Dynamical characteristics of Amphan and its impact on COVID-19 cases in Bangladesh

In May 2020, a category-5 tropical cyclone (TC) Amphan formed in the Bay of Bengal and struck the coasts of India and Bangladesh. In this study, the relevant dynamic characteristics and aftermaths of Amphan are documented. Through detailed investigation of the reanalysis and observation data, spatiotemporal varying characteristics of the atmospheric and oceanic parameters during the Amphan propagation process were analyzed. Due to a wide range of high sea surface temperature anomaly, Amphan developed rapidly and ultimately led to the local heavy precipitation and strong winds in the coastal areas during its passage. It is also noted that the recorded wave height, wave period, and current speed all amplified when Amphan passed by and the characteristics of wave and current directions are also consistent with the temporal variation of the corresponding wind field. Meanwhile, Amphan occurred in accompany with the ongoing COVID-19 pandemic. In Khulna Division of Bangladesh, the number of newly confirmed COVID-19 cases increased rapidly after Amphan landing, which however was almost nil before the event, indicating there might exist a possible correlation between Amphan and the intensive outbreak of the local COVID-19, and particular attentions should be paid to deal with the multi-type, coexisting disasters if different or even conflicting measures are required.