Tropical Cyclone Research and Review (Mar 2022)
Spatio-temporal behaviours of tropical cyclones over the bay of Bengal Basin in last five decades
Abstract
Present research is an endeavour to scrutinise the spatio-temporal climatic characteristics of tropical cyclones (TCs) bustle in the Bay of Bengal basin, found in RSMC-IMD data all through 1971–2020. A large number of TCs, i.e. 121 with a decadal average of 35.2 TCs has been examined for the last 50 years where depression (D) and deep depression (DD) have not been taken into account as these are less violent in nature. During the study periods, inter-annual and inter-decadal variation in cyclogenesis, landfall, length, speed, track shape and sinuosity, energy metrics and damage profile have been perceived. The study is clearly showing TCs took the northward track during the pre-monsoon season and made their landfall across the coasts of Bangladesh and Myanmar, while post-monsoon TCs made their landfall directly on the coasts of Orissa and West Bengal. In the post-monsoon phase, VF, ACE and PDI are significantly higher than in the monsoon season in the case of TCs and higher in the pre-monsoon season than in the monsoon season in the case of TCs comparing the energy metrics in different seasons. TC activity is comparatively pronounced during La Niña and El Niño regimes respectively and the genesis position in the BoB is moves to the east (west) of 87° E. During the cold regime, the number of extreme TC above the VSCS category, increased intensely. It is believed that the research findings will help stakeholders of the nation to take accurate strides to combat such violent events with persistent intensification.
