低纬地区电离层电流的人工调制数值模拟  

Numerical modeling of ionospheric current artificial modulation at low latitude

作　　者：汪枫[1] 赵正予[1] 张援农[1] 

机构地区：[1]武汉大学电子信息学院空间物理系,武汉430079

出　　处：《地球物理学报》2009年第4期887-894,共8页Chinese Journal of Geophysics

基　　金：国家自然科学基金项目(40774100)资助

摘　　要：利用高频泵波能对低电离层进行有效的人工扰动.采用ELF/VLF调幅高频电波对电离层进行加热,电子温度会随着调制频率振荡,并引起电导率周期性变化,从而使加热区内电离层电流周期性变化,形成等效的ELF/VLF电离层虚拟天线,辐射调制频率范围内的无线电波.早期的电离层人工调制研究主要集中在高纬和极区,本文讨论低纬地区电离层人工调制的可能性.本文的理论研究和数值模拟结果表明,低纬地区低电离层电导率在周期性加热的条件下能有效地被调制,使加热区域形成ELF/VLF波的电流辐射源,并分析了不同加热参数和入射条件对调制效果的影响.Powerful high-frequency radio waves can efficiently heat the lower ionosphere. If using HF heater modulated at ELF/VLF, the electron temperature will oscillate with the modulation frequency and lead to the periodic changes of the electric conductivity, resulting in periodic change of the current present in the heated region which can act as an equivalent ELF/VLF virtual antenna for the generation of electromagnetic waves at the modulation frequency. These early researches mainly focused on the high latitude and polar area. In this paper, the possibility of the ionospheric artificial modulation at low latitude will be discussed. The theoretical method and numerical modeling shows that the periodical modification will lead to the conductivities at low latitude periodically changing efficiently and the heated ionospheric area acts as a radiation current source of the ELF/VLF waves. Furthermore, the effects of different parameters and incident conditions on the modification are also studied.

关 键 词：高频泵波 人工调制 低纬地区 数值模拟 

分 类 号：P352[天文地球—空间物理学]