Impact of climate change on tropical cyclones frequency and intensity on indian coasts

Abstract

Climate change is projected to exacerbate intensity of tropical cyclonic storms in selected ocean basins with the rise in sea surface temperatures. Almost all of the tropical cyclonic storms are concentrated in the East Asia, North America, and the Central American regions. The North Indian Ocean—the Bay of Bengal and the Arabian Sea, generates only 7% of the world’s cyclones. However, their impact is comparatively high and devastating, especially when they strike the East Indian and Bangladesh coasts bordering the North Bay of Bengal due to high population density clustered around low lying areas along these coastlines. The tropical storms typically do not reach a high intensity in the Arabian Sea due to the unfavorable wind shear; dry air feed from Thar Desert and relatively lower sea surface temperatures. However, the Arabian Sea basin has also produced a few strong tropical cyclones particularly as seen in the recent years. In general, cyclones in North Indian Ocean tend to peak during May, October and November. This paper presents comprehensive analyses of the cyclonic disturbances data of the North Indian Ocean of 140 years (1877–2016) and investigates the likely impacts of climate change on tropical cyclones frequency and intensity on Indian coasts based on historical cyclone data and recent model based findings on plausible changes in Indian Ocean SSTs and circulation systems.