The study of Martian dunes to help better model the global climate circulation of Mars
Dune systems provide unique information about wind regimes on the surface of planetary bodies where there are no direct meteorological data as on Earth. On Mars, in the Olympia Undae region near the northern polar cap, the orientation of the dunes and their sedimentary cover was measured using satellite imagery provided by NASA's Mars Reconnaissance Orbiter probe by a team of researchers from the Institut de Physique du Globe de Paris.
Publication date: 26/04/2018
General public, Press, Research
Related teams :
Geological Fluid Dynamics, Planetology and Space Sciences
Related themes : Earth and Planetary Interiors
For the first time, analysis of these data has revealed a relationship between sediment availability, i.e. the supply of sand grains, and the orientation of dune structures (dune crests). This study highlights two modes of transition: an abrupt one and a gentle one, corresponding respectively to dunes that migrate towards an aeolian sediment accumulation basin and dunes that eject from it. Using these new observations and a model of dune morphodynamics, the researchers solved the inverse problem, enabling them to trace the wind conditions that explain the measurements. From these results, the study shows that variations in surface albedo on the edges of the Martian polar cap are responsible for strong gradients in wind dynamics that are not currently modelled in global climate circulation (GCM) models. In this way, the researchers have developed a new method for constraining wind regimes at the surface of Mars, thereby helping climatologists to better model the climate on planets with an atmosphere.
Ref: EPSL Article – L. Fernandez-Cascales, A. Lucas, S. Rodriguez, X. Gao, A.Spiga, C.Narteau, First quantification of relationship between dune orientation and sediment availability, Olympia Undae, Mars, Earth and Planetary Science Letters, Volume 489, 1 May 2018, Pages 241-250
