Large-scale atmospheric disturbances and plasma inhomogeneities in the topside ionosphere

The results of the satellite measurements of plasma density in the outer ionosphere are presented. It was shown that the appearance of large-scale plasma inhomogeneities in the mid-latitude and near-equatorial ionosphere may be caused by the influence of external sources (the solar radiation and charged particle fluxes, precipitating from the magnetosphere) and atmospheric disturbances on the ionosphere. Small-scale plasma structures may appear due to the electrostatic instability of large-scale plasma inhomogeneities. The temporal variations in the form of space scale spectra of plasma inhomogeneities may reflect the formation and instabilities of vortices in plasma irregularities.