贵州地区强对流天气防雹雷达回波特征研究

Difference of Radar Echo Characteristics before and after a Hail Suppression in Severe Convective Weather in Guizhou

冰雹是一种常见的天气灾害,所以科学检验防雹效果成为重要工作。利用贵州威宁县2019年4-8月3次典型强对流天气,实行人工防雹前后的雷达数据回波差别研究,降雹前后雷达反射率因子、强回波区域强度及垂直累计液态水含量、垂直累计液态水含量密度的变化关系。结果表明:兔街站6月14日17:40,防雹作业前雷达反射率达到峰值60.2 dBz,防雹作业20分钟,雷达反射率下降至28.1 dBz,人工防雹控制了VIL及VILD的增长,防雹效果很好。嘎基站4月27日20:53,防雹作业前雷达反射率峰值达62.4 dBz,防雹作业22分钟雷达反射率下降至38.6 dBz,防雹前期VIL达31.61 kg/m^(2),在防雹作业后VIL与VILD迅速减小,有效遏制对流云单体形成冰雹。炉山站8月13日14:25,防雹作业前雷达反射率峰值达61.3 dBz,防雹作业27分钟后雷达反射率下降至44.4 dBz,防雹作业前VIL达24.37 kg/m^(2),防雹作业后虽然控制了VIL及VILD增长,但雷达反射率在防雹作业后并未立即迅速减小,对流云单体形成冰雹,防雹作业效果不理想。通过防雹前后雷达回波参数、VIL及VILD的变化与实际情况变化检验防雹效果,为选择防雹时机、弹药量的使用等提供参考价值。

Hail is a common weather disaster,so scientific test of hail suppression effect has become an important work.Based on three typical severe convective weather events in Weining County of Guizhou Province from April to August in2019,the radar data echo difference before and after hail suppression is studied,and the radar reflectivity factor and strong echo area intensity before and after hail suppression are obtained.The calculation of vertical cumulative liquid water content and vertical cumulative liquid water content density and the change relationship before and after hail suppression are realized through the algorithm.The results show that:at 17:40 on June 14,the radar reflectivity of Tujie station reaches the peak value of 60.2 dBz before hail suppression operation,and drops to 28.1 dBz after 20 minutes of hail suppression operation.The artificial hail suppression controls the growth of VIL and VILD,and the hail suppression effect is great.At 20:53 on April 27,the radar reflectivity of Gaji station reached the peak value of 62.4 dBz before hail suppression operation.After 22 minutes of hail suppression operation,the radar reflectivity dropped to 38.6 dBz,and the VIL reached 31.61 kg/m^(2) in the early stage of hail suppression.After hail suppression operation,VIL and VILD decreased rapidly,effectively curbing the formation of Hail by convective cloud cells.At 14:25 pm on August 13,Lushan station’s radar reflectivity reached a peak value of 61.3 dBz before hail suppression operation.After 27 minutes of hail suppression operation,the radar reflectivity dropped to 44.4 dBz,and VIL reached 24.37 kg/m^(2) before hail suppression operation.Although the growth of VIL and VILD was controlled after hail suppression operation,the radar reflectivity did not decrease rapidly after hail suppression operation,and the convective cloud monomer formed hail,the hail suppression effect is not ideal.Through the changes of radar echo parameters,VIL and VILD before and after hail suppression and the actual situation,the hail suppression effect is tested,which provides reference value for the selection of hail suppression time and the use of ammunition.