Saltation under Martian Gravity and its Influence on the Global Dust Distribution

Grzegorz Musiolik, Maximilian Kruss, Tunahan Demirci, Björn Schrinski, Jens Teiser, Frank Daerden, Michael D. Smith, Lori Neary, Gerhard Wurm
(Submitted on 26 Jan 2018)

Dust and sand motion are a common sight on Mars. Understanding the interaction of atmosphere and Martian soil is fundamental to describe the planet’s weather, climate and surface morphology.

We set up a wind tunnel to study the lift of a mixture between very fine sand and dust in a Mars simulant soil. The experiments were carried out under Martian gravity in a parabolic flight. The reduced gravity was provided by a centrifuge under external microgravity. The onset of saltation was measured for a fluid threshold shear velocity of 0.82±0.04 m/s. This is considerably lower than found under Earth gravity.

In addition to a reduction in weight, this low threshold can be attributed to gravity dependent cohesive forces within the sand bed, which drop by 2/3 under Martian gravity. The new threshold for saltation leads to a simulation of the annual dust cycle with a Mars GCM that is in agreement with observations.

Subjects:    Earth and Planetary Astrophysics (astro-ph.EP)
DOI:    10.1016/j.icarus.2018.01.007
Cite as:    arXiv:1801.08787 [astro-ph.EP] (or arXiv:1801.08787v1 [astro-ph.EP] for this version)
Submission history
From: Grzegorz Musiolik
[v1] Fri, 26 Jan 2018 12:52:18 GMT (5219kb)
https://arxiv.org/abs/1801.08787