Seasonal to decadal variability in ice discharge from the Greenland Ice Sheet.
peer reviewed Rapid changes in thickness and velocity have been observed at many marine-terminating glaciers in Greenland, impacting the volume of ice they export, or discharge, from the ice sheet. While annual estimates of ice-sheet wide discharge have been previously derived, higher-resolution rec...
Published in: | The Cryosphere |
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Language: | English |
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Copernicus GmbH
2018
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Online Access: | https://orbi.uliege.be/handle/2268/301916 https://orbi.uliege.be/bitstream/2268/301916/1/King_TC_2018.pdf https://doi.org/10.5194/tc-12-3813-2018 |
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ftorbi:oai:orbi.ulg.ac.be:2268/301916 2024-04-21T08:02:30+00:00 Seasonal to decadal variability in ice discharge from the Greenland Ice Sheet. King, Michalea D Howat, Ian M Jeong, Seongsu Noh, Myoung J Wouters, Bert Noël, Brice van den Broeke, Michiel R 2018 https://orbi.uliege.be/handle/2268/301916 https://orbi.uliege.be/bitstream/2268/301916/1/King_TC_2018.pdf https://doi.org/10.5194/tc-12-3813-2018 en eng Copernicus GmbH https://tc.copernicus.org/articles/12/3813/2018/tc-12-3813-2018.pdf urn:issn:1994-0416 urn:issn:1994-0424 https://orbi.uliege.be/handle/2268/301916 info:hdl:2268/301916 https://orbi.uliege.be/bitstream/2268/301916/1/King_TC_2018.pdf doi:10.5194/tc-12-3813-2018 scopus-id:2-s2.0-85057744550 info:pmid:31217911 open access http://purl.org/coar/access_right/c_abf2 info:eu-repo/semantics/openAccess The Cryosphere, 12 (12), 3813 - 3825 (2018) Water Science and Technology Earth-Surface Processes Physical chemical mathematical & earth Sciences Earth sciences & physical geography Physique chimie mathématiques & sciences de la terre Sciences de la terre & géographie physique journal article http://purl.org/coar/resource_type/c_6501 info:eu-repo/semantics/article peer reviewed 2018 ftorbi https://doi.org/10.5194/tc-12-3813-2018 2024-03-27T14:58:15Z peer reviewed Rapid changes in thickness and velocity have been observed at many marine-terminating glaciers in Greenland, impacting the volume of ice they export, or discharge, from the ice sheet. While annual estimates of ice-sheet wide discharge have been previously derived, higher-resolution records are required to fully constrain the temporal response of these glaciers to various climatic and mechanical drivers that vary in sub-annual scales. Here we sample outlet glaciers wider than 1 km (N = 230) to derive the first continuous, ice-sheet wide record of total ice sheet discharge for the 2000-2016 period, resolving a seasonal variability of 6 %. The amplitude of seasonality varies spatially across the ice sheet from 5 % in the southeastern region to 9 % in the northwest region. We analyze seasonal to annual variability in the discharge time series with respect to both modelled meltwater runoff, obtained from RACMO2.3p2, and glacier front position changes over the same period. We find that year-to-year changes in total ice sheet discharge are related to annual front changes (r 2 = 0.59, p = 10-4) and that the annual magnitude of discharge is closely related to cumulative front position changes (r 2 = 0.79), which show a net retreat of > 400 km, or an average retreat of > 2 km at each surveyed glacier. Neither maximum seasonal runoff or annual runoff totals are correlated to annual discharge, which suggests that larger annual quantities of runoff do not relate to increased annual discharge. Discharge and runoff, however, follow similar patterns of seasonal variability with near-coincident periods of acceleration and seasonal maxima. These results suggest that changes in glacier front position drive secular trends in discharge, whereas the impact of runoff is likely limited to the summer months when observed seasonal variations are substantially controlled by the timing of meltwater input. Article in Journal/Newspaper glacier Greenland Ice Sheet The Cryosphere University of Liège: ORBi (Open Repository and Bibliography) The Cryosphere 12 12 3813 3825 |
institution |
Open Polar |
collection |
University of Liège: ORBi (Open Repository and Bibliography) |
op_collection_id |
ftorbi |
language |
English |
topic |
Water Science and Technology Earth-Surface Processes Physical chemical mathematical & earth Sciences Earth sciences & physical geography Physique chimie mathématiques & sciences de la terre Sciences de la terre & géographie physique |
spellingShingle |
Water Science and Technology Earth-Surface Processes Physical chemical mathematical & earth Sciences Earth sciences & physical geography Physique chimie mathématiques & sciences de la terre Sciences de la terre & géographie physique King, Michalea D Howat, Ian M Jeong, Seongsu Noh, Myoung J Wouters, Bert Noël, Brice van den Broeke, Michiel R Seasonal to decadal variability in ice discharge from the Greenland Ice Sheet. |
topic_facet |
Water Science and Technology Earth-Surface Processes Physical chemical mathematical & earth Sciences Earth sciences & physical geography Physique chimie mathématiques & sciences de la terre Sciences de la terre & géographie physique |
description |
peer reviewed Rapid changes in thickness and velocity have been observed at many marine-terminating glaciers in Greenland, impacting the volume of ice they export, or discharge, from the ice sheet. While annual estimates of ice-sheet wide discharge have been previously derived, higher-resolution records are required to fully constrain the temporal response of these glaciers to various climatic and mechanical drivers that vary in sub-annual scales. Here we sample outlet glaciers wider than 1 km (N = 230) to derive the first continuous, ice-sheet wide record of total ice sheet discharge for the 2000-2016 period, resolving a seasonal variability of 6 %. The amplitude of seasonality varies spatially across the ice sheet from 5 % in the southeastern region to 9 % in the northwest region. We analyze seasonal to annual variability in the discharge time series with respect to both modelled meltwater runoff, obtained from RACMO2.3p2, and glacier front position changes over the same period. We find that year-to-year changes in total ice sheet discharge are related to annual front changes (r 2 = 0.59, p = 10-4) and that the annual magnitude of discharge is closely related to cumulative front position changes (r 2 = 0.79), which show a net retreat of > 400 km, or an average retreat of > 2 km at each surveyed glacier. Neither maximum seasonal runoff or annual runoff totals are correlated to annual discharge, which suggests that larger annual quantities of runoff do not relate to increased annual discharge. Discharge and runoff, however, follow similar patterns of seasonal variability with near-coincident periods of acceleration and seasonal maxima. These results suggest that changes in glacier front position drive secular trends in discharge, whereas the impact of runoff is likely limited to the summer months when observed seasonal variations are substantially controlled by the timing of meltwater input. |
format |
Article in Journal/Newspaper |
author |
King, Michalea D Howat, Ian M Jeong, Seongsu Noh, Myoung J Wouters, Bert Noël, Brice van den Broeke, Michiel R |
author_facet |
King, Michalea D Howat, Ian M Jeong, Seongsu Noh, Myoung J Wouters, Bert Noël, Brice van den Broeke, Michiel R |
author_sort |
King, Michalea D |
title |
Seasonal to decadal variability in ice discharge from the Greenland Ice Sheet. |
title_short |
Seasonal to decadal variability in ice discharge from the Greenland Ice Sheet. |
title_full |
Seasonal to decadal variability in ice discharge from the Greenland Ice Sheet. |
title_fullStr |
Seasonal to decadal variability in ice discharge from the Greenland Ice Sheet. |
title_full_unstemmed |
Seasonal to decadal variability in ice discharge from the Greenland Ice Sheet. |
title_sort |
seasonal to decadal variability in ice discharge from the greenland ice sheet. |
publisher |
Copernicus GmbH |
publishDate |
2018 |
url |
https://orbi.uliege.be/handle/2268/301916 https://orbi.uliege.be/bitstream/2268/301916/1/King_TC_2018.pdf https://doi.org/10.5194/tc-12-3813-2018 |
genre |
glacier Greenland Ice Sheet The Cryosphere |
genre_facet |
glacier Greenland Ice Sheet The Cryosphere |
op_source |
The Cryosphere, 12 (12), 3813 - 3825 (2018) |
op_relation |
https://tc.copernicus.org/articles/12/3813/2018/tc-12-3813-2018.pdf urn:issn:1994-0416 urn:issn:1994-0424 https://orbi.uliege.be/handle/2268/301916 info:hdl:2268/301916 https://orbi.uliege.be/bitstream/2268/301916/1/King_TC_2018.pdf doi:10.5194/tc-12-3813-2018 scopus-id:2-s2.0-85057744550 info:pmid:31217911 |
op_rights |
open access http://purl.org/coar/access_right/c_abf2 info:eu-repo/semantics/openAccess |
op_doi |
https://doi.org/10.5194/tc-12-3813-2018 |
container_title |
The Cryosphere |
container_volume |
12 |
container_issue |
12 |
container_start_page |
3813 |
op_container_end_page |
3825 |
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1796942676478656512 |