库尔勒市2015年两次冰雹天气成因及雷达回波特征对比分析  

Comparative analysis of weather conditions and Doppler radar characteristics of two hailstorm events in Korla in 2015

作　　者：彭军 汤达章[1] 周雪英 PENG Jun;TANG Da-zhang;ZHOU Xue-ying(Nanjing University of Information Science and Technology, Department of Atmospheric Sciences, Nanjing 210044, Jiangsu, China;Bayingolin Mongol Autonomous Prefecture Meteorological Observatory, Korla 841000,Xinjiang, China)

机构地区：[1]南京信息工程大学大气科学学院,江苏南京210044 [2]新疆巴州气象局,新疆库尔勒841001

出　　处：《干旱区地理》2019年第4期753-761,共9页Arid Land Geography

基　　金：国家自然科学基金项目(41565003);中亚大气科学研究基金(CAAS201823);科技部公益性行业科研专项(GYHY201506009)

摘　　要：利用常规探测资料、库尔勒多普勒天气雷达、风云2E静止卫星以及NCEP/NCAR提供的0.5°×0.5°再分析资料,对2015年发生在库尔勒市的两次冰雹天气从天气形势、环境背景及强对流云团结构等方面进行了成因分析,并重点对比了雷达回波特征。结果表明:4月17日冰雹天气为弱短波槽影响,系统浅薄,6月1日为低涡降雹,系统深厚。两次冰雹共性特征很多:在冰雹发生前,有强的垂直风切变,0℃层和-20℃层高度适宜且之间伴有浅薄的饱和湿层。通过塔里木盆地东南缘水汽的输送,云团在天山南麓及切变线附近合并降雹是这两次冰雹最突出的特征。雷达图中冰雹云发展中强回波中心值>55 dBz,配合有逆风区,存在明显的回波悬垂和弱回波区,强的垂直风切变是其发展和维持的主要原因。冰雹云形成于云顶亮温<-50℃的冷云盖东南边缘的云团合并处附近,并且主要沿中低层平均风方向移动。By using conventional detection data,Doppler weather radar data,FY-2 E geostationary satellite and the 0.5°×0.5° reanalysis data provided by NCEP/NCAR,the comparison between two hail weather courses occurred in Korla City,Xinjiang,China in 2015 were analyzed in this paper.The results showed that it was a shallow system with short-wave trough on 17th April 2015 while it was a deep system with vortex circulation on 1st June 2015.Before the occurrence of the hail,there was strong vertical wind shear and the height from the 0 ℃ layer to the-20 ℃ layer was suitable to have a shallow saturated wet layer between them.Due to the humidifying by the rainfall in the southeastern part of the Tarim Basin,water vapor was transported to the area with the cyclonic flow field and raised in front of mountain.The strong convection was triggered by the shear line between the southeast wind and northeast wind over Korla City and Luntai County.From the satellite image,the rapid development of hail clouds near the shear line was also reflected.The hail appeared near the southeast edge of the cold cloud cover with a cloud top temperature less than-50 ℃,where the cloud clusters merged.The hail system mainly moved along the average wind direction in the middle and lower layers.Both the two hail processes,the echo intensity of the center exceeded 55 dBz and the upwind zone occurred along with the development of the hail.The strong echo broke through the-20 ℃ layer and there was a strong echo with the intensity more than 50 dBz between 0 and-20 ℃ layer.The intensity and the time of duration of the hail on 1st June were much more than those on 17th April,especially for the echo overhang and weak echo regions,which was directly related to the strong upwind with long duration.When the center of the strong echo dropped to the lower level and the flow field of the lower layer was divergent,the hail weather tended to end.Under favorable environmental conditions,it was the most prominent feature of the two hails that the water vapor w

关 键 词：冰雹 触发机制 雷达特征 VWP 

分 类 号：P458.121.2[天文地球—大气科学及气象学] P412.25