noaa-ocean-22390 860,000 Years of foraminifera-bound nitrogen isotope data from the South China Sea Ren, H.; Sigman, D.M.; Martínez-Garcia, A.; Anderson, R.F.; Chen, M.-T.; Ravelo, A.C.; Straub, M.; Wong, G.T.F.; Haug, G.H. 860,000 Years of foraminifera-bound nitrogen isotope data from the South China Sea 2017-08-13 NCDC-Paleoclimatology ONLINE Files Pending https://www.ncdc.noaa.gov/paleo/study/22390 Investigator H. Ren Investigator D.M. Sigman Investigator A. Martínez-Garcia Investigator R.F. Anderson Investigator M.-T. Chen Investigator A.C. Ravelo Investigator M. Straub Investigator G.T.F. Wong Investigator G.H. Haug earth science paleoclimate paleoceanography age,null,null,calendar kiloyear before present,null,paleoceanography,null,null,N,null earth science paleoclimate paleoceanography delta 15N,Globigerinoides ruber,null,per mil AIR,null,paleoceanography,null,null,N,null earth science paleoclimate paleoceanography delta 15N,Orbulina universa,null,per mil AIR,null,paleoceanography,null,null,N,null earth science paleoclimate paleoceanography delta 18O,Cibicidoides wuellerstorfi,null,per mil VPDB,null,paleoceanography,null,null,N,null earth science paleoclimate paleoceanography depth,null,null,centimeter,null,paleoceanography,null,null,N,null earth science paleoclimate paleocean oxygen isotopes earth science paleoclimate paleocean nitrogen isotopes geoscientificInformation 860000 cal yr BP 0 cal yr BP Complete 12.68 12.68 119.45 119.45 -1557 -1557 Ocean Pacific Ocean Western Pacific Ocean South China Sea MD97-2142>LATITUDE 12.68>LONGITUDE 119.45 None Please cite original publication, online resource, dataset and publication DOIs (where available), and date accessed when using downloaded data. If there is no publication information, please cite investigator, title, online resource, and date accessed. The appearance of external links associated with a dataset does not constitute endorsement by the Department of Commerce/National Oceanic and Atmospheric Administration of external Web sites or the information, products or services contained therein. For other than authorized activities, the Department of Commerce/NOAA does not exercise any editorial control over the information you may find at these locations. These links are provided consistent with the stated purpose of this Department of Commerce/NOAA Web site. English DOC/NOAA/NESDIS/NCEI National Centers for Environmental Information, NESDIS, NOAA, U.S. Department of Commerce https://www.ncdc.noaa.gov/data-access/paleoclimatology-data DATA Center Contact Bruce Bauer bruce.a.bauer@noaa.gov paleo@noaa.gov 303-497-6280 303-497-6513

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Boulder CO 80305-3328 USA online ASCII Ren, H.; Sigman, D.M.; Martinez-Garcia, A.; Anderson, R.F.; Chen, M.-T.; Ravelo, A.C.; Straub, M.; Wong, G.T.F.; Haug, G.H. 2017 Proceedings of the National Academy of Sciences www.pnas.org/cgi/doi/10.1073/pnas.1701315114

The continental shelves are the most biologically dynamic regions of the ocean, and they are extensive worldwide, especially in the western North Pacific. Their area has varied dramatically over the glacial/interglacial cycles of the last million years, but the effects of this variation on ocean biological and chemical processes remain poorly understood. Conversion of nitrate to N2 by denitrification in sediments accounts for half or more of the removal of biologically available nitrogen (Ԧixed Nԩ from the ocean. The emergence of continental shelves during ice ages and their flooding during interglacials have been hypothesized to drive changes in sedimentary denitrification. Denitrification leads to the occurrence of phosphorus-bearing, N-depleted surface waters, which encourages N2 fixation, the dominant N input to the ocean. An 860,000-y record of foraminifera shell-bound N isotopes from the South China Sea indicates that N2 fixation covaried with sea level. The N2 fixation changes are best explained as a response to changes in regional excess phosphorus supply due to sea level-driven variations in shallow sediment denitrification associated with the cyclic drowning and emergence of the continental shelves. This hypothesis is consistent with a glacial ocean that hosted globally lower rates of fixed N input and loss and a longer residence time for oceanic fixed Nء ԳluggishԠocean N budget during ice ages. In addition, this work provides a clear sign of sea level-driven glacial/interglacial oscillations in biogeochemical fluxes at and near the ocean margins, with implications for coastal organisms and ecosystems. STUDY NOTES: A 860,000-year nitrogen isotope record from South China Sea foraminifera shells indicates that regional nitrogen fixation rates are associated with changes in sea level. Updated with d18O data table on 11/27/17.

GET DATA https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/ren2017/ren2017-fb-d15n.txt NOAA Template File; MD97-2142 d15N Data GET DATA https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/ren2017/ren2017-d18o.txt NOAA Template File; MD97-2142 d18O Data USA/NOAA DIF Version 9.8.4 2018-12-11 2018-12-11