Regional circulation around Heard and McDonald Islands and through the Fawn Trough, central Kerguelen Plateau
The fine-scale circulation around the Heard and McDonald Islands and through the Fawn Trough, Kerguelen Plateau, is described using data from three high-resolution CTD sections, Argo floats and satellite maps of chlorophyll a, sea surface temperature (SST) and absolute sea surface height (SSH). We c...
Published in: | Deep Sea Research Part I: Oceanographic Research Papers |
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Online Access: | https://doi.org/10.1016/j.dsr.2010.03.001 http://ecite.utas.edu.au/71309 |
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ftunivtasecite:oai:ecite.utas.edu.au:71309 2023-05-15T16:33:57+02:00 Regional circulation around Heard and McDonald Islands and through the Fawn Trough, central Kerguelen Plateau van Wijk, EM Rintoul, SR Ronai, BM Williams, GD 2010 https://doi.org/10.1016/j.dsr.2010.03.001 http://ecite.utas.edu.au/71309 en eng Pergamon-Elsevier Science Ltd http://dx.doi.org/10.1016/j.dsr.2010.03.001 van Wijk, EM and Rintoul, SR and Ronai, BM and Williams, GD, Regional circulation around Heard and McDonald Islands and through the Fawn Trough, central Kerguelen Plateau, Deep-Sea Research. Part 1: Oceanographic Research Papers, 57, (5) pp. 653-669. ISSN 0967-0637 (2010) [Refereed Article] http://ecite.utas.edu.au/71309 Earth Sciences Oceanography Physical Oceanography Refereed Article PeerReviewed 2010 ftunivtasecite https://doi.org/10.1016/j.dsr.2010.03.001 2019-12-13T21:38:51Z The fine-scale circulation around the Heard and McDonald Islands and through the Fawn Trough, Kerguelen Plateau, is described using data from three high-resolution CTD sections, Argo floats and satellite maps of chlorophyll a, sea surface temperature (SST) and absolute sea surface height (SSH). We confirm that the Polar Front (PF) is split into two branches over the Kerguelen Plateau, with the NPF crossing the north-eastern limits of our survey carrying 25 Sv to the southeast. The SPF was associated with a strong eastward-flowing jet carrying 12 Sv of baroclinic transport through the deepest part of Fawn Trough (relative to the bottom). As the section was terminated midway through the trough this estimate is very likely to be a lower bound for the total transport. We demonstrate that the SPF contributes to the Fawn Trough Current identified by previous studies. After exiting the Fawn Trough, the SPF crossed Chun Spur and continued as a strong north-westward flowing jet along the eastern flank of the Kerguelen Plateau before turning offshore between 50 degrees S and 51.5 degrees S. Measured bottom water temperatures suggest a deep water connection between the northern and southern parts of the eastern Kerguelen Plateau indicating that the deep western boundary current continues at least as far north as 50.5 degrees S. Analysis of satellite altimetry derived SSH streamlines demonstrates a southward shift of both the northern and southern branches of the Polar Front from 1994 to 2004. In the direct vicinity of the Heard and McDonald islands, cool waters of southern origin flow along the Heard Island slope and through the Eastern Trough bringing cold Winter Water (WW) onto the plateau. Complex topography funnels flow through canyons, deepens the mixed layer and increases productivity, resulting in this area being the preferred foraging region for a number of satellite-tracked land-based predators. Article in Journal/Newspaper Heard Island McDonald Islands eCite UTAS (University of Tasmania) Chun Spur ENVELOPE(80.806,80.806,-53.289,-53.289) Fawn Trough ENVELOPE(75.500,75.500,-57.750,-57.750) Heard ENVELOPE(73.510,73.510,-53.117,-53.117) Heard Island Heard Island ENVELOPE(73.510,73.510,-53.117,-53.117) Kerguelen McDonald Islands ENVELOPE(72.600,72.600,-53.033,-53.033) Deep Sea Research Part I: Oceanographic Research Papers 57 5 653 669 |
institution |
Open Polar |
collection |
eCite UTAS (University of Tasmania) |
op_collection_id |
ftunivtasecite |
language |
English |
topic |
Earth Sciences Oceanography Physical Oceanography |
spellingShingle |
Earth Sciences Oceanography Physical Oceanography van Wijk, EM Rintoul, SR Ronai, BM Williams, GD Regional circulation around Heard and McDonald Islands and through the Fawn Trough, central Kerguelen Plateau |
topic_facet |
Earth Sciences Oceanography Physical Oceanography |
description |
The fine-scale circulation around the Heard and McDonald Islands and through the Fawn Trough, Kerguelen Plateau, is described using data from three high-resolution CTD sections, Argo floats and satellite maps of chlorophyll a, sea surface temperature (SST) and absolute sea surface height (SSH). We confirm that the Polar Front (PF) is split into two branches over the Kerguelen Plateau, with the NPF crossing the north-eastern limits of our survey carrying 25 Sv to the southeast. The SPF was associated with a strong eastward-flowing jet carrying 12 Sv of baroclinic transport through the deepest part of Fawn Trough (relative to the bottom). As the section was terminated midway through the trough this estimate is very likely to be a lower bound for the total transport. We demonstrate that the SPF contributes to the Fawn Trough Current identified by previous studies. After exiting the Fawn Trough, the SPF crossed Chun Spur and continued as a strong north-westward flowing jet along the eastern flank of the Kerguelen Plateau before turning offshore between 50 degrees S and 51.5 degrees S. Measured bottom water temperatures suggest a deep water connection between the northern and southern parts of the eastern Kerguelen Plateau indicating that the deep western boundary current continues at least as far north as 50.5 degrees S. Analysis of satellite altimetry derived SSH streamlines demonstrates a southward shift of both the northern and southern branches of the Polar Front from 1994 to 2004. In the direct vicinity of the Heard and McDonald islands, cool waters of southern origin flow along the Heard Island slope and through the Eastern Trough bringing cold Winter Water (WW) onto the plateau. Complex topography funnels flow through canyons, deepens the mixed layer and increases productivity, resulting in this area being the preferred foraging region for a number of satellite-tracked land-based predators. |
format |
Article in Journal/Newspaper |
author |
van Wijk, EM Rintoul, SR Ronai, BM Williams, GD |
author_facet |
van Wijk, EM Rintoul, SR Ronai, BM Williams, GD |
author_sort |
van Wijk, EM |
title |
Regional circulation around Heard and McDonald Islands and through the Fawn Trough, central Kerguelen Plateau |
title_short |
Regional circulation around Heard and McDonald Islands and through the Fawn Trough, central Kerguelen Plateau |
title_full |
Regional circulation around Heard and McDonald Islands and through the Fawn Trough, central Kerguelen Plateau |
title_fullStr |
Regional circulation around Heard and McDonald Islands and through the Fawn Trough, central Kerguelen Plateau |
title_full_unstemmed |
Regional circulation around Heard and McDonald Islands and through the Fawn Trough, central Kerguelen Plateau |
title_sort |
regional circulation around heard and mcdonald islands and through the fawn trough, central kerguelen plateau |
publisher |
Pergamon-Elsevier Science Ltd |
publishDate |
2010 |
url |
https://doi.org/10.1016/j.dsr.2010.03.001 http://ecite.utas.edu.au/71309 |
long_lat |
ENVELOPE(80.806,80.806,-53.289,-53.289) ENVELOPE(75.500,75.500,-57.750,-57.750) ENVELOPE(73.510,73.510,-53.117,-53.117) ENVELOPE(73.510,73.510,-53.117,-53.117) ENVELOPE(72.600,72.600,-53.033,-53.033) |
geographic |
Chun Spur Fawn Trough Heard Heard Island Heard Island Kerguelen McDonald Islands |
geographic_facet |
Chun Spur Fawn Trough Heard Heard Island Heard Island Kerguelen McDonald Islands |
genre |
Heard Island McDonald Islands |
genre_facet |
Heard Island McDonald Islands |
op_relation |
http://dx.doi.org/10.1016/j.dsr.2010.03.001 van Wijk, EM and Rintoul, SR and Ronai, BM and Williams, GD, Regional circulation around Heard and McDonald Islands and through the Fawn Trough, central Kerguelen Plateau, Deep-Sea Research. Part 1: Oceanographic Research Papers, 57, (5) pp. 653-669. ISSN 0967-0637 (2010) [Refereed Article] http://ecite.utas.edu.au/71309 |
op_doi |
https://doi.org/10.1016/j.dsr.2010.03.001 |
container_title |
Deep Sea Research Part I: Oceanographic Research Papers |
container_volume |
57 |
container_issue |
5 |
container_start_page |
653 |
op_container_end_page |
669 |
_version_ |
1766023688780513280 |