Participants 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, agreed to establish a global surface fCO₂ data set that would bring together, in a common format, all publicly available fCO₂ data for the surface oceans.

This Surface Ocean CO₂ Atlas (SOCAT) data set serves a wide range of user communities. Two distinct data products are available:

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

(The fugacity of carbon dioxide, or fCO₂, is the partial pressure of CO₂ (pCO₂) corrected for non-ideal behaviour of the gas.)

SOCAT version 5, made public in 2017, includes data from more than 10 countries. It has 21.5 million quality controlled surface ocean fCO2 measurements from 1957 to 2017. The SOCAT data set uses IOCCP recommended formats for metadata and data reporting. SOCAT quality control is carried out by regional working groups with a global group for coordination.