秦巴山区一次致灾冰雹过程分析  

Analysis of Hail Process in Qinba Mountain Area

作　　者：孟明霞 瑚娟 程运旺 徐琪惠 MENG Ming-xia(Shangluo Meteorological Bureau,Shangluo,Shaan-xi 726000)

机构地区：[1]商洛市气象局

出　　处：《农业灾害研究》2020年第1期37-40,共4页Journal of Agricultural Catastrophology

基　　金：陕西省气象局面上科研项目（2016M-14）

摘　　要：利用常规资料、多普勒雷达及自动站等资料,对秦巴山区一次致灾冰雹过程综合分析。结果表明,此次强对流天气是在高空前倾槽东移过程中产生的,中低层切变线为对流的发生提供了动力条件,地面辐合线是此次强冰雹天气的触发机制;适宜的0℃和-20℃层高度、地面暖低压和特殊的“喇叭口”地形等有利于强冰雹天气的发生;冰雹发生在低空急流左前方、高空急流出口区的左侧和地面辐合线附近。较强不稳定层结和垂直风切变是导致对流快速发展并维持的原因之一;多普勒雷达反射率因子图上对流单体中心强度大于68 dBZ且维持5个体扫,有超级单体生成;反射率因子剖面图上有有界弱回波、回波悬垂等出现;速度图上具有低层辐合和中气旋等特征;在反射率因子和速度图上均可看到三体散射;VIL跃增和骤降的时间与冰雹发生的时间相对应。Based on conventional data,Doppler radar and automatic station data,a comprehensive analysis of the hail process in Qinba mountain area was made.The results showed that the strong convective weather was generated during the eastward movement of the high altitude forward trough,the shear line in the middle and lower layers provided the dynamic conditions for the occurrence of convection,and the convergence line on the ground was the trigger mechanism of the severe hail weather.The suitable layer height of 0℃ and -20℃,the warm and low pressure of the ground and the special bell-mouth topography were conducive to the occurrence of strong hail weather.Hail occurred in the front left of low level jet,the left side of high level jet exit area and near the convergence line of the ground.Strong unstable stratification and vertical wind shear were the reasons for the rapid development and maintenance of convection.The center intensity of convective cell on the reflectivity factor of Doppler radar was greater than 68 dBZ and 5 scans were maintained,supermonomer was generated.There were bounded weak echoes and echo overhang on the reflectivity factor profile.The radial velocity map was characterized by low level convergence and mesocyclone.Three-body scattering could be seen in reflectivity factor and velocity map.The time of VIL jump and sudden drop corresponded to the time of hail occurrence.

关 键 词：超级单体 地面辐合线 三体散射 中气旋 

分 类 号：P458.121.2[天文地球—大气科学及气象学]