Decay of eddies at the South-West Indian Ridge
The South-West Indian Ridge in the Indian sector of the Southern Ocean is a region recognised for the creation of particularly intense eddy disturbances in the mean flow of the Antarctic Circumpolar Current. Eddies formed at this ridge have been extensively studied over the past decade using hydrogr...
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ftnerc:oai:nora.nerc.ac.uk:308541 2023-05-15T13:48:07+02:00 Decay of eddies at the South-West Indian Ridge Durgadoo, Jonathan V. Ansorge, Isabelle J. de Cuevas, Beverly A. Lutjeharms, Johann R.E. Coward, Andrew C. 2011-11 http://nora.nerc.ac.uk/id/eprint/308541/ unknown Durgadoo, Jonathan V.; Ansorge, Isabelle J.; de Cuevas, Beverly A.; Lutjeharms, Johann R.E.; Coward, Andrew C. orcid:0000-0002-9111-7700 . 2011 Decay of eddies at the South-West Indian Ridge. South African Journal of Science, 107 (11-12). 14-23. https://doi.org/10.4102/sajs.v107i11/12.673 <https://doi.org/10.4102/sajs.v107i11/12.673> Publication - Article PeerReviewed 2011 ftnerc https://doi.org/10.4102/sajs.v107i11/12.673 2023-02-04T19:35:57Z The South-West Indian Ridge in the Indian sector of the Southern Ocean is a region recognised for the creation of particularly intense eddy disturbances in the mean flow of the Antarctic Circumpolar Current. Eddies formed at this ridge have been extensively studied over the past decade using hydrographic, satellite, drifter and float data and it is hypothesised that they could provide a vehicle for localised meridional heat and salt exchange. The effectiveness of this process is dependent on the rate of decay of the eddies. However, in order to investigate eddy decay, logistically difficult hydrographic monitoring is required. This study presents the decay of cold eddies at the South-West Indian Ridge, using outputs from a high-resolution ocean model. The model’s representation of the dynamic nature of this region is fully characteristic of observations. On average, 3–4 intense and well-defined cold eddies are generated per year; these eddies have mean longevities of 5.0±2.2 months with average advection speeds of 5±2 km/day. Most simulated eddies reach their peak intensity within 1.5–2.5 months after genesis and have depths of 2000 m – 3000 m. Thereafter they dissipate within approximately 3 months. The decay of eddies is generally characterised by a decrease in their sea surface height signature, a weakening in their rotation rates and a modification in their temperature–salinity characteristics. Subantarctic top predators are suspected to forage preferentially along the edges of eddies. The process of eddy dissipation may thus influence their feeding behaviour. Article in Journal/Newspaper Antarc* Antarctic Southern Ocean Natural Environment Research Council: NERC Open Research Archive Antarctic Southern Ocean The Antarctic Indian South African Journal of Science 107 11/12 |
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Natural Environment Research Council: NERC Open Research Archive |
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ftnerc |
language |
unknown |
description |
The South-West Indian Ridge in the Indian sector of the Southern Ocean is a region recognised for the creation of particularly intense eddy disturbances in the mean flow of the Antarctic Circumpolar Current. Eddies formed at this ridge have been extensively studied over the past decade using hydrographic, satellite, drifter and float data and it is hypothesised that they could provide a vehicle for localised meridional heat and salt exchange. The effectiveness of this process is dependent on the rate of decay of the eddies. However, in order to investigate eddy decay, logistically difficult hydrographic monitoring is required. This study presents the decay of cold eddies at the South-West Indian Ridge, using outputs from a high-resolution ocean model. The model’s representation of the dynamic nature of this region is fully characteristic of observations. On average, 3–4 intense and well-defined cold eddies are generated per year; these eddies have mean longevities of 5.0±2.2 months with average advection speeds of 5±2 km/day. Most simulated eddies reach their peak intensity within 1.5–2.5 months after genesis and have depths of 2000 m – 3000 m. Thereafter they dissipate within approximately 3 months. The decay of eddies is generally characterised by a decrease in their sea surface height signature, a weakening in their rotation rates and a modification in their temperature–salinity characteristics. Subantarctic top predators are suspected to forage preferentially along the edges of eddies. The process of eddy dissipation may thus influence their feeding behaviour. |
format |
Article in Journal/Newspaper |
author |
Durgadoo, Jonathan V. Ansorge, Isabelle J. de Cuevas, Beverly A. Lutjeharms, Johann R.E. Coward, Andrew C. |
spellingShingle |
Durgadoo, Jonathan V. Ansorge, Isabelle J. de Cuevas, Beverly A. Lutjeharms, Johann R.E. Coward, Andrew C. Decay of eddies at the South-West Indian Ridge |
author_facet |
Durgadoo, Jonathan V. Ansorge, Isabelle J. de Cuevas, Beverly A. Lutjeharms, Johann R.E. Coward, Andrew C. |
author_sort |
Durgadoo, Jonathan V. |
title |
Decay of eddies at the South-West Indian Ridge |
title_short |
Decay of eddies at the South-West Indian Ridge |
title_full |
Decay of eddies at the South-West Indian Ridge |
title_fullStr |
Decay of eddies at the South-West Indian Ridge |
title_full_unstemmed |
Decay of eddies at the South-West Indian Ridge |
title_sort |
decay of eddies at the south-west indian ridge |
publishDate |
2011 |
url |
http://nora.nerc.ac.uk/id/eprint/308541/ |
geographic |
Antarctic Southern Ocean The Antarctic Indian |
geographic_facet |
Antarctic Southern Ocean The Antarctic Indian |
genre |
Antarc* Antarctic Southern Ocean |
genre_facet |
Antarc* Antarctic Southern Ocean |
op_relation |
Durgadoo, Jonathan V.; Ansorge, Isabelle J.; de Cuevas, Beverly A.; Lutjeharms, Johann R.E.; Coward, Andrew C. orcid:0000-0002-9111-7700 . 2011 Decay of eddies at the South-West Indian Ridge. South African Journal of Science, 107 (11-12). 14-23. https://doi.org/10.4102/sajs.v107i11/12.673 <https://doi.org/10.4102/sajs.v107i11/12.673> |
op_doi |
https://doi.org/10.4102/sajs.v107i11/12.673 |
container_title |
South African Journal of Science |
container_volume |
107 |
container_issue |
11/12 |
_version_ |
1766248625401233408 |