Processes at the margins of supraglacial debris cover: Quantifying dirty ice ablation and debris redistribution

Autor: Philip Deline, Catriona Fyffe, Amy Woodget, Ben Brock, Matthew J. Westoby, Martin P. Kirkbride
Rok vydání: 2020
Předmět:
Zdroj: Earth Surface Processes and Landforms. 45:2272-2290
ISSN: 1096-9837
0197-9337
DOI: 10.1002/esp.4879
Popis: Current glacier ablation models have difficulty simulating the high‐melt transition zone between clean and debris‐covered ice. In this zone, thin debris cover is thought to increase ablation compared to clean ice, but often this cover is patchy rather than continuous. There is a need to understand ablation and debris dynamics in this transition zone to improve the accuracy of ablation models and the predictions of future debris cover extent. To quantify the ablation of partially debris‐covered ice (or ‘dirty ice’), a high‐resolution, spatially‐continuous ablation map was created from repeat unmanned aerial systems (UAS) surveys, corrected for glacier flow in a novel way using on‐glacier ablation stakes. Surprisingly, ablation is similar (range ~5 mm w.e. per day) across a wide range of percentage debris covers (~30‐80%) due to the opposing effects of a positive correlation between percentage debris cover and clast size, countered by a negative correlation with albedo. Once debris cover becomes continuous, ablation is significantly reduced (by 61.6% compared to a partial debris cover), and there is some evidence that the cleanest ice (
Databáze: OpenAIRE
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