化学物质释放人工改变电离层

考虑中性气体在电离层高度的扩散过程和相应的电离层离子化学过程，研究了利用主动化学物质释放来改变电离层的方法，理论计算了H2O和SF6两种气体释放后电离层随时间的响应过程，结果表明，在电离层高度上气体的扩散过程非常迅速，电离层F区的电子密度有很大程度的减少，而扩散慢且化学反应快的气体对电离层的影响更大，就更加有利于电离层洞的形成。

Ionospheric Disturbances Produced by Artificially Chemical Releases

Active experiments in the ionosphere, which give rise to artificial disturbances of electron density, are usually conducted by the injection of chemical clouds at ionospheric altitudes. Their effect has often been called an ionospheric hole simply to dramatize the localized nature of the disturbances, which had been observed in many experiments. For example, the injection of rocket exhaust neutral molecules into ionosphere, predominantly H2O and H2, can result in ionospheric electron density depletion. Main physical mechanism in these experiments is due to ion and molecule exchange reactions, which enhance the effective rate of recombination of electron. Ionospheric disturbances produced by artificially chemical releases have many applications in radio propagation and exploring ionosphere and plasma physics study. In terms of diffusion process of neutral gas and relevant chemical reactions in terrestrial ionosphere, the theoretical model of ionospheric modification created by active chemical releases is investigated in this paper. The influences of injected H2O and SF6 gas on the ionosphere under exponential atmosphere background are theoretically calculated, respectively. The results show that diffusion process of the injected neutral gas at ionospheric height is very quick, and the two released chemical materials can produce localized electron density depletions in F-regions, and those released materials, which have slow diffusion speed and large chemical reaction rates, will substantially affect ionosphere, and facilitate formation of artificial ionospheric hole.