Expected Precipitating, Upflowing, and Mirroring Electron Spectra by Location, Geomagnetic and Ionospheric Conditions, and Precipitation Mechanism Proportions

Auroral electrons are one of the primary components of magnetosphere-ionosphere-thermosphere (MIT) coupling. Their precipitation, mirroring, interaction in the ionosphere and backscatter account for and affect many of the MIT coupling processes, ionospheric conditions, and IT chemistry. Realistic precipitating electron spectra are necessary for accurate modeling, while realistic related outflowing electrons are necessary to validate the models. Additionally, understanding electron characteristics and dependence on geomagnetic conditions is critical for understanding MIT coupling and dynamics. The FAST mission was specifically designed to investigate these populations and processes at high spatial, angular, and temporal resolutions, and computer processing has reached a level where the FAST data can be fully analyzed. We present the statistically expected effective spectra and variance of downgoing, upgoing, and mirroring electron populations by geomagnetic conditions and location utilizing data from the entire FAST mission. Since the electron populations can be anisotropic and this is not accounted for in most ionospheric models, the effective spectra are calculated. That is, the equivalent isotropic spectra over the entire loss cone that would result in the same downgoing or upgoing electron energy flux by energy as the actual distribution. We also provide the results, again by geomagnetic activity and location, of a new method of full mission FAST distribution electron data analysis that determines the wave scattered or directly precipitating population temperature, density and kappa values as well as the potential of any quasistatic potential structure (QSPS) present even when multiple precipitation mechanisms are occurring simultaneously and the QSPS potentials are low compared to the isotropic precipitation temperature.