Радиофизика и электроника (Mar 2019)
SHIFT OF ANTIPODE MAXIMUM OF ELECTRIC FIELD IN THE RESONATOR THE EARTH–IONOSPHERE CAVITY CAUSED BY DAY–NIGHT NON-UNIFORMITY
Abstract
Subject and purpose of the work. In the present work, the perturbations are simulated of the amplitude of the vertical electric and horizontal magnetic fields of global electromagnetic (Schumann) resonance caused by the local ionosphere disturbance over the earthquake center with an account for the day–night non-uniformity. The source and the receiver are located at the same meridian symmetrically with respect to the equator at the points with coordinates 22.5° N and 22.5° S respectively. Position of the propagation paths is fixed relative the morning terminator: on its night (60° E) or the dayside (120° E). Variations of the amplitudes perturbation of the fields are considered when the localized non-uniformity moves along or across the propagation path. Methods and methodology. To determine the propagation parameters of extremely low frequency (ELF) radio waves, the full wave solution is used, which leads to the solution of the Riccati equation. The spectral components of the fields are found numerically using the two-dimensional telegraph equation. The results of the work. Numerical estimates are obtained of the influence of the local non-uniformity of the ionosphere on the amplitude of the electric and magnetic fields at different frequencies in the global electromagnetic (Schumann) resonance band for different positions of disturbance relative the propagation path located at the night or the dayside of the morning terminator. Conclusion. The influence of localized non-uniformity on the field amplitude increases with frequency. Field modifications in the presence of a local disturbance are of the interference nature due to interaction of the direct and the reflected from the local inhomogeneity radio waves. The day-night regular non-uniformity of the ionosphere plays a minor role and its influence might be neglected.
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