Tropical cyclone-driven rainfall in the northeast Indian Ocean and adjoining land regions during the period 2000–2020

Abstract

Cyclone-induced rainfall analysis plays a significant role in cyclone-related disaster mitigation and management. Here, we present a comprehensive analysis of tropical cyclone (TC)-induced rainfall in Bay of Bengal (BoB) and its adjacent land regions by the land falling TCs for the past two decades (2000–2020). An average of 12.6 mm/day of land precipitation and 28.75 mm/day of oceanic precipitation are found within 300 km radius of the cyclones, as analysed from the 54 cyclones occurred during the study period. It is observed that the highest TC rainfall contribution to the total rainfall is in the winter months of January and February (40%), whereas the smallest is in the monsoon months of June, July, August and September (0.85%). The TC rainfall contributes about 10% to the annual rainfall over the land regions. The quadrant analysis shows that the TC rainfall depends on the season of TC formation and its direction. About 40.47% of BoB cyclones has the highest rainfall in the right-top quadrant, 35.15% in the left-top quadrant and 14.18% in the left-bottom quadrant. Our study provides key information on land falling TCs and their potential to inflict disasters and thus, this information can be used to provide better safety measures for TC-related hazards such as heavy rainfall and floods. This is particularly important, as the TCs can be more intense and frequent in the context of climate change.