资源环境科技发展态势分析平台

Infrared brightness temperature and tropical cyclone data from 2000–2018 were used to investigate the relationships between the radius of maximum wind (RMW), radius of gale-force winds (34 kt or 17 m/s; R34), and intensity for intensifying and expanding North Atlantic TCs. Different relationships between intensity and R34 were found for different RMWs. Very deep convective clouds with infrared brightness temperatures ≤ 208 K are mainly observed on the outer edge of the RMW when it is stable. In such a case, the tropical cyclone intensifies and R34 expands rapidly when very deep convective clouds occur in both the inner and outer regions, and thus a linear relationship between the intensity and R34 occurs when the RMW is stable.