安徽一次局地极端大风观测与成因探讨  

Observation and Genesis of an Extreme Local Gale in Anhui Province

作　　者：周后福[1,2,3,4] 范伟 陶寅[1] 赵倩[1] ZHOU Houfu;FAN Wei;TAO Ying;ZHAO Qian(Anhui Institute of Meteorological Sciences,Hefei 230031,China;Anhui Province Key Lab of Atmospheric Science and Satellite Remote Sensing,Hefei 230031,China;Huaihe River Basin Typical Farm Eco-meteorological Experiment Field of CMA,Shouxian 232200,China;Shouxian National Climatology Observatory,Shouxian 232200,China)

机构地区：[1]安徽省气象科学研究所,安徽合肥230031 [2]大气科学与卫星遥感安徽省重点实验室,安徽合肥230031 [3]中国气象局淮河流域典型农田生态气象野外科学试验基地,安徽寿县232200 [4]寿县国家气候观象台,安徽寿县232200

出　　处：《灾害学》2020年第2期97-101,121,共6页Journal of Catastrophology

基　　金：国家自然科学基金(U1533131,41875171);安徽省公益性研究项目(1604f0804002);华东气象协同创新基金(QYHZ201816)。

摘　　要：利用地面、雷达、卫星、探空等资料,从精细化观测角度对发生在安徽一次局地极端大风进行分析,并从不稳定、动力、负浮力、拖曳等角度探讨其形成原因。研究结果主要有:近地层的垂直风切变很大,对流指数表明大气有较强不稳定性;地面辐合线是产生局地大风的触发条件;超级单体风暴由1个分裂成2个,湿下击暴流就是由2个超级单体风暴所产生的;降水和冰雹粒子的共同拖曳作用,促进下沉气流的快速下冲;短时间内气温的迅速下降,近地层冷池密度流现象出现,引起的负浮力作用非常明显;超级单体风暴质心高度或者最强回波高度的不断下降,加剧了下沉气流速度。在降水和冰雹的拖曳作用,中层干层和气温的负浮力作用,加上风暴质心高度和最强回波高度的下降作用,这些共同为局地大风的产生因素,导致地面产生极端大风;绘制了下击暴流的概念模型,解释下击暴流的形成机理。Using ground, radar, satellite and sounding data, an extreme local gale in Anhui Province is analyzed from the perspective of refined observation, and its causes are discussed from the perspectives of instability, power, negative buoyancy and dragging.The main results are as followings.Vertical wind shear near the stratum is very large, convective index indicated that the atmosphere is highly unstable, and the ground convergence line is the triggering condition for local gale.The wet downburst is divided into two supercells by one supercell, and extreme gales are produced by different supercell storms respectively.The common drag effect of precipitation and hail particles promoted rapid subsidence airflow.The negative buoyancy effect is more obvious when the temperature dropped rapidly in a short time, and the descending of the centroid height or the strongest echo height of the supercell storm aggravated the velocity of the downdraft.The dragging effect of precipitation and hail, the negative buoyancy effect of middle dry layer and temperature, and the decrease of the height of storm center of mass and the height of strong echo all contributed to the generation of local gale, which resulted in extreme gale on the ground.The models of the downburst are drawn, and the formation concept of the downburst is explained.

关 键 词：局地极端大风 精细化观测 超级单体风暴 湿下击暴流 成因 

分 类 号：X43[环境科学与工程—灾害防治] P642[天文地球—工程地质学]