Relationship Between Size and Intensity in North Atlantic Tropical Cyclones With Steady Radii of Maximum Wind

Abstract

Infrared brightness temperature and tropical cyclone (TC) data from 2000 to 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 TC 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.