CLIVAR Repeat Hydrography Cruise A13.5 in the South Atlantic on NOAA ship Ronald H. Brown was completed successfully during the period 8 March 2010- 18 April 2010. The 2010 A13.5 expedition began in Cape Town, South Africa and ended in Takoradi, Ghana. The A13.5 section ran nominally along the prime meridian (~3°W-1°E) from approximately 54°S to 5°N, repeating a section occupied on the AJAX expedition in 1983/1984. A total of 129 full water column CTD/O₂/LADCP/rosette casts were completed along the A13.5 section at ~30 nautical mile (nm) spacing, with closer (20 nm) spacing between 3°S and 3°N. Approximately 3,123 water samples were collected on these casts for analyses of a variety of parameters, including salinity, dissolved oxygen, nutrients, chlorofluorocarbons, (CFCs), SF₆, dissolved inorganic carbon (DIC), alkalinity, pCO₂ ,pH, carbon isotopes, dissolved organic carbon (DOC), total dissolved nitrogen (TDN), tritium and helium.

Carbon Data
CTD and other hydrographic data
Section designation: A13.5
Chief Scientists: John Bullister and Robert Key
Dates 8 March 2010 to 18 April 2010
NOAA Ship Ronald H. Brown
Ports of call Cape Town, South Africa to Takoradi, Ghana
Stations: 129
Geographic boundaries: 54°S to 5°N by 3°W to 1°E