广东两次罕见大范围持续性冬季暴雨对比分析  

Comparison and Analysis of Two Unusually Extensive andPersistent Wintertime Heavy Rains in Guangdong

作　　者：吴瑞雅 梁家杰 周武 陈敏 庄家辉 WU Rui-ya;LIANG Jia-jie;ZHOU Wu;CHEN Min;ZHUANG Jia-hui(Meteorological Bureau of Yangjiang,Yangjiang 529500)

机构地区：[1]阳江市气象局,广东阳江529500

出　　处：《广东气象》2023年第2期27-31,共5页Guangdong Meteorology

摘　　要：利用气象常规资料、ERA5高分辨率再分析资料综合对比分析低温条件下广东2016年1月和2022年2月的两次大范围持续性冬季暴雨过程。结果表明:两个过程虽都处于冬季低温,但500 hPa上为两槽一脊,东亚大槽较弱,受南支槽东移影响,副高异常偏北偏强;850 hPa异常偏强的南风、切变线、充足的水汽、最大超过12 g/kg的比湿以及中低层21℃左右温差的层结条件都为暴雨的产生提供了有利的条件。但对比发现,2016年过程的副高更强更北,南支槽更深,垂直速度更大,冷空气更为浅薄,暖湿层结更为深厚,t850-500更高且维持时间更长,这些均导致2016年过程降水范围更广、降雨更强,并出现了短时强降水;而2022年过程则以持续性的层云降水为主。Using conventional meteorological data and high⁃resolution reanalysis from ERA5,this work makes a comprehensive comparison and analysis of two processes of extensive and persistent wintertime heavy rains that happened in January 2016 and February 2022,both under chilly temperature conditions.The re⁃sults are shown as follows.Although both of the heavy rains took place in winter when the temperature was low,they were accompanied by two troughs versus a ridge at the level of 500 hPa,a weak major trough in East Asia,and a subtropical high pressure that was more northward and stronger than usual due to the effect of an east⁃moving southern branch of the westerlies.They were generated as there were such favorable condi⁃tions as a abnormally strong southerly wind at 850 hPa,a shear,sufficient amount of water vapor,specific humidity with the maximum exceeding 12 g/kg,and stratification that was marked with a temperature differ⁃ence of about 21℃between the middle and low levels.It is found by the comparison,however,that the 2016 process was with a stronger and more northward subtropical high,a deeper southern branch,a larger vertical velocity,a shallower layer of cold air,a deeper warm and humid stratification,and a t850-500 that was higher and persisted longer.All of these made the 2016 process cover wider area and have stronger pre⁃cipitation with short⁃range intense spans of rain.In contrast,the 2022 process was mainly of persistent stra⁃tus precipitation.

关 键 词：天气学 冬季暴雨 副高 比湿 广东 

分 类 号：P44[天文地球—大气科学及气象学]