Predicting radar attenuation within the Antarctic ice sheet
To better understand the ability of ice-penetrating radar to diagnose the subglacial environment from bed-returned power, we model the englacial radar attenuation of Antarctic ice. First, we use a one-dimensional thermo-mechanical model to evaluate the sensitivity of the depth-averaged attenuation r...
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ftunivbruxelles:oai:dipot.ulb.ac.be:2013/168469 2023-05-15T13:37:29+02:00 Predicting radar attenuation within the Antarctic ice sheet Matsuoka, Kenichi MacGregor, Joseph A. Pattyn, Frank 2012-12 1 full-text file(s): application/pdf http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/168469 https://dipot.ulb.ac.be/dspace/bitstream/2013/168469/1/Elsevier_152099.pdf en eng uri/info:doi/10.1016/j.epsl.2012.10.018 uri/info:pii/S0012821X1200578X uri/info:scp/84868591086 https://dipot.ulb.ac.be/dspace/bitstream/2013/168469/1/Elsevier_152099.pdf http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/168469 1 full-text file(s): info:eu-repo/semantics/restrictedAccess Earth and planetary science letters, 359-360 Sciences de l'espace Géographie physique Pétrologie Géochimie Sciences de la terre et du cosmos Antarctic ice sheet Englacial attenuation Radar remote sensing Subglacial environment Thermo-mechanical modeling info:eu-repo/semantics/article info:ulb-repo/semantics/articlePeerReview info:ulb-repo/semantics/openurl/article 2012 ftunivbruxelles 2022-06-12T22:09:17Z To better understand the ability of ice-penetrating radar to diagnose the subglacial environment from bed-returned power, we model the englacial radar attenuation of Antarctic ice. First, we use a one-dimensional thermo-mechanical model to evaluate the sensitivity of the depth-averaged attenuation rates to ice temperature as a function of surface accumulation rate, geothermal flux, and ice thickness. We find that attenuation is most sensitive to variations in geothermal flux and accumulation rate when the bed temperature is close to the pressure-melting point. But even if geothermal flux and accumulation rate remain fixed, attenuation can easily vary with ice thickness. Such high sensitivities show that one should not assume a uniform attenuation rate in the radar data analysis. Then, using ensembles of modeled ice temperatures with different boundary conditions, we generate multiple attenuation predictions for the Antarctic ice sheet and evaluate the resulting uncertainties. The largest contributor to uncertainty in these predictions is the geothermal flux. This uncertainty is localized within the deeper half of the ice sheet. By combining these temperature ensembles with ice-core chemistry data, we show that the sea salt adds little to the attenuation, but the contribution from acids accounts for ~29% (inland) to ~53% (coast) of the total attenuation. We conclude that improving radar diagnosis of the subglacial environment using bed-returned power requires both (1) better data-interpretation algorithms that account for attenuation variations and (2) better constraints of geothermal flux and bulk chemistry. © 2012 Elsevier B.V. SCOPUS: ar.j info:eu-repo/semantics/published Article in Journal/Newspaper Antarc* Antarctic ice core Ice Sheet DI-fusion : dépôt institutionnel de l'Université libre de Bruxelles (ULB) Antarctic The Antarctic |
institution |
Open Polar |
collection |
DI-fusion : dépôt institutionnel de l'Université libre de Bruxelles (ULB) |
op_collection_id |
ftunivbruxelles |
language |
English |
topic |
Sciences de l'espace Géographie physique Pétrologie Géochimie Sciences de la terre et du cosmos Antarctic ice sheet Englacial attenuation Radar remote sensing Subglacial environment Thermo-mechanical modeling |
spellingShingle |
Sciences de l'espace Géographie physique Pétrologie Géochimie Sciences de la terre et du cosmos Antarctic ice sheet Englacial attenuation Radar remote sensing Subglacial environment Thermo-mechanical modeling Matsuoka, Kenichi MacGregor, Joseph A. Pattyn, Frank Predicting radar attenuation within the Antarctic ice sheet |
topic_facet |
Sciences de l'espace Géographie physique Pétrologie Géochimie Sciences de la terre et du cosmos Antarctic ice sheet Englacial attenuation Radar remote sensing Subglacial environment Thermo-mechanical modeling |
description |
To better understand the ability of ice-penetrating radar to diagnose the subglacial environment from bed-returned power, we model the englacial radar attenuation of Antarctic ice. First, we use a one-dimensional thermo-mechanical model to evaluate the sensitivity of the depth-averaged attenuation rates to ice temperature as a function of surface accumulation rate, geothermal flux, and ice thickness. We find that attenuation is most sensitive to variations in geothermal flux and accumulation rate when the bed temperature is close to the pressure-melting point. But even if geothermal flux and accumulation rate remain fixed, attenuation can easily vary with ice thickness. Such high sensitivities show that one should not assume a uniform attenuation rate in the radar data analysis. Then, using ensembles of modeled ice temperatures with different boundary conditions, we generate multiple attenuation predictions for the Antarctic ice sheet and evaluate the resulting uncertainties. The largest contributor to uncertainty in these predictions is the geothermal flux. This uncertainty is localized within the deeper half of the ice sheet. By combining these temperature ensembles with ice-core chemistry data, we show that the sea salt adds little to the attenuation, but the contribution from acids accounts for ~29% (inland) to ~53% (coast) of the total attenuation. We conclude that improving radar diagnosis of the subglacial environment using bed-returned power requires both (1) better data-interpretation algorithms that account for attenuation variations and (2) better constraints of geothermal flux and bulk chemistry. © 2012 Elsevier B.V. SCOPUS: ar.j info:eu-repo/semantics/published |
format |
Article in Journal/Newspaper |
author |
Matsuoka, Kenichi MacGregor, Joseph A. Pattyn, Frank |
author_facet |
Matsuoka, Kenichi MacGregor, Joseph A. Pattyn, Frank |
author_sort |
Matsuoka, Kenichi |
title |
Predicting radar attenuation within the Antarctic ice sheet |
title_short |
Predicting radar attenuation within the Antarctic ice sheet |
title_full |
Predicting radar attenuation within the Antarctic ice sheet |
title_fullStr |
Predicting radar attenuation within the Antarctic ice sheet |
title_full_unstemmed |
Predicting radar attenuation within the Antarctic ice sheet |
title_sort |
predicting radar attenuation within the antarctic ice sheet |
publishDate |
2012 |
url |
http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/168469 https://dipot.ulb.ac.be/dspace/bitstream/2013/168469/1/Elsevier_152099.pdf |
geographic |
Antarctic The Antarctic |
geographic_facet |
Antarctic The Antarctic |
genre |
Antarc* Antarctic ice core Ice Sheet |
genre_facet |
Antarc* Antarctic ice core Ice Sheet |
op_source |
Earth and planetary science letters, 359-360 |
op_relation |
uri/info:doi/10.1016/j.epsl.2012.10.018 uri/info:pii/S0012821X1200578X uri/info:scp/84868591086 https://dipot.ulb.ac.be/dspace/bitstream/2013/168469/1/Elsevier_152099.pdf http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/168469 |
op_rights |
1 full-text file(s): info:eu-repo/semantics/restrictedAccess |
_version_ |
1766092504576294912 |