Pune: A new study by the Indian Institute of Tropical Meteorology (IITM), Pune, scientists has said that by 2050, post-monsoon tropical cyclones in the Bay of Bengal are projected to shift significantly northwards — potentially bringing increased cyclone activity to West Bengal and northern Odisha, while reducing the threat on Tamil Nadu and Andhra Pradesh.The research used high-resolution climate models to analyse cyclone patterns up to 2050. It found that cyclones moving in a north-northeastward direction are expected to increase from 21.2% to 31.5%, while west-northwestward moving cyclones will decline.One of the authors of the study, Dr Anant Parekh, said, “In the future, cyclone tracks will shift more towards the north. It means more cyclones for the eastern coast of India over Odisha and West Bengal and further towards Bangladesh and Myanmar — suggesting relief for Tamil Nadu and Andhra Pradesh.” Currently, most cyclones over the Bay of Bengal move north-northwest, typically hitting Andhra Pradesh and Tamil Nadu.The study focused specifically on post-monsoon cyclones (Oct-Dec), when the Bay of Bengal sees maximum cyclone activity.The projections are based on the SSP5-8.5 scenario — the highest greenhouse gas emission scenario — but for the near future period of 2015-2050. “The inference reliability is relatively better than earlier models as these projections come from high-resolution models,” Parekh said.The study found that the northward shift is driven primarily by changes in upper-level atmospheric winds — especially enhanced westerly winds over the western and central Bay of Bengal and stronger southerly winds over the northern part of the basin. The wind changes create a cyclonic circulation pattern that steers cyclones northward, instead of allowing them westward movement.Meanwhile, the study also emphasises the need to improve disaster preparedness in cyclone-affected regions. “Considering the nature of projected cyclone tracks, the study highlights potential adverse impacts on Bay of Bengal rim countries and advocates for enhanced disaster preparedness,” a scientist said.The study has been published in the journal Scientific Reports. The research was conducted by Rushikesh Adsul, Vineet Kumar Singh, Anant Parekh and C Gnanaseelan from the Climate Variability and Prediction division at the IITM, Pune.
