Articles | Volume 15, issue 8
https://doi.org/10.5194/bg-15-2361-2018
© Author(s) 2018. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/bg-15-2361-2018
© Author(s) 2018. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| Highlight paper
| 
19 Apr 2018
Research article | Highlight paper |
| 19 Apr 2018
Interannual drivers of the seasonal cycle of CO2 in the Southern Ocean
Southern Ocean Carbon-Climate Observatory (SOCCO), CSIR, Cape Town,
South Africa
University of Cape Town, Department of Oceanography,
Cape Town, South Africa
Schalk Kok
University of Pretoria, Department of
Mechanical and Aeronautical Engineering, Pretoria, South Africa
Pedro M. S. Monteiro
Southern Ocean Carbon-Climate Observatory (SOCCO), CSIR, Cape Town,
South Africa
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Short summary
Short summary
The Global Carbon Budget 2022 describes the datasets and methodology used to quantify the anthropogenic emissions of carbon dioxide (CO2) and their partitioning among the atmosphere, the land ecosystems, and the ocean. These living datasets are updated every year to provide the highest transparency and traceability in the reporting of CO2, the key driver of climate change.
Laique M. Djeutchouang, Nicolette Chang, Luke Gregor, Marcello Vichi, and Pedro M. S. Monteiro
Biogeosciences, 19, 4171–4195, https://doi.org/10.5194/bg-19-4171-2022, https://doi.org/10.5194/bg-19-4171-2022, 2022
Short summary
Short summary
Based on observing system simulation experiments using a mesoscale-resolving model, we found that to significantly improve uncertainties and biases in carbon dioxide (CO2) mapping in the Southern Ocean, it is essential to resolve the seasonal cycle (SC) of the meridional gradient of CO2 through high frequency (at least daily) observations that also span the region's meridional axis. We also showed that the estimated SC anomaly and mean annual CO2 are highly sensitive to seasonal sampling biases.
Pierre Friedlingstein, Matthew W. Jones, Michael O'Sullivan, Robbie M. Andrew, Dorothee C. E. Bakker, Judith Hauck, Corinne Le Quéré, Glen P. Peters, Wouter Peters, Julia Pongratz, Stephen Sitch, Josep G. Canadell, Philippe Ciais, Rob B. Jackson, Simone R. Alin, Peter Anthoni, Nicholas R. Bates, Meike Becker, Nicolas Bellouin, Laurent Bopp, Thi Tuyet Trang Chau, Frédéric Chevallier, Louise P. Chini, Margot Cronin, Kim I. Currie, Bertrand Decharme, Laique M. Djeutchouang, Xinyu Dou, Wiley Evans, Richard A. Feely, Liang Feng, Thomas Gasser, Dennis Gilfillan, Thanos Gkritzalis, Giacomo Grassi, Luke Gregor, Nicolas Gruber, Özgür Gürses, Ian Harris, Richard A. Houghton, George C. Hurtt, Yosuke Iida, Tatiana Ilyina, Ingrid T. Luijkx, Atul Jain, Steve D. Jones, Etsushi Kato, Daniel Kennedy, Kees Klein Goldewijk, Jürgen Knauer, Jan Ivar Korsbakken, Arne Körtzinger, Peter Landschützer, Siv K. Lauvset, Nathalie Lefèvre, Sebastian Lienert, Junjie Liu, Gregg Marland, Patrick C. McGuire, Joe R. Melton, David R. Munro, Julia E. M. S. Nabel, Shin-Ichiro Nakaoka, Yosuke Niwa, Tsuneo Ono, Denis Pierrot, Benjamin Poulter, Gregor Rehder, Laure Resplandy, Eddy Robertson, Christian Rödenbeck, Thais M. Rosan, Jörg Schwinger, Clemens Schwingshackl, Roland Séférian, Adrienne J. Sutton, Colm Sweeney, Toste Tanhua, Pieter P. Tans, Hanqin Tian, Bronte Tilbrook, Francesco Tubiello, Guido R. van der Werf, Nicolas Vuichard, Chisato Wada, Rik Wanninkhof, Andrew J. Watson, David Willis, Andrew J. Wiltshire, Wenping Yuan, Chao Yue, Xu Yue, Sönke Zaehle, and Jiye Zeng
Earth Syst. Sci. Data, 14, 1917–2005, https://doi.org/10.5194/essd-14-1917-2022, https://doi.org/10.5194/essd-14-1917-2022, 2022
Short summary
Short summary
The Global Carbon Budget 2021 describes the data sets and methodology used to quantify the emissions of carbon dioxide and their partitioning among the atmosphere, land, and ocean. These living data are updated every year to provide the highest transparency and traceability in the reporting of CO2, the key driver of climate change.
Amanda R. Fay, Luke Gregor, Peter Landschützer, Galen A. McKinley, Nicolas Gruber, Marion Gehlen, Yosuke Iida, Goulven G. Laruelle, Christian Rödenbeck, Alizée Roobaert, and Jiye Zeng
Earth Syst. Sci. Data, 13, 4693–4710, https://doi.org/10.5194/essd-13-4693-2021, https://doi.org/10.5194/essd-13-4693-2021, 2021
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The movement of carbon dioxide from the atmosphere to the ocean is estimated using surface ocean carbon (pCO2) measurements and an equation including variables such as temperature and wind speed; the choices of these variables lead to uncertainties. We introduce the SeaFlux ensemble which provides carbon flux maps calculated in a consistent manner, thus reducing uncertainty by using common choices for wind speed and a set definition of "global" coverage.
Luke Gregor and Nicolas Gruber
Earth Syst. Sci. Data, 13, 777–808, https://doi.org/10.5194/essd-13-777-2021, https://doi.org/10.5194/essd-13-777-2021, 2021
Short summary
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Ocean acidification (OA) has altered the ocean's carbonate chemistry, with consequences for marine life. Yet, no observation-based data set exists that permits us to study changes in OA. We fill this gap with a global data set of relevant surface ocean parameters over the period 1985–2018. This data set, OceanSODA-ETHZ, was created by using satellite and other data to extrapolate ship-based measurements of carbon dioxide and total alkalinity from which parameters for OA were computed.
Luke Gregor, Alice D. Lebehot, Schalk Kok, and Pedro M. Scheel Monteiro
Geosci. Model Dev., 12, 5113–5136, https://doi.org/10.5194/gmd-12-5113-2019, https://doi.org/10.5194/gmd-12-5113-2019, 2019
Short summary
Short summary
The ocean plays a vital role in mitigating climate change by taking up atmospheric carbon dioxide (CO2). Historically sparse ship-based measurements of surface ocean CO2 make direct estimates of CO2 exchange changes unreliable. We introduce a machine-learning ensemble approach to fill these observational gaps. Our method performs incrementally better relative to past methods, leading to our hypothesis that we are perhaps reaching the limitation of machine-learning algorithms' capability.
Luke Gregor, Schalk Kok, and Pedro M. S. Monteiro
Biogeosciences, 14, 5551–5569, https://doi.org/10.5194/bg-14-5551-2017, https://doi.org/10.5194/bg-14-5551-2017, 2017
Short summary
Short summary
We use machine learning to extrapolate ship measurements of CO2 using satellite data. We present two ML methods new to this field. These methods perform well in the context of previous work and reproduce the decadal trends of previous estimates. To test the methods, we simulate the exact observed setup in biogeochemical ocean model output. We show that the new methods perform well in synthetic data. Lastly, we show that there is only a weak bias due to undersampling in the SOCAT v3 dataset.
Dorothee C. E. Bakker, Benjamin Pfeil, Camilla S. Landa, Nicolas Metzl, Kevin M. O'Brien, Are Olsen, Karl Smith, Cathy Cosca, Sumiko Harasawa, Stephen D. Jones, Shin-ichiro Nakaoka, Yukihiro Nojiri, Ute Schuster, Tobias Steinhoff, Colm Sweeney, Taro Takahashi, Bronte Tilbrook, Chisato Wada, Rik Wanninkhof, Simone R. Alin, Carlos F. Balestrini, Leticia Barbero, Nicholas R. Bates, Alejandro A. Bianchi, Frédéric Bonou, Jacqueline Boutin, Yann Bozec, Eugene F. Burger, Wei-Jun Cai, Robert D. Castle, Liqi Chen, Melissa Chierici, Kim Currie, Wiley Evans, Charles Featherstone, Richard A. Feely, Agneta Fransson, Catherine Goyet, Naomi Greenwood, Luke Gregor, Steven Hankin, Nick J. Hardman-Mountford, Jérôme Harlay, Judith Hauck, Mario Hoppema, Matthew P. Humphreys, Christopher W. Hunt, Betty Huss, J. Severino P. Ibánhez, Truls Johannessen, Ralph Keeling, Vassilis Kitidis, Arne Körtzinger, Alex Kozyr, Evangelia Krasakopoulou, Akira Kuwata, Peter Landschützer, Siv K. Lauvset, Nathalie Lefèvre, Claire Lo Monaco, Ansley Manke, Jeremy T. Mathis, Liliane Merlivat, Frank J. Millero, Pedro M. S. Monteiro, David R. Munro, Akihiko Murata, Timothy Newberger, Abdirahman M. Omar, Tsuneo Ono, Kristina Paterson, David Pearce, Denis Pierrot, Lisa L. Robbins, Shu Saito, Joe Salisbury, Reiner Schlitzer, Bernd Schneider, Roland Schweitzer, Rainer Sieger, Ingunn Skjelvan, Kevin F. Sullivan, Stewart C. Sutherland, Adrienne J. Sutton, Kazuaki Tadokoro, Maciej Telszewski, Matthias Tuma, Steven M. A. C. van Heuven, Doug Vandemark, Brian Ward, Andrew J. Watson, and Suqing Xu
Earth Syst. Sci. Data, 8, 383–413, https://doi.org/10.5194/essd-8-383-2016, https://doi.org/10.5194/essd-8-383-2016, 2016
Short summary
Short summary
Version 3 of the Surface Ocean CO2 Atlas (www.socat.info) has 14.5 million CO2 (carbon dioxide) values for the years 1957 to 2014 covering the global oceans and coastal seas. Version 3 is an update to version 2 with a longer record and 44 % more CO2 values. The CO2 measurements have been made on ships, fixed moorings and drifting buoys. SOCAT enables quantification of the ocean carbon sink and ocean acidification, as well as model evaluation, thus informing climate negotiations.
Pierre Friedlingstein, Michael O'Sullivan, Matthew W. Jones, Robbie M. Andrew, Luke Gregor, Judith Hauck, Corinne Le Quéré, Ingrid T. Luijkx, Are Olsen, Glen P. Peters, Wouter Peters, Julia Pongratz, Clemens Schwingshackl, Stephen Sitch, Josep G. Canadell, Philippe Ciais, Robert B. Jackson, Simone R. Alin, Ramdane Alkama, Almut Arneth, Vivek K. Arora, Nicholas R. Bates, Meike Becker, Nicolas Bellouin, Henry C. Bittig, Laurent Bopp, Frédéric Chevallier, Louise P. Chini, Margot Cronin, Wiley Evans, Stefanie Falk, Richard A. Feely, Thomas Gasser, Marion Gehlen, Thanos Gkritzalis, Lucas Gloege, Giacomo Grassi, Nicolas Gruber, Özgür Gürses, Ian Harris, Matthew Hefner, Richard A. Houghton, George C. Hurtt, Yosuke Iida, Tatiana Ilyina, Atul K. Jain, Annika Jersild, Koji Kadono, Etsushi Kato, Daniel Kennedy, Kees Klein Goldewijk, Jürgen Knauer, Jan Ivar Korsbakken, Peter Landschützer, Nathalie Lefèvre, Keith Lindsay, Junjie Liu, Zhu Liu, Gregg Marland, Nicolas Mayot, Matthew J. McGrath, Nicolas Metzl, Natalie M. Monacci, David R. Munro, Shin-Ichiro Nakaoka, Yosuke Niwa, Kevin O'Brien, Tsuneo Ono, Paul I. Palmer, Naiqing Pan, Denis Pierrot, Katie Pocock, Benjamin Poulter, Laure Resplandy, Eddy Robertson, Christian Rödenbeck, Carmen Rodriguez, Thais M. Rosan, Jörg Schwinger, Roland Séférian, Jamie D. Shutler, Ingunn Skjelvan, Tobias Steinhoff, Qing Sun, Adrienne J. Sutton, Colm Sweeney, Shintaro Takao, Toste Tanhua, Pieter P. Tans, Xiangjun Tian, Hanqin Tian, Bronte Tilbrook, Hiroyuki Tsujino, Francesco Tubiello, Guido R. van der Werf, Anthony P. Walker, Rik Wanninkhof, Chris Whitehead, Anna Willstrand Wranne, Rebecca Wright, Wenping Yuan, Chao Yue, Xu Yue, Sönke Zaehle, Jiye Zeng, and Bo Zheng
Earth Syst. Sci. Data, 14, 4811–4900, https://doi.org/10.5194/essd-14-4811-2022, https://doi.org/10.5194/essd-14-4811-2022, 2022
Short summary
Short summary
The Global Carbon Budget 2022 describes the datasets and methodology used to quantify the anthropogenic emissions of carbon dioxide (CO2) and their partitioning among the atmosphere, the land ecosystems, and the ocean. These living datasets are updated every year to provide the highest transparency and traceability in the reporting of CO2, the key driver of climate change.
Laique M. Djeutchouang, Nicolette Chang, Luke Gregor, Marcello Vichi, and Pedro M. S. Monteiro
Biogeosciences, 19, 4171–4195, https://doi.org/10.5194/bg-19-4171-2022, https://doi.org/10.5194/bg-19-4171-2022, 2022
Short summary
Short summary
Based on observing system simulation experiments using a mesoscale-resolving model, we found that to significantly improve uncertainties and biases in carbon dioxide (CO2) mapping in the Southern Ocean, it is essential to resolve the seasonal cycle (SC) of the meridional gradient of CO2 through high frequency (at least daily) observations that also span the region's meridional axis. We also showed that the estimated SC anomaly and mean annual CO2 are highly sensitive to seasonal sampling biases.
Pierre Friedlingstein, Matthew W. Jones, Michael O'Sullivan, Robbie M. Andrew, Dorothee C. E. Bakker, Judith Hauck, Corinne Le Quéré, Glen P. Peters, Wouter Peters, Julia Pongratz, Stephen Sitch, Josep G. Canadell, Philippe Ciais, Rob B. Jackson, Simone R. Alin, Peter Anthoni, Nicholas R. Bates, Meike Becker, Nicolas Bellouin, Laurent Bopp, Thi Tuyet Trang Chau, Frédéric Chevallier, Louise P. Chini, Margot Cronin, Kim I. Currie, Bertrand Decharme, Laique M. Djeutchouang, Xinyu Dou, Wiley Evans, Richard A. Feely, Liang Feng, Thomas Gasser, Dennis Gilfillan, Thanos Gkritzalis, Giacomo Grassi, Luke Gregor, Nicolas Gruber, Özgür Gürses, Ian Harris, Richard A. Houghton, George C. Hurtt, Yosuke Iida, Tatiana Ilyina, Ingrid T. Luijkx, Atul Jain, Steve D. Jones, Etsushi Kato, Daniel Kennedy, Kees Klein Goldewijk, Jürgen Knauer, Jan Ivar Korsbakken, Arne Körtzinger, Peter Landschützer, Siv K. Lauvset, Nathalie Lefèvre, Sebastian Lienert, Junjie Liu, Gregg Marland, Patrick C. McGuire, Joe R. Melton, David R. Munro, Julia E. M. S. Nabel, Shin-Ichiro Nakaoka, Yosuke Niwa, Tsuneo Ono, Denis Pierrot, Benjamin Poulter, Gregor Rehder, Laure Resplandy, Eddy Robertson, Christian Rödenbeck, Thais M. Rosan, Jörg Schwinger, Clemens Schwingshackl, Roland Séférian, Adrienne J. Sutton, Colm Sweeney, Toste Tanhua, Pieter P. Tans, Hanqin Tian, Bronte Tilbrook, Francesco Tubiello, Guido R. van der Werf, Nicolas Vuichard, Chisato Wada, Rik Wanninkhof, Andrew J. Watson, David Willis, Andrew J. Wiltshire, Wenping Yuan, Chao Yue, Xu Yue, Sönke Zaehle, and Jiye Zeng
Earth Syst. Sci. Data, 14, 1917–2005, https://doi.org/10.5194/essd-14-1917-2022, https://doi.org/10.5194/essd-14-1917-2022, 2022
Short summary
Short summary
The Global Carbon Budget 2021 describes the data sets and methodology used to quantify the emissions of carbon dioxide and their partitioning among the atmosphere, land, and ocean. These living data are updated every year to provide the highest transparency and traceability in the reporting of CO2, the key driver of climate change.
Amanda R. Fay, Luke Gregor, Peter Landschützer, Galen A. McKinley, Nicolas Gruber, Marion Gehlen, Yosuke Iida, Goulven G. Laruelle, Christian Rödenbeck, Alizée Roobaert, and Jiye Zeng
Earth Syst. Sci. Data, 13, 4693–4710, https://doi.org/10.5194/essd-13-4693-2021, https://doi.org/10.5194/essd-13-4693-2021, 2021
Short summary
Short summary
The movement of carbon dioxide from the atmosphere to the ocean is estimated using surface ocean carbon (pCO2) measurements and an equation including variables such as temperature and wind speed; the choices of these variables lead to uncertainties. We introduce the SeaFlux ensemble which provides carbon flux maps calculated in a consistent manner, thus reducing uncertainty by using common choices for wind speed and a set definition of "global" coverage.
Luke Gregor and Nicolas Gruber
Earth Syst. Sci. Data, 13, 777–808, https://doi.org/10.5194/essd-13-777-2021, https://doi.org/10.5194/essd-13-777-2021, 2021
Short summary
Short summary
Ocean acidification (OA) has altered the ocean's carbonate chemistry, with consequences for marine life. Yet, no observation-based data set exists that permits us to study changes in OA. We fill this gap with a global data set of relevant surface ocean parameters over the period 1985–2018. This data set, OceanSODA-ETHZ, was created by using satellite and other data to extrapolate ship-based measurements of carbon dioxide and total alkalinity from which parameters for OA were computed.
Luke Gregor, Alice D. Lebehot, Schalk Kok, and Pedro M. Scheel Monteiro
Geosci. Model Dev., 12, 5113–5136, https://doi.org/10.5194/gmd-12-5113-2019, https://doi.org/10.5194/gmd-12-5113-2019, 2019
Short summary
Short summary
The ocean plays a vital role in mitigating climate change by taking up atmospheric carbon dioxide (CO2). Historically sparse ship-based measurements of surface ocean CO2 make direct estimates of CO2 exchange changes unreliable. We introduce a machine-learning ensemble approach to fill these observational gaps. Our method performs incrementally better relative to past methods, leading to our hypothesis that we are perhaps reaching the limitation of machine-learning algorithms' capability.
N. Precious Mongwe, Marcello Vichi, and Pedro M. S. Monteiro
Biogeosciences, 15, 2851–2872, https://doi.org/10.5194/bg-15-2851-2018, https://doi.org/10.5194/bg-15-2851-2018, 2018
Short summary
Short summary
Here we analyze seasonal cycle of CO2 biases in 10 CMIP5 models in the SO. We find two main model biases; exaggeration of primary production such that biologically driven DIC changes mainly regulates FCO2 variability, and an overestimation of the role of solubility, such that changes in temperature dominantly drive FCO2 seasonal changes to an extent of opposing biological CO2 uptake in spring. CMIP5 models show greater zonal homogeneity in the seasonal cycle of FCO2 than observational products.
Corinne Le Quéré, Robbie M. Andrew, Pierre Friedlingstein, Stephen Sitch, Julia Pongratz, Andrew C. Manning, Jan Ivar Korsbakken, Glen P. Peters, Josep G. Canadell, Robert B. Jackson, Thomas A. Boden, Pieter P. Tans, Oliver D. Andrews, Vivek K. Arora, Dorothee C. E. Bakker, Leticia Barbero, Meike Becker, Richard A. Betts, Laurent Bopp, Frédéric Chevallier, Louise P. Chini, Philippe Ciais, Catherine E. Cosca, Jessica Cross, Kim Currie, Thomas Gasser, Ian Harris, Judith Hauck, Vanessa Haverd, Richard A. Houghton, Christopher W. Hunt, George Hurtt, Tatiana Ilyina, Atul K. Jain, Etsushi Kato, Markus Kautz, Ralph F. Keeling, Kees Klein Goldewijk, Arne Körtzinger, Peter Landschützer, Nathalie Lefèvre, Andrew Lenton, Sebastian Lienert, Ivan Lima, Danica Lombardozzi, Nicolas Metzl, Frank Millero, Pedro M. S. Monteiro, David R. Munro, Julia E. M. S. Nabel, Shin-ichiro Nakaoka, Yukihiro Nojiri, X. Antonio Padin, Anna Peregon, Benjamin Pfeil, Denis Pierrot, Benjamin Poulter, Gregor Rehder, Janet Reimer, Christian Rödenbeck, Jörg Schwinger, Roland Séférian, Ingunn Skjelvan, Benjamin D. Stocker, Hanqin Tian, Bronte Tilbrook, Francesco N. Tubiello, Ingrid T. van der Laan-Luijkx, Guido R. van der Werf, Steven van Heuven, Nicolas Viovy, Nicolas Vuichard, Anthony P. Walker, Andrew J. Watson, Andrew J. Wiltshire, Sönke Zaehle, and Dan Zhu
Earth Syst. Sci. Data, 10, 405–448, https://doi.org/10.5194/essd-10-405-2018, https://doi.org/10.5194/essd-10-405-2018, 2018
Short summary
Short summary
The Global Carbon Budget 2017 describes data sets and methodology to quantify the five major components of the global carbon budget and their uncertainties. It is the 12th annual update and the 6th published in this journal.
Luke Gregor, Schalk Kok, and Pedro M. S. Monteiro
Biogeosciences, 14, 5551–5569, https://doi.org/10.5194/bg-14-5551-2017, https://doi.org/10.5194/bg-14-5551-2017, 2017
Short summary
Short summary
We use machine learning to extrapolate ship measurements of CO2 using satellite data. We present two ML methods new to this field. These methods perform well in the context of previous work and reproduce the decadal trends of previous estimates. To test the methods, we simulate the exact observed setup in biogeochemical ocean model output. We show that the new methods perform well in synthetic data. Lastly, we show that there is only a weak bias due to undersampling in the SOCAT v3 dataset.
Corinne Le Quéré, Robbie M. Andrew, Josep G. Canadell, Stephen Sitch, Jan Ivar Korsbakken, Glen P. Peters, Andrew C. Manning, Thomas A. Boden, Pieter P. Tans, Richard A. Houghton, Ralph F. Keeling, Simone Alin, Oliver D. Andrews, Peter Anthoni, Leticia Barbero, Laurent Bopp, Frédéric Chevallier, Louise P. Chini, Philippe Ciais, Kim Currie, Christine Delire, Scott C. Doney, Pierre Friedlingstein, Thanos Gkritzalis, Ian Harris, Judith Hauck, Vanessa Haverd, Mario Hoppema, Kees Klein Goldewijk, Atul K. Jain, Etsushi Kato, Arne Körtzinger, Peter Landschützer, Nathalie Lefèvre, Andrew Lenton, Sebastian Lienert, Danica Lombardozzi, Joe R. Melton, Nicolas Metzl, Frank Millero, Pedro M. S. Monteiro, David R. Munro, Julia E. M. S. Nabel, Shin-ichiro Nakaoka, Kevin O'Brien, Are Olsen, Abdirahman M. Omar, Tsuneo Ono, Denis Pierrot, Benjamin Poulter, Christian Rödenbeck, Joe Salisbury, Ute Schuster, Jörg Schwinger, Roland Séférian, Ingunn Skjelvan, Benjamin D. Stocker, Adrienne J. Sutton, Taro Takahashi, Hanqin Tian, Bronte Tilbrook, Ingrid T. van der Laan-Luijkx, Guido R. van der Werf, Nicolas Viovy, Anthony P. Walker, Andrew J. Wiltshire, and Sönke Zaehle
Earth Syst. Sci. Data, 8, 605–649, https://doi.org/10.5194/essd-8-605-2016, https://doi.org/10.5194/essd-8-605-2016, 2016
Short summary
Short summary
The Global Carbon Budget 2016 is the 11th annual update of emissions of carbon dioxide (CO2) and their partitioning among the atmosphere, land, and ocean. This data synthesis brings together measurements, statistical information, and analyses of model results in order to provide an assessment of the global carbon budget and their uncertainties for years 1959 to 2015, with a projection for year 2016.
Dorothee C. E. Bakker, Benjamin Pfeil, Camilla S. Landa, Nicolas Metzl, Kevin M. O'Brien, Are Olsen, Karl Smith, Cathy Cosca, Sumiko Harasawa, Stephen D. Jones, Shin-ichiro Nakaoka, Yukihiro Nojiri, Ute Schuster, Tobias Steinhoff, Colm Sweeney, Taro Takahashi, Bronte Tilbrook, Chisato Wada, Rik Wanninkhof, Simone R. Alin, Carlos F. Balestrini, Leticia Barbero, Nicholas R. Bates, Alejandro A. Bianchi, Frédéric Bonou, Jacqueline Boutin, Yann Bozec, Eugene F. Burger, Wei-Jun Cai, Robert D. Castle, Liqi Chen, Melissa Chierici, Kim Currie, Wiley Evans, Charles Featherstone, Richard A. Feely, Agneta Fransson, Catherine Goyet, Naomi Greenwood, Luke Gregor, Steven Hankin, Nick J. Hardman-Mountford, Jérôme Harlay, Judith Hauck, Mario Hoppema, Matthew P. Humphreys, Christopher W. Hunt, Betty Huss, J. Severino P. Ibánhez, Truls Johannessen, Ralph Keeling, Vassilis Kitidis, Arne Körtzinger, Alex Kozyr, Evangelia Krasakopoulou, Akira Kuwata, Peter Landschützer, Siv K. Lauvset, Nathalie Lefèvre, Claire Lo Monaco, Ansley Manke, Jeremy T. Mathis, Liliane Merlivat, Frank J. Millero, Pedro M. S. Monteiro, David R. Munro, Akihiko Murata, Timothy Newberger, Abdirahman M. Omar, Tsuneo Ono, Kristina Paterson, David Pearce, Denis Pierrot, Lisa L. Robbins, Shu Saito, Joe Salisbury, Reiner Schlitzer, Bernd Schneider, Roland Schweitzer, Rainer Sieger, Ingunn Skjelvan, Kevin F. Sullivan, Stewart C. Sutherland, Adrienne J. Sutton, Kazuaki Tadokoro, Maciej Telszewski, Matthias Tuma, Steven M. A. C. van Heuven, Doug Vandemark, Brian Ward, Andrew J. Watson, and Suqing Xu
Earth Syst. Sci. Data, 8, 383–413, https://doi.org/10.5194/essd-8-383-2016, https://doi.org/10.5194/essd-8-383-2016, 2016
Short summary
Short summary
Version 3 of the Surface Ocean CO2 Atlas (www.socat.info) has 14.5 million CO2 (carbon dioxide) values for the years 1957 to 2014 covering the global oceans and coastal seas. Version 3 is an update to version 2 with a longer record and 44 % more CO2 values. The CO2 measurements have been made on ships, fixed moorings and drifting buoys. SOCAT enables quantification of the ocean carbon sink and ocean acidification, as well as model evaluation, thus informing climate negotiations.
A. Weeber, S. Swart, and P. M. S. Monteiro
Biogeosciences Discuss., https://doi.org/10.5194/bgd-12-1653-2015, https://doi.org/10.5194/bgd-12-1653-2015, 2015
Revised manuscript not accepted
Short summary
Short summary
As anthropogenic CO2 increases and sea ice dynamics change with climate, understanding the trend in these characteristics of variability in the seasonal drivers of ΩA will become increasingly important. We investigate the major drivers of interannual to seasonal scale variability of ΩA. We show that the critical climate (physical-biogeochemical) sensitivities for ΩA at the Antarctic ice self are the timing and rate of sea ice thaw and the resulting onset and persistence of phytoplankton blooms.
W. R. Joubert, S. Swart, A. Tagliabue, S. J. Thomalla, and P. M. S. Monteiro
Biogeosciences Discuss., https://doi.org/10.5194/bgd-11-4335-2014, https://doi.org/10.5194/bgd-11-4335-2014, 2014
Revised manuscript not accepted
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Biogeochemistry: Air - Sea Exchange
Air–sea gas exchange in a seagrass ecosystem – results from a 3He ∕ SF6 tracer release experiment
Concentrations of dissolved dimethyl sulfide (DMS), methanethiol and other trace gases in context of microbial communities from the temperate Atlantic to the Arctic Ocean
Marine nitrogen fixation as a possible source of atmospheric water-soluble organic nitrogen aerosols in the subtropical North Pacific
Global analysis of the controls on seawater dimethylsulfide spatial variability
Ice nucleating properties of the sea ice diatom Fragilariopsis cylindrus and its exudates
On physical mechanisms enhancing air–sea CO2 exchange
Winter season Southern Ocean distributions of climate-relevant trace gases
How biogenic polymers control surfactant dynamics in the surface microlayer: insights from a coastal Baltic Sea study
Identifying the biological control of the annual and multi-year variations in South Atlantic air–sea CO2 flux
The sensitivity of pCO2 reconstructions to sampling scales across a Southern Ocean sub-domain: a semi-idealized ocean sampling simulation approach
Physical mechanisms for biological carbon uptake during the onset of the spring phytoplankton bloom in the northwestern Mediterranean Sea (BOUSSOLE site)
Methane flux estimates from continuous atmospheric measurements and surface-water observations in the northern Labrador Sea and Baffin Bay
Wintertime process study of the North Brazil Current rings reveals the region as a larger sink for CO2 than expected
New constraints on biological production and mixing processes in the South China Sea from triple isotope composition of dissolved oxygen
Tidal mixing of estuarine and coastal waters in the western English Channel is a control on spatial and temporal variability in seawater CO2
A seamless ensemble-based reconstruction of surface ocean pCO2 and air–sea CO2 fluxes over the global coastal and open oceans
Sea ice concentration impacts dissolved organic gases in the Canadian Arctic
Evaluating the Arabian Sea as a regional source of atmospheric CO2: seasonal variability and drivers
An empirical MLR for estimating surface layer DIC and a comparative assessment to other gap-filling techniques for ocean carbon time series
Derivation of seawater pCO2 from net community production identifies the South Atlantic Ocean as a CO2 source
Eukaryotic community composition in the sea surface microlayer across an east–west transect in the Mediterranean Sea
Enhancement of the North Atlantic CO2 sink by Arctic Waters
Global ocean dimethyl sulfide climatology estimated from observations and an artificial neural network
Atmospheric deposition of organic matter at a remote site in the central Mediterranean Sea: implications for the marine ecosystem
Underway seawater and atmospheric measurements of volatile organic compounds in the Southern Ocean
Dimethylsulfide (DMS), marine biogenic aerosols and the ecophysiology of coral reefs
Spatial variations in CO2 fluxes in the Saguenay Fjord (Quebec, Canada) and results of a water mixing model
Gas exchange estimates in the Peruvian upwelling regime biased by multi-day near-surface stratification
Insights from year-long measurements of air–water CH4 and CO2 exchange in a coastal environment
On the role of climate modes in modulating the air–sea CO2 fluxes in eastern boundary upwelling systems
Reviews and syntheses: the GESAMP atmospheric iron deposition model intercomparison study
Increase of dissolved inorganic carbon and decrease in pH in near-surface waters in the Mediterranean Sea during the past two decades
Utilizing the Drake Passage Time-series to understand variability and change in subpolar Southern Ocean pCO2
Effect of wind speed on the size distribution of gel particles in the sea surface microlayer: insights from a wind–wave channel experiment
The seasonal cycle of pCO2 and CO2 fluxes in the Southern Ocean: diagnosing anomalies in CMIP5 Earth system models
Marine phytoplankton stoichiometry mediates nonlinear interactions between nutrient supply, temperature, and atmospheric CO2
Constraints on global oceanic emissions of N2O from observations and models
Arctic Ocean CO2 uptake: an improved multiyear estimate of the air–sea CO2 flux incorporating chlorophyll a concentrations
Uncertainty in the global oceanic CO2 uptake induced by wind forcing: quantification and spatial analysis
Phytoplankton growth response to Asian dust addition in the northwest Pacific Ocean versus the Yellow Sea
Global high-resolution monthly pCO2 climatology for the coastal ocean derived from neural network interpolation
Changes in the partial pressure of carbon dioxide in the Mauritanian–Cap Vert upwelling region between 2005 and 2012
Impact of ocean acidification on Arctic phytoplankton blooms and dimethyl sulfide concentration under simulated ice-free and under-ice conditions
Coral reef origins of atmospheric dimethylsulfide at Heron Island, southern Great Barrier Reef, Australia
Bioavailable atmospheric phosphorous supply to the global ocean: a 3-D global modeling study
Coastal-ocean uptake of anthropogenic carbon
Role of zooplankton dynamics for Southern Ocean phytoplankton biomass and global biogeochemical cycles
Surfactant control of gas transfer velocity along an offshore coastal transect: results from a laboratory gas exchange tank
Climate impacts on multidecadal pCO2 variability in the North Atlantic: 1948–2009
The organic sea-surface microlayer in the upwelling region off the coast of Peru and potential implications for air–sea exchange processes
Ryo Dobashi and David T. Ho
Biogeosciences, 20, 1075–1087, https://doi.org/10.5194/bg-20-1075-2023, https://doi.org/10.5194/bg-20-1075-2023, 2023
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Seagrass meadows are productive ecosystems and bury much carbon. Understanding their role in the global carbon cycle requires knowledge of air–sea CO2 fluxes and hence the knowledge of gas transfer velocity (k). In this study, k was determined from the dual tracer technique in Florida Bay. The observed gas transfer velocity was lower than previous studies in the coastal and open oceans at the same wind speeds, most likely due to wave attenuation by seagrass and limited wind fetch in this area.
Valérie Gros, Bernard Bonsang, Roland Sarda-Estève, Anna Nikolopoulos, Katja Metfies, Matthias Wietz, and Ilka Peeken
Biogeosciences, 20, 851–867, https://doi.org/10.5194/bg-20-851-2023, https://doi.org/10.5194/bg-20-851-2023, 2023
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The oceans are both sources and sinks for trace gases important for atmospheric chemistry and marine ecology. Here, we quantified selected trace gases (including the biological metabolites dissolved dimethyl sulfide, methanethiol and isoprene) along a 2500 km transect from the North Atlantic to the Arctic Ocean. In the context of phytoplankton and bacterial communities, our study suggests that methanethiol (rarely measured before) might substantially influence ocean–atmosphere cycling.
Tsukasa Dobashi, Yuzo Miyazaki, Eri Tachibana, Kazutaka Takahashi, Sachiko Horii, Fuminori Hashihama, Saori Yasui-Tamura, Yoko Iwamoto, Shu-Kuan Wong, and Koji Hamasaki
Biogeosciences, 20, 439–449, https://doi.org/10.5194/bg-20-439-2023, https://doi.org/10.5194/bg-20-439-2023, 2023
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Water-soluble organic nitrogen (WSON) in marine aerosols is important for biogeochemical cycling of bioelements. Our shipboard measurements suggested that reactive nitrogen produced and exuded by nitrogen-fixing microorganisms in surface seawater likely contributed to the formation of WSON aerosols in the subtropical North Pacific. This study provides new implications for the role of marine microbial activity in the formation of WSON aerosols in the ocean surface.
George Manville, Thomas G. Bell, Jane P. Mulcahy, Rafel Simó, Martí Galí, Anoop S. Mahajan, Shrivardhan Hulswar, and Paul R. Halloran
Biogeosciences Discuss., https://doi.org/10.5194/bg-2022-250, https://doi.org/10.5194/bg-2022-250, 2023
Revised manuscript accepted for BG
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We present the first global investigation of controls on seawater dimethylsulfide (DMS) spatial variability over scales up to 100 km. Sea surface height anomalies, density, and chlorophyll-a help explain almost 80 % of DMS variability. The results suggest that physical and biogeochemical processes play an equally important role in controlling DMS variability. These data provide independent confirmation that existing parameterisations of seawater DMS concentration use appropriate variables.
Lukas Eickhoff, Maddalena Bayer-Giraldi, Naama Reicher, Yinon Rudich, and Thomas Koop
Biogeosciences, 20, 1–14, https://doi.org/10.5194/bg-20-1-2023, https://doi.org/10.5194/bg-20-1-2023, 2023
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The formation of ice is an important process in Earth’s atmosphere, biosphere, and cryosphere, in particular in polar regions. Our research focuses on the influence of the sea ice diatom Fragilariopsis cylindrus and of molecules produced by it upon heterogenous ice nucleation. For that purpose, we studied the freezing of tiny droplets containing the diatoms in a microfluidic device. Together with previous studies, our results suggest a common freezing behaviour of various sea ice diatoms.
Lucía Gutiérrez-Loza, Erik Nilsson, Marcus B. Wallin, Erik Sahlée, and Anna Rutgersson
Biogeosciences, 19, 5645–5665, https://doi.org/10.5194/bg-19-5645-2022, https://doi.org/10.5194/bg-19-5645-2022, 2022
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The exchange of CO2 between the ocean and the atmosphere is an essential aspect of the global carbon cycle and is highly relevant for the Earth's climate. In this study, we used 9 years of in situ measurements to evaluate the temporal variability in the air–sea CO2 fluxes in the Baltic Sea. Furthermore, using this long record, we assessed the effect of atmospheric and water-side mechanisms controlling the efficiency of the air–sea CO2 exchange under different wind-speed conditions.
Li Zhou, Dennis Booge, Miming Zhang, and Christa A. Marandino
Biogeosciences, 19, 5021–5040, https://doi.org/10.5194/bg-19-5021-2022, https://doi.org/10.5194/bg-19-5021-2022, 2022
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Trace gas air–sea exchange exerts an important control on air quality and climate, especially in the Southern Ocean (SO). Almost all of the measurements there are skewed to summer, but it is essential to expand our measurement database over greater temporal and spatial scales. Therefore, we report measured concentrations of dimethylsulfide (DMS, as well as related sulfur compounds) and isoprene in the Atlantic sector of the SO. The observations of isoprene are the first in the winter in the SO.
Theresa Barthelmeß and Anja Engel
Biogeosciences, 19, 4965–4992, https://doi.org/10.5194/bg-19-4965-2022, https://doi.org/10.5194/bg-19-4965-2022, 2022
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Greenhouse gases released by human activity cause a global rise in mean temperatures. While scientists can predict how much of these gases accumulate in the atmosphere based on not only human-derived sources but also oceanic sinks, it is rather difficult to predict the major influence of coastal ecosystems. We provide a detailed study on the occurrence, composition, and controls of substances that suppress gas exchange. We thus help to determine what controls coastal greenhouse gas fluxes.
Daniel J. Ford, Gavin H. Tilstone, Jamie D. Shutler, and Vassilis Kitidis
Biogeosciences, 19, 4287–4304, https://doi.org/10.5194/bg-19-4287-2022, https://doi.org/10.5194/bg-19-4287-2022, 2022
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This study explores the seasonal, inter-annual, and multi-year drivers of the South Atlantic air–sea CO2 flux. Our analysis showed seasonal sea surface temperatures dominate in the subtropics, and the subpolar regions correlated with biological processes. Inter-annually, the El Niño–Southern Oscillation correlated with the CO2 flux by modifying sea surface temperatures and biological activity. Long-term trends indicated an important biological contribution to changes in the air–sea CO2 flux.
Laique M. Djeutchouang, Nicolette Chang, Luke Gregor, Marcello Vichi, and Pedro M. S. Monteiro
Biogeosciences, 19, 4171–4195, https://doi.org/10.5194/bg-19-4171-2022, https://doi.org/10.5194/bg-19-4171-2022, 2022
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Based on observing system simulation experiments using a mesoscale-resolving model, we found that to significantly improve uncertainties and biases in carbon dioxide (CO2) mapping in the Southern Ocean, it is essential to resolve the seasonal cycle (SC) of the meridional gradient of CO2 through high frequency (at least daily) observations that also span the region's meridional axis. We also showed that the estimated SC anomaly and mean annual CO2 are highly sensitive to seasonal sampling biases.
Liliane Merlivat, Michael Hemming, Jacqueline Boutin, David Antoine, Vincenzo Vellucci, Melek Golbol, Gareth A. Lee, and Laurence Beaumont
Biogeosciences, 19, 3911–3920, https://doi.org/10.5194/bg-19-3911-2022, https://doi.org/10.5194/bg-19-3911-2022, 2022
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We use in situ high-temporal-resolution measurements of dissolved inorganic carbon and atmospheric parameters at the air–sea interface to analyse phytoplankton bloom initiation identified as the net rate of biological carbon uptake in the Mediterranean Sea. The shift from wind-driven to buoyancy-driven mixing creates conditions for blooms to begin. Active mixing at the air–sea interface leads to the onset of the surface phytoplankton bloom due to the relaxation of wind speed following storms.
Judith Vogt, David Risk, Kumiko Azetsu-Scott, Evan N. Edinger, and Owen A. Sherwood
EGUsphere, https://doi.org/10.5194/egusphere-2022-545, https://doi.org/10.5194/egusphere-2022-545, 2022
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The release of the greenhouse gas methane from Arctic permafrost and submarine sources could exacerbate climate change in a positive feedback. Continuous monitoring conducted over a 5100 km voyage in the western margin of the Labrador Sea and Baffin Bay highlighted both onshore and offshore sources of atmospheric methane. The ocean-atmosphere flux of methane was positive at all measured stations, suggesting that the region in summer 2021 was a net positive source of methane to the atmosphere.
Léa Olivier, Jacqueline Boutin, Gilles Reverdin, Nathalie Lefèvre, Peter Landschützer, Sabrina Speich, Johannes Karstensen, Matthieu Labaste, Christophe Noisel, Markus Ritschel, Tobias Steinhoff, and Rik Wanninkhof
Biogeosciences, 19, 2969–2988, https://doi.org/10.5194/bg-19-2969-2022, https://doi.org/10.5194/bg-19-2969-2022, 2022
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We investigate the impact of the interactions between eddies and the Amazon River plume on the CO2 air–sea fluxes to better characterize the ocean carbon sink in winter 2020. The region is a strong CO2 sink, previously underestimated by a factor of 10 due to a lack of data and understanding of the processes responsible for the variability in ocean carbon parameters. The CO2 absorption is mainly driven by freshwater from the Amazon entrained by eddies and by the winter seasonal cooling.
Hana Jurikova, Osamu Abe, Fuh-Kwo Shiah, and Mao-Chang Liang
Biogeosciences, 19, 2043–2058, https://doi.org/10.5194/bg-19-2043-2022, https://doi.org/10.5194/bg-19-2043-2022, 2022
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We studied the isotopic composition of oxygen dissolved in seawater in the South China Sea. This tells us about the origin of oxygen in the water column, distinguishing between biological oxygen produced by phytoplankton communities and atmospheric oxygen entering seawater through gas exchange. We found that the East Asian Monsoon plays an important role in determining the amount of oxygen produced vs. consumed by the phytoplankton, as well as in inducing vertical water mass mixing.
Richard P. Sims, Michael Bedington, Ute Schuster, Andrew J. Watson, Vassilis Kitidis, Ricardo Torres, Helen S. Findlay, James R. Fishwick, Ian Brown, and Thomas G. Bell
Biogeosciences, 19, 1657–1674, https://doi.org/10.5194/bg-19-1657-2022, https://doi.org/10.5194/bg-19-1657-2022, 2022
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The amount of carbon dioxide (CO2) being absorbed by the ocean is relevant to the earth's climate. CO2 values in the coastal ocean and estuaries are not well known because of the instrumentation used. We used a new approach to measure CO2 across the coastal and estuarine zone. We found that CO2 and salinity were linked to the state of the tide. We used our CO2 measurements and model salinity to predict CO2. Previous studies overestimate how much CO2 the coastal ocean draws down at our site.
Thi Tuyet Trang Chau, Marion Gehlen, and Frédéric Chevallier
Biogeosciences, 19, 1087–1109, https://doi.org/10.5194/bg-19-1087-2022, https://doi.org/10.5194/bg-19-1087-2022, 2022
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Air–sea CO2 fluxes and associated uncertainty over the open ocean to coastal shelves are estimated with a new ensemble-based reconstruction of pCO2 trained on observation-based data. The regional distribution and seasonality of CO2 sources and sinks are consistent with those suggested in previous studies as well as mechanisms discussed therein. The ensemble-based uncertainty field allows identifying critical regions where improvements in pCO2 and air–sea CO2 flux estimates should be a priority.
Charel Wohl, Anna E. Jones, William T. Sturges, Philip D. Nightingale, Brent Else, Brian J. Butterworth, and Mingxi Yang
Biogeosciences, 19, 1021–1045, https://doi.org/10.5194/bg-19-1021-2022, https://doi.org/10.5194/bg-19-1021-2022, 2022
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We measured concentrations of five different organic gases in seawater in the high Arctic during summer. We found higher concentrations near the surface of the water column (top 5–10 m) and in areas of partial ice cover. This suggests that sea ice influences the concentrations of these gases. These gases indirectly exert a slight cooling effect on the climate, and it is therefore important to measure the levels accurately for future climate predictions.
Alain de Verneil, Zouhair Lachkar, Shafer Smith, and Marina Lévy
Biogeosciences, 19, 907–929, https://doi.org/10.5194/bg-19-907-2022, https://doi.org/10.5194/bg-19-907-2022, 2022
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The Arabian Sea is a natural CO2 source to the atmosphere, but previous work highlights discrepancies between data and models in estimating air–sea CO2 flux. In this study, we use a regional ocean model, achieve a flux closer to available data, and break down the seasonal cycles that impact it, with one result being the great importance of monsoon winds. As demonstrated in a meta-analysis, differences from data still remain, highlighting the great need for further regional data collection.
Jesse M. Vance, Kim Currie, John Zeldis, Peter W. Dillingham, and Cliff S. Law
Biogeosciences, 19, 241–269, https://doi.org/10.5194/bg-19-241-2022, https://doi.org/10.5194/bg-19-241-2022, 2022
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Long-term monitoring is needed to detect changes in our environment. Time series of ocean carbon have aided our understanding of seasonal cycles and provided evidence for ocean acidification. Data gaps are inevitable, yet no standard method for filling gaps exists. We present a regression approach here and compare it to seven other common methods to understand the impact of different approaches when assessing seasonal to climatic variability in ocean carbon.
Daniel J. Ford, Gavin H. Tilstone, Jamie D. Shutler, and Vassilis Kitidis
Biogeosciences, 19, 93–115, https://doi.org/10.5194/bg-19-93-2022, https://doi.org/10.5194/bg-19-93-2022, 2022
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This study identifies the most accurate biological proxy for the estimation of seawater pCO2 fields, which are key to assessing the ocean carbon sink. Our analysis shows that the net community production (NCP), the balance between photosynthesis and respiration, was more accurate than chlorophyll a within a neural network scheme. The improved pCO2 estimates, based on NCP, identified the South Atlantic Ocean as a net CO2 source, compared to a CO2 sink using chlorophyll a.
Birthe Zäncker, Michael Cunliffe, and Anja Engel
Biogeosciences, 18, 2107–2118, https://doi.org/10.5194/bg-18-2107-2021, https://doi.org/10.5194/bg-18-2107-2021, 2021
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Fungi are found in numerous marine environments. Our study found an increased importance of fungi in the Ionian Sea, where bacterial and phytoplankton counts were reduced, but organic matter was still available, suggesting fungi might benefit from the reduced competition from bacteria in low-nutrient, low-chlorophyll (LNLC) regions.
Jon Olafsson, Solveig R. Olafsdottir, Taro Takahashi, Magnus Danielsen, and Thorarinn S. Arnarson
Biogeosciences, 18, 1689–1701, https://doi.org/10.5194/bg-18-1689-2021, https://doi.org/10.5194/bg-18-1689-2021, 2021
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The Atlantic north of 50° N is an intense ocean sink area for atmospheric CO2. Observations in the vicinity of Iceland reveal a previously unrecognized Arctic contribution to the North Atlantic CO2 sink. Sustained CO2 influx to waters flowing from the Arctic Ocean is linked to their excess alkalinity derived from sources in the changing Arctic. The results relate to the following question: will the North Atlantic continue to absorb CO2 in the future as it has in the past?
Wei-Lei Wang, Guisheng Song, François Primeau, Eric S. Saltzman, Thomas G. Bell, and J. Keith Moore
Biogeosciences, 17, 5335–5354, https://doi.org/10.5194/bg-17-5335-2020, https://doi.org/10.5194/bg-17-5335-2020, 2020
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Dimethyl sulfide, a volatile compound produced as a byproduct of marine phytoplankton activity, can be emitted to the atmosphere via gas exchange. In the atmosphere, DMS is oxidized to cloud condensation nuclei, thus contributing to cloud formation. Therefore, oceanic DMS plays an important role in regulating the planet's climate by influencing the radiation budget. In this study, we use an artificial neural network model to update the global DMS climatology and estimate the sea-to-air flux.
Yuri Galletti, Silvia Becagli, Alcide di Sarra, Margherita Gonnelli, Elvira Pulido-Villena, Damiano M. Sferlazzo, Rita Traversi, Stefano Vestri, and Chiara Santinelli
Biogeosciences, 17, 3669–3684, https://doi.org/10.5194/bg-17-3669-2020, https://doi.org/10.5194/bg-17-3669-2020, 2020
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This paper reports the first data about atmospheric deposition of dissolved organic matter (DOM) on the island of Lampedusa. It also shows the implications for the surface marine layer by studying the impact of atmospheric organic carbon deposition in the marine ecosystem. It is a preliminary study, but it is pioneering and important for having new data that can be crucial in order to understand the impact of atmospheric deposition on the marine carbon cycle in a global climate change scenario.
Charel Wohl, Ian Brown, Vassilis Kitidis, Anna E. Jones, William T. Sturges, Philip D. Nightingale, and Mingxi Yang
Biogeosciences, 17, 2593–2619, https://doi.org/10.5194/bg-17-2593-2020, https://doi.org/10.5194/bg-17-2593-2020, 2020
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The oceans represent a poorly understood source of organic carbon to the atmosphere. In this paper, we present ship-based measurements of specific compounds in ambient air and seawater of the Southern Ocean. We present fluxes of these gases between air and sea at very high resolution. The data also contain evidence for day and night variations in some of these compounds. These measurements can be used to better understand the role of the Southern Ocean in the cycling of these compounds.
Rebecca L. Jackson, Albert J. Gabric, Roger Cropp, and Matthew T. Woodhouse
Biogeosciences, 17, 2181–2204, https://doi.org/10.5194/bg-17-2181-2020, https://doi.org/10.5194/bg-17-2181-2020, 2020
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Coral reefs are a strong source of atmospheric sulfur through stress-induced emissions of dimethylsulfide (DMS). This biogenic sulfur can influence aerosol and cloud properties and, consequently, the radiative balance over the ocean. DMS emissions may therefore help to mitigate coral physiological stress via increased low-level cloud cover and reduced sea surface temperature. The importance of DMS in coral physiology and climate is reviewed and the implications for coral bleaching are discussed.
Louise Delaigue, Helmuth Thomas, and Alfonso Mucci
Biogeosciences, 17, 547–566, https://doi.org/10.5194/bg-17-547-2020, https://doi.org/10.5194/bg-17-547-2020, 2020
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This paper reports on the first compilation and analysis of the surface water pCO2 distribution in the Saguenay Fjord, the southernmost subarctic fjord in the Northern Hemisphere, and thus fills a significant knowledge gap in current regional estimates of estuarine CO2 emissions.
Tim Fischer, Annette Kock, Damian L. Arévalo-Martínez, Marcus Dengler, Peter Brandt, and Hermann W. Bange
Biogeosciences, 16, 2307–2328, https://doi.org/10.5194/bg-16-2307-2019, https://doi.org/10.5194/bg-16-2307-2019, 2019
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We investigated air–sea gas exchange in oceanic upwelling regions for the case of nitrous oxide off Peru. In this region, routine concentration measurements from ships at 5 m or 10 m depth prove to overestimate surface (bulk) concentration. Thus, standard estimates of gas exchange will show systematic error. This is due to very shallow stratified layers that inhibit exchange between surface water and waters below and can exist for several days. Maximum bias occurs in moderate wind conditions.
Mingxi Yang, Thomas G. Bell, Ian J. Brown, James R. Fishwick, Vassilis Kitidis, Philip D. Nightingale, Andrew P. Rees, and Timothy J. Smyth
Biogeosciences, 16, 961–978, https://doi.org/10.5194/bg-16-961-2019, https://doi.org/10.5194/bg-16-961-2019, 2019
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We quantify the emissions and uptake of the greenhouse gases carbon dioxide and methane from the coastal seas of the UK over 1 year using the state-of-the-art eddy covariance technique. Our measurements show how these air–sea fluxes vary twice a day (tidal), diurnally (circadian) and seasonally. We also estimate the air–sea gas transfer velocity, which is essential for modelling and predicting coastal air-sea exchange.
Riley X. Brady, Nicole S. Lovenduski, Michael A. Alexander, Michael Jacox, and Nicolas Gruber
Biogeosciences, 16, 329–346, https://doi.org/10.5194/bg-16-329-2019, https://doi.org/10.5194/bg-16-329-2019, 2019
Stelios Myriokefalitakis, Akinori Ito, Maria Kanakidou, Athanasios Nenes, Maarten C. Krol, Natalie M. Mahowald, Rachel A. Scanza, Douglas S. Hamilton, Matthew S. Johnson, Nicholas Meskhidze, Jasper F. Kok, Cecile Guieu, Alex R. Baker, Timothy D. Jickells, Manmohan M. Sarin, Srinivas Bikkina, Rachel Shelley, Andrew Bowie, Morgane M. G. Perron, and Robert A. Duce
Biogeosciences, 15, 6659–6684, https://doi.org/10.5194/bg-15-6659-2018, https://doi.org/10.5194/bg-15-6659-2018, 2018
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The first atmospheric iron (Fe) deposition model intercomparison is presented in this study, as a result of the deliberations of the United Nations Joint Group of Experts on the Scientific Aspects of Marine Environmental Protection (GESAMP; http://www.gesamp.org/) Working Group 38. We conclude that model diversity over remote oceans reflects uncertainty in the Fe content parameterizations of dust aerosols, combustion aerosol emissions and the size distribution of transported aerosol Fe.
Liliane Merlivat, Jacqueline Boutin, David Antoine, Laurence Beaumont, Melek Golbol, and Vincenzo Vellucci
Biogeosciences, 15, 5653–5662, https://doi.org/10.5194/bg-15-5653-2018, https://doi.org/10.5194/bg-15-5653-2018, 2018
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The fugacity of carbon dioxide in seawater (fCO2) was measured hourly in the surface waters of the NW Mediterranean Sea during two 3-year sequences separated by 18 years. A decrease of pH of 0.0022 yr−1 was computed. About 85 % of the accumulation of dissolved inorganic carbon (DIC) comes from chemical equilibration with increasing atmospheric CO2; the remaining 15 % accumulation is consistent with estimates of transfer of Atlantic waters through the Gibraltar Strait.
Amanda R. Fay, Nicole S. Lovenduski, Galen A. McKinley, David R. Munro, Colm Sweeney, Alison R. Gray, Peter Landschützer, Britton B. Stephens, Taro Takahashi, and Nancy Williams
Biogeosciences, 15, 3841–3855, https://doi.org/10.5194/bg-15-3841-2018, https://doi.org/10.5194/bg-15-3841-2018, 2018
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The Southern Ocean is highly under-sampled and since this region dominates the ocean sink for CO2, understanding change is critical. Here we utilize available observations to evaluate how the seasonal cycle, variability, and trends in surface ocean carbon in the well-sampled Drake Passage region compare to that of the broader subpolar Southern Ocean. Results indicate that the Drake Passage is representative of the broader region; however, additional winter observations would improve comparisons.
Cui-Ci Sun, Martin Sperling, and Anja Engel
Biogeosciences, 15, 3577–3589, https://doi.org/10.5194/bg-15-3577-2018, https://doi.org/10.5194/bg-15-3577-2018, 2018
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Biogenic gel particles such as transparent exopolymer particles (TEP) and Coomassie stainable particles (CSP) are important components in the sea-surface microlayer (SML). Their potential role in air–sea gas exchange and in primary organic aerosol emission has generated considerable research interest. Our wind wave channel experiment revealed how wind speed controls the accumulation and size distribution of biogenic gel particles in the SML.
N. Precious Mongwe, Marcello Vichi, and Pedro M. S. Monteiro
Biogeosciences, 15, 2851–2872, https://doi.org/10.5194/bg-15-2851-2018, https://doi.org/10.5194/bg-15-2851-2018, 2018
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Here we analyze seasonal cycle of CO2 biases in 10 CMIP5 models in the SO. We find two main model biases; exaggeration of primary production such that biologically driven DIC changes mainly regulates FCO2 variability, and an overestimation of the role of solubility, such that changes in temperature dominantly drive FCO2 seasonal changes to an extent of opposing biological CO2 uptake in spring. CMIP5 models show greater zonal homogeneity in the seasonal cycle of FCO2 than observational products.
Allison R. Moreno, George I. Hagstrom, Francois W. Primeau, Simon A. Levin, and Adam C. Martiny
Biogeosciences, 15, 2761–2779, https://doi.org/10.5194/bg-15-2761-2018, https://doi.org/10.5194/bg-15-2761-2018, 2018
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To bridge the missing links between variable marine elemental stoichiometry, phytoplankton physiology and carbon cycling, we embed four environmentally controlled stoichiometric models into a five-box ocean model. As predicted each model varied in its influence on the biological pump. Surprisingly, we found that variation can lead to nonlinear controls on atmospheric CO2 and carbon export, suggesting the need for further studies of ocean C : P and the impact on ocean carbon cycling.
Erik T. Buitenhuis, Parvadha Suntharalingam, and Corinne Le Quéré
Biogeosciences, 15, 2161–2175, https://doi.org/10.5194/bg-15-2161-2018, https://doi.org/10.5194/bg-15-2161-2018, 2018
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Thanks to decreases in CFC concentrations, N2O is now the third-most important greenhouse gas, and the dominant contributor to stratospheric ozone depletion. Here we estimate the ocean–atmosphere N2O flux. We find that an estimate based on observations alone has a large uncertainty. By combining observations and a range of model simulations we find that the uncertainty is much reduced to 2.45 ± 0.8 Tg N yr−1, and better constrained and at the lower end of the estimate in the latest IPCC report.
Sayaka Yasunaka, Eko Siswanto, Are Olsen, Mario Hoppema, Eiji Watanabe, Agneta Fransson, Melissa Chierici, Akihiko Murata, Siv K. Lauvset, Rik Wanninkhof, Taro Takahashi, Naohiro Kosugi, Abdirahman M. Omar, Steven van Heuven, and Jeremy T. Mathis
Biogeosciences, 15, 1643–1661, https://doi.org/10.5194/bg-15-1643-2018, https://doi.org/10.5194/bg-15-1643-2018, 2018
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We estimated monthly air–sea CO2 fluxes in the Arctic Ocean and its adjacent seas north of 60° N from 1997 to 2014, after mapping pCO2 in the surface water using a self-organizing map technique. The addition of Chl a as a parameter enabled us to improve the estimate of pCO2 via better representation of its decline in spring. The uncertainty in the CO2 flux estimate was reduced, and a net annual Arctic Ocean CO2 uptake of 180 ± 130 Tg C y−1 was determined to be significant.
Alizée Roobaert, Goulven G. Laruelle, Peter Landschützer, and Pierre Regnier
Biogeosciences, 15, 1701–1720, https://doi.org/10.5194/bg-15-1701-2018, https://doi.org/10.5194/bg-15-1701-2018, 2018
Chao Zhang, Huiwang Gao, Xiaohong Yao, Zongbo Shi, Jinhui Shi, Yang Yu, Ling Meng, and Xinyu Guo
Biogeosciences, 15, 749–765, https://doi.org/10.5194/bg-15-749-2018, https://doi.org/10.5194/bg-15-749-2018, 2018
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This study compares the response of phytoplankton growth in the northwest Pacific to those in the Yellow Sea. In general, larger positive responses of phytoplankton induced by combined nutrients (in the subtropical gyre of the northwest Pacific) than those induced by a single nutrient (in the Kuroshio Extension and the Yellow Sea) from the dust are observed. We also emphasize the importance of an increase in bioavailable P stock for phytoplankton growth following dust addition.
Goulven G. Laruelle, Peter Landschützer, Nicolas Gruber, Jean-Louis Tison, Bruno Delille, and Pierre Regnier
Biogeosciences, 14, 4545–4561, https://doi.org/10.5194/bg-14-4545-2017, https://doi.org/10.5194/bg-14-4545-2017, 2017
Melchor González-Dávila, J. Magdalena Santana Casiano, and Francisco Machín
Biogeosciences, 14, 3859–3871, https://doi.org/10.5194/bg-14-3859-2017, https://doi.org/10.5194/bg-14-3859-2017, 2017
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The Mauritanian–Cap Vert upwelling is shown to be sensitive to climate change forcing on upwelling processes, which strongly affects the CO2 surface distribution, ocean acidification rates, and air–sea CO2 exchange. We confirmed an upwelling intensification, an increase in the CO2 outgassing, and an important decrease in the pH of the surface waters. Upwelling areas are poorly studied and VOS lines are shown as one of the most significant contributors to our knowledge of the ocean's response.
Rachel Hussherr, Maurice Levasseur, Martine Lizotte, Jean-Éric Tremblay, Jacoba Mol, Helmuth Thomas, Michel Gosselin, Michel Starr, Lisa A. Miller, Tereza Jarniková, Nina Schuback, and Alfonso Mucci
Biogeosciences, 14, 2407–2427, https://doi.org/10.5194/bg-14-2407-2017, https://doi.org/10.5194/bg-14-2407-2017, 2017
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This study assesses the impact of ocean acidification on phytoplankton and its synthesis of the climate-active gas dimethyl sulfide (DMS), as well as its modulation, by two contrasting light regimes in the Arctic. The light regimes tested had no significant impact on either the phytoplankton or DMS concentration, whereas both variables decreased linearly with the decrease in pH. Thus, a rapid decrease in surface water pH could alter the algal biomass and inhibit DMS production in the Arctic.
Hilton B. Swan, Graham B. Jones, Elisabeth S. M. Deschaseaux, and Bradley D. Eyre
Biogeosciences, 14, 229–239, https://doi.org/10.5194/bg-14-229-2017, https://doi.org/10.5194/bg-14-229-2017, 2017
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We measured the sulfur gas dimethylsulfide (DMS) in marine air at a coral cay on the Great Barrier Reef. DMS is well known to be released from the world's oceans, but environmental evidence of coral reefs releasing DMS has not been clearly demonstrated. We showed the coral reef can sometimes release DMS to the air, which was seen as spikes above the DMS released from the ocean. The DMS from the reef supplements the DMS from the ocean to assist formation of clouds that influence local climate.
Stelios Myriokefalitakis, Athanasios Nenes, Alex R. Baker, Nikolaos Mihalopoulos, and Maria Kanakidou
Biogeosciences, 13, 6519–6543, https://doi.org/10.5194/bg-13-6519-2016, https://doi.org/10.5194/bg-13-6519-2016, 2016
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The global atmospheric cycle of P is simulated accounting for natural and anthropogenic sources, acid dissolution of dust aerosol and changes in atmospheric acidity. Simulations show that P-containing dust dissolution flux may have increased in the last 150 years but is expected to decrease in the future, and biological particles are important carriers of bioavailable P to the ocean. These insights to the P cycle have important implications for marine ecosystem responses to climate change.
Timothée Bourgeois, James C. Orr, Laure Resplandy, Jens Terhaar, Christian Ethé, Marion Gehlen, and Laurent Bopp
Biogeosciences, 13, 4167–4185, https://doi.org/10.5194/bg-13-4167-2016, https://doi.org/10.5194/bg-13-4167-2016, 2016
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The global coastal ocean took up 0.1 Pg C yr−1 of anthropogenic carbon during 1993–2012 based on new biogeochemical simulations with an eddying 3-D global model. That is about half of the most recent estimate, an extrapolation based on surface areas. It should not be confused with the continental shelf pump, perhaps 10 times larger, which includes natural as well as anthropogenic carbon. Coastal uptake of anthropogenic carbon is limited by its offshore transport.
Corinne Le Quéré, Erik T. Buitenhuis, Róisín Moriarty, Séverine Alvain, Olivier Aumont, Laurent Bopp, Sophie Chollet, Clare Enright, Daniel J. Franklin, Richard J. Geider, Sandy P. Harrison, Andrew G. Hirst, Stuart Larsen, Louis Legendre, Trevor Platt, I. Colin Prentice, Richard B. Rivkin, Sévrine Sailley, Shubha Sathyendranath, Nick Stephens, Meike Vogt, and Sergio M. Vallina
Biogeosciences, 13, 4111–4133, https://doi.org/10.5194/bg-13-4111-2016, https://doi.org/10.5194/bg-13-4111-2016, 2016
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We present a global biogeochemical model which incorporates ecosystem dynamics based on the representation of ten plankton functional types, and use the model to assess the relative roles of iron vs. grazing in determining phytoplankton biomass in the Southern Ocean. Our results suggest that observed low phytoplankton biomass in the Southern Ocean during summer is primarily explained by the dynamics of the Southern Ocean zooplankton community, despite iron limitation of phytoplankton growth.
R. Pereira, K. Schneider-Zapp, and R. C. Upstill-Goddard
Biogeosciences, 13, 3981–3989, https://doi.org/10.5194/bg-13-3981-2016, https://doi.org/10.5194/bg-13-3981-2016, 2016
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Understanding controls of air–sea gas exchange is necessary for predicting regional- and global-scale trace gas fluxes and feedbacks. Recent studies demonstrated the importance of surfactants, which occur naturally in the uppermost layer of coastal water bodies, to suppress the gas transfer velocity (kw). Here we present data for seawater samples collected from the North Sea. Using a novel analytical approach we show a strong seasonal and spatial relationship between natural surfactants and kw.
Melissa L. Breeden and Galen A. McKinley
Biogeosciences, 13, 3387–3396, https://doi.org/10.5194/bg-13-3387-2016, https://doi.org/10.5194/bg-13-3387-2016, 2016
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Natural variability of the North Atlantic carbon cycle is modeled for 1948–2009. The dominant mode of surface ocean CO2 variability is associated with sea surface temperature (SST) variability composed of (a) the Atlantic Multidecadal Oscillation (AMO) and (b) a positive SST trend. In the subpolar gyre, positive AMO is associated with reduced vertical mixing that lowers pCO2. In the subtropical gyre, AMO-associated warming increases pCO2. Since 1980, the SST trend has amplified AMO impacts.
Anja Engel and Luisa Galgani
Biogeosciences, 13, 989–1007, https://doi.org/10.5194/bg-13-989-2016, https://doi.org/10.5194/bg-13-989-2016, 2016
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The sea-surface microlayer (SML) is a very thin layer at the interface between the ocean and the atmosphere. Organic compounds in the SML may influence the exchange of gases between seawater and air, as well as primary aerosol emission. Here, we report results from the SOPRAN M91 cruise, a field study to the coastal upwelling regime off Peru's coast in 2012. Our study provides novel insight to the relationship between plankton productivity, wind speed and organic matter accumulation in the SML.
Cited articles
Abernathey, R., Marshall, J. C., and Ferreira, D.: The Dependence of Southern Ocean Meridional Overturning on Wind Stress, J. Phys. Oeanogr., 41, 2261–2278, https://doi.org/10.1175/JPO-D-11-023.1, 2011.
Arrigo, K. R., van Dijken, G. L., and Bushinsky, S.: Primary production in the Southern Ocean, 1997–2006, J. Geophys. Res., 113, 1–27, https://doi.org/10.1029/2007JC004551, 2008.
Atlas, R., Hoffman, R. N., Ardizzone, J., Leidner, S. M., Jusem, J. C., Smith, D. K., and Gombos, D.: A Cross-calibrated, Multiplatform Ocean Surface Wind Velocity Product for Meteorological and Oceanographic Applications, B. Am. Meteorol. Soc., 92, 157–174, https://doi.org/10.1175/2010BAMS2946.1, 2011.
Bakker, D. C. E., Hoppema, M., Schröder, M., Geibert, W., and de Baar, H. J. W.: A rapid transition from ice covered CO2-rich waters to a biologically mediated CO2 sink in the eastern Weddell Gyre, Biogeosciences, 5, 1373–1386, https://doi.org/10.5194/bg-5-1373-2008, 2008.
Bakker, D. C. E., Pfeil, B., Landa, C. S., Metzl, N., O'Brien, K. M., Olsen, A., Smith, K., Cosca, C., Harasawa, S., Jones, S. D., Nakaoka, S.-I., Nojiri, Y., Schuster, U., Steinhoff, T., Sweeney, C., Takahashi, T., Tilbrook, B., Wada, C., Wanninkhof, R., Alin, S. R., Balestrini, C. F., Barbero, L., Bates, N. R., Bianchi, A. A., Bonou, F., Boutin, J., Bozec, Y., Burger, E. F., Cai, W.-J., Castle, R. D., Chen, L., Chierici, M., Currie, K., Evans, W., Featherstone, C., Feely, R. A., Fransson, A., Goyet, C., Greenwood, N., Gregor, L., Hankin, S., Hardman-Mountford, N. J., Harlay, J., Hauck, J., Hoppema, M., Humphreys, M. P., Hunt, C. W., Huss, B., Ibánhez, J. S. P., Johannessen, T., Keeling, R., Kitidis, V., Körtzinger, A., Kozyr, A., Krasakopoulou, E., Kuwata, A., Landschützer, P., Lauvset, S. K., Lefèvre, N., Lo Monaco, C., Manke, A., Mathis, J. T., Merlivat, L., Millero, F. J., Monteiro, P. M. S., Munro, D. R., Murata, A., Newberger, T., Omar, A. M., Ono, T., Paterson, K., Pearce, D., Pierrot, D., Robbins, L. L., Saito, S., Salisbury, J., Schlitzer, R., Schneider, B., Schweitzer, R., Sieger, R., Skjelvan, I., Sullivan, K. F., Sutherland, S. C., Sutton, A. J., Tadokoro, K., Telszewski, M., Tuma, M., van Heuven, S. M. A. C., Vandemark, D., Ward, B., Watson, A. J., and Xu, S.: A multi-decade record of high-quality fCO2 data in version 3 of the Surface Ocean CO2 Atlas (SOCAT), Earth Syst. Sci. Data, 8, 383–413, https://doi.org/10.5194/essd-8-383-2016, 2016.
Barnes, E. A. and Hartmann, D. L.: Dynamical Feedbacks of the Southern Annular Mode in Winter and Summer, J. Atmos. Sci., 67, 2320–2330, https://doi.org/10.1175/2010JAS3385.1, 2010.
Boyd, P. W. and Ellwood, M. J.: The biogeochemical cycle of iron in the ocean, Nat. Geosci., 3, 675–682, https://doi.org/10.1038/ngeo964, 2010.
Carranza, M. M. and Gille, S. T.: Southern Ocean wind-driven entrainment enhances satellite chlorophyll a through the summer, J. Geophys. Res.-Oceans, 120, 304–323, https://doi.org/10.1002/2014JC010203, 2015.
CDIAC: Multi-laboratory compilation of atmospheric carbon dioxide data for the period 1957–2016, NOAA Earth System Research Laboratory, Global Monitoring Division, available at: https://doi.org/10.15138/G3CW4Q, last access: 15 June 2017.
de Boyer Montégut, C., Madec, G., Fischer, A. S., Lazar, A., and Iudicone, D.: Mixed layer depth over the global ocean: An examination of profile data and a profile-based climatology, J. Geophys. Res., 109, 1–20, https://doi.org/10.1029/2004JC002378, 2004.
DeVries, T., Holzer, M., and Primeau, F.: Recent increase in oceanic carbon uptake driven by weaker upper-ocean overturning, Nature, 542, 215–218, https://doi.org/10.1038/nature21068, 2017.
du Plessis, M., Swart, S., Ansorge, I. J., and Mahadevan, A.: Submesoscale processes promote seasonal restratification in the Subantarctic Ocean, J. Geophys. Res., 12, 2960–2975, https://doi.org/10.1002/2016JC012494, 2017.
Fay, A. R. and McKinley, G. A.: Global open-ocean biomes: mean and temporal variability, Earth Syst. Sci. Data, 6, 273–284, https://doi.org/10.5194/essd-6-273-2014, 2014a.
Fay, A. R., McKinley, G. A., and Lovenduski, N. S.: Southern Ocean carbon trends: Sensitivity to methods, Geophys. Res. Lett., 41, 6833–6840, https://doi.org/10.1002/2014GL061324, 2014.
Fogt, R. L., Jones, J. M., and Renwick, J.: Seasonal zonal asymmetries in the southern annular mode and their impact on regional temperature anomalies, J. Climate, 25, 6253–6270, https://doi.org/10.1175/JCLI-D-11-00474.1, 2012.
Gade, K.: A Non-singular Horizontal Position Representation, J. Navigation, 63, 395–417, https://doi.org/10.1017/S0373463309990415, 2010.
Gregor, L., Kok, S., and Monteiro, P. M. S.: Empirical methods for the estimation of Southern Ocean CO2: support vector and random forest regression, Biogeosciences, 14, 5551–5569, https://doi.org/10.5194/bg-14-5551-2017, 2017.
Gregor, L., Monteiro, P. M. S., and Kok, S.: Dataset for empirically estimated pCO2 for the Southern Ocean: RFR and SVR, available at: https://doi.org/10.6084/m9.figshare.5369038.v3, last access 23 July 2017.
Gurney, K. R., Law, R. M., Denning, A. S., Rayner, P. J., Pak, B. C., Baker, D., and Taguchi, S.: Transcom 3 inversion intercomparison: Model mean results for the estimation of seasonal carbon sources and sinks, Global Biogeochem. Cy., 18, GB1010, https://doi.org/10.1029/2003GB002111, 2004.
Hauck, J., Völker, C., Wang, T., Hoppema, M., Losch, M., and Wolf-Gladrow, D. A.: Seasonally different carbon flux changes in the Southern Ocean in response to the southern annular mode, Global Biogeochem. Cy., 27, 1236–1245, https://doi.org/10.1002/2013GB004600, 2013.
Hauck, J. and Völker, C.: A multi-model study on the Southern Ocean CO2 uptake and the role of the biological carbon pump in the 21st century, EGU General Assembly, 17, 12225, https://doi.org/10.1002/2015GB005140, 2015.
Hoppema, M., Fahrbach, E., Stoll, M. H. C., and de Baar, H. J. W.: Annual uptake of atmospheric CO2 by the Weddell sea derived from a surface layer balance, including estimations of entrainment and new production, J. Marine Syst., 19, 219–233, https://doi.org/10.1016/S0924-7963(98)00091-8, 1999.
Jones, S. D., Le Quéré, C., and Rödenbeck, C.: Autocorrelation characteristics of surface ocean pCO2 and air-sea CO2 fluxes, Global Biogeochem. Cy., 26, 1–12, https://doi.org/10.1029/2010GB004017, 2012.
Kanamitsu, M., Ebisuzaki, W., Woollen, J., Yang, S. K., Hnilo, J. J., Fiorino, M., and Potter, G. L.: NCEP-DOE AMIP-II reanalysis (R-2), B. Am. Meteorol. Soc., 83, 1631–1643, https://doi.org/10.1175/BAMS-83-11-1631, 2002.
Khatiwala, S., Tanhua, T., Mikaloff Fletcher, S., Gerber, M., Doney, S. C., Graven, H. D., Gruber, N., McKinley, G. A., Murata, A., Ríos, A. F., and Sabine, C. L.: Global ocean storage of anthropogenic carbon, Biogeosciences, 10, 2169–2191, https://doi.org/10.5194/bg-10-2169-2013, 2013.
Landschützer, P., Gruber, N., Bakker, D. C. E., and Schuster, U.: Recent variability of the global ocean carbon sink, Global Biogeochem. Cy., 28, 927–949, https://doi.org/10.1002/2014GB004853, 2014.
Landschützer, P., Gruber, N., Haumann, F. A., Rödenbeck, C., Bakker, D. C. E., Van Heuven, S. M. A. C., and Wanninkhof, R. H.: The reinvigoration of the Southern Ocean carbon sink, Science, 349, 1221–1224, https://doi.org/10.1126/science.aab2620, 2015.
Landschützer, P., Gruber, N., and Bakker, D. C. E.: Decadal variations and trends of the global ocean carbon sink, Global Biogeochem. Cy., 30, 1396–1417, https://doi.org/10.1002/2015GB005359, 2016.
Landschützer, P., Gruber, N., and Bakker, D. C. E.: An updated observation-based global monthly gridded sea surface pCO2 and air-sea CO2 flux product from 1982 through 2015 and its monthly climatology (NCEI Accession 0160558) Version 2.2, 2017.
Lenton, A. and Matear, R. J.: Role of the Southern Annular Mode (SAM) in Southern Ocean CO2 uptake, Global Biogeochem. Cy., 21, 1–17, https://doi.org/10.1029/2006GB002714, 2007.
Lenton, A., Codron, F., Bopp, L., Metzl, N., Cadule, P., Tagliabue, A., and Le Sommer, J.: Stratospheric ozone depletion reduces ocean carbon uptake and enhances ocean acidification, Geophys. Res. Lett., 36, 1–5, https://doi.org/10.1029/2009GL038227, 2009.
Lenton, A., Metzl, N., Takahashi, T. T., Kuchinke, M., Matear, R. J., Roy, T., and Tilbrook, B.: The observed evolution of oceanic pCO2 and its drivers over the last two decades, Global Biogeochem. Cy., 26, 1–14, https://doi.org/10.1029/2011GB004095, 2012.
Lenton, A., Tilbrook, B., Law, R. M., Bakker, D., Doney, S. C., Gruber, N., Ishii, M., Hoppema, M., Lovenduski, N. S., Matear, R. J., McNeil, B. I., Metzl, N., Mikaloff Fletcher, S. E., Monteiro, P. M. S., Rödenbeck, C., Sweeney, C., and Takahashi, T.: Sea-air CO2 fluxes in the Southern Ocean for the period 1990–2009, Biogeosciences, 10, 4037–4054, https://doi.org/10.5194/bg-10-4037-2013, 2013.
Le Quéré, C., Rödenbeck, C., Buitenhuis, E. T., Conway, T. J., Langenfelds, R., Gomez, A., and Heimann, M.: Saturation of the Southern Ocean CO2 Sink Due to Recent Climate Change, Science, 316, 1735–1738, https://doi.org/10.1126/science.1137004, 2007.
Lévy, M., Iovino, D., Resplandy, L., Klein, P., Madec, G., Tréguier, A. M., and Takahashi, K.: Large-scale impacts of submesoscale dynamics on phytoplankton: Local and remote effects, Ocean Model., 43–44, 77–93, https://doi.org/10.1016/j.ocemod.2011.12.003, 2012.
Lovenduski, N. S., Gruber, N., Doney, S. C., and Lima, I. D.: Enhanced CO2 outgassing in the Southern Ocean from a positive phase of the Southern Annular Mode, Global Biogeochem. Cy., 21, 1–14, https://doi.org/10.1029/2006GB002900, 2007.
Lovenduski, N. S., Gruber, N., and Doney, S. C.: Toward a mechanistic understanding of the decadal trends in the Southern Ocean carbon sink, Global Biogeochem. Cy., 22, GB3016, https://doi.org/10.1029/2007GB003139, 2008.
Mahadevan, A., Tagliabue, A., Bopp, L., Lenton, A., Mémery, L., and Lévy, M.: Impact of episodic vertical fluxes on sea surface pCO2, Philos. T. R. Soc. A., 369, 2009–2025, https://doi.org/10.1098/rsta.2010.0340, 2011.
Mahadevan, A., D'Asaro, E., Lee, C., and Perry, M. J.: Eddy-Driven Stratification Initiates North Atlantic Spring Phytoplankton Blooms, Science, 337, 54–58, https://doi.org/10.1126/science.1218740, 2012.
Maritorena, S. and Siegel, D. A.: Consistent merging of satellite ocean color data sets using a bio-optical model, Remote Sens. Environ., 94, 429–440, https://doi.org/10.1016/j.rse.2004.08.014, 2005.
Marshall, G. J.: Trends in the Southern Annular Mode from observations and reanalyses, J. Climate, 16, 4134–4143, https://doi.org/10.1175/1520-0442(2003)016<4134:TITSAM>2.0.CO;2, 2003.
McGillicuddy, D. J.: Mechanisms of Physical-Biological-Biogeochemical Interaction at the Oceanic Mesoscale, Annu. Rev. Mar. Sci., 8, 125–159, https://doi.org/10.1146/annurev-marine-010814-015606, 2016.
McNeil, B. I. and Matear, R. J.: The non-steady state oceanic CO2 signal: its importance, magnitude and a novel way to detect it, Biogeosciences, 10, 2219–2228, https://doi.org/10.5194/bg-10-2219-2013, 2013.
Menemenlis, D., Campin, J., Heimbach, P., Hill, C. N., Lee, T., Nguyen, A., and Campin J.-M.: ECCO2: High Resolution Global Ocean and Sea Ice Data Synthesis, Mercator Ocean Quarterly Newsletter, 31, 13–21, 2008.
Meredith, M. P.: Understanding the structure of changes in the Southern Ocean eddy field, Geophys. Res. Lett., 43, 5829–5832, https://doi.org/10.1002/2014JC010066, 2016.
Metzl, N., Brunet, C., Jabaud-Jan, A., Poisson, A., and Schauer, B.: Summer and winter air-sea CO2 fluxes in the Southern Ocean, Deep-Sea Res. Pt. I, 53, 1548–1563, https://doi.org/10.1016/j.dsr.2006.07.006, 2006.
Mongwe, N. P., Chang, N., and Monteiro, P. M. S.: The seasonal cycle as a mode to diagnose biases in modelled CO2 fluxes in the Southern Ocean, Ocean Model., 106, 90–103, https://doi.org/10.1016/j.ocemod.2016.09.006, 2016.
Monteiro, P. M. S., Gregor, L., Lévy, M., Maenner, S., Sabine, C. L., and Swart, S.: Intraseasonal variability linked to sampling alias in air-sea CO2 fluxes in the Southern Ocean, Geophys. Res. Lett., 42, 8507–8514, https://doi.org/10.1002/2015GL066009, 2015.
Munro, D. R., Lovenduski, N. S., Takahashi, T. T., Stephens, B. B., Newberger, T., and Sweeney, C.: Recent evidence for a strengthening CO2 sink in the Southern Ocean from carbonate system measurements in the Drake Passage (2002–2015), Geophys. Res. Lett., 42, 7623–7630, https://doi.org/10.1002/2015GL065194, 2015.
Nicholson, S. A., Lévy, M., Llort, J., Swart, S., and Monteiro, P. M. S.: Investigation into the impact of storms on sustaining summer primary productivity in the Sub-Antarctic Ocean, Geophys. Res. Lett., 43, 9192–9199, https://doi.org/10.1002/2016GL069973, 2016.
Pfeil, B., Olsen, A., Bakker, D. C. E., Hankin, S., Koyuk, H., Kozyr, A., Malczyk, J., Manke, A., Metzl, N., Sabine, C. L., Akl, J., Alin, S. R., Bates, N., Bellerby, R. G. J., Borges, A., Boutin, J., Brown, P. J., Cai, W.-J., Chavez, F. P., Chen, A., Cosca, C., Fassbender, A. J., Feely, R. A., González-Dávila, M., Goyet, C., Hales, B., Hardman-Mountford, N., Heinze, C., Hood, M., Hoppema, M., Hunt, C. W., Hydes, D., Ishii, M., Johannessen, T., Jones, S. D., Key, R. M., Körtzinger, A., Landschützer, P., Lauvset, S. K., 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, A. M., Padin, X. A., Park, G.-H., Paterson, K., Perez, F. F., Pierrot, D., Poisson, A., Ríos, A. F., Santana-Casiano, J. M., Salisbury, J., Sarma, V. V. S. S., 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, A. J., Weiss, R., Wong, C. S., and Yoshikawa-Inoue, H.: A uniform, quality controlled Surface Ocean CO2 Atlas (SOCAT), Earth Syst. Sci. Data, 5, 125–143, https://doi.org/10.5194/essd-5-125-2013, 2013.
Reynolds, R. W., Smith, T. M., Liu, C., Chelton, D. B., Casey, K. S., and Schlax, M. G.: Daily high-resolution-blended analyses for sea surface temperature, J. Climate, 20, 5473–5496, https://doi.org/10.1175/2007JCLI1824.1, 2007.
Ritter, R., Landschützer, P., Gruber, N., Fay, A. R., Iida, Y., Jones, S., and Zeng, J.: Observation-Based Trends of the Southern Ocean Carbon Sink, Geophys. Res. Lett., 2, 339–348, https://doi.org/10.1002/2017GL074837, 2017.
Rödenbeck, C., Bakker, D. C. E., Metzl, N., Olsen, A., Sabine, C., Cassar, N., Reum, F., Keeling, R. F., and Heimann, M.: Interannual sea-air CO2 flux variability from an observation-driven ocean mixed-layer scheme, Biogeosciences, 11, 4599–4613, https://doi.org/10.5194/bg-11-4599-2014, 2014.
Rödenbeck, C., Bakker, D. C. E., Gruber, N., Iida, Y., Jacobson, A. R., Jones, S., Landschützer, P., Metzl, N., Nakaoka, S., Olsen, A., Park, G.-H., Peylin, P., Rodgers, K. B., Sasse, T. P., Schuster, U., Shutler, J. D., Valsala, V., Wanninkhof, R., and Zeng, J.: Data-based estimates of the ocean carbon sink variability – first results of the Surface Ocean pCO2 Mapping intercomparison (SOCOM), Biogeosciences, 12, 7251–7278, https://doi.org/10.5194/bg-12-7251-2015, 2015.
Rodgers, K. B., Aumont, O., Mikaloff Fletcher, S. E., Plancherel, Y., Bopp, L., de Boyer Montégut, C., Iudicone, D., Keeling, R. F., Madec, G., and Wanninkhof, R.: Strong sensitivity of Southern Ocean carbon uptake and nutrient cycling to wind stirring, Biogeosciences, 11, 4077–4098, https://doi.org/10.5194/bg-11-4077-2014, 2014.
Sabine, C. L., Hankin, S., Koyuk, H., Bakker, D. C. E., Pfeil, B., Olsen, A., Metzl, N., Kozyr, A., Fassbender, A., Manke, A., Malczyk, J., Akl, J., Alin, S. R., Bellerby, R. G. J., Borges, A., Boutin, J., Brown, P. J., Cai, W.-J., Chavez, F. P., Chen, A., Cosca, C., Feely, R. A., González-Dávila, M., Goyet, C., Hardman-Mountford, N., Heinze, C., Hoppema, M., Hunt, C. W., Hydes, D., Ishii, M., Johannessen, T., Key, R. M., Körtzinger, A., Landschützer, P., Lauvset, S. K., 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, A. M., Padin, X. A., Park, G.-H., Paterson, K., Perez, F. F., Pierrot, D., Poisson, A., Ríos, A. F., Salisbury, J., Santana-Casiano, J. M., Sarma, V. V. S. S., 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, A. J., Weiss, R., Wong, C. S., and Yoshikawa-Inoue, H.: Surface Ocean CO2 Atlas (SOCAT) gridded data products, Earth Syst. Sci. Data, 5, 145–153, https://doi.org/10.5194/essd-5-145-2013, 2013.
Sallée, J.-B., Speer, K., and Rintoul, S. R.: Zonally asymmetric response of the Southern Ocean mixed-layer depth to the Southern Annular Mode, Nat. Geosci., 3, 273–279, https://doi.org/10.1038/ngeo812, 2010.
Sasse, T. P., McNeil, B. I., and Abramowitz, G.: A novel method for diagnosing seasonal to inter-annual surface ocean carbon dynamics from bottle data using neural networks, Biogeosciences, 10, 4319–4340, https://doi.org/10.5194/bg-10-4319-2013, 2013.
Shetye, S. S., Mohan, R., Patil, S., Jena, B., Chacko, R., George, J. V., and Sudhakar, M.: Oceanic pCO2 in the Indian sector of the Southern Ocean during the austral summer–winter transition phase, Deep-Sea Res. Pt. II, 118, 250–260, https://doi.org/10.1016/j.dsr2.2015.05.017, 2015.
Swart, N. C. and Fyfe, J. C.: Observed and simulated changes in the Southern Hemisphere surface westerly wind-stress, Geophys. Res. Lett., 39, 6–11, https://doi.org/10.1029/2012GL052810, 2012.
Swart, S., Speich, S., Ansorge, I. J., and Lutjeharms, J. R. E.: An altimetry-based gravest empirical mode south of Africa: 1. Development and validation, J. Geophys. Res., 115, 1–19, https://doi.org/10.1029/2009JC005299, 2010.
Swart, N. C., Fyfe, J. C., Gillett, N., and Marshall, G. J.: Comparing trends in the southern annular mode and surface westerly jet, J. Climate, 28, 8840–8859, https://doi.org/10.1175/JCLI-D-15-0334.1, 2015a.
Swart, S., Thomalla, S. J., and Monteiro, P. M. S.: The seasonal cycle of mixed layer dynamics and phytoplankton biomass in the Sub-Antarctic Zone: A high-resolution glider experiment, J. Marine Syst., 147, 103–115, https://doi.org/10.1016/j.jmarsys.2014.06.002, 2015b.
Tagliabue, A., Sallée, J.-B., Bowie, A. R., Lévy, M., Swart, S., and Boyd, P. W.: Surface-water iron supplies in the Southern Ocean sustained by deep winter mixing, Nat. Geosci., 7, 314–320, https://doi.org/10.1038/NGEO2101, 2014.
Tagliabue, A., Bowie, A. R., Philip, W., Buck, K. N., Johnson, K. S., and Saito, M. A.: The integral role of iron in ocean biogeochemistry, Nature, 543, 51–59, https://doi.org/10.1038/nature21058, 2017.
Takahashi, T. T., Olafsson, J., Goddard, J. G., Chipman, D. W., and Sutherland, S. C.: Seasonal variation of CO2 and nutrients in the high-latitude surface oceans: A comparative study, Global Biogeochem. Cy., 7, 843–878, https://doi.org/10.1029/93GB02263, 1993.
Takahashi, T. T., Sutherland, S. C., Sweeney, C., Poisson, A., Metzl, N., Tilbrook, B., and Nojiri, Y.: Global sea-air CO2 flux based on climatological surface ocean pCO2, and seasonal biological and temperature effects, Deep-Sea Res. Pt. II, 49, 1601–1622, https://doi.org/10.1016/S0967-0645(02)00003-6, 2002.
Takahashi, T. T., Sutherland, S. C., Wanninkhof, R. H., Sweeney, C., Feely, R. A., Chipman, D. W., and de Baar, H. J. W.: Climatological mean and decadal change in surface ocean pCO2, and net sea–air CO2 flux over the global oceans, Deep-Sea Res. Pt. II, 56, 554–577, https://doi.org/10.1016/j.dsr2.2008.12.009, 2009.
Thomalla, S. J., Fauchereau, N., Swart, S., and Monteiro, P. M. S.: Regional scale characteristics of the seasonal cycle of chlorophyll in the Southern Ocean, Biogeosciences, 8, 2849–2866, https://doi.org/10.5194/bg-8-2849-2011, 2011.
Wang, S. and Moore, J. K.: Variability of primary production and air-sea CO2 flux in the Southern Ocean, Global Biogeochem. Cy., 26, 1–12, https://doi.org/10.1029/2010GB003981, 2012.
Wentz, F. J., Scott, J., Hoffman, R., Leidner, M., Atlas, R., and Ardizzone, J.: Remote Sensing Systems Cross-Calibrated Multi-Platform (CCMP) 6-hourly ocean vector wind analysis product on 0.25 deg grid, Version 2.0, available at: www.remss.com/measurements/ccmp(last access: 5 March 2017), 2015.
Whitt, D. B., Lévy, M., and Taylor, J. R.: Low-frequency and high-frequency oscillatory winds synergistically enhance nutrient entrainment and phytoplankton at fronts, J. Geophys. Res., 122, 1016–1041, https://doi.org/10.1002/2016JC012400, 2017.
Xue, L., Gao, L., Cai, W. J., Yu, W., and Wei, M.: Response of sea surface fugacity of CO2 to the SAM shift south of Tasmania: Regional differences, Geophys. Res. Lett., 42, 3973–3979, https://doi.org/10.1002/2015GL063926, 2015.
Short summary
The Southern Ocean accounts for a large portion of the variability in oceanic CO2 uptake. However, the drivers of these changes are not understood due to a lack of observations. In this study, we used an ensemble of gap-filling methods to estimate surface CO2. We found that winter was a more important driver of longer-term variability driven by changes in wind stress. Summer variability of CO2 was driven primarily by increases in primary production.
The Southern Ocean accounts for a large portion of the variability in oceanic CO2 uptake....
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