Seasonal occurrence of unique sediment plume in the Bay of Bengal

Abstract

The movement of sediment plumes, detectable from ocean color sensors, depends primarily on coastal circulation. Hence, sediment plumes become tracers for studying circulation patterns. The Indian remote sensing satellite Oceansat 1 carries an ocean color monitor (OCM) sensor along with a microwave sensor. Using the OCM data, we studied the suspended sediment concentrations (SSC) during 1999-2006 and observed a plume coming off the Krishna-Godavari River Basin (KGB) that is the only plume within the Bay of Bengal whose movement is controlled by prevailing currents. The KGB is located in the central part of the east coast of India between 16 degrees 43 minutes, 17 degrees 00 minutes N and 82 degrees 15 minutes, 82 degrees 22 minutes E (Figure 1a). Though high sediment concentration is present all along India's east coast, the offshoot of the plume is present only at the coast of Kakinada, Andhra Pradesh, India. The presence, extent, orientation, and intensity of this plume have both seasonal and interannual variations