Modelling the transfer of supraglacial meltwater to the bed of Leverett Glacier, Southwest Greenland
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 lak...
Main Authors: | , , , , , , |
---|---|
Format: | Text |
Language: | English |
Published: |
Universität Potsdam
2019
|
Subjects: | |
Online Access: | https://dx.doi.org/10.25932/publishup-40905 https://publishup.uni-potsdam.de/40905 |
id |
ftdatacite:10.25932/publishup-40905 |
---|---|
record_format |
openpolar |
spelling |
ftdatacite:10.25932/publishup-40905 2023-05-15T16:21:22+02:00 Modelling the transfer of supraglacial meltwater to the bed of Leverett Glacier, Southwest Greenland Clason, Caroline C. Mair, D. W. F. Nienow, P. W. Bartholomew, I. D. Sole, Andrew Palmer, Steven Schwanghart, Wolfgang 2019 application/pdf application/zip https://dx.doi.org/10.25932/publishup-40905 https://publishup.uni-potsdam.de/40905 en eng Universität Potsdam Creative Commons - Namensnennung, 4.0 International https://creativecommons.org/licenses/by/4.0 CC-BY article-journal Text ScholarlyArticle 2019 ftdatacite https://doi.org/10.25932/publishup-40905 2021-11-05T12:55:41Z 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. : Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe, 513 Text glacier Greenland Ice Sheet Leverett Glacier DataCite Metadata Store (German National Library of Science and Technology) Greenland Leverett Glacier ENVELOPE(-147.583,-147.583,-85.633,-85.633) |
institution |
Open Polar |
collection |
DataCite Metadata Store (German National Library of Science and Technology) |
op_collection_id |
ftdatacite |
language |
English |
description |
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. : Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe, 513 |
format |
Text |
author |
Clason, Caroline C. Mair, D. W. F. Nienow, P. W. Bartholomew, I. D. Sole, Andrew Palmer, Steven Schwanghart, Wolfgang |
spellingShingle |
Clason, Caroline C. Mair, D. W. F. Nienow, P. W. Bartholomew, I. D. Sole, Andrew Palmer, Steven Schwanghart, Wolfgang Modelling the transfer of supraglacial meltwater to the bed of Leverett Glacier, Southwest Greenland |
author_facet |
Clason, Caroline C. Mair, D. W. F. Nienow, P. W. Bartholomew, I. D. Sole, Andrew Palmer, Steven Schwanghart, Wolfgang |
author_sort |
Clason, Caroline C. |
title |
Modelling the transfer of supraglacial meltwater to the bed of Leverett Glacier, Southwest Greenland |
title_short |
Modelling the transfer of supraglacial meltwater to the bed of Leverett Glacier, Southwest Greenland |
title_full |
Modelling the transfer of supraglacial meltwater to the bed of Leverett Glacier, Southwest Greenland |
title_fullStr |
Modelling the transfer of supraglacial meltwater to the bed of Leverett Glacier, Southwest Greenland |
title_full_unstemmed |
Modelling the transfer of supraglacial meltwater to the bed of Leverett Glacier, Southwest Greenland |
title_sort |
modelling the transfer of supraglacial meltwater to the bed of leverett glacier, southwest greenland |
publisher |
Universität Potsdam |
publishDate |
2019 |
url |
https://dx.doi.org/10.25932/publishup-40905 https://publishup.uni-potsdam.de/40905 |
long_lat |
ENVELOPE(-147.583,-147.583,-85.633,-85.633) |
geographic |
Greenland Leverett Glacier |
geographic_facet |
Greenland Leverett Glacier |
genre |
glacier Greenland Ice Sheet Leverett Glacier |
genre_facet |
glacier Greenland Ice Sheet Leverett Glacier |
op_rights |
Creative Commons - Namensnennung, 4.0 International https://creativecommons.org/licenses/by/4.0 |
op_rightsnorm |
CC-BY |
op_doi |
https://doi.org/10.25932/publishup-40905 |
_version_ |
1766009378571288576 |