Aperiodic large-scale disturbances in the ionospheric E region stimulated by high-power HF heating

Abstract

We describe the observation results of ionospheric disturbances at altitudes of 100 to 140 km, which occurred at a distance of about 1000 km from the Sura facility. The observations have been made using the incoherent scatter radar located near Kharkov. The electron density increase by 10–70 % had a temporal duration of 10–20 min and accompanied the high-power HF heating. The time of disturbance evolution was about 10 min. The observation effect can be explained by the intensification of the subsystem coupling in the ionosphere–magnetosphere–upper atmosphere– ionosphere system, which leads to a precipitation of energetic electrons from the magnetosphere. Parameters of the precipitating particles and precipitation-produced ionization are estimated.