滇东一次局地特大暴雨的中尺度特征和地闪特征分析

 利用雷电定位资料、多普勒雷达资料和FY-2E卫星红外资料对2010年6月25-26日发生在马龙的一次局地特大暴雨过程进行分析,结果表明:高层冷空气和低层暖湿气流在滇中以东地区交汇,形成明显的辐合是本次局地特大暴雨过程的主要影响系统.多普勒雷达上表现为2条带状回波合并加强,后部小单体快速东移合并入同一地点,在马龙上空形成明显的"列车效应",中尺度低空急流和逆风区的出现使得抬升辐合运动加强,触发了马龙上空对流不稳定能量的释放,产生了特大暴雨.卫星云图上,多个MCS合并为中-β尺度对流云团再发展为中-β尺度对流云带,产生强降水的过程始终保持较大面积的低于-60℃的冷中心,冷中心长时间在马龙上空维持.暴雨过程伴随着频繁的地闪活动,地闪密集地出现在单体回波合并后的强回波区域、对应着径向速度≤10 m/s的辐合区和逆风区后部及≥15 km的回波顶高位置,TBB和地闪的峰值超前于强降水1~2 h.

An analysis on mesoscale characteristics and cloud-to-ground lightning features of a local rainstorm in the east of Yunnan

An analysis for the local rainstorm which occurred at the Malong county on 25-26 June 2010 has been made with the data from thunderbolt position,Doppler radar and FY-2E satellite.The result shows that the obvious convergence of dry-cold air of upper level and the moist-airflow of low level in the east of the centre of Yunnan is the main influential system.The features in Doppler radar are the merging and enhancement of two echo ribbon,and the obvious "train domino effect" overhead of Malong formed by that many small individually echo moving eastward quickly and incorporating into the same spot.The emergence of meso-scale low-level jet and Converse wind region enhances the movement of lifting and convergence and release Convection unstable energy at the upper level of Malong,leading to the Severe rainstorm over Malong.The features in satellite are the large cold-cloud center area that TBB less than -60℃ and the maintaining of this feature long time at the up per level of Malong during MCS merge to meso-β-scale Convective clouds,then develop to Convective cloud band and Produce heavy rainfall.Frequent C-G lightning activities always appear during heavy rainfall,The CG flashes clustered in the area of intense echo where small individually echo merge,which corresponded to the Convergent region (Radial velocity≤10 m/s),the back of Converse wind region and the region of Echo top height≥15 km, the peak time of TBB and CG flashes is 1-2 hours ahead of heavy rainfall.