The Coldest and Densest Overflow Branch Into the North Atlantic is Stable in Transport, But Warming
The overflow of cold water through the Faroe Bank Channel (FBC) is the densest water crossing the Greenland-Scotland Ridge and the densest source for the Atlantic Meridional Overturning Circulation (AMOC). Here, we show that the overflow volume transport remained stable from 1996 to 2022, but that t...
Published in: | Geophysical Research Letters |
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Online Access: | https://hdl.handle.net/11250/3151641 https://doi.org/10.1029/2024GL110097 |
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ftnorce:oai:norceresearch.brage.unit.no:11250/3151641 2024-09-30T14:35:54+00:00 The Coldest and Densest Overflow Branch Into the North Atlantic is Stable in Transport, But Warming Larsen, Karin Margretha Húsgarð Hansen, Bogi Hátún, Egil Hjálmar Johansen, Guðrið Eriksdóttir Østerhus, Svein Olsen, Steffen Malskær 2024 application/pdf https://hdl.handle.net/11250/3151641 https://doi.org/10.1029/2024GL110097 eng eng Geophysical Research Letters. 2024, 51 (16), . urn:issn:0094-8276 https://hdl.handle.net/11250/3151641 https://doi.org/10.1029/2024GL110097 cristin:2291869 Attribution-NonCommercial-NoDerivatives 4.0 Internasjonal http://creativecommons.org/licenses/by-nc-nd/4.0/deed.no ©2024, the Author(s) Geophysical Research Letters 51 16 9 Peer reviewed Journal article 2024 ftnorce https://doi.org/10.1029/2024GL110097 2024-09-16T14:08:03Z The overflow of cold water through the Faroe Bank Channel (FBC) is the densest water crossing the Greenland-Scotland Ridge and the densest source for the Atlantic Meridional Overturning Circulation (AMOC). Here, we show that the overflow volume transport remained stable from 1996 to 2022, but that the bottom water warmed at an average rate of 0.1°C per decade, mainly caused by warming of deep waters upstream. The salinity of the overflow water has increased as a lagged and reduced response to the salinity increase seen in the upper-layer source waters. Therefore, the potential density of the bottom water over the FBC sill shows no statistically significant trend. After entrainment of warmer ambient waters downstream of the FBC, the nonlinear density dependence upon temperature implies, however, that the overflow contributed water of reduced density to the local overturning and the deep limb of the AMOC. publishedVersion Article in Journal/Newspaper Greenland Greenland-Scotland Ridge North Atlantic NORCE vitenarkiv (Norwegian Research Centre) Faroe Bank ENVELOPE(-8.667,-8.667,60.917,60.917) Greenland Geophysical Research Letters 51 16 |
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Open Polar |
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NORCE vitenarkiv (Norwegian Research Centre) |
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ftnorce |
language |
English |
description |
The overflow of cold water through the Faroe Bank Channel (FBC) is the densest water crossing the Greenland-Scotland Ridge and the densest source for the Atlantic Meridional Overturning Circulation (AMOC). Here, we show that the overflow volume transport remained stable from 1996 to 2022, but that the bottom water warmed at an average rate of 0.1°C per decade, mainly caused by warming of deep waters upstream. The salinity of the overflow water has increased as a lagged and reduced response to the salinity increase seen in the upper-layer source waters. Therefore, the potential density of the bottom water over the FBC sill shows no statistically significant trend. After entrainment of warmer ambient waters downstream of the FBC, the nonlinear density dependence upon temperature implies, however, that the overflow contributed water of reduced density to the local overturning and the deep limb of the AMOC. publishedVersion |
format |
Article in Journal/Newspaper |
author |
Larsen, Karin Margretha Húsgarð Hansen, Bogi Hátún, Egil Hjálmar Johansen, Guðrið Eriksdóttir Østerhus, Svein Olsen, Steffen Malskær |
spellingShingle |
Larsen, Karin Margretha Húsgarð Hansen, Bogi Hátún, Egil Hjálmar Johansen, Guðrið Eriksdóttir Østerhus, Svein Olsen, Steffen Malskær The Coldest and Densest Overflow Branch Into the North Atlantic is Stable in Transport, But Warming |
author_facet |
Larsen, Karin Margretha Húsgarð Hansen, Bogi Hátún, Egil Hjálmar Johansen, Guðrið Eriksdóttir Østerhus, Svein Olsen, Steffen Malskær |
author_sort |
Larsen, Karin Margretha Húsgarð |
title |
The Coldest and Densest Overflow Branch Into the North Atlantic is Stable in Transport, But Warming |
title_short |
The Coldest and Densest Overflow Branch Into the North Atlantic is Stable in Transport, But Warming |
title_full |
The Coldest and Densest Overflow Branch Into the North Atlantic is Stable in Transport, But Warming |
title_fullStr |
The Coldest and Densest Overflow Branch Into the North Atlantic is Stable in Transport, But Warming |
title_full_unstemmed |
The Coldest and Densest Overflow Branch Into the North Atlantic is Stable in Transport, But Warming |
title_sort |
coldest and densest overflow branch into the north atlantic is stable in transport, but warming |
publishDate |
2024 |
url |
https://hdl.handle.net/11250/3151641 https://doi.org/10.1029/2024GL110097 |
long_lat |
ENVELOPE(-8.667,-8.667,60.917,60.917) |
geographic |
Faroe Bank Greenland |
geographic_facet |
Faroe Bank Greenland |
genre |
Greenland Greenland-Scotland Ridge North Atlantic |
genre_facet |
Greenland Greenland-Scotland Ridge North Atlantic |
op_source |
Geophysical Research Letters 51 16 9 |
op_relation |
Geophysical Research Letters. 2024, 51 (16), . urn:issn:0094-8276 https://hdl.handle.net/11250/3151641 https://doi.org/10.1029/2024GL110097 cristin:2291869 |
op_rights |
Attribution-NonCommercial-NoDerivatives 4.0 Internasjonal http://creativecommons.org/licenses/by-nc-nd/4.0/deed.no ©2024, the Author(s) |
op_doi |
https://doi.org/10.1029/2024GL110097 |
container_title |
Geophysical Research Letters |
container_volume |
51 |
container_issue |
16 |
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1811639112859385856 |