Climatological characteristics of Bay of Bengal tropical cyclones: 1972-2017

The present study is an attempt to investigate the spatial and temporal climatology of tropical cyclone (TC) activity in the Bay of Bengal (BoB) based on the Joint Typhoon Warning Centre (JTWC) best track data for the period 1972-2017. A total of 152 TCs, with a rate of 3.30 TCs per year, were formed in the BoB during the 46-year period. A large interannual variability was witnessed in TC activity with non-significant upward or downward trend in their frequency, intensity, duration, accumulated cyclone energy (ACE), and power dissipation index (PDI). Majority of TCs were formed between the 5 degrees N to 16 degrees N latitudes and made their landfall over the coasts of India, Bangladesh, Myanmar, and Sri Lanka. About two-thirds of annual TCs occurred during the post-monsoon season, whereas monthly distribution exhibited a unique bimodal pattern. The number of cyclonic storms (34-47 kt) showed a slightly increasing trend, whereas intense cyclonic storms (>= 48 kt) showed a slightly decreasing trend. Additionally, about 40% and 11% of the TC events were found intensifying at 15 kt 24 h(-1) and rapidly intensifying at 30 kt 24 h(-1), respectively in the BoB. It is believed that the results of the present study will update the current knowledge which will assist the scientific community as well as academicians.