Turbulence of tropical cyclone ‘Fani’ in the Bay of Bengal and Indian subcontinent

The present study is focused on the movement and impact of extremely severe tropical cyclone ‘Fani,’ which developed in the Bay of Bengal near the Equator during April 2019 and caused a severe impact on landmass due to high wind speed (max.180 km/h) and extreme precipitation (150–300 mm/day). The multi-satellite-based study exhibited that the cyclone remained in the oceans for a longer duration (7 days; 70% of its life span) since its formation, providing a substantial strength and moisture to travel a very long trajectory (2136 km on the ocean and 1040 km on land). The high-intensive Fani cyclone had severely affected a large area in the eastern Indian subcontinent (primarily Odisha, West Bengal, Assam in India and Bangladesh). The precipitation pattern over the landmass was estimated using temporal tropical rainfall measurement mission (TRMM) satellite dataset. The TRMM-based study exhibited a very high-intensity precipitation (>300 mm/day) in the Bay of Bengal, whereas high- (150–300 mm/day) to low-intensity precipitation (< 50 mm/day) was observed in the coastal Andhra Pradesh, Odisha and West Bengal due to the influence of extremely severe cyclonic storm during the landfall and its progression on the landmass. The tropical cyclone significantly affected the agricultural land (128,019 km2; 57% of total area) and least affected the built-up land (2758 km2; 1.2% of total area) in the region. Nevertheless, the cyclonic impact on built-up land was extensive as it devastated human life, property and assets, with the high-speed wind, torrential rain and extensive flooding. The premonsoon cyclone is a sporadic history in BoB, and Fani was one of the most influential cyclones of the region. The study provides the nature of the 10th most severe cyclone in the Indian subcontinent in the last 52 years, through its movement, wind direction and impact in terms of heavy rainfall and on land use/land cover in the region.