Sergey Alexander Pulinets

Quasielectrostatic model of atmosphere-thermosphere-ionosphere coupling

Abstract Multiple experimental evidences obtained recently convincingly show the strong influence of near ground atmospheric processes (volcano eruptions, sand storms, radioactive air pollution, earthquakes etc.) on the upper layers of thermosphere and ionosphere. The correspondent model explains the observed phenomena by the quasi-electrostatic field effects. The model consist of three parts: 1-electric field generation model, 2-electric field penetration at thermosphere-ionosphere heights, and 3-effects of electric field in the thermosphere-ionosphere. In the first part a model of ion kinetics in a near-ground layer of troposphere is considered. It explains the appearance of strong vertical electric field up to several kV/m. Second part with the help of existing model of atmosphere conductivity vertical distribution makes calculations of penetrated electric field at the heights from 90 up to 1000 km. It explains the horizontal electric field ∼ 1 mV/m at the ionospheric heights as a result of original vertical electric field ∼ 1 kV/m at the ground surface. The third part demonstrates the effects of electron concentration modification over the vertical electric field source. Self-consistence of the model is demonstrated by correspondence of the calculated parameters to the measured experimentally.

Seismic activity as a source of the ionospheric variability

Abstract Ionospheric variations, observed mainly by vertical sounding technique, over the seismically active regions are interpreted in terms of lithosphere-ionosphere coupling. The methods of identification of variations induced by seismic activity within the ionosphere are proposed. It is shown that such variations have their individual features, different from variations induced by magnetic disturbances and other kinds of external activity. The magnitude and occurrence of such variability lead to conclusion that seismic activity is important source of the ionospheric variability.

Radon and metallic aerosols emanation before strong earthquakes and their role in atmosphere and ionosphere modification

Abstract One of the widely used techniques for earthquakes prediction research is radon concentration measurements within the seismo-active area. Radon concentration gradually grows during several months before a strong earthquake with a sharp increase few days before and abrupt drop few hours before the shock. This phenomenon usually is restricted to the region where the ground water trapped in the vicinity of the region of the earthquake, hollows out due to stress and escapes through the cracks developed. At the same time electromagnetic precursors exist showing the ionosphere modification before the earthquakes. One of them is the phase variations of the VLF signals passing over the region of anticipated earthquake. As it was shown by theoretical calculations this effect is connected with the changing of the conductivity of the “Earth-ionosphere” waveguide. The second effect is the ionosphere peak electron density variations. Scaled for particular local times (3 h, 6 h, 18 h LT) they show very high level of anticorrelation with the radon variations behavior. The observed variations imply existence of a coupling between them and radon concentration in the ionosphere. This coupling is interpreted in terms of modification of electrodynamic properties of atmosphere-ionosphere system before the earthquakes over the seismo-active zone. The atmosphere conductivity changes itself cannot explain the observed variations. The submicron metal aerosols emanated from earth together with radon have great influence on the modification processes. The same combination of radiation and dust occurred during Chernobyl atomic plant catastrophe and similar phase variations of VLF transmitters signal were observed when the signal passed over the Chernobyl plant during active emanation of the radioactive dust from the exploded reactor. Radon and metallic aerosols monitoring over the seismo-active regions could be used for strong earthquake prediction, and their effects on the electrodynamics of atmosphere-ionosphere system can explain the observed variations within the ionosphere.

Ionospheric foF2 variations prior to strong earthquakes in Taiwan area

Abstract Many studies of the seismo-ionospheric coupling effects have been reported. On 17 July 1998(M=6.2), 20 September 1999 (M=7.3) and 22 October 1999 (M=6.4) three large earthquakes respectively struck Rei-Li, Chi-Chi and Chia-Yi in central Taiwan. The three earthquakes severely damaged structures, heavily changed landforms and disturbed geophysical environments. This paper examines variations of the ionospheric penetration frequency, foF2 , observed by Chung-Li ionosonde station (25.0° N, 121.1° E) several days before the three earthquakes. The mean- and median-based statistical techniques are introduced to investigate the ionospheric electron density prior to the three earthquakes. Results show that the foF2 decrease significantly before the three earthquakes.

RECENT ADVANCES IN TOPSIDE PROFILE MODELING

Abstract A parameterized model for topside profile was developed based on the Epstein function approximation. Using the Intercosmos-19 database, model parameters were obtained for different geophysical conditions, including strong-magnetic storms. In some specific conditions the F3 layer was observed on topside ionograms. A physical explanation is proposed as well as results based on modeling approach. Topside ionograms from the sounder on MIR Space Station were studied. Some exotic cases are presented including oblique propagation, station position under the peak height etc. Peak height global distribution is described as well as neutral wind parameters derived from the topside peak height values.

Unique variations of the total electron content in the preparation period of Haitian earthquake (M7.9) on January 12, 2010

Variations of the total electron content according to the index IONEX IGS in the period of preparation of the earthquake in Haiti (M7.9) on January 12, 2010, are considered. The situation is exceptional owing to the unique position of the island of Haiti relative to the structure of the ionosphere over the Caribbean Sea: the ionospheric region over Haiti is in the trough formed by the northern slope of the equatorial anomaly and additional maximum formed at latitudes of approximately 30° N within this longitudinal interval. Distortion of the shape of the equatorial anomaly, total decrease in the electron content in the equatorial anomaly a few days prior to the earthquake, increase in the electron concentration directly over the earthquake epicenter a few days prior to the earthquake, increase in the additional maximum at latitudes of ∼30° N, and formation of an additional maximum in the Southern Hemisphere in the region conjugated to the additional maximum in the Northern Hemisphere in the periods of its intensification are observed. The configuration of the equatorial anomaly is restored after the earthquake.

The first results of the pilot project on complex diagnosing earthquake precursors on Sakhalin

The results of the first stage of the pilot project on the complex monitoring of the atmospheric and ionospheric parameters, conducted on the instructions of the Russian Federation Government in order to decrease risk of destructive earthquakes in the Far East, are presented. The experiment was performed before and during a strong (M = 6.3) earthquake that occurred on August 2, 2007, on Sakhalin. The meteorological data (relative humidity and temperature), cloudiness anomalies according to the TERRA and AQUA satellite data, thermal anomalies of outgoing IR radiation according to the NOAA satellite data, variations in the total electron content according to the GPS data, and tomographic reconstructions of the ionosphere vertical structure according to the TRANSIT satellite data have been analyzed. The indications, typical of earthquake preparation and previously presented in the publications devoted to studying earthquake precursors, have been detected in all analyzed parameters. Synchronism and localization of the anomalies, registered using different methods in different geophysical fields, make it possible to assume that these anomalies have a common source, which could be the earthquake preparation process that is explained using the developed complex model of the lithosphere-atmosphere-ionosphere coupling (LAIC).

Broad-band hectometric emission in the topside ionosphere created by ground-based transmitters

Abstract The Appleton-Hartree magneto-ionic theory predicts that interference from ground-based transmitters can be registered at satellite orbiting above the F layer peak when foF2

GLOBAL DISTRIBUTION OF NIGHT-TIME F2 PEAK DENSITY (INTERCOSMOS-19 DATA)

Abstract Global distribution of the night-time F layer maximum electron density was obtained by topside sounding on board the INTERCOSMOS-19 satellite (1979–1981, high solar activity). These data were compared with those provided by reference CCIR and URSI models. The fact of the presence of large-scale stationary electron density inhomogeneities was established. Explanation of their appearance could be by traditional modes, such as longitudinal variations of aeronomical parameters, and possibly terrestrial source effects.

MODELLING BOTTOM AND TOPSIDE ELECTRON DENSITY AND TEC WITH PROFILE DATA FROM TOPSIDE IONOGRAMS

Abstract The paper describes the technique that has been implemented to model the electron density distribution above and below the F2 peak making use of only the profiles obtained from the INTERCOSMOS-19 topside ionograms. Each single profile from the satellite height to the ionosphere peak has been fitted by a semi-Epstein layer function of the type used in the DGR model with shape factor variable with altitude. The topside above the satellite height has been extrapolated to match given values of plasmaspheric electron densities to obtain the full topside profile. The bottomside electron density has been calculated by using the maximum electron density and its altitude estimated from the topside ionogram as input for a modified version of the DGR derived profiler that uses model values for the foF1 and foE layers of the ionosphere. Total electron content has also been calculated. Longitudinal cross sections of vertical profiles from latitudes 50° N to 50° S latitude are shown for low and high geomagnetic activity. These cross sections indicate the equatorial anomaly effect and the changes of the shape of low latitude topside ionosphere during geomagnetic active periods. These results and the potentiality of the technique are discussed.