Eolian dust input to the Subarctic North Pacific
| Type | Article | ||||||||||||||||||||
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| Date | 2014-02-01 | ||||||||||||||||||||
| Language | English | ||||||||||||||||||||
| Author(s) | Serno Sascha1, 2, Winckler Gisela1, 3, Anderson Robert F.1, 3, Hayes Christopher T.1, 3, McGee David4, Machalett Bjoern5, 6, Ren Haojia1, Straub Susanne M.1, Gersonde Rainer7, Haug Gerald H.8 | ||||||||||||||||||||
| Affiliation(s) | 1 : Columbia Univ, Lamont Doherty Earth Observ, Palisades, NY 10964 USA. 2 : Univ Potsdam, Inst Earth & Environm Sci, DFG Leibniz Ctr Surface Proc & Climate Studies, D-14476 Potsdam, Germany. 3 : Columbia Univ, Dept Earth & Environm Sci, New York, NY 10027 USA. 4 : MIT, Dept Earth Atmospher & Planetary Sci, Cambridge, MA 02139 USA. 5 : Humboldt Univ, Climatol Grp, Inst Geog, D-10099 Berlin, Germany. 6 : Bentley Univ, Dept Nat & Appl Sci, Waltham, MA 02452 USA. 7 : Alfred Wegener Inst Polar & Marine Res, D-27568 Bremerhaven, Germany. 8 : Swiss Fed Inst Technol, Inst Geol, CH-8092 Zurich, Switzerland. |
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| Source | Earth And Planetary Science Letters (0012-821X) (Elsevier Science Bv), 2014-02-01 , Vol. 387 , P. 252-263 | ||||||||||||||||||||
| DOI | 10.1016/j.epsl.2013.11.008 | ||||||||||||||||||||
| WOS© Times Cited | 64 | ||||||||||||||||||||
| Keyword(s) | eolian dust, Subarctic North Pacific, INOPEX, helium-4, Th-232, REE | ||||||||||||||||||||
| Abstract | Eolian dust is a significant source of iron and other nutrients that are essential for the health of marine ecosystems and potentially a controlling factor of the high nutrient-low chlorophyll status of the Subarctic North Pacific. We map the spatial distribution of dust input using three different geochemical tracers of eolian dust, He-4, Th-232 and rare earth elements, in combination with grain size distribution data, from a set of core-top sediments covering the entire Subarctic North Pacific. Using the suite of geochemical proxies to fingerprint different lithogenic components, we deconvolve eolian dust input from other lithogenic inputs such as volcanic ash, ice-rafted debris, riverine and hemipelagic input. While the open ocean sites far away from the volcanic arcs are dominantly composed of pure eolian dust, lithogenic components other than eolian dust play a more crucial role along the arcs. In sites dominated by dust, eolian dust input appears to be characterized by a nearly uniform grain size mode at similar to 4 mu m. Applying the Th-230-normalization technique, our proxies yield a consistent pattern of uniform dust fluxes of 1-2 g/m(2)/yr across the Subarctic North Pacific. Elevated eolian dust fluxes of 2-4 g/m(2)/yr characterize the westernmost region off Japan and the southern Kurile Islands south of 45 degrees N and west of 165 degrees E along the main pathway of the westerly winds. The core-top based dust flux reconstruction is consistent with recent estimates based on dissolved thorium isotope concentrations in seawater from the Subarctic North Pacific. The dust flux pattern compares well with state-of-the-art dust model predictions in the western and central Subarctic North Pacific, but we find that dust fluxes are higher than modeled fluxes by 0.5-1 g/m(2)/yr in the northwest, northeast and eastern Subarctic North Pacific. Our results provide an important benchmark for biogeochemical models and a robust approach for downcore studies testing dust-induced iron fertilization of past changes in biological productivity in the Subarctic North Pacific. | ||||||||||||||||||||
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