Comparison of the Effects Induced by the Ordinary (O-Mode) and Extraordinary (X-Mode) Polarized Powerful HF Radio Waves in the High-Latitude Ionospheric F Region

摘要

Using the results of coordinated experiments on the modification of the high-latitude ionosphere by powerful HF radio emission of the EISCAT/Heating facility, effects of the impact of powerful HF radio waves of the ordinary (O-mode) and extraordinary (X-mode) polarization on the high-latitude ionospheric F region have been compared. During the experiments, a powerful HF radio wave was emitted in the magnetic zenith direction at frequencies within the 4.5-7.9 MHz range. The effective power of the emission was 150650 MW. The behavior and characteristics of small-scale artificial ionospheric irregularities (SAIIs) during O-and X-heating at low and high frequencies are considered in detail. A principal difference has been found in the development of the Langmuir and ion-acoustic turbulence (intensified by the heating of the plasma and ion-acoustic lines in the spectrum of the EISCAT radar of incoherent scatter of radio waves) in the O and X-heating cycles after switching on the heating facility. It has been shown that, under the influence on the ionospheric plasma of a powerful HF radio wave of the.-polarization, intense spectral components in the spectrum of the narrow-band artificial ionospheric radio emission (ARI) were registered at distances on the order of 1200 km from the heating facility.