Surface Ocean CO2 Atlas (SOCAT) Project

At the “Surface Ocean CO2 Variability and Vulnerability” (SOCOVV) workshop at UNESCO, Paris in April 2007, co-sponsored by IOCCP, SOLAS, IMBER, and the Global Carbon Project, participants agreed to establish a global surface CO2 data set that would bring together, in a common format, all publicly available fCO2 data for the surface oceans. (The fugacity of carbon dioxide, or fCO2, is the partial pressure of CO2 (pCO2) corrected for non-ideal behaviour of the gas.) This is an activity that has been called for by many international groups for many years, and has now become a priority activity for the marine carbon community.  This data set will serve as a foundation upon which the community will continue to build in the future, based on agreed data and metadata formats and standard 1st level quality-control procedures, building on earlier agreements established at the 2004 Tsukuba workshop on “Ocean Surface pCO2 Data Integration and Database Development”. This activity also supports the SOLAS and IMBER science plans and their joint carbon implementation plan.

This data set is meant to serve a wide range of user communities and it is envisaged that, in the future, 2 distinct data products will be made available in this Surface Ocean CO2 Atlas (SOCAT): 

• a 2nd level quality controlled global surface ocean fCO2  data set following agreed procedures and regional review, and
• a gridded SOCAT product of monthly surface water fCO2 means on a 1° x 1° grid with no temporal or spatial interpolation.

The extended 1st level quality-controlled data set builds on the work started in 2001 as part of the EU ORFOIS project by Dorothee Bakker , which now continues as part of the EU CarboOcean project, where Benjamin Pfeil and Are Olsen ) have compiled the publicly-available surface CO2 data held at CDIAC (Carbon Dioxide Information Analysis Center) and elsewhere into a common format database based on the IOCCP recommended formats for metadata and data reporting. This compilation currently includes data from more than 10 countries, producing an initial database composed of more than 1250 cruises from 1968 to 2007 with approximately 4.5 million measurements of various carbon parameters, available in a common format, 1st level quality-controlled data set.

A small technical meeting was held in Bremen, Germany, on 5 December 2007 (associated with the 3rd CarboOcean Annual Meeting) to agree on 1st level QC for the data set and to decide on a way forward for the 2nd level QC issues, and a 2nd technical meeting was held at UNESCO, Paris from 16-17 June 2008.

The IOCCP and the SOLAS-IMBER Carbon Coordination Group established 5 regional working groups to identify data not yet included in the global standard data set by December 2007. The groups are:

North Atlantic (including Arctic) – Ute Schuster (UEA, UK) and Nathalie Lefevre (L'Ocean, France)
Pacific – Richard Feely (NOAA/PMEL, USA) and co-chair to be determined.
Southern Ocean – Bronte Tilbrook (CSIRO, Australia)
Indian Ocean – V.V.S.S. Sarma (NIO, India)
Coastal Ocean – Arthur Chen (National Sun Yat-sen University, Taiwan) and Alberto Borges (U. Liege, Belgium)

For more information:See Workshops and Meeting page for reports

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