一次飑线过程的全闪活动特征分析

Analysis on Total Lightning Characteristics of a Squall Line

结合VLF／LF全闪定位系统、多普勒天气雷达、探空资料，对2013年7月5日江苏地区一次典型飑线过程的全闪活动特征进行了详细分析。结果表明：云地闪比的下降、上升预示着飑线过程中雷暴的加强、减弱；云闪主要分布在4～8 km高度，云闪频数最大值出现在5 km处；结合云闪变化情况和探空资料推测雷暴云内电荷为三极性电荷结构；对流区的闪电密度远大于层状云区。相比于正地闪，负地闪集中在雷达回波的强对流区。云闪发生位置更具随机性，易发生在弱回波区和层状云区；闪电的发生与云顶高度有很高的相关性，云闪发生位置与剖面反射率因子中强回波区的发展有很好的一致性。

The characteristics of total lightning in a squall line in Jiangsu on July 5 ,201 3 are studied in detail by combining the data from VLF total lightning location system,Doppler radar and air sounding data.Results show that the descending,ascending of intracloud lightning ratio can respectively indicate the reinforcing,receding of thunderstorm in the process of the squall line.Intracloud lightning mainly distribute in 4-8 km.The maximum of introcloud lightning frequency appears in 5 km.Charge structure in thunderstorm cloud is inferred as tripole charge structure by combining the change of introcloud activity and sounding data.Lightning density in the convective re-gion is far higher than that in the stratiform region.Comparing with positive cloud-to-ground lightning,negative cloud-to-ground lightning draws its focus on the severe convection region of radar echoes.The location of intracloud lightning are more random and easy to happen in weak echoes region and stratiform region.There is a high correla-tion between the occurrence of lightning and cloud top height.The occurrence of introcloud lightning is consistent with the development of strong echo region in profile of reflectivity factor.