西北太平洋热带气旋尺度变化过程中降水云系的演变特征及其作用  

Evolution Characteristics and Role of Precipitation Cloud Systems in the Size Change Process of Tropical Cyclones over the Western North Pacific

作　　者：饶晨泓 陈光华[1,2] 陈可鑫 鲁小琴 RAO Chenhong;CHEN Guanghua;CHEN Kexin;LU Xiaoqin(Key Laboratory of Cloud-Precipitation Physics and Severe Storms,Institute of Atmospheric Physics,Chinese Academy of Sciences,Beijing 100029;Shanghai Typhoon Institute,China Meteorological Administration,Shanghai 200032;University of Chinese Academy of Science,Beijing 100049)

机构地区：[1]中国科学院大气物理研究所云降水物理与强风暴重点实验室,北京100029 [2]中国气象局上海台风研究所,上海200032 [3]中国科学院大学,北京100049

出　　处：《大气科学》2023年第6期1796-1806,共11页Chinese Journal of Atmospheric Sciences

基　　金：国家自然科学基金项目42175073、41975071;上海台风研究基金项目TFJJ202003。

摘　　要：基于2007~2016年热带降水观测计划(TRMM)和全球降水观测计划(GPM)的卫星降水资料、最佳路径(IBTrACS)数据集和多平台TC风场资料(MTCSWA),根据西北太平洋(WNP)热带气旋(TC)的七级风圈半径(R17)变化速率将其分为尺度快速扩张(RE)和尺度快速收缩(RC)事件,主要研究RE和RC事件不同时期中TC外核区的降水云系演变特征及其影响R17变化的物理机制。研究结果表明:(1)RE事件中TC外核区的降水强度明显高于RC事件,说明TC外核区的降水强度对R17扩张具有重要作用;且RE事件前期强降水分布较RC事件更松散,这是区分RE和RC事件的一个前期信号;(2)TC外核区在RE和RC事件中降水的共同特征表现为:层云(对流)降水的强度小(大),面积大(小),主要加热中高层(中低层)大气,层云降水和对流降水的标准化降雨率数值相当;差异为:RE事件中TC外核区前、中、后期的降水面积、降水强度和标准化降雨率都高于RC事件;(3)RE事件中TC外核区不仅惯性稳定度大,且非绝热加热大,因而风场动能大,有利于尺度扩张;动能的增强还有利于低层入流的发展,促进R17的扩张和对流单体的发展。Based on the change rate of the gale-force wind radius(R17)of tropical cyclones(TCs)over the Western North Pacific,the evolution of TCs is categorized into size rapid expansion(RE)and size rapid contraction(RC)events.This study explored the evolution characteristics of precipitation cloud systems in the outer core regions of TC in RE and RC events as well as the physical mechanism responsible for the R17 change.The satellite data of Tropical Rainfall Measurement Missions and Global Precipitation Measurement,the International Best Track Archive for Climate Stewardship dataset,and Multiplatform Tropical Cyclone Surface Winds Analysis from 2007 to 2016 were employed.The results demonstrate that(1)the precipitation intensity in the TC outer core region of RE events is significantly higher than that in the RC events,showing that the TC outer core region's precipitation intensity plays a key role in the growth of R17.The heavy precipitation distribution in the initial stage of RE events is more scattered than that in RC events,which can serve as a precursory signal to differentiate the two kinds of events.(2)The common characteristics of precipitation in the outer core region of TC in the RE and RC events include stratiform(convective)precipitation with slow(high)precipitation intensity and large(small)precipitation area and dominant diabatic heating in the middle and upper(middle and lower)atmosphere.Convective and stratiform precipitation have comparable standardized precipitation rates.However,the precipitation area,precipitation intensity,and standardized precipitation rate in the outer core region of RE events are higher than those in RC events.(3)In RE occurrences,the outer core region of the TC exhibits high inertial stability and strong diabatic heating,resulting in a high kinetic energy wind field that is conducive to TC size expansion.Additionally,the increase in kinetic energy encourages the growth of low-level input,which aids in the expansion of R17 and the formation of convective cells.

关 键 词：TRMM和GPM卫星 热带气旋 快速扩张 快速收缩 

分 类 号：P458.124[天文地球—大气科学及气象学]