Relation of Traveling Ionospheric Disturbances Characteristics with Planetary Waves in the Middle Atmosphere

For the first time, based on long-term data of the SuperDARN radar (Hokkaido, 2007-2014), the influence of planetary waves in the middle atmosphere on short-period (~1-4 hours) disturbances in the ionosphere was revealed, and the mechanism of such influence was suggested. It was found, that the strongest variations in the zonal wind velocity at 60°N, 10 hPa correspond to the most significant changes in the distributions of TIDs azimuth. To formalize the task, methods for the numerical estimation of the disturbances of TIDs azimuth distributions and the zonal wind velocity variations, were developed. Comparison of TID distributions on time and azimuth with neutral wind projections distributions was done, which made it possible to suggest the following mechanism. Planetary waves (not necessarily associated with the reversal of the zonal wind) lead to changes of the neutral wind in the mesopause, which leads to changes of TID propagation directions blocked by the neutral wind.