An ice-sheet-wide framework for englacial attenuation from ice-penetrating radar data
International audience Radar inference of the bulk properties of glacier beds, most notably identifying basal melting, is, in general, derived from the basal reflection coefficient. On the scale of an ice sheet, unambiguous determination of basal reflection is primarily limited by uncertainty in the...
Published in: | The Cryosphere |
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Main Authors: | , , , , , , , |
Other Authors: | , , , , , , , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
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HAL CCSD
2016
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Online Access: | https://insu.hal.science/insu-01391628 https://insu.hal.science/insu-01391628/document https://insu.hal.science/insu-01391628/file/CRYOSPHERE%20-%20An%20ice-sheet-wide%20framework%20for%20englacial%20attenuation%20from%20ice-penetrating%20radar%20data.pdf https://doi.org/10.5194/tc-10-1547-2016 |
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ftunigrenoble:oai:HAL:insu-01391628v1 |
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institution |
Open Polar |
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Université Grenoble Alpes: HAL |
op_collection_id |
ftunigrenoble |
language |
English |
topic |
[SDE]Environmental Sciences |
spellingShingle |
[SDE]Environmental Sciences Jordan, T.M Bamber, J. L. Williams, C.N Paden, J.D Siegert, M.J. Huybrechts, P, D Gagliardini, Olivier Gillet-Chaulet, F, N An ice-sheet-wide framework for englacial attenuation from ice-penetrating radar data |
topic_facet |
[SDE]Environmental Sciences |
description |
International audience Radar inference of the bulk properties of glacier beds, most notably identifying basal melting, is, in general, derived from the basal reflection coefficient. On the scale of an ice sheet, unambiguous determination of basal reflection is primarily limited by uncertainty in the englacial attenu-ation of the radio wave, which is an Arrhenius function of temperature. Existing bed-returned power algorithms for deriving attenuation assume that the attenuation rate is regionally constant, which is not feasible at an ice-sheet-wide scale. Here we introduce a new semi-empirical framework for deriving englacial attenuation, and, to demonstrate its efficacy, we apply it to the Greenland Ice Sheet. A central feature is the use of a prior Arrhenius temperature model to estimate the spatial variation in englacial attenuation as a first guess input for the radar algorithm. We demonstrate regions of solution convergence for two input temperature fields and for independently analysed field campaigns. The coverage achieved is a trade-off with uncertainty and we propose that the algorithm can be " tuned " for discrimination of basal melt (attenuation loss uncertainty ∼ 5 dB). This is supported by our physically realistic (∼ 20 dB) range for the basal reflection coefficient. Finally, we show that the attenuation solution can be used to predict the temperature bias of thermomechan-ical ice sheet models and is in agreement with known model temperature biases at the Dye 3 ice core. |
author2 |
Bristol Glaciology Centre School of Geographical Sciences Center for Remote Sensing of Ice Sheets (CReSIS) University of Kansas Lawrence (KU) Grantham Institute and Earth Science and Engineering Imperial College London Earth System Sciences & Department of Geography Vrije Universiteit Brussel (VUB) Laboratoire de glaciologie et géophysique de l'environnement (LGGE) Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Observatoire des Sciences de l'Univers de Grenoble (OSUG ) Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB Université de Savoie Université de Chambéry )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes 2016-2019 (UGA 2016-2019 )-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB Université de Savoie Université de Chambéry )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes 2016-2019 (UGA 2016-2019 ) |
format |
Article in Journal/Newspaper |
author |
Jordan, T.M Bamber, J. L. Williams, C.N Paden, J.D Siegert, M.J. Huybrechts, P, D Gagliardini, Olivier Gillet-Chaulet, F, N |
author_facet |
Jordan, T.M Bamber, J. L. Williams, C.N Paden, J.D Siegert, M.J. Huybrechts, P, D Gagliardini, Olivier Gillet-Chaulet, F, N |
author_sort |
Jordan, T.M |
title |
An ice-sheet-wide framework for englacial attenuation from ice-penetrating radar data |
title_short |
An ice-sheet-wide framework for englacial attenuation from ice-penetrating radar data |
title_full |
An ice-sheet-wide framework for englacial attenuation from ice-penetrating radar data |
title_fullStr |
An ice-sheet-wide framework for englacial attenuation from ice-penetrating radar data |
title_full_unstemmed |
An ice-sheet-wide framework for englacial attenuation from ice-penetrating radar data |
title_sort |
ice-sheet-wide framework for englacial attenuation from ice-penetrating radar data |
publisher |
HAL CCSD |
publishDate |
2016 |
url |
https://insu.hal.science/insu-01391628 https://insu.hal.science/insu-01391628/document https://insu.hal.science/insu-01391628/file/CRYOSPHERE%20-%20An%20ice-sheet-wide%20framework%20for%20englacial%20attenuation%20from%20ice-penetrating%20radar%20data.pdf https://doi.org/10.5194/tc-10-1547-2016 |
geographic |
Greenland |
geographic_facet |
Greenland |
genre |
Dye 3 Dye-3 glacier Greenland ice core Ice Sheet The Cryosphere |
genre_facet |
Dye 3 Dye-3 glacier Greenland ice core Ice Sheet The Cryosphere |
op_source |
ISSN: 1994-0424 EISSN: 1994-0416 The Cryosphere https://insu.hal.science/insu-01391628 The Cryosphere, 2016, 10, pp.1547 - 1570. ⟨10.5194/tc-10-1547-2016⟩ |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.5194/tc-10-1547-2016 insu-01391628 https://insu.hal.science/insu-01391628 https://insu.hal.science/insu-01391628/document https://insu.hal.science/insu-01391628/file/CRYOSPHERE%20-%20An%20ice-sheet-wide%20framework%20for%20englacial%20attenuation%20from%20ice-penetrating%20radar%20data.pdf doi:10.5194/tc-10-1547-2016 |
op_rights |
info:eu-repo/semantics/OpenAccess |
op_doi |
https://doi.org/10.5194/tc-10-1547-2016 |
container_title |
The Cryosphere |
container_volume |
10 |
container_issue |
4 |
container_start_page |
1547 |
op_container_end_page |
1570 |
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1798845124572086272 |
spelling |
ftunigrenoble:oai:HAL:insu-01391628v1 2024-05-12T08:03:00+00:00 An ice-sheet-wide framework for englacial attenuation from ice-penetrating radar data Jordan, T.M Bamber, J. L. Williams, C.N Paden, J.D Siegert, M.J. Huybrechts, P, D Gagliardini, Olivier Gillet-Chaulet, F, N Bristol Glaciology Centre School of Geographical Sciences Center for Remote Sensing of Ice Sheets (CReSIS) University of Kansas Lawrence (KU) Grantham Institute and Earth Science and Engineering Imperial College London Earth System Sciences & Department of Geography Vrije Universiteit Brussel (VUB) Laboratoire de glaciologie et géophysique de l'environnement (LGGE) Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Observatoire des Sciences de l'Univers de Grenoble (OSUG ) Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB Université de Savoie Université de Chambéry )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes 2016-2019 (UGA 2016-2019 )-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB Université de Savoie Université de Chambéry )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes 2016-2019 (UGA 2016-2019 ) 2016 https://insu.hal.science/insu-01391628 https://insu.hal.science/insu-01391628/document https://insu.hal.science/insu-01391628/file/CRYOSPHERE%20-%20An%20ice-sheet-wide%20framework%20for%20englacial%20attenuation%20from%20ice-penetrating%20radar%20data.pdf https://doi.org/10.5194/tc-10-1547-2016 en eng HAL CCSD Copernicus info:eu-repo/semantics/altIdentifier/doi/10.5194/tc-10-1547-2016 insu-01391628 https://insu.hal.science/insu-01391628 https://insu.hal.science/insu-01391628/document https://insu.hal.science/insu-01391628/file/CRYOSPHERE%20-%20An%20ice-sheet-wide%20framework%20for%20englacial%20attenuation%20from%20ice-penetrating%20radar%20data.pdf doi:10.5194/tc-10-1547-2016 info:eu-repo/semantics/OpenAccess ISSN: 1994-0424 EISSN: 1994-0416 The Cryosphere https://insu.hal.science/insu-01391628 The Cryosphere, 2016, 10, pp.1547 - 1570. ⟨10.5194/tc-10-1547-2016⟩ [SDE]Environmental Sciences info:eu-repo/semantics/article Journal articles 2016 ftunigrenoble https://doi.org/10.5194/tc-10-1547-2016 2024-04-18T04:15:31Z International audience Radar inference of the bulk properties of glacier beds, most notably identifying basal melting, is, in general, derived from the basal reflection coefficient. On the scale of an ice sheet, unambiguous determination of basal reflection is primarily limited by uncertainty in the englacial attenu-ation of the radio wave, which is an Arrhenius function of temperature. Existing bed-returned power algorithms for deriving attenuation assume that the attenuation rate is regionally constant, which is not feasible at an ice-sheet-wide scale. Here we introduce a new semi-empirical framework for deriving englacial attenuation, and, to demonstrate its efficacy, we apply it to the Greenland Ice Sheet. A central feature is the use of a prior Arrhenius temperature model to estimate the spatial variation in englacial attenuation as a first guess input for the radar algorithm. We demonstrate regions of solution convergence for two input temperature fields and for independently analysed field campaigns. The coverage achieved is a trade-off with uncertainty and we propose that the algorithm can be " tuned " for discrimination of basal melt (attenuation loss uncertainty ∼ 5 dB). This is supported by our physically realistic (∼ 20 dB) range for the basal reflection coefficient. Finally, we show that the attenuation solution can be used to predict the temperature bias of thermomechan-ical ice sheet models and is in agreement with known model temperature biases at the Dye 3 ice core. Article in Journal/Newspaper Dye 3 Dye-3 glacier Greenland ice core Ice Sheet The Cryosphere Université Grenoble Alpes: HAL Greenland The Cryosphere 10 4 1547 1570 |