Weakening of Cold Halocline Layer Exposes Sea Ice to Oceanic Heat in the Eastern Arctic Ocean
A 15-yr duration record of mooring observations from the eastern (>70°E) Eurasian Basin (EB) of the Arctic Ocean is used to show and quantify the recently increased oceanic heat flux from intermediate-depth (~150–900 m) warm Atlantic Water (AW) to the surface mixed layer and sea ice. The upward r...
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Online Access: | https://hdl.handle.net/11250/2683355 https://doi.org/10.1175/JCLI-D-19-0976.1 |
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ftimr:oai:imr.brage.unit.no:11250/2683355 2023-05-15T13:11:33+02:00 Weakening of Cold Halocline Layer Exposes Sea Ice to Oceanic Heat in the Eastern Arctic Ocean Polyakov, Igor V. Rippeth, Tom Fer, Ilker Alkire, Matthew B. Carmack, Eddy Ingvaldsen, Randi Brunvær Ivanov, Vladimir V. Janout, Markus Lind, Sigrid Padman, Laurie Pnyushkov, Andrey V. Rember, Robert 2020 application/pdf https://hdl.handle.net/11250/2683355 https://doi.org/10.1175/JCLI-D-19-0976.1 eng eng urn:issn:0894-8755 https://hdl.handle.net/11250/2683355 https://doi.org/10.1175/JCLI-D-19-0976.1 cristin:1825538 33 Journal of Climate Peer reviewed Journal article 2020 ftimr https://doi.org/10.1175/JCLI-D-19-0976.1 2021-09-23T20:14:53Z A 15-yr duration record of mooring observations from the eastern (>70°E) Eurasian Basin (EB) of the Arctic Ocean is used to show and quantify the recently increased oceanic heat flux from intermediate-depth (~150–900 m) warm Atlantic Water (AW) to the surface mixed layer and sea ice. The upward release of AW heat is regulated by the stability of the overlying halocline, which we show has weakened substantially in recent years. Shoaling of the AW has also contributed, with observations in winter 2017–18 showing AW at only 80 m depth, just below the wintertime surface mixed layer, the shallowest in our mooring records. The weakening of the halocline for several months at this time implies that AW heat was linked to winter convection associated with brine rejection during sea ice formation. This resulted in a substantial increase of upward oceanic heat flux during the winter season, from an average of 3–4 W m−2 in 2007–08 to >10 W m−2 in 2016–18. This seasonal AW heat loss in the eastern EB is equivalent to a more than a twofold reduction of winter ice growth. These changes imply a positive feedback as reduced sea ice cover permits increased mixing, augmenting the summer-dominated ice-albedo feedback. publishedVersion Article in Journal/Newspaper albedo Arctic Arctic Ocean Sea ice Institute for Marine Research: Brage IMR Arctic Arctic Ocean Journal of Climate 33 18 8107 8123 |
institution |
Open Polar |
collection |
Institute for Marine Research: Brage IMR |
op_collection_id |
ftimr |
language |
English |
description |
A 15-yr duration record of mooring observations from the eastern (>70°E) Eurasian Basin (EB) of the Arctic Ocean is used to show and quantify the recently increased oceanic heat flux from intermediate-depth (~150–900 m) warm Atlantic Water (AW) to the surface mixed layer and sea ice. The upward release of AW heat is regulated by the stability of the overlying halocline, which we show has weakened substantially in recent years. Shoaling of the AW has also contributed, with observations in winter 2017–18 showing AW at only 80 m depth, just below the wintertime surface mixed layer, the shallowest in our mooring records. The weakening of the halocline for several months at this time implies that AW heat was linked to winter convection associated with brine rejection during sea ice formation. This resulted in a substantial increase of upward oceanic heat flux during the winter season, from an average of 3–4 W m−2 in 2007–08 to >10 W m−2 in 2016–18. This seasonal AW heat loss in the eastern EB is equivalent to a more than a twofold reduction of winter ice growth. These changes imply a positive feedback as reduced sea ice cover permits increased mixing, augmenting the summer-dominated ice-albedo feedback. publishedVersion |
format |
Article in Journal/Newspaper |
author |
Polyakov, Igor V. Rippeth, Tom Fer, Ilker Alkire, Matthew B. Carmack, Eddy Ingvaldsen, Randi Brunvær Ivanov, Vladimir V. Janout, Markus Lind, Sigrid Padman, Laurie Pnyushkov, Andrey V. Rember, Robert |
spellingShingle |
Polyakov, Igor V. Rippeth, Tom Fer, Ilker Alkire, Matthew B. Carmack, Eddy Ingvaldsen, Randi Brunvær Ivanov, Vladimir V. Janout, Markus Lind, Sigrid Padman, Laurie Pnyushkov, Andrey V. Rember, Robert Weakening of Cold Halocline Layer Exposes Sea Ice to Oceanic Heat in the Eastern Arctic Ocean |
author_facet |
Polyakov, Igor V. Rippeth, Tom Fer, Ilker Alkire, Matthew B. Carmack, Eddy Ingvaldsen, Randi Brunvær Ivanov, Vladimir V. Janout, Markus Lind, Sigrid Padman, Laurie Pnyushkov, Andrey V. Rember, Robert |
author_sort |
Polyakov, Igor V. |
title |
Weakening of Cold Halocline Layer Exposes Sea Ice to Oceanic Heat in the Eastern Arctic Ocean |
title_short |
Weakening of Cold Halocline Layer Exposes Sea Ice to Oceanic Heat in the Eastern Arctic Ocean |
title_full |
Weakening of Cold Halocline Layer Exposes Sea Ice to Oceanic Heat in the Eastern Arctic Ocean |
title_fullStr |
Weakening of Cold Halocline Layer Exposes Sea Ice to Oceanic Heat in the Eastern Arctic Ocean |
title_full_unstemmed |
Weakening of Cold Halocline Layer Exposes Sea Ice to Oceanic Heat in the Eastern Arctic Ocean |
title_sort |
weakening of cold halocline layer exposes sea ice to oceanic heat in the eastern arctic ocean |
publishDate |
2020 |
url |
https://hdl.handle.net/11250/2683355 https://doi.org/10.1175/JCLI-D-19-0976.1 |
geographic |
Arctic Arctic Ocean |
geographic_facet |
Arctic Arctic Ocean |
genre |
albedo Arctic Arctic Ocean Sea ice |
genre_facet |
albedo Arctic Arctic Ocean Sea ice |
op_source |
33 Journal of Climate |
op_relation |
urn:issn:0894-8755 https://hdl.handle.net/11250/2683355 https://doi.org/10.1175/JCLI-D-19-0976.1 cristin:1825538 |
op_doi |
https://doi.org/10.1175/JCLI-D-19-0976.1 |
container_title |
Journal of Climate |
container_volume |
33 |
container_issue |
18 |
container_start_page |
8107 |
op_container_end_page |
8123 |
_version_ |
1766247942016991232 |