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 2019, made public in 2019, includes data from more than 10 countries. It has 25.7 million quality controlled surface ocean fCO₂ measurements from 1957 to 2019. 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.