The Irminger Gyre: Circulation, convection, and interannual variability

In this study 36 hydrographic transects occupied between 1991 and 2007 in the vicinity of the WOCE A1E/AR7E section are used to investigate various aspects of the Irminger Gyre, a narrow cyclonic recirculation in the southwest Irminger Sea. Vertical sections of absolute geostrophic velocity were con...

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Published in:Deep Sea Research Part I: Oceanographic Research Papers
Main Authors: Våge, Kjetil, Pickart, Robert S., Sarafanov, Artem, Knutsen, Øyvind, Mercier, Herlé, Lherminier, Pascale, van Aken, Hendrik M., Meincke, Jens, Quadfasel, Detlef, Bacon, Sheldon
Format: Article in Journal/Newspaper
Language:unknown
Published: 2011
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Online Access:http://nora.nerc.ac.uk/id/eprint/287393/
id ftnerc:oai:nora.nerc.ac.uk:287393
record_format openpolar
spelling ftnerc:oai:nora.nerc.ac.uk:287393 2023-05-15T17:06:08+02:00 The Irminger Gyre: Circulation, convection, and interannual variability Våge, Kjetil Pickart, Robert S. Sarafanov, Artem Knutsen, Øyvind Mercier, Herlé Lherminier, Pascale van Aken, Hendrik M. Meincke, Jens Quadfasel, Detlef Bacon, Sheldon 2011-05 http://nora.nerc.ac.uk/id/eprint/287393/ unknown Våge, Kjetil; Pickart, Robert S.; Sarafanov, Artem; Knutsen, Øyvind; Mercier, Herlé; Lherminier, Pascale; van Aken, Hendrik M.; Meincke, Jens; Quadfasel, Detlef; Bacon, Sheldon orcid:0000-0002-2471-9373 . 2011 The Irminger Gyre: Circulation, convection, and interannual variability. Deep Sea Research Part I Oceanographic Research Papers, 58 (5). 590-614. https://doi.org/10.1016/j.dsr.2011.03.001 <https://doi.org/10.1016/j.dsr.2011.03.001> Publication - Article PeerReviewed 2011 ftnerc https://doi.org/10.1016/j.dsr.2011.03.001 2023-02-04T19:35:49Z In this study 36 hydrographic transects occupied between 1991 and 2007 in the vicinity of the WOCE A1E/AR7E section are used to investigate various aspects of the Irminger Gyre, a narrow cyclonic recirculation in the southwest Irminger Sea. Vertical sections of absolute geostrophic velocity were constructed using satellite and shipboard velocity measurements, and analyzed in conjunction with the hydrographic data and meteorological fields. The Irminger Gyre is a weakly baroclinic feature with a mean transport of 6.8±1.9 Sv (View the MathML source). At mid-depth it contains water with the same properties as Labrador Sea Water (LSW). During the 17-year study period large changes occurred in the gyre and also within the boundary flow encircling the Irminger Sea. The gyre intensified and became more stratified, while the upper-layer circulation of the boundary current system weakened. The latter is consistent with the overall decline of the North Atlantic subpolar gyre reported earlier. However, the decline of the upper-ocean boundary currents was accompanied by an intensification of the circulation at deeper levels. The deep component of both the northward-flowing boundary current (the Irminger Current) and the southward-flowing boundary current (the Deep Western Boundary Current) strengthened. The increase in transport of the deep Irminger Current is due to the emergence of a second deep limb of the current, presumably due to a shift in pathways of the branches of the subpolar gyre. Using a volumetric water mass analysis it is argued that LSW was formed locally within the Irminger Gyre via deep convection in the early 1990s. In contrast, LSW appeared outside of the gyre in the eastern part of the Irminger Sea with a time lag of 2–3 years, consistent with transit from the Labrador Sea. Thus, our analysis clarifies the relative contributions of locally-versus remotely-formed LSW in the Irminger Sea. Article in Journal/Newspaper Labrador Sea North Atlantic Natural Environment Research Council: NERC Open Research Archive Irminger Sea ENVELOPE(-34.041,-34.041,63.054,63.054) Deep Sea Research Part I: Oceanographic Research Papers 58 5 590 614
institution Open Polar
collection Natural Environment Research Council: NERC Open Research Archive
op_collection_id ftnerc
language unknown
description In this study 36 hydrographic transects occupied between 1991 and 2007 in the vicinity of the WOCE A1E/AR7E section are used to investigate various aspects of the Irminger Gyre, a narrow cyclonic recirculation in the southwest Irminger Sea. Vertical sections of absolute geostrophic velocity were constructed using satellite and shipboard velocity measurements, and analyzed in conjunction with the hydrographic data and meteorological fields. The Irminger Gyre is a weakly baroclinic feature with a mean transport of 6.8±1.9 Sv (View the MathML source). At mid-depth it contains water with the same properties as Labrador Sea Water (LSW). During the 17-year study period large changes occurred in the gyre and also within the boundary flow encircling the Irminger Sea. The gyre intensified and became more stratified, while the upper-layer circulation of the boundary current system weakened. The latter is consistent with the overall decline of the North Atlantic subpolar gyre reported earlier. However, the decline of the upper-ocean boundary currents was accompanied by an intensification of the circulation at deeper levels. The deep component of both the northward-flowing boundary current (the Irminger Current) and the southward-flowing boundary current (the Deep Western Boundary Current) strengthened. The increase in transport of the deep Irminger Current is due to the emergence of a second deep limb of the current, presumably due to a shift in pathways of the branches of the subpolar gyre. Using a volumetric water mass analysis it is argued that LSW was formed locally within the Irminger Gyre via deep convection in the early 1990s. In contrast, LSW appeared outside of the gyre in the eastern part of the Irminger Sea with a time lag of 2–3 years, consistent with transit from the Labrador Sea. Thus, our analysis clarifies the relative contributions of locally-versus remotely-formed LSW in the Irminger Sea.
format Article in Journal/Newspaper
author Våge, Kjetil
Pickart, Robert S.
Sarafanov, Artem
Knutsen, Øyvind
Mercier, Herlé
Lherminier, Pascale
van Aken, Hendrik M.
Meincke, Jens
Quadfasel, Detlef
Bacon, Sheldon
spellingShingle Våge, Kjetil
Pickart, Robert S.
Sarafanov, Artem
Knutsen, Øyvind
Mercier, Herlé
Lherminier, Pascale
van Aken, Hendrik M.
Meincke, Jens
Quadfasel, Detlef
Bacon, Sheldon
The Irminger Gyre: Circulation, convection, and interannual variability
author_facet Våge, Kjetil
Pickart, Robert S.
Sarafanov, Artem
Knutsen, Øyvind
Mercier, Herlé
Lherminier, Pascale
van Aken, Hendrik M.
Meincke, Jens
Quadfasel, Detlef
Bacon, Sheldon
author_sort Våge, Kjetil
title The Irminger Gyre: Circulation, convection, and interannual variability
title_short The Irminger Gyre: Circulation, convection, and interannual variability
title_full The Irminger Gyre: Circulation, convection, and interannual variability
title_fullStr The Irminger Gyre: Circulation, convection, and interannual variability
title_full_unstemmed The Irminger Gyre: Circulation, convection, and interannual variability
title_sort irminger gyre: circulation, convection, and interannual variability
publishDate 2011
url http://nora.nerc.ac.uk/id/eprint/287393/
long_lat ENVELOPE(-34.041,-34.041,63.054,63.054)
geographic Irminger Sea
geographic_facet Irminger Sea
genre Labrador Sea
North Atlantic
genre_facet Labrador Sea
North Atlantic
op_relation Våge, Kjetil; Pickart, Robert S.; Sarafanov, Artem; Knutsen, Øyvind; Mercier, Herlé; Lherminier, Pascale; van Aken, Hendrik M.; Meincke, Jens; Quadfasel, Detlef; Bacon, Sheldon orcid:0000-0002-2471-9373 . 2011 The Irminger Gyre: Circulation, convection, and interannual variability. Deep Sea Research Part I Oceanographic Research Papers, 58 (5). 590-614. https://doi.org/10.1016/j.dsr.2011.03.001 <https://doi.org/10.1016/j.dsr.2011.03.001>
op_doi https://doi.org/10.1016/j.dsr.2011.03.001
container_title Deep Sea Research Part I: Oceanographic Research Papers
container_volume 58
container_issue 5
container_start_page 590
op_container_end_page 614
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