Hydrological cycle in the Martian atmosphere general circulation numerical model MAOAM
We consider the numerical modeling problem formulation of the Martian atmosphere general circulation using the meteorology primitive equations approximate solution. We use model MAOAM (The Martian Atmosphere: Observation and Modeling) with a spectral dynamic kernel KMCM (Kühlungsborn Mechanistic general Circulation Model) as a basic model.
Hydrological cycle model is one of the essential components in modern Mars atmosphere general circulation models, for which, in turn, an aerosol unit and surface physics unit have been required. Primarily we were supposed to develop three-dimensional advection scheme (transfer) of a passive tracer atmospheric flows to create these units in such a way that numerical scheme hasn't lost conservatism with allowance water-ice phase transitions. In addition, it was necessary to develop the scheme for energy and matter (water and carbon dioxide) exchange between the atmosphere and the surface, as well as the deposited ice influence on the planet's surface physical parameters such as albedo and thermal inertia.
We have achieved sustainable model accounts for several Martian years during the implementation of the objectives, while maintaining stable and conservative scheme. We have investigated the hydrological cycle dependence on the initial conditions (the water vapor latitudinal gradient) and on the model parameters such as the ice particles sizes in 4 bins with different dust core nucleation sizes, affecting sedimentation, surface albedo and thermal inertia. Also it is using special schemes for nucleation, particle grows and vertical turbulent water diffusion. One of the modeling arising tasks from the observed data is the South Pole clouds mass increasing in the summer on the South Pole and the tropical belt clouds mass reducing in the aphelion season. These results were obtained thanks to the model parameters selection and to the using of the spectral numerical scheme, which has a smaller numerical viscosity and therefore provides a more intense meridional circulation, compared with the previously used grid scheme.