EI- Nino and tropical storm tracks over Bay of Bengal during post monsoon season

Abstract

The role of EI-Nino in modulating tropical cyclone motion over Bay of Bengal during post monsoon season has been examined. Storms which formed during the years 1901-1987 have been classified into recuriving or those of which crossing north of 17° N and non-recurving or those of which crossing south of 17° N the east coast of India.

It has been found that in most of the cases (87 %) during EI-Nino years, the tropical cyclones which formed over Bay of Bengal crossed south of 17° N, i.e. south Andhra Pradesh Tamil Nadu coast, whereas tropical cyclones, ed during the year prior to the EI-Nino years [El- Nino (-1 ) year] are seen crossing mostly (in 79% of cases) either h of 17°N or recurving m northeastward direction. In other years this kind of behaviour is not generally onseerved. The correlation between southern oscillation indices and the fractional values of storms crossing south of 17⁰ N for the period 1901-1987 (n=87) is found to be ---0.63 which is significant at 1 per cent level.