MARTIAN AEOLIAN SYSTEMS
1) In the great northern polar sand sea, Ewing et al. (2010) used pattern analysis to show that at least one part of the vast Olympia Undae was produced in two constructional events. An older, well-organized generation of transverse dunes, formed by circumpolar easterly winds, is slowly being reworked by a new influx of sand eroding from the edge of the nearby polar cap.
2) Deep in Ganges Chasma, an offshoot of the extensive Valles Marineris, lie several dune fields and sand sheets. The largest, with an area of ~400 km2, abuts a ~5 km high scarp. Combined application of the principle of maximum gross bedform-normal transport (MGBNT) and a mesoscale atmospheric model shows that sand converged upon this spot from four directions, under transport-limited conditions.
3) Meridiani Planum is a flat plain pocked by impact craters. The plains are covered by coarse-grained ripples, whereas TARs and dark dunes formed on the crater floors. Pattern and MGBNT analysis reveals four generations of bedform construction within ~300 Ma, each formed by a distinct wind regime. Uniform bedform size suggests the coarse-grained ripples formed from erosion of the ~3 billion year sediments which they superpose. Bedform construction occurred during brief transport-limited conditions that likely correspond to variations in climate.