Modelling the transfer of supraglacial meltwater to the bed of Leverett Glacier, Southwest Greenland

C. C. Clason*, D. W F Mair, P. W. Nienow, I. D. Bartholomew, A. Sole, S. Palmer, W. Schwanghart

*Corresponding author for this work

Research output: Contribution to journalArticle

30 Citations (Scopus)
5 Downloads (Pure)

Abstract

Meltwater delivered to the bed of the Greenland Ice Sheet is a driver of variable ice-motion through changes in effective pressure and enhanced basal lubrication. Ice surface velocities have been shown to respond rapidly both to meltwater production at the surface and to drainage of supraglacial lakes, suggesting efficient transfer of meltwater from the supraglacial to subglacial hydrological systems. Although considerable effort is currently being directed towards improved modelling of the controlling surface and basal processes, modelling the temporal and spatial evolution of the transfer of melt to the bed has received less attention. Here we present the results of spatially distributed modelling for prediction of moulins and lake drainages on the Leverett Glacier in Southwest Greenland. The model is run for the 2009 and 2010 ablation seasons, and for future increased melt scenarios. The temporal pattern of modelled lake drainages are qualitatively comparable with those documented from analyses of repeat satellite imagery. The modelled timings and locations of delivery of meltwater to the bed also match well with observed temporal and spatial patterns of ice surface speed-ups. This is particularly true for the lower catchment (<1000 m a.s.l.) where both the model and observations indicate that the development of moulins is the main mechanism for the transfer of surface meltwater to the bed. At higher elevations (e.g. 1250-1500 m a.s.l.) the development and drainage of supraglacial lakes becomes increasingly important. At these higher elevations, the delay between modelled melt generation and subsequent delivery of melt to the bed matches the observed delay between the peak air temperatures and subsequent velocity speed-ups, while the instantaneous transfer of melt to the bed in a control simulation does not. Although both moulins and lake drainages are predicted to increase in number for future warmer climate scenarios, the lake drainages play an increasingly important role in both expanding the area over which melt accesses the bed and in enabling a greater proportion of surface melt to reach the bed.

Original languageEnglish
Pages (from-to)123-138
Number of pages16
JournalEarth's Cryosphere
Volume9
Issue number1
DOIs
Publication statusPublished - 22 Jan 2015

Fingerprint

meltwater
glacier
melt
drainage
lake
modeling
ice
ablation
satellite imagery
ice sheet
air temperature
catchment
climate
prediction
simulation

ASJC Scopus subject areas

  • Earth and Planetary Sciences(all)

Cite this

Clason, C. C., Mair, D. W. F., Nienow, P. W., Bartholomew, I. D., Sole, A., Palmer, S., & Schwanghart, W. (2015). Modelling the transfer of supraglacial meltwater to the bed of Leverett Glacier, Southwest Greenland. Earth's Cryosphere, 9(1), 123-138. https://doi.org/10.5194/tc-9-123-2015

Modelling the transfer of supraglacial meltwater to the bed of Leverett Glacier, Southwest Greenland. / Clason, C. C.; Mair, D. W F; Nienow, P. W.; Bartholomew, I. D.; Sole, A.; Palmer, S.; Schwanghart, W.

In: Earth's Cryosphere, Vol. 9, No. 1, 22.01.2015, p. 123-138.

Research output: Contribution to journalArticle

Clason, CC, Mair, DWF, Nienow, PW, Bartholomew, ID, Sole, A, Palmer, S & Schwanghart, W 2015, 'Modelling the transfer of supraglacial meltwater to the bed of Leverett Glacier, Southwest Greenland', Earth's Cryosphere, vol. 9, no. 1, pp. 123-138. https://doi.org/10.5194/tc-9-123-2015
Clason, C. C. ; Mair, D. W F ; Nienow, P. W. ; Bartholomew, I. D. ; Sole, A. ; Palmer, S. ; Schwanghart, W. / Modelling the transfer of supraglacial meltwater to the bed of Leverett Glacier, Southwest Greenland. In: Earth's Cryosphere. 2015 ; Vol. 9, No. 1. pp. 123-138.
@article{a82631f1b51046a98066ae6536b775ae,
title = "Modelling the transfer of supraglacial meltwater to the bed of Leverett Glacier, Southwest Greenland",
abstract = "Meltwater delivered to the bed of the Greenland Ice Sheet is a driver of variable ice-motion through changes in effective pressure and enhanced basal lubrication. Ice surface velocities have been shown to respond rapidly both to meltwater production at the surface and to drainage of supraglacial lakes, suggesting efficient transfer of meltwater from the supraglacial to subglacial hydrological systems. Although considerable effort is currently being directed towards improved modelling of the controlling surface and basal processes, modelling the temporal and spatial evolution of the transfer of melt to the bed has received less attention. Here we present the results of spatially distributed modelling for prediction of moulins and lake drainages on the Leverett Glacier in Southwest Greenland. The model is run for the 2009 and 2010 ablation seasons, and for future increased melt scenarios. The temporal pattern of modelled lake drainages are qualitatively comparable with those documented from analyses of repeat satellite imagery. The modelled timings and locations of delivery of meltwater to the bed also match well with observed temporal and spatial patterns of ice surface speed-ups. This is particularly true for the lower catchment (<1000 m a.s.l.) where both the model and observations indicate that the development of moulins is the main mechanism for the transfer of surface meltwater to the bed. At higher elevations (e.g. 1250-1500 m a.s.l.) the development and drainage of supraglacial lakes becomes increasingly important. At these higher elevations, the delay between modelled melt generation and subsequent delivery of melt to the bed matches the observed delay between the peak air temperatures and subsequent velocity speed-ups, while the instantaneous transfer of melt to the bed in a control simulation does not. Although both moulins and lake drainages are predicted to increase in number for future warmer climate scenarios, the lake drainages play an increasingly important role in both expanding the area over which melt accesses the bed and in enabling a greater proportion of surface melt to reach the bed.",
author = "Clason, {C. C.} and Mair, {D. W F} and Nienow, {P. W.} and Bartholomew, {I. D.} and A. Sole and S. Palmer and W. Schwanghart",
note = "{\circledC} Author(s) 2015. This work is distributed under the Creative Commons Attribution 3.0 License. Acknowledgements. We acknowledge the College of Physical Sciences, University of Aberdeen, the Leverhulme Trust through a Study Abroad Studentship and the Swedish Radiation Safety Authority, for funding awarded to C. Clason. Data collection was supported by the UK Natural Environment Research Council (through a studentship to I. Bartholomew and grants to P. Nienow and D. Mair) and the Edinburgh University Moss Centenary Scholarship (I. Bartholomew). We acknowledge I. Joughin for providing InSAR velocity data, and the National Snow and Ice Data Centre, University of Colorado, and J. Bamber for ice thickness data. We thank two anonymous reviewers for their comments which helped to improve the paper.",
year = "2015",
month = "1",
day = "22",
doi = "10.5194/tc-9-123-2015",
language = "English",
volume = "9",
pages = "123--138",
journal = "Earth's Cryosphere",
issn = "1560-7496",
publisher = "Russian Academy of Sciences",
number = "1",

}

TY - JOUR

T1 - Modelling the transfer of supraglacial meltwater to the bed of Leverett Glacier, Southwest Greenland

AU - Clason, C. C.

AU - Mair, D. W F

AU - Nienow, P. W.

AU - Bartholomew, I. D.

AU - Sole, A.

AU - Palmer, S.

AU - Schwanghart, W.

N1 - © Author(s) 2015. This work is distributed under the Creative Commons Attribution 3.0 License. Acknowledgements. We acknowledge the College of Physical Sciences, University of Aberdeen, the Leverhulme Trust through a Study Abroad Studentship and the Swedish Radiation Safety Authority, for funding awarded to C. Clason. Data collection was supported by the UK Natural Environment Research Council (through a studentship to I. Bartholomew and grants to P. Nienow and D. Mair) and the Edinburgh University Moss Centenary Scholarship (I. Bartholomew). We acknowledge I. Joughin for providing InSAR velocity data, and the National Snow and Ice Data Centre, University of Colorado, and J. Bamber for ice thickness data. We thank two anonymous reviewers for their comments which helped to improve the paper.

PY - 2015/1/22

Y1 - 2015/1/22

N2 - Meltwater delivered to the bed of the Greenland Ice Sheet is a driver of variable ice-motion through changes in effective pressure and enhanced basal lubrication. Ice surface velocities have been shown to respond rapidly both to meltwater production at the surface and to drainage of supraglacial lakes, suggesting efficient transfer of meltwater from the supraglacial to subglacial hydrological systems. Although considerable effort is currently being directed towards improved modelling of the controlling surface and basal processes, modelling the temporal and spatial evolution of the transfer of melt to the bed has received less attention. Here we present the results of spatially distributed modelling for prediction of moulins and lake drainages on the Leverett Glacier in Southwest Greenland. The model is run for the 2009 and 2010 ablation seasons, and for future increased melt scenarios. The temporal pattern of modelled lake drainages are qualitatively comparable with those documented from analyses of repeat satellite imagery. The modelled timings and locations of delivery of meltwater to the bed also match well with observed temporal and spatial patterns of ice surface speed-ups. This is particularly true for the lower catchment (<1000 m a.s.l.) where both the model and observations indicate that the development of moulins is the main mechanism for the transfer of surface meltwater to the bed. At higher elevations (e.g. 1250-1500 m a.s.l.) the development and drainage of supraglacial lakes becomes increasingly important. At these higher elevations, the delay between modelled melt generation and subsequent delivery of melt to the bed matches the observed delay between the peak air temperatures and subsequent velocity speed-ups, while the instantaneous transfer of melt to the bed in a control simulation does not. Although both moulins and lake drainages are predicted to increase in number for future warmer climate scenarios, the lake drainages play an increasingly important role in both expanding the area over which melt accesses the bed and in enabling a greater proportion of surface melt to reach the bed.

AB - Meltwater delivered to the bed of the Greenland Ice Sheet is a driver of variable ice-motion through changes in effective pressure and enhanced basal lubrication. Ice surface velocities have been shown to respond rapidly both to meltwater production at the surface and to drainage of supraglacial lakes, suggesting efficient transfer of meltwater from the supraglacial to subglacial hydrological systems. Although considerable effort is currently being directed towards improved modelling of the controlling surface and basal processes, modelling the temporal and spatial evolution of the transfer of melt to the bed has received less attention. Here we present the results of spatially distributed modelling for prediction of moulins and lake drainages on the Leverett Glacier in Southwest Greenland. The model is run for the 2009 and 2010 ablation seasons, and for future increased melt scenarios. The temporal pattern of modelled lake drainages are qualitatively comparable with those documented from analyses of repeat satellite imagery. The modelled timings and locations of delivery of meltwater to the bed also match well with observed temporal and spatial patterns of ice surface speed-ups. This is particularly true for the lower catchment (<1000 m a.s.l.) where both the model and observations indicate that the development of moulins is the main mechanism for the transfer of surface meltwater to the bed. At higher elevations (e.g. 1250-1500 m a.s.l.) the development and drainage of supraglacial lakes becomes increasingly important. At these higher elevations, the delay between modelled melt generation and subsequent delivery of melt to the bed matches the observed delay between the peak air temperatures and subsequent velocity speed-ups, while the instantaneous transfer of melt to the bed in a control simulation does not. Although both moulins and lake drainages are predicted to increase in number for future warmer climate scenarios, the lake drainages play an increasingly important role in both expanding the area over which melt accesses the bed and in enabling a greater proportion of surface melt to reach the bed.

UR - http://www.scopus.com/inward/record.url?scp=84921467175&partnerID=8YFLogxK

U2 - 10.5194/tc-9-123-2015

DO - 10.5194/tc-9-123-2015

M3 - Article

VL - 9

SP - 123

EP - 138

JO - Earth's Cryosphere

JF - Earth's Cryosphere

SN - 1560-7496

IS - 1

ER -