Thermal response of upper layers of Bay of Bengal to forcing of a severe cyclonic storm : A case study

Abstract

Upper ocean response to forcing of a severe cyclonic storm during May 1990 in the western Bay of Bengal was studied using the XBT data sets collected (4 d after passage of storm) under Indian TOGA programme. A maximum lowering in the sea surface temperature (SST) by 2.7-degrees-C relative to prestorm conditions and an increase in SST by 1-degrees-C during the poststorm regime of about 2 weeks were noticed close to the storm centre on the right side of the storm track. Presence of upwelling of cold water from deeper depths relative to prestorm conditions and its persistence during poststorm regime in the vicinity of the storm centre were revealed. Deep homogeneous surface layer of thickness about 55 m was developed at a distance of 110 km from the storm centre under the influence of strong winds.