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Title: The evolution of snow bedforms in the Colorado Front Range and the processes that shape them
Abstract. When wind blows over dry snow, the snow surface self-organizesinto bedforms such as dunes, ripples, snow waves, and sastrugi. Thesebedforms govern the interaction between wind, heat, and the snowpack, butthus far they have attracted few scientific studies.We present the first time-lapse documentation of snow bedform movement and evolution, as part of a series of detailed observations of snow bedform movement in the Colorado Front Range.We show examples of the movement of snow ripples, snow waves, barchan dunes,snow steps, and sastrugi. We also introduce a previously undocumentedbedform: the stealth dune. These observations show that (1) snow dunesaccelerate minute-by-minute in response to gusts, (2) sastrugi and snow stepspresent steep edges to the wind and migrate downwind as those edges erode,(3) snow waves and dunes deposit layers of cohesive snow in their wake, and(4) bedforms evolve along complex cyclic trajectories. These observationsprovide the basis for new conceptual models of bedform evolution, based onthe relative fluxes of snowfall, aeolian transport, erosion, and snowsintering across and into the surface. We find that many snow bedforms aregenerated by complex interactions between these processes. The prototypicalexample is the snow wave, in which deposition, sintering, and erosion occurin transverse stripes across the snowscape.
Authors:
; ;
Award ID(s):
1637686
Publication Date:
NSF-PAR ID:
10126840
Journal Name:
The Cryosphere
Volume:
13
Issue:
4
Page Range or eLocation-ID:
1267 to 1281
ISSN:
1994-0424
Sponsoring Org:
National Science Foundation
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