Delta C-14, Sigma CO2 and salinity of the western Indian Ocean deep waters: Spatial and temporal variations

Indian Ocean Deep waters (IDW) show an increase in salinity and Sigma CO2 b etween 64 degrees S and 16+/-4 degrees N by 0.106-0.110 parts per thousand and 82-104 mu M kg(-1) respectively with a corresponding decrease in Delta( 14)C by 42 parts per thousand as revealed by the GEOSECS data (1977-78), Th e Delta(14)C-Sigma CO2-Salinity relationships show better correlation in th e western sector. High biological productivity induced changes and corrosiv e deepwaters could account for Sigma CO2 increase in the northern regions. Reoccupation of GEOSECS stations during 1985-95 do not show distinctly disc ernible short-term temporal changes in Delta(14)C, Sigma CO2 and salinity.