A study of cyclonic disturbances over India and the adjacent ocean

Annual and seasonal frequencies of cyclonic disturbances that occurred over the area extending from 5 degreesN to 30 degreesN and 50 degreesE to 100 degreesE are examined for the period 1891-1998. The analysis revealed a significant decreasing trend in annual as well as seasonal frequency of cyclonic disturbances in the monsoon season, The frequency of cyclonic disturbances in the monsoon season also shows the typical quasi-biennial oscillation. On the decadal time scale, frequencies in the monsoon season, as well as annual cyclonic disturbances, show a decreasing trend. Copyright (C) 2001 Royal Meteorological Society.