Effect of river discharge on the circulation in the western Bay of Bengal

Abstract

SUMMARYA three-dimensional numerical model has been applied to study the impact of freshwater discharge from a river on the coastal circulation in the western Bay of Bengal. The basic dynamical framework of the model follows closely that described by Johns et al.' for the simulation of coastal upwelling off the east coast of India. Using this model, experiments have been performed to investigate the impact of the freshwater discharge at the location of Godavari river along the east coast of India. A comparison of the model results, with and without the inclusion of river discharge, shows that the river discharge into the western Bay of Bengal suppresses the upwelling near the river mouth. Though there are no detailed observations on the flow structure near the mouth of the Godavari river, the computed results are in qualitative agreement with the observations documented by Rao and Jayaraman2 and R~o ,~ who have shown that during monsoon period the upwelling off Godavari estuary is suppressed.