Salt balance and mixing in the Bay of Bengal

Abstract

Basic fields of temperature salinity, density and currents in the Bay of Bengal are investigated using data archieved at the National Oceanographic Data Centre (NODC) Washington, D.C. and the Indian National Oceanographic Data Centre (INODC), National Institute of Oceanography, Dona Paula, Goa for the purpose of evaluating the profiles of mixing, both vertical and horizontal. The surface salinity field is found to be controlled primarily by the circulation in the surface layer. The coastal salinity field with large surface salinity variations observed along the coasts especially near to river mouths and in the South West Monsoon period is evolved primarily by the coastal currents which are mainly caused by the river runoff and is influenced and steered by the wind induced surface currents. The geostrophic circulation in the Bay of Bengal is found to consist of three gyres, (1) an inner gyre in the north western Bay, (2) the outer gyre in the southern Bay and (3) the Andaman double gyre with cyclonic and anticyclonic cells