Spatial Structure of Plasma Density Disturbances in the Topside Ionosphere Caused by High-Power HF Heating of the F2 Layer

The study analyzes the results of low-orbital satellite radio tomography measurements of the spatial structure of artificial electron-density variations Earth’s topside ionosphere excited during modification of the F2 layer of the mid-latitude ionosphere by high-power O-polarized HF radio waves emitted by the SURA heating facility. The article considers the characteristics of the cavity with a reduced plasma density that forms near the reflection height of a high-power HF radio wave, ducts with increased plasma density that form in the topside ionosphere due to displacement of plasma from the heated region along the geomagnetic field, and various wave disturbances induced at ionospheric heights. In addition, the properties of detected plasma density disturbances of a special nature in the vertical column above the central part of the disturbed region of the ionosphere are also investigated. The sizes of the studied irregularities are from several tens to several hundreds of kilometers, and the area of their existence goes far beyond the region of resonance interaction of a high-power O-polarized radio wave with ionospheric plasma near its reflection height, where the most intense artificial ionospheric turbulence is excited.