Thermospheric winds and their influence on the ionosphere (review)

New results of observations and theoretical calculations of thermospheric winds in the upper atmosphere above 150 km are presented. The effects of the winds on the ionospheric F2-layer are considered in some detail. Many features of the F-layer behavior at middle and high latitudes during magnetically quiet conditions can be explained in terms of calculated winds using standard atmospheric models. At lower latitudes, however, calculations using model winds have not been successful in explaining the observed F-layer behavior. Special investigations using atmospheric models which take into account a variation of atmospheric composition and temperature during different seasons and increased geomagnetic activity were carried out. Thermospheric winds resulting from these models and their influence on the ionosphere are discussed.