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Zusammenfassung:
This study provides unique results, which will supplement our knowledge about sources of traveling ionospheric disturbances (TIDs) and contribute to a more accurate creation of regional and global models.
By using data recorded at Kharkiv incoherent scatter radar (49.6° N, 36.3° E), the statistical features of different TIDs types occurrence were analyzed. Data obtained near the equinoxes and solstices during the period of the 24th Solar Cycle were processed. The disturbances with the main periods of 40 - 90 min, relative amplitudes varied between 0.05 - 0.4 and a duration of 2 - 5 periods that extended at altitudes of 100 to 300 km were observed . Vertical and horizontal components of phase velocity (Vz and Vh), as well as wavelengths (Λz, Λh) were estimated. The results showed that the parameters and occurrences of large-scale (LS) and medium-scale (MS) TIDs had obvious dependence on geomagnetic conditions and levels of solar activity. Also, regularly disturbances associated with the morning and evening solar terminators passage have been recorded. Furthermore, TIDs during the period from sunset to evening were stronger. Time intervals for the disturbances existence relative to the season were determined. The greatest number of TIDs were observed near winter solstices and autumnal equinoxes. These disturbances were more intense than in other seasons.
