Adaptively constraining radar attenuation and temperature across the Thwaites Glacier catchment using bed echoes
ABSTRACT Englacial temperature is a major control on ice rheology and flow. However, it is difficult to measure at the glacier to ice-sheet scale. As a result, ice-sheet models must make assumptions about englacial temperature and rheology, which affect sea level projections. This is problematic if...
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Online Access: | http://dx.doi.org/10.1017/jog.2016.100 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143016001003 |
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crcambridgeupr:10.1017/jog.2016.100 2024-09-15T17:47:43+00:00 Adaptively constraining radar attenuation and temperature across the Thwaites Glacier catchment using bed echoes SCHROEDER, DUSTIN M. SEROUSSI, HELENE CHU, WINNIE YOUNG, DUNCAN A. 2016 http://dx.doi.org/10.1017/jog.2016.100 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143016001003 en eng Cambridge University Press (CUP) http://creativecommons.org/licenses/by/4.0/ Journal of Glaciology volume 62, issue 236, page 1075-1082 ISSN 0022-1430 1727-5652 journal-article 2016 crcambridgeupr https://doi.org/10.1017/jog.2016.100 2024-08-21T04:04:36Z ABSTRACT Englacial temperature is a major control on ice rheology and flow. However, it is difficult to measure at the glacier to ice-sheet scale. As a result, ice-sheet models must make assumptions about englacial temperature and rheology, which affect sea level projections. This is problematic if fundamental processes are not captured by models due to a lack of observationally constrained ice temperature values. Although radar sounding data have been exploited to constrain the temperature structure of the Greenland ice sheet using englacial layers, this approach is limited to areas and depths where these layers exist intact. In order to extend empirical radar-based temperature estimation beyond this limitation, we present a new technique for estimating englacial attenuation rates for the entire ice column using adaptive fitting of unfocused radar bed echoes based on the correlation of ice thickness and corrected bed echo power. We apply this technique to an airborne survey of Thwaites Glacier in West Antarctica and compare the results with temperatures and attenuation rates from a numerical ice-sheet model. We find that the estimated attenuation rates reproduce modelled patterns and values across the catchment with the greatest differences near steeply sloping bed topography. Article in Journal/Newspaper Antarc* Antarctica glacier Greenland Ice Sheet Journal of Glaciology Thwaites Glacier West Antarctica Cambridge University Press Journal of Glaciology 62 236 1075 1082 |
institution |
Open Polar |
collection |
Cambridge University Press |
op_collection_id |
crcambridgeupr |
language |
English |
description |
ABSTRACT Englacial temperature is a major control on ice rheology and flow. However, it is difficult to measure at the glacier to ice-sheet scale. As a result, ice-sheet models must make assumptions about englacial temperature and rheology, which affect sea level projections. This is problematic if fundamental processes are not captured by models due to a lack of observationally constrained ice temperature values. Although radar sounding data have been exploited to constrain the temperature structure of the Greenland ice sheet using englacial layers, this approach is limited to areas and depths where these layers exist intact. In order to extend empirical radar-based temperature estimation beyond this limitation, we present a new technique for estimating englacial attenuation rates for the entire ice column using adaptive fitting of unfocused radar bed echoes based on the correlation of ice thickness and corrected bed echo power. We apply this technique to an airborne survey of Thwaites Glacier in West Antarctica and compare the results with temperatures and attenuation rates from a numerical ice-sheet model. We find that the estimated attenuation rates reproduce modelled patterns and values across the catchment with the greatest differences near steeply sloping bed topography. |
format |
Article in Journal/Newspaper |
author |
SCHROEDER, DUSTIN M. SEROUSSI, HELENE CHU, WINNIE YOUNG, DUNCAN A. |
spellingShingle |
SCHROEDER, DUSTIN M. SEROUSSI, HELENE CHU, WINNIE YOUNG, DUNCAN A. Adaptively constraining radar attenuation and temperature across the Thwaites Glacier catchment using bed echoes |
author_facet |
SCHROEDER, DUSTIN M. SEROUSSI, HELENE CHU, WINNIE YOUNG, DUNCAN A. |
author_sort |
SCHROEDER, DUSTIN M. |
title |
Adaptively constraining radar attenuation and temperature across the Thwaites Glacier catchment using bed echoes |
title_short |
Adaptively constraining radar attenuation and temperature across the Thwaites Glacier catchment using bed echoes |
title_full |
Adaptively constraining radar attenuation and temperature across the Thwaites Glacier catchment using bed echoes |
title_fullStr |
Adaptively constraining radar attenuation and temperature across the Thwaites Glacier catchment using bed echoes |
title_full_unstemmed |
Adaptively constraining radar attenuation and temperature across the Thwaites Glacier catchment using bed echoes |
title_sort |
adaptively constraining radar attenuation and temperature across the thwaites glacier catchment using bed echoes |
publisher |
Cambridge University Press (CUP) |
publishDate |
2016 |
url |
http://dx.doi.org/10.1017/jog.2016.100 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143016001003 |
genre |
Antarc* Antarctica glacier Greenland Ice Sheet Journal of Glaciology Thwaites Glacier West Antarctica |
genre_facet |
Antarc* Antarctica glacier Greenland Ice Sheet Journal of Glaciology Thwaites Glacier West Antarctica |
op_source |
Journal of Glaciology volume 62, issue 236, page 1075-1082 ISSN 0022-1430 1727-5652 |
op_rights |
http://creativecommons.org/licenses/by/4.0/ |
op_doi |
https://doi.org/10.1017/jog.2016.100 |
container_title |
Journal of Glaciology |
container_volume |
62 |
container_issue |
236 |
container_start_page |
1075 |
op_container_end_page |
1082 |
_version_ |
1810497218264694784 |