气候变化领域集成服务门户(CCPortal): Experimentally Derived Thresholds for Windblown Sand on Mars

CCPortal

DOI	10.1029/2019GL084484
	Experimentally Derived Thresholds for Windblown Sand on Mars
	Swann C.; Sherman D.J.; Ewing R.C.
发表日期	2020
ISSN	0094-8276
卷号	47 期号:3
英文摘要	Aeolian sand transport frequently occurs on Mars despite wind speeds rarely exceeding predicted thresholds for motion. This dissonance is problematic for understanding aeolian processes and the resulting geomorphologic responses in contemporary and ancient atmospheres. To address the apparent discrepancy between speeds required to initiate sand motion and transport observed from orbital and in situ observations, we conducted a series of wind tunnel experiments at Martian atmospheric pressures and used buoyancy as the similitude parameter to simulate the force required to initiate particle motion on Mars. Shear velocities were derived from velocity profiles corresponding to the onset of sporadic transport, which can induce downwind cascading motion. Here, we find that threshold shear velocities are slower than previously thought by a factor of 1.6 to 2.5. Measured wind speeds on Mars exceed our observed thresholds, thus offering one mechanism behind the dissonance between observations of transport below previous thresholds of motion. ©2019. The Authors.
英文关键词	Atmospheric pressure; Shear flow; Wind; Wind tunnels; Aeolian transport; cascading transport; In-situ observations; mars; Particle motions; threshold of motion; Velocity profiles; Wind tunnel experiment; Transport properties; buoyancy; eolian process; Mars; particle motion; threshold; wind tunnel
语种	英语
来源期刊	Geophysical Research Letters
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/170757
作者单位	Sediment Dynamics Section, Seafloor Sciences Branch, Marine Geosciences Division, U.S. Naval Research Laboratory, Stennis Space CenterMS, United States; Department of Geography, University of Alabama, Tuscaloosa, AL, United States; Department of Geology and Geophysics, Texas A&M University, College Station, TX, United States
推荐引用方式 GB/T 7714	Swann C.,Sherman D.J.,Ewing R.C.. Experimentally Derived Thresholds for Windblown Sand on Mars[J],2020,47(3).
APA	Swann C.,Sherman D.J.,&Ewing R.C..(2020).Experimentally Derived Thresholds for Windblown Sand on Mars.Geophysical Research Letters,47(3).
MLA	Swann C.,et al."Experimentally Derived Thresholds for Windblown Sand on Mars".Geophysical Research Letters 47.3(2020).