J. Geophys. Res http://dx.doi.org/10.1029/2010JE003792 (2011)

Credit: © NASA-JPL

The highlands of Mars are scarred with channels that seem to have been formed by liquid water. Numerical simulations suggest that precipitation during local storms around three billion years ago could have created some of these patches of fluvial erosion.

Edwin Kite of the University of California, Berkeley, and colleagues used an atmospheric numerical model to simulate the influence of short-lived lakes formed by vast groundwater floods on the local atmosphere of the northern Valles Marineris. In their simulations, evaporation of water from the lakes generated local storm clouds. And precipitation from the clouds, in the form of snow, settled downwind from the lakes. The simulated area of maximum snowfall correlates well with the eroded channel networks.

The researchers suggest that snow storms fed by lake water could generate highly localized erosion in the Valles Marineris region, while other parts of the planet remained dry.