Current trend and future projection of tropical cyclone intensity over the Bay of Bengal

The current trend in tropical cyclone (TC) intensity in terms of lifetime maximum intensity (LMI), power dissipation index (PDI), and potential intensity (PI) was examined to detect the impact of climate change on TC intensity. The PI was further evaluated using an ensemble of ten global circulation models that participated in the sixth phase of the Coupled Model Intercomparison Project (CMIP6) and compared with the present climate (2001-2020). The Mann-Kendall (MK) test showed no significant trend for the LMI and PDI, however, the PI showed a significant trend with an MK test value of 2.43 and a Sen's slope value of 0.04. No statistically significant changes in the PI were observed in both the near-future (2041-2060) and far-future (2081-2100) climates compared to the present climate. The PI associated thermodynamic factors were also examined. Thermodynamic efficiency was found to be unchanged in the future climates. Two competing processes were identified that influenced the PI in future climates. Firstly, increased sea surface temperature created a favorable environment for higher PI. Secondly, increased surface moisture and dry static stability resulted in decreased upward mass flux. These two contrasting processes resulted in a net zero effect of a warmer climate on the PI of future TCs.