Structure of electrodynamic and particle heating in the undisturbed polar thermosphere

Abstract

This paper describes the variations in N2 densities in the polar regions above 400-km altitude as measured by the Ogo 6 neutral atmospheric composition experiment. These variations are magnetically controlled and have persistent features which are associated with localized heating effects. These are identified with electrodynamic and particle heating sources. Neutral N2 enhancements are a persistent feature in the polar cusp and postmidnight westward electrojet. Regions of the N2 density variability are localized in magnetic local time.