ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • Iron  (2)
  • Adsorption  (1)
  • Aluminum  (1)
  • Climate
  • trace metals
  • 2020-2023  (2)
  • 2015-2019  (2)
Collection
Keywords
Publisher
Years
Year
  • 1
    facet.materialart.
    Unknown
    Intensity of Th and Pa scavenging partitioned by particle chemistry in the North Atlantic Ocean (2015)
    Details
    Publication Date: 2022-05-25
    Description: Author Posting. © The Author(s), 2015. This is the author's version of the work. It is posted here by permission of Elsevier for personal use, not for redistribution. The definitive version was published in Marine Chemistry 170 (2015): 49-60, doi:10.1016/j.marchem.2015.01.006.
    Description: The natural radionuclides 231Pa and 230Th are incorporated into the marine sediment record by scavenging, or adsorption to various particle types, via chemical reactions that are not fully understood. Because these isotopes have potential value in tracing several oceanographic processes, we investigate the nature of scavenging using trans-Atlantic measurements of dissolved (〈0.45 μm) and particulate (0.8-51 μm) 231Pa and 230Th, together with major particle composition. We find widespread impact of intense scavenging by authigenic Fe/Mn (hydr)oxides, in the form of hydrothermal particles emanating from the Mid-Atlantic ridge and particles resuspended from reducing conditions near the seafloor off the coast of West Africa. Biogenic opal was not found to be a significant scavenging phase for either element in this sample set, essentially because of its low abundance and small dynamic range at the studied sites. Distribution coefficients in shallow (〈 200 m) depths are anomalously low which suggests either the unexpected result of a low scavenging intensity for organic matter or that, in water masses containing abundant organic-rich particles, a greater percentage of radionuclides exist in the colloidal or complexed phase. In addition to particle concentration, the oceanic distribution of particle types likely plays a significant role in the ultimate distribution of sedimentary 230Th and 231Pa.
    Description: Cruise management for GA03 was funded by the U. S. National Science Foundation to W. Jenkins (OCE-0926423), E. Boyle (OCE-0926204), and G. Cutter (OCE-0926092). Radionuclide studies were supported by NSF (OCE-0927064 to LDEO, OCE-0926860 to WHOI, OCE- 0927757 to URI, and OCE-0927754 to UMN). Additional support came from the European Research Council (278705) to LFR and the Ford Foundation Predoctoral Fellowship to SMV. Particle studies were supported by NSF OCE-0963026 to PJL.
    Keywords: GEOTRACES ; Suspended particulate matter ; Adsorption ; Radioactive tracers ; Trace elements
    Repository Name: Woods Hole Open Access Server
    Type: Preprint
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 2
    facet.materialart.
    Unknown
    Cycling of lithogenic marine particles in the US GEOTRACES North Atlantic transect (2015)
    Elsevier
    Details
    Publication Date: 2022-05-25
    Description: © The Author(s), 2014. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Deep Sea Research Part II: Topical Studies in Oceanography 116 (2015): 283-302, doi:10.1016/j.dsr2.2014.11.019.
    Description: In this paper, we present, describe, and model the first size-fractionated (0.8–51 µm; 〉51 µm) water-column particulate trace metal results from the US GEOTRACES North Atlantic Zonal Transect in situ pumping survey, with a focus on the lithogenic tracer elements Al, Fe and Ti. This examination of basin-wide, full-depth distributions of particulate elements elucidates many inputs and processes—some for bulk lithogenic material, others element-specific—which are presented via concentration distributions, elemental ratios, size-fractionation dynamics, and steady-state inventories. Key lithogenic inputs from African dust, North American boundary interactions, the Mediterranean outflow, hydrothermal systems, and benthic nepheloid layers are described. Using the refractory lithogenic tracer Ti, we develop a 1-D model for lithogenic particle distributions and test the sensitivities of size-fractionated open-ocean particulate Ti profiles to biotically driven aggregation, disaggregation rates, vertical sinking speeds, and dust input rates. We discuss applications of this lithogenic model to particle cycling in general, and to POC cycling specifically.
    Description: International and US GEOTRACES Offices (OCE-0850963 and OCE-1129603), and fellowship assistance from the Williams College Tyng Fellowship and MIT/WHOI Academic Programs Office to DCO.
    Keywords: Marine particles ; Lithogenic ; Particulate trace metals ; Aluminum ; Iron ; Titanium ; GEOTRACES ; Aeolian dust ; Aggregation ; Disaggregation ; Sinking speed ; Scavenging
    Repository Name: Woods Hole Open Access Server
    Type: Article
    Format: application/pdf
    Format: application/msword
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 3
    facet.materialart.
    Unknown
    Strong margin influence on the Arctic Ocean Barium Cycle revealed by pan‐Arctic synthesis (2022)
    American Geophysical Union
    Details
    Publication Date: 2022-10-26
    Description: © The Author(s), 2022. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Whitmore, L., Shiller, A., Horner, T., Xiang, Y., Auro, M., Bauch, D., Dehairs, F., Lam, P., Li, J., Maldonado, M., Mears, C., Newton, R., Pasqualini, A., Planquette, H., Rember, R., & Thomas, H. Strong margin influence on the Arctic Ocean Barium Cycle revealed by pan‐Arctic synthesis. Journal of Geophysical Research: Oceans, 127(4), (2022): e2021JC017417, https://doi.org/10.1029/2021jc017417.
    Description: Early studies revealed relationships between barium (Ba), particulate organic carbon and silicate, suggesting applications for Ba as a paleoproductivity tracer and as a tracer of modern ocean circulation. But, what controls the distribution of barium (Ba) in the oceans? Here, we investigated the Arctic Ocean Ba cycle through a one-of-a-kind data set containing dissolved (dBa), particulate (pBa), and stable isotope Ba ratio (δ138Ba) data from four Arctic GEOTRACES expeditions conducted in 2015. We hypothesized that margins would be a substantial source of Ba to the Arctic Ocean water column. The dBa, pBa, and δ138Ba distributions all suggest significant modification of inflowing Pacific seawater over the shelves, and the dBa mass balance implies that ∼50% of the dBa inventory (upper 500 m of the Arctic water column) was supplied by nonconservative inputs. Calculated areal dBa fluxes are up to 10 μmol m−2 day−1 on the margin, which is comparable to fluxes described in other regions. Applying this approach to dBa data from the 1994 Arctic Ocean Survey yields similar results. The Canadian Arctic Archipelago did not appear to have a similar margin source; rather, the dBa distribution in this section is consistent with mixing of Arctic Ocean-derived waters and Baffin Bay-derived waters. Although we lack enough information to identify the specifics of the shelf sediment Ba source, we suspect that a sedimentary remineralization and terrigenous sources (e.g., submarine groundwater discharge or fluvial particles) are contributors.
    Description: This research was supported by the National Science Foundation [OCE-1434312 (AMS), OCE-1436666 (RN), OCE-1535854 (PL), OCE-1736949, OCE-2023456 (TJH), and OCE-1829563 (R. Anderson for open access support)], Natural Sciences and Engineering Research Council of Canada (NSERC)-Climate Change and Atmospheric Research (CCAR) Program (MTM), and LEFE-CYBER EXPATE (HP). HT acknowledges support by the Canadian GEOTRACES via NSERC-CCAR and the German Academic Exchange Service (DAAD): MOPGA-GRI (Make Our Planet Great Again—Research Initiative) sponsored by BMBF (Federal German Ministry of Education and Research; Grant No. 57429828).
    Keywords: GEOTRACES ; Barium isotopes ; Geochemical cycles ; Climate ; Continental shelves
    Repository Name: Woods Hole Open Access Server
    Type: Article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 4
    facet.materialart.
    Unknown
    Ironing out Fe residence time in the dynamic upper ocean (2020)
    American Geophysical Union
    Details
    Publication Date: 2022-10-26
    Description: © The Author(s), 2020. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Black, E. E., Kienast, S. S., Lemaitre, N., Lam, P. J., Anderson, R. F., Planquette, H., Planchon, F., & Buesseler, K. O. Ironing out Fe residence time in the dynamic upper ocean. Global Biogeochemical Cycles, 34(9), (2020): e2020GB006592, doi:10.1029/2020GB006592.
    Description: Although iron availability has been shown to limit ocean productivity and influence marine carbon cycling, the rates of processes driving iron's removal and retention in the upper ocean are poorly constrained. Using 234Th‐ and sediment‐trap data, most of which were collected through international GEOTRACES efforts, we perform an unprecedented observation‐based assessment of iron export from and residence time in the upper ocean. The majority of these new residence time estimates for total iron in the surface ocean (0–250 m) fall between 10 and 100 days. The upper ocean residence time of dissolved iron, on the other hand, varies and cycles on sub‐annual to annual timescales. Collectively, these residence times are shorter than previously thought, and the rates and timescales presented here will contribute to ongoing efforts to integrate iron into global biogeochemical models predicting climate and carbon dioxide sequestration in the ocean in the 21st century and beyond.
    Description: We would like to thank S. Albani for providing the dust model results (Community Atmosphere Model, C4fn) and the three anonymous reviewers for their constructive comments. The U.S. GEOTRACES work was supported by the National Science Foundation (OCE‐1232669 and OCE‐1518110) and E. Black was also funded by a NASA Earth and Space Science Graduate Fellowship (NNX13AP31H) and the Ocean Frontier Institute. The GEOVIDE work was funded by the Flanders Research Foundation (G071512N), the Vrije Universiteit Brussel (SRP‐2), the French ANR Blanc GEOVIDE (ANR‐13‐BS06‐0014), ANR RPDOC BITMAP (ANR‐12‐PDOC‐0025‐01), IFREMER, CNRS‐INSU (programme LEFE), INSU OPTIMISP, and Labex‐Mer (ANR‐10‐LABX‐19).
    Keywords: Thorium‐234 ; Iron ; Export ; GEOTRACES ; Residence time
    Repository Name: Woods Hole Open Access Server
    Type: Article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...