The evolution of snow bedforms in the Colorado Front Range and the processes that shape them
<p>When wind blows over dry snow, the snow surface self-organizes into bedforms such as dunes, ripples, snow waves, and sastrugi. These bedforms govern the interaction between wind, heat, and the snowpack, but thus far they have attracted few scientific studies. We present the first time-lapse...
| Main Authors: | , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2019-04-01
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| Series: | The Cryosphere |
| Online Access: | https://www.the-cryosphere.net/13/1267/2019/tc-13-1267-2019.pdf |
| Summary: | <p>When wind blows over dry snow, the snow surface self-organizes
into bedforms such as dunes, ripples, snow waves, and sastrugi. These
bedforms govern the interaction between wind, heat, and the snowpack, but
thus 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 undocumented
bedform: the stealth dune. These observations show that (1) snow dunes
accelerate minute-by-minute in response to gusts, (2) sastrugi and snow steps
present 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 observations
provide the basis for new conceptual models of bedform evolution, based on
the relative fluxes of snowfall, aeolian transport, erosion, and snow
sintering across and into the surface. We find that many snow bedforms are
generated by complex interactions between these processes. The prototypical
example is the snow wave, in which deposition, sintering, and erosion occur
in transverse stripes across the snowscape.</p> |
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| ISSN: | 1994-0416 1994-0424 |