Probable reasons for enhanced cyclogenesis in the Bay of Bengal during July–August of ENSO years

This work presents the results of a study made to identify the probable causes of the higher frequency of monsoon depressions over the northern and adjoining central Bay of Bengal during July–August of ENSO years. For this purpose, 0.5° grid point satellite-derived NOAA–AVHRR sea surface temperature (SST) data and Multivariate ENSO Index (MEI) data for the period 1985–1998 have been used. SST distributions over various parts of Bay of Bengal have been obtained for MEI >1 (Warm ENSO phase) and MEI <−1 (Cold phase). The analysis has been carried out for the entire summer monsoon season with special emphasis on July–August, during which the majority of monsoon depressions occur.