Variability in the Deep Western Boundary Current : local versus remote forcing
Author Posting. © American Geophysical Union, 2012. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research 117 (2012): C12022, doi:10.1029/2012JC008369. Horizontal veloc...
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ftwhoas:oai:darchive.mblwhoilibrary.org:1912/5742 2023-05-15T17:06:15+02:00 Variability in the Deep Western Boundary Current : local versus remote forcing Pena-Molino, Beatriz Joyce, Terrence M. Toole, John M. 2012-12-22 application/pdf text/plain https://hdl.handle.net/1912/5742 en_US eng American Geophysical Union https://doi.org/10.1029/2012JC008369 Journal of Geophysical Research 117 (2012): C12022 https://hdl.handle.net/1912/5742 doi:10.1029/2012JC008369 Journal of Geophysical Research 117 (2012): C12022 doi:10.1029/2012JC008369 DWBC Gulf Stream Line W Transport Variability Water mass Article 2012 ftwhoas https://doi.org/10.1029/2012JC008369 2022-05-28T22:58:47Z Author Posting. © American Geophysical Union, 2012. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research 117 (2012): C12022, doi:10.1029/2012JC008369. Horizontal velocity, temperature and salinity measurements from the Line W array for the period 2004–2008 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 2007–2008. 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. Financial support for the Line W program (2004–2008) was provided by the U.S. National Science Foundation (grants OCE-0241354 and OCE-0726720) as well as funding from the WHOI’s Ocean and Climate Change Institute. ... Article in Journal/Newspaper Labrador Sea Woods Hole Scientific Community: WHOAS (Woods Hole Open Access Server) Journal of Geophysical Research: Oceans 117 C12 n/a n/a |
institution |
Open Polar |
collection |
Woods Hole Scientific Community: WHOAS (Woods Hole Open Access Server) |
op_collection_id |
ftwhoas |
language |
English |
topic |
DWBC Gulf Stream Line W Transport Variability Water mass |
spellingShingle |
DWBC Gulf Stream Line W Transport Variability Water mass Pena-Molino, Beatriz Joyce, Terrence M. Toole, John M. Variability in the Deep Western Boundary Current : local versus remote forcing |
topic_facet |
DWBC Gulf Stream Line W Transport Variability Water mass |
description |
Author Posting. © American Geophysical Union, 2012. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research 117 (2012): C12022, doi:10.1029/2012JC008369. Horizontal velocity, temperature and salinity measurements from the Line W array for the period 2004–2008 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 2007–2008. 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. Financial support for the Line W program (2004–2008) was provided by the U.S. National Science Foundation (grants OCE-0241354 and OCE-0726720) as well as funding from the WHOI’s Ocean and Climate Change Institute. ... |
format |
Article in Journal/Newspaper |
author |
Pena-Molino, Beatriz Joyce, Terrence M. Toole, John M. |
author_facet |
Pena-Molino, Beatriz Joyce, Terrence M. Toole, John M. |
author_sort |
Pena-Molino, Beatriz |
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 |
American Geophysical Union |
publishDate |
2012 |
url |
https://hdl.handle.net/1912/5742 |
genre |
Labrador Sea |
genre_facet |
Labrador Sea |
op_source |
Journal of Geophysical Research 117 (2012): C12022 doi:10.1029/2012JC008369 |
op_relation |
https://doi.org/10.1029/2012JC008369 Journal of Geophysical Research 117 (2012): C12022 https://hdl.handle.net/1912/5742 doi:10.1029/2012JC008369 |
op_doi |
https://doi.org/10.1029/2012JC008369 |
container_title |
Journal of Geophysical Research: Oceans |
container_volume |
117 |
container_issue |
C12 |
container_start_page |
n/a |
op_container_end_page |
n/a |
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1766061285302075392 |