teemu and Sevanto, Sanna and Nikinmaa, Eero},
title = {Concurrent measurements of change in the bark and xylem diameters of trees reveal a phloem-generated turgor signal},
journal = {New Phytologist},
year = {2013},
volume = {198},
number = {4},
pages = {1143--1154},
doi = {10.1111/nph.12224}
}
|
| Mizunuma T, Wilkinson M, L. Eaton E, Mencuccini M, I. L. Morison J and Grace J (2013), "The relationship between carbon dioxide uptake and canopy colour from two camera systems in a deciduous forest in southern England", Functional Ecology., feb, 2013. Vol. 27(1), pp. 196-207. |
| Abstract: Carbon dioxide flux measurements using the eddy covariance (EC) methodology have helped researchers to develop models of ecosystem carbon balance. However, making reliable predictions of carbon fluxes is not straightforward due to phenological changes and possible abiotic/biotic stresses that profoundly influence tree functioning. To assess the influence of canopy phenological state on CO2 flux, we installed two different digital camera systems at different viewing angles (an outdoor webcam with a near-horizontal view and a commercial 'fisheye' digital camera with a downward view) on a flux measurement tower in southern England and tracked the visual change of the canopy in this oak-dominated (Quercus robur L.) forest over two growing seasons. Changes in the setting of the camera's white balance substantially affected the quality of the webcam images. However, the timing of the onset of greening and senescence was, nevertheless, detectable for the individual trees as well as the overall canopy for both years. The greening-up date assessed from the downward images from a hemispherical lens was ˜5 days earlier than from the horizontal-view images, because of ground vegetation development (not visible in the horizontal view). The effects of a late air frost in 2010 were evident in the canopy greenness, and these led to reductions in daily gross primary productivity (GPP). The cameras recorded differences between individual tree crowns, showing their different responses to the late frost. A major new finding from this work is the strong relationship between GPP and Hue, which was stronger than the relationship between GPP and NDVI. textcopyright 2012 The Authors. Functional Ecology textcopyright 2012 British Ecological Society. |
BibTeX:
@article{Mizunuma2013,
author = {Mizunuma, Toshie and Wilkinson, Matthew and L. Eaton, Edward and Mencuccini, Maurizio and I. L. Morison, James and Grace, John},
title = {The relationship between carbon dioxide uptake and canopy colour from two camera systems in a deciduous forest in southern England},
journal = {Functional Ecology},
year = {2013},
volume = {27},
number = {1},
pages = {196--207},
doi = {10.1111/1365-2435.12026}
}
|
| Njakou Djomo S, El Kasmioui O, De Groote T, Broeckx LS, Verlinden MS, Berhongaray G, Fichot R, Zona D, Dillen SY, King JS, Janssens IA and Ceulemans R (2013), "Energy and climate benefits of bioelectricity from low-input short rotation woody crops on agricultural land over a two-year rotation", Applied Energy., nov, 2013. Vol. 111, pp. 862-870. |
| Abstract: Short-rotation woody crops (SRWCs) are a promising means to enhance the EU renewable energy sources while mitigating greenhouse gas (GHG) emissions. However, there are concerns that the GHG mitigation potential of bioelectricity may be nullified due to GHG emissions from direct land use changes (dLUCs). In order to evaluate quantitatively the GHG mitigation potential of bioelectricity from SRWC we managed an operational SRWC plantation (18.4ha) for bioelectricity production on a former agricultural land without supplemental irrigation or fertilization. We traced back to the primary energy level all farm labor, materials, and fossil fuel inputs to the bioelectricity production. We also sampled soil carbon and monitored fluxes of GHGs between the SRWC plantation and the atmosphere. We found that bioelectricity from SRWCs was energy efficient and yielded 200-227% more energy than required to produce it over a two-year rotation. The associated land requirement was 0.9m2kWhe-1 for the gasification and 1.1m2kWhe-1 for the combustion technology. Converting agricultural land into the SRWC plantation released 2.8 ± 0.2tCO2eha-1, which represented ˜89% of the total GHG emissions (256-272gCO2ekWhe-1) of bioelectricity production. Despite its high share of the total GHG emissions, dLUC did not negate the GHG benefits of bioelectricity. Indeed, the GHG savings of bioelectricity relative to the EU non-renewable grid mix power ranged between 52% and 54%. SRWC on agricultural lands with low soil organic carbon stocks are encouraging prospects for sustainable production of renewable energy with significant climate benefits. textcopyright 2013 The Authors. |
BibTeX:
@article{NjakouDjomo2013,
author = {Njakou Djomo, S and El Kasmioui, O and De Groote, T and Broeckx, L S and Verlinden, M S and Berhongaray, G and Fichot, R and Zona, D and Dillen, S Y and King, J S and Janssens, I A and Ceulemans, R},
title = {Energy and climate benefits of bioelectricity from low-input short rotation woody crops on agricultural land over a two-year rotation},
journal = {Applied Energy},
year = {2013},
volume = {111},
pages = {862--870},
url = {http://linkinghub.elsevier.com/retrieve/pii/S0306261913004169},
doi = {10.1016/j.apenergy.2013.05.017}
}
|
| Nordbo A, Kekäläinen P, Siivola E, Lehto R, Vesala T and Timonen J (2013), "Tube transport of water vapor with condensation and desorption", Applied Physics Letters., may, 2013. Vol. 102(19) |
| Abstract: Attenuation and delay of active tracers in tube transport is an important current problem, but its full explanation is still lacking. To this end a model is introduced, where part of a tracer undergoes condensation and evaporation, treated as a diffusion-type process, in addition to Taylor dispersion. Condensation of water was verified by high-speed imaging, and the model solution fitted the breakthrough curves of laboratory measurements with pulses of water vapor of varying relative humidity. The model provides a transfer function whose performance was verified against field measurements. textcopyright 2013 AIP Publishing LLC. |
BibTeX:
@article{Nordbo2013,
author = {Nordbo, Annika and Kekäläinen, Pekka and Siivola, Erkki and Lehto, Roope and Vesala, Timo and Timonen, Jussi},
title = {Tube transport of water vapor with condensation and desorption},
journal = {Applied Physics Letters},
year = {2013},
volume = {102},
number = {19},
doi = {10.1063/1.4804639}
}
|
| Nordbo A, Järvi L, Haapanala S, Moilanen J and Vesala T (2013), "Intra-City Variation in Urban Morphology and Turbulence Structure in Helsinki, Finland", Boundary-Layer Meteorology. Vol. 146(3), pp. 469-496. |
| Abstract: Most atmospheric boundary-layer theories are developed over vegetative surfaces and their applicability at urban sites is questionable. Here, we study the intra-city variation of turbulence characteristics and the applicability of boundary-layer theory using building-morphology data across Helsinki, and eddy-covariance data from three sites: two in central Helsinki (400 m apart) and one 4 km away from the city centre. The multi-site measurements enable the analysis of the horizontal scales at which quantities that characterize turbulent transport vary: (i) Roughness characteristics vary at a 10-m scale, and morphometric estimation of surface-roughness characteristics is shown to perform better than the often used rule-of-thumb estimates (average departures from the logarithmic wind profile are 14 and 44 %, respectively). (ii) The drag coefficient varies at a 100-m scale, and we provide an updated parametrization of the drag coefficient as a function of z/zH (the ratio of the measurement height to the mean building height). (iii) The transport efficiency of heat, water vapour and CO2 is shown to be weaker the more heterogeneous the site is, in terms of sources and sinks, and strong scalar dissimilarity is observed at all sites. (iv) Atmospheric stability varies markedly even within 4 km across the city: the median difference in nocturnal sensible heat fluxes between the three sites was over 50W m-2. Furthermore, (v) normalized power spectra and cospectra do not vary between sites, and they follow roughly the canonical theory as developed over vegetated terrain. textcopyright 2012 Springer Science+Business Media Dordrecht. |
BibTeX:
@article{Nordbo2013a,
author = {Nordbo, Annika and Järvi, Leena and Haapanala, Sami and Moilanen, Joonas and Vesala, Timo},
title = {Intra-City Variation in Urban Morphology and Turbulence Structure in Helsinki, Finland},
journal = {Boundary-Layer Meteorology},
year = {2013},
volume = {146},
number = {3},
pages = {469--496},
doi = {10.1007/s10546-012-9773-y}
}
|
| Nordbo A and Katul G (2013), "A Wavelet-Based Correction Method for Eddy-Covariance High-Frequency Losses in Scalar Concentration Measurements", Boundary-Layer Meteorology. Vol. 146(1), pp. 81-102. |
| Abstract: Eddy-covariance (EC) scalar-flux measurements suffer from unavoidable biases introduced by high-frequency losses in the sampled scalar concentration fluctuations. This bias alone leads to an underestimation of scalar fluxes by as much as 20% in some cases, especially when a closed-path gas analyzer is used to sample concentration far from the inlet location. A novel method that directly corrects for these high-frequency losses using only the sampled scalar-concentration time series is proposed and tested. The sampled concentration fluctuation time series is adjusted, point-by-point, in the wavelet half-plane for each EC averaging interval (≈30 min). Similarity between scalars (and temperature) is not necessary and a pre-defined theoretical shape of the cospectrum is not required, making this method attractive at meteorologically non-ideal sites. When closed-path gas analyzers are used to measure H2O concentration fluctuations, the method is shown to reproduce the dependence of the attenuation on air relative humidity. Nevertheless, the method is not able to account for excessively large spectral attenuation that occurs close to the spectral peak, as might be the case with long tubes and high relative humidity. Since the method corrects the original scalar concentration time series and not the cospectrum, other flow statistics-such as variances and integral time scales-are also adjusted. The proposed method can be used synergistically with conventional high-frequency cospectral correction methods given the differences in assumptions and approaches among these methods. When the conventional and the proposed methods agree, added confidence to the estimate of the high frequency correction is gained, and vice versa. textcopyright 2012 Springer Science+Business Media B.V. |
BibTeX:
@article{Nordbo2013b,
author = {Nordbo, Annika and Katul, Gabriel},
title = {A Wavelet-Based Correction Method for Eddy-Covariance High-Frequency Losses in Scalar Concentration Measurements},
journal = {Boundary-Layer Meteorology},
year = {2013},
volume = {146},
number = {1},
pages = {81--102},
doi = {10.1007/s10546-012-9759-9}
}
|
| Oshchepkov S, Bril A, Yokota T, Yoshida Y, Blumenstock T, Deutscher NM, Dohe S, MacAtangay R, Morino I, Notholt J, Rettinger M, Petri C, Schneider M, Sussman R, Uchino O, Velazco V, Wunch D and Belikov D (2013), "Simultaneous retrieval of atmospheric CO2 and light path modification from space-based spectroscopic observations of greenhouse gases: Methodology and application to GOSAT measurements over TCCON sites", Applied Optics., feb, 2013. Vol. 52(6), pp. 1339-1350. |
| Abstract: This paper presents an improved photon path length probability density function method that permits simultaneous retrievals of column-average greenhouse gas mole fractions and light path modifications through the atmosphere when processing high-resolution radiance spectra acquired from space. We primarily describe the methodology and retrieval setup and then apply them to the processing ofspectra measured by the Greenhouse gases Observing SATellite (GOSAT). We have demonstrated substantial improvements of the data processing with simultaneous carbon dioxide and light path retrievals and reasonable agreement of the satellite-based retrievals against ground-based Fourier transform spectrometer measurements provided by the Total Carbon Column Observing Network (TCCON). textcopyright 2013 Optical Society of America. |
BibTeX:
@article{Oshchepkov2013,
author = {Oshchepkov, Sergey and Bril, Andrey and Yokota, Tatsuya and Yoshida, Yukio and Blumenstock, Thomas and Deutscher, Nicholas M and Dohe, Susanne and MacAtangay, Ronald and Morino, Isamu and Notholt, Justus and Rettinger, Markus and Petri, Christof and Schneider, Matthias and Sussman, Ralf and Uchino, Osamu and Velazco, Voltaire and Wunch, Debra and Belikov, Dmitry},
title = {Simultaneous retrieval of atmospheric CO2 and light path modification from space-based spectroscopic observations of greenhouse gases: Methodology and application to GOSAT measurements over TCCON sites},
journal = {Applied Optics},
year = {2013},
volume = {52},
number = {6},
pages = {1339--1350},
url = {https://www.osapublishing.org/abstract.cfm?URI=ao-52-6-1339},
doi = {10.1364/AO.52.001339}
}
|
| Oshchepkov S, Bril A, Yokota T, Wennberg PO, Deutscher NM, Wunch D, Toon GC, Yoshida Y, O'Dell CW, Crisp D, Miller CE, Frankenberg C, Butz A, Aben I, Guerlet S, Hasekamp O, Boesch H, Cogan A, Parker R, Griffith D, Macatangay R, Notholt J, Sussmann R, Rettinger M, Sherlock V, Robinson J, Kyrö E, Heikkinen P, Feist DG, Morino I, Kadygrov N, Belikov D, Maksyutov S, Matsunaga T, Uchino O and Watanabe H (2013), "Effects of atmospheric light scattering on spectroscopic observations of greenhouse gases from space. Part 2: Algorithm intercomparison in the GOSAT data processing for CO2 retrievals over TCCON sites", Journal of Geophysical Research Atmospheres., feb, 2013. Vol. 118(3), pp. 1493-1512. |
| Abstract: This report is the second in a series of companion papers describing the effects of atmospheric light scattering in observations of atmospheric carbon dioxide (CO2) by the Greenhouse gases Observing SATellite (GOSAT), in orbit since 23 January 2009. Here we summarize the retrievals from six previously published algorithms; retrieving column-averaged dry air mole fractions of CO2 (XCO2) during 22 months of operation of GOSAT from June 2009. First, we compare data products from each algorithm with ground-based remote sensing observations by Total Carbon Column Observing Network (TCCON). Our GOSAT-TCCON coincidence criteria select satellite observations within a 5°radius of 11 TCCON sites. We have compared the GOSAT-TCCON XCO2 regression slope, standard deviation, correlation and determination coefficients, and global and station-to-station biases. The best agreements with TCCON measurements were detected for NIES 02.xx and RemoTeC. Next, the impact of atmospheric light scattering on XCO2 retrievals was estimated for each data product using scan by scan retrievals of light path modification with the photon path length probability density function (PPDF) method. After a cloud pre-filtering test, approximately 25% of GOSAT soundings processed by NIES 02.xx, ACOS B2.9, and UoL-FP: 3G and 35% processed by RemoTeC were found to be contaminated by atmospheric light scattering. This study suggests that NIES 02.xx and ACOS B2.9 algorithms tend to overestimate aerosol amounts over bright surfaces, resulting in an underestimation of X CO2 for GOSAT observations. Cross-comparison between algorithms shows that ACOS B2.9 agrees best with NIES 02.xx and UoL-FP: 3G while RemoTeC X CO2 retrievals are in a best agreement with NIES PPDF-D. Key PointsWe summarize GOSAT CO2 retrievals from six previously published algorithmsCO2 retrievals from each algorithm were compared with ground-based TCCON dataAn algorithm cross-comparison has been performed textcopyright2013. American Geophysical Union. All Rights Reserved. |
BibTeX:
@article{Oshchepkov2013a,
author = {Oshchepkov, Sergey and Bril, Andrey and Yokota, Tatsuya and Wennberg, Paul O and Deutscher, Nicholas M and Wunch, Debra and Toon, Geoffrey C and Yoshida, Yukio and O'Dell, Christopher W and Crisp, David and Miller, Charles E and Frankenberg, Christian and Butz, André and Aben, Ilse and Guerlet, Sandrine and Hasekamp, Otto and Boesch, Hartmut and Cogan, Austin and Parker, Robert and Griffith, David and Macatangay, Ronald and Notholt, Justus and Sussmann, Ralf and Rettinger, Markus and Sherlock, Vanessa and Robinson, John and Kyrö, Esko and Heikkinen, Pauli and Feist, Dietrich G and Morino, Isamu and Kadygrov, Nikolay and Belikov, Dmitry and Maksyutov, Shamil and Matsunaga, Tsuneo and Uchino, Osamu and Watanabe, Hiroshi},
title = {Effects of atmospheric light scattering on spectroscopic observations of greenhouse gases from space. Part 2: Algorithm intercomparison in the GOSAT data processing for CO2 retrievals over TCCON sites},
journal = {Journal of Geophysical Research Atmospheres},
year = {2013},
volume = {118},
number = {3},
pages = {1493--1512},
url = {http://doi.wiley.com/10.1002/jgrd.50146},
doi = {10.1002/jgrd.50146}
}
|
| O'Shea SJ, Bauguitte SJB, Gallagher MW, Lowry D and Percival CJ (2013), "Development of a cavity-enhanced absorption spectrometer for airborne measurements of CH4and CO2", Atmospheric Measurement Techniques., may, 2013. Vol. 6(5), pp. 1095-1109. |
| Abstract: High-resolution CH4 and CO2 measurements were made on board the FAAM BAe-146 UK (Facility for Airborne Atmospheric Measurements, British Aerospace-146) atmospheric research aircraft during a number of field campaigns. The system was based on an infrared spectrometer using the cavity-enhanced absorption spectroscopy technique. Correction functions to convert the mole fractions retrieved from the spectroscopy to dry-air mole fractions were derived using laboratory experiments and over a 3 month period showed good stability. Long-term performance of the system was monitored using WMO (World Meteorological Office) traceable calibration gases. During the first year of operation (29 flights) analysis of the system's in-flight calibrations suggest that its measurements are accurate to 1.28 ppb (1σ repeatability at 1 Hz = 2.48 ppb) for CH4 and 0.17 ppm (1σ repeatability at 1 Hz = 0.66 ppm) for CO2. The system was found to be robust, no major motion or altitude dependency could be detected in the measurements. An inter-comparison between whole-air samples that were analysed post-flight for CH4 and CO2 by cavity ring-down spectroscopy showed a mean difference between the two techniques of -2.4 ppb (1σ = 2.3 ppb) for CH4 and -0.22 ppm (1σ = 0.45 ppm) for CO2. In September 2012, the system was used to sample biomass-burning plumes in Brazil as part of the SAMBBA project (South AMerican Biomass Burning Analysis). From these and simultaneous CO measurements, emission factors for savannah fires were calculated. These were found to be 2.2 ± 0.2 g (kg dry matter) -1 for CH4 and 1710 ± 171 g (kg dry matter) -1 for CO2, which are in excellent agreement with previous estimates in the literature. textcopyright Author(s) 2013. |
BibTeX:
@article{OShea2013,
author = {O'Shea, S J and Bauguitte, S J B and Gallagher, M W and Lowry, D and Percival, C J},
title = {Development of a cavity-enhanced absorption spectrometer for airborne measurements of CH4and CO2},
journal = {Atmospheric Measurement Techniques},
year = {2013},
volume = {6},
number = {5},
pages = {1095--1109},
url = {http://www.atmos-meas-tech.net/6/1095/2013/},
doi = {10.5194/amt-6-1095-2013}
}
|
| Pal S, Haeffelin M and Batchvarova E (2013), "Exploring a geophysical process-based attribution technique for the determination of the atmospheric boundary layer depth using aerosol lidar and near-surface meteorological measurements", Journal of Geophysical Research Atmospheres., aug, 2013. Vol. 118(16), pp. 9277-9295. Blackwell Publishing Ltd. |
| Abstract: A new objective method for the determination of the atmospheric boundary layer (ABL) depth using routine vertically pointing aerosol lidar measurements is presented. A geophysical process-based analysis is introduced to improve the attribution of the lidar-derived aerosol gradients, which is so far the most challenging part in any gradient-based technique. Using micrometeorological measurements of Obukhov length scale, both early morning and evening transition periods are determined which help separate the turbulence regimes during well-mixed convective ABL and nocturnal/stable ABL. The lidar-derived aerosol backscatter signal intensity is used to determine the hourly-averaged vertical profiles of variance of the fluctuations of particle backscatter signal providing the location of maximum turbulent mixing within the ABL; thus, obtained mean ABL depth guides the attribution by searching for the appropriate minimum of the gradients. An empirical classification of the ABL stratification patterns into three different types is proposed by determining the changes in the near-surface stability scenarios. First results using the lidar observations obtained between March and July in 2011 at SIRTA atmospheric observatory near Palaiseau (Paris suburb) in France demonstrate that the new attribution technique makes the lidar estimations of ABL depth more physically reliable under a wide spectrum of meteorological conditions. While comparing lidar and nearby radiosonde measurements of ABL depths, an excellent concordance was found with a correlation coefficient of 0.968 and 0.927 for daytime and nighttime measurements, respectively. A brief climatology of the characteristics of the ABL depth, its diurnal cycle, a detailed discussion of the morning and evening transitions are presented. textcopyright 2013. Her Majesty the Queen in Right of Canada. American Geophysical Union. |
BibTeX:
@article{Pal2013,
author = {Pal, Sandip and Haeffelin, Martial and Batchvarova, Ekaterina},
title = {Exploring a geophysical process-based attribution technique for the determination of the atmospheric boundary layer depth using aerosol lidar and near-surface meteorological measurements},
journal = {Journal of Geophysical Research Atmospheres},
publisher = {Blackwell Publishing Ltd},
year = {2013},
volume = {118},
number = {16},
pages = {9277--9295},
doi = {10.1002/jgrd.50710}
}
|
| Peltola O, Mammarella I, Haapanala S, Burba G and Vesala T (2013), "Field intercomparison of four methane gas analyzers suitable for eddy covariance flux measurements", Biogeosciences., jun, 2013. Vol. 10(6), pp. 3749-3765. |
| Abstract: Performances of four methane gas analyzers suitable for eddy covariance measurements are assessed. The assessment and comparison was performed by analyzing eddy covariance data obtained during summer 2010 (1 April to 26 October) at a pristine fen, Siikaneva, Southern Finland. High methane fluxes with pronounced seasonality have been measured at this fen. The four participating methane gas analyzers are commercially available closed-path units TGA-100A (Campbell Scientific Inc., USA), RMT-200 (Los Gatos Research, USA), G1301-f (Picarro Inc., USA) and an early prototype open-path unit Prototype-7700 (LI-COR Biosciences, USA). The RMT-200 functioned most reliably throughout the measurement campaign, during low and high flux periods. Methane fluxes from RMT-200 and G1301-f had the smallest random errors and the fluxes agree remarkably well throughout the measurement campaign. Cospectra and power spectra calculated from RMT-200 and G1301-f data agree well with corresponding temperature spectra during a high flux period. None of the gas analyzers showed statistically significant diurnal variation for methane flux. Prototype-7700 functioned only for a short period of time, over one month, in the beginning of the measurement campaign during low flux period, and thus, its overall accuracy and season-long performance were not assessed. The open-path gas analyzer is a practical choice for measurement sites in remote locations due to its low power demand, whereas for G1301-f methane measurements interference from water vapor is straightforward to correct since the instrument measures both gases simultaneously. In any case, if only the performance in this intercomparison is considered, RMT-200 performed the best and is the recommended choice if a new fast response methane gas analyzer is needed. textcopyright 2013 Author(s). |
BibTeX:
@article{Peltola2013,
author = {Peltola, O and Mammarella, I and Haapanala, S and Burba, G and Vesala, T},
title = {Field intercomparison of four methane gas analyzers suitable for eddy covariance flux measurements},
journal = {Biogeosciences},
year = {2013},
volume = {10},
number = {6},
pages = {3749--3765},
url = {http://www.biogeosciences.net/10/3749/2013/},
doi = {10.5194/bg-10-3749-2013}
}
|
| Pérez-Priego O, Serrano-Ortiz P, Sánchez-Cañete EP, Domingo F and Kowalski AS (2013), "Isolating the effect of subterranean ventilation on CO2 emissions from drylands to the atmosphere", Agricultural and Forest Meteorology., oct, 2013. Vol. 180, pp. 194-202. |
| Abstract: Recent studies show the importance of CO2 exchange processes by subterranean ventilation, not directly related to concurrent biological activity, in net ecosystem exchanges between drylands and the atmosphere. We present seven years of eddy covariance measurements over a carbonate ecosystem in southern Spain and offer a practical, empirical approach that isolates such processes. Net fluxes represent emissions by ecosystem respiration and subterranean ventilation (Vs), reduced by the gross photosynthetic flux (Fc=-Fgp+Reco+Vs). Large daytime emissions due to decreases in subterranean storage (Sstextless0) - destocking subterranean CO2 (-Ss=Vs) - are hypothesized as the dominant process decoupling Fc from biological sources (Reco) and sinks (Fgp) during dry periods. Since the latter are regulated by stomatal conductance (gs), and can be characterized in terms of evapotranspiration (E), our approach exploits the extreme seasonality of gas exchanges in such ecosystems to disentangle the role of Vs in eddy fluxes.Diurnal trends in Fc and gs were strongly linked during growing periods. During dry periods however, daytime CO2 emissions greatly exceeding modelled Reco when gs was low, precluded physiological interpretation of the negative quantity (Reco-Fc) as Fgp. Since physiological inhibition of photosynthesis by drought coincided with large CO2 emissions, Vs was isolated as Fc-Reco. Analysis of different environmental factors showed that wind speed is most strongly correlated with Vs over the dataset. Although the ecosystem under study was nearly carbon neutral annually (Reco≈Fgp+Ss; all respired CO2 is either offset by photosynthetic uptake or stored underground), during long periods with dry soils and wind, Vs represented up to 62% of annual emissions. Once the effects of subterranean ventilation are considered, net exchanges correspond credibly to a net flux due to concurrent biological processes that can be better decomposed into Fgp and Reco. These findings suggest that the flux-partitioning and gap-filling models used by the FLUXNET community require adaptation to explicitly account for such processes in drylands. textcopyright 2013 Elsevier B.V. |
BibTeX:
@article{Perez-Priego2013,
author = {Pérez-Priego, Oscar and Serrano-Ortiz, Penélope and Sánchez-Cañete, Enrique P. and Domingo, Francisco and Kowalski, Andrew S.},
title = {Isolating the effect of subterranean ventilation on CO2 emissions from drylands to the atmosphere},
journal = {Agricultural and Forest Meteorology},
year = {2013},
volume = {180},
pages = {194--202},
doi = {10.1016/j.agrformet.2013.06.014}
}
|
| Peylin P, Law RM, Gurney KR, Chevallier F, Jacobson AR, Maki T, Niwa Y, Patra PK, Peters W, Rayner PJ, Rödenbeck C, Van Der Laan-Luijkx IT and Zhang X (2013), "Global atmospheric carbon budget: Results from an ensemble of atmospheric CO2 inversions", Biogeosciences., oct, 2013. Vol. 10(10), pp. 6699-6720. |
| Abstract: Atmospheric CO2 inversions estimate surface carbon fluxes from an optimal fit to atmospheric CO2 measurements, usually including prior constraints on the flux estimates. Eleven sets of carbon flux estimates are compared, generated by different inversions systems that vary in their inversions methods, choice of atmospheric data, transport model and prior information. The inversions were run for at least 5 yr in the period between 1990 and 2010. Mean fluxes for 2001-2004, seasonal cycles, interannual variability and trends are compared for the tropics and northern and southern extra-tropics, and separately for land and ocean. Some continental/basin-scale subdivisions are also considered where the atmospheric network is denser. Four-year mean fluxes are reasonably consistent across inversions at global/latitudinal scale, with a large total (land plus ocean) carbon uptake in the north (-3.4 PgC yr-1 (±0.5 PgC yr-1 standard deviation), with slightly more uptake over land than over ocean), a significant although more variable source over the tropics (1.6±0.9 P6gC yr -1) and a compensatory sink of similar magnitude in the south (-1.4±0.5 PgC yr-1) corresponding mainly to an ocean sink. Largest differences across inversions occur in the balance between tropical land sources and southern land sinks. Interannual variability (IAV) in carbon fluxes is larger for land than ocean regions (standard deviation around 1.06 versus 0.33 PgC yr-1 for the 1996-2007 period), with much higher consistency among the inversions for the land. While the tropical land explains most of the IAV (standard deviation ∼0.65 PgC yr-1), the northern and southern land also contribute (standard deviation ∼0.39 PgC yr -1). Most inversions tend to indicate an increase of the northern land carbon uptake from late 1990s to 2008 (around 0.1 Pg Cyr-1), predominantly in North Asia. The mean seasonal cycle appears to be well constrained by the atmospheric data over the northern land (at the continental scale), but still highly dependent on the prior flux seasonality over the ocean. Finally we provide recommendations to interpret the regional fluxes, along with the uncertainty estimates. textcopyright Author(s) 2013. |
BibTeX:
@article{Peylin2013,
author = {Peylin, P and Law, R M and Gurney, K R and Chevallier, F and Jacobson, A R and Maki, T and Niwa, Y and Patra, P K and Peters, W and Rayner, P J and Rödenbeck, C and Van Der Laan-Luijkx, I T and Zhang, X},
title = {Global atmospheric carbon budget: Results from an ensemble of atmospheric CO2 inversions},
journal = {Biogeosciences},
year = {2013},
volume = {10},
number = {10},
pages = {6699--6720},
url = {http://www.biogeosciences.net/10/6699/2013/},
doi = {10.5194/bg-10-6699-2013}
}
|
| Pfeil B, Olsen A, Bakker DCE, Hankin S, Koyuk H, Kozyr A, Malczyk J, Manke A, Metzl N, Sabine CL, Akl J, Alin SR, Bates N, Bellerby RGJ, Borges A, Boutin J, Brown PJ, Cai WJ, Chavez FP, Chen A, Cosca C, Fassbender AJ, Feely RA, González-Dávila M, Goyet C, Hales B, Hardman-Mountford N, Heinze C, Hood M, Hoppema M, Hunt CW, Hydes D, Ishii M, Johannessen T, Jones SD, Key RM, Körtzinger A, Landschützer P, Lauvset SK, Lefèvre N, Lenton A, Lourantou A, Merlivat L, Midorikawa T, Mintrop L, Miyazaki C, Murata A, Nakadate A, Nakano Y, Nakaoka S, Nojiri Y, Omar AM, Padin XA, Park GH, Paterson K, Perez FF, Pierrot D, Poisson A, Ríos AF, Santana-Casiano JM, Salisbury J, Sarma VVSS, Schlitzer R, Schneider B, Schuster U, Sieger R, Skjelvan I, Steinhoff T, Suzuki T, Takahashi T, Tedesco K, Telszewski M, Thomas H, Tilbrook B, Tjiputra J, Vandemark D, Veness T, Wanninkhof R, Watson AJ, Weiss R, Wong CS and Yoshikawa-Inoue H (2013), "A uniform, quality controlled Surface Ocean CO2 Atlas (SOCAT)", Earth System Science Data., apr, 2013. Vol. 5(1), pp. 125-143. |
| Abstract: A well-documented, publicly available, global data set of surface ocean carbon dioxide (CO2) parameters has been called for by international groups for nearly two decades. The Surface Ocean CO2 Atlas (SOCAT) project was initiated by the international marine carbon science community in 2007 with the aim of providing a comprehensive, publicly available, regularly updated, global data set of marine surface CO2, which had been subject to quality control (QC). Many additional CO2 data, not yet made public via the Carbon Dioxide Information Analysis Center (CDIAC), were retrieved from data originators, public websites and other data centres. All data were put in a uniform format following a strict protocol. Quality control was carried out according to clearly defined criteria. Regional specialists performed the quality control, using state-of-the-art web-based tools, specially developed for accomplishing this global team effort. SOCAT version 1.5 was made public in September 2011 and holds 6.3 million quality controlled surface CO2 data points from the global oceans and coastal seas, spanning four decades (1968&ndash;2007). Three types of data products are available: individual cruise files, a merged complete data set and gridded products. With the rapid expansion of marine CO2 data collection and the importance of quantifying net global oceanic CO2 uptake and its changes, sustained data synthesis and data access are priorities. textcopyright 2013 Author(s). |
BibTeX:
@article{Pfeil2013,
author = {Pfeil, B and Olsen, A and Bakker, D C E and Hankin, S and Koyuk, H and Kozyr, A and Malczyk, J and Manke, A and Metzl, N and Sabine, C L and Akl, J and Alin, S R and Bates, N and Bellerby, R G J and Borges, A and Boutin, J and Brown, P J and Cai, W J and Chavez, F P and Chen, A and Cosca, C and Fassbender, A J and Feely, R A and González-Dávila, M and Goyet, C and Hales, B and Hardman-Mountford, N and Heinze, C and Hood, M and Hoppema, M and Hunt, C W and Hydes, D and Ishii, M and Johannessen, T and Jones, S D and Key, R M and Körtzinger, A and Landschützer, P and Lauvset, S K and Lefèvre, N and Lenton, A and Lourantou, A and Merlivat, L and Midorikawa, T and Mintrop, L and Miyazaki, C and Murata, A and Nakadate, A and Nakano, Y and Nakaoka, S and Nojiri, Y and Omar, A M and Padin, X A and Park, G H and Paterson, K and Perez, F F and Pierrot, D and Poisson, A and Ríos, A F and Santana-Casiano, J M and Salisbury, J and Sarma, V V S S and Schlitzer, R and Schneider, B and Schuster, U and Sieger, R and Skjelvan, I and Steinhoff, T and Suzuki, T and Takahashi, T and Tedesco, K and Telszewski, M and Thomas, H and Tilbrook, B and Tjiputra, J and Vandemark, D and Veness, T and Wanninkhof, R and Watson, A J and Weiss, R and Wong, C S and Yoshikawa-Inoue, H},
title = {A uniform, quality controlled Surface Ocean CO2 Atlas (SOCAT)},
journal = {Earth System Science Data},
year = {2013},
volume = {5},
number = {1},
pages = {125--143},
url = {http://www.earth-syst-sci-data.net/5/125/2013/},
doi = {10.5194/essd-5-125-2013}
}
|
| Pieterse G, Krol MC, Batenburg AM, M. Brenninkmeijer CA, Popa ME, O'Doherty S, Grant A, Steele LP, Krummel PB, Langenfelds RL, Wang HJ, Vermeulen AT, Schmidt M, Yver C, Jordan A, Engel A, Fisher RE, Lowry D, Nisbet EG, Reimann S, Vollmer MK, Steinbacher M, Hammer S, Forster G, Sturges WT and Röckmann T (2013), " Reassessing the variability in atmospheric H 2 using the two-way nested TM5 model ", Journal of Geophysical Research: Atmospheres., may, 2013. Vol. 118(9), pp. 3764-3780. |
| Abstract: This work reassesses the global atmospheric budget of H2 with the TM5 model. The recent adjustment of the calibration scale for H2 translates into a change in the tropospheric burden. Furthermore, the ECMWF Reanalysis-Interim (ERA-Interim) data from the European Centre for Medium-Range Weather Forecasts (ECMWF) used in this study show slower vertical transport than the operational data used before. Consequently, more H2 is removed by deposition. The deposition parametrization is updated because significant deposition fluxes for snow, water, and vegetation surfaces were calculated in our previous study. Timescales of 1–2 h are asserted for the transport of H2 through the canopies of densely vegetated regions. The global scale variability of H2 and ıD[H2] is well represented by the updated model. H2 is slightly overestimated in the Southern Hemisphere because too little H2 is removed by dry deposition to rainforests and savannahs. The variability in H2 over Europe is further investigated using a high-resolution model subdomain. It is shown that discrepancies between the model and the observations are mainly caused by the finite model resolution. The tropospheric burden is estimated at 165 ˙ 8 Tg H2. The removal rates of H2 by deposition and photochemical oxidation are estimated at 53 ˙ 4 and 23 ˙ 2 Tg H2/yr, resulting in a tropospheric lifetime of 2.2 ˙ 0.2 year. |
BibTeX:
@article{Pieterse2013,
author = {Pieterse, G and Krol, M C and Batenburg, A M and M. Brenninkmeijer, C A and Popa, M E and O'Doherty, S and Grant, A and Steele, L P and Krummel, P B and Langenfelds, R L and Wang, H J and Vermeulen, A T and Schmidt, M and Yver, C and Jordan, A and Engel, A and Fisher, R E and Lowry, D and Nisbet, E G and Reimann, S and Vollmer, M K and Steinbacher, M and Hammer, S and Forster, G and Sturges, W T and Röckmann, T},
title = { Reassessing the variability in atmospheric H 2 using the two-way nested TM5 model },
journal = {Journal of Geophysical Research: Atmospheres},
year = {2013},
volume = {118},
number = {9},
pages = {3764--3780},
url = {http://doi.wiley.com/10.1002/jgrd.50204},
doi = {10.1002/jgrd.50204}
}
|
| Pita G, Gielen B, Zona D, Rodrigues A, Rambal S, Janssens IA and Ceulemans R (2013), "Carbon and water vapor fluxes over four forests in two contrasting climatic zones", Agricultural and Forest Meteorology., oct, 2013. Vol. 180, pp. 211-224. |
| Abstract: The inter- and seasonal patterns of water vapor and canopy carbon fluxes were compared for four forest ecosystems in two contrasting climatic zones in Europe. The eddy covariance and ancillary data were taken from the Carboeurope and FLUXNET databases and a linear modeling statistical analysis was made. The four sites were a high-density poplar (Populus spp.) short rotation coppice plantation (in Lochristi, Belgium) and a mature Scots pine (Pinus sylvestris) forest (in Brasschaat, Belgium) in the Temperate climate versus a fast-growing Eucalypt (Eucalyptus) plantation (in Espirra, Portugal) and a Holm oak (Quercus ilex) forest (in Puechabon, France) in the Mediterranean climate.•The Eucalypt stand showed an efficient stomatal control in response to changes in vapor pressure deficit (VPD), suggesting an ideal adaptation of this species to the severe Mediterranean climate.•The fast-growing poplar stand did not show a similar stomatal control under conditions of moderate water stress. But during an intensive dry period a decrease in the development of the leaf area index (LAI) was observed.•The Holm oak stand showed a low GPP, which is typical for a low productive species with a long rotation cycle. The GPP showed low diurnal variability, even under high solar radiation. This behavior suggested a strong stomatal control caused by the severe water stress, a mechanism that allowed this stand to cope with diurnal and seasonal water deficits.•The mature Scots pine forest in the Temperate climate showed no variation in the GPP - radiation relationship. In this forest no water stress was observed, probably because the trees always had access to the water table. Irrespective of the climate the evapotranspiration of the Scots pine forest presented a tight coupling with the atmosphere, i.e. a low decoupling factor, Ω, comparable with the Holm oak and the Eucalypt forests.The high Ω values of the young poplar plantation were not typical for forest canopies. These values confirmed the strong influence of solar radiation and available energy on evapotranspiration and on the dynamics of this fast-developing canopy. At all four sites the forests showed their capacity to react to the environmental drivers, characteristic from their respective climatic types. However, drastic climatic changes - such as heat waves or long drought spells - may compromise the productivity of fast-growing plantations such as the Eucalypt and poplar stands. The response of the poplars to these events is mainly achieved through LAI control in contrast to the stomatal control in the Eucalypts. textcopyright 2013 Elsevier B.V. |
BibTeX:
@article{Pita2013,
author = {Pita, Gabriel and Gielen, Bert and Zona, Donatella and Rodrigues, Abel and Rambal, Serge and Janssens, Ivan A and Ceulemans, Reinhart},
title = {Carbon and water vapor fluxes over four forests in two contrasting climatic zones},
journal = {Agricultural and Forest Meteorology},
year = {2013},
volume = {180},
pages = {211--224},
url = {http://linkinghub.elsevier.com/retrieve/pii/S0168192313001615},
doi = {10.1016/j.agrformet.2013.06.003}
}
|
| Reichstein M, Bahn M, Ciais P, Frank D, Mahecha MD, Seneviratne SI, Zscheischler J, Beer C, Buchmann N, Frank DC, Papale D, Rammig A, Smith P, Thonicke K, Van Der Velde M, Vicca S, Walz A and Wattenbach M (2013), "Climate extremes and the carbon cycle", Nature., aug, 2013. Vol. 500(7462), pp. 287-295. |
| Abstract: The terrestrial biosphere is a key component of the global carbon cycle and its carbon balance is strongly influenced by climate. Continuing environmental changes are thought to increase global terrestrial carbon uptake. But evidence is mounting that climate extremes such as droughts or storms can lead to a decrease in regional ecosystem carbon stocks and therefore have the potential to negate an expected increase in terrestrial carbon uptake. Here we explore the mechanisms and impacts of climate extremes on the terrestrial carbon cycle, and propose a pathway to improve our understanding of present and future impacts of climate extremes on the terrestrial carbon budget. textcopyright 2013 Macmillan Publishers Limited. All rights reserved. |
BibTeX:
@article{Reichstein2013,
author = {Reichstein, Markus and Bahn, Michael and Ciais, Philippe and Frank, Dorothea and Mahecha, Miguel D and Seneviratne, Sonia I and Zscheischler, Jakob and Beer, Christian and Buchmann, Nina and Frank, David C and Papale, Dario and Rammig, Anja and Smith, Pete and Thonicke, Kirsten and Van Der Velde, Marijn and Vicca, Sara and Walz, Ariane and Wattenbach, Martin},
title = {Climate extremes and the carbon cycle},
journal = {Nature},
year = {2013},
volume = {500},
number = {7462},
pages = {287--295},
url = {http://www.nature.com/articles/nature12350},
doi = {10.1038/nature12350}
}
|
| Rella CW, Chen H, Andrews AE, Filges A, Gerbig C, Hatakka J, Karion A, Miles NL, Richardson SJ, Steinbacher M, Sweeney C, Wastine B and Zellweger C (2013), "High accuracy measurements of dry mole fractions of carbon dioxide and methane in humid air", Atmospheric Measurement Techniques., mar, 2013. Vol. 6(3), pp. 837-860. |
| Abstract: Traditional techniques for measuring the mole fractions of greenhouse gases in the well-mixed atmosphere have required dry sample gas streams (dew point -25°C) to achieve the inter-laboratory compatibility goals set forth by the Global Atmosphere Watch programme of the World Meteorological Organisation (WMO/GAW) for carbon dioxide (±0.1 ppm in the Northern Hemisphere and ±0.05 ppm in the Southern Hemisphere) and methane (±2 ppb). Drying the sample gas to low levels of water vapour can be expensive, time-consuming, and/or problematic, especially at remote sites where access is difficult. Recent advances in optical measurement techniques, in particular cavity ring down spectroscopy, have led to the development of greenhouse gas analysers capable of simultaneous measurements of carbon dioxide, methane and water vapour. Unlike many older technologies, which can suffer from significant uncorrected interference from water vapour, these instruments permit accurate and precise greenhouse gas measurements that can meet the WMO/GAW inter-laboratory compatibility goals (WMO, 2011a) without drying the sample gas. In this paper, we present laboratory methodology for empirically deriving the water vapour correction factors, and we summarise a series of in-situ validation experiments comparing the measurements in humid gas streams to well-characterised dry-gas measurements. By using the manufacturer-supplied correction factors, the dry-mole fraction measurements have been demonstrated to be well within the GAW compatibility goals up to a water vapour concentration of at least 1%. By determining the correction factors for individual instruments once at the start of life, this water vapour concentration range can be extended to at least 2% over the life of the instrument, and if the correction factors are determined periodically over time, the evidence suggests that this range can be extended up to and even above 4% water vapour concentrations. textcopyright Author(s) 2013. |
BibTeX:
@article{Rella2013,
author = {Rella, C W and Chen, H and Andrews, A E and Filges, A and Gerbig, C and Hatakka, J and Karion, A and Miles, N L and Richardson, S J and Steinbacher, M and Sweeney, C and Wastine, B and Zellweger, C},
title = {High accuracy measurements of dry mole fractions of carbon dioxide and methane in humid air},
journal = {Atmospheric Measurement Techniques},
year = {2013},
volume = {6},
number = {3},
pages = {837--860},
url = {http://www.atmos-meas-tech.net/6/837/2013/},
doi = {10.5194/amt-6-837-2013}
}
|
| Sabine CL, Hankin S, Koyuk H, Bakker DCE, Pfeil B, Olsen A, Metzl N, Kozyr A, Fassbender A, Manke A, Malczyk J, Akl J, Alin SR, Bellerby RGJ, Borges A, Boutin J, Brown PJ, Cai WJ, Chavez FP, Chen A, Cosca C, Feely RA, González-Dávila M, Goyet C, Hardman-Mountford N, Heinze C, Hoppema M, Hunt CW, Hydes D, Ishii M, Johannessen T, Key RM, Körtzinger A, Landschützer P, Lauvset SK, Lefèvre N, Lenton A, Lourantou A, Merlivat L, Midorikawa T, Mintrop L, Miyazaki C, Murata A, Nakadate A, Nakano Y, Nakaoka S, Nojiri Y, Omar AM, Padin XA, Park GH, Paterson K, Perez FF, Pierrot D, Poisson A, Ríos AF, Salisbury J, Santana-Casiano JM, S. Sarma VVS, Schlitzer R, Schneider B, Schuster U, Sieger R, Skjelvan I, Steinhoff T, Suzuki T, Takahashi T, Tedesco K, Telszewski M, Thomas H, Tilbrook B, Vandemark D, Veness T, Watson AJ, Weiss R, Wong CS and Yoshikawa-Inoue H (2013), "Surface Ocean CO2 Atlas (SOCAT) gridded data products", Earth System Science Data., apr, 2013. Vol. 5(1), pp. 145-153. |
| Abstract: As a response to public demand for a well-documented, quality controlled, publically available, global surface ocean carbon dioxide (CO2) data set, the international marine carbon science community developed the Surface Ocean CO2 Atlas (SOCAT). The first SOCAT product is a collection of 6.3 million quality controlled surface CO2 data from the global oceans and coastal seas, spanning four decades (1968-2007). The SOCAT gridded data presented here is the second data product to come from the SOCAT project. Recognizing that some groups may have trouble working with millions of measurements, the SOCAT gridded product was generated to provide a robust, regularly spaced CO2 fugacity (if/iCO2) product with minimal spatial and temporal interpolation, which should be easier to work with for many applications. Gridded SOCAT is rich with information that has not been fully explored yet (e.g., regional differences in the seasonal cycles), but also contains biases and limitations that the user needs to recognize and address (e.g., local influences on values in some coastal regions). textcopyright 2013 Author(s). |
BibTeX:
@article{Sabine2013,
author = {Sabine, C L and Hankin, S and Koyuk, H and Bakker, D C E and Pfeil, B and Olsen, A and Metzl, N and Kozyr, A and Fassbender, A and Manke, A and Malczyk, J and Akl, J and Alin, S R and Bellerby, R G J and Borges, A and Boutin, J and Brown, P J and Cai, W J and Chavez, F P and Chen, A and Cosca, C and Feely, R A and González-Dávila, M and Goyet, C and Hardman-Mountford, N and Heinze, C and Hoppema, M and Hunt, C W and Hydes, D and Ishii, M and Johannessen, T and Key, R M and Körtzinger, A and Landschützer, P and Lauvset, S K and Lefèvre, N and Lenton, A and Lourantou, A and Merlivat, L and Midorikawa, T and Mintrop, L and Miyazaki, C and Murata, A and Nakadate, A and Nakano, Y and Nakaoka, S and Nojiri, Y and Omar, A M and Padin, X A and Park, G H and Paterson, K and Perez, F F and Pierrot, D and Poisson, A and Ríos, A F and Salisbury, J and Santana-Casiano, J M and S. Sarma, V V S and Schlitzer, R and Schneider, B and Schuster, U and Sieger, R and Skjelvan, I and Steinhoff, T and Suzuki, T and Takahashi, T and Tedesco, K and Telszewski, M and Thomas, H and Tilbrook, B and Vandemark, D and Veness, T and Watson, A J and Weiss, R and Wong, C S and Yoshikawa-Inoue, H},
title = {Surface Ocean CO2 Atlas (SOCAT) gridded data products},
journal = {Earth System Science Data},
year = {2013},
volume = {5},
number = {1},
pages = {145--153},
url = {http://www.earth-syst-sci-data.net/5/145/2013/},
doi = {10.5194/essd-5-145-2013}
}
|
| Simmonds PG, Manning AJ, Athanassiadou M, Scaife AA, Derwent RG, O'Doherty S, Harth CM, Weiss RF, Dutton GS, Hall BD, Sweeney C and Elkins JW (2013), "Interannual fluctuations in the seasonal cycle of nitrous oxide and chlorofluorocarbons due to the Brewer-Dobson circulation", Journal of Geophysical Research Atmospheres., oct, 2013. Vol. 118(19), pp. 10694-10706. |
| Abstract: The tropospheric seasonal cycles of Ninf2/infO, CFC-11 (CCl inf3/infF), and CFC-12 (CClinf2/infFinf2/inf) are influenced by atmospheric dynamics. The interannually varying summertime minima in mole fractions of these trace gases have been attributed to interannual variations in mixing of stratospheric air (depleted in CFCs and Ninf2/infO) with tropospheric air with a few months lag. The amount of wave activity that drives the stratospheric circulation and influences the winter stratospheric jet and subsequent mass transport across the tropopause appears to be the primary cause of this interannual variability. We relate the observed seasonal minima of species at three Northern Hemisphere sites (Mace Head, Ireland; Trinidad Head, U.S.; and Barrow, Alaska) with the behavior of the winter stratospheric jet. As a result, a good correlation is obtained between zonal winds in winter at 10 hPa, 58°N-68°N, and the detrended seasonal minima in the stratosphere-influenced tracers. For these three tracers, individual Pearson correlation coefficients (r) between 0.51 and 0.71 were found, with overall correlations of between 0.67 and 0.77 when "composite species" were considered. Finally, we note that the long-term observations of CFCs and N inf2/infO in the troposphere provide an independent monitoring method complementary to satellite data. Furthermore, they could provide a useful observational measure of the strength of stratosphere-troposphere exchange and, thus, could be used to monitor any long-term trend in the Brewer-Dobson circulation which is predicted by climate models to increase over the coming decades. Key Points Relates atmospheric dynamics (STE) with N2O and CFC tracers species Inter-annually varying summertime minima and mixing of stratospheric air Prediction of changes in Brewer Donson circulation textcopyright2013. American Geophysical Union. All Rights Reserved. |
BibTeX:
@article{Simmonds2013,
author = {Simmonds, P G and Manning, A J and Athanassiadou, M and Scaife, A A and Derwent, R G and O'Doherty, S and Harth, C M and Weiss, R F and Dutton, G S and Hall, B D and Sweeney, C and Elkins, J W},
title = {Interannual fluctuations in the seasonal cycle of nitrous oxide and chlorofluorocarbons due to the Brewer-Dobson circulation},
journal = {Journal of Geophysical Research Atmospheres},
year = {2013},
volume = {118},
number = {19},
pages = {10694--10706},
url = {http://doi.wiley.com/10.1002/jgrd.50832},
doi = {10.1002/jgrd.50832}
}
|
| Šimpraga M, Verbeeck H, Bloemen J, Vanhaecke L, Demarcke M, Joó E, Pokorska O, Amelynck C, Schoon N, Dewulf J, Van Langenhove H, Heinesch B, Aubinet M and Steppe K (2013), "Vertical canopy gradient in photosynthesis and monoterpenoid emissions: An insight into the chemistry and physiology behind", Atmospheric Environment., dec, 2013. Vol. 80, pp. 85-95. |
| Abstract: It is well known that vertical canopy gradients and varying sky conditions influence photosynthesis (Pn), specific leaf area (SLA), leaf thickness (LT) and leaf pigments (lutein, â-carotene and chlorophyll). In contrast, little is known about these effects on monoterpenoid (MT) emissions. Our study examines simultaneously measured Pn, MT emissions and the MT/Pn ratio along the canopy of an adult European beech tree (Fagus sylvatica L.) in natural forest conditions. Dynamic branch enclosure systems were used at four heights in the canopy (7, 14, 21 and 25m) in order to establish relationships and better understand the interaction between Pn and MT emissions under both sunny and cloudy sky conditions. Clear differences in Pn, MT emissions and the MT/Pn ratio were detected within the canopy. The highest Pn rates were observed in the sun leaves at 25m due to the higher intercepted light levels, whereas MT emissions (and the MT/Pn ratio) were unexpectedly highest in the semi-shaded leaves at 21m. The higher Pn rates and, apparently contradictory, lower MT emissions in the sun leaves may be explained by the hypothesis of Owen and Peñuelas (2005), stating synthesis of more photo-protective carotenoids may decrease the emissions of volatile isoprenoids (including MTs) because they both share the same biochemical precursors. In addition, leaf traits like SLA, LT and leaf pigments clearly differed with height in the canopy, suggesting that the leaf's physiological status cannot be neglected in future research on biogenic volatile organic compounds (BVOCs) when aiming at developing new and/or improved emission algorithms. textcopyright 2013 Elsevier Ltd. |
BibTeX:
@article{Simpraga2013,
author = {Šimpraga, M and Verbeeck, H and Bloemen, J and Vanhaecke, L and Demarcke, M and Joó, E and Pokorska, O and Amelynck, C and Schoon, N and Dewulf, J and Van Langenhove, H and Heinesch, B and Aubinet, M and Steppe, K},
title = {Vertical canopy gradient in photosynthesis and monoterpenoid emissions: An insight into the chemistry and physiology behind},
journal = {Atmospheric Environment},
year = {2013},
volume = {80},
pages = {85--95},
url = {http://linkinghub.elsevier.com/retrieve/pii/S1352231013005785},
doi = {10.1016/j.atmosenv.2013.07.047}
}
|
| Stoy PC, Mauder M, Foken T, Marcolla B, Boegh E, Ibrom A, Arain MA, Arneth A, Aurela M, Bernhofer C, Cescatti A, Dellwik E, Duce P, Gianelle D, van Gorsel E, Kiely G, Knohl A, Margolis H, Mccaughey H, Merbold L, Montagnani L, Papale D, Reichstein M, Saunders M, Serrano-Ortiz P, Sottocornola M, Spano D, Vaccari F and Varlagin A (2013), "A data-driven analysis of energy balance closure across FLUXNET research sites: The role of landscape scale heterogeneity", Agricultural and Forest Meteorology., apr, 2013. Vol. 171-172, pp. 137-152. |
| Abstract: The energy balance at most surface-atmosphere flux research sites remains unclosed. The mechanisms underlying the discrepancy between measured energy inputs and outputs across the global FLUXNET tower network are still under debate. Recent reviews have identified exchange processes and turbulent motions at large spatial and temporal scales in heterogeneous landscapes as the primary cause of the lack of energy balance closure at some intensively-researched sites, while unmeasured storage terms cannot be ruled out as a dominant contributor to the lack of energy balance closure at many other sites. We analyzed energy balance closure across 173 ecosystems in the FLUXNET database and explored the relationship between energy balance closure and landscape heterogeneity using MODIS products and GLOBEstat elevation data. Energy balance closure per research site (CEB,s) averaged 0.84±0.20, with best average closures in evergreen broadleaf forests and savannas (0.91-0.94) and worst average closures in crops, deciduous broadleaf forests, mixed forests and wetlands (0.70-0.78). Half-hourly or hourly energy balance closure on a percent basis increased with friction velocity (u*) and was highest on average under near-neutral atmospheric conditions. CEB,s was significantly related to mean precipitation, gross primary productivity and landscape-level enhanced vegetation index (EVI) from MODIS, and the variability in elevation, MODIS plant functional type, and MODIS EVI. A linear model including landscape-level variability in both EVI and elevation, mean precipitation, and an interaction term between EVI variability and precipitation had the lowest Akaike's information criterion value. CEB,s in landscapes with uniform plant functional type approached 0.9 and CEB,s in landscapes with uniform EVI approached 1. These results suggest that landscape-level heterogeneity in vegetation and topography cannot be ignored as a contributor to incomplete energy balance closure at the flux network level, although net radiation measurements, biological energy assimilation, unmeasured storage terms, and the importance of good practice including site selection when making flux measurements should not be discounted. Our results suggest that future research should focus on the quantitative mechanistic relationships between energy balance closure and landscape-scale heterogeneity, and the consequences of mesoscale circulations for surface-atmosphere exchange measurements. textcopyright 2012 Elsevier B.V. |
BibTeX:
@article{Stoy2013,
author = {Stoy, Paul C and Mauder, Matthias and Foken, Thomas and Marcolla, Barbara and Boegh, Eva and Ibrom, Andreas and Arain, M Altaf and Arneth, Almut and Aurela, Mika and Bernhofer, Christian and Cescatti, Alessandro and Dellwik, Ebba and Duce, Pierpaolo and Gianelle, Damiano and van Gorsel, Eva and Kiely, Gerard and Knohl, Alexander and Margolis, Hank and Mccaughey, Harry and Merbold, Lutz and Montagnani, Leonardo and Papale, Dario and Reichstein, Markus and Saunders, Matthew and Serrano-Ortiz, Penelope and Sottocornola, Matteo and Spano, Donatella and Vaccari, Francesco and Varlagin, Andrej},
title = {A data-driven analysis of energy balance closure across FLUXNET research sites: The role of landscape scale heterogeneity},
journal = {Agricultural and Forest Meteorology},
year = {2013},
volume = {171-172},
pages = {137--152},
url = {http://linkinghub.elsevier.com/retrieve/pii/S0168192312003413},
doi = {10.1016/j.agrformet.2012.11.004}
}
|
| Sussmann R, Ostler A, Forster F, Rettinger M, Deutscher NM, Griffith DWT, Hannigan JW, Jones N and Patra PK (2013), "First intercalibration of column-averaged methane from the total carbon column observing network and the network climate for the detection of atmospheric composition change", Atmospheric Measurement Techniques., feb, 2013. Vol. 6(2), pp. 397-418. |
| Abstract: We present the first intercalibration of dry-air column-averaged mole fractions of methane (XCH4) retrieved from solar Fourier transform infrared (FTIR) measurements of the Network for the Detection of Atmospheric Composition Change (NDACC) in the mid-infrared (MIR) versus near-infrared (NIR) soundings from the Total Carbon Column Observing Network (TCCON). The study uses multi-annual quasi-coincidentMIR and NIR measurements from the stations Garmisch, Germany (47.48°N, 11.06°E, 743ma.s.l.), andWollongong, Australia (34.41°S, 150.88°E, 30ma.s.l.). Direct comparison of the retrieved MIR and NIR XCH4 time series for Garmisch shows a quasi-periodic seasonal bias leading to a standard deviation (stdv) of the difference time series (NIR-MIR) of 7.2 ppb. After reducing time-dependent a priori impact by using realistic site- and timedependent ACTM-simulated profiles as a common prior, the seasonal bias is reduced (stdv = 5.2 ppb). A linear fit to the MIR/NIR scatter plot of monthly means based on sameday coincidences does not show a y-intercept that is statistically different from zero, and the MIR/NIR intercalibration factor is found to be close to ideal within 2-σ uncertainty, i.e. 0.9996(8). The difference time series (NIR-MIR) do not show a significant trend. The same basic findings hold for Wollongong. In particular an overall MIR/NIR intercalibration factor close to the ideal 1 is found within 2-σ uncertainty. At Wollongong the seasonal cycle of methane is less pronounced and corresponding smoothing errors are not as significant, enabling standard MIR and NIR retrievals to be used directly, without correction to a common a priori. Our results suggest that it is possible to set up a harmonized NDACC and TCCON XCH4 data set which can be exploited for joint trend studies, satellite validation, or the inverse modeling of sources and sinks. textcopyright Author(s) 2013. CC Attribution 3.0 License. |
BibTeX:
@article{Sussmann2013,
author = {Sussmann, R and Ostler, A and Forster, F and Rettinger, M and Deutscher, N M and Griffith, D W T and Hannigan, J W and Jones, N and Patra, P K},
title = {First intercalibration of column-averaged methane from the total carbon column observing network and the network climate for the detection of atmospheric composition change},
journal = {Atmospheric Measurement Techniques},
year = {2013},
volume = {6},
number = {2},
pages = {397--418},
url = {http://www.atmos-meas-tech.net/6/397/2013/},
doi = {10.5194/amt-6-397-2013}
}
|
| Teuling AJ, Van Loon AF, Seneviratne SI, Lehner I, Aubinet M, Heinesch B, Bernhofer C, Grünwald T, Prasse H and Spank U (2013), "Evapotranspiration amplifies European summer drought", Geophysical Research Letters., may, 2013. Vol. 40(10), pp. 2071-2075. |
| Abstract: Drought is typically associated with a lack of precipitation, whereas the contribution of evapotranspiration and runoff to drought evolution is not well understood. Here we use unique long-term observations made in four headwater catchments in central and western Europe to reconstruct storage anomalies and study the drivers of storage anomaly evolution during drought. We provide observational evidence for the "drought-paradox" in that region: a consistent and significant increase in evapotranspiration during drought episodes, which acts to amplify the storage anomalies. In contrast, decreases in runoff act to limit storage anomalies. Our findings stress the need for the correct representation of evapotranspiration and runoff processes in drought indices. textcopyright 2013 American Geophysical Union. All Rights Reserved. |
BibTeX:
@article{Teuling2013,
author = {Teuling, Adriaan J and Van Loon, Anne F and Seneviratne, Sonia I and Lehner, Irene and Aubinet, Marc and Heinesch, Bernard and Bernhofer, Christian and Grünwald, Thomas and Prasse, Heiko and Spank, Uwe},
title = {Evapotranspiration amplifies European summer drought},
journal = {Geophysical Research Letters},
year = {2013},
volume = {40},
number = {10},
pages = {2071--2075},
url = {http://doi.wiley.com/10.1002/grl.50495},
doi = {10.1002/grl.50495}
}
|
| Unger N, Harper K, Zheng Y, Kiang NY, Aleinov I, Arneth A, Schurgers G, Amelynck C, Goldstein A, Guenther A, Heinesch B, Hewitt CN, Karl T, Laffineur Q, Langford B, McKinney KA, Misztal P, Potosnak M, Rinne J, Pressley S, Schoon N and Serça D (2013), "Photosynthesis-dependent isoprene emission from leaf to planet in a global carbon-chemistry-climate model", Atmospheric Chemistry and Physics., oct, 2013. Vol. 13(20), pp. 10243-10269. |
| Abstract: We describe the implementation of a biochemical model of isoprene emission that depends on the electron requirement for isoprene synthesis into the Farquhar-Ball-Berry leaf model of photosynthesis and stomatal conductance that is embedded within a global chemistry-climate simulation framework. The isoprene production is calculated as a function of electron transport-limited photosynthesis, intercellular and atmospheric carbon dioxide concentration, and canopy temperature. The vegetation biophysics module computes the photosynthetic uptake of carbon dioxide coupled with the transpiration of water vapor and the isoprene emission rate at the 30 min physical integration time step of the global chemistry-climate model. In the model, the rate of carbon assimilation provides the dominant control on isoprene emission variability over canopy temperature. A control simulation representative of the present-day climatic state that uses 8 plant functional types (PFTs), prescribed phenology and generic PFT-specific isoprene emission potentials (fraction of electrons available for isoprene synthesis) reproduces 50% of the variability across different ecosystems and seasons in a global database of 28 measured campaign-average fluxes. Compared to time-varying isoprene flux measurements at 9 select sites, the model authentically captures the observed variability in the 30 min average diurnal cycle (R2 = 64-96 %) and simulates the flux magnitude to within a factor of 2. The control run yields a global isoprene source strength of 451 TgC yr?1 that increases by 30% in the artificial absence of plant water stress and by 55% for potential natural vegetation. textcopyright Author(s) 2013. |
BibTeX:
@article{Unger2013,
author = {Unger, N and Harper, K and Zheng, Y and Kiang, N Y and Aleinov, I and Arneth, A and Schurgers, G and Amelynck, C and Goldstein, A and Guenther, A and Heinesch, B and Hewitt, C N and Karl, T and Laffineur, Q and Langford, B and McKinney, K A and Misztal, P and Potosnak, M and Rinne, J and Pressley, S and Schoon, N and Serça, D},
title = {Photosynthesis-dependent isoprene emission from leaf to planet in a global carbon-chemistry-climate model},
journal = {Atmospheric Chemistry and Physics},
year = {2013},
volume = {13},
number = {20},
pages = {10243--10269},
url = {http://www.atmos-chem-phys.net/13/10243/2013/},
doi = {10.5194/acp-13-10243-2013}
}
|
| Van Der Laan-Luijkx IT, Van Der Laan S, Uglietti C, Schibig MF, Neubert REM, Meijer HAJ, Brand WA, Jordan A, Richter JM, Rothe M and Leuenberger MC (2013), "Atmospheric CO2, δ(O2/N2) and δ13CO2 measurements at Jungfraujoch, Switzerland: Results from a flask sampling intercomparison program", Atmospheric Measurement Techniques., jul, 2013. Vol. 6(7), pp. 1805-1815. |
| Abstract: We present results from an intercomparison program of CO2, δ(O2/N2) and δ13CO2 measurements from atmospheric flask samples. Flask samples are collected on a biweekly basis at the High Altitude Research Station Jungfraujoch in Switzerland for three European laboratories: the University of Bern, Switzerland, the University of Groningen, the Netherlands and the Max Planck Institute for Biogeochemistry in Jena, Germany. Almost 4 years of measurements of CO 2, δ(O2/N2) and δ 13CO2 are compared in this paper to assess the measurement compatibility of the three laboratories. While the average difference for the CO2 measurements between the laboratories in Bern and Jena meets the required compatibility goal as defined by the World Meteorological Organization, the standard deviation of the average differences between all laboratories is not within the required goal. However, the obtained annual trend and seasonalities are the same within their estimated uncertainties. For δ(O2/N2) significant differences are observed between the three laboratories. The comparison for δ13CO 2 yields the least compatible results and the required goals are not met between the three laboratories. Our study shows the importance of regular intercomparison exercises to identify potential biases between laboratories and the need to improve the quality of atmospheric measurements. textcopyright Author(s) 2013. CC Attribution 3.0 License. |
BibTeX:
@article{VanDerLaan-Luijkx2013,
author = {Van Der Laan-Luijkx, I T and Van Der Laan, S and Uglietti, C and Schibig, M F and Neubert, R E M and Meijer, H A J and Brand, W A and Jordan, A and Richter, J M and Rothe, M and Leuenberger, M C},
title = {Atmospheric CO2, δ(O2/N2) and δ13CO2 measurements at Jungfraujoch, Switzerland: Results from a flask sampling intercomparison program},
journal = {Atmospheric Measurement Techniques},
year = {2013},
volume = {6},
number = {7},
pages = {1805--1815},
url = {http://www.atmos-meas-tech.net/6/1805/2013/},
doi = {10.5194/amt-6-1805-2013}
}
|
| Van Der Velde IR, Miller JB, Schaefer K, Masarie KA, Denning S, White JWC, Tans PP, Krol MC and Peters W (2013), "Biosphere model simulations of interannual variability in terrestrial 13C/12C exchange", Global Biogeochemical Cycles., sep, 2013. Vol. 27(3), pp. 637-649. |
| Abstract: Previous studies suggest that a large part of the variability in the atmospheric ratio of 13CO2/12CO 2originates from carbon exchange with the terrestrial biosphere rather than with the oceans. Since this variability is used to quantitatively partition the total carbon sink, we here investigate the contribution of interannual variability (IAV) in biospheric exchange to the observed atmospheric 13C variations. We use the Simple Biosphere - Carnegie-Ames-Stanford Approach biogeochemical model, including a detailed isotopic fractionation scheme, separate 12C and 13C biogeochemical pools, and satellite-observed fire disturbances. This model of 12CO2 and 13CO2 thus also produces return fluxes of 13CO2from its differently aged pools, contributing to the so-called disequilibrium flux. Our simulated terrestrial 13C budget closely resembles previously published model results for plant discrimination and disequilibrium fluxes and similarly suggests that variations in C 3 discrimination and year-to-year variations in C3and C4 productivity are the main drivers of their IAV. But the year-to-year variability in the isotopic disequilibrium flux is much lower (1σ=±1.5 PgC ‰ yr-1) than required (±12.5 PgC ‰ yr-1) to match atmospheric observations, under the common assumption of low variability in net ocean CO2 fluxes. This contrasts with earlier published results. It is currently unclear how to increase IAV in these drivers suggesting that SiBCASA still misses processes that enhance variability in plant discrimination and relative C 3/C4productivity. Alternatively, 13C budget terms other than terrestrial disequilibrium fluxes, including possibly the atmospheric growth rate, must have significantly different IAV in order to close the atmospheric 13C budget on a year-to-year basis. textcopyright2013. American Geophysical Union. All Rights Reserved. |
BibTeX:
@article{VanDerVelde2013,
author = {Van Der Velde, I R and Miller, J B and Schaefer, K and Masarie, K A and Denning, S and White, J W C and Tans, P P and Krol, M C and Peters, W},
title = {Biosphere model simulations of interannual variability in terrestrial 13C/12C exchange},
journal = {Global Biogeochemical Cycles},
year = {2013},
volume = {27},
number = {3},
pages = {637--649},
url = {http://doi.wiley.com/10.1002/gbc.20048},
doi = {10.1002/gbc.20048}
}
|
| van der Werf GR, Peters W, van Leeuwen TT and Giglio L (2013), "What could have caused pre-industrial biomass burning emissions to exceed current rates?", Climate of the Past., jan, 2013. Vol. 9(1), pp. 289-306. |
| Abstract: Abstract. Recent studies based on trace gas mixing ratios in ice cores and charcoal data indicate that biomass burning emissions over the past millennium exceeded contemporary emissions by up to a factor of 4 for certain time periods. This is surprising because various sources of biomass burning are linked with population density, which has increased over the past centuries. We have analysed how emissions from several landscape biomass burning sources could have fluctuated to yield emissions that are in correspondence with recent results based on ice core mixing ratios of carbon monoxide (CO) and its isotopic signature measured at South Pole station (SPO). Based on estimates of contemporary landscape fire emissions and the TM5 chemical transport model driven by present-day atmospheric transport and OH concentrations, we found that CO mixing ratios at SPO are more sensitive to emissions from South America and Australia than from Africa, and are relatively insensitive to emissions from the Northern Hemisphere. We then explored how various landscape biomass burning sources may have varied over the past centuries and what the resulting emissions and corresponding CO mixing ratio at SPO would be, using population density variations to reconstruct sources driven by humans (e.g., fuelwood burning) and a new model to relate savanna emissions to changes in fire return times. We found that to match the observed ice core CO data, all savannas in the Southern Hemisphere had to burn annually, or bi-annually in combination with deforestation and slash and burn agriculture exceeding current levels, despite much lower population densities and lack of machinery to aid the deforestation process. While possible, these scenarios are unlikely and in conflict with current literature. However, we do show the large potential for increased emissions from savannas in a pre-industrial world. This is mainly because in the past, fuel beds were probably less fragmented compared to the current situation; satellite data indicates that the majority of savannas have not burned in the past 10 yr, even in Africa, which is considered "the burning continent". Although we have not considered increased charcoal burning or changes in OH concentrations as potential causes for the elevated CO concentrations found at SPO, it is unlikely they can explain the large increase found in the CO concentrations in ice core data. Confirmation of the CO ice core data would therefore call for radical new thinking about causes of variable global fire rates over recent centuries. |
BibTeX:
@article{VanderWerf2013,
author = {van der Werf, G R and Peters, W and van Leeuwen, T T and Giglio, L},
title = {What could have caused pre-industrial biomass burning emissions to exceed current rates?},
journal = {Climate of the Past},
year = {2013},
volume = {9},
number = {1},
pages = {289--306},
url = {http://www.clim-past.net/9/289/2013/},
doi = {10.5194/cp-9-289-2013}
}
|
| Van Leeuwen TT, Peters W, Krol MC and Van Der Werf GR (2013), "Dynamic biomass burning emission factors and their impact on atmospheric CO mixing ratios", Journal of Geophysical Research Atmospheres., jun, 2013. Vol. 118(12), pp. 6797-6815. |
| Abstract: Biomass burning is a major source of trace gases and aerosols, influencing atmospheric chemistry and climate. To quantitatively assess its impact, an accurate representation of fire emissions is crucial for the atmospheric modeling community. So far, most studies rely on static emission factors (EF) which convert estimates of dry matter burned to trace gas and aerosol emissions. These EFs are often based on the arithmetic mean of field measurements stratified by biome, neglecting the variability in time and space. Here we present global carbon monoxide (CO) emission estimates from fires based on six EF scenarios with different spatial and temporal variability, using dry matter emission estimates from the Global Fire Emissions Database (GFED). We used the TM5 model to transport these different bottom-up estimates in the atmosphere and found that including spatial and temporal variability in EFs impacted CO mixing ratios substantially. Most scenarios estimated higher CO mixing ratios (up to 40% more CO from fires during the burning season) over boreal regions compared to the GFED standard run, while a decrease (˜15%) was estimated over the continent of Africa. A comparison to atmospheric CO observations showed differences of 10-20 ppb between the scenarios and systematic deviations from local observations. Although temporal correlations of specific EF scenarios improved for certain regions, an overall "best" set of EFs could not be selected. Our results provide a new set of emission estimates that can be used for sensitivity analyses and highlight the importance of better understanding spatial and temporal variability in EFs for atmospheric studies in general and specifically when using CO or aerosols concentration measurements to top-down constrain fire carbon emissions. Key Points New biomass burning emission factor scenarios were developed New emission factor scenarios impacted CO mixing ratios substantially Better understanding of spatial and temporal variability in EFs is important textcopyright 2013. American Geophysical Union. All Rights Reserved. |
BibTeX:
@article{VanLeeuwen2013,
author = {Van Leeuwen, T T and Peters, W and Krol, M C and Van Der Werf, G R},
title = {Dynamic biomass burning emission factors and their impact on atmospheric CO mixing ratios},
journal = {Journal of Geophysical Research Atmospheres},
year = {2013},
volume = {118},
number = {12},
pages = {6797--6815},
url = {http://doi.wiley.com/10.1002/jgrd.50478},
doi = {10.1002/jgrd.50478}
}
|
| Vargas R, Sonnentag O, Abramowitz G, Carrara A, Chen JM, Ciais P, Correia A, Keenan TF, Kobayashi H, Ourcival JM, Papale D, Pearson D, Pereira JS, Piao S, Rambal S and Baldocchi DD (2013), "Drought Influences the Accuracy of Simulated Ecosystem Fluxes: A Model-Data Meta-analysis for Mediterranean Oak Woodlands", Ecosystems., aug, 2013. Vol. 16(5), pp. 749-764. |
| Abstract: Water availability is the dominant control of global terrestrial primary productivity with concurrent effects on evapotranspiration and ecosystem respiration, especially in water-limited ecosystems. Process-oriented ecosystem models are critical tools for understanding land-atmosphere exchanges and for up-scaling this information to regional and global scales. Thus, it is important to understand how ecosystem models simulate ecosystem fluxes under changing weather conditions. Here, we applied both time-series analysis and meta-analysis techniques to study how five ecosystem process-oriented models-simulated gross primary production (GPP), ecosystem respiration (Reco), and evapotranspiration (ET). Ecosystem fluxes were simulated for 3 years at a daily time step from four evergreen and three deciduous Mediterranean oak woodlands (21 site-year measurements; 105 site-year-simulations). Mediterranean ecosystems are important test-beds for studying the interannual dynamics of soil moisture on ecosystem mass and energy exchange as they experience cool, wet winters with hot, dry summers and are typically subject to drought. Results show data-model disagreements at multiple temporal scales for GPP, Reco, and ET at both plant functional types. Overall there was a systematic underestimation of the temporal variation of Reco at both plant functional types at temporal scales between weeks and months, and an overestimation at the yearly scale. Modeled Reco was systematically overestimated during drought for all sites, but daily GPP was systematically underestimated only for deciduous sites during drought. In contrast, daily estimates of ET showed good data-model agreement even during drought conditions. This meta-analysis brings attention to the importance of drought conditions for modeling purposes in representing forest dynamics in water-limited ecosystems. textcopyright 2013 Springer Science+Business Media New York. |
BibTeX:
@article{Vargas2013,
author = {Vargas, Rodrigo and Sonnentag, Oliver and Abramowitz, Gab and Carrara, Arnaud and Chen, Jing Ming and Ciais, Philippe and Correia, Alexandra and Keenan, Trevor F and Kobayashi, Hideki and Ourcival, Jean Marc and Papale, Dario and Pearson, David and Pereira, Joao S and Piao, Shilong and Rambal, Serge and Baldocchi, Dennis D},
title = {Drought Influences the Accuracy of Simulated Ecosystem Fluxes: A Model-Data Meta-analysis for Mediterranean Oak Woodlands},
journal = {Ecosystems},
year = {2013},
volume = {16},
number = {5},
pages = {749--764},
url = {http://link.springer.com/10.1007/s10021-013-9648-1},
doi = {10.1007/s10021-013-9648-1}
}
|
| Verlinden MS, Broeckx LS, Van den Bulcke J, Van Acker J and Ceulemans R (2013), "Comparative study of biomass determinants of 12 poplar (Populus) genotypes in a high-density short-rotation culture", Forest Ecology and Management., nov, 2013. Vol. 307, pp. 101-111. |
| Abstract: The success of the production of renewable bioenergy with short-rotation coppice (SRC) cultures primarily depends on their sustainability and biomass yield. The choice of the genotypic materials largely determines how much biomass can be produced; therefore there is a need to study the performance of genotypes in situ to select the best performing ones. Twelve poplar (Populus) genotypes, of which two only recently commercialized, were planted in a large-scale operational SRC culture for the production of biomass for bioenergy. The objectives of the study were: (i) to describe and compare the 12 genotypes based on their growth, structural and developmental characteristics, and (ii) to analyze causal relationships between determining traits and productivity characteristics assessed at leaf, tree and population level by performing a hierarchical cluster analysis. The clustering of the poplar genotypes was clearly determined by parentage and genetic origin. Distinct differences between clusters were expressed in the biomass related traits; genotypes of similar parentage and origin showed comparable characteristics. Populus nigra genotypes were the least performing among the studied genotypes. The recently commercialized P. trichocarpa ×. P. maximowiczii hybrids on the other hand, were among the most productive genotypes. The P. deltoides ×. P. nigra hybrids showed intermediary results, with genotype Hees showing the highest biomass production among the 12 genotypes. As higher heating value was rather uniform among the genotypes, biomass production appeared the primary trait with regard to bioenergy production. This has significant implications for SRC cultures aiming at maximization of biomass production for maximum bioenergy yield. Besides the direct measurements of woody biomass growth (i.e. stem diameter), leaf area index is one of the most important early selection criteria for poplar with bioenergy purposes. The negative correlation of biomass and leaf rust infection reconfirmed the importance of disease vulnerability in breeding and selection programs. textcopyright 2013 The Authors. |
BibTeX:
@article{Verlinden2013,
author = {Verlinden, M S and Broeckx, L S and Van den Bulcke, J and Van Acker, J and Ceulemans, R},
title = {Comparative study of biomass determinants of 12 poplar (Populus) genotypes in a high-density short-rotation culture},
journal = {Forest Ecology and Management},
year = {2013},
volume = {307},
pages = {101--111},
url = {http://linkinghub.elsevier.com/retrieve/pii/S0378112713004313},
doi = {10.1016/j.foreco.2013.06.062}
}
|
| Verlinden MS, Broeckx LS, Wei H and Ceulemans R (2013), "Soil CO2 efflux in a bioenergy plantation with fast-growing Populus trees - influence of former land use, inter-row spacing and genotype", Plant and Soil., aug, 2013. Vol. 369(1-2), pp. 631-644. |
| Abstract: Aims: In this study we quantified the annual soil CO2 efflux (annual SCE) of a short rotation coppice plantation in its establishment phase. We aimed to examine the effect of former (agricultural) land use type, inter-row spacing and genotype. Methods: Annual SCE was quantified during the second growth year of the establishment rotation in a large scale poplar plantation in Flanders. Automated chambers were distributed over the two former land use types, the two different inter-row spacings and under two poplar genotypes. Additional measurements of C, N, P, K, Mg, Ca and Na concentrations of the soil, pH, bulk density, fine root biomass, microbial biomass C, soil mineralization rate, distance to trees and tree diameters were performed at the end of the second growth year. Results: Total carbon loss from soil CO2 efflux was valued at 589 g m-2 yr-1. Annual SCE was higher in former pasture as compared to cropland, higher in the narrow than in the wider inter-row spacings, but no effect of genotype was found. Conclusions: Spatial differences in site characteristics are of great importance for understanding the effect of ecosystem management and land use change on soil respiration processes and need to be taken into account in modeling efforts of the carbon balance. textcopyright 2013 The Author(s). |
BibTeX:
@article{Verlinden2013a,
author = {Verlinden, M S and Broeckx, L S and Wei, H and Ceulemans, R},
title = {Soil CO2 efflux in a bioenergy plantation with fast-growing Populus trees - influence of former land use, inter-row spacing and genotype},
journal = {Plant and Soil},
year = {2013},
volume = {369},
number = {1-2},
pages = {631--644},
url = {http://link.springer.com/10.1007/s11104-013-1604-5},
doi = {10.1007/s11104-013-1604-5}
}
|
| Vogel FR, Thiruchittampalam B, Theloke J, Kretschmer R, Gerbig C, Hammer S and Levin I (2013), "Can we evaluate a fine-grained emission model using high-resolution atmospheric transport modelling and regional fossil fuel CO2 observations?", Tellus, Series B: Chemical and Physical Meteorology., dec, 2013. Vol. 65(1), pp. 18681. |
| Abstract: Quantifying carbon dioxide emissions from fossil fuel burning (FFCO2) is a crucial task to assess continental carbon fluxes and to track anthropogenic emissions changes in the future. In the present study, we investigate potentials and challenges when combining observational data with simulations using high-resolution atmospheric transport and emission modelling. These challenges concern, for example, erroneous vertical mixing or uncertainties in the disaggregation of national total emissions to higher spatial and temporal resolution. In our study, the hourly regional fossil fuel CO2 offset (δFFCO2) is simulated by transporting emissions from a 5 min×5 min emission model (IER2005) that provides FFCO2 emissions from different emission categories. Our Lagrangian particle dispersion model (STILT) is driven by 25 km×25 km meteorological data from the European Center for Medium-Range Weather Forecast (ECMWF). We evaluate this modelling framework (STILT/ECMWF+IER2005) for the year 2005 using hourly DFFCO2 estimates derived from 14C, CO and 222Radon (222Rn) observations at an urban site in south-western Germany (Heidelberg). Analysing the mean diurnal cycles of δFFCO2 for different seasons, we find that the large seasonal and diurnal variation of emission factors used in the bottom-up emission model (spanning one order of magnitude) are adequate. Furthermore, we show that the use of 222Rn as an independent tracer helps to overcome problems in timing as well as strength of the vertical mixing in the transport model. By applying this variability correction, the model-observation agreement is significantly improved for simulated δFFCO2. We found a significant overestimation of δFFCO2 concentrations during situations where the air masses predominantly originate from densely populated areas. This is most likely caused by the spatial disaggregation methodology for the residential emissions, which to some extent relies on a constant per capita-based distribution. In the case of domestic heating emissions, this does not appear to be sufficient. textcopyright 2013 F. R. Vogel et al. |
BibTeX:
@article{Vogel2013,
author = {Vogel, Felix R and Thiruchittampalam, Balendra and Theloke, Jochen and Kretschmer, Roberto and Gerbig, Christoph and Hammer, Samuel and Levin, Ingeborg},
title = {Can we evaluate a fine-grained emission model using high-resolution atmospheric transport modelling and regional fossil fuel CO2 observations?},
journal = {Tellus, Series B: Chemical and Physical Meteorology},
year = {2013},
volume = {65},
number = {1},
pages = {18681},
url = {https://www.tandfonline.com/doi/full/10.3402/tellusb.v65i0.18681},
doi = {10.3402/tellusb.v65i0.18681}
}
|
| Vondrák J and Kubásek J (2013), "Algal stacks and fungal stacks as adaptations to high light in lichens", Lichenologist., jan, 2013. Vol. 45(1), pp. 115-124. |
| Abstract: Some lichens that occur in mountains and arid regions have developed an unusual anatomy resembling window-leaved plants. In these lichens, algal cells occur in thick vertical stacks (algal stacks) separated by vertical channels of light-transferring fungal hyphae (fungal stacks). We present experimental evidence that this anatomy permits higher rates of area-based CO2 assimilation in strong light, but that it also leads to higher respiration resulting in higher compensation irradiance. The net effect of this anatomy must be beneficial in regions of high insolation, as it has arisen many times in different parts of the world, and in unrelated lichens, and these lichens often dominate the communities in which they occur. Copyright textcopyright 2013 British Lichen Society. |
BibTeX:
@article{Vondrak2013,
author = {Vondrák, Jan and Kubásek, Jiří},
title = {Algal stacks and fungal stacks as adaptations to high light in lichens},
journal = {Lichenologist},
year = {2013},
volume = {45},
number = {1},
pages = {115--124},
doi = {10.1017/S0024282912000722}
}
|
| Wang K, Liu C, Zheng X, Pihlatie M, Li B, Haapanala S, Vesala T, Liu H, Wang Y, Liu G and Hu F (2013), "Comparison between eddy covariance and automatic chamber techniques for measuring net ecosystem exchange of carbon dioxide in cotton and wheat fields", Biogeosciences. Vol. 10(11), pp. 6865-6877. |
| Abstract: Static and transparent automatic chamber (AC) technique is a necessary choice for measuring net ecosystem exchange (NEE) of carbon dioxide (CO2) in circumstances where eddy covariance (EC) technique is not applicable. However, a comparison of the two techniques for measurements on croplands has seldom been undertaken. We carried out NEE observations in a cotton field (for one year) and a winter wheat field (for one cropping season) using both AC and EC techniques, to (a) compare the NEE fluxes measured using each technique, and (b) test the NEE measurement performance of an automatic chamber system (AMEG), which was designed for simultaneous flux measurements of multiple gases. The half-hourly NEE fluxes measured with the two techniques were in approximate agreement, with the AC fluxes being 0.78 (cotton) and 1.06 (wheat) times the size of the EC fluxes. When integrated to daily timescale, the fluxes of the two techniques were in better agreement, showing an average ratio of 0.94 and 1.00 for the cotton and wheat, respectively. During the periods with comparable field conditions and normal performance of both instruments, the cumulative NEE fluxes revealed small differences between the two techniques (-9.0% ∼ 7%, with a mean of 0.1%). The measurements resulted in an annual cumulative NEE of -40 g C m-2 yr-1 (EC) and -42 g C m-2 yr-1 (AC) in the cotton field, and a seasonal cumulative NEE of -251 g C m-2 (EC) and -205 g C m-2 (AC) in the wheat field. Our results indicate that, for cropland populated by short plants, the AMEG system and the data processing procedures applied in this study are able to provide NEE estimates comparable to those from EC measurements. textcopyright Author(s) 2013. CC Attribution 3.0 License. |
BibTeX:
@article{Wang2013,
author = {Wang, K. and Liu, C. and Zheng, X. and Pihlatie, M. and Li, B. and Haapanala, S. and Vesala, T. and Liu, H. and Wang, Y. and Liu, G. and Hu, F.},
title = {Comparison between eddy covariance and automatic chamber techniques for measuring net ecosystem exchange of carbon dioxide in cotton and wheat fields},
journal = {Biogeosciences},
year = {2013},
volume = {10},
number = {11},
pages = {6865--6877},
doi = {10.5194/bg-10-6865-2013}
}
|
| Wang K, Zheng X, Pihlatie M, Vesala T, Liu C, Haapanala S, Mammarella I, Rannik Ü and Liu H (2013), "Comparison between static chamber and tunable diode laser-based eddy covariance techniques for measuring nitrous oxide fluxes from a cotton field", Agricultural and Forest Meteorology., apr, 2013. Vol. 171-172, pp. 9-19. |
| Abstract: Nitrous oxide (N2O) fluxes from a cotton field in northern China were measured for a year using the static chamber method based on a gas chromatograph (GC) and the eddy covariance (EC) technique based on a tunable diode laser (TDL). The aims were to compare the N2O fluxes obtained from both techniques, assess the uncertainties in the fluxes and evaluate the annual direct emission factors (EFds, i.e. the loss rate of fertilizer nitrogen via N2O emission) using the year-round datasets. During the experimental period, the hourly and daily mean chamber fluxes ranged from 0.6 to 781.8 and from 1.2 to 468.8μgNm-2h-1, respectively. The simultaneously measured daily mean EC fluxes varied between -10.8 and 912.0μgNm-2h-1. The EC measurements only provided trustworthy 30-min fluxes during high-emission period (a 20-day period immediately after the irrigation that followed the nitrogen fertilization event). A reliable comparison was confined to the high-emission period and showed that the chamber fluxes were 17-20% lower than the EC fluxes. This difference may implicate the magnitude of systematic underestimation in the fluxes from chamber measurements. The annual emission from the fertilized cotton field was estimated at 1.43kgNha-1yr-1 by the chamber observations and 3.15kgNha-1yr-1 by the EC measurements. The EFds calculated from the chamber and EC data were 1.04% and 1.65%, respectively. The chamber-based estimate was very close to the default value (1.0%) recommended by the Intergovernmental Panel on Climate Change. However, the difference in the EFds based on the two measurement techniques may vary greatly with changing environmental conditions and management practices. Further comparison studies are still needed to elucidate this issue. textcopyright 2012 Elsevier B.V. |
BibTeX:
@article{Wang2013a,
author = {Wang, Kai and Zheng, Xunhua and Pihlatie, Mari and Vesala, Timo and Liu, Chunyan and Haapanala, Sami and Mammarella, Ivan and Rannik, Üllar and Liu, Huizhi},
title = {Comparison between static chamber and tunable diode laser-based eddy covariance techniques for measuring nitrous oxide fluxes from a cotton field},
journal = {Agricultural and Forest Meteorology},
year = {2013},
volume = {171-172},
pages = {9--19},
url = {http://linkinghub.elsevier.com/retrieve/pii/S0168192312003462},
doi = {10.1016/j.agrformet.2012.11.009}
}
|
| Wood CR, Kouznetsov RD, Gierens R, Nordbo A, Jä rvi L, Kallistratova MA and Kukkonen J (2013), "On the temperature structure parameter and sensible heat flux over helsinki from sonic anemometry and scintillometry", Journal of Atmospheric and Oceanic Technology. Vol. 30(8), pp. 1604-1615. |
| Abstract: Two commercial large-aperture scintillometers, Scintec BLS900, were tested on pathlengths of 1840 and 4200m at about 45-65m above ground in Helsinki, Finland. From July 2011 through June 2012, large variability in diurnal and annual cycles of both the temperature structure parameter C2T and sensible heat flux H were observed. Scintillometer data were compared with data from two eddy-covariance stations. A robust method was developed for the calculation of C2T from raw sonic-anemometer data. In contrast to many earlier studies that solely present the values of H, the main focus here is on comparisons of C2T itself. This has advantages, because optical-wavelength scintillometers measure C2T with few assumptions, while the determination of H implies the applicability of the Monin-Obukhov similarity theory, which has several inherent limitations. The histograms of C2T compare well between sonic and scintillometer. In-depth analysis is focused on one of the scintillometer paths: both C2T and H comparisons gave similar and surprisingly high correlation coefficients (0.85 for C2T and 0.84-0.95 for H in unstable conditions), given the differences between the two measurement techniques, substantial sensor separation, and different source areas. textcopyright 2013 American Meteorological Society. |
BibTeX:
@article{Wood2013,
author = {Wood, C. R. and Kouznetsov, R. D. and Gierens, R. and Nordbo, A. and Jä rvi, L. and Kallistratova, M. A. and Kukkonen, J.},
title = {On the temperature structure parameter and sensible heat flux over helsinki from sonic anemometry and scintillometry},
journal = {Journal of Atmospheric and Oceanic Technology},
year = {2013},
volume = {30},
number = {8},
pages = {1604--1615},
doi = {10.1175/JTECH-D-12-00209.1}
}
|
| Wood CR, Järvi L, Kouznetsov RD, Nordbo A, Joffre S, Drebs A, Vihma T, Hirsikko A, Suomi I, Fortelius C, O'Connor E, Moiseev D, Haapanala S, Moilanen J, Kangas M, Karppinen A, Vesala T and Kukkonen J (2013), "An overview of the urban boundary layer atmosphere network in Helsinki". nov, 2013. |
BibTeX:
@misc{Wood2013a,
author = {Wood, C. R. and Järvi, L. and Kouznetsov, R. D. and Nordbo, A. and Joffre, S. and Drebs, A. and Vihma, T. and Hirsikko, A. and Suomi, I. and Fortelius, C. and O'Connor, E. and Moiseev, D. and Haapanala, S. and Moilanen, J. and Kangas, M. and Karppinen, A. and Vesala, T. and Kukkonen, J.},
title = {An overview of the urban boundary layer atmosphere network in Helsinki},
booktitle = {Bulletin of the American Meteorological Society},
year = {2013},
volume = {94},
number = {11},
pages = {1675--1690},
doi = {10.1175/BAMS-D-12-00146.1}
}
|
| Wu C, Chen JM, Black TA, Price DT, Kurz WA, Desai AR, Gonsamo A, Jassal RS, Gough CM, Bohrer G, Dragoni D, Herbst M, Gielen B, Berninger F, Vesala T, Mammarella I, Pilegaard K and Blanken PD (2013), "Interannual variability of net ecosystem productivity in forests is explained by carbon flux phenology in autumn", Global Ecology and Biogeography., aug, 2013. Vol. 22(8), pp. 994-1006. |
| Abstract: Aim: To investigate the importance of autumn phenology in controlling interannual variability of forest net ecosystem productivity (NEP) and to derive new phenological metrics to explain the interannual variability of NEP. Location: North America and Europe. Method: Flux data from nine deciduous broadleaf forests (DBF) and 13 evergreen needleleaf forests (ENF) across North America and Europe (212 site-years) were used to explore the relationships between the yearly anomalies of annual NEP and several carbon flux based phenological indicators, including the onset/end of the growing season, onset/end of the carbon uptake period, the spring lag (time interval between the onset of growing season and carbon uptake period) and the autumn lag (time interval between the end of the carbon uptake period and the growing season). Meteorological variables, including global shortwave radiation, air temperature, soil temperature, soil water content and precipitation, were also used to explain the phenological variations. Results: We found that interannual variability of NEP can be largely explained by autumn phenology, i.e. the autumn lag. While variation in neither annual gross primary productivity (GPP) nor in annual ecosystem respiration (Re) alone could explain this variability, the negative relationship between annual NEP and autumn lag was due to a larger Re/GPP ratio in years with a prolonged autumn lag. For DBF sites, a longer autumn lag coincided with a significant decrease in annual GPP but showed no correlation with annual Re. However, annual GPP was insensitive to a longer autumn lag in ENF sites but annual Re increased significantly. Main conclusions: These results demonstrate that autumn phenology plays a more direct role than spring phenology in regulating interannual variability of annual NEP. In particular, the importance of respiration may be potentially underestimated in deriving phenological indicators. textcopyright 2013 John Wiley & Sons Ltd. |
BibTeX:
@article{Wu2013,
author = {Wu, Chaoyang and Chen, Jing M and Black, T Andrew and Price, David T and Kurz, Werner A and Desai, Ankur R and Gonsamo, Alemu and Jassal, Rachhpal S and Gough, Christopher M and Bohrer, Gil and Dragoni, Danilo and Herbst, Mathias and Gielen, Bert and Berninger, Frank and Vesala, Timo and Mammarella, Ivan and Pilegaard, Kim and Blanken, Peter D},
title = {Interannual variability of net ecosystem productivity in forests is explained by carbon flux phenology in autumn},
journal = {Global Ecology and Biogeography},
year = {2013},
volume = {22},
number = {8},
pages = {994--1006},
url = {http://doi.wiley.com/10.1111/geb.12044},
doi = {10.1111/geb.12044}
}
|
| Yoshida Y, Kikuchi N, Morino I, Uchino O, Oshchepkov S, Bril A, Saeki T, Schutgens N, Toon GC, Wunch D, Roehl CM, Wennberg PO, Griffith DWT, Deutscher NM, Warneke T, Notholt J, Robinson J, Sherlock V, Connor B, Rettinger M, Sussmann R, Ahonen P, Heikkinen P, Kyrö E, Mendonca J, Strong K, Hase F, Dohe S and Yokota T (2013), "Improvement of the retrieval algorithm for GOSAT SWIR XCO2and XCH4and their validation using TCCON data", Atmospheric Measurement Techniques., jun, 2013. Vol. 6(6), pp. 1533-1547. |
| Abstract: The column-averaged dry-air mole fractions of carbon dioxide and methane (XCO2 and XCH4) have been retrieved from Greenhouse gases Observing SATellite (GOSAT) Short-Wavelength InfraRed (SWIR) observations and released as a SWIR L2 product from the National Institute for Environmental Studies (NIES). XCO2 and XCH4 retrieved using the version 01.xx retrieval algorithm showed large negative biases and standard deviations (-8.85 and 4.75 ppm for XCO2 and -20.4 and 18.9 ppb for XCH 4, respectively) compared with data of the Total Carbon Column Observing Network (TCCON). Multiple reasons for these error characteristics (e.g., solar irradiance database, handling of aerosol scattering) are identified and corrected in a revised version of the retrieval algorithm (version 02.xx). The improved retrieval algorithm shows much smaller biases and standard deviations (-1.48 and 2.09 ppm for XCO2 and -5.9 and 12.6 ppb for XCH4, respectively) than the version 01.xx. Also, the number of post-screened measurements is increased, especially at northern mid- and high-latitudinal areas. textcopyright Author(s) 2013. |
BibTeX:
@article{Yoshida2013,
author = {Yoshida, Y and Kikuchi, N and Morino, I and Uchino, O and Oshchepkov, S and Bril, A and Saeki, T and Schutgens, N and Toon, G C and Wunch, D and Roehl, C M and Wennberg, P O and Griffith, D W T and Deutscher, N M and Warneke, T and Notholt, J and Robinson, J and Sherlock, V and Connor, B and Rettinger, M and Sussmann, R and Ahonen, P and Heikkinen, P and Kyrö, E and Mendonca, J and Strong, K and Hase, F and Dohe, S and Yokota, T},
title = {Improvement of the retrieval algorithm for GOSAT SWIR XCO2and XCH4and their validation using TCCON data},
journal = {Atmospheric Measurement Techniques},
year = {2013},
volume = {6},
number = {6},
pages = {1533--1547},
url = {http://www.atmos-meas-tech.net/6/1533/2013/},
doi = {10.5194/amt-6-1533-2013}
}
|
| Zona D, Janssens IA, Gioli B, Jungkunst HF, Serrano MC and Ceulemans R (2013), "N2o fluxes of a bio-energy poplar plantation during a two years rotation period", GCB Bioenergy., sep, 2013. Vol. 5(5), pp. 536-547. |
| Abstract: Nitrous oxide emissions are of critical importance for the assumed climate neutrality of bio-energy. In this study we report on the N2O fluxes from a bio-energy poplar plantation measured with eddy covariance for 2 years, after conversion of agricultural fields to few months after harvesting of the plantation. A pulse peak of N2O was detected after the land use change and in the wake of the first heavy rainfall. The N2O-N emission during just a single week was 2.7 kg N2O-N ha -1 which represented approximately 42% of the total N2O-N emitted during the 2 years of measurements. After this peak emission, N2O fluxes were constantly rather low, not increasing after rainfall events any longer. Lowest emissions (and even N2O sink) occurred mostly during the end of the second growing season with maximum canopy development, and water table deeper than 80 cm. Gross primary production (GPP) explained 68% of the monthly averaged variability in N2O emission from August to December 2011. Probably N uptake by vegetation during the peak of the second growing season limited N2O emission, which in fact increased again after the plantation was coppiced. For the majority of the measuring period, N2O fluxes did not present a well-defined diurnal pattern, with the exception of two periods: (1) from 19-22 August 2010 and (2) from September-November 2011. In both cases wind speed played a major role in controlling the diurnal pattern in these fluxes (explaining up to 80% of the diurnal variability in N2O fluxes on 19-22 August 2010), whereas at the end of the second growing season (September-November 2011), GPP explained 73% of the diurnal pattern in N2O fluxes.textcopyright 2013 John Wiley & Sons Ltd. |
BibTeX:
@article{Zona2013,
author = {Zona, Donatella and Janssens, Ivan A and Gioli, Beniamino and Jungkunst, Hermann F and Serrano, Marta C and Ceulemans, Reinhart},
title = {N2o fluxes of a bio-energy poplar plantation during a two years rotation period},
journal = {GCB Bioenergy},
year = {2013},
volume = {5},
number = {5},
pages = {536--547},
url = {http://doi.wiley.com/10.1111/gcbb.12019},
doi = {10.1111/gcbb.12019}
}
|
| Zona D, Janssens IA, Aubinet M, Gioli B, Vicca S, Fichot R and Ceulemans R (2013), "Fluxes of the greenhouse gases (CO2, CH4 and N2O) above a short-rotation poplar plantation after conversion from agricultural land", Agricultural and Forest Meteorology., feb, 2013. Vol. 169, pp. 100-110. |
| Abstract: The increasing demand for renewable energy may lead to the conversion of millions of hectares into bioenergy plantations with a possible substantial transitory carbon (C) loss. In this study we report on the greenhouse gas fluxes (CO2, CH4, and N2O) measured using eddy covariance of a short-rotation bioenergy poplar plantation converted from agricultural fields. During the first six months after the establishment of the plantation (June-December 2010) there were substantial CO2, CH4, and N2O emissions (a total of 5.36±0.52MgCO2eqha-1 in terms of CO2 equivalents). Nitrous oxide loss mostly occurred during a week-long peak emission after an unusually large rainfall. This week-long N2O emission represented 52% of the entire N2O loss during one and an half years of measurements. As most of the N2O loss occurred in just this week-long period, accurately capturing these emission events are critical to accurate estimates of the GHG balance of bioenergy. While initial establishment (June-December 2010) of the plantation resulted in a net CO2 loss into the atmosphere (2.76±0.16MgCO2eqha-1), in the second year (2011) there was substantial net CO2 uptake (-3.51±0.56MgCO2eqha-1). During the entire measurement period, CH4 was a source to the atmosphere (0.63±0.05MgCO2eqha-1 in 2010, and 0.49±0.05MgCO2eqha-1 in 2011), and was controlled by water table depth. Importantly, over the entire measurement period, the sum of the CH4 and N2O losses was much higher (3.51±0.52MgCO2eqha-1) than the net CO2 uptake (-0.76±0.58MgCO2eqha-1). As water availability was an important control on the GHG emission of the plantation, expected climate change and altered rainfall pattern could increase the negative environmental impacts of bioenergy. textcopyright 2012 Elsevier B.V. |
BibTeX:
@article{Zona2013a,
author = {Zona, D and Janssens, I A and Aubinet, M and Gioli, B and Vicca, S and Fichot, R and Ceulemans, R},
title = {Fluxes of the greenhouse gases (CO2, CH4 and N2O) above a short-rotation poplar plantation after conversion from agricultural land},
journal = {Agricultural and Forest Meteorology},
year = {2013},
volume = {169},
pages = {100--110},
url = {http://linkinghub.elsevier.com/retrieve/pii/S0168192312003000},
doi = {10.1016/j.agrformet.2012.10.008}
}
|
| Zona D, Janssens IA, Aubinet M, Gioli B, Vicca S, Fichot R and Ceulemans R (2013), "Corrigendum to " Fluxes of the greenhouse gases (CO2, CH4 and N2O) above a short-rotation poplar plantation after conversion from agricultural land" [Agric. For. Meteorol. 169 (2012) 100-110]", Agricultural and Forest Meteorology., feb, 2013. Vol. 169, pp. 211. |
BibTeX:
@article{Zona2013b,
author = {Zona, D and Janssens, I A and Aubinet, M and Gioli, B and Vicca, S and Fichot, R and Ceulemans, R},
title = {Corrigendum to " Fluxes of the greenhouse gases (CO2, CH4 and N2O) above a short-rotation poplar plantation after conversion from agricultural land" [Agric. For. Meteorol. 169 (2012) 100-110]},
journal = {Agricultural and Forest Meteorology},
year = {2013},
volume = {169},
pages = {211},
url = {http://linkinghub.elsevier.com/retrieve/pii/S0168192312003620},
doi = {10.1016/j.agrformet.2012.12.002}
}
|
| Baldocchi D, Reichstein M, Papale D, Koteen L, Vargas R, Agarwal D and Cook R (2012), "The role of trace gas flux networks in the biogeosciences", Eos., jun, 2012. Vol. 93(23), pp. 217-218. |
| Abstract: Vast networks of meteorological sensors ring the globe, providing continuous measurements of an array of atmospheric state variables such as temperature, humidity, rainfall, and the concentration of carbon dioxide [New et al., 1999; Tans et al., 1996]. These measurements provide input to weather and climate models and are key to detecting trends in climate, greenhouse gases, and air pollution. Yet to understand how and why these atmospheric state variables vary in time and space, biogeoscientists need to know where, when, and at what rates important gases are flowing between the land and the atmosphere. Tracking trace gas fluxes provides information on plant or microbial metabolism and climate-ecosystem interactions. textcopyright 2012 American Geophysical Union. All Rights Reserved. |
BibTeX:
@article{Baldocchi2012,
author = {Baldocchi, Dennis and Reichstein, Markus and Papale, Dario and Koteen, Laurie and Vargas, Rodrigo and Agarwal, Deborah and Cook, Robert},
title = {The role of trace gas flux networks in the biogeosciences},
journal = {Eos},
year = {2012},
volume = {93},
number = {23},
pages = {217--218},
url = {http://doi.wiley.com/10.1029/2012EO230001},
doi = {10.1029/2012EO230001}
}
|
| Brunner D, Henne S, Keller CA, Reimann S, Vollmer MK, O'Doherty S and Maione M (2012), "An extended Kalman-filter for regional scale inverse emission estimation", Atmospheric Chemistry and Physics., apr, 2012. Vol. 12(7), pp. 3455-3478. |
| Abstract: A Kalman-filter based inverse emission estimation method for long-lived trace gases is presented for use in conjunction with a Lagrangian particle dispersion model like FLEXPART. The sequential nature of the approach allows tracing slow seasonal and interannual changes rather than estimating a single period-mean emission field. Other important features include the estimation of a slowly varying concentration background at each measurement station, the possibility to constrain the solution to non-negative emissions, the quantification of uncertainties, the consideration of temporal correlations in the residuals, and the applicability to potentially large inversion problems. The method is first demonstrated for a set of synthetic observations created from a prescribed emission field with different levels of (correlated) noise, which closely mimics true observations. It is then applied to real observations of the three halocarbons HFC-125, HFC-152a and HCFC-141b at the remote research stations Jungfraujoch and Mace Head for the quantification of emissions in Western European countries from 2006 to 2010. Estimated HFC-125 emissions are mostly consistent with national totals reported to UNFCCC in the framework of the Kyoto Protocol and show a generally increasing trend over the considered period. Results for HFC-152a are much more variable with estimated emissions being both higher and lower than reported emissions in different countries. The highest emissions of the order of 700-800 Mg yr-1 are estimated for Italy, which so far does not report HFC-152a emissions. Emissions of HCFC-141b show a continuing strong decrease as expected due to its controls in developed countries under the Montreal Protocol. Emissions from France, however, were still rather large, in the range of 700-1000 Mg yr-1 in the years 2006 and 2007 but strongly declined thereafter. textcopyright Author(s) 2012. |
BibTeX:
@article{Brunner2012,
author = {Brunner, D and Henne, S and Keller, C A and Reimann, S and Vollmer, M K and O'Doherty, S and Maione, M},
title = {An extended Kalman-filter for regional scale inverse emission estimation},
journal = {Atmospheric Chemistry and Physics},
year = {2012},
volume = {12},
number = {7},
pages = {3455--3478},
url = {http://www.atmos-chem-phys.net/12/3455/2012/},
doi = {10.5194/acp-12-3455-2012}
}
|
| Burkhardt J, Basi S, Pariyar S and Hunsche M (2012), "Stomatal penetration by aqueous solutions - an update involving leaf surface particles", New Phytologist., nov, 2012. Vol. 196(3), pp. 774-787. |
BibTeX:
@article{Burkhardt2012,
author = {Burkhardt, Juergen and Basi, Sabin and Pariyar, Shyam and Hunsche, Mauricio},
title = {Stomatal penetration by aqueous solutions - an update involving leaf surface particles},
journal = {New Phytologist},
year = {2012},
volume = {196},
number = {3},
pages = {774--787},
url = {http://doi.wiley.com/10.1111/j.1469-8137.2012.04307.x},
doi = {10.1111/j.1469-8137.2012.04307.x}
}
|
| Cape JN, Tang YS, González-Ben&amp, iacute, ez JM, Mitošinková M, Makkonen U, Jocher M and Stolk A (2012), "Organic nitrogen in precipitation across Europe", Biogeosciences., nov, 2012. Vol. 9(11), pp. 4401-4409. |
| Abstract: pAbstract. Measurements of total nitrogen and inorganic nitrogen in precipitation samples from NitroEurope sites across Europe permit the calculation of organic nitrogen concentrations and wet deposition, by difference. The contribution of organic N to total N in precipitation ranged from only a few % to around 40% across 18 sites from northern Finland to Italy, similar to results from previous individual studies. This paper presents the absolute and relative contributions of organic N to wet N deposition across Europe, and examines seasonal trends. There were only weak correlations with other solutes in precipitation. These simple statistics indicate that sources of organic N in precipitation vary across Europe, and that no single source is responsible. The organic N contributes to total N deposition, yet this input is rarely quantified in nitrogen budgets./p |
BibTeX:
@article{Cape2012,
author = {Cape, J N and Tang, Y S and González-Ben&amp;iacute;ez, J M and Mitošinková, M and Makkonen, U and Jocher, M and Stolk, A},
title = {Organic nitrogen in precipitation across Europe},
journal = {Biogeosciences},
year = {2012},
volume = {9},
number = {11},
pages = {4401--4409},
url = {https://www.biogeosciences.net/9/4401/2012/},
doi = {10.5194/bg-9-4401-2012}
}
|
| Chevallier F, Wang T, Ciais P, Maignan F, Bocquet M, Altaf Arain M, Cescatti A, Chen J, Dolman AJ, Law BE, Margolis HA, Montagnani L and Moors EJ (2012), "What eddy-covariance measurements tell us about prior land flux errors in CO textlesssubtextgreater2textless/subtextgreater -flux inversion schemes", Global Biogeochemical Cycles., mar, 2012. Vol. 26(1), pp. n/a-n/a. |
| Abstract: To guide the future development of CO2-atmospheric inversion modeling systems, we analyzed the errors arising from prior information about terrestrial ecosystem fluxes. We compared the surface fluxes calculated by a process-based terrestrial ecosystem model with daily averages of CO2 flux measurements at 156 sites across the world in the FLUXNET network. At the daily scale, the standard deviation of the model-data fit was 2.5 gCm -2d-1; temporal autocorrelations were significant at the weekly scale (textgreater0.3 for lags less than four weeks), while spatial correlations were confined to within the first few hundred kilometers (textless0.2 after 200km). Separating out the plant functional types did not increase the spatial correlations, except for the deciduous broad-leaved forests. Using the statistics of the flux measurements as a proxy for the statistics of the prior flux errors was shown not to be a viable approach. A statistical model allowed us to upscale the site-level flux error statistics to the coarser spatial and temporal resolutions used in regional or global models. This approach allowed us to quantify how aggregation reduces error variances, while increasing correlations. As an example, for a typical inversion of grid point (300km × 300km) monthly fluxes, we found that the prior flux error follows an approximate e-folding correlation length of 500km only, with correlations from one month to the next as large as 0.6. textcopyright 2012 by the American Geophysical Union. |
BibTeX:
@article{Chevallier2012,
author = {Chevallier, Frédéric and Wang, Tao and Ciais, Philippe and Maignan, Fabienne and Bocquet, Marc and Altaf Arain, M. and Cescatti, Alessandro and Chen, Jiquan and Dolman, A. Johannes and Law, Beverly E. and Margolis, Hank A. and Montagnani, Leonardo and Moors, Eddy J.},
title = {What eddy-covariance measurements tell us about prior land flux errors in CO textlesssubtextgreater2textless/subtextgreater -flux inversion schemes},
journal = {Global Biogeochemical Cycles},
year = {2012},
volume = {26},
number = {1},
pages = {n/a--n/a},
url = {http://doi.wiley.com/10.1029/2010GB003974},
doi = {10.1029/2010GB003974}
}
|
| Fratini G, Ibrom A, Arriga N, Burba G and Papale D (2012), "Relative humidity effects on water vapour fluxes measured with closed-path eddy-covariance systems with short sampling lines", Agricultural and Forest Meteorology., nov, 2012. Vol. 165, pp. 53-63. |
| Abstract: It has been formerly recognised that increasing relative humidity in the sampling line of closed-path eddy-covariance systems leads to increasing attenuation of water vapour turbulent fluctuations, resulting in strong latent heat flux losses. This occurrence has been analyzed for very long (50. m) and long (7. m) sampling lines. To date, only a few analytical or in situ analyses have been proposed to quantify and correct such effects, among which the comprehensive method by Ibrom et al. (2007) was proved effective for the very long sampling line of a forest eddy-covariance setup.Here we analyze data from eddy-covariance systems featuring short (4m) and very short (1m) sampling lines running at the same clover field and show that relative humidity effects persist also for these setups, and should not be neglected. Starting from the work of Ibrom and co-workers, we propose a mixed method, a composite of two existing approaches, for correcting eddy-covariance fluxes. By means of a comparison with parallel open-path measurements, we show that the mixed method leads to an improved estimation of latent heat fluxes, with respect to the method described by Ibrom et al. (2007). The quantification and correction method proposed here is deemed applicable to closed-path systems featuring a broad range of sampling lines, and indeed applicable also to passive gases as a special case. The methods described in this paper are incorporated, as processing options, in the free and open-source eddy-covariance software packages ECO 2S and EddyPro. textcopyright 2012 Elsevier B.V.. |
BibTeX:
@article{Fratini2012,
author = {Fratini, Gerardo and Ibrom, Andreas and Arriga, Nicola and Burba, George and Papale, Dario},
title = {Relative humidity effects on water vapour fluxes measured with closed-path eddy-covariance systems with short sampling lines},
journal = {Agricultural and Forest Meteorology},
year = {2012},
volume = {165},
pages = {53--63},
url = {http://linkinghub.elsevier.com/retrieve/pii/S0168192312001955},
doi = {10.1016/j.agrformet.2012.05.018}
}
|
| Fratini G, Ibrom A, Arriga N, Burba G and Papale D (2012), "Corrigendum to "Relative humidity effects on water vapour fluxes measured with closed-path eddy-covariance systems with short sampling lines" [Agric. Forest Meteorol. 165 (2012) 53-63]", Agricultural and Forest Meteorology., dec, 2012. Vol. 166-167, pp. 234. |
BibTeX:
@article{Fratini2012a,
author = {Fratini, Gerardo and Ibrom, Andreas and Arriga, Nicola and Burba, George and Papale, Dario},
title = {Corrigendum to "Relative humidity effects on water vapour fluxes measured with closed-path eddy-covariance systems with short sampling lines" [Agric. Forest Meteorol. 165 (2012) 53-63]},
journal = {Agricultural and Forest Meteorology},
year = {2012},
volume = {166-167},
pages = {234},
url = {http://linkinghub.elsevier.com/retrieve/pii/S016819231200305X},
doi = {10.1016/j.agrformet.2012.10.013}
}
|
| Heymann J, Bovensmann H, Buchwitz M, Burrows JP, Deutscher NM, Notholt J, Rettinger M, Reuter M, Schneising O, Sussmann R and Warneke T (2012), "Sciamachy WFM-DOAS XCO2: Reduction of scattering related errors", Atmospheric Measurement Techniques., oct, 2012. Vol. 5(10), pp. 2375-2390. |
| Abstract: Global observations of column-averaged dry air mole fractions of carbon dioxide (CO2), denoted by iX/iCO2 , retrieved from SCIAMACHY on-board ENVISAT can provide important and missing global information on the distribution and magnitude of regional CO2 surface fluxes. This application has challenging precision and accuracy requirements. In a previous publication (Heymann et al., 2012), it has been shown by analysing seven years of SCIAMACHY WFM-DOAS X CO2 (WFMDv2.1) that unaccounted thin cirrus clouds can result in significant errors. In order to enhance the quality of the SCIAMACHY XCO2 data product, we have developed a new version of the retrieval algorithm (WFMDv2.2), which is described in this manuscript. It is based on an improved cloud filtering and correction method using the 1.4 μm strong water vapour absorption and 0.76 μm O2-A bands. The new algorithm has been used to generate a SCIAMACHY XCO2 data set covering the years 2003-2009. The new X CO2 data set has been validated using ground-based observations from the Total Carbon Column Observing Network (TCCON). The validation shows a significant improvement of the new product (v2.2) in comparison to the previous product (v2.1). For example, the standard deviation of the difference to TCCON at Darwin, Australia, has been reduced from 4 ppm to 2 ppm. The monthly regional-scale scatter of the data (defined as the mean intra-monthly standard deviation of all quality filtered X CO2 retrievals within a radius of 350 km around various locations) has also been reduced, typically by a factor of about 1.5. Overall, the validation of the new WFMDv2.2 XCO2 data product can be summarised by a single measurement precision of 3.8 ppm, an estimated regional-scale (radius of 500 km) precision of monthly averages of 1.6 ppm and an estimated regional-scale relative accuracy of 0.8 ppm. In addition to the comparison with the limited number of TCCON sites, we also present a comparison with NOAA's global CO2 modelling and assimilation system Carbon Tracker. This comparison also shows significant improvements especially over the Southern Hemisphere. textcopyright 2012 Author(s). |
BibTeX:
@article{Heymann2012,
author = {Heymann, J and Bovensmann, H and Buchwitz, M and Burrows, J P and Deutscher, N M and Notholt, J and Rettinger, M and Reuter, M and Schneising, O and Sussmann, R and Warneke, T},
title = {Sciamachy WFM-DOAS XCO2: Reduction of scattering related errors},
journal = {Atmospheric Measurement Techniques},
year = {2012},
volume = {5},
number = {10},
pages = {2375--2390},
url = {http://www.atmos-meas-tech.net/5/2375/2012/},
doi = {10.5194/amt-5-2375-2012}
}
|
| Houweling S, Badawy B, Baker DF, Basu S, Belikov D, Bergamaschi P, Bousquet P, Broquet G, Butler T, Canadell JG, Chen J, Chevallier F, Ciais P, Collatz JG, Denning S, Engelen R, Enting IG, Fischer ML, Fraser A, Gerbig C, Gloor M, Jacobson AR, Jones DBA, Heimann M, Khalil A, Kaminski T, Kasibhatla PS, Krakauer NY, Krol M, Maki T, Maksyutov S, Manning A, Meesters A, Miller JB, Palmer PI, Patra P, Peters W, Peylin P, Poussi Z, Prather MJ, Randerson JT, Röckmann T, Rödenbeck C, Sarmiento JL, Schimel DS, Scholze M, Schuh A, Suntharalingam P, Takahashi T, Turnbull J, Yurganov L and Vermeulen A (2012), "Iconic CO2 time series at risk", Science., aug, 2012. Vol. 337(6098), pp. 1038-1040. |
BibTeX:
@article{Houweling2012,
author = {Houweling, Sander and Badawy, Bakr and Baker, David F and Basu, Sourish and Belikov, Dmitry and Bergamaschi, Peter and Bousquet, Philippe and Broquet, Gregoire and Butler, Tim and Canadell, Josep G and Chen, Jing and Chevallier, Frederic and Ciais, Philippe and Collatz, James G and Denning, Scott and Engelen, Richard and Enting, Ian G and Fischer, Marc L and Fraser, Annemarie and Gerbig, Christoph and Gloor, Manuel and Jacobson, Andrew R and Jones, Dylan B A and Heimann, Martin and Khalil, Aslam and Kaminski, Thomas and Kasibhatla, Prasad S and Krakauer, Nir Y and Krol, Maarten and Maki, Takashi and Maksyutov, Shamil and Manning, Andrew and Meesters, Antoon and Miller, John B and Palmer, Paul I and Patra, Prabir and Peters, Wouter and Peylin, Philippe and Poussi, Zegbeu and Prather, Michael J and Randerson, James T and Röckmann, Thomas and Rödenbeck, Christian and Sarmiento, Jorge L and Schimel, David S and Scholze, Marko and Schuh, Andrew and Suntharalingam, Parv and Takahashi, Taro and Turnbull, Jocelyn and Yurganov, Leonid and Vermeulen, Alex},
title = {Iconic CO2 time series at risk},
journal = {Science},
year = {2012},
volume = {337},
number = {6098},
pages = {1038--1040},
url = {http://www.sciencemag.org/cgi/doi/10.1126/science.337.6098.1038-b},
doi = {10.1126/science.337.6098.1038-b}
}
|
| Järvi L, Nordbo A, Junninen H, Riikonen A, Moilanen J, Nikinmaa E and Vesala T (2012), "Seasonal and annual variation of carbon dioxide surface fluxes in Helsinki, Finland, in 2006-2010", Atmospheric Chemistry and Physics. Vol. 12(18), pp. 8475-8489. |
| Abstract: Five years of carbon dioxide exchange measured with the eddy covariance technique at the world's northernmost urban flux station SMEAR III located in Helsinki, Finland, were analyzed. The long-term measurements and high-latitude location enabled us to examine the seasonal and annual variations of CO2 exchange, and to identify different factors controlling the measured exchange. Online traffic counts and soil respiration measurements were utilized in the study. Furthermore, the advantage of the station is that the complex surrounding area enables us to distinguish three different surface cover areas that can be evaluated separately. We also tested different m. textcopyright 2012 Author(s). |
BibTeX:
@article{Jarvi2012,
author = {Järvi, L. and Nordbo, A. and Junninen, H. and Riikonen, A. and Moilanen, J. and Nikinmaa, E. and Vesala, T.},
title = {Seasonal and annual variation of carbon dioxide surface fluxes in Helsinki, Finland, in 2006-2010},
journal = {Atmospheric Chemistry and Physics},
year = {2012},
volume = {12},
number = {18},
pages = {8475--8489},
doi = {10.5194/acp-12-8475-2012}
}
|
| Jung M, Reichstein M, Margolis HA, Cescatti A, Richardson AD, Arain MA, Arneth A, Bernhofer C, Bonal D, Chen J, Gianelle D, Gobron N, Kiely G, Kutsch W, Lasslop G, Law BE, Lindroth A, Merbold L, Montagnani L, Moors EJ, Papale D, Sottocornola M, Vaccari F and Williams C (2012), "Erratum: Global patterns of land-atmosphere fluxes of carbon dioxide, latent heat, and sensible heat derived from eddy covariance, satellite, and meteorological observations (Journal of Geophysical Research G: Biogeosciences (2011) 116 (G00J07) DOI: 10.1029/2010JG001566)", Journal of Geophysical Research G: Biogeosciences., sep, 2012. Vol. 117(4), pp. G00J07. |
BibTeX:
@article{Jung2012,
author = {Jung, Martin and Reichstein, Markus and Margolis, Hank A and Cescatti, Alessandro and Richardson, Andrew D and Arain, M Altaf and Arneth, Almut and Bernhofer, Christian and Bonal, Damien and Chen, Jiquan and Gianelle, Damiano and Gobron, Nadine and Kiely, Gerald and Kutsch, Werner and Lasslop, Gitta and Law, Beverly E and Lindroth, Anders and Merbold, Lutz and Montagnani, Leonardo and Moors, Eddy J and Papale, Dario and Sottocornola, Matteo and Vaccari, Francesco and Williams, Christopher},
title = {Erratum: Global patterns of land-atmosphere fluxes of carbon dioxide, latent heat, and sensible heat derived from eddy covariance, satellite, and meteorological observations (Journal of Geophysical Research G: Biogeosciences (2011) 116 (G00J07) DOI: 10.1029/2010JG001566)},
journal = {Journal of Geophysical Research G: Biogeosciences},
year = {2012},
volume = {117},
number = {4},
pages = {G00J07},
url = {http://doi.wiley.com/10.1029/2010JG001566 http://doi.wiley.com/10.1029/2012JG002190},
doi = {10.1029/2012JG002190}
}
|
| Kovac D, Navratil M, Malenovsk Z, Stroch M, Spunda V and Urban O (2012), "Reflectance continuum removal spectral index tracking the xanthophyll cycle photoprotective reactions in Norway spruce needles", Functional Plant Biology. Vol. 39(12), pp. 987-998. |
| Abstract: This laboratory experiment tested the ability of the spectral index called 'area under curve normalised to maximal band depth' (ANMB) to track dynamic changes in the xanthophyll cycle of Norway spruce (Picea abies (L.) Karsten) needles. Four-year-old spruce seedlings were gradually acclimated to different photosynthetic photon flux densities (PPFDs) and air temperature regimes. The measurements were conducted at the end of each acclimation period lasting for 11 days. A significant decline in the chlorophylls to carotenoids ratio and the increase of the amount of xanthophyll cycle pigments indicated a higher need for carotenoid-mediated photoprotection in spruce leaves acclimated to high PPFD conditions. Similarly, the photochemical reflectance index (PRI) changed from positive to negative values after changing light conditions from low to high intensity as a consequence of the increase in carotenoid content. Systematic responses of PRI to the de-epoxidation state of xanthophyll cycle pigments (DEPS) were, however, observed only during high temperature treatments and after the exposition of needles to high irradiance. The ANMB index computed from needle reflectance between 507 and 556nm was able to track dynamic changes in DEPS without any influence induced by changing the content of leaf photosynthetic pigments (chlorophylls, carotenoids). textcopyright CSIRO 2012. |
BibTeX:
@article{Kovac2012,
author = {Kovac, Daniel and Navratil, Martin and Malenovsk, Zbynek and Stroch, Michal and Spunda, Vladimr and Urban, Otmar},
title = {Reflectance continuum removal spectral index tracking the xanthophyll cycle photoprotective reactions in Norway spruce needles},
journal = {Functional Plant Biology},
year = {2012},
volume = {39},
number = {12},
pages = {987--998},
doi = {10.1071/FP12107}
}
|
| Lasslop G, Migliavacca M, Bohrer G, Reichstein M, Bahn M, Ibrom A, Jacobs C, Kolari P, Papale D, Vesala T, Wohlfahrt G and Cescatti A (2012), "On the choice of the driving temperature for eddy-covariance carbon dioxide flux partitioning", Biogeosciences., dec, 2012. Vol. 9(12), pp. 5243-5259. |
| Abstract: Networks that merge and harmonise eddy-covariance measurements from many different parts of the world have become an important observational resource for ecosystem science. Empirical algorithms have been developed which combine direct observations of the net ecosystem exchange of carbon dioxide with simple empirical models to disentangle photosynthetic (GPP) and respiratory fluxes (Reco). The increasing use of these estimates for the analysis of climate sensitivities, model evaluation and calibration demands a thorough understanding of assumptions in the analysis process and the resulting uncertainties of the partitioned fluxes. The semi-empirical models used in flux partitioning algorithms require temperature observations as input, but as respiration takes place in many parts of an ecosystem, it is unclear which temperature input-air, surface, bole, or soil at a specific depth-should be used. This choice is a source of uncertainty and potential biases. In this study, we analysed the correlation between different temperature observations and nighttime NEE (which equals nighttime respiration) across FLUXNET sites to understand the potential of the different temperature observations as input for the flux partitioning model. We found that the differences in the correlation between different temperature data streams and nighttime NEE are small and depend on the selection of sites. We investigated the effects of the choice of the temperature data by running two flux partitioning algorithms with air and soil temperature. We found the time lag (phase shift) between air and soil temperatures explains the differences in the GPP and Reco estimates when using either air or soil temperatures for flux partitioning. The impact of the source of temperature data on other derived ecosystem parameters was estimated, and the strongest impact was found for the temperature sensitivity. Overall, this study suggests that the choice between soil or air temperature must be made on site-by-site basis by analysing the correlation between temperature and nighttime NEE. We recommend using an ensemble of estimates based on different temperature observations to account for the uncertainty due to the choice of temperature and to assure the robustness of the temporal patterns of the derived variables. textcopyright Author(s) 2012. CC Attribution 3.0 License. |
BibTeX:
@article{Lasslop2012,
author = {Lasslop, G and Migliavacca, M and Bohrer, G and Reichstein, M and Bahn, M and Ibrom, A and Jacobs, C and Kolari, P and Papale, D and Vesala, T and Wohlfahrt, G and Cescatti, A},
title = {On the choice of the driving temperature for eddy-covariance carbon dioxide flux partitioning},
journal = {Biogeosciences},
year = {2012},
volume = {9},
number = {12},
pages = {5243--5259},
url = {http://www.biogeosciences.net/9/5243/2012/},
doi = {10.5194/bg-9-5243-2012}
}
|
| Luo GJ, Brüggemann N, Wolf B, Gasche R, Grote R and Butterbach-Bahl K (2012), "Decadal variability of soil CO sub2/sub , NO, N sub2/sub O, and CH sub4/sub fluxes at the Höglwald Forest, Germany", Biogeosciences., may, 2012. Vol. 9(5), pp. 1741-1763. |
| Abstract: pAbstract. Besides agricultural soils, temperate forest soils have been identified as significant sources of or sinks for important atmospheric trace gases (N2O, NO, CH4, and CO2). Although the number of studies for this ecosystem type increased more than tenfold during the last decade, studies covering an entire year and spanning more than 1–2 years remained scarce. This study reports the results of continuous measurements of soil-atmosphere C- and N-gas exchange with high temporal resolution carried out since 1994 at the Höglwald Forest spruce site, an experimental field station in Southern Germany. Annual soil N2O, NO and CO2 emissions and CH4 uptake (1994–2010) varied in a range of 0.2–3.0 kg N2O-N haâˆ'1yrâˆ'1, 6.4–11.4 kg NO-N haâˆ'1yrâˆ'1, 7.0–9.2 t CO2-C haâˆ'1yrâˆ'1, and 0.9–3.5 kg CH4-C haâˆ'1yrâˆ'1, respectively. The observed high fluxes of N-trace gases are most likely a consequence of high rates of atmospheric nitrogen deposition (20 kg N haâˆ'1yrâˆ'1) of NH3 and NOx to our site. For N2O, cumulative annual emissions were ≥ 0.8 kg N2O-N haâˆ'1yrâˆ'1 in years with freeze-thaw events (5 out 14 of years). This shows that long-term, multi-year measurements are needed to obtain reliable estimates of N2O fluxes for a given ecosystem. Cumulative values of soil respiratory CO2 fluxes tended to be highest in years with prolonged freezing periods, i.e. years with below average annual mean soil temperatures and high N2O emissions (e.g. the years 1996 and 2006). Furthermore, based on our unique database on trace gas fluxes we analyzed if soil temperature, soil moisture measurements can be used to approximate trace gas fluxes at daily, weekly, monthly, or annual scale. Our analysis shows that simple-to-measure environmental drivers such as soil temperature or soil moisture are suitable to approximate fluxes of NO and CO2 at weekly and monthly resolution reasonably well (accounting for up to 59 % of the variance). However, for CH4 we so far failed to find meaningful correlations, and also for N2O the predictive power is rather low. This is most likely due to the complexity of involved processes and counteracting effects of soil moisture and temperature, specifically with regard to N2O production and consumption by denitrification and microbial community dynamics. At monthly scale, including information on gross primary production (CO2, NO), and N deposition (N2O), increased significantly the explanatory power of the obtained empirical regressions (CO2: r2 =0.8; NO: r2 = 0.67; N2O, all data: r2 = 0.5; N2O, with exclusion of freeze-thaw periods: r2 = 0.65)./p |
BibTeX:
@article{Luo2012,
author = {Luo, G J and Brüggemann, N and Wolf, B and Gasche, R and Grote, R and Butterbach-Bahl, K},
title = {Decadal variability of soil CO sub2/sub , NO, N sub2/sub O, and CH sub4/sub fluxes at the Höglwald Forest, Germany},
journal = {Biogeosciences},
year = {2012},
volume = {9},
number = {5},
pages = {1741--1763},
url = {https://www.biogeosciences.net/9/1741/2012/},
doi = {10.5194/bg-9-1741-2012}
}
|
| Luyssaert S, Abril G, Andres R, Bastviken D, Bellassen V, Bergamaschi P, Bousquet P, Chevallier F, Ciais P, Corazza M, Dechow R, Erb KH, Etiope G, Fortems-Cheiney A, Grassi G, Hartmann J, Jung M, Lathière J, Lohila A, Mayorga E, Moosdorf N, Njakou DS, Otto J, Papale D, Peters W, Peylin P, Raymond P, Rödenbeck C, Saarnio S, Schulze ED, Szopa S, Thompson R, Verkerk PJ, Vuichard N, Wang R, Wattenbach M and Zaehle S (2012), "The European land and inland water CO2, CO, CH4 and N2O balance between 2001 and 2005", Biogeosciences., aug, 2012. Vol. 9(8), pp. 3357-3380. |
| Abstract: Globally, terrestrial ecosystems have absorbed about 30% of anthropogenic greenhouse gas emissions over the period 2000-2007 and inter-hemispheric gradients indicate that a significant fraction of terrestrial carbon sequestration must be north of the Equator. We present a compilation of the CO2, CO, CH4 and N2O balances of Europe following a dual constraint approach in which (1) a land-based balance derived mainly from ecosystem carbon inventories and (2) a land-based balance derived from flux measurements are compared to (3) the atmospheric data-based balance derived from inversions constrained by measurements of atmospheric GHG (greenhouse gas) concentrations. Good agreement between the GHG balances based on fluxes (1294 ± 545 Tg C in CO2-eq yr-1), inventories (1299 ± 200 Tg C in CO2-eq yr-1) and inversions (1210 ± 405 Tg C in CO2-eq yr-1) increases our confidence that the processes underlying the European GHG budget are well understood and reasonably sampled. However, the uncertainty remains large and largely lacks formal estimates. Given that European net land to atmosphere exchanges are determined by a few dominant fluxes, the uncertainty of these key components needs to be formally estimated before efforts could be made to reduce the overall uncertainty. The net land-to-atmosphere flux is a net source for CO2, CO, CH4 and N2O, because the anthropogenic emissions by far exceed the biogenic sink strength. The dual-constraint approach confirmed that the European biogenic sink removes as much as 205 ± 72 Tg C yr-1 from fossil fuel burning from the atmosphere. However, This C is being sequestered in both terrestrial and inland aquatic ecosystems. If the C-cost for ecosystem management is taken into account, the net uptake of ecosystems is estimated to decrease by 45% but still indicates substantial C-sequestration. However, when the balance is extended from CO2 towards the main GHGs, C-uptake by terrestrial and aquatic ecosystems is offset by emissions of non-CO2 GHGs. As such, the European ecosystems are unlikely to contribute to mitigating the effects of climate change. textcopyright 2012 Author(s). CC Attribution 3.0 License. |
BibTeX:
@article{Luyssaert2012,
author = {Luyssaert, S and Abril, G and Andres, R and Bastviken, D and Bellassen, V and Bergamaschi, P and Bousquet, P and Chevallier, F and Ciais, P and Corazza, M and Dechow, R and Erb, K H and Etiope, G and Fortems-Cheiney, A and Grassi, G and Hartmann, J and Jung, M and Lathière, J and Lohila, A and Mayorga, E and Moosdorf, N and Njakou, D S and Otto, J and Papale, D and Peters, W and Peylin, P and Raymond, P and Rödenbeck, C and Saarnio, S and Schulze, E D and Szopa, S and Thompson, R and Verkerk, P J and Vuichard, N and Wang, R and Wattenbach, M and Zaehle, S},
title = {The European land and inland water CO2, CO, CH4 and N2O balance between 2001 and 2005},
journal = {Biogeosciences},
year = {2012},
volume = {9},
number = {8},
pages = {3357--3380},
url = {http://www.biogeosciences.net/9/3357/2012/},
doi = {10.5194/bg-9-3357-2012}
}
|
| Meesters AGCA, Tolk LF, Peters W, Hutjes RWA, Vellinga OS, Elbers JA, Vermeulen AT, Van Der Laan S, Neubert REM, Meijer HAJ and Dolman AJ (2012), "Inverse carbon dioxide flux estimates for the Netherlands", Journal of Geophysical Research Atmospheres., oct, 2012. Vol. 117(20), pp. n/a-n/a. |
| Abstract: [1] COinf2/inf fluxes for the Netherlands and surroundings are estimated for the year 2008, from concentration measurements at four towers, using an inverse model. The results are compared to direct COinf2/inf flux measurements by aircraft, for 6 flight tracks over the Netherlands, flown multiple times in each season. We applied the Regional Atmospheric Mesoscale Modeling system (RAMS) coupled to a simple carbon flux scheme (including fossil fuel), which was run at 10 km resolution, and inverted with an Ensemble Kalman Filter. The domain had 6 eco-regions, and inversions were performed for the four seasons separately. Inversion methods with pixel-dependent and -independent parameters for each eco-region were compared. The two inversion methods, in general, yield comparable flux averages for each eco-region and season, whereas the difference from the prior flux may be large. Posterior fluxes co-sampled along the aircraft flight tracks are usually much closer to the observations than the priors, with a comparable performance for both inversion methods, and with best performance for summer and autumn. The inversions showed more negative COinf2/inf fluxes than the priors, though the latter are obtained from a biosphere model optimized using the Fluxnet database, containing observations from more than 200 locations worldwide. The two different crop ecotypes showed very different COinf2/inf uptakes, which was unknown from the priors. The annual-average uptake is practically zero for the grassland class and for one of the cropland classes, whereas the other cropland class had a large net uptake, possibly because of the abundance of maize there. textcopyright 2012. American Geophysical Union. All Rights Reserved. |
BibTeX:
@article{Meesters2012,
author = {Meesters, A G C A and Tolk, L F and Peters, W and Hutjes, R W A and Vellinga, O S and Elbers, J A and Vermeulen, A T and Van Der Laan, S and Neubert, R E M and Meijer, H A J and Dolman, A J},
title = {Inverse carbon dioxide flux estimates for the Netherlands},
journal = {Journal of Geophysical Research Atmospheres},
year = {2012},
volume = {117},
number = {20},
pages = {n/a--n/a},
url = {http://doi.wiley.com/10.1029/2012JD017797},
doi = {10.1029/2012JD017797}
}
|
| Milroy C, Martucci G, Lolli S, Loaec S, Sauvage L, Xueref-Remy I, Lavrič JV, Ciais P, Feist DG, Biavati G and O'Dowd CD (2012), "An assessment of pseudo-operational ground-based light detection and ranging sensors to determine the boundary-layer structure in the coastal atmosphere", Advances in Meteorology. Vol. 2012 |
| Abstract: Twenty-one cases of boundary-layer structure were retrieved by three co-located remote sensors, One LIDAR and two ceilometers at the coastal site of Mace Head, Ireland. Data were collected during the ICOS field campaign held at the GAW Atmospheric Station of Mace Head, Ireland, from 8th to 28th of June, 2009. The study is a two-step investigation of the BL structure based on (i) the intercomparison of the backscatter profiles from the three laser sensors, namely the Leosphere ALS300 LIDAR, the Vaisala CL31 ceilometer and the Jenoptik CHM15K ceilometer; (ii) and the comparison of the backscatter profiles with twenty-three radiosoundings performed during the period from the 8th to the 15th of June, 2009. The sensor-independent Temporal Height-Tracking algorithm was applied to the backscatter profiles as retrieved by each instrument to determine the decoupled structure of the BL over Mace Head. The LIDAR and ceilometers-retrieved BL heights were compared to the radiosoundings temperature profiles. The comparison between the remote and the in-situ data proved the existence of the inherent link between temperature and aerosol backscatter profiles and opened at future studies focusing on the further assessment of LIDAR-ceilometer comparison. textcopyright 2012 Conor Milroy et al. |
BibTeX:
@article{Milroy2012,
author = {Milroy, Conor and Martucci, Giovanni and Lolli, Simone and Loaec, Sophie and Sauvage, Laurent and Xueref-Remy, Irène and Lavrič, Jošt V. and Ciais, Philippe and Feist, Dietrich G. and Biavati, Gionata and O'Dowd, Colin D.},
title = {An assessment of pseudo-operational ground-based light detection and ranging sensors to determine the boundary-layer structure in the coastal atmosphere},
journal = {Advances in Meteorology},
year = {2012},
volume = {2012},
doi = {10.1155/2012/929080}
}
|
| Nordbo A, Järvi L, Haapanala S, Wood CR and Vesala T (2012), "Fraction of natural area as main predictor of net CO2 emissions from cities", Geophysical Research Letters., oct, 2012. Vol. 39(20) Blackwell Publishing Ltd. |
| Abstract: Cities account for most anthropogenic greenhouse-gas emissions, CO 2 being most important. We evaluate the net urban contribution to CO2 emissions by performing a meta-analysis of all available 14 annual CO2 budget studies. The studies are based on direct flux measurements using the eddy-covariance technique which excludes all strong point sources. We show that the fraction of natural area is the strongest predictor of urban CO2 budgets, and this fraction can be used as a robust proxy for net urban CO2 emissions. Up-scaling, based on that proxy and satellite mapping of the fraction of natural area, identifies urban hotspots of CO2 emissions; and extraction of 56 individual cities corroborates their inventory-based estimates. Furthermore, cities are estimated as carbon-neutral when the natural fraction is about 80%. This fresh view on the importance of cities in climate change treats cities as urban ecosystems: incorporating natural areas like vegetation. textcopyright 2012. American Geophysical Union. All Rights Reserved. |
BibTeX:
@article{Nordbo2012,
author = {Nordbo, Annika and Järvi, Leena and Haapanala, Sami and Wood, Curtis R. and Vesala, Timo},
title = {Fraction of natural area as main predictor of net CO2 emissions from cities},
journal = {Geophysical Research Letters},
publisher = {Blackwell Publishing Ltd},
year = {2012},
volume = {39},
number = {20},
doi = {10.1029/2012GL053087}
}
|
| Oram DE, Mani FS, Laube JC, Newland MJ, Reeves CE, Sturges WT, Penkett SA, Brenninkmeijer CAM, Röckmann T and Fraser PJ (2012), "Long-term tropospheric trend of octafluorocyclobutane (c-C4F8 or PFC-318)", Atmospheric Chemistry and Physics., jan, 2012. Vol. 12(1), pp. 261-269. |
| Abstract: Air samples collected at Cape Grim, Tasmania between 1978 and 2008 and during a series of more recent aircraft sampling programmes have been analysed to determine the atmospheric abundance and trend of octafluorocyclobutane (c- C4F8 or PFC-318). c-C4F8 has an atmospheric lifetime in excess of 3000 yr and a global warming potential (GWP) of 10 300 (100 yr time horizon), making it one of the most potent greenhouse gases detected in the atmosphere to date. The abundance of c-C4F8 in the Southern Hemisphere has risen from 0.35 ppt in 1978 to 1.2 ppt in 2010, and is currently increasing at a rate of around 0.03 ppt yr-1. It is the third most abundant perfluorocarbon (PFC) in the present day atmosphere, behind CF4 (∼75 ppt) and C2F6 (∼4 ppt). Although a number of potential sources of c-C4F8 have been reported, including the electronics and semi-conductor industries, there remains a large discrepancy in the atmospheric budget. Using a 2-D global model to derive top-down global emissions based on the Cape Grim measurements yields a recent (2007) emission rate of around 1.1 Gg yr-1 and a cumulative emission up to and including 2007 of 38.1 Gg. Emissions reported on the EDGAR emissions database for the period 1986-2005 represent less than 1% of the top-down emissions for the same period, which suggests there is a large unaccounted for source of this compound. It is also apparent that the magnitude of this source has varied considerably over the past 30 yr, declining sharply in the late 1980s before increasing again in the mid-1990s. textcopyright 2012 Author(s). CC Attribution 3.0 License. |
BibTeX:
@article{Oram2012,
author = {Oram, D E and Mani, F S and Laube, J C and Newland, M J and Reeves, C E and Sturges, W T and Penkett, S A and Brenninkmeijer, C A M and Röckmann, T and Fraser, P J},
title = {Long-term tropospheric trend of octafluorocyclobutane (c-C4F8 or PFC-318)},
journal = {Atmospheric Chemistry and Physics},
year = {2012},
volume = {12},
number = {1},
pages = {261--269},
url = {http://www.atmos-chem-phys.net/12/261/2012/},
doi = {10.5194/acp-12-261-2012}
}
|
| Orza JAG, Cabello M, Galiano V, Vermeulen AT and Stein AF (2012), "The association between the north atlantic oscillation and the interannual variability of the tropospheric transport pathways in Western Europe", In Geophysical Monograph Series. Vol. 200, pp. 127-141. American Geophysical Union. |
| Abstract: The variations in tropospheric transport pathways over a 20 year period, 1990- 2009, are studied at six locations in Europe. Three Atlantic (Lisbon, Mace Head, and Cabauw) and three Mediterranean sites (Málaga and Elche in the western part and Lecce in the central Mediterranean) are considered. The work is based on the identification of flow types at each location by robust cluster analysis of the trajectories, the assessment of temporal trends for each advection pattern, and subsequent quantification of the association, at the monthly scale, between the North Atlantic Oscillation (NAO) index (NAOi) and the frequency of occurrence of the identified flows. This exploratory study demonstrates the usefulness of the approach for specific locations in a context where synoptic circulation/weathertype classifications are usually used. A different number of advection pathways were identified at each location. Common features to all the sites were prevalence of westerly flows, strong seasonal variability, and association of the air flow types to known synoptic situations in both phases of the NAO. The degree of association varies strongly with latitude, location within the Mediterranean basin, and closeness to the action centers. Overall, flows reaching Mace Head and Cabauw present stronger association to the NAO, which is substantially reduced at lower latitudes and is not significant at Lisbon. Significant temporal trends are found for northerly flows at Mace Head andMálaga, associated to changes at the beginning of the study period that are also present in the NAOi time series. WSW flows at Mace Head exhibit a steady decreasing trend over the whole period. textcopyright 2012. American Geophysical Union. All Rights Reserved. |
BibTeX:
@incollection{Orza2012,
author = {Orza, J A G and Cabello, M and Galiano, V and Vermeulen, A T and Stein, A F},
editor = {Lin, J C and Gerbig, C},
title = {The association between the north atlantic oscillation and the interannual variability of the tropospheric transport pathways in Western Europe},
booktitle = {Geophysical Monograph Series},
publisher = {American Geophysical Union},
year = {2012},
volume = {200},
pages = {127--141},
doi = {10.1029/2012GM001315}
}
|
| Oshchepkov S, Bril A, Yokota T, Morino I, Yoshida Y, Matsunaga T, Belikov D, Wunch D, Wennberg P, Toon G, O'Dell C, Butz A, Guerlet S, Cogan A, Boesch H, Eguchi N, Deutscher N, Griffith D, MacAtangay R, Notholt J, Sussmann R, Rettinger M, Sherlock V, Robinson J, Kyrö E, Heikkinen P, Feist DG, Nagahama T, Kadygrov N, Maksyutov S, Uchino O and Watanabe H (2012), "Effects of atmospheric light scattering on spectroscopic observations of greenhouse gases from space: Validation of PPDF-based CO2 retrievals from GOSAT", Journal of Geophysical Research Atmospheres., jun, 2012. Vol. 117(12), pp. n/a-n/a. |
| Abstract: This report describes a validation study of Greenhouse gases Observing Satellite (GOSAT) data processing using ground-based measurements of the Total Carbon Column Observing Network (TCCON) as reference data for column-averaged dry air mole fractions of atmospheric carbon dioxide (XCO2). We applied the photon path length probability density function method to validate XCO2 retrievals from GOSAT data obtained during 22months starting from June 2009. This method permitted direct evaluation of optical path modifications due to atmospheric light scattering that would have a negligible impact on ground-based TCCON measurements but could significantly affect gas retrievals when observing reflected sunlight from space. Our results reveal effects of optical path lengthening over Northern Hemispheric stations, essentially from May-September of each year, and of optical path shortening for sun-glint observations in tropical regions. These effects are supported by seasonal trends in aerosol optical depth derived from an offline three-dimensional aerosol transport model and by cirrus optical depth derived from space-based measurements of the Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) instrument. Removal of observations that were highly contaminated by aerosol and cloud from the GOSAT data set resulted in acceptable agreement in the seasonal variability of XCO2 over each station as compared with TCCON measurements. Statistical comparisons between GOSAT and TCCON coincident measurements of CO2 column abundance show a correlation coefficient of 0.85, standard deviation of 1.80ppm, and a sub-ppm negative bias of -0.43ppm for all TCCON stations. Global distributions of monthly mean retrieved XCO2 with a spatial resolution of 2.5° latitude×2.5° longitude show agreement within∼2.5°ppm with those predicted by the atmospheric tracer transport model. textcopyright 2012 American Geophysical Union. All Rights Reserved. |
BibTeX:
@article{Oshchepkov2012,
author = {Oshchepkov, Sergey and Bril, Andrey and Yokota, Tatsuya and Morino, Isamu and Yoshida, Yukio and Matsunaga, Tsuneo and Belikov, Dmitry and Wunch, Debra and Wennberg, Paul and Toon, Geoffrey and O'Dell, Christopher and Butz, André and Guerlet, Sandrine and Cogan, Austin and Boesch, Hartmut and Eguchi, Nawo and Deutscher, Nicholas and Griffith, David and MacAtangay, Ronald and Notholt, Justus and Sussmann, Ralf and Rettinger, Markus and Sherlock, Vanessa and Robinson, John and Kyrö, Esko and Heikkinen, Pauli and Feist, Dietrich G and Nagahama, Tomoo and Kadygrov, Nikolay and Maksyutov, Shamil and Uchino, Osamu and Watanabe, Hiroshi},
title = {Effects of atmospheric light scattering on spectroscopic observations of greenhouse gases from space: Validation of PPDF-based CO2 retrievals from GOSAT},
journal = {Journal of Geophysical Research Atmospheres},
year = {2012},
volume = {117},
number = {12},
pages = {n/a--n/a},
url = {http://doi.wiley.com/10.1029/2012JD017505},
doi = {10.1029/2012JD017505}
}
|
| Petri C, Warneke T, Jones N, Ridder T, Messerschmidt J, Weinzierl T, Geibel M and Notholt J (2012), "Remote sensing of CO2 and CH4 using solar absorption spectrometry with a low resolution spectrometer", Atmospheric Measurement Techniques., jul, 2012. Vol. 5(7), pp. 1627-1635. |
| Abstract: Throughout the last few years solar absorption Fourier Transform Spectrometry (FTS) has been further developed to measure the total columns of CO2 and CH4. The observations are performed at high spectral resolution, typically at 0.02 cm-1. The precision currently achieved is generally better than 0.25%. However, these high resolution instruments are quite large and need a dedicated room or container for installation. We performed these observations using a smaller commercial interferometer at its maximum possible resolution of 0.11 cm-1. The measurements have been performed at Bremen and have been compared to observations using our high resolution instrument also situated at the same location. The high resolution instrument has been successfully operated as part of the Total Carbon Column Observing Network (TCCON). The precision of the low resolution instrument is 0.32% for XCO2 and 0.46% for XCH 4. A comparison of the measurements of both instruments yields an average deviation in the retrieved daily means of 0.2% for CO2. For CH4 an average bias between the instruments of 0.47% was observed. For test cases, spectra recorded by the high resolution instrument have been truncated to the resolution of 0.11 cm-1. This study gives an offset of 0.03% for CO2 and 0.26% for CH4. These results indicate that for CH4 more than 50% of the difference between the instruments results from the resolution dependent retrieval. We tentatively assign the offset to an incorrect a-priori concentration profile or the effect of interfering gases, which may not be treated correctly. textcopyright 2012 Author(s). |
BibTeX:
@article{Petri2012,
author = {Petri, C and Warneke, T and Jones, N and Ridder, T and Messerschmidt, J and Weinzierl, T and Geibel, M and Notholt, J},
title = {Remote sensing of CO2 and CH4 using solar absorption spectrometry with a low resolution spectrometer},
journal = {Atmospheric Measurement Techniques},
year = {2012},
volume = {5},
number = {7},
pages = {1627--1635},
url = {http://www.atmos-meas-tech.net/5/1627/2012/},
doi = {10.5194/amt-5-1627-2012}
}
|
| Pino D, Vilà-Guerau De Arellano J, Peters W, Schröter J, Van Heerwaarden CC and Krol MC (2012), "A conceptual framework to quantify the influence of convective boundary layer development on carbon dioxide mixing ratios", Atmospheric Chemistry and Physics., mar, 2012. Vol. 12(6), pp. 2969-2985. |
| Abstract: Interpretation of observed diurnal carbon dioxide (CO2) mixing ratios near the surface requires knowledge of the local dynamics of the planetary boundary layer. In this paper, we study the relationship between the boundary layer dynamics and the CO2 budget in convective conditions through a newly derived set of analytical equations. From these equations, we are able to quantify how uncertainties in boundary layer dynamical variables or in the morning CO2 distribution in the mixed-layer or in the free atmosphere (FA) influence the bulk CO2 mixing ratio. We find that the largest uncertainty incurred on the mid-day CO2 mixing ratio comes from the prescribed early morning CO2 mixing ratios in the stable boundary layer, and in the free atmosphere. Errors in these values influence CO2 mixing ratios inversely proportional to the boundary layer depth (h), just like uncertainties in the assumed initial boundary layer depth and surface CO2 flux. The influence of uncertainties in the boundary layer depth itself is one order of magnitude smaller. If we "invert" the problem and calculate CO2 surface exchange from observed or simulated CO2 mixing ratios, the sensitivities to errors in boundary layer dynamics also invert: they become linearly proportional to the boundary layer depth. We demonstrate these relations for a typical well characterized situation at the Cabauw site in The Netherlands, and conclude that knowledge of the temperature and carbon dioxide profiles of the atmosphere in the early morning are of vital importance to correctly interpret observed CO2 mixing ratios during midday. textcopyright Author(s) 2012. |
BibTeX:
@article{Pino2012,
author = {Pino, D and Vilà-Guerau De Arellano, J and Peters, W and Schröter, J and Van Heerwaarden, C C and Krol, M C},
title = {A conceptual framework to quantify the influence of convective boundary layer development on carbon dioxide mixing ratios},
journal = {Atmospheric Chemistry and Physics},
year = {2012},
volume = {12},
number = {6},
pages = {2969--2985},
url = {http://www.atmos-chem-phys.net/12/2969/2012/},
doi = {10.5194/acp-12-2969-2012}
}
|
| Plancherel Y, Rodgers KB, Key RM, Jacobson AR and Sarmiento JL (2012), "Role of regression model selection and station distribution on the estimation of oceanic anthropogenic carbon change by eMLR", Biogeosciences Discuss. Vol. 9, pp. 14589-14638. |
| Abstract: Differencing predictions of linear regression models generated from hydrographic data collected at different times (the eMLR method) was proposed as a means of quantifying the dominant patterns of change in oceanic anthropogenic carbon in the context of sparse data sets subject to natural variability. The ability of eMLR to recover the anthro-5 pogenic carbon signal in the North Atlantic was tested using a global circulation and biogeochemistry model. Basin-scale applications of eMLR on horizontal layers can estimate the change in anthropogenic carbon inventory with an accuracy typically better than 10 %. Regression model selection influences the distribution of the recovered an-thropogenic carbon change signal. The systematic use of statistically optimum regres-10 sion formulae does not produce the best estimates of anthropogenic carbon change if the distribution of the station locations emphasizes hydrographic features differently in time. Additional factors, such as a balanced station distribution and vertical continuity of the regression formulae should be considered to guide model selection. Accurate results are obtained when multiple formulae are used throughout the water column. 15 Different formulae can yield results of similar quality. The fact that good results are obtained in the hydrographically complex North Atlantic suggests that eMLR can produce accurate estimates in other basins. |
BibTeX:
@article{Plancherel2012,
author = {Plancherel, Y and Rodgers, K B and Key, R M and Jacobson, A R and Sarmiento, J L},
title = {Role of regression model selection and station distribution on the estimation of oceanic anthropogenic carbon change by eMLR},
journal = {Biogeosciences Discuss},
year = {2012},
volume = {9},
pages = {14589--14638},
url = {www.biogeosciences-discuss.net/9/14589/2012/},
doi = {10.5194/bgd-9-14589-2012}
}
|
| Rey A, Belelli-Marchesini L, Were A, Serrano-ortiz P, Etiope G, Papale D, Domingo F and Pegoraro E (2012), "Wind as a main driver of the net ecosystem carbon balance of a semiarid Mediterranean steppe in the South East of Spain", Global Change Biology., feb, 2012. Vol. 18(2), pp. 539-554. |
| Abstract: Despite the advance in our understanding of the carbon exchange between terrestrial ecosystems and the atmosphere, semiarid ecosystems have been poorly investigated and little is known about their role in the global carbon balance. We used eddy covariance measurements to determine the exchange of CO 2 between a semiarid steppe and the atmosphere over 3 years. The vegetation is a perennial grassland of Stipa tenacissima L. located in the SE of Spain. We examined diurnal, seasonal and interannual variations in the net ecosystem carbon balance (NECB) in relation to biophysical variables. Cumulative NECB was a net source of 65.7, 143.6 and 92.1 g C m -2 yr -1 for the 3 years studied, respectively. We separated the year into two distinctive periods: dry period and growing season. The ecosystem was a net source of CO 2 to the atmosphere, particularly during the dry period when large CO 2 positive fluxes of up to 15 μmol m -2 s -1 were observed in concomitance with large wind speeds. Over the growing season, the ecosystem was a slight sink or neutral with maximum rates of -2.3 μmol m -2 s -1. Rainfall events caused large fluxes of CO 2 to the atmosphere and determined the length of the growing season. In this season, photosynthetic photon flux density controlled day-time NECB just below 1000 μmol m -2 s -1. The analyses of the diurnal and seasonal data and preliminary geological and gas-geochemical evaluations, including C isotopic analyses, suggest that the CO 2 released was not only biogenic but most likely included a component of geothermal origin, presumably related to deep fluids occurring in the area. These results highlight the importance of considering geological carbon sources, as well as the need to carefully interpret the results of eddy covariance partitioning techniques when applied in geologically active areas potentially affected by CO 2-rich geofluid circulation. textcopyright 2011 Blackwell Publishing Ltd. |
BibTeX:
@article{Rey2012,
author = {Rey, Ana and Belelli-Marchesini, Luca and Were, Ana and Serrano-ortiz, Penelope and Etiope, Giuseppe and Papale, Dario and Domingo, Francisco and Pegoraro, Emiliano},
title = {Wind as a main driver of the net ecosystem carbon balance of a semiarid Mediterranean steppe in the South East of Spain},
journal = {Global Change Biology},
year = {2012},
volume = {18},
number = {2},
pages = {539--554},
url = {http://doi.wiley.com/10.1111/j.1365-2486.2011.02534.x},
doi = {10.1111/j.1365-2486.2011.02534.x}
}
|
| Rey A, Etiope G, Belelli-Marchesini L, Papale D and Valentini R (2012), "Geologic carbon sources may confound ecosystem carbon balance estimates: Evidence from a semiarid steppe in the southeast of Spain", Journal of Geophysical Research: Biogeosciences., sep, 2012. Vol. 117(3), pp. n/a-n/a. |
| Abstract: At a semiarid steppe site located in the SE of Spain, relatively large COinf2/inf emissions were measured that could not be attributed to the ecosystem activity alone. Since the study site was located in a tectonically active area, it was hypothesized that a part of the measured COinf2/inf was of geologic origin. This investigation included a survey of soil COinf2/inf efflux, together with carbon isotope analyses of the COinf2/inf in the soil atmosphere, soil COinf2/inf efflux (i.e., Keeling plots), groundwater and local thermal springs. These measurements confirmed the hypothesis of degassing from geologic sources. In areas with local faults and ancient volcanic structures, soil COinf2/inf efflux rates were significantly higher (i.e., up to 6.3 and 1.4 mmol COinf2/inf msup-2/sup ssup-1/sup) than measurements in a comparable site that was some distance from fault sites (means of 1.0 and 0.43 mmol COinf2/inf msup-2/sup ssup-1/sup in March and June, respectively). The COinf2/inf concentration in the soil atmosphere at the eddy covariance site reached 0.14% v/v at 0.70 m soil depth with a sup13/supC-enriched isotopic composition (δsup13/supC from -10.2% to -16.6%), consistent with the isotopic composition of the soil COinf2/inf efflux estimated by Keeling plots (i.e., -16.6%). sup13/supC-enriched COinf2/inf also occurred in local aquifers, and there was evidence of degassing from deep crust and mantle at regional scale by the helium isotopic ratio in spring waters located about 30 km (R/Ra: 0.12) and 200 km (R/Ra: 0.95) NW of the eddy covariance site. This study highlights the importance of considering COinf2/inf sources of geologic origin when assessing the net ecosystem carbon balance of sites that may possibly be affected by circulation of such COinf2/inf-rich fluids. textcopyright 2012. American Geophysical Union. All Rights Reserved. |
BibTeX:
@article{Rey2012a,
author = {Rey, A and Etiope, G and Belelli-Marchesini, L and Papale, D and Valentini, R},
title = {Geologic carbon sources may confound ecosystem carbon balance estimates: Evidence from a semiarid steppe in the southeast of Spain},
journal = {Journal of Geophysical Research: Biogeosciences},
year = {2012},
volume = {117},
number = {3},
pages = {n/a--n/a},
url = {http://doi.wiley.com/10.1029/2012JG001991},
doi = {10.1029/2012JG001991}
}
|
| Rödenbeck C, Keeling RF, Bakker DCE, Metzl N, Olsen A, Sabine C and Heimann M (2012), "Sea-air CO 2 flux estimated from SOCAT surface-ocean CO 2 partial pressure data and atmospheric CO 2 mixing ratio data", Ocean Science Discussions., jun, 2012. Vol. 9(3), pp. 2273-2326. Copernicus GmbH. |
| Abstract: Abstract. Surface-ocean CO2 partial pressure data have been assimilated into a simple diagnostic model of surface-ocean biogeochemistry to estimate the spatio-temporal CO2 partial pressure field and ultimately the sea-air CO2 fluxes. Results compare well with the widely used monthly climatology by Takahashi et al. (2009) but also contain some short-term and interannual variations. Fitting the same model to atmospheric CO2 data yields less robust but consistent estimates, confirming that using the partial pressure based estimates as ocean prior in atmospheric CO2 inversions may improve land CO2 flux estimates. Estimated seasonality of ocean-internal carbon sources and sinks is discussed in the light of observed nutrient variations. |
BibTeX:
@article{Rodenbeck2012,
author = {Rödenbeck, C. and Keeling, R. F. and Bakker, D. C. E. and Metzl, N. and Olsen, A. and Sabine, C. and Heimann, M.},
title = {Sea-air CO 2 flux estimated from SOCAT surface-ocean CO 2 partial pressure data and atmospheric CO 2 mixing ratio data},
journal = {Ocean Science Discussions},
publisher = {Copernicus GmbH},
year = {2012},
volume = {9},
number = {3},
pages = {2273--2326},
url = {https://os.copernicus.org/preprints/9/2273/2012/},
doi = {10.5194/osd-9-2273-2012}
}
|
| Saito R, Patra PK, Deutscher N, Wunch D, Ishijima K, Sherlock V, Blumenstock T, Dohe S, Griffith D, Hase F, Heikkinen P, Kyrö E, MacAtangay R, Mendonca J, Messerschmidt J, Morino I, Notholt J, Rettinger M, Strong K, Sussmann R and Warneke T (2012), "Technical Note: Latitude-time variations of atmospheric column-average dry air mole fractions of CO 2, CH 4 and N 2O", Atmospheric Chemistry and Physics., aug, 2012. Vol. 12(16), pp. 7767-7777. |
| Abstract: We present a comparison of an atmospheric general circulation model (AGCM)-based chemistry-transport model (ACTM) simulation with total column measurements of CO 2, CH 4 and N 2O from the Total Carbon Column Observing Network (TCCON). The model is able to capture observed trends, seasonal cycles and inter hemispheric gradients at most sampled locations for all three species. The model-observation agreements are best for CO 2, because the simulation uses fossil fuel inventories and an inverse model estimate of non-fossil fuel fluxes. The ACTM captures much of the observed seasonal variability in CO 2 and N 2O total columns (∼81 % variance, R 0.9 between ACTM and TCCON for 19 out of 22 cases). These results suggest that the transport processes in troposphere and stratosphere are well represented in ACTM. Thus the poor correlation between simulated and observed CH 4 total columns, particularly at tropical and extra-tropical sites, have been attributed to the uncertainties in surface emissions and loss by hydroxyl radicals. While the upward-looking total column measurements of CO 2 contains surface flux signals at various spatial and temporal scales, the N 2O measurements are strongly affected by the concentration variations in the upper troposphere and stratosphere. textcopyright 2012 Author(s). |
BibTeX:
@article{Saito2012,
author = {Saito, R and Patra, P K and Deutscher, N and Wunch, D and Ishijima, K and Sherlock, V and Blumenstock, T and Dohe, S and Griffith, D and Hase, F and Heikkinen, P and Kyrö, E and MacAtangay, R and Mendonca, J and Messerschmidt, J and Morino, I and Notholt, J and Rettinger, M and Strong, K and Sussmann, R and Warneke, T},
title = {Technical Note: Latitude-time variations of atmospheric column-average dry air mole fractions of CO 2, CH 4 and N 2O},
journal = {Atmospheric Chemistry and Physics},
year = {2012},
volume = {12},
number = {16},
pages = {7767--7777},
url = {http://www.atmos-chem-phys.net/12/7767/2012/},
doi = {10.5194/acp-12-7767-2012}
}
|
| Sriskantharajah S, Fisher RE, Lowry D, Aalto T, Hatakka J, Aurela M, Laurila T, Lohila A, Kuitunen E and Nisbet EG (2012), "Stable carbon isotope signatures of methane from a Finnish subarctic wetland", Tellus, Series B: Chemical and Physical Meteorology., jun, 2012. Vol. 64(1) |
| Abstract: Methane emissions from Lompolojänkkä, a Finnish aapa mire within the Arctic Circle, were studied by nonintrusive Keeling plot methods, to place better constraints on the seasonal variations in isotopic signature of methane (δ 13C CH4) emitted from Arctic wetland. Air samples were collected in Tedlar bags over the wetland at heights of 42 and 280 cm between May and October 2009 and in August 2008. The mixing ratio and δ 13C of the methane in the samples were incorporated into Keeling plot analyses to derive bulk δ 13C CH4 signatures for the methane inputs to the air above the wetland. The results show an unexpected consistence in δ 13C CH4 from early to late summer, clustered around -68.5±0.7‰, but during spring thaw and autumnal freezing, δ 13C CH4 is enriched by approximately 2 and 4‰, respectively. The techniques reported in this paper are simple and economical to employ, and give a bulk source signature for the methane inputs to the air above the entire wetland that can be extrapolated to a larger regional area. textcopyright 2012 S. Sriskantharajah et al. |
BibTeX:
@article{Sriskantharajah2012,
author = {Sriskantharajah, S and Fisher, R E and Lowry, D and Aalto, T and Hatakka, J and Aurela, M and Laurila, T and Lohila, A and Kuitunen, E and Nisbet, E G},
title = {Stable carbon isotope signatures of methane from a Finnish subarctic wetland},
journal = {Tellus, Series B: Chemical and Physical Meteorology},
year = {2012},
volume = {64},
number = {1},
url = {http://www.tellusb.net/index.php/tellusb/article/view/18818},
doi = {10.3402/tellusb.v64i0.18818}
}
|
| Sturges WT, Oram DE, Laube JC, Reeves CE, Newland MJ, Hogan C, Martinerie P, Witrant E, Brenninkmeijer CAM, Schuck TJ and Fraser PJ (2012), "Emissions halted of the potent greenhouse gas SF 5CF 3", Atmospheric Chemistry and Physics., apr, 2012. Vol. 12(8), pp. 3653-3658. |
| Abstract: Long term measurements in background air (Cape Grim, Tasmania) and firn air (NEEM, Greenland) of the potent long-lived greenhouse gas SF 5CF 3 show that emissions declined after the late 1990s, having grown since the 1950s, and became indistinguishable from zero after 2003. The timing of this decline suggests that emissions of this gas may have been related to the production of certain fluorochemicals; production of which have been recently phased out. An earlier observation of closely correlated atmospheric abundances of SF 5CF 3 and SF6 are shown here to have likely been purely coincidental, as their respective trends diverged after 2002. Due to its long lifetime (ca. 900 yr), atmospheric concentrations of SF 5CF 3 have not declined, and it is now well mixed between hemispheres, as is also shown here from interhemispheric aircraft measurements. Total cumulative emissions of SF 5CF 3 amount to around 5 kT. textcopyright 2012 Author(s). |
BibTeX:
@article{Sturges2012,
author = {Sturges, W T and Oram, D E and Laube, J C and Reeves, C E and Newland, M J and Hogan, C and Martinerie, P and Witrant, E and Brenninkmeijer, C A M and Schuck, T J and Fraser, P J},
title = {Emissions halted of the potent greenhouse gas SF 5CF 3},
journal = {Atmospheric Chemistry and Physics},
year = {2012},
volume = {12},
number = {8},
pages = {3653--3658},
url = {http://www.atmos-chem-phys.net/12/3653/2012/},
doi = {10.5194/acp-12-3653-2012}
}
|
| Tørseth K, Aas W, Breivik K, Fjeraa AM, Fiebig M, Hjellbrekke AG, Lund Myhre C, Solberg S and Yttri KE (2012), "Introduction to the European Monitoring and Evaluation Programme (EMEP) and observed atmospheric composition change during 1972-2009", Atmospheric Chemistry and Physics., jun, 2012. Vol. 12(12), pp. 5447-5481. |
| Abstract: European scale harmonized monitoring of atmospheric composition was initiated in the early 1970s, and the activity has generated a comprehensive dataset (available at http://www.emep.int) which allows the evaluation of regional and spatial trends of air pollution during a period of nearly 40 yr. Results from the monitoring made within EMEP, the European Monitoring and Evaluation Programme, show large reductions in ambient concentrations and deposition of sulphur species during the last decades. Reductions are in the order of 70-90% since the year 1980, and correspond well with reported emission changes. Also reduction in emissions of nitrogen oxides (NO x) are reflected in the measurements, with an average decrease of nitrogen dioxide and nitrate in precipitation by about 23% and 25% respectively since 1990. Only minor reductions are however seen since the late 1990s. The concentrations of total nitrate in air have decreased on average only by 8% since 1990, and fewer sites show a significant trend. A majority of the EMEP sites show a decreasing trend in reduced nitrogen both in air and precipitation on the order of 25% since 1990. Deposition of base cations has decreased during the past 30 yr, and the pH in precipitation has increased across Europe. Large inter annual variations in the particulate matter mass concentrations reflect meteorological variability, but still there is a relatively clear overall decrease at several sites during the last decade. With few observations going back to the 1990s, the observed chemical composition is applied to document a change in particulate matter (PM) mass even since 1980. These data indicate an overall reduction of about 5 μg m -3 from sulphate alone. Despite the significant reductions in sulphur emissions, sulphate still remains one of the single most important compounds contributing to regional scale aerosol mass concentration. Long-term ozone trends at EMEP sites show a mixed pattern. The year-to-year variability in ozone due to varying meteorological conditions is substantial, making it hard to separate the trends caused by emission change from other effects. For the Nordic countries the data indicate a reduced occurrence of very low concentrations. The most pronounced change in the frequency distribution is seen at sites in the UK and the Netherlands, showing a reduction in the higher values. Smaller changes are seen in Germany, while in Switzerland and Austria, no change is seen in the frequency distribution of ozone. The lack of long-term data series is a major obstacle for studying trends in volatile organic compounds (VOC). The scatter in the data is large, and significant changes are only found for certain components and stations. Concentrations of the heavy metals lead and cadmium have decreased in both air and precipitation during the last 20 yr, with reductions in the order of 80-90% for Pb and 64-84% for Cd (precipitation and air respectively). The measurements of total gaseous mercury indicate a dramatic decrease in concentrations during 1980 to about 1993. Trends in hexachlorocyclohexanes (HCHs) show a significant decrease in annual average air concentrations. For other persistent organic pollutants (POPs) the patterns is mixed, and differs between sites and between measurements in air versus precipitation. textcopyright 2012 Author(s). |
BibTeX:
@article{Tørseth2012,
author = {Tørseth, K and Aas, W and Breivik, K and Fjeraa, A M and Fiebig, M and Hjellbrekke, A G and Lund Myhre, C and Solberg, S and Yttri, K E},
title = {Introduction to the European Monitoring and Evaluation Programme (EMEP) and observed atmospheric composition change during 1972-2009},
journal = {Atmospheric Chemistry and Physics},
year = {2012},
volume = {12},
number = {12},
pages = {5447--5481},
url = {http://www.atmos-chem-phys.net/12/5447/2012/},
doi = {10.5194/acp-12-5447-2012}
}
|
| Vicca S, Luyssaert S, Peñuelas J, Campioli M, Chapin FS, Ciais P, Heinemeyer A, Högberg P, Kutsch WL, Law BE, Malhi Y, Papale D, Piao SL, Reichstein M, Schulze ED and Janssens IA (2012), "Fertile forests produce biomass more efficiently", Ecology Letters., jun, 2012. Vol. 15(6), pp. 520-526. |
| Abstract: Trees with sufficient nutrition are known to allocate carbon preferentially to aboveground plant parts. Our global study of 49 forests revealed an even more fundamental carbon allocation response to nutrient availability: forests with high-nutrient availability use 58±3% (mean±SE; 17 forests) of their photosynthates for plant biomass production (BP), while forests with low-nutrient availability only convert 42±2% (mean±SE; 19 forests) of annual photosynthates to biomass. This nutrient effect largely overshadows previously observed differences in carbon allocation patterns among climate zones, forest types and age classes. If forests with low-nutrient availability use 16±4% less of their photosynthates for plant growth, what are these used for? Current knowledge suggests that lower BP per unit photosynthesis in forests with low- versus forests with high-nutrient availability reflects not merely an increase in plant respiration, but likely results from reduced carbon allocation to unaccounted components of net primary production, particularly root symbionts. textcopyright 2012 Blackwell Publishing Ltd/CNRS. |
BibTeX:
@article{Vicca2012,
author = {Vicca, S and Luyssaert, S and Peñuelas, J and Campioli, M and Chapin, F S and Ciais, P and Heinemeyer, A and Högberg, P and Kutsch, W L and Law, B E and Malhi, Y and Papale, D and Piao, S L and Reichstein, M and Schulze, E D and Janssens, I A},
title = {Fertile forests produce biomass more efficiently},
journal = {Ecology Letters},
year = {2012},
volume = {15},
number = {6},
pages = {520--526},
url = {http://doi.wiley.com/10.1111/j.1461-0248.2012.01775.x},
doi = {10.1111/j.1461-0248.2012.01775.x}
}
|
| Wang T, Brender P, Ciais P, Piao S, Mahecha MD, Chevallier F, Reichstein M, Ottlé C, Maignan F, Arain A, Bohrer G, Cescatti A, Kiely G, Law BE, Lutz M, Montagnani L, Moors E, Osborne B, Panferov O, Papale D and Vaccari FP (2012), "State-dependent errors in a land surface model across biomes inferred from eddy covariance observations on multiple timescales", Ecological Modelling., nov, 2012. Vol. 246(C), pp. 11-25. |
| Abstract: Characterization of state-dependent model biases in land surface models can highlight model deficiencies, and provide new insights into model development. In this study, artificial neural networks (ANNs) are used to estimate the state-dependent biases of a land surface model (ORCHIDEE: ORganising Carbon and Hydrology in Dynamic EcosystEms). To characterize state-dependent biases in ORCHIDEE, we use multi-year flux measurements made at 125 eddy covariance sites that cover 7 different plant functional types (PFTs) and 5 climate groups. We determine whether the state-dependent model biases in five flux variables (H: sensible heat, LE: latent heat, NEE: net ecosystem exchange, GPP: gross primary productivity and R eco: ecosystem respiration) are transferable within and between three different timescales (diurnal, seasonal-annual and interannual), and between sites (categorized by PFTs and climate groups). For each flux variable at each site, the spectral decomposition method (singular system analysis) was used to reconstruct time series on the three different timescales.At the site level, we found that the share of state-dependent model biases (hereafter called " error transferability" ) is larger for seasonal-annual and interannual timescales than for the diurnal timescale, but little error transferability was found between timescales in all flux variables. Thus, performing model evaluations at multiple timescales is essential for diagnostics and future development. For all PFTs, climate groups and timescale components, the state-dependent model biases are found to be transferable between sites within the same PFT and climate group, suggesting that specific model developments and improvements based on specific eddy covariance sites can be used to enhance the model performance at other sites within the same PFT-climate group. This also supports the legitimacy of upscaling from the ecosystem scale of eddy covariance sites to the regional scale based on the similarity of PFT and climate group. However, the transferability of state-dependent model biases between PFTs or climate groups is not always found on the seasonal-annual and interannual timescales, which is contrary to transferability found on the diurnal timescale and the original time series. textcopyright 2012 Elsevier B.V. |
BibTeX:
@article{Wang2012,
author = {Wang, Tao and Brender, Pierre and Ciais, Philippe and Piao, Shilong and Mahecha, Miguel D and Chevallier, Frédéric and Reichstein, Markus and Ottlé, Catherine and Maignan, Fabienne and Arain, Altaf and Bohrer, Gil and Cescatti, Alessandro and Kiely, Gerard and Law, Beverly Elizabeth and Lutz, Merbold and Montagnani, Leonardo and Moors, Eddy and Osborne, Bruce and Panferov, Oleg and Papale, Dario and Vaccari, Francesco Primo},
title = {State-dependent errors in a land surface model across biomes inferred from eddy covariance observations on multiple timescales},
journal = {Ecological Modelling},
year = {2012},
volume = {246},
number = {C},
pages = {11--25},
url = {http://linkinghub.elsevier.com/retrieve/pii/S0304380012003456},
doi = {10.1016/j.ecolmodel.2012.07.017}
}
|
| Bonan GB, Lawrence PJ, Oleson KW, Levis S, Jung M, Reichstein M, Lawrence DM and Swenson SC (2011), "Improving canopy processes in the Community Land Model version 4 (CLM4) using global flux fields empirically inferred from FLUXNET data", Journal of Geophysical Research., may, 2011. Vol. 116(G2) American Geophysical Union (AGU). |
| Abstract: The Community Land Model version 4 (CLM4) overestimates gross primary production (GPP) compared with data-driven estimates and other process models. We use global, spatially gridded GPP and latent heat flux upscaled from the FLUXNET network of eddy covariance towers to evaluate and improve canopy processes in CLM4. We investigate differences in GPP and latent heat flux arising from model parameterizations (termed model structural error) and from uncertainty in the photosynthetic parameter V(c max) (termed model parameter uncertainty). Model structural errors entail radiative transfer, leaf photosynthesis and stomatal conductance, and canopy scaling of leaf processes. Model structural revisions reduce global GPP over the period 1982-2004 from 165 Pg C yr(-1) to 130 Pg C yr(-1), and global evapotranspiration decreases from 68,000 km(3) yr(-1) to 65,000 km(3) yr(-1), within the uncertainty of FLUXNET-based estimates. Colimitation of photosynthesis is a cause of the improvements, as are revisions to photosynthetic parameters and their temperature dependency. Improvements are seen in all regions and seasonally over the course of the year. Similar improvements occur in latent heat flux. Uncertainty in V(c max) produces effects of comparable magnitude as model structural errors, but of offsetting sign. This suggests that model structural errors can be compensated by parameter adjustment, and this may explain the lack of consensus in values for V(c max) used in terrestrial biosphere models. Our analyses show that despite inherent uncertainties global flux fields empirically inferred from FLUXNET data are a valuable tool to guide terrestrial biosphere model development and evaluation. |
BibTeX:
@article{Bonan2011,
author = {Bonan, Gordon B. and Lawrence, Peter J. and Oleson, Keith W. and Levis, Samuel and Jung, Martin and Reichstein, Markus and Lawrence, David M. and Swenson, Sean C.},
title = {Improving canopy processes in the Community Land Model version 4 (CLM4) using global flux fields empirically inferred from FLUXNET data},
journal = {Journal of Geophysical Research},
publisher = {American Geophysical Union (AGU)},
year = {2011},
volume = {116},
number = {G2},
url = {https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2010JG001593 https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2010JG001593 https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2010JG001593},
doi = {10.1029/2010jg001593}
}
|
| Broquet G, Chevallier F, Rayner P, Aulagnier C, Pison I, Ramonet M, Schmidt M, Vermeulen AT and Ciais P (2011), "A European summertime CO2 biogenic flux inversion at mesoscale from continuous in situ mixing ratio measurements", Journal of Geophysical Research Atmospheres., dec, 2011. Vol. 116(23), pp. D23303. |
| Abstract: A regional variational inverse modeling system for the estimation of European biogenic CO2 fluxes is presented. This system is based on a 50 km horizontal resolution configuration of a mesoscale atmospheric transport model and on the adjoint of its tracer transport code. It exploits hourly CO2 in situ data from 15 CarboEurope-Integrated Project stations. Particular attention in the inversion setup is paid to characterizing the transport model error and to selecting the observations to be assimilated as a function of this error. Comparisons between simulations and data of CO 2 and 222Rn concentrations indicate that the model errors should have a standard deviation which is less than 7 ppm when simulating the hourly variability of CO2 at low altitude during the afternoon and evening or at high altitude at night. Synthetic data are used to estimate the uncertainty reduction for the fluxes using this inverse modeling system. The improvement brought by the inversion to the prior estimate of the fluxes for both the mean diurnal cycle and the monthly to synoptic variability in the fluxes and associated mixing ratios are checked against independent atmospheric data and eddy covariance flux measurements. Inverse modeling is conducted for summers 2002-2007 which should reduce the uncertainty in the biogenic fluxes by ∼60% during this period. The trend in the mean flux corrections between June and September is to increase the uptake of CO2 by ∼12 gCm -2. Corrections at higher resolution are also diagnosed that reveal some limitations of the underlying prior model of the terrestrial biosphere. Copyright 2011 by the American Geophysical Union. |
BibTeX:
@article{Broquet2011,
author = {Broquet, Grégoire and Chevallier, Frédéric and Rayner, Peter and Aulagnier, Céline and Pison, Isabelle and Ramonet, Michel and Schmidt, Martina and Vermeulen, Alex T and Ciais, Philippe},
title = {A European summertime CO2 biogenic flux inversion at mesoscale from continuous in situ mixing ratio measurements},
journal = {Journal of Geophysical Research Atmospheres},
year = {2011},
volume = {116},
number = {23},
pages = {D23303},
url = {http://doi.wiley.com/10.1029/2011JD016202},
doi = {10.1029/2011JD016202}
}
|
| Bruhn D, Mikkelsen TN, Herbst M, Kutsch WL, Ball MC and Pilegaard K (2011), "Estimating daytime ecosystem respiration from eddy-flux data", Biosystems., feb, 2011. Vol. 103(2), pp. 309-313. |
BibTeX:
@article{Bruhn2011,
author = {Bruhn, Dan and Mikkelsen, Teis N and Herbst, Mathias and Kutsch, Werner L and Ball, Marilyn C and Pilegaard, Kim},
title = {Estimating daytime ecosystem respiration from eddy-flux data},
journal = {Biosystems},
year = {2011},
volume = {103},
number = {2},
pages = {309--313},
url = {https://linkinghub.elsevier.com/retrieve/pii/S0303264710001814},
doi = {10.1016/j.biosystems.2010.10.007}
}
|
| Campioli M, Gielen B, Göckede M, Papale D, Bouriaud O and Granier A (2011), "Temporal variability of the NPP-GPP ratio at seasonal and interannual time scales in a temperate beech forest", Biogeosciences., sep, 2011. Vol. 8(9), pp. 2481-2492. |
| Abstract: The allocation of carbon (C) taken up by the tree canopy for respiration and production of tree organs with different construction and maintenance costs, life span and decomposition rate, crucially affects the residence time of C in forests and their C cycling rate. The carbon-use efficiency, or ratio between net primary production (NPP) and gross primary production (GPP), represents a convenient way to analyse the C allocation at the stand level. In this study, we extend the current knowledge on the NPP-GPP ratio in forests by assessing the temporal variability of the NPP-GPP ratio at interannual (for 8 years) and seasonal (for 1 year) scales for a young temperate beech stand, reporting dynamics for both leaves and woody organs, in particular stems. NPP was determined with biometric methods/litter traps, whereas the GPP was estimated via the eddy covariance micrometeorological technique. The interannual variability of the proportion of C allocated to leaf NPP, wood NPP and leaf plus wood NPP (on average 11% yr-1, 29% yr-1 and 39% yr-1, respectively) was significant among years with up to 12% yr-1 variation in NPP-GPP ratio. Studies focusing on the comparison of NPP-GPP ratio among forests and models using fixed allocation schemes should take into account the possibility of such relevant interannual variability. Multiple linear regressions indicated that the NPP-GPP ratio of leaves and wood significantly correlated with environmental conditions. Previous year drought and air temperature explained about half of the NPP-GPP variability of leaves and wood, respectively, whereas the NPP-GPP ratio was not decreased by severe drought, with large NPP-GPP ratio on 2003 due mainly to low GPP. During the period between early May and mid June, the majority of GPP was allocated to leaf and stem NPP, whereas these sinks were of little importance later on. Improved estimation of seasonal GPP and of the contribution of previous-year reserves to stem growth, as well as reduction of data uncertainty, will be of relevance to increase the accuracy of the seasonal assessment of the NPP-GPP ratio in forests. textcopyright Author(s) 2011. |
BibTeX:
@article{Campioli2011,
author = {Campioli, M and Gielen, B and Göckede, M and Papale, D and Bouriaud, O and Granier, A},
title = {Temporal variability of the NPP-GPP ratio at seasonal and interannual time scales in a temperate beech forest},
journal = {Biogeosciences},
year = {2011},
volume = {8},
number = {9},
pages = {2481--2492},
url = {http://www.biogeosciences.net/8/2481/2011/},
doi = {10.5194/bg-8-2481-2011}
}
|
| Chiti T, Certini G, Perugini L, Mastrolonardo G, Papale D and Valentini R (2011), "Soil carbon dynamics in a Mediterranean forest during the Kyoto Protocol commitment periods", Regional Environmental Change., jun, 2011. Vol. 11(2), pp. 371-376. |
| Abstract: The purpose of the present work is to asses the possibility of detecting changes in soil organic carbon (SOC) at the end of the 5-years of the first Commitment Period (CP) of the Kyoto Protocol of the United Nation's Framework Convention on Climate Change (1 January, 2008-31 December, 2012), by both direct measurement and the use of an opportunely evaluated SOC model, CENTURY. The investigated soil is young, developed since 28 years on virtually C-free spoil banks and under the influence of two managed forest stands, one a mix of English oak (Quercus robur L.) and Italian alder (Alnus cordata Loisel.) and the other pure English oak. The SOC stock of either stand was monitored since the time the stands were planted in 1981, and it was used together with other parameters for the model evaluation, while the future projections for the end of the first (2012) and second (2017) CP were made according to two extreme IPCC climatic scenarios: A1F1, the most dramatic, and B2, among the less impacting. Direct SOC measurements performed at the beginning and at the end of a time frame equivalent to a commitment period (2004-2008) had not shown significant variations in either stands. Compared to the 2008 SOC stock, in both stands the model shows variations at the end of the first CP from 0.7 to 1.8 Mg C ha-1 for the A1F1 scenario and from 0.3 to 1.7 Mg C ha-1 for the B2. These variations are within the standard deviations of the C stocks measured in 2008. On the contrary, at the end of the second CP, the modelled SOC increments range from 2.5 to 3.6 Mg C ha-1 (A1F1) or from 1.9 to 3.4 Mg C ha-1 (B2), indicating the possibility to detect the SOC changes by direct measurement, since the values well agree with the minimum detectable variation estimated for both sites in 3.3-4.5 Mg C ha-1. This work shows that SOC stock changes measured directly in the field can be minimal at the end of both CPs, and that CENTURY well simulates the SOC dynamics of the stands. The use of such a model, validated at long-term experimental sites, hence represents an effective tool for estimating future changes in SOC amounts in support of direct measurements when a short period of time, such as the CP, is considered. textcopyright 2010 Springer-Verlag. |
BibTeX:
@article{Chiti2011,
author = {Chiti, Tommaso and Certini, Giacomo and Perugini, Lucia and Mastrolonardo, Giovanni and Papale, Dario and Valentini, Riccardo},
title = {Soil carbon dynamics in a Mediterranean forest during the Kyoto Protocol commitment periods},
journal = {Regional Environmental Change},
year = {2011},
volume = {11},
number = {2},
pages = {371--376},
url = {http://link.springer.com/10.1007/s10113-010-0141-5},
doi = {10.1007/s10113-010-0141-5}
}
|
| Clarke N, Fischer R, de Vries W, Lundin L, Papale D, Vesala T, Merilä P, Matteucci G, Mirtl M, Simpson D and Paoletti E (2011), "Availability, accessibility, quality and comparability of monitoring data for European forests for use in air pollution and climate change science", IForest., aug, 2011. Vol. 4(AUGUST), pp. 162-166. |
| Abstract: Data from existing monitoring programmes such as ICP Forests, ICP Integrated Monitoring and EMEP, as well as from large-scale international projects such as CarboEurope IP and NitroEurope, can be used to answer questions about the impacts of air pollution and climate change on forest ecosystems and the feedbacks of forest to climate. However, for full use to be made of the available data, a number of questions need to be answered related to the availability, accessibility, quality and comparability of the data. For example, how can these databases be accessed, e.g., freely, over the internet, on request, by authorisation? How should intellectual property rights be protected, while improving access to data? What possibilities exist for harmonisation? Which quality assurance/quality control (QA/QC) procedures have been used and for how long? These and other relevant questions are discussed. textcopyright iForest - Biogeosciences and Forestry. |
BibTeX:
@article{Clarke2011,
author = {Clarke, Nicholas and Fischer, R and de Vries, W and Lundin, L and Papale, D and Vesala, T and Merilä, P and Matteucci, G and Mirtl, M and Simpson, D and Paoletti, E},
title = {Availability, accessibility, quality and comparability of monitoring data for European forests for use in air pollution and climate change science},
journal = {IForest},
year = {2011},
volume = {4},
number = {AUGUST},
pages = {162--166},
url = {http://www.sisef.it/iforest/?doi=10.3832/ifor0582-004},
doi = {10.3832/ifor0582-004}
}
|
| Corazza M, Bergamaschi P, Vermeulen AT, Aalto T, Haszpra L, Meinhardt F, O'Doherty S, Thompson R, Moncrieff J, Popa E, Steinbacher M, Jordan A, Dlugokencky E, Brühl C, Krol M and Dentener F (2011), "Inverse modelling of European N2O emissions: Assimilating observations from different networks", Atmospheric Chemistry and Physics., mar, 2011. Vol. 11(5), pp. 2381-2398. |
| Abstract: We describe the setup and first results of an inverse modelling system for atmospheric N2O, based on a four-dimensional variational (4DVAR) technique and the atmospheric transport zoom model TM5. We focus in this study on the European domain, utilizing a comprehensive set of quasi-continuous measurements over Europe, complemented by N2O measurements from the Earth System Research Laboratory of the National Oceanic and Atmospheric Administration (NOAA/ESRL) cooperative global air sampling network. Despite ongoing measurement comparisons among networks parallel measurements at a limited number of stations show that significant offsets exist among the different laboratories. Since the spatial gradients of N2O mixing ratios are of the same order of magnitude as these biases, the direct use of these biased datasets would lead to significant errors in the derived emissions. Therefore, in order to also use measurements with unknown offsets, a new bias correction scheme has been implemented within the TM5-4DVAR inverse modelling system, thus allowing the simultaneous assimilation of observations from different networks. The N2O bias corrections determined in the TM5-4DVAR system agree within ∼0.1 ppb (dry-air mole fraction) with the bias derived from the measurements at monitoring stations where parallel NOAA discrete air samples are available. The N2O emissions derived for the northwest European and east European countries for 2006 show good agreement with the bottom-up emission inventories reported to the United Nations Framework Convention on Climate Change (UNFCCC). Moreover, the inverse model can significantly narrow the uncertainty range reported in N2O emission inventories for these countries, while the lack of measurements does not allow to reduce the uncertainties of emission estimates in southern Europe. Several sensitivity experiments were performed to test the robustness of the results. It is shown that also inversions without detailed a priori spatio-temporal emission distributions are capable to reproduce major regional emission patterns within the footprint of the existing atmospheric network, demonstrating the strong constraints of the atmospheric observations on the derived emissions. textcopyright 2011 Author(s). |
BibTeX:
@article{Corazza2011,
author = {Corazza, M and Bergamaschi, P and Vermeulen, A T and Aalto, T and Haszpra, L and Meinhardt, F and O'Doherty, S and Thompson, R and Moncrieff, J and Popa, E and Steinbacher, M and Jordan, A and Dlugokencky, E and Brühl, C and Krol, M and Dentener, F},
title = {Inverse modelling of European N2O emissions: Assimilating observations from different networks},
journal = {Atmospheric Chemistry and Physics},
year = {2011},
volume = {11},
number = {5},
pages = {2381--2398},
url = {http://www.atmos-chem-phys.net/11/2381/2011/ http://www.atmos-chem-phys-discuss.net/10/26319/2010/},
doi = {10.5194/acp-11-2381-2011}
}
|
| Etzold S, Ruehr NK, Zweifel R, Dobbertin M, Zingg A, Pluess P, Häsler R, Eugster W and Buchmann N (2011), "The Carbon Balance of Two Contrasting Mountain Forest Ecosystems in Switzerland: Similar Annual Trends, but Seasonal Differences", Ecosystems., dec, 2011. Vol. 14(8), pp. 1289-1309. |
BibTeX:
@article{Etzold2011,
author = {Etzold, Sophia and Ruehr, Nadine K and Zweifel, Roman and Dobbertin, Matthias and Zingg, Andreas and Pluess, Peter and Häsler, Rudolf and Eugster, Werner and Buchmann, Nina},
title = {The Carbon Balance of Two Contrasting Mountain Forest Ecosystems in Switzerland: Similar Annual Trends, but Seasonal Differences},
journal = {Ecosystems},
year = {2011},
volume = {14},
number = {8},
pages = {1289--1309},
url = {http://link.springer.com/10.1007/s10021-011-9481-3},
doi = {10.1007/s10021-011-9481-3}
}
|
| Fischer R, Aas W, de Vries W, Clarke N, Cudlin P, Leaver D, Lundin L, Matteucci G, Matyssek R, Mikkelsen TN, Mirtl M, Öztürk Y, Papale D, Potocic N, Simpson D, Tuovinen JP, Vesala T, Wieser G and Paoletti E (2011), "Towards a transnational system of supersites for forest monitoring and research in Europe - An overview on present state and future recommendations", IForest., aug, 2011. Vol. 4(AUGUST), pp. 167-171. |
| Abstract: Science-based approaches in addressing future risks and challenges for forests require close collaboration among the communities operating different monitoring and research networks as well as experts in process and large-scale modelling. Results of the COST FP0903 conference which took place in October 2010 in Rome, reveal valuable results from different European forest monitoring and research networks. However, the need for closer integration of these activities is obvious. In this paper, representatives from major European networks recommend a new approach for forest monitoring and research in Europe, based on a reasonable number of highly instrumented "supersites" and a larger number of intensive monitoring plots linked to these. This system needs to be built on existing infrastructures but requires increased coordination, harmonisation and a joint long term platform for data exchange and modelling. textcopyright iForest - Biogeosciences and Forestry. |
BibTeX:
@article{Fischer2011,
author = {Fischer, Richard and Aas, W and de Vries, W and Clarke, N and Cudlin, P and Leaver, D and Lundin, L and Matteucci, G and Matyssek, R and Mikkelsen, T N and Mirtl, M and Öztürk, Y and Papale, D and Potocic, N and Simpson, D and Tuovinen, J P and Vesala, T and Wieser, G and Paoletti, E},
title = {Towards a transnational system of supersites for forest monitoring and research in Europe - An overview on present state and future recommendations},
journal = {IForest},
year = {2011},
volume = {4},
number = {AUGUST},
pages = {167--171},
url = {http://www.sisef.it/iforest/?doi=10.3832/ifor0584-004},
doi = {10.3832/ifor0584-004}
}
|
| Fisher RE, Sriskantharajah S, Lowry D, Lanoisellé M, Fowler CMR, James RH, Hermansen O, Lund Myhre C, Stohl A, Greinert J, Nisbet-Jones PBR, Mienert J and Nisbet EG (2011), "Arctic methane sources: Isotopic evidence for atmospheric inputs", Geophysical Research Letters., nov, 2011. Vol. 38(21), pp. n/a-n/a. |
| Abstract: By comparison of the methane mixing ratio and the carbon isotope ratio (δsup13/supCinfCH4/inf) in Arctic air with regional background, the incremental input of CHinf4/inf in an air parcel and the source δsup13/supCinfCH4/inf signature can be determined. Using this technique the bulk Arctic CHinf4/inf source signature of air arriving at Spitsbergen in late summer 2008 and 2009 was found to be-68‰, indicative of the dominance of a biogenic CHinf4/inf0020source. This is close to the source signature of CHinf4/inf emissions from boreal wetlands. In spring, when wetland was frozen, the CHinf4/inf source signature was more enriched in sup13/supC at-53 ± 6‰ with air mass back trajectories indicating a large influence from gas field emissions in the Ob River region. Emissions of CHinf4/inf to the water column from the seabed on the Spitsbergen continental slope are occurring but none has yet been detected reaching the atmosphere. The measurements illustrate the significance of wetland emissions. Potentially, these may respond quickly and powerfully to meteorological variations and to sustained climate warming. Copyright 2011 by the American Geophysical Union. |
BibTeX:
@article{Fisher2011,
author = {Fisher, R E and Sriskantharajah, S and Lowry, D and Lanoisellé, M and Fowler, C M R and James, R H and Hermansen, O and Lund Myhre, C and Stohl, A and Greinert, J and Nisbet-Jones, P B R and Mienert, J and Nisbet, E G},
title = {Arctic methane sources: Isotopic evidence for atmospheric inputs},
journal = {Geophysical Research Letters},
year = {2011},
volume = {38},
number = {21},
pages = {n/a--n/a},
url = {http://doi.wiley.com/10.1029/2011GL049319},
doi = {10.1029/2011GL049319}
}
|
| Flechard CR, Nemitz E, Smith RI, Fowler D, Vermeulen AT, Bleeker A, Erisman JW, Simpson D, Zhang L, Tang YS and Sutton MA (2011), "Dry deposition of reactive nitrogen to European ecosystems: a comparison of inferential models across the NitroEurope network", Atmospheric Chemistry and Physics., mar, 2011. Vol. 11(6), pp. 2703-2728. |
| Abstract: pAbstract. Inferential models have long been used to determine pollutant dry deposition to ecosystems from measurements of air concentrations and as part of national and regional atmospheric chemistry and transport models, and yet models still suffer very large uncertainties. An inferential network of 55 sites throughout Europe for atmospheric reactive nitrogen (Nr) was established in 2007, providing ambient concentrations of gaseous NH3, NO2, HNO3 and HONO and aerosol NH4+ and NO3âˆ' as part of the NitroEurope Integrated Project. Network results providing modelled inorganic Nr dry deposition to the 55 monitoring sites are presented, using four existing dry deposition routines, revealing inter-model differences and providing ensemble average deposition estimates. Dry deposition is generally largest over forests in regions with large ambient NH3 concentrations, exceeding 30–40 kg N haâˆ'1 yrâˆ'1 over parts of the Netherlands and Belgium, while some remote forests in Scandinavia receive less than 2 kg N haâˆ'1 yrâˆ'1. Turbulent Nr deposition to short vegetation ecosystems is generally smaller than to forests due to reduced turbulent exchange, but also because NH3 inputs to fertilised, agricultural systems are limited by the presence of a substantial NH3 source in the vegetation, leading to periods of emission as well as deposition. Differences between models reach a factor 2–3 and are often greater than differences between monitoring sites. For soluble Nr gases such as NH3 and HNO3, the non-stomatal pathways are responsible for most of the annual uptake over many surfaces, especially the non-agricultural land uses, but parameterisations of the sink strength vary considerably among models. For aerosol NH4+ and NO3âˆ' discrepancies between theoretical models and field flux measurements lead to much uncertainty in dry deposition rates for fine particles (0.1–0.5 μm). The validation of inferential models at the ecosystem scale is best achieved by comparison with direct long-term micrometeorological Nr flux measurements, but too few such datasets are available, especially for HNO3 and aerosol NH4+ and NO3âˆ'./p |
BibTeX:
@article{Flechard2011,
author = {Flechard, C R and Nemitz, E and Smith, R I and Fowler, D and Vermeulen, A T and Bleeker, A and Erisman, J W and Simpson, D and Zhang, L and Tang, Y S and Sutton, M A},
title = {Dry deposition of reactive nitrogen to European ecosystems: a comparison of inferential models across the NitroEurope network},
journal = {Atmospheric Chemistry and Physics},
year = {2011},
volume = {11},
number = {6},
pages = {2703--2728},
url = {https://www.atmos-chem-phys.net/11/2703/2011/},
doi = {10.5194/acp-11-2703-2011}
}
|
| Francez A-J, Pinay G, Josselin N and Williams BL (2011), "Denitrification triggered by nitrogen addition in Sphagnum magellanicum peat", Biogeochemistry., nov, 2011. Vol. 106(3), pp. 435-441. |
BibTeX:
@article{Francez2011,
author = {Francez, André-Jean and Pinay, Gilles and Josselin, Nathalie and Williams, Berwyn L},
title = {Denitrification triggered by nitrogen addition in Sphagnum magellanicum peat},
journal = {Biogeochemistry},
year = {2011},
volume = {106},
number = {3},
pages = {435--441},
url = {http://link.springer.com/10.1007/s10533-010-9523-5},
doi = {10.1007/s10533-010-9523-5}
}
|
| Gielen B, Neirynck J, Luyssaert S and Janssens IA (2011), "The importance of dissolved organic carbon fluxes for the carbon balance of a temperate Scots pine forest", Agricultural and Forest Meteorology., mar, 2011. Vol. 151(3), pp. 270-278. |
BibTeX:
@article{Gielen2011,
author = {Gielen, B and Neirynck, J and Luyssaert, S and Janssens, I A},
title = {The importance of dissolved organic carbon fluxes for the carbon balance of a temperate Scots pine forest},
journal = {Agricultural and Forest Meteorology},
year = {2011},
volume = {151},
number = {3},
pages = {270--278},
url = {https://linkinghub.elsevier.com/retrieve/pii/S016819231000287X},
doi = {10.1016/j.agrformet.2010.10.012}
}
|
| Goerner A, Reichstein M, Tomelleri E, Hanan N, Rambal S, Papale D, Dragoni D and Schmullius C (2011), "Remote sensing of ecosystem light use efficiency with MODIS-based PRI", Biogeosciences., jan, 2011. Vol. 8(1), pp. 189-202. |
| Abstract: Several studies sustained the possibility that a photochemical reflectance index (PRI) directly obtained from satellite data can be used as a proxy for ecosystem light use efficiency (LUE) in diagnostic models of gross primary productivity. This modelling approach would avoid the complications that are involved in using meteorological data as constraints for a fixed maximum LUE. However, no unifying model predicting LUE across climate zones and time based on MODIS PRI has been published to date. In this study, we evaluate the effectiveness with which MODIS-based PRI can be used to estimate ecosystem light use efficiency at study sites of different plant functional types and vegetation densities. Our objective is to examine if known limitations such as dependence on viewing and illumination geometry can be overcome and a single PRI-based model of LUE (i.e. based on the same reference band) can be applied under a wide range of conditions. Furthermore, we were interested in the effect of using different faPAR (fraction of absorbed photosynthetically active radiation) products on the in-situ LUE used as ground truth and thus on the whole evaluation exercise. We found that estimating LUE at site-level based on PRI reduces uncertainty compared to the approaches relying on a maximum LUE reduced by minimum temperature and vapour pressure deficit. Despite the advantages of using PRI to estimate LUE at site-level, we could not establish an universally applicable light use efficiency model based on MODIS PRI. Models that were optimised for a pool of data from several sites did not perform well. textcopyright Author(s) 2011. |
BibTeX:
@article{Goerner2011,
author = {Goerner, A and Reichstein, M and Tomelleri, E and Hanan, N and Rambal, S and Papale, D and Dragoni, D and Schmullius, C},
title = {Remote sensing of ecosystem light use efficiency with MODIS-based PRI},
journal = {Biogeosciences},
year = {2011},
volume = {8},
number = {1},
pages = {189--202},
url = {http://www.biogeosciences.net/8/189/2011/},
doi = {10.5194/bg-8-189-2011}
}
|
| Huotari J, Ojala A, Peltomaa E, Nordbo A, Launiainen S, Pumpanen J, Rasilo T, Hari P and Vesala T (2011), "Long-term direct CO2 flux measurements over a boreal lake: Five years of eddy covariance data", Geophysical Research Letters., sep, 2011. Vol. 38(18) Blackwell Publishing Ltd. |
| Abstract: Significant amounts of terrestrial carbon are processed in lakes and emitted into the atmosphere as CO2. However, due to lack of appropriate measurements the absolute role of lakes in the landscape as sinks or sources of CO2 is still uncertain. We conducted the first long-term, ecosystem-level CO2 flux measurements with eddy covariance technique in a boreal lake within a natural-state catchment covering 5 years. The aim was to reveal the natural level of CO2 flux between a lake and the atmosphere and its role in regional carbon cycling. On average, the lake emitted ca 10% of the terrestrial net ecosystem production of the surrounding old-growth forest and the main immediate drivers behind the fluxes were physical rather than biological. Our results suggest that lakes are an integral part of terrestrial carbon cycling. Copyright 2011 by the American Geophysical Union. |
BibTeX:
@article{Huotari2011,
author = {Huotari, Jussi and Ojala, Anne and Peltomaa, Elina and Nordbo, Annika and Launiainen, Samuli and Pumpanen, Jukka and Rasilo, Terhi and Hari, Pertti and Vesala, Timo},
title = {Long-term direct CO2 flux measurements over a boreal lake: Five years of eddy covariance data},
journal = {Geophysical Research Letters},
publisher = {Blackwell Publishing Ltd},
year = {2011},
volume = {38},
number = {18},
doi = {10.1029/2011GL048753}
}
|
| KINDLER R, SIEMENS JAN, KAISER K, WALMSLEY DC, BERNHOFER C, BUCHMANN N, CELLIER P, EUGSTER W, GLEIXNER G, GRŨNWALD T, HEIM A, IBROM A, JONES SK, JONES M, KLUMPP K, KUTSCH W, LARSEN KS, LEHUGER S, LOUBET B, MCKENZIE R, MOORS E, OSBORNE B, PILEGAARD KIM, REBMANN C, SAUNDERS M, SCHMIDT MWI, SCHRUMPF M, SEYFFERTH J, SKIBA UTE, SOUSSANA J-F, SUTTON MA, TEFS C, VOWINCKEL B, ZEEMAN MJ and KAUPENJOHANN M (2011), "Dissolved carbon leaching from soil is a crucial component of the net ecosystem carbon balance", Global Change Biology., feb, 2011. Vol. 17(2), pp. 1167-1185. |
BibTeX:
@article{KINDLER2011,
author = {KINDLER, REIMO and SIEMENS, J A N and KAISER, KLAUS and WALMSLEY, DAVID C and BERNHOFER, CHRISTIAN and BUCHMANN, NINA and CELLIER, PIERRE and EUGSTER, WERNER and GLEIXNER, GERD and GRŨNWALD, THOMAS and HEIM, ALEXANDER and IBROM, ANDREAS and JONES, STEPHANIE K and JONES, MIKE and KLUMPP, KATJA and KUTSCH, WERNER and LARSEN, KLAUS STEENBERG and LEHUGER, SIMON and LOUBET, BENJAMIN and MCKENZIE, REBECCA and MOORS, EDDY and OSBORNE, BRUCE and PILEGAARD, K I M and REBMANN, CORINNA and SAUNDERS, MATTHEW and SCHMIDT, MICHAEL W I and SCHRUMPF, MARION and SEYFFERTH, JANINE and SKIBA, U T E and SOUSSANA, JEAN-FRANCOIS and SUTTON, MARK A and TEFS, CINDY and VOWINCKEL, BERNHARD and ZEEMAN, MATTHIAS J and KAUPENJOHANN, MARTIN},
title = {Dissolved carbon leaching from soil is a crucial component of the net ecosystem carbon balance},
journal = {Global Change Biology},
year = {2011},
volume = {17},
number = {2},
pages = {1167--1185},
url = {http://doi.wiley.com/10.1111/j.1365-2486.2010.02282.x},
doi = {10.1111/j.1365-2486.2010.02282.x}
}
|
| Levin I, Hammer S, Eichelmann E and Vogel FR (2011), "Verification of greenhouse gas emission reductions: The prospect of atmospheric monitoring in polluted areas", Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences., may, 2011. Vol. 369(1943), pp. 1906-1924. |
| Abstract: Independent verification of greenhouse gas emissions reporting is a legal requirement of the Kyoto Protocol, which has not yet been fully accomplished. Here, we show that dedicated long-term atmospheric measurements of greenhouse gases, such as carbon dioxide (CO2) and methane (CH4), continuously conducted at polluted sites can provide the necessary tool for this undertaking. From our measurements at the semi-polluted Heidelberg site in the upper Rhine Valley, we find that in the catchment area CH4 emissions decreased on average by 32 ± 6% from the second half of the 1990s until the first half of the 2000s, but the observed long-term trend of emissions is considerably smaller than that previously reported for southwest Germany. In contrast, regional fossil fuel CO2 levels, estimated from high-precision 14CO2 observations, do not show any significant decreasing trend since 1986, in agreement with the reported emissions for this region. In order to provide accurate verification, these regional measurements would best be accompanied by adequate atmospheric transport modelling as required to precisely determine the relevant catchment area of the measurements. Furthermore, reliable reconciliation of reported emissions will only be possible if these are known at high spatial resolution in the catchment area of the observations. This information should principally be available in all countries that regularly report their greenhouse gas emissions to the United Nations Framework Convention on Climate Change. textcopyright 2011 The Royal Society. |
BibTeX:
@article{Levin2011,
author = {Levin, Ingeborg and Hammer, Samuel and Eichelmann, Elke and Vogel, Felix R.},
title = {Verification of greenhouse gas emission reductions: The prospect of atmospheric monitoring in polluted areas},
journal = {Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences},
year = {2011},
volume = {369},
number = {1943},
pages = {1906--1924},
doi = {10.1098/rsta.2010.0249}
}
|
| Limpens J, Granath G, Gunnarsson U, Aerts R, Bayley S, Bragazza L, Bubier J, Buttler A, van den Berg LJL, Francez A-J, Gerdol R, Grosvernier P, Heijmans MMPD, Hoosbeek MR, Hotes S, Ilomets M, Leith I, Mitchell EAD, Moore T, Nilsson MB, Nordbakken J-F, Rochefort L, Rydin H, Sheppard LJ, Thormann M, Wiedermann MM, Williams BL and Xu B (2011), "Climatic modifiers of the response to nitrogen deposition in peat-forming iSphagnum/i mosses: a meta-analysis", New Phytologist., jul, 2011. Vol. 191(2), pp. 496-507. |
BibTeX:
@article{Limpens2011,
author = {Limpens, J and Granath, G and Gunnarsson, U and Aerts, R and Bayley, S and Bragazza, L and Bubier, J and Buttler, A and van den Berg, L J L and Francez, A-J. and Gerdol, R and Grosvernier, P and Heijmans, M M P D and Hoosbeek, M R and Hotes, S and Ilomets, M and Leith, I and Mitchell, E A D and Moore, T and Nilsson, M B and Nordbakken, J-F. and Rochefort, L and Rydin, H and Sheppard, L J and Thormann, M and Wiedermann, M M and Williams, B L and Xu, B},
title = {Climatic modifiers of the response to nitrogen deposition in peat-forming iSphagnum/i mosses: a meta-analysis},
journal = {New Phytologist},
year = {2011},
volume = {191},
number = {2},
pages = {496--507},
url = {http://doi.wiley.com/10.1111/j.1469-8137.2011.03680.x},
doi = {10.1111/j.1469-8137.2011.03680.x}
}
|
| Masarie KA, Pétron G, Andrews A, Bruhwiler L, Conway TJ, Jacobson AR, Miller JB, Tans PP, Worthy DE and Peters W (2011), "Impact of CO2 measurement bias on CarbonTracker surface flux estimates", Journal of Geophysical Research Atmospheres., sep, 2011. Vol. 116(17), pp. D17305. |
| Abstract: For over 20 years, atmospheric measurements of CO2 dry air mole fractions have been used to derive estimates of CO2 surface fluxes. Historically, only a few research laboratories made these measurements. Today, many laboratories are making CO2 observations using a variety of analysis techniques and, in some instances, using different calibration scales. As a result, the risk of biases in individual CO2 mole fraction records, or even in complete monitoring networks, has increased over the last decades. Ongoing experiments comparing independent, well-calibrated measurements of atmospheric CO2 show that biases can and do exist between measurement records. Biases in measurements create artificial spatial and temporal CO2 gradients, which are then interpreted by an inversion system, leading to erroneous flux estimates. Here we evaluate the impact of a constant bias introduced into the National Oceanic and Atmospheric Administration (NOAA) quasi-continuous measurement record at the Park Falls, Wisconsin (LEF), tall tower site on CarbonTracker flux estimates. We derive a linear relationship between the magnitude of the introduced bias at LEF and the CarbonTracker surface flux responses. Temperate North American net flux estimates are most sensitive to a bias at LEF in our CarbonTracker inversion, and its linear response rate is 68 Tg C yr-1 (∼10% of the estimated North American annual terrestrial uptake) for every 1 ppm of bias in the LEF record. This sensitivity increases when (1) measurement biases approached assumed model errors and (2) fewer other measurement records are available to anchor the flux estimates despite the presence of bias in one record. Flux estimate errors are also calculated beyond North America. For example, biospheric uptake in Europe and boreal Eurasia combined increases by 25 Tg C yr-1 per ppm CO2 to partially compensate for changes in the North American flux totals. These results illustrate the importance of well-calibrated, high-precision CO2 dry air mole fraction measurements, as well as the value of an effective strategy for detecting bias in measurements. This study stresses the need for a monitoring network with the necessary density to anchor regional, continental, and hemispheric fluxes more tightly and to lessen the impact of potentially undetected biases in observational networks operated by different national and international research programs. Copyright 2011 by the American Geophysical Union. |
BibTeX:
@article{Masarie2011,
author = {Masarie, K A and Pétron, G and Andrews, A and Bruhwiler, L and Conway, T J and Jacobson, A R and Miller, J B and Tans, P P and Worthy, D E and Peters, W},
title = {Impact of CO2 measurement bias on CarbonTracker surface flux estimates},
journal = {Journal of Geophysical Research Atmospheres},
year = {2011},
volume = {116},
number = {17},
pages = {D17305},
url = {http://doi.wiley.com/10.1029/2011JD016270},
doi = {10.1029/2011JD016270}
}
|
| Migliavacca M, Reichstein M, Richardson AD, Colombo R, Sutton MA, Lasslop G, Tomelleri E, Wohlfahrt G, Carvalhais N, Cescatti A, Mahecha MD, Montagnani L, Papale D, Zaehle S, Arain A, Arneth A, Black TA, Carrara A, Dore S, Gianelle D, Helfter C, Hollinger D, Kutsch WL, Lafleur PM, Nouvellon Y, Rebmann C, Humberto R, Rodeghiero M, Roupsard O, Sebastià MT, Seufert G, Soussana JF and Van Der Molen MK (2011), "Semiempirical modeling of abiotic and biotic factors controlling ecosystem respiration across eddy covariance sites", Global Change Biology., jan, 2011. Vol. 17(1), pp. 390-409. |
| Abstract: In this study we examined ecosystem respiration (RECO) data from 104 sites belonging to FLUXNET, the global network of eddy covariance flux measurements. The goal was to identify the main factors involved in the variability of RECO: temporally and between sites as affected by climate, vegetation structure and plant functional type (PFT) (evergreen needleleaf, grasslands, etc.). We demonstrated that a model using only climate drivers as predictors of RECOfailed to describe part of the temporal variability in the data and that the dependency on gross primary production (GPP) needed to be included as an additional driver of RECO. The maximum seasonal leaf area index (LAIMAX) had an additional effect that explained the spatial variability of reference respiration (the respiration at reference temperature Tref=15 °C, without stimulation introduced by photosynthetic activity and without water limitations), with a statistically significant linear relationship (r2=0.52, P0.001, n=104) even within each PFT. Besides LAIMAX, we found that reference respiration may be explained partially by total soil carbon content (SoilC). For undisturbed temperate and boreal forests a negative control of total nitrogen deposition (Ndepo) on reference respiration was also identified. We developed a new semiempirical model incorporating abiotic factors (climate), recent productivity (daily GPP), general site productivity and canopy structure (LAIMAX) which performed well in predicting the spatio-temporal variability of RECO, explaining 70% of the variance for most vegetation types. Exceptions include tropical and Mediterranean broadleaf forests and deciduous broadleaf forests. Part of the variability in respiration that could not be described by our model may be attributed to a series of factors, including phenology in deciduous broadleaf forests and management practices in grasslands and croplands. textcopyright 2010 Blackwell Publishing Ltd. |
BibTeX:
@article{Migliavacca2011,
author = {Migliavacca, Mirco and Reichstein, Markus and Richardson, Andrew D and Colombo, Roberto and Sutton, Mark A and Lasslop, Gitta and Tomelleri, Enrico and Wohlfahrt, Georg and Carvalhais, Nuno and Cescatti, Alessandro and Mahecha, Miguel D and Montagnani, Leonardo and Papale, Dario and Zaehle, Sönke and Arain, Altaf and Arneth, Almut and Black, T Andrew and Carrara, Arnaud and Dore, Sabina and Gianelle, Damiano and Helfter, Carole and Hollinger, David and Kutsch, Werner L and Lafleur, Peter M and Nouvellon, Yann and Rebmann, Corinna and Humberto, R and Rodeghiero, Mirco and Roupsard, Olivier and Sebastià, Maria Teresa and Seufert, Guenther and Soussana, Jean Francoise and Van Der Molen, Michiel K},
title = {Semiempirical modeling of abiotic and biotic factors controlling ecosystem respiration across eddy covariance sites},
journal = {Global Change Biology},
year = {2011},
volume = {17},
number = {1},
pages = {390--409},
url = {http://doi.wiley.com/10.1111/j.1365-2486.2010.02243.x},
doi = {10.1111/j.1365-2486.2010.02243.x}
}
|
| Pan Y, Birdsey RA, Fang J, Houghton R, Kauppi PE, Kurz WA, Phillips OL, Shvidenko A, Lewis SL, Canadell JG, Ciais P, Jackson RB, Pacala SW, McGuire AD, Piao S, Rautiainen A, Sitch S and Hayes D (2011), "A Large and Persistent Carbon Sink in the World's Forests", Science., aug, 2011. Vol. 333(6045), pp. 988-993. |
BibTeX:
@article{Pan2011,
author = {Pan, Y and Birdsey, R A and Fang, J and Houghton, R and Kauppi, P E and Kurz, W A and Phillips, O L and Shvidenko, A and Lewis, S L and Canadell, J G and Ciais, P and Jackson, R B and Pacala, S W and McGuire, A D and Piao, S and Rautiainen, A and Sitch, S and Hayes, D},
title = {A Large and Persistent Carbon Sink in the World's Forests},
journal = {Science},
year = {2011},
volume = {333},
number = {6045},
pages = {988--993},
url = {https://www.sciencemag.org/lookup/doi/10.1126/science.1201609},
doi = {10.1126/science.1201609}
}
|
| Peylin P, Houweling S, Krol MC, Karstens U, Rödenbeck C, Geels C, Vermeulen A, Badawy B, Aulagnier C, Pregger T, Delage F, Pieterse G, Ciais P and Heimann M (2011), "Importance of fossil fuel emission uncertainties over Europe for CO2 modeling: Model intercomparison", Atmospheric Chemistry and Physics., jul, 2011. Vol. 11(13), pp. 6607-6622. |
| Abstract: Inverse modeling techniques used to quantify surface carbon fluxes commonly assume that the uncertainty of fossil fuel CO2 (FFCO2) emissions is negligible and that intra-annual variations can be neglected. To investigate these assumptions, we analyzed the differences between four fossil fuel emission inventories with spatial and temporal differences over Europe and their impact on the model simulated CO2 concentration. Large temporal flux variations characterize the hourly fields (∼40 % and ∼80 % for the seasonal and diurnal cycles, peak-to-peak) and annual country totals differ by 10 % on average and up to 40 % for some countries (i.e., the Netherlands). These emissions have been prescribed to seven different transport models, resulting in 28 different FFCO2 concentrations fields. The modeled FFCO 2 concentration time series at surface sites using time-varying emissions show larger seasonal cycles (+2 ppm at the Hungarian tall tower (HUN)) and smaller diurnal cycles in summer (ÄÌ‚'1 ppm at HUN) than when using constant emissions. The concentration range spanned by all simulations varies between stations, and is generally larger in winter (up to ∼10 ppm peak-to-peak at HUN) than in summer (∼5 ppm). The contribution of transport model differences to the simulated concentration std-dev is 2-3 times larger than the contribution of emission differences only, at typical European sites used in global inversions. These contributions to the hourly (monthly) std-dev's amount to ∼1.2 (0.8) ppm and ∼0.4 (0.3) ppm for transport and emissions, respectively. First comparisons of the modeled concentrations with 14C-based fossil fuel CO2 observations show that the large transport differences still hamper a quantitative evaluation/validation of the emission inventories. Changes in the estimated monthly biosphere flux (Fbio) over Europe, using two inverse modeling approaches, are relatively small (less that 5 %) while changes in annual Fbio (up to ∼0.15 % GtC yr-1) are only slightly smaller than the differences in annual emission totals and around 30 % of the mean European ecosystem carbon sink. These results point to an urgent need to improve not only the transport models but also the assumed spatial and temporal distribution of fossil fuel emission inventories. textcopyright 2011 Author(s). |
BibTeX:
@article{Peylin2011,
author = {Peylin, P and Houweling, S and Krol, M C and Karstens, U and Rödenbeck, C and Geels, C and Vermeulen, A and Badawy, B and Aulagnier, C and Pregger, T and Delage, F and Pieterse, G and Ciais, P and Heimann, M},
title = {Importance of fossil fuel emission uncertainties over Europe for CO2 modeling: Model intercomparison},
journal = {Atmospheric Chemistry and Physics},
year = {2011},
volume = {11},
number = {13},
pages = {6607--6622},
url = {http://www.atmos-chem-phys.net/11/6607/2011/},
doi = {10.5194/acp-11-6607-2011}
}
|
| Popa ME, Vermeulen AT, Van Den Bulk WCM, Jongejan PAC, Batenburg AM, Zahorowski W and Röckmann T (2011), "H2 vertical profiles in the continental boundary layer: Measurements at the Cabauw tall tower in the Netherlands", Atmospheric Chemistry and Physics., jul, 2011. Vol. 11(13), pp. 6425-6443. |
| Abstract: In-situ, quasi-continuous measurements of atmospheric hydrogen (H 2) have been performed since October 2007 at the Cabauw tall tower station in the Netherlands. Mole fractions of H2, CO and several greenhouse gases are determined simultaneously in air sampled successively at four heights, between 20 and 200 m above ground level. 222Rn measurements are performed in air sampled at 20 and 200 m. This H2 dataset represents the first in-situ, quasi-continuous long-term measurement series of vertical profiles of H2 in the lower continental boundary layer. Seasonal cycles are present at all heights in both H2 and CO, and their amplitude varies with the sampling height. The seasonality is evident in both the baseline values and in the short term (diurnal to synoptic time scales) variability, the latter being significantly larger during winter. The observed H2 short term signals and vertical gradients are in many cases well correlated to other species, especially to CO. On the other hand, H2 has at times a unique behaviour, due to its particular distribution of sources and sinks. Our estimation for the regional H2 soil uptake flux, using the radon tracer method, is (1.89 ± 0.26) × 10 5 g/(m2 h), significantly smaller than other recent results from Europe. H2/CO ratios of the traffic emissions computed from our data, with an average of 0.54 ± 0.07 mol:mol, are larger and more variable than estimated in some of the previous studies in Europe. This difference can be explained by a different driving regime, due to the frequent traffic jams in the influence area of Cabauw. The H2/CO ratios of the large scale pollution events have an average of 0.36 ± 0.05 mol:mol; these ratios were observed to slightly increase with sampling height, possibly due to a stronger influence of soil uptake at the lower sampling heights. textcopyright 2011 Author(s). |
BibTeX:
@article{Popa2011,
author = {Popa, M E and Vermeulen, A T and Van Den Bulk, W C M and Jongejan, P A C and Batenburg, A M and Zahorowski, W and Röckmann, T},
title = {H2 vertical profiles in the continental boundary layer: Measurements at the Cabauw tall tower in the Netherlands},
journal = {Atmospheric Chemistry and Physics},
year = {2011},
volume = {11},
number = {13},
pages = {6425--6443},
url = {http://www.atmos-chem-phys.net/11/6425/2011/},
doi = {10.5194/acp-11-6425-2011}
}
|
| Sulkava M, Luyssaert S, Zaehle S and Papale D (2011), "Assessing and improving the representativeness of monitoring networks: The European flux tower network example", Journal of Geophysical Research: Biogeosciences., may, 2011. Vol. 116(2), pp. G00J04. |
| Abstract: It is estimated that more than 500 eddy covariance sites are operated globally, providing unique information about carbon and energy exchanges between terrestrial ecosystems and the atmosphere. These sites are often organized in regional networks like CarboEurope-IP, which has evolved over the last 15 years without following a predefined network design. Data collected by these networks are used for a wide range of applications. In this context, the representativeness of the current network is an important aspect to consider in order to correctly interpret the results and to quantify uncertainty. This paper proposes a cluster-based tool for quantitative network design, which was developed in order to suggest the best network for a defined number of sites or to assess the representativeness of an existing network to address the scientific question of interest. The paper illustrates how the tool can be used to assess the performance of the current CarboEurope-IP network and to improve its design. The tool was tested and validated with modeled European GPP data as the target variable and by using an empirical upscaling method (Artificial Neural Network (ANN)) to assess the improvements in the ANN prediction with different design scenarios and for different scientific questions, ranging from a simple average GPP of Europe to spatial, temporal, and spatiotemporal variability. The results show how quantitative network design could improve the predictive capacity of the ANN. However, the analysis also reveals a fundamental shortcoming of optimized networks, namely their poor capacity to represent the spatial variability of the fluxes. Copyright 2011 by the American Geophysical Union. |
BibTeX:
@article{Sulkava2011,
author = {Sulkava, Mika and Luyssaert, Sebastiaan and Zaehle, Sönke and Papale, Dario},
title = {Assessing and improving the representativeness of monitoring networks: The European flux tower network example},
journal = {Journal of Geophysical Research: Biogeosciences},
year = {2011},
volume = {116},
number = {2},
pages = {G00J04},
url = {http://doi.wiley.com/10.1029/2010JG001562},
doi = {10.1029/2010JG001562}
}
|
| Van der Molen MK, Dolman AJ, Ciais P, Eglin T, Gobron N, Law BE, Meir P, Peters W, Phillips OL, Reichstein M, Chen T, Dekker SC, Doubková M, Friedl MA, Jung M, van den Hurk BJJM, de Jeu RAM, Kruijt B, Ohta T, Rebel KT, Plummer S, Seneviratne SI, Sitch S, Teuling AJ, van der Werf GR and Wang G (2011), "Drought and ecosystem carbon cycling", Agricultural and Forest Meteorology., jul, 2011. Vol. 151(7), pp. 765-773. |
| Abstract: Drought as an intermittent disturbance of the water cycle interacts with the carbon cycle differently than the 'gradual' climate change. During drought plants respond physiologically and structurally to prevent excessive water loss according to species-specific water use strategies. This has consequences for carbon uptake by photosynthesis and release by total ecosystem respiration. After a drought the disturbances in the reservoirs of moisture, organic matter and nutrients in the soil and carbohydrates in plants lead to longer-term effects in plant carbon cycling, and potentially mortality. Direct and carry-over effects, mortality and consequently species competition in response to drought are strongly related to the survival strategies of species. Here we review the state of the art of the understanding of the relation between soil moisture drought and the interactions with the carbon cycle of the terrestrial ecosystems. We argue that plant strategies must be given an adequate role in global vegetation models if the effects of drought on the carbon cycle are to be described in a way that justifies the interacting processes. textcopyright 2011 Elsevier B.V. |
BibTeX:
@article{VanderMolen2011,
author = {Van der Molen, M K and Dolman, A J and Ciais, P and Eglin, T and Gobron, N and Law, B E and Meir, P and Peters, W and Phillips, O L and Reichstein, M and Chen, T and Dekker, S C and Doubková, M and Friedl, M A and Jung, M and van den Hurk, B J J M and de Jeu, R A M and Kruijt, B and Ohta, T and Rebel, K T and Plummer, S and Seneviratne, S I and Sitch, S and Teuling, A J and van der Werf, G R and Wang, G},
title = {Drought and ecosystem carbon cycling},
journal = {Agricultural and Forest Meteorology},
year = {2011},
volume = {151},
number = {7},
pages = {765--773},
url = {http://linkinghub.elsevier.com/retrieve/pii/S0168192311000517},
doi = {10.1016/j.agrformet.2011.01.018}
}
|
| Vermeulen AT, Hensen A, Popa ME, Van Den Bulk WCM and Jongejan PAC (2011), "Greenhouse gas observations from Cabauw Tall Tower (1992-2010)", Atmospheric Measurement Techniques., mar, 2011. Vol. 4(3), pp. 617-644. |
| Abstract: Since 1992 semi-continuous in-situ observations of greenhouse gas concentrations have been performed at the tall tower of Cabauw (4.927° E, 51.971° N, -0.7 m a.s.l.). Through 1992 up to now, the measurement system has been gradually extended and improved in precision, starting with CO 2 and CH 4 concentrations from 200 m a.g.l. in 1992 to vertical gradients at 4 levels of the gases CO 2, CH 4, SF 6, N 2O, H 2, CO and gradients at 2 levels for 222Rn. In this paper the measurement systems and measurement results are described for the main greenhouse gases and CO, for the whole period. The automatic measurement system now provides half-hourly concentration gradients with a precision better than or close to the WMO recommendations. The observations at Cabauw show a complex pattern caused by the influence of sources and sinks from a large area around the tower with significant contributions of sources and sinks at distances up to 500-700 km. The concentration footprint area of Cabauw is one the most intensive and complex source areas of greenhouse gases in the world. Despite this, annual mean trends for the most important greenhouse gases, compatible with the values derived using the global network, can be reproduced from the measured concentrations at Cabauw over the entire measurement period, with a measured increase in the period 2000-2009 for CO 2 of 1.90 ± 0.1 ppm yr -1, for CH 4 of 4.4 ± 0.6 ppb yr -1, for N 2O of 0.86 ± 0.04 ppb yr -1, and for SF 6 of 0.27 ± 0.01 ppt yr -1; for CO no significant trend could be detected. The influences of strong local sources and sinks are reflected in the amplitude of the mean seasonal cycles observed at Cabauw, that are larger than the mean Northern Hemisphere average; Cabauw mean seasonal amplitude for CO 2 is 25-30 ppm (higher value for lower sampling levels). The observed CH 4 seasonal amplitude is 50-110 ppb. All gases except N 2O show highest concentrations in winter and lower concentrations in summer, N 2O observations show two additional concentration maxima in early summer and in autumn. Seasonal cycles of the day-time mean concentrations show that surface concentrations or high elevation concentrations alone do not give a representative value for the boundary layer concentrations, especially in winter time, but that the vertical profile data along the mast can be used to construct a useful boundary layer mean value. The variability at Cabauw in the atmospheric concentrations of CO 2 on time scales of minutes to hours is several ppm and is much larger than the precision of the measurements (0.1 ppm). The diurnal and synoptical variability of the concentrations at Cabauw carry information on the sources and sinks in the footprint area of the mast, that will be useful in combination with inverse atmospheric transport model to verify emission estimates and improve ecosystem models. For this purpose a network of tall tower stations like Cabauw forms a very useful addition to the existing global observing network for greenhouse gases. textcopyright Author(s) 2011. |
BibTeX:
@article{Vermeulen2011,
author = {Vermeulen, A T and Hensen, A and Popa, M E and Van Den Bulk, W C M and Jongejan, P A C},
title = {Greenhouse gas observations from Cabauw Tall Tower (1992-2010)},
journal = {Atmospheric Measurement Techniques},
year = {2011},
volume = {4},
number = {3},
pages = {617--644},
url = {http://www.atmos-meas-tech.net/4/617/2011/},
doi = {10.5194/amt-4-617-2011}
}
|
| Arnold D, Vargas A, Vermeulen AT, Verheggen B and Seibert P (2010), "Analysis of radon origin by backward atmospheric transport modelling", Atmospheric Environment., feb, 2010. Vol. 44(4), pp. 494-502. Elsevier Ltd. |
| Abstract: This work shows how ambient radon concentrations measured at Cabauw station in central Netherlands are influenced by transport from different regions under typical transport conditions occurring during April and November, 2007 by means of atmospheric Lagrangian particle dispersion modelling in a receptor-oriented approach. Four specific regions have been isolated to assess their contribution to the modelled radon ambient concentrations at Cabauw, and two different radon flux assumptions. Westerly flows coming from the ocean are poor in radon and do not increase radon air concentrations unless there is some fetch over the British Isles. Continental transport, mainly from eastern and southern Europe, significantly increases radon background concentrations, reaching increments of 3 Bq m-3. A constant 0.66 atoms cm-2 s-1 radon flux over land and zero over water bodies is a good approximation for the source term in order to study regional contributions and modulation of the radon background. textcopyright 2009 Elsevier Ltd. All rights reserved. |
BibTeX:
@article{Arnold2010,
author = {Arnold, D and Vargas, A and Vermeulen, A T and Verheggen, B and Seibert, P},
title = {Analysis of radon origin by backward atmospheric transport modelling},
journal = {Atmospheric Environment},
publisher = {Elsevier Ltd},
year = {2010},
volume = {44},
number = {4},
pages = {494--502},
url = {http://linkinghub.elsevier.com/retrieve/pii/S1352231009009339},
doi = {10.1016/j.atmosenv.2009.11.003}
}
|
| Aubinet M, Feigenwinter C, Heinesch B, Bernhofer C, Canepa E, Lindroth A, Montagnani L, Rebmann C, Sedlak P and Van Gorsel E (2010), "Direct advection measurements do not help to solve the night-time CO2 closure problem: Evidence from three different forests", Agricultural and Forest Meteorology., may, 2010. Vol. 150(5), pp. 655-664. |
BibTeX:
@article{Aubinet2010,
author = {Aubinet, M and Feigenwinter, C and Heinesch, B and Bernhofer, C and Canepa, E and Lindroth, A and Montagnani, L and Rebmann, C and Sedlak, P and Van Gorsel, E},
title = {Direct advection measurements do not help to solve the night-time CO2 closure problem: Evidence from three different forests},
journal = {Agricultural and Forest Meteorology},
year = {2010},
volume = {150},
number = {5},
pages = {655--664},
url = {https://linkinghub.elsevier.com/retrieve/pii/S0168192310000390},
doi = {10.1016/j.agrformet.2010.01.016}
}
|
| Beer C, Reichstein M, Tomelleri E, Ciais P, Jung M, Carvalhais N, Rödenbeck C, Arain MA, Baldocchi D, Bonan GB, Bondeau A, Cescatti A, Lasslop G, Lindroth A, Lomas M, Luyssaert S, Margolis H, Oleson KW, Roupsard O, Veenendaal E, Viovy N, Williams C, Woodward FI and Papale D (2010), "Terrestrial gross carbon dioxide uptake: Global distribution and covariation with climate", Science., aug, 2010. Vol. 329(5993), pp. 834-838. |
| Abstract: Terrestrial gross primary production (GPP) is the largest global CO 2 flux driving several ecosystem functions. We provide an observation-based estimate of this flux at 123 ± 8 petagrams of carbon per year (Pg C year-1) using eddy covariance flux data and various diagnostic models. Tropical forests and savannahs account for 60%. GPP over 40% of the vegetated land is associated with precipitation. State-of-the-art process-oriented biosphere models used for climate predictions exhibit a large between-model variation of GPP's latitudinal patterns and show higher spatial correlations between GPP and precipitation, suggesting the existence of missing processes or feedback mechanisms which attenuate the vegetation response to climate. Our estimates of spatially distributed GPP and its covariation with climate can help improve coupled climate-carbon cycle process models. |
BibTeX:
@article{Beer2010,
author = {Beer, Christian and Reichstein, Markus and Tomelleri, Enrico and Ciais, Philippe and Jung, Martin and Carvalhais, Nuno and Rödenbeck, Christian and Arain, M Altaf and Baldocchi, Dennis and Bonan, Gordon B and Bondeau, Alberte and Cescatti, Alessandro and Lasslop, Gitta and Lindroth, Anders and Lomas, Mark and Luyssaert, Sebastiaan and Margolis, Hank and Oleson, Keith W and Roupsard, Olivier and Veenendaal, Elmar and Viovy, Nicolas and Williams, Christopher and Woodward, F Ian and Papale, Dario},
title = {Terrestrial gross carbon dioxide uptake: Global distribution and covariation with climate},
journal = {Science},
year = {2010},
volume = {329},
number = {5993},
pages = {834--838},
url = {http://www.sciencemag.org/cgi/doi/10.1126/science.1184984},
doi = {10.1126/science.1184984}
}
|
| Bergamaschi P, Krol M, Meirink JF, Dentener F, Segers A, Van Aardenne J, Monni S, Vermeulen AT, Schmidt M, Ramonet M, Yver C, Meinhardt F, Nisbet EG, Fisher RE, O'Doherty S and Dlugokencky EJ (2010), "Inverse modeling of European CH4 emissions 2001-2006", Journal of Geophysical Research Atmospheres., nov, 2010. Vol. 115(22), pp. D22309. |
| Abstract: European CH4 emissions are estimated for the period 2001-2006 using a four-dimensional variational (4DVAR) inverse modeling system, based on the atmospheric zoom model TM5. Continuous observations are used from various European monitoring stations, complemented by European and global flask samples from the NOAA/ESRL network. The available observations mainly provide information on the emissions from northwest Europe (NWE), including the UK, Ireland, the BENELUX countries, France and Germany. The inverse modeling estimates for the total anthropogenic emissions from NWE are 21% higher compared to the EDGARv4.0 emission inventory and 40% higher than values reported to U.N. Framework Convention on Climate Change. Assuming overall uncertainties on the order of 30% for both bottom-up and top-down estimates, all three estimates can be still considered to be consistent with each other. However, the uncertainties in the uncertainty estimates prevent us from verifying (or falsifying) the bottom-up inventories in a strict sense. Sensitivity studies show some dependence of the derived spatial emission patterns on the set of atmospheric monitoring stations used, but the total emissions for the NWE countries appear to be relatively robust. While the standard inversions include a priori information on the spatial and temporal emission patterns from bottom-up inventories, a further sensitivity inversion without this a priori information results in very similar NWE country totals, demonstrating that the available observations provide significant constraints on the emissions from the NWE countries independent from bottom-up inventories. textcopyright Copyright 2010 by the American Geophysical Union. |
BibTeX:
@article{Bergamaschi2010,
author = {Bergamaschi, P and Krol, M and Meirink, J F and Dentener, F and Segers, A and Van Aardenne, J and Monni, S and Vermeulen, A T and Schmidt, M and Ramonet, M and Yver, C and Meinhardt, F and Nisbet, E G and Fisher, R E and O'Doherty, S and Dlugokencky, E J},
title = {Inverse modeling of European CH4 emissions 2001-2006},
journal = {Journal of Geophysical Research Atmospheres},
year = {2010},
volume = {115},
number = {22},
pages = {D22309},
url = {http://doi.wiley.com/10.1029/2010JD014180},
doi = {10.1029/2010JD014180}
}
|
| Burkhardt J (2010), "Hygroscopic particles on leaves: nutrients or desiccants?", Ecological Monographs., aug, 2010. Vol. 80(3), pp. 369-399. |
BibTeX:
@article{Burkhardt2010,
author = {Burkhardt, Juergen},
title = {Hygroscopic particles on leaves: nutrients or desiccants?},
journal = {Ecological Monographs},
year = {2010},
volume = {80},
number = {3},
pages = {369--399},
url = {http://doi.wiley.com/10.1890/09-1988.1},
doi = {10.1890/09-1988.1}
}
|
| Ceschia E, Béziat P, Dejoux JF, Aubinet M, Bernhofer C, Bodson B, Buchmann N, Carrara A, Cellier P, Di Tommasi P, Elbers JA, Eugster W, Grünwald T, Jacobs CMJ, Jans WWP, Jones M, Kutsch W, Lanigan G, Magliulo E, Marloie O, Moors EJ, Moureaux C, Olioso A, Osborne B, Sanz MJ, Saunders M, Smith P, Soegaard H and Wattenbach M (2010), "Management effects on net ecosystem carbon and GHG budgets at European crop sites", Agriculture, Ecosystems & Environment., nov, 2010. Vol. 139(3), pp. 363-383. |
BibTeX:
@article{Ceschia2010,
author = {Ceschia, E and Béziat, P and Dejoux, J F and Aubinet, M and Bernhofer, Ch. and Bodson, B and Buchmann, N and Carrara, A and Cellier, P and Di Tommasi, P and Elbers, J A and Eugster, W and Grünwald, T and Jacobs, C M J and Jans, W W P and Jones, M and Kutsch, W and Lanigan, G and Magliulo, E and Marloie, O and Moors, E J and Moureaux, C and Olioso, A and Osborne, B and Sanz, M J and Saunders, M and Smith, P and Soegaard, H and Wattenbach, M},
title = {Management effects on net ecosystem carbon and GHG budgets at European crop sites},
journal = {Agriculture, Ecosystems & Environment},
year = {2010},
volume = {139},
number = {3},
pages = {363--383},
url = {https://linkinghub.elsevier.com/retrieve/pii/S0167880910002537},
doi = {10.1016/j.agee.2010.09.020}
}
|
| Chevallier F, Ciais P, Conway TJ, Aalto T, Anderson BE, Bousquet P, Brunke EG, Ciattaglia L, Esaki Y, Fröhlich M, Gomez A, Gomez-Pelaez AJ, Haszpra L, Krummel PB, Langenfelds RL, Leuenberger M, MacHida T, Maignan F, Matsueda H, Morguí JA, Mukai H, Nakazawa T, Peylin P, Ramonet M, Rivier L, Sawa Y, Schmidt M, Steele LP, Vay SA, Vermeulen AT, Wofsy S and Worthy D (2010), "CO2 surface fluxes at grid point scale estimated from a global 21 year reanalysis of atmospheric measurements", Journal of Geophysical Research Atmospheres., nov, 2010. Vol. 115(21), pp. D21307. |
| Abstract: This paper documents a global Bayesian variational inversion of CO 2 surface fluxes during the period 1988-2008. Weekly fluxes are estimated on a 3.75 × 2.5 (longitude-latitude) grid throughout the 21 years. The assimilated observations include 128 station records from three large data sets of surface CO2 mixing ratio measurements. A Monte Carlo approach rigorously quantifies the theoretical uncertainty of the inverted fluxes at various space and time scales, which is particularly important for proper interpretation of the inverted fluxes. Fluxes are evaluated indirectly against two independent CO2 vertical profile data sets constructed from aircraft measurements in the boundary layer and in the free troposphere. The skill of the inversion is evaluated by the improvement brought over a simple benchmark flux estimation based on the observed atmospheric growth rate. Our error analysis indicates that the carbon budget from the inversion should be more accurate than the a priori carbon budget by 20% to 60% for terrestrial fluxes aggregated at the scale of subcontinental regions in the Northern Hemisphere and over a year, but the inversion cannot clearly distinguish between the regional carbon budgets within a continent. On the basis of the independent observations, the inversion is seen to improve the fluxes compared to the benchmark: the atmospheric simulation of CO2 with the Bayesian inversion method is better by about 1 ppm than the benchmark in the free troposphere, despite possible systematic transport errors. The inversion achieves this improvement by changing the regional fluxes over land at the seasonal and at the interannual time scales. Copyright textcopyright 2010 by the American Geophysical Union. |
BibTeX:
@article{Chevallier2010,
author = {Chevallier, F and Ciais, P and Conway, T J and Aalto, T and Anderson, B E and Bousquet, P and Brunke, E G and Ciattaglia, L and Esaki, Y and Fröhlich, M and Gomez, A and Gomez-Pelaez, A J and Haszpra, L and Krummel, P B and Langenfelds, R L and Leuenberger, M and MacHida, T and Maignan, F and Matsueda, H and Morguí, J A and Mukai, H and Nakazawa, T and Peylin, P and Ramonet, M and Rivier, L and Sawa, Y and Schmidt, M and Steele, L P and Vay, S A and Vermeulen, A T and Wofsy, S and Worthy, D},
title = {CO2 surface fluxes at grid point scale estimated from a global 21 year reanalysis of atmospheric measurements},
journal = {Journal of Geophysical Research Atmospheres},
year = {2010},
volume = {115},
number = {21},
pages = {D21307},
url = {http://doi.wiley.com/10.1029/2010JD013887},
doi = {10.1029/2010JD013887}
}
|
| Ciais P, Canadell JG, Luyssaert S, Chevallier F, Shvidenko A, Poussi Z, Jonas M, Peylin P, King AW, Schulze E-D, Piao S, Rödenbeck C, Peters W and Bréon F-M (2010), "Can we reconcile atmospheric estimates of the Northern terrestrial carbon sink with land-based accounting?", Current Opinion in Environmental Sustainability., oct, 2010. Vol. 2(4), pp. 225-230. |
BibTeX:
@article{Ciais2010,
author = {Ciais, Philippe and Canadell, Josep G and Luyssaert, Sebastiaan and Chevallier, Frédéric and Shvidenko, Anatoly and Poussi, Zegbeu and Jonas, Matthias and Peylin, Philippe and King, Anthony Wayne and Schulze, Ernest-Detlef and Piao, Shilong and Rödenbeck, Christian and Peters, Wouter and Bréon, François-Marie},
title = {Can we reconcile atmospheric estimates of the Northern terrestrial carbon sink with land-based accounting?},
journal = {Current Opinion in Environmental Sustainability},
year = {2010},
volume = {2},
number = {4},
pages = {225--230},
url = {https://linkinghub.elsevier.com/retrieve/pii/S1877343510000539},
doi = {10.1016/j.cosust.2010.06.008}
}
|
| DEZI S, MEDLYN BE, TONON G and MAGNANI F (2010), "The effect of nitrogen deposition on forest carbon sequestration: a model-based analysis", Global Change Biology., may, 2010. Vol. 16(5), pp. 1470-1486. |
BibTeX:
@article{DEZI2010,
author = {DEZI, S and MEDLYN, B E and TONON, G and MAGNANI, F},
title = {The effect of nitrogen deposition on forest carbon sequestration: a model-based analysis},
journal = {Global Change Biology},
year = {2010},
volume = {16},
number = {5},
pages = {1470--1486},
url = {http://doi.wiley.com/10.1111/j.1365-2486.2009.02102.x},
doi = {10.1111/j.1365-2486.2009.02102.x}
}
|
| DINSMORE KJ, BILLETT MF, SKIBA UTEM, REES RM, DREWER J and HELFTER C (2010), "Role of the aquatic pathway in the carbon and greenhouse gas budgets of a peatland catchment", Global Change Biology., oct, 2010. Vol. 16(10), pp. 2750-2762. |
BibTeX:
@article{DINSMORE2010,
author = {DINSMORE, KERRY J and BILLETT, MICHAEL F and SKIBA, U T E M and REES, ROBERT M and DREWER, JULIA and HELFTER, CAROLE},
title = {Role of the aquatic pathway in the carbon and greenhouse gas budgets of a peatland catchment},
journal = {Global Change Biology},
year = {2010},
volume = {16},
number = {10},
pages = {2750--2762},
url = {http://doi.wiley.com/10.1111/j.1365-2486.2009.02119.x},
doi = {10.1111/j.1365-2486.2009.02119.x}
}
|
| Drewer J, Lohila A, Aurela M, Laurila T, Minkkinen K, Penttilä T, Dinsmore KJ, McKenzie RM, Helfter C, Flechard C, Sutton MA and Skiba UM (2010), "Comparison of greenhouse gas fluxes and nitrogen budgets from an ombotrophic bog in Scotland and a minerotrophic sedge fen in Finland", European Journal of Soil Science., oct, 2010. Vol. 61(5), pp. 640-650. |
BibTeX:
@article{Drewer2010,
author = {Drewer, J and Lohila, A and Aurela, M and Laurila, T and Minkkinen, K and Penttilä, T and Dinsmore, K J and McKenzie, R M and Helfter, C and Flechard, C and Sutton, M A and Skiba, U M},
title = {Comparison of greenhouse gas fluxes and nitrogen budgets from an ombotrophic bog in Scotland and a minerotrophic sedge fen in Finland},
journal = {European Journal of Soil Science},
year = {2010},
volume = {61},
number = {5},
pages = {640--650},
url = {http://doi.wiley.com/10.1111/j.1365-2389.2010.01267.x},
doi = {10.1111/j.1365-2389.2010.01267.x}
}
|
| Etzold S, Buchmann N and Eugster W (2010), "Contribution of advection to the carbon budget measured by eddy covariance at a steep mountain slope forest in Switzerland", Biogeosciences., aug, 2010. Vol. 7(8), pp. 2461-2475. |
| Abstract: pAbstract. We calculated the contribution of advection to the C budget measured by the eddy covariance (EC) technique for a steep and forested mountain site (CarboEurope site CH-Lae, Lägeren, Switzerland) during the growing season 2007 (May to August). Thereby we followed two approaches: (1) the physical correction of the EC data for directly measured advection terms and (2) the u∗ filter approach that replaces periods with u∗ below a site-specific threshold with empirically modelled fluxes. We found good agreement between the two approaches in terms of daily (linear regression slope: 0.78 ± 0.04, intercept: 0.68 ± 0.29 μmol mâˆ'2 sâˆ'1, adj. R2=0.78) and seasonal sums of gross fluxes (difference ≤ 12%), when using a u∗ threshold of 0.3 m sâˆ'1 and correcting EC for horizontal advection only. Incorporating also vertical advection into the mass balance equation resulted in unrealistic and highly erratic fluxes. However, on a daily basis vertical advection cancelled out to nearly zero. The u∗ filter seems to account primarily for respiration fluxes, which are mainly affected by horizontal advection. We could confirm our corrections by a cross-validation with independent approaches, such as soil respiration chamber measurements, light curves and energy budget closure. Our results show that flux measurements on steep sites with complex topography are possible. Actually, sloping sites seem to have the advantage over flat sites that advection measurements can be reduced to a simplified two-dimensional measurement approach due to the two-dimensional characteristics of the wind field at those sites./p |
BibTeX:
@article{Etzold2010,
author = {Etzold, S and Buchmann, N and Eugster, W},
title = {Contribution of advection to the carbon budget measured by eddy covariance at a steep mountain slope forest in Switzerland},
journal = {Biogeosciences},
year = {2010},
volume = {7},
number = {8},
pages = {2461--2475},
url = {https://www.biogeosciences.net/7/2461/2010/},
doi = {10.5194/bg-7-2461-2010}
}
|
| Eugster W, Moffat AM, Ceschia E, Aubinet M, Ammann C, Osborne B, Davis PA, Smith P, Jacobs C, Moors E, Le Dantec V, Béziat P, Saunders M, Jans W, Grünwald T, Rebmann C, Kutsch WL, Czerný R, Janouš D, Moureaux C, Dufranne D, Carrara A, Magliulo V, Di Tommasi P, Olesen JE, Schelde K, Olioso A, Bernhofer C, Cellier P, Larmanou E, Loubet B, Wattenbach M, Marloie O, Sanz M-J, Søgaard H and Buchmann N (2010), "Management effects on European cropland respiration", Agriculture, Ecosystems & Environment., nov, 2010. Vol. 139(3), pp. 346-362. |
BibTeX:
@article{Eugster2010,
author = {Eugster, Werner and Moffat, Antje M and Ceschia, Eric and Aubinet, Marc and Ammann, Christof and Osborne, Bruce and Davis, Phillip A and Smith, Pete and Jacobs, Cor and Moors, Eddy and Le Dantec, Valérie and Béziat, Pierre and Saunders, Matthew and Jans, Wilma and Grünwald, Thomas and Rebmann, Corinna and Kutsch, Werner L and Czerný, Radek and Janouš, Dalibor and Moureaux, Christine and Dufranne, Delphine and Carrara, Arnaud and Magliulo, Vincenzo and Di Tommasi, Paul and Olesen, Jørgen E and Schelde, Kirsten and Olioso, Albert and Bernhofer, Christian and Cellier, Pierre and Larmanou, Eric and Loubet, Benjamin and Wattenbach, Martin and Marloie, Olivier and Sanz, Maria-José and Søgaard, Henrik and Buchmann, Nina},
title = {Management effects on European cropland respiration},
journal = {Agriculture, Ecosystems & Environment},
year = {2010},
volume = {139},
number = {3},
pages = {346--362},
url = {https://linkinghub.elsevier.com/retrieve/pii/S0167880910002197},
doi = {10.1016/j.agee.2010.09.001}
}
|
| Garbulsky MF, Peñuelas J, Papale D, Ardö J, Goulden ML, Kiely G, Richardson AD, Rotenberg E, Veenendaal EM and Filella I (2010), "Patterns and controls of the variability of radiation use efficiency and primary productivity across terrestrial ecosystems", Global Ecology and Biogeography., mar, 2010. Vol. 19(2), pp. 253-267. |
| Abstract: Aim: The controls of gross radiation use efficiency (RUE), the ratio between gross primary productivity (GPP) and the radiation intercepted by terrestrial vegetation, and its spatial and temporal variation are not yet fully understood. Our objectives were to analyse and synthesize the spatial variability of GPP and the spatial and temporal variability of RUE and its climatic controls for a wide range of vegetation types. Location: A global range of sites from tundra to rain forest. Methods: We analysed a global dataset on photosynthetic uptake and climatic variables from 35 eddy covariance (EC) flux sites spanning between 100 and 2200 mm mean annual rainfall and between -13 and 26°C mean annual temperature. RUE was calculated from the data provided by EC flux sites and remote sensing (MODIS). Results: Rainfall and actual evapotranspiration (AET) positively influenced the spatial variation of annual GPP, whereas temperature only influenced the GPP of forests. Annual and maximum RUE were also positively controlled primarily by annual rainfall. The main control parameters of the growth season variation of gross RUE varied for each ecosystem type. Overall, the ratio between actual and potential evapotranspiration and a surrogate for the energy balance explained a greater proportion of the seasonal variation of RUE than the vapour pressure deficit (VPD), AET and precipitation. Temperature was important for determining the intra-annual variability of the RUE at the coldest energy-limited sites. Main conclusions: Our analysis supports the idea that the annual functioning of vegetation that is adapted to its local environment is more constrained by water availability than by temperature. The spatial variability of annual and maximum RUE can be largely explained by annual precipitation, more than by vegetation type. The intra-annual variation of RUE was mainly linked to the energy balance and water availability along the climatic gradient. Furthermore, we showed that intra-annual variation of gross RUE is only weakly influenced by VPD and temperature, contrary to what is frequently assumed. Our results provide a better understanding of the spatial and temporal controls of the RUE and thus could lead to a better estimation of ecosystem carbon fixation and better modelling. textcopyright 2009 Blackwell Publishing Ltd. |
BibTeX:
@article{Garbulsky2010,
author = {Garbulsky, Martín F and Peñuelas, Josep and Papale, Dario and Ardö, Jonas and Goulden, Michael L and Kiely, Gerard and Richardson, Andrew D and Rotenberg, Eyal and Veenendaal, Elmar M and Filella, Iolanda},
title = {Patterns and controls of the variability of radiation use efficiency and primary productivity across terrestrial ecosystems},
journal = {Global Ecology and Biogeography},
year = {2010},
volume = {19},
number = {2},
pages = {253--267},
url = {http://doi.wiley.com/10.1111/j.1466-8238.2009.00504.x},
doi = {10.1111/j.1466-8238.2009.00504.x}
}
|
| Jans WWP, Jacobs CMJ, Kruijt B, Elbers JA, Barendse S and Moors EJ (2010), "Carbon exchange of a maize (Zea mays L.) crop: Influence of phenology", Agriculture, Ecosystems & Environment., nov, 2010. Vol. 139(3), pp. 316-324. |
BibTeX:
@article{Jans2010,
author = {Jans, Wilma W P and Jacobs, Cor M J and Kruijt, Bart and Elbers, Jan A and Barendse, Suzanne and Moors, Eddy J},
title = {Carbon exchange of a maize (Zea mays L.) crop: Influence of phenology},
journal = {Agriculture, Ecosystems & Environment},
year = {2010},
volume = {139},
number = {3},
pages = {316--324},
url = {https://linkinghub.elsevier.com/retrieve/pii/S0167880910001623},
doi = {10.1016/j.agee.2010.06.008}
}
|
| Janssens IA, Dieleman W, Luyssaert S, Subke JA, Reichstein M, Ceulemans R, Ciais P, Dolman AJ, Grace J, Matteucci G, Papale D, Piao SL, Schulze ED, Tang J and Law BE (2010), "Reduction of forest soil respiration in response to nitrogen deposition", Nature Geoscience., may, 2010. Vol. 3(5), pp. 315-322. |
| Abstract: The use of fossil fuels and fertilizers has increased the amount of biologically reactive nitrogen in the atmosphere over the past century. As a consequence, forests in industrialized regions have experienced greater rates of nitrogen deposition in recent decades. This unintended fertilization has stimulated forest growth, but has also affected soil microbial activity, and thus the recycling of soil carbon and nutrients. A meta-analysis suggests that nitrogen deposition impedes organic matter decomposition, and thus stimulates carbon sequestration, in temperate forest soils where nitrogen is not limiting microbial growth. The concomitant reduction in soil carbon emissions is substantial, and equivalent in magnitude to the amount of carbon taken up by trees owing to nitrogen fertilization. As atmospheric nitrogen levels continue to rise, increased nitrogen deposition could spread to older, more weathered soils, as found in the tropics; however, soil carbon cycling in tropical forests cannot yet be assessed. textcopyright 2010 Macmillan Publishers Limited. |
BibTeX:
@article{Janssens2010,
author = {Janssens, I A and Dieleman, W and Luyssaert, S and Subke, J A and Reichstein, M and Ceulemans, R and Ciais, P and Dolman, A J and Grace, J and Matteucci, G and Papale, D and Piao, S L and Schulze, E D and Tang, J and Law, B E},
title = {Reduction of forest soil respiration in response to nitrogen deposition},
journal = {Nature Geoscience},
year = {2010},
volume = {3},
number = {5},
pages = {315--322},
url = {http://www.nature.com/articles/ngeo844},
doi = {10.1038/ngeo844}
}
|
| Jung M, Reichstein M, Ciais P, Seneviratne SI, Sheffield J, Goulden ML, Bonan G, Cescatti A, Chen J, De Jeu R, Dolman AJ, Eugster W, Gerten D, Gianelle D, Gobron N, Heinke J, Kimball J, Law BE, Montagnani L, Mu Q, Mueller B, Oleson K, Papale D, Richardson AD, Roupsard O, Running S, Tomelleri E, Viovy N, Weber U, Williams C, Wood E, Zaehle S and Zhang K (2010), "Recent decline in the global land evapotranspiration trend due to limited moisture supply", Nature., oct, 2010. Vol. 467(7318), pp. 951-954. |
| Abstract: More than half of the solar energy absorbed by land surfaces is currently used to evaporate water. Climate change is expected to intensify the hydrological cycle and to alter evapotranspiration, with implications for ecosystem services and feedback to regional and global climate. Evapotranspiration changes may already be under way, but direct observational constraints are lacking at the global scale. Until such evidence is available, changes in the water cycle on land-a key diagnostic criterion of the effects of climate change and variability-remain uncertain. Here we provide a data-driven estimate of global land evapotranspiration from 1982 to 2008, compiled using a global monitoring network, meteorological and remote-sensing observations, and a machine-learning algorithm. In addition, we have assessed evapotranspiration variations over the same time period using an ensemble of process-based land-surface models. Our results suggest that global annual evapotranspiration increased on average by 7.1 ± 1.0 millimetres per year per decade from 1982 to 1997. After that, coincident with the last major El Ni±o event in 1998, the global evapotranspiration increase seems to have ceased until 2008. This change was driven primarily by moisture limitation in the Southern Hemisphere, particularly Africa and Australia. In these regions, microwave satellite observations indicate that soil moisture decreased from 1998 to 2008. Hence, increasing soil-moisture limitations on evapotranspiration largely explain the recent decline of the global land-evapotranspiration trend. Whether the changing behaviour of evapotranspiration is representative of natural climate variability or reflects a more permanent reorganization of the land water cycle is a key question for earth system science. textcopyright 2010 Macmillan Publishers Limited. All rights reserved. |
BibTeX:
@article{Jung2010,
author = {Jung, Martin and Reichstein, Markus and Ciais, Philippe and Seneviratne, Sonia I and Sheffield, Justin and Goulden, Michael L and Bonan, Gordon and Cescatti, Alessandro and Chen, Jiquan and De Jeu, Richard and Dolman, A Johannes and Eugster, Werner and Gerten, Dieter and Gianelle, Damiano and Gobron, Nadine and Heinke, Jens and Kimball, John and Law, Beverly E and Montagnani, Leonardo and Mu, Qiaozhen and Mueller, Brigitte and Oleson, Keith and Papale, Dario and Richardson, Andrew D and Roupsard, Olivier and Running, Steve and Tomelleri, Enrico and Viovy, Nicolas and Weber, Ulrich and Williams, Christopher and Wood, Eric and Zaehle, Sönke and Zhang, Ke},
title = {Recent decline in the global land evapotranspiration trend due to limited moisture supply},
journal = {Nature},
year = {2010},
volume = {467},
number = {7318},
pages = {951--954},
url = {http://www.nature.com/articles/nature09396},
doi = {10.1038/nature09396}
}
|
| Kroon PS, Hensen A, Jonker HJJ, Ouwersloot HG, Vermeulen AT and Bosveld FC (2010), "Uncertainties in eddy covariance flux measurements assessed from CH4 and N2O observations", Agricultural and Forest Meteorology., jun, 2010. Vol. 150(6), pp. 806-816. Elsevier B.V.. |
| Abstract: The uncertainty in eddy covariance (EC) flux measurements is assessed for CH4 and N2O using data measured at a dairy farm site in the Netherlands in 2006 and 2007. An overview is given of the contributing uncertainties and their magnitude. The relative and absolute uncertainty of a 30min EC flux are estimated for CH4 and N2O using N=2185 EC fluxes. The average absolute uncertainty and its standard deviation are 500±400ng Cm-2s-1 for CH4 and 100±100ng Nm-2s-1 for N2O. The corresponding relative uncertainties have 95% confidence interval ranging from 20% to 300% for CH4 and from 30% to 1800% for N2O. The large relative uncertainties correspond to relatively small EC fluxes. The uncertainties are mainly caused by the uncertainty due to one-point sampling which contributes on average more than 90% to the total uncertainty. The other 10% includes the uncertainty in the correction algorithm for the systematic errors. The uncertainty in a daily and monthly averaged EC flux are estimated for several flux magnitude ranges. The daily and monthly average uncertainty are smaller than 25% and 10% for CH4 and smaller than 50% and 10% for N2O, respectively, based on fluxes larger than 100ng Cm-2s-1 and 15ng Nm-2s-1. textcopyright 2009 Elsevier B.V. |
BibTeX:
@article{Kroon2010,
author = {Kroon, P S and Hensen, A and Jonker, H J J and Ouwersloot, H G and Vermeulen, A T and Bosveld, F C},
title = {Uncertainties in eddy covariance flux measurements assessed from CH4 and N2O observations},
journal = {Agricultural and Forest Meteorology},
publisher = {Elsevier B.V.},
year = {2010},
volume = {150},
number = {6},
pages = {806--816},
url = {http://linkinghub.elsevier.com/retrieve/pii/S0168192309002160},
doi = {10.1016/j.agrformet.2009.08.008}
}
|
| Kutsch WL, Aubinet M, Buchmann N, Smith P, Osborne B, Eugster W, Wattenbach M, Schrumpf M, Schulze ED, Tomelleri E, Ceschia E, Bernhofer C, Béziat P, Carrara A, Di Tommasi P, Grünwald T, Jones M, Magliulo V, Marloie O, Moureaux C, Olioso A, Sanz MJ, Saunders M, Søgaard H and Ziegler W (2010), "The net biome production of full crop rotations in Europe", Agriculture, Ecosystems & Environment., nov, 2010. Vol. 139(3), pp. 336-345. |
BibTeX:
@article{Kutsch2010,
author = {Kutsch, W L and Aubinet, M and Buchmann, N and Smith, P and Osborne, B and Eugster, W and Wattenbach, M and Schrumpf, M and Schulze, E D and Tomelleri, E and Ceschia, E and Bernhofer, C and Béziat, P and Carrara, A and Di Tommasi, P and Grünwald, T and Jones, M and Magliulo, V and Marloie, O and Moureaux, C and Olioso, A and Sanz, M J and Saunders, M and Søgaard, H and Ziegler, W},
title = {The net biome production of full crop rotations in Europe},
journal = {Agriculture, Ecosystems & Environment},
year = {2010},
volume = {139},
number = {3},
pages = {336--345},
url = {https://linkinghub.elsevier.com/retrieve/pii/S0167880910002008},
doi = {10.1016/j.agee.2010.07.016}
}
|
| Lasslop G, Reichstein M, Papale D, Richardson A, Arneth A, Barr A, Stoy P and Wohlfahrt G (2010), "Separation of net ecosystem exchange into assimilation and respiration using a light response curve approach: Critical issues and global evaluation", Global Change Biology., jan, 2010. Vol. 16(1), pp. 187-208. |
| Abstract: The measured net ecosystem exchange (NEE) of CO2 between the ecosystem and the atmosphere reflects the balance between gross CO2 assimilation [gross primary production (GPP)] and ecosystem respiration (Reco). For understanding the mechanistic responses of ecosystem processes to environmental change it is important to separate these two flux components. Two approaches are conventionally used: (1) respiration measurements made at night are extrapolated to the daytime or (2) light-response curves are fit to daytime NEE measurements and respiration is estimated from the intercept of the ordinate, which avoids the use of potentially problematic nighttime data. We demonstrate that this approach is subject to biases if the effect of vapor pressure deficit (VPD) modifying the light response is not included. We introduce an algorithm for NEE partitioning that uses a hyperbolic light response curve fit to daytime NEE, modified to account for the temperature sensitivity of respiration and the VPD limitation of photosynthesis. Including the VPD dependency strongly improved the model's ability to reproduce the asymmetric diurnal cycle during periods with high VPD, and enhances the reliability of Reco estimates given that the reduction of GPP by VPD may be otherwise incorrectly attributed to higher Reco. Results from this improved algorithm are compared against estimates based on the conventional nighttime approach. The comparison demonstrates that the uncertainty arising from systematic errors dominates the overall uncertainty of annual sums (median absolute deviation of GPP: 47 g C m-2 yr-1), while errors arising from the random error (median absolute deviation: ˜ 2gCm-2 yr-1) are negligible. Despite sitespecific differences between the methods, overall patterns remain robust, adding confidence to statistical studies based on the FLUXNET database. In particular, we show that the strong correlation between GPP and Reco is not spurious but holds true when quasi-independent, i.e. daytime and nighttime based estimates are compared. textcopyright 2009 Blackwell Publishing Ltd. |
BibTeX:
@article{Lasslop2010,
author = {Lasslop, Gitta and Reichstein, Markus and Papale, Dario and Richardson, Andrewd and Arneth, Almut and Barr, Alan and Stoy, Paul and Wohlfahrt, Georg},
title = {Separation of net ecosystem exchange into assimilation and respiration using a light response curve approach: Critical issues and global evaluation},
journal = {Global Change Biology},
year = {2010},
volume = {16},
number = {1},
pages = {187--208},
url = {http://doi.wiley.com/10.1111/j.1365-2486.2009.02041.x},
doi = {10.1111/j.1365-2486.2009.02041.x}
}
|
| Luyssaert S, Ciais P, Piao SL, Schulze ED, Jung M, Zaehle S, Schelhaas MJ, Reichstein M, Churkina G, Papale D, Abril G, Beer C, Grace J, Loustau D, Matteucci G, Magnani F, Nabuurs GJ, Verbeeck H, Sulkava M, van der Werf GR and Janssens IA (2010), "The European carbon balance. Part 3: Forests", Global Change Biology., may, 2010. Vol. 16(5), pp. 1429-1450. |
| Abstract: We present a new synthesis, based on a suite of complementary approaches, of the primary production and carbon sink in forests of the 25 member states of the European Union (EU-25) during 1990-2005. Upscaled terrestrial observations and model-based approaches agree within 25% on the mean net primary production (NPP) of forests, i.e. 520±75 g C m-2 yr-1 over a forest area of 1.32 × 106 km2 to 1.55 × 106 km2 (EU-25). New estimates of the mean long-term carbon forest sink (net biome production, NBP) of EU-25 forests amounts 75±20 g C m-2 yr-1. The ratio of NBP to NPP is 0.15±0.05. Estimates of the fate of the carbon inputs via NPP in wood harvests, forest fires, losses to lakes and rivers and heterotrophic respiration remain uncertain, which explains the considerable uncertainty of NBP. Inventory-based assessments and assumptions suggest that 29±15% of the NBP (i.e., 22 g C m-2 yr-1) is sequestered in the forest soil, but large uncertainty remains concerning the drivers and future of the soil organic carbon. The remaining 71±15% of the NBP (i.e., 53 g C m-2 yr-1) is realized as woody biomass increments. In the EU-25, the relatively large forest NBP is thought to be the result of a sustained difference between NPP, which increased during the past decades, and carbon losses primarily by harvest and heterotrophic respiration, which increased less over the same period. textcopyright 2009 Blackwell Publishing Ltd. |
BibTeX:
@article{Luyssaert2010,
author = {Luyssaert, S and Ciais, P and Piao, S L and Schulze, E D and Jung, M and Zaehle, S and Schelhaas, M J and Reichstein, M and Churkina, G and Papale, D and Abril, G and Beer, C and Grace, J and Loustau, D and Matteucci, G and Magnani, F and Nabuurs, G J and Verbeeck, H and Sulkava, M and van der Werf, G R and Janssens, I A},
title = {The European carbon balance. Part 3: Forests},
journal = {Global Change Biology},
year = {2010},
volume = {16},
number = {5},
pages = {1429--1450},
url = {http://doi.wiley.com/10.1111/j.1365-2486.2009.02056.x},
doi = {10.1111/j.1365-2486.2009.02056.x}
}
|
| Mammarella I, Werle P, Pihlatie M, Eugster W, Haapanala S, Kiese R, Markkanen T, Rannik ¨U and Vesala T (2010), "A case study of eddy covariance flux of N 2 O measured within forest ecosystems: quality control and flux error analysis", In Biogeosciences. Vol. 7, pp. 427-440. |
| Abstract: Eddy covariance (EC) flux measurements of ni-trous oxide (N 2 O) obtained by using a 3-D sonic anemometer and a tunable diode laser gas analyzer for N 2 O were investigated. Two datasets (Sorø, Denmark and Kalevansuo, Fin-land) from different measurement campaigns including sub-canopy flux measurements of energy and carbon dioxide are discussed with a focus on selected quality control aspects and flux error analysis. Although fast response trace gas analyz-ers based on spectroscopic techniques are increasingly used in ecosystem research, their suitability for reliable estimates of EC fluxes is still limited, and some assumptions have to be made for filtering and processing data. The N 2 O concentration signal was frequently dominated by offset drifts (fringe effect), which can give an artificial extra contribution to the fluxes when the resulting concentration fluctuations are correlated with the fluctuations of the vertical wind velocity. Based on Allan variance analysis of the N 2 O signal , we found that a recursive running mean filter with a time constant equal to 50 s was suitable to damp the influence of the periodic drift. Although the net N 2 O fluxes over the whole campaign periods were quite small at both sites (∼ 5 µg N m −2 h −1 for Kalevansuo and ∼ 10 µg N m −2 h −1 for Sorø), the calculated sub-canopy EC fluxes were in good agreement with those estimated by automatic soil chambers. However, EC N 2 O flux measurements show larger random uncertainty than the sensible heat fluxes, and classification according to statistical significance of single flux values indicates that downward N 2 O fluxes have larger random error. |
BibTeX:
@techreport{Mammarella2010,
author = {Mammarella, I and Werle, P and Pihlatie, M and Eugster, W and Haapanala, S and Kiese, R and Markkanen, T and Rannik, ¨ U and Vesala, T},
title = {A case study of eddy covariance flux of N 2 O measured within forest ecosystems: quality control and flux error analysis},
booktitle = {Biogeosciences},
year = {2010},
volume = {7},
pages = {427--440},
url = {www.biogeosciences.net/7/427/2010/}
}
|
| Montagnani L, Manca G, Canepa E and Georgieva E (2010), "Assessing the method-specific differences in quantification of CO2 advection at three forest sites during the ADVEX campaign", Agricultural and Forest Meteorology., may, 2010. Vol. 150(5), pp. 702-711. |
BibTeX:
@article{Montagnani2010,
author = {Montagnani, Leonardo and Manca, Giovanni and Canepa, Elisa and Georgieva, Emilia},
title = {Assessing the method-specific differences in quantification of CO2 advection at three forest sites during the ADVEX campaign},
journal = {Agricultural and Forest Meteorology},
year = {2010},
volume = {150},
number = {5},
pages = {702--711},
url = {https://linkinghub.elsevier.com/retrieve/pii/S0168192310000365},
doi = {10.1016/j.agrformet.2010.01.013}
}
|
| Moors EJ, Jacobs C, Jans W, Supit I, Kutsch WL, Bernhofer C, Béziat P, Buchmann N, Carrara A, Ceschia E, Elbers J, Eugster W, Kruijt B, Loubet B, Magliulo E, Moureaux C, Olioso A, Saunders M and Soegaard H (2010), "Variability in carbon exchange of European croplands", Agriculture, Ecosystems & Environment., nov, 2010. Vol. 139(3), pp. 325-335. |
BibTeX:
@article{Moors2010,
author = {Moors, Eddy J and Jacobs, Cor and Jans, Wilma and Supit, Iwan and Kutsch, Werner L and Bernhofer, Christian and Béziat, Pierre and Buchmann, Nina and Carrara, Arnaud and Ceschia, Eric and Elbers, Jan and Eugster, Werner and Kruijt, Bart and Loubet, Benjamin and Magliulo, Enzo and Moureaux, Christine and Olioso, Albert and Saunders, Matt and Soegaard, Henrik},
title = {Variability in carbon exchange of European croplands},
journal = {Agriculture, Ecosystems & Environment},
year = {2010},
volume = {139},
number = {3},
pages = {325--335},
url = {https://linkinghub.elsevier.com/retrieve/pii/S0167880910001210},
doi = {10.1016/j.agee.2010.04.013}
}
|
| Osborne B, Saunders M, Walmsley D, Jones M and Smith P (2010), "Key questions and uncertainties associated with the assessment of the cropland greenhouse gas balance", Agriculture, Ecosystems & Environment., nov, 2010. Vol. 139(3), pp. 293-301. |
BibTeX:
@article{Osborne2010,
author = {Osborne, Bruce and Saunders, Matt and Walmsley, David and Jones, Michael and Smith, Pete},
title = {Key questions and uncertainties associated with the assessment of the cropland greenhouse gas balance},
journal = {Agriculture, Ecosystems & Environment},
year = {2010},
volume = {139},
number = {3},
pages = {293--301},
url = {https://linkinghub.elsevier.com/retrieve/pii/S0167880910001490},
doi = {10.1016/j.agee.2010.05.009}
}
|
| Peters W, Krol MC, van der Werf GR, Houweling S, Jones CD, Hughes J, Schaefer K, Masarie KA, Jacobson AR, Miller JB, Cho CH, Ramonet M, Schmidt M, Ciattaglia L, Apadula F, Heltai D, Meinhardt F, di Sarra AG, Piacentino S, Sferlazzo D, Aalto T, Hatakka J, StröM J, Haszpra L, Meijer HAJ, van Der Laan S, Neubert REM, Jordan A, Rodó X, Morguí JA, Vermeulen AT, Popa E, Rozanski K, Zimnoch M, Manning AC, Leuenberger M, Uglietti C, Dolman AJ, Ciais P, Heimann M and Tans P (2010), "Seven years of recent European net terrestrial carbon dioxide exchange constrained by atmospheric observations", Global Change Biology., apr, 2010. Vol. 16(4), pp. 1317-1337. |
| Abstract: We present an estimate of net ecosystem exchange (NEE) of CO2 in Europe for the years 2001-2007. It is derived with a data assimilation that uses a large set of atmospheric CO2 mole fraction observations (∼70 000) to guide relatively simple descriptions of terrestrial and oceanic net exchange, while fossil fuel and fire emissions are prescribed. Weekly terrestrial sources and sinks are optimized (i.e., a flux inversion) for a set of 18 large ecosystems across Europe in which prescribed climate, weather, and surface characteristics introduce finer scale gradients. We find that the terrestrial biosphere in Europe absorbed a net average of -165 Tg C yr-1 over the period considered. This uptake is predominantly in non-EU countries, and is found in the northern coniferous (-94 Tg C yr-1) and mixed forests (-30 Tg C yr-1) as well as the forest/field complexes of eastern Europe (-85 Tg C yr-1). An optimistic uncertainty estimate derived using three biosphere models suggests the uptake to be in a range of -122 to -258 Tg C yr-1, while a more conservative estimate derived from the a-posteriori covariance estimates is -165±437 Tg C yr-1. Note, however, that uncertainties are hard to estimate given the nature of the system and are likely to be significantly larger than this. Interannual variability in NEE includes a reduction in uptake due to the 2003 drought followed by 3 years of more than average uptake. The largest anomaly of NEE occurred in 2005 concurrent with increased seasonal cycles of observed CO2. We speculate these changes to result from the strong negative phase of the North Atlantic Oscillation in 2005 that lead to favorable summer growth conditions, and altered horizontal and vertical mixing in the atmosphere. All our results are available through http://www.carbontracker.eu. textcopyright 2009 Blackwell Publishing Ltd. |
BibTeX:
@article{Peters2010,
author = {Peters, W and Krol, M C and van der Werf, G R and Houweling, S and Jones, C D and Hughes, J and Schaefer, K and Masarie, K A and Jacobson, A R and Miller, J B and Cho, C H and Ramonet, M and Schmidt, M and Ciattaglia, L and Apadula, F and Heltai, D and Meinhardt, F and di Sarra, A G and Piacentino, S and Sferlazzo, D and Aalto, T and Hatakka, J and StröM, J and Haszpra, L and Meijer, H A J and van Der Laan, S and Neubert, R E M and Jordan, A and Rodó, X and Morguí, J A and Vermeulen, A T and Popa, E and Rozanski, K and Zimnoch, M and Manning, A C and Leuenberger, M and Uglietti, C and Dolman, A J and Ciais, P and Heimann, M and Tans, P},
title = {Seven years of recent European net terrestrial carbon dioxide exchange constrained by atmospheric observations},
journal = {Global Change Biology},
year = {2010},
volume = {16},
number = {4},
pages = {1317--1337},
url = {http://doi.wiley.com/10.1111/j.1365-2486.2009.02078.x},
doi = {10.1111/j.1365-2486.2009.02078.x}
}
|
| Smith P, Lanigan G, Kutsch WL, Buchmann N, Eugster W, Aubinet M, Ceschia E, Béziat P, Yeluripati JB, Osborne B, Moors EJ, Brut A, Wattenbach M, Saunders M and Jones M (2010), "Measurements necessary for assessing the net ecosystem carbon budget of croplands", Agriculture, Ecosystems & Environment., nov, 2010. Vol. 139(3), pp. 302-315. |
BibTeX:
@article{Smith2010,
author = {Smith, Pete and Lanigan, Gary and Kutsch, Werner L and Buchmann, Nina and Eugster, Werner and Aubinet, Marc and Ceschia, Eric and Béziat, Pierre and Yeluripati, Jagadeesh B and Osborne, Bruce and Moors, Eddy J and Brut, Aurore and Wattenbach, Martin and Saunders, Matt and Jones, Mike},
title = {Measurements necessary for assessing the net ecosystem carbon budget of croplands},
journal = {Agriculture, Ecosystems & Environment},
year = {2010},
volume = {139},
number = {3},
pages = {302--315},
url = {https://linkinghub.elsevier.com/retrieve/pii/S016788091000112X},
doi = {10.1016/j.agee.2010.04.004}
}
|
| Smith P, Jones M, Osborne B and Wattenbach M (2010), "The carbon and greenhouse gas budget of European croplands", Agriculture, Ecosystems & Environment., nov, 2010. Vol. 139(3), pp. v-vi. |
BibTeX:
@article{Smith2010a,
author = {Smith, Pete and Jones, Mike and Osborne, Bruce and Wattenbach, Martin},
title = {The carbon and greenhouse gas budget of European croplands},
journal = {Agriculture, Ecosystems & Environment},
year = {2010},
volume = {139},
number = {3},
pages = {v--vi},
url = {https://linkinghub.elsevier.com/retrieve/pii/S0167880910002732},
doi = {10.1016/S0167-8809(10)00273-2}
}
|
| Sus O, Williams M, Bernhofer C, Béziat P, Buchmann N, Ceschia E, Doherty R, Eugster W, Grünwald T, Kutsch W, Smith P and Wattenbach M (2010), "A linked carbon cycle and crop developmental model: Description and evaluation against measurements of carbon fluxes and carbon stocks at several European agricultural sites", Agriculture, Ecosystems & Environment., nov, 2010. Vol. 139(3), pp. 402-418. |
BibTeX:
@article{Sus2010,
author = {Sus, O and Williams, M and Bernhofer, C and Béziat, P and Buchmann, N and Ceschia, E and Doherty, R and Eugster, W and Grünwald, T and Kutsch, W and Smith, P and Wattenbach, M},
title = {A linked carbon cycle and crop developmental model: Description and evaluation against measurements of carbon fluxes and carbon stocks at several European agricultural sites},
journal = {Agriculture, Ecosystems & Environment},
year = {2010},
volume = {139},
number = {3},
pages = {402--418},
url = {https://linkinghub.elsevier.com/retrieve/pii/S0167880910001660},
doi = {10.1016/j.agee.2010.06.012}
}
|
| Ter Maat HW, Hutjes RWA, Miglietta F, Gioli B, Bosveld FC, Vermeulen AT and Fritsch H (2010), "Simulating carbon exchange using a regional atmospheric model coupled to an advanced land-surface model", Biogeosciences., aug, 2010. Vol. 7(8), pp. 2397-2417. |
| Abstract: This paper is a case study to investigate what the main controlling factors are that determine atmospheric carbon dioxide content for a region in the centre of The Netherlands. We use the Regional Atmospheric Modelling System (RAMS), coupled with a land surface scheme simulating carbon, heat and momentum fluxes (SWAPS-C), and including also submodels for urban and marine fluxes, which in principle should include the dominant mechanisms and should be able to capture the relevant dynamics of the system. To validate the model, observations are used that were taken during an intensive observational campaign in central Netherlands in summer 2002. These include flux-tower observations and aircraft observations of vertical profiles and spatial fluxes of various variables. The simulations performed with the coupled regional model (RAMS-SWAPS-C) are in good qualitative agreement with the observations. The station validation of the model demonstrates that the incoming shortwave radiation and surface fluxes of water and CO2 are well simulated. The comparison against aircraft data shows that the regional meteorology (i.e. wind, temperature) is captured well by the model. Comparing spatially explicitly simulated fluxes with aircraft observed fluxes we conclude that in general latent heat fluxes are underestimated by the model compared to the observations but that the latter exhibit large variability within all flights. Sensitivity experiments demonstrate the relevance of the urban emissions of carbon dioxide for the carbon balance in this particular region. The same tests also show the relation between uncertainties in surface fluxes and those in atmospheric concentrations. textcopyright 2010 Author(s). |
BibTeX:
@article{TerMaat2010,
author = {Ter Maat, H W and Hutjes, R W A and Miglietta, F and Gioli, B and Bosveld, F C and Vermeulen, A T and Fritsch, H},
title = {Simulating carbon exchange using a regional atmospheric model coupled to an advanced land-surface model},
journal = {Biogeosciences},
year = {2010},
volume = {7},
number = {8},
pages = {2397--2417},
url = {http://www.biogeosciences.net/7/2397/2010/},
doi = {10.5194/bg-7-2397-2010}
}
|
| Vogel FR, Hammer S, Steinhof A, Kromer B and Levin I (2010), "Implication of weekly and diurnal 14C calibration on hourly estimates of CO-based fossil fuel CO2 at a moderately polluted site in southwestern Germany", Tellus, Series B: Chemical and Physical Meteorology., nov, 2010. Vol. 62(5), pp. 512-520. |
| Abstract: A 7-year-long data set of integrated high-precision 14CO2 observations combined with occasional hourly 14CO2 flask data from the Heidelberg sampling site is presented. Heidelberg is located in the highly populated and industrialized upper Rhine valley in southwestern Germany. The 14CO2 data are used in combination with hourly carbon monoxide (CO) observations to estimate regional hourly fossil fuel CO2 (δFFCO2) mixing ratios. We investigate three different 14C calibration schemes to calculate δFFCO2: (1) the long-term median δCO/δFFCO2 ratio of 14.6 ppb ppm-1 (mean: 15.5 ± 5.6 ppb ppm-1), (2) individual (2-)week-long integrated δCO/δFFCO2 ratios, which take into account the large week-to-week variability of ±5.6 ppb ppm-1 (1σ; interquartile range: 5.5 ppb ppm-1), and (3) a calibration which also includes diurnal changes of the δCO/δFFCO2 ratio. We show that in winter a diurnally changing δCO/δFFCO2 ratio provides a much better agreement with the direct 14C-based hourly δFFCO2 estimates whereas summer values are not significantly improved with a diurnal calibration. Using integrated 14CO2 samples to determine weekly mean δCO/δFFCO2 ratios introduces a bias in the CO-based δFFCO2 estimates which can be corrected for with diurnal grab sample data. Altogether our 14C-calibrated CO-based method allows determining δFFCO2 at a semi-polluted site with a precision of approximately ±25%. textcopyright 2010 The Authors Tellus B textcopyright 2010 International Meteorological Institute in Stockholm. |
BibTeX:
@article{Vogel2010,
author = {Vogel, Felix R. and Hammer, Samuel and Steinhof, Axel and Kromer, Bernd and Levin, Ingeborg},
title = {Implication of weekly and diurnal 14C calibration on hourly estimates of CO-based fossil fuel CO2 at a moderately polluted site in southwestern Germany},
journal = {Tellus, Series B: Chemical and Physical Meteorology},
year = {2010},
volume = {62},
number = {5},
pages = {512--520},
doi = {10.1111/j.1600-0889.2010.00477.x}
}
|
| Winderlich J, Chen H, Gerbig C, Seifert T, Kolle O, Lavrič JV, Kaiser C, Höfer A and Heimann M (2010), "Continuous low-maintenance CO2/CH4/H2O measurements at the Zotino Tall Tower Observatory (ZOTTO) in Central Siberia", Atmospheric Measurement Techniques., aug, 2010. Vol. 3(4), pp. 1113-1128. |
| Abstract: To monitor the continental carbon cycle, a fully automated low maintenance measurement system is installed at the Zotino Tall Tower Observatory in Central Siberia (ZOTTO, 60°48' N, 89°21' E) since April 2009. A cavity ring-down spectroscopy (CRDS) analyzer continuously measures carbon dioxide (CO 2) and methane (CH4) from six heights up to 301 m a.g.l. Buffer volumes in each air line remove short term CO2 and CH 4 mixing ratio fluctuations associated with turbulence, and allow continuous, near-concurrent measurements from all tower levels. Instead of drying the air sample, the simultaneously measured water vapor is used to correct the dilution and pressure-broadening effects for the accurate determination of dry air CO2 and CH4 mixing ratios. The stability of the water vapor correction was demonstrated by repeated laboratory and field tests. The effect of molecular adsorption in the wet air lines was shown to be negligible. The low consumption of four calibration tanks that need recalibration only on decadal timescale further reduces maintenance. The measurement precision (accuracy) of 0.04 ppm (0.09 ppm) for CO2 and 0.3 ppb (1.5 ppb) for CH4 is compliant with the WMO recommendations. The data collected so far (until April 2010) reveals a seasonal cycle amplitude for CO2 of 30.4 ppm at the 301 m level. textcopyright 2010 Author(s). |
BibTeX:
@article{Winderlich2010,
author = {Winderlich, J and Chen, H and Gerbig, C and Seifert, T and Kolle, O and Lavrič, J V and Kaiser, C and Höfer, A and Heimann, M},
title = {Continuous low-maintenance CO2/CH4/H2O measurements at the Zotino Tall Tower Observatory (ZOTTO) in Central Siberia},
journal = {Atmospheric Measurement Techniques},
year = {2010},
volume = {3},
number = {4},
pages = {1113--1128},
url = {http://www.atmos-meas-tech.net/3/1113/2010/},
doi = {10.5194/amt-3-1113-2010}
}
|
| Zweifel R, Eugster W, Etzold S, Dobbertin M, Buchmann N and Häsler R (2010), "Link between continuous stem radius changes and net ecosystem productivity of a subalpine Norway spruce forest in the Swiss Alps", New Phytologist., aug, 2010. Vol. 187(3), pp. 819-830. |
| Abstract: Continuous stem radius changes (DR) include growth and water-related processes on the individual tree level. DR is assumed to provide carbon turnover information complementary to net ecosystem productivity (NEP) which integrates fluxes over the entire forest ecosystem. Here, we investigated the unexpectedly close relationship between NEP and DR and asked for causalities. NEP (positive values indicate carbon sink) measured by eddy covariance over 11 yr was analysed at three time scales alongside automated point dendrometer DR data from a Swiss subalpine Norway spruce forest. On annual and monthly scales, the remarkably close relationship between NEP and DR was positive, whereas on a half-hourly scale the relationship was negative. Gross primary production (GPP) had a similar explanatory power at shorter time scales, but was significantly less correlated with DR on an annual scale. The causal explanation for the NEP-DR relationship is still fragmentary; however, it is partially attributable to the following: radial stem growth with a strong effect on monthly and annual increases in NEP and DR; frost-induced bark tissue dehydration with a parallel decrease in both measures on a monthly scale; and transpiration-induced DR shrinkage which is negatively correlated with assimilation and thus with NEP on a half-hourly scale. textcopyright The Authors (2010). Journal compilation textcopyright New Phytologist Trust (2010). |
BibTeX:
@article{Zweifel2010,
author = {Zweifel, R. and Eugster, W. and Etzold, S. and Dobbertin, M. and Buchmann, N. and Häsler, R.},
title = {Link between continuous stem radius changes and net ecosystem productivity of a subalpine Norway spruce forest in the Swiss Alps},
journal = {New Phytologist},
year = {2010},
volume = {187},
number = {3},
pages = {819--830},
doi = {10.1111/j.1469-8137.2010.03301.x}
}
|
| Ilvesniemi H, Levula J, Ojansuu R, Kolari P, Kulmala L, Pumpanen J, Launiainen S, Vesala T and Nikinmaa E (2009), "Long-term measurements of the carbon balance of a boreal Scots pine dominated forest ecosystem" |
| Abstract: Ilvesniemi, H., Levula, J., Ojansuu, R., Kolari, P., Kulmala, L., Pumpanen, J., Launiainen, S., Vesala, T. & Nikinmaa, E. 2009: Long-term measurements of the carbon balance of a boreal Scots pine dominated forest ecosystem. Boreal Env. Res. 14: 731-753. We measured on annual basis the magnitude and relative importance of different components of the carbon balance of a boreal Scots pine dominated forest ecosystem. The continuous 10-year-long measurement period of this study and the miscellaneous measurements of the components of the ecosystem carbon balance carried out at the same site are almost unique. The ecosystem was shown to be a carbon sink in all measured years. The average net ecosystem exchange (NEE) estimated with the eddy covariance (EC) method was-206 g C m-2 a-1 and the average annual accumulation of carbon into trees was 242 g C m-2 a-1. The above-ground litter production was 186 g C m-2 a-1 of which 92 g consisted of needles and leaves. The average respiration rates of the soil, canopy and stems were 646, 316 and 62 g C m-2 a-1 , respectively and the TER deduced from EC measurements was 826 g C m-2 a-1. The average rate of the tree and ground vegetation photosynthesis was 982 and 114 g C m-2 a-1 , respectively. In forest ecosystems the application of biomass equations to measurements of tree dimensions and increment cores can give a reliable and unbiased estimate of carbon accumulation into trees. The chamber based fl ux measurements are useful in showing short term response to changes in light, temperature and moisture conditions, but the generalization of the results over time and space is diffi cult. |
BibTeX:
@article{Ilvesniemi2009,
author = {Ilvesniemi, Hannu and Levula, Janne and Ojansuu, Risto and Kolari, Pasi and Kulmala, Liisa and Pumpanen, Jukka and Launiainen, Samuli and Vesala, Timo and Nikinmaa, Eero},
title = {Long-term measurements of the carbon balance of a boreal Scots pine dominated forest ecosystem},
year = {2009}
}
|
| Katul GG, Cava D, Launiainen S and Vesala T (2009), "An analytical model for the two-scalar covariance budget inside a uniform dense canopy", Boundary-Layer Meteorology. Vol. 131(2), pp. 173-192. |
| Abstract: The two-scalar covariance budget is significant within the canopy sublayer (CSL) given its role in modelling scalar flux budgets using higher-order closure principles and in estimating the segregation ratio for chemically reactive species. Despite its importance, an explicit expression describing how the two-scalar covariance is modified by inhomogeneity in the flow statistics and in the vertical variation in scalar emission or uptake rates within the canopy volume remains elusive even for passive scalars. To progress on a narrower version of this problem, an analytical solution to the two-scalar covariance budget in the CSL is proposed for the most idealized flow conditions: a stationary and planar homogeneous flow inside a uniform and dense canopy with a constant leaf area density distribution. The foliage emission (or uptake) source strengths are assumed to vary exponentially with depth while the forest floor emission is represented as a scalar flux. The analytical solution is a superposition of a homogeneous part that describes how the two-scalar covariance at the canopy top is transported and dissipated within the canopy volume, and an inhomogeneous part governed by local production mechanisms of the two-scalar covariance. The homogeneous part is primarily described by the canopy adjustment length scale, and the attenuation coefficients of the turbulent kinetic energy and the mean velocity. Conditions for which the vertical variation of the two-scalar covariance is controlled by the rapid attenuation in the mean velocity and turbulent kinetic energy profiles, vis- -vis the vertical variation of the scalar source strength, are explicitly established. This model also demonstrates how dissimilarity in the emissions from the ground, even for the extreme binary case with one scalar turned on and the other scalar turned off, modifies the vertical variation of the two-scalar covariance within the CSL. To assess its applicability to field conditions, the analytical model predictions were compared with observations made at two different forest types-a sparse pine forest at the Hyytiälä SMEAR II-station (in Finland) and a dense alpine hardwood forest at Lavarone (in Italy). While the model assumptions do not represent the precise canopy morphology, attenuation properties of the turbulent kinetic energy and the mean velocity, observed mixing length, and scalar source attenuation properties for these two forest types, good agreement was found between measured and modelled two scalar covariances for multiple scalars and for the triple moments at the Hyytiälä site. textcopyright Springer Science+Business Media B.V. 2009. |
BibTeX:
@article{Katul2009,
author = {Katul, Gabriel G. and Cava, Daniela and Launiainen, Samuli and Vesala, Timo},
title = {An analytical model for the two-scalar covariance budget inside a uniform dense canopy},
journal = {Boundary-Layer Meteorology},
year = {2009},
volume = {131},
number = {2},
pages = {173--192},
doi = {10.1007/s10546-009-9361-y}
}
|
| Mammarella I, Launiainen S, Gronholm T, Keronen P, Pumpanen J, Rannik Ü and Vesala T (2009), "Relative humidity effect on the high-frequency attenuation of water vapor flux measured by a closed-path eddy covariance system", Journal of Atmospheric and Oceanic Technology., sep, 2009. Vol. 26(9), pp. 1856-1866. |
| Abstract: In this study the high-frequency loss of carbon dioxide (CO2) and water vapor (H2O) fluxes, measured by a closed-path eddy covariance system, were studied, and the related correction factors through the cospectral transfer function method were calculated. As already reported by other studies, it was found that the age of the sampling tube is a relevant factor to consider when estimating the spectral correction of water vapor fluxes. Moreover, a time-dependent relationship between the characteristic time constant (or response time) for water vapor and the ambient relative humidity was disclosed. Such dependence is negligible when the sampling tube is new, but it becomes important already when the tube is only 1 yr old and increases with the age of the tube. With a new sampling tube, the correction of water vapor flux measurements over a Scots pine forest in Hyytiälä, Finland, amounted on average to 7%. After 4 yr the correction increased strongly, ranging from 10%-15% during the summer to 30%-40% in wintertime, when the relative humidity is typically high. For this site the effective correction improved the long-term energy and water balance. Results suggest that the relative humidity effect on high-frequency loss of water vapor flux should be taken into account and that the effective transfer function should be estimated experimentally at least once per year. On the other hand, this high correction can be avoided by a correct choice and periodic maintenance of the eddy covariance system tube, for example, by cleaning or changing it at least once per year. textcopyright 2009 American Meteorological Society. |
BibTeX:
@article{Mammarella2009,
author = {Mammarella, Ivan and Launiainen, Samuli and Gronholm, Tiia and Keronen, Petri and Pumpanen, Jukka and Rannik, Üllar and Vesala, Timo},
title = {Relative humidity effect on the high-frequency attenuation of water vapor flux measured by a closed-path eddy covariance system},
journal = {Journal of Atmospheric and Oceanic Technology},
year = {2009},
volume = {26},
number = {9},
pages = {1856--1866},
doi = {10.1175/2009JTECHA1179.1}
}
|
| Peichl M, Martínez-García E, Fransson JES, Wallerman J, Laudon H, Lundmark T and Nilsson MB (), "Landscape-variability of the carbon balance across managed boreal forests", Global Change Biology. Vol. n/a(n/a) |
| Abstract: Abstract Boreal forests are important global carbon (C) sinks and, therefore, considered as a key element in climate change mitigation policies. However, their actual C sink strength is uncertain and under debate, particularly for the actively managed forests in the boreal regions of Fennoscandia. In this study, we use an extensive set of biometric- and chamber-based C flux data collected in 50 forest stands (ranging from 5 to 211 years) over 3 years (2016–2018) with the aim to explore the variations of the annual net ecosystem production (NEP; i.e., the ecosystem C balance) across a 68 km2 managed boreal forest landscape in northern Sweden. Our results demonstrate that net primary production rather than heterotrophic respiration regulated the spatio-temporal variations of NEP across the heterogeneous mosaic of the managed boreal forest landscape. We further find divergent successional patterns of NEP in our managed forests relative to naturally regenerating boreal forests, including (i) a fast recovery of the C sink function within the first decade after harvest due to the rapid establishment of a productive understory layer and (ii) a sustained C sink in old stands (131–211 years). We estimate that the rotation period for optimum C sequestration extends to 138 years, which over multiple rotations results in a long-term C sequestration rate of 86.5 t C ha−1 per rotation. Our study highlights the potential of forest management to maximize C sequestration of boreal forest landscapes and associate climate change mitigation effects by developing strategies that optimize tree biomass production rather than heterotrophic soil C emissions. |
BibTeX:
@article{Peichl,
author = {Peichl, Matthias and Martínez-García, Eduardo and Fransson, Johan E S and Wallerman, Jörgen and Laudon, Hjalmar and Lundmark, Tomas and Nilsson, Mats B},
title = {Landscape-variability of the carbon balance across managed boreal forests},
journal = {Global Change Biology},
volume = {n/a},
number = {n/a},
url = {https://onlinelibrary.wiley.com/doi/abs/10.1111/gcb.16534},
doi = {10.1111/gcb.16534}
}
|