滇西南两次飑线过程的地闪演变特征分析

利用雷电定位资料、多普勒雷达资料和FY-2E卫星资料对发生在滇西南的两次台风低压西行形成飑线过程的地闪变化特征进行了对比分析，结果表明：2次飑线过程均以负地闪占主导地位，“7．17”过程正、负地闪频数峰值均出现在飑线成熟阶段，正地闪峰值超前于负地闪峰值10～15min；正、负地闪集中发生在冷中心区后侧的温度梯度大值区和辐合线附近回波强度t〉40dBz、回波顶高≥12km的强回波区域；“9．22”过程正地闪频数呈单峰型变化，负地闪出现3个峰值，对应着3次飑线发展，密集负地闪出现在前侧TBB温度梯度大值区和强回波区左后侧强度≥40dBz、回波顶高≥12km的强回波区；负地闪减弱阶段正地闪开始活跃正地闪出现在后侧冷云中心。两次飑线过程中-10℃层回波强度的跃增总超前于负地闪的跃增6—30min左右。

CHARACTERISTICS ANALYSES ON CLOUD TO GROUND LIGHTNING EVOLUTION OF TWO SQUALL LINE PROCESSESS IN SOUTH- WEST OF YUNNAN

the comparative analysis of the diversity of Cloud to ground （CG） Lightning at the processes of two squall line that moved to the west by using the lighting data . Doppler radar data and FY - 2E satellite infrared data, the result showed that the negative CG lightning is predominant during two squall line processes, for the squall line process occured on July 17 2010, positive and negative CG lightning frequency peak all appeared at squall line mature stage, and the peak of positive lightning was ahead of that of negative CG lightning 10 - 15minutes; CG lightning concentrated in the rear of cold center where corresponding to the largest Temperature gradient and concentrated in the area of strong echo near the convergence line where the echo intensity was greater than 40dBz the height of echo top was greater than 12km. For the squall line process occured on September 22 2010, The frequency of Positive CG lightning showed single peak type, negative lightning appeared 3 peaks which was corresponded to 3 squall line processes, negative CG lightning clustered in the left behind region of strong echo which corresponded to the intense echo （ 〉 40 dBz） and the higher echo top （ ≥12 km） region. Positive CG lightning became active when negative CG lightning began to weaken, and Positive CG lightning appeared in the back of the center of cold cloud, the jumping times of echo intensity on - 10℃ level were Staying ahead of the jumping times of negative CG lightning about 6 -30minutes.