干旱区生态环境知识资源中心(Arid): Scaling Laws in Aeolian Sand Transport Under Low Sand Availability

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DOI	10.1029/2022GL097767
	Scaling Laws in Aeolian Sand Transport Under Low Sand Availability
	Kamath, Sandesh; Shao, Yaping; Parteli, Eric J. R.
通讯作者	Kamath, S
来源期刊	GEOPHYSICAL RESEARCH LETTERS
ISSN	0094-8276
EISSN	1944-8007
出版年	2022
卷号	49 期号:11
英文摘要	Previous studies of wind-blown sand have considered either fully erodible or non-erodible soils, but the transport over sparsely sand-covered soils is still poorly understood. The quantitative modeling of this transport is important for parameterizing Aeolian processes under low sand availability. Here we show, by means of numerical simulations, that the sand transport rate Q scales with the wind shear velocity u() as Q = a center dot [1 + b center dot(u()/u()t - 1)]center dot root d/g center dot rho(f)center dot(u()(2) - u(t)(2)), where u(t) is the minimal threshold u() for sustained transport, d is particle size, g is gravity and rho(f) is air density, while u(t) and the empirical parameters a and b depend on the sand cover thickness. Our model explains the transition from the quadratic to cubic scaling of Q with u(*) as soil conditions change from fully erodible to rigid and provides constraints for modeling Aeolian transport under low sand availability. Plain Language Summary The transport of sand by wind shapes the Earth's surface and constitutes one major factor for the emission of dust aerosols. The accurate modeling of wind-blown sand transport is thus important to achieve reliable climate simulations and to make predictions about the propagation of desertification. Previous models of wind-blown sand were designed to compute sand transport rates over a thick sand layer, such as the surface of large, active sand dunes. However, natural soils encompass a broad range of low sand availability conditions, such as crusted or bare soils. It has been a long-standing open question how wind-blown sand transport rates respond to wind velocity when the bare ground is covered by a thin layer of sand. Here we calculate the trajectories of wind-blown sand grains and find that sand transport rates increase faster with wind speed under low sand availability conditions than over sand dunes. The reason for this behavior is elucidated in our simulations: The hopping sand grains fly higher the less sand is covering the hard surface. We obtain mathematical expressions for the sand transport rates as a function of the thickness of sand covering the bare soil, which will be important to improve climate models.
英文关键词	Aeolian sand transport discrete element method limited sediment supply saltation
类型	Article
语种	英语
开放获取类型	hybrid, Green Published
收录类别	SCI-E
WOS记录号	WOS:000806208100001
WOS关键词	CONTACT-FORCE MODELS ; SALTATION ; PARTICLES ; SIMULATIONS ; COLLISIONS ; DUNES
WOS类目	Geosciences, Multidisciplinary
WOS研究方向	Geology
资源类型	期刊论文
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/392949
推荐引用方式 GB/T 7714	Kamath, Sandesh,Shao, Yaping,Parteli, Eric J. R.. Scaling Laws in Aeolian Sand Transport Under Low Sand Availability[J],2022,49(11).
APA	Kamath, Sandesh,Shao, Yaping,&Parteli, Eric J. R..(2022).Scaling Laws in Aeolian Sand Transport Under Low Sand Availability.GEOPHYSICAL RESEARCH LETTERS,49(11).
MLA	Kamath, Sandesh,et al."Scaling Laws in Aeolian Sand Transport Under Low Sand Availability".GEOPHYSICAL RESEARCH LETTERS 49.11(2022).