Over-winter persistence of supraglacial lakes on the Greenland Ice Sheet: results and insights from a new model. Issue 257 (18th June 2020)

• Record Type: Journal Article
• Authors: Law, Robert; Arnold, Neil; Benedek, Corinne; Tedesco, Marco; Banwell, Alison; Willis, Ian
• Is Part Of: Journal of Glaciology. Volume 66:Issue 257(2020)
• Page Start: 362
• Page End: 372
• Publication Date: 2020-06-18
• Subjects: glacier hydrology, -- melt-surface, -- glacier modelling
• DOI: 10.1017/jog.2020.7
• Languages: English
• ISSNs: 0022-1430

Abstract

Abstract: We present a newly developed 1-D numerical energy-balance and phase transition supraglacial lake model: GlacierLake. GlacierLake incorporates snowfall, in situ snow and ice melt, incoming water from the surrounding catchment, ice lid formation, basal freeze-up and thermal stratification. Snow cover and temperature are varied to test lake development through winter and the maximum lid thickness is recorded. Average wintertime temperatures of −2 to $-30^{\circ }{\rm C}$ and total snowfall of 0 to 3.45 m lead to a range of the maximum lid thickness from 1.2 to 2.8 m after ${\sim }250$ days, with snow cover exerting the dominant control. An initial ice temperature of $-15^{\circ }{\rm C}$ with simulated advection of cold ice from upstream results in 0.6 m of basal freeze-up. This suggests that lakes with water depths above 1.3 to 3.4 m (dependent on winter snowfall and temperature) upon lid formation will persist through winter. These buried lakes can provide a sizeable water store at the start of the melt season, expedite future lake formation and warm underlying ice even in winter.