Influence of Ionospheric Wind on the Formation of VLF/LF Anomalies Related to Earthquake Preparation

The influence of the ionospheric wind on internal gravity waves is considered. It is shown that interaction of wind in the ionosphere with the geomagnetic field leads to occurrence of the Ampére force, the vertical gradient of which modifies the properties of internal gravity waves. Such interaction results in the discrete spectrum of ionospheric fluctuations with the main period about 30 min. The increase in the Ampére force due to an electric field of seismic origin leads to the appearance of a maximum with shorter periods of about 10 and 22 min in the spectrum of ionosphere fluctuations. Observations of phase and amplitude fluctuation of a radio wave reflected from the ionosphere during increasing seismic activity are confirmed by the results of the considered model.