2007年丹东和阜新地区地闪特征

Characteristics of cloud-to-ground lightning in 2007 over Dandong and Fuxin,Liaoning province

针对2007年辽宁地闪资料进行分析。结果表明:丹东和阜新是辽宁南北两个地区地闪高发区,其地闪变化既有相同之处,也有差异点。两地均为负地闪次数远远多于正地闪次数,正闪比相差不大;正闪比为春季大、夏季少;丹东平均正、负地闪峰值电流强度平均值大于阜新。地闪多发生于午后到夜间,丹东多发于早晨。定义了地闪持续时数,分析发现地闪多集中发生在持续6 h及以上的地闪活动过程中,因而持续6 h及以上的地闪活动过程潜在危害较大。丹东地闪活动易发月份为5—10月,阜新为5—8月;丹东地闪活动最活跃期为8月,阜新地区为7月。

The cloud-to-ground （CG） lightning data in 2007 were analyzed in Liaoning province. The results show that Dandong and Fuxin are two high risk regions of CG lightning in Liaoning province. CG lightning changes in two regions are of not only homology, but also difference. The negative CG lightning is far more than the positive CG lightning, while the ratio of positive and negative CG lightning is close in two regions. The ratio of positive and negative CG lightning is higher in spring and lower in summer. The average current intensity of CG lightning peak value in Dandong is higher than that in Fuxin. CG lightning usually appears from afternoon to night, while it is in morning over Dandong. The concept of CG lightning continued hours is defined. It indicates that CG lightning concentrates in 6 hours or more than 6 hours CG lightning process. Thus, CG lightning remained more than 6 hours is of larger potential hazards. CG lightning events often happen from May to October in Dandong and from May to August in Fuxin. CG lightning activities in August and July are the most active in Dandong and Fuxin,respectively.