Articles | Volume 20, issue 5
https://doi.org/10.5194/os-20-1325-2024
© Author(s) 2024. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/os-20-1325-2024
© Author(s) 2024. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Temperature effect on seawater fCO2 revisited: theoretical basis, uncertainty analysis and implications for parameterising carbonic acid equilibrium constants
Matthew P. Humphreys
CORRESPONDING AUTHOR
Department of Ocean Sciences, NIOZ Royal Netherlands Institute for Sea Research, P.O. Box 59, 1790 AB Den Burg (Texel), the Netherlands
Related authors
Louise Delaigue, Gert-Jan Reichart, Chris Galley, Yasmina Ourradi, and Matthew Paul Humphreys
EGUsphere, https://doi.org/10.5194/egusphere-2024-2853, https://doi.org/10.5194/egusphere-2024-2853, 2024
Short summary
Short summary
Our study analyzed pH in ocean surface waters to understand how they fluctuate with changes in temperature, salinity, and biological activities. We found that temperature mainly controls daily pH variations, but biological processes also play a role, especially in affecting CO2 levels between the ocean and atmosphere. Our research shows how these factors together maintain the balance of ocean chemistry, which is crucial for predicting changes in marine environments.
Siv K. Lauvset, Nico Lange, Toste Tanhua, Henry C. Bittig, Are Olsen, Alex Kozyr, Marta Álvarez, Kumiko Azetsu-Scott, Peter J. Brown, Brendan R. Carter, Leticia Cotrim da Cunha, Mario Hoppema, Matthew P. Humphreys, Masao Ishii, Emil Jeansson, Akihiko Murata, Jens Daniel Müller, Fiz F. Pérez, Carsten Schirnick, Reiner Steinfeldt, Toru Suzuki, Adam Ulfsbo, Anton Velo, Ryan J. Woosley, and Robert M. Key
Earth Syst. Sci. Data, 16, 2047–2072, https://doi.org/10.5194/essd-16-2047-2024, https://doi.org/10.5194/essd-16-2047-2024, 2024
Short summary
Short summary
GLODAP is a data product for ocean inorganic carbon and related biogeochemical variables measured by the chemical analysis of water bottle samples from scientific cruises. GLODAPv2.2023 is the fifth update of GLODAPv2 from 2016. The data that are included have been subjected to extensive quality controlling, including systematic evaluation of measurement biases. This version contains data from 1108 hydrographic cruises covering the world's oceans from 1972 to 2021.
Siv K. Lauvset, Nico Lange, Toste Tanhua, Henry C. Bittig, Are Olsen, Alex Kozyr, Simone Alin, Marta Álvarez, Kumiko Azetsu-Scott, Leticia Barbero, Susan Becker, Peter J. Brown, Brendan R. Carter, Leticia Cotrim da Cunha, Richard A. Feely, Mario Hoppema, Matthew P. Humphreys, Masao Ishii, Emil Jeansson, Li-Qing Jiang, Steve D. Jones, Claire Lo Monaco, Akihiko Murata, Jens Daniel Müller, Fiz F. Pérez, Benjamin Pfeil, Carsten Schirnick, Reiner Steinfeldt, Toru Suzuki, Bronte Tilbrook, Adam Ulfsbo, Anton Velo, Ryan J. Woosley, and Robert M. Key
Earth Syst. Sci. Data, 14, 5543–5572, https://doi.org/10.5194/essd-14-5543-2022, https://doi.org/10.5194/essd-14-5543-2022, 2022
Short summary
Short summary
GLODAP is a data product for ocean inorganic carbon and related biogeochemical variables measured by the chemical analysis of water bottle samples from scientific cruises. GLODAPv2.2022 is the fourth update of GLODAPv2 from 2016. The data that are included have been subjected to extensive quality controlling, including systematic evaluation of measurement biases. This version contains data from 1085 hydrographic cruises covering the world's oceans from 1972 to 2021.
Olivier Sulpis, Matthew P. Humphreys, Monica M. Wilhelmus, Dustin Carroll, William M. Berelson, Dimitris Menemenlis, Jack J. Middelburg, and Jess F. Adkins
Geosci. Model Dev., 15, 2105–2131, https://doi.org/10.5194/gmd-15-2105-2022, https://doi.org/10.5194/gmd-15-2105-2022, 2022
Short summary
Short summary
A quarter of the surface of the Earth is covered by marine sediments rich in calcium carbonates, and their dissolution acts as a giant antacid tablet protecting the ocean against human-made acidification caused by massive CO2 emissions. Here, we present a new model of sediment chemistry that incorporates the latest experimental findings on calcium carbonate dissolution kinetics. This model can be used to predict how marine sediments evolve through time in response to environmental perturbations.
Matthew P. Humphreys, Erik H. Meesters, Henk de Haas, Szabina Karancz, Louise Delaigue, Karel Bakker, Gerard Duineveld, Siham de Goeyse, Andreas F. Haas, Furu Mienis, Sharyn Ossebaar, and Fleur C. van Duyl
Biogeosciences, 19, 347–358, https://doi.org/10.5194/bg-19-347-2022, https://doi.org/10.5194/bg-19-347-2022, 2022
Short summary
Short summary
A series of submarine sinkholes were recently discovered on Luymes Bank, part of Saba Bank, a carbonate platform in the Caribbean Netherlands. Here, we investigate the waters inside these sinkholes for the first time. One of the sinkholes contained a body of dense, low-oxygen and low-pH water, which we call the
acid lake. We use measurements of seawater chemistry to work out what processes were responsible for forming the acid lake and discuss the consequences for the carbonate platform.
Matthew P. Humphreys, Ernie R. Lewis, Jonathan D. Sharp, and Denis Pierrot
Geosci. Model Dev., 15, 15–43, https://doi.org/10.5194/gmd-15-15-2022, https://doi.org/10.5194/gmd-15-15-2022, 2022
Short summary
Short summary
The ocean helps to mitigate our impact on Earth's climate by absorbing about a quarter of the carbon dioxide (CO2) released by human activities each year. However, once absorbed, chemical reactions between CO2 and water reduce seawater pH (
ocean acidification), which may have adverse effects on marine ecosystems. Our Python package, PyCO2SYS, models the chemical reactions of CO2 in seawater, allowing us to quantify the corresponding changes in pH and related chemical properties.
Luca Possenti, Ingunn Skjelvan, Dariia Atamanchuk, Anders Tengberg, Matthew P. Humphreys, Socratis Loucaides, Liam Fernand, and Jan Kaiser
Ocean Sci., 17, 593–614, https://doi.org/10.5194/os-17-593-2021, https://doi.org/10.5194/os-17-593-2021, 2021
Short summary
Short summary
A Seaglider was deployed for 8 months in the Norwegian Sea mounting an oxygen and, for the first time, a CO2 optode and a chlorophyll fluorescence sensor. The oxygen and CO2 data were used to assess the spatial and temporal variability and calculate the net community production, N(O2) and N(CT). The dataset was used to calculate net community production from inventory changes, air–sea flux, diapycnal mixing and entrainment.
Hannah K. Donald, Gavin L. Foster, Nico Fröhberg, George E. A. Swann, Alex J. Poulton, C. Mark Moore, and Matthew P. Humphreys
Biogeosciences, 17, 2825–2837, https://doi.org/10.5194/bg-17-2825-2020, https://doi.org/10.5194/bg-17-2825-2020, 2020
Short summary
Short summary
The boron isotope pH proxy is increasingly being used to reconstruct ocean pH in the past. Here we detail a novel analytical methodology for measuring the boron isotopic composition (δ11B) of diatom opal and apply this to the study of the diatom Thalassiosira weissflogii grown in culture over a range of pH. To our knowledge this is the first study of its kind and provides unique insights into the way in which diatoms incorporate boron and their potential as archives of palaeoclimate records.
Robyn E. Tuerena, Raja S. Ganeshram, Matthew P. Humphreys, Thomas J. Browning, Heather Bouman, and Alexander P. Piotrowski
Biogeosciences, 16, 3621–3635, https://doi.org/10.5194/bg-16-3621-2019, https://doi.org/10.5194/bg-16-3621-2019, 2019
Short summary
Short summary
The carbon isotopes in algae can be used to predict food sources and environmental change. We explore how dissolved carbon is taken up by algae in the South Atlantic Ocean and how this affects their carbon isotope signature. We find that cell size controls isotope fractionation. We use our results to investigate how climate change may impact the carbon isotopes in algae. We suggest a shift to smaller algae in this region would decrease the carbon isotope ratio at the base of the food web.
Yingxu Wu, Mathis P. Hain, Matthew P. Humphreys, Sue Hartman, and Toby Tyrrell
Biogeosciences, 16, 2661–2681, https://doi.org/10.5194/bg-16-2661-2019, https://doi.org/10.5194/bg-16-2661-2019, 2019
Short summary
Short summary
This study takes advantage of the GLODAPv2 database to investigate the processes driving the surface ocean dissolved inorganic carbon distribution, with the focus on its latitudinal gradient between the polar oceans and the low-latitude oceans. Based on our quantitative study, we find that temperature-driven CO2 gas exchange and high-latitude upwelling of DIC- and TA-rich deep waters are the two major drivers, with the importance of the latter not having been previously realized.
Meike Becker, Nils Andersen, Helmut Erlenkeuser, Matthew P. Humphreys, Toste Tanhua, and Arne Körtzinger
Earth Syst. Sci. Data, 8, 559–570, https://doi.org/10.5194/essd-8-559-2016, https://doi.org/10.5194/essd-8-559-2016, 2016
Short summary
Short summary
The stable carbon isotope composition of dissolved inorganic carbon (δ13C-DIC) can be used to quantify fluxes within the marine carbon system such as the exchange between ocean and atmosphere or the amount of anthropogenic carbon in the water column. In this study, an internally consistent δ13C-DIC dataset for the North Atlantic is presented. The data have undergone a secondary quality control during which systematic biases between the respective cruises have been quantified and adjusted.
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.
Matthew P. Humphreys, Florence M. Greatrix, Eithne Tynan, Eric P. Achterberg, Alex M. Griffiths, Claudia H. Fry, Rebecca Garley, Alison McDonald, and Adrian J. Boyce
Earth Syst. Sci. Data, 8, 221–233, https://doi.org/10.5194/essd-8-221-2016, https://doi.org/10.5194/essd-8-221-2016, 2016
Short summary
Short summary
This paper reports the stable isotope composition of dissolved inorganic carbon in seawater for a transect from west to east across the North Atlantic Ocean. The results can be used to study oceanic uptake of anthropogenic carbon dioxide, and also to investigate the natural biological carbon pump. We also provide stable DIC isotope results for two batches of Dickson seawater CRMs to enable intercomparisons with other studies.
M. P. Humphreys, E. P. Achterberg, A. M. Griffiths, A. McDonald, and A. J. Boyce
Earth Syst. Sci. Data, 7, 127–135, https://doi.org/10.5194/essd-7-127-2015, https://doi.org/10.5194/essd-7-127-2015, 2015
Short summary
Short summary
We present measurements of the stable carbon isotope composition of seawater dissolved inorganic carbon. The samples were collected during two research cruises in boreal summer 2012 in the northeastern Atlantic and Nordic Seas. The results can be used to investigate the marine carbon cycle, providing information about biological productivity and oceanic uptake of anthropogenic carbon dioxide.
Louise Delaigue, Gert-Jan Reichart, Chris Galley, Yasmina Ourradi, and Matthew Paul Humphreys
EGUsphere, https://doi.org/10.5194/egusphere-2024-2853, https://doi.org/10.5194/egusphere-2024-2853, 2024
Short summary
Short summary
Our study analyzed pH in ocean surface waters to understand how they fluctuate with changes in temperature, salinity, and biological activities. We found that temperature mainly controls daily pH variations, but biological processes also play a role, especially in affecting CO2 levels between the ocean and atmosphere. Our research shows how these factors together maintain the balance of ocean chemistry, which is crucial for predicting changes in marine environments.
Siv K. Lauvset, Nico Lange, Toste Tanhua, Henry C. Bittig, Are Olsen, Alex Kozyr, Marta Álvarez, Kumiko Azetsu-Scott, Peter J. Brown, Brendan R. Carter, Leticia Cotrim da Cunha, Mario Hoppema, Matthew P. Humphreys, Masao Ishii, Emil Jeansson, Akihiko Murata, Jens Daniel Müller, Fiz F. Pérez, Carsten Schirnick, Reiner Steinfeldt, Toru Suzuki, Adam Ulfsbo, Anton Velo, Ryan J. Woosley, and Robert M. Key
Earth Syst. Sci. Data, 16, 2047–2072, https://doi.org/10.5194/essd-16-2047-2024, https://doi.org/10.5194/essd-16-2047-2024, 2024
Short summary
Short summary
GLODAP is a data product for ocean inorganic carbon and related biogeochemical variables measured by the chemical analysis of water bottle samples from scientific cruises. GLODAPv2.2023 is the fifth update of GLODAPv2 from 2016. The data that are included have been subjected to extensive quality controlling, including systematic evaluation of measurement biases. This version contains data from 1108 hydrographic cruises covering the world's oceans from 1972 to 2021.
Siv K. Lauvset, Nico Lange, Toste Tanhua, Henry C. Bittig, Are Olsen, Alex Kozyr, Simone Alin, Marta Álvarez, Kumiko Azetsu-Scott, Leticia Barbero, Susan Becker, Peter J. Brown, Brendan R. Carter, Leticia Cotrim da Cunha, Richard A. Feely, Mario Hoppema, Matthew P. Humphreys, Masao Ishii, Emil Jeansson, Li-Qing Jiang, Steve D. Jones, Claire Lo Monaco, Akihiko Murata, Jens Daniel Müller, Fiz F. Pérez, Benjamin Pfeil, Carsten Schirnick, Reiner Steinfeldt, Toru Suzuki, Bronte Tilbrook, Adam Ulfsbo, Anton Velo, Ryan J. Woosley, and Robert M. Key
Earth Syst. Sci. Data, 14, 5543–5572, https://doi.org/10.5194/essd-14-5543-2022, https://doi.org/10.5194/essd-14-5543-2022, 2022
Short summary
Short summary
GLODAP is a data product for ocean inorganic carbon and related biogeochemical variables measured by the chemical analysis of water bottle samples from scientific cruises. GLODAPv2.2022 is the fourth update of GLODAPv2 from 2016. The data that are included have been subjected to extensive quality controlling, including systematic evaluation of measurement biases. This version contains data from 1085 hydrographic cruises covering the world's oceans from 1972 to 2021.
Olivier Sulpis, Matthew P. Humphreys, Monica M. Wilhelmus, Dustin Carroll, William M. Berelson, Dimitris Menemenlis, Jack J. Middelburg, and Jess F. Adkins
Geosci. Model Dev., 15, 2105–2131, https://doi.org/10.5194/gmd-15-2105-2022, https://doi.org/10.5194/gmd-15-2105-2022, 2022
Short summary
Short summary
A quarter of the surface of the Earth is covered by marine sediments rich in calcium carbonates, and their dissolution acts as a giant antacid tablet protecting the ocean against human-made acidification caused by massive CO2 emissions. Here, we present a new model of sediment chemistry that incorporates the latest experimental findings on calcium carbonate dissolution kinetics. This model can be used to predict how marine sediments evolve through time in response to environmental perturbations.
Matthew P. Humphreys, Erik H. Meesters, Henk de Haas, Szabina Karancz, Louise Delaigue, Karel Bakker, Gerard Duineveld, Siham de Goeyse, Andreas F. Haas, Furu Mienis, Sharyn Ossebaar, and Fleur C. van Duyl
Biogeosciences, 19, 347–358, https://doi.org/10.5194/bg-19-347-2022, https://doi.org/10.5194/bg-19-347-2022, 2022
Short summary
Short summary
A series of submarine sinkholes were recently discovered on Luymes Bank, part of Saba Bank, a carbonate platform in the Caribbean Netherlands. Here, we investigate the waters inside these sinkholes for the first time. One of the sinkholes contained a body of dense, low-oxygen and low-pH water, which we call the
acid lake. We use measurements of seawater chemistry to work out what processes were responsible for forming the acid lake and discuss the consequences for the carbonate platform.
Matthew P. Humphreys, Ernie R. Lewis, Jonathan D. Sharp, and Denis Pierrot
Geosci. Model Dev., 15, 15–43, https://doi.org/10.5194/gmd-15-15-2022, https://doi.org/10.5194/gmd-15-15-2022, 2022
Short summary
Short summary
The ocean helps to mitigate our impact on Earth's climate by absorbing about a quarter of the carbon dioxide (CO2) released by human activities each year. However, once absorbed, chemical reactions between CO2 and water reduce seawater pH (
ocean acidification), which may have adverse effects on marine ecosystems. Our Python package, PyCO2SYS, models the chemical reactions of CO2 in seawater, allowing us to quantify the corresponding changes in pH and related chemical properties.
Luca Possenti, Ingunn Skjelvan, Dariia Atamanchuk, Anders Tengberg, Matthew P. Humphreys, Socratis Loucaides, Liam Fernand, and Jan Kaiser
Ocean Sci., 17, 593–614, https://doi.org/10.5194/os-17-593-2021, https://doi.org/10.5194/os-17-593-2021, 2021
Short summary
Short summary
A Seaglider was deployed for 8 months in the Norwegian Sea mounting an oxygen and, for the first time, a CO2 optode and a chlorophyll fluorescence sensor. The oxygen and CO2 data were used to assess the spatial and temporal variability and calculate the net community production, N(O2) and N(CT). The dataset was used to calculate net community production from inventory changes, air–sea flux, diapycnal mixing and entrainment.
Hannah K. Donald, Gavin L. Foster, Nico Fröhberg, George E. A. Swann, Alex J. Poulton, C. Mark Moore, and Matthew P. Humphreys
Biogeosciences, 17, 2825–2837, https://doi.org/10.5194/bg-17-2825-2020, https://doi.org/10.5194/bg-17-2825-2020, 2020
Short summary
Short summary
The boron isotope pH proxy is increasingly being used to reconstruct ocean pH in the past. Here we detail a novel analytical methodology for measuring the boron isotopic composition (δ11B) of diatom opal and apply this to the study of the diatom Thalassiosira weissflogii grown in culture over a range of pH. To our knowledge this is the first study of its kind and provides unique insights into the way in which diatoms incorporate boron and their potential as archives of palaeoclimate records.
Robyn E. Tuerena, Raja S. Ganeshram, Matthew P. Humphreys, Thomas J. Browning, Heather Bouman, and Alexander P. Piotrowski
Biogeosciences, 16, 3621–3635, https://doi.org/10.5194/bg-16-3621-2019, https://doi.org/10.5194/bg-16-3621-2019, 2019
Short summary
Short summary
The carbon isotopes in algae can be used to predict food sources and environmental change. We explore how dissolved carbon is taken up by algae in the South Atlantic Ocean and how this affects their carbon isotope signature. We find that cell size controls isotope fractionation. We use our results to investigate how climate change may impact the carbon isotopes in algae. We suggest a shift to smaller algae in this region would decrease the carbon isotope ratio at the base of the food web.
Yingxu Wu, Mathis P. Hain, Matthew P. Humphreys, Sue Hartman, and Toby Tyrrell
Biogeosciences, 16, 2661–2681, https://doi.org/10.5194/bg-16-2661-2019, https://doi.org/10.5194/bg-16-2661-2019, 2019
Short summary
Short summary
This study takes advantage of the GLODAPv2 database to investigate the processes driving the surface ocean dissolved inorganic carbon distribution, with the focus on its latitudinal gradient between the polar oceans and the low-latitude oceans. Based on our quantitative study, we find that temperature-driven CO2 gas exchange and high-latitude upwelling of DIC- and TA-rich deep waters are the two major drivers, with the importance of the latter not having been previously realized.
Meike Becker, Nils Andersen, Helmut Erlenkeuser, Matthew P. Humphreys, Toste Tanhua, and Arne Körtzinger
Earth Syst. Sci. Data, 8, 559–570, https://doi.org/10.5194/essd-8-559-2016, https://doi.org/10.5194/essd-8-559-2016, 2016
Short summary
Short summary
The stable carbon isotope composition of dissolved inorganic carbon (δ13C-DIC) can be used to quantify fluxes within the marine carbon system such as the exchange between ocean and atmosphere or the amount of anthropogenic carbon in the water column. In this study, an internally consistent δ13C-DIC dataset for the North Atlantic is presented. The data have undergone a secondary quality control during which systematic biases between the respective cruises have been quantified and adjusted.
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.
Matthew P. Humphreys, Florence M. Greatrix, Eithne Tynan, Eric P. Achterberg, Alex M. Griffiths, Claudia H. Fry, Rebecca Garley, Alison McDonald, and Adrian J. Boyce
Earth Syst. Sci. Data, 8, 221–233, https://doi.org/10.5194/essd-8-221-2016, https://doi.org/10.5194/essd-8-221-2016, 2016
Short summary
Short summary
This paper reports the stable isotope composition of dissolved inorganic carbon in seawater for a transect from west to east across the North Atlantic Ocean. The results can be used to study oceanic uptake of anthropogenic carbon dioxide, and also to investigate the natural biological carbon pump. We also provide stable DIC isotope results for two batches of Dickson seawater CRMs to enable intercomparisons with other studies.
M. P. Humphreys, E. P. Achterberg, A. M. Griffiths, A. McDonald, and A. J. Boyce
Earth Syst. Sci. Data, 7, 127–135, https://doi.org/10.5194/essd-7-127-2015, https://doi.org/10.5194/essd-7-127-2015, 2015
Short summary
Short summary
We present measurements of the stable carbon isotope composition of seawater dissolved inorganic carbon. The samples were collected during two research cruises in boreal summer 2012 in the northeastern Atlantic and Nordic Seas. The results can be used to investigate the marine carbon cycle, providing information about biological productivity and oceanic uptake of anthropogenic carbon dioxide.
Cited articles
Álvarez, M., Fajar, N. M., Carter, B. R., Guallart, E. F., Pérez, F. F., Woosley, R. J., and Murata, A.: Global Ocean Spectrophotometric pH Assessment: Consistent Inconsistencies, Environ. Sci. Technol., 54, 10977–10988, https://doi.org/10.1021/acs.est.9b06932, 2020.
Archer, D. G.: Thermodynamic Properties of the NaCl + H2O System. II. Thermodynamic Properties of NaCl(aq), NaCl⋅2H2(cr), and Phase Equilibria, J. Phys. Chem. Ref. Data, 21, 793–829, https://doi.org/10.1063/1.555915, 1992.
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., 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.
Cai, W.-J. and Wang, Y.: The chemistry, fluxes, and sources of carbon dioxide in the estuarine waters of the Satilla and Altamaha Rivers, Georgia, Limnol. Oceanogr., 43, 657–668, https://doi.org/10.4319/lo.1998.43.4.0657, 1998.
Carter, B. R., Sharp, J. D., Dickson, A. G., Álvarez, M., Fong, M. B., García-Ibáñez, M. I., Woosley, R. J., Takeshita, Y., Barbero, L., Byrne, R. H., Cai, W.-J., Chierici, M., Clegg, S. L., Easley, R. A., Fassbender, A. J., Fleger, K. L., Li, X., Martín-Mayor, M., Schockman, K. M., and Wang, Z. A.: Uncertainty sources for measurable ocean carbonate chemistry variables, Limnol. Oceanogr., 69, 1–21, https://doi.org/10.1002/lno.12477, 2024.
Clarke, E. C. W. and Glew, D. N.: Evaluation of thermodynamic functions from equilibrium constants, T. Faraday Soc., 62, 539–547, https://doi.org/10.1039/TF9666200539, 1966.
Copin-Montegut, C.: A new formula for the effect of temperature on the partial pressure of CO2 in seawater, Mar. Chem., 25, 29–37, https://doi.org/10.1016/0304-4203(88)90012-6, 1988.
Dickson, A. G.: Standard potential of the reaction: , and the standard acidity constant of the ion in synthetic sea water from 273.15 to 318.15 K, J. Chem. Thermodyn., 22, 113–127, https://doi.org/10.1016/0021-9614(90)90074-Z, 1990a.
Dickson, A. G.: Thermodynamics of the dissociation of boric acid in synthetic seawater from 273.15 to 318.15 K, Deep-Sea Res., 37, 755–766, https://doi.org/10.1016/0198-0149(90)90004-F, 1990b.
Dickson, A. G. and Millero, F. J.: A comparison of the equilibrium constants for the dissociation of carbonic acid in seawater media, Deep-Sea Res., 34, 1733–1743, https://doi.org/10.1016/0198-0149(87)90021-5, 1987.
Dickson, A. G. and Riley, J. P.: The estimation of acid dissociation constants in sea-water media from potentiometric titrations with strong base. II. The dissociation of phosphoric acid, Mar. Chem., 7, 101–109, https://doi.org/10.1016/0304-4203(79)90002-1, 1979.
Dickson, A. G., Sabine, C. L., and Christian, J. R. (Eds.): Guide to Best Practices for Ocean CO2 Measurements, PICES Special Publication 3, 191 pp., ISBN 1-897176-07-4, 2007.
Dong, Y., Bakker, D. C. E., Bell, T. G., Huang, B., Landschützer, P., Liss, P. S., and Yang, M.: Update on the Temperature Corrections of Global Air-Sea CO2 Flux Estimates, Global Biogeochem. Cy., 36, e2022GB007360, https://doi.org/10.1029/2022GB007360, 2022.
Fassbender, A. J., Schlunegger, S., Rodgers, K. B., and Dunne, J. P.: Quantifying the Role of Seasonality in the Marine Carbon Cycle Feedback: An ESM2M Case Study, Global Biogeochem. Cy., 36, e2021GB007018, https://doi.org/10.1029/2021GB007018, 2022.
Fay, A. R., Munro, D. R., McKinley, G. A., Pierrot, D., Sutherland, S. C., Sweeney, C., and Wanninkhof, R.: Updated climatological mean ΔfCO2 and net sea–air CO2 flux over the global open ocean regions, Earth Syst. Sci. Data, 16, 2123–2139, https://doi.org/10.5194/essd-16-2123-2024, 2024.
Feely, R. A., Takahashi, T., Wanninkhof, R., McPhaden, M. J., Cosca, C. E., Sutherland, S. C., and Carr, M.-E.: Decadal variability of the air-sea CO2 fluxes in the equatorial Pacific Ocean, J. Geophys. Res.-Oceans, 111, C08S90, https://doi.org/10.1029/2005JC003129, 2006.
Fong, M. B. and Dickson, A. G.: Insights from GO-SHIP hydrography data into the thermodynamic consistency of CO2 system measurements in seawater, Mar. Chem., 211, 52–63, https://doi.org/10.1016/j.marchem.2019.03.006, 2019.
Goddijn-Murphy, L. M., Woolf, D. K., Land, P. E., Shutler, J. D., and Donlon, C.: The OceanFlux Greenhouse Gases methodology for deriving a sea surface climatology of CO2 fugacity in support of air–sea gas flux studies, Ocean Sci., 11, 519–541, https://doi.org/10.5194/os-11-519-2015, 2015.
Gordon, L. I. and Jones, L. B.: The effect of temperature on carbon dioxide partial pressures in seawater, Mar. Chem., 1, 317–322, https://doi.org/10.1016/0304-4203(73)90021-2, 1973.
Goyet, C. and Poisson, A.: New determination of carbonic acid dissociation constants in seawater as a function of temperature and salinity, Deep-Sea Res., 36, 1635–1654, https://doi.org/10.1016/0198-0149(89)90064-2, 1989.
Goyet, C., Millero, F. J., Poisson, A., and Shafer, D. K.: Temperature dependence of CO2 fugacity in seawater, Mar. Chem., 44, 205–219, https://doi.org/10.1016/0304-4203(93)90203-Z, 1993.
Gregor, L. and Gruber, N.: OceanSODA-ETHZ: a global gridded data set of the surface ocean carbonate system for seasonal to decadal studies of ocean acidification, Earth Syst. Sci. Data, 13, 777–808, https://doi.org/10.5194/essd-13-777-2021, 2021.
Gregor, L. and Gruber, N.: OceanSODA-ETHZ: A global gridded dataset of the surface ocean carbonate system for seasonal to decadal studies of ocean acidification (v2023) (NCEI Accession 0220059), NOAA National Centers for Environmental Information [data set], https://doi.org/10.25921/m5wx-ja34, 2020.
Hansson, I.: A new set of acidity constants for carbonic acid and boric acid in sea water, Deep-Sea Res., 20, 461–478, https://doi.org/10.1016/0011-7471(73)90100-9, 1973a.
Hansson, I.: The Determination of Dissociation Constants of Carbonic Acid in Synthetic Sea Water in the Salinity Range of 20 ‰–40 ‰ and Temperature Range of 5–30 °C, Acta Chem. Scand., 27, 931–944, https://doi.org/10.3891/acta.chem.scand.27-0931, 1973b.
Harris, C. R., Millman, K. J., van der Walt, S. J., Gommers, R., Virtanen, P., Cournapeau, D., Wieser, E., Taylor, J., Berg, S., Smith, N. J., Kern, R., Picus, M., Hoyer, S., van Kerkwijk, M. H., Brett, M., Haldane, A., del Río, J. F., Wiebe, M., Peterson, P., Gérard-Marchant, P., Sheppard, K., Reddy, T., Weckesser, W., Abbasi, H., Gohlke, C., and Oliphant, T. E.: Array programming with NumPy, Nature, 585, 357–362, https://doi.org/10.1038/s41586-020-2649-2, 2020.
Holding, T., Ashton, I. G., Shutler, J. D., Land, P. E., Nightingale, P. D., Rees, A. P., Brown, I., Piolle, J.-F., Kock, A., Bange, H. W., Woolf, D. K., Goddijn-Murphy, L., Pereira, R., Paul, F., Girard-Ardhuin, F., Chapron, B., Rehder, G., Ardhuin, F., and Donlon, C. J.: The FluxEngine air–sea gas flux toolbox: simplified interface and extensions for in situ analyses and multiple sparingly soluble gases, Ocean Sci., 15, 1707–1728, https://doi.org/10.5194/os-15-1707-2019, 2019.
Hoyer, S. and Hamman, J.: xarray: N-D labeled arrays and datasets in Python, J. Open Res. Softw., 5, 10, https://doi.org/10.5334/jors.148, 2017.
Hu, X.: Effect of Organic Alkalinity on Seawater Buffer Capacity: A Numerical Exploration, Aquat. Geochem., 26, 161–178, https://doi.org/10.1007/s10498-020-09375-x, 2020.
Humphreys, M. P.: Climate sensitivity and the rate of ocean acidification: future impacts, and implications for experimental design, ICES J. Mar. Sci., 74, 934–940, https://doi.org/10.1093/icesjms/fsw189, 2017.
Humphreys, M. P.: Code for “Temperature effect on seawater fCO2 revisited: theoretical basis, uncertainty analysis, and implications for parameterising carbonic acid equilibrium constants” (Version v1), Zenodo [code], https://doi.org/10.5281/zenodo.13492773, 2024.
Humphreys, M. P., Daniels, C. J., Wolf-Gladrow, D. A., Tyrrell, T., and Achterberg, E. P.: On the influence of marine biogeochemical processes over CO2 exchange between the atmosphere and ocean, Mar. Chem., 199, 1–11, https://doi.org/10.1016/j.marchem.2017.12.006, 2018.
Humphreys, M. P., Lewis, E. R., Sharp, J. D., and Pierrot, D.: PyCO2SYS v1.8: marine carbonate system calculations in Python, Geosci. Model Dev., 15, 15–43, https://doi.org/10.5194/gmd-15-15-2022, 2022.
Humphreys, M. P., Schiller, A. J., Sandborn, D., Gregor, L., Pierrot, D., van Heuven, S. M. A. C., Lewis, E. R., and Wallace, D. W. R.: PyCO2SYS: marine carbonate system calculations in Python, version 1.8.3, Zenodo, https://doi.org/10.5281/zenodo.10671397, 2024.
Hunter, J. D.: Matplotlib: A 2D graphics environment, Comput. Sci. Eng., 9, 90–95, https://doi.org/10.1109/MCSE.2007.55, 2007.
JCGM: JCGM 100:2008 Evaluation of measurement data – Guide to the expression of uncertainty in measurement, Bureau International des Poids et Mesures, Sèvres, France, 120 pp., https://doi.org/10.59161/JCGM100-2008E, 2008.
Jones, D. C., Ito, T., Takano, Y., and Hsu, W.-C.: Spatial and seasonal variability of the air-sea equilibration timescale of carbon dioxide, Global Biogeochem. Cy., 28, 1163–1178, https://doi.org/10.1002/2014GB004813, 2014.
Kanwisher, J.: pCO2 in Sea Water and its Effect on the Movement of CO2 in Nature, Tellus, 12, 209–215, https://doi.org/10.1111/j.2153-3490.1960.tb01302.x, 1960.
Kerr, D. E., Brown, P. J., Grey, A., and Kelleher, B. P.: The influence of organic alkalinity on the carbonate system in coastal waters, Mar. Chem., 237, 104050, https://doi.org/10.1016/j.marchem.2021.104050, 2021.
Kettle, H., Merchant, C. J., Jeffery, C. D., Filipiak, M. J., and Gentemann, C. L.: The impact of diurnal variability in sea surface temperature on the central Atlantic air-sea CO2 flux, Atmos. Chem. Phys., 9, 529–541, https://doi.org/10.5194/acp-9-529-2009, 2009.
Land, P. E., Shutler, J. D., Cowling, R. D., Woolf, D. K., Walker, P., Findlay, H. S., Upstill-Goddard, R. C., and Donlon, C. J.: Climate change impacts on sea–air fluxes of CO2 in three Arctic seas: a sensitivity study using Earth observation, Biogeosciences, 10, 8109–8128, https://doi.org/10.5194/bg-10-8109-2013, 2013.
Lauvset, S. K., Key, R. M., Olsen, A., van Heuven, S., Velo, A., Lin, X., Schirnick, C., Kozyr, A., Tanhua, T., Hoppema, M., Jutterström, S., Steinfeldt, R., Jeansson, E., Ishii, M., Perez, F. F., Suzuki, T., and Watelet, S.: A new global interior ocean mapped climatology: the 1°×1° GLODAP version 2, Earth Syst. Sci. Data, 8, 325–340, https://doi.org/10.5194/essd-8-325-2016, 2016.
Lauvset, S. K., Lange, N., Tanhua, T., Bittig, H. C., Olsen, A., Kozyr, A., Álvarez, M., Azetsu-Scott, K., Brown, P. J., Carter, B. R., Cotrim da Cunha, L., Hoppema, M., Humphreys, M. P., Ishii, M., Jeansson, E., Murata, A., Müller, J. D., Pérez, F. F., Schirnick, C., Steinfeldt, R., Suzuki, T., Ulfsbo, A., Velo, A., Woosley, R. J., and Key, R. M.: The annual update GLODAPv2.2023: the global interior ocean biogeochemical data product, Earth Syst. Sci. Data, 16, 2047–2072, https://doi.org/10.5194/essd-16-2047-2024, 2024.
Lee, C.-H., Lee, K., Lee, J.-S., Jeong, K.-Y., and Ko, Y.-H.: Persistent organic alkalinity in the ocean, Geochim. Cosmochim. Ac., https://doi.org/10.1016/j.gca.2024.06.010, in press, 2024.
Lee, K. and Millero, F. J.: Thermodynamic studies of the carbonate system in seawater, Deep-Sea Res. Pt. I, 42, 2035–2061, https://doi.org/10.1016/0967-0637(95)00077-1, 1995.
Lee, K., Tong, L. T., Millero, F. J., Sabine, C. L., Dickson, A. G., Goyet, C., Park, G.-H., Wanninkhof, R., Feely, R. A., and Key, R. M.: Global relationships of total alkalinity with salinity and temperature in surface waters of the world's oceans, Geophys. Res. Lett., 33, L19605, https://doi.org/10.1029/2006GL027207, 2006.
Lee, K., Kim, T.-W., Byrne, R. H., Millero, F. J., Feely, R. A., and Liu, Y.-M.: The universal ratio of boron to chlorinity for the North Pacific and North Atlantic oceans, Geochim. Cosmochim. Ac., 74, 1801–1811, https://doi.org/10.1016/j.gca.2009.12.027, 2010.
Lewis, E. and Wallace, D. W. R.: Program Developed for CO2 System Calculations, ORNL/CDIAC-105, Carbon Dioxide Information Analysis Center, Oak Ridge National Laboratory, U. S. Department of Energy, Oak Ridge, TN, USA, https://doi.org/10.15485/1464255, 1998.
Lueker, T. J., Dickson, A. G., and Keeling, C. D.: Ocean pCO2 calculated from dissolved inorganic carbon, alkalinity, and equations for K1 and K2: validation based on laboratory measurements of CO2 in gas and seawater at equilibrium, Mar. Chem., 70, 105–119, https://doi.org/10.1016/S0304-4203(00)00022-0, 2000.
Maclaurin, D.: Autograd: Automatic Differentiation for Python, in: Modeling, Inference and Optimization with Composable Differentiable Procedures, PhD thesis, Harvard University, Cambridge, MA, 41–57, https://dougalmaclaurin.com/phd-thesis.pdf (last access: 23 October 2024), 2016.
McGillis, W. R. and Wanninkhof, R.: Aqueous CO2 gradients for air–sea flux estimates, Mar. Chem., 98, 100–108, https://doi.org/10.1016/j.marchem.2005.09.003, 2006.
Mehrbach, C., Culberson, C. H., Hawley, J. E., and Pytkowicz, R. M.: Measurement of the Apparent Dissociation Constants of Carbonic Acid in Seawater at Atmospheric Pressure, Limnol. Oceanogr., 18, 897–907, https://doi.org/10.4319/lo.1973.18.6.0897, 1973.
Met Office: Cartopy: a cartographic python library with a Matplotlib interface, Exeter, Devon, https://scitools.org.uk/cartopy/docs/latest/ (last access: 23 October 2024), 2010.
Metzl, N., Corbière, A., Reverdin, G., Lenton, A., Takahashi, T., Olsen, A., Johannessen, T., Pierrot, D., Wanninkhof, R., Ólafsdóttir, S. R., Olafsson, J., and Ramonet, M.: Recent acceleration of the sea surface fCO2 growth rate in the North Atlantic subpolar gyre (1993–2008) revealed by winter observations, Global Biogeochem. Cy., 24, GB4004, https://doi.org/10.1029/2009GB003658, 2010.
Millero, F. J.: The thermodynamics of the carbonate system in seawater, Geochim. Cosmochim. Ac., 43, 1651–1661, https://doi.org/10.1016/0016-7037(79)90184-4, 1979.
Millero, F. J.: Carbonate constants for estuarine waters, Mar. Freshwater Res., 61, 139–142, https://doi.org/10.1071/MF09254, 2010.
Millero, F. J. and Pierrot, D.: A Chemical Equilibrium Model for Natural Waters, Aquat. Geochem., 4, 153–199, https://doi.org/10.1023/A:1009656023546, 1998.
Millero, F. J., Pierrot, D., Lee, K., Wanninkhof, R., Feely, R., Sabine, C. L., Key, R. M., and Takahashi, T.: Dissociation constants for carbonic acid determined from field measurements, Deep-Sea Res. Pt. I, 49, 1705–1723, https://doi.org/10.1016/S0967-0637(02)00093-6, 2002.
Millero, F. J., Graham, T. B., Huang, F., Bustos-Serrano, H., and Pierrot, D.: Dissociation constants of carbonic acid in seawater as a function of salinity and temperature, Mar. Chem., 100, 80–94, https://doi.org/10.1016/j.marchem.2005.12.001, 2006.
Mojica Prieto, F. J. and Millero, F. J.: The values of pK1 + pK2 for the dissociation of carbonic acid in seawater, Geochim. Cosmochim. Ac., 66, 2529–2540, https://doi.org/10.1016/S0016-7037(02)00855-4, 2002.
Newton, J. A., Feely, R. A., Jewett, E. B., Williamson, P., and Mathis, J.: Global Ocean Acidification Observing Network: Requirements and Governance Plan, 2nd edn., http://goa-on.org/documents/general/GOA-ON_2nd_edition_final.pdf (last access: 23 October 2024), 2015.
Orr, J. C., Epitalon, J.-M., Dickson, A. G., and Gattuso, J.-P.: Routine uncertainty propagation for the marine carbon dioxide system, Mar. Chem., 207, 84–107, https://doi.org/10.1016/j.marchem.2018.10.006, 2018.
Papadimitriou, S., Loucaides, S., Rérolle, V. M. C., Kennedy, P., Achterberg, E. P., Dickson, A. G., Mowlem, M., and Kennedy, H.: The stoichiometric dissociation constants of carbonic acid in seawater brines from 298 to 267 K, Geochim. Cosmochim. Ac., 220, 55–70, https://doi.org/10.1016/j.gca.2017.09.037, 2018.
Peng, T.-H., Takahashi, T., Broecker, W. S., and Olafsson, J.: Seasonal variability of carbon dioxide, nutrients and oxygen in the northern North Atlantic surface water: observations and a model, Tellus B, 39, 439–458, https://doi.org/10.3402/tellusb.v39i5.15361, 1987.
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.
Pierrot, D., Neill, C., Sullivan, K., Castle, R., Wanninkhof, R., Lüger, H., Johannessen, T., Olsen, A., Feely, R. A., and Cosca, C. E.: Recommendations for autonomous underway pCO2 measuring systems and data-reduction routines, Deep-Sea Res. Pt. II, 56, 512–522, https://doi.org/10.1016/j.dsr2.2008.12.005, 2009.
Pitzer, K. S.: Ion Interaction Approach: Theory and Data Correlation, in: Activity Coefficients in Electrolyte Solutions, 2nd edn., edited by: Pitzer, K. S., CRC Press, Florida, USA, 75–153, ISBN 978-1-315-89037-1, 1991.
Poisson, A., Culkin, F., and Ridout, P.: Intercomparison of CO2 measurements, Deep-Sea Res., 37, 1647–1650, https://doi.org/10.1016/0198-0149(90)90067-6, 1990.
Rodgers, K. B., Schwinger, J., Fassbender, A. J., Landschützer, P., Yamaguchi, R., Frenzel, H., Stein, K., Müller, J. D., Goris, N., Sharma, S., Bushinsky, S., Chau, T.-T.-T., Gehlen, M., Gallego, M. A., Gloege, L., Gregor, L., Gruber, N., Hauck, J., Iida, Y., Ishii, M., Keppler, L., Kim, J.-E., Schlunegger, S., Tjiputra, J., Toyama, K., Vaittinada Ayar, P., and Velo, A.: Seasonal Variability of the Surface Ocean Carbon Cycle: A Synthesis, Global Biogeochem. Cy., 37, e2023GB007798, https://doi.org/10.1029/2023GB007798, 2023.
Roy, R. N., Roy, L. N., Vogel, K. M., Porter-Moore, C., Pearson, T., Good, C. E., Millero, F. J., and Campbell, D. M.: The dissociation constants of carbonic acid in seawater at salinities 5 to 45 and temperatures 0 to 45 °C, Mar. Chem., 44, 249–267, https://doi.org/10.1016/0304-4203(93)90207-5, 1993.
Ruscic, B. and Bross, D.: Active Thermochemical Tables (ATcT) Thermochemical Values ver. 1.130, https://doi.org/10.17038/CSE/1997229, 2023.
Schockman, K. M. and Byrne, R. H.: Spectrophotometric Determination of the Bicarbonate Dissociation Constant in Seawater, Geochim. Cosmochim. Ac., 300, 231–245, https://doi.org/10.1016/j.gca.2021.02.008, 2021.
Shutler, J. D., Land, P. E., Piolle, J.-F., Woolf, D. K., Goddijn-Murphy, L., Paul, F., Girard-Ardhuin, F., Chapron, B., and Donlon, C. J.: FluxEngine: A Flexible Processing System for Calculating Atmosphere–Ocean Carbon Dioxide Gas Fluxes and Climatologies, J. Atmos. Ocean. Tech., 33, 741–756, https://doi.org/10.1175/JTECH-D-14-00204.1, 2016.
Sulpis, O., Lauvset, S. K., and Hagens, M.: Current estimates of and appear inconsistent with measured CO2 system parameters in cold oceanic regions, Ocean Sci., 16, 847–862, https://doi.org/10.5194/os-16-847-2020, 2020.
Takahashi, 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., Sutherland, S. C., Sweeney, C., Poisson, A., Metzl, N., Tilbrook, B., Bates, N., Wanninkhof, R., Feely, R. A., Sabine, C., Olafsson, J., 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., Sutherland, S. C., Feely, R. A., and Cosca, C. E.: Decadal Variation of the Surface Water PCO2 in the Western and Central Equatorial Pacific, Science, 302, 852–856, https://doi.org/10.1126/science.1088570, 2003.
Takahashi, T., Sutherland, S. C., Feely, R. A., and Wanninkhof, R.: Decadal change of the surface water pCO2 in the North Pacific: A synthesis of 35 years of observations, J. Geophys. Res.-Oceans, 111, C07S05, https://doi.org/10.1029/2005JC003074, 2006.
Takahashi, T., Sutherland, S. C., Wanninkhof, R., Sweeney, C., Feely, R. A., Chipman, D. W., Hales, B., Friederich, G., Chavez, F., Sabine, C., Watson, A., Bakker, D. C. E., Schuster, U., Metzl, N., Yoshikawa-Inoue, H., Ishii, M., Midorikawa, T., Nojiri, Y., Körtzinger, A., Steinhoff, T., Hoppema, M., Olafsson, J., Arnarson, T. S., Tilbrook, B., Johannessen, T., Olsen, A., Bellerby, R., Wong, C. S., Delille, B., Bates, N. R., 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.
Ulfsbo, A., Kuliński, K., Anderson, L. G., and Turner, D. R.: Modelling organic alkalinity in the Baltic Sea using a Humic-Pitzer approach, Mar. Chem., 168, 18–26, https://doi.org/10.1016/j.marchem.2014.10.013, 2015.
Uppström, L. R.: The boron/chlorinity ratio of deep-sea water from the Pacific Ocean, Deep-Sea Res., 21, 161–162, https://doi.org/10.1016/0011-7471(74)90074-6, 1974.
Virtanen, P., Gommers, R., Oliphant, T. E., Haberland, M., Reddy, T., Cournapeau, D., Burovski, E., Peterson, P., Weckesser, W., Bright, J., van der Walt, S. J., Brett, M., Wilson, J., Millman, K. J., Mayorov, N., Nelson, A. R. J., Jones, E., Kern, R., Larson, E., Carey, C. J., Polat, İ., Feng, Y., Moore, E. W., VanderPlas, J., Laxalde, D., Perktold, J., Cimrman, R., Henriksen, I., Quintero, E. A., Harris, C. R., Archibald, A. M., Ribeiro, A. H., Pedregosa, F., van Mulbregt, P., and SciPy 1.0 Contributors: SciPy 1.0: Fundamental Algorithms for Scientific Computing in Python, Nat. Methods, 17, 261–272, https://doi.org/10.1038/s41592-019-0686-2, 2020.
Wang, P., Meng, Q., Xue, L., Zhao, Y., Qiao, H., Hu, H., Wei, Q., Xin, M., Ran, X., Han, C., Zhou, F., and Liu, C.: Preliminary assessment of carbonic acid dissociation constants: Insights from observations in China's east coastal oceans, Mar. Environ. Res., 192, 106219, https://doi.org/10.1016/j.marenvres.2023.106219, 2023.
Wanninkhof, R.: Relationship between wind speed and gas exchange over the ocean revisited: Gas exchange and wind speed over the ocean, Limnol. Oceanogr.-Meth., 12, 351–362, https://doi.org/10.4319/lom.2014.12.351, 2014.
Wanninkhof, R., Pierrot, D., Sullivan, K., Mears, P., and Barbero, L.: Comparison of discrete and underway CO2 measurements: Inferences on the temperature dependence of the fugacity of CO2 in seawater, Mar. Chem., 247, 104178, https://doi.org/10.1016/j.marchem.2022.104178, 2022a.
Wanninkhof, R., Pierrot, D., Sullivan, K. F., Mears, P., Barbero, L.: Comparison of discrete and underway carbon dioxide (CO2) related measurements obtained during 21 cruises spanning the Pacific, Atlantic, Indian Oceans and Gulf of Mexico between 1991 and 2020: inferences on the temperature dependence of the fugacity of CO2 (fCO2) in seawater (NCEI Accession 0247018), NOAA National Centers for Environmental Information [data set], https://doi.org/10.25921/8c3k-vz52, 2022b.
Waters, J. F. and Millero, F. J.: The free proton concentration scale for seawater pH, Mar. Chem., 149, 8–22, https://doi.org/10.1016/j.marchem.2012.11.003, 2013.
Watson, A. J., Schuster, U., Shutler, J. D., Holding, T., Ashton, I. G. C., Landschützer, P., Woolf, D. K., and Goddijn-Murphy, L.: Revised estimates of ocean-atmosphere CO2 flux are consistent with ocean carbon inventory, Nat. Commun., 11, 4422, https://doi.org/10.1038/s41467-020-18203-3, 2020.
Weiss, R. F.: Carbon dioxide in water and seawater: the solubility of a non-ideal gas, Mar. Chem., 2, 203–215, https://doi.org/10.1016/0304-4203(74)90015-2, 1974.
Weiss, R. F., Jahnke, R. A., and Keeling, C. D.: Seasonal effects of temperature and salinity on the partial pressure of CO2 in seawater, Nature, 300, 511–513, https://doi.org/10.1038/300511a0, 1982.
Woosley, R. J.: Evaluation of the temperature dependence of dissociation constants for the marine carbon system using pH and certified reference materials, Mar. Chem., 229, 103914, https://doi.org/10.1016/j.marchem.2020.103914, 2021.
Woosley, R. J. and Moon, J.-Y.: Re-evaluation of carbonic acid dissociation constants across conditions and the implications for ocean acidification, Mar. Chem., 250, 104247, https://doi.org/10.1016/j.marchem.2023.104247, 2023.
Zeebe, R. E. and Wolf-Gladrow, D.: CO2 in Seawater: Equilibrium, Kinetics, Isotopes, Elsevier B. V., Amsterdam, the Netherlands, 346 pp., ISBN 0-444-50946-1, 2001.
Short summary
The ocean takes up carbon dioxide (CO2) from the atmosphere, slowing climate change. This CO2 uptake is controlled by a property called ƒCO2. Seawater ƒCO2 changes as seawater warms or cools, although by an uncertain amount; measurements and calculations give inconsistent results. Here, we work out how ƒCO2 should, in theory, respond to temperature. This matches field data and model calculations but still has discrepancies with scarce laboratory results, which need more measurements to resolve.
The ocean takes up carbon dioxide (CO2) from the atmosphere, slowing climate change. This CO2...