江苏一次梅雨期疑似龙卷现场调查报告  

Survey report on a doubtful tornado during the Meiyu period in Jiangsu Province

作　　者：王啸华[1,2] 黄荣 李杨 沈阳[1] 慕瑞琪[1] WANG Xiaohua;HUANG Rong;LI Yang;SHEN Yang;MU Ruiqi(Jiangsu Meteorological Observatory,Nanjing 210008,China;Joint Laboratory of Aeronautical Meteorology of Yangtai Airport,Jiangsu Yangzhou 225235,China;Guangxi Meteorological Observatory,Nanning 530022,China)

机构地区：[1]江苏省气象台,南京210008 [2]扬泰机场航空气象联合实验室,江苏扬州225235 [3]广西壮族自治区气象台,南宁530022

出　　处：《气象科学》2020年第4期546-553,共8页Journal of the Meteorological Sciences

基　　金：江苏省“333工程”科研项目(BRA17521);中国气象局预报员专项(CMAYBY2018-029);重大自然灾害监测预警与防范(2018YFC1507503)。

摘　　要：利用现场调查资料,结合多普勒天气雷达、自动气象站、闪电定位资料,对2019年6月29日发生在宝应县的一次风灾过程的强风类型和风灾强度进行评估。结果表明:(1)本次被大风损坏的物体倒伏方向比较一致,没有辐合状特征,碎片散落范围较小,符合直线型雷暴大风特征物的分布特征。从瓦片碎片分布和树木折断后倒伏的方向判断,地面大风的风向主要为西南或偏南。对照EF等级标准估计产生风灾时短时阵风最大风力为11级左右。(2)6月29日02时,地面气旋从金湖进入宝应后向东偏北方向移动,在低压中心附近由于气压梯度力产生了极大风速4~6级的旋转风,风速较大的区域位于低压中心南侧,风向为西南风。闪电监测资料显示当时宝应境内雷电活动较弱,表明与之对应的对流风暴强度较弱,达不到形成龙卷风所需要的对流强度。(3)雷达资料分析表明该对流单体不具备超级单体回波结构特征,径向速度也没有识别出中气旋和TVS。中层的径向速度大值区下传,在近地面产生强辐散气流叠加在气旋中心南侧西南风上,增大了地面风速,因此,此次风灾是由气旋中心南侧西南风与小尺度对流风暴导致的下沉出流叠加所形成的强风造成的。By using on-site survey data,combined with Doppler weather radar,automatic weather station,and lightning data,the wind type and wind intensity of wind damage occurred in Baoying County on June 29,2019 were analyzed.The results show that:(1)the objects damaged by the strong wind were distributed in the same direction,with no sign of wind convergence,and the fragment scattering range was small,which was consistent with the distribution characteristics of linear thunderstorm gale features.Judging from the distribution of tile fragments and the direction of the broken trees,the wind direction of the ground strong wind was southwest or south.When the wind damage occurred,the highest intensity of gusts was about violent storms according to the EF grade standard.(2)At 02∶00 BST of June 29,the surface cyclone moved northward from Jinhu to Baoying.Due to the pressure gradient force,a rotating wind with a maximum wind speed of 4—6 grade was generated in the vicinity of the low-pressure center.The maximal wind was located on the south side of the low-pressure center and the wind direction was southwest.The lightning data showed that the lightning activity in Baoying was weak during the time of the wind damage occurred,indicating that the corresponding convective storm intensity was weak and could not generate a tornado.(3)Radar data analysis shows that the convective monomer does not have the super-cell echo structure,and the radial velocity map does not recognize the medium cyclone and TVS.The radial velocity showed that a jet stream appeared in the middle layer,and the strong divergent airflow was superimposed on the southwest wind on the south side of the cyclone center,which increased the surface wind speed.Therefore,the wind damage was caused by the strong wind formed by the superposition of the sinking and outflow caused by the convective storm southwest wind and the Barometric gradient wind caused by the cyclone.

关 键 词：风灾 现场调查 雷暴大风 龙卷 

分 类 号：P458.123[天文地球—大气科学及气象学]