Highly temporally resolved response to seasonal surface melt of the Zachariae and 79N outlet glaciers in Northeast Greenland

N. M. Rathmann, C. S. Hvidberg, A. M. Solgaard, Aslak Grinsted, G. Hilmar Gudmundsson, Peter L. Langen, K. P. Nielsen, Anders Kusk

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Abstract

The seasonal response to surface melting of the Northeast Greenland Ice Stream outlets, Zachariae and 79N, is investigated using new highly temporally resolved surface velocity maps for 2016 combined with numerical modelling. The seasonal speed-up at 79N of 0.15km/yr is suggested to be driven by a decrease in effective basal pressure induced by surface melting, whereas for Zachariae its 0.11km/yr seasonal speed-up correlates equally well with the break-up of its large ice mélange. We investigate the influence 76km long floating tongue at 79N, finding it provides little resistance and that most of it could be lost without impacting the dynamics of the area. Furthermore, we show that reducing the slipperiness along the tongue–wall interfaces produces a velocity change spatially inconsistent with the observed seasonal speed-up. Finally, we find that subglacial sticky spots such as bedrock bumps play a negligible role in the large-scale response to a seasonally enhanced basal slipperiness of the region.
Original languageEnglish
JournalGeophysical Research Letters
Volume44
Issue number19
Pages (from-to)9805–9814
ISSN0094-8276
DOIs
Publication statusPublished - 2017

Keywords

  • Remote sensing
  • Glaciers
  • Mass balance
  • Ice-sheet modelling
  • Greenland ice sheet
  • Climate change
  • Sea-level changes

Cite this

Rathmann, N. M. ; Hvidberg, C. S. ; Solgaard, A. M. ; Grinsted, Aslak ; Gudmundsson, G. Hilmar ; Langen, Peter L. ; Nielsen, K. P. ; Kusk, Anders. / Highly temporally resolved response to seasonal surface melt of the Zachariae and 79N outlet glaciers in Northeast Greenland. In: Geophysical Research Letters. 2017 ; Vol. 44, No. 19. pp. 9805–9814 .
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title = "Highly temporally resolved response to seasonal surface melt of the Zachariae and 79N outlet glaciers in Northeast Greenland",
abstract = "The seasonal response to surface melting of the Northeast Greenland Ice Stream outlets, Zachariae and 79N, is investigated using new highly temporally resolved surface velocity maps for 2016 combined with numerical modelling. The seasonal speed-up at 79N of 0.15km/yr is suggested to be driven by a decrease in effective basal pressure induced by surface melting, whereas for Zachariae its 0.11km/yr seasonal speed-up correlates equally well with the break-up of its large ice m{\'e}lange. We investigate the influence 76km long floating tongue at 79N, finding it provides little resistance and that most of it could be lost without impacting the dynamics of the area. Furthermore, we show that reducing the slipperiness along the tongue–wall interfaces produces a velocity change spatially inconsistent with the observed seasonal speed-up. Finally, we find that subglacial sticky spots such as bedrock bumps play a negligible role in the large-scale response to a seasonally enhanced basal slipperiness of the region.",
keywords = "Remote sensing, Glaciers, Mass balance, Ice-sheet modelling, Greenland ice sheet, Climate change, Sea-level changes",
author = "Rathmann, {N. M.} and Hvidberg, {C. S.} and Solgaard, {A. M.} and Aslak Grinsted and Gudmundsson, {G. Hilmar} and Langen, {Peter L.} and Nielsen, {K. P.} and Anders Kusk",
year = "2017",
doi = "10.1002/2017GL074368",
language = "English",
volume = "44",
pages = "9805–9814",
journal = "Geophysical Research Letters",
issn = "0094-8276",
publisher = "Wiley-Blackwell",
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Rathmann, NM, Hvidberg, CS, Solgaard, AM, Grinsted, A, Gudmundsson, GH, Langen, PL, Nielsen, KP & Kusk, A 2017, 'Highly temporally resolved response to seasonal surface melt of the Zachariae and 79N outlet glaciers in Northeast Greenland', Geophysical Research Letters, vol. 44, no. 19, pp. 9805–9814 . https://doi.org/10.1002/2017GL074368

Highly temporally resolved response to seasonal surface melt of the Zachariae and 79N outlet glaciers in Northeast Greenland. / Rathmann, N. M.; Hvidberg, C. S.; Solgaard, A. M.; Grinsted, Aslak; Gudmundsson, G. Hilmar; Langen, Peter L.; Nielsen, K. P.; Kusk, Anders.

In: Geophysical Research Letters, Vol. 44, No. 19, 2017, p. 9805–9814 .

Research output: Contribution to journalJournal articleResearchpeer-review

TY - JOUR

T1 - Highly temporally resolved response to seasonal surface melt of the Zachariae and 79N outlet glaciers in Northeast Greenland

AU - Rathmann, N. M.

AU - Hvidberg, C. S.

AU - Solgaard, A. M.

AU - Grinsted, Aslak

AU - Gudmundsson, G. Hilmar

AU - Langen, Peter L.

AU - Nielsen, K. P.

AU - Kusk, Anders

PY - 2017

Y1 - 2017

N2 - The seasonal response to surface melting of the Northeast Greenland Ice Stream outlets, Zachariae and 79N, is investigated using new highly temporally resolved surface velocity maps for 2016 combined with numerical modelling. The seasonal speed-up at 79N of 0.15km/yr is suggested to be driven by a decrease in effective basal pressure induced by surface melting, whereas for Zachariae its 0.11km/yr seasonal speed-up correlates equally well with the break-up of its large ice mélange. We investigate the influence 76km long floating tongue at 79N, finding it provides little resistance and that most of it could be lost without impacting the dynamics of the area. Furthermore, we show that reducing the slipperiness along the tongue–wall interfaces produces a velocity change spatially inconsistent with the observed seasonal speed-up. Finally, we find that subglacial sticky spots such as bedrock bumps play a negligible role in the large-scale response to a seasonally enhanced basal slipperiness of the region.

AB - The seasonal response to surface melting of the Northeast Greenland Ice Stream outlets, Zachariae and 79N, is investigated using new highly temporally resolved surface velocity maps for 2016 combined with numerical modelling. The seasonal speed-up at 79N of 0.15km/yr is suggested to be driven by a decrease in effective basal pressure induced by surface melting, whereas for Zachariae its 0.11km/yr seasonal speed-up correlates equally well with the break-up of its large ice mélange. We investigate the influence 76km long floating tongue at 79N, finding it provides little resistance and that most of it could be lost without impacting the dynamics of the area. Furthermore, we show that reducing the slipperiness along the tongue–wall interfaces produces a velocity change spatially inconsistent with the observed seasonal speed-up. Finally, we find that subglacial sticky spots such as bedrock bumps play a negligible role in the large-scale response to a seasonally enhanced basal slipperiness of the region.

KW - Remote sensing

KW - Glaciers

KW - Mass balance

KW - Ice-sheet modelling

KW - Greenland ice sheet

KW - Climate change

KW - Sea-level changes

U2 - 10.1002/2017GL074368

DO - 10.1002/2017GL074368

M3 - Journal article

VL - 44

SP - 9805

EP - 9814

JO - Geophysical Research Letters

JF - Geophysical Research Letters

SN - 0094-8276

IS - 19

ER -