Low elevation of Svalbard glaciers drives high mass loss variability

• Published in: Nature Communications
• Main Authors: Noël, Brice, Jakobs, C. L., van Pelt, W. J. J., Lhermitte, S., Wouters, B., Kohler, J., Hagen, J. O., Luks, B., Reijmer, C. H., van de Berg, W. J., van den Broeke, M. R.
• Other Authors: Nederlandse Organisatie voor Wetenschappelijk Onderzoek
• Format: Article in Journal/Newspaper
• Language: English
• Published: Springer Science and Business Media LLC 2020
• Subjects: General Physics and Astronomy; General Biochemistry, Genetics and Molecular Biology; General Chemistry; Arctic; Svalbard
• Online Access: http://dx.doi.org/10.1038/s41467-020-18356-1; https://www.nature.com/articles/s41467-020-18356-1.pdf; https://www.nature.com/articles/s41467-020-18356-1

Abstract Compared to other Arctic ice masses, Svalbard glaciers are low-elevated with flat interior accumulation areas, resulting in a marked peak in their current hypsometry (area-elevation distribution) at ~450 m above sea level. Since summer melt consistently exceeds winter snowfall, these low-lying glaciers can only survive by refreezing a considerable fraction of surface melt and rain in the porous firn layer covering their accumulation zones. We use a high-resolution climate model to show that modest atmospheric warming in the mid-1980s forced the firn zone to retreat upward by ~100 m to coincide with the hypsometry peak. This led to a rapid areal reduction of firn cover available for refreezing, and strongly increased runoff from dark, bare ice areas, amplifying mass loss from all elevations. As the firn line fluctuates around the hypsometry peak in the current climate, Svalbard glaciers will continue to lose mass and show high sensitivity to temperature perturbations.