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Surface Ocean CO2 Atlas Database Version 2025 (SOCATv2025) (NCEI Accession 0304549)

Published by NOAA National Centers for Environmental Information | National Oceanic and Atmospheric Administration, Department of Commerce | Metadata Last Checked: February 28, 2026 | Last Modified: 2025-06-25T00:00:00.000+00:00
The ocean absorbs one quarter of the global CO2 emissions from human activity. The community-led Surface Ocean CO2 Atlas (www.socat.info) is key for the quantification of ocean CO2 uptake and its variation, now and in the future. SOCAT version 2025 has quality-controlled in situ surface ocean fCO2 (fugacity of CO2) measurements on ships, moorings, sailing yachts, autonomous and drifting surface platforms for the global ocean and coastal seas from 1957 to 2025. The main SOCAT synthesis and gridded products contain fCO2 values with an estimated accuracy of better than 5 μatm. Sensor fCO2 data with an estimated accuracy of better than 10 μatm are separately available. During secondary quality control, marine scientists assign a flag to each data set, as well as WOCE flags of 2 (good), 3 (questionable) or 4 (bad) to individual fCO2 values. Data sets are assigned flags of A and B for an estimated accuracy of better than 2 μatm, flag of C (and D) for an accuracy of better than 5 μatm and a flag of E for an accuracy of better than 10 μatm. Bakker et al. (2016) describe the quality control criteria used from SOCAT version 3 onward. SOCAT quality control cookbooks provide quality control updates (www.socat.info), with (Gkritzalis et al., 2024) used for version 2025. Quality control comments for individual data sets can be accessed via the SOCAT Data Set Viewer (www.socat.info). All data sets, where data quality has been deemed acceptable, have been made public. The main SOCAT synthesis files and the gridded products contain all data sets with an estimated accuracy of better than 5 µatm (data set flags of A to D) and fCO2 values with a WOCE flag of 2. Access to data sets with an estimated accuracy of better than 10 µatm (flag of E) and fCO2 values with flags of 3 and 4 is via additional data products and the Data Set Viewer (Table 8 in Bakker et al., 2016). SOCAT publishes a global gridded product with a 1° longitude by 1° latitude resolution without gap filling. A second product with a higher resolution of 0.25° longitude by 0.25° latitude is available for the coastal seas. The gridded products contain all data sets with an estimated accuracy of better than 5 µatm (data set flags of A to D) and fCO2 values with a WOCE flag of 2. Gridded products are available monthly, per year and per decade. Two powerful, interactive, online viewers, the Data Set Viewer and the Gridded Data Viewer (www.socat.info), enable investigation of the SOCAT synthesis and gridded data products. SOCAT data products can be downloaded. Matlab code is available for reading these files. Ocean Data View also provides access to the SOCAT data products (www.socat.info). SOCAT data products are discoverable, accessible and citable. The SOCAT Data Use Statement (www.socat.info) asks users to generously acknowledge the contribution of SOCAT scientists by invitation to co-authorship, especially for data providers in regional studies, and/or reference to relevant scientific articles. It also asks users to cite the relevant SOCAT data set, the relevant methods paper(s), and to use acknowledgement text (https://socat.info/index.php/citing-socat/). The SOCAT website (www.socat.info) provides a single access point for online viewers, downloadable data sets, the Data Use Statement, a list of contributors and an overview of scientific publications on SOCAT and using SOCAT. Automation of data upload and initial data checks have allowed annual releases of SOCAT from version 4 onwards. Automation of metadata upload is ongoing. SOCAT is used for quantification of ocean CO2 uptake and ocean acidification and for evaluation of earth system models and sensor data. SOCAT products inform on ocean CO2 uptake in the annual Global Carbon Budget since 2013. SOCAT is a key element of the World Meteorological Organization’s (WMO) Global Greenhouse Gas Watch (G3W) program and is a key resource for Copernicus’ evaluations. The annual SOCAT releases by the SOCAT scientific community contribute to United Nations (UN) Sustainable Development Goal (SDG) 13 and SDG 14 (Life Below Water), and to the UN Decade of Ocean Science for Sustainable Development. However, since 2022 SOCAT critically relies on support provided by the Pacific Marine Environmental Laboratory of the National Oceanic and Atmospheric Administration in the US. This has been sufficient to keep the basic operation running, however this limited support has resulted in SOCAT data architecture not being updated, leading to a system with limited resilience that is highly vulnerable to external factors. Hundreds of peer-reviewed scientific publications and high-impact reports cite SOCAT. The SOCAT community-led synthesis product is a key step in the value chain based on in situ surface ocean carbon measurements, which provides policy makers with critical information on ocean CO2 uptake for policy makers. The need for accurate knowledge of global ocean CO2 uptake and its (future) variation makes sustained funding of in situ surface ocean CO2 observations and their synthesis imperative.

Resources

17 resources available

  • Project Metadata

    FILE
  • NCEI Dataset Landing Page

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  • Descriptive Information

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  • HTTPS

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  • FTP

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  • https://doi.org/10.5194/essd-8-383-2016

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  • https://doi.org/10.5194/essd-5-145-2013

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  • https://socat.info/wp-content/uploads/2025/01/2024_SOCAT_QC_Cookbook_Update.pdf

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  • https://www.socat.info/

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  • https://odv.awi.de/data/ocean/socat-fco2-data/

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  • https://explore.webodv.awi.de/ocean/carbon/socat/

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  • https://www.ncei.noaa.gov/products/ocean-carbon-acidification-data-system

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  • https://www.ncei.noaa.gov/access/ocean-carbon-acidification-data-system/oceans/VOS_Program/

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  • https://www.ncei.noaa.gov/access/ocean-carbon-acidification-data-system/oceans/time_series_moorings.html

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  • https://www.ncei.noaa.gov/access/ocean-carbon-acidification-data-system/oceans/ASV/

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  • GCMD Keyword Forum Page

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  • NCEI Contact Information

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0304549 BAROMETRIC PRESSURE Partial pressure (or fugacity) of carbon dioxide - atmosphere partial pressure of carbon dioxide - water SALINITY - SURFACE WATER WATER TEMPERATURE barometric pressure sensor bubble type equilibrator for autonomous carbon dioxide (CO2) measurement carbon dioxide (CO2) gas analyzer salinometer showerhead equilibrator temperature sensor chemical meteorological physical surface underway VARIOUS CHARTERED VESSELS Alfred-Wegener Institute, Helmholtz Centre for Polar and Marine Research Argentina National Institute for Fishery Research and Development Bedford Institute of Oceanography Bermuda Institute of Ocean Sciences Bjerknes Centre for Climate Research Commonwealth Scientific and Industrial Research Organization Flanders Marine Institute GEOMAR Helmholtz Centre for Ocean Research Kiel Hakai Institute Helmholtz-Zentrum Hereon Icelandic Marine Research Institute IO PAS Japan Meteorological Agency, Climate and Maritime Meteorology Department Laboratoire d'Océanographie et du Climat : Expérimentations et Approches Numériques Lamont-Doherty Earth Observatory Leibniz Institute for Baltic Sea Research Warnemünde Marine Institute Ireland National Institute for Environmental Studies National Institute of Water and Atmospheric Research Limited NOAA Atlantic Oceanographic and Meteorological Laboratory NOAA Pacific Marine Environmental Laboratory NORCE Norwegian Research Centre Norwegian Polar Institute Scripps Institution of Oceanography Sorbonne University UAF College of Fisheries and Ocean Science University of Bergen, Geophysical Institute University of Cape Town, Department of Environmental and Geographical Science University of Colorado Boulder, Cooperative Institute for Research In Environmental Sciences University of Montana University of Otago University of South Florida College of Marine Science University of Washington Cooperative Institute for Climate, Ocean and Ecosystem Studies Uppsala University Woods Hole Oceanographic Institution NOAA Pacific Marine Environmental Laboratory Global CO2 Time-series and Moorings Project (CDIAC) Ship of Opportunity Programme (SOOP) Surface Ocean CO2 Atlas (SOCAT) Arctic Ocean Indian Ocean North Atlantic Ocean North Pacific Ocean South Atlantic Ocean South Pacific Ocean Southern Ocean World-Wide Distribution oceanography AWI > Alfred Wegener Institute for Polar and Marine Research BE/VLIZ > Flanders Marine Institute, Belgium BJERKNES > Bjerknes Centre for Climate Research CA/DFO/BIO > Bedford Institute of Oceanography, Fisheries and Oceans, Canada COLUMBIA/LDEO > Lamont-Doherty Earth Observatory, Columbia University DE/GEOMAR > GEOMAR - Helmholtz Centre for Ocean Research Kiel, Germany DOC/NOAA/OAR/AOML > Atlantic Oceanographic and Meteorological Laboratory, OAR, NOAA, U.S. Department of Commerce DOC/NOAA/OAR/PMEL > Pacific Marine Environmental Laboratory, OAR, NOAA, U.S. Department of Commerce IE/MARINE > Marine Institute, Ireland IOW > Leibniz Institute Baltic Sea Research Institute, Warnemuende, Germany JP/JMA > Japan Meteorological Agency, Japan JP/NIES > National Institute for Environmental Studies, Japan NO/NPI > Norwegian Polar Institute, Norway U-BERGEN/GEOPH > Geophysical Institute, University of Bergen UAK > University of Alaska, School of Fisheries UCO/CIRES > Cooperative Institute for Research in Environmental Sciences, University of Colorado UMT > University of Montana WHOI > WOODS HOLE OCEANOGRAPHIC INSTITUTION Multiple Multiple Ocean Carbon and Acidification Data System (OCADS) Project Coastal Carbon Project Moorings and Time Series project SOOP Coastal Carbon Project Moorings and Time Series Project Ship Of Opportunity Program (SOOP) EARTH SCIENCE > ATMOSPHERE > ATMOSPHERIC CHEMISTRY > CARBON AND HYDROCARBON COMPOUNDS > ATMOSPHERIC CARBON DIOXIDE > PARTIAL PRESSURE OF CARBON DIOXIDE EARTH SCIENCE > ATMOSPHERE > ATMOSPHERIC PRESSURE EARTH SCIENCE > CLIMATE INDICATORS > ATMOSPHERIC/OCEAN INDICATORS > SURFACE SALINITY EARTH SCIENCE > OCEANS > OCEAN CHEMISTRY > CARBON DIOXIDE EARTH SCIENCE > OCEANS > OCEAN TEMPERATURE > WATER TEMPERATURE EARTH SCIENCE > OCEANS > SALINITY/DENSITY > SALINITY Data synthesis product Surface measurement SOCAT SOCATv2025 Data Synthesis Product SOCATv2025 database SOCATv2025 gridded data product ATM_PPRE EQ_PRE EQ_TMP SSS SST fCO2 BAROMETERS > BAROMETERS CO2 ANALYZERS > CO2 ANALYZERS EQUILIBRATORS SALINOMETERS TEMPERATURE SENSORS > TEMPERATURE SENSORS GEOGRAPHIC REGION > GLOBAL OCEAN OCEAN > ARCTIC OCEAN OCEAN > ATLANTIC OCEAN > NORTH ATLANTIC OCEAN OCEAN > ATLANTIC OCEAN > SOUTH ATLANTIC OCEAN OCEAN > INDIAN OCEAN OCEAN > PACIFIC OCEAN > NORTH PACIFIC OCEAN OCEAN > PACIFIC OCEAN > SOUTH PACIFIC OCEAN OCEAN > SOUTHERN OCEAN Arctic Ocean Atlantic Ocean Indian Ocean Pacific Ocean Southern Ocean

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