双偏振多普勒天气雷达监测雷电的分析

为了更有效开展雷电的实时监测和预警,利用S波段双线偏振多普勒天气雷达回波资料和闪电定位仪数据,对2009年7月初发生在江苏的一次雷暴天气过程进行了分析。在有闪电的回波区,闪电频次峰值出现在水平反射率因子42dBZ处,集中在34~46dBZ之间;闪电频次峰值出现在差分反射率因子ZDR的0.4dB处,主要集中在-0.4~1.4dB;闪电频次峰值出现在差分传播相位常数KDP的1°/km处,集中在0~2°/km附近;闪电频次峰值出现在相关系数ρhv的0.98处,集中在0.96以上。而无闪电回波的偏振参量都明显小于发生闪电回波的值。通过对雷暴回波单体偏振参量随时间变化的分析,发现偏振参量和闪电频次之间有较好的一致性。随着闪电的发生和频次的增加,回波单体的反射率因子ZH、差分反射率因子ZDR、差分传播相位常数KDP都有不同程度的逐步增加。最大时ZH达47dBZ、ZDR达到2dB以上、KDP达到2.5°/km。

Analysis of lightning detection with dual-polarization Doppler weather radar

To develop lighting monitoring and early warning more efficiently,the thunderstorms weather was analyzed based on data of S-band dual-polarization Doppler weather radar and lightning position indicator on July of 2009. The results show that the polarization parameters of non-lightning echoes are apparently less than that of the lightning echoes. And ZH focuses between 34 and 46 dBZ, with the peak in 42 dBZ. ZDR focuses between -0.4 and 1.4 dBZ, with the peak in 0.4 dBZ.KDP concentrates around 0~2°/km and has the peak in 1°/km.ρhv concentrates on the scope over 0.96, and maximally in 0.98. There is good consistence between the polarization parameters and the flash rate by the analysis of the polarization parameters of the thunderstorm cells as a function of time. ZH,ZDR and KDP gradually increase in certain extent with the flash rate, and have the maximum value of 47 dBZ, 2 dB and 2.5°/km respectively.