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arXiv 1801.08787astro-ph.EP
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火星重力作用下的跃移及其对全球尘埃分布的影响

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

摘要:

沙尘暴是火星上常见的景象。了解大气和火星土壤的相互作用是描述火星天气、气候和表面形态的基础。我们建立了一个风洞来研究火星模拟土壤中非常细的沙子和灰尘之间的混合物的升力。这些实验是在火星重力下进行的抛物线飞行。在外部微重力下,通过离心机提供降低的重力。对于0.82 $\pm$ 0.04 m/s的流体阈值剪切速度,测量跃变的开始。这比在地球引力下发现的要低得多。除了重量的减少,这种低阈值可以归因于重力依赖的cohesion内聚力内的砂床,下降了2/3的火星重力。新的跃移阈值导致模拟的年度尘埃循环与火星大气环流模式,是在协议的意见。

英文摘要:

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$\pm$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.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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