Articles | Volume 8, issue 2
Earth Syst. Sci. Data, 8, 383–413, 2016
Earth Syst. Sci. Data, 8, 383–413, 2016

  15 Sep 2016

15 Sep 2016

A multi-decade record of high-quality fCO2 data in version 3 of the Surface Ocean CO2 Atlas (SOCAT)

Dorothee C. E. Bakker1, Benjamin Pfeil2,3, Camilla S. Landa2,3, Nicolas Metzl4, Kevin M. O'Brien5,6, Are Olsen2,3, Karl Smith5,6, Cathy Cosca5, Sumiko Harasawa7, Stephen D. Jones2,3, Shin-ichiro Nakaoka7, Yukihiro Nojiri7, Ute Schuster8, Tobias Steinhoff9, Colm Sweeney10,11, Taro Takahashi12, Bronte Tilbrook13,14, Chisato Wada7, Rik Wanninkhof15, Simone R. Alin5, Carlos F. Balestrini16, Leticia Barbero15,17, Nicholas R. Bates18,19, Alejandro A. Bianchi16, Frédéric Bonou20, Jacqueline Boutin4, Yann Bozec21, Eugene F. Burger5, Wei-Jun Cai22, Robert D. Castle15, Liqi Chen23,24, Melissa Chierici25,26, Kim Currie27, Wiley Evans5,28,29, Charles Featherstone15, Richard A. Feely5, Agneta Fransson30, Catherine Goyet31,32, Naomi Greenwood33, Luke Gregor34, Steven Hankin5,6, Nick J. Hardman-Mountford35, Jérôme Harlay36, Judith Hauck37, Mario Hoppema37, Matthew P. Humphreys19, Christopher W. Hunt38, Betty Huss15, J. Severino P. Ibánhez39,20, Truls Johannessen2,3,40, Ralph Keeling41, Vassilis Kitidis42, Arne Körtzinger9, Alex Kozyr43, Evangelia Krasakopoulou44, Akira Kuwata45, Peter Landschützer46, Siv K. Lauvset40,2, Nathalie Lefèvre4, Claire Lo Monaco4, Ansley Manke5, Jeremy T. Mathis5, Liliane Merlivat4, Frank J. Millero47, Pedro M. S. Monteiro34, David R. Munro48, Akihiko Murata49, Timothy Newberger10,11, Abdirahman M. Omar40,2, Tsuneo Ono50, Kristina Paterson13, David Pearce33, Denis Pierrot15,17, Lisa L. Robbins51, Shu Saito52, Joe Salisbury38, Reiner Schlitzer37, Bernd Schneider53, Roland Schweitzer54, Rainer Sieger37, Ingunn Skjelvan40,2, Kevin F. Sullivan15,17, Stewart C. Sutherland12, Adrienne J. Sutton5,6, Kazuaki Tadokoro45, Maciej Telszewski55, Matthias Tuma56, Steven M. A. C. van Heuven57, Doug Vandemark38, Brian Ward58, Andrew J. Watson8, and Suqing Xu23 Dorothee C. E. Bakker et al.
  • 1Centre for Ocean and Atmospheric Sciences, School of Environmental Sciences, University of East Anglia, Norwich NR4 7TJ, UK
  • 2Geophysical Institute, University of Bergen, 5020 Bergen, Norway
  • 3Bjerknes Centre for Climate Research, 5007 Bergen, Norway
  • 4Sorbonne Universités (UPMC, Univ Paris 06), CNRS, IRD, MNHN, LOCEAN/IPSL Laboratory, 75005 Paris, France
  • 5Pacific Marine Environmental Laboratory, National Oceanic and Atmospheric Administration, Seattle, WA 98115, USA
  • 6Joint Institute for the Study of the Atmosphere and Ocean, University of Washington, Seattle, WA 98105, USA
  • 7National Institute for Environmental Studies, Tsukuba, Ibaraki, 305-8506, Japan
  • 8College of Life and Environmental Sciences, University of Exeter, Exeter EX4 4QE, UK
  • 9GEOMAR Helmholtz Centre for Ocean Research Kiel, 24105 Kiel, Germany
  • 10Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder, CO 80309, USA
  • 11Earth System Research Laboratory, National Oceanic and Atmospheric Administration, Boulder, CO 80305-3337, USA
  • 12Lamont Doherty Earth Observatory, Columbia University, Palisades, NY 10964, USA
  • 13CSIRO Oceans and Atmosphere, Hobart, Tasmania 7001, Australia
  • 14Antarctic Climate and Ecosystems Cooperative Research Centre, University of Tasmania, Hobart, Tasmania 7001, Australia
  • 15Atlantic Oceanographic and Meteorological Laboratory, National Oceanic and Atmospheric Administration, Miami, FL 33149, USA
  • 16Departemento Oceanografía, Servicio de Hidrografía Naval, C1270ABV Buenos Aires, Argentina
  • 17Cooperative Institute for Marine and Atmospheric Studies, Rosenstiel School for Marine and Atmospheric Science, University of Miami, Miami, FL 33149-1098, USA
  • 18Bermuda Institute of Ocean Sciences, Ferry Reach, St. Georges, GE01, Bermuda
  • 19Ocean and Earth Science, University of Southampton, Southampton SO14 3ZH, UK
  • 20Centro de Estudos e Ensaios em Risco e Modelagem Ambiental, Universidade Federal de Pernambuco, 50740-550 Recife, Brazil
  • 21Sorbonne Universités, UPMC Univ Paris 06, CNRS, Adaptation et Diversité en Milieu Marin (UMR7144), Station Biologique de Roscoff, 29680 Roscoff, France
  • 22School of Marine Science and Policy, University of Delaware, Newark, DE 19716, USA
  • 23Key Laboratory of Global Change and Marine-Atmospheric Chemistry, Third Institute of Oceanography, State Oceanic Administration, Xiamen, 361005, China
  • 24Chinese Arctic and Antarctic Administration, Beijing, 100860, China
  • 25Institute of Marine Research, 9294 Tromsø, Norway
  • 26Department of Marine Sciences, University of Gothenburg, 40530 Gothenburg, Sweden
  • 27National Institute of Water and Atmospheric Research, Dunedin 9054, New Zealand
  • 28Ocean Acidification Research Center, University of Alaska Fairbanks, Fairbanks, AK 99775-7220, USA
  • 29Hakai Institute, British Columbia V0P 1H0, Canada
  • 30Norwegian Polar Institute, Fram Centre, 9296 Tromsø, Norway
  • 31IMAGES_ESPACE-DEV, Université de Perpignan, 66860 Perpignan, France
  • 32UMR ESPACE-DEV, Maison de la teledétection, 34000 Montpellier, France
  • 33Centre for Environment, Fisheries and Aquaculture Science, Lowestoft NR33 0HT, UK
  • 34Ocean Systems and Climate, CSIR-CHPC, Cape Town, 7700, South Africa
  • 35CSIRO Oceans and Atmosphere, Floreat, Western Australia 6014, Australia
  • 36University of Hawaii at Manoa, Department of Oceanography, Honolulu, HI 96822, USA
  • 37Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research, 27515 Bremerhaven, Germany
  • 38Ocean Process Analysis Laboratory, University of New Hampshire, Durham, NH 03824, USA
  • 39IRD – Institut de Recherche pour le Développement, Lago Sul, 71640-230 Brasilia, Brazil
  • 40Uni Research Climate, Bjerknes Centre for Climate Research, 5007 Bergen, Norway
  • 41University of California, San Diego, CA 92093, USA
  • 42Plymouth Marine Laboratory, Plymouth PL1 3DH, UK
  • 43Carbon Dioxide Information Analysis Center, Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831-6290, USA
  • 44University of the Aegean, Department of Marine Sciences, 81100, Mytilene, Lesvos, Greece
  • 45Tohoku National Fisheries Research Institute, Japan Fisheries Research and Education Agency, Shiogama, Miyagi, 985-0001, Japan
  • 46Max Planck Institute for Meteorology, 20146 Hamburg, Germany
  • 47Department of Ocean Sciences, Rosenstiel School of Marine and Atmospheric Science, University of Miami, Miami, FL 33149-1031, USA
  • 48Department of Atmospheric and Oceanic Sciences and Institute of Arctic and Alpine Research, University of Colorado, Boulder, CO 80309-0450, USA
  • 49Japan Agency for Marine-Earth Science and Technology, Yokosuka, Kanagawa, 237-0061, Japan
  • 50National Research Institute for Fisheries Science, Japan Fisheries Research and Education Agency, Yokohama, Kanagawa, 236-8648, Japan
  • 51US Geological Survey, Saint Petersburg, FL 33701, USA
  • 52Marine Division, Global Environment and Marine Department, Japan Meteorological Agency, Tokyo 100-8122, Japan
  • 53Leibniz Institute for Baltic Sea Research, 18119 Rostock (Warnemünde), Germany
  • 54Weathertop Consulting LLC, College Station, TX 77845, USA
  • 55International Ocean Carbon Coordination Project, Institute of Oceanology of the Polish Academy of Sciences, 81-712 Sopot, Poland
  • 56WCRP Joint Planning Staff, World Meteorological Organization, 1211 Geneva 2, Switzerland
  • 57Royal Netherlands Institute for Sea Research, 1797 SZ 't Horntje, Texel, the Netherlands
  • 58AirSea Laboratory, School of Physics and Ryan Institute, National University of Ireland, Galway, Ireland

Abstract. The Surface Ocean CO2 Atlas (SOCAT) is a synthesis of quality-controlled fCO2 (fugacity of carbon dioxide) values for the global surface oceans and coastal seas with regular updates. Version 3 of SOCAT has 14.7 million fCO2 values from 3646 data sets covering the years 1957 to 2014. This latest version has an additional 4.6 million fCO2 values relative to version 2 and extends the record from 2011 to 2014. Version 3 also significantly increases the data availability for 2005 to 2013. SOCAT has an average of approximately 1.2 million surface water fCO2 values per year for the years 2006 to 2012. Quality and documentation of the data has improved. A new feature is the data set quality control (QC) flag of E for data from alternative sensors and platforms. The accuracy of surface water fCO2 has been defined for all data set QC flags. Automated range checking has been carried out for all data sets during their upload into SOCAT. The upgrade of the interactive Data Set Viewer (previously known as the Cruise Data Viewer) allows better interrogation of the SOCAT data collection and rapid creation of high-quality figures for scientific presentations. Automated data upload has been launched for version 4 and will enable more frequent SOCAT releases in the future. High-profile scientific applications of SOCAT include quantification of the ocean sink for atmospheric carbon dioxide and its long-term variation, detection of ocean acidification, as well as evaluation of coupled-climate and ocean-only biogeochemical models. Users of SOCAT data products are urged to acknowledge the contribution of data providers, as stated in the SOCAT Fair Data Use Statement. This ESSD (Earth System Science Data) "living data" publication documents the methods and data sets used for the assembly of this new version of the SOCAT data collection and compares these with those used for earlier versions of the data collection (Pfeil et al., 2013; Sabine et al., 2013; Bakker et al., 2014). Individual data set files, included in the synthesis product, can be downloaded here: doi:10.1594/PANGAEA.849770. The gridded products are available here: doi:10.3334/CDIAC/OTG.SOCAT_V3_GRID.

Short summary
Version 3 of the Surface Ocean CO2 Atlas ( 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.