河南省强雷暴地闪活动与雷达回波的关系探析

利用ADTD雷电定位显示监测系统资料和郑州714CD多普勒雷达回波资料,对河南省2004--2006年8次雷雨大风伴局地冰雹和强暴雨两类强雷暴天气的地闪和雷达回波的特征及关系进行了分析,从观测事实出发,分析了河南8次强雷暴地闪活动与雷达回波的关系。结果表明:大风冰雹类回波强度为50～60 dBz,暴雨回波强度一般为40～55 dBz。暴雨地闪频数明显多于大风冰雹类;大风冰雹类天气以正闪为主,正闪比例在50%以上,暴雨正闪比例在6%以下;最大正、负闪强度可以出现在强雷暴过程的开始、持续、结束时段。块状单体回波出现或出现前,地闪已经出现,移动过程中的强回波带,少量地闪出现在强回波移动方向的前方20～30 km内,此地闪能很好地预示强回波未来移动方向;对于暴雨类天气,地闪不能很好预示降水的开始,地闪频数的增加预示强暴雨进入持续阶段,地闪减弱比暴雨回波减弱有明显的提前量。雷雨大风冰雹和暴雨持续阶段其正闪密集区和负闪密集区都同40 dBz的强回波区有很好的对应关系。雷雨大风持续阶段地闪数频数突增,整个时段地闪频次具有单峰特征;暴雨整个时段地闪频次具有双峰或多峰值特点以及高频数地闪持续性特点;1小时地闪频数强暴雨远大于雷雨大风冰雹类。暴雨类0℃、-10℃、-20℃层高度及云顶高度一般高于大风冰雹类,△H_(-10～0℃),△H_(-20～0℃),△H_((?)～0℃)三层高度差也大于大风冰雹类。

Analysis of Relationship Between Cloud-to-Ground Lightning Activities of Severe Thunderstorm and Radar Echo in Henan

Based on datasets of ADTD lightning's location and graphic system and 714CD Doppler radar echo,characteristics and relationship of cloud-to-ground lightning and radar echo between the thunderstorm with hail and the strong rainstorm,which happened eight times from 2004 to 2006,are analyzed. The results show that,the radar echo intensity of thunderstorm with hail is between 50 to 60 dBz,while that of rainstorm is between 40 to 55 dBz.The lightning frequency of rainstorm is obviously more than that of thunders...