Detecting high spatial variability of ice shelf basal mass balance, Roi Baudouin Ice Shelf, Antarctica
Ice shelves control the dynamic mass loss of ice sheets through buttressing and their integrity depends on the spatial variability of their basal mass balance (BMB), i.e. the difference between refreezing and melting. Here, we present an improved technique – based on satellite observations – to capt...
Published in: | The Cryosphere |
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Format: | Article in Journal/Newspaper |
Language: | English |
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Copernicus Publications
2017
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Online Access: | https://doi.org/10.5194/tc-11-2675-2017 https://www.the-cryosphere.net/11/2675/2017/tc-11-2675-2017.pdf https://doaj.org/article/26167eb2994544408941123dea2a7118 |
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fttriple:oai:gotriple.eu:oai:doaj.org/article:26167eb2994544408941123dea2a7118 2023-05-15T14:00:45+02:00 Detecting high spatial variability of ice shelf basal mass balance, Roi Baudouin Ice Shelf, Antarctica S. Berger R. Drews V. Helm S. Sun F. Pattyn 2017-11-01 https://doi.org/10.5194/tc-11-2675-2017 https://www.the-cryosphere.net/11/2675/2017/tc-11-2675-2017.pdf https://doaj.org/article/26167eb2994544408941123dea2a7118 en eng Copernicus Publications doi:10.5194/tc-11-2675-2017 1994-0416 1994-0424 https://www.the-cryosphere.net/11/2675/2017/tc-11-2675-2017.pdf https://doaj.org/article/26167eb2994544408941123dea2a7118 undefined The Cryosphere, Vol 11, Pp 2675-2690 (2017) geo envir Journal Article https://vocabularies.coar-repositories.org/resource_types/c_6501/ 2017 fttriple https://doi.org/10.5194/tc-11-2675-2017 2023-01-22T17:49:51Z Ice shelves control the dynamic mass loss of ice sheets through buttressing and their integrity depends on the spatial variability of their basal mass balance (BMB), i.e. the difference between refreezing and melting. Here, we present an improved technique – based on satellite observations – to capture the small-scale variability in the BMB of ice shelves. As a case study, we apply the methodology to the Roi Baudouin Ice Shelf, Dronning Maud Land, East Antarctica, and derive its yearly averaged BMB at 10 m horizontal gridding. We use mass conservation in a Lagrangian framework based on high-resolution surface velocities, atmospheric-model surface mass balance and hydrostatic ice-thickness fields (derived from TanDEM-X surface elevation). Spatial derivatives are implemented using the total-variation differentiation, which preserves abrupt changes in flow velocities and their spatial gradients. Such changes may reflect a dynamic response to localized basal melting and should be included in the mass budget. Our BMB field exhibits much spatial detail and ranges from −14.7 to 8.6 m a−1 ice equivalent. Highest melt rates are found close to the grounding line where the pressure melting point is high, and the ice shelf slope is steep. The BMB field agrees well with on-site measurements from phase-sensitive radar, although independent radar profiling indicates unresolved spatial variations in firn density. We show that an elliptical surface depression (10 m deep and with an extent of 0.7 km × 1.3 km) lowers by 0.5 to 1.4 m a−1, which we tentatively attribute to a transient adaptation to hydrostatic equilibrium. We find evidence for elevated melting beneath ice shelf channels (with melting being concentrated on the channel's flanks). However, farther downstream from the grounding line, the majority of ice shelf channels advect passively (i.e. no melting nor refreezing) toward the ice shelf front. Although the absolute, satellite-based BMB values remain uncertain, we have high confidence in the spatial variability on ... Article in Journal/Newspaper Antarc* Antarctica Dronning Maud Land East Antarctica Ice Shelf Ice Shelves The Cryosphere Unknown Dronning Maud Land East Antarctica Roi Baudouin ENVELOPE(24.461,24.461,-70.438,-70.438) The Cryosphere 11 6 2675 2690 |
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Open Polar |
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Unknown |
op_collection_id |
fttriple |
language |
English |
topic |
geo envir |
spellingShingle |
geo envir S. Berger R. Drews V. Helm S. Sun F. Pattyn Detecting high spatial variability of ice shelf basal mass balance, Roi Baudouin Ice Shelf, Antarctica |
topic_facet |
geo envir |
description |
Ice shelves control the dynamic mass loss of ice sheets through buttressing and their integrity depends on the spatial variability of their basal mass balance (BMB), i.e. the difference between refreezing and melting. Here, we present an improved technique – based on satellite observations – to capture the small-scale variability in the BMB of ice shelves. As a case study, we apply the methodology to the Roi Baudouin Ice Shelf, Dronning Maud Land, East Antarctica, and derive its yearly averaged BMB at 10 m horizontal gridding. We use mass conservation in a Lagrangian framework based on high-resolution surface velocities, atmospheric-model surface mass balance and hydrostatic ice-thickness fields (derived from TanDEM-X surface elevation). Spatial derivatives are implemented using the total-variation differentiation, which preserves abrupt changes in flow velocities and their spatial gradients. Such changes may reflect a dynamic response to localized basal melting and should be included in the mass budget. Our BMB field exhibits much spatial detail and ranges from −14.7 to 8.6 m a−1 ice equivalent. Highest melt rates are found close to the grounding line where the pressure melting point is high, and the ice shelf slope is steep. The BMB field agrees well with on-site measurements from phase-sensitive radar, although independent radar profiling indicates unresolved spatial variations in firn density. We show that an elliptical surface depression (10 m deep and with an extent of 0.7 km × 1.3 km) lowers by 0.5 to 1.4 m a−1, which we tentatively attribute to a transient adaptation to hydrostatic equilibrium. We find evidence for elevated melting beneath ice shelf channels (with melting being concentrated on the channel's flanks). However, farther downstream from the grounding line, the majority of ice shelf channels advect passively (i.e. no melting nor refreezing) toward the ice shelf front. Although the absolute, satellite-based BMB values remain uncertain, we have high confidence in the spatial variability on ... |
format |
Article in Journal/Newspaper |
author |
S. Berger R. Drews V. Helm S. Sun F. Pattyn |
author_facet |
S. Berger R. Drews V. Helm S. Sun F. Pattyn |
author_sort |
S. Berger |
title |
Detecting high spatial variability of ice shelf basal mass balance, Roi Baudouin Ice Shelf, Antarctica |
title_short |
Detecting high spatial variability of ice shelf basal mass balance, Roi Baudouin Ice Shelf, Antarctica |
title_full |
Detecting high spatial variability of ice shelf basal mass balance, Roi Baudouin Ice Shelf, Antarctica |
title_fullStr |
Detecting high spatial variability of ice shelf basal mass balance, Roi Baudouin Ice Shelf, Antarctica |
title_full_unstemmed |
Detecting high spatial variability of ice shelf basal mass balance, Roi Baudouin Ice Shelf, Antarctica |
title_sort |
detecting high spatial variability of ice shelf basal mass balance, roi baudouin ice shelf, antarctica |
publisher |
Copernicus Publications |
publishDate |
2017 |
url |
https://doi.org/10.5194/tc-11-2675-2017 https://www.the-cryosphere.net/11/2675/2017/tc-11-2675-2017.pdf https://doaj.org/article/26167eb2994544408941123dea2a7118 |
long_lat |
ENVELOPE(24.461,24.461,-70.438,-70.438) |
geographic |
Dronning Maud Land East Antarctica Roi Baudouin |
geographic_facet |
Dronning Maud Land East Antarctica Roi Baudouin |
genre |
Antarc* Antarctica Dronning Maud Land East Antarctica Ice Shelf Ice Shelves The Cryosphere |
genre_facet |
Antarc* Antarctica Dronning Maud Land East Antarctica Ice Shelf Ice Shelves The Cryosphere |
op_source |
The Cryosphere, Vol 11, Pp 2675-2690 (2017) |
op_relation |
doi:10.5194/tc-11-2675-2017 1994-0416 1994-0424 https://www.the-cryosphere.net/11/2675/2017/tc-11-2675-2017.pdf https://doaj.org/article/26167eb2994544408941123dea2a7118 |
op_rights |
undefined |
op_doi |
https://doi.org/10.5194/tc-11-2675-2017 |
container_title |
The Cryosphere |
container_volume |
11 |
container_issue |
6 |
container_start_page |
2675 |
op_container_end_page |
2690 |
_version_ |
1766270097160142848 |