Rapid Growth of Outer Size of Tropical Cyclones: A New Perspective on Their Destructive Potential

Abstract

The destructive potential of a tropical cyclone (TC) is primarily determined by its intensity and outer size. Although TC intensification has been researched extensively, the growth rate of its outer size remains obscure. This prompts us to develop the concept of rapid growth of outer size (RG) of TCs. RG is defined as an increase of at least 75 km in the gale-force wind radius within 24 hr using an objective anomaly detection algorithm. RG is intrinsically linked to the life cycle of the outer size and comprises most of the peak for large TCs (>300 km) in the distribution of lifetime maximum size. Compared with rapid intensification, RG is a more dangerous change in the TC structure, leveling up the destructive potential more rapidly. This is the first attempt to reveal the importance of RG to the outer size climatology, life cycle, and destructive potential of TCs.