ASIAN CONFERENCE ON REMOTE SENSING. IM)~SroRE FLUX DIVERGENCE OVER THE TROPICAL INDIAN OCEAN USING INSAT 18 DATA

The evaporation rates over the tropical Indian Ocean have been.computed using the bulk-aerodynamic formulae from the unpublished ~Bunkar data set and Indian Daily Weather Reports. The satellite derived precipitation from the Indian national satellite (INSAT-IB) VIiRR (Very High Resolution Radiomp.tE~r) sensor operating in the runge 10.5 to 12.5 urn has been used for computing the precipitation over tt1e tropical Indian Ocean. The moisture flux divergence has been computed as the difference betwe~n the evaporation and ptec1pitation. The study shows that the Bay of Bengal region i8 highly conducive for large scal ~ convergence. As 8 ca.e study the moisture flux divergence over the Arabian See for the summer monsoon mOnths (June tYoseptembed of 1987 hr~e been _comp~Oed and the v81~Os being-0.02 x 10 ~ 2.55 x 10, 0.70 x 10 and 0.44 x 10 ton~/day respectively and compaf;ed with the previous estimftteIJ for other year..., INTRODUCTlOO A detailed knowledge of the moisture flux divergence over the tropical Indian Ocean is essential for identifyi ~ the source of the '"~lsture fort-the summer monsoon rainfall which contributes to about 70 to 9oy. of the mean annual rainfall for the variou8 meteorological subdivisions over India.. 'A majbr difficulty in assessing the relative role of th ~ contributions ftom the Arabian Sea and the southern Indian Ocean has been the paucity of the evaporation eltlm"tes and precipitation measurements over the oceanic regions.. Several investigators (Howland and Sikdar, 19831 Murakami e