Geochemical evidence of denitrification in the Benguela upwelling system

dc.contributor.authorTyrrell, Toby
dc.contributor.authorLucas, Michael I
dc.date.accessioned2018-06-07T08:46:07Z
dc.date.available2018-06-07T08:46:07Z
dc.date.issued2002
dc.date.updated2016-01-14T06:46:19Z
dc.description.abstractThis paper presents analysis of nitrate, phosphate and silicate data from the Benguela upwelling system. Evidence is presented that suggests denitrification occurring close to shore, and also nutrient trapping. Denitrification leaves an imprint on the water properties in terms of a nitrate deficit, that is to say nitrate concentrations that are significantly less than predicted by multiplying the phosphate concentrations by the Redfield ratio. It is probable that denitrification also causes a decoupling of nitrate and carbon compared to Redfield processes, and large-scale losses of nitrate in the Benguela which are not accompanied by losses of carbon. Nitrate-driven CO2 drawdown following upwelling will be less than it might otherwise be, because of denitrification. Nutrient trapping (secondary remineralisation) is apparent as enhanced phosphate concentrations, some of which are several Full-size image (<1 K) higher than in the offshore source waters for upwelling. Waters also become enriched in silicate and to a lesser extent nitrate as they advect across the shelf. By implication the same process should also “supercharge” waters in dissolved inorganic carbon, leading to stronger outgassing of CO2 immediately after upwelling. The effect is again to increase the size of the estimated Benguela upwelling system CO2 source.
dc.identifierhttp://dx.doi.org/10.1016/S0278-4343(02)00077-8
dc.identifier.apacitationTyrrell, T., & Lucas, M. I. (2002). Geochemical evidence of denitrification in the Benguela upwelling system. <i>Continental Shelf Research</i>, http://hdl.handle.net/11427/28243en_ZA
dc.identifier.chicagocitationTyrrell, Toby, and Michael I Lucas "Geochemical evidence of denitrification in the Benguela upwelling system." <i>Continental Shelf Research</i> (2002) http://hdl.handle.net/11427/28243en_ZA
dc.identifier.citationTyrrell, T., & Lucas, M. I. (2002). Geochemical evidence of denitrification in the Benguela upwelling system. Continental Shelf Research, 22(17), 2497-2511.
dc.identifier.ris TY - AU - Tyrrell, Toby AU - Lucas, Michael I AB - This paper presents analysis of nitrate, phosphate and silicate data from the Benguela upwelling system. Evidence is presented that suggests denitrification occurring close to shore, and also nutrient trapping. Denitrification leaves an imprint on the water properties in terms of a nitrate deficit, that is to say nitrate concentrations that are significantly less than predicted by multiplying the phosphate concentrations by the Redfield ratio. It is probable that denitrification also causes a decoupling of nitrate and carbon compared to Redfield processes, and large-scale losses of nitrate in the Benguela which are not accompanied by losses of carbon. Nitrate-driven CO2 drawdown following upwelling will be less than it might otherwise be, because of denitrification. Nutrient trapping (secondary remineralisation) is apparent as enhanced phosphate concentrations, some of which are several Full-size image (<1 K) higher than in the offshore source waters for upwelling. Waters also become enriched in silicate and to a lesser extent nitrate as they advect across the shelf. By implication the same process should also “supercharge” waters in dissolved inorganic carbon, leading to stronger outgassing of CO2 immediately after upwelling. The effect is again to increase the size of the estimated Benguela upwelling system CO2 source. DA - 2002 DB - OpenUCT DP - University of Cape Town J1 - Continental Shelf Research LK - https://open.uct.ac.za PB - University of Cape Town PY - 2002 T1 - Geochemical evidence of denitrification in the Benguela upwelling system TI - Geochemical evidence of denitrification in the Benguela upwelling system UR - http://hdl.handle.net/11427/28243 ER - en_ZA
dc.identifier.urihttp://hdl.handle.net/11427/28243
dc.identifier.vancouvercitationTyrrell T, Lucas MI. Geochemical evidence of denitrification in the Benguela upwelling system. Continental Shelf Research. 2002; http://hdl.handle.net/11427/28243.en_ZA
dc.language.isoeng
dc.publisher.departmentDepartment of Biological Sciencesen_ZA
dc.publisher.facultyFaculty of Scienceen_ZA
dc.publisher.institutionUniversity of Cape Town
dc.sourceContinental Shelf Research
dc.source.urihttps://www.journals.elsevier.com/continental-shelf-research/
dc.subject.otherDenitrification
dc.subject.otherNutrient trapping
dc.subject.otherNitrate deficit
dc.subject.otherNitrate
dc.subject.otherPhosphate
dc.titleGeochemical evidence of denitrification in the Benguela upwelling system
dc.typeJournal Article
uct.type.filetypeText
uct.type.filetypeImage
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