Preliminary ozone distribution on Mars using the Global Mars Multiscale Model (G3M)

Ozone is an important oxidant in the Martian atmosphere. However, it does not provide a shielding of the surface from UV radiation below 300 nm as on the Earth. Combined with water vapour it is also an important source of HOx radicals which appear to play an important role in determining the chemical stability of the Mars atmosphere. Using the G3M (Global Mars Multiscale Model) as a host we have added chemistry modules and investigate the global distribution of ozone in the Martian atmosphere. The underlying dynamical framework is based on the Global Environmental Multiscale (GEM) model developed by the Meteorological Service of Canada and employs a SL/SI dynamical framework. G3M includes comprehensive physics and has been extended to over 150 km and can be run in global uniform resolution or in zoom mode with high interior resolution. The version that we will present has a top at 150 km with uniform horizontal resolution. The chemistry added is fueled by photolysis of CO_2, water vapour, ozone and related products. Long-lived chemical species are subject to transport by the resolved circulation and by diffusion within the PBL. At present we have not included heterogeneous chemistry. We will present seasonal distributions of ozone and compare with the limited available observations.