Near future projections of tropical cyclone tracks over the Bay of Bengal using high resolution CMIP6 models

Future changes in tropical cyclone (TC) characteristics play a critical role in shaping the impacts and risks associated with climate change. In this study, we analyzed the near-future projections (2015–2050) by the high-resolution CMIP6-HighResMIP models and assessed the projected changes in the TC track characteristics in the Bay of Bengal. The multi model mean projects a northward shift in TC tracks in the near-future under the SSP5-8.5 scenario. The projected increasing number of north-northeastward TCs tracks and decline in west-northwestward moving TCs are primarily driven by strong background upper-level winds steering (southerly) over the Bay of Bengal without any significant contribution from other processes. These upper-level wind changes are caused by increase in the wave activity along the subtropical westerly jet axis, mainly originating from the western Mediterranean region and propagating downstream across the Indian subcontinent. The findings highlight the poleward shift in the projected TC tracks due to change in large scale wave dynamics in the subtropics. The study emphasizes the need for improved understanding of large-scale atmospheric dynamics influencing TC steering in a changing climate. Considering the nature of projected TC tracks, present study speculates its adverse impacts on the Bay of Bengal rim countries and advocates for future disaster preparedness associated with the TCs. The study further highlights the urgent need of more number of high-resolution models and their projections for accurate future projections of TC.