Model Studies of Ionosphere/Thermosphere Coupling Phenomena on Both Large and Small Spatial Scales and from High to Low Altitudes

Abstract

Significant progress has been made during the last decade with regard to our understanding of ionosphere-thermosphere coupling phenomena. However, the bulk of the modelling studies have been concerned with global-scale features and have been based on empirical (average) inputs for the important magnetospheric parameters (electric fields, particle precipitation, Birkeland currents, etc.). Therefore, the bulk of the studies pertain to the climatology of the ionosphere-thermosphere system, On the other hand, it is well known that the ionosphere-thermosphere system exhibits a considerable amount of structure. In the ionosphere, there are small-scale (≤1km), medium-scale (-10km), and large-scale (≥100km) density structures. The small-scale structures are generally produced on the edges of the larger structures via plasma instabilities and are called irregularities, while the medium- and large-scale structures are called blobs and patches. The extent to which these structures affect the global-scale coupling of the ionosphere and thermosphere is unknown. These and other ionosphere-thermosphere coupling issues will be discussed.