Vertical Plasma Motions in the Dynamics of the Mesosphere and Lower Thermosphere of the Earth

Vertical motions of the medium in the mesosphere and lower thermosphere are one of the key factors in atmospheric dynamics. This paper discusses the results of a study of vertical motions as part of the dynamics of the ionosphere at altitudes of 60-130 km based on measurements of the parameters of its ionized and neutral components by the method of resonant scattering of radio waves on artificial periodic plasma inhomogeneities created when the ionosphere is exposed to high-power high-frequency radio emission. The results of measuring the vertical velocity of plasma (hereinafter referred to as the vertical velocity) under different natural conditions are presented. It has been found that its average values are mainly a few meters per second. The role of vertical transport in the altitude-temporal variations in the temperature and density of the neutral atmosphere in the specified altitude range is demonstrated. The parameters of atmospheric waves obtained from these variations are given. The effect of vertical velocity variations on the formation of the sporadic E layer (E-s) is studied. In many cases, the change in the direction of the vertical velocity took place at the height of the layer formation, and the magnitude of its vertical gradient is sufficient for the formation of midlatitude E-s layers observed in experiments on the SURA heating facility (56.1 degrees N, 46.1 degrees E). The study of atmospheric turbulence below the level of the turbopause showed that the velocity of turbulent motion at the heights of the mesosphere-lower thermosphere can be comparable with the velocity of regular vertical motion of the environment.