An Insolation Activated Dust Layer on Mars

Caroline de Beule, Gerhard Wurm, Thorben Kelling, Marc Koester, Miroslav Kocifaj
(Submitted on 21 Jul 2015)

The illuminated dusty surface of Mars acts like a gas pump. It is driven by thermal creep at low pressure within the soil. In the top soil layer this gas flow has to be sustained by a pressure gradient. This is equivalent to a lifting force on the dust grains. The top layer is therefore under tension which reduces the threshold wind speed for saltation. We carried out laboratory experiments to quantify the thickness of this activated layer. We use basalt with an average particle size of 67 μm. We find a depth of the active layer of 100 to 200 μm. Scaled to Mars the activation will reduce threshold wind speeds for saltation by about 10%.

Comments: 6 pages, 9 figures, accepted by Icarus
Subjects: Earth and Planetary Astrophysics (astro-ph.EP)
Journal reference: An insolation activated dust layer on Mars, Icarus, 260, 23-28 (2015)
DOI: 10.1016/j.icarus.2015.06.002
Cite as: arXiv:1507.05764 [astro-ph.EP] (or arXiv:1507.05764v1 [astro-ph.EP] for this version)
Submission history
From: Caroline De Beule
[v1] Tue, 21 Jul 2015 09:41:08 GMT (3590kb)
http://arxiv.org/abs/1507.05764