Norwegian Atlantic Slope Current along the Lofoten Escarpment
International audience Observations from moored instruments are analyzed to describe the Norwegian Atlantic Slope Current at the Lofoten Escarpment (13 ∘ E, 69 ∘ N). The data set covers a 14-month period from June 2016 to September 2017 and resolves the core of the current from 200 to 650 m depth be...
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Format: | Article in Journal/Newspaper |
Language: | English |
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HAL CCSD
2020
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Online Access: | https://insu.hal.science/insu-03668097 https://insu.hal.science/insu-03668097/document https://insu.hal.science/insu-03668097/file/os-16-685-2020.pdf https://doi.org/10.5194/os-16-685-2020 |
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ftccsdartic:oai:HAL:insu-03668097v1 2023-12-17T10:33:10+01:00 Norwegian Atlantic Slope Current along the Lofoten Escarpment Fer, Ilker Bosse, Anthony Dugstad, Johannes Institut méditerranéen d'océanologie (MIO) Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS) 2020 https://insu.hal.science/insu-03668097 https://insu.hal.science/insu-03668097/document https://insu.hal.science/insu-03668097/file/os-16-685-2020.pdf https://doi.org/10.5194/os-16-685-2020 en eng HAL CCSD info:eu-repo/semantics/altIdentifier/doi/10.5194/os-16-685-2020 insu-03668097 https://insu.hal.science/insu-03668097 https://insu.hal.science/insu-03668097/document https://insu.hal.science/insu-03668097/file/os-16-685-2020.pdf BIBCODE: 2020OcSci.16.685F doi:10.5194/os-16-685-2020 http://creativecommons.org/licenses/by/ info:eu-repo/semantics/OpenAccess OCEAN SCIENCE https://insu.hal.science/insu-03668097 OCEAN SCIENCE, 2020, 16, pp.685-701. ⟨10.5194/os-16-685-2020⟩ [SDU]Sciences of the Universe [physics] [SDU.STU.OC]Sciences of the Universe [physics]/Earth Sciences/Oceanography info:eu-repo/semantics/article Journal articles 2020 ftccsdartic https://doi.org/10.5194/os-16-685-2020 2023-11-19T00:11:39Z International audience Observations from moored instruments are analyzed to describe the Norwegian Atlantic Slope Current at the Lofoten Escarpment (13 ∘ E, 69 ∘ N). The data set covers a 14-month period from June 2016 to September 2017 and resolves the core of the current from 200 to 650 m depth between the 650 and 1500 m isobaths. The along-isobath current, vertically averaged between 200 and 600 m depth, has an annual cycle amplitude of 0.1 m s -1 , with the strongest currents in winter, and a temporal average of 0.15 m s -1 . Higher-frequency variability is characterized by fluctuations that reach 0.8 m s -1 , lasting for 1 to 2 weeks, and extend as deep as 600 m. In contrast to observations in Svinøy (2 ∘ E, 63 ∘ N), the slope current is not barotropic and varies strongly with depth (a shear of 0.05 to 0.1 m s -1 per 100 m in all seasons). Within the limitations of the data, the average volume transport of Atlantic Water is estimated at 2.0±0.8 Sv (1 Sv =10 6 m 3 s -1 ), with summer and winter averages of 1.6 and 2.9 Sv, respectively. The largest transport is associated with the high temperature classes (>7 ∘ C) in all seasons, with the largest values of both transport and temperature in winter. Calculations of the barotropic and baroclinic conversion rates using the moorings are supplemented by results from a high-resolution numerical model. While the conversion from mean to eddy kinetic energy (e.g., barotropic instability) is likely negligible over the Lofoten Escarpment, the baroclinic conversion from mean potential energy into eddy kinetic energy (e.g., baroclinic instability) can be substantial, with volume-averaged values of (1-2)× 10-4 W m -3 . Article in Journal/Newspaper Lofoten Archive ouverte HAL (Hyper Article en Ligne, CCSD - Centre pour la Communication Scientifique Directe) Lofoten Svinøy ENVELOPE(10.992,10.992,64.866,64.866) Ocean Science 16 3 685 701 |
institution |
Open Polar |
collection |
Archive ouverte HAL (Hyper Article en Ligne, CCSD - Centre pour la Communication Scientifique Directe) |
op_collection_id |
ftccsdartic |
language |
English |
topic |
[SDU]Sciences of the Universe [physics] [SDU.STU.OC]Sciences of the Universe [physics]/Earth Sciences/Oceanography |
spellingShingle |
[SDU]Sciences of the Universe [physics] [SDU.STU.OC]Sciences of the Universe [physics]/Earth Sciences/Oceanography Fer, Ilker Bosse, Anthony Dugstad, Johannes Norwegian Atlantic Slope Current along the Lofoten Escarpment |
topic_facet |
[SDU]Sciences of the Universe [physics] [SDU.STU.OC]Sciences of the Universe [physics]/Earth Sciences/Oceanography |
description |
International audience Observations from moored instruments are analyzed to describe the Norwegian Atlantic Slope Current at the Lofoten Escarpment (13 ∘ E, 69 ∘ N). The data set covers a 14-month period from June 2016 to September 2017 and resolves the core of the current from 200 to 650 m depth between the 650 and 1500 m isobaths. The along-isobath current, vertically averaged between 200 and 600 m depth, has an annual cycle amplitude of 0.1 m s -1 , with the strongest currents in winter, and a temporal average of 0.15 m s -1 . Higher-frequency variability is characterized by fluctuations that reach 0.8 m s -1 , lasting for 1 to 2 weeks, and extend as deep as 600 m. In contrast to observations in Svinøy (2 ∘ E, 63 ∘ N), the slope current is not barotropic and varies strongly with depth (a shear of 0.05 to 0.1 m s -1 per 100 m in all seasons). Within the limitations of the data, the average volume transport of Atlantic Water is estimated at 2.0±0.8 Sv (1 Sv =10 6 m 3 s -1 ), with summer and winter averages of 1.6 and 2.9 Sv, respectively. The largest transport is associated with the high temperature classes (>7 ∘ C) in all seasons, with the largest values of both transport and temperature in winter. Calculations of the barotropic and baroclinic conversion rates using the moorings are supplemented by results from a high-resolution numerical model. While the conversion from mean to eddy kinetic energy (e.g., barotropic instability) is likely negligible over the Lofoten Escarpment, the baroclinic conversion from mean potential energy into eddy kinetic energy (e.g., baroclinic instability) can be substantial, with volume-averaged values of (1-2)× 10-4 W m -3 . |
author2 |
Institut méditerranéen d'océanologie (MIO) Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS) |
format |
Article in Journal/Newspaper |
author |
Fer, Ilker Bosse, Anthony Dugstad, Johannes |
author_facet |
Fer, Ilker Bosse, Anthony Dugstad, Johannes |
author_sort |
Fer, Ilker |
title |
Norwegian Atlantic Slope Current along the Lofoten Escarpment |
title_short |
Norwegian Atlantic Slope Current along the Lofoten Escarpment |
title_full |
Norwegian Atlantic Slope Current along the Lofoten Escarpment |
title_fullStr |
Norwegian Atlantic Slope Current along the Lofoten Escarpment |
title_full_unstemmed |
Norwegian Atlantic Slope Current along the Lofoten Escarpment |
title_sort |
norwegian atlantic slope current along the lofoten escarpment |
publisher |
HAL CCSD |
publishDate |
2020 |
url |
https://insu.hal.science/insu-03668097 https://insu.hal.science/insu-03668097/document https://insu.hal.science/insu-03668097/file/os-16-685-2020.pdf https://doi.org/10.5194/os-16-685-2020 |
long_lat |
ENVELOPE(10.992,10.992,64.866,64.866) |
geographic |
Lofoten Svinøy |
geographic_facet |
Lofoten Svinøy |
genre |
Lofoten |
genre_facet |
Lofoten |
op_source |
OCEAN SCIENCE https://insu.hal.science/insu-03668097 OCEAN SCIENCE, 2020, 16, pp.685-701. ⟨10.5194/os-16-685-2020⟩ |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.5194/os-16-685-2020 insu-03668097 https://insu.hal.science/insu-03668097 https://insu.hal.science/insu-03668097/document https://insu.hal.science/insu-03668097/file/os-16-685-2020.pdf BIBCODE: 2020OcSci.16.685F doi:10.5194/os-16-685-2020 |
op_rights |
http://creativecommons.org/licenses/by/ info:eu-repo/semantics/OpenAccess |
op_doi |
https://doi.org/10.5194/os-16-685-2020 |
container_title |
Ocean Science |
container_volume |
16 |
container_issue |
3 |
container_start_page |
685 |
op_container_end_page |
701 |
_version_ |
1785587081715646464 |