What is GEM-Mars?

GEM-Mars is a three-dimensional global climate model (GCM) used for the simulation of the present Martian atmosphere. The model is used to better understand the processes occurring in the atmosphere, as observed from satellites, rovers, and ground-based telescopes. By comparing the model simulations to observations of temperature and composition, we can enhance our understanding of the physical processes taking place in the Martian atmosphere.

The History of GEM-Mars

The foundation of the model is its "dynamical core". This is the discretisation of the equations of motion and describes how the air flows. For GEM-Mars, the dynamical core comes from the operational weather prediction model, GEM (GEM=Global Environmental Multiscale). 

GEM was first adapted to Mars at York University in 2005 and development continued for several years there under the name GM3 (Global Mars Multiscale Model). At the same time, GEM was adapted to include atmospheric chemistry of the Earth's troposphere (GEM-AQ for air quality). The parallel advancements in these experimental versions of GEM laid the groundwork for where the model is today. A collaboration began with BIRA-IASB a few years later and model development continues to progress here.

Where are we now?

 The current version of GEM-Mars is based on V4.2 of GEM. Work is ongoing with the adaptation of V5.2, which contains some major changes, including the definition of the horizontal grid.

The GCM includes the relevant physical processes such as CO2 condensation, planetary boundary layer mixing, gravity wave drag and surface parameterizations.  A water cycle, basic gas-phase chemistry and passive tracers are also included in the model. Dust and water ice clouds are "radiatively active", meaning they modify the temperature structure of the atmosphere. Because of the vertical extent of the model, UV heating, non-LTE effects, and molecular diffusion are also included.

Check out the latest applications and evaluations of GEM-Mars in the Publications tab.