Read more at: http://phys.org/news/2013-12-mars-giant-planetary.html#jCp
The surface of Mars is full of activity, with dust storms, dust devils, and drifting dunes in constant motion. Scientists suspect that similarly rich activity may exist underneath the surface, even though it has never been seen. Now in a new study, scientists have found that Mars' low-pressure atmosphere and porous soil provide the perfect conditions for the planet's entire surface to act as a giant gas pump, quickly cycling gas and dust particles a few centimeters above and below the soil.
No analogue of this type of planet-wide pump exists on Earth. In fact, the scientists think that Mars is the only body in the Solar System on which such large-scale, continuous pumping can naturally occur. If it does indeed occur as theorized, the pumping might serve as a dominant mechanism for transporting water vapor across Mars' surface.