Density staircases are disappearing in the Canada Basin of the Arctic Ocean
In the Canada Basin of the Arctic Ocean, warm and salty Atlantic-origin Water (AW) lies in the intermediate layer (250 m–800 m) below a colder and fresher surface layer. It results in a depth range where vertical thermohaline gradients are propitious to double-diffusion. Indeed, thermohaline stairca...
Published in: | Journal of Geophysical Research: Oceans |
---|---|
Main Authors: | , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
American Geophysical Union (AGU)
2022
|
Subjects: | |
Online Access: | https://archimer.ifremer.fr/doc/00804/91586/97527.pdf https://doi.org/10.1029/2022JC018877 https://archimer.ifremer.fr/doc/00804/91586/ |
id |
ftarchimer:oai:archimer.ifremer.fr:91586 |
---|---|
record_format |
openpolar |
spelling |
ftarchimer:oai:archimer.ifremer.fr:91586 2023-05-15T14:56:44+02:00 Density staircases are disappearing in the Canada Basin of the Arctic Ocean Ménesguen, Claire Lique, Camille Caspar-cohen, Zoe 2022-11 application/pdf https://archimer.ifremer.fr/doc/00804/91586/97527.pdf https://doi.org/10.1029/2022JC018877 https://archimer.ifremer.fr/doc/00804/91586/ eng eng American Geophysical Union (AGU) https://archimer.ifremer.fr/doc/00804/91586/97527.pdf doi:10.1029/2022JC018877 https://archimer.ifremer.fr/doc/00804/91586/ info:eu-repo/semantics/openAccess restricted use Journal Of Geophysical Research-oceans (2169-9275) (American Geophysical Union (AGU)), 2022-11 , Vol. 127 , N. 11 , P. e2022JC018877 (17p.) text Publication info:eu-repo/semantics/article 2022 ftarchimer https://doi.org/10.1029/2022JC018877 2023-03-14T23:55:22Z In the Canada Basin of the Arctic Ocean, warm and salty Atlantic-origin Water (AW) lies in the intermediate layer (250 m–800 m) below a colder and fresher surface layer. It results in a depth range where vertical thermohaline gradients are propitious to double-diffusion. Indeed, thermohaline staircases are commonly observed and associated with double-diffusive processes. Using observations from the Beaufort Gyre Exploration Project large database and Ice-Tethered Profilers, we document the presence of density staircases in the 300 m–700 m depth range with a striking strong spatial and temporal coherence. However, since 2007, a progressive smoothing of these staircases has occurred, beginning from the western half of the basin. Quantifying this evolution, we find that a general pattern is a clear evolution over time from numerous thick steps ( ≃ 40 m) with sharp interfaces to fewer and thinner steps ( ≃ 30 m) with smoother interfaces. After 2014, marked density staircases have almost disappeared in most of the Canada Basin. The vanishing of staircases occurs over a few years and coincides with modifications of the large scale circulation and thermohaline large scale horizontal gradients. As the small scale thermohaline structures are thought to play an important role for the vertical and horizontal exchanges of heat within the Canada Basin, the disappearance of the steps may impact the heat distribution at depth, with potential consequences for the evolution of the sea ice cover. Key Points Density staircases are detected over the past two decades in in situ observations in the Beaufort Gyre Density staircases have been gradually smoothed, with a transition that begins in the western part of the Canada Basin Smoothing of staircases occurs simultaneously with changes in the large scale dynamics Plain Language Summary In the western side of the Arctic Ocean, Atlantic-origin water lies around 400m deep, and is warmer and saltier than the surface layer, resulting in a peculiar stratification compared to the other ... Article in Journal/Newspaper Arctic Arctic Ocean canada basin Sea ice Archimer (Archive Institutionnelle de l'Ifremer - Institut français de recherche pour l'exploitation de la mer) Arctic Arctic Ocean Canada Journal of Geophysical Research: Oceans 127 11 |
institution |
Open Polar |
collection |
Archimer (Archive Institutionnelle de l'Ifremer - Institut français de recherche pour l'exploitation de la mer) |
op_collection_id |
ftarchimer |
language |
English |
description |
In the Canada Basin of the Arctic Ocean, warm and salty Atlantic-origin Water (AW) lies in the intermediate layer (250 m–800 m) below a colder and fresher surface layer. It results in a depth range where vertical thermohaline gradients are propitious to double-diffusion. Indeed, thermohaline staircases are commonly observed and associated with double-diffusive processes. Using observations from the Beaufort Gyre Exploration Project large database and Ice-Tethered Profilers, we document the presence of density staircases in the 300 m–700 m depth range with a striking strong spatial and temporal coherence. However, since 2007, a progressive smoothing of these staircases has occurred, beginning from the western half of the basin. Quantifying this evolution, we find that a general pattern is a clear evolution over time from numerous thick steps ( ≃ 40 m) with sharp interfaces to fewer and thinner steps ( ≃ 30 m) with smoother interfaces. After 2014, marked density staircases have almost disappeared in most of the Canada Basin. The vanishing of staircases occurs over a few years and coincides with modifications of the large scale circulation and thermohaline large scale horizontal gradients. As the small scale thermohaline structures are thought to play an important role for the vertical and horizontal exchanges of heat within the Canada Basin, the disappearance of the steps may impact the heat distribution at depth, with potential consequences for the evolution of the sea ice cover. Key Points Density staircases are detected over the past two decades in in situ observations in the Beaufort Gyre Density staircases have been gradually smoothed, with a transition that begins in the western part of the Canada Basin Smoothing of staircases occurs simultaneously with changes in the large scale dynamics Plain Language Summary In the western side of the Arctic Ocean, Atlantic-origin water lies around 400m deep, and is warmer and saltier than the surface layer, resulting in a peculiar stratification compared to the other ... |
format |
Article in Journal/Newspaper |
author |
Ménesguen, Claire Lique, Camille Caspar-cohen, Zoe |
spellingShingle |
Ménesguen, Claire Lique, Camille Caspar-cohen, Zoe Density staircases are disappearing in the Canada Basin of the Arctic Ocean |
author_facet |
Ménesguen, Claire Lique, Camille Caspar-cohen, Zoe |
author_sort |
Ménesguen, Claire |
title |
Density staircases are disappearing in the Canada Basin of the Arctic Ocean |
title_short |
Density staircases are disappearing in the Canada Basin of the Arctic Ocean |
title_full |
Density staircases are disappearing in the Canada Basin of the Arctic Ocean |
title_fullStr |
Density staircases are disappearing in the Canada Basin of the Arctic Ocean |
title_full_unstemmed |
Density staircases are disappearing in the Canada Basin of the Arctic Ocean |
title_sort |
density staircases are disappearing in the canada basin of the arctic ocean |
publisher |
American Geophysical Union (AGU) |
publishDate |
2022 |
url |
https://archimer.ifremer.fr/doc/00804/91586/97527.pdf https://doi.org/10.1029/2022JC018877 https://archimer.ifremer.fr/doc/00804/91586/ |
geographic |
Arctic Arctic Ocean Canada |
geographic_facet |
Arctic Arctic Ocean Canada |
genre |
Arctic Arctic Ocean canada basin Sea ice |
genre_facet |
Arctic Arctic Ocean canada basin Sea ice |
op_source |
Journal Of Geophysical Research-oceans (2169-9275) (American Geophysical Union (AGU)), 2022-11 , Vol. 127 , N. 11 , P. e2022JC018877 (17p.) |
op_relation |
https://archimer.ifremer.fr/doc/00804/91586/97527.pdf doi:10.1029/2022JC018877 https://archimer.ifremer.fr/doc/00804/91586/ |
op_rights |
info:eu-repo/semantics/openAccess restricted use |
op_doi |
https://doi.org/10.1029/2022JC018877 |
container_title |
Journal of Geophysical Research: Oceans |
container_volume |
127 |
container_issue |
11 |
_version_ |
1766328812634636288 |