雷达资料在高原东北侧雷电预警中的应用

Application of Radar Data in Lightning Warning over the Northeast of Tibetan Plateau

利用LD-Ⅱ闪电定位仪资料和兰州CINRAD/CC雷达资料,对甘肃中部2011和2012年夏季对流性降水过程中雷达回波单体与雷电活动之间的对应关系进行分析,提取反映较好的雷达产品特征量,建立雷电预警方案。结果表明,35 dBz回波顶高(ET)突破-10℃层高度和40 dBz回波顶突破过-10℃层高度等2个指标的雷电预警效果较好,预警时间可分别平均提前23和16 min;垂直累积液态含水量(VIL)可作为判断雷电发生的充分条件,但其值应小于30 kg·m^(-3);ET大于10 km预警雷电发生,预警时间可提前平均为7 min。利用建立的雷电预警方案对2013年的个例进行效果检验分析,结果表明该方案在雷暴天气具有较好的预警效果。

Based on the LD-Ⅱ lightning locator and Lanzhou CINRAD/CC radar datasets,the relationship between the radar echo parameter and lightning activity area was analyzed using the summer precipitation cases in the central of Gansu Province in 2011 and 2012 respectively.Then,the key characteristics of the radar data were summarized and a lightning warning program was established.The results show that the echo top of 35 dBz and 40 dBz reflectivity above the height of-10℃ layer can be used in the lightning warning,which can make the prediction time of lightning warning be 23 and 16 minutes in advance respectively.Vertically integrated liquid（VIL） with values less than 30 kg·m-3 can be utilized as a sufficient condition to judge whether thunderstorm will occur.Generally the warning should be 7 minutes earlier than the ocurrence of lightning when the echo top（ET） exceeds 10 km.The lightning warning program was tested using the cases in 2013,and the result indicates that this program has a good effect on the thunderstorm warning.