Satellite investigations of ice dynamics and supraglacial lake development in Greenland
This thesis aims to improve the current understanding of the processes which control the flow variability of Greenland Ice Sheet (GrIS) outlet glaciers. The most recent Intergovernmental Governmental Panel on Climate Change (IPCC) report (Meehl et al., 2007) identifies that a critical limitation to...
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Language: | English |
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The University of Edinburgh
2012
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ftunivedinburgh:oai:era.ed.ac.uk:1842/6247 2023-07-30T04:03:37+02:00 Satellite investigations of ice dynamics and supraglacial lake development in Greenland Briggs, Kate Hannah Nienow, Peter Shepherd, Andrew Natural Environment Research Council (NERC) 2012-06-25 application/pdf http://hdl.handle.net/1842/6247 en eng The University of Edinburgh http://hdl.handle.net/1842/6247 supraglacial lakes Thesis or Dissertation Doctoral PhD Doctor of Philosophy 2012 ftunivedinburgh 2023-07-09T20:33:11Z This thesis aims to improve the current understanding of the processes which control the flow variability of Greenland Ice Sheet (GrIS) outlet glaciers. The most recent Intergovernmental Governmental Panel on Climate Change (IPCC) report (Meehl et al., 2007) identifies that a critical limitation to forecasts of sea-level rise are uncertainties in modelling the ice dynamics of the GrIS. Using Synthetic Aperture Radar (SAR) feature tracking, seasonal velocities of land- and marine- terminating glaciers in a region in the northeast of Greenland are measured. Records of air temperature in conjunction with seasonal observations of supraglacial lake development, sea ice conditions and ice front positions, derived from SAR imagery, are used to investigate the controls on the observed variations in ice velocity. A clear link between ice velocities and glacier hydrology is found. These findings are consistent with observations from other glaciers in Greenland and are suggestive of a universal hydrological forcing of ice velocity for the whole of the GrIS ablation zone. Lake drainage events have been identified as a key factor in linking atmospheric changes, glacier hydrology and ice velocities in Greenland. For modelling purposes, a means of parameterising the distribution and evolution of supraglacial lakes is therefore needed. Assuming that water will pond in surface depressions, this thesis assesses the ability of using Digital Elevation Models (DEMs) for this purpose. High resolution DEMs are created using Interferometric SAR (InSAR) for two, separate regions of the GrIS. The positions and areal extent of surface depressions are compared with those of lakes observed in optical satellite imagery. The level of correspondence between the two datasets is found to be poor as a result of the resolution of the DEMs and the physical differences between surface depressions and lakes (e.g. lakes may not fill the capacity of the depression). An alternative method for parameterising the seasonal distribution of supra-glacial ... Doctoral or Postdoctoral Thesis glacier Greenland Ice Sheet Sea ice Edinburgh Research Archive (ERA - University of Edinburgh) Greenland |
institution |
Open Polar |
collection |
Edinburgh Research Archive (ERA - University of Edinburgh) |
op_collection_id |
ftunivedinburgh |
language |
English |
topic |
supraglacial lakes |
spellingShingle |
supraglacial lakes Briggs, Kate Hannah Satellite investigations of ice dynamics and supraglacial lake development in Greenland |
topic_facet |
supraglacial lakes |
description |
This thesis aims to improve the current understanding of the processes which control the flow variability of Greenland Ice Sheet (GrIS) outlet glaciers. The most recent Intergovernmental Governmental Panel on Climate Change (IPCC) report (Meehl et al., 2007) identifies that a critical limitation to forecasts of sea-level rise are uncertainties in modelling the ice dynamics of the GrIS. Using Synthetic Aperture Radar (SAR) feature tracking, seasonal velocities of land- and marine- terminating glaciers in a region in the northeast of Greenland are measured. Records of air temperature in conjunction with seasonal observations of supraglacial lake development, sea ice conditions and ice front positions, derived from SAR imagery, are used to investigate the controls on the observed variations in ice velocity. A clear link between ice velocities and glacier hydrology is found. These findings are consistent with observations from other glaciers in Greenland and are suggestive of a universal hydrological forcing of ice velocity for the whole of the GrIS ablation zone. Lake drainage events have been identified as a key factor in linking atmospheric changes, glacier hydrology and ice velocities in Greenland. For modelling purposes, a means of parameterising the distribution and evolution of supraglacial lakes is therefore needed. Assuming that water will pond in surface depressions, this thesis assesses the ability of using Digital Elevation Models (DEMs) for this purpose. High resolution DEMs are created using Interferometric SAR (InSAR) for two, separate regions of the GrIS. The positions and areal extent of surface depressions are compared with those of lakes observed in optical satellite imagery. The level of correspondence between the two datasets is found to be poor as a result of the resolution of the DEMs and the physical differences between surface depressions and lakes (e.g. lakes may not fill the capacity of the depression). An alternative method for parameterising the seasonal distribution of supra-glacial ... |
author2 |
Nienow, Peter Shepherd, Andrew Natural Environment Research Council (NERC) |
format |
Doctoral or Postdoctoral Thesis |
author |
Briggs, Kate Hannah |
author_facet |
Briggs, Kate Hannah |
author_sort |
Briggs, Kate Hannah |
title |
Satellite investigations of ice dynamics and supraglacial lake development in Greenland |
title_short |
Satellite investigations of ice dynamics and supraglacial lake development in Greenland |
title_full |
Satellite investigations of ice dynamics and supraglacial lake development in Greenland |
title_fullStr |
Satellite investigations of ice dynamics and supraglacial lake development in Greenland |
title_full_unstemmed |
Satellite investigations of ice dynamics and supraglacial lake development in Greenland |
title_sort |
satellite investigations of ice dynamics and supraglacial lake development in greenland |
publisher |
The University of Edinburgh |
publishDate |
2012 |
url |
http://hdl.handle.net/1842/6247 |
geographic |
Greenland |
geographic_facet |
Greenland |
genre |
glacier Greenland Ice Sheet Sea ice |
genre_facet |
glacier Greenland Ice Sheet Sea ice |
op_relation |
http://hdl.handle.net/1842/6247 |
_version_ |
1772814646078603264 |