Increasing risk of compound wind and precipitation extremes due to tropical cyclones in India

Abstract

Tropical cyclones (TC) cause compound extremes of rainfall and wind gust. However, their occurrence and impacts on India still need to be better understood. Using ERA5 reanalysis and cyclone eAtlas, we examine the compound extremes of precipitation and wind gust driven by TCs that made landfall over India during 1981-2021. Based on the joint return period of compound extremes, the five worst TCs occurred in May 1990, May 1999, May 2010 (Laila), October 2014 (Hudhud), and May 2020 (Amphan). A majority of TCs during 1981-2021 originated from the Bay of Bengal (BoB) and only a few from the Arabian Sea (AS). While the frequency of all the TCs has either declined or remained stable in the North Indian Ocean (NIO, BoB, AS) during 1981-2021, the frequency of TCs with compound extremes has increased by about three-fold during the most recent decade (2011-2021). Compound extremes driven by TCs affect large regions along the coast and risk infrastructure and human lives. The frequency of TCs with large area of impact (greater than 200,000 km2) compound wind and precipitation extreme extent exhibits a three-fold rise during 1981-2021, indicating an increase in the hazard associated with the compound extremes driven by TCs in India.