منابع مشابه
Giant saltation on Mars.
Saltation, the motion of sand grains in a sequence of ballistic trajectories close to the ground, is a major factor for surface erosion, dune formation, and triggering of dust storms on Mars. Although this mode of sand transport has been matter of research for decades through both simulations and wind tunnel experiments under Earth and Mars conditions, it has not been possible to provide accura...
متن کاملSaltation transport on Mars.
We present the first calculation of saltation transport and dune formation on Mars and compare it to real dunes. We find that the rate at which grains are entrained into saltation on Mars is 1 order of magnitude higher than on Earth. With this fundamental novel ingredient, we reproduce the size and different shapes of Mars dunes, and give an estimate for the wind velocity on Mars.
متن کاملSaltation impact as a means for raising dust on Mars
Experiments were conducted under atmospheric pressures appropriate for Earth and Mars to determine the e,ciency of sand in saltation as a means for raising dust into the atmosphere under wind speeds which would otherwise be too low for dust entrainment. Experiments involving intimate mixtures of sand and dust (1:1 ratio by mass) showed that after an initial .urry of activity of a few seconds du...
متن کاملPlant Canopy Effects on Wind Erosion Saltation
Maintaining standing vegetative soil cover is an important method of wind erosion control. However^ an improved physical understanding of the mechanisms by which standing vegetation control wind erosion is needed so the erosion control level of vegetation not previously tested in a wind tunnel can be calculated. In this report, a theoretical approach that accounts for both the surface friction ...
متن کاملDust resuspension without saltation.
Wind resuspension (or entrainment) provides a source of dust and contaminants for the atmosphere. Conventional wind erosion models parameterize dust resuspension flux with a threshold velocity or with a horizontal abrasion flux; in the absence of abrasion the models assume dust flux is transient only. Our experiments with an uncrusted, fine material at relative humidities exceeding 40% show a l...
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ژورنال
عنوان ژورنال: Proceedings of the National Academy of Sciences
سال: 2008
ISSN: 0027-8424,1091-6490
DOI: 10.1073/pnas.0800202105