Recent discoveries on Mars suggest ice may be or recently was present at latitudes where it is not expected and at unexplained abundance. As ice may be unstable under present Martian climatic conditions, a mechanism may be needed to explain the presence of ice in the near surface at these latitudes. Water release history, chemical composition, and heat fluxes are variable over the surface of Mars, and there could be more than one mechanism responsible for near-surface ice. The purpose of this numerical modeling study is to show that thermochemical circulation of brines in the subsurface of Mars is a possible mechanism that can deposit ice and brine, close to, or even at, the surface of Mars.
Numerical simulations indicate that brine convection can occur over a range of parameter values. Furthermore, the action of brine convection can be related to some of the surface features associated with subsurface water and ice during previous or even present epochs, such as polygonal ground and sorted stone circles. The numerical simulator developed for this study is versatile; besides Mars, it has been applied to other cold environments, such as asteroids and water moons, where fluid circulation may be or may have been a factor in the dynamics of such bodies.