Insights into the structure of the Wyville Thomson Ridge overflow current from a fine-scale numerical model
One of the major pathways in the northern part of the Meridional Overturning Circulation (MOC) is that of the deep water in the Nordic Seas that runs through the Faroe-Shetland Channel (FSC) and Faroe Bank Channel (FBC), as well as crossing the Wyville Thomson Ridge (WTR), on its way into the Atlant...
Published in: | Deep Sea Research Part I: Oceanographic Research Papers |
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Online Access: | http://hdl.handle.net/10026.1/3848 https://doi.org/10.1016/j.dsr.2010.06.006 |
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ftunivplympearl:oai:pearl.plymouth.ac.uk:10026.1/3848 2024-05-19T07:44:22+00:00 Insights into the structure of the Wyville Thomson Ridge overflow current from a fine-scale numerical model Stashchuk, N Vlasenko, V Sherwin, TJ 2010-10 1192-1205 http://hdl.handle.net/10026.1/3848 https://doi.org/10.1016/j.dsr.2010.06.006 en eng Elsevier BV ISSN:0967-0637 0967-0637 http://hdl.handle.net/10026.1/3848 doi:10.1016/j.dsr.2010.06.006 Not known Overflows Meridional Overturning Circulation Numerical model North Atlantic journal-article Article 2010 ftunivplympearl https://doi.org/10.1016/j.dsr.2010.06.006 2024-05-01T00:07:16Z One of the major pathways in the northern part of the Meridional Overturning Circulation (MOC) is that of the deep water in the Nordic Seas that runs through the Faroe-Shetland Channel (FSC) and Faroe Bank Channel (FBC), as well as crossing the Wyville Thomson Ridge (WTR), on its way into the Atlantic Ocean. The WTR overflow cascades down the southern side of the ridge via the narrow Ellett Gully to the Cirolana Deep (CD) which, at 1700. m, is the deepest hole in the extreme north of the Rockall Trough. The overflow accounts for nearly 1/10th of the total Faroe-Shetland Channel Bottom Water (FSCBW) discharged through the Faroese channels and is an important intermediate water mass in the Rockall Trough. Over a period of only seven days in April 2003 bottom water temperatures cooled dramatically, from 4.46 to 3.03°C in the CD and from 3.93 to 2.54°C in the Ymir Trough (YT). A numerical general circulation model (MITgcm) has been applied in order to reproduce the details of this dense water overflow event. Model results were consistent with the observed cooling and total water transport. It was found that the descending gravity current forms a pair of mesoscale eddies with cyclonic and anticyclonic vorticity at the exit to the CD. Analysis of mixing processes were obtained when a passive tracer was included in the model. It was found that downstream flow is characterized by an explosive detrainment regime in the CD. The model sensitivity runs revealed that the final depth to which the overflow descends depends on the initial upstream velocity of the overflow, as well as the buoyancy difference. It is argued that models of overflows need to have realistic representations of the density structure of the overflow, and sufficiently fine vertical resolution, for the subsequent fate of the overflow to be accurately represented. © 2010 Elsevier Ltd. Article in Journal/Newspaper Nordic Seas North Atlantic PEARL (Plymouth Electronic Archiv & ResearchLibrary, Plymouth University) Deep Sea Research Part I: Oceanographic Research Papers 57 10 1192 1205 |
institution |
Open Polar |
collection |
PEARL (Plymouth Electronic Archiv & ResearchLibrary, Plymouth University) |
op_collection_id |
ftunivplympearl |
language |
English |
topic |
Overflows Meridional Overturning Circulation Numerical model North Atlantic |
spellingShingle |
Overflows Meridional Overturning Circulation Numerical model North Atlantic Stashchuk, N Vlasenko, V Sherwin, TJ Insights into the structure of the Wyville Thomson Ridge overflow current from a fine-scale numerical model |
topic_facet |
Overflows Meridional Overturning Circulation Numerical model North Atlantic |
description |
One of the major pathways in the northern part of the Meridional Overturning Circulation (MOC) is that of the deep water in the Nordic Seas that runs through the Faroe-Shetland Channel (FSC) and Faroe Bank Channel (FBC), as well as crossing the Wyville Thomson Ridge (WTR), on its way into the Atlantic Ocean. The WTR overflow cascades down the southern side of the ridge via the narrow Ellett Gully to the Cirolana Deep (CD) which, at 1700. m, is the deepest hole in the extreme north of the Rockall Trough. The overflow accounts for nearly 1/10th of the total Faroe-Shetland Channel Bottom Water (FSCBW) discharged through the Faroese channels and is an important intermediate water mass in the Rockall Trough. Over a period of only seven days in April 2003 bottom water temperatures cooled dramatically, from 4.46 to 3.03°C in the CD and from 3.93 to 2.54°C in the Ymir Trough (YT). A numerical general circulation model (MITgcm) has been applied in order to reproduce the details of this dense water overflow event. Model results were consistent with the observed cooling and total water transport. It was found that the descending gravity current forms a pair of mesoscale eddies with cyclonic and anticyclonic vorticity at the exit to the CD. Analysis of mixing processes were obtained when a passive tracer was included in the model. It was found that downstream flow is characterized by an explosive detrainment regime in the CD. The model sensitivity runs revealed that the final depth to which the overflow descends depends on the initial upstream velocity of the overflow, as well as the buoyancy difference. It is argued that models of overflows need to have realistic representations of the density structure of the overflow, and sufficiently fine vertical resolution, for the subsequent fate of the overflow to be accurately represented. © 2010 Elsevier Ltd. |
format |
Article in Journal/Newspaper |
author |
Stashchuk, N Vlasenko, V Sherwin, TJ |
author_facet |
Stashchuk, N Vlasenko, V Sherwin, TJ |
author_sort |
Stashchuk, N |
title |
Insights into the structure of the Wyville Thomson Ridge overflow current from a fine-scale numerical model |
title_short |
Insights into the structure of the Wyville Thomson Ridge overflow current from a fine-scale numerical model |
title_full |
Insights into the structure of the Wyville Thomson Ridge overflow current from a fine-scale numerical model |
title_fullStr |
Insights into the structure of the Wyville Thomson Ridge overflow current from a fine-scale numerical model |
title_full_unstemmed |
Insights into the structure of the Wyville Thomson Ridge overflow current from a fine-scale numerical model |
title_sort |
insights into the structure of the wyville thomson ridge overflow current from a fine-scale numerical model |
publisher |
Elsevier BV |
publishDate |
2010 |
url |
http://hdl.handle.net/10026.1/3848 https://doi.org/10.1016/j.dsr.2010.06.006 |
genre |
Nordic Seas North Atlantic |
genre_facet |
Nordic Seas North Atlantic |
op_relation |
ISSN:0967-0637 0967-0637 http://hdl.handle.net/10026.1/3848 doi:10.1016/j.dsr.2010.06.006 |
op_rights |
Not known |
op_doi |
https://doi.org/10.1016/j.dsr.2010.06.006 |
container_title |
Deep Sea Research Part I: Oceanographic Research Papers |
container_volume |
57 |
container_issue |
10 |
container_start_page |
1192 |
op_container_end_page |
1205 |
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1799484157173170176 |