An analysis of sea surface temperature and maximum potential intensity of tropical cyclones over the Bay of Bengal between 1981 and 2000

摘要

From the consideration of thermal energy, the maximum intensity of tropical cyclones largely depends upon the Sea Surface Temperature (SST). In this paper an empirical relationship between SST and Maximum Potential Intensity (MPI) of tropical cyclones over the Bay of Bengal has been developed using a sample of 60 cyclones from 20 years data (1981-2000). The relationship between SST and MPI is found to be linear. The MPI of each storm is computed using this empirical relationship and compared with observed intensity to examine how close the cyclones come to reaching their MPI. The result shows that about 18% of cyclones reach more than 80% of their MPI and about 38% of cyclones reach more than 50% of their MPI at their peak intensity. In general, cyclones attain about 51% of their MPI. The inter-seasonal variability shows cyclones in the pre-monsoon and the post-monsoon seasons tend to reach a higher percentage of their MPI than in the monsoon season. The inter-annual variability suggests there is appreciable variation in the yearly average of the ratio of observed maximum intensity to the MPI. The MPI could provide useful information to a forecaster about the possible extreme intensity of tropical cyclones, which has direct relevance to disaster management preparedness.