Increase in annual frequency of the severe cyclonic storms of the Bay after 1964- Possible causes

Abstract

The series of annual frequency of severe cyclonic storms which struck the coast around the Bay of Bengal during the period 1877-1977 has been examined to find out if any significant change has occurred in the mean frequency, It is observed that while the series for the period is homogeneous, a highly significant increase in the mean annual frequency has occurred after 1964. The larger annual mean frequency may be due to better facilities of detection of severe storms and/ or meteorological conditions over the Bay being more frequently favourable for intensification of storms into severe storms, An estimate of the mean annual frequency is made for the next 50-year period and the frequency distribution on the basis of this mean is given for the period, utilising the Poisson probability model which has shown good fit to past data.