Impact of altimeter-derived river discharge on Bay of Bengal salinity: A case study for 1998 and 2002

Abstract

This study is concerned with the impact of altimeter-derived Ganga–Brahmaputra river discharge on Bay of Bengal salinity during the years 1993-2005. Simulations of an ocean general circulation model have been used for this purpose. Well-defined seasonal cycles superimposed with pronounced inter annual variability are noticed in the river discharge dataset. This gets reflected into a strong interannual variability of sea surface salinity (SSS), particularly near the river mouths. Also, there is marked difference in the extent of southward penetration of SSS anomaly during excess and deficit years. Salinity differences are found to be primarily aligned along the east coast of India because of the prevailing East India Coastal Current (EICC). Subsurface penetration of the low salinity tongue has also been studied and a salinity inversion during the deficit year of 2002 has been noticed.