脉冲电晕与地闪负先导梯级性机制模式探讨  

Pulse Corona and a New Mechanism of the Negative Stepped Leader in Cloud-to-Ground(CG) Lightning Discharge

作　　者：苟学强[1] 张义军[1] 

机构地区：[1]中国科学院寒区旱区环境与工程研究所

出　　处：《高原气象》2002年第4期408-413,共6页Plateau Meteorology

基　　金：国家自然科学基金项目 (4 9975 0 0 3 ) ;中国科学院寒区旱区环境与工程研究所创新项目 (2 10 0 3 7)共同资助

摘　　要：根据新的观测事实 ,提出了地闪负先导明亮脉冲可能不是被一慢而弱的流光 (引路流光 )所引导 ,而是被一快而短暂的电晕 (脉冲电晕 )所引导的梯级性流光机制的不同观点。由此出发 ,对流光间歇时间、梯级长度等重要特征参数进行了新的分析 ;结合对梯级先导辐射特征脉冲产生机制的进一步分析 ,提出并论证了明亮脉冲的双向传输 ,通过一个简单的数值模式对梯级过程进行了计算模拟 。Based on latest observation, we make an assumption that the bright pulse of negative stepped leader in the CG lightning discharge is not initiated by a slow and faint streamer (pilot streamer ), but is initiated by a fast and instant corona (pulse corona). Thus a new conceptual model of stepped leader was proposed and a simple numerical model was set up. The characteristic parameters of streamer time intervals and the stepped length were discussed. The characteristic radiation pulse of stepped leader was explained more clearly and the bidirectional propagation process of the stepped pulse was analyzed. The result is basically agreed with observation.

关 键 词：脉冲电晕 地闪 负先导梯级性机制模式 特征脉冲 辐射脉冲 发光脉冲 

分 类 号：P427.3[天文地球—大气科学及气象学]