Characteristics of meltwater export from Jakobshavn Isbræ and Ilulissat Icefjord
© The Author(s), 2017. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Annals of Glaciology 58 (2017): 107-117, doi:10.1017/aog.2017.19. Jakobshavn Isbræ, which terminates in Ilulissat Icefjord, has undergone rapid retr...
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Online Access: | https://hdl.handle.net/1912/9433 |
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ftwhoas:oai:darchive.mblwhoilibrary.org:1912/9433 2023-05-15T13:29:07+02:00 Characteristics of meltwater export from Jakobshavn Isbræ and Ilulissat Icefjord Beaird, Nicholas Straneo, Fiamma Jenkins, William J. 2017-09-04 https://hdl.handle.net/1912/9433 en_US eng Cambridge University Press https://doi.org/10.1017/aog.2017.19 Annals of Glaciology 58 (2017): 107-117 https://hdl.handle.net/1912/9433 doi:10.1017/aog.2017.19 Attribution 4.0 International http://creativecommons.org/licenses/by/4.0/ CC-BY Annals of Glaciology 58 (2017): 107-117 doi:10.1017/aog.2017.19 Glacier discharge Icebergs Ice/ocean interactions Meltwater chemistry Polar and subpolar oceans Article 2017 ftwhoas https://doi.org/10.1017/aog.2017.19 2022-05-28T23:00:04Z © The Author(s), 2017. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Annals of Glaciology 58 (2017): 107-117, doi:10.1017/aog.2017.19. Jakobshavn Isbræ, which terminates in Ilulissat Icefjord, has undergone rapid retreat and is currently the largest contributor to ice-sheet mass loss among Greenland’s marine terminating glaciers. Accelerating mass loss is increasing fresh water discharge to the ocean, which can feed back on ice melt, impact marine ecosystems and potentially modify regional and larger scale ocean circulation. Here we present hydrographic observations, including inert geochemical tracers, that allow the first quantitative description of the glacially-modified waters exported from the Jakobshavn/Icefjord system. Observations within the fjord suggest a deep-reaching overturning cell driven by glacial buoyancy forcing. Modified waters containing submarine meltwater (up to 2.5 ± 0.12%), subglacial discharge (up to 6 ± 0.37%) and large portions of entrained ocean waters are seen to exit the fjord and flow north. The exported meltwaters form a buoyant coastal gravity current reaching to 100 m depth and extending 10 km offshore. We gratefully acknowledge support from WHOI’s Ocean and Climate Change Institute, the WHOI Doherty Postdoctoral Scholarship, the US National Science Foundation grant NSF OCE-1536856, and the leaders and participants of the Advanced Climate Dynamics Summer School (SiU grant NNA-2012/10151). Ship-based CTD data are freely available from the NOAA National Centers for Environmental Information, discoverable with Accession Number 0162649. Expendable CTD data are included in the Supplementary Material. Article in Journal/Newspaper Annals of Glaciology Ice Sheet Ilulissat Jakobshavn Jakobshavn isbræ Woods Hole Scientific Community: WHOAS (Woods Hole Open Access Server) Ilulissat ENVELOPE(-51.099,-51.099,69.220,69.220) Jakobshavn Isbræ ENVELOPE(-49.917,-49.917,69.167,69.167) Annals of Glaciology 58 74 107 117 |
institution |
Open Polar |
collection |
Woods Hole Scientific Community: WHOAS (Woods Hole Open Access Server) |
op_collection_id |
ftwhoas |
language |
English |
topic |
Glacier discharge Icebergs Ice/ocean interactions Meltwater chemistry Polar and subpolar oceans |
spellingShingle |
Glacier discharge Icebergs Ice/ocean interactions Meltwater chemistry Polar and subpolar oceans Beaird, Nicholas Straneo, Fiamma Jenkins, William J. Characteristics of meltwater export from Jakobshavn Isbræ and Ilulissat Icefjord |
topic_facet |
Glacier discharge Icebergs Ice/ocean interactions Meltwater chemistry Polar and subpolar oceans |
description |
© The Author(s), 2017. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Annals of Glaciology 58 (2017): 107-117, doi:10.1017/aog.2017.19. Jakobshavn Isbræ, which terminates in Ilulissat Icefjord, has undergone rapid retreat and is currently the largest contributor to ice-sheet mass loss among Greenland’s marine terminating glaciers. Accelerating mass loss is increasing fresh water discharge to the ocean, which can feed back on ice melt, impact marine ecosystems and potentially modify regional and larger scale ocean circulation. Here we present hydrographic observations, including inert geochemical tracers, that allow the first quantitative description of the glacially-modified waters exported from the Jakobshavn/Icefjord system. Observations within the fjord suggest a deep-reaching overturning cell driven by glacial buoyancy forcing. Modified waters containing submarine meltwater (up to 2.5 ± 0.12%), subglacial discharge (up to 6 ± 0.37%) and large portions of entrained ocean waters are seen to exit the fjord and flow north. The exported meltwaters form a buoyant coastal gravity current reaching to 100 m depth and extending 10 km offshore. We gratefully acknowledge support from WHOI’s Ocean and Climate Change Institute, the WHOI Doherty Postdoctoral Scholarship, the US National Science Foundation grant NSF OCE-1536856, and the leaders and participants of the Advanced Climate Dynamics Summer School (SiU grant NNA-2012/10151). Ship-based CTD data are freely available from the NOAA National Centers for Environmental Information, discoverable with Accession Number 0162649. Expendable CTD data are included in the Supplementary Material. |
format |
Article in Journal/Newspaper |
author |
Beaird, Nicholas Straneo, Fiamma Jenkins, William J. |
author_facet |
Beaird, Nicholas Straneo, Fiamma Jenkins, William J. |
author_sort |
Beaird, Nicholas |
title |
Characteristics of meltwater export from Jakobshavn Isbræ and Ilulissat Icefjord |
title_short |
Characteristics of meltwater export from Jakobshavn Isbræ and Ilulissat Icefjord |
title_full |
Characteristics of meltwater export from Jakobshavn Isbræ and Ilulissat Icefjord |
title_fullStr |
Characteristics of meltwater export from Jakobshavn Isbræ and Ilulissat Icefjord |
title_full_unstemmed |
Characteristics of meltwater export from Jakobshavn Isbræ and Ilulissat Icefjord |
title_sort |
characteristics of meltwater export from jakobshavn isbræ and ilulissat icefjord |
publisher |
Cambridge University Press |
publishDate |
2017 |
url |
https://hdl.handle.net/1912/9433 |
long_lat |
ENVELOPE(-51.099,-51.099,69.220,69.220) ENVELOPE(-49.917,-49.917,69.167,69.167) |
geographic |
Ilulissat Jakobshavn Isbræ |
geographic_facet |
Ilulissat Jakobshavn Isbræ |
genre |
Annals of Glaciology Ice Sheet Ilulissat Jakobshavn Jakobshavn isbræ |
genre_facet |
Annals of Glaciology Ice Sheet Ilulissat Jakobshavn Jakobshavn isbræ |
op_source |
Annals of Glaciology 58 (2017): 107-117 doi:10.1017/aog.2017.19 |
op_relation |
https://doi.org/10.1017/aog.2017.19 Annals of Glaciology 58 (2017): 107-117 https://hdl.handle.net/1912/9433 doi:10.1017/aog.2017.19 |
op_rights |
Attribution 4.0 International http://creativecommons.org/licenses/by/4.0/ |
op_rightsnorm |
CC-BY |
op_doi |
https://doi.org/10.1017/aog.2017.19 |
container_title |
Annals of Glaciology |
container_volume |
58 |
container_issue |
74 |
container_start_page |
107 |
op_container_end_page |
117 |
_version_ |
1765998569390604288 |