广西沿海一次冬季暖区暴雨的多尺度能量诊断  

Multiscale diagnosis of the energy budget for a warm-sector rainstorm event in winter in the coastal area of Guangxi

作　　者：覃皓 王志毅 石怡宁 翟舒楠 祁丽燕 QIN Hao;WANG Zhiyi;SHI Yinning;ZHAI Shunan;QI Liyan(Guangxi Meteorological Observatory,Nanning 530022;China Meteorological Administration Economic Transformation of Climate Resources Key Laboratory,Chongqing Meteorological Observatory,Chongqing 401147;CMA Earth System Modeling and Prediction Centre,Beijing 100081;State Key Laboratory of Severe Weather,Chinese Academy of Meteorological Sciences,Beijing 100081)

机构地区：[1]广西壮族自治区气象台,南宁530022 [2]中国气象局气候资源经济转化重点开放实验室,重庆市气象台,重庆401147 [3]中国气象局地球系统数值预报中心,北京100081 [4]中国气象科学研究院灾害天气国家重点实验室,北京100081

出　　处：《暴雨灾害》2023年第3期283-292,共10页Torrential Rain and Disasters

基　　金：广西自然科学基金项目(2022GXNSFBA035565);广西气象科研计划项目(桂气科2021Z03)。

摘　　要：利用常规气象观测、多普勒天气雷达、风云2G卫星、ERA5再分析资料,基于多尺度子空间变换及局地多尺度能量分析方法,对2020年1月24—26日广西沿海一次漏报的暖区暴雨天气进行了诊断研究,结果表明:暖区暴雨期间南支槽前西南急流的暖湿输送为暴雨发生提供有利背景场;对流系统不断在越南东北部喇叭口地形作用下触发,受高层气流引导移入广西沿海一带造成明显降水;暖区暴雨的发生发展主要由对流尺度动能主导,两者演变具有较好的匹配关系;对流能量主要来源于对流层中、低层,而在对流层高层为能量的流失;背景尺度向对流尺度的动能转换贡献最大;对流层中层、低层背景流场的正压失稳主导了暖区暴雨的发展;对流层中层对流尺度有效位能向动能的浮力转换进一步促进了系统的发展;动能的空间输送使得对流动能在空间上均匀分配,有利于对流系统平稳发展,使其维持较长生命史并移动较远距离造成多地降水;天气尺度动能转换和气压梯度力做功的贡献很小,体现了暖区暴雨弱天气尺度强迫的性质。Based on multiscale diagnosis method of energy budget,the missing-forecast coastal warm-sector rainstorm process of Guangxi oc-curred in 24-26 January 2020 was analyzed by using the stational data,Doppler radar,FY-2G satellite data and the ERA5 reanalysis data.The results are shown below:The warm and moisture southwest jet in front of the southern branch trough provides a favorable synoptic condi-tion for the rainstorm.The convection system was constantly triggered by the trumpet topography in the northeast of Vietnam,and moved north-eastward to the coastal of Guangxi,which was influenced by the upper level airflow and produced significant amount of precipitation.It is found that the occurrence and development of warm-sector rainstorm were mainly dominated by the convection-scale kinetic energy that cor-related well with the former in evolution.The convective energy mainly come from the middle and lower troposphere and losts in the upper tro-posphere.The kinetic energy from the background scale contributed the most,and the barotropic instability of the background flow field in the middle and lower troposphere dominated the development of rainstorm in the warm-sector.The buoyancy conversion of convection-scale available potential energy to kinetic energy in the middle troposphere further promoted the development of system.The transport of kinetic en-ergy made the convection-scale kinetic energy distribute evenly spatially,which led to the stable development of the convective system and enabled it to maintain for long time and thus produce large amount of precipitation over its path.The contribution of synoptic-scale kinetic en-ergy conversion and pressure gradient work is small,which reflects the nature of weak synoptic-scale forcing of warm-sector rainstorm.

关 键 词：暖区暴雨 多尺度子空间变化 正则传输 正压不稳定 对流能量 

分 类 号：P4321.1[天文地球—大气科学及气象学]