Global 3D modeling of the atmosphere of Mars
GEM-Mars is a 3D general circulation model (GCM) for the atmosphere of Mars which describes the meteorology, circulation, dust, clouds, water, polar caps, radiation, and atmospheric chemistry from the surface up to 170 km altitude.
It applies the dynamical core of the Global Environmental Multiscale model (GEM) which is the standard weather forecast model of Environment Canada.
GEM-Mars is applied at BIRA-IASB, for instance:
In the BRAIN-Be project MAGICS (Mars Atmosphere Global Interactive Chemistry Simulator), the chemistry of the GEM-Mars model was extended with reactions involving methane. This will be important for the interpretation of measurements by NOMAD.
The animation above shows the simulation of a plume of methane released from Nili Fossae just before the northern hemisphere autumn (around Ls = 150). After around 10 martian days (or sols), the plume has encircled the globe and formed a layer at around 20 km height. After 20 sols, the methane is dispersing but a layer is still visible above 40 km. (Simulation data from Viscardy et al., 2016)
The GEM-Mars model has been used to examine dust in the Mars atmosphere as observed with the LIDAR instrument on the Phoenix lander. Back trajectories calculated from the model show that the air parcel measured had previously passed through a dust cloud. The model simulations showed that the air was ascending under the influence of the solar radiation heating up the dust in the air parcel, a process call a "solar escalator" that was previously observed on Earth as well. (From Daerden et al., 2015)