Surface emergence of glacial plumes determined by fjord stratification
Meltwater and sediment-laden plumes at tidewater glaciers, resulting from the localized subglacial discharge of surface melt, influence submarine melting of the glacier and the delivery of nutrients to the fjord's surface waters. It is usually assumed that increased subglacial discharge will pr...
Published in: | The Cryosphere |
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Main Authors: | , , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
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2020
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Online Access: | https://risweb.st-andrews.ac.uk/portal/en/researchoutput/surface-emergence-of-glacial-plumes-determined-by-fjord-stratification(27936657-c3bb-4bbf-83a0-78ac3113b3a4).html https://doi.org/10.5194/tc-14-1951-2020 https://research-repository.st-andrews.ac.uk/bitstream/10023/20143/1/DeAndr_s_2020_Cryosphere_Surface_CC.pdf |
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ftunstandrewcris:oai:risweb.st-andrews.ac.uk:publications/27936657-c3bb-4bbf-83a0-78ac3113b3a4 2023-05-15T16:21:17+02:00 Surface emergence of glacial plumes determined by fjord stratification De Andrés, E. Slater, Donald A. Straneo, F. Otero, J. Das, S. Navarro, F. 2020-06-18 application/pdf https://risweb.st-andrews.ac.uk/portal/en/researchoutput/surface-emergence-of-glacial-plumes-determined-by-fjord-stratification(27936657-c3bb-4bbf-83a0-78ac3113b3a4).html https://doi.org/10.5194/tc-14-1951-2020 https://research-repository.st-andrews.ac.uk/bitstream/10023/20143/1/DeAndr_s_2020_Cryosphere_Surface_CC.pdf eng eng info:eu-repo/semantics/openAccess De Andrés , E , Slater , D A , Straneo , F , Otero , J , Das , S & Navarro , F 2020 , ' Surface emergence of glacial plumes determined by fjord stratification ' , The Cryosphere , vol. 14 , no. 6 , pp. 1951-1969 . https://doi.org/10.5194/tc-14-1951-2020 article 2020 ftunstandrewcris https://doi.org/10.5194/tc-14-1951-2020 2021-12-26T14:36:54Z Meltwater and sediment-laden plumes at tidewater glaciers, resulting from the localized subglacial discharge of surface melt, influence submarine melting of the glacier and the delivery of nutrients to the fjord's surface waters. It is usually assumed that increased subglacial discharge will promote the surfacing of these plumes. Here, at a western Greenland tidewater glacier, we investigate the counterintuitive observation of a non-surfacing plume in July 2012 (a year of record surface melting) compared to the surfacing of the plume in July 2013 (an average melt year). We combine oceanographic observations, subglacial discharge estimates and an idealized plume model to explain the observed plumes' behavior and evaluate the relative impact of fjord stratification and subglacial discharge on plume dynamics. We find that increased fjord stratification prevented the plume from surfacing in 2012, show that the fjord was more stratified in 2012 due to increased freshwater content and speculate that this arose from an accumulation of ice sheet surface meltwater in the fjord in this record melt year. By developing theoretical scalings, we show that fjord stratification in general exerts a dominant control on plume vertical extent (and thus surface expression), so that studies using plume surface expression as a means of diagnosing variability in glacial processes should account for possible changes in stratification. We introduce the idea that, despite projections of increased surface melting over Greenland, the appearance of plumes at the fjord surface could in the future become less common if the increased freshwater acts to stratify fjords around the Greenland ice sheet. We discuss the implications of our findings for nutrient fluxes, trapping of atmospheric CO 2 and the properties of water exported from Greenland's fjords. Article in Journal/Newspaper glacier Greenland Ice Sheet The Cryosphere Tidewater University of St Andrews: Research Portal Greenland The Cryosphere 14 6 1951 1969 |
institution |
Open Polar |
collection |
University of St Andrews: Research Portal |
op_collection_id |
ftunstandrewcris |
language |
English |
description |
Meltwater and sediment-laden plumes at tidewater glaciers, resulting from the localized subglacial discharge of surface melt, influence submarine melting of the glacier and the delivery of nutrients to the fjord's surface waters. It is usually assumed that increased subglacial discharge will promote the surfacing of these plumes. Here, at a western Greenland tidewater glacier, we investigate the counterintuitive observation of a non-surfacing plume in July 2012 (a year of record surface melting) compared to the surfacing of the plume in July 2013 (an average melt year). We combine oceanographic observations, subglacial discharge estimates and an idealized plume model to explain the observed plumes' behavior and evaluate the relative impact of fjord stratification and subglacial discharge on plume dynamics. We find that increased fjord stratification prevented the plume from surfacing in 2012, show that the fjord was more stratified in 2012 due to increased freshwater content and speculate that this arose from an accumulation of ice sheet surface meltwater in the fjord in this record melt year. By developing theoretical scalings, we show that fjord stratification in general exerts a dominant control on plume vertical extent (and thus surface expression), so that studies using plume surface expression as a means of diagnosing variability in glacial processes should account for possible changes in stratification. We introduce the idea that, despite projections of increased surface melting over Greenland, the appearance of plumes at the fjord surface could in the future become less common if the increased freshwater acts to stratify fjords around the Greenland ice sheet. We discuss the implications of our findings for nutrient fluxes, trapping of atmospheric CO 2 and the properties of water exported from Greenland's fjords. |
format |
Article in Journal/Newspaper |
author |
De Andrés, E. Slater, Donald A. Straneo, F. Otero, J. Das, S. Navarro, F. |
spellingShingle |
De Andrés, E. Slater, Donald A. Straneo, F. Otero, J. Das, S. Navarro, F. Surface emergence of glacial plumes determined by fjord stratification |
author_facet |
De Andrés, E. Slater, Donald A. Straneo, F. Otero, J. Das, S. Navarro, F. |
author_sort |
De Andrés, E. |
title |
Surface emergence of glacial plumes determined by fjord stratification |
title_short |
Surface emergence of glacial plumes determined by fjord stratification |
title_full |
Surface emergence of glacial plumes determined by fjord stratification |
title_fullStr |
Surface emergence of glacial plumes determined by fjord stratification |
title_full_unstemmed |
Surface emergence of glacial plumes determined by fjord stratification |
title_sort |
surface emergence of glacial plumes determined by fjord stratification |
publishDate |
2020 |
url |
https://risweb.st-andrews.ac.uk/portal/en/researchoutput/surface-emergence-of-glacial-plumes-determined-by-fjord-stratification(27936657-c3bb-4bbf-83a0-78ac3113b3a4).html https://doi.org/10.5194/tc-14-1951-2020 https://research-repository.st-andrews.ac.uk/bitstream/10023/20143/1/DeAndr_s_2020_Cryosphere_Surface_CC.pdf |
geographic |
Greenland |
geographic_facet |
Greenland |
genre |
glacier Greenland Ice Sheet The Cryosphere Tidewater |
genre_facet |
glacier Greenland Ice Sheet The Cryosphere Tidewater |
op_source |
De Andrés , E , Slater , D A , Straneo , F , Otero , J , Das , S & Navarro , F 2020 , ' Surface emergence of glacial plumes determined by fjord stratification ' , The Cryosphere , vol. 14 , no. 6 , pp. 1951-1969 . https://doi.org/10.5194/tc-14-1951-2020 |
op_rights |
info:eu-repo/semantics/openAccess |
op_doi |
https://doi.org/10.5194/tc-14-1951-2020 |
container_title |
The Cryosphere |
container_volume |
14 |
container_issue |
6 |
container_start_page |
1951 |
op_container_end_page |
1969 |
_version_ |
1766009287424868352 |