UPGOING ELECTRONS PRODUCED IN AN ELECTRON-PROTON-HYDROGEN ATOM AURORA

The first test of a self-consistent theory for the combined electron-proton-hydrogen (H) atom aurora is presented. Specifically, the upgoing differential electron flux that results from precipitating protons and electrons is modeled and compared to observations. The observations are from the Low Altitude Plasma instrument (LAPI) on board the Dynamics Explorer 2 satellite. Excellent agreement between data and theory is produced when a kappa distribution is used to extrapolate the observed proton spectra to energies beyond the instrument's energy cutoff (27 keV). More definitive tests of the model will require more comprehensive observations as well as improvements in available proton-H atom cross sections. However, it is concluded that data clearly supports the theoretical prediction that the secondary electron spectra due to precipitating protons and H atoms is much softer than that produced by precipitating electrons. Also, the implication that the incoming proton spectra have a high-energy power law tail raises the possibility that previous determinations of the total ion energy flux are too low.