Hydrogen and Oxygen Hot Ion Precipitation in the Martian Ionosphere

High energy H/H+ ion precipitation into Earth's upper atmosphere has previously been modeled (Fang et al., 2004; 2005). Recently, we have extended this work for the Martian ionosphere using different cross sections for relevant Martian "background" species. Additionally, we have included O+/O precipitation with the view to keeping track of secondary hot ions/neutrals in future work, which important for sputtering in the Martian upper atmosphere. Atmospheric effects of these precipitating hot ions in the Martian atmosphere are studied and reported on.