noaa-ocean-17917 Southern Ocean 120KYr Nitrogen and Silicon Isotope Data Robinson, R.S.; Brzezinski, M.A.; Beucher, C.P.; Horn, M.G.S.; Bedsole, P. Southern Ocean 120KYr Nitrogen and Silicon Isotope Data 2015-01-27 NCDC-Paleoclimatology ONLINE Files Pending https://www.ncdc.noaa.gov/paleo/study/17917 Investigator R.S. Robinson Investigator M.A. Brzezinski Investigator C.P. Beucher Investigator M.G.S. Horn Investigator P. Bedsole earth science paleoclimate paleoceanography depth,null,null,meter,null,paleoceanography,null,null,N,meters below sea floor earth science paleoclimate paleoceanography age,null,null,calendar kiloyear before present,null,paleoceanography,null,null,N,null earth science paleoclimate paleoceanography depth,null,null,meter,null,paleoceanography,null,null,N,common meters earth science paleoclimate paleoceanography delta 30Si,diatom,null,per mil,null,paleoceanography,null,null,N,per mil v. NBS28 earth science paleoclimate paleoceanography delta 15N,diatom,null,per mil AIR,null,paleoceanography,null,null,N,null earth science paleoclimate paleoceanography delta 30Si,diatom,one standard deviation,per mil,null,paleoceanography,null,null,N,per mil v. NBS28 earth science paleoclimate paleoceanography notes,null,null,null,null,paleoceanography,null,null,C,Sample Description earth science paleoclimate paleoceanography depth,null,null,centimeter,null,paleoceanography,null,null,N,null earth science paleoclimate paleocean nitrogen isotopes geoscientificInformation biogeochemical cycles 284500 cal yr BP 1000 cal yr BP Complete -63.08 -53.18035 -170.2 5.130333 -4851 -2807 Ocean Atlantic Ocean South Atlantic Ocean ODP1094>LATITUDE -53.18035>LONGITUDE 5.130333 Ocean Southern Ocean NBP9802-06PC>LATITUDE -61.88>LONGITUDE -169.98 Ocean Pacific Ocean South Pacific Ocean NBP9802-09PC>LATITUDE -56.9>LONGITUDE -170.2 Ocean Pacific Ocean South Pacific Ocean E11-2>LATITUDE -56.07>LONGITUDE -115.1 Ocean Pacific Ocean South Pacific Ocean E17-9>LATITUDE -63.08>LONGITUDE -135.12 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 Rebecca S. Robinson, Mark A. Brzezinski, Charlotte P. Beucher, Matthew G. S. Horn and Patrick Bedsole 2014 Paleoceanography 29 12 1179-1195 10.1002/2014PA002686 http://www.sciencedirect.com/science/article/pii/S0012821X13007280

The Southern Ocean plays a critical role in the air-sea CO2 balance through biological and physical mechanisms. Vertical supply of deep waters returns nutrients and CO2 to the surface and stimulates phytoplankton growth. Photosynthesis in the Southern Ocean is limited by iron and only a fraction of the carbon and nutrients that return to the surface are consumed for potential sequestration in the deep sea. Here we present the most spatially extensive data set of silicon and nitrogen isotope measurements from diatom frustules to date to examine the controls on nutrient drawdown during the last glacial period and across the glacial termination in both the Antarctic and Subantarctic zones. The new data confirm existing views that differing silicon and nitrate consumption patterns in the Antarctic zone are likely the result, at least in part, of iron addition during the last glacial maximum (LGM). However, earlier in the glacial, a more coordinated response in the two proxy records, with both reflecting enhanced consumption during episodes of increased iron accumulation and export production, implies a different system response than observed for the LGM. A collapse of the expected equatorward gradient in silicon isotope values and contraction of the nitrogen isotope gradient during the deglaciation suggests that nutrient supply increased not only in the Antarctic Zone, but also in the Subantarctic, perhaps due to enhanced deep mixing locally. Enhanced deep water ventilation across the Southern Ocean likely increased the nutrient content of mode waters during the deglaciation. STUDY NOTES: Nitrogen (d15N) and Silicon (d30Si) isotope data measured on diatoms from Southern Ocean sediment cores.

GET DATA https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/robinson2014b/robinson2014e11-2.txt Data File; E11-2 Silicon Isotope Data GET DATA https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/robinson2014b/robinson2014nbp9802-06.txt Data File; NBP9802-06PC Silicon Isotope Data GET DATA https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/robinson2014b/robinson2014e17-9.txt Data File; E17-9 Nitrogen and Silicon Isotope Data GET DATA https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/robinson2014b/robinson2014nbp9802-09.txt Data File; NBP9802-09PC Nitrogen and Silicon Isotope Data GET DATA https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/robinson2014b/robinson2014odp1094.txt Data File; ODP1094 Nitrogen and Silicon Isotope Data USA/NOAA DIF Version 9.8.4 2018-12-11 2018-12-11