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dc.contributor.authorBuchwald, Carolyn  Concept link
dc.coverage.spatialCosta Rica Upwelling Dome
dc.date.accessioned2013-01-25T16:10:48Z
dc.date.available2013-01-25T16:10:48Z
dc.date.issued2013-02
dc.identifier.urihttps://hdl.handle.net/1912/5739
dc.descriptionSubmitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy at the Massachusetts Institute of Technology and the Woods Hole Oceanographic Institution February 2013en_US
dc.description.abstractThe stable isotopes, δ15N and δ18O, of nitrite and nitrate can be powerful tools used to interpret nitrogen cycling in the ocean. In order to interpret isotope profiles, the isotope systematics of each process involved must be known. This thesis describes numerous experiments using both cultures of nitrifying organisms as well as natural seawater samples to determine the oxygen isotope systematics of nitrification. These experiments show that the accumulation of nitrite has a large effect on the resulting δ18ONO3. Also, the δ18ONO2 was developed as a unique tracer because it undergoes abiotic equilibration with water δ18O at a predictable rate based on pH, temperature and salinity. This rate, its dependencies, and how the δ18ONO2 values can be used as not only biological source indicators but also indicators of age are described. Finally, using the isotope systematics of nitrification as well as the properties of nitrite oxygen isotope exchange described in this thesis, the final chapter interprets multi-isotope nitrate and nitrite profiles in the Costa Rica Upwelling Dome using a simple 1D model. Overall, this thesis describes new nitrogen and oxygen isotopic tracers and uses them to elucidate the complicated nitrogen biogeochemistry in oxygen deficient zones.en_US
dc.description.sponsorshipThe work described in this thesis was funded by the National Science Foundation grants OCE 05-26277 and OCE 09-610998 to KLC, the MIT Presidential Fellowship, the WHOI Coastal Ocean Institute, the WHOI Academic Programs Office, and the MIT Houghton fund.en_US
dc.format.mimetypeapplication/pdf
dc.language.isoen_USen_US
dc.publisherMassachusetts Institute of Technology and Woods Hole Oceanographic Institutionen_US
dc.relation.ispartofseriesWHOI Thesesen_US
dc.subjectNitrificationen_US
dc.subjectNitrogen fixationen_US
dc.subjectMelville (Ship) Cruise MV1008en_US
dc.subjectMelville (Ship) Cruise MV1104en_US
dc.subjectRoger Revelle (Ship) Cruiseen_US
dc.titleNitrogen cycling in oxygen deficient zones : insights from δ15N and δ18O of nitrite and nitrateen_US
dc.typeThesisen_US
dc.identifier.doi10.1575/1912/5739


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