地震电离层异常电场模拟及初步研究  

A numerical study of seismic-related electric field in the ionosphere

作　　者：杨许铂 周晨[1] 刘静[2] 赵正予[1] 张援农[1] 

机构地区：[1]武汉大学电子信息学院,武汉430072 [2]中国地震局地震预测研究所,北京100036

出　　处：《地球物理学报》2014年第11期3650-3658,共9页Chinese Journal of Geophysics

基　　金：中俄合作研究项目(2014DFR21280);国家863项目(2012AA121004);国家自然科学基金青年科学基金(41204111);中国地震局行业专项(201008007)资助

摘　　要：强地震会造成电离层电场发生异常变化.基于大气层-电离层电动力学理论对地震电离层异常电场开展数值模拟和研究,将理论推导出来的电离层异常电场方程扩展到球面坐标系中,并且考虑到电离层层电导率的各向异性,建立新的地震电离层异常电场模式.引进一个电离层层电导率经验公式(Nopper and Carovillano,1979),对中低纬度地震电离层异常电场特性进行数值模拟.模拟结果表明:附加电流引起电离层异常电场范围远大于自身在地表上的分布.且发生在低纬地区的异常电场主要成分是纬向电场,在东西两侧显偶极子分布.在额外电流分布相同的情况下,夜晚生成的异常电场更显著,存在昼夜差异.This paper explores the properties of seismic-related DC electric field in the ionosphere based on an electrodynamic model of the lower atmosphere-ionosphere coupling. According to this model, the external electric current is a source of conductivity current perturbation in the atmosphere-ionosphere electric circuit. We develop the model to spherical coordinate and solve it numerically for an inhomogeneous anisotropic conductivity. The results show that the horizontal scale of electric field in the ionosphere is larger than the horizontal scale of external current in the atmosphere. The electric field in the low latitude ionosphere is mostly zonal, and its structure is dipole-like. The external current induced DC night-time than during the day. electric field in ionosphere is much stronger at night-time than during the day.

关 键 词：地震 电离层电场 附加电流 各向异性电导率 

分 类 号：P352[天文地球—空间物理学]