Short description: Bowl-shaped open depressions into a snow surface
Suncups on a snow patch near Gibby Beam, UK.
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]
↑Post, Austin; LaChapelle, E. R. (1971). Glacier ice. Seattle and London: University of Washington Press. ISBN978-0-8020-1813-7. OCLC207844.
↑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 (Wiley) 17 (3): 619–649. doi:10.1002/hyp.1158. ISSN0885-6087. Bibcode: 2003HyPr...17..619H.
↑ 3.03.1Rhodes, Jonathon J.; Armstrong, Richard L.; Warren, Stephen G. (1987). "Mode of Formation of "Ablation Hollows" Controlled by Dirt Content of Snow". Journal of Glaciology (Cambridge University Press (CUP)) 33 (114): 135–139. doi:10.3189/s0022143000008601. ISSN0022-1430.