基于三种不同阈值条件下快速增强热带气旋的统计分析

Statistical Characteristic of the Rapid Intensification Tropical Cyclones Based on Three Different Thresholds

利用美国联合台风警报中心(JTWC)整编的热带气旋(TC)最佳路径资料,采用不同的方法,分别定义TC近中心风速24 h变化达到25 kt、30 kt、35 kt为TC快速增强的阈值。统计结果表明:热带风暴和台风是快速增强热带气旋的主要组成部分。TC快速增强概率最高的月份是9月,分别达到了21.7%,22.3,21.9%;TC快速增强概率最高的初始强度是[65 kt,75kt)。在菲律宾以东(12.5"N,130"E)为中心的区域是TC经历快速增强过程的高频率中心。我国的台湾岛和东南沿海附近也是TC经历快速增强区域。

Using the tropical cyclone best track data of Joint Typhoon Warning Center（JTWC）,the thresholds of tropical cyclone rapid intensification（RI） as 25 kt,30 kt,35 kt,are defined which respectively represent the 24 h overwater intensity changes of tropical cyclones in the Northwest-Pacific area.Results show that the vast majority of RI cases occur in September with 22% of the RI cases that satisfy the RI thresholds occurring during 12 months.Cases with 65—70 kt initial intensities compose the largest fraction of RI cases.（12.5 ＂N,130 ＂E） is the high frequency center for tropical cyclone to undergo rapid intensification.