Study of Ionospheric Plasma Turbulence Caused by Powerful Ground-Based HF Radio Transmissions

建议继续观测电离层等离子体 通过雷达后向散射测量湍流。 1990年和1991年的观察 大大增加了对电离层朗缪尔的了解 无线电波在F区反射产生的湍流。 在拟议的观测中，朗缪尔湍流的光谱将 每隔150 m的高度间隔获得。初步 1991年8月获得的这类结果表明， 朗缪尔湍流谱的发展和衰减 10个高度，相距150 m，用于10 ms的脉冲HF传输 时间间隔为1 ms。 还建议进行 使用朗缪尔分析模型的理论研究 急流. 该模型考虑了自由朗缪尔模 作为长波长等离子体湍流的未捕获部分， 受到调制不稳定性的影响 的推广 有限磁场情况下的现有分析模型 并提出了适合于电离层实验的方法。

It is proposed to continue the observations of ionospheric plasma turbulence by radar back-scatter. Observations in 1990 and 1991 greatly increased the understanding of ionospheric Langmuir turbulence generated by a radio wave reflected in the F-region. In the proposed observations spectra of Langmuir turbulence will be obtained at 150 m height intervals every ms. Preliminary results of this type obtained in August 1991 show the temporal development and decay of the spectrum of Langmuir turbulence for 10 heights 150 m apart, for pulsed HF transmissions of 10 ms duration at 1 ms time intervals. It is also proposed to conduct theoretical investigations using an analytical model of Langmuir turbulence. In that model the free Langmuir mode is considered as the untrapped part of long wavelength plasma turbulence excited by the modulational instability. A generalization of the existing analytical model for the case of a finite magnetic field appropriate for the ionospheric experiments is also proposed.