  We present an empirical model for auroral (90--150 km) electron--ion pair
production rates, ionization rates for short, derived from SSUSI (Special
Sensor Ultraviolet Spectrographic Imager) electron energy and flux data. Using
the Fang et al., 2010 parametrization for mono-energetic electrons, and the
NRLMSISE-00 neutral atmosphere model, the calculated ionization rate profiles
are binned in 2-h magnetic local time (MLT) and 3.6$^{\circ}$ geomagnetic
latitude to yield time series of ionization rates at 5-km altitude steps. We
fit each of these time series to the geomagnetic indices Kp, PC, and Ap, the
81-day averaged solar F$_{\text{10.7}}$ radio flux index, and a constant term.
The resulting empirical model can easily be incorporated into coupled
chemistry--climate models to include particle precipitation effects.
