Understanding snow bedform formation by adding sintering to a cellular automata model

Cellular-automata-based modelling for simulating snow bedforms and snow deposition is introduced in this study. The well-known ReSCAL model, previously used for sand bedforms, is adapted for this purpose by implementing a simple sintering mechanism. The effect of sintering is first explored for solitary barchan dunes of different sizes and flow conditions. Three types of behaviour are observed: small barchans continue their motion without any perceptible difference while large barchans sinter immediately. Barchans of intermediate size split, leaving behind a sintered core and a smaller barchan is formed. It is found that sintering introduces an upper limit to the size of bedforms that can remain mobile. The concept of "maximum streamwise length" (MSL) is introduced and MSL is identified for different wind speeds using the solitary dune scenario. Simulations of the full evolution from an initially flat snow layer to a complex dune field are performed next. It is found that the largest bedforms lie below the MSL threshold. Additionally, it is found that shallow snow layers are most susceptible to mechanical destabilization by the wind.


Publié dans:
Cryosphere, 13, 12, 3239-3260
Année
Dec 09 2019
Publisher:
Gottingen, COPERNICUS GESELLSCHAFT MBH
ISSN:
1994-0416
1994-0424
Mots-clefs:
Laboratoires:




 Notice créée le 2019-12-26, modifiée le 2020-01-06


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