Evidence for stable Holocene basin-scale overturning circulation despite variable currents along the Deep Western Boundary Current of the North Atlantic Ocean

noaa-ocean-26330 Holocene sedimentary radiogenic nuclide and sortable silt records from the Carolina Slope Hoffmann, S.S.; McManus, J.F.; Swank, E. Holocene sedimentary radiogenic nuclide and sortable silt records from the Carolina Slope 2019-03-04 NCDC-Paleoclimatology ONLINE Files Pending https://www.ncdc.noaa.gov/paleo/study/26330 Investigator S.S. Hoffmann Investigator J.F. McManus Investigator E. Swank earth science paleoclimate paleocean geochemistry earth science paleoclimate paleocean radiogenic isotope earth science paleoclimate paleocean physical properties geoscientificInformation 11190 cal yr BP 90 cal yr BP Complete 32.78 32.78 -76.283 -76.283 -1790 -1790 Ocean Atlantic Ocean North Atlantic Ocean KN140-2-51>LATITUDE 32.78>LONGITUDE -76.283 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 Hoffmann, S.S., J.F. McManus, and E. Swank 2018 Evidence for stable Holocene basin-scale overturning circulation despite variable currents along the Deep Western Boundary Current of the North Atlantic Ocean Geophysical Research Letters 45 24 13427-13436 10.1029/2018GL080187

While substantial changes in thermohaline circulation related to deglacial climate variability are well established, the role of this circulation in Holocene climate variability remains uncertain. Here we use two dynamical proxies, 231Pa/230Th ratios and mean sortable silt size (SS), to reconstruct Holocene bottom water circulation at the intermediate-depth Carolina Slope. We find no substantial change in deep current speed or 231Pa export at this site during the Holocene, suggesting consistent 231Pa export via the Deep Western Boundary Current. SS shows increasing millennial-scale variability in the middle-late Holocene, which may reflect Labrador Sea Water contribution to current speed. We conclude that deepwater export from the North Atlantic has remained remarkably stable during the Holocene, decoupled from changing rates of specific water masses, while production of these water masses varied at millennial to centennial time scales. The persistence of the large-scale overturning may reflect the ocean's stabilizing influence on Holocene climate. STUDY NOTES: Provided Keywords: Holocene, sediment geochemistry, sediment grain size

GET DATA https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/hoffmann2018/hoffmann2018-silt.txt NOAA Template File; 51GGC Silt Data GET DATA https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/hoffmann2018/hoffmann2018-radiogenic.txt NOAA Template File; 51GGC Radiogenic Isotope Data USA/NOAA DIF Version 9.8.4 2019-03-11 2019-03-11