Ionosphere response to the impact of an extraordinary radio wave when located at a frequency close to the heating frequency

The paper presents the results of experiments on the impact of powerful high-frequency radio emission from the SURA mid-latitude heating facility (56.1° N, 46.1° E) on Earth's ionosphere. The disturbance in the ionosphere was created by a radio wave of extraordinary polarization under conditions when the ordinary component of the powerful wave was not reflected by the ionosphere. The sounding of the disturbed region was carried out with a probe radio wave of the same polarization at a frequency higher than the heating frequency by 228–400 kHz. During the impact on the ionosphere, a weak scattered signal with an amplitude 40–60 dB lower than the amplitude of the specular reflection signal from the F-region was received from the height of reflection of the powerful radio wave. This means that the artificial disturbance of the plasma density occurred in the region of reflection of the powerful radio wave of extraordinary polarization. Possible causes of the disturbance are discussed.