Interactions Between a Marine Heatwave and Tropical Cyclone Amphan in the Bay of Bengal in 2020

Frontiers in Climate

Mayank Mishra¹  Caroline C. Ummenhofer²  Ming Feng³  Saurabh Rathore⁶  Babita Jangir⁸  Rishav Goyal⁹ 

[1] 0Centre for Oceans, Rivers, Atmosphere and Land Sciences, Indian Institute of Technology Kharagpur, Kharagpur, India;Australian Research Council Centre of Excellence for Climate Extremes, Sydney, NSW, Australia;Centre for Southern Hemisphere Oceans Research, Commonwealth Scientific and Industrial Research Organisation, Hobart, TAS, Australia;Climate Change Research Centre, University of New South Wales, Sydney, NSW, Australia;Commonwealth Scientific and Industrial Research Organisation, Oceans and Atmosphere, Indian Ocean Marine Research Centre, Crawley, WA, Australia;Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, TAS, Australia;LOCEAN-IPSL Sorbonne University, Paris, France;Soil, Water, and Environmental Sciences, Volcani Institute, Agricultural Research Organization, Rishon LeZion, Israel;The Australian Centre for Excellence in Antarctic Science, University of New South Wales, Sydney, NSW, Australia;Woods Hole Oceanographic Institution, Woods Hole, MA, United States;

关键词: compound extreme events;    marine heatwave;    tropical cyclone;    Amphan;    Fani;    super cyclone;   

DOI  :  10.3389/fclim.2022.861477

来源: DOAJ

【 摘 要 】

Interactions are diagnosed between a marine heatwave (MHW) event and tropical super cyclone Amphan in the Bay of Bengal. In May 2020, an MHW developed in the Bay of Bengal driven by coupled ocean-atmosphere processes which included shoaling of the mixed layer depth due to reduced wind speed, increased net surface shortwave radiation flux into the ocean, increased upper ocean stratification, and increased sub-surface warming. Ocean temperature, rather than salinity, dominated the stratification that contributed to the MHW development and the subsurface ocean warming that also increased tropical cyclone heat potential. The presence of this strong MHW with sea surface temperature anomalies >2.5°C in the western Bay of Bengal coincided with the cyclone track and facilitated the rapid intensification of tropical cyclone Amphan to a super cyclone in just 24 h. This rapid intensification of a short-lived tropical cyclone, with a lifespan of 5 days over the ocean, is unprecedented in the Bay of Bengal during the pre-monsoon period (March-May). As the cyclone approached landfall in northern India, the wind-induced mixing deepened the mixed layer, cooled the ocean's surface, and reduced sub-surface warming in the bay, resulting in the demise of the MHW. This study provides new perspectives on the interactions between MHWs and tropical cyclones that could aid in improving the current understanding of compound extreme events that have severe socio-economic consequences in affected countries.

【 授权许可】

Unknown