广西一次持续性强降水的机理特征分析  

Analysis of the mechanism characteristics of a persistent heavy precipitation in Guangxi

作　　者：李华实 黄菲 朱鹏程 罗小莉 梁永强 Li Huashi;Huang Fei;Zhu Pengcheng;Luo Xiaoli;Liang Yongqiang(Chongzuo Meteorological Bureau,Chongzuo 532200;Service Center of Public Meteorology for Zhuhai,Zhuhai 519000;Guangxi Climate Center,Nanning 530022)

机构地区：[1]广西壮族自治区崇左市气象局,崇左532200 [2]珠海市公共气象服务中心,珠海519000 [3]广西壮族自治区气候中心,南宁530022

出　　处：《气象水文海洋仪器》2024年第2期24-27,共4页Meteorological,Hydrological and Marine Instruments

基　　金：广西气象科研计划项目(桂气科2023M29);广西自然科学基金(2023GXNSFAA026511);崇左市科技计划项目(崇科20231210)资助。

摘　　要：文章利用2019年7月中国地面气象站逐小时降水资料、ECMWF ERA5再分析资料及美国“奋进”号航天飞机的SRTM 250 m地形数字高程模型(DEM)数据,对广西壮族自治区北部一次低涡(切变)引起的持续性强降水进行了成因和机理特征探究。结果表明:该过程是冷空气南下受桂北地形阻挡并与暖湿空气交绥引起锋生和旺盛对流,水汽源源不断向桂北输送和辐合,较强锋生起始高度较高且不深厚,但在中低层存在一定的干冷空气侵入,增强了大气的不稳定度,进一步激发强锋生和对流;随着地面冷空气的补充,强锋生高度更低、强度更强,表征更高效率的暖云降水,指示极端日降水的发生。锋生结构变化在一定程度上能指示降水强度变化,能为强降水预报提供有意义的着眼点。Based on the hourly precipitation data of China's ground meteorological station in July 2019,ECMWF ERA5 reanalysis data and the DEM data from SRTM 250 m terrain digital elevation model of the US space shuttle"struggle",the causes and mechanisms characteristics of the persistent heavy precipitation in northern Guangxi caused by a low vortex(shear)are investigated.The results show that this process is caused by cold air moving southward and being obstructed by the terrain of northern Guangxi,and intersecting with warm and humid air,leading to frontogenesis and vigorous convection.Water vapor continuously transports and converges towards northern Guangxi,and the initial height of strong frontogenesis is relatively high and not deep.However,there is a certain amount of dry and cold air intrusion in the middle and lower layers,which enhances atmospheric instability and further stimulates strong frontogenesis and convection.With the supplement of cold air on the ground,the strong frontogenesis is lower in height and stronger in intensity,which represents the warm cloud precipitation with higher efficiency and indicates the occurrence of extreme daily precipitation.The change of frontogenesis structure can indicate the change of precipitation intensity to a certain extent,and can provide a meaningful focus for heavy precipitaiton forecast.

关 键 词：持续性强降水 地形 水汽辐合 锋生结构 暖云降水 

分 类 号：P466[天文地球—大气科学及气象学]