Spatio-temporal characteristics of the Agulhas leakage: a model inter-comparison study

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dc.contributor.advisorDeshayes, Julieen_ZA
dc.contributor.authorHolton, Lisa Een_ZA
dc.date.accessioned2015-12-03T14:18:27Z
dc.date.available2015-12-03T14:18:27Z
dc.date.issued2015en_ZA
dc.description.abstractInvestigating the variability of the Agulhas leakage, the volume transport of water from the Indian Ocean to the South Atlantic Ocean, is highly relevant due to its potential contribution to the Atlantic Meridional Overturning Circulation (AMOC) and the global circulation of heat, salt and freshwater, hence to the global climate. As observations of the leakage are scattered in time and space, ocean model outputs are unavoidable to describe its mechanisms of variability. However, the Agulhas leakage is part of a system that still represents a challenge to modellers, because of its degree of non-linearity. As a consequence, this thesis reports the study of the mechanisms of variability of the Agulhas leakage in six ocean model outputs of varying resolution, vertical discretization and boundary conditions. Inter-comparing several model outputs allow one to identify which characteristics of variability are robust. It also provides valuable information on the model speci_cs required to correctly represent the mechanisms of variability of the Agulhas leakage and hence its contribution to climate variability. The Agulhas leakage is estimated at the Good Hope line, a section through the centre of the Cape Basin, using a Eulerian threshold integration method based on the thermo- haline properties of water masses along the line. The threshold method also takes into account the thermohaline biases of each model. Other methods have been tested but the former was selected because it yields an Agulhas Leakage that represents 60% of the actual magnitude as determined by a passive tracer method (only available in one simulation) and captures nearly all of the temporal variability.en_ZA
dc.identifier.apacitationHolton, L. E. (2015). <i>Spatio-temporal characteristics of the Agulhas leakage: a model inter-comparison study</i>. (Thesis). University of Cape Town ,Faculty of Science ,Department of Oceanography. Retrieved from http://hdl.handle.net/11427/15563en_ZA
dc.identifier.chicagocitationHolton, Lisa E. <i>"Spatio-temporal characteristics of the Agulhas leakage: a model inter-comparison study."</i> Thesis., University of Cape Town ,Faculty of Science ,Department of Oceanography, 2015. http://hdl.handle.net/11427/15563en_ZA
dc.identifier.citationHolton, L. 2015. Spatio-temporal characteristics of the Agulhas leakage: a model inter-comparison study. University of Cape Town.en_ZA
dc.identifier.ris TY - Thesis / Dissertation AU - Holton, Lisa E AB - Investigating the variability of the Agulhas leakage, the volume transport of water from the Indian Ocean to the South Atlantic Ocean, is highly relevant due to its potential contribution to the Atlantic Meridional Overturning Circulation (AMOC) and the global circulation of heat, salt and freshwater, hence to the global climate. As observations of the leakage are scattered in time and space, ocean model outputs are unavoidable to describe its mechanisms of variability. However, the Agulhas leakage is part of a system that still represents a challenge to modellers, because of its degree of non-linearity. As a consequence, this thesis reports the study of the mechanisms of variability of the Agulhas leakage in six ocean model outputs of varying resolution, vertical discretization and boundary conditions. Inter-comparing several model outputs allow one to identify which characteristics of variability are robust. It also provides valuable information on the model speci_cs required to correctly represent the mechanisms of variability of the Agulhas leakage and hence its contribution to climate variability. The Agulhas leakage is estimated at the Good Hope line, a section through the centre of the Cape Basin, using a Eulerian threshold integration method based on the thermo- haline properties of water masses along the line. The threshold method also takes into account the thermohaline biases of each model. Other methods have been tested but the former was selected because it yields an Agulhas Leakage that represents 60% of the actual magnitude as determined by a passive tracer method (only available in one simulation) and captures nearly all of the temporal variability. DA - 2015 DB - OpenUCT DP - University of Cape Town LK - https://open.uct.ac.za PB - University of Cape Town PY - 2015 T1 - Spatio-temporal characteristics of the Agulhas leakage: a model inter-comparison study TI - Spatio-temporal characteristics of the Agulhas leakage: a model inter-comparison study UR - http://hdl.handle.net/11427/15563 ER - en_ZA
dc.identifier.urihttp://hdl.handle.net/11427/15563
dc.identifier.vancouvercitationHolton LE. Spatio-temporal characteristics of the Agulhas leakage: a model inter-comparison study. [Thesis]. University of Cape Town ,Faculty of Science ,Department of Oceanography, 2015 [cited yyyy month dd]. Available from: http://hdl.handle.net/11427/15563en_ZA
dc.language.isoengen_ZA
dc.publisher.departmentDepartment of Oceanographyen_ZA
dc.publisher.facultyFaculty of Scienceen_ZA
dc.publisher.institutionUniversity of Cape Town
dc.subject.otherOceanographyen_ZA
dc.titleSpatio-temporal characteristics of the Agulhas leakage: a model inter-comparison studyen_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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