Recent Increase of Tropical Cyclone Rapid Intensification in Global Coastal Regions

Abstract: Rapid intensification (RI) is likely the most crucial contributor to the development of strong tropical cyclones and the largest source of prediction error resulting in great threats to life and property, which can become more threatening with proximity to landfall. While enormous efforts have been devoted to studying the basin-wide fluctuation, temporal-spatial variations of global RI events remain uncertain. Here, we show that, compared with open oceans where the annual RI counts do not show any significant change, the coastal offshore regions within 400 km from the coastline host significantly more RI events, with the RI count tripled from 1980 to 2020. Reasons responsible for the coastal RI occurrence are analysed, with the dominant large-scale environmental factors identified. This work yields an important new finding that an increasing threat of RI in coastal regions has occurred in the preceding decades, which may continue in a future warming climate.