noaa-ocean-25870 Mid-Atlantic 70,000 Year Dust Deposition Fluxes Middleton, J.L.; Mukhopadhyay, S.; Langmuir, C.H.; McManus, J.F.; Huybers, P.J. Mid-Atlantic 70,000 Year Dust Deposition Fluxes 2018-12-18 NCDC-Paleoclimatology ONLINE Files Pending https://www.ncdc.noaa.gov/paleo/study/25870 Investigator J.L. Middleton Investigator S. Mukhopadhyay Investigator C.H. Langmuir Investigator J.F. McManus Investigator P.J. Huybers earth science paleoclimate paleocean geochemistry geoscientificInformation 68800 cal yr BP 500 cal yr BP Complete 26.14 29.21 -44.8 -43.23 -3433 -3018 Ocean Atlantic Ocean North Atlantic Ocean KN207-2-GGC6>LATITUDE 29.21>LONGITUDE -43.23 Ocean Atlantic Ocean North Atlantic Ocean KN207-2-GGC3>LATITUDE 26.14>LONGITUDE -44.8 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 Jennifer L. Middleton, Sujoy Mukhopadhyay, Charles H. Langmuir, Jerry F. McManus, and Peter J. Huybers 2018 Earth and Planetary Science Letters 482 12-22 10.1016/j.epsl.2017.10.034 https://www.sciencedirect.com/science/article/pii/S0012821X17306027

Sedimentary records of dust deposition in the subtropical Atlantic provide important constraints on millennial- and orbital-scale variability in atmospheric circulation and North African aridity. Constant flux proxies, such as extraterrestrial helium-3, yield dust flux records that are independent of the biases caused by lateral sediment transport and limited resolution that may be associated with age-model-derived mass accumulation rates. However, Atlantic dust records constrained using constant flux proxies are sparsely distributed and generally limited to the past 20 ka. Here we extend the Atlantic record of North African dust deposition to 70 ka using extraterrestrial helium-3 and measurements of titanium, thorium, and terrigenous helium-4 in two sediment cores collected at 26N and 29N on the Mid-Atlantic Ridge and compare results to model estimates for dust deposition in the subtropical North Atlantic. Dust proxy fluxes between 26N and 29N are well correlated, despite variability in lateral sediment transport, and underscore the utility of extraterrestrial helium-3 for constraining millennial-scale variability in dust deposition. Similarities between Mid-Atlantic dust flux trends and those observed along the Northwest African margin corroborate previous interpretations of dust flux variability over the past 20 ka and suggest that long distance transport and depositional processes do not overly obscure the signal of North African dust emissions. The 70 ka Mid-Atlantic record reveals a slight increase in North African dustiness from Marine Isotope Stage 4 through the Last Glacial Maximum and a dramatic decrease in dustiness associated with the African Humid Period. On the millennial-scale, the new records exhibit brief dust maxima coincident with North Atlantic cold periods such as the Younger Dryas, and multiple Heinrich Stadials. The correlation between Mid-Atlantic dust fluxes and previous constraints on North African aridity is high. However, precipitation exerts less control on dust flux variability prior to the African Humid Period, when wind variability governs dust emissions from consistently dry dust source regions. Thus, the Mid-Atlantic dust record supports the hypothesis that both aridity and wind strength drive dust flux variability across changing climatic conditions. STUDY NOTES: Dust flux data plus helium, titanium, and thorium measurements for 2 mid Atlantic sediment cores for the past 70,000 years

GET DATA https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/middleton2018/middleton2018kn207-2-ggc3.txt NOAA Template File; Core KN207-2-GGC3 Dust Deposition Fluxes GET DATA https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/middleton2018/middleton2018kn207-2-ggc6.txt NOAA Template File; Core KN207-2-GGC6 Dust Deposition Fluxes USA/NOAA DIF Version 9.8.4 2018-12-19 2018-12-19