Regional estimates of potential new production in the southern Benguela upwelling system

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dc.contributor.advisorBrundrit, Geoffen_ZA
dc.contributor.advisorProbyn, Trevor Aen_ZA
dc.contributor.authorWaldron, Howard Neilen_ZA
dc.date.accessioned2016-03-28T14:44:42Z
dc.date.available2016-03-28T14:44:42Z
dc.date.issued1996en_ZA
dc.description.abstractThe estimation of annual potential new production at a regional scale for the decade of the 1980s provides the main focus of this thesis. New production is the proportion of total primary production which relies on the uptake of NO₃-N by the phytoplankton while potential new production assumes that all the NO₃-N available to primary producers is assimilated. The Redfield ratio between carbon and nitrogen in the marine environment was used to express rates of potential new production in terms of carbon. In order to arrive at annual estimates of potential new production it was necessary to progress from the event-scale to the annual scale. This was achieved by the adoption of two novel methods of approach. Event-scale estimates of potential new production were made by assessing the amount of NO₃-N present in the nominal euphotic zone as a result of upwelling. Remotely-sensed images of sea surface temperature (SST) coincident with or shortly after upwelling events were used in combination with a derived relationship between SST and NO₃-N concentrations integrated over the depth range of the productive surface layer in the southern Benguela region. In this way it was possible to overcome the main shortcoming of passive satellite imagery by quantifying a sub-surface variable. The event-scale estimates of potential new production were extrapolated to the annual-scale by taking into account the dynamics of the system. Sea level fluctuation at the coast preceding upwelling events was found to be related to the event-scale estimates of introduced NO₃-N and hence used as a proxy for upwelling. Using a ten year record of sea level, estimates of annual potential new production, spanning the period June to May inclusive, were made for the period 1980/81 to 1989/90. Bibliography: pages 92-108.en_ZA
dc.identifier.apacitationWaldron, H. N. (1996). <i>Regional estimates of potential new production in the southern Benguela upwelling system</i>. (Thesis). University of Cape Town ,Faculty of Science ,Department of Oceanography. Retrieved from http://hdl.handle.net/11427/18343en_ZA
dc.identifier.chicagocitationWaldron, Howard Neil. <i>"Regional estimates of potential new production in the southern Benguela upwelling system."</i> Thesis., University of Cape Town ,Faculty of Science ,Department of Oceanography, 1996. http://hdl.handle.net/11427/18343en_ZA
dc.identifier.citationWaldron, H. 1996. Regional estimates of potential new production in the southern Benguela upwelling system. University of Cape Town.en_ZA
dc.identifier.ris TY - Thesis / Dissertation AU - Waldron, Howard Neil AB - The estimation of annual potential new production at a regional scale for the decade of the 1980s provides the main focus of this thesis. New production is the proportion of total primary production which relies on the uptake of NO₃-N by the phytoplankton while potential new production assumes that all the NO₃-N available to primary producers is assimilated. The Redfield ratio between carbon and nitrogen in the marine environment was used to express rates of potential new production in terms of carbon. In order to arrive at annual estimates of potential new production it was necessary to progress from the event-scale to the annual scale. This was achieved by the adoption of two novel methods of approach. Event-scale estimates of potential new production were made by assessing the amount of NO₃-N present in the nominal euphotic zone as a result of upwelling. Remotely-sensed images of sea surface temperature (SST) coincident with or shortly after upwelling events were used in combination with a derived relationship between SST and NO₃-N concentrations integrated over the depth range of the productive surface layer in the southern Benguela region. In this way it was possible to overcome the main shortcoming of passive satellite imagery by quantifying a sub-surface variable. The event-scale estimates of potential new production were extrapolated to the annual-scale by taking into account the dynamics of the system. Sea level fluctuation at the coast preceding upwelling events was found to be related to the event-scale estimates of introduced NO₃-N and hence used as a proxy for upwelling. Using a ten year record of sea level, estimates of annual potential new production, spanning the period June to May inclusive, were made for the period 1980/81 to 1989/90. Bibliography: pages 92-108. DA - 1996 DB - OpenUCT DP - University of Cape Town LK - https://open.uct.ac.za PB - University of Cape Town PY - 1996 T1 - Regional estimates of potential new production in the southern Benguela upwelling system TI - Regional estimates of potential new production in the southern Benguela upwelling system UR - http://hdl.handle.net/11427/18343 ER - en_ZA
dc.identifier.urihttp://hdl.handle.net/11427/18343
dc.identifier.vancouvercitationWaldron HN. Regional estimates of potential new production in the southern Benguela upwelling system. [Thesis]. University of Cape Town ,Faculty of Science ,Department of Oceanography, 1996 [cited yyyy month dd]. Available from: http://hdl.handle.net/11427/18343en_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.titleRegional estimates of potential new production in the southern Benguela upwelling systemen_ZA
dc.typeDoctoral Thesis
dc.type.qualificationlevelDoctoral
dc.type.qualificationnamePhDen_ZA
uct.type.filetypeText
uct.type.filetypeImage
uct.type.publicationResearchen_ZA
uct.type.resourceThesisen_ZA
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