EGU2020-15184, updated on 16 Oct 2020
https://doi.org/10.5194/egusphere-egu2020-15184
EGU General Assembly 2020
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.

Low-elevation of Svalbard glaciers drives high mass loss variability

Brice Noël1, Constantijn Jakobs1, Ward Van Pelt2, Stef Lhermitte3, Bert Wouters1,3, Carleen Reijmer1, Willem Jan Van de Berg1, and Michiel Van den Broeke1
Brice Noël et al.
  • 1Utrecht University, IMAU, Utrecht, Netherlands (b.p.y.noel@uu.nl)
  • 2Uppsala University, Department of Earth Sciences, Uppsala, Sweden
  • 3Delft University of Technology, Department of Geoscience & Remote Sensing, Delft, Netherlands

With a maximum in glaciated area below 450 m elevation (peak in the hypsometry), most Svalbard glaciers currently experience summer melt that consistently exceeds winter snowfall. Consequently, these glaciers can only exist through efficient meltwater refreezing in their porous firn layers. Before the mid-1980s, refreezing retained 54% of the meltwater in firn above 350 m. In 1985-2018, atmospheric warming migrated the firn line upward by 100 m, close to the hypsometry peak, which triggered a rapid ablation zone expansion (+62%). The resulting melt increase in the accumulation zones reduced the firn refreezing capacity by 25%, enhancing runoff at all elevations. In this dry climate, the loss of refreezing capacity is quasipermanent: a temporary return to pre-1985 climate conditions between 2005 and 2012 could not recover the meltwater buffer mechanism, causing strongly amplified mass loss in subsequent warm years (e.g. 2013), when ablation zones extend beyond the hypsometry peak.

How to cite: Noël, B., Jakobs, C., Van Pelt, W., Lhermitte, S., Wouters, B., Reijmer, C., Van de Berg, W. J., and Van den Broeke, M.: Low-elevation of Svalbard glaciers drives high mass loss variability, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-15184, https://doi.org/10.5194/egusphere-egu2020-15184, 2020

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