Effect of River Discharge on Bay of Bengal Circulation

Abstract

The bay of Bengal circulation is modeled using three-dimensional Princeton ocean model (POM). Along the coastal boundaries a higher resolution is accomplished using the curvilinear orthogonal grid. With a free-surface, terrain following sigma coordinates is used with fine resolution near the surface and bottom. The initial climatological salinity and temperature fields for the model are derived from the Levitus 94: World Ocean Atlas. The Model is forced w ith wind-stress derived from satellite information of UWM/COADS (a product of Department of Geosciences of the University of Wisconsin-Milwaukee and the National Oceanographic Data Centre/NOAA of the COADS). Bilinear interpolation is used to obtain the initial fields and wind stress to the required model specification. Using the monthly fields and wind stress the model is integrated for simulating bay of Bengal circulation. The numerical simulations on climatological scale for monsoon months were conducted to study the evolution of dynamics. The simulations bring out not only the typical characteristic features of fresh water plumes along the coast, but also intensification of the flow over the monsoon period. Also the increase in the fresh water flow was found to affect only the western parts of the bay of Bengal. The opposing currents due to monsoon winds and southward flowing fresh water discharge were also delineated.