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dc.contributor.authorLehmann, Moritz F.  Concept link
dc.contributor.authorSigman, Daniel M.  Concept link
dc.contributor.authorMcCorkle, Daniel C.  Concept link
dc.contributor.authorBrunelle, Brigitte G.  Concept link
dc.contributor.authorHoffmann, Sharon S.  Concept link
dc.contributor.authorKienast, Markus  Concept link
dc.contributor.authorCane, Greg  Concept link
dc.contributor.authorClement, Jaclyn  Concept link
dc.date.accessioned2010-05-06T17:23:59Z
dc.date.available2010-05-06T17:23:59Z
dc.date.issued2005-10-12
dc.identifier.citationGlobal Biogeochemical Cycles 19 (2005): GB4005en_US
dc.identifier.urihttps://hdl.handle.net/1912/3399
dc.descriptionAuthor Posting. © American Geophysical Union, 2005. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Global Biogeochemical Cycles 19 (2005): GB4005, doi:10.1029/2005GB002508.en_US
dc.description.abstractOn the basis of the normalization to phosphate, a significant amount of nitrate is missing from the deep Bering Sea (BS). Benthic denitrification has been suggested previously to be the dominant cause for the BS nitrate deficit. We measured water column nitrate 15N/14N and 18O/16O as integrative tracers of microbial denitrification, together with pore water-derived benthic nitrate fluxes in the deep BS basin, in order to gain new constraints on the mechanism of fixed nitrogen loss in the BS. The lack of any nitrate isotope enrichment into the deep part of the BS supports the benthic denitrification hypothesis. On the basis of the nitrate deficit in the water column with respect to the adjacent North Pacific and a radiocarbon-derived ventilation age of ∼50 years, we calculate an average deep BS (>2000 m water depth) sedimentary denitrification rate of ∼230 μmol N m−2 d−1 (or 1.27 Tg N yr−1), more than 3 times higher than high-end estimates of the average global sedimentary denitrification rate for the same depth interval. Pore water-derived estimates of benthic denitrification were variable, and uncertainties in estimates were large. A very high denitrification rate measured from the base of the steep northern slope of the basin suggests that the elevated average sedimentary denitrification rate of the deep Bering calculated from the nitrate deficit is driven by organic matter supply to the base of the continental slope, owing to a combination of high primary productivity in the surface waters along the shelf break and efficient down-slope sediment focusing along the steep continental slopes that characterize the BS.en_US
dc.description.sponsorshipThis study was supported by NSF grants OCE-0136449 and OCE-9981479 to D. M. S., OCE-0118126 and OCE-0324987 to D. C. M., and DFG grant LE 1326/1-1 to M. F. L. The BS cruise was funded by grant OPP-9912122.en_US
dc.format.mimetypeapplication/pdf
dc.format.mimetypetext/plain
dc.language.isoen_USen_US
dc.publisherAmerican Geophysical Unionen_US
dc.relation.urihttps://doi.org/10.1029/2005GB002508
dc.subjectBering Seaen_US
dc.subjectDenitrificationen_US
dc.subjectNitrate isotopesen_US
dc.titleOrigin of the deep Bering Sea nitrate deficit : constraints from the nitrogen and oxygen isotopic composition of water column nitrate and benthic nitrate fluxesen_US
dc.typeArticleen_US
dc.identifier.doi10.1029/2005GB002508


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