Over-winter persistence of supraglacial lakes on the Greenland Ice Sheet: Results and insights from a new model

• Main Authors: Law, R, Arnold, N, Benedek, C, Tedesco, M, Banwell, A, Willis, I
• Format: Article in Journal/Newspaper
• Language: English
• Published: Cambridge University Press (CUP) 2020
• Subjects: glacier hydrology; melt-surface; glacier modelling; Greenland; glacier; Ice Sheet
• Online Access: https://www.repository.cam.ac.uk/handle/1810/300845; https://doi.org/10.17863/CAM.47922

<jats:title>Abstract</jats:title><jats:p>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<jats:inline-formula><jats:alternatives><jats:tex-math>$-30^{\circ }{\rm C}$</jats:tex-math><jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" mime-subtype="png" mimetype="image" xlink:href="S0022143020000076_inline2.png" /></jats:alternatives></jats:inline-formula>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<jats:inline-formula><jats:alternatives><jats:tex-math>${\sim }250$</jats:tex-math><jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" mime-subtype="png" mimetype="image" xlink:href="S0022143020000076_inline3.png" /></jats:alternatives></jats:inline-formula>days, with snow cover exerting the dominant control. An initial ice temperature of<jats:inline-formula><jats:alternatives><jats:tex-math>$-15^{\circ }{\rm C}$</jats:tex-math><jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" mime-subtype="png" mimetype="image" xlink:href="S0022143020000076_inline4.png" /></jats:alternatives></jats:inline-formula>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 ...