西北太平洋台风尺度与强度变化之间关系初探

A Preliminary Study on the RelationshipBetween Tropical Cyclone Size and Intensityover the Northwest Pacific

为探究西北太平洋台风尺度对台风强度变化的影响,从美国联合台风预警中心(JTWC)2006—2015年最优路径(best track)观测资料中筛选出快速增强和非快速增强两类台风样本,采用台风最大风速半径(RMW)、34 kn(1 kn=0.51 m/s)风速等值线半径(AR34)和最外围闭合等压线半径(ROCI)三个尺度参数,初步分析了台风尺度与强度变化之间的关系。结果表明:内核尺度(RMW和AR34)与台风强度变化之间存在显著负相关,而外核尺度(ROCI)与台风强度变化之间的相关性较弱。经历和未经历快速增强过程的两类台风的初始尺度,前者显著小于后者。可以使用RMW和AR34代表的尺度参数来辅助中小尺度台风的强度预报和快速增强过程的预测。

To study the influence of tropical cyclone size on its intensity over the northwest Pacific,based on the best track data from Joint Typhoon Warning Center(JTWC),the rapid intensification(RI)samples and non-RI samples were selected to initially analyze the relationship between tropical cyclone size and its intensity over the northwest Pacific using the radius of maximum wind(RMW),the average 34-knot(kn;1 kn=0.51 m/s)radius(AR34),and the radius of the outermost closed isobar(ROCI).The results showed that the RMW and AR34 presented strong negative correlation with the variation of intensity,while ROCI exhibited weak relationship with the variation of intensity.The size of tropical cyclones that undergo RI was smaller than that with non-RI.It suggested that intensity forecasts of Meso-small scale tropical cyclone and RI predictions may be aided by the use of the initial size as measured by RMW and AR34.