Satellite investigations of ice-ocean interactions in the Amundsen Sea sector of West Antarctica
This thesis analyses satellite-based radar data to improve our understanding of the interactions between the Antarctic Ice Sheet and the ocean in the Amundsen Sea Sector of West Antarctica. Over the last two decades, the European Remote Sensing (ERS) Satellites have provided extensive observations o...
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The University of Edinburgh
2012
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ftunivedinburgh:oai:era.ed.ac.uk:1842/6242 2023-07-30T03:56:01+02:00 Satellite investigations of ice-ocean interactions in the Amundsen Sea sector of West Antarctica McMillan, Malcolm John Nienow, Peter Shepherd, Andrew Natural Environment Research Council (NERC) 25/06/2012 application/pdf http://hdl.handle.net/1842/6242 en eng The University of Edinburgh McMillan, M., Shepherd, A., Vaughan, D.G., Laxon, S. and McAdoo, D. (2009). Amundsen Sea Bathymetry: The Benefits of Using Gravity Data for Bathymetric Prediction. IEEE Transactions on Geoscience and Remote Sensing, 47, 4223–4228. http://hdl.handle.net/1842/6242 remote sensing glaciology Antarctica radar ice shelves Global Change Research Institute Thesis or Dissertation Doctoral PhD Doctor of Philosophy 2012 ftunivedinburgh 2023-07-09T20:30:54Z This thesis analyses satellite-based radar data to improve our understanding of the interactions between the Antarctic Ice Sheet and the ocean in the Amundsen Sea Sector of West Antarctica. Over the last two decades, the European Remote Sensing (ERS) Satellites have provided extensive observations of the marine and cryospheric environments of this region. Here I use this data record to develop new datasets and methods for studying the nature and drivers of ongoing change in this sector. Firstly, I develop a new bathymetric map of the Amundsen Sea, which serves to provide improved boundary conditions for models of (1) ocean heat transfer to the ice sheet margin, and (2) past ice sheet behaviour and extent. This new map augments sparse ship-based depth soundings with dense gravity data acquired from ERS altimetry and achieves an RMS depth accuracy of 120 meters. An evaluation of this technique indicates that the inclusion of gravity data improves the depth accuracy by up to 17 % and reveals glaciologically-important features in regions devoid of ship surveys. Secondly, I use ERS synthetic aperture radar observations of the tidal motion of ice shelves to assess the accuracy of tide models in the Amundsen Sea. Tide models contribute to simulations of ocean circulation and are used to remove unwanted signals from estimates of ice shelf flow velocities. The quality of tide models directly affects the accuracy of such estimates yet, due to a lack of in situ records, tide model accuracy in this region is poorly constrained. Here I use two methods to determine that tide model accuracy in the Amundsen Sea is of the order of 10 cm. Finally, I develop a method to map 2-d ice shelf flow velocity from stacked conventional and multiple aperture radar interferograms. Estimates of ice shelf flow provide detail of catchment stability, and the processes driving glaciological change in the Amundsen Sea. However, velocity estimates can be contaminated by ocean tide and atmospheric pressure signals. I minimise these signals by ... Doctoral or Postdoctoral Thesis Amundsen Sea Antarc* Antarctic Antarctica Ice Sheet Ice Shelf Ice Shelves West Antarctica Edinburgh Research Archive (ERA - University of Edinburgh) Antarctic The Antarctic West Antarctica Amundsen Sea |
institution |
Open Polar |
collection |
Edinburgh Research Archive (ERA - University of Edinburgh) |
op_collection_id |
ftunivedinburgh |
language |
English |
topic |
remote sensing glaciology Antarctica radar ice shelves Global Change Research Institute |
spellingShingle |
remote sensing glaciology Antarctica radar ice shelves Global Change Research Institute McMillan, Malcolm John Satellite investigations of ice-ocean interactions in the Amundsen Sea sector of West Antarctica |
topic_facet |
remote sensing glaciology Antarctica radar ice shelves Global Change Research Institute |
description |
This thesis analyses satellite-based radar data to improve our understanding of the interactions between the Antarctic Ice Sheet and the ocean in the Amundsen Sea Sector of West Antarctica. Over the last two decades, the European Remote Sensing (ERS) Satellites have provided extensive observations of the marine and cryospheric environments of this region. Here I use this data record to develop new datasets and methods for studying the nature and drivers of ongoing change in this sector. Firstly, I develop a new bathymetric map of the Amundsen Sea, which serves to provide improved boundary conditions for models of (1) ocean heat transfer to the ice sheet margin, and (2) past ice sheet behaviour and extent. This new map augments sparse ship-based depth soundings with dense gravity data acquired from ERS altimetry and achieves an RMS depth accuracy of 120 meters. An evaluation of this technique indicates that the inclusion of gravity data improves the depth accuracy by up to 17 % and reveals glaciologically-important features in regions devoid of ship surveys. Secondly, I use ERS synthetic aperture radar observations of the tidal motion of ice shelves to assess the accuracy of tide models in the Amundsen Sea. Tide models contribute to simulations of ocean circulation and are used to remove unwanted signals from estimates of ice shelf flow velocities. The quality of tide models directly affects the accuracy of such estimates yet, due to a lack of in situ records, tide model accuracy in this region is poorly constrained. Here I use two methods to determine that tide model accuracy in the Amundsen Sea is of the order of 10 cm. Finally, I develop a method to map 2-d ice shelf flow velocity from stacked conventional and multiple aperture radar interferograms. Estimates of ice shelf flow provide detail of catchment stability, and the processes driving glaciological change in the Amundsen Sea. However, velocity estimates can be contaminated by ocean tide and atmospheric pressure signals. I minimise these signals by ... |
author2 |
Nienow, Peter Shepherd, Andrew Natural Environment Research Council (NERC) |
format |
Doctoral or Postdoctoral Thesis |
author |
McMillan, Malcolm John |
author_facet |
McMillan, Malcolm John |
author_sort |
McMillan, Malcolm John |
title |
Satellite investigations of ice-ocean interactions in the Amundsen Sea sector of West Antarctica |
title_short |
Satellite investigations of ice-ocean interactions in the Amundsen Sea sector of West Antarctica |
title_full |
Satellite investigations of ice-ocean interactions in the Amundsen Sea sector of West Antarctica |
title_fullStr |
Satellite investigations of ice-ocean interactions in the Amundsen Sea sector of West Antarctica |
title_full_unstemmed |
Satellite investigations of ice-ocean interactions in the Amundsen Sea sector of West Antarctica |
title_sort |
satellite investigations of ice-ocean interactions in the amundsen sea sector of west antarctica |
publisher |
The University of Edinburgh |
publishDate |
2012 |
url |
http://hdl.handle.net/1842/6242 |
geographic |
Antarctic The Antarctic West Antarctica Amundsen Sea |
geographic_facet |
Antarctic The Antarctic West Antarctica Amundsen Sea |
genre |
Amundsen Sea Antarc* Antarctic Antarctica Ice Sheet Ice Shelf Ice Shelves West Antarctica |
genre_facet |
Amundsen Sea Antarc* Antarctic Antarctica Ice Sheet Ice Shelf Ice Shelves West Antarctica |
op_relation |
McMillan, M., Shepherd, A., Vaughan, D.G., Laxon, S. and McAdoo, D. (2009). Amundsen Sea Bathymetry: The Benefits of Using Gravity Data for Bathymetric Prediction. IEEE Transactions on Geoscience and Remote Sensing, 47, 4223–4228. http://hdl.handle.net/1842/6242 |
_version_ |
1772810660829200384 |