Large-scale forcing of the European Slope Current and associated inflows to the North Sea
The European <q>Slope Current</q> provides a shelf-edge conduit for Atlantic Water, a substantial fraction of which is destined for the northern North Sea, with implications for regional hydrography and ecosystems. Drifters drogued at 50 m in the European Slope Current at the Hebridean s...
Published in: | Ocean Science |
---|---|
Main Authors: | , , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
Copernicus Publications
2017
|
Subjects: | |
Online Access: | https://doi.org/10.5194/os-13-315-2017 https://doaj.org/article/2c0ced320a0742d78c3083531b13ba50 |
id |
ftdoajarticles:oai:doaj.org/article:2c0ced320a0742d78c3083531b13ba50 |
---|---|
record_format |
openpolar |
spelling |
ftdoajarticles:oai:doaj.org/article:2c0ced320a0742d78c3083531b13ba50 2023-05-15T17:36:00+02:00 Large-scale forcing of the European Slope Current and associated inflows to the North Sea R. Marsh I. D. Haigh S. A. Cunningham M. E. Inall M. Porter B. I. Moat 2017-04-01T00:00:00Z https://doi.org/10.5194/os-13-315-2017 https://doaj.org/article/2c0ced320a0742d78c3083531b13ba50 EN eng Copernicus Publications http://www.ocean-sci.net/13/315/2017/os-13-315-2017.pdf https://doaj.org/toc/1812-0784 https://doaj.org/toc/1812-0792 1812-0784 1812-0792 doi:10.5194/os-13-315-2017 https://doaj.org/article/2c0ced320a0742d78c3083531b13ba50 Ocean Science, Vol 13, Iss 2, Pp 315-335 (2017) Geography. Anthropology. Recreation G Environmental sciences GE1-350 article 2017 ftdoajarticles https://doi.org/10.5194/os-13-315-2017 2022-12-31T00:44:08Z The European <q>Slope Current</q> provides a shelf-edge conduit for Atlantic Water, a substantial fraction of which is destined for the northern North Sea, with implications for regional hydrography and ecosystems. Drifters drogued at 50 m in the European Slope Current at the Hebridean shelf break follow a wide range of pathways, indicating highly variable Atlantic inflow to the North Sea. Slope Current pathways, timescales and transports over 1988–2007 are further quantified in an eddy-resolving ocean model hindcast. Particle trajectories calculated with model currents indicate that Slope Current water is largely recruited from the eastern subpolar North Atlantic. Observations of absolute dynamic topography and climatological density support theoretical expectations that Slope Current transport is to first order associated with meridional density gradients in the eastern subpolar gyre, which support a geostrophic inflow towards the slope. In the model hindcast, Slope Current transport variability is dominated by abrupt 25–50 % reductions of these density gradients over 1996–1998. Concurrent changes in wind forcing, expressed in terms of density gradients, act in the same sense to reduce Slope Current transport. This indicates that coordinated regional changes of buoyancy and wind forcing acted together to reduce Slope Current transport during the 1990s. Particle trajectories further show that 10–40 % of Slope Current water is destined for the northern North Sea within 6 months of passing to the west of Scotland, with a general decline in this percentage over 1988–2007. Salinities in the Slope Current correspondingly decreased, evidenced in ocean analysis data. Further to the north, in the Atlantic Water conveyed by the Slope Current through the Faroe–Shetland Channel (FSC), salinity is observed to increase over this period while declining in the hindcast. The observed trend may have broadly compensated for a decline in the Atlantic inflow, limiting salinity changes in the northern North Sea during ... Article in Journal/Newspaper North Atlantic Directory of Open Access Journals: DOAJ Articles Hebridean Shelf ENVELOPE(-5.500,-5.500,59.250,59.250) Ocean Science 13 2 315 335 |
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 R. Marsh I. D. Haigh S. A. Cunningham M. E. Inall M. Porter B. I. Moat Large-scale forcing of the European Slope Current and associated inflows to the North Sea |
topic_facet |
Geography. Anthropology. Recreation G Environmental sciences GE1-350 |
description |
The European <q>Slope Current</q> provides a shelf-edge conduit for Atlantic Water, a substantial fraction of which is destined for the northern North Sea, with implications for regional hydrography and ecosystems. Drifters drogued at 50 m in the European Slope Current at the Hebridean shelf break follow a wide range of pathways, indicating highly variable Atlantic inflow to the North Sea. Slope Current pathways, timescales and transports over 1988–2007 are further quantified in an eddy-resolving ocean model hindcast. Particle trajectories calculated with model currents indicate that Slope Current water is largely recruited from the eastern subpolar North Atlantic. Observations of absolute dynamic topography and climatological density support theoretical expectations that Slope Current transport is to first order associated with meridional density gradients in the eastern subpolar gyre, which support a geostrophic inflow towards the slope. In the model hindcast, Slope Current transport variability is dominated by abrupt 25–50 % reductions of these density gradients over 1996–1998. Concurrent changes in wind forcing, expressed in terms of density gradients, act in the same sense to reduce Slope Current transport. This indicates that coordinated regional changes of buoyancy and wind forcing acted together to reduce Slope Current transport during the 1990s. Particle trajectories further show that 10–40 % of Slope Current water is destined for the northern North Sea within 6 months of passing to the west of Scotland, with a general decline in this percentage over 1988–2007. Salinities in the Slope Current correspondingly decreased, evidenced in ocean analysis data. Further to the north, in the Atlantic Water conveyed by the Slope Current through the Faroe–Shetland Channel (FSC), salinity is observed to increase over this period while declining in the hindcast. The observed trend may have broadly compensated for a decline in the Atlantic inflow, limiting salinity changes in the northern North Sea during ... |
format |
Article in Journal/Newspaper |
author |
R. Marsh I. D. Haigh S. A. Cunningham M. E. Inall M. Porter B. I. Moat |
author_facet |
R. Marsh I. D. Haigh S. A. Cunningham M. E. Inall M. Porter B. I. Moat |
author_sort |
R. Marsh |
title |
Large-scale forcing of the European Slope Current and associated inflows to the North Sea |
title_short |
Large-scale forcing of the European Slope Current and associated inflows to the North Sea |
title_full |
Large-scale forcing of the European Slope Current and associated inflows to the North Sea |
title_fullStr |
Large-scale forcing of the European Slope Current and associated inflows to the North Sea |
title_full_unstemmed |
Large-scale forcing of the European Slope Current and associated inflows to the North Sea |
title_sort |
large-scale forcing of the european slope current and associated inflows to the north sea |
publisher |
Copernicus Publications |
publishDate |
2017 |
url |
https://doi.org/10.5194/os-13-315-2017 https://doaj.org/article/2c0ced320a0742d78c3083531b13ba50 |
long_lat |
ENVELOPE(-5.500,-5.500,59.250,59.250) |
geographic |
Hebridean Shelf |
geographic_facet |
Hebridean Shelf |
genre |
North Atlantic |
genre_facet |
North Atlantic |
op_source |
Ocean Science, Vol 13, Iss 2, Pp 315-335 (2017) |
op_relation |
http://www.ocean-sci.net/13/315/2017/os-13-315-2017.pdf https://doaj.org/toc/1812-0784 https://doaj.org/toc/1812-0792 1812-0784 1812-0792 doi:10.5194/os-13-315-2017 https://doaj.org/article/2c0ced320a0742d78c3083531b13ba50 |
op_doi |
https://doi.org/10.5194/os-13-315-2017 |
container_title |
Ocean Science |
container_volume |
13 |
container_issue |
2 |
container_start_page |
315 |
op_container_end_page |
335 |
_version_ |
1766135331258630144 |