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
Vertical distribution of grain size for wind blown sand
TL;DR: Grain size-sorting characteristics from twenty-five vertical, mass-flux profiles for a mixed grain population were presented from a field study conducted in Jericoacoara, Brazil as mentioned in this paper.
Journal ArticleDOI
Evidence for indurated sand dunes in the Martian north polar region
Volker Schatz,Haim Tsoar,Kenneth S. Edgett,Eric J. R. Parteli,Hans J. Herrmann,Hans J. Herrmann +5 more
TL;DR: In this article, the authors investigated the relevance of induration as an explanation for the occurrence of dunes of unusual morphology in the Martian north polar region, and provided evidence for induration of aeolian deposits on Mars.
Journal ArticleDOI
Bedform migration on Mars: Current results and future plans
TL;DR: In this article, the authors used high-resolution HiRISE data, with a pixel scale as fine as 25 cm, shows displacements of sand patches, dunes and ripples up to several meters per Earth year, demonstrating that significant landscape modification occurs in the current environment.
Journal ArticleDOI
Dune formation on the present Mars.
TL;DR: It is found that different dune shapes as those imaged by Mars Global Surveyor could have been formed by the action of sand-moving winds occurring on today's Mars, but calculations show that Martian dunes could be only formed due to the higher efficiency of Martian winds in carrying grains into saltation.
Journal ArticleDOI
Martian Aeolian Activity at the Bagnold Dunes, Gale Crater: The View from the Surface and Orbit
Nathan T. Bridges,Nathan T. Bridges,Ryan C. Sullivan,Claire E. Newman,Sara Navarro,J. Van Beek,Ryan C. Ewing,F. Ayoub,Simone Silvestro,Olivier Gasnault,S. Le Mouélic,Mathieu G.A. Lapotre,William Rapin,William Rapin +13 more
TL;DR: The first in situ investigation of an active dune field on another planetary surface occurred in 2015-2016 when the MSL Curiosity rover investigated the Bagnold Dunes on Mars.
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.