“0711”山西晋城极端强降水过程的宏微观特征分析  

Macro and Micro Characteristics of Extreme Heavy Rainfall Process in Jincheng of Shanxi Province on 11 July 2021

作　　者：王洪霞[1] 苗爱梅[1] 邱贵强[1] 屈志勇[2] 杨俊梅 吕林宜 WANG Hongxia;MIAO Aimei;QIU Guiqiang;QU Zhiyong;YANG Junmei;LÜLinyi(Shanxi Meteorological Observatory,Taiyuan 030006,Shanxi,China;Shani Meteorological Information Center,Taiyuan 030006,Shanxi,China;Shanxi Artificial Precipitation Enhancement and Lightning Protection Technical Center,Taiyuan 030032,Shanxi,China;Henan Meteorological Observatory,Zhengzhou 450003,Henan,China)

机构地区：[1]山西省气象台,山西太原030006 [2]山西省气象信息中心,山西太原030006 [3]山西省人工增雨防雷技术中心,山西太原030032 [4]河南省气象台,河南郑州450003

出　　处：《高原气象》2023年第5期1232-1246,共15页Plateau Meteorology

基　　金：中国气象局创新发展专项(CXFZ2022J016,CXFZ2021Z034);山西省基础研究计划面上项目(202203021211080);山西省气象局重点项目(SXKZDTQ20236301)。

摘　　要：利用ERA5逐小时0.25°×0.25°再分析资料、地面自动监测站以及FY-4A卫星、多普勒雷达、激光雨滴谱仪等精细化监测资料,对2021年7月11日山西晋城极端强降水过程的宏微观特征进行分析。结果表明:(1)此次极端强降水是继1961年以来晋城7月降水出现的第二高极端降水;高空急流入口区右侧强辐散、低空急流出口区风速辐合、低涡暖式切变线附近强辐合是极端强降水的宏观动力条件;低空急流将水汽源源不断向极端强降水区输送,整层大气可降水量高达65 mm以上是极端强降水发生的宏观水汽条件;500 hPa高度槽超前700 hPa和850 hPa冷式切变线是此次极端强降水发生的宏观动力不稳定条件。(2)极端强降水落区位于500 hPa高度槽、850 hPa和700 hPa暖切变线、地面干线所围成的不规则四边形区域,且与500 hPa T-Td≤4℃、700 hPa T-Td≤3℃、850 hPa T-Td≤2℃、Ki指数≥38℃、Si指数≤-1℃所控制的区域相重叠,在对流云团西南侧亮温梯度的大值区和云团西南部的低亮温区,即在地面干线和地面中尺度切变线0~30 km范围内极端降水量最大。(3)位于极端强降水区上空的中α尺度850 hPa暖式切变线与地面干线以及中β尺度的地面切变线和辐合线共同作用触发了晋城地区的极端强降水;近地层加强的偏东气流在遇到中条山、王屋山,熊耳山、嵩山形成的向东开口的喇叭口地形时被迫辐合抬升,促使极端降水区辐合上升运动增强,降水增幅。(4)闪电位于云顶亮温≤220 K的区域和云顶亮温梯度的大值区,闪电频数峰值超前降水量峰值10~35 min,这对降水峰值的预警很有意义。(5)中α尺度的低涡暖切变系统激发了中α尺度的低涡云系发展,对流云团的发展演变为后向发展型,在中α尺度低涡暖式切变线云系上有数个具有独立回波核的γ中尺度对流单体有组织地排列,受西南气流引导向东北移动相继经过极端降水�Using ERA5 reanalysis data,automatic weather station data,FY4A satellite data,Doppler radar and Laser raindrop spectrometer data,the macro and micro characteristics of the extreme rainfall process in Jincheng,Shanxi Province on July 11,2021 are analyzed.The results show that:(1)This extreme rainfall in Jincheng is the second highest rainfall in July since 1961.The strong divergence on the right of the upper jet entrance,the convergence of wind speed at the exit of lower jet,and the strong convergence near the warm shear line of the low vortex are the macro dynamic conditions of the extreme rainfall.The water vapor transfer by the low-level jet and the whole layer precipitable water above 65 mm,are the macro water vapor conditions,while 500 hPa trough is ahead of the cold shear lines on 700 hPa and 850 hPa is the macro dynamic unstable condition for this extreme heavy rainfall.(2)The extreme heavy rainfall is located in an irregular quadrilateral area surrounded by 500 hPa trough,850 hPa and 700 hPa warm shear lines and ground dry line,which overlaps with the areas controlled by 500 hPa T-Td≤4℃,700 hPa T-Td≤3℃,850 hPa T-Td≤2℃,K index≥38℃and Si index≤-1℃.The maximum extreme precipitation occurs in the large value area of the brightness temperature gradient on the southwest side of the convective cloud cluster and the low brightness temperature area in the southwest of the cloud cluster,which is within 0~30 km of the surface dry line and surface mesoscale shear lines.(3)The meso-α-scale warm shear line on 850 hPa,ground dry line and meso-β-scale surface shear lines and convergence lines triggered this extreme heavy rainfall in Jincheng.The strengthened easterly air flow on the surface layer is forced to converge and lift when it meets the trumpet shaped terrain opening eastward formed by Zhongtiao Mountain,Wangwu Mountain,Xionger Mountain and Song Mountain,promoting the convergence and rising movement in extreme precipitation areas and increasing the precipitation.(4)The lightning is located in

关 键 词：山西晋城 极端强降水 宏观结构 微观结构 特征分析 

分 类 号：P458[天文地球—大气科学及气象学]