华南一次典型雷暴过程双偏振雷达参量与 闪电活动关系研究

RELATIONSHIP BETWEEN DUAL-POLARIZATION RADAR PARAMETERS AND LIGHTNING ACTIVITY DURING A TYPICAL THUNDERSTORM IN SOUTH CHINA

关键词:  双偏振雷达  雷达参量  飑线  闪电活动  闪电临近预警

Key words:  dual-polarization radar  radar parameters  squall line  lightning activity  lightning nowcasting

摘要:

基于2017年5月8日华南地区一次典型飑线过程，分析了此次过程中闪电活动和-35~0 ℃温度层内双偏振雷达参量的分布特征以及双偏振雷达参量与闪电活动之间的关系。结果表明：此次飑线过程中，双偏振雷达参量与闪电频次的趋势在时间变化上有较好的一致性，且随着闪电活动的发生及雷暴过程的增强，双偏振雷达参量中的冰水含量、雷达反射率因子、差分反射率、差分相移率等偏振参量都有不同程度的增加，闪电频次高峰时间段对应各个参量最大值时间段。双偏振雷达各个参量最大值与闪电活动的线性拟合关系均优于多项式拟合关系。定性地发现了双偏振雷达参量与闪电活动的关系，可为将来将双偏振雷达参量加入到闪电临近预警预报提供一定的参考依据。

Abstract:

Based on a typical squall line process in South China on May 8, 2017, this paper analyzed the lightning activity and the distribution characteristics of dual-polarization radar parameters in the -35 ~ 0 ℃ temperature layer as well as the relationship between the dual-polarization radar parameters and lightning activities during this process. The results show that during the squall line process, the dual-polarization radar parameters and the trend of lightning frequency have a good consistency in time variation. And with the occurrence of lightning activity and the enhancement of thunderstorm process, the polarization parameters of dual polarization radar such as ice water content, radar reflectivity factor, differential reflectivity, and differential phase shift rate all increase by varying degree. The peak time of lightning frequency corresponds to the peak time of each parameter. The linear fitting relationship between the maximum value of each parameter of dual-polarization radar and lightning activity is better than the polynomial fitting relationship. The present research finds the relationship between the parameters of dual-polarization radar and lightning activity, providing reference for the introduction of dual-polarization radar parameters to lightning nowcasting.