Delta sup(14)C, sigma CO sub(2) salinity of the western Indian Ocean deep waters: Spatial and temporal variations

Abstract

Indian Ocean Deep waters (IDW) show an increase in salinity and sigma CO sub(2) between 64 degrees S and 16 plus or minus 4 degrees N by 0.106-0.110 ppt and 82-104 mu M kg sup(-1) respectively with a corresponding decrease in delta sup(14)C by 42 ppt, as revealed by the GEOSECS data (1977-78). The delta sup(14)C-sigma CO sub(2)-salinity relationships show better correlation in the western sector. High biological productivity induced changes and corrosive deepwaters could account for sigma CO sub(2) increase in the northern regions. Reoccupation of GEOSECS stations during 1985-95 do not show distinctly discemible short-term temporal changes in delta sup(14)C, sigma CO sub(2) and salinity