Variability in the Deep Western Boundary Current: Local versus remote forcing
Horizontal velocity, temperature and salinity measurements from the Line W array for the period 20042008 show large changes in the water mass structure and circulation of the Deep Western Boundary Current (DWBC). Fluctuations in the flow with periods from 10 to 60 days are bottom intensified: signal...
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Online Access: | https://doi.org/10.1029/2012JC008369 http://ecite.utas.edu.au/83512 |
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ftunivtasecite:oai:ecite.utas.edu.au:83512 2023-05-15T17:06:12+02:00 Variability in the Deep Western Boundary Current: Local versus remote forcing Pena-Molino, B Joyce, TM Toole, JM 2012 application/pdf https://doi.org/10.1029/2012JC008369 http://ecite.utas.edu.au/83512 en eng Amer Geophysical Union http://ecite.utas.edu.au/83512/1/PenaMolino_boundary_current2012.pdf http://dx.doi.org/10.1029/2012JC008369 Pena-Molino, B and Joyce, TM and Toole, JM, Variability in the Deep Western Boundary Current: Local versus remote forcing, Journal of Geophysical Research-Oceans, 117 Article C12022. ISSN 0148-0227 (2012) [Refereed Article] http://ecite.utas.edu.au/83512 Earth Sciences Oceanography Physical Oceanography Refereed Article PeerReviewed 2012 ftunivtasecite https://doi.org/10.1029/2012JC008369 2019-12-13T21:48:07Z Horizontal velocity, temperature and salinity measurements from the Line W array for the period 20042008 show large changes in the water mass structure and circulation of the Deep Western Boundary Current (DWBC). Fluctuations in the flow with periods from 10 to 60 days are bottom intensified: signals most likely associated with topographic Rossby waves (TRW). A fraction (∼15%) of the DWBC transport variability is caused by Gulf Stream rings and meanders. These flow anomalies are surface intensified and fluctuate at frequencies lower than the TRW. Interannual variability in the velocity field appears to be related to changes in the hydrographic properties. The dominant mode of variability is characterized by an overall freshening, cooling, a potential vorticity (PV) increase in the deep Labrador Sea Water (dLSW) and a PV decrease in the Overflow Water (OW). The variability in the flow associated with these property changes is not spatially homogeneous. Offshore (water depths larger than 3500 m) changes in the velocity are in phase with PV changes in the OW: a decrease in the OW PV is accompanied by an increase in the southward (negative) transport. Conversely, variations of the inshore flow are in phase with changes in the dLSW PV (increasing PV and decreasing transport). This trend, true for most of the record, reverses after the winter of 20072008. A sudden decrease of the dLSW PV is observed, with a corresponding intensification of the flow in the inner DWBC as well as a northward shift in the Gulf Stream axis. Article in Journal/Newspaper Labrador Sea eCite UTAS (University of Tasmania) Journal of Geophysical Research: Oceans 117 C12 n/a n/a |
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eCite UTAS (University of Tasmania) |
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ftunivtasecite |
language |
English |
topic |
Earth Sciences Oceanography Physical Oceanography |
spellingShingle |
Earth Sciences Oceanography Physical Oceanography Pena-Molino, B Joyce, TM Toole, JM Variability in the Deep Western Boundary Current: Local versus remote forcing |
topic_facet |
Earth Sciences Oceanography Physical Oceanography |
description |
Horizontal velocity, temperature and salinity measurements from the Line W array for the period 20042008 show large changes in the water mass structure and circulation of the Deep Western Boundary Current (DWBC). Fluctuations in the flow with periods from 10 to 60 days are bottom intensified: signals most likely associated with topographic Rossby waves (TRW). A fraction (∼15%) of the DWBC transport variability is caused by Gulf Stream rings and meanders. These flow anomalies are surface intensified and fluctuate at frequencies lower than the TRW. Interannual variability in the velocity field appears to be related to changes in the hydrographic properties. The dominant mode of variability is characterized by an overall freshening, cooling, a potential vorticity (PV) increase in the deep Labrador Sea Water (dLSW) and a PV decrease in the Overflow Water (OW). The variability in the flow associated with these property changes is not spatially homogeneous. Offshore (water depths larger than 3500 m) changes in the velocity are in phase with PV changes in the OW: a decrease in the OW PV is accompanied by an increase in the southward (negative) transport. Conversely, variations of the inshore flow are in phase with changes in the dLSW PV (increasing PV and decreasing transport). This trend, true for most of the record, reverses after the winter of 20072008. A sudden decrease of the dLSW PV is observed, with a corresponding intensification of the flow in the inner DWBC as well as a northward shift in the Gulf Stream axis. |
format |
Article in Journal/Newspaper |
author |
Pena-Molino, B Joyce, TM Toole, JM |
author_facet |
Pena-Molino, B Joyce, TM Toole, JM |
author_sort |
Pena-Molino, B |
title |
Variability in the Deep Western Boundary Current: Local versus remote forcing |
title_short |
Variability in the Deep Western Boundary Current: Local versus remote forcing |
title_full |
Variability in the Deep Western Boundary Current: Local versus remote forcing |
title_fullStr |
Variability in the Deep Western Boundary Current: Local versus remote forcing |
title_full_unstemmed |
Variability in the Deep Western Boundary Current: Local versus remote forcing |
title_sort |
variability in the deep western boundary current: local versus remote forcing |
publisher |
Amer Geophysical Union |
publishDate |
2012 |
url |
https://doi.org/10.1029/2012JC008369 http://ecite.utas.edu.au/83512 |
genre |
Labrador Sea |
genre_facet |
Labrador Sea |
op_relation |
http://ecite.utas.edu.au/83512/1/PenaMolino_boundary_current2012.pdf http://dx.doi.org/10.1029/2012JC008369 Pena-Molino, B and Joyce, TM and Toole, JM, Variability in the Deep Western Boundary Current: Local versus remote forcing, Journal of Geophysical Research-Oceans, 117 Article C12022. ISSN 0148-0227 (2012) [Refereed Article] http://ecite.utas.edu.au/83512 |
op_doi |
https://doi.org/10.1029/2012JC008369 |
container_title |
Journal of Geophysical Research: Oceans |
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117 |
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C12 |
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n/a |
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1766061223770587136 |