北极区低电离层加热效应的数值模拟研究

从等离子体能量守恒方程和连续性方程出发,以国际参考电离层(IR I2000)和大气模型(MSIS)为背景,通过数值方法模拟研究大功率无线电波对北极低电离层的电子密度和电子温度的扰动效应。结果表明,在外加强电磁场作用下,电离层等离子体中的带电粒子(主要是电子)动力学温度得以升高而产生等离子体温度扰动;由于电子温度升高,等离子体碰撞频率增加且电子的复合系数减小,诱发电子密度扰动;电子密度和电子温度的扰动幅度随着加热时间的推移而减小,即扰动趋于饱和;电子密度扰动的弛豫时间较电子温度扰动的弛豫时间大;在泵波频率大于电离层临界频率的条件下,泵波频率越高,其激发的电子温度和电子密度扰动效应也就越弱。

A SIMULATION OF THE HEATING EFFECT OF HIGH POWER RADIO WAVE ON THE LOWER POLAR IONOSPHERE

In this paper,the Ohm effect of high power radio wave on the lower polar ionosphere was studied.Based on the heat balance function and continuity function,the modification of ionospheric electron temperature and density by high power radio wave was simulated by using IRI2000 and MSIS as a background.The results show that the external pump can modify the temperature of ionospheric plasma and lead to the rising of the temperature of electron,the increase in the collision frequency and the decrease in the loss rate of electron,and furthermore,induce the modification of electron density.The intensity of modification of temperature and density of electron decreases with the increase of the heating time,that is,it tends to be saturated.In addition,it can be concluded that the characteristic time of electron density is larger than that of electron temperature.Also,the higher the frequency of pump,the weaker the Ohm effect of pump.