Features of artificial ionosphere turbulence induced by the O- and X-mode HF heating near the F2-layer critical frequency

Abstract

We present experimental results from the studies of large-scale inhomogeneities along the external magnetic field with increased electron density, electron temperature, and excitation of elongated plasma waves (Langmuir and ion-acoustic), induced by the ordinary (O-mode) and extraordinary (X-mode) HF heating near the F2-layer critical frequency, in the high-latitude ionospheric F-region. The experiments have been carried out at the EISCAT/Heating facility (Tromsø, Norway). Powerful HF radio waves radiated towards the magnetic zenith through a step change in the effective radiated power at frequencies fH near and below the F2-layer critical frequency fₒF2. The EISCAT incoherent scatter radar (930 MHz), co-located with the EISCAT/Heating facility, was utilized for diagnostics of ionospheric modification effects. We calculated the electric field of a powerful HF radio wave near the reflection altitude, taking into account the non-deflective absorption along the propagation path. We determined the conditions for electric field generation and its threshold (minimum) values required for electron density enhancements in a wide altitude range, excitation of Langmuir and ion-acoustic plasma waves under fH~fₒF2 and fH

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f - 2层临界频率附近O和x模HF加热诱导的人工电离层湍流特征

我们展示了在高纬度电离层f区，在f2层临界频率附近，由普通(o模式)和特殊(x模式)HF加热引起的长形等离子体波(Langmuir和离子声)激发下，随着电子密度、电子温度的增加，沿外磁场的大规模不均匀性的实验结果。这些实验是在EISCAT/加热设施(挪威特罗姆瑟)进行的。在F2层临界频率fₒF2附近及以下的频率fH处，通过有效辐射功率的阶跃变化向磁天顶辐射强大的HF无线电波。EISCAT非相干散射雷达(930 MHz)与EISCAT/加热设施同设，用于电离层改变效应的诊断。我们计算了强高频无线电波在反射高度附近的电场，并考虑了沿传播路径的非偏转吸收。我们确定了在fH~fₒF2和fH<fₒF2下，在宽海拔范围内增强电子密度、激发Langmuir和离子声等离子体波所需的电场产生条件及其阈值。讨论了强高频无线电波在0极化和x极化反射高度以上电子密度增强的可能产生机制。

本文章由计算机程序翻译，如有差异，请以英文原文为准。