地闪梯级先导电场波形特征研究  

Numerical evaluation of electric field changes radiated by cloud-to-ground lightning stepped leader

作　　者：江志东[1] 周璧华[1] 张琪[1] 

机构地区：[1]解放军理工大学电磁环境效应与电光工程国家级重点实验室,江苏南京210007

出　　处：《电波科学学报》2015年第2期365-370,382,共7页Chinese Journal of Radio Science

摘　　要：为研究地闪梯级先导电场波形特征,采用偶极子法结合衰减函数计算了有限大地电导率下不同距离处、不同梯级先导底部高度条件下的电场波形特征.计算结果表明:当观测点距离先导通道较近时,电场峰值随着先导通道底部高度的增大而减小;随着观测点和先导通道距离的增大,梯级先导通道底部高度对电场的影响逐步减小.对于给定高度的先导通道,其对应的电场峰值随着观测点和先导通道距离的增加,峰值先变大而后变小随着电导率的减小,先导电场波形上升时间明显增加,电场峰值衰减加快.In order to investigate the characteristics of electric field changes radiated by lightning stepped leader,a dipole method with attenuation function is proposed.Electric field changes associated with the lightning stepped leader channel at various observation points with different ground conductivity are explored.The results show that when the observation point is near the bottom of the stepped leader channel,the electric field amplitude decrease with the increase of the height of the stepped leader tip.However,as the distance increase,the height of the stepped leader tip has less effect on the electric field changes.For the stepped leader channel at given distance,the amplitude becomes larger first and then smaller.The rise time the peak of the electric field changes significantly in propagating over finitely conducting ground.Due to the decrease of ground surface conductivity,the simulated rise time of the electric field changes increase obviously and the amplitude of the electric field attenuate faster.

关 键 词：闪电 梯级先导 电场变化 传播效应 

分 类 号：P427.3[天文地球—大气科学及气象学]