两类不同风灾个例的灾情调查与观测对比分析  

Comparative analysis of damage surveys and observations with two different types of wind disaster

作　　者：植江玲 蔡康龙 黄先香 叶朗明[3] ZHI Jiangling;CAI Kanglong;HUANG Xianxiang;YE Langming(Foshan Meteorological Office of Guangdong Province,Foshan 528000;Foshan Tornado Research Center,Foshan 528000;Jiangmen Meteorological Office of Guangdong Province,Jiangmen 529000)

机构地区：[1]广东省佛山市气象局,佛山528000 [2]广东省佛山市龙卷风研究中心,佛山528000 [3]广东省江门市气象局,江门529000

出　　处：《暴雨灾害》2020年第4期418-426,共9页Torrential Rain and Disasters

基　　金：广东省科技厅社会发展科技协同创新体系建设专项(2019B020208015);广东省气象局青年基金科技项目(GRMC2018Q19);佛山市气象局科技项目(201905)。

摘　　要：利用灾情调查、常规观测和雷达资料对比分析2018年6月8日佛山南海龙卷和2016年8月18日湛江雷州微下击暴流两次强风天气过程。结果表明:南海龙卷强度为F1级和EF1级,雷州微下击暴流强度为F2级和EF2级,且导致风灾的气流具有多尺度性以及时空尺度小的特征。两次过程均发生在低层辐合、高层辐散和中低层急流汇合有利的环流背景,但龙卷发生在台风环流内部,而微下击暴流发生在台风外围。环境参数表现为弱的条件不稳定、对流抑制能量小和抬升凝结高度低,但龙卷过程的0—1 km风垂直切变较强。导致风灾的风暴单体均伴有中气旋,但形成龙卷的微超级单体具有明显的钩状回波特征,低层存在中等强度中气旋,中气旋尺度较微下击暴流过程的小得多,底高较低,龙卷出现前中气旋底高降低,直径缩小。形成微下击暴流的为一椭圆形的β中尺度风暴单体,低层存在强中气旋,中气旋为辐散性气旋,底高较高,直径逐渐增大,垂直剖面图上存在中层径向速度辐合、强反射率因子核心下降特征。Damage survey,conventional observations and Doppler weather radar data are used to analyze the tornado occurred on 8 June 2018 at Nanhai District in Foshan City and microbursts occurred on 18 August 2016 at Leizhou County in Zhangjiang City.Results show that Nanhai tornado intensity is rated F1 and EF1 and the microburst at Leizhou is rated F2 and EF2.The flows caused by microburst have multiscale and small spatio-temporal scale characteristics.Two high wind events both occurred in the environmental conditions including low-level convergence,upper-level divergence and superposition of strong jet at mid and low levels.The tornado occurred in the inner region of typhoon Ewiniar,while the microburst occurred in the peripheral of typhoon Dianmu.Environmental parameters are shown to be relatively weak conditional instability,low convection inhibition and low condensation uplift height.However,the low level(0-1 km)vertical wind shear in the tornado case is much stronger.Two storm cells are both accompanied by mesocyclones.However,the mini supercell forming the tornado has obvious hook echo feature,which is accompanied by medium-intensity mesocyclones,and the scale of mesocyclones is much smaller.The mesocyclone has the smallest scale and the lowest vertical extension height when tornado appears.The microbursts are formed in an ellipticalβmesoscale storm which is accompanied by moderate to strong mesocyclone.The mesocyclones have divergent rotating structure with higher base height and larger diameter.Features of mid-level radial velocity convergence and strong reflectivity factor core drop can be detected when the microbursts come.

关 键 词：灾情调查 龙卷 微下击暴流 环境条件 雷达回波特征 

分 类 号：P458.121.1[天文地球—大气科学及气象学]