Radio Physics and Radio Astronomy (Mar 2019)
MANIFESTATIONS OF WAVE PROCESSES IN IONOSPHERIC PLASMA PARAMETERS DURING THE GEOSPACE STORM ON 1–3 SEPTEMBER, 2016
Abstract
Purpose: Analysis of wave processes during the geospace storms in the mid-latitude ionosphere, obtaining the height-temporal dependences of relative variations of the incoherent scattering radar signal power, temperatures of electrons and ions, calculation of the parameters of traveling ionospheric disturbances – relative amplitudes, vertical and and horizontal components of phase velocity (Vz and Vh) and wavelengths (Λz и Λh). Design/methodology/approach: In obtaining the results, the spectral analysis using the Аdaptive Fourier Transform was used. Then the data were subjected to band-filtering using a digital filter. Phase rates of perturbations were determined by the cross-correlation analysis of temporal variations in signal strength. Findings: It was established that the observed storm, during which the geomagnetic activity index was reaching the value of Kp = 6, contributed to the enhancement of acoustic-gravity waves and traveling ionospheric disturbances. The spectral analysis showed that the periods of prevailing oscillations were in the range of 60-100 min, with the duration of no more than two periods. The signal power relative amplitudes varied within 0.02-0.2, and relative amplitudes of electron and ion temperatures – within 0.03-0.12. It was demonstrated that the values of amplitudes of quasigarmonic variations in signal power on September 1 and 2, 2016 approximately 2 times exceeded those in the adjacent days when the Kp -index was lower. It is shown that Vz = 26-50 m/s, Vh = 210÷455 m/s and Λz = 120-290 km, Λh = 1075-2450 km. Conclusions: The disturbances in the ionosphere were found at altitudes of 150-400 km, with the extension of their vertical group velocities upwards. The values of parameters of disturbances obtained in data processing indicate that large-scale traveling ionospheric disturbances took place at the observation day. Possible sources of such waves are Joule heating, the Lorentz force effect and eruption of energetic particles.
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