Dynamics of the Earth's thermosphere

The earth's thermosphere is that region of the atmosphere above the mesopause (80–90 km) where the neutral gas temperature begins to increase from about 200°K to values as high as 600–2,000°K depending upon solar activity. The dynamics of this region of our atmosphere is primarily governed by solar EUV and UV heating, heat and momentum sources associated with high‐latitude auroral processes, upward‐propagating tides and waves from the lower atmosphere, and ion drag interactions with the ionosphere. The general properties of the thermosphère and the research on thermospheric dynamics prior to 1979 have been reviewed previously in this IUGG series by Dickinson (1975) and Mayr and Harris (1979). Ionospheric processes and large‐scale neutral gas‐plasma interactions have been reviewed by Evans (1975), and reviews covering thermospheric composition have been given by Carrignan (1975) and Hedin (1979).