Distribution of CO₂ species in seawater of central west coast of India

Abstract

During the 89 cruise of R V Gaveshani water samples were collected at 5 stations from different depths to study to distribution of CO₂ and CO₂- bearing species. Total CO₂ (TCO₂), PCO, HCO<img src='/image/spc_char/3_bar.gif' border=0>, and CO<img src='http://www.niscair.res.in/jinfo/three.gif' border=0> were computed from salinity, temperature, <i>p</i>H and total alkalinity measurements. In deep water stations (0-1500 m), there was a decrease of TCO₂ from surface to 150 m depth whereas in shallow water stations (0-100 m) it was higher at the surface layers. Partial pressure of CO₂ was more or less constant in the upper layers up to 100 m and then gradually increased reaching maximum levels up to 1500 m. In general contribution of HCO<img src='/image/spc_char/3_bar.gif' border=0> towards TCO content was about 80-90% while that of CO<img src='http://www.niscair.res.in/jinfo/three.gif' border=0> was 2-12%.