Variations in the ionospheric wave perturbation spectrum during periodic heating of the plasma by high-power high-frequency radio waves

Abstract

We present the results of spectral analysis of temporal variations in the Doppler frequency shift of the ionosphere-reflected signals from a high-frequency vertical ionospheric sounding radar located near the city of Kharkov in the days of exposure of the ionospheric plasma to the high-power radio emission of the Sura facility (Nizhny Novgorod) and in the reference day in the absence of such an exposure. It was established that the spectral characteristics of quasiperiodic variations in the Doppler frequency shift in the range of periods 10-60 min in the days of work of the facility and in the reference day differed significantly. This is considered as evidence in favor of the generation (amplification) of acoustic-gravity waves propagating at the ionospheric altitudes by high-power periodic high-frequency radiation of the Sura facility.

Geomagnetic Pulsation Amplitude and Spectrum Variations Accompanying the Ionospheric Heating by High-Power Radio waves from the Sura Facility

“…In this case, the disturbance propagation velocity cannot be determined from Eq. (16). Apparently, the velocity v is equal to the velocity of the MHD waves in the ionosphere (near 1000 km/s).…”

“…The first of them, aperiodic, are caused by the increased electron number density N at the altitudes of the ionospheric D and E regions, which is due most probably to the precipitation of energetic electrons (with 40-100 keV energies) from the Earth's inner radiation belt [7][8][9][10][11][12][13]. The second, quasiperiodic disturbances are related with the generation (amplification) and propagation of acoustic-gravity waves with the period T ≈ 1-60 min in the upper atmosphere of the Earth and modulation of the electron number density [7,8,[14][15][16][17][18][19][20].…”

Observations of the Ionospheric Wave Disturbances Using the Kharkov Incoherent Scatter Radar upon RF Heating of the Near-Earth Plasma

“…The results of modern experimental studies are presented in [14][15][16][17][18][19][20]. In these papers, the ionospheric wave disturbances were usually detected using a Doppler radar [15,16,[18][19][20] and, less frequently, the Kharkov incoherent scatter radar [14,17].…”

“…In these papers, the ionospheric wave disturbances were usually detected using a Doppler radar [15,16,[18][19][20] and, less frequently, the Kharkov incoherent scatter radar [14,17]. The main properties of the ionospheric wave disturbances in the range of acoustic-gravity waves (periods T ≈ 1-180 min), which appeared in the near-Earth plasma affected by high-power periodic radiation of the SURA facility were established there.…”

“…The main properties of the ionospheric wave disturbances in the range of acoustic-gravity waves (periods T ≈ 1-180 min), which appeared in the near-Earth plasma affected by high-power periodic radiation of the SURA facility were established there. It was also shown in [14][15][16][17][18][19][20] that the generation efficiency of traveling ionospheric disturbances significantly depends on the heater radiation mode, the time of the day, and the state of space weather.…”