HIGH-RESOLUTION SURFACE CIRCULATION OF THE BAY OF BENGAL DERIVED FROM SATELLITE OBSERVATION DATA

High-resolution surface circulation and its variability of the Bay of Bengal are derived by combining surface drifter and satellite observation data. The satellite altimetry data, satellite tracked surface drifter data and ocean surface winds from satellite scatterometers during 1993-2012 are used. The estimated velocities show good agreement with in-situ acoustic Doppler current profiler observations. The estimated velocity components are significantly correlated with monthly mean velocity components from Research Moored Array for African Asian-Australian Monsoon Analysis and Prediction buoy data. The mean circulation exhibits the strong western boundary current, zonal currents and weak eastern boundary flow. Large spatial and temporal variations are found in the western boundary current and intense mesoscale eddy activity in the western Bay of Bengal. Significant changes in surface circulation during positive and negative Indian Ocean Dipole (IOD) events are evident. During positive IOD, the eastward equatorial jet is reversed and the western boundary current is much weakened. Meanwhile, the western boundary current is the prominent flow during negative IOD events. High eddy kinetic energy is found during strong IOD events.