Abrupt changes in high-latitude nutrient supply to the Atlantic during the last glacial cycle

noaa-ocean-12360 South Atlantic GeoB2107-3 30KYr Glacial Silicon Isotope Data Hendry, K.R.; Robinson, L.F.; Meredith, M.P.; Mulitza, S.; Chiessi, C.M.; Arz, H.W. South Atlantic GeoB2107-3 30KYr Glacial Silicon Isotope Data 2011-12-31 NCDC-Paleoclimatology ONLINE Files Pending https://www.ncdc.noaa.gov/paleo/study/12360 Investigator K.R. Hendry Investigator L.F. Robinson Investigator M.P. Meredith Investigator S. Mulitza Investigator C.M. Chiessi Investigator H.W. Arz earth science paleoclimate paleoceanography age,null,null,calendar kiloyear before present,null,paleoceanography,null,null,N,null earth science paleoclimate paleoceanography delta 30Si,sponge,null,per mil,null,paleoceanography,null,null,N,sponge spicules earth science paleoclimate paleoceanography depth,null,null,centimeter,null,paleoceanography,null,null,N,null earth science paleoclimate paleocean geochemistry geoscientificInformation Meridional Overturning Circulation (MOC) 30300 cal yr BP 1600 cal yr BP Complete -27.18 -27.18 -46.45 -46.45 -1048 -1048 Ocean Atlantic Ocean South Atlantic Ocean GeoB2107-3>LATITUDE -27.18>LONGITUDE -46.45 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 K.R. Hendry, L.F. Robinson, M.P. Meredith, S. Mulitza, C.M. Chiessi, H. Arz 2012 Abrupt changes in high-latitude nutrient supply to the Atlantic during the last glacial cycle Geology 40 2 10.1130/G32779.1 https://pubs.geoscienceworld.org/gsa/geology/article-abstract/40/2/123/130776/abrupt-changes-in-high-latitude-nutrient-supply-to

The supply of nutrients to the low-latitude thermocline is largely controlled by intermediate-depth waters formed at the surface in the high southern latitudes. Silicic acid is an essential macronutrient for diatoms, which are responsible for a significant portion of marine carbon export production. Changes in ocean circulation, such as those observed during the last deglaciation, would influence the nutrient composition of the thermocline and, therefore, the relative abundance of diatoms in the low latitudes. Here we present the first record of the silicic acid content of the Atlantic over the last glacial cycle. Our results show that at intermediate depths of the South Atlantic, the silicic acid concentration was the same at the Last Glacial Maximum (LGM) as it is today, overprinted by high silicic acid pulses that coincided with abrupt changes in ocean and atmospheric circulation during Heinrich Stadials and the Younger Dryas. We suggest these pulses were caused by changes in intermediate water formation resulting from shifts in the subpolar hydrological cycle, with fundamental implications for the nutrient supply to the Atlantic. STUDY NOTES: This file contains the silicon isotope compositions (denoted by d30Si relative to NBS28) of sponge spicules extracted from GeoB2107-3. The spicules were cleaned using hydrogen peroxide and dissolved in sodium hydroxide solution; the solutions were purified by passing through a cation exchange resin. Analysis was carried out using the Neptune MC-ICP-MS at Woods Hole Oceanographic Institution. Reproducibility is plus/minus 0.16 per mil (2sd). Age model is based on radiocarbon dates, and tuned to the Antarctic deuterium record.

GET DATA https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/hendry2012/hendry2012.xls GET DATA https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/hendry2012/hendry2012.txt USA/NOAA DIF Version 9.8.4 2018-12-11 2018-12-11