Peculiarities of Excitation of Large-Scale Plasma Density Irregularities During Modification of the Ionospheric F<inf>2</inf> Region by High-Power HF Radio Waves

© 2016 Springer Science+Business Media New YorkWe present the experimental results concerning the features of large-scale artificial plasma-density irregularities excited in the ionospheric F2 region by high-power HF radio waves. The experiments were performed in recent years using the SURA heating facility. It is shown that at the altitude of the pump-wave reflection, these irregularities are most efficiently generated in the magnetic zenith region. The effect of enhancement of the large-scale irregularity generation at the edge of the pump-wave beam is revealed. The results of studying large-scale irregularities recorded at the altitudes of the topside ionosphere are presented. Experimental results concerning the features of the internal gravity waves generated at the ionospheric altitudes during periodic heating of the ionospheric plasma by high-power HF radio waves are summarized and their possible influence on generation of artificial ionospheric irregularities at a long distance from the heater is discussed

Peculiarities of excitation of large-scale plasma density irregularities during modification of the ionospheric F<inf>2</inf> region by high-power HF radio waves

© 2016 Springer Science+Business Media New York.We present the experimental results concerning the features of large-scale artificial plasma-density irregularities excited in the ionospheric F2 region by high-power HF radio waves. The experiments were performed in recent years using the SURA heating facility. It is shown that at the altitude of the pump-wave reflection, these irregularities are most efficiently generated in the magnetic zenith region. The effect of enhancement of the large-scale irregularity generation at the edge of the pump-wave beam is revealed. The results of studying large-scale irregularities recorded at the altitudes of the topside ionosphere are presented. Experimental results concerning the features of the internal gravity waves generated at the ionospheric altitudes during periodic heating of the ionospheric plasma by high-power HF radio waves are summarized and their possible influence on generation of artificial ionospheric irregularities at a long distance from the heater is discussed

Radiotomography and HF ray tracing of the artificially disturbed ionosphere above the Sura heating facility

©2016. American Geophysical Union. All Rights Reserved.We present the results of the radiotomographic imaging of the artificial ionospheric disturbances obtained in the recent experiments on the modification of the midlatitude ionosphere by powerful HF radiowaves carried out at the Sura heater. Radio transmissions from low orbital PARUS beacon satellites recorded at the specially installed network of three receiving sites were used for the remote sensing of the heated ionosphere. We discuss the possibility to generate acoustic-gravity waves (AGWs) with special regimes of ionospheric heating (with the square wave modulation of the effective radiated power at the frequency lower than or of the order of the Brunt-Vaisala frequency of the neutral atmosphere at ionospheric heights during several hours) and present radiotomographic images of the spatial structure of the disturbed volume of the ionosphere corresponding to the directivity pattern of the heater, as well as the spatial structure of the wave-like disturbances, which are possibly heating-induced AGWs, diverging from the heated area of the ionosphere. We also studied the HF propagation of the pumping wave through the reconstructed disturbed ionosphere above the Sura heater, showing the presence of heater-created, field-aligned irregularities that effectively serve as “artificial radio windows.”

Generation of Artificial Ionospheric Irregularities in the Midlatitude Ionosphere Modified by High-Power High-Frequency X-Mode Radio Waves

© 2014, Springer Science+Business Media New York. We consider the properties of the artificial ionospheric irregularities excited in the ionospheric F2 region modified by high-power high-frequency X-mode radio waves. It is shown that small-scale (decameter) irregularities are not generated in the midlatitude ionosphere. The intensity of irregularities with the scales l⊥≈50 m to 3 km is severalfold weaker compared with the case where the irregularities are excited by high-power O-mode radio waves. The intensity of the larger-scale irregularities is even stronger attenuated. It is found that the generation of large-scale (l⊥ ≈5–10 km) artificial ionospheric irregularities is enhanced at the edge of the directivity pattern of a beam of high-power radio waves

Gyroharmonic features of the hf-induced ionospheric irregularities

Gyroharmonic features of the different-scale artificial plasma-density irregularities excited by HF modification of the ionospheric F2 region under conditions where the frequency of the O-mode pump wave is close to the fourth gyroharmonic frequency of electrons in the pump wave - plasma interaction region are considered. © 2012 Springer Science+Business Media New York

Peculiarities of excitation of large-scale plasma density irregularities during modification of the ionospheric F<inf>2</inf> region by high-power HF radio waves

© 2016 Springer Science+Business Media New York.We present the experimental results concerning the features of large-scale artificial plasma-density irregularities excited in the ionospheric F2 region by high-power HF radio waves. The experiments were performed in recent years using the SURA heating facility. It is shown that at the altitude of the pump-wave reflection, these irregularities are most efficiently generated in the magnetic zenith region. The effect of enhancement of the large-scale irregularity generation at the edge of the pump-wave beam is revealed. The results of studying large-scale irregularities recorded at the altitudes of the topside ionosphere are presented. Experimental results concerning the features of the internal gravity waves generated at the ionospheric altitudes during periodic heating of the ionospheric plasma by high-power HF radio waves are summarized and their possible influence on generation of artificial ionospheric irregularities at a long distance from the heater is discussed