广西汛期大范围持续性强降水特征与天气学分型研究  

STUDY ON CHARACTERISTICS AND SYNOPTIC CLASSIFICATION OF LARGE-SCALE PERSISTENT SEVER RAINFALL EVENTS DURING RAINY SEASON IN GUANGXI

作　　者：李华实 王东海 陆虹[2] 陈思蓉[2] 曾智琳 张春燕 LI Huashi;WANG Donghai;LU Hong;CHEN Sirong;ZENG Zhilin;ZHANG Chunyan(School of Atmospheric Sciences/Guangdong Provincial Key Laboratory for Climate Change and Natural Disaster Studies/Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai),Sun Yat-sen University,Zhuhai,Guangdong 519082,China;Guangxi Climate Center,Nanning 530022,China;Chongzuo Meteorological Bureau,Chongzuo,Guangxi 532200,China)

机构地区：[1]中山大学大气科学学院/广东省气候变化与自然灾害研究重点实验室/南方海洋科学与工程广东省实验室,广东珠海519082 [2]广西壮族自治区气候中心,广西南宁530022 [3]崇左市气象局,广西崇左532200

出　　处：《热带气象学报》2023年第2期242-255,共14页Journal of Tropical Meteorology

基　　金：国家重点研发计划(2019YFC1510400);国家自然科学基金项目(41775097、41861164027);广西气象科研计划项目(桂气科2023M29)共同资助。

摘　　要：利用1979—2019年国家级气象观测站日降水资料、ERA5再分析资料以及CMA热带气旋最佳路径集,对51例发生在广西的汛期大范围持续性强降水过程进行了统计分析与天气学分型研究,重点探索了不同类型过程的关键环流特征与锋生结构差异。主要研究结论如下:大范围持续性强降水过程有华北槽、南支槽、低涡切变、副高边缘、热带气旋以及季风低压等六种主要类型,均以稳定天气环流背景为共同特征。华北槽型发生频率最高,南支槽型平均持续时间最长且平均影响范围最广。华北槽、南支槽和低涡切变型过程的降水强度相当,主要落区在桂东北,由该区特殊地形及其与冷暖空气交绥共同作用而引起锋生,较强锋生起始高度较高且不深厚,但在中低层都存在一定干冷空气的侵入,尤以华北槽型最明显,有利于增强大气不稳定度以及锋生发展;另外,南支槽型在沿海伴有暖区雨带。副高边缘、热带气旋和季风低压型降水强度较大,主要落区位于桂南,大多则由地形抬升暖空气、狭管效应以及地形摩擦辐合作用而引起锋生,触发和维持高效的暖云降水,后两者强锋生起始高度较低且深厚,暖云降水效率更高,而南支槽型沿海锋生区和副高边缘型强锋生相较浅薄。Based on the daily precipitation data from national meteorological stations,ERA5 reanalysis data and the CMA Tropical Cyclone Best Track Dataset during 1979-2019,this paper sets out to conduct statistical analysis and synoptic classification of 51 large-scale persistent severe rainfall(LPSR)events during the rainy season in Guangxi Autonomous Region,and study the key circulation characteristics and differences in frontogenetic structure.The main conclusions are as follows:There are six synoptic types of the LPSR events,namely North China Trough(NCT),South Branch Trough(SBT),Low Vortex&Shear(LVS),Subtropical High Edge(SHE),Tropical Cyclone(TC)and Monsoon Depression(MD),all of which are characterized by a background of stable synoptic circulation.The NCT has the highest frequency,and the SBT has the longest average duration and the widest average influence range.The precipitation intensity of NCT,SBT and LVS is almost the same,and their precipitation areas overlap in northeast Guangxi.The frontogenesis is caused by the special terrain of this area and its interaction with cold and warm air.The initial height of strong frontogenesis is higher and shallow.There are some intrusions of dry and cold air in the middle and low layers,especially in the NCT,and such intrusions increase atmospheric instability and induce frontogenesis development.Moreover,SBT is accompanied by warm rain belt along the coast.The precipitation intensity of SHE,TC and MD is more intense,and their main precipitation area is in southern Guangxi.In these cases,the frontogenesis is mostly caused by the warm air lifted by the terrain,the narrow tube effect,and the friction convergence,which triggers and maintains efficient warm cloud precipitation.The initial height of strong frontogenesis of the latter two are lower and deeper,and their efficiency of warm cloud precipitation is higher,while the strong frontogenesis of the SBT’s coastal frontogenesis area and SHE are relatively shallower.

关 键 词：持续性强降水 天气学分型 降水差异 锋生结构特征 地形 

分 类 号：P426.62[天文地球—大气科学及气象学]