Flow Field in the Inner Shelf Along the Central East Coast of India During the Southwest Monsoon Season

Abstract

Current measurements collected along the inner shelf off the central East Coast of India at seven stations during August–September 1988 are discussed. Data indicate a southerly flowing alongshore current, which occupies the whole of the water column over the inner continental shelf. The southerly flow was found to be continuous over the period of measurement except at the northern most station, where southerly flow was interrupted by short period reversals. The velocity of the southerly flowing alongshore current increases from north to south and reaching maximum off Madras (37 cm s−1). Residual water circulation patterns show that there is an outflow of water to the south/south west from the entire water column except at the surface of the Stations 1 and 6. The mean kinetic energy and the eddy kinetic energy show direct relationship with the turning of the flow direction with depth. The energy associated is high if the turning of the flow with depth is more to the right and vice versa. The flow is normally opposed to the mean northeastward directed wind stress and it is thought to be associated with an alongshore pressure gradient. The source of this pressure gradient may be the large scale general circulation of the Bay of Bengal due to the influence of freshwater run off or it may be the result of some upstream or downstream forcing mechanism of a Munk layer driven Sverdrup flow due to wind stress curl.