中高层电参数的昼夜差异对地闪回击电磁场传播的影响  

Influence of Diurnal Differences in Atmospheric Electrical Parameters at High Altitudes on the Propagation of Cloud⁃Ground Lightning Return Stroke Electromagnetic Field

作　　者：杨许铂 黄翰林 YANG Xubo;HUANG Hanlin(School of Marine Information Engineering,Hainan Tropical Ocean University,Sanya Hainan 572022,China;School of Science,Shenyang University of Technology,Shenyang 110159,China)

机构地区：[1]海南热带海洋学院海洋信息工程学院,海南三亚570022 [2]沈阳理工大学理学院,沈阳110159

出　　处：《海南热带海洋学院学报》2023年第5期108-117,共10页Journal of Hainan Tropical Ocean University

基　　金：海南省自然科学基金青年基金项目(119QN239)。

摘　　要：基于麦克斯韦方程组,计入中高层大气电场对电子加热、电离、吸附的非线性效应,以标准经验模式(NRLMSISE,IRI)提供的参数及构建的大气电导率剖面作为背景值,采用二维时域有限差分算法,建立一个地闪回击电磁场在大地-电离层波导中传播模型。选取海南岛北部夏日12时为日间参数,00时为夜间参数,分别模拟220 kA峰值的强地闪回击产生的大气电场变化。结果显示:日间辐射场值在海拔60 km处开始衰减,而夜间辐射场则到海拔80 km处开始衰减,回击产生的强电磁波在晚上能穿透到更高的高度上,因而夜间高层比白天更容易产生空气击穿效应,发生电子密度短暂增强和瞬态发光事件等现象。Based on Maxwell’s equations,taking into account the nonlinear effects of atmospheric electric fields at high altitudes on electron heating,ionization and adsorption,and using the parameters provided by the standard empirical model(NRLMSISE,IRI)and the constructed atmospheric conductivity profile as the background values,a 2D time-domain finite-difference algorithm was used to establish a model for the propagation of lightning return stroke in the earth-ionosphere waveguide.The daytime parameter at 1200 hours and the nighttime parameter at 0000 hours were selected to simulate the atmospheric electric field variations generated by a strong lightning return stroke with a peak value of 220 kA,respectively,on a summer day in the northern part of Hainan Island.The results showed that the daytime radiation field value starts to decay at 60 km above sea level,while the nighttime radiation field starts to decay at 80 km above sea level,and the strong electromagnetic wave generated by the lightning return stroke can penetrate to a higher altitude at night,and thus the nighttime upper levels are more prone to produce the air breakdown effect than the daytime,and phenomena,such as electron density enhancement and transient luminous events,occur.

关 键 词：天电 电离层 闪电电磁脉冲影响 时域有限差分法 

分 类 号：P352.3[天文地球—空间物理学] P427.34[天文地球—地球物理学]