Earth Syst. Sci. Data, 8, 383413, 2016www.earth-syst-sci-data.net/8/383/2016/doi:10.5194/essd-8-383-2016 Author(s) 2016. CC Attribution 3.0 License.

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

Dorothee C. E. Bakker1, Benjamin Pfeil2,3, Camilla S. Landa2,3, Nicolas Metzl4, Kevin M. OBrien5,6,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,Frdric 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,Jrme Harlay36, Judith Hauck37, Mario Hoppema37, Matthew P. Humphreys19,

Christopher W. Hunt38, Betty Huss15, J. Severino P. Ibnhez39,20, Truls Johannessen2,3,40,Ralph Keeling41, Vassilis Kitidis42, Arne Krtzinger9, Alex Kozyr43, Evangelia Krasakopoulou44,Akira Kuwata45, Peter Landschtzer46, Siv K. Lauvset40,2, Nathalie Lefvre4, 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

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, Norway3Bjerknes Centre for Climate Research, 5007 Bergen, Norway

4Sorbonne Universits (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, USA7National Institute for Environmental Studies, Tsukuba, Ibaraki, 305-8506, Japan

8College of Life and Environmental Sciences, University of Exeter, Exeter EX4 4QE, UK9GEOMAR 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, USA13CSIRO 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

Published by Copernicus Publications.

384 D. C. E. Bakker et al.: A multi-decade record of high-quality f CO2 data

16Departemento Oceanografa, Servicio de Hidrografa Naval, C1270ABV Buenos Aires, Argentina17Cooperative Institute for Marine and Atmospheric Studies, Rosenstiel School for Marine and Atmospheric

Science, University of Miami, Miami, FL 33149-1098, USA18Bermuda Institute of Ocean Sciences, Ferry Reach, St. Georges, GE01, Bermuda

19Ocean and Earth Science, University of Southampton, Southampton SO14 3ZH, UK20Centro de Estudos e Ensaios em Risco e Modelagem Ambiental, Universidade Federal de Pernambuco,

50740-550 Recife, Brazil21Sorbonne Universits, UPMC Univ Paris 06, CNRS, Adaptation et Diversit en Milieu Marin (UMR7144),

Station Biologique de Roscoff, 29680 Roscoff, France22School 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, China25Institute of Marine Research, 9294 Troms, Norway

26Department of Marine Sciences, University of Gothenburg, 40530 Gothenburg, Sweden27National Institute of Water and Atmospheric Research, Dunedin 9054, New Zealand

28Ocean Acidification Research Center, University of Alaska Fairbanks, Fairbanks, AK 99775-7220, USA29Hakai Institute, British Columbia V0P 1H0, Canada

30Norwegian Polar Institute, Fram Centre, 9296 Troms, Norway31IMAGES_ESPACE-DEV, Universit de Perpignan, 66860 Perpignan, France32UMR ESPACE-DEV, Maison de la teledtection, 34000 Montpellier, France

33Centre for Environment, Fisheries and Aquaculture Science, Lowestoft NR33 0HT, UK34Ocean Systems and Climate, CSIR-CHPC, Cape Town, 7700, South Africa35CSIRO Oceans and Atmosphere, Floreat, Western Australia 6014, Australia

36University of Hawaii at Manoa, Department of Oceanography, Honolulu, HI 96822, USA37Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research, 27515 Bremerhaven, Germany

38Ocean Process Analysis Laboratory, University of New Hampshire, Durham, NH 03824, USA39IRD Institut de Recherche pour le Dveloppement, Lago Sul, 71640-230 Brasilia, Brazil

40Uni Research Climate, Bjerknes Centre for Climate Research, 5007 Bergen, Norway41University of California, San Diego, CA 92093, USA

42Plymouth Marine Laboratory, Plymouth PL1 3DH, UK43Carbon Dioxide Information Analysis Center, Environmental Sciences Division,

Oak Ridge National Laboratory, Oak Ridge, TN 37831-6290, USA44University 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, Germany47Department of Ocean Sciences, Rosenstiel School of Marine and Atmospheric Science, University of Miami,

Miami, FL 33149-1031, USA48Department of Atmospheric and Oceanic Sciences and Institute of Arctic and Alpine Research,

University of Colorado, Boulder, CO 80309-0450, USA49Japan 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, USA52Marine Division, Global Environment and Marine Department, Japan Meteorological Agency,

Tokyo 100-8122, Japan53Leibniz Institute for Baltic Sea Research, 18119 Rostock (Warnemnde), Germany

54Weathertop Consulting LLC, College Station, TX 77845, USA55International Ocean Carbon Coordination Project, Institute of Oceanology of the Polish Academy of

Sciences, 81-712 Sopot, Poland56WCRP Joint Planning Staff, World Meteorological Organization, 1211 Geneva 2, Switzerland

57Royal Netherlands Institute for Sea Research, 1797 SZ t Horntje, Texel, the Netherlands58AirSea Laboratory, School of Physics and Ryan Institute, National University of Ireland, Galway, Ireland

Correspondence to: Dorothee C. E. Bakker (d.bakker@uea.ac.uk)

Earth Syst. Sci. Data, 8, 383413, 2016 www.earth-syst-sci-data.net/8/383/2016/

D. C. E. Bakker et al.: A multi-decade record of high-quality f CO2 data 385

Received: 26 April 2016 Published in Earth Syst. Sci. Data Discuss.: 25 May 2016Revised: 22 July 2016 Accepted: 22 July 2016 Published: 15 September 2016

Abstract. The Surface Ocean CO2 Atlas (SOCAT) is a synthesis of quality-controlled f CO2 (fugacity of car-bon dioxide) values for the global surface oceans and coastal seas with regular updates. Version 3 of SOCAThas 14.7 million f CO2 values from 3646 data sets covering the years 1957 to 2014. This latest version has anadditional 4.6 million f CO2 values relative to version 2 and extends the record from 2011 to 2014. Version3 also significantly increases the data availability for 2005 to 2013. SOCAT has an average of approximately1.2 million surface water f CO2 values per year for the years 2006 to 2012. Quality and documentation ofthe data has improved. A new feature is the data set quality control (QC) flag of E for data from alternativesensors and platforms. The accuracy of surface water f CO2 has been defined for all data set QC flags. Auto-mated range checking has been carried out for all data sets during their upload into SOCAT. The upgrade ofthe interactive Data Set Viewer (previously known as the Cruise Data Viewer) allows better interrogation of theSOCAT data collection and rapid creation of high-quality figures for scientific presentations. Automated dataupload 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 diox-ide and its long-term variation, detection of ocean acidification, as well as evaluation of coupled-climate andocean-only biogeochemical models. Users of SOCAT data products are urged to acknowledge the contribu-tion of data providers, as stated in the SOCAT Fair Data Use Statement. This ESSD (Earth System ScienceData) living data publication documents