A New Saturn Model of Ionospheric Transport and Electrodynamics (SMITE)

We introduce the Saturn Model of Ionospheric Transport and Electrodynamics (SMITE), a new model that incorporates inter-hemispheric plasma transport using a dipole magnetic field aligned grid, and a range of dynamic processes that influence Saturn's ionosphere. SMITE includes tunable parameters for inflow of exogenous material, seasonal and local time atmospheric variations, the ring shadow, and plasma transport driven by neutral winds and low latitude electrodynamics. SMITE is an adaptation of the terrestrial SAMI2 model, which has successfully reproduced numerous ionospheric phenomena at Earth. SMITE is the first model to show that strong plasma density gradients, such as those caused by Saturn's ring shadow in the winter hemisphere, drive inter-hemispheric field-aligned transport from the sunlit hemisphere to the winter hemisphere, which has previously been hypothesized from Cassini spacecraft measurements. In this presentation, we will show that SMITE can reproduce latitudinal trends in total electron content and altitudinal electron density distributions observed by the Cassini spacecraft, and will further present model-data comparisons between SMITE and in-situ measurements of Saturn’s ionosphere from the Cassini Grand Finale. We will also present model-data comparisons which show that diurnally variable low latitude electrodynamics may intermittently be active at Saturn.