Equatorward western boundary current in the Bay of Bengal during November - December 1983

Abstract

Geostrophic circulation derived from the observed hydrographic data for the period November-December (1983) indicates the presence of a strong equatorward western boundary current (WBC) in the Bay of Bengal. The curl sub(z) phi based on the climatological mean wind field for the same period brodly shows a negative field in the northern part which suggests a southward current away from the western boundary with an expected Munk layer flowing northward opposing. The WBC takes a turn and flows zonally eastward at about 12 degrees N where curlz is zero. Subsequently, a cold core gyre (CCG) is formed in the central Bay when the zonal flow merges with the northward current at 9 degrees C. It is concluded that the WBC is mainly driven by the cross-shore density gradients causEd. by large quantity of river run-off