Articles | Volume 17, issue 11
https://doi.org/10.5194/essd-17-6071-2025
© Author(s) 2025. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/essd-17-6071-2025
© Author(s) 2025. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
A surface ocean pCO2 product with improved representation of interannual variability using a vision transformer-based model
Xueying Zhang
State Key Laboratory of Submarine Geoscience, School of Oceanography, Shanghai Jiao Tong University, Shanghai, 200240, China
Key Laboratory of Polar Ecosystem and Climate Change, Ministry of Education, School of Oceanography, Shanghai Jiao Tong University, Shanghai, 200240, China
Shanghai Key Laboratory of Polar Life and Environment Sciences, School of Oceanography, Shanghai Jiao Tong University, Shanghai, 200240, China
State Key Laboratory of Submarine Geoscience, School of Oceanography, Shanghai Jiao Tong University, Shanghai, 200240, China
Key Laboratory of Polar Ecosystem and Climate Change, Ministry of Education, School of Oceanography, Shanghai Jiao Tong University, Shanghai, 200240, China
Shanghai Key Laboratory of Polar Life and Environment Sciences, School of Oceanography, Shanghai Jiao Tong University, Shanghai, 200240, China
Wenfang Lu
School of Marine Sciences, State Key Laboratory of Environmental Adaptability for Industrial Products, Sun Yat-sen University, Zhuhai, Guangdong, 519082, China
Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Zhuhai, Guangdong, 519082, China
School of Marine Science and Policy, University of Delaware, Newark, Delaware, 19716, USA
Guansuo Wang
Observation and Research Station of Huaniaoshan East China Sea Ocean-Atmosphere Integrated Ecosystem, Ministry of Natural Resources, Shanghai, 200137, China
East China Sea Forecasting and Hazard Mitigation Center, Ministry of Natural Resources, Shanghai, 200137, China
Xueming Zhu
Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Zhuhai, Guangdong, 519082, China
Shiyu Liang
CORRESPONDING AUTHOR
John Hopcroft Center for Computer Science, Shanghai Jiao Tong University, Shanghai, 200240, China
Related authors
Yetang Wang, Xueying Zhang, Wentao Ning, Matthew A. Lazzara, Minghu Ding, Carleen H. Reijmer, Paul C. J. P. Smeets, Paolo Grigioni, Petra Heil, Elizabeth R. Thomas, David Mikolajczyk, Lee J. Welhouse, Linda M. Keller, Zhaosheng Zhai, Yuqi Sun, and Shugui Hou
Earth Syst. Sci. Data, 15, 411–429, https://doi.org/10.5194/essd-15-411-2023, https://doi.org/10.5194/essd-15-411-2023, 2023
Short summary
Short summary
Here we construct a new database of Antarctic automatic weather station (AWS) meteorological records, which is quality-controlled by restrictive criteria. This dataset compiled all available Antarctic AWS observations, and its resolutions are 3-hourly, daily and monthly, which is very useful for quantifying spatiotemporal variability in weather conditions. Furthermore, this compilation will be used to estimate the performance of the regional climate models or meteorological reanalysis products.
Enhui Liao, Laure Resplandy, Fan Yang, Yangyang Zhao, Sam Ditkovsky, Manon Malsang, Jenna Pearson, Andrew C. Ross, Robert Hallberg, and Charles Stock
Geosci. Model Dev., 18, 6553–6596, https://doi.org/10.5194/gmd-18-6553-2025, https://doi.org/10.5194/gmd-18-6553-2025, 2025
Short summary
Short summary
The northern Indian Ocean is central to the livelihoods and economies of countries that comprise about one-third of the world's population. We present a high-resolution (~10 km) ocean model that simulates seasonal and year-to-year variability in ocean, including currents, oxygen levels, and phytoplankton growth. This model is a powerful tool to study how climate change and human activities influence the northern Indian Ocean, which can be used for marine resource applications and management.
Hui Gao, Zelun Wu, Zhentao Sun, Diana Cai, Meibing Jin, and Wei-Jun Cai
Earth Syst. Sci. Data Discuss., https://doi.org/10.5194/essd-2025-517, https://doi.org/10.5194/essd-2025-517, 2025
Preprint under review for ESSD
Short summary
Short summary
Observations of stable carbon isotopes in dissolved inorganic carbon are sparse, limiting their potential in carbon cycle studies. We compiled 51 cruises and used a machine learning method trained on 37 cruises that passed secondary quality control to reconstruct isotope values in the Atlantic. The reconstruction expands usable samples from 8,941 to 68,435, reducing noise, filling gaps, preserving decadal trend, and strengthening studies of carbon variability and model validation.
Xinxin Wang, Jiuke Wang, Wenfang Lu, Changming Dong, Hao Qin, and Haoyu Jiang
Geosci. Model Dev., 18, 5101–5114, https://doi.org/10.5194/gmd-18-5101-2025, https://doi.org/10.5194/gmd-18-5101-2025, 2025
Short summary
Short summary
Large-scale wave modeling is essential for science and society, typically relying on resource-intensive numerical methods to simulate wave dynamics. In this study, we introduce a rolling AI-based method for modeling global significant wave height. Our model achieves accuracy comparable to traditional numerical methods while significantly improving speed, making it operable on standard laptops. This work demonstrates AI's potential to enhance the accuracy and efficiency of global wave modeling.
Sung-Won Cho, Jang-Geun Choi, Deoksu Kim, Wenfang Lu, and Young-Heon Jo
EGUsphere, https://doi.org/10.5194/egusphere-2025-2748, https://doi.org/10.5194/egusphere-2025-2748, 2025
Short summary
Short summary
The Yellow Sea is known for its strong tidal and wind forcing that influence surface currents. However, traditional methods assume steady-state surface current, making it hard to capture effects of tide and typhoon. In this study, we developed a new method that considers inertia. By comparing our results with observations, we found that this approach provides improved accuracy compared to previous methods. This improvement can contribute to better understanding of dynamics in the Yellow Sea.
Li-Qing Jiang, Amanda Fay, Jens Daniel Müller, Lydia Keppler, Dustin Carroll, Siv K. Lauvset, Tim DeVries, Judith Hauck, Christian Rödenbeck, Luke Gregor, Nicolas Metzl, Andrea J. Fassbender, Jean-Pierre Gattuso, Peter Landschützer, Rik Wanninkhof, Christopher Sabine, Simone R. Alin, Mario Hoppema, Are Olsen, Matthew P. Humphreys, Kumiko Azetsu-Scott, Dorothee C. E. Bakker, Leticia Barbero, Nicholas R. Bates, Nicole Besemer, Henry C. Bittig, Albert E. Boyd, Daniel Broullón, Wei-Jun Cai, Brendan R. Carter, Thi-Tuyet-Trang Chau, Chen-Tung Arthur Chen, Frédéric Cyr, John E. Dore, Ian Enochs, Richard A. Feely, Hernan E. Garcia, Marion Gehlen, Lucas Gloege, Melchor González-Dávila, Nicolas Gruber, Yosuke Iida, Masao Ishii, Esther Kennedy, Alex Kozyr, Nico Lange, Claire Lo Monaco, Derek P. Manzello, Galen A. McKinley, Natalie M. Monacci, Xose A. Padin, Ana M. Palacio-Castro, Fiz F. Pérez, Alizée Roobaert, J. Magdalena Santana-Casiano, Jonathan Sharp, Adrienne Sutton, Jim Swift, Toste Tanhua, Maciej Telszewski, Jens Terhaar, Ruben van Hooidonk, Anton Velo, Andrew J. Watson, Angelicque E. White, Zelun Wu, Hyelim Yoo, and Jiye Zeng
Earth Syst. Sci. Data Discuss., https://doi.org/10.5194/essd-2025-255, https://doi.org/10.5194/essd-2025-255, 2025
Preprint under review for ESSD
Short summary
Short summary
This review article provides an overview of 60 existing ocean carbonate chemistry data products, encompassing a broad range of types, including compilations of cruise datasets, gap-filled observational products, model simulations, and more. It is designed to help researchers identify and access the data products that best support their scientific objectives, thereby facilitating progress in understanding the ocean's changing carbonate chemistry.
Zelun Wu, Wenfang Lu, Alizée Roobaert, Luping Song, Xiao-Hai Yan, and Wei-Jun Cai
Earth Syst. Sci. Data, 17, 43–63, https://doi.org/10.5194/essd-17-43-2025, https://doi.org/10.5194/essd-17-43-2025, 2025
Short summary
Short summary
This study addresses the lack of comprehensive sea surface partial pressure of CO2 (pCO2) data in the North American Atlantic Coastal Ocean Margin (NAACOM) by developing the Reconstructed Coastal Acidification Database (ReCAD-NAACOM-pCO2). The product reconstructed sea surface pCO2 from 1993 to 2021 using machine-learning and environmental data, capturing seasonal cycles, regional variations, and long-term trends of pCO2 for coastal carbon research.
Na Li, Xueming Zhu, Hui Wang, Shouwen Zhang, and Xidong Wang
Ocean Sci., 19, 1437–1451, https://doi.org/10.5194/os-19-1437-2023, https://doi.org/10.5194/os-19-1437-2023, 2023
Short summary
Short summary
Observations of the sea surface temperature in the Arabian Sea show exceptional warming before the onset of the Indian Ocean summer monsoon. The sea surface temperature change is mainly caused by sea surface heat flux forcing, horizontal advection, and vertical entrainment. Here, we quantify the contribution of those factors to the Arabian Sea warm pool using heat budget analysis and highlight how large-scale ocean modes control its change.
Yetang Wang, Xueying Zhang, Wentao Ning, Matthew A. Lazzara, Minghu Ding, Carleen H. Reijmer, Paul C. J. P. Smeets, Paolo Grigioni, Petra Heil, Elizabeth R. Thomas, David Mikolajczyk, Lee J. Welhouse, Linda M. Keller, Zhaosheng Zhai, Yuqi Sun, and Shugui Hou
Earth Syst. Sci. Data, 15, 411–429, https://doi.org/10.5194/essd-15-411-2023, https://doi.org/10.5194/essd-15-411-2023, 2023
Short summary
Short summary
Here we construct a new database of Antarctic automatic weather station (AWS) meteorological records, which is quality-controlled by restrictive criteria. This dataset compiled all available Antarctic AWS observations, and its resolutions are 3-hourly, daily and monthly, which is very useful for quantifying spatiotemporal variability in weather conditions. Furthermore, this compilation will be used to estimate the performance of the regional climate models or meteorological reanalysis products.
Xueming Zhu, Ziqing Zu, Shihe Ren, Miaoyin Zhang, Yunfei Zhang, Hui Wang, and Ang Li
Geosci. Model Dev., 15, 995–1015, https://doi.org/10.5194/gmd-15-995-2022, https://doi.org/10.5194/gmd-15-995-2022, 2022
Short summary
Short summary
SCSOFS has provided daily updated marine forecasting in the South China Sea for the next 5 d since 2013. Comprehensive updates have been conducted to the configurations of SCSOFS's physical model and data assimilation scheme in order to improve its forecasting skill. The three most sensitive updates are highlighted. Scientific comparison and accuracy assessment results indicate that remarkable improvements have been achieved in SCSOFSv2 with respect to the original version SCSOFSv1.
Alizée Roobaert, Laure Resplandy, Goulven G. Laruelle, Enhui Liao, and Pierre Regnier
Ocean Sci., 18, 67–88, https://doi.org/10.5194/os-18-67-2022, https://doi.org/10.5194/os-18-67-2022, 2022
Short summary
Short summary
This study uses a global oceanic model to investigate the seasonal dynamics of the sea surface partial pressure of CO2 (pCO2) in the global coastal ocean. Our method quantifies the respective effects of thermal changes, biological activity, ocean circulation and freshwater fluxes on the temporal pCO2 variations. The performance of our model is also evaluated against a data product derived from observations to identify coastal regions where our approach is most robust.
Xueming Zhu, Ziqing Zu, Shihe Ren, Yunfei Zhang, Miaoyin Zhang, and Hui Wang
Ocean Sci. Discuss., https://doi.org/10.5194/os-2020-104, https://doi.org/10.5194/os-2020-104, 2020
Preprint withdrawn
Short summary
Short summary
In order to improve forecasting skills of South China Sea Operational Forecasting System operated in NMEFC of China, comprehensive updates have been conducted to the configurations of physical model and data assimilation scheme. Scientific inter-comparison and accuracy assessment has been performed by employing GODAE IV-TT Class 4 metrics. The results indicate that remarkable improvements have been achieved in the new version of SCSOFS.
Cited articles
Adcroft, A., Anderson, W., Balaji, V., Blanton, C., Bushuk, M., Dufour, C. O., Dunne, J. P., Griffies, S. M., Hallberg, R., Harrison, M. J., Held, I. M., Jansen, M. F., John, J. G., Krasting, J. P., Langenhorst, A. R., Legg, S., Liang, Z., McHugh, C., Radhakrishnan, A., Reichl, B. G., Rosati, T., Samuels, B. L., Shao, A., Stouffer, R., Winton, M., Wittenberg, A. T., Xiang, B., Zadeh, N., and Zhang, R.: The GFDL Global Ocean and Sea Ice Model OM4.0: Model Description and Simulation Features, J. Adv. Model. Earth Syst., 11, 3167–3211, https://doi.org/10.1029/2019MS001726, 2019.
Arcucci, R., Zhu, J., Hu, S., and Guo, Y.-K.: Deep Data Assimilation: Integrating Deep Learning with Data Assimilation, Appl. Sci., 11, 1114, https://doi.org/10.3390/app11031114, 2021.
Arrigo, K. R. and Dijken, G. L. V.: Secular trends in Arctic Ocean net primary production, J. Geophys. Res.-Oceans, 116, C09011, https://doi.org/10.1029/2011JC007151, 2011.
Arrigo, K. R., Dijken, G. V., and Pabi, S.: Impact of a shrinking Arctic ice cover on marine primary production, Geophys. Res. Lett., 35, L19603, https://doi.org/10.1029/2008GL035028, 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.
Bates, N. R. and Mathis, J. T.: The Arctic Ocean marine carbon cycle: evaluation of air–sea CO2 exchanges, ocean acidification impacts and potential feedbacks, Biogeosciences, 6, 2433–2459, https://doi.org/10.5194/bg-6-2433-2009, 2009.
Bauer, J. E., Cai, W.-J., Raymond, P. A., Bianchi, T. S., Hopkinson, C. S., Regnier, P. A. G., Bauer, J. E., Cai, W.-J., Raymond, P. A., Bianchi, T. S., Hopkinson, C. S., and Regnier, P. A. G.: The changing carbon cycle of the coastal ocean, Nature, 504, 61–70, https://doi.org/10.1038/nature12857, 2013.
Behrenfeld, M. J., O'Malley, R. T., Siegel, D. A., McClain, C. R., Sarmiento, J. L., Feldman, G. C., Milligan, A. J., Falkowski, P. G., Letelier, R. M., and Boss, E. S.: Climate-driven trends in contemporary ocean productivity, Nature, 444, 752–755, https://doi.org/10.1038/nature05317, 2006.
Boyce, D. G., Lewis, M. R., and Worm, B.: Global phytoplankton decline over the past century, Nature, 466, 591–596, https://doi.org/10.1038/nature09268, 2010.
Brajard, J., Carrassi, A., Bocquet, M., and Bertino, L.: Combining data assimilation and machine learning to infer unresolved scale parametrization, Philos. T. Roy. Soc. A, 379, 1–16, https://doi.org/10.1098/rsta.2020.0086, 2021.
Cai, W.-J., Xu, Y.-Y., Feely, R. A., Wanninkhof, R., Jönsson, B., Alin, S. R., Barbero, L., Cross, J. N., Azetsu-Scott, K., Fassbender, A. J., Carter, B. R., Jiang, L.-Q., Pepin, P., Chen, B., Hussain, N., Reimer, J. J., Xue, L., Salisbury, J. E., Hernández-Ayón, J. M., Langdon, C., Li, Q., Sutton, A. J., Chen, C.-T. A., Gledhill, D. K., Cai, W.-J., Xu, Y.-Y., Feely, R. A., Wanninkhof, R., Jönsson, B., Alin, S. R., Barbero, L., Cross, J. N., Azetsu-Scott, K., Fassbender, A. J., Carter, B. R., Jiang, L.-Q., Pepin, P., Chen, B., Hussain, N., Reimer, J. J., Xue, L., Salisbury, J. E., Hernández-Ayón, J. M., Langdon, C., Li, Q., Sutton, A. J., Chen, C.-T. A., and Gledhill, D. K.: Controls on surface water carbonate chemistry along North American ocean margins, Nat. Commun., 11, 1–13, https://doi.org/10.1038/s41467-020-16530-z, 2020.
Chau, T. T. T., Gehlen, M., and Chevallier, F.: A seamless ensemble-based reconstruction of surface ocean pCO2 and air–sea CO2 fluxes over the global coastal and open oceans, Biogeosciences, 19, 1087–1109, https://doi.org/10.5194/bg-19-1087-2022, 2022.
Chen, C., Zhang, H., Shi, W., Zhang, W., and Xue, Y.: A novel paradigm for integrating physics-based numerical and machine learning models: A case study of eco-hydrological model, Environ. Model. Softw., 163, 105669, https://doi.org/10.1016/j.envsoft.2023.105669, 2023.
Claustre, H., Johnson, K. S., and Takeshita, Y.: Observing the Global Ocean with Biogeochemical-Argo, Annu. Rev. Mar. Sci., 12, 23–48, https://doi.org/10.1146/annurev-marine-010419-010956, 2020.
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.-Oceans, 109, C12003, https://doi.org/10.1029/2004JC002378, 2004.
Denvil-Sommer, A., Gehlen, M., Vrac, M., and Mejia, C.: LSCE-FFNN-v1: a two-step neural network model for the reconstruction of surface ocean pCO2 over the global ocean, Geosci. Model Dev., 12, 2091–2105, https://doi.org/10.5194/gmd-12-2091-2019, 2019.
DeVries, T.: Atmospheric CO2 and Sea Surface Temperature Variability Cannot Explain Recent Decadal Variability of the Ocean CO2 Sink, Geophys. Res. Lett., 49, e2021GL096018, https://doi.org/10.1029/2021GL096018, 2022.
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.
Dickson, A. G., Sabine, C. L., and Christian, J. R.: Guide to best practices for ocean CO2 measurements, PICES Special Publication 3, 3, 191, https://doi.org/10.1159/000331784, 2007.
Dlugokencky, E. J., Thoning, K. W., Lang, P. M., and Tans, P. P.: NOAA Greenhouse Gas Reference from Atmospheric Car bon Dioxide Dry Air Mole Fractions from the NOAA ESRL Carbon Cycle Cooperative, Global Air Sampling Network [data set], https://www.esrl.noaa.gov/gmd/ccgg/mbl/data.php (last access: 20 February 2025), 2019.
Dosovitskiy, A., Beyer, L., Kolesnikov, A., Weissenborn, D., Zhai, X., Unterthiner, T., Dehghani, M., Minderer, M., Heigold, G., Gelly, S., Uszkoreit, J., and Houlsby, N.: An Image is Worth 16x16 Words: Transformers for Image Recognition at Scale, arXiv [preprint], arXiv:2010.11929, https://doi.org/10.48550/arXiv.2010.11929, 2020.
Fennel, K., Long, M. C., Algar, C., Carter, B., Keller, D., Laurent, A., Mattern, J. P., Musgrave, R., Oschlies, A., Ostiguy, J., Palter, J. B., and Whitt, D. B.: Modelling considerations for research on ocean alkalinity enhancement (OAE), in: Guide to Best Practices in Ocean Alkalinity Enhancement Research, edited by: Oschlies, A., Stevenson, A., Bach, L. T., Fennel, K., Rickaby, R. E. M., Satterfield, T., Webb, R., and Gattuso, J.-P., Copernicus Publications, State Planet, 2-oae2023, 9, https://doi.org/10.5194/sp-2-oae2023-9-2023, 2023.
Gal, Y. and Ghahramani, Z.: Dropout as a Bayesian Approximation: Representing Model Uncertainty in Deep Learning, arXiv [preprint], arXiv:1506.02142, https://doi.org/10.48550/arXiv.1506.02142, 2016.
Geurts, P., Ernst, D., Wehenkel, L., Geurts, P., Ernst, D., and Wehenkel, L.: Extremely randomized trees, Mach. Learn., 63, 3–42, https://doi.org/10.1007/s10994-006-6226-1, 2006.
Gloege, L., McKinley, G. A., Landschützer, P., Fay, A. R., Frölicher, T. L., Fyfe, J. C., Ilyina, T., Jones, S., Lovenduski, N. S., Rodgers, K. B., Schlunegger, S., and Takano, Y.: Quantifying Errors in Observationally Based Estimates of Ocean Carbon Sink Variability, Global Biogeochem. Cy., 35, e2020GB006788, https://doi.org/10.1029/2020GB006788, 2021.
Good, S. A., Martin, M. J., and Rayner, N. A.: EN4: Quality controlled ocean temperature and salinity profiles and monthly objective analyses with uncertainty estimates, J. Geophys. Res.-Oceans, 118, 6704–6716, https://doi.org/10.1002/2013JC009067, 2013.
Graven, H. D., Gruber, N., Key, R., Khatiwala, S., and Giraud, X.: Changing controls on oceanic radiocarbon: New insights on shallow-to-deep ocean exchange and anthropogenic CO2 uptake, J. Geophys. Res.-Oceans, 117, C10005, https://doi.org/10.1029/2012JC008074, 2012.
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., Kok, S., and Monteiro, P. M. S.: Interannual drivers of the seasonal cycle of CO2 in the Southern Ocean, Biogeosciences, 15, 2361–2378, https://doi.org/10.5194/bg-15-2361-2018, 2018.
Gregor, L., Lebehot, A. D., Kok, S., and Scheel Monteiro, P. M.: A comparative assessment of the uncertainties of global surface ocean CO2 estimates using a machine-learning ensemble (CSIR-ML6 version 2019a) – have we hit the wall?, Geosci. Model Dev., 12, 5113–5136, https://doi.org/10.5194/gmd-12-5113-2019, 2019.
Gruber, N., Bakker, D. C. E., DeVries, T., Gregor, L., Hauck, J., Landschützer, P., McKinley, G. A., and Müller, J. D.: Trends and variability in the ocean carbon sink, Nat. Rev. Earth Environ., 4, 119–134, https://doi.org/10.1038/s43017-022-00381-x, 2023.
Hauck, J., Nissen, C., Landschützer, P., Rödenbeck, C., Bushinsky, S., and Olsen, A.: Sparse observations induce large biases in estimates of the global ocean CO2 sink: an ocean model subsampling experiment, Philos. T. Roy. Soc. A, 381, 1–24, https://doi.org/10.1098/rsta.2022.0063, 2023.
Hersbach, H., Bell, B., Berrisford, P., Biavati, G., Horányi, A., Muñoz Sabater, J., Nicolas, J., Peubey, C., Radu, R., Rozum, I., Schepers, D., Simmons, A., Soci, C., Dee, D., Thépaut, J-N.: ERA5 monthly averaged data on single levels from 1940 to present, Copernicus Climate Change Service (C3S) Climate Data Store (CDS), https://doi.org/10.24381/cds.f17050d7, 2023.
Huang, B., Liu, C., Banzon, V., Freeman, E., Graham, G., Hankins, B., Smith, T., Zhang, H.-M., Huang, B., Liu, C., Banzon, V., Freeman, E., Graham, G., Hankins, B., Smith, T., and Zhang, H.-M.: Improvements of the Daily Optimum Interpolation Sea Surface Temperature (DOISST) Version 2.1, J. Climate, 34, 2923–2939, https://doi.org/10.1175/JCLI-D-20-0166.1, 2021.
Iida, Y., Takatani, Y., Kojima, A., and Ishii, M.: Global trends of ocean CO2 sink and ocean acidification: an observation-based reconstruction of surface ocean inorganic carbon variables, J. Oceanogr., 77, 323–358, https://doi.org/10.1007/s10872-020-00571-5, 2020.
Jackson, T., Sathyendranath, S., and Mélin, F.: An improved optical classification scheme for the Ocean Colour Essential Climate Variable and its applications, Remote Sens. Environ., 203, 152–161, https://doi.org/10.1016/j.rse.2017.03.036, 2017.
Jaegle, A., Gimeno, F., Brock, A., Zisserman, A., Vinyals, O., and Carreira, J.: Perceiver: General Perception with Iterative Attention, arXiv [preprint], arXiv:2103.03206, https://doi.org/10.48550/arXiv.2103.03206, 2021.
Ji, J., He, J., Lei, M., Wang, M., and Tang, W.: Spatio-Temporal Transformer Network for Weather Forecasting, IEEE T. Big Data, 11, 372–387, https://doi.org/10.1109/TBDATA.2024.3378061, 2025.
Keppler, L., Landschützer, P., Gruber, N., Lauvset, S. K., and Stemmler, I.: Seasonal Carbon Dynamics in the Near-Global Ocean, Global Biogeochem. Cy., 34, e2020GB006571, https://doi.org/10.1029/2020GB006571, 2020.
Kern, S., McGuinn, M. E., Smith, K. M., Pinardi, N., Niemeyer, K. E., Lovenduski, N. S., and Hamlington, P. E.: Computationally efficient parameter estimation for high-dimensional ocean biogeochemical models, Geosci. Model Dev., 17, 621–649, https://doi.org/10.5194/gmd-17-621-2024, 2024.
Lakshminarayanan, B., Pritzel, A., and Blundell, C.: Simple and Scalable Predictive Uncertainty Estimation using Deep Ensembles, arXiv [preprint], arXiv:1612.01474, https://doi.org/10.48550/arXiv.1612.01474, 2016.
Landschützer, P., Gruber, N., Bakker, D. C. E., Schuster, U., Nakaoka, S., Payne, M. R., Sasse, T. P., and Zeng, J.: A neural network-based estimate of the seasonal to inter-annual variability of the Atlantic Ocean carbon sink, Biogeosciences, 10, 7793–7815, https://doi.org/10.5194/bg-10-7793-2013, 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., 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., Bakker, D. C. E., Stemmler, I., Six, K. D., Landschützer, P., Gruber, N., Bakker, D. C. E., Stemmler, I., and Six, K. D.: Strengthening seasonal marine CO2 variations due to increasing atmospheric CO2, Nat. Clim. Change, 8, 146–150, https://doi.org/10.1038/s41558-017-0057-x, 2018.
Landschützer, P., Laruelle, G. G., Roobaert, A., and Regnier, P.: A uniform pCO2 climatology combining open and coastal oceans, Earth Syst. Sci. Data, 12, 2537–2553, https://doi.org/10.5194/essd-12-2537-2020, 2020.
Leal, A. M. M., Kyas, S., Kulik, D. A., and Saar, M. O.: Accelerating Reactive Transport Modeling: On-Demand Machine Learning Algorithm for Chemical Equilibrium Calculations, Transp. Porous Media, 133, 161–204, https://doi.org/10.1007/s11242-020-01412-1, 2020.
Liao, E., Resplandy, L., Liu, J., and Bowman, K. W.: Amplification of the Ocean Carbon Sink During El Niños: Role of Poleward Ekman Transport and Influence on Atmospheric CO2, Global Biogeochem. Cy., 34, e2020GB006574, https://doi.org/10.1029/2020GB006574, 2020.
Liao, E., Lu, W., Xue, L., and Du, Y.: weakening Indian ocean carbon uptake in 2015: the role of amplified basin-wide warming and reduced Indonesian throughflow, Limnol. Oceanogr. Lett., 4, 442–451, https://doi.org/10.1002/lol2.10397, 2024.
Liu, Y., Lu, W., Wang, D., Lai, Z., Ying, C., Li, X., Han, Y., Wang, Z., and Dong, C.: Spatiotemporal wave forecast with transformer-based network: A case study for the northwestern Pacific Ocean, Ocean Model., 188, 102323, https://doi.org/10.1016/j.ocemod.2024.102323, 2024.
Mackay, N. and Watson, A.: Winter Air-Sea CO2 Fluxes Constructed From Summer Observations of the Polar Southern Ocean Suggest Weak Outgassing, J. Geophys. Res.-Oceans, 126, e2020JC016600, https://doi.org/10.1029/2020JC016600, 2021.
McKinley, G. A., Fay, A. R., Eddebbar, Y. A., Gloege, L., and Lovenduski, N. S.: External Forcing Explains Recent Decadal Variability of the Ocean Carbon Sink, AGU Adv., 1, e2019AV000149, https://doi.org/10.1029/2019AV000149, 2020.
Mongwe, N. P., Vichi, M., and Monteiro, P. M. S.: The seasonal cycle of pCO2 and CO2 fluxes in the Southern Ocean: diagnosing anomalies in CMIP5 Earth system models, Biogeosciences, 15, 2851–2872, https://doi.org/10.5194/bg-15-2851-2018, 2018.
Müller, S. A., Joos, F., Plattner, G.-K., Edwards, N. R., and Stocker, T. F.: Modeled natural and excess radiocarbon: Sensitivities to the gas exchange formulation and ocean transport strength, Global Biogeochem. Cy., 22, GB3011, https://doi.org/10.1029/2007GB003065, 2008.
Nguyen, T., Brandstetter, J., Kapoor, A., Gupta, J. K., and Grover, A.: ClimaX: A foundation model for weather and climate, arXiv [preprint], arXiv:2301.10343, https://doi.org/10.48550/arXiv.2301.10343, 2023.
Rayner, N. A., Parker, D. E., Horton, E. B., Folland, C. K., Alexander, L. V., Rowell, D. P., Kent, E. C., and Kaplan, A.: Global analyses of sea surface temperature, sea ice, and night marine air temperature since the late nineteenth century, J. Geophys. Res.-Atmos., 108, 4407, https://doi.org/10.1029/2002JD002670, 2003.
Reichstein, M., Camps-Valls, G., Stevens, B., Jung, M., Denzler, J., Carvalhais, N., and Prabhat, M.: Deep learning and process understanding for data-driven Earth system science, Nature, 566, 195–204, https://doi.org/10.1038/s41586-019-0912-1, 2019.
Resplandy, L., Hogikyan, A., Müller, J. D., Najjar, R. G., Bange, H. W., Bianchi, D., Weber, T., Cai, W.-J., Doney, S. C., Fennel, K., Gehlen, M., Hauck, J., Lacroix, F., Landschützer, P., Quéré, C. L., Roobaert, A., Schwinger, J., Berthet, S., Bopp, L., Chau, T. T. T., Dai, M., Gruber, N., Ilyina, T., Kock, A., Manizza, M., Lachkar, Z., Laruelle, G. G., Liao, E., Lima, I. D., Nissen, C., Rödenbeck, C., Séférian, R., Toyama, K., Tsujino, H., and Regnier, P.: A Synthesis of Global Coastal Ocean Greenhouse Gas Fluxes, Global Biogeochem. Cy., 38, e2023GB007803, https://doi.org/10.1029/2023GB007803, 2024.
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.
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.
Roobaert, A., Resplandy, L., Laruelle, G. G., Liao, E., and Regnier, P.: A framework to evaluate and elucidate the driving mechanisms of coastal sea surface pCO2 seasonality using an ocean general circulation model (MOM6-COBALT), Ocean Sci., 18, 67–88, https://doi.org/10.5194/os-18-67-2022, 2022.
Roobaert, A., Regnier, P., Landschützer, P., and Laruelle, G. G.: A novel sea surface pCO2-product for the global coastal ocean resolving trends over 1982–2020, Earth Syst. Sci. Data, 16, 421–441, https://doi.org/10.5194/essd-16-421-2024, 2024a.
Roobaert, A., Resplandy, L., Laruelle, G. G., Liao, E., and Regnier, P.: Unraveling the Physical and Biological Controls of the Global Coastal CO2 Sink, Global Biogeochem. Cy., 38, e2023GB007799, https://doi.org/10.1029/2023GB007799, 2024b.
Sarmiento, J. L., Gruber, N., Brzezinski, M. A., and Dunne, J. P.: High-latitude controls of thermocline nutrients and low latitude biological productivity, Nature, 427, 56–60, https://doi.org/10.1038/nature02127, 2004.
Stock, C. A., Dunne, J. P., Fan, S., Ginoux, P., John, J., Krasting, J. P., Laufkötter, C., Paulot, F., and Zadeh, N.: Ocean Biogeochemistry in GFDL's Earth System Model 4.1 and Its Response to Increasing Atmospheric CO2, J. Adv. Model. Earth Syst., 12, e2019MS002043, https://doi.org/10.1029/2019MS002043, 2020.
Sun, C., Liao, E., and Zhu, X.: Asymmetrical ocean carbon responses in the tropical pacific ocean to La Niña and El Niño, Geophys. Res. Lett., 4, e2024GL112039, https://doi.org/10.1029/2024GL112039, 2025.
Sweeney, C., Gloor, E., Jacobson, A. R., Key, R. M., McKinley, G., Sarmiento, J. L., and Wanninkhof, R.: Constraining global air–sea gas exchange for CO2 with recent bomb 14C measurements, Global Biogeochem. Cy., 21, GB2015, https://doi.org/10.1029/2006GB002784, 2007.
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., 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., and Baar, H. J. W. d.: 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.
Valsala, V., Sreeush, M. G., and Chakraborty, K.: The IOD Impacts on the Indian Ocean Carbon Cycle, J. Geophys. Res.-Oceans, 125, e2020JC016485, https://doi.org/10.1029/2020JC016485, 2020.
Valsala, V., Sreeush, M. G., Anju, M., Sreenivas, P., Tiwari, Y. K., Chakraborty, K., and Sijikumar, S.: An observing system simulation experiment for Indian Ocean surface pCO2 measurements, Prog. Oceanogr., 194, 102570, https://doi.org/10.1016/j.pocean.2021.102570, 2021.
Vaswani, A., Shazeer, N., Parmar, N., Uszkoreit, J., Jones, L., Gomez, A. N., Kaiser, L., and Polosukhin, I.: Attention Is All You Need, arXiv [preprint], arXiv:1706.03762, https://doi.org/10.48550/arXiv.1706.03762, 2017.
Wang, H., Hosseini, S. A., Tartakovsky, A. M., Leng, J., and Fan, M.: A deep learning-based workflow for fast prediction of 3D state variables in geological carbon storage: A dimension reduction approach, J. Hydrol., 636, 131219, https://doi.org/10.1016/j.jhydrol.2024.131219, 2024.
Wang, Y.-H. and Gupta, H. V.: A Mass-Conserving-Perceptron for Machine-Learning-Based Modeling of Geoscientific Systems, Water Resour. Res., 60, e2023WR036461, https://doi.org/10.1029/2023WR036461, 2024.
Wanninkhof, R.: Relationship between wind speed and gas exchange over the ocean revisited, Limnol. Oceanogr. Meth., 12, 351–362, https://doi.org/10.4319/lom.2014.12.351, 2014.
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, 1–6, 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.
Willard, J., Jia, X., Xu, S., Steinbach, M., and Kumar, V.: Integrating Scientific Knowledge with Machine Learning for Engineering and Environmental Systems, arXiv [preprint], arXiv:2003.04919, https://doi.org/10.48550/arXiv.2003.04919, 2020.
Willard, J. D., Harrington, P., Subramanian, S., Mahesh, A., O'Brien, T. A., and Collins, W. D.: Analyzing and Exploring Training Recipes for Large-Scale Transformer-Based Weather Prediction, arXiv [preprint], arXiv:2404.19630, https://doi.org/10.48550/arXiv.2404.19630, 2024.
Williams, N. L., Juranek, L. W., Feely, R. A., Johnson, K. S., Sarmiento, J. L., Talley, L. D., Dickson, A. G., Gray, A. R., Wanninkhof, R., Russell, J. L., Riser, S. C., and Takeshita, Y.: Calculating surface ocean pCO2 from biogeochemical Argo floats equipped with pH: An uncertainty analysis, Global Biogeochem. Cy., 31, 591–604, https://doi.org/10.1002/2016GB005541, 2017.
Wu, H., Xiao, B., Codella, N., Liu, M., Dai, X., Yuan, L., and Zhang, L.: CvT: Introducing Convolutions to Vision Transformers, arXiv [preprint], arXiv:2103.15808, https://doi.org/10.48550/arXiv.2103.15808, 2021.
Wu, Z., Lu, W., Roobaert, A., Song, L., Yan, X.-H., and Cai, W.-J.: A machine-learning reconstruction of sea surface pCO2 in the North American Atlantic Coastal Ocean Margin from 1993 to 2021, Earth Syst. Sci. Data, 17, 43–63, https://doi.org/10.5194/essd-17-43-2025, 2025.
Zeng, J., Nojiri, Y., Landschützer, P., Telszewski, M., and Nakaoka, S.: A Global Surface Ocean fCO2 Climatology Based on a Feed-Forward Neural Network, J. Atmos. Ocean. Tech., 31, 1838–1849, https://doi.org/10.1175/JTECH-D-13-00137.1, 2014.
Zhang, X., Liao, E., Lu, W., Wu, Z., Wang, G., and Liang, S.: A surface ocean pCO2 product with improved representation of interannual variability using a vision transformer-based model, Zenodo [data set], https://doi.org/10.5281/zenodo.15331978, 2025.
Zhou, L. and Zhang, R.-H.: A self-attention–based neural network for three-dimensional multivariate modeling and its skillful ENSO predictions, Sci. Adv., 9, eadf282, https://doi.org/10.1126/sciadv.adf2827, 2023.
Short summary
We created a new global dataset that reveals how ocean surface carbon dioxide has changed each month over the past four decades. By applying a deep learning model trained on both observational data and model simulations, we improved the representation of interannual variability and more accurately captured ocean responses to climate events like El Niño. This work supports global efforts to understand the ocean’s role in the carbon cycle and its response to climate change.
We created a new global dataset that reveals how ocean surface carbon dioxide has changed each...
Altmetrics
Final-revised paper
Preprint