The geostrophic dynamics of meridional transport variability in the sub-polar North Atlantic
The North Atlantic meridional overturning 6 circulation (MOC) is believed to play an important role in regulating the Earth’s climate. Yet, there is still much uncertainty regarding the dynamics of the MOC and its variability. It is well established, however, that, through geostrophy, the zonally in...
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ftnerc:oai:nora.nerc.ac.uk:8187 2023-05-15T17:31:42+02:00 The geostrophic dynamics of meridional transport variability in the sub-polar North Atlantic Bingham, Rory Hughes, Christopher 2009 text http://nora.nerc.ac.uk/id/eprint/8187/ https://nora.nerc.ac.uk/id/eprint/8187/1/Bingham_-_the_geostrophic_dynamics_of_meridional_transport.pdf en eng https://nora.nerc.ac.uk/id/eprint/8187/1/Bingham_-_the_geostrophic_dynamics_of_meridional_transport.pdf Bingham, Rory; Hughes, Christopher orcid:0000-0002-9355-0233 . 2009 The geostrophic dynamics of meridional transport variability in the sub-polar North Atlantic. Journal of Geophysical Research, 114, C12029. https://doi.org/10.1029/2009JC005492 <https://doi.org/10.1029/2009JC005492> Marine Sciences Meteorology and Climatology Publication - Article PeerReviewed 2009 ftnerc https://doi.org/10.1029/2009JC005492 2023-02-04T19:25:21Z The North Atlantic meridional overturning 6 circulation (MOC) is believed to play an important role in regulating the Earth’s climate. Yet, there is still much uncertainty regarding the dynamics of the MOC and its variability. It is well established, however, that, through geostrophy, the zonally integrated meridional transport at a particular latitude and depth can be determined from the east-west bottom pressure difference across the basin. Therefore, rather than consider the MOC as a large-scale system, this paper focuses on the dynamics of this geostrophic relationship in two numerical ocean models at a single latitude (50◦14 N) in the sub-polar Atlantic. First, it is shown that the bottom pressure on the western boundary is sufficient to recover, with high fidelity, the interannual meridional transport variability at 50◦17 N over a one hundred year period in the climate model HadCM3. It is found that the variability of western boundary pressure is closely associated with density changes over the continental slope. These changes lead to a large zonal gradient in potential energy and an unfeasible, depth-mean velocity over the slope. The western boundary pressure, from which the meridional transport can be recovered, is generated as a compensation to this, and limits the depth-mean flow. This demonstrates that in numerical ocean models, at least, meridional transport variability is generated as a local response to density changes on the western slope. Whether this is a true representation of actual ocean variability is uncertain, but if it were, then meridional transport variability could largely be determined using only the density field on the western slope. Article in Journal/Newspaper North Atlantic Natural Environment Research Council: NERC Open Research Archive Journal of Geophysical Research 114 C12 |
institution |
Open Polar |
collection |
Natural Environment Research Council: NERC Open Research Archive |
op_collection_id |
ftnerc |
language |
English |
topic |
Marine Sciences Meteorology and Climatology |
spellingShingle |
Marine Sciences Meteorology and Climatology Bingham, Rory Hughes, Christopher The geostrophic dynamics of meridional transport variability in the sub-polar North Atlantic |
topic_facet |
Marine Sciences Meteorology and Climatology |
description |
The North Atlantic meridional overturning 6 circulation (MOC) is believed to play an important role in regulating the Earth’s climate. Yet, there is still much uncertainty regarding the dynamics of the MOC and its variability. It is well established, however, that, through geostrophy, the zonally integrated meridional transport at a particular latitude and depth can be determined from the east-west bottom pressure difference across the basin. Therefore, rather than consider the MOC as a large-scale system, this paper focuses on the dynamics of this geostrophic relationship in two numerical ocean models at a single latitude (50◦14 N) in the sub-polar Atlantic. First, it is shown that the bottom pressure on the western boundary is sufficient to recover, with high fidelity, the interannual meridional transport variability at 50◦17 N over a one hundred year period in the climate model HadCM3. It is found that the variability of western boundary pressure is closely associated with density changes over the continental slope. These changes lead to a large zonal gradient in potential energy and an unfeasible, depth-mean velocity over the slope. The western boundary pressure, from which the meridional transport can be recovered, is generated as a compensation to this, and limits the depth-mean flow. This demonstrates that in numerical ocean models, at least, meridional transport variability is generated as a local response to density changes on the western slope. Whether this is a true representation of actual ocean variability is uncertain, but if it were, then meridional transport variability could largely be determined using only the density field on the western slope. |
format |
Article in Journal/Newspaper |
author |
Bingham, Rory Hughes, Christopher |
author_facet |
Bingham, Rory Hughes, Christopher |
author_sort |
Bingham, Rory |
title |
The geostrophic dynamics of meridional transport variability in the sub-polar North Atlantic |
title_short |
The geostrophic dynamics of meridional transport variability in the sub-polar North Atlantic |
title_full |
The geostrophic dynamics of meridional transport variability in the sub-polar North Atlantic |
title_fullStr |
The geostrophic dynamics of meridional transport variability in the sub-polar North Atlantic |
title_full_unstemmed |
The geostrophic dynamics of meridional transport variability in the sub-polar North Atlantic |
title_sort |
geostrophic dynamics of meridional transport variability in the sub-polar north atlantic |
publishDate |
2009 |
url |
http://nora.nerc.ac.uk/id/eprint/8187/ https://nora.nerc.ac.uk/id/eprint/8187/1/Bingham_-_the_geostrophic_dynamics_of_meridional_transport.pdf |
genre |
North Atlantic |
genre_facet |
North Atlantic |
op_relation |
https://nora.nerc.ac.uk/id/eprint/8187/1/Bingham_-_the_geostrophic_dynamics_of_meridional_transport.pdf Bingham, Rory; Hughes, Christopher orcid:0000-0002-9355-0233 . 2009 The geostrophic dynamics of meridional transport variability in the sub-polar North Atlantic. Journal of Geophysical Research, 114, C12029. https://doi.org/10.1029/2009JC005492 <https://doi.org/10.1029/2009JC005492> |
op_doi |
https://doi.org/10.1029/2009JC005492 |
container_title |
Journal of Geophysical Research |
container_volume |
114 |
container_issue |
C12 |
_version_ |
1766129399917182976 |