辽宁一次区域性暴雨的特征条件与成因分析  

Analysis of the Characteristics and Mechanism of a RegionalHeavy Rain Event in Liaoning Province

作　　者：史月琴[1,2] 高松影 孙晶[1,2] 谌芸 SHI Yueqin;GAO Songying;SUN Jing;CHEN Yun(State Key Laboratory of Severe Weather,Chinese Academy of Meteorological Sciences,Beijing 100081,China;Key Laboratory for Cloud Physics of China Meteorological Administration,Beijing 100081,China;Dandong Meteorological Observatory of Liaoning Province,Dandong 118000,Liaoning,China;National Meteorological Center,Beijing 100081,China)

机构地区：[1]中国气象科学研究院灾害天气国家重点实验室,北京100081 [2]中国气象局云雾物理环境重点开放实验室,北京100081 [3]辽宁省丹东市气象局,辽宁丹东118000 [4]国家气象中心,北京100081

出　　处：《高原气象》2022年第3期630-645,共16页Plateau Meteorology

基　　金：国家重点研发计划项目课题(2018YFC1507901);西北区域人工影响天气能力建设项目(RYSY201908)。

摘　　要：利用ERA5再分析资料、FY-4A卫星反演云特征参量、地面自动站风和雨量资料,对2020年5月17-19日辽宁东南部一次区域性暴雨、局地大暴雨、伴有短时强降水过程进行详细分析。研究表明:东北冷涡叠加北上强烈发展的气旋是此次过程的天气形势特征,短时强降水出现在冷涡发展接近成熟、气旋强烈发展加深阶段,局地地面辐合型切变线是导致短时强降水的中尺度条件。冷涡东南侧水汽输送通道与来自孟加拉湾热带低压东侧经南海海域由西南低空急流向北输送的水汽通道合并,成为了暴雨产生和维持的必要条件。辽宁中东部的降水产生在冷涡系统的东北部-北部-西北部区域,降水落区与850 hPa风场的相关性最高,降水产生及维持阶段700 hPa以下为辐合区,辐散出现在600~200 hPa,降水强度大于5 mm·h-1的区域上升运动区近似直立地贯穿整个湿层,降水区域上空假相当位温密集区向西北方向倾斜,400 hPa高度之下存在热力不稳定。冷涡发展强盛到成熟阶段,干冷空气的入侵使冷涡云系内部边缘逐渐清晰,形成“逗点状”云系。强降水区呈条带状分布,云顶高度普遍大于9 km,云光学厚度大于60,属于水凝物含量丰富的冷暖混合云;远离冷涡中心区域的云系光学厚度小于20,云层松散属于高层冷云,地面基本无降水。Using ERA5 reanalysis data,cloud characteristic parameters retrieved by FY-4A satellite data,wind and rainfall data of ground automatic weather stations,a regional rainstorm accompany with short-term heavy rainfall in southeastern Liaoning Province from May 17 to 19,2020 is studied in detail.The results show that northeast cold vortex superimposed on the strong northward development of the cyclone is the main weather situation in this process.The short-term heavy rainfall occurs when the cold vortex is close to mature and the cyclone is strongly developed.The local ground convergent shear line is the mesoscale condition leading to short-term heavy precipitation.The water vapor transporting channel on the southeast side of the cold vortex merges with the water vapor transported to north through the South China Sea by the southwestern low-level jet on the east side of the tropical depression,which comes from Bengal Bay.This has become the necessary condition for the occurrence and maintenance of the rainstorm.The precipitation in the central and eastern part of Liaoning Province appears in the northeast-north-northwest region of the cold vortex system.The precipitation area has the highest correlation with the 850 hPa wind field.In the generation and maintenance stage of precipitation,the convergence area appears below 700 hPa,and the divergence occurs between 600 and 200 hPa.Where the rainfall intensity is greater than 5 mm·h-1,the updrafts ascend approximately upright through the whole wet layer.There is a dense pseudo equivalent potential temperature tilt above the precipitation areas toward the northwest,and a thermal instability exits below 400 hPa.The cold vortex develops to a mature stage,and the intrusion of dry and cold air makes the inner edge of cold vortex clouds clear gradually,forming a comma-shaped clouds.The heavy precipitation area is distributed in strips,the cloud top height is generally greater than 9 km,and the cloud optical thickness is greater than 60,which is a cold-warm mixed cloud with ab

关 键 词：区域性暴雨 东北冷涡 水汽输送 切变线 云系特征 

分 类 号：P458.121.1[天文地球—大气科学及气象学]