Modelling of the heating and ionizing of the polar thermosphere by magnetospheric electron and ion precipitation.

Energetic electrons and ions bombard the polar thermosphere, particularly in the region of the auroral oval. The energy flux and the spectral characteristics of the precipitation are highly variable in time and space, producing non-uniform heating and ionization in the polar regions. The physical and chemical processes responsible for producing ionization and heating are set forth with emphasis on the coupled nature of the various reactions. Parameterized results of detailed model computations are presented and applied to representative observational data.