The Results of Experimental Studies Conducted in 2018–2023 in the Framework of the Sura– Program

The results of experiments conducted in 2018–2023 to study the characteristics of plasma perturbations, that were generated in the Earth's outer ionosphere when ionospheric F layer was modified by powerful HF radio waves radiated by the mid-latitude SURA heating facility, are discussed. Measurements were taken during the daytime and evening (night) hours at low and high levels of solar activity. Plasma perturbations were registered by the onboard instruments of the Chinese low-orbit satellite (ZH-1) both above the SURA heating facility and in the magnetically conjugate ionosphere. The characteristics of a powerful radio wave penetrating into the outer ionosphere, the influence of ionospheric disturbances of natural and artificial origins on the propagation of a powerful radio wave through the ionosphere, the conditions of VLF radio wave generation due to nonlinear demodulation of a powerful radio wave, etc. were studied. In the paper, it is considered the influence of the main ionospheric trough on the development of interaction of powerful HF radio waves with the ionospheric plasma and on the generation of artificial ionospheric turbulence in the trough.