Investigating the seasonal and interannual variability of the poleward undercurrent in the northern Benguela system

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dc.contributor.advisorRouault, Mathieuen_ZA
dc.contributor.advisorVeitch, Jennifer Anneen_ZA
dc.contributor.authorYates, Sarah Elizabethen_ZA
dc.date.accessioned2014-11-28T09:55:09Z
dc.date.available2014-11-28T09:55:09Z
dc.date.issued2012en_ZA
dc.descriptionIncludes bibliographical references.en_ZA
dc.description.abstractThe Benguela Current System is unique as both the equatorward and poleward boundaries are warm water current systems. Between 15° S – 37° S the surface currents are generally equatorwards, with 7 distinct upwelling cells, narrow equatorward shelf-edge jets and a poleward undercurrent along the continental slope. Model data was used to determine the seasonal and interannual variability of the poleward undercurrent (PUC) in the northern Benguela system. The PUC is the southward extension of the Angolan Current that carries low oxygen water (LOW) originating from the Angola Dome. The LOW flows from the Angolan region southwards in the Benguela system. The focus of the study is on the PUC associated with the Sverdrup relation. The model ORCA-025 was used to reproduce zonal transects from 17° S to 30° S to determine the changing characteristics of the PUC with latitude as well as seasonal and interannual variability of this current. The PUC is faster moving in the north (~17° S) and decreases in velocity moving south (~30° S). The PUC is shallower in the north increasing in depth in the south. The model data shows the velocity of the PUC has a seasonal cycle that is faster in the austral summer and autumn and weakens in the winter. The transport of the PUC is amplified during austral winter and spring, which is consistent with the increased negative wind stress curl during those seasons. The wind stress curl in the region exhibits a strong connection with the transport of the PUC via the Sverdrup relation. The PUC exhibits interannual variability when comparing to the Benguela Niño events, but does not show a correlation with El Niño Southern Oscillation.en_ZA
dc.identifier.apacitationYates, S. E. (2012). <i>Investigating the seasonal and interannual variability of the poleward undercurrent in the northern Benguela system</i>. (Thesis). University of Cape Town ,Faculty of Science ,Department of Oceanography. Retrieved from http://hdl.handle.net/11427/9808en_ZA
dc.identifier.chicagocitationYates, Sarah Elizabeth. <i>"Investigating the seasonal and interannual variability of the poleward undercurrent in the northern Benguela system."</i> Thesis., University of Cape Town ,Faculty of Science ,Department of Oceanography, 2012. http://hdl.handle.net/11427/9808en_ZA
dc.identifier.citationYates, S. 2012. Investigating the seasonal and interannual variability of the poleward undercurrent in the northern Benguela system. University of Cape Town.en_ZA
dc.identifier.ris TY - Thesis / Dissertation AU - Yates, Sarah Elizabeth AB - The Benguela Current System is unique as both the equatorward and poleward boundaries are warm water current systems. Between 15° S – 37° S the surface currents are generally equatorwards, with 7 distinct upwelling cells, narrow equatorward shelf-edge jets and a poleward undercurrent along the continental slope. Model data was used to determine the seasonal and interannual variability of the poleward undercurrent (PUC) in the northern Benguela system. The PUC is the southward extension of the Angolan Current that carries low oxygen water (LOW) originating from the Angola Dome. The LOW flows from the Angolan region southwards in the Benguela system. The focus of the study is on the PUC associated with the Sverdrup relation. The model ORCA-025 was used to reproduce zonal transects from 17° S to 30° S to determine the changing characteristics of the PUC with latitude as well as seasonal and interannual variability of this current. The PUC is faster moving in the north (~17° S) and decreases in velocity moving south (~30° S). The PUC is shallower in the north increasing in depth in the south. The model data shows the velocity of the PUC has a seasonal cycle that is faster in the austral summer and autumn and weakens in the winter. The transport of the PUC is amplified during austral winter and spring, which is consistent with the increased negative wind stress curl during those seasons. The wind stress curl in the region exhibits a strong connection with the transport of the PUC via the Sverdrup relation. The PUC exhibits interannual variability when comparing to the Benguela Niño events, but does not show a correlation with El Niño Southern Oscillation. DA - 2012 DB - OpenUCT DP - University of Cape Town LK - https://open.uct.ac.za PB - University of Cape Town PY - 2012 T1 - Investigating the seasonal and interannual variability of the poleward undercurrent in the northern Benguela system TI - Investigating the seasonal and interannual variability of the poleward undercurrent in the northern Benguela system UR - http://hdl.handle.net/11427/9808 ER - en_ZA
dc.identifier.urihttp://hdl.handle.net/11427/9808
dc.identifier.vancouvercitationYates SE. Investigating the seasonal and interannual variability of the poleward undercurrent in the northern Benguela system. [Thesis]. University of Cape Town ,Faculty of Science ,Department of Oceanography, 2012 [cited yyyy month dd]. Available from: http://hdl.handle.net/11427/9808en_ZA
dc.language.isoengen_ZA
dc.publisher.departmentDepartment of Oceanographyen_ZA
dc.publisher.facultyFaculty of Scienceen_ZA
dc.publisher.institutionUniversity of Cape Town
dc.titleInvestigating the seasonal and interannual variability of the poleward undercurrent in the northern Benguela systemen_ZA
dc.typeMaster Thesis
dc.type.qualificationlevelMasters
dc.type.qualificationnameMScen_ZA
uct.type.filetypeText
uct.type.filetypeImage
uct.type.publicationResearchen_ZA
uct.type.resourceThesisen_ZA
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