高频泵波加热电离层的数值模拟

基于高频泵波扰动电离层的欧姆加热理论,建立数值模型模拟加热过程中电子温度、电子密度和离子密度随时间的演化及泵波频率、发射功率对加热效果的影响.结果表明,地面以1.5MW的功率发射一个13MHz的电波,可以引起电子温度升高80%、电子密度升高16%的显著变化.电子温度和电子密度的变化分别在加热开始后几十秒和几分钟内达到饱和.泵波频率和发射功率大小显著影响最终的加热效果,但数值结果并没有体现它们之间具有线性关系.和EISCAT雷达1985年2月26日对一次加热实验观测结果(它的发射功率和本文选定的1.5MW一致)的比较表明,在180km以下区域,该文模型和上述实验观测结果具有很好的一致性;更高高度上模拟结果和实验结果的偏差是由于模拟过程中没有考虑F层异常吸收的作用.

Numerical modeling of ionospheric modificiation with powerful HF pump waves

A numerical model of the typical ionosphere based on ohm heating has been developed and utilized to simulate the ionospheric response to high power radio waves. This model produces the time variations of the electron temperature, electron and ion densities, as well the dependence of the artificial turbulence on radio frequency and transmitted power. The results indicate that a salient ionospheric turbulence with electron temperature increased by 80 percent and electron density by 16 percent can be obtained with a 13MHz pump wave and 1.5MW transmitted power. Electron temperature and electron density reach their saturation in several seconds and a few minutes, respectively. A close but nonlinear correlation is also present between their changes and pump frequency and radiation power. The comparison of these numerical results with the EISCAT observation of one heating experiment on 02/26/1985 indicates that these two results match each other well below 180 kilometer. The distinct difference between the numerical results and the experimental one at higher altitudes is due to anomalous heat-ing of the F layer ionosphere.