不同下垫面雷暴雷达回波特征与地闪的关系

Correlation Analysis of Lightning Activity and Radar Echo Characteristics of Thunderstorm under Different Underlying Surface

利用闪电定位资料和雷达资料,研究了宁波市城区、山区和海陆三种地区增强型雷暴的闪电活动特征,结果表明:城区增强型雷暴的≥50dBz组合反射率面积和≥9km、≥10km回波顶高的回波面积,以及山区增强型雷暴的≥45dBz组合反射率面积和≥12km的回波顶高的回波面积,这些指标与每6min地闪次数都有很好的相关性;而海陆增强型雷暴的≥10km回波顶高的回波面积与每6 min地闪次数的线性关系明显,相关系数高达0.916;3种增强型雷暴对地闪密度分布的影响各有不同,城区增强型雷暴会产生更多的地闪。

Based on the lightning detection and radar echo data, the CG （Cloud-to-Ground） lightning characteristics of three kinds of enhanced thunderstorms （namely downtown, hilly and coastal areas） on the three different underlying surfaces are investigated. Result shows that there exists relationship between the CG lightning frequency at 6 min intervals and the coverage of composite reflectivity and echo top for the three kinds of intensified thunderstorms. In the downtown areas, the CG lightning frequency at 6 rain intervals is closely related to the coverage of the composite reflectivity above 50 dBz, and the coverage of echo top exceeding 9 km and 10 km respectively. In the hilly areas, the frequency is correlated with the coverage of the composite reflectivity above 45 dBz and the coverage of echo top exceeding 12 kin, while in the hilly areas, there is obvious linear relation between the CG lightning frequency and the coverage of echo top exceeding 10 kin, with correlation coefficient up to 0. 916. The CG lightning characteristics in three kinds of the intensified thunderstorm are different, and more CG lightning happens in urban thunderstorms.