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Almaty, Kazakhstan

Belov A.V.,Russian Academy of Sciences | Eroshenko E.A.,Russian Academy of Sciences | Kryakunova O.N.,Institute of the Ionosphere | Kurt V.G.,Moscow State University | Yanke V.G.,Russian Academy of Sciences
Geomagnetism and Aeronomy | Year: 2010

The catalog of ground level enhancements of solar cosmic rays during cycles 21-23 of solar activity has been presented. The main properties, time distribution, and relation of these events to solar sources and proton enhancements observed on satellites have been studied. © Pleiades Publishing, Ltd., 2010. Source

Chernogor L.F.,University of Kharkiv | Frolov V.L.,Radiophysical Research Institute | Barabash V.V.,Institute of the Ionosphere
Radiophysics and Quantum Electronics | Year: 2014

We present the observed disturbances of the parameters of the ionosphere affected by high-power radio waves from the SURA heating facility. Ionosondes located in Nizhny Novgorod and Moscow (Russia), Kharkov (Ukraine), and Pruhonice (Czechia) were used for the observations. The diagnostic tools were from 560 to 2200 km away from SURA. Additional ionization layers with a cutoff frequency of 2.6-3.4 MHz were occasionally observed on the ionograms of the Nizhny Novgorod and Moscow stations. The effective altitude of these layers was 120-160 km and the true altitude was about 110-130 km. The occurrence of additional ionization layers below 100-130 km was controlled by an increase in the minimum observable frequency (MOF). For the Moscow station, the MOF increased by about 1 MHz in the daytime and almost did not change in the night time. MOF variations on the ionograms of the Kharkov and Pruhonice stations were less significant (0.3-0.4 MHz) in all time of the day. The observed effects are most probably due to the midlatitude precipitation of electrons from the inner radiation belt, which increased the electron number density in the ionosphere, absorption of the sounding radio waves, and the MOF. Estimated particle flux density was 10 8-109 m-2 ·s-1. The electron number density in the daytime increased by a factor of 2-3. © 2014 Springer Science+Business Media New York. Source

Somsikov V.M.,Institute of the Ionosphere
Geomagnetism and Aeronomy | Year: 2011

The theoretical and experimental results of studies of the solar terminator as a source of inhomogeneous atmospheric structures are analytically reviewed. A classification of the mechanisms by which waves and atmospheric irregularities are generated is presented and briefly described. Several urgent problems related to further studies of the solar terminator and effects created by it in the near-Earth space are considered. © 2011 Pleiades Publishing, Ltd. Source

Burmaka V.P.,Institute of the Ionosphere | Chernogor L.F.,University of Kharkiv
Geomagnetism and Aeronomy | Year: 2012

Using the Kharkov incoherent scatter radar, observations of wave disturbances in electron concentration N in the ionosphere at heights of 120-600 km are conducted. The measurements were carried out in the periods of the spring and fall equinoxes and winter and summer solstices. The height-time dependences of the absolute ΔN and relative ΔN/N amplitudes of wave disturbances, as well as their spectral composition, were analyzed. It is shown that wave disturbances in the ionosphere with periods of 10-180 min were present at almost any time of the day and in all seasons. Their absolute and relative amplitudes varied from 6 × 10 9 to 6 × 10 10 m -3 and from 0.01 to 0.5, respectively. The maximum values of ΔN and ΔN/N were observed at a height of ~200 km. The passage of the solar terminator changed substantially the wave disturbance parameters. © 2012 Pleiades Publishing, Ltd. Source

Chernogor L.F.,Institute of the Ionosphere | Chernogor L.F.,University of Kharkiv | Domnin I.F.,Institute of the Ionosphere | Panasenko S.V.,Institute of the Ionosphere | Uryadov V.P.,Radiophysical Research Institute
Radiophysics and Quantum Electronics | Year: 2012

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. © 2012 Springer Science+Business Media, Inc. Source

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