During the last few years, the major emphasis of tropical observational programs has been on examining processes in the Pacific Ocean. Now, with the recently completed Joint Air-Sea Monsoon Interaction Experiment (JASMINE), held in the eastern Indian Ocean during the summer of 1999, it is possible to make comparisons between characteristics of circulations and convection in the two major warm pools of the tropics.

In this study we concentration on a comparison of the characteristics of convection in the two ocean regimes. In particular, we compare JASMINE convection (depth, intensity, convective cell properties, stratiform region properties, & mesoscale circulations) to convection observed by radar in the Pacific Ocean experiments; TOGA COARE, TEPPS (in the tropical eastern Pacific), and KWAJEX. Whereas disturbed convection exists in a completely different synoptic regime in each of the oceans, it is found that mesoscale momentum transports perform very similar roles in the two regimes. A striking difference, however, is the diurnal variability experienced in the Bay of Bengal and eastern equatorial Indian Ocean which is more pronounced than in the Pacific and clearly influenced by continental convection at the head of the Bay. The Bay of Bengal diurnal convection that can be seen to propagate across the equator as intense squall lines occasionally lasting for two days, may represent a mode of organization of tropical convection not previously recognized.