Lomidze, L., Gudadze, N. and Didebulidze, G.
Georgian National Astrophysical Observatory (former Abastumani Astrophysical Observatory), Tbilisi, Georgia
It is found that the mid-latitude nighttime ionosphere F2 region electron density height distribution under the influence of a vortical perturbations excited in the horizontal shear flow (horizontal wind with horizontal linear shear) is characterised with a multi-layer structure. The atmospheric shear wave (vortical perturbations excited in the horizontal shear flow) property to transform into short-period atmospheric gravity waves (AGWs) is reflected in the oscillations of the peak heights of the ionosphere F2 region electron density. The analytical description for the ionosphere F2 region electron density height distribution was obtained by solving the ambipolar diffusion equation taking into account the presence of atmospheric shear waves. The peak height and the corresponding multi-layer F2 region electron density depend on the values of the meridional wind zonal shear and the shear wave vertical wavenumber. The oscillation of the atomic oxygen red 630.0 nm line total nightglow intensity with two different short-period AGW frequencies (observed mostly on magnetically disturbed days) is considered as a possible result of the appearance of a secondary maximum in the ionosphere F2 region electron density under the influence of atmospheric shear waves.