We use direct numerical simulation to examine a variety of atmospheric phenomena on Jupiter’s moon Io and try to match simulations to observations. We have developed a rarefied gas dynamic global circulation model of the entire atmosphere subject to time-variable boundary conditions, a 3D electron transport code to model auroral glows, and a 3D molecular-based model of the gas/dust dynamics in the giant volcanic plumes. I will present recent results from each area as well as how we have linked them together with a collaborative effort with a Penn State group who models 3D photon transport and QCT high energy chemistry.