Decay of eddies at the South-West Indian Ridge
| dc.contributor.author | Durgadoo, Jonathan V | |
| dc.contributor.author | Ansorge, Isabelle J | |
| dc.contributor.author | de Cuevas, Beverly A | |
| dc.contributor.author | Lutjeharms, Johann R E | |
| dc.contributor.author | Coward, Andrew C | |
| dc.date.accessioned | 2019-03-11T10:44:08Z | |
| dc.date.available | 2019-03-11T10:44:08Z | |
| dc.date.issued | 2011 | |
| dc.date.updated | 2019-03-11T09:50:28Z | |
| dc.description.abstract | 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 highresolution 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. | |
| dc.identifier | http://dx.doi.org/10.4102/sajs. v107i11/12.673 | |
| dc.identifier.apacitation | Durgadoo, J. V., Ansorge, I. J., de Cuevas, B. A., Lutjeharms, J. R. E., & Coward, A. C. (2011). Decay of eddies at the South-West Indian Ridge. <i>South African Journal of Science</i>, http://hdl.handle.net/11427/29910 | en_ZA |
| dc.identifier.chicagocitation | Durgadoo, Jonathan V, Isabelle J Ansorge, Beverly A de Cuevas, Johann R E Lutjeharms, and Andrew C Coward "Decay of eddies at the South-West Indian Ridge." <i>South African Journal of Science</i> (2011) http://hdl.handle.net/11427/29910 | en_ZA |
| dc.identifier.citation | Durgadoo, Jonathan V; Ansorge, Isabelle J; de Cuevas, Beverly A; Lutjeharms, Johann R E; Coward, Andrew C. (2011). Decay of eddies at the South-West Indian Ridge, 107:1-10 | |
| dc.identifier.ris | TY - AU - Durgadoo, Jonathan V AU - Ansorge, Isabelle J AU - de Cuevas, Beverly A AU - Lutjeharms, Johann R E AU - Coward, Andrew C AB - 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 highresolution 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. DA - 2011 DB - OpenUCT DP - University of Cape Town J1 - South African Journal of Science LK - https://open.uct.ac.za PY - 2011 T1 - Decay of eddies at the South-West Indian Ridge TI - Decay of eddies at the South-West Indian Ridge UR - http://hdl.handle.net/11427/29910 ER - | en_ZA |
| dc.identifier.uri | http://hdl.handle.net/11427/29910 | |
| dc.identifier.vancouvercitation | Durgadoo JV, Ansorge IJ, de Cuevas BA, Lutjeharms JRE, Coward AC. Decay of eddies at the South-West Indian Ridge. South African Journal of Science. 2011; http://hdl.handle.net/11427/29910. | en_ZA |
| dc.language.iso | eng | |
| dc.publisher.department | Department of Oceanography | |
| dc.publisher.faculty | Faculty of Science | |
| dc.source | South African Journal of Science | |
| dc.source.uri | https://www.sajs.co.za/ | |
| dc.subject.other | South-West Indian Ridge | |
| dc.subject.other | Indian sector | |
| dc.subject.other | Southern Ocean | |
| dc.subject.other | eddy disturbances | |
| dc.subject.other | Antarctic Circumpolar Current | |
| dc.title | Decay of eddies at the South-West Indian Ridge | |
| dc.type | Journal Article |