Instability and Mesoscale Eddy Fluxes in an Idealized 3‐Layer Beaufort Gyre
We study the impacts of a continental slope on instability and mesoscale eddy fluxes in idealized 3‐layer numerical model simulations. The simulations are inspired by and mimic the situation in the Arctic Ocean's Beaufort Gyre, where anti‐cyclonic winds drive anti‐cyclonic currents that are gui...
Published in: | Journal of Geophysical Research: Oceans |
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Main Authors: | , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
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American Geophysical Union
2024
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Online Access: | https://doi.org/10.1029/2023jc020757 https://ora.ox.ac.uk/objects/uuid:805f2227-0c54-4e8a-9fdc-9da31c8db1e2 |
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ftuloxford:oai:ora.ox.ac.uk:uuid:805f2227-0c54-4e8a-9fdc-9da31c8db1e2 2024-09-09T19:25:46+00:00 Instability and Mesoscale Eddy Fluxes in an Idealized 3‐Layer Beaufort Gyre Isachsen, PE Vogt‐Vincent, NS Johnson, HL Nilsson, J 2024-08-06 https://doi.org/10.1029/2023jc020757 https://ora.ox.ac.uk/objects/uuid:805f2227-0c54-4e8a-9fdc-9da31c8db1e2 eng eng American Geophysical Union doi:10.1029/2023jc020757 https://ora.ox.ac.uk/objects/uuid:805f2227-0c54-4e8a-9fdc-9da31c8db1e2 https://doi.org/10.1029/2023jc020757 info:eu-repo/semantics/openAccess CC Attribution-NonCommercial-NoDerivatives (CC BY-NC-ND) Journal article 2024 ftuloxford https://doi.org/10.1029/2023jc020757 2024-08-19T14:08:59Z We study the impacts of a continental slope on instability and mesoscale eddy fluxes in idealized 3‐layer numerical model simulations. The simulations are inspired by and mimic the situation in the Arctic Ocean's Beaufort Gyre, where anti‐cyclonic winds drive anti‐cyclonic currents that are guided by the continental slope. The forcing and currents are retrograde with respect to topographic Rossby waves. The focus of the analysis is on eddy potential vorticity (PV) fluxes and eddy‐mean flow interactions under the Transformed Eulerian Mean framework. Eddy lateral vorticity fluxes dominate over the continental slope where eddy form stress, that is, vertical momentum flux, is suppressed due to the topographic PV gradient. The diagnosis also shows that while eddy momentum fluxes are up‐gradient over parts of the slope, the total quasi‐geostrophic PV flux is down‐gradient everywhere. We then calculate the linearly unstable modes of the time‐mean state and find that the most unstable mode contains several key features of the observed finite‐amplitude fluxes over the slope, including down‐gradient PV fluxes. When accounting for additional unstable modes, more qualitative features of the observed eddy fluxes in the numerical model are reproduced. Article in Journal/Newspaper Arctic ORA - Oxford University Research Archive Arctic Journal of Geophysical Research: Oceans 129 8 |
institution |
Open Polar |
collection |
ORA - Oxford University Research Archive |
op_collection_id |
ftuloxford |
language |
English |
description |
We study the impacts of a continental slope on instability and mesoscale eddy fluxes in idealized 3‐layer numerical model simulations. The simulations are inspired by and mimic the situation in the Arctic Ocean's Beaufort Gyre, where anti‐cyclonic winds drive anti‐cyclonic currents that are guided by the continental slope. The forcing and currents are retrograde with respect to topographic Rossby waves. The focus of the analysis is on eddy potential vorticity (PV) fluxes and eddy‐mean flow interactions under the Transformed Eulerian Mean framework. Eddy lateral vorticity fluxes dominate over the continental slope where eddy form stress, that is, vertical momentum flux, is suppressed due to the topographic PV gradient. The diagnosis also shows that while eddy momentum fluxes are up‐gradient over parts of the slope, the total quasi‐geostrophic PV flux is down‐gradient everywhere. We then calculate the linearly unstable modes of the time‐mean state and find that the most unstable mode contains several key features of the observed finite‐amplitude fluxes over the slope, including down‐gradient PV fluxes. When accounting for additional unstable modes, more qualitative features of the observed eddy fluxes in the numerical model are reproduced. |
format |
Article in Journal/Newspaper |
author |
Isachsen, PE Vogt‐Vincent, NS Johnson, HL Nilsson, J |
spellingShingle |
Isachsen, PE Vogt‐Vincent, NS Johnson, HL Nilsson, J Instability and Mesoscale Eddy Fluxes in an Idealized 3‐Layer Beaufort Gyre |
author_facet |
Isachsen, PE Vogt‐Vincent, NS Johnson, HL Nilsson, J |
author_sort |
Isachsen, PE |
title |
Instability and Mesoscale Eddy Fluxes in an Idealized 3‐Layer Beaufort Gyre |
title_short |
Instability and Mesoscale Eddy Fluxes in an Idealized 3‐Layer Beaufort Gyre |
title_full |
Instability and Mesoscale Eddy Fluxes in an Idealized 3‐Layer Beaufort Gyre |
title_fullStr |
Instability and Mesoscale Eddy Fluxes in an Idealized 3‐Layer Beaufort Gyre |
title_full_unstemmed |
Instability and Mesoscale Eddy Fluxes in an Idealized 3‐Layer Beaufort Gyre |
title_sort |
instability and mesoscale eddy fluxes in an idealized 3‐layer beaufort gyre |
publisher |
American Geophysical Union |
publishDate |
2024 |
url |
https://doi.org/10.1029/2023jc020757 https://ora.ox.ac.uk/objects/uuid:805f2227-0c54-4e8a-9fdc-9da31c8db1e2 |
geographic |
Arctic |
geographic_facet |
Arctic |
genre |
Arctic |
genre_facet |
Arctic |
op_relation |
doi:10.1029/2023jc020757 https://ora.ox.ac.uk/objects/uuid:805f2227-0c54-4e8a-9fdc-9da31c8db1e2 https://doi.org/10.1029/2023jc020757 |
op_rights |
info:eu-repo/semantics/openAccess CC Attribution-NonCommercial-NoDerivatives (CC BY-NC-ND) |
op_doi |
https://doi.org/10.1029/2023jc020757 |
container_title |
Journal of Geophysical Research: Oceans |
container_volume |
129 |
container_issue |
8 |
_version_ |
1809895501860962304 |