Norwegian Atlantic Slope Current along the Lofoten Escarpment
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...
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2020
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ftdoajarticles:oai:doaj.org/article:271b3c55b9b34c4598785b24daf94c17 2023-05-15T17:08:15+02:00 Norwegian Atlantic Slope Current along the Lofoten Escarpment I. Fer A. Bosse J. Dugstad 2020-06-01T00:00:00Z https://doi.org/10.5194/os-16-685-2020 https://doaj.org/article/271b3c55b9b34c4598785b24daf94c17 EN eng Copernicus Publications https://www.ocean-sci.net/16/685/2020/os-16-685-2020.pdf https://doaj.org/toc/1812-0784 https://doaj.org/toc/1812-0792 doi:10.5194/os-16-685-2020 1812-0784 1812-0792 https://doaj.org/article/271b3c55b9b34c4598785b24daf94c17 Ocean Science, Vol 16, Pp 685-701 (2020) Geography. Anthropology. Recreation G Environmental sciences GE1-350 article 2020 ftdoajarticles https://doi.org/10.5194/os-16-685-2020 2022-12-31T11:37:24Z 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 <math xmlns="http://www.w3.org/1998/Math/MathML" id="M15" display="inline" overflow="scroll" dspmath="mathml"><mrow><mo>)</mo><mo>×</mo><msup><mn mathvariant="normal">10</mn><mrow><mo>-</mo><mn mathvariant="normal">4</mn></mrow></msup></mrow></math> <svg:svg ... Article in Journal/Newspaper Lofoten Directory of Open Access Journals: DOAJ Articles Lofoten Svinøy ENVELOPE(10.992,10.992,64.866,64.866) Ocean Science 16 3 685 701 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
Geography. Anthropology. Recreation G Environmental sciences GE1-350 |
spellingShingle |
Geography. Anthropology. Recreation G Environmental sciences GE1-350 I. Fer A. Bosse J. Dugstad Norwegian Atlantic Slope Current along the Lofoten Escarpment |
topic_facet |
Geography. Anthropology. Recreation G Environmental sciences GE1-350 |
description |
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 <math xmlns="http://www.w3.org/1998/Math/MathML" id="M15" display="inline" overflow="scroll" dspmath="mathml"><mrow><mo>)</mo><mo>×</mo><msup><mn mathvariant="normal">10</mn><mrow><mo>-</mo><mn mathvariant="normal">4</mn></mrow></msup></mrow></math> <svg:svg ... |
format |
Article in Journal/Newspaper |
author |
I. Fer A. Bosse J. Dugstad |
author_facet |
I. Fer A. Bosse J. Dugstad |
author_sort |
I. Fer |
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 |
Copernicus Publications |
publishDate |
2020 |
url |
https://doi.org/10.5194/os-16-685-2020 https://doaj.org/article/271b3c55b9b34c4598785b24daf94c17 |
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, Vol 16, Pp 685-701 (2020) |
op_relation |
https://www.ocean-sci.net/16/685/2020/os-16-685-2020.pdf https://doaj.org/toc/1812-0784 https://doaj.org/toc/1812-0792 doi:10.5194/os-16-685-2020 1812-0784 1812-0792 https://doaj.org/article/271b3c55b9b34c4598785b24daf94c17 |
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_ |
1766063959643783168 |