barchan dune

bar·chan dune

 (bär-kän′)
n.
A crescent-shaped dune, reaching heights of up to 30 meters (98 feet) and widths of 350 meters (1,148 feet), and having a steep, concave leeward side with crescent tips pointing downwind.

[Russian barkhan, barchan dune, from Kazakh barxan; akin to Uyghur bargan, dune that moves.]
American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
References in periodicals archive ?
A geometry quantitative model describing barchan dune shape proposed by Sauermann et al.
The Kalahari Sands Hotel is sponsoring accommodation for the visiting legends, while Air Namibia chipped in with a good discount, AVIS Car Rental is sponsoring two mini buses to transport the sports legends, Barchan Dune Retreat is sponsoring a hunt and accommodation for some of the players, Xco Namibia assisted with promotional items The sister companies in the CIH Group of companies will also be part of the day.
Half of the traps were set on the advancing side of a barchan dune (Muma 1980).
When this happens, the dune's leading edges curve around to form a crescent or barchan dune. Inevitably, the points of the barchan dune become snagged and firmly anchored.
Now, a new mathematical model for wind-driven sand, as well as computer simulations of the same, reveal that one Barchan dune can, indeed, act as a soliton and pass through a slower-moving dune.
The management has also 1) carried out studies to assess the viability of replanting and stabilizing the barchan dune fields, 2) conducted research into the physiology of native plants and animals to see how they react to changes in salinity, temperature, and aridity, 3) studied the changes in the soil moisture regime, and 4) measured the effects of grazing on plant productivity.
NASA also recently (https://twitter.com/NASA/status/1094721173252907008?ref_src=twsrc%5Etfw%7Ctwcamp%5Etweetembed%7Ctwterm%5E1094721173252907008&ref_url=https%3A%2F%2Fcms.ibtimes.com%2Fnasa-captures-stunning-mars-sand-dunes-incredibly-detailed-image-2761827) shared a stunning image of Martian "barchan dunes." Located near Mars' Nili Patera, the barchan dunes are characterized by their elongated crescent form and were formed due to wind continuously and consistently blowing in the same direction. 
While Barchan dunes are common on Mars, the newly spotted crater has a rare configuration and over the next few tens of thousands of years, the sand will be blown out of the crater.
"It's unclear why barchan dunes exist at all," says Pieter Vermeesch, a geologist at University College London.
The Empty Quarter is the biggest desert in the world, so rolling dunes, the challenging barchan dunes (arc-shaped sand ridges) I know to expect, but am most looking forward to sleeping under the stars in the Empty Quarter."
It appears that a change in wind direction has blown the crescent tails from a field of so-called barchan dunes. Barchans are crescent-shaped dunes formed on relatively hard desert floors where there is a limited supply of sand and a strong prevailing wind.
The study area lies on the south-east edge of the Tengger Desert at Shapotou, north-central China (37[degrees]28'N, 105[degrees]00'E) at an elevation of 1300-1350 m a.s.l., and is characterised by large and concentrated sand dunes in the form of reticulated chains of barchan dunes with natural vegetation cover of <1%.