How barchan sand dunes pattern the desert
DOI: 10.1063/PT.5.027296
Science News : Barchan dunes are curved ridges of sand that form as wind blows across stretches of desert. Because the structures are inherently unstable, how they persist and maintain a certain size has been a subject of debate. Now two studies propose different mechanisms: Mathieu Génois of Paris Diderot University and colleagues say that collisions redistribute the sand among dunes and thus limit their size, whereas Stacey Worman of Duke University and colleagues believe that when large dunes reach a certain size, smaller dunes calve off of them. Because both collisions and calving have been observed in barchan fields, determining whether one process plays a more important role than the other may require the use of satellite images taken over several years.
