Polarisation of electromagnetic waves in the ionosphere containing anisotropic conductivity

Acta physica Academiae Scientiarum Hungaricae -     

Field-aligned scattering of HF radio waves under conditions of action of high-power oblique radio waves on the ionosphere

We present the results of experimental studies of the features of field-aligned scattering of HF radio waves for different angles of incidence of high-power radio waves on the ionosphere. The amplitude, Doppler frequency shift, and azimuthal and vertical arrival angles of the scattered signals are measured. Calculated ray paths in the magnetoactive ionosphere are compared with experimental data on the scattered-signal reception under conditions of action of high-power oblique radio waves on the ionosphere. __________ Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 50, No. 8, pp. 669–677, August 2007.     

Singlet molecular nitrogen in the Auroral ionosphere and under the conditions of laboratory discharge

Using the suggested model of the electron kinetics of N₂ singlet states, the population of the vibrational levels in the molecular nitrogen states (a′)¹Σ _u ⁻, a ¹Π _g , and w ¹Δ _u is calculated for the case when fast auroral electrons penetrate into the Earth’s ionosphere. It is shown for the first time that the population distribution of the vibrational levels v = 0−6 in the state a ¹Π _g in the auroral ionosphere and also in a laboratory discharge varies with atmospheric pressure insignificantly. Similar calculations for pure nitrogen atmosphere show a considerable increase in the populations of lower vibrational levels (v = 0−2) with rising pressure.     

Hybrid surface waves under conditions of reflection transformation of waves

It was shown that hybrid surface waves can exist at the magnetoactive plasma-vacuum interface, which is caused by the phenomenon of reflection transformation of waves.     

Wave ionosphere perturbations with small periods under magnetic storm conditions

The characteristics of total electron content (TEC) variations obtained using the data of middle-latitude stations for receiving GPS satellite signals were studied. An analysis showed that perturbations of diurnal TEC variations during a geomagnetic storm were determined by strengthening of harmonics with periods of 4–5 and 6–8 h. Perturbations in diurnal TEC variations were retained for several days after a geomagnetic storm. An analysis of the frequency and amplitude characteristics of perturbed variations showed that differences between variations at different latitudes could be explained by the propagation of Poincaré planetary waves in an atmospheric wave channel. The atmospheric channel was formed because of increased heating of pole regions during geomagnetic storms. A comparative analysis of observations made at different stations was used to estimate the width of the atmospheric channel and Poincaré wave frequencies and wave vector components.     

Scattering of electromagnetic waves by traveling-wave structures in the ionosphere

The diffraction of electromagnetic waves, incident obliquely on an ionospheric layer with density inhomogeneities of the traveling-wave type, is investigated by S. M. Rytov's method of smooth perturbations. The spatial dependencies of the properties of the ionosphere and of the wavelike inhomogeneities are taken into consideration. The diffraction patterns are analyzed for several variants of height profiles of the wave perturbations. The solutions obtained make it possible to estimate the effect of the form of ionospheric profile and the distribution of the level of disturbance of the wavelike inhomogeneities with respect to altitude on the diffraction effects.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 21, No. 12, pp. 1717–1727, December, 1978.The author expresses his appreciation to V. N. Krasil'nikov for attention and advice.     

Plasma waves near the double resonance layer in the ionosphere

Dispersion properties of plasma waves with frequencies close to the upper hybrid frequency _u and the multiple electron cyclotron frequency n_Be (double resonance) are considered for an inhomogeneous plasma with opposite gradients of the electron density and magnetic field magnitude. We show that a region of possible solutions of the dispersion relation decreases in real space as well as in wave vector space as of the wave frequency approaches double resonance. The results are applied to an interpretation of experiments on ionospheric modification by high-power radio waves with frequencies close to n_Be.Radiophysical Research Institute, Nizhny Novgorod, Russia. Swedish Institute of Space Physics, Uppsala Division, Sweden. Swedish Institute of Space Physics, Kiruna Division, Sweden. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 37, No. 5, pp. 617–633, May, 1994.     

Nonlocal nonlinear interaction of HF waves with the ionosphere

We analyze the behavior of an HF wave beam near the peak of the F₂ layer of the ionosphere taking into account the electron diffusion. The formulation of the problem is presented and its numerical solution is obtained in a physically reasonable approximation. Institute for Terrestrial Magnetism, Ionosphere, and Radio Wave Propagation (IZMIRAN), Troitsk, Moscow region, Russia. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 42, No. 7, pp. 700–703, July 1999.