Numerical Studies of Seasonal and Latitudinal Variability in a Model Thermosphere

Abstract

A numerical model of the diurnal pattern of heating and subsequent structural changes in the thermosphere has been used to investigate the seasonal and latitudinal variability of neutral atmospheric properties in that region. The model calculations indicate the requirement for poleward energy transport in middle and high latitudes at equinox and at all latitudes in the winter hemisphere at solstice. Maximum temperatures in the summer hemisphere at solstice occur at about 45 deg latitude. No explicit horizontal variability is permitted in the present model, and a comparison of the model results with the data available from satellite drag observations indicates that horizontal motions must be important in the determination of the phase and amplitude of the diurnal temperature oscillation and of the temperature structure at high latitudes during winter.