Journal ArticleDOI
A two-species model of aeolian sand transport
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TLDR
In this article, a model based on a discrete number of states is derived, which solves the problems of self-consistent and unstable solutions to the transport of sand by wind, which results from the equilibrium between the erosion of grains dragged by the flow and the resulting slow down of the wind velocity.Abstract:
The transport of sand by wind results from the equilibrium between the erosion of grains dragged by the flow and the resulting slow down of the wind velocity. The dynamical mechanisms governing the saturation of the sand flux are investigated theoretically. We first demonstrate that previous models, based on the assumption that all the grains have the same trajectory, are either not self-consistent or lead to unstable solutions. A model based on a discrete number of states is derived, which solves these problems. Two well-defined species of grain appear, which correspond to saltons (high-energy grains) and reptons (grains ejected from the sand bed by the impact of saltons). They play specific roles: the negative feedback of the transport on the wind is limited to the reptation layer while most of the transport is due to saltation. The model is further simplified, benefiting from the existence of these two species and the dependencies of the threshold velocity, the saturated flux, the aerodynamic roughness and the saturation length are derived and compared to experimental measurements.read more
Citations
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Journal ArticleDOI
Predicting aeolian sand transport rates: A reevaluation of models
Douglas J. Sherman,Bailiang Li +1 more
TL;DR: In this article, eight aeolian sand-transport models are evaluated using a field data set and a new approach to estimate shear velocities using wind profile data (log-linear slope) with the von Karman constant and with the apparent vonKarman parameter and the results of different approaches are evaluated based on comparison of regression statistics and RMS error.
Journal ArticleDOI
Aeolian sand ripples: experimental study of fully developed states.
TL;DR: Investigating the evolution of an initially corrugated bed, it is shown that both initial and final wavelengths, as well as the propagative speed of the ripples, are linear functions of the wind velocity.
Journal ArticleDOI
Does the size distribution of mineral dust aerosols depend on the wind speed at emission
Jasper F. Kok,Jasper F. Kok +1 more
TL;DR: In this article, the size distribution of mineral dust aerosols is investigated using a compilation of published measurements of the size-resolved vertical dust flux emitted by eroding soils, and it is shown that the size of naturally emitted dust aerosol is independent of the wind speed.
Journal ArticleDOI
Barchan dune corridors: Field characterization and investigation of control parameters
TL;DR: In this article, the structure of the barchan field located between Tarfaya and Laayoune (Atlantic Sahara, Morocco) is quantitatively investigated and compared to that in La Pampa de la Joya (Arequipa, Peru).
Posted Content
Bedforms in a turbulent stream.Part 2: Formation of ripples by primary linear instability and of dunes by non-linear pattern coarsening
TL;DR: In this paper, the relationship between the wavelength at which ripples form and the flux saturation length is quantitatively derived, and experimental data is used to determine the saturation length as a function of grain size and shear velocity.
References
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Book
The Physics of Blown Sand and Desert Dunes
TL;DR: The physics of blown sand and desert dunes, The physics of windblown sand and sand dunes, this paper, and the physics of dunes in the Middle East and Africa.
Journal ArticleDOI
The Physics of Blown Sand and Desert Dunes
TL;DR: Bagnold as mentioned in this paper described his travels in the Egyptian and Libyan Deserts, and combined the results of experimental research in a wind tunnel with personal observations in the desert, and the explanations of many desert features vitally affecting such operations will interest a wide range of readers.
Journal ArticleDOI
Saltation of uniform grains in air
TL;DR: In this paper, the interaction between a turbulent wind and the motion of uniform saltating grains of sand or soil, so massive as to fail to enter into suspension, is examined on the basis of two complementary hypotheses.
Journal ArticleDOI
Soil Transport by Winds on Mars
TL;DR: In this paper, a semi-empirical formula is developed for estimating the total amount of surface material moving in eolian saltation, surface traction, and suspension on the surface of Mars, and the ratio of final particle speed to the particle threshold friction speed is found to be several times that of saltation on earth.
Book ChapterDOI
Wind modification and bed response during saltation of sand in air
Robert S. Anderson,Peter K. Haff +1 more
TL;DR: In this article, a model of eolian sediment transport was constructed, which is a special case of sand-sized mineral grains subjected to moderate winds: saltation, and the model consists of four compartments corresponding to aerodynamic entrainment, grain trajectories, grain-bed impacts, and momentum extraction from the wind.