南京地区低电离层加热效应的初步模拟

Preliminary simulation of heating effects of the lower ionosphere in Nanjing District

从电子能量方程和连续性方程出发,利用国际参考电离层(IRI-2007)和中性大气模型(NRLMSISE-00)得出背景参数,数值计算了大功率无线电波加热南京地区低电离层的电子温度和电子密度扰动幅度,并对比了不同加热条件下的电离层扰动效应.结果表明,大功率无线电波入射到电离层后,与等离子体相互作用,能够有效造成电子温度的升高而产生电子温度扰动;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,导致电子密度扰动;电子温度和电子密度的扰动幅度随着加热时间的推移而减小,即扰动逐渐趋于饱和;电子温度扰动的弛豫时间尺度为微秒量级,电子密度扰动的弛豫时间尺度为毫秒量级;在欠密加热条件下,X波模比O波模更容易吸收.

Based on the energy conservation equation and continuity equation of electron, the disturbance amplitude of ionospheric electron temperature and density by high power radio wave were simulated by using the International Reference Ionosphere （IRI-2007） and the neutral atmospheric model （NRLMS1SE-00） to provide background parameters. And the effects of ionospheric disturbances under different heating conditions are compared. The results show that the terrestrial ionosphere plasma can be heated by powerful high-frequency radio waves, which can result in the rising of the temperature of electron; and furthermore, the increase in the collision frequency and the decrease in the loss rate of electron, induce the modification of electron density. The perturbation amplitude of electron temperature and density over the heating time decreases, which gradually becomes saturated. The characteristic saturation time of electron temperature is μs, while it is ms for the electron density. Under the under-dense heating condition, X wave is more easily absorbed than O wave.