Distributed Global Debris Thickness Estimates Reveal Debris Significantly Impacts Glacier Mass Balance

Rounce DR, Hock R, McNabb RW, Millan R, Sommer C, Braun M, Malz P, Maussion F, Mouginot J, Seehaus T, Shean DE (2021)

Publication Type: Journal article

Publication year: 2021

Journal

Book Volume: 48

Article Number: e2020GL091311

Journal Issue: 8

DOI: 10.1029/2020GL091311

Abstract

Supraglacial debris affects glacier mass balance as a thin layer enhances surface melting, while a thick layer reduces it. While many glaciers are debris-covered, global glacier models do not account for debris because its thickness is unknown. We provide the first globally distributed debris thickness estimates using a novel approach combining sub-debris melt and surface temperature inversion methods. Results are evaluated against observations from 22 glaciers. We find the median global debris thickness is ∼0.15 ± 0.06 m. In all regions, the net effect of accounting for debris is a reduction in sub-debris melt, on average, by 37%, which can impact regional mass balance by up to 0.40 m water equivalent (w.e.) yr^-1. We also find recent observations of similar thinning rates over debris-covered and clean ice glacier tongues is primarily due to differences in ice dynamics. Our results demonstrate the importance of accounting for debris in glacier modeling efforts.

Authors with CRIS profile

Involved external institutions

Carnegie Mellon University United States (USA) (US) University of Alaska Fairbanks United States (USA) (US) University of Oslo Norway (NO) University of Grenoble Alpes (UGA) / Université de Grenoble France (FR) University of Washington United States (USA) (US) Leopold-Franzens-Universität Innsbruck / University of Innsbruck Austria (AT)

How to cite

APA:

Rounce, D.R., Hock, R., McNabb, R.W., Millan, R., Sommer, C., Braun, M.,... Shean, D.E. (2021). Distributed Global Debris Thickness Estimates Reveal Debris Significantly Impacts Glacier Mass Balance. Geophysical Research Letters, 48(8). https://doi.org/10.1029/2020GL091311

MLA:

Rounce, D. R., et al. "Distributed Global Debris Thickness Estimates Reveal Debris Significantly Impacts Glacier Mass Balance." Geophysical Research Letters 48.8 (2021).

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