Suncups are bowl-shaped open depressions into a snow surface, normally wider than they are deep. They form closely packed, honeycomb, often hexagonal patterns with sharp narrow ridges separating smoothly concave hollows. For a given set of suncups, the hollows are normally all around the same size, meaning that the pattern is quasi-periodic on 20–80 cm scales. [1] [2] The depressions are typically 2–50 cm deep. [3]
Suncups form during the ablation (melting away) of snowy surfaces. It is thought they can form in a number of different ways. These include melting of clean snow by incident solar radiation in bright sunny conditions, [3] but also during melting away of dirty snow under windy or overcast conditions, during which particles in the snow accumulate on the crests between hollows, insulating them. [4]
See also
- Penitente (snow formation), another snow ablation texture
References
- ^ Post, Austin; LaChapelle, E. R. (1971). Glacier ice. Seattle and London: University of Washington Press. ISBN 978-0-8020-1813-7. OCLC 207844.
- ^ Herzfeld, Ute C.; Mayer, Helmut; Caine, Nel; Losleben, Mark; Erbrecht, Tim (2003). "Morphogenesis of typical winter and summer snow surface patterns in a continental alpine environment". Hydrological Processes. 17 (3). Wiley: 619–649. Bibcode: 2003HyPr...17..619H. doi: 10.1002/hyp.1158. ISSN 0885-6087. S2CID 128948173.
- ^ a b Rhodes, Jonathon J.; Armstrong, Richard L.; Warren, Stephen G. (1987). "Mode of Formation of "Ablation Hollows" Controlled by Dirt Content of Snow". Journal of Glaciology. 33 (114). Cambridge University Press (CUP): 135–139. doi: 10.3189/s0022143000008601. ISSN 0022-1430.
- ^ Betterton, M. D. (2001-04-26). "Theory of structure formation in snowfields motivated by penitentes, suncups, and dirt cones". Physical Review E. 63 (5). American Physical Society (APS): 056129. arXiv: physics/0007099. Bibcode: 2001PhRvE..63e6129B. doi: 10.1103/physreve.63.056129. ISSN 1063-651X. PMID 11414983.