摘要
利用地面雷电探测网,多普勒天气雷达和常规天气资料,分析了2005年8月1日发生在山东北部的一次具有前部对流线,后部大范围层状云降水（LLTS）的典型中尺度对流系统（MCS）的闪电活动演变特征。结果表明：整个过程中负地闪占主导地位,最高频数达到260次/5min;与负地闪比较,正地闪呈现不活跃状态。负地闪主要落在〉40 dBz的强回波区内部及其边缘区域,而正地闪则分布在前部云砧和后部层状云降水区内。对地闪位置与回波强度的进一步对比分析发现,45～55 dBz的回波是最有利于地闪发生的区域,回波强度低于这一区域,随着回波强度的增大,地闪活动呈递增趋势,地闪频数在50～55 dBz的回波区域内达到峰值,〉55 dBz的回波区域内地闪频数明显降低。
Based on the lightning location detection（DF） data,Doppler radar data and synoptic information,the lightning characteristics of a typical mesoscale convective system in the north of Shandong Province on August 1st,2005 are presented.It is found that the negative lightning（-CG） is predominant to positive lightning（＋CG） during the whole lifetime of thunderstorm.The maximum flash rate is 260 flashes in per five minutes.The comparison of location of lightning activity and radar echo shows that-CG usually cluster in the intense echo region with high reflectivity（〉40 dBz）,while ＋CG usually disperse in the weak echo such as stratiform region or cloud anvil.The lightning flash changes with different echos,the maximum lightning flash rate occurred in the echo within 45～55 dBz.A good correlation is observed between the cloud height of 30 dBz and lightning flash rate,and validates the exponential relationship between them.
出处
《高原气象》
CSCD
北大核心
2008年第2期358-364,共7页
Plateau Meteorology
基金
国家杰出青年科学基金项目(40325013)
国家自然科学基金项目(40505001)共同资助
关键词
中尺度对流系统
地闪频数
多普勒雷达
Mesoscale convective system
Cloud-to-ground lightning
Doppler radar
