2021年吉林中部一次极端雷暴大风的中尺度成因分析  

Mesoscale Analysis of an Extreme Thunderstorm Galein Central Jilin Province in 2021

作　　者：王婷婷[1] 朱文剑 姚凯 全思航 毕潇潇[1] 姚瑶[1] WANG Tingting;ZHU Wenjian;YAO Kai;QUAN Sihang;BI Xiaoxiao;YAO Yao(Jilin Meteorological Observatory,Changchun 130062;National Meteorological Centre,Beijing 100081)

机构地区：[1]吉林省气象台,长春130062 [2]国家气象中心,北京100081

出　　处：《气象》2023年第10期1215-1226,共12页Meteorological Monthly

基　　金：吉林省气象局自立科研项目(2015002)资助。

摘　　要：基于常规观测资料、地面加密自动气象观测站、多普勒天气雷达和ERA5再分析资料等,对2021年9月9日上午发生在吉林省中部一次罕见的极端雷暴大风的中尺度成因进行了详细分析。结果表明:产生雷暴大风的飑线系统是在深厚的东北冷涡配合大尺度锋生作用在冷锋尾部激发形成的。中层较强干空气和逆温层以下接近干绝热的温度递减率有利于极端雷暴大风产生。干暖盖的存在导致低层暖湿空气迅速增强,临近时刻CAPE值超过1600 J·kg~(-1),层结在短时间内变为极不稳定结构,夹卷层平均风达到20 m·s~(-1)以上,动量下传有利于地面风速增强,极端雷暴大风发生在断裂后飑线尾部前沿γ中尺度涡旋附近,但涡旋附近2个站点极端雷暴大风形成原因明显不同,其中农大站极端雷暴大风发生时气压陡降,气温陡升且分钟降水量弱,是由飑线前侧强下沉辐散气流(冷池出流)在较强的偏南风气流作用下加速流入涡旋内部、辐合上升气流迅速增强导致,与其附近农博园站和长春站由降水粒子拖曳作用形成的强下沉辐散气流导致的极端雷暴大风明显不同。Based on conventional observation data,frequently observed data of automatic weather station,Doppler weather radar data and ERA5 reanalysis data,the mesoscale causes for a rarely-seen extreme thunderstorm gale in the central part of Jilin Province on the morning of 9 September 2021 is analyzed.The results show that the squall line system that produced thunderstorm was formed by the deep northeast cold vortex and the large-scale frontogenesis at the tail of the cold front.The strong dry air in middle layer and the temperature lapse rate closed to dry adiabatic below the inversion layer were conducive to the generation of extreme thunderstorm gale.The existence of dry and warm cover led to rapid enhancement of low-level warm and humid air,and the CAPE value surpassed 1600 J·kg-1 at the nearing moment,which made the stratification become extremely unstable in a short period of time.The average wind speed in the entrainment layer was above 20 m·s-1,and the downward transfer of momentum was beneficial to the enhancement of ground wind speed.The extreme thunderstorm gale occurred near the meso-γscale vortex in the tail front of squall line after fracture,but the causes for the extreme thunderstorm gale at the two stations near the vortex were obviously different,of which the thunderstorm gale at Nongda Station occurred when the air pressure dropped sharply,the temperature rose sharply and the minute precipitation was weak.Thus,it was caused by the strong sinking divergent airflow(cold pool outflow)in front of the squall line accelerating into the vortex under the action of strong southerly airflow,and the convergence updraft was rapidly enhanced.It was significantly different from the extreme thunderstorm gale caused by the strong sinking divergent airflow formed by the drag of precipitation particles at the nearby Nongboyuan Station and Changchun Station.

关 键 词：极端雷暴大风 飑线 γ中尺度涡旋 辐合上升气流 

分 类 号：P458[天文地球—大气科学及气象学]