THE CENTRAL AND EASTERN ARABIAN SEA AS A PERENNIAL SOURCE OF ATMOSPHERIC CARBON-DIOXIDE

Seasonal (winter monsoon, intermonsoon and southwest monsoon) and inte rannual (between southwest monsoon seasons of 1995 and 1996) variation s in total carbon dioxide (TCO2) and partial pressure of CO2 (pCO(2)) were studied in the central and eastern Arabian Sea as a part of the J GOFS (India) Programme. The pCO(2) values were computed from the resul ts of coulometric TCO2 and spectrophotometric pH measurements. Seasona l variability in TCO2 is evident with the changing circulation and bio logical production. In all seasons, the pCO(2) is higher in surface wa ters of the Arabian Sea, except along the Indian coast in the southwes t monsoon, than that in atmosphere, and thus this region appears to be a perennial source of atmospheric CO2. Significantly, an average of s imilar to 45 Tg y(-1) could be ejected to atmosphere from the study re gion, that seems to far exceed the earlier estimations. The estimated fluxes, however, are in agreement with those from the eastern equatori al Pacific Ocean.